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FIELD OF THE INVENTION
This invention relates to a method and device for cleaning and sealing a well in connection with drilling—and well operations.
BACKGROUND
A conventional method of cleaning a well is to flush it with fluid. To accomplish this, a long pipe, hereinafter called a tool string, is lowered into the well. The tool string is generally lowered to the bottom of the well, and may contain, for example, drilling tools, flushing tools, cementing tools, measuring tools and the like. When fluid is pumped from the surface down through the tool string to the bottom of the well, the fluid will return to the surface through the annular space on the outside of the tool string in the well, hereinafter called an annulus. The pumping causes particles from the drilling process or from other activities to be transported out of the well through the annulus on the outside of the tool string. Since the fluid velocity in the annulus is often low, the efficiency of the well cleaning performed in this manner will therefore also often be low.
The cleaning efficiency is usually low in the case of drilling and maintenance of wells with a large angular deviation from the vertical direction. This applies particularly to horizontal wells, where the particles have a tendency to be deposited in the lower part of the wellbore on account of gravity. This hampers the cleaning process and greatly prolongs the operation.
The cleaning efficiency is also often limited by low pressure or weak formation in the well, making it necessary to keep the fluid velocity in the annulus at a low level. This in order to avoid loss of drilling fluid or to prevent other dangerous well control situations from arising.
An alternative method of cleaning the well is so-called “reverse circulation”. This means that instead of pumping fluid down through the tool string with return in the annulus, it is pumped in the opposite direction. “Reverse circulation” means that fluid is pumped down into the annulus and return fluid is taken from the well up through the tool string. This method has the advantage that particles entering the tool string are transported to the surface quickly and efficiently. With this method, however, the flushing effect in the bottom of the well is low, due to limitations in pressure for this.
A third alternative method of cleaning the well is to employ a double string, where one channel in the string is used for pumping fluid down into the well, while the other channel is used for the return flow from the well. This technique is employed for well operations with coilable pipes (coiled tubing), particularly for cleaning horizontal wells. The technique is also employed with double-walled screwed pipes, but is restricted to shallow wells with specific pressure ratios, since the pressure loss in the return flow pipe becomes too high for it to be used on a practical level for normal drilling.
Wells which are leaking also represent substantial problems, both in new wells in the process of establishment and in older wells on account of corrosion or wear. Sealing such leaks is a challenge, and should preferably be carried out in connection with cleaning of the well.
SUMMARY OF THE INVENTION
The object of the invention is to provide an alternative device and method for cleaning and/or sealing a well, thereby reducing the drawbacks existing in the prior art.
The object is achieved according to the invention by the features set out in the following patent claims.
In this application the term drilling operation should be understood to refer to establishing a hole in a material by means of a tool string. It particularly applies to drilling a well in the earth's crust for petroleum recovery, tunnels, canals or, for example, for recovery of geothermal energy. Similarly, the term well operation in this application should be understood to refer to completion and maintenance carried out in the well after it is established.
In the following description, upper and lower refer to relative positions when the tool string is located in a vertical well. The invention, however, is not dependent on the spatial orientation of the well and the invention may be employed with advantage for construction and maintenance of, for example, horizontal wells. The present invention relates to a method of cleaning a subsurface well during a drilling operation or a well operation. A multi-channel tool string, comprising an adapter on a first end of the multi-channel tool string and a guide device at the second end of the tool string, is run into the well, with the guide device arranged to lead into the well and the adapter by an installation for initiating the operation, whereupon the guide device is activated in order to permit the well to be flushed by the supply of fluid through at least one of the channels in connection with the tool string and fluids and particles from the well are transported back to the surface through at least one other of the channels in the string.
According to an aspect of the invention at least one of the channels in the tool string is pressure tested during run-in and/or after it is run into the well. This pressure testing may be performed by means of a device which shuts off the fluid flow to the channel in one direction at a second end of the tool string. This shut-off device is either a permanent valve, or it is in the form of a movable plug valve which is moved through and out of the channel by the second end being pressurised on the opposite side.
According to another aspect the guide device may comprise at least one valve, which is operated between different modes by means of hydraulic communication between the well and the channels in the tool string, by pump pressure or by other signals from the surface. The guide device may be designed in such a manner that it goes into an open position when it opens at least two of the channels in the tool string simultaneously or time-delayed, and goes into a closed position by closing at least two of the channels in the tool string simultaneously or time-delayed. In addition the guide device may comprise a bypass valve, where the bypass valve according to the method opens up communication between at least two of the channels in the tool string when the guide device is in a closed position, and the bypass valve shuts off communication between at least two of the channels in the tool string when the guide device is in an open position. With this method solution, the invention enables internal circulation to be established in the tool string before the guide device is activated.
According to yet another aspect of the invention, the method may comprise a tool string composed of an outer string of screwed-together pipes and an inner string consisting of pipes suspended inside the outer string at suspension points in the outer pipe. In a variant the outer pipe may be attached to the guide device and inserted partially into the well, inner channels are inserted in outer pipes and placed against the guide device, whereupon a new outer pipe is screwed to the already-installed outer pipe, locking the inner channels securely in the tool string, the tool string is further inserted partially into the well and the steps are repeated. The tool string can be dismantled either by removing inner channels from outer pipes, or handling them together as a multi-channel tool string. Where there are inner channels in the outer pipe, these are screwed together, thereby joining the inner channels together.
According to a variant, an inner string of pipes connected by seals which are activated by screwing together outer pipes and an adapter on the top of the tool string (x) may lock the inner string securely in the tool string and has a built-in transmission unit for hydraulic communication to at least one of the channels in the tool string. The adapter on the top of the tool string may be provided with an electric swivel which is used for transmitting electrical signals and electric power from the surface down to tools in the well through the inner pipe string. Alternatively, the adapter on the top of the tool string may also be supplied with swivels for optical communication or extra channels with fluids, cement or chemical substances from the surface down to tools in the well through the inner pipe string.
According to a further aspect, an extension pipe, which can be attached to the tool string when it is run into the well, may be released and left in the well before the tool string is withdrawn from the well for sealing the well wall. In another variant the extension pipe may also be expanded so that it is fixed to the well wall for sealing thereof. Furthermore, at least one of the channels in connection with the tool string may be employed for injecting a sealing material for the wall of the well. In an aspect the sealing material may contain a hardening agent which reinforces the well wall after setting.
The present invention also relates to a device for cleaning a subsurface well. The device comprises a multi-channel tool string comprising an adapter at a first end of the multi-channel tool string and a guide device at a second end of the multi-channel tool string in order to guide fluid into a given return channel relative to the tool string. The multi-channel tool string may comprise a tool string with one or more concentric inner pipes arranged in an outer pipe, or alternatively there may be one or more pipes arranged inside an outer pipe, where the inner pipes can form a centre axis which is substantially parallel to the centre axis for the outer pipe, but where they extend beside each other. A variant may also be envisaged where some pipes are arranged concentrically but some others are not. The outer pipe and the internal pipes may be substantially circular in cross section, but may also have other shapes such as edged, oval, etc. and where the pipes have the same or different cross sectional shapes.
According to an aspect of the invention, a control system may be provided at an upper end of the tool string. This control system may be employed for controlling the activities carried out by the tool string, while at the same time providing communication with and between the various channels in the tool string at the upper end of the tool string.
A first end of the tool string may be arranged on board a floating or fixed installation at the earth surface. The given return channel may be composed of one or more inner pipes. In use, a second end of the tool string is located down in the well at the location in the well which requires to be cleaned. In an embodiment of the device, the given return channel may be a specially selected return channel. This return channel may also be composed of more than one channel. A variant may also be envisaged where the return channel is varied over time during use, where the return channel is chosen as the most appropriate channel for achieving the desired cleaning of the well. This means that in a period during use a channel is employed as a return channel, but later during the cleaning operation other channels are also used in addition as return channels. According to an aspect of the invention the return channel may be composed of at least one of the channels in the tool string. In another variant the annulus around the tool string may also be used as one of the return channels.
According to an aspect the device also comprises a control system which also covers an arrangement and regulating system on the surface. This includes the arrangement of lines for fluid flow and communication, together with the arrangement of valves and equipment for safe and efficient well control during the operations.
According to an aspect the guide device may comprise at least one valve arranged in connection with at least one of the channels in the drill string. According to an aspect one or more of the valves may be pressure-controlled and can open up or shut off the hydraulic communication between the well and the channels in the tool string by pump pressure or by other signals from the surface.
According to yet another aspect one or more valves in the guide device may open at least two of the channels in the tool string simultaneously or time-delayed and close at least two of the channels in the tool string simultaneously or time-delayed. In a variant one or more pressure-controlled valves may be equipped with a bypass valve, where the bypass valve opens up communication between at least two of the channels in the tool string when the pressure-controlled valve is closed, and the bypass valve shuts off communication between at least two of the channels in the tool string when the pressure-controlled valve is open. With such an arrangement it is possible to achieve internal communication between two channels in the tool string while at the same time having them closed off from the environment, thereby achieving internal circulation in the tool string. The above-mentioned pressure-controlled valves may alternatively be controlled in another way than by pressure, such as by optical or electrical signals from the surface.
According to an aspect of the invention the guide device may comprise a temporary check valve arranged for shutting off the fluid communication between two channels in one direction but opening up communication in the other direction. According to an aspect this temporary check valve may be releasably mounted in the channel, thereby shutting off fluid communication in one direction but when the fluid communication is in the other direction, the temporary valve will be transported with the fluid flow to the first end of the tool string.
According to an aspect the tool string may consist of an outer pipe string with screw connections and at least one inner pipe string with connectors which are activated by screwing together the outer pipes. The at least one inner pipe string can be kept in position relative to the outer pipe by a connecting device, where this connecting device may also form a part of the connection between the different segments of the inner pipe strings. The connections between the inner pipe segments may be hydraulically activated, mechanical or other known connecting systems that create a sealed connection, for example O-ring seals. The inner pipes are connected by the end of the one pipe being pushed into a coupling with sealing elements in the opposite pipe. With the simple solution according to the invention, a standard screwed drill string can be easily modified to form a two-channel or multi-channel drill string by means of this method. It is also conceivable for the tool string to be of the coiled tubing type with at least two channels.
According to an aspect at least one of the pipes forming the tool string with the inner channels may be electrically isolated from the rest of the tool string. In a variant the outer pipe string may be electrically isolated from the inner pipe string. This offers the possibility of transferring electrical energy through at least one of the walls of the pipe string, for example the inner pipe string.
According to another aspect the adapter at the first end of the tool string may be provided with a transmission unit, for example a swivel unit, which is employed for transmitting signals and/or electrical power from the first end to the second end of the multi-channel tool string. The signals may be electrical, optical, magnetic, etc. Alternatively or in addition the adapter may also comprise devices for transferring different types of fluid through different channels in the tool string and the environment and internally in the tool string. In a further aspect the tool string may be provided with electric motors and/or pumps which receive power from the surface through the adapter and the tool string in order to increase the efficiency of the process. Examples which may be mentioned in this connection are an electric downhole motor for rotation of drilling equipment and an electric downhole pump for pressurisation and circulation of the drilling fluid.
According to an aspect the tool string is composed of an outer string of screwed-together pipes and an inner string consisting of pipes suspended on suspension points inside the outer pipe. As an alternative, the adapter on the top of the tool string may lock the inner string securely in the tool string.
For movement of the tool string along the well path a packer may be employed, which is arranged to form a seal between the tool string and an inner wall of the well. The tool string can then be moved by means of a surface-controlled pressure differential between the top and bottom of this packer. In a variant the packer may comprise a valve device for regulating the fluid flow past the piston packing. In another variant the packer may have a built-in check valve which shuts off fluid flow from over the packer to under the packer, but which permits fluid flow from under the packer to over the packer. Furthermore, the packer may be expandable and can be activated or deactivated by a signal through the tool string or the well fluid from the surface. A valve in this packer can also be controlled in this manner.
According to an aspect of the invention the device will be activated from the surface by pressure or other control signals and the cleaning operation is generally performed in combination with other operations such as drilling, scraping, scale removal, logging and the like. The method involves “vacuuming” the well free from particles, and this can easily be done by a low-density fluid.
In a further aspect the tool string may have an outer piston packing mounted which seals the well wall continuously, or by being activated to perform such sealing by pressure or other signals through the tool string.
Furthermore, the guide device may contain an attachment device for an extension pipe, where the extension pipe is attached to the tool string when it is run into the well and can be released from the tool string by pressure or other signals from the surface before the tool string is withdrawn from the well. This guide device may be arranged so that it can be drawn through the extension pipe, thereby causing it to be expanded so that it is fixed to the well wall for sealing thereof.
The piston packing, moreover, may be provided in such a manner that it can be pushed through the extension pipe by means of pressure from the surface, thereby causing the extension pipe to be expanded so that it is fixed to the well wall for sealing thereof.
The advantages of the invention are improved efficiency for cleaning wells during drilling and well operations, better control of the pressure in the well, together with the ability to seal the well by means of an extension pipe or by injection of chemicals or materials which prevent loss of drilling fluid and reinforce the formation during drilling. The method and the device can be implemented in a simple manner for conventional drilling equipment by means of screwed drill pipes as a tool string, or alternatively employed for wholly or partially coilable tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
A non-limiting example of a preferred method and embodiment will now be described and illustrated in the accompanying drawings, in which:
FIGS. 1A and 1B are a schematic views of an embodiment of the device according to the invention installed in a vertical well,
FIG. 2 is a schematic view of a two-channel tool string consisting of standard screwed drill pipes with an insert which is suspended from and affixed concentrically inside the string according to the invention,
FIGS. 3A and 3B are a schematic views of an adapter which is placed on the top of the tool string,
FIGS. 4A , B and C are views of a downhole pressure-controlled valve for communication between the well and the surface through the tool string,
FIG. 5 illustrates a downhole pressure-controlled valve in combination with “Flow x-over”, which guides the fluid flow from the well into a channel in the tool string, and
FIG. 6 is a schematic view of a downhole piston packing which is used to apply downhole forces for propulsion of the tool string, and is used for pressure control and safety of the well.
DETAILED DESCRIPTION
FIG. 1 illustrates a first and a second embodiment of a device according to the invention installed in a well. The device which is employed for washing, drilling, measuring etc. is lowered into the well 1 in order to remove material 2 in the well 1 . Material 2 which is to be removed may either be new formation which has to be drilled out, or it may be deposits or other types of material which require to be removed from the well 1 , either in the bottom thereof or wherever it may be required. The well 1 is generally isolated from the surrounding formation by an outer casing 5 located down in the ground. In the upper edge of the casing 5 is a blowout preventer 4 which provides a shutdown capability and a connection to a riser 3 leading up to, for example, a floating installation (not shown).
The device according to the invention comprises a tool string 10 , a control system 20 , a guide device 30 at a second end of the tool string and an adapter 40 at the first end of the tool string 10 . The tool string may be composed of various types of multichannel tool strings. A particularly advantageous embodiment, however, is the string depicted in FIG. 2 , consisting of standard drill pipes 11 , with inner pipe 12 suspended in the pipe connection at a connecting element 13 . When the outer pipes 11 are screwed together by a screw connection, the inner pipe 12 is pushed into a coupling 17 with hydraulic sealing, which prevents leakage between the two channels, the central channel 16 and the annulus formed between the inner pipe 12 and the outer pipe 11 , in the connected pipe. The inner pipe 12 may be arranged electrically isolated from the outer pipe 11 , thereby permitting electrical signals and electrical power transmission between the surface and elements in the device through the string. The part of the inner pipe 12 which is pushed into the hydraulic seal generally has a hard and wear-resistant surface and is usually protected by a protective cover when not in use in order to prevent scraping and possible leakage.
In the upper end of the tool string 10 an adapter 40 is located, see FIG. 3 , with a rotary coupling which leads fluid flow into the tool string 10 from a pump on the surface (not shown in the figure). A second channel in the adapter leads fluid flow out of the tool string 10 into a separate channel of a not shown valve system, tank and subsequent cleaning of the fluid on the surface. An additional transmission unit (not shown) may be mounted on the adapter 40 for transmitting electrical signals/current, optical or other communication or alternative power transmission through the tool string to sensors or actuators in the well. The adapter 40 may also be supplied with more fluid channels (not shown) if so desired.
In the lower end of the tool string 10 a guide device 30 is located comprising a pressure-controlled valve 31 , see FIG. 4 , which allows the fluid to pass if the pressure of the fluid pumped down is greater than the ambient pressure in the well 1 . This valve 31 opens up and shuts off the central channel 16 and the annulus 15 simultaneously, thereby providing both supply and return flow by means of the pressure control of the valve 31 . The result is that when the valve opens, the return flow channel opens simultaneously, and when the valve closes, the return flow channel closes simultaneously. In an embodiment the supply and return channels may be supply in the annulus 15 and return in the central channel 16 .
In addition the pressure-controlled check valve may be arranged in combination with a third bypass valve, see FIG. 4 , for a channel between the return flow channel and the channel for flow into the well. This bypass valve 32 is controlled by means of its shape, with the result that the bypass valve is open when the pressure-controlled valve 31 is closed, and the bypass valve 32 is closed when the pressure-controlled valve 31 is open. The pressure-controlled valve may be a check valve. A possible physical embodiment for the guide device with the two valves is to mount a ball body 310 in a valve housing 317 , where the valve housing is connected to the inner pipe 12 and where the ball body 310 opens and closes the central channel 16 . The ball body is provided with a guide pin 311 , extending in a guide track 312 , where the guide track 312 is provided in a guide sleeve 313 arranged substantially round the internally located valve housing 317 . An axial movement of the guide sleeve 313 will rotate the ball body 310 at guide groove 312 and guide pin 311 , with the result that a through-going bore 322 through the ball body 310 is either arranged in line with the central channel or closes it. The ball body 310 is provided with an outer sealing surface 320 abutting sealing surfaces 319 provided in the valve housing 317 . The guide sleeve 313 further comprises through-going holes 314 and an abutment surface 316 . The valve housing 318 also comprises through-going holes 315 which in a position of the valve provide communication between the annulus 15 and the central passage 16 at one side of the ball body 130 , thereby enabling internal circulation to be established between the central passage 16 and the annulus 15 . The valve housing also has an external abutment surface 318 which, when it is an abutment against the abutment surface 316 of the guide sleeve, in the event of an axial movement thereof, will provide a sealing abutment and shut off the communication between the annulus 15 and the central passage 16 via the through-going holes 314 , 315 . Furthermore, the guide sleeve 313 is prestressed by an elastic element 321 in abutment between a shoulder on the valve housing 317 and a surface of the guide sleeve 313 with the result that in an unloaded state the valve will displace the guide sleeve 313 thereby causing the ball body 130 to close the central passage and an outer abutment surface 323 of the guide sleeve to be located in abutment against an internal abutment surface of the outer pipes 11 , thereby closing the annulus passage 15 . At the same time the holes 314 , 315 will be located in alignment with each other, providing fluid communication between the annulus 15 and the central passage 16 .
In this way, continuous circulation will be permitted inside the double tool string during a drilling operation, even though both channels through the pressure-controlled check valve are closed. The pressure-controlled check valve 31 may be duplicated or replaced by corresponding valves controlled by signals from the surface, for example of an electrical nature as described earlier. This is in order to increase safety and reliability by means of redundancy in the system for well control.
Under the pressure-controlled check valve 31 a “flow x-over” tool is usually arranged to lead the fluid flow from the well into the return flow channel in the tool string, see FIG. 5 . Under this flow x-over tool, standard washing equipment, pumps, drilling equipment and measuring equipment of a known type may be employed. It is also possible to provide such equipment with electric power through the tool string, as described above.
On the tool string 10 a piston packing 50 may be placed, see FIG. 6 , to permit transport of the tool in and out of the hole by regulating the differential pressure across the piston packing from the surface. The piston packing will thereby act as a “tractor” for transporting the tool in or out of the wellbore. This is particularly important in wells with a large angular deviation from the vertical direction, such as horizontal wells.
During the operation an extension pipe 60 may be installed in the well, where the extension pipe is arranged as a part of the tool string under the piston packing 50 . The extension pipe 60 will increase the flexural strength in order to prevent buckling, thereby improving the propulsion during the operation, particularly in horizontal boreholes. The extension pipe 60 may be left in the well after the end of the operation, for reinforcing or sealing the well against the environment, and it may be of the expandable type, being expanded against the well wall by pressure or mechanical tools during or after completion of the operation, in order to reduce the restriction in the well. The expansion tool may be a part of the piston packing and be pushed through the extension pipe by pressure from the surface through the annulus on the outside of the tool string, and/or it may be a part of the guide device and be drawn through the extension pipe for expansion thereof. The expansion tool may consist of units with longitudinal holes or rollers, which roll out the extension pipe with little frictional resistance to a given diameter during the expansion process.
The invention has now been explained with reference to the attached drawings. A number of technical variations may be made to the illustrated embodiment which will fall within the scope of the invention as defined in the attached claims.
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The present invention relates to a method for cleaning and possibly sealing a subsurface well. According to the method a multichannel tool string comprising an adapter on a first end of the tool string, a guide device at the second end of the tool string are run into the well, whereupon the guide device is activated in order to permit the well to be flushed by the supply of fluid through at least one of the channels in connection with the tool string and fluids and particles from the well are transported back to the surface through at least one other of the channels in connection with the tool string. The invention also relates to a device for cleaning and possibly sealing a subsurface well.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to power supply circuits, and particularly to a capacitor-less LED drive.
2. Description of the Related Art
Light emitting diodes (LEDs) are beginning to experience widespread use in many lighting applications. LED lighting is replacing the florescent lighting because of its advantages, mainly low power consumption and long life expectancy. However, commercial LED drive circuits limit the life expectancy of the LED lighting system by around one-fifth of the lifetime of the LED itself. The main source of shortening the lifetime of the drive is the smoothing capacitor. This is due to the leakage in this capacitor and, hence, degradation in the drive circuit with time. Several works on electrolytic capacitor-less LED drives have been presented to maximize the overall lifetime of the LED system. However, most of the works presented require relatively complicated power circuit or current-controlled technique to reduce the size of the energy storage capacitor.
Thus, a capacitor-less LED drive solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The capacitor-less LED drive circuit is based on a buck converter circuit where an LED replaces the smoothing capacitor. The internal capacitance of the LED (or an LED array) will act as smoothing capacitor when a proper switching frequency and duty cycle are chosen.
These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the capacitor-less LED drive according to the present invention.
FIG. 2 is a schematic diagram showing a DC mode model of a light emitting diode (LED).
FIG. 3 is a schematic diagram showing an AC mode model of a light emitting diode (LED).
FIG. 4 is a plot showing V-I characteristics curve of a single white LED.
FIG. 5 is a plot showing effective capacitance vs load current (LED current) at different frequencies.
FIG. 6 is a plot showing output voltage and ripple voltage as a function of duty cycle at different frequencies in a capacitor-less LED drive according to the present invention.
FIG. 7 is a plot showing error percent (deviation of experimental output voltage from theoretical calculations) as a function of duty cycle at different frequencies in a capacitor-less LED drive according to the present invention.
FIG. 8 is a plot showing ripple voltage as a function of time of the capacitor-less LED drive according to the present invention at 100 kHz with a duty cycle of 18%.
FIG. 9 is a plot showing ripple voltage as a function of time of the capacitor-less LED drive according to the present invention at 100 kHz with a duty cycle of 40%.
FIG. 10 is a plot showing DC output voltage and ripple voltage as a function of frequency of the capacitor-less LED drive according to the present invention with a duty cycle of 40%.
FIG. 11 is a plot showing efficiency as a function of duty cycle at selected frequencies for the capacitor-less LED drive according to the present invention.
FIG. 12 is a plot showing efficiency as a function of frequency for the capacitor-less LED drive according to the present invention.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The capacitor-less LED drive circuit is based on a buck converter circuit where an LED replaces the smoothing capacitor. The internal capacitance of the LED (or an LED array) will act as smoothing capacitor when a proper switching frequency and duty cycle are chosen.
As shown in FIG. 1 , the capacitor-less LED drive circuit 100 rectifies an AC source VAC using an AC-DC rectifier circuit 101 . The negative terminal of the rectifier circuit 101 is connected to the source of a switching transistor Q 1 in parallel with a diode, as shown at 104 . A gate of the transistor Q 1 is connected to a pulse source, Vpulse, which switches the transistor Q 1 on and off at a selected duty cycle. The drain of Q 1 is connected to the anode of diode D 1 and to a first lead of inductor L, The cathode of diode D 1 is connected to the positive terminal of the AC-DC rectifier circuit 101 . An LED 102 (or an array of LEDs connected in parallel to each other) is connected between the cathode of diode D 1 and a second lead of inductor L (the anode of the LED 102 being connected to cathode of diode D 1 , and hence the positive terminal of the rectifier circuit 102 , and the cathode of LED 102 being connected to the second lead of the inductor L).
An LED in conduction mode can be modeled using a resistor and an ideal diode for DC mode 200 and a capacitor and a resistor in parallel for AC mode 300 as shown in FIGS. 2 and 3 , i.e., an LED inherently exhibits capacitance, which enables substitution of an LED for an electrolytic capacitor in buck converter circuits in power supplies. We have carried out many experimental tests to come up with a new mathematical model that represents the DC output voltage across the LEDs. The LED equivalent circuits shown in FIGS. 2 and 3 are used. The DC output voltage is given by:
V O ( D C ) = D ( Vin - V ds ) - D ′ V d 1 + R L R LED , ( 1 )
where RLED is the LED's internal resistance. The value of RLED depends on the current passing through the LED, and it can be deduced from the I-V characteristics curve of the LED shown in graph 400 of FIG. 4 . It is clear from plot 400 that as the current increases, the value of RLED will decrease. In the AC model 300 of FIG. 3 , r s represents the constant series contact resistance and quasi-neutral region resistance of the LED, r d represents the small signal resistance of the LED at certain DC current, and C d represents the diffusion capacitance at a certain DC current. In conduction mode, r d is the reciprocal of the conductance, which is equal to the DC current divided by the thermal voltage. This indicates that as the DC current increases, the value of the resistance r d will decrease. Moreover, the value of C d also is a function of the conductance, and its value will increase as the current increases. The behavior of r d and C d gives an indication that as the DC current increases, the ripple voltage will decrease, which is another parameter that can control and affect the ripple voltage. This fact is supported by experimental results.
It is important to point out that the value of C d is linearly changing with the DC current only in strong conduction mode. However, during the OFF period in the switching Buck converter pulse, the LED internal resistance will draw the stored charge, and the output voltage will decrease. If the OFF period is long enough, the value of the diffusion capacitor will be very small, causing a dramatic drop in the output voltage that might cause flicker in the LED light. Consequently, this will limit the OFF period, therefore limiting the frequency and duty cycle to certain ranges. The effective capacitance of the LED is found as follows:
I pp = V i n - ( V o + V d s + V r L ) Lf s D , ( 2 )
where I pp is the ripple current through the inductor L. From circuit 100 and model 300 , assume no diffusion capacitance, C d . Then:
V r =I pp R LOAD =I pp ( r d +r s ) (3)
If we assume a capacitance C d and an infinite parallel resistance r d , then:
V r = I pp ( 1 8 fC d + r s ) . ( 4 )
From equation 4, the effective impedance of the capacitor is 1/(8f C d ). Equations 3 and 4 can be written as:
V r =αI pp r d +I pp r s , (5)
and
V r = β I pp ( 1 8 fC d ) + I pp r s , ( 6 )
where α+β=1 and from the current divider rule,
α = 1 1 + 8 fC d r d and β = 8 fC d r d 1 + 8 fC d r d . ( 7 )
Using the small model approximation for the pn junction diode, the DC current is related to the value of the dynamic resistance and the diffusion capacitor by:
r d = 1 g d and C d = τ g d , ( 8 )
where τ is the diffusion time constant and g d is the known transconductance, defined as g d =I DC /ηV t , and V t is the thermal voltage. By incorporating the definitions of equation (8) in the values of α and β then:
α
=
1
1
+
8
f
τ
and
β
=
8
f
τ
1
+
8
f
τ
.
(
9
)
From equation (9), if the value of 8fτ>>1, then the impedance of the capacitor is very small compared to the resistance r d , leading to α=0 and β=1. This case will satisfy the ideal situation with a negligible load effect on the ripple voltage. In other words, all the current I pp will flow through the capacitor. Substituting the values of α and β from equation (9) in equations (5) and (6) leads to the ripple equation, which is given by:
V r = I pp ( 1 g d ( 1 + 8 f τ ) + r s ) = I pp ( 1 g d + 8 fC d + r s ) . ( 10 )
Rewriting equation (10) to find the effective capacitance C d using the experimental data yields:
C d = 1 8 f ( 1 V r I pp - r s - g d ) . ( 11 )
A plot of the effective capacitance as a function of the LED current for different frequencies is shown in plot 500 of FIG. 5 . It is evident from the plot that the effective capacitance at 200 kHz is high, since the impedance of the capacitance is much smaller than that of the dynamic resistance.
The capacitor-less LED drive circuit 100 shown in FIG. 1 was connected in the laboratory using off-the-shelf components to test the proposed design experimentally. The LED used is the sum of three series packages of 11 parallel LEDs per package, giving a total of 33 LEDs. The output voltage is measured across the LED packages. The components used are as follows: L is an inductor of 470 μH, Q 1 is an N-MOS power transistor BUZ71, Vpulse is the switching control pulse with an amplitude of 10V, and D 1 is a silicon fast-switching diode 1N914. The inductor's series resistance is measured, and its value is around 4Ω. We assume the ac source is rectified and provides a DC output called Vin with nominal voltage of 35V. The LED's I-V characteristics are shown in plot 400 , which has been used to extract the value of R LED for different DC current values.
The behavior of the circuit was studied by varying the duty cycle of Vpulse from 18% to 44% at three different frequencies (100 KHz, 150 KHz and 200 KHz). The maximum duty cycle was set to 44% because this duty cycle will produce the maximum current that can be handled by the LEDs. The output voltage was probed across the LEDs for the DC output and ripple voltage, and results were plotted as shown in plot 600 of FIG. 6 . It is clear from plot 600 that as the duty cycle increases, the DC output voltage increases. The ripple voltage is decreasing with the increase of frequency.
The deviation between theoretical and experimental results is shown in plot 700 of FIG. 7 . It is evident from plot 700 that a designer should select the switching pulse duty cycle to be greater than 30% to minimize the error and use higher frequencies to minimize the ripple voltage.
From plot 600 , the DC voltage is linearly changing with the duty cycle for D>30%. Also, the error curve in plot 700 shows that for duty cycle greater than 30%, the error is less than 3%. However, the error is much greater with less than 30% duty cycle, and this is due to the long OFF period of the buck switch, resulting in non-linear behavior of the LED voltage. If the voltage across the LED is below a certain value, there will be no diffusion capacitor and the LED's voltage will drop logarithmically, causing the large error shown. This value can be estimated from the knees of each curve in plot 700 , and it depends on the forward current as well, since it depends on how deep the LED is in the conduction region.
Plots 800 and 900 of FIGS. 8 and 9 , respectively, show the ripple voltage at 100 kHz, with a duty cycle of 18% and 40%, respectively. The non-linearity is clearly shown in plot 800 , where the off period was long enough to drive the LED to the weak conduction region, while the ripple of plot 900 is almost linear. It is clear that the ripple is linear for higher duty cycle.
To see the changes on the DC output voltages and ripple, the frequency was swept at a fixed duty cycle of 40% from 50 kHz to 300 kHz, and the output was probed. The result is shown in plot 1000 of FIG. 10 . It is clear that the ripple voltage is decreasing as the frequency is increasing, and the DC voltage is almost constant. The minimum ratio of ripple voltage to DC voltage is around 1.4%, and it can be decreased further by increasing the frequency.
Efficiency is an important factor in an LED drive. The efficiency was found by measuring the DC output voltage, the output current, the DC input voltage and the input current for each duty cycle for different frequencies. Experimental results are displayed in plot 1100 of FIG. 11 , and show that the average efficiency is 85%. The efficiency can be improved further using an inductor with smaller internal resistance and transistor with smaller ON resistance.
Because of the slight changes in the DC output voltage, the efficiency is barely changing with the change of the frequency, as shown in plot 1200 of FIG. 12 . The average of the efficiency over the frequency range was about 88%. Increasing the frequency further will lead to smaller ripple voltage and smaller components for better integration. However, increasing the switching frequency will reduce the efficiency of the drive because of the switching power loss for light loads. As for LED lighting applications, the LED load needs to draw high current specially when using a capacitor-less drive. This is because it is better to use many parallel LEDs for higher summation of LED capacitance, which gives this method one more advantage.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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The capacitor-less LED drive is an LED drive circuit having a design based on the utilization of the internal capacitance of the LED to replace the smoothing capacitor in a conventional buck converter in a power supply. LED lighting systems usually have many LEDs for better illumination that can reach multiple tens of LEDs. Such a configuration can be utilized to enlarge the total internal capacitance, and hence minimize the output ripple. Also, the switching frequency of the buck converter is selected such that minimum ripple appears at the output. The functionality of the present design is confirmed experimentally, and the efficiency of the drive is 85% at full load.
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FIELD OF THE INVENTION
The present invention relates to devices for producing noise. The invention has particular application in devices for producing noise when mounted on an vehicle without an engine, such as a bicycle, tricycle, or motorless scooter.
BACKGROUND OF THE INVENTION
Children using bicycles will often add a simple device for producing noise to simulate the sound of a combustion engine. This may be done by attaching a playing card to a frame member of the bicycle, usually the rear stay, with a clip such as a clothes peg so that the card projects between the spokes. When the wheels turn, the spokes rapidly strike the card producing a noise which somewhat approximates that of an engine.
Various custom-designed devices have been proposed to improve on such home made arrangements. Examples of such devices are described in U.S. Pat. Nos. 3,716,944, 3,905,151, 4,701,149, 4,875,885, 5,226,846, 5,611,558 and U.S. Pat. No. 6,394,875.
These devices suffer from various shortcomings which the present invention is intended to address.
SUMMARY OF THE INVENTION
The invention provides a noise-producing device comprising a body having means for mounting the body to a frame member of a bicycle, a card holder for securing a resiliently flexible card-like member (“card”) to the body such that the card extends freely outwardly from the body, and a resonant chamber in the body for amplifying the sound produced by the intermittent interaction of the free end of the card with a bicycle wheel.
The term “bicycle” as used herein is intended to encompass bicycles, tricycles, scooters and other motorless vehicles having wheels of a type which when rotated will vibrate a card to produce a noise, such as spoked wheels.
Preferably the device includes a hollow component in the form of a simulated exhaust removably mountable on the body with its interior in communication with the resonant chamber for further amplifying the sound produced by the card.
The means for mounting the body to a frame member of a bicycle may comprise an open channel extending into the body in which a frame member can be received. In such case the open channel may comprise a pair of side walls and a base for receiving the frame member, the device further including a fastening means to draw the side walls together and thereby grip the frame member in the base.
Preferably the card holder comprises a slot which is adapted to retain the card by its edges so that a majority of the surface of the card facing away from the body is exposed.
Further, the resonant chamber is preferably open to the surface of the card facing towards the body.
The invention further comprises the combination of a device as specified above and a resiliently flexible card-like member mounted in the card holder.
BRIEF DESCRIPTION OF DRAWINGS
The invention will now be illustrated by the following descriptions of embodiments thereof given by way of example only with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view from above of a noise-producing device according to a first embodiment of the invention.
FIG. 2 is a perspective view from below of the device of FIG. 1 .
FIG. 3 is a top plan view of the device of FIG. 1 .
FIG. 4 is a bottom plan view of the device of FIG. 1 .
FIG. 5 is a side view of the device of FIG. 1 .
FIG. 6 is a front elevation of the device of FIG. 1 .
FIG. 7 is a rear elevation of the device of FIG. 1 .
FIG. 8 shows the device of FIG. 1 when mounted on a bicycle.
FIG. 9 is a perspective view from below of a noise-producing device according to a second embodiment of the invention.
FIG. 10 is a perspective view from above of the device of FIG. 9 .
FIG. 11 is a perspective view from above of the main body of the device of FIG. 9 , omitting the card, base liner, simulated exhaust and other attachments.
FIG. 12 is a perspective view of the card used in the device of FIG. 11 .
FIGS. 13 and 14 are perspective views of the simulated exhaust used with the device of FIG. 11 .
FIG. 15 is a perspective view of an apertured reflector fitted to the simulated exhaust of FIGS. 13 and 14 .
FIG. 16 is a perspective view of a base liner used in the device of FIG. 11 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 to 7 together show a first embodiment of noise-producing device according to the invention. The device 10 comprises a body 12 into which a resiliently flexible card-like member 14 (“card”) is mounted. The card 14 may be replaceable or it may be fixed in place at the time of assembly of the device by the user. The body 12 is moulded of a semi-rigid plastics material and the card 14 is made, for example, of polypropylene.
The card 14 is retained by its edges in a slot 15 which snugly receives and surrounds one end of the card on three sides so that a free end 16 of the card extends from the body 12 and a majority of the surface of the card facing away from the body 12 is exposed. The free end 16 , when it protrudes into the spokes of a rotating spokes wheel, is repeatedly urged forward by successive spokes before snapping back towards its usual flat shape. This repetitive motion gives rise to an engine-like noise. In the present embodiment the card 14 is replaceable in the body 12 and is secured in place by a small allen bolt 11 which engages the end of the card within the slot 15 .
A resonant chamber 18 , in the form of a bore having a roughly triangular cross-section and open at each opposite end 20 , extends through the body 12 in a direction transverse to the direction in which the card 14 extends from the body 12 . The chamber 18 amplifies the noise transmitted from the card to the body providing a more realistic, fuller sound. A pair of end caps (not shown) may be provided to seal the open chamber ends 20 to vary the resonant characteristics of the chamber.
The device is mounted on the frame of a bicycle 30 (see also FIG. 8 ) by means of an open channel 22 having opposed sidewalls 24 and a base 26 which is shaped to receive a frame member such as a rear stay 28 of bicycle 30 . The channel 22 is substantially parallel to the resonant chamber 18 .
A castellated compressible material 32 lines the base 26 to improve the grip of the mounting. A pair of alien bolts 34 each extends through a pair of threaded holes 36 in opposite sidewalls 24 to allow the sidewalls to be drawn together when a frame member, such as the rear stay 28 , is engaged in the base 26 . Tightening or loosening the allen bolts increases or relaxes the grip of the base on the frame member. When the allen bolts are removed, the device can be engaged or disengaged from the frame member.
When the device is mounted on a bicycle 30 as shown in FIG. 8 , a display area 38 having a flat surface faces generally outward (i.e. away from the wheel). This display area provides a surface for receiving printed indicia or adhesive labels, to provide branding or advertising space which is readily visible on the device. Alternatively, a brand name or logo can be moulded in relief on the display area 38 , as an integral part of the body 12 , as shown FIGS. 9 and 10 of the second embodiment to be described. Due to the noise produced by the device in use, and the natural tendency of the eye to be drawn to a source of noise, the display area 38 is particularly prominent and therefore valuable.
FIGS. 9 to 16 show a device 100 according to a second embodiment of the invention. In FIGS. 9 to 16 , features and components the same or functionally equivalent to those shown in FIGS. 1 to 8 are given the same reference numerals will not be further described. The following description will therefore concentrate on the differences between the first and second embodiments.
The primary difference is that in the device 100 the resonant chamber 18 is only open at one end, i.e. the end 20 seen in FIG. 11 , and that in use a hollow simulated exhaust 40 ( FIGS. 9 , 10 , 13 and 14 ) is removably mounted on the body 12 with its interior in communication with the chamber 18 via the open end 20 . The simulated exhaust 40 has a generally funnel-like shape with an open, relatively narrow, front end 42 and an open, relatively wide, rear end 44 , the main body of the exhaust being in the form of a hollow cylinder 46 . The narrow front end 42 of the exhaust 40 has an external cross-section complementary to the interior cross section of the open end 20 of the bore 18 , and the exhaust 40 is fitted to the body 12 by inserting the end 42 into the open end 20 as seen in FIGS. 9 and 10 . The simulated exhaust 40 acts like a megaphone or loudspeaker to further amplify the sound produced by the card 14 . A circular safety reflector 48 , FIG. 15 , may be fitted across the wide rear end 44 of the exhaust 40 . This has a plurality of apertures 50 to allow the sound to escape from the simulated exhaust.
In this embodiment, too, the resonant chamber 18 has a top opening 52 within the area defined by the three sides of the slot 15 so that, in use, the chamber 18 is open to the surface of the card 14 facing towards the body 12 . This enhances the transmission of sound from the card to the resonant chamber 18 . Also, the card 14 has a tab 17 which projects out of the slot 15 when the card is fully inserted in the body 12 , the tab 17 facilitating the user to insert and remove the card.
The card 14 and simulated exhaust 40 are retained in position on the body by a removable pin 54 , shown in dashed lines in FIG. 10 , which passes down into the chamber 18 through a hole 56 ( FIG. 11 ) in the body 12 . The pin 54 engages a semi-circular recess 58 ( FIG. 12 ) in the card 14 to prevent its withdrawal from the body 12 , and enters a groove 60 in the front end 42 of the exhaust to likewise prevent removal of the exhaust from the body 12 . The pin 54 itself is prevented from coming out of the hole 56 by a strap 62 , the pin 62 being integral with one end of the strap 62 and the other end of the strap being formed with a hole which is engaged by one of the bolts 34 .
In this embodiment the castellated material 32 is in the form of a replaceable liner of a semi-rigid plastics material, FIG. 16 , so that bicycle frame members of different diameters can be accommodated by the use of liners 32 of different radial dimensions. Alternatively, a set of nested liners 32 can be provided, one or more being used according to the diameter of the frame member.
The moulded body 12 of the device 100 also has a number of features designed to assist cooling of the device in use and/or to assist flexing of the body to conform to different bicycle frame members. Slots 64 ( FIG. 11 ) allow the body 12 to bend along a longitudinal axis at this point to clamp on to the bicycle frame member when the bolts 34 are tightened. Longitudinal holes 66 are formed in the body 12 above and below the slots 64 to provide mounting points for future items to be fitted to the body 12 , as well as providing a weight and material saving and increasing the total surface area of the body 12 to assist its cooling in use. Recesses 68 ( FIG. 9 ) running transversely of the channel 22 through the sidewalls 24 allow a slight bending of the body 12 in the longitudinal direction to accommodate any slight curvature in the bicycle frame member, as well as reducing weight/material usage and increasing the surface area of the body for cooling. Finally, a slot 70 in the side of the body 12 again reduces weight/material usage and increases the surface area of the body for cooling.
The invention is not limited to the foregoing examples which may be varied without departing from the scope of the claimed invention.
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A noise-producing device comprises a body ( 12 ) having a clamp ( 24 ) for mounting the body to a frame member of a bicycle or other motorless vehicle with spoked wheels. The device includes a card holder ( 15 ) for securing a resiliently flexible card ( 14 ) to the body such hat the card extends freely outwardly from the body. A resonant chamber ( 18 ) in the body amplifies the sound produced by the intermittent interaction of the free end of the card with the spokes of the bicycle wheel.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/827,903, filed Oct. 3, 2006, the entire contents of which is hereby incorporated by reference.
FIELD
[0002] The technology herein relates to methods and systems for determining cellular and other radio transmitter mappings. More particularly, the technology herein provides methods and systems which enable the calculation of cellular and other radio transmitter mappings based upon factors including transmitter locations, projected signal strength maps, and signal strength measurements. The methods and systems provided by exemplary illustrative non-limiting implementations are useful for determining potential locations of new communications towers, and predicting which communications providers would be interested in leasing space on those towers. The technology herein thus has applications in the fields of electronics, computing, and telecommunications.
BACKGROUND AND SUMMARY
[0003] Cellular operators often rely on maps of cellular signal strength calculated on the basis of signal propagation theory, terrain, tower location, and transmitter power. These calculations are sometimes imprecise and result in locations being erroneously reported as having acceptable signal levels when actual coverage is inadequate. These deficiencies can lead to poor signal quality, which results in cellular users complaining about bad call quality and dropped calls. Cellular operators thus have a strong interest in determining where their cellular signals are weak. They often will install additional transmitters, at additional expense and effort, to provide better signal coverage.
[0004] A map that associates cellular transmitters, cellular operators, and signal strength by cellular operator is often not readily available using current estimation methods. Nevertheless, enterprising third-party tower owners often attempt to obtain land and construct towers. Often, they attempt to purchase land and sometimes construct a radio tower before cellular operators determine that they have a signal quality problem that requires an additional transmitter. Such third parties thus are in a position to lease tower or other radio transmitter locations to cellular operators, providing a return on investment and better service to cellular customers.
[0005] Thus, there is an urgent need for better methods and systems to estimate signal strength for cellular and other radio signals. The technology herein meets these and other needs.
[0006] In one aspect, the exemplary illustrative non-limiting technology herein provides methods to estimate the location of at least one cellular transceiver tower used by a cellular telephone carrier. In another aspect, the exemplary illustrative non-limiting technology herein provides methods to estimate a network or sub-network of cellular transceiver towers used by a cellular telephone carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features and advantages will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative implementations in conjunction with the drawings of which:
[0008] FIG. 1 is an exemplary illustrative non-limiting example use of an algorithm that projects signal strength indicated by bands surrounding towers;
[0009] FIG. 2 is an exemplary illustrative non-limiting flowchart; and
[0010] FIG. 3 is an exemplary illustrative non-limiting system.
DETAILED DESCRIPTION
[0011] An exemplary illustrative non-limiting implementation provides methods and systems for determining cellular signal strength in a geographical location. A non-limiting exemplary implementation includes the following operations:
[0000] Steps
[0012] An initial step identifies locations of existing cellular towers and transmitters ( FIG. 3 block 202 ). The set of identified existing cellular towers and transmitters is called T(x) below. The set of identified cellular towers can be commercially obtained in various databases of cellular towers and locations and/or by observation.
[0013] The exemplary illustrative implementation then determines the projected signal strength for each transmitter in T(x) at one or more locations L(i), to produce a set of projected signal strengths according to each tower and location ( FIG. 3 block 204 ). The set of projected strengths is referred to below as P(T(x), L(i)). Various models and calculations can be used to estimate the signal strength around a tower or other transmitter. One example of such as model is the well-known Langley-Rice model, which approximates signal strength at a specific location to within +/−10 dB.
[0014] Actual signal strength may range in value depending upon the distance and terrain between the transmitter (tower) and the measurement location. Expected values are in the −40 dBm to −100 dBm range, where −40 dBm is present at the transmitter (tower) and −100 dBm may be at the minimum level for a usable signal.
[0015] The measuring equipment and predictive modeling software is, in one exemplary illustrative non-limiting implementation, “ground truthed” before starting measurements using this algorithm. Ground truthing is a process by which the several known locations and cellular transmitters/towers are measured to determine the correlation between the actual transmission strength from specific cellular transmitters i tower and the projected transmission strength using the preferred model. In some cases, a plurality of models may be used and the measurements cross-correlated between them.
[0016] For each location L(i), the exemplary illustrative non-limiting implementation identifies the projected signal strength for each transmitter with a projected non-zero signal strength, and measures the actual signal strength, transmitter identification, and cellular operator information attributes for each non-zero signal at location L(i) (block 206 ). This yields a set of signals, their strengths, their associated transmitter ID, and other information about each signal. This set is called S(j, L(i)) below
[0017] One example illustrative non-limiting implementation then associates S(j, L(i)) with T(x) using P(T(x), L(i)) to make a correlation (block 208 ). The exemplary illustrative non-limiting implementation then associates cellular operator information attributes from S(j, L(i)) with tower T(x) to determine coverage by cellular operator (block 210 ). In one example illustrative non-limiting implementation, the correlation will occur when the difference between the actual measurement and P(T(x), L(i)) is +/−6 dBm.
[0000] Results
[0018] The resulting set of associations of cellular operators with towers T(x) provides useful information about:
where each cellular operator might want to lease tower space to fill in low signal strength areas. the existing cellular infrastructure, allowing companies to identify locations where specific operators may wish to locate additional transmitters on existing towers (block 212 ).
[0021] An example illustrative non-limiting system 100 includes a processor 102 programmed with signal strength modeling software. The processor 102 has access to a database 104 of cellular telephone site information including cellular telephone operators. Local or remote receiver(s) 110 coupled to antennas 112 can measure actual signal strength. An input device 108 inputs collected data, and a display 106 or other output device displays results.
EXAMPLE
[0022] FIG. 1 illustrates an example use of the algorithm when applied using a set of towers T(x), with projected signal strength indicated by bands surrounding towers T(x). Each band represents the set of points L(i), such that the values of P(T(x), L(i)) for each point L(i) are approximately equal.
[0023] Points M(1), M(2), and M(3) represent three example actual measurements at locations L(M(1)), L(M(2)), L(M(3)). The table below presents these example measurements:
Estimated T(1) Estimated T(2) Estimated T(3) Location P(T(1), L(M(1)) P(T(2), L(M(2)) P(T(3), L(M(3)) Actual Measurement(s) L(M(1)) −73 dBm 0 0 Cingular 123 - −70 dBm L(M(2)) −71 dBm −76 dBm −96 dBm Cingular 123 - −70 dBm T-Mobile 456 - −81 dBm Verizon 789 - −102 bDm L(M(3)) 0 0 −65 dBm Vertzon 789 - −66 dBm
[0024] Based upon the above information, we can correlate the non-zero P(T(i), L(M(j)) with the actual readings to determine T(1) is likely Cingular transmitter #123, T(2) is likely T-Mobile transmitter #456, and T(3) is likely Verizon transmitter #789. Furthermore, we can conclude that both T-Mobile and Verizon would be candidates to lease tower space on Tower T(1), and that both Cingular and T-Mobile would be candidates to lease tower space on Tower T(3) in order to complete their coverage of the area. Furthermore, after correlation, we can determine that location T(4) would be an advantageous location to construct a tower and offer to lease space on it to Verizon because the coverage from T(4) for Verizon would save them having to place transmitters on either T(1) or T(2).
[0025] It should be noted that the example has been simplified to facilitate understanding. In normal usage, each tower generally has a plurality of transmitters from a plurality of vendors, and each location will have a plurality of transmitters from each vendor visible.
[0026] While the technology herein has been described in connection with exemplary illustrative non-limiting implementations, the invention is not to be limited by the disclosure. The invention is intended to be defined by the claims and to cover all corresponding and equivalent arrangements whether or not specifically disclosed herein.
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This technology herein relates to methods and systems for determining cellular and other radio transmitter mappings based upon calculated and actual values. Cellular and other radio transmitter mappings are calculated based upon factors including transmitter locations, projected signal strength maps, and signal strength measurements. This technique can be used to determine prospective and actual locations of communications towers, and which communications providers would be interested in leasing space on those towers.
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This application is a continuation-in-part of Ser. No. 08/249,221, filed May 25, 1994, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to ovens used for heating or cooking food items. Particularly, the invention relates to a convectively-enhanced radiant heat oven which permits quick and reliable preparation of a wide variety of foods.
Individuals and businesses who prepare food have long searched for the quickest and most efficient approach to cooking. The problem of designing an oven which cooks quickly is exacerbated by the need to accommodate a number of food types having different sizes, textures, and other characteristics. Even a quick-cooking oven, however, may be not be satisfactory in many situations. The ultimate measure of an oven's utility is consumer satisfaction with the taste of food cooked by the oven. Many approaches have been taken to design ovens which meet the above requirements and which produce quality food items.
For example, conventional conductive or radiant ovens have been found suitable for a number of food types. These ovens use either gas or electricity to heat an oven chamber containing food. The ovens are simple to design, fabricate and use and achieve good results for a number of types of foods. However, conductive and radiative ovens are slow. Efficiency, for individual, restaurant, and institutional users, demands that quality food products be produced more quickly than produced in typical conductive or radiant heat ovens. Further, these ovens are generally not able to produce foods with a deep-fried texture. In conventional ovens, moisture from the foods evaporates into the oven, taking, e.g., juices from red-meat steaks and other foods when it is desirable to retain those juices.
It is well known that moist air heat cooks faster than dry air heat; however, this results in a mushy rather than a crisp exterior of certain items, defeating the goal of retaining the crisp exterior of many foods. This problem may be alleviated somewhat by placing the food directly under a radiant heat source (e.g., "broiling"); however, the food is easily charred or burned before it is fully cooked. Thus, although conventional radiant or conductive ovens are suited for certain foods, they generally cook slowly. Further, they often require a lengthy warm-up time to bring the oven chamber to a desired cooking temperature. This is undesirable in situations where a quick response is required.
Microwave ovens have been found to satisfy the need to cook quickly. These ovens use microwave-length radiation to heat and cook foods. Unfortunately, however, microwave ovens are limited in the types and textures of foods which can be cooked. For example, it is not practical to cook baked goods, traditionally fried or deep-fried foods, or foods requiring a crisp or crunchy texture within a microwave. The microwave leaves these types of foods soggy and otherwise unappetizing.
Another approach to cooking is fry cooking. Foods which are usually fried or deep-fried, such as french fries or onion rings, are best cooked using a uniform high-temperature. Frying the foods in hot oil produces a characteristic crispiness in the food. Deep-fry cooking is a form of convective cooking in which the high-temperature cooking medium (oil or fat) presents a generally uniform high temperature to the food surface. The high temperature causes the outer surface of the food to crisp and further causes the food to cook quickly. However, the food also absorbs an amount of the oil or fat which makes the food less healthy. Another disadvantage of deep fry cooking is that it is only suited for a limited range of foods.
Forced-air convective cooking is another form of cooking which has been used to some success. It is well-known that forced-air convective cooking requires lower temperatures to achieve cooking comparable to a conventional oven. This is generally attributed to the fact that hot air is quickly and uniformly brought to the food surface. Again, however, this type of cooking is not suited to all food types. For example, they are unsuited to cook red meat or traditionally deep-fried food.
Thus, although a number of cooking approaches have been developed, none is ideal. No approach provides a quick, efficient means for cooking a wide range of food items. Further, existing approaches fail to provide control to enable accurate cooking of foods requiring differential heats (e.g., a pizza may need greater heat on the bottom than on the top). Other existing approaches are unsatisfactory because they cook using unhealthy greases or oils or require a relatively lengthy warm-up period.
SUMMARY OF THE INVENTION
Accordingly, a convectively-enhanced radiant heat oven is provided which quickly cooks a wide range of food types without unhealthy oils.
A convectively-enhanced radiant heat oven includes an elongated cooking chamber with first and second ends positioned opposite each other. A removable holder is positioned in the chamber to hold food items for cooking. One or more heating devices are placed in the chamber to create radiant heat. An air circulating device for circulating heated air within the chamber is positioned within the chamber on the first end. A vent, positioned along a wall of the internal chamber nearest the second end, is used to adjust cooking characteristics of the oven.
In one specific embodiment, the cooking chamber is formed with an octagonal cross section to enhance air flow within the chamber. The fan is positioned so that air is forced radially outward and against the end of the chamber. This causes air turbulence around the heating devices, effectively stripping radiant heat from the devices to create convective heat. The combination of radiative and convective heat operates to quickly and efficiently cook a wide range of foods.
The fan and the heating devices may be individually controlled to create specific cooking environments. Control of the fan and heating devices may be facilitated by entry through a keypad positioned on the exterior of an oven cabinet. The keypad may be coupled to electronic control circuitry to directly provide control signals to the heating elements and to the fan. Ovens according to the present invention allow a wide range of foods to be cooked quickly, efficiently, and without unhealthy oils or fats. The ovens require no preheating time.
Initial experimental versions of the present oven employed all three methods of transferring heat to the foods. Conduction was achieved by heating a metal cooking container in which the foods were placed. Radiative heating was employed by placing a heating coil over the food to add a crispness in the foods. Convection was achieved by blowing air transversely over the heating coil and over the foods. It was determined through experimentation with this oven that cooking principally by conduction produced the least authentic fried taste and texture. It was rather determined that the authentic texture and taste of fried foods was best obtained using a combination of convective and radiant cooking as in deep-frying but with air instead of oil or fat as the convective medium.
The oven was therefore improved to exploit convection and radiation and to minimize conduction. A metal basket was substituted for the solid metal food container to surround the food with heated air and substantially reduce the effect of conduction and enhance the effect of convection. Heating rods were placed around the food basket. Because distance from the food greatly changes the cooking result as in broiling, an optimum distance from the food was empirically determined, and a fan was added to obtain the advantages of forced-air convection. The shape of the chamber was also modified and changed to a 8-sided, reflective surface to achieve uniform radiative heat transfer about the food. The result produced a food clearly superior to previous designs and prior ovens.
Fan speed was yet to be optimized, so a variable-speed fan was introduced to facilitate experimentation. The intent was to determine an optimum constant fan speed, but it was discovered that fan speed and air flow had an unexpected effect on the texture of the food. Appropriately adjusting the fan speed during cooking yielded a change in the internal food texture while also varying the crispness of the outer surface texture.
On analysis of the cause and effect of the discovery, it was surmised that the balance between radiative cooking and convective cooking was critical in achieving a desired crispness and texture in the food product. Thus, the oven was further modified to force laminar air flow over the food basket to the fan and then redirected along the oven chamber walls and longitudinally over the heating rods to maximize heat transfer between the rods and the air. The air was thereby heated and the rods were cooled with high air flow resulting in reduced radiative cooking and increased convective cooking. Thus in this mode, the contribution by convection was maximized and the food surface texture was less crisp with the food within more moist and flavorful. Conversely, when the fan speed was reduced, the balance was reversed with less heat being transferred to the air with the heating rods becoming higher in temperature and therefore radiating to the food surface at the higher temperature. With the increased temperature of the food surface from radiative cooking, the food was more crisp.
It was also discovered that the total heat and moisture in the chamber also made an important contribution--it is well-known that moisture in the cooking environment will change the food to a less crisp texture, so a bottom vent was introduced that provided an air exchange. Thus, the fan speed also served to regulate the oven temperature by how much air was exchanged while also regulating the moisture in the oven air.
For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of one embodiment of an oven according to the present invention;
FIG. 2 is a front cut-away view of the oven of FIG. 1;
FIG. 3A is a side cut-away view of the oven of FIG. 1 showing air flow within the chamber of the oven;
FIG. 3B is a second side cut-away view of the oven of FIG. 1;
FIG. 4 is a block diagram of the control electronics used in an embodiment of the oven according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One specific embodiment of an oven 10 according to the present invention is shown in FIG. 1. The exterior of the oven 10 includes a cabinet 12, and an access door 14. Preferably, the access door is formed from heat resistant glass to permit viewing of the food items cooking inside the oven 10. The access door 14 has at least one handle 16 on it to permit removal of the door 14 for access to the interior of the oven 10. The oven 10 is controlled via a control panel 20 which may include a display 22 and keypad 24. The control panel, as will be discussed, permits operator control of the oven. The cabinet may be raised from a surface such as a counter by placing feet 26 on the base of the cabinet. Those skilled in the art will recognize that a number of cabinet configurations may be employed, including cabinets which may be built-in to existing cabinetry or the like. Similarly, the control panel of the oven 10 may consist of any of a number of configurations. Digital or analog displays may be used. Simple knob controls may also be used. Those skilled in the art, upon reading this specification, will be able to adapt the present invention to a number of installations and control panel configurations.
Throughout this description, a "consumer" embodiment and a "commercial" embodiment will be referred to. The consumer embodiment is envisioned for home use with 110 Volt electricity service while the commercial embodiment is designed for use in establishments with 220 Volt service. Details of these two specific embodiments will be given. Those skilled in the art, upon reading this disclosure, will be equipped to modify the two specific embodiments by scaling the described teachings to achieve desirable results in different sized ovens.
The internal components of the oven 10 are shown in FIG. 2. The oven 10 includes a cooking chamber 18 into which a food basket 38 is positioned. In a currently preferred embodiment, the cooking chamber 18 has an octagonal cross section. It has been found that this shape of chamber provides desirable results, believed due to the air flow characteristics of the chamber. The chamber 18 is completely contained within the cabinet 12 of the oven. Insulation 28 may be placed between the chamber and the cabinet to minimize heat transfer to the cabinet. The food chamber 18 has a left Side wall 30 and a right side wall 32. The back and top of the chamber may be formed from a single piece of material. The bottom of the chamber is formed from a separate sheet of material to form a drip tray 35. The drip tray 35 may be removed from the chamber 18 through the access door 14 for cleaning. In a preferred embodiment, the food chamber is formed from metal sheeting which is coated on all interior surfaces with a reflective material such as teflon coating. Other coatings and finishes may be used which reflect heat, enable unrestricted air flow, and permit easy cleaning of exposed surfaces. In another specific embodiment, heat absorbent material may be used to coat the interior surfaces of the chamber 18. It has been found that black teflon coating produces satisfactory results;,however, the cooking times are slightly slower for most foods than when a reflective surface is used.
The back edge of the drip tray 35 has an opening formed therein to permit air flow frog a vent 56. In a preferred embodiment the vent 56 is positioned at the opposite end of the chamber 18 from a fan 40. The vent 56 may be adjustable and, preferably, is approximately 1/3 of the length of the chamber. A number of vent sizes have been experimented with. It has been found that the vent 56 is preferably placed along the bottom edge of the chamber 18 at the end furthest from the fan 40. Although variable vents may be used, it has been found that, for one specific embodiment of oven, a preferred vent opening is 0.40 inches in height. Experimentation has shown that vertical adjustments in the vent opening affect the cooking temperature as well as the flavor and moisture content of food cooked in the oven. Placing the vent away from the fan 40 has been found to ensure even cooking within the chamber 18. It has been found that positioning the vent in the manner shown in FIG. 1 produces desirable cooking results. Vents with vertical and/or horizontal adjustment capability may also be used. Further, more than one vent may be used to supply air to the chamber 18.
The food basket 38 is positioned in the cooking chamber 18 by closing the access door 14. The basket 38 is made of, e.g., a wire mesh and has side walls and a bottom. Mesh is used to allow relatively unrestricted convective air flow throughout the chamber. In one specific embodiment, the basket is made of 1/4 inch wire mesh. The basket is used to hold food for cooking within the oven. The side walls prevent food items from slipping off the basket while the basket is handled. In one specific embodiment, the food basket 38 is securely attached to the access door 14 so that removal of the access door results in removal of the basket 38. Likewise, when the door 14 is properly closed on the oven, the basket 38 is properly positioned within the cooking chamber 18 of the oven 10. The door and basket may be coupled to the oven 10 in other ways as well. For example, the basket may be slidably coupled to the oven on one or more rails positioned within the chamber. The door may attach to the face of the oven 10 via hinges. However, in the specific embodiment shown, the door 14 is coupled to the basket 38 so they may be completely removed from the oven 10 for cleaning.
The oven 10 also includes a number of heating elements 58. In one specific embodiment, four heating rods 58a-d are used, two above the basket 38 and two below it. These heating rods 38 are used to supply a source of both radiative and convective heat to the food. The rods 38 are anchored at both ends 30, 32 of the cooking chamber 18. The right hand end 32 of the cooking chamber 18 includes a heat shield 50 which separates the chamber from control circuitry which will be described. Power is supplied to each of the rods 58 through wiring connected to the heat shield end of the rods. A number of heating elements may be used, depending upon the application for which the oven will be used. For example, in one specific consumer unit, four heating rods are placed within a cooking chamber 18 12" long, 8" high and 81/2" deep (contained within a cabinet 12 91/8" high, 171/4" long, 91/8" deep). Two 400W heating rods 58 are placed about four inches above the food basket 38 and are spaced approximately three inches apart, while two 350W rods are placed approximately two inches below the basket and'spaced about 11/2" apart. In consumer models, any heating rod may be used which operates on house current (110 Volts at under 14 amps) may be used. Quartz, metal, halogen or infrared or other rods may be used. The number of rods was chosen to maintain uniformity of radiative heating on the food while maximizing the rod temperature within the limits of energy that can be drawn from household 120 volt power outlet. More rods would require the power per rod to be reduced and hence would reduce the temperature of each rod.
In embodiments for use in commercial settings (i.e., having access to 220 volts), a larger cooking chamber 18 may be used. For example, the chamber 18 may be 15" long, 10.5" high, and 11" wide and may fit within a 21.5" by 12" by 12" cabinet 12. In such an application, the heating capacity may be increased by using larger heating rods. For example, 0.44 inch Calrods may be used. In one specific embodiment, the heating rods 58 are placed 5.5 inches above and below the food basket 38. Again, heating capacity may be increased by using higher output rods such as rods made from quartz.
The relative positioning of the heating rods 58, the food basket 38, and the vent 56 within the oven 10 are shown in FIGS. 3A and 3B. The vent 56 may include a filter 57 which is placed on the exterior of the oven cabinet 12. The filter 57 may be removable for cleaning or replacement. The exterior of the cabinet 12 may also include a damper for adjusting the airflow through the vent 56. FIGS. 3A and 3B also show that the upper and rear portions of the octagonal chamber 37 may be formed from a single sheet of material. The removable drip tray 35 is formed from a separate sheet of material to permit removal and cleaning of the tray. The drip tray 35 may rest directly on the floor of the oven 34. A notch is formed in the rear portion of the drip tray 35 to form a vent 56. The chamber 37 is separated from the cabinet 12 by insulating material 28. The floor of the oven 28 may also be formed from heat insulative material to prevent heat transfer through the feet 26 of the oven.
A sensor 60 may be placed either outside the chamber 37 or inside the chamber 37. The sensor may be coupled to the control electronics 48 and is used to detect the temperature within the chamber. In one specific embodiment, the sensor is designed to act as a safety kill switch which ensures that no further power is applied to the heating elements 58 when the temperature exceeds a certain value (e.g., 450° F.). The heat limit may be set higher as well. Further, the sensor 60 may be used as a thermostat to set and maintain a target temperature within the oven chamber 18. In another embodiment, the sensor 60 is placed through wall 32 of the chamber, and extends through the heat shield 50.
Referring again to FIG. 2, a fan blade 40 is mounted inside chamber 18. The fan 40 is positioned centrally on wall 32 of the chamber. The fan 40 spins on a spindle driven by a fan motor 44 which is cooled by a cooling fan 42 coupled to the drive spindle. For a consumer unit, a 4.75" fan blade may be used, while a commercial unit may employ a larger fan blade such as a 6.25" blade. In one specific embodiment, the fan 40 may be driven at up to 3200 RPM. The motor 44 is preferably adjustable and may be controlled via the control electronics 48. The size of the motor 44 is, of course, dictated by the size of the fan 40, the speed required, and the amount of current available for a specific use. A screen 52 may be positioned between the fan and the food basket 38 to prevent user injury from the fan. As shown by briefly referring to FIG. 4, the screen 52 may be a wire mesh screen and is positioned in front of the fan 40 by a mounting bracket 55 attached to wall 32 of the chamber. The bracket 55 may be easily removed if a single release screw 54 is used and if tabs 59a, 59b are extended through the chamber walls. This allows easy removal of the fan screen 52 for cleaning or repair.
As shown in FIG. 2, the fan blade is positioned in an orientation opposite to typical fan blade orientations. The blades function to force air against wall 32 and swirl in a cyclone effect inside chamber. That is, the fan is mounted so that air is drawn from the vent 56 via the chamber and is distributed radially by the blades. This, in conjunction with the octagonal shape of the chamber 18, causes turbulent air flow with a swirling cyclone effect around the food. Heated air is exhausted from the vent 56 at the far end of the chamber near wall 30. This swirling flow of air causes radiant heat to be stripped from each of the heating elements 58, cooling the rods while transferring heat throughout the chamber. Experimentation has shown that the combination of chamber shape, heating element positioning, and air flow caused by the orientation of the fan produces considerably more convection heat as the fan moves turbulent air down the length of the heating rods. The radiant heat stripped from the rods is converted to evenly-distributed convection heat. The result is an oven which cooks a variety of foods quickly and uniquely. Experimentation has shown that variations in fan size and speed, heating element temperature, and vent size produce a number of distinct cooking characteristics. Experiments have also shown that other fan orientations do not provide similarly desirable results. For example, placement of the fan blade outside of the cooking chamber has been found to be much less effective as the needed swirling/cyclone type air flow is not provided.
It was found that, for the fan orientation shown in FIG. 2, fan speed had a direct impact on the outer surface and texture of food being cooked within the chamber 18. As fan speed is increased, the turbulent air forced down the length of the chamber 18 strips heat from the heating elements 58 and transfers it to the food. As the fan speed is decreased, the amount of radiant heat emitted to the food surface is increased. Different food types require different amounts of convective and radiant heating. Thus, control electronics 48 are provided to allow custom cooking control for different foods. The speed of the fan can be manually controlled or electronically controlled to effect different effects during cooking. For example, if the speed is reduced at the beginning of the cooking process to accentuate the effect of radiative cooking, the food outer surface will tend to seal closed, useful for retaining natural juices in meats. Similarly, if the speed is reduced at the end of the cooking process, the food surface becomes more crispy after the desired internal food texture is achieved, useful for extra crispy french fries or other foods with a deep fry texture.
Referring now to FIG. 6, a block diagram depicting one specific embodiment of control electronics 48 for use in the present invention is shown. The control electronics 48 may include a microprocessor 62 or microcontroller coupled to a memory 64. The memory may be an EEPROM, ROM, or other memory. In the commercial embodiment, information is stored in the memory 64 to allow pre-programming of control information for specific food types. A simpler approach used in a specific embodiment of a consumer unit uses three discrete fan speeds which may be selected from the keypad 24 of the control pad 20. This permits operator selection of cooking modes. Recipes may be produced directing the operator in the proper use of the keys (e.g., two minutes with high fan speed followed by one minute at low fan speed). The processor 62 is coupled to receive input commands from a keypad 24 which is mounted, e.g., on the exterior of the oven 10 as a control pad 20. A display 22 is also provided on the control pad 20 and is coupled to receive display information from the microprocessor 62. The display 22 may be an LCD display or the like. The keypad 24, microprocessor 62, and memory 64 are used together to control the cooking environment within the oven 10. Several basic parameters may be controlled: cooking time; fan speed; heat of each heating element; and the overall temperature of the chamber. Not all of these parameters need be controlled for an oven. For example, in one specific embodiment designed for use by a residential consumer, the individual heating elements 58 are not separately controlled. Instead, adjustments are made by relying solely on the overall time of cooking and fan speed. Experimentation has shown that heat input to the heating elements may be kept constant for a given cooking cycle with cooking completely controlled by adjustments in air flow instead of input energy. In another specific embodiment, all parameters may be controlled by the microprocessor 62, allowing wide control over individual cooking characteristics.
In one specific commercial embodiment, a number of cooking parameters are stored in the memory 64. A user intent on cooking a specific item, e.g., a twelve-inch frozen pizza, may look up the cooking code for the pizza in a users manual, and enter a code (e.g., a four-digit code) into the control electronics 48 via the keypad 24. The microprocessor 62 will retrieve the required record from the memory 64 and perform the steps prescribed to cook a twelve-inch frozen pizza. The steps may include setting an initial heat for each of the heating elements (e.g., 40% of maximum for the top elements and 60% of capacity for the bottom elements), setting an initial fan speed, and setting an internal timer for an initial cooking period. Upon completion of the initial cooking period, the steps stored in memory 64 may then prescribe that the heat from the heating elements be increased for a certain period or that the fan speed be reduced to increase the amount of radiative heat applied to the pizza. Such pre-set computer control of different parameters of the oven 10 allows easy control of the wide capabilities of the oven. Users may also be able to customize oven controls by entering new parameters for different foods into the memory via the keypad 24.
Features and capabilities of ovens 10 according to the present invention are understood by referring to Table 1, where sample control settings for a variety of food items are shown. For the consumer embodiment, the settings will be entered via the keypad manually for each item. The commercial embodiment will include pre-stored instructions which are activated by entering a key several digits long into the keypad. The Table also compares the overall cooking time of each food item to the time required to cook similar items in a conventional oven and, if possible, the time for cooking in a microwave oven. Repeated experimentation has shown that ovens of the present invention produce cooked food having superior taste, texture and quality over previous ovens. The comparative cooking times of the oven of the present invention is reduced further as compared to conventional ovens because the oven 10 does not require a warm up or preheat period. Further, oven 10 does not require a period to thaw, e.g., meats or the like.
TABLE 1______________________________________COOKING TIME (Minutes)FOOD CONVEN-ITEM OVEN TIONAL CONVECTION MICROWAVE______________________________________12" 3-5 15-25 6-15 3-4PIZZAONION 3-4 15-20 10-15 NotRING RecommendedTATER 4-5 15-25 10-17 NotTOTS RecommendedSTEAK 6-9 20-30 15-22 Not RecommendedCHICKEN 6-9 20-30 15-22 5-7PASTRY 3-5 15-20 10-15 NotROLLS Recommended______________________________________
Repeated experimentation has shown that ovens according to the present invention are capable of cooking a wide range of foods not satisfactorily cooked by other ovens. Table 2 shows some differences between cooking characteristics.
TABLE 2______________________________________ CONVEN- CON-Food TIONAL VECTION MICROWAVEItem Oven 10 OVEN OVEN OVEN______________________________________12" Done on top, Done on top Done on top Done on top,Pizza toasted on but not but not soggy crust and bottom toasted on toasted on not toasted on bottom bottom bottomOnion Moist & Dried out & Dried out & Limp & soggy,Rings flavorful less flavor less flavor no deep fried inside crisp inside & no inside & no texture & deep fried deep fired deep fried texture texture texture outsideTater Moist & Dried out & Dried cut & Mushy & soggy,Tots flavorful less flavor less flavor no deep fried inside, inside & no inside & no texture crisp & deep deep fried deep fried texture texture outsideRed Meat Browned top Not browned Not browned No browning,Steak & bottom, top & top and poor taste, juicy, bottom, bottom, texture & flavorful & dried out & dried out & appearance tender tough toughChicken Browned, Less Less No browning,Parts juicy, browning, browning, poor taste, flavorful less flavor, less flavor, texture & and tender meat not as meat not as appearance moist moistCinnamon Browned, Less Less No browning,Rolls plump, moist browning, browning, dough soggy, very less flavor, less flavor, very poor flavorful not as plump not as plump appearance & or moist or moist taste______________________________________
As will be appreciated by those familiar with the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For example, a convectively-enhanced radiant heat oven may be constructed which is smaller or larger than the ovens described in this specification. Further, other shapes of the cooking chamber may be employed which preserve the essential air-flow characteristics of the octagonal shape. Partially circular, pentagonal, hexagonal, or other shapes may also provide desirable results. It is believed that, based upon the foregoing disclosure, those of skill in the art will now be able to produce convectively-enhanced radiant heat ovens having different performance characteristics by modifying the dimensions and scaling of the specific embodiments described. The shape and size of the fan blade may be modified as may the placement and wattage of the heating rods. Further, It is apparent that the present invention may be utilized to cook a wide range of food items quickly and efficiently. Control electronics may be custom designed for specific applications.
Accordingly, the disclosure of the invention is intended to be illustrative, but not limiting, of the scope of the invention which is set forth in the following claims.
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A convectively-enhanced radiant heat oven includes an elongated cooking chamber with first and second ends positioned opposite each other. A removable holder is positioned in the chamber to hold food items for cooking. One or more heating devices are placed in the chamber to create radiant heat. An air circulating device for circulating heated air within the chamber is positioned within the chamber on the first end. A vent, positioned along a wall of the internal chamber nearest the second end is used to adjust cooking characteristics of the oven. The oven cooks a wide range of foods quickly and efficiently.
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RELATED APPLICATIONS
[0001] This application claims priority from German Patent Application No. 202 09 663.7, filed on Jun. 21, 2002, incorporated herein by reference for all legitimate purposes and relied upon for priority.
FIELD OF INVENTION
[0002] The invention refers to an infusion pump comprising an pump hose with respective transition pieces at the opposite ends, a housing accommodating a pump finger mechanism and having two holders for attaching the two transition pieces, and a door provided at the housing which forms a counter bearing for supporting the pump hose.
DESCRIPTION OF RELATED ART
[0003] From teachings in DE 8406203 U1, co-owned with the present application, an infusion pump is known comprising a housing for accommodating an exchangeable pump hose. A housing is provided with a pump finger mechanism continually squeezing the hose from top to bottom, thereby causing a volumetric conveying of the liquid contained in the pump hose. The pump hose is made of a relatively soft flexible material, especially silicone, its two ends being equipped with transition pieces to which a supply hose and a discharge hose of flexible plastics material respectively, are connected. The housing in provided with holders into which the transition pieces are hooked. In this manner, it is possible to attach the pump hose to the housing in a defined manner. Both holders and the associated transition pieces are designed such that the upper transition piece only fits into the upper holder and the lower transition piece only fits into the lower holder. However, the length of the pump hose allows a twisting of the pump hose, where, for example, the lower holder is twisted by 360 ° with respect to the upper holder. This bears the risk of a greater deviation from the set output volume or, in the worst case, a free flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] In the figures:
[0005] [0005]FIG. 1—is a perspective view of a part of the infusion pump with a housing and a pump hose exchangeably fastened thereto,
[0006] [0006]FIG. 2—is a schematic vertical section through the upper holder and the transition piece fastened thereto,
[0007] [0007]FIG. 3—is a front view of the pump hose fastened to the housing, and
[0008] [0008]FIG. 4—is a perspective view of the upper transition piece prior to being fastened to the hose part of the pump hose.
DETAILED DESCRIPTION
[0009] The following is a detailed description of an embodiment of the invention with reference to the drawings. 1000101 The infusion pump illustrated in FIG. 1 comprises a housing 10 generally designed similar to the housing of the infusion pump of DE 8406203 U1. In a front wall 11 of the housing 10 , an opening 11 a is provided behind which a pump finger mechanism 12 of a finger pump (not illustrated) is arranged. The finger pump comprises numerous sequentially arranged fingers which are pressed one after the other from top to bottom against the pump hose and compress the same, so that the liquid contained therein is transported peristaltically from top to bottom. The pump finger mechanism 12 is covered by an elastic cover.
[0010] A pump hose 13 is installed in front of the opening 11 a . The pump hose 13 comprises a length 14 of soft elastic hose, preferably made of silicone. For example, the length may be about 90 mm, the inner diameter 4 mm, and the outer diameter 6 mm. Fastened at the upper end of the length 14 of hose is an upper transition piece 15 . This transition piece 15 is hung into an upper holder 16 of the housing 10 . This holder 16 has two pins 17 arranged side by side and on the same level, projecting obliquely upward from the front wall 11 of the housing, as illustrated in FIG. 2. The transition piece 15 has two channel-shaped holes 18 extending obliquely upward, the axis thereof extending at the same angle as that of the pins 17 . The transition piece 15 is connected with a supply hose 19 of flexible plastic material.
[0011] The transition piece has a front side 15 a and a rear side 15 b . The rear side 15 b faces the front wall 11 of the housing. If the transition piece were mounted such that its front side 15 a faced the front wall 11 of the housing, the transition piece would not flatly abut on the front wall 11 of the housing, but would project obliquely therefrom.
[0012] Accordingly, at least one of the holders cooperates with the associated transition piece by at least a combination of an oblique pin and an oblique hole to be slipped thereon, the pin and the hole being inclined the same with respect to the longitudinal axis of the installed pump hose.
[0013] With the pump hose installed properly, the oblique pin fits into the hole that has the same inclination so that the transition piece flatly abuts on the housing. When the transition piece is improperly applied to the housing, the transition piece is orientated obliquely with respect to the housing so that a bulge is caused in the hose, thereby impeding or preventing the door from being closed. Thus, an orderly operation of the pump is made impossible when the hose is placed improperly (rear up front). A construction according to certain aspects of the invention, serves to reduce improper placement of the pump hose.
[0014] In an exemplary embodiment, the at least one oblique pin is formed at the holder and the at least one oblique bole is formed in the transition piece. Further, in a preferred embodiment of the invention, two parallel pins are provided at the holder and two parallel holes are provided in the transition piece. Yet, it is also possible to provide the pin at the transition piece and the hole in the holder.
[0015] The hole is not a mere opening in a flat plate, but a cylindrical channel extending obliquely to the central plane of the transition piece.
[0016] The lower end of the pump hose 13 is equipped with a lower transition piece 20 hooked into a holder 21 of the housing. The transition piece 20 has two hook-shaped locking clamps 22 embracing the holder 21 . The holder 21 is a transverse bar formed to the front wall 11 . The bar has an opening for the passage of the discharge hose 23 connected to the transition piece 20 . The transition pieces 15 , 20 , together with the length 14 of hose, form the pump hose 13 . Together with a supply hose 19 and a discharge hose 23 , the pump hose 13 forms a hose set which is a disposable article replaced after use.
[0017] A door 24 is provided at the housing 10 as a counter-bearing for the pump hose 13 , the door being adapted to be swiveled about a vertical axis 25 and being locked at a closing member 26 . The door 24 is arranged opposite the pump finger mechanism 12 and has an abutment surface 27 where the length 14 of hose is compressed by the pump finger mechanism 12 . Above the abutment surface 27 , the door 24 has recesses 28 for receiving the ends of the pins 17 of the holder 16 .
[0018] Thus, according to an exemplary embodiment of the invention, both holders are of different construction, each of the two transition pieces being adapted to the construction of the associated holder. In this manner, top and bottom of the pump hose cannot be interchanged, since the lower transition piece does not mate with the upper holder and the upper transition piece does not mate with the lower holder.
[0019] [0019]FIG. 3 illustrates a front view of the properly installed pump hose 13 . At the front side of the length 14 of hose that is visible to the user when the door 24 is open, a longitudinal color strip 29 is provided. The color strip may consist of food colors applied as by rolling on to hose during extrusion prior to the hardening of the hose material. The color strip 29 would make visible a twisting of the lower transition piece 20 by 360° in the event that the length 14 of hose were helically twisted.
[0020] In an exemplary embodiment, the pump hose is provided with a longitudinal color strip. In this manner, torsional twisting of the pump hose can easily be recognized visually.
[0021] In FIG. 4, the transition piece 15 is illustrated in its open state prior to its being mounted to the length 14 of hose. The transition piece 15 has a tubular pin 30 onto which the length 14 of hose can be slipped. A transverse hinge portion 31 extends at an end of the tubular pin 30 , which projects towards opposite ends from the upper opening 32 of the tubular pin 30 . The supply hose 19 is inserted into the upper opening 32 and glued. The hinge portion 31 is bent in U-shape and flanges 33 and 34 project from its legs, respectively. The flanges 33 , 34 each include a tunnel 35 and form two half shells 36 , 37 whose flanges 33 , 34 can be pressed against each other and whose tunnels 35 then combine to a cylindrical channel coaxially enclosing the tubular pin 30 . The tubular pin 30 forms an inner support for the end of the length 14 of hose clamped and fixed by the half shells 36 , 37 .
[0022] The invention addresses a problem of improving the attachment of transition pieces to a pump hose. Where the soft elastic pump hose, often made of silicone, cannot be glued or welded to other components, a mechanical connection between these parts has been found to be required. Presently, the end of the pump hose is slipped onto a tubular pin of the transition piece. Subsequently, a tensioning ring is placed around the slipped-on end of the pump hose to fix the same on the tubular pin in a sealing manner.
[0023] The two transition pieces 15 and 20 consist of hard plastic material such as ABS. They are fixed in the final position by ultra sound or heating stamps wherein they press the length of hose onto the hard tubular pin. The entire transition piece 15 illustrated in FIG. 4 is an integral plastics part that may be produced as an injection molded part. The hinge portion 31 radially abuts the upper end of the tubular pin 30 from opposite sides and passes into the same.
[0024] Thus, what has been disclosed in one embodiment is an infusion pump with a pump hose such that both in case of an axial twist of the transition pieces with respect to each other and in case of an erroneous placement of the pump element (rear up front), the error is immediately visible and an operation of the pump becomes impossible, respectively.
[0025] In one embodiment of the invention, a pump hose is provided with transition pieces at both ends, which has a high tensile strength and a substantially improved compression strength and is simple to manufacture.
Variations And Equivalents
[0026] Spatial references such as “bottom”, “top”, “front”, “back”, “lower”, “upper”, “under”, and “central” are for purposes of illustration only, relative to the figures shown and are not limited to the specific orientation of the structure or movement directions as described.
[0027] Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many other modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims.
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An infusion pump has a housing ( 10 ) accommodating a pump finger mechanism ( 12 ). The pump finger mechanism ( 12 ) acts on a pump hose ( 13 ) fastened at holders ( 16, 21 ) of the housing. The pump hose ( 13 ) is supported by a door ( 24 ). In order to facilitate proper and positionally correct placement of the pump hose, one of the holders ( 16 ) includes an oblique pin. The associated transition piece ( 15 ) of the pump hose ( 13 ) has a hole ( 18 ) with the same inclination angle as the oblique pin. The other transition piece ( 20 ) is of a different structure so that the transition pieces cannot be mixed up. A longitudinal color strip ( 29 ) on the pump hose is provided to visually indicate any twisting of the hose.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an electric discharge machine in which machining fluid is supplied to an electric discharge machining area, and more particularly to a machining fluid cooling device for cooling machining fluid and an electric discharge machine equipped with the machining fluid cooling device.
[0003] 2. Description of Related Art
[0004] In a wire cut electric discharge machine, a workpiece is machined by generating a spark discharge between a workpiece and a wire electrode. Machining fluid is supplied to the workpiece and the wire electrode by a pump, thereby removing sludge as well as cooling the electric discharge machining area so as to prevent a rise in temperature.
[0005] The faster the machining, the greater the pressure with which the machining fluid is supplied to the machining area, and consequently the quicker the post-machining sludge can be removed from the machining area, and furthermore, the cooling effect on the wire (the temperature of which rises due to electric discharge machining) can be increased as well. Typically, a machining fluid supply pressure of approximately 1.5 MPa maximum is used.
[0006] In addition, with a wire cut electric discharge machine, in order to increase the accuracy of machining, it is preferable to keep not only the machining area but also a work table that fixes the workpiece in place, a machining tank for machining in fluid, and further the machine as a whole, at the same constant temperature.
[0007] The electric discharge machine discharges heat upon discharge during electric discharge machining, and moreover, generates heat by the action of the pump. This heat generated by electric discharge and by the pump is absorbed by the machining fluid, causing the temperature of the machining fluid to rise. Conventionally, in order to cool this heated machining fluid, the machining fluid is temporarily collected in a tank of the machining fluid cooling device and from there sent to a cooler that is a part of the machining fluid cooling device, and, after being cooled to a constant temperature, returned to the machining fluid cooling device tank (see, for example JP 2562197Y).
[0008] FIG. 11 is a diagram illustrating schematically the structure of a conventional machining fluid cooling device used in an electric discharge machine. In FIG. 11 , the electric discharge machine electrically discharges and machines the workpiece by generating an electric discharge between the electric discharge machine wire and the workpiece. In order to remove the sludge generated during electric discharge machining and to restrain the rise in temperature due to the heat generated by electric discharge machining, machining fluid is supplied to a machining area 5 . The machining fluid is discharged to the machining area 5 by a discharge pump 6 from a clean fluid tank 12 , passed through a machining tank 11 and finally collected at a contaminated fluid tank 13 . The collected machining fluid is then sent from the contaminated fluid tank 13 to a filter 14 by a filter pump 16 and, after the sludge is filtered, returned to the clean fluid tank 12 , after which it is sent to a machining fluid temperature control device 3 and the temperature raised by electric discharge machining is lowered.
[0009] In an electric discharge machine, in order to perform even faster machining, it is necessary to discharge the machining fluid at even higher pressure (for example, 2.0 MPa or greater). In order to increase the supply pressure of the machining fluid, it is necessary to use a higher output discharge pump. However, with a high-output discharge pump, the amount of heat discharged also increases because the amount of energy consumed increases. As a result, the machining fluid passed through and discharged by the discharge pump also absorbs more heat, and the rise in temperature of the machining fluid discharged from the discharge pump increases as well.
[0010] The machining fluid discharged from the machining fluid discharge pump is supplied directly to the machining area, and thus, even though the machining fluid is temperature controlled when pumped from the machining fluid cooling device, the temperature of the machining fluid rises due to passage through the machining fluid discharge pump and is supplied to the machining area in that heated state. Accordingly, in the machining area, the temperature is greater than the temperature of the surrounding machining fluid and a temperature gradient arises, leading to deterioration in accuracy.
[0011] Furthermore, as shown in FIG. 12 , mechanisms along a route over which machining fluid is supplied from the machining fluid discharge pump are also heated. In particular, because the structure is such that the machining fluid passes through such mechanisms as upper and lower wire guides and the upper arms and lower arms that support them that in turn hold the wire as well as hold a position relative to the workpiece and maintain accuracy, these mechanisms are greatly affected by the rise in temperature of the machining fluid. If these mechanisms are displaced, then the relative positions of the wire electrode and the workpiece change, leading to deterioration in accuracy.
[0012] In a case in which machining always takes place at the same pump pressure, then it is possible to maintain the temperature at a steady state as well. However, machining of a workpiece usually involves a whole range of machining steps, from rough machining requiring high pressure to delicate finishing requiring very low pressure, and thus, for example, a temperature differential is generated at the upper and lower guides and arms between the temperature of rough machining and the temperature of fine finishing, and this temperature differential causes positional error.
[0013] That is, in a case of performing rough machining at high speed, the machining fluid discharge pump runs at high speed, and therefore the machining fluid passing through the machining fluid discharge pump is heated by the pump drive so that the temperature of the machining fluid rises, causing the temperature of the mechanism components through which it passes to rise and creating heat fluctuations.
[0014] In other words, although the wire guides that support the wire electrode that carries out the machining are attached to the tips of the mechanism components, the positions of these tips relative to the workpiece during machining slips due to heat fluctuations caused by the rise in temperature described above.
[0015] By contrast, because the machining fluid discharge pump switches to low-speed operation during finishing, the rise in fluid temperature decreases, the temperature of the mechanism components, which had increased during rough machining, decreases, and the wire guides that support the wire electrode return to their original positions.
[0016] Therefore, finishing machining is performed at locations off the track that the wire electrode machines during rough machining, and a gap arises between the rough machining track and the finishing machining track, leading to machining accuracy malfunction.
[0017] As described above, although conventionally the temperature of the machining fluid is controlled, this temperature control is exercised at the clean fluid tank on the intake side of the machining fluid discharge pump, with no temperature control exercised on the discharged machining fluid on the discharge side of the machining fluid discharge pump, and hence no consideration is given to the temperature fluctuations of the machining fluid due to the machining fluid discharge pump itself.
SUMMARY OF THE INVENTION
[0018] The present invention provides an electric discharge machine in which temperature fluctuations of machining fluid discharged by a discharge pump is controlled to improve machining accuracy. The present invention also provides a machining fluid cooling device capable of maintaining temperature of machining fluid sent to a machining area at a constant value regardless of an operating state of a discharge pump.
[0019] According to the present invention, a cooling device for cooling the machining fluid is provided on a discharge side of the machining fluid discharge pump so as to restrain a rise in temperature of the machining fluid discharged from the discharge pump and maintain the machining area at a constant temperature, thereby improving machining accuracy.
[0020] The electric discharge machine of the present invention comprises: a clean fluid tank containing machining fluid with temperature thereof controlled; a discharge pump for discharging machining fluid in the clean fluid tank to a machining area through piping; and a machining fluid cooling device provided between said discharge pump and the machining area, for cooling the machining fluid discharged from the discharge pump.
[0021] The machining fluid cooling device may comprise a part of the piping passing through said clean fluid tank to exchange heat between the machining fluid inside the part of the piping and the machining fluid contained in the clean fluid tank. The part of the piping may be provided with fins.
[0022] A machining fluid temperature control device may be provided for controlling the temperature of the machining fluid in the clean fluid tank, and the machining fluid temperature control device may function as the machining fluid cooling device for cooling the machining fluid discharged from the discharge pump.
[0023] The machining fluid cooling device of the present invention is provided for an electric discharge machine in which machining fluid contained in a clean fluid tank with temperature thereof controlled is discharged by a discharge pump to be sent to a machining area. The machining fluid cooling device comprises: piping for conducting the machining fluid discharged from the discharge pump to the machining area; and a heat exchanger connected with the piping and arranged in the machining fluid in the clean fluid tank, for cooling the machining fluid discharged from the discharge pump by heat exchange with the machining fluid in the clean fluid tank.
[0024] The heat exchanger may comprise a part of the piping passing through the clean fluid tank to exchange heat between the machining fluid inside the piping and the machining fluid in the clean fluid tank. The portion of the piping passing through the clean fluid tank may be provided with fins.
[0025] The machining fluid cooling device described above can be given a simple heat-exchange pipe structure that uses no power whatsoever. This heat-exchange pipe can be given the form of multiple fins attached to piping from the discharge pump and disposed within the temperature-controlled machining fluid clean fluid tank. The machining fluid discharged from the discharge pump flows into the heat-exchange pipe, and by passing through this heat-exchange pipe warm machining fluid from the discharge pump is cooled to a temperature virtually identical to the temperature of the fluid inside the temperature-controlled clean fluid tank. The cooled machining fluid is then supplied to the upper and lower guides of the machining part, removing sludge as well as maintaining the machining area at a predetermined temperature.
[0026] In addition, the electric discharge machine of the present invention is provided with a machining fluid temperature control device that controls the temperature of the machining fluid in the clean fluid tank. Moreover, the function of the above-described machining fluid cooling device can be combined with this machining fluid temperature control device. In such a configuration, the machining fluid temperature control device can not only control the temperature of the clean fluid in the clean fluid tank but can also cool the machining fluid discharged from the discharge pump.
[0027] According to the electric discharge machine of the present invention, by adopting the structure described above, even with high-speed, precision machining, in which the operating state of the discharge pump fluctuates between rough machining and finishing machining and hence the amount of heat added to the machining fluid changes, the machining fluid supplied to the machining area can always be maintained at the same temperature. As a result, the machining track during rough machining and the machining track during finishing machining match, providing the ability to perform stable precision machining. Moreover, the present invention controls temperature fluctuations of the machining fluid discharged by the discharge pump and can thus improve machining accuracy. Furthermore, the machining fluid cooling device can maintain the machining fluid to be discharged at a constant temperature regardless of the operating state of the discharge pump.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a diagram illustrating the mechanical structure of the electric discharge machine;
[0029] FIG. 2 is a diagram illustrating a route system of a wire electrode of the electric discharge machine;
[0030] FIG. 3 is a diagram illustrating the flow of an electric discharge machining current of the electric discharge machine;
[0031] FIG. 4 is a diagram illustrating the flow of machining fluid of the electric discharge machine;
[0032] FIG. 5 is a diagram illustrating schematically the general structure of the electric discharge machine of the present invention;
[0033] FIG. 6 is a diagram illustrating one example of the structure of a machining fluid cooling device;
[0034] FIG. 7 is a diagram illustrating one example of the structure of a heat exchanger;
[0035] FIGS. 8 a and 8 b are diagrams illustrating one example of the structure of a heat exchanger;
[0036] FIG. 9 is a diagram illustrating another example of the structure of a heat exchanger;
[0037] FIG. 10 is a diagram illustrating another example of the structure of a machining fluid cooling device;
[0038] FIG. 11 is a diagram illustrating schematically the structure of a conventional machining fluid cooling device used in an electric discharge machine; and
[0039] FIG. 12 is a diagram illustrating displacement of mechanical parts due to a rise in temperature of the machining fluid.
DETAILED DESCRIPTION
[0040] A detailed description is now given of preferred embodiments of the present invention, with reference to the accompanying drawings.
[0041] FIGS. 1-4 are diagrams illustrating schematically the structure of an electric discharge machine. FIG. 1 is a diagram illustrating the mechanical structure of the electric discharge machine, FIG. 2 is a diagram illustrating the routing system of a wire electrode, FIG. 3 is a diagram illustrating the flow of an electric discharge machining current and FIG. 4 is a diagram illustrating the flow of machining fluid.
[0042] In FIG. 1 , the electric discharge machine 1 comprises a table 4 on which a workpiece is mounted and a column 10 which supports an upper guide for guiding a wire electrode. The table 4 is movable in the direction of the X- and Y-axes atop a bed 8 , and is equipped with a drive mechanism 4 x composed of a motor and a ball screw for moving in the X-direction and a drive mechanism 4 y composed of a motor and a ball screw for moving in the Y-direction. In addition, the column 10 is comprised of a drive mechanism 9 that in turn includes two drive mechanism 9 u , 9 v for moving in the two horizontal directions and a drive mechanism 9 z for moving in the vertical direction. The table 4 and the drive mechanism 9 are driven by drive current from a servo amp 19 controlled by control signals from a CNC 18 .
[0043] In FIG. 2 , the wire electrode routing system includes a supply part, a machining area and a collection part. The wire electrode is sent from the supply part to machine a workpiece in the machining area, and is collected by the collection part after machining.
[0044] The supply part is comprised of a supply motor 31 that supplies the wire electrode 30 , and a brake 33 and a brake shoe 34 for imparting a predetermined tension to the supplied wire electrode 30 . An upper guide 35 and a lower guide 36 are provided at a position in the machining area that holds the workpiece. The wire electrode 30 is sent to the collection part by a lower guide roller 37 after passing through the upper guide 35 and the lower guide 36 .
[0045] The collection part is comprised of a feed roller 39 for reeling in the wire electrode 30 from the lower guide roller 37 and a feed motor for driving the feed roller 39 . A pinch roller 38 is juxtaposed against the feed roller 39 and the wire electrode 30 is held between the two rollers so as to impart tension to the wire electrode 30 as well as to collect the machined wire electrode 30 within a wire collection box 41 .
[0046] In FIG. 3 , the electric discharge machining current is supplied from a power supply device 48 to electrode pins (feeder pins) 42 , 43 by feed cables 44 , 45 , and after performing electric discharge machining between the wire electrode and the workpiece 50 , is returned to the power supply device 48 by earth cables 46 , 47 .
[0047] The electrode pin 42 is disposed upstream of the upper guide 35 so as to contact the wire electrode 30 , and the electrode pin 43 is disposed downstream of the lower guide 36 so as to contact the wire electrode 30 , by means of which the electric discharge machining current is supplied to the wire electrode 30 . The electric discharge machining current supplied to the wire electrode 30 generates an electric discharge in the gap with the workpiece and machines the workpiece 50 . The electric discharge machining current then returns from the workpiece to the power supply device 48 through the earth cables 46 , 47 .
[0048] There are two supply routes for the electric discharge machining current. One route runs from the feed cable 44 to the electrode pin 42 , the wire electrode 30 , the workpiece 50 and the earth cable 46 . The other route runs from the feed cable 45 to the electrode 43 , the wire electrode 30 , the workpiece 50 and the earth cable 47 .
[0049] The power supply device 48 supplies the electric discharge machining current whose characteristics depend on the machining step to the wire electrode 30 . The power supply device 48 is comprised of an MPG (Main Pulse Generator) and an SPG (Sub-Pulse Generator) that controls the supply of the electric discharge machining current, and supplies electric discharge machining current according to a program set in the CNC and machining conditions.
[0050] In FIG. 4 , the electric discharge machine is comprised of a machining tank 11 , a clean fluid tank 12 and a contaminated fluid tank 13 , circulates the machining fluid circulated between these using pumps P 1 -P 4 , supplies machining fluid to the machining area, collects the machining fluid, decontaminates the collected machining fluid, and controls resistivity and temperature.
[0051] The machining fluid that collects in the clean fluid tank 12 is pumped by the machining fluid discharge pump P 1 and discharged to the machining area. The machining fluid discharged to the machining area removes sludge generated by machining from the machining part and cools the machining area, the temperature of which has risen due to electric discharge machining.
[0052] After the machining fluid is discharged to the machining area it is collected in the machining tank 11 . The machining fluid collecting in the machining tank 11 contains the sludge generated at the machining part and also absorbs the heat generated by electric discharge machining, and experiences a rise in temperature.
[0053] The machining fluid in the machining tank 11 spills into the contaminated fluid tank 13 and is collected. The machining fluid in the contaminated fluid tank 13 is sent to a filter 14 by a filter pump P 2 and decontaminated, after which the machining fluid is returned to the clean fluid tank 12 .
[0054] The machining fluid collecting in the clean fluid tank 12 is sent to a machining fluid temperature control device 3 by a circulation pump P 3 . The machining fluid temperature control device 3 cools the heated machining fluid to a predetermined temperature and returns it to the clean fluid tank 12 . The machining fluid collecting in the clean fluid tank 12 is then sent to an ion exchanger 15 by the circulation pump P 3 . The ion exchanger 15 controls the resistivity of the machining fluid and adjusts it to a predetermined resistivity, after which the ion exchanger 15 returns the machining fluid to the clean fluid tank 12 .
[0055] As thus described above, the temperature and the resistivity of the machining fluid in the clean fluid tank 12 are adjusted to predetermined levels. A supply pump P 4 is activated when supplying a predetermined amount of fluid to the machining tank 11 when machining starts.
[0056] The electric discharge machine 1 of the present invention, with the device configuration shown in FIGS. 1-4 described above, by cooling the machining fluid discharged from the discharge pump, restrains the rise in temperature of the machining fluid caused by the discharge pump.
[0057] FIG. 5 is a diagram illustrating schematically the general structure of the electric discharge machine of the present invention. In FIG. 5 , the machining fluid is discharged from the clean fluid tank 12 to the machining area 5 by the discharge pump 6 and collected at the machining tank 11 . The collected machining fluid flows from the machining tank 11 to the contaminated fluid tank 13 , is discharged by the filter pump 16 to be filtered by the filter 14 , returned to the clean fluid tank 12 , and sent to the machining fluid temperature control device 3 by the pump 7 . The machining fluid temperature control device 3 adjusts the machining fluid, heated by the heat generated by electric discharge machining (heat 1 ), to a predetermined temperature.
[0058] In addition to the above-described structure, the electric discharge machine 1 of the present invention is comprised of a machining fluid cooling device 2 disposed between the machining area 5 and the discharge pump 6 that discharges machining fluid from the clean fluid tank 12 to the machining area 5 . The machining fluid cooling device 2 cools the machining fluid, which has been heated by the heat from the discharge pump 6 (heat 2 ), to a predetermined temperature. By so doing, the machining fluid, which has been heated by the discharge pump, is adjusted to a predetermined temperature so that machining fluid of a predetermined temperature is always supplied to the machining area 5 .
[0059] FIG. 6 is a diagram illustrating one example of the structure of the machining fluid cooling device. In FIG. 6 , the machining fluid cooling device 2 shown in FIG. 5 is composed of a heat exchanger 20 . The heat exchanger 20 exchanges heat between the machining fluid discharged by the discharge pump and the machining fluid in the clean fluid tank 12 , and by this heat exchange the temperature of the machining fluid on the clean fluid tank 12 side is controlled. The machining fluid on the clean fluid tank 12 side is temperature controlled by the machining fluid temperature control device 3 , and therefore the temperature of the machining fluid heated by the discharge pump 6 is cooled to a predetermined temperature by the heat exchange.
[0060] The heat exchanger 20 has no power, motor or other such heat source, and thus can maintain the machining fluid to be supplied to the machining area that passes through the heat exchanger 20 at a controlled predetermined temperature.
[0061] FIG. 7 and FIGS. 8 a and 8 b are diagrams illustrating one example of the structure of the heat exchanger. The heat exchanger 20 is comprised of a pipe 21 through which the machining fluid passes and fins 22 attached to the outside of the pipe 21 . The pipe 21 and the fins 22 can be formed using a material with a good coefficient of thermal conductivity, such as stainless steel. One end of pipe 21 is connected to the discharge side of the discharge pump 6 and the other end of pipe 21 is disposed toward the machining area, for example, the upper and lower guide mechanisms. The pipe 21 and the fins 22 are both immersed in the machining fluid in the clean fluid tank 12 .
[0062] The machining fluid that flows through the pipe 21 exchanges heat with the machining fluid in the clean fluid tank 12 through the fins 22 , thus cooling the machining fluid heated by the discharge pump 6 to the temperature of the machining fluid in the clean fluid tank 12 .
[0063] FIGS. 8 a and 8 b show cross-sectional views of the pipe 21 and fins 22 from different angles. The fins 22 are formed so as to radiate outward from the outer surface of the pipe 21 , so as to obtain a broad surface area of contact with the machining fluid inside the clean fluid tank 12 . It should be noted that, although in FIG. 8 b the diameter of the pipe 21 is given as 30 mm and the shape of the fins is given as rectangles 100-200 mm long on each side, the invention is not limited to such dimensions and shapes and may be of other dimensions and shapes.
[0064] In addition, the heat exchanger 20 may be configured so as to provide temperature sensors 23 , 24 inside the pipe 21 where the pipe 21 is not immersed in the machining fluid in the clean fluid tank 12 . For example, the temperature of the machining fluid before it enters the clean fluid tank 12 can be detected by installing the temperature sensor 23 between the discharge pump 6 and the fins 22 , and the temperature of the machining fluid after heat exchange in the clean fluid tank 12 and just before it is supplied to the machining area can be detected by installing the temperature sensor 24 between the fins 22 and the machining area.
[0065] That the heat exchanger 20 is working can be confirmed from the temperature information of the machining fluid in the pipe 21 detected by the temperature sensors 23 , 24 .
[0066] FIG. 9 is a diagram illustrating another example of the structure of a heat exchanger. A heat exchanger 25 comprises a cylinder provided with a plurality of through-holes that completely penetrate the cylinder. One side of the cylinder is connected to a pipe from the discharge pump 6 and the other side of the cylinder is connected to a pipe that leads to the machining area. The heat exchanger 25 is immersed in the machining fluid in the clean fluid tank 12 , so that the through-holes are filled with machining fluid. The machining fluid discharged from the discharge pump 6 exchanges heat with the machining fluid in the clean fluid tank 12 through the outer surface of the cylinder as well as through the walls of the through-holes, thus cooling the heated machining fluid.
[0067] It should be noted that the heat exchangers shown in FIGS. 8 a , 8 b and 9 are illustrative examples only, and that other configurations are also possible.
[0068] FIG. 10 is a diagram illustrating another example of the structure of a machining fluid cooling device. In this example, the machining fluid cooling device 2 is combined with the machining fluid temperature control device 3 . The machining fluid pumped by the discharge pump 6 is cooled by the machining fluid cooling device 2 combined with the machining fluid temperature control device 3 . With such a configuration, the devices that control the machining fluid can be consolidated into a single unit.
[0069] The present invention is not limited to the above-described embodiments and variations, and various modifications may be made thereto within the spirit and scope of the present invention. Therefore, in order to apprise the public of the scope of the present invention, the following claims are made.
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An electric discharge machine controls temperature fluctuations of machining fluid discharged by a discharge pump so as to improve machining accuracy, and a machining fluid cooling device keeps the temperature of the discharged machining fluid constant regardless of the operating state of the discharge pump. The electric discharge machine pumps machining fluid in a temperature controlled clean fluid tank with a discharge pump and discharges the machining fluid to a machining area through piping, and has a machining fluid cooling device for cooling machining fluid discharged from the discharge pump. The machining fluid cooling device passes a portion of the piping through the clean fluid tank and exchanges heat between the machining fluid inside the piping and the clean fluid in the clean fluid tank, thus dispersing the heat added from the discharge pump to the clean fluid side and lowering the temperature of the machining fluid inside the piping.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Continuation-in-Part of U.S. Non-Provisional patent application Ser. No. 12/862,117, filed on Aug. 24, 2010, which claims the benefits of U.S. Provisional Application No. 61/236,265, filed on Aug. 24, 2009, the contents of which are hereby incorporated by reference in its entirety. The present application further claims the benefit of U.S. Provisional patent application No. 61/551,877, filed on Oct. 26, 2011. The contents of each of the afore-mentioned patent applications are hereby incorporated by reference in their entireties.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the field of providing safety systems that includes a force multiplier and an algorithm that drastically increases the effect of emergency aid by combining multiple safety acts, responses, or systems.
[0004] 2. Description of Related Art
[0005] We are constantly reminded of the need for personal safety in today's society. All too often in the news we hear of missing persons and the dramatic searches which ensue. For each heroic story of a “just-in-time” rescue of a person who is abducted, lost, in a threatening situation, or in need of emergency medical care, there are many more personal dramas which unfortunately end in tragedy. It follows that immediate notification of an emergency situation and a prompt response from police, paramedics, fire department, or another service organization are essential for the well-being of the individual.
[0006] Today's technology provides us with public services such as the 911 telephone number for rapidly summoning emergency help if we are able to access a telephone, dial the number, and communicate our location. However, these services fall short in the case of a young child, a mentally incompetent or medically incapacitated person, someone lost in the woods, or the victim of an abduction or kidnapping. These situations necessitate a security system that travels with the individual, is not limited in range, is able to define and signal an emergency situation without human intervention, and identifies the individual's location. Such a system would provide protection to the individual and peace of mind to those responsible for his or her care and well-being.
[0007] Current available technology does not address the case of an individual who is helpless in an emergency situation where information is required so that the appropriate authorities can respond quickly and efficiently to a distress signal generated by the individual. Providing personal safety for persons at risk demands a fully automated and responsive system for summoning assistance.
[0008] Additionally, children are abducted daily in our society by strangers, family and known people. Police response frequently occurs hours after such abduction. In many cases the children are harmed and in some cases they are killed. There are child-tracking devices commercially available which are capable of monitoring the location of the missing child but there are no known commercially available devices that monitor the children's' activities and surroundings that may indicate danger is imminent. These commercially available devices cannot monitor the movements of a person with the intent to abduct or harm a child as the person approaches the child. Further, these devices cannot warn the child to run away and seek safety.
[0009] In addition, current personal GPS devices that are worn or carried allow an individual's location to be tracked and, in some cases, allow help to be summoned in an emergency by transmitting the current location of the individual to providers of emergency services. However, these systems fail to convey potentially valuable information such as a voice message, an image and/or a movie/video. For example, this information could be useful in identifying a criminal suspect or for determining what type of emergency response (e.g., police, ambulance, and fire) is appropriate. Another drawback of current systems is that they fail to integrate other common portable devices, such as cellular phones and PDAs (Personal Digital Assistants). Having one more electronic device to carry reduces the likelihood that an individual will use it.
[0010] Therefore, there is a need for systems and methods that overcome the deficiencies of traditional personal safety signaling and alerting devices.
SUMMARY
[0011] In one embodiment, the disclosure relates to a method of providing multiple safety responses, comprising: receiving an alarm signal at a remote monitoring center from a first mobile device; determining, by a processor, a location the first mobile device; determining, by the processor, at least one nearby mobile device that is within a pre-determined distance of the location of the first mobile device; and transmitting, by the remote monitoring center, an instruction message to the nearby mobile device, wherein the instruction message includes a response type and a first response frequency at which the response is to be delivered.
[0012] In another embodiment, the disclosure relates to a method of coordinating multiple responders to provide safety services, comprising: receiving an alarm signal at a remote monitoring center from a first mobile device; determining, by a processor, a location the first mobile device; determining, by the processor, at least one nearby mobile device that is within a pre-determined distance of the location of the first mobile device; determining, by the remote monitoring center, a first location of a responder; and transmitting, by the remote monitoring center, an instruction message to the nearby mobile device, wherein the instruction message includes a response type and a first response frequency based on the first location of the responder.
[0013] In still another embodiment, the disclosure relates includes a multiple response algorithm which coordinates the types, combinations and timing of the 911-related responses to match the type of crime, the perpetrator (with actual or estimated profiles stored on the security network, or accessed via the security network), the situation, the availability of first responders and other forms of aid such as safety networks, volunteers, fire departments, the public, etc., and the user themselves.
[0014] In still another embodiment, the disclosure relates to a system of coordinating multiple responders to provide safety services, comprising: a processor configured to receive an alarm signal from a first mobile device; a database coupled to the processor, the database including a list of member mobile devices; a location determining means coupled to the processor and configured to identify at least two member mobile devices from the list of member mobile devices that are within a predetermined distance of the first mobile device; and an instruction generator coupled to the processor and configured to transmit first response instructions to the identified member mobile devices, wherein each identified member mobile devices receives a different response instruction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other embodiments of the disclosure will be discussed with reference to the following exemplary and non-limiting illustrations, in which like elements are numbered similarly, and where:
[0016] FIG. 1 is a schematic of a personal safety and tracking system in accordance with an embodiment of the present invention;
[0017] FIG. 2 is an exemplary illustration of a personal safety device in accordance with an embodiment of the present invention;
[0018] FIG. 3 is a flowchart illustrating the steps of providing assistance to a user in accordance with an embodiment of the present invention;
[0019] FIG. 4 is an illustration of an exemplary dispatch interface in accordance to certain embodiments of the invention; and
[0020] FIG. 5 is a block diagram of a personal safety device system in accordance to certain embodiments of the invention.
DETAILED DESCRIPTION
[0021] FIG. 1 is a schematic of a personal safety and tracking system in accordance with an embodiment of the present invention. Referring to FIG. 1 , the personal safety and tracking system according to the present invention generally includes a personal safety device 102 which is located on or near the user 100 . In a preferred embodiment, the user 100 can be a person, such as a child, elderly person, disabled person, or a person living alone.
[0022] The personal safety device 102 can be a standalone personal safety device, or can be incorporated into a cellular phone, portable music player, keychain, pager, PDA, or other portable communication device. In another embodiment, the personal safety device 102 can be worn on the user 100 , such as around the user's neck or as a wristband. In a preferred embodiment, the personal safety device 102 is a multi-function device that includes signal reception and transmission capabilities, and includes a cellular phone capability that allows the user 100 to communicate with a remote location. The personal safety device 102 is described in more detail in FIG. [xx].
[0023] The personal safety device 102 is configured to transmit an alarm signal to a satellite or global positioning system (GPS) which makes up a communications system 104 . The communications system 104 is configured to identify the origination location of an alarm signal transmitted from a personal safety device 102 . It should be appreciated by one skilled in the art that various types of locating and satellite systems, such as, but not limited to, LORAN-C or GLONASS, may perform the function of providing accurate position coordinates and may be substituted thereof. Hence, the present invention should not be construed as limited to the communications system 104 .
[0024] In another embodiment, the personal safety device 102 does not employ GPS for communications with a remote monitoring center 108 , but rather utilizes Earth-based telecommunications towers, such as communication tower 106 , which are part of the current wireless communications and cellular grids. In this embodiment, the GPS only provides latitude and longitude coordinate determining means to locate the global position of the user 100 via the personal safety device 102 .
[0025] The communications system 104 further provides a means for data and voice communications between the personal safety device 102 and a remote monitoring center 108 . In an embodiment, a communication tower 106 receives an alarm signal from the communications system 104 and routes it to the remote monitoring center 108 . Multiple remote monitoring centers 108 are scattered throughout the country, so that an alarm signal sent from a personal safety device 102 is routed to the nearest remote monitoring center 108 .
[0026] The communications system 104 provides a means for data and voice communications between the personal safety device 102 and a remote monitoring center 108 . The communications system 104 may be any conventional cellular or wireless communications system. It should also be appreciated by one skilled in the art that other types of communication devices such as satellite transceivers or any other two-way wireless communication system may perform the function of the communications system 104 , and these may easily be substituted thereof. Hence, the present invention should not be construed as limited to communications system 104 as described herein.
[0027] The remote monitoring center 108 serves as a go-between the user 100 and various service providers, such as police departments 110 , emergency medical service (EMS) providers 112 , fire and rescue departments 114 , private security providers 116 , and 911 emergency centers 118 , as well as other users who are connected to the network and/or opted-in or designated as contacts for the user 100 .
[0028] In an embodiment, several emergency response protocols can be initiated in parallel, in a pre-determined sequence, or in a random sequence, to exacerbate, frustrate, confuse, scare, or distract a potential perpetrator. The system is coined Multiple Response 911 (hereinafter, “MR-911”), and it enhances the effect of any safety system including traditional 911 systems and methods by raising doubt in the mind of a potential perpetrator as to who, what, why, and how a security response is occurring, by increasing both the speed, options, and variety of help, as well as by improving the situation of the user 100 , as far as their mental state and confidence level.
[0029] When there are multiple “911” or security-type responses, this means the perpetrator has to deal with multiple goals or task.
[0030] But the key action of MR-911 is that it creates a lot of uncertainty for a perpetrator. For example, a hardened criminal may know that police take 5-10 minutes to arrive and he may further know their likely route of approach so that he can watch it and essentially contain that threat by putting it into known parameter, thinking to themselves, “I′ll see them coming” or “I′ve got at least five minutes”. MR-911, creates too many variables for him to deal with and further adds uncertainty. While police response times may be predictable (although more in perception than in reality), a father or loved one coming to help is a very unpredictable situation for the perpetrator as regards to timing, capability, rationality (most would expect a father to be fairly angry and not necessarily rational, thus increasing the downside risk to a perpetrator—the worst case with law enforcement is normally incarceration, however, with an angry father, it is not predictable.
[0031] More importantly, MR-911 can include an air response, good Samaritans, UAV's, neighbors, security companies, cameras that are turned on, house lights that are turned on, passing cars that use their mobile cameras, and more. When there is a minimum of three 911-type responses, which can include everything from a beeping noise to an armed officer, the perpetrator quickly loses his ability to estimate and manage the risk of his crime.
[0032] Another benefit to MR-911 is that it will increase apprehension rates by confusing, disorienting and generally putting the perpetrator in a situation where they cannot predict or manage the number, type, or degree of responses they must deal with. If, for example, a neighbor shines a light in the window, this can cause a delay in the crime. When a friend knocks on the door, the perpetrator may try to leave and be further delayed or perhaps observed clearly. Then when law enforcement or private security arrive on the scene, they benefit from the delay, the additional information (i.e., such as a good description) and anything else that has happened from the initial traditional and non-traditional responses.
[0033] The 911 Force Multiplier utilizes three or more responses of a different nature, which therefore leads to a multiple of variables that the perpetrator must deal with. For example, in a non-limiting example, the system includes six responses, questions, and issues that accompany each for a perpetrator in the middle of a crime:
[0000] (1) 911 is called: How long do I have before the police arrive?
(2) A red light is flashing: what does it mean? How do I turn it off?
(3) A safety network has been contacted: who is coming? How close are they?
(4) A neighbor shines a light in the window: who is that? Someone knows we're here. What are they going to do? If the police weren't called already, are they going to call the police?
(5) A speaker is relaying “evidence collection has begun . . . ”: what evidence? Does this mean they'll catch me? Should I not touch that device?
[0034] For example, when dealing with following types of crimes and situations, different MR-911 combinations with varying intensity, tempo, and delivery times will prove most useful.
[0035] Date rape inside the user's home: neighbors would be contacted to knock on the wall or come over, which may stop or delay the crime.
[0036] Robbery on a city street: localized cameras could be activated or store managers could be contacted to witness the crime with cameras which will provide a long term deterrent effect as robbers would soon learn that public places had coordinated camera and other responses.
[0037] Violent Assault in a building: building lights could be turned on and, off, immediate response would be needed so local volunteers might rush to the scene or occupants could be asked to film the access areas which would help to deter and delay that and any future crimes.
[0038] Gang Rape of a College Student: playing a recording on the user's speakerphone clarifying what is and is not legal might impact the thinking process of young men who are confused about what is legally or morally acceptable and thus deter or decrease the crime.
[0039] In each of these non-limiting examples, there would be multiple response but the above gives an idea of the how the MR-911 system can adjust to maximize the impact on a particular perpetrator, or crime type.
[0040] In an embodiment, the speed of an emergency response delivery on the scene of the user 100 is drastically increased, as the remote monitoring center 108 can notify a nearby person, such as the user's neighbor immediately upon receiving an alarm signal from the user 100 . The neighbor can, for example, bang of an adjoining wall, knock on the user's door, shine a flashlight into the user's home, honk their car horn outside of the user's home, and/or call the neighbor's home or mobile phone.
[0041] Furthermore, the level of response provided by the neighbor can be dictated by the remote monitoring center 108 . For example, if law enforcement officials are 10 minutes away, the neighbor can lightly bang on the wall, and when first responders are 30 seconds away, the neighbor can bang heavily on the wall. The level of response provided by the neighbor can increase as the first responders near. Such action serves to delay and distract a perpetrator, and when first responders arrive the perpetrator may be focusing its attention on the banging sound instead of further committing a crime or harming the user 100 .
[0042] In an embodiment, multiple nearby persons are simultaneously notified, and each is instructed to person a certain response or act by the remote monitoring center 108 . The remote monitoring center 108 can determine if any members of its security network are within a pre-determined vicinity of the user 100 , based on located-based sensing technologies utilizing the members' personal safety devices. The remote monitoring center 108 can then transmit a message to each of the identified nearby persons, where the message includes directions or a route to the user 100 , as well as instructions on how to respond.
[0043] In an embodiment, each identified nearby person is given a different act to perform, at a different level, tempo, beat, or frequency. As the distance of the first responders to the user 100 decreases, the intensity of the acts performed by the identified nearby persons can increase. The remote monitoring center 108 can continually transmit new instructions to the identified nearby persons based on the location data of the first responders.
[0044] In another embodiment, depending on the status of the first responders, the action of the neighbor and/or others nearby can vary. Also, alternative, more advanced responses such as UAV's can be deployed to the scene if first responders are stuck in traffic, or cannot reach the scene in a timely fashion. For example, unmanned helicopters controlled from the remote monitoring center 108 can be deployed to record a scene from a safe distance, transmit audio messages/warnings, as well as deploy deterrents and firepower if needed.
[0045] In conjunction with notifying nearby persons to assist the user 100 , the personal safety device 102 can emit a notification that first responders are en route, either through an automated message or a live message spoken by a dispatch operator 120 .
[0046] In an embodiment, the remote monitoring center 108 is staffed by one or more dispatch operators 120 and includes a communication and dispatch system 122 which may include a telephone system, one or more data modems, a computer system, and one or more display consoles. The communication and dispatch system 122 comprises means to store and access communications information, a user database, an emergency services database, map display information, and unit identifier and alarm status display information. The communication and dispatch system 122 further comprises one or more data-to-voice switches and has remote activation capability, plotting algorithms, boundary monitoring alarm features, and the capability to store and retrieve historical data as well as data related to the user 100 or the personal safety device 102 . In a preferred embodiment, display console displays the alarm signal origination location, the user identification, and an alarm code, as described in more detail in FIG. [xx] below. A number of suitable map programs incorporating many of these features are commercially available and suitable for use with the present invention.
[0047] FIG. 2 is an exemplary illustration of a personal safety device in accordance with an embodiment of the present invention. A personal safety device 102 in one embodiment can be hand-held and/or wearable with a form factor similar to that of a portable electronic device such as (but not limited to) a cellular phone, digital music player or digital camera. In one embodiment, the housing is a special color that warns criminals of its special purpose. A GPS receiver or other geographic location determination device (e.g., GSM transceiver) is integrated with the personal safety device 102 and can be used to determine the location, speed and direction of travel of a personal safety device 102 user.
[0048] The personal safety device 102 includes a display 202 (e.g., liquid crystal, light emitting diode, plasma, or other suitable display) which can be used to display status information and messages. By way of a non-limiting example, status information could include location information, battery life, an indication of whether or not the personal safety device 102 is within range of a receiver, paging/e-mail messages, caller identification, music selections, images, games, and information entered from keypad 206 .
[0049] The keypad 206 (e.g., numeric or alphanumeric) can be used to place phone calls, send pager/e-mail messages, play games, and otherwise allow a user to interact with the device. The keypad can be a full QWERTY keyboard or a standard 10-key numeric keypad. Specialized ergonomic controls to operate integrated modules such as a camera, a digital music player, game player, and/or cellular phone can be located on the keypad or elsewhere on the device and are fully within the scope and spirit of the present disclosure.
[0050] In an embodiment, special signaling keys 212 are positioned on the personal safety device 102 . The signaling keys 212 are each specific to a different service provide, such as, but not limited to, police departments, EMS providers, fire and rescue departments, private security providers 116 , and 911 emergency centers 118 . Thus, the user 100 has a one-touch access to send an alarm signal to a specific provider.
[0051] Furthermore, the personal safety device 102 includes a panic button 204 , which can be button, switch, or other-touch sensitive device can be used to activate a safety feature of the personal safety device 102 . By way of a non-limiting example, the user can depress the panic button 104 once to begin recording sound through microphone 210 and optionally begin recording still or moving images (e.g., MPEG-4) through a digital camera having lens 214 . If the user believes that they may be in danger, additionally pressing the panic button 104 one or more times in succession can activate an emergency channel wherein the user's current location, speed, direction of travel and some or all of the collected sound and/or image information can be transmitted (e.g., as one or more data packets on a mobile telephone, such as a cellular telephone, a mobile telephone network or a mobile LAN or other wireless network as described above) from the personal safety device 102 to a remote monitoring center 108 wherein help can be automatically summoned on behalf of the user 100 .
[0052] In another embodiment, the panic feature can be activated with a voice command or by a sound, or by applying pressure to the surface of the personal safety device 102 . For example, the personal safety device 102 can be programmed to automatically send an alarm signal to the remote monitoring center 108 upon the user saying a particular word or panic phrase. The personal safety device 102 can include voice recognition software so that only a registered user's voice can activate the panic feature. In another embodiment, a family may choose to register the voices of all family members (e.g. parents, children, elderly grandparents) into the personal safety device 102 so that it can be activated by numerous family members.
[0053] In another embodiment, the personal safety device 102 includes a touch sensitive case 208 that can activate the panic feature upon application of a certain amount of pressure. When the user 100 exerts pressure in excess of a threshold amount, the panic feature is activated. This feature is especially useful in situations where the user 100 cannot speak or make sounds.
[0054] It will be appreciated that the present disclosure is not limited to any one particular method of activating the panic feature of the personal safety device 102 . In one embodiment, the information can be encrypted and/or compressed prior to or during transmission. If the personal safety device 102 cannot reach the communication system 104 or the remote monitoring center 108 due to its being out of range or for some other reason, the personal safety device 102 will buffer the information and transmit the alarm signal once it is able to establish contact with the communication system 104 .
[0055] In another embodiment, the personal safety device 102 can include a biometric identification device that can be used to authenticate its user. In one embodiment, the biometric identification device can be integrated into the panic button 204 or voice recognition system. Such biometric sensing devices can include, but are not limited to, finger print detection, voice recognition, retinal scanning (e.g., via the camera lens), blood or saliva analysis, facial feature analysis, vein analysis, and other suitable automated methods of recognizing a person. It will be appreciated by those of skill in the art that many more biometric identification methods which are not discussed herein are nonetheless fully within the scope and spirit of the present disclosure. In one embodiment, an offender may be required by their probation officer to periodically perform biometric identification to ensure that the offender has the device on their person.
[0056] In another embodiment, the personal safety device 102 can be integrated with other devices/form factors such as wristwatches, digital cameras, digital music players, PDAs, Pocket PCs or other suitable devices. In yet another embodiment, the personal safety device 102 can be integrated into a self-defense weapon. By way of a non-limiting example, the personal safety device 102 can be incorporated into a conducted energy weapon such as a stun gun or Taser, available from Taser International, Inc. of Scottsdale, Ariz. In such an embodiment, the panic button 204 could be ergonomically located on the weapon handle or integrated with the trigger mechanism. Likewise, the digital camera lens and microphone could be positioned on the weapon's barrel so that by pointing the weapon at an attacker, the weapon would be able to record the attacker's image and voice. This would allow the user to both summon help and provide a means for self-defense.
[0057] In another embodiment, a personal safety device 102 can include one or more tamper-resistant or tamper-proof bracelets, anklets, straps or harnesses to secure the personal safety device 102 to a person. In this way, small children who might be libel to remove and lose the personal safety device 102 will be thwarted. Similarly, a criminal probation program can use a personal safety device 102 to track an offender's location without the risk that the offender will remove the device. In one embodiment, if the personal safety device 102 is removed, the personal safety device 102 can automatically transmit a message to a relay to a remote monitoring center 108 indicating this event.
[0058] FIG. 3 is a flowchart illustrating the steps of providing assistance to a user in accordance with an embodiment of the present invention. Once a user 100 activates the panic feature of a personal safety device 102 in step 300 , the personal safety device 102 transmits information including the individual's location to a communication system 104 in step 302 as described above.
[0059] After activation of one or more personal safety devices 102 , an alarm signal is transmitted to one or more communication systems 104 in step 302 via one or more public or private networks. By way of a non-limiting example, a network can include one or more of satellite, cellular (e.g., CDMA, GSM, UMTS), local area wireless (e.g., Wi-Fi), Ethernet, token ring, Internet and ATM networks. In one embodiment, the communication system 104 can associate the transmitted location, speed, direction of travel, of the personal safety device 102 , as well as the sound/image/video/movie information with time stamps and/or electronic signatures personal safety device 102 in order to provide a tamper-proof record of the information.
[0060] In another embodiment, the communication system 104 can be integrated into a network access point, such as a cellar base station, satellite uplink, or point-of-presence, such that personal safety device 102 information is made tamper-proof before it enters a network at large. Multiple communication systems 104 can be organized in clusters or grids to provide automatic load balancing and fail-over as is well known in the art wherein if one communication system fails or is busy, a second communication system can pick up where the first one left off. The communication systems can share a database management system (DBMS) to persist the information received from personal safety device 102 .
[0061] In step 304 , the alarm signal is transmitted from the communications system 104 to a communication tower 106 that is within the closest proximity to the GPS coordinates of the portable safety device 102 . In an embodiment, the communication system 104 compares the GPS coordinates from the portable safety device 102 with the coordinates of various communication towers stored in a database (either locally on the communications system 104 or remotely).
[0062] Next, in step 306 , the alarm signal is routed from the communication tower 106 to a remote monitoring center 108 . In an embodiment, the remote monitoring center 108 determines at step 310 if the alarm signal has been sent from an authentic or registered user or personal safety device. In embodiment, the alarm signal may be encrypted, and requires a decryption key that is located on the communication and dispatch system 122 at the remote monitoring center 108 . In another embodiment, the alarm signal can include identification information from the user 100 and/or the personal safety device 102 that can be compared to stored information on a database located on the communication and dispatch system 122 at the remote monitoring center 108 .
[0063] If the alarm signal is determined to be fraudulent, or sent from an unregistered or unverified personal safety device, the process ends and no further action is taken by the remote monitoring center 108 . However, if the alarm signal is verified, then the remote monitoring center 108 initiates an appropriate response at step 312 .
[0064] At this stage, a dispatch operator 120 is presented with information related to the user 100 and/or the personal security device 102 as further described in FIG. 4 . The dispatch operator 120 can be a trained response provider, and may be former law enforcement personnel, 911 operator, or other person with an appropriate background and training in emergency and disaster response.
[0065] The dispatch operator 120 can assist the user 100 and provide a number of services, such as patching the user 100 to an emergency response provider, and staying on the call with the user 100 until help has arrived at the user's location. Furthermore, the dispatch operator 120 can act as a go-between the user 100 and a 911 center in the event that the user 100 is uncomfortable with directly dialing 911 in the absence of a certain emergency or a threat. In another embodiment, the dispatch operator 120 can be patched directly to a speaker on the personal safety device 102 and can announce that emergency response is on the way to the user's location. This may help in deterring any real or potential threats, such as burglars, intruders, and attackers that may be in the vicinity of the user.
[0066] In one embodiment, the communication and dispatch system 122 can allow interaction with a personal safety device 102 user through one or more communication channels. This interaction can be accomplished using any number of network protocols and data formats, including but not limited to IP, UDP, TCP/IP, HTTP, HTTPS, POP, VoIP, SOAP, XML, or any other suitable standard or non-standard format/protocol. In one embodiment, a “Contact” button allows a text, voice or video message to be sent to a personal safety device 102 . A “Send Help” button allows the dispatch operator 120 to issue a command to dispatch emergency services to the user 100 . Finally, the “Configure” button allows commands to be sent to a personal safety device 102 . By way of a non-limiting example, such commands can include the ability to remotely unlock a tamper-resistant or tamper-proof bracelet or anklet that secures the personal safety device 102 to a user, the ability to remotely enable/disable the personal safety device 102 “Panic” button, and the ability to remotely enable/disable any other features of the personal safety device 102 .
[0067] In addition, the dispatch operator 120 can activate the camera 214 on the personal safety device 102 and is able to see the scene at the user's location. In another embodiment, the communication and dispatch system 122 can record any images and video transmitted from the personal safety device 102 so that this evidence can be reviewed and analyzed by authorities if needed at a later time.
[0068] In another embodiment, upon receiving information from a personal safety device 102 , the communication system 104 and/or remote monitoring center 108 , in addition to contacting the emergency response systems, can also automatically contact one or more other clients (e.g., a child's parents, a friend or spouse, an employer, etc.). The notification can take many forms including, but not limited to, an electronic message sent over the one or more networks, an automated voice message sent via a telephone network or via VoIP, e-mail message, an automatically placed 911 call, a facsimile, and/or a pager message. The notification can include a user's current location, direction of travel, speed, and/or voice/image/video/movie data recorded by the personal safety device 102 . This embodiment is useful if the user 100 is a child or elderly person, and a parent or guardian wishes to receive a notification when the panic feature is activated by the user 100 .
[0069] In one embodiment, the notification delivery can be escalated automatically if an acknowledgement of its receipt is not received by the communications system 104 and/or remote monitoring center 108 . For example, if an electronic message is sent but is not acknowledged within a certain time frame by a parent or guardian, the relay can attempt to automatically contact the parties through alternate and/or higher priority paths (e.g., via e-mail, telephone, etc.) until a confirmation that help is on the way is received.
[0070] FIG. 4 is an illustration of an exemplary dispatch interface in accordance to certain embodiments of the invention. The dispatch interface 400 visually depicts the path of a personal safety device 102 on a satellite or street map display 402 as well as a projected path based on the current direction and travel speed of the personal safety device 102 . This allows the dispatch operator 120 to quickly ascertain where a user 100 with a personal safety device 102 is and where they might be going. In addition, the dispatch interface 400 provides the ability to playback images/movies/videos and sounds that were recorded on the personal safety device 102 at given geographic locations in the audio/visual display 406 . The audio/visual display 406 can include controls for the dispatch operator 120 to pause, fast forward, rewind, slow down, or take a snapshot of the audio or visual data that is being transmitted from the personal safety device 102 .
[0071] Besides providing this information, the dispatch interface 400 permits messages to be sent to the personal safety device 102 (e.g., a page or voice message) as well as configuration information which can control feature activation on the personal safety device 102 . The dispatch interface 400 also has the capability of configuring escalation strategies and communicating and coordinating between various emergency response providers.
[0072] By way of a non-limiting example, the dispatch interface 400 can include one or more of the following: 1) a dispatch interface 400 (e.g., rendered with HTML); 2) an ability to respond to sounds and/or voice commands; 3) an ability to respond to input from a remote control device (e.g., a mobile communications device, such as a mobile telephone such as a cellular telephone, a PDA, or other suitable remote control); 4) an ability to respond to gestures (e.g., facial and otherwise); 5) an ability to respond to commands from a process on the same or another computing device; and 6) an ability to respond to input from a computer mouse and/or keyboard. This disclosure is not limited to any particular dispatch interface 400 . Those of skill in the art will recognize that many other dispatch interface 400 embodiments are possible and fully within the scope and spirit of this disclosure.
[0073] In one embodiment, dispatch interface 400 can include a location history display 408 that contains a history of where a user has been. Each row in the list can include a date and time stamp for a location in latitude, longitude, and altitude, and the approximate street address. By default, the list can be automatically sorted so that the most recent information is at the top of the list. Selection of a row in the list can cause the location to be displayed in the map. As seen in FIG. 4 , The street map display 402 shows the user's current location “*” 412 , where user has been “solid line” 414 , and where it is projected that the user is going “dashed line” 416 . In one embodiment, the user's projected path can be based on the user's current direction, speed and prior location(s). The street map display 402 can be displayed as a street map, a satellite image, or an overlay of a street map on a satellite image. By default, a map of the user's current location is displayed and refreshed each time new location information is received by from the communication system 104 . If the user 100 has activated the panic button 204 , the relevant row in the location history display 408 can be displayed in red or otherwise highlighted to draw attention to it.
[0074] The dispatch interface 400 further includes a text display 410 which transcribes the communication between the user 100 and the dispatch operator 120 . This text is stored in a database along with the audio/video recording as described above and can be retrieved for later review and analysis.
[0075] Furthermore, the dispatch interface 400 includes a user information display 404 which provides stored information related to the user 100 . In an exemplary embodiment, the personal safety and tracking system is provided by a third-party provider, and requires users to registers for monitoring and safety services via a monthly or yearly subscription fee. When a user registers for the service, they provide the third-party provider with personal information which is then stored on a database on the communication and dispatch system 122 . When an alarm signal is received from a user 100 , a lookup is performed and the user's information is retrieved from the database and displayed to the dispatch operator 120 in the user information display 404 .
[0076] FIG. 5 is a block diagram of a personal safety device system in accordance to certain embodiments of the invention. Although this diagram depicts subsystems as logically separate, such depiction is merely for illustrative purposes. It will be apparent to those skilled in the art that the subsystems portrayed in this figure can be arbitrarily combined or divided into separate software, firmware and/or hardware modules. Furthermore, it will also be apparent to those skilled in the art that such modules, regardless of how they are combined or divided, can execute on the same computing device or can be distributed among different computing devices connected by one or more networks or other suitable communication means.
[0077] System 500 has an open architecture that allows for infinite expandability. The system is composed of one or more modules that implement a common communication mechanism. Component communication can be facilitated through a logical message bus or other paradigm that allows modules can send and receive asynchronous messages. In one embodiment, the message bus can be based on the JMS API available from Sun Microsystems, Inc. of San Jose, Calif. JMS is a messaging standard that allows application modules to create, send and receive messages. The message bus allows individual modules to take actions based on messages they receive and, likewise, to drive the action of other modules by sending messages. In one embodiment, a message can include a code identifying the source module of the message, the message type, and optional parameters. Such a flexible system allows for easy integration with new devices (e.g., PDAs, cell phones, music players, digital cameras, computer games) as these technologies evolve.
[0078] In one embodiment, the system 500 includes a sound recorder module 501 and image recorder module 502 that provide sound and image/movie/video recording capabilities, respectively. As with the other modules, modules 501 and 502 can provide services for capturing sound and images to other modules through a message interface. In one embodiment, the modules can store captured information in the database 512 . In another embodiment, the modules can provide captured sounds/images/movies/videos in a message. Both modules can also implement hardware interfaces to allow any number of hardware devices (e.g., microphones, digital still/video cameras) to be easily plugged into the system. In another embodiment, modules 416 and 418 can be integrated into a single module.
[0079] The system includes a GPS transponder module 504 that can continuously or periodically receive location information from a compact GPS receiver or other device for determining geographic location and store said information in the database 512 . In one embodiment, the database 512 can be any type of storage medium including floppy disks, optical discs, DVD, CD-ROMs, microdrive, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, memory stick, flash RAM, static RAM, non-volatile memory, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of media or device suitable for storing instructions and/or data.
[0080] The GPS transponder module 504 can receive messages that correspond to requests for current or historical position information and respond with the requested information. In one embodiment, the GPS transponder module 504 has a standard hardware interface, which allows any location determination device that conforms to the interface to provide location information to the system 500 .
[0081] Communication manager module 508 can provide a standard interface for sending and receiving information over one or more communication mediums (e.g., cellular, satellite, Wi-Fi, pager, or other suitable medium). The communication manager module 508 can offer connected, connectionless, reliable and/or unreliable communication channels. In one embodiment, the communication manager module 508 implements a message interface that allows other modules on the message bus to access these services. By way of a non-limiting example, a module can send a message to: open a communication channel of with a given destination; send a message over the channel; register to receive a message when information is received on the channel; register to receive a message when information transmittal fails; and set transmission parameters such as retry count, message length, compression, and encryption. In one embodiment, the communication manager module 508 has a standard hardware interface, which allows any communication hardware that conforms to the interface to integrate with the communication manager module 508 .
[0082] User interface module 506 can provide a standard interface for obtaining user input (e.g., keypad interaction, panic button, voice recognition, finger and hand articulation, etc.) and for providing visual, audio and other sensor output to the user. In one embodiment, the user interface module 506 implements a message interface that allows other modules on the message bus to access services related to input events and output functions. By way of a non-limiting example, a module can send a message to the user interface module 506 to register to receive input events from, for example, the keypad. Thereafter, whenever the user interface module 506 detects input from the keypad, it will send a message and any relevant data to modules that have registered to receive this input event. Likewise, a module can send a message to the user interface module 506 to cause output on a personal safety device, such as a display, speaker, vibrator or other output device. In one embodiment, the user interface module 506 has a standard hardware interface that allows any input/output hardware that conforms to the interface to provide authentication information to the user authenticator module 510 .
[0083] A user authenticator module 510 can provide a standard authentication interface for the system components by hiding the particulars of the underlying authentication mechanism. This allows new and developing authentication mechanisms (e.g., finger print detection, voice recognition, retinal scanning, blood or saliva analysis, facial feature analysis, vein analysis, etc.) to be seamlessly adopted without requiring modifications to other system modules. In one embodiment, the user authenticator module 510 can accept requests to perform authentication and can respond with a determination of whether or not the authentication was successful. In one embodiment, the authenticator has a standard hardware interface, which allows any authentication hardware that conforms to the interface to provide authentication information to the authenticator.
[0084] It will be appreciated by those of skill in the art that many more biometric identification methods which are not discussed herein are nonetheless fully within the scope and spirit of the present disclosure. In one embodiment, an offender may be required by their probation officer to periodically perform biometric identification to ensure that the offender has the device on their person.
[0085] In an embodiment, the personal safety device 100 further includes various self-defense mechanisms to assist the user 100 to ward off, thwart, or fight back against attackers or intruders. For example, the personal safety device 100 can include a hidden blade which, upon activation by the user 100 , is deployed from an edge of the personal safety device 100 and acts as a weapon. The personal safety device 100 can also include a pepper-spray or mace deployment system. Furthermore, the personal safety device 100 can be equipped with a high-intensity strobe light mechanism to emit blinding light to an attacker or intruder.
[0086] In another embodiment, the personal safety device 100 can be equipped with deafening alarm speaker to alert passer-bys and to scare off intruders. The speaker can emit static sounds, emergency sounds such as police sirens, the sound of gun shots, or the sound of a barking dog.
[0087] While the principles of the disclosure have been illustrated in relation to the exemplary embodiments shown herein, the principles of the disclosure are not limited thereto and include any modification, variation or permutation thereof.
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The disclosure generally relates to methods and systems for providing multiple coordinated safety responses. In an exemplary embodiment, the disclosure relates to notifying multiple persons who are within a vicinity of a victim, and instructing those persons to provide various safety responses at various frequencies, where the frequency of the response can be related to the closeness of first responders to the scene. The invention uses a safety force multiplier that frustrates, confuses, scares, and/or distracts a potential perpetrator by delivering multiple responses to a scene.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from German Ser. No. 20 2010 015 525.8 filed Nov. 18, 2010, the entire contents of which are incorporated herein by reference.
FIGURE SELECTED FOR PUBLICATION
FIG. 6
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lock system and method involving profile strips and a slider for connecting and separating such a lock system. More particularly, the present invention relates to system and method for slidably securing bounded volumes.
2. Description of the Related Art
Liquid or solid bulk materials are often held in bundles. The bundles may be at least partially-flexibly configured as bundles. Such bundles are, for example, obtained as sacks that are hung in containers. Preferably the bundles are manufactured from endless hoses and closed in various ways and means as hose sections. Especially frequently, such bundles are used for packaging, transporting or storing liquid or solid bulk materials. The term bundle in this application comprises not only completely closed flexible bags, but also for example an adapter that is flexible and open on at least two sides, that can be attached to a device or a container.
During operation, emptying, filling or re-filling such bundles in practice turns out to be difficult or even risky. Particularly when the bulk material of the bundles is dangerous or sensitive, contamination of the bulk material as well as contamination of the environment by bulk material is to be avoided. For this all the locks and connections, especially for docking such bundles, must be manufactured to be as environmentally sealed as possible. With these problems as a background, limited special locks for the bundles described initially have been developed which are to provide support to prevent contamination in the particular case.
Such locks can be perceived for example for DE 10 2004 003 511 B4, the entire contents of which are incorporated herein by reference. However, as regards the stability of the connections, such locks are often not sufficiently safe and provide a substantial detriment.
Accordingly, there is a need for an improved system that overcomes at least one of the concerns noted above.
ASPECTS AND SUMMARY OF THE INVENTION
The proposed invention provides a lock system involves a first lock and a second lock each with two profile strips operable for engagement with an at least partially flexible bundle and effective to enable an environmentally-sealed connection of a first bundle with a second bundle in a closed docking position and for an environmentally-sealed guidance of a flow in a flow direction (D) through the lock members from the first bundle into the second bundle in an open docking position. The second bundle provides similar lock members facing toward the first bundle, which lock members in the opened docking position engage the lock members of the first bundle and jointly with the lock members of the first bundle forms a flow channel for flow in the flow direction. Additionally the invention relates to a slider for connecting and separating such locks. The slider has an insertion side on which the locks are insertable in insertion directions (A, B) which enclose an acute angle (γ) in which the slider is insertable, and opposite the insertion side an outlet side on which the locks connected there with each other can be removed in a joint sliding direction (C) from the slider.
At least one problem that is the basis for the invention is to provide a lock for a bundle, which makes possible an environmentally-sealed connection of such bundles with each other or with other procedural mechanisms, as well as environmentally-sealed guidance for a flow between bundles connected with each other or the connected devices. In addition, it is proposed in one embodiment that the proposed system and method is effective for substantially universal use on at least one at least partially flexible bundle, also without the lock needing to be part of the bundle. It is preferable that between the bundles such locks should produce as secure a connection as possible, which does not tear especially when impulses occur along the flow direction. Also, the locks are to be produced in preferably as cost-effective a manner as possible, in the best case as piece goods without substantial re-working or assembly.
An aspect of the present invention is thus to provide a locking system with two profile strips with features as noted and a slider member in an effort to overcome at least one of the detriments noted. It will also be understood that an aspect of the present invention is to provide a method for operating such a system in the matter discussed herein.
In addition, according to a further refinement of the invention, there is provided a system and method for an environmentally-sealed linkage of a first bundle with a second bundle, so that a through flow can be guided in environmentally-sealed fashion in a flow direction through the lock from the first bundle into the second bundle in an open docking position.
As discussed herein facing a first bundle, the second bundle has an identical lock, which can be operated in the proposed manner and made to engage the lock of the first bundle to attain the opened docking position. In this opened docking position the connected locks of the bundle form a channel for flow of the bulk goods in the flow direction.
As ill be understood from study of the entire disclosure, the lock system and method comprises two profile strips for locking the at least partially flexible bundle: a wide profile strip and a narrow profile strip. The wide profile strip extends out in the flow direction via the bundle and the narrow profile strip oriented parallel to the first profile strip. Both profile strips comprise locking elements oriented exclusively transverse to the flow direction, which are meant to engage with each other in the manner of an interlocked connection.
All of the locking elements of the profile strips are oriented transverse to the flow direction, into the channel or out of the channel, so that loads in the flow direction can be compensated with a high level of safety. In the flow direction when one bulk product is poured for example from the first bundle into the second bundle, impulse loads occur on the locks if the bulk goods fall on the floor of the second bundle. The locking elements placed transverse to the flow direction withstand such impulses in the flow direction, since they effectively prevent a stripping off of the profile strips.
In advantageous fashion, and during operation of the method, the bundles can be and are pressed laterally against each other with identically configured locks, to produce environmentally-sealed connections of the profile strips with each other. Lateral pressing against each other also leads, when a bundle is locked with the lock, to a safe connection, as well as when the identical lock is pressed laterally on the lock, to create a flow between two bundles. In this case two bundles are docked to each other.
For the user, lateral docking in addition to the strength of the connection and has a practical advantage in that a lateral arrangement of the bundles to each other is considerably more comfortable to implement. For example, an empty bundle can readily be made to come to a full bundle. To dock the bundles to each other, neither of the bundles needs to be moved vertically, since docking is laterally provided (relative to a bundle direction).
For connecting and parting of the locks, a slider is provided and is operatively removable from the locks between uses. The slider is operative to slide up to the closed locks to make connection transverse to the flow direction by engaging the related profile strips and locking elements as will be discussed.
Oriented in the flow direction and lying opposite, the slider has an insertion side and an outlet side. On the insertion side the locks of the two bundles can be inserted in insertion directions. The insertion directions run transverse to the flow direction and cross at an acute angle. During use, in the angle, oriented to each other, the locks on the insertion side are inserted into the slider. On the outlet side, the locks connected with each other by means of the slider are guided out of the slider in a common sliding direction, with the respective lock, viewed for itself, first being locked.
Additionally, the locking elements acting between the profile strips are advantageously loosen-able in a controlled fashion by means of an actuator either between the profile strips of a lock or between the profile strips of two locks, so that the bundles avoid an uncontrolled opening. The actuator can, for example, be operated manually, especially as actuators configured as straps. According to the invention this occurs after the sliders have connected the locks with each other. The straps are pulled laterally apart from each other. With this the desired locking elements become loose, according to on what straps at what angle a lateral tension is applied according to the method of use.
A configuration of locking elements for acting together in an interlocking connection is advantageous, because an appropriate extrusion of the profile strips as plastic strips can be shaped in especially favorable geometric forms. Aside from that, the locking elements thus shaped lock especially well due to the normally weak and small wall thickness of the bundles. Such embodiment forms of stronger locking elements are especially robust and stable against multiple loadings, and in addition interlock securely until they are loosened from the interlocking in a reverse of the locking method employed. For this they can be angled off parallel to the flow direction from the profile strips so that each locking element separates in turn
The above, and other aspects, features and advantages of the present invention will become apparent from the following description read in conduction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described detail below on the basis of exemplary embodiments with reference to the accompanying figures, in which:
FIG. 1 is a perspective view of a slider with a slanted view of its exit side.
FIG. 2 is a perspective view of the slider of FIG. 1 with a slanted view of the insertion side.
FIG. 3 is a partial perspective view of the exit side of the slider of FIG. 1 , with a slanted view of its exit side with no bundles, locked by two locks guided through the slider and connected during a use by means of the slider
FIG. 4 , is a partial perspective view of the insertion side of the slider of FIG. 2 , with no bundles and with two locks locked in the insertion direction into the slider and run through the slider from right to left on the page for joining together thereof.
FIG. 5 is a partial sectional illustration of a slider with inserted locks as noted in FIGS. 3 and 4 through a plane defined along the insertion direction.
FIG. 6 is a perspective view of two bundles connected to each other through the slider in an opened docking position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms, such as top, bottom, up, down, over, above, and below may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope of the invention in any manner. The words “connect,” “couple,” and similar terms with their inflectional morphemes do not necessarily denote direct and immediate connections, but also include connections through mediate elements or devices.
Referring now to FIGS. 1 and 2 , and generally through all FIGS. 1-6 , a slider 30 is depicted according to an embodiment example in a perspective view from two sides, an insertion side 31 and an outlet side 32 of slider 30 . The perspective views of FIGS. 1 and 2 are supplemented by the perspective views of FIGS. 3 and 4 in that two locks 10 , 20 are shown inserted into slider 30 with no bundle.
FIG. 5 shows a section through the plane of slider 30 with inserted locks 10 , 20 as per FIGS. 3 and 4 through a plane which is set via insertion directions A, B, in which locks 10 , 20 have been inserted into slider 30 . FIG. 6 shows slider 30 as per the embodiment example from FIG. 1 in an open docking position of two bundles 1 , 2 which are equipped with one of the locks 10 , 20 as per FIGS. 3 and 4 .
Identical parts are provided with similar reference symbols. To afford a better view, not all reference symbols are indicated in all the figures but will be understood by those of skill in the art having studied the disclosure.
The slider 30 comprises a body with two wing-like handles attached on opposite sides on the longitudinal sides. The body has roughly the shape of a cuboid. Joining the longitudinal sides with each other, as further longitudinal sides along the insertion directions A, B, the body has a first cover side 35 and an opposite second cover side 36 .
On the front side, slider 30 comprises an insertion side 31 transverse to insertion directions A, B. On insertion side 31 the locks 10 , 20 are insertable in insertion directions A, B into slider 30 , wherein the insertion directions A, B enclose an acute angle γ. Opposite insertion side 31 , slider 30 comprises an outlet side 32 . On outlet side 32 , the locks 10 , 20 that are connectable to each other via slider 30 and locked are able to be brought out in a common sliding direction C through a gap 44 that is run through slider 30 oriented in a flow direction D, out of slider 30 . The gap 44 is open toward the two cover sides 35 , 36 .
On the insertion side, slider 30 has a first U-shaped cross section 33 that is open toward the first cover side 35 , transverse to one of the insertion directions A. The first U-shaped cross section connects two legs with each other with a first base 37 which legs terminate in the first cover side 35 . The legs have contours facing toward each other that are fitted to locks 10 , 20 .
Adjoining the first U-shaped cross section and specular as regards a plane ( FIG. 5 ) extended through insertion directions A, B, slider 30 comprises a second U-shaped cross section 34 open to the second cover side 36 , and running transverse to the other insertion direction B. Its second base 38 which also connects two legs with each other faces away from first base 37 . The two legs of the second U-shaped cross section likewise terminate in open fashion in the second cover side 36 . Also, at least one of these legs is fitted to the locks 10 , 20 with a contour.
The lock 10 , 20 comprises two profile strips 11 , 12 ; 21 , 22 for an at least partially flexible bundle 1 , 2 ( FIG. 6 ) for environmentally-sealed connection of a first bundle 1 with a second bundle 2 and for environmentally-sealed guidance of a flow in flow direction D through the lock 10 , 20 from first bundle 1 into second bundle 2 in an opened docking position. Second bundle 2 has an identical lock 10 , 20 facing first bundle 1 .
In the opened docking position as per FIG. 6 , lock 10 of first bundle 1 is engaged with lock 20 of second bundle 2 . The locks 10 , 20 thus jointly form a flow channel 3 for flow in flow direction D.
According to FIGS. 3 to 5 , profile strips 11 , 12 ; 21 , 22 are placed opposite each other; they pick up bundle 1 , 2 between them and close it. The wider of the profile strips 12 , 22 extends in flow direction D via the narrower of the profile strips 11 , 21 . Both profile strips 11 , 12 ; 21 , 22 comprise locking elements 13 , 13 oriented exclusively transverse to flow direction D, both out of the channel and into the channel. The locking elements 13 , 23 securely engage with each other in the manner of an interlocked connection.
As per FIGS. 3 to 5 , by means of appropriately placed first and second bases 37 , 38 , the locks 10 , 20 placed opposite each other are insertable into U-shaped cross sections 33 , 34 —in a method of using. In use, the first lock 10 is guided with a projecting locking element 13 to about the height of an additional locking element of narrow profile strip 21 of second lock 20 .
The slider 30 exhibits U-shaped cross sections 33 , 34 and gap 44 joining inlet channels 41 , 42 and an outlet channel 43 . The inlet channels 41 , 42 are oriented transverse to flow direction D and opened with the U-shaped cross sections 33 , 34 . According to the embodiment example of FIGS. 3 to 5 they are closed on three sides and empty out roughly in the center in slider 30 in outlet channel 43 . The locks 10 , 20 are guided through in the insertion directions A, B in the angle γ toward each other through insertion channels 41 , 42 into outlet channel 43 and through it. The outlet channel 43 terminates on the outlet side 32 in gap 44 .
In the insertion channels 41 , 42 facing away from the base 37 , 38 as well as in the outlet channel 43 , slider 30 has grooves running transverse to flow direction D graduating in an area of the particular cover side 35 , 36 . In use, into the grooves, guide rails 46 are inserted, here clipped in. The guide rails 46 narrow insertion channels 41 , 42 and outlet channel 43 of the cover side 35 , 36 facing, to hold a lock 10 , 20 in the guide.
In the insertion channels 41 , 42 on the insertion side a stopper 45 is provided which prevents slider 30 from sliding out of the locks 10 , 20 connected with each other. During use, the stopper 45 acts together with a local alteration of at least one of the profile strips 11 , 12 ; 21 , 22 . In advantageous fashion, in use a welded seam oriented in flow direction D is placed on or in profile strips 11 , 12 ; 21 , 22 as the local alteration.
LIST OF REFERENCE SYMBOLS
1 first bundle
2 second bundle
3 Flow channel
10 first lock
11 first narrow profile strip
12 first wide profile strip
13 first projecting lock element
20 second lock
21 second narrow profile strip
22 second wide profile strip
23 second projecting lock element
30 slider
31 insertion side
32 exit side
33 U-shaped cross section
34 second U-shaped cross section
35 first cover side
36 second cover side
37 first base
38 second base
41 first insertion channel
42 second insertion channel
43 outlet channel
44 gap
45 stopper
46 guide rail
γ angle
A insertion direction
B additional insertion direction
C sliding direction
D Flow direction
In the claims, means or step-plus-function clauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface, a screw's helical surface positively engages the wooden part, and a bolt's head and nut compress opposite sides of a wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures.
Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes, modifications, and adaptations may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A lock system includes a first lock and a second lock each with two profile strips operable for engagement with an at least partially flexible bundle and effective to enable a connection of a first bundle with a second bundle in a closed docking position and for guidance of a flow in a flow direction through lock members from the first bundle into the second bundle in an open docking position. The second bundle provides the lock members facing toward the first bundle, which lock members in the open docking position engage the lock members of the first bundle and jointly with the lock members of the first bundle form a flow channel for flow in the flow direction. Additionally, a slider for connecting and separating such locks is provided.
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FIELD OF THE INVENTION
[0001] The present invention relates to rechargeable battery systems such as those used for electronic devices including, without restriction, cameras, computers, medical and audiovisual equipment.
[0002] The present invention is a wireless communication system for batteries and battery-powered systems that includes a network connection element that transmits information regarding the battery to one or more electronic devices. The present invention may be integrated into the battery, integrated into an electronic device powered by a battery or may be an attachment for such an electronic device that interoperates with the battery powering the device.
BACKGROUND OF THE INVENTION
[0003] Many devices, including computers, cameras, lights, phones, radios and other equipment, use rechargeable batteries for power. These batteries typically attach to the device by mechanical latches or connections. In particular, in many items of audiovisual recording equipment, a rechargeable battery attaches to a battery mount plate which is attached to the device, which incorporates the power terminals that receive power from the battery and data terminals for communication between the battery and the device. Such battery mount plates are attached semi-permanently to the audiovisual recording equipment and provide an industry-standard mounting surface which a rechargeable battery may be quickly and easily attached to or detached from. Such industry-standard mounting surfaces include, without restriction, 3-stud mounts and V-mounts. Some rechargeable batteries may be recharged through the device, while others may be recharged through a dedicated charging device, and some batteries may be recharged either through the device or through a dedicated charging device.
[0004] Many currently available rechargeable batteries include sub-systems that enable battery management, reporting or other features referred to as smart battery features. Such smart battery features may report the current battery charge, power and other state information. Such smart battery features may also report information such as current battery load, time until the battery is charged when charging, or time until the battery is discharged when in use. Smart battery features may also allow the user to manage the battery by monitoring its output voltage, reserve power, or alerts. Dedicated charging devices may also incorporate smart battery features.
[0005] Smart battery features are usually implemented using the System Management Bus (“SMBus”) standard, which allows communication between a computer processor and computer hardware. In addition to the SMBus standard, other standards including, without restriction, the Power Management Bus (“PMBus”), Smart Battery System (“SBS”), HDQ and Inter-Integrated Circuit (“I2C”) are used by various manufacturers to allow communication between a battery and a computer processor or device. These standards may be referred to as smart battery management standards. As used herein, the term smart battery management standards also includes analogue connections that communicate only one battery attribute such as voltage and/or amperage.
[0006] Current smart battery management standards all rely on a directly wired connection between the smart battery and the device receiving the information regarding smart battery features and/or managing the smart battery. This architecture is acceptable when a single device is powered by the battery and manages the battery. In an environment, however, where the device powered by the battery is not directly attended by a user or where a user is using multiple battery-powered devices at once, this can result in a device unexpectedly shutting off as its battery runs out of power. Additionally, it prevents the use of smart battery features on devices that do not incorporate computer processors and/or displays. Current smart battery features and systems cannot report or otherwise communicate battery status to device other than a device the battery is connected to by a wired connection. Further, multiple smart batteries or smart battery systems do not aggregate the statuses of their batteries or offer an interface where a user can review the status of multiple batteries at once. This can be a problem in a workplace or other setting where multiple devices, each powered by one or more rechargeable batteries, are all continuously or intermittently operating, and the loss of power to one device can interrupt work or other tasks. Additionally, devices that do not implement fully-featured smart battery communication systems may only communicate particular attributes, such as voltage or amperage, via an analogue port or connector. The current invention solves these problems.
SUMMARY OF THE INVENTION
[0007] The current invention is a wireless smart battery communication system, incorporating a processor, a connector complying with a smart battery management standard and a wireless communication system. The wireless smart battery connector allows a user to view the status of one or more smart batteries using a wireless device. Multiple smart battery communication systems, each connected to and/or incorporating one smart battery, may be connected to a single wireless device. The preferred embodiment of the invention is a smart battery connector incorporated into a battery mount plate that connects a device and a smart battery. The current invention allows a user to remotely and wirelessly monitor and manage multiple smart batteries powering multiple devices and/or being recharged in devices or dedicated charging devices.
[0008] The preferred embodiment of the invention is a battery mount plate that includes a battery power terminal, a device power terminal, a battery communication terminal, a device communication terminal, a processor, a wireless communication system and a battery mounting system. All of the foregoing are incorporated into a housing having two sides, which is configured to semi-permanently attach to a device requiring power, such as by screws, and releasably attach to a rechargeable battery, such as by, without restriction, latches or other mechanical mounting. The battery power terminal, battery communication terminal and battery mounting system are disposed on a battery side of the housing and the device power terminal and device communication terminal are disposed on a device side of the housing. In this configuration, the invention is semi-permanently affixed to the device and a smart battery is releasably attached to the invention such that electrical power flowing from the battery to the device or from the device to the battery passes through the invention and communications passing from the battery to the device or from the device to the battery pass through the invention. In a related embodiment, the processor and wireless communication system are directly incorporated into the battery housing and receive battery information and/or communications directly from the internal battery systems.
[0009] Information regarding power and/or communications passing through the invention may then be processed by the processor and transmitted using the wireless communication system to any system or device capable of receiving wireless communications. Such a device may be a computer, tablet or smartphone device with an application installed for presenting the received information to a user.
[0010] Another embodiment of the invention is a battery charger with a processor, wireless communication system, battery power terminal, battery communication terminal and battery mounting system integrated into the battery charger. In this embodiment, information regarding battery power and/or communications between the charger and a connected battery may then be processed by the processor and transmitted using the wireless communication system to any system or device capable of receiving wireless communications.
[0011] A third embodiment of the invention is a smart battery module attachable to a battery by a standard analogue port. In this embodiment, the module incorporates a processor, wireless communication system and battery connector into a housing. When the module is connected to a battery
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of the present invention, reference may be had to the following detailed description of the invention taken in conjunction with the drawings herein, of which:
[0013] FIG. 1A is a rear view of the preferred embodiment of the current invention configured for v-mount batteries;
[0014] FIG. 1B is a rear cutaway view of the preferred embodiment of the current invention configured for v-mount batteries;
[0015] FIG. 2A is a rear view of the preferred embodiment of the current invention configured for 3-stud batteries;
[0016] FIG. 2B is a rear cutaway view of the preferred embodiment of the current invention configured for 3-stud batteries;
[0017] FIG. 3A is a schematic view of multiple battery charging devices incorporating the current invention; and
[0018] FIG. 3B is a plan view of a tablet communicating with the current inventions depicted in FIG. 3A ;
[0019] FIG. 4 is a schematic view of a workplace using multiple devices incorporating the current invention;
[0020] FIG. 5 is a front view of the embodiment of FIG. 1A ;
[0021] FIG. 6 is a front view of the embodiment of FIG. 2A ;
[0022] FIG. 7A is a rear view of the embodiment of FIG. 1A ;
[0023] FIG. 7B is a rear view of the embodiment of FIG. 2A ;
[0024] FIG. 8A is a perspective view of the embodiment of FIG. 1A attached to a powered device;
[0025] FIG. 8B is a perspective view of the embodiment of FIG. 1B attached to a powered device
[0026] FIG. 9 is a perspective view of a dongle embodiment of the present invention;
[0027] FIG. 10 is a cutaway view of the dongle embodiment of the present invention;
[0028] FIG. 11 is a side perspective view of an alternate embodiment of the embodiment of FIG. 3A ; and
[0029] FIG. 12 is an exploded view of a battery pack embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] In a first embodiment, as depicted in FIGS. 1A, 1B, 2A and 2B , the present invention comprises a mount plate housing 10 , a battery attachment mount 20 , a battery power terminal 30 , a battery communication terminal 40 , a wireless communication systems 50 , a processor 60 , a device power terminal 70 and a device communication terminal 80 . The mount plate housing 10 is of similar size, shape and design to the battery mount plates known to those skilled in the relevant art and used in the audiovisual recording industry. The battery attachment mount 20 may be an industry-standard V-mount 20 as shown in FIG. 1A and FIG. 1B , a 3-stud mount 20 ′ as shown in FIG. 2A and FIG. 2B or any other system or mechanism for attaching a battery to a mount plate. The battery power terminal 30 is located and configured as standard for the type of battery attachment mount 20 used. The battery power terminal 30 is a plurality of connectors such as, without restriction, prongs, contacts or sockets that connect to connectors on a rechargeable battery 110 as shown in FIG. 5 and FIG. 6 . Preferably, the battery power terminal 30 is a negative and a positive connector. The battery communication terminal 40 is located and configured as standard for the type of battery attachment mount 20 used. The battery communication terminal 40 is one or more connectors such as, without restriction, prongs, contacts or sockets that connect to connectors on a rechargeable battery. Preferably, the battery communication terminal 40 is an SMBus-compliant DATA connector and CLOCK connector. The battery communication terminal 40 may also be, without restriction, a single-wire connection such as HDQ or an analog voltage output. The wireless communication system 50 is disposed inside the battery mount plate housing 10 and may be any wireless communication device including, without restriction, a chip or chipset implementing any version of the Bluetooth standard and/or any version of the WiFi standard, but is preferably a chip implementing the Bluetooth 4.0 (also known as Bluetooth Low Energy or Bluetooth Smart) standard. The processor 60 is disposed inside the battery mount plate housing 10 and may be any microprocessor capable of receiving data from the battery communication terminal 40 . The processor 60 is connected to the battery power terminal 30 , the battery communication terminal 40 and the wireless communication system 50 . The processor 60 may be disposed on the same circuit board or in the same chip or chipset as the wireless communication system 50 . As depicted in FIG. 7A and FIG. 7B , the present invention further comprises a device power terminal 70 , a device communication terminal 80 and device attachment means 90 . FIG. 7A and FIG. 7B also show alternative positions of the wireless communication systems 50 and the processor 60 inside the mount plate housing 10 .
[0031] Turning now to FIG. 8A , when the battery mount plate housing 10 is attached to a device 100 by device attachment means 90 , the device power terminal 70 and the device communication terminal 80 connect to the device 100 . When a rechargeable battery 110 is mounted on the battery mount plate housing 10 by the battery attachment mount 20 , the battery power terminal 30 and the battery communication terminal 40 connect to the rechargeable battery 110 . The battery power terminal 30 and the device power terminal 70 are connected so that a power circuit 120 is created between the rechargeable battery 110 and the device 100 . The processor 60 is connected to power circuit 120 and powered by power circuit 120 . The battery communication terminal 40 and the device communication terminal 80 are connected so that a communication circuit 130 is created between the rechargeable battery 110 and the device 100 . The processor 60 is connected to communication circuit 130 and receives all information sent between the rechargeable battery 110 and the device 100 . The processor 60 is connected to the wireless communication system 50 . The wireless communication system 50 is connected to power circuit 120 and powered by power circuit 120 . The processor 60 processes information sent between the rechargeable battery 110 and the device 100 and transmits the result of said processing to the wireless communication system 50 and/or relays information sent between the rechargeable battery 110 and the device 100 to the wireless communication system 50 without processing it first. The wireless communication system 50 transmits information regarding the rechargeable battery 110 to a user device 140 to which it is wirelessly connected.
[0032] In another embodiment of the invention as shown in FIG. 3A , the battery power terminal 30 , the battery communication terminal 40 , the wireless communication system 50 and the processor 60 are incorporated into a charger housing 150 . The charger housing 150 also incorporates a power connector 160 . FIG. 11 shows an alternate configuration of the battery charger embodiment of the invention shown in FIG. 3A . In preferred embodiments of the battery charger embodiment of the invention, power connector 160 plugs directly into a power outlet, preferably a standard U.S. 110 volt power outlet, but this embodiment may, without restriction, connect to a DC converter, be configured for any power outlet or connect to any other power source, including large batteries, generators, solar power, or any other source of power that may be connected to provide power to the invention. The power connector 160 is connected to the battery power terminal 30 and provides power at the correct voltage and amperage to charge the rechargeable battery 110 . When the rechargeable battery 110 is seated in the charger housing 150 so that it connects to the battery power terminal 30 and the battery communication terminal 40 , it can receive power from through the battery power terminal 30 and communicate status through the battery communication terminal 40 . The processor 60 processes status information communicated by the rechargeable battery 110 and transmits the result of said processing to the wireless communication system 50 and/or relays information to the wireless communication system 50 . The wireless communication system 50 transmits information regarding the rechargeable battery 110 to a user device 140 to which it is wirelessly connected.
[0033] In another embodiment of the invention, as shown in FIG. 9 and FIG. 10 , a dongle 180 is comprised of a housing 190 formed to connect to a battery analog port of a rechargeable battery 110 . Said analog port may, without restriction, also function as an auxiliary power output. The housing 190 encloses an analog connector 200 disposed in the portion of the housing 190 formed to connect to the battery analog port, a processor 60 connected to said analog connector 200 and a wireless communication system 50 connected to said processor. The analog connector 200 may receive information from the battery analog port in the form of, without restriction, voltage levels and amperage.
[0034] In another embodiment of the invention, as shown in FIG. 12 , the processor 60 and wireless communication system 50 are disposed inside of the housing 170 of a battery 110 . The housing includes one or more battery cells 210 that are connected to a power circuit 220 , which terminates at a power terminal 230 . By attaching a device 100 to the battery 110 by connecting to power terminal 230 , the battery 110 provides power to the device 100 . The processor 60 and wireless communication system 50 are attached to and receive power from power circuit 220 . The processor 60 detects and processes information regarding the battery 110 from the power circuit 220 . Such information can include current voltage, amperage, charge level and/or any other information that can be determined by an electrical connection to a battery cell. As in the other embodiments of the invention, the wireless communication system 50 receives said information from the processor 60 and transmits information regarding the rechargeable battery 110 to a user device 140 to which it is wirelessly connected.
[0035] In all embodiments of the invention, the user device 140 may be any device capable of receiving wireless signals, preferably a tablet capable of acting as a Bluetooth 4.0 client as depicted in FIG. 3B . The user device 140 may also be, without restriction, a smartphone, a desktop computer or a wireless hub. Each user device 140 may connect wirelessly to multiple wireless communication systems 50 , each such wireless communication system 50 incorporated into a battery mount plate housing 10 , charger housing 150 , dongle housing 190 or other housing incorporating a wireless communication system 50 and connecting to a rechargeable battery 110 .
[0036] The user device 140 displays to the user the status of each battery attached to each wireless smart battery connector. The status can include, without restriction, the current charge of each rechargeable battery 110 , whether each device 100 is current operating, the time until charged for any rechargeable batteries 110 that are charging, and the time until discharge for any rechargeable batteries 110 that are powering devices 100 . The user device 140 may also act as a network hub and allow a user to connect to it via a network to view the foregoing information. The user is thereby enabled to view the status of multiple rechargeable batteries 110 without needing to examine each rechargeable batteries 110 and/or devices 100 and, furthermore, can obtain such information while at a single location, whereas the rechargeable batteries 110 and/or devices 100 may be spread across a workplace.
[0037] While the foregoing description and drawings represent the preferred embodiments of the present invention, it will be understood that various changes and modifications may be made without departing from the scope of the present invention.
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A wireless system for monitoring rechargeable and single-use batteries. The wireless system is usable with existing batteries that implement a smart battery standard and/or an analog port. The wireless system may be installed in the battery, in a battery-powered device, in a battery mount plate, in an attachment that connects to an analog port and/or in a battery charging station or charging device. The wireless system transmits the battery's status to a remote user device, which may be a tablet, smartphone or other wireless device. The system allows a user to monitor one or more batteries remotely.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a terminal used in a bulb socket for use in automotive lights and, more particularly, to a terminal positioned inside the bulb socket and having a contacting element whose deterioration of the spring characteristics is prevented to improve the contact reliability to the negative terminal of the bulb base.
2. Description of the Prior Art
In FIGS. 9 and 10, a conventional socket-side negative terminal 1 for use in a bulb socket 2 formed by bending a single thin metal band is shown. The socket-side negative terminal 1 comprises a bulb-side connecting element 1a for electrically connecting with the bulb 3 formed flexibly stamped out at one end portion thereof, and a connector 1b for electrically connecting with the external connectors provided at the other end portion thereof.
As shown in FIG. 11, the terminal 1 is inserted to an insertion channel 2c with a T-shaped cross section formed in a perimeter wall 2b of a bulb insertion opening 2a of the socket 2. The tip of the connecting element 1a protruding to the inside from the insertion channel 2c contacts the negative terminal face of the bulb base 3a inserted to the bulb insertion opening 2a.
The connector 1b of the terminal 1 protrudes into the connector insertion opening 2g from the insertion hole formed in the bottom wall 2f of the bulb insertion opening 2a, and contacts the external connector (not shown).
A positive terminal 4 formed by bending a single metal piece is inserted to a positive terminal insertion channel 2d, which is formed diagonally to the negative terminal insertion channel 2c of the socket 2. A bulb-side connector 4a contacts the positive terminal of the bulb bottom 3d, and the other connector 4d protruding from the bottom wall 2f connects with the external connector.
A bulb 3 depicted by an imaginary line is secured in the socket 2 by inserting from the top a pair of pins 3b, which protrude at the outside circumference of the bulb base 3a, into J-shaped pin insertion channels 2h formed in the bulb insertion opening perimeter wall 2b, and then turning the bulb 3 after insertion to secure the bulb 3 in the socket 2.
As best shown in FIG. 9, the bulb-side connecting element 1a of this conventional negative terminal 1 is stamped out at the center near the end of the thin metal band lc to project at a specified angle θp and extends by a predetermined length Lc from the base 1d of the stamping and to flexibly contact the bulb base 3a with the contact 1e on the end of the projection.
When the negative terminal 1 shaped as described above is inserted to the socket 2 and contacts the bulb 3, the stamped base 1d of the connecting element 1a is positioned at the open end of the bulb insertion opening 2a approximately opposite the bulb base 3a, as best shown in FIG. 11.
When the bulb 3 is continuously turned on, the base 1d becomes hot because of the heat generated by the bulb 3. In particular, for example when a high output bulbs or double bulb are used for the bulb 3, the temperature at the base 1d sometimes reaches approximately 180° C.
When the base 1d of connecting element 1a gets hot, the spring characteristics thereof deteriorate so that the contact pressure of the contact 1e drops, and the contact resistance at the circumference of the bulb base 3a increases. This causes the already high temperature to rise further, resulting eventually in non-conductivity.
The deterioration of the spring characteristics of the base 1d will be described with reference to FIGS. 12A, 12B, and 12C. Since the connecting element 1a initially has sufficient spring, the connecting element 1a extrudes from the terminal 1 by a predetermined length To and positioned thereat, an original position inside the bulb insertion opening, as indicated by the imaginary line in FIG. 12A. When the bulb 3 is inserted in the bulb socket 2, the connecting element 1a is pressed by the bulb base 3 so that the connecting element 1a is moved from the original position to a contacting position at which the connecting 1a is resiliently contacted with the bulb base 3, as indicated by a solid line.
However, as the spring characteristics of the base 1d deteriorates, the connecting element 1a will eventually not return to the original position and stops at a deteriorated position below the terminal 1 by a length Td, as indicated by a imaginary line in FIG. 12B, even when the bulb 3 is removed from the socket 2. In this case, when other bulb 3 with a smaller base diameter is inserted into the socket 2, a gap Tg occurs between the outside circumference of the bulb base 3a and the contact 1e, as shown in FIG. 12C. Thus, the connecting element 1a can not contact with the bulb base 3a, resulting in the lack of conductivity between the terminal 1 and the bulb 3.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to provide a terminal which solves these problems.
The present invention has been developed with a view to substantially solving the above described disadvantages and has for its essential object to provide an improved terminal.
In order to achieve the aforementioned objective, a terminal formed by a single metal piece for use in a bulb socket having a bulb insertion opening for accommodating a bulb, wherein said terminal makes an electric connection with a base electrode formed on outer perimeter of said bulb upon insertion of said bulb, said terminal comprises a flat plate portion; and a contact portion raised from said flat plate portion for contacting said base electrode, said contact portion integrally connected to said flat plate portion through a base portion, said base portion being located remote from said base electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings throughout which like parts are designated by like reference numerals, and in which:
FIG. 1 is a cross-sectional view showing a bulb socket comprising a terminal according to a first embodiment of the present invention the invention,
FIG. 2 is an enlarged side view showing the terminal of FIG. 1,
FIG. 3 is a plan view showing the terminal, viewed from the bottom side thereof, of FIG. 2,
FIG. 4 is a fragmentary cross-sectional view showing a portion of the terminal taken along a line IV--IV in FIG. 3,
FIG. 5 is a cross-sectional view showing a terminal according to a second embodiment of the present invention, a side view of a negative terminal according to the second embodiment of the invention,
FIG. 6A is a plan view showing the terminal, viewed from the bottom side thereof, of FIG. 5,
FIG. 6B is a plan view showing the terminal at a partially developed state, of FIG. 6A,
FIG. 7 is a front view showing the terminal, viewed from the left side, of FIG. 5,
FIG. 8 is a fragmentary cross-sectional view showing a portion of the terminal taken along a line VIII--VIII in FIG. 6A,
FIG. 9 is a side view showing a conventional terminal for use in a bulb socket,
FIG. 10 is a plan view showing the terminal, viewed from the bottom side thereof, of FIG. 9,
FIG. 11 is a cross-sectional view showing a bulb socket comprising the conventional terminal of FIG. 9, and
FIGS. 12A, 12B, and 12C are fragmentary side views in assistance of explaining the deterioration state of the conventional terminal of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 2, 3, and 4, a negative terminal used for the connection with a negative electrode of a bulb according to a first embodiment of the present invention is shown. The terminal 10 is formed in an elongated shape by bending a single metal piece. The terminal 10 includes a flat member 10b formed in an elongated thin band-shape extending in a direction, and a vertical support 10s formed at one end of the flat member 10b and extending perpendicularly therefrom. The terminal 10 further includes a connector member 10g formed at one end of the vertical support 10s opposed to the flat member 10b. The connector member 10g extends therefrom in such a direction that the connector member 10g is apart from the flat member 10a. Thus, the flat member 10b and connector member 10g are connected by the vertical support 10s. A stopper 10z is stamped out from the vertical support 10s to open to the direction opposed to the connector member 10g.
The flat member 10b has a contact element 10a cut in the middle portion thereof generally in a U-shaped configuration so that a base portion 10d by which the contact element 10a is integrally connected with the flat member 10b is formed on the side contiguous to the vertical support 10z. The contact element 10a is further stamped in generally a V-shaped configuration when viewed from the side, as best shown in FIG. 4, such that a stamped end 10e is positioned at the end portion of the flat member 10b. The contact member 10a projects at a specified angle 8 downward (toward the vertical support side) from the stamped base 10d and is bent upward (toward the flat member 10b) at a position distant from the base 10g by a predetermined length Ld. Thus, a contact portion 10c is formed at the valley portion of thus bent member 10a. Preferably, the tip of stamped end 10e is bent down to extend parallel to the flat member 10b. Since the contact element 10a is elastically stamped out, the base portion 10d provides spring effect to the contacting element 10a so that the contacting element 10 can swing elastically with respect to the base portion 10d against the external force.
Each of longitudinal sides of the flat member 10b is bent inside to provide a side rim 10h extending on both sides thereof.
Referring to FIG. 1, the terminal 10 used in a bulb socket 2 is shown. The terminal 10 is inserted to an insertion channel 2c with a T-shaped cross section formed in a perimeter wall 2b of a bulb insertion opening 2a of the socket 2. The tip 10c of the connecting element 10a protrudes to the inside from the insertion channel 2c and contacts the terminal face of a bulb base 3a. The base portion 10d is positioned at the bottom wall 2f side of the bulb insertion opening 2a, and the stamped end 10e is positioned at the open end side. And the stopper 10z is engaged with the socket 2 to prevent the terminal 10 from being removed. Then, the bulb 3 depicted by an imaginary line is inserted to the bulb insertion opening 2a from the bulb base 3a, the stamped base portion 10d is positioned at the open end of the bulb insertion opening 2a away from the bulb base 3a.
The connector member 10g of the terminal 10 protrudes into the connector insertion opening 2g from the insertion hole formed in the bottom wall 2f of the bulb insertion opening 2a, and contacts the external connectors (not shown) coming from the outside of the socket 2.
A positive terminal 4 used for the connection with a positive electrode of the bulb 3 is formed by bending a single metal piece, and is inserted to a positive terminal insertion channel 2d, which is formed diagonally to the negative terminal insertion channel 2c of the socket 2. A bulb-side connector 4a contacts the positive terminal of the bulb bottom 3d, and the other connector 4d protruding from the bottom wall 2f connects with the external connector.
The bulb 3 is secured in the socket 2 by inserting from the top a pair of pins 3b, which protrude at the outside circumference of the bulb base 3a, into J-shaped pin insertion channels 2h formed in the bulb insertion opening perimeter wall 2b, and then turning the bulb 3 after insertion to secure the bulb 3 in the socket 2.
In the first embodiment thus comprised, it is difficult for the base 10d to reach a high temperature, making it difficult for the spring characteristics to deteriorate, because the base 10d of the contact element 10a is separated away from the bulb base 3a of the heat-emitting bulb 3. Furthermore, the base 10d is positioned at a side contiguous to the connector member 10g through the vertical support member 10s. Since these members 10g and 10s are located in positions remote from the bulb base 3a, and are connected with heat/electrical conductive materials such as connectors and wires having lower temperature and greater heat capacity, the heat transmitted to the base 10d is scattered outside through these members. Thus, the base 10d can be kept within the temperature range in which the spring characteristics thereof will not deteriorates. Based on tests, the temperature at the base 10d is less than approximately 150° C., meaning that the improved cooling ability of more than 30° C. is obtained by the terminal 10 according to the present invention when compared with the conventional terminals.
Contact reliability of the negative terminal 10 is thus improved without inducing a drop in the contact pressure of the contact portion 10c because deterioration of the spring characteristics of the contact element 10a is difficult according to the present invention.
It is to be noted that the stamped end 10e of the contact element 10a is positioned at the insertion side of the bulb base 3a, but insertion of the bulb base 3a can be done smoothly because the stamped end 10e is folded back opposite to the stamped direction.
In the first embodiment, the length Ld between the base 10d and the contact 10c can be set longer than the conventional length Lc (see FIG. 9), and the lift angle θ of the base 10d can be less than the lift angle θp of the conventional terminal (FIG. 9) because the base 10d of the contact element 10a is provided on the side of the bottom wall 2f of the bulb insertion opening 2a in the socket 2. As a result, the stress acting on the base 10d is reduced, there is no concentration of excessive stress, and deterioration of the spring characteristics is inhibited. In the first embodiment, the contact reliability of the negative terminal 10 can also be improved because of this.
Referring to FIGS. 5, 6A, 6B, 7, and 8, a terminal according to a second embodiment of the present invention is shown. The terminal 10' has the construction similar to that of the terminal 10 according to the first embodiment, as shown in FIGS. 5 and 6A.
In FIG. 6B, a developed state of a flat member 10b ' of the terminal 10' before bending is shown. The negative terminal 10' has a first side members 10j' on the one of elongated sides, and a second side member 10k' on the other elongated side. The first side member 10j' is folded inside in the arrow direction D1 with respect to a first side line L1 indicated by a dot line to overlap with the center portion 10m' of the flat member 10b'. Also, the second side member 10k' is folded inside in the arrow direction D2 with respect to a second side line L2 indicated by a dot line. Thus, the terminal 10' can be completed, as shown in FIG. 6A.
In this terminal 10', the contact element 10a' is formed at the outside edge of the first side members 10j'. The contact element 10a' is positioned at the midpoint of the center portion 10m', and an inside edge 10n' of the first side member 10j' is doubled along the first side line L1, forming a first side edge of the center portion 10m'.
The second side member 10k' is folded double along the second side line L2, forming a second side edge of the center portion 10m'. As a result, both outside edge members of the center portion 10m' are completely doubled.
At the center of the center portion 10m' overlapping the contact element 10a', a small clearance hole 10i' for passing the stamped end 10e' when the contact element 10a ' is in contact with the bulb base 3 is formed at a position opposing to the stamped end 10e'. The remainder other than the clearance hole 10i' reinforces the other parts of the contact element 10a', specifically backing the base 10d' of the contact 10c'.
In this second embodiment, both sides of the flat member 10b' on which the contact element 10a' is provided are completely doubled, the center portion 10m' is positioned behind the projecting part of the contact element 10a', and the open space from forming the contact element 10a' is reduced, making it possible to improve the strength.
In addition, because it is sufficient to provide the clearance hole 10i' formed in the center portion 10m' to oppose to the stamped end 10e', the clearance hole 10' can be made small. The overall area of the flat member 10b' can thus be increased, increasing the heat dissipation area much, and improving the heat dissipation characteristics because the area of the center portion 10m' can be increased and both side members 10j' and 10k' are folded back.
Furthermore, since the terminal 10' has the contact element 10a' which is additionally provided thereto, as shown in FIGS. 6A and 6B, the terminal 10' has the heat capacity greater than that of the terminal 10 according to the first embodiment. Therefore, it is more difficult to elevate the temperature of the base 10d' of the terminal 10' when compared with the terminal 10.
As will be obvious from the above description, the bases 10d and 10d' do not easily reach a high temperature because the base 10d and 10d' are provided on the bottom wall side, remote from the bulb base 3a, of the insertion end of the bulb insertion opening of the bulb socket 2. Good spring characteristics can thus be maintained, and contact reliability can be improved, because the bases 10d and 10d' are not exposed to high temperatures and deterioration of the spring characteristics can be prevented.
Furthermore, since the bases 10d and 10d' are located on a side contiguous to the connector element 10g which will be connected with heat/electrical conductive materials such as connectors and wires having lower temperature and greater heat capacity, the bases 10d and 10d' can be kept in a lower temperature range in which the deterioration of spring characteristics thereof can be prevented.
In addition, stress acting on the contact elements 10a and 10a' are low, excessive stress is not concentrated on the bases 10d and 10d', deterioration of the spring characteristics is prevented, and contact reliability can also be improved accordingly because the length Ld between the base portion 10d (10d') and the contact 10c (10c') can be long, and the lift angle θ of the base can be low.
In addition, strength is improved, the heat dissipation area is increased, and heat dissipation characteristics can be improved because the flat member is reinforced by the folded side members and the hole for stamping is eliminated in the flat member when both sides of the flat member of the negative terminal are folded in two and the connector is provided at one of the folded sides.
Although the present invention has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
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A terminal formed by bending from a single metal piece for use in a bulb socket having a bulb insertion opening for accommodating a bulb, where the terminal is used for connecting with a base electrode formed in the outer perimeter of the bulb includes a contact element. The contact element is formed by stamping the metal piece to have a contact portion and a spring portion for resiliently hold the contact portion in contact with the base electrode. The spring portion is located on a position away from the base electrode when the bulb is inserted in the bulb insertion opening. Therefore, the spring porion of the contact element is kept from deterioration of spring characteristics caused by the heat from the bulb.
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BACKGROUND OF THE INVENTION
This invention relates generally to hydraulic shock absorbers and more particularly to hydraulic shock absorbers that dissipate the kinetic energy of an automotive suspension system.
Conventional hydraulic shock absorbers work in a damping range which is a compromise between suspension control and ride comfort. In the past this compromise has been addressed by adjusting damping levels in various ways.
For example, in a known semi-active suspension system, the hydraulic shock absorber has a by-pass channel between the upper or rebound chamber of the pressure tube and the reservoir of the shock absorber that is controlled by a solenoid valve that is computer actuated in response to suspension conditions to provide two discrete damping levels. When open the solenoid valve allows hydraulic fluid escaping the rebound chamber to bypass the piston valve assembly so that the shock absorber provides a low damping force or soft mode of operation. However, when the solenoid valve is closed, the escaping hydraulic fluid cannot bypass the piston valve assembly so that the shock absorber provides a high damping force or firm mode of operation in the rebound direction. See for instance, the shock absorber that is shown and described in connection with FIGS. 41-43 of U.S. Pat. No. 4,650,042 granted to Heinz Knecht et al Mar. 17, 1987 for an adjustable hydraulic shock absorber.
Adjustable hydraulic shock absorbers, such as those exemplified by the Knecht et al patent, provide satisfactory operation under many conditions. However, certain events, such as a vehicle driving off a curb or squared edge, are too fast for these computer controlled shock absorbers to sense and react to in time to dissipate the excessive suspension energy.
SUMMARY OF THE INVENTION
The object of this invention is to provide an adjustable hydraulic shock absorber for a semi-active suspension system that changes to the firm mode of operation even under very rapid changes in suspension conditions such as a vehicle driving off a curb or squared edge.
Briefly, the adjustable hydraulic shock absorber of this invention accommodates abrupt or rapid changes in suspension conditions by incorporating an override mechanism that reacts mechanically to those events that occur too fast for the semi-active suspension system noted above to sense and actuate a solenoid valve in time to dissipate excessive suspension energy effectively.
A feature of the invention is that the adjustable hydraulic shock absorber of this invention is equipped with a mechanical override in the form of a valve that closes off the bypass channel in response to a predetermined position of the shock absorber piston so that the shock absorber changes to a firm mode of operation regardless of the speed of the suspension events requiring the mode change in the shock absorber.
Another feature of the invention is that the adjustable hydraulic shock absorber of the invention is equipped with a mechanical override in the form of a slide valve that moves with the shock absorber piston to close off the by-pass channel in response to a predetermined position of the shock absorber piston so that the shock absorber changes to a firm mode of operation even if the solenoid valve cannot close quickly enough in response to those events that require a firm mode of operation.
Yet another feature of the invention is that the adjustable hydraulic shock absorber of the invention is equipped with a mechanical override that is easily tuned to provide a precisely timed response to conditions that require a high level of damping.
Yet another feature of the invention is that the adjustable hydraulic shock absorber of the invention is equipped with a mechanical override that is very versatile in providing the necessary response to conditions that require a high level of damping.
Still yet another feature of the invention is that the adjustable hydraulic shock absorber of the invention is equipped with a mechanical override that accommodates bending of a long narrow construction such as might be found in an hydraulic strut.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings wherein like references refer to like parts and wherein:
FIG. 1 is a longitudinal sectional view of an adjustable hydraulic shock absorber of the invention;
FIG. 2 is an enlargement of a portion of FIG. 1; and
FIG. 3 is a section taken substantially along the line 3--3 of FIG. 1 looking in the direction of the arrows.
DESCRIPTION OF THE INVENTION
Referring now to the drawing, a vehicle suspension strut includes an adjustable hydraulic shock absorber of the invention that is indicated generally at 10. The shock absorber 10 has an outer tube or housing 12 that is closed at its lower end by an end plate 14. A mounting bracket (not shown) is welded onto the housing 12 near its lower end for fastening the shock absorber to the unsprung mass of a vehicle in well known manner. The upper end of the housing 12 is closed by an annular seal plate assembly 18.
A pressure tube 20 is concentrically arranged within the housing 12 to define a reservoir 21 between the pressure tube 20 and the housing 12. The pressure tube 20 is closed at its lower end by a valve plate assembly 22 that has inner and outer ports 24 and 26. The inner ports 24 are closed by a firm lower spring disk 28 while the outer ports 26 are closed by a lighter upper spring disk 30. The spring disks 28 and 30 are retained by a rivet-like fastener that rests on the lower end plate 14 and spaces the valve plate assembly 22 from the lower end plate. The valve plate assembly 22 operates in a well known manner to transfer hydraulic fluid back and forth between the pressure tube 20 and the reservoir 21 during operation of the hydraulic shock absorber 10.
The upper end of the pressure tube 20 is mounted on a rod guide 32 that is seated in the housing 12 below the seal plate 18. A piston 34 reciprocates within the pressure tube 20 which is filled with hydraulic fluid and divides the pressure tube 20 into an upper rebound chamber 36 and a lower compression chamber 38. The piston 34 is attached to the end of a rod 40 that extends through the rod guide 32 and the seal plate assembly 18. The upper end of the rod 40 has a fitting (not shown) for attaching the shock absorber 10 to the sprung mass of the vehicle in well known manner.
The piston 34 has inner and outer ports 44 and 46 that form piston valves that operate in well know manner to transfer hydraulic fluid back and forth between the rebound chamber 36 and the compression chamber 38 during operation. Briefly, the inner ports 44 are closed by a lower washer 48 that is held against the lower face of the piston 34 by a strong coil spring 50 to provide a firm piston valve that provides a firm mode of operation in the rebound direction as further explained below. The outer ports 46 are closed by a lighter spring disk 52.
The shock absorber 10 includes an intermediate tube 54 that is mounted on the medial portion of the pressure tube 20. The intermediate tube 54 is sealed at the upper and lower ends to form a bypass channel 56 that communicates with the interior of the pressure tube 20 via a plurality of circumferentially spaced bleed holes 58 that extend through the pressure tube 20 at the upper end of the intermediate tube 54. The bleed holes 58 are sized and located as explained below. The intermediate tube 54 has an outlet 60 for the bypass channel 56 that communicates with the reservoir 21. The outlet 60 is opened and closed by a solenoid valve assembly 62 as best shown in FIGS. 1 and 3.
Focusing on FIG. 1, the bleed holes 58 at the inlet of the by-pass channel 56 are open and closed by a slide valve 64 in the form of a cup that is disposed in the rebound chamber 36 and attached to the piston rod 40 ahead of the piston 34. The bottom of the cup has ports so that slide valve 64 does not obstruct the flow of hydraulic fluid into or out of the rebound chamber 36 via the piston valves.
The shock absorber 10 also includes a coil spring 66 that surrounds the piston rod 40 in the pressure tube 20. The lower end of the coil spring 66 engages a stop attached to the piston rod 40 above the slide valve 60 and the upper end of the coil spring 66 engages the rod guide 32.
The solenoid valve 62 is actuated by an electronic control 68 that receives input signals from vehicle components that can be used to determine the suspension motion of the vehicle wheel relative to the vehicle body. The control 68 operates on these signals according to a programmable computer within the control 68 and generates a command that is transmitted to coil 70 via conductor 72 to open or close the solenoid valve 62 in response to various suspension conditions.
The solenoid valve 62 is a well known type comprising a valve body 74 that is inserted into the outlet 60 and a moveable valve disk 76 that is biased against a valve seat 78 of the valve body 74 by a compression coil spring 80. The solenoid valve 62 further comprises a valve cap 82, an armature 84 and an armature spring 86 that bias the armature 84 and valve cap 82 against valve disk 76.
The valve cap 82 and armature 84 are hydraulically balanced via a plurality of throttle bores 88 in the valve disk 76 that communicate with a control chamber 90 above the valve disk 76 that in turn communicates with a space 92 above the armature 84 via concentric bores 94 and 96 of the valve cap 82 and armature 84.
When the coil 70 is deenergized as shown in FIG. 3, the flow of hydraulic fluid out of the by-pass outlet 60 is substantially blocked off by the valve cap 82. However, a small portion of the hydraulic fluid does flow through the throttle bores 88 into the control chamber 90 to equalize the pressure on the valve cap 82 and thence into the space 92 via the concentric bores 94 and 96 to equalize the pressure on the armature 84. Consequently, the valve disk 76, the valve cap 82 and the armature 84 are firmly held in their respective seated positions shown in FIG. 3 by the compression coil spring 80 and the armature spring 86 regardless of the pressure of the hydraulic fluid in the bypass channel 56 and outlet 60.
When the coil 70 is energized, the armature 84 is retracted against the action of the armature spring 86 and the valve cap 82 is moved away from the valve disk 76 by the hydraulic pressure in the control chamber 90. The hydraulic fluid in the control chamber 90 then flows out of the control chamber 90 between the valve cap 82 and the valve disk 76 and into the reservoir 21 via the respective outer outlet passages 98 and 100 of the valve disk 76 and the valve body 74. This collapses the pressure of the hydraulic fluid in the control chamber 90 so that the valve disk 76 is moved away from the valve seat 78 to the open position by the hydraulic pressure in the bypass channel 56 and outlet 60. This allows hydraulic fluid in the rebound chamber 36 to flow to the reservoir 21 via bleed holes 58, by-pass channel 56, outlet 60, and outlet passages 100.
During normal operation, the solenoid valve 62 adjusts the operation of the hydraulic shock absorber 10 by shifting the damping level back and forth between a low damping level or soft mode of operation and a high damping level or firm mode of operation. More particularly the solenoid 70 is energized to retract the armature 84 which opens the solenoid valve 62 and provides a low damping level or soft mode of operation. With the solenoid valve 62 open, the hydraulic fluid that is displaced from the rebound chamber 36 as the piston 34 moves upwardly in pressure tube 20 during rebound flows through the bleed holes 58 into the bypass channel 56 and thence out the outlet 60 and into the reservoir 21 via the open solenoid valve 62. The bleed holes 58 are sized to provide a soft damping effect as the piston 34 rebounds and the displaced hydraulic fluid from the rebound chamber 36 flows through the by-pass channel 56 by virtue of the open solenoid valve 62. However when suspension conditions that are sensed by the electronic control 68 require firm or high level rebound damping, the solenoid 70 is deenergized and the solenoid valve 62 is closed by the compression coil spring 80 and the armature spring 86. When the solenoid valve 62 is closed, the hydraulic fluid in the rebound chamber 36 cannot flow through the bypass channel 56 as the piston 34 rises in the pressure tube 20. Consequently hydraulic pressure builds in the rebound chamber 36 until the force is sufficient to open the piston valve against the action of the coil spring 50. This provides a high damping level or firm mode of operation in the rebound direction.
During normal operation the piston 34 reciprocates between a low position shown in phantom at L in FIG. 1 and an upper position shown in phantom at U in FIG. 1. The bleed holes 58 are specifically positioned so that the bleed holes 58 are not blocked by slide valve 64 under normal operating conditions, that is, those conditions that the electronic control 68 and solenoid valve 62 can sense and react to in a timely fashion. Thus under normal operating conditions the damping level of the adjustable hydraulic shock absorber 10 is controlled solely by the solenoid valve 62 and the electronic control 68.
However, as indicated above, the electronic control 68 and solenoid valve 62 do not sense and react quickly enough to some suspension conditions that require the high damping level and firm mode of operation in the rebound direction such as a vehicle driving off a curb. In such circumstances, the slide valve 64 overrides the electronic control 68 and solenoid valve 62 by closing the bleed holes 58 when the piston 34 reaches a predetermined position such as the fully extended position shown in solid line in FIG. 1 which is above the extension of the shock absorber 10 during normal operation. This piston position changes the shock absorber 10 from the soft mode of operation to the firm mode of operation mechanically. Thus under extraordinary conditions, the damping level of the hydraulic shock absorber 10 is controlled by the piston 34 and slide valve 64 independently of the solenoid valve 62.
The point at which the bleed holes 58 are blocked to provide the mechanical override is preferably selected so as to avoid metal-to-metal contact at the top of the piston stroke such as would occur when the rebound coil spring 66 bottoms out. This override point can be adjusted and fine tuned by the selecting the length of the slide valve 64 and/or the placement of the bleed holes 58. Moreover the use of a separate slide valve 64 makes it possible to activate the mechanical override at different piston positions simply by changing the length of the slide valve 64. Thus the override characteristics are altered easily to meet the requirements of various suspension applications.
Another feature of the slide valve 64 is that it is sized so that there is a gap 76 between the outer surface of the slide valve 64 and the bore of the pressure tube 20. This gap 76 accommodates a slight bending of the shock absorber 10 during use which is particularly advantageous in a long narrow construction such as a hydraulic strut.
Still another feature of the slide valve override arrangement is that the transition between the low level damping of the open bleed holes 58 and the high level damping of the blocked bleed holes 58 can be altered in several ways. These include adjusting the size of gap 70 and/or the bleed holes 58 and using a series of bleed holes of the same or different sizes along the pressure tube 20 that are closed sequentially as the piston 34 rebounds. Thus the slide valve arrangement of the invention is also very versatile.
The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.
Obviously, many modifications and variations of the present invention in light of the above teachings may be made. 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 hydraulic shock absorber having discrete damping levels in the rebound direction includes a piston that reciprocates within a pressure tube and divides the pressure tube into rebound and pressure chambers. A passage extends through the piston for establishing fluid communication between the rebound and pressure chambers. A one-way, pressure responsive valve normally closing the passage opens in response to fluid pressure of a predetermined magnitude in the rebound chamber when the piston moves in the rebound direction. The side wall of the pressure tube has bleed holes that lead to a bypass channel that is controlled by an electronically controlled or actuated solenoid valve that opens and closes the outlet of the bypass channel to change the damping characteristics in the rebound and jounce directions in response to suspension conditions. The piston carries a slide valve that closes the bleed holes to the bypass channel mechanically in the rebound direction in response to rapid changes in suspension conditions that the solenoid valve cannot react to quick enough.
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FIELD OF THE INVENTION
The present invention relates generally to position controllers for rotational adjustments and more specifically to position controllers for making adjustments to an ink form roll in a printing press.
RELATED TECHNOLOGY
As shown in FIG. 1 and discussed later, a prior art printing press has an adjustment mechanism for an adjustable cam for making ink form roll adjustments. A hexagonal (hex) adjusting rod with an hexagonal cross section at one end and a gear at another end can be used to adjust the position of the cam. When the hex adjusting rod is rotated, the gear rotates a shaft, on which an adjustable part is mounted. Due to an internal threading of the cam and the fact that the cam cannot rotate, the rotation of the shaft causes a translation of the cam. A compression spring provides resistance to the movement of cam, so that the various components of the adjustment mechanism are not free to move without a sufficient torque at the hex adjusting rod. Thus the hex adjusting rod can be used to adjust an adjustable part in a printing press.
However, the compression spring located at the cam has been known to malfunction or deteriorate over time, and also not to provide a sufficient resistance while still permitting adjustment of the hex adjusting rod.
SUMMARY OF THE INVENTION
The present invention provides a position controller comprising an adjusting rod having a first end with at least three flat sides and a second end, an adjustable part connected to the second end and adjustable through rotation of the adjusting rod, and a first set and a second set of leaf springs, the first set interacting with a first of the at least three flat sides and the second set interacting with a second of the at least three flat sides.
A resistance torque is thus provided to the various components of the position controller through the leaf spring sets.
Advantageously, the first end of the adjusting rod has six flat sides, i.e. is hexagonally shaped. The first set of leaf springs interacts with the first of the hexagonal sides and advantageously the second set can act on the second of the hexagonal sides, the second side being directly opposite the first side. It is also advantageous in this arrangement that the first set of leaf springs be parallel to the second set.
Each set of leaf springs may comprise one or advantageously a plurality of leaf springs. The holding torque provided by the leaf springs on the adjusting rod can be easily varied by adjusting the properties, number and/or thickness of the leaf springs. While the holding torque can vary, a holding torque of 10 to 15 in-lb may be advantageous for a typical ink form roller socket in a printing press.
The present invention advantageously also provides an equal torque resistance for both clockwise and counterclockwise motions of the adjusting rod. The holding force provided by the sets of leaf springs operates over a large surface area, which minimizes surface wear. No special settings are required. Friction such as found in a threaded relationship is not used to provide resistance, so that stripping of threads is not a problem. The present invention permits a compact design, and also permits the adjusting rod to move axially or "float" in a third direction while still providing torque resistance in the other two directions.
A cover may be provided over the leaf springs to prevent or reduce contamination. The cover may either cover the first end or permit the first end to protrude through a hole.
The present invention advantageously is used for adjustment of rolls in a printing press, including for adjustment of the position of an ink form roll. Thus the adjustable part advantageously may be a cam for adjusting an ink form roll.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the present invention may be better understood based on the following figures, in which:
FIG. 1 shows a prior art position controller for a printing press part;
FIG. 2 shows a first embodiment of the position controller of the present invention;
FIG. 3 shows a second embodiment of the position controller of the present invention;
FIG. 4 shows a third embodiment of the position controller of the present invention;
FIG. 5 shows a side view of the third embodiment; and
FIGS. 6A, 6B, and 6C show the third embodiment at different stages.
DETAILED DESCRIPTION
FIG. 1 shows a prior art position controller 10 for use in a printing press 1. The controller 10 includes an hexagonal (hex) adjusting rod 12 with an hexagonal cross section at one end 14 and a gear 16 at another end 18 can be used to adjust the position of an adjustable part 20 in the printing press 1. The adjustable part 20 may be for example a cam for adjusting an ink form roll.
The adjustable part 20 has internal threads and is threadedly connected on a shaft 22 supported by arms 21, one end of the shaft forming a gear 26. The gear 26 interacts with a housing section 30 of the printing press to prevent rotation of the adjustable part but to permit translation along the shaft 22 direction. The housing section 30 also rotatably supports the shaft 22 through the arms 21.
When the hex adjusting rod 12 is rotated, the gear 16 rotates the gear 26 to rotate the shaft 22, on which the adjustable part 20 is threadedly mounted. Due to the internal threading of the part 20 and the fact the part 20 cannot rotate, the rotation of the shaft causes a translation of the part 20 along the axis of the shaft 22. A compression spring 24 provides resistance to the movement of part 22, so that, the various components of the adjustment mechanism are not free to move without a sufficient torque at the hex adjusting rod 12.
FIG. 2 shows a position controller 40 according to one embodiment of the present invention having a hex adjusting rod 42, a first leaf spring set 46 and a second leaf spring set 48. The hex adjustment rod has a first end 43 with six flat sides, including a first side 44 and second opposing side 45. As shown, the first leaf spring set 46 interacts with the first flat side and the second leaf spring set 48 interacts with the second flat side 45. (Although these sides change as the rod 42 rotates).
Each leaf spring set 46, 48 has a plurality of leaf springs, as shown, each of which has a certain thickness and is a flat thin, advantageously metal and rectangular, sheet with a defined spring resistance or constant. Each flat thin sheet has a hole (not shown) at one end through which a fastener may be fitted for holding the leaf spring in place. The first leaf spring set 46 has a fastener 47, such as a screw or nut and bolt combination. The second leaf spring set 48 likewise has a fastener 49. With the fasteners of the present invention it is possible to quickly and easily adjust the spring constant of the entire leaf spring sets 46 and 48 by adding or removing individual leaf springs. The fasteners 47, 49 may connect the leaf spring sets to a housing 3.
In this embodiment, the leaf spring set 46 and 48 are advantageously parallel to one another, although located on opposite sides of the hex adjusting rod 42.
As would be understood to one of skill in the art, the leaf springs interact with the hex adjusting rod 42 to provide a resistance to turning of the rod. The position controller 40 of the present invention thus prevents unwanted turning of the rod 42 or other interconnected parts.
It should be noted that the leaf spring sets 46 and 48 are located axially away from the very end of the hex adjusting rod 42, as with the embodiment shown in FIG. 5.
As will be understood by one in the art, the position controller 40, as well as those position controllers shown in FIGS. 3 and 4, can be used in conjunction with the prior art device shown in FIG. 1, or advantageously can be used with a device designed so that the spring 24 shown in FIG. 1 may be eliminated.
FIG. 3 shows a position controller 50 according to another embodiment of the present invention in which a first leaf spring set includes a single leaf spring 56 and a spring plunger 57 for forcing the leaf spring 56 against a flat face of hex adjusting rod 52. Likewise, a second leaf spring set includes a single leaf spring 58 and a spring plunger 59 for forcing the leaf spring 58 against an opposing flat face of hex adjusting rod 52.
FIG. 4 shows a position controller 60 according to yet another embodiment of the present invention in which a first leaf spring set 66 interacts with a flat face of a hex adjusting rod 62 and a second leaf spring set 68 interacts with an opposing flat face to restrict free movement of the hex adjusting rod 62 and connected parts of the position controller 60. The leaf spring sets 66 and 68 are parallel to one another and are fastened by a common fastener 64 located on a mounting bracket 65.
FIG. 5 shows a partial side view of the embodiment of FIG. 4, from which it is clear that the leaf spring sets 66 and 68 are set away axially from a tip 61 of the adjusting rod 62 by a distance D. Retaining rings 70 and 71 on either axial side of the leaf spring sets 66 and 68 can be provided to prevent rotation of the leaf springs about the fastener 64. It will be understood by one in the art that a second end 78 may have a gear for interacting with an adjustable part as shown in FIG. 1. A cover 80 may partially or fully cover the leaf spring sets 66 and 68 to provide protection and may be attached to the housing section.
FIGS. 6A, 6B and 6C show the different deflection positions of the leaf spring sets 66 and 68 of the embodiment of FIG. 4 as the adjusting rod 62 is rotated. FIG. 6A shows a rest position of the rod 62. FIG. 6B shows an intermediate deflection position, as might occur at the beginning of a rotation and FIG. 6C shows a maximum deflection position of the leaf spring sets 66 and 68, before the adjusting rod 62 reaches a new rest position as it is turned further in the same direction. The resistance torque from the leaf spring sets may be varied easily by the amount, thickness or type of leaf springs used, although advantageously the same number of springs are used for each leaf spring set.
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A position controller comprising an adjusting rod having a first end having at least three flat sides and a second end and an adjustable part interacting with the second end and adjustable through rotation of the adjusting rod. A leaf spring set interacts with a first of the at least three flat sides to prevent unwanted movement within the position controller. A particular application is found in making printing press adjustments.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to recording of seismic data by individual recording units located remotely from a central station.
2. Description of the Prior Art
During the course of seismic exploration, a plurality of seismic transducers or transducer groups are emplaced at desired intervals along a line of survey. The respective transducers are coupled to corresponding input channels of a multichannel recording system in a central station. The input channels include filters and signal-conditioning amplifiers. Signals from the transducers are processed through the input amplifiers, digitized and multiplexed to a recording medium such as magnetic tape. The transducer signals may be transmitted over land lines through a multiconductor cable wherein each transducer and corresponding input channel are interconnected by a dedicated wire pair. In another arrangement, the seismic signals are transmitted via a single-channel telemetric system using time division multiplexing. The transducers are generally spaced 200-300 feet apart. Up to 100 transducers and input channels may be used. Thus, several miles of cable must be laid out if land lines are used.
A number of systems are known or have been proposed to eliminate the need for the many miles of interconnecting cable. These systems either transmit seismic signals from the respective transducers to the central station by radio or the seismic signals are processed and recorded locally at each individual transducer, operating under radio commands from the central station. In such systems, some of the data-processing electronics are removed from the central station and installed in remote modules, one of which is associated with each of the transducers or transducer groups. The remote module may include a recording device such as a cassette tape for recording seismic signals resulting from several seismic shots during a recording period.
Representative known radio-controlled remote seismic data recorders are disclosed in U.S. Pat. Nos.: 3,062,315 to Herzog; 3,075,607 to Aitken et al; 3,283,295 to Montgomery; 3,288,242 to Loeb; 3,806,864, 3,987,406, and 4,010,442 all to Broding; 3,886,494 to Kostelnichek; 3,946,357 to Weinstein; and 4,042,906 to Ezell.
In the above-listed systems, selected units are turned on after receipt from the central station of a coded radio command. The coding determines the selection of the remote modules to be activated. To synchronize the various recorders, one with the other, and to provide accurate timing during a recording cycle, timing pulses are also transmitted to the remote modules. In some of the systems above, the recorded seismic data may be played back via radio to a master recorder in the central station for permanent storage. In others of the above systems, at the end of a recording period such as at the end of a day's work, the cassette tapes are harvested from the various recording modules and are played back either at the central recorder or in a data processing center.
The problems with the known art employing remote radio-controlled units are manifold. Each individual recording module must be separately addressed by a suitable radio code. This requirement necessitates complex coding-decoding circuitry in both the central station and in each individual module. The individual identification numbers of the respective modules must be recorded in the header of each seismic recording. If the data recorded at each module are to be played back over a radio link, then each module must play its data back in sequence because there are not available enough separate radio-channel frequencies to play back 100 recordings in parallel. Other remote playback techniques such as time-division or frequency-division multiplexing over a limited number of channels add extra complexity to the system. Furthermore, in known systems it is essential to transmit separate timing signals for accurate time synchronization of the remote recording modules, one with the other and with the central station. Additionally, many radio-controlled systems use radio frequencies that are effective only along line-of-sight. Therefore they are often not effective in mountainous or obstructed terrain, the very environment in which remote individual recording units are most useful. And finally, the requirement for at least a radio receiver, if not also a data transmitter, plus an antenna at each remote recording unit adds substantial complexity and bulk to the units.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a decentralized seismic data recording system consisting of a central station and a plurality of remote recording units, each unit being associated with a single seismic transducer or transducer group. The units are independent of the central station during a working day in that they are not connected to the central station by either land lines or radio links. The units include a self-contained time counter and means for programming a plurality of recording cycles at desired intervals in synchronism with seismic shots fired by the central station although the units are incommunicado therewith.
In accordance with a preferred aspect of this invention, each hand-portable remote unit includes a resettable time counter. At the beginning of a recording period, such as a field working day, during which a plurality of recording cycles will be established, the local time counter in each remote unit is compared to the present value of the accumulated time count in a master clock time counter. The master clock may conveniently be located in the central station. At the end of the recording period, the local accumulated time count in each remote unit is again compared with the time count resident in the master clock time counter. The local accumulated time count as read from the respective remote-unit time counters and the accumulated time count of the master clock are separately recorded on special data files on the archival storage medium in each of the corresponding remote units. The difference in accumulated time between the local clock and the master clock may then be linearly pro-rated among all of the recorded data files for each of the remote units, thereby to synchronize them with the master clock and with each other.
In accordance with another aspect of this invention, the local time counter is reset to the present value of the accumulated time in the master time counter.
In an embodiment of this invention, the recording circuitry of the remote units, except for the time counter, remain inactive during most of the recording period. At selected intervals during a recording period, the time counter turns on the seismic signal detecting electronics in the remote units for the length of a desired recording cycle to record seismic signals.
In another embodiment of this invention the remote units are turned on for a predetermined time prior to the actual beginning of a proposed recording cycle to determine the average level of the ambient noise. At the end of a recording cycle, the average seismic signal level during the recording cycle is compared to the average ambient noise level. So long as the average seismic signal level during the recording cycle exceeds the ambient noise level by a predetermined amount, the recorded seismic signals are accepted as valid data and are transferred to an archival storage medium.
In yet another embodiment of this invention, the average ambient noise level is determined at the end of a recording cycle.
In accordance with an aspect of this invention, the prerecorded ambient noise signals and the recorded seismic signals are stored in a temporary storage prior to comparison. Following the comparison step, the seismic signals, if valid, are transferred to the archival storage medium. If the seismic signals are determined to be invalid, transfer is inhibited.
In accordance with another aspect of this invention, the archival storage medium of a recording unit is permanently locked therein until the accumulated time counts of both the remote unit and the master clock have been recorded as separate entries on the archival storage medium.
BRIEF DESCRIPTION OF THE DRAWINGS
The benefits and advantages of this invention will be better understood by reference to the detailed description and the accompanying drawings wherein:
FIG. 1 is a view of a typical field layout employing the teachings of this invention;
FIG. 2A shows a block circuit diagram of a remote recording unit;
FIG. 2B shows a block diagram of the circuitry in a central station;
FIG. 3 is a timing diagram of the sequence of system functions;
FIG. 4 is a graph of the relative tuning error between two oscillators; and
FIGS. 5 and 5b show means for inhibiting unloading of the archival storage medium from the remote module until the local and master time counts have been recorded.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a number of hand-portable remote recording units (RRU) 1, 2, . . . M are deployed on the ground 9 along a seismic line of survey. Coupled to each RRU are one or more seismic transducers 1 a , 2 a , . . . M a for detecting seismic signals. Within each RRU is circuitry for receiving and recording signals from the corresponding transducers. A crystal-controlled clock is installed inside each RRU. At selected intervals such as every five minutes during the course of a recording period which might comprise one working day, the RRUs are enabled to initiate a six- to eight-second listening and recording cycle. Seismic signals received during each recording cycle are monitored for validity and, if valid, are permanently recorded on an archival storage medium.
A central station 11 is provided. Central station 11 may be a vehicle 8 containing circuitry 10 including a master clock 12 and means 13 for triggering a seismic source. A common type of seismic source is an explosive charge 14 in a borehole 16 having an electrical detonator that is connected to trigger 13 by cable 18. Any other source such as a chirp signal generator, a gas gun, or an air gun could be used. At selected shot intervals during a recording period as determined by master clock 12, seismic source 14 is triggered. The seismic waves generated by the source travel along ray paths 20-22, 24-26 and, after reflection from a subsurface earth layer such as 28, are detected by the transducers such as 1 a through M a .
It is necessary to synchronize the shot intervals at central station 14 with the initiation of the listening cycles in the RRUs which during normal seismic recording operations are incommunicado with respect to central station 11. Before the RRUs are deployed at the beginning of a work period, each RRU is individually connected to the master clock at the central station. The time count in the local RRU clock is reset to the exact time count of the master clock. Thereafter the RRUs may be distributed along the line of survey. At the end of the work period, the RRUs are returned to the central station. Each RRU is individually connected in turn to the master clock. The master time count and the local time count are then separately recorded in the RRU under comparison. When the data previously recorded in an RRU are dumped for later processing, the recorded count difference between local and master clocks is linearly prorated over each listening or recording cycle, thereby exactly synchronizing the shot intervals with the listening-cycle intervals in the various RRUs.
FIG. 2A shows the circuitry included within a typical RRU such as unit 1. An external transducer 1 a feeds seismic signals to signal processor 30 through connecting plug 31. Other principal components in the RRU are temporary data-storage register 32, archival storage 34, clock 36, unload-inhibit solenoid 38, power supply 40 such as a battery and power distribution circuitry 42.
Signal processor 30 includes a preamplifier, filters, gain-conditioning amplifiers and an analog-to-digital converter. These components are quite conventional. The received analog signals are processed, sampled, and converted to a digital representation of the amplitude and polarity of the analog signals. Any convenient digital number system may be used such as binary magnitude plus sign, floating point, etc.
Temporary data-storage register 32 stores seismic signal samples received during a recording or data acquisition cycle. The received signal samples are stored here, pending signal validation to be discussed below. Data register 32 may be any desired type of memory having a capacity sufficient to hold all of the signal samples from a single recording cycle. For a six-second record, sampled at 1 millisecond (ms) intervals for example, a capacity of at least 6000 data words is necessary.
A header block precedes the data that is acquired during each recording cycle to provide the identification number of the RRU. The identification may be entered at each RRU manually by the operator by use of a digital thumbwheel switch 44 of any conventional type. The RRU identification is available at temporary data-storage register 32 and time count register 45. The time count from clock 36 at the instant of initiation of a recording cycle is also entered in the header through register 32. In this disclosure, the words "time count" and "time" are synonomous.
Archival storage 34 is designed to receive and record valid data from temporary data-storage register 32. Removable storage 34 may conveniently be a digital-grade magnetic cassette type module or it may be a plug-in type, non-volatile memory module having sufficient capacity to store all of the seismic data samples that accumulate during the course of a recording or work period.
By way of example but not by way of limitation, use of a magnetic cassette type will be assumed. In the case of a magnetic tape, the data acquired during each recording cycle are recorded on tape as a separate data file as in conventional seismic operations.
Local clock 36 consists of two main parts, an oscillator 46 and a time counter or accumulator 48. A preferred oscillator is the model 1115 crystal oscillator made by Austron of Austin, Texas. This oscillator operates at 5 MHz and, for purposes of this disclosure, may be counted down to a desired count rate such as 1 KHz, thus providing a count every millisecond. Other count rates, corresponding to desired data-sampling rates could of course be used. The stability of the model 1115 oscillator depends upon such things as aging, supply voltage fluctuations, circuit loading and temperature variations. Typically, all else being constant the drift rate is 3×10 -9 per 24 hours after 72 hours of operation in the short term.
Time counter 48 as well as master time counter 12b (FIG. 2B) may be any well known presettable synchronous counter such as an SN74LS169 module made by Texas Instruments of Dallas, Tex. These counters are cascadable to provide the necessary number of bits to represent the maximum count expected during a normal work period. Over 24 hours, assuming 1-ms counts, the maximum count would be nearly 1×10 9 so that a 32-bit counter would be quite adequate.
Insofar as seismic operations are concerned, drift error due to temperature and aging is so miniscule as to be negligible. Of great importance however is the timing drift between any two oscillators due tuning error. Any one oscillator can be "tuned" or set within a precision of one part in 10 6 . Thus over a 24-hour period, assuming a 1-KHz count rate, the differential time error between two oscillators can be of the order of 100 milliseconds.
It would theoretically, of course, be possible to employ atomic clocks. The tuning error of such clocks is negligible insofar as seismic work is concerned. But atomic clocks are very expensive, consume an unacceptable amount of power and are far too bulky for use with portable RRUs. Hence, atomic clocks are impractical for field use. The lightweight, inexpensive crystal oscillator mentioned supra is preferred from a practical and economic standpoint.
The system of this invention includes a plurality of RRUs, each one having an oscillator or frequency standard that runs independently of the others. Hence, for useful results to be obtained, the accumulated time counts in the various RRUs must be reduced to a common time base. The required time base reduction is accomplished as follows.
At the beginning of a recording work day, each RRU is transported in turn to central station 11 (FIG. 1). By means of a jumper cable 50, FIGS. 2A and 2B, and suitable connector plugs 52a,b and 54a,b the time counter 12b of master clock 12 is coupled to the time counter 48 of local RRU clock 36. The master time count is available at the input of time count register 45 as is also the local time count of the RRU and the RRU ident. A manually-operated time-count reset switch 56 is pressed. Time accumulator 48 is thereby reset to the exact time count of the master clock 12. At the same time, by means of record-time pushbutton 57, a special pre-record file may be recorded on archival storage 34 by transferring the RRU ident and both the master time count and the local time count following the reset operation, from register 45 to the archival storage 34. Obviously, at the time of reset, the two recorded time counts must be identical. Of course, if desired, rather than resetting the local time counter, one could simply compare and record the difference between local and master time counts. Following the pre-record clock reset operation, jumper cable 50 is disconnected so that the RRUs may be deployed as desired with no further communication whatsoever between the RRUs and the central station until the end of a recording period.
At the end of a work period, the RRUs are brought back to the central station where the master time accumulator is coupled to the local time accumulator as before by jumper cable 50. By means of record-time-counts pushbutton 57, the local time count, the master time count and the RRU ident transferred from time count register 45 and are recorded as a separate post-record file as before. The difference between the two time counts is the relative timing error ΔT, between local and master clocks distributed over the length of the work period, during which a plurality of data recordings were made. Note that at the end of the recording or work period, the manual reset 56 is not activated. If the local time-count reset option were not used, then of course the time count differences at the beginning and ending of a recording period could be recorded. From these differences, the relative timing error ΔT can easily be determined.
It has been found by tests that the relative timing error ΔT between any two clocks is substantially a linear function of duty time as shown in FIG. 4. Accordingly, the relative timing error may be removed from the individual data recordings by linearly prorating the error ΔT over the work period. Because the error is of the order of 10 -6 , the error during any one six-second data recording will be of the order of six microseconds and hence totally negligible. Only the start time or time of receipt of the seismic signals of each record need, therefore be corrected or altered. The proportioning of the tuning error to determine the time alteration for each start time is preferably accomplished at the time that the cassette tape is played back in a data processing center as part of the conventional statics and normal moveout application routine.
From the above discussion, it may be readily appreciated that it is essential that the actual time count of a local clock and the time count of the master clock (or the time count differences) be known and recorded at the end of a work period. If the two time counts were not available, it would be impossible to synchronize the two time bases and the recorded data would be useless. Therefore, means are provided to inhibit unloading of the archival storage medium unless the local and master time counts have been properly recorded. The storage medium, such as a cassette magnetic tape (not shown) fits in a compartment 90 (FIG. 5a) located in each RRU that is closed by an access door 92 having a magnetic latch 37. The access door cannot be opened unless the latch is disengaged from a catch 94 by unload-inhibit solenoid 38. In turn, solenoid 38 cannot be actuated unless jumper cable 50 is plugged in and record-time-counts button 57 is depressed. Button 57 serves the dual purpose of (1) sending a record pulse from a suitable pulse generation circuit 96 over line 55 to storage 34 and register 45 and (2) of applying power to solenoid 38 over conductor pair 51 from power supply 53. Alternatively as in FIG. 5b, power from local power supply 40 could be connected in series with solenoid 38. Conductors 51 in jumper cable could be shorted out. Insertion of plug 52b into plug 52a would then complete the solenoid circuit through the shorted conductor pair 51.
Having considered the major RRU components and timing synchronization, let us turn our attention to the detailed operation of the data recording system as shown in FIGS. 2A, 2B and 3. Time counter 12b, part of the master clock 12, is designed to furnish a signal that enables the operator to trigger seismic source 14, at selected shot intervals. A seismic pulse may therefore not be initiated except at one of the preselected times during the work period. Time counter 48 in a typical RRU initiates a recording cycle at recording intervals corresponding to the shot intervals. The intervals may be operator selectable and typically might range from one to five minutes apart. A recording cycle is enabled at the beginning of each interval. FIG. 3 is a timing diagram of the sequence of events in an RRU between two recording intervals. A pulse 60, trace E from time counter 48 initiates a recording cycle consisting of a noise acquisition phase as indicated by enable pulse 62, trace A, about 1/2 to 1 second long; a data acquisition phase about 6 seconds long, as shown by enable pulse 64, trace B; a data validation phase, as represented by enable pulse 66 that is a few microseconds long, trace C; and a data recording phase, initiated by enable pulse 67, trace D. Enable pulse 67 may be substantially shorter than the data recording phase provided that data recording can be done at a rate that is faster than real time. The trailing edge of enable pulse 67 places the system on standby until the next recording-cycle initiation of a pulse 68.
Pulse 60 enables the system from a standby state by closing switch 70 to apply power to the system and by activating sequencer-controller 72. Power is, of course, always furnished to clock 36. Sequencer 72 thereafter controls the remaining system functions in the proper order.
During the pre-record noise acquisition period, signal processor 30 accepts and processes ambient noise signals. Switch 74 is opened so that nothing is sent to temporary data storage register 32 but the signals representing ambient noise are sent to absolute value formatter 76 over line 77. Assuming that the digital signal samples from processor 30 are expressed as magnitude plus sign, formatter 76 strips the sign from each signal sample and accumulates the sum of all of the samples acquired during the noise acquisition phase. At the end of the noise acquisition phase, the accumulated sum is divided by the number of samples to obtain the average absolute magnitude ⊥N⊥. The average absolute noise magnitude is transferred to a holding register 78. Formatter 76 may conveniently be a 4-bit cascadable serial binary accumulator and shift register such as the SN74S281 integrated circuit chip made by Texas Instruments Inc. Sufficient chips are cascaded to provide capacity to accumulate the largest expected sum. At the end of the noise acquisition phase, division is accomplished by an n-bit binary right shift, where n is a function of the number of accumulated samples. For example, if there are 512 samples (1/2 second at a 1-ms sample interval), a 9-bit right shift is required.
Upon completion of the noise acquisition phase, sequencer 72 initiates a data acquisition phase. At this time, switch 74 is closed and signal data samples are directed into both temporary data storage register 32 and into formatter 76 in parallel. At the beginning of data acquisition the current local time count is entered along with the RRU ident as a header entry in register 32. Header and data samples are held temporarily in register 32 until after the data validation phase. In formatter 76, the average absolute magnitude ⊥D⊥ of the data samples for a preselected interval such as two or more seconds is computed in register 80 which is a counterpart of register 78.
At the end of the data acquisition phase, sequencer 72 transfers ⊥N⊥ and ⊥D⊥ to a comparator 82. If ⊥D⊥ exceeds ⊥N⊥ by a predetermined amount such as 6 dB, the recorded data are considered to be valid and comparator 82 causes register 32 to transfer its contents to archival storage 34 where the data samples are recorded as a data file. If ⊥D⊥≦⊥N⊥, that is if the average absolute amplitude level of the supposed data signal is not substantially greater than the level of the ambient noise, it is assumed that no shot was fired or that a misfire occurred at the central station for that recording interval and so no data-sample transfer is made. Upon completion of the data recording phase, the system reverts to standby, to conserve power, until the next recording interval.
It will be remembered that a noise acquisition phase immediately precedes the data acquisition phase of the recording cycle. Accordingly, time counter 48 may be set to initiate a recording cycle one-half to one second ahead of the expected shot time. Alternatively the recording and shot intervals may be set indentically in time counters 48 and 12b, but a delay line is inserted between time counter 12b and seismic source trigger 13. Such a delay line would delay triggering the seismic source until the end of the noise acquisition phase. In another operational sequence, the noise acquisition phase could immediately follow, rather than precede, the data acquisition phase so that each recording cycle would start at the time the acoustic source is triggered.
As described above, over a period of 24 hours or so, the cumulative tuning error may cause one or more of the RRU clocks to run fast or slow relative to the master. To avoid missing a shot, a pad of several tens or hundreds of milliseconds may be added to the beginning of the noise acquisition phase and the data acquisition phase may be lengthed by an equal amount to insure that no data is lost.
The above embodiment is described in terms of exemplary components which in no way limits the scope of this invention which is limited only by the appended claims. For example, the master clock as above described simply counts elapsed time from an arbitrarily chosen instant. As an obvious variant the clock could be configured to provide Julian date and time of day. Means could be provided to assign an ordinal number to each seismic source triggering cycle during a recording period, correlating same with the time of day. These data could be recorded on an auxiliary archival storage medium such as a magnetic tape associated with the master station (not shown in the Figures).
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A decentralized seismic data recording system includes a central station and a plurality of remote seismic recording units that are incommunicado with the central station during a normal recording operation. A master clock is provided in the central station. A local clock is provided in each remote recording unit. At the beginning of a work period, the local clocks are synchronized with the master clock. Thereafter, a plurality of seismic data recordings are made. At the end of a work period, the time difference due to tuning drift between the master clock and each respective local clock is ascertained and is recorded. The time difference is linearly prorated over the recordings made during the work period, thereby synchronizing the time base of each seismic data recording with the master clock. Provision is made to validate each seismic data recording to prevent accidental recording of false data in event of a misfire or a non-fire of the seismic source.
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REFERENCE TO RELATED APPLICATIONS
This is a divisional application of U.S. patent application Ser. No. 09/149,723, filed Sep. 8, 1998 now U.S. Pat. No. 6,058,043.
This application claims priority benefits to U.S. provisional application Ser. No. 60/058,279, filed on Sep. 9, 1997, and to European Patent application EP 98870108.2 filed May 14, 1998.
FIELD OF THE INVENTION
The present invention is related to methods of erasing a memory device such as a nonvolatile memory cell with a specific aim of low-voltage and low-power applications.
The present invention is also related to a method of programming a memory device such as a nonvolatile memory cell with a specific aim of low-voltage and low-power applications.
BACKGROUND OF THE INVENTION
Nowadays, most Flash memories use Channel Hot Electron Injection (CHEI) at the drain side of the memory cell, or Fowler-Nordheim Tunneling (FNT) for programming. The CHEI mechanism provides a relatively high programming speed (˜10 μs) at the expense of a high power consumption (-1 mA/bit) which limits the number of cells that can be programmed simultaneously (so-called page-mode programming) to a maximum of 8 bytes (Y. Miyawaki et al., IEEE J. Solid-State Circuits, vol. 27, p. 583, 1992). Furthermore, in order to allow a further scaling of the transistor dimensions towards 0.35 μm and below, supply voltage scaling from 5V towards 3.3V and below also becomes mandatory. This supply voltage scaling is known to degrade the CHEI efficiency--and hence the corresponding programming speed--considerably, because the high power needed to trigger the CHEI can not be easily supplied on-chip from a high voltage generator or charge pumping circuit.
Fowler-Nordheim tunneling on the other hand, provides slower programming times (˜100 μs) and a low power consumption which allows larger pages (˜4 kbit) and therefore reduces the effective programming time to 1 μs/byte (T. Tanaka et al., IEEE J. Solid-State Circuits, vol. 29, p. 1366, 1994). A further improvement is, however, limited by tunnel-oxide scaling limits and by the very high voltages (˜18V) needed on chip for FNT, both compromising device reliability and process scalability.
The recent success of Source Side Injection (SSI) as a viable alternative over FNT and CHEI for Flash programming is mainly due to its unique combination of moderate-to-low power consumption with very high programming speed at moderate voltages. A typical example of such a device relying on SSI for programming is the Applicants' High Injection Metal-Oxide-Semiconductor or HIMOS memory cell (J. Van Houdt et al., 11th IEEE Nonvolatile Semiconductor Memory Workshop, Feb. 1991; J. Van Houdt et al., IEEE Trans. Electron Devices, vol. ED-40, p. 2255, 1993). As also described in the U.S. Pat. Nos. 5,583,810 and 5,583,811, both of which are incorporated by reference, a speed-optimized implementation of the HIMOS (High Injection MOS) cell in a 0.7 μm CMOS technology exhibits a 400 nanoseconds programming time while consuming only a moderate current (˜35 μA/cell) from a 5V supply. This result is obtained when biasing the device at the maximum gate current, i.e. at a control-gate (CG) voltage (V cg ) of 1.5V. The corresponding cell area is in the order of 15 μm 2 for a 0.7-μMm embedded Flash memory technology when implemented in a contactless virtual ground array as described in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996, which is hereby incorporated by reference. In terms of the feature size (i.e. the smallest dimension on chip for a given technology), this corresponds to ˜30F 2 for a 0.7-μm technology.
However, due to the growing demand for higher densities, also in embedded memory applications like e.g. smart-cards and embedded microcontrollers, a continuous increase in array density and the scaling of the supply voltage become mandatory. This evolution calls for more aggressive cell area scaling and for low-voltage and low-power operation. In U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996, a novel programming scheme is described which reduces the power consumption during the write operation considerably. Also, the used write voltages are expected to scale with the supply voltage V supply since the SSI mechanism only requires the floating gate channel to stay in the linear regime for fast programming (see e.g. J. Van Houdt et al., IEEE Trans. Electron Devices, vol. ED-40, p. 2255, 1993). Therefore, the necessary Program-Gate voltage V pg for fast programming is given by:
V.sub.pg ˜(V.sub.supply +V.sub.th)/p (1)
where V th is the intrinsic threshold voltage of the floating gate transistor (˜0.5V) and p is the coupling ratio from Program Gate to Floating Gate (typically ˜50%). According to Eq. (1), V pg is thus expected to scale twice as fast as the supply voltage in a first order calculation. It can be concluded that the high programming voltage is scaling very well with the supply voltage which offers enough latitude in order for the high voltage circuitry to follow the minimum design rule.
However, another problem in further Flash memory scaling is related to the erase operation. In most cases, Fowler-Nordheim tunneling through a triangular barrier is used as the erase mechanism and this requires a high oxide field (˜10 MV/cm). In order to establish this, the tunnel oxide has to be further scaled down if the erase voltage is to decrease with the supply voltage (as required by normal CMOS scaling rules, cf. the programming operation in the previous paragraph). Otherwise, it becomes impossible to generate and switch these high voltages on-chip. However, the tunnel oxide cannot be scaled below ˜6 nm because of retention limits and, even more important, Stress-Induced Leakage Current (SILC). The latter mechanism reduces the disturb margins of the memory cells after write/erase cycling. In U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996, a novel erase scheme has been presented that allows the reduction of the negative erase voltage from -12V, well below -8V down to -7V for the same erase speed by exploiting the triple gate structure of the HIMOS cell. Although this novelty offers significant advantages (a 5V reduction in voltage to be switched on-chip is considerable), it may--in the long run--lead to 2 problems:
(1) Due to SILC and retention limits, the tunnel oxide may need to stay thicker than the gate oxide under the control gate at a certain point along the scaling curve. Although the HIMOS cell is less sensitive to such a situation (the read-out current is dominated by the control-gate channel), it can give rise to scaling problems due to the decreasing control over the floating gate transistor. Ideally, the oxide under the floating gate should at least follow the scaling of the gate oxide under the control gate to keep sufficient symmetry in the cell concept. Moreover, this is also beneficial for the endurance of the device: the thinner the oxide, the more cycles can be applied (apart from the SILC issue, as discussed subsequently).
(2) The larger problem, however, is the fact that the built-in select device has to endure the still relatively high negative voltage. In a 0.7-μm technology, this corresponds to -7V across a 15-17 nm oxide which is still tolerable (the associated stress is only present for a limited time equal to the erase time multiplied with the number of cycles, i.e. typically 1,000 seconds). In a 0.35-μm technology, the gate oxide is only 7 nm and the negative voltage should go down to ˜-4V. At the same time, however, the bitline voltage has decreased from 5V to 3.3V due to supply voltage scaling, which means that the tunnel oxide cannot be scaled sufficiently to compensate for this reduction in erase voltages without entering the SILC regime. Increasing the bitline voltage internally on-chip is a possibility but it requires charge pumps in the column decoder (with a design complexity) and it compromises the scalability of the cell's channel length.
So, there is clearly a need for a new erase scheme which offers the possibility to scale down the erase voltages without having the SILC problem. Several solutions to this problem are given in this specification.
Other references to SSI devices that are relevant with respect to the present invention are listed below:
(1) U.S Pat. No. 5,280,446, issued Jan. 18, 1994, to Y. Y. Ma et al.
(2) U.S. Pat. No. 5,029,130, issued Jul. 2, 1991, to B. Yeh
(3) "An 18 Mb Serial Flash EEPROM for Solid-State Disk Applications", by D. J. Lee et al., paper presented at the 1994 Symposium on VLSI Circuits, tech. digest p. 59
(4) "A 5 Volt high density poly-poly erase Flash EPROM cell". by R. Kazerounian, paper presented at the 1988 International Electron Devices Meeting, tech. digest p. 436.
In contrast with the invention described below, these references all suffer from a higher processing complexity and/or the need for higher erase voltages.
Ma et al. (1) use a triple poly cell where first and second poly are etched in a stacked way. It is well-known to anyone skilled in the art that such a processing scheme introduces considerable complexity which makes it impossible to use in a.o. an embedded memory application. On the other hand, the used erase voltage is still -12V provided that the bitline is biased at 5V. In future generations, aggressive tunnel oxide scaling will be required in order not to have an increase in this negative voltage.
Yeh et al. (2) show a split gate cell with very complicated interpoly formation scheme which, again, makes this concept unsuited for embedded memory. The used erase voltage is still 15V although special processing features have been introduced specifically to enhance the interpoly conduction for efficient erasure.
The papers by Lee (3) and by Kazerounian (4) show less details on processing issues but it is clear from the disclosure that the erase voltages are on the order of 20V in order to tunnel through a polyoxide.
AIMS OF THE INVENTION
It is an aim of the present invention to present novel erase methods or schemes that are using substantially the lowest possible voltage to erase a nonvolatile memory cell of the floating-gate type without having the above-mentioned SILC problem. Therefore, these schemes are expected to allow a further scaling of the minimum feature size of Flash memory products which is necessary for cost reduction and density increase.
The present invention also aims to further decrease the voltages necessary to erase/program the memory device without degrading the corresponding performance.
SUMMARY OF THE INVENTION
The present invention is related to the field of fast-programmable Flash EEPROM (Electrically Erasable Programmable Read-Only Memory) devices relying on the Source-Side Injection (SSI) mechanism for programming and suited for medium-to-high density low-voltage low-power applications.
Specifically, according to a first aspect, the present invention relates to novel low-voltage erase methods which allow low-voltage erase and programming operation on-chip in order to reduce the additional cost of incorporating the resulting Flash array in a CMOS (Complementary Metal-Oxide-Semiconductor) process flow. The methods are also relevant for so-called embedded memory applications where the Flash process modules have to be economically reconciled with an already existing CMOS baseline process for fabricating chips that contain large amounts of digital or analog functions as well as Flash memory, such as e.g. smart cards.
A nonvolatile memory cell is disclosed comprising a semiconductor substrate including a source and a drain region with a channel therebetween, a floating gate formed in a first polysilicon layer and extending over a portion of said channel with a thin insulating layer therebetween, a control gate formed in a second polysilicon layer and extending over another portion of the channel region. The nonvolatile memory cell further comprises an additional program gate being capacitively coupled through a dielectric layer to said floating gate and extending over said floating gate.
In a first aspect of the present invention, an erase method is presented which allows to reduce the erase voltage from -12V to -5V and below for a 0.35-μm CMOS technology without any erase time penalty. This low-voltage erase method allows to reduce the internally generated negative erase voltage which enhances reliability margins and which further decreases the development entry cost for implementing the HIMOS concept in an existing CMOS baseline process such as a 0.35 μm CMOS technology.
More particularly, the present invention is related to a method of erasing a nonvolatile memory cell in a chip, comprising the steps of:
applying a first negative voltage to said program gate;
applying a third negative voltage to said control gate whereby establishing an electric field between said control gate and said substrate;
said first and said third negative voltage coupling a second negative voltage to said floating gate;
applying a fourth voltage equal or higher than the supply voltage of said chip to said drain region; and
applying a fifth negative voltage to the substrate, said negative voltage being large enough to reduce the electric field between the control gate and the substrate and to couple a sixth negative voltage to the floating gate, thereby enhancing the voltage across the drain-to-floating gate overlap region.
In a second aspect of the present invention, the method of erasing a nonvolatile memory in a chip, comprises the steps of:
applying a first negative voltage to the program gate; thereby coupling a second negative voltage to said floating gate;
applying a third positive voltage to the control gate; to thereby establish a relatively high electric field across the dielectric between the control gate and the floating gate, and thereby causing a tunneling current to flow from the floating gate towards the control gate in order to discharge the floating gate and therefore erase the memory cell.
Thus, the memory cell is erased without considerable power consumption and with moderate voltages only.
In a third aspect of the present invention a method of programming a nonvolatile memory cell is disclosed, the method comprising the steps of:
applying a first high voltage to said program gate thereby coupling a second high voltage to said floating gate of said cell;
applying a third low voltage equal or smaller than the threshold voltage of the control-gate channel to said control gate;
applying a fourth voltage equal or higher than the supply voltage to said drain region of said cell; and
applying a fifth low negative voltage to the substrate to thereby cause a small current to flow from the source region of said cell towards the floating-gate channel of said cell while achieving programming of said memory cell.
The third low voltage can also be slightly larger than the threshold of the control gate channel.
Thus, programming of said memory cell is achieved by means of source-side injection of hot-electrons generated through primary as well as secondary impact ionization, and this without the need for an additional high supply voltage nor a high power consumption from the supply voltage.
In a fourth aspect of the present invention, a triple poly nonvolatile memory cell being based on the cell concept described in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996 is also presented. This triple poly cell, for the first time, reconciles the possibility for having a small cell size with a high degree of CMOS compatibility.
Thus, a nonvolatile memory cell is disclosed comprising a semiconductor substrate including a source and a drain region with a channel therebetween, a floating gate formed in a first polysilicon layer and extending over a portion of said channel with a thin insulating layer therebetween, a control gate formed in a second polysilicon layer and extending over another portion of the channel region. The nonvolatile memory cell further comprises an additional program gate formed in a third polysilicon layer being capacitively coupled through a dielectric layer to said floating gate and extending over said floating gate.
Thus, the present invention in this aspect, aims to reach a very compact, though still CMOS-compatible, cell geometry that paves the way to even higher density low-voltage applications. This geometry is fully compatible with the above-mentioned low-voltage erase schemes.
The term "supply voltage" is well understood by one of ordinary skill in the art. The term "supply voltage" is meant to be any external voltage that delivers the power to make an electronic circuit operate. By preference, the "supply voltage" of a chip including nonvolatile memory cells is the voltage used to supply the power to any logic circuit fabricated in the CMOS technology in which the nonvolatile memory cells are incorporated. For the 0.7 μm nonvolatile memory technology as disclosed in this and related applications, the supply voltage is 5 Volts. Any externally applied voltage other than the supply voltage defined above will be referred to herein simply as an "external voltage".
A voltage that is outside the range between the supply voltage and ground and that only needs to deliver a limited amount of current can be generated without the need for an external voltage. Such voltage is referred to as an on-chip generated voltage and can be generated by charge pumps incorporated on the chip.
In the specification, the terms low voltage, moderate voltage and high voltage are also used. A low voltage is meant to be a voltage that in absolute value is lower than or equal to the supply voltage (|V|≦Vcc). A moderate voltage is a voltage that in absolute value is higher than or equal to the supply voltage but is smaller than or equal to the double of the supply voltage (Vcc≦|V|≦2 Vcc). A high voltage is a voltage that in absolute value is higher than 2 Vcc (|V|≧2 Vcc).
The objects, features, and advantages of the present invention, are discussed or apparent in the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in detail with reference to the following drawings, which describe several preferred embodiments of the present invention:
FIG. 1 shows a cross-section of a memory cell and an erase method according to the invention which allows a reduction of the negative erase voltage and which removes the reliability problem associated with the stress in the control-gate oxide.
FIG. 2 shows a cross-section of a memory cell and a novel programming scheme which enhances the injection efficiency of the source-side hot-electron injection mechanism thereby allowing a further reduction of the programming voltage.
FIG. 3 compares the gate currents measured at the (contacted) floating gate for the `traditional` SSI case and for the modified programming scheme schematically shown in FIG. 2. Open symbols are for V b =0V; closed symbols are for V b =-3V. V b is the applied bulk voltage.
FIG. 4 shows an erase scheme which uses polyoxide tunneling from the floating gate towards the control gate.
FIG. 5 shows the erase characteristics according to the scheme of FIG. 4. Due to the small coupling ratio between these respective gates, the cell can already be overerased to a negative threshold voltage using only 8V at the control gate.
FIG. 6 shows an erase scheme which allows to reduce the erase voltages to |5V| and even below. This polyoxide erase scheme uses low negative voltages on the Program Gate in order to remove the stress on the control-gate transistor without causing any penalty from the point of view of erase speed nor cycling endurance.
FIG. 7 shows the erase characteristics for the scheme of FIG. 6 as measured on memory cells fabricated in a 0.35-μm CMOS technology.
FIG. 8 shows the endurance characteristics as measured on cells from a 0.35-μm CMOS technology.
FIG. 9 shows the novel erase scheme of FIG. 6 where also a bulk voltage is applied for further enhancing the oxide field during erasure.
FIG. 10 shows alternative cell geometry employing 3 layers of polysilicon which enables a considerable reduction of the cell size down to 15F 2 . All erase and programming schemes shown in the other FIGS. 1-9 are compatible with this device structure as well as with the device structure disclosed in U.S. Pat. No. 5,583,810.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exemplary devices have been fabricated in a 0.7 μm nonvolatile technology embedded in a CMOS technology and represented on FIGS. 1, 2, 4, and 6. On these schematic cross-sections, each time a substrate (1), a source region (2), a drain region (3), and a channel region (4) are represented. In these examples of FIGS. 1, 2, 4, and 6, the substrate is p-type doped. Further is shown a floating gate (5), a control gate (6) and a program gate (7). In a preferred embodiment of the invention, the program gate (7) is to be separated in space from the control gate. In FIG. 1, exemplary voltages applied on the source region (2), the drain region (3) and the substrate (1) are 0V, +3.3V, and -4V respectively, while--7V is applied both to the control gate (6) and the program gate (7). Such voltages are applied on the different parts of the memory cell. These voltages are indicated as circled numbers above or below a vertical line.
According to other embodiments, the source region can also be Vcc or floating.
In FIG. 2, exemplary voltages applied to the source region (2), the drain region (3) and the substrate (1) are 0V, +3.3V and -3V, respectively, while +1V and +9V are applied to the control gate (6) and the program gate (7), respectively.
In FIG. 4, exemplary voltages applied to the source region (2), the drain region (3) and the substrate (1) are all connected to the ground potential while the control gate voltage (6) has a value of +8V and the program gate (7) is also connected to ground potential.
In FIG. 6, ground potential is applied to the source region (2), the drain region (3) as well as to the substrate (1) while the control gate (6) and the program gate (7) are biased at +5V and -5V, respectively.
These exemplary devices have a thin oxide (11) (7-9 nm) under the floating gate (5). The interpoly dielectric (13) is a polyoxide of thickness 25-30 nm, and the oxide (12) between the control gate and the channel region is 15 nm. The length of the floating gate (5) is 0.7 μm, the length of the control gate (6) is 1.0 μm, and the overall size is 13-15 μm 2 .
The several methods as disclosed in the present application can also be applied to a 1.25 μm nonvolatile technology stand alone or embedded in a CMOS technology or in a 0.35 μm or smaller gate length nonvolatile technology stand alone or embedded in a CMOS technology.
1. Low Voltage Erase Scheme Based on Fowler-Nordheim Tunneling
An important feature of this invention is a novel erase scheme that allows to reduce considerably the negative gate bias necessary for Flash erase. Especially for embedded memory applications where the minimization of the impact of the memory technology on the surrounding CMOS circuits is a prime issue, the reduction of the negative erase voltage is of major importance. Furthermore, a voltage reduction also simplifies the design of the high voltage generating and switching circuitry, and increases reliability margins for the entire process. Referring to FIGS. 12 and 17 in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996, the application of a negative voltage to both control gate(CG) and program gate(PG) already allows a considerable reduction in necessary erase voltage. However, as already mentioned above in the prior art section, when control gate oxides (12) scale down towards 7 nm and below, this erase scheme may not be further scalable towards the 0.25-μm generation because of the stress associated with the -still fairly high- negative voltage on the control gate. To remove this problem, a compensating smaller negative voltage can be applied at the substrate of the cell as shown in FIG. 1. This offers 2 advantages:
(1) the voltage across the control gate oxide (12) is only equal to the difference between the negative erase voltage and the bulk voltage. The latter can thus be adjusted in order to obtain proper margins for process reliability.
(2) also, the negative voltage at the bulk side (1) of the cell will be partially coupled towards the floating gate (5) which further enhances the electric field across the floating-gate-to-drain overlap region where tunneling is to be established.
In this case, the voltage across the tunnel oxide (11) between the FG and the drain is approximately given by the following equation:
|V.sub.fg -V.sub.d |≅p(V.sub.t -V.sub.g)+(1-d)V.sub.d -c V.sub.g -s V.sub.b (2)
where p, c, d and s are the PG-to-FG, the CG-to-FG, the drain-to-FG and the bulk-to-FG capacitive coupling ratio's, respectively. Typical values are p=50%, c=20%, s=15% and d=10%. V g represents the (common) gate voltage applied to both gates, V fg and V d are the FG voltage and the drain voltage during erasure, respectively, V t is the threshold voltage of the memory cell measured from the PG and V b is the applied negative bulk voltage. Taking typical values for the parameters into account (V d 5V, V t varies between 2V and -4V) it can be calculated that, in order to obtain a reasonable erase time in the order of milliseconds, a PG voltage of -7V is typically required for a state-of-the-art tunnel oxide of 8 nm if no bulk voltage is applied. In order to generate this high negative voltage on-chip and to switch it onto the PG during the Flash erase operation, an even higher voltage in the order of -10V has to be generated locally inside the charge pump.
As compared to Eq. (4) in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996, it is clear that the additional term sV b (indicated in Eq. (2) in bold font) will further increase the oxide field independently of the value of the threshold voltage of the cell. This allows to use a lower voltage of ˜-5.5V at the gate for the same erase speed as can be calculated from Eq. (2). Moreover, due to this smaller erase voltage, and due to the distribution of the different voltages contributing to the tunneling field across the entire device structure, the electric field inside the cell is nowhere large except at the FG-to-drain overlap where tunneling is required. Therefore, the necessary reliability margins are much easier to accomplish than in the case where the bulk voltage is not present. If erase speed is not an issue, as in e.g. EPROM replacement applications, the erase voltage can even be allowed to decrease further to -5V.
It has already been demonstrated and explained in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996 that the erase scheme with a negative voltage applied to both external gates exhibits a peculiar relationship between erase speed and PG coupling ratio: the erase speed increases with decreasing coupling capacitance, and hence with decreasing cell area. This is a remarkable property since the smaller the cell, the faster it erases, in contrast to all other erase schemes known in the prior art. It makes device design much easier since the optimum coupling ratio for programming is never compromised by erase speed requirements. Also, this erase scheme is clearly interesting for scaled-down Flash memories. Repeating the same arguments that have been displayed in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996, it can be easily demonstrated that this result holds for the novel scheme of FIG. 1. Due to the fact that the contributions of the negative control gate and bulk voltages are adding up to the field independently of the charge on the floating gate (FG), the phenomenon described above will even be enhanced, i.e. the influence of the PG coupling ratio on erase speed will become even less important.
The additional bulk voltage will not compromise the complexity of the array operation. Since in the case of Flash memories, an entire sector is erased at once, the sector can simply coincide with all cells connected to the same negative bulk voltage. Moreover, even if the substrates of the different sectors would be connected (e.g. by placing these in a common p-well), the disturb effect introduced by the bulk voltage would be negligible.
2. Low Voltage Programming Scheme Based on Secondary Impact Ionization Enhanced Source Side Injection
Applying a negative bias to the substrate (1) of the memory cell during programming shows a further increase in injection efficiency with respect to the conventional programming scheme as described in U.S. Pat. No. 5,583,810. FIG. 2 shows this programming scheme, and FIG. 3 shows the corresponding gate currents measured at the floating gate of the memory cell as a function of the control-gate voltage.
From FIG. 3, it is clear that the injection is increased by applying a negative bulk bias of -3V. The gain in injection current is determined by several factors:
(1) the technology generation (the effect is becoming strongly significant from 0.35-μm CMOS on).
(2) the drain voltage (the effect becomes visible when the drain voltage or the voltage supply is scaled to 2.5V and below)
(3) the gate voltage (the gain is larger as the floating gate voltage decreases).
This can be explained from secondary impact ionization effects in the bulk of the device: if the drain-bulk junction is biased considerably higher than the drain-source voltage (in the present case 5.5V as compared to 2.5V), the influence of secondary impact ionization becomes considerable. On the other hand, it is known that this secondary impact ionization requires high doping levels and/or thin gate oxides to become significant and these conditions are only reached in deep-submicron technologies. Finally, at lower floating-gate voltages, the direct injection due to primary impact ionization (the conventional SSI current) is decreasing rapidly due to the saturation of the floating-gate transistor. As a consequence, the injection due to secondary impact ionization becomes relatively more important. Although the gain in injection current due to the bulk bias is still small for a 0.35-μm technology, it is expected to become larger and larger with device scaling. The interesting point is that the available potential drop for hot electron generation is now determined by the sum of 2 voltages: the bulk bias and the drain bias. This makes it possible to further scale down the channel length since the latter is limited by the drain voltage only.
From a practical point of view, the implementation of the secondary impact ionization enhanced SSI mechanism requires no additional processing nor design efforts, especially if the bulk bias is also applied in the erase mode as described in FIG. 1. In the latter case, the necessary technology and circuits are already provided to switch, e.g. -3V, on the substrate or bulk during erasing. The fact that Flash memories require byte-selective programming (in contrast to the erase operation which is performed in sectors) is not an issue because the low bulk bias is not able to alter the content of the non-addressed cells. In other words, there is no reason to decouple the bulk potential of addressed and non-addressed cells which means that the switching circuitry can be kept identical for both programming and erasing.
3. Low Voltage Erase Scheme Based on Polyoxide Conduction
FIG. 4 illustrates this erase scheme when applied to a HIMOS cell. In the Applicants' U.S. Pat. No. 5,583,810, it has already been disclosed that the HIMOS+n cell can be erased by applying a high positive bias to the control gate (see FIG. 12 in that patent where 10-14V is applied for a 1.25-μm CMOS technology). Similar characteristics for scaled-down technologies, i.e. a 0.7-μm CMOS technology with a 30 nm interpoly oxide (13) and a 0.5-μm technology with a 17 nm interpoly oxide (13), are shown in FIG. 5. It is clear from this Figure that the cell can be erased to negative threshold voltages using about 8V on the control gate. A very large speed improvement is observed if the interpoly oxide is scaled below 20 nm. This is in contrast to the results presented by Yeh et al. where a thick (˜100 nm) oxide is used for high reliability and the conduction is enhanced by a dedicated processing scheme which forms an injector at the floating gate edge. These complicated processing steps are completely avoided in the current invention which allows also to reduce the erase voltage considerably: in the Yeh patent a 15V gate voltage is mentioned as typical value for erasing. In fact, the paper "A novel 3 volts-only, small sector erase, high density Flash E 2 PROM" presented by S. Kianian at the 1994 Symposium on VLSI Technology (same device as in the Yeh patent, assigned to Silicon Storage Technology, Sunnyvale, Calif.) also mentions a 14V erase voltage to be applied to the wordline to erase the cell. Moreover, the referred device also requires 11V on the source line during programming which makes the design much more difficult due to the presence of charge pumps in the column decoder.
In contrast to this device known in the prior art, the HIMOS cell only uses a simple processing scheme wherein the gate oxide under the control gate is grown directly in combination with a thin polyoxide which is used for tunneling in the erase mode. This offers 3 major advantages over the prior art:
(1) no additional processing steps are needed for interpoly dielectric formation which lowers processing cost considerably with respect to the prior art
(2) the gate oxide under the control gate can be scaled down in relation to the CMOS scaling which implies that the high read-out current is maintained, also in future generations.
(3) the erase voltages used are very low in comparison with the prior art.
However, as a consequence of this oxidation scheme, the control gate transistor has 8V at its gate in the case of FIG. 4. For a 15-17 nm gate oxide (12) (0.7-μm technology), this can be tolerated. However, when scaling down to less than 10 nm, an additional reliability problem arises. To avoid this, the unique triple gate structure of the HIMOS cell can be exploited as indicated in FIG. 6: due to the presence of a third (program) gate (7), the possibility exists to replace the high control gate voltage by a combination of a moderate positive voltage at the control gate and moderate negative voltage at the Program Gate (7) in order to establish the same interpoly oxide field. The experimental results for a 17 nm polyoxide layer (13) are shown in FIG. 7. It is clear that the cell can already be erased to a negative threshold voltage of -3V using voltages as low as +5V at the CG and -5V at the PG. The advantages of such a scheme are:
(1) the possibility to erase with the smallest possible voltages (typically Vcg=5 and Vpg=-5V without any process optimization) as compared to the prior art.
(2) the gate oxide under the control gate can be scaled down easily in order to maintain a high read-out current
(3) the high voltage switching circuitry becomes a lot smaller
(4) the high voltage processing module becomes much easier to implement
(5) the polyoxide conduction mechanism consumes virtually no power (apart from the tunneling current itself) because all bitlines are grounded.
More specifically, the following disadvantages of the Fowler-Nordheim mechanism are removed in this scheme:
(1) the presence of |Vg|+Vd across the oxide which is grown on the bitline (see e.g. the contactless arrays described in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996 is avoided: the largest voltage difference inside the array in the new erase scheme is only |Vg| or typically 5V instead of 12V in the old erase scheme as described in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996.
(2) the sector size has a lower limit due to the large and cumbersome negative voltage switches and, eventually, due to the need to bias the bulk of the cell (see above). In the present case, however, the minimum sector size becomes equal to a wordline which is the theoretical minimum.
(3) the FN case requires triple well technology in deep-submicron generations in order to be able to transport the high negative voltages on chip. For polyoxide erase, this requirement is largely relaxed which offers the possibility to implement this in a conventional twin well process. This is beneficial for processing cost.
(4) The Stress Induced Leakage Current: in poly erase schemes, the SILC is simply non-existent since the stress induced by programming and erasing now corresponds to a much lower oxide field which is not able to generate SILC traps. Further reduction of the oxide thickness under the floating gate becomes a viable way to improve the number of cycles.
(5) In the FN case, the bitline voltage also decreases with scaling and therefore, the negative erase voltage does not have the tendency to scale with the CMOS generation. This can hardly be solved by aggressive tunnel oxide scaling nor by bitline charge pumps. In the poly erase scheme, this problem is removed: the necessary erase voltages at the gates are no longer a function of the supply voltage.
(6) In the FN case, inhibit voltages are required in the non-addressed sectors during the sector erase operation. This is due to the fact that the presence of the bitline voltage (Vsupply) can cause a slow erase operation in a certain sector every time another sector is being erased. This is a direct consequence of the absence of a select transistor in Flash arrays. These inhibit voltages and the associated circuitry are no longer necessary in the case of the presented polyoxide erase operation since no bitline voltage is applied anywhere inside the array.
(7) Using FN, the positive as well as the negative voltages are to be applied to the WordLine WL (connected to the control gates of a row of cells, see e.g U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996) and to the ProgramLine PL. This implies a complication in the row decoder which has to pass 0V on the PL during read-out and 0V on the unselected WL's during read-out as well as during programming. Because of the negative voltage during erase, a pMOS device has to be provided in the row decoder which is unable to pass a perfect zero potential. Therefore, a small negative charge pumping circuit is required in the row decoder which increases the decoder size and the power consumption during read-out. This problem is almost entirely solved by using only negative voltages at the PL. The threshold-voltage window of the cell can even be adjusted in such a way that this complication is also removed in the programming regime.
The endurance characteristics for the polyoxide erase case are compared to the conventional Fowler-Nordheim case (drain erase) in FIG. 8. The drain erase case is still better than the polyoxide erase option for a 30 nm interpoly oxide. However, when scaling the interpoly layer down to only 17 nm, the poly erase case becomes considerably better than the drain erase case. These tests were performed on identical devices (apart from the interpoly oxide layer) and with identical programming conditions, and, therefore, prove that the polyoxide erase option is becoming better than the tunneling towards the drain, unlike in former technology generations. For the example shown in FIG. 8, it is concluded that--for a given read-out current--the number of cycles can be increased from 10,000 to 100,000 by choosing the presented erase scheme using a 17 nm polyoxide on top of the floating gate.
Finally, the presented erase scheme can eventually be combined with a negative bulk bias, much in the same way as described in the first section (see FIG. 9). The additional voltage which is then coupled from the substrate towards the floating gate helps to erase the device with even lower gate voltages. In this case, the bulk bias is, however, limited to low voltage values because it adds up with the control gate voltage as far as the stress on the select transistor is concerned.
4. Novel Cell Structure With Three Polysilicon Layers
As mentioned in the prior art section, the HIMOS cell takes at least about 30F 2 in a 0.7-μm double polysilicon CMOS process. This is larger than state-of-the-art stand-alone memory technologies. In order to meet the increasing demand for high density embedded as well as stand-alone memories, another cell geometry may be required. The main reason for this larger cell size is the need to form two gates in the same polysilicon layer, i.e. the control gate and the program gate. These two gates have laterally isolated edges which increase the cell size considerably with respect to other cell concepts that only use 2 gates (1 floating gate and 1 control gate) at the expense of a lower performance. Secondly, the double polysilicon version suffers from a severe technological problem when scaling down to very thin gate oxides: the second polysilicon layer has to be overetched in order to remove the stringers that would otherwise stay behind at the edges of the first polysilicon layer. For very thin gate oxides, this becomes harder and harder to do since the overetch step has to stop on this thin oxide in order not to damage the silicon surface. This problem is a direct consequence of the two gates inside the cell which are to be formed in the same polysilicon layer. The problem can be removed by adding a third mask to selectively remove these stringers, but this introduces an additional processing cost. Therefore, a triple polysilicon version becomes highly attractive since a higher density is obtained and the stringer problem is removed automatically.
FIG. 10 shows such a high density concept which is basically the same as the concept described in Applicants' U.S. Pat. No. 5,583,811, from the point of view of memory operation. From the structural point of view, however, this cell is considerably smaller since the program gate (7) is now formed in a third polysilicon layer and placed on top of the split-gate transistor which removes the above-mentioned area penalty. If we start from the assumption that a third poly mask is necessary anyway (even if only 2 polysilicon layers are being used, see above), the additional cost for processing the device of FIG. 10 is relatively small:
(1) a second interpoly insulating layer between second and third poly is to be introduced, preferably a high quality composite ONO layer (13), which has to isolate the high programming voltage from the split-gate structure.
(2) a 3rd polysilicon layer has to be introduced.
In contrast to earlier attempts (e.g. Ma et al.), the presented solution is staying close to the original double polysilicon version as described in Applicants' U.S. Pat. No. 5,583,811, without however excluding any of the operational modes described in Applicants' U.S. Pat. No. 5,583,810, nor in U.S. patent application Ser. No. 08/694,812 filed on Aug. 9, 1996.
The first polysilicon layer is used for the floating gate (5) and is isolated from the substrate through a thin insulating layer (11), e.g. an oxide (typically 7 nm in a 0.35-μm CMOS process). The second poly serves as the control gate (6) and is isolated from the substrate by a thin insulating layer (12), e.g. oxide which is grown at the same time as the interpoly oxide (13) which is present between the floating gate (5) and the control gate (6). This cell can still be erased through FN tunnelling or through polyoxide conduction as described above. The third poly is added to be able to put the Program Gate (7) on top of the split-gate structure instead of beside it. Typical programming voltages in a 0.35 μm technology are also indicated: the control gate bias is around 1V, while the program gate is provided with 8-9V from a charge pumping circuit. The drain (3) is biased at 3.3V, which is the supply voltage. This brings the floating gate to a potential of about 4V which is sufficient to efficiently trigger the SSI mechanism. During erase, gates are biased negatively (around -6V) while the drain (3) is at 3.3V in case of the drain erase scheme. For the polyoxide erase scheme, 5V is applied to the CG (6) and -5V or -4V to the PG (7) while the bitlines are kept grounded. Read-out is accomplished by applying small voltages at CG (6) and drain (3) while the PG (7) is grounded.
Preferred embodiments of the present invention have been described herein. It is to be understood, however, that changes and modifications can be made without departing from the true scope and spirit of the present invention. The true scope and spirit of the present invention are defined by the following claims, to be interpreted in light of the foregoing specification.
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A method of erasing and a method of programming a nonvolatile memory cell in a chip is disclosed. Said cell comprises a semiconductor substrate including a source and a drain region and a channel therebetween, a floating gate extending over a portion of said channel, a control gate extending over another portion of the channel region, and a program gate capacitively coupled through a dielectric layer to said floating gate. The methods or schemes are using substantially the lowest possible voltage to erase a nonvolatile memory cell of the floating-gate type without having the SILC problem. Therefore, these schemes are expected to allow a further scaling of the minimum feature size of Flash memory products which is necessary for cost reduction and density increase.
The present invention also aims to further decrease the voltages necessary to erase/program the memory device without degrading the corresponding performance.
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[0001] This nonprovisional application claims priority under 35 U.S.C. § 119(a) on German Patent Application No. DE 203 11 950.9 filed in Germany on Aug. 2, 2003, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a corrosion-resistant tension member, particularly a tendon for prestressed concrete.
[0004] 2. Description of the Background Art
[0005] In the construction of buildings with prestressed concrete, bonded or unbonded prestressing is commonly known. With bonded prestressing, the tendons are located longitudinally movable within the concrete cross section and, after tensioning against the hardened concrete, are bonded to the surrounding concrete by injecting cement paste. With unbonded prestressing, the tendons are most often located outside of the concrete cross section, however, they are supported against a structure; in this way, they can be inspected, re-tightened, and if necessary replaced at any time.
[0006] With tension members of this kind, so-called monostrands are frequently used as tension elements, that is, strands made of seven steel wires, each being enclosed by a plastic sheath, for example, polyethylene, that is applied by extrusion, to protect against corrosion, and which are embedded in a corrosion-protection substance, for example, grease, which fills wedges between the steel wires and a ring space between the strand and the sheath; also known are strands that are enclosed by two sheaths of this kind, for reinforced protection against corrosion.
[0007] The anchorage of the strands at the ends of the tendons usually includes anchoring discs made of steel, with conical, and subsequently cylindrical bores in the number of strands, through which these are threaded and in which they are anchored with multiple-part ring wedges. To anchor the strands, it is, however, necessary to remove the sheaths from the strands in the area of the anchorage, so that the anchorage wedges can directly grip the bare strand.
[0008] For reasons of corrosion protection, the hollow spaces in the anchorage areas, where the sheaths were removed from the strands, must be filled with a material, for example, grease, to insure protection against corrosion. When the hollow spaces between the individual strands in the areas of the tendons in between the anchorings are filled in at their ends with a hardened material, for example, mortar, to safeguard against corrosion, it is necessary to tightly delimit the anchorage areas that are to be filled with corrosion-resistant materials from those areas.
[0009] To separate the anchorage areas, which are to be filled in with corrosion-resistant materials, of a tension member from the free areas, it is known to use sealing elements made of an elastic material around the individual sheathed strands, the sealing elements being brought to a transverse extension by a surface pressure in an axial direction of the tendon, to tightly seal off the individual strands and an interior wall of the outer sheathing. Seals such as these, designed somewhat like a compression gland, are known from EP 0 323 285 B2 and WO 01/20098 A1. In there, to activate the seals, pressure is applied to the sealing elements embedded between pressure plates by bolts that can be actuated from the exposed side of the anchor plate. This type of activation of the seals, however, necessitates a lot of effort.
[0010] If signs of corrosions appear on the individual strands despite all safety measures, their tension must be decreased to replace them. To do this, the bolts, which compress the seals between the pressure plates, must be loosened prior to loosening the ring wedges of the strands. Due to deformations that took place, the sealing parts frequently cannot be returned to their original position without additional expenditure of energy. Thus, the entire anchor plate has to be dismantled in order to replace individual strands to avoid the risk of damaging the deformed sealing elements and/or the sheaths of the strands when the strands are pulled.
[0011] Unbonded tendons, which traditionally have been used basically as external tendons, that is, tendons guided outside the concrete cross section, are increasingly also used as internal tendons, that is, tendons guided inside the concrete cross section. As tendons arranged inside the concrete cross-section they have an advantage from a static view point, namely, with regard to a lever arm of internal forces that can be utilized. Moreover, the tension can be controlled by re-tightening, which is not possible with bonded pre-loading. Lastly, this type of tendons allows replacement of individual tension members as well as the entire bundle.
[0012] Particularly advantageous compared to external tendons is the fact that the tendons are embedded in concrete so that reversing forces at reversing points can be absorbed without taking any particular measures. For this purpose, strands with reinforced sheaths or twice-extruded strands are also frequently used.
SUMMARY OF THE INVENTION
[0013] It is therefore an object of the invention to provide a simpler and more economical means for a seal of the anchoring area of a tension member of this kind, particularly for the use as unbonded tendons, which allows not only for easy installation but also for a more simplified replacement of individual strands as well as the opportunity to used twice-extruded strands.
[0014] The invention is based on the idea to avoid the activation of the compression gland-like seal of the anchoring area by additional steps like screw bolts, which are actuated from an open air side of the anchoring, or such. Rather, according to the invention, the seal is activated in a simple way in that the anchor plate is held at a predetermined distance from the anchor body by a pressure-transferring means during the installation of the tension member, and that the longitudinal displacement of the anchor plate in the direction of the anchor body, which is caused by the tensioning of the tension member, is by applying a required surface pressure via the pressure-transferring means to the sealing element, which in turn is fixed in place to prevent longitudinal displacement.
[0015] It is thereby beneficial that the perforated disk that is provided as a spacer for the individual tension elements also serves as an abutment for the sealing plate, which can be made of, for example, soft rubber or foamed material. However, in this circumstance, a longitudinal displacement of the perforated disk is avoided by an abutment on the tube-shaped part of the anchor body. This can be accomplished with suitable types of stops on the interior wall of the anchor body. If necessary, a steel plate for creating a three-dimensional state of tension can be inserted between the perforated disks. Due to the transverse deformation of the sealing element thus activated, the hollow space is reliably sealed off to the PE sheaths of the strands as well as to the interior wall of the anchor body as an exterior sheath.
[0016] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
[0018] FIG. 1 a is a longitudinal cross-section of an anchoring area of a tension member of according to a preferred embodiment of the present invention;
[0019] FIG. 1 b is an enlarged illustration of a portion of the anchoring area of FIG. 1 a;
[0020] FIG. 2 is a cross-sectional view along line II-II in FIG. 1 ; and
[0021] FIG. 3 is a diagram illustrating individual parts of the anchoring.
DETAILED DESCRIPTION
[0022] In FIG. 1 a , the anchoring area 1 of a tension member 2 of this invention is illustrated in a longitudinal section. In the illustration, the tension member 2 is a tendon, which, as shown in FIG. 2 , can be formed of fifteen individual tension elements 3 . The tension elements 3 , in turn, are formed of, for example, monostrands, that is, steel wire strands 4 , which are surrounded by sheaths 5 made of plastic, particularly PE (poly ethylene), to protect against corrosion. The spaces between the individual wires (not shown) of the strands 4 and the PE sheath 5 are filled in with a corrosion-resistant material, for example, grease.
[0023] The strands 4 are anchored to a steel anchor plate 6 by multi-part ring wedges 7 . For this purpose, the anchor plate 6 has bores with an inner cylindrical area, which on its exposed side extends into a conical area ( FIG. 1 b ).
[0024] On the outer surface 8 of a structure, the anchor plate 6 is supported, via an intermediate ring 22 , against a flange-like abutment ring 9 of a tube-shaped anchor body 10 , which is cemented into the structure. In the anchoring area 1 , the anchor body 10 forms the tube-shaped sheathing of the bundle of tension elements 3 , which can extend into an additional sheathing 18 , if necessary, via an adaptor 11 . For the sheathing 18 , smooth or profiled PE tubes, metal tubes, etc. can be used. The adaptor 11 is made of plastic, most often of PE; it serves at the same time as a soft redirect for the tension elements 3 .
[0025] Whereas the structure of a tension member such as described above is basically known, the invention relates foremost to the connection of the previously applied corrosion protection of the tension element 3 to the anchoring, since in the actual anchoring area the PE sheaths 5 of the tension elements 3 must be removed so that the wedges 7 can directly grip the bare strands 4 .
[0026] Whereas the tension elements 3 , being tightly packed in the normal area of the tension member 2 between the anchoring areas 1 , are spread towards the outside in the area of the adaptor 11 to put them at a distance necessary for anchoring with the ring wedges 7 in the area of the anchor plate 6 , they are, when entering the actual anchoring area, redirected towards a longitudinal axis of the tension member by a perforated disk 12 serving as a spacer. The perforated disk 12 , which can be made of plastic and has suitable bores, is dimensioned in such a way that the tension elements 3 are guided parallel to axes of the wedges 7 , thereby absorbing the reversing forces, which are thus created and which are directed radially to the longitudinal axis.
[0027] In turn, the perforated disk 12 serves as an abutment for a sealing plate 13 that can be made of soft rubber of foamed material, and can be put under surface pressure by using a steel pressure plate 14 a . To be able to exert such pressure, the perforated disk 12 must be safeguarded against longitudinal displacement. In the illustrated embodiment, this is achieved with a stopper pipe 15 , which butts against the interior wall of the anchor body 10 , and which, for example, is secured with screws. However, safeguarding against longitudinal displacement can only be achieved when a suitable stop is formed on the interior wall of the steel-cast anchor body 10 .
[0028] To achieve a fixing of the perforated disk 12 and a three-axial state of tension, an additional steel plate 14 b can be arranged on the side of the perforated disk 12 that faces away from the anchor plate 6 , analogous to the pressure plate 14 a . This steel plate 14 b simultaneously supports the perforated disk 12 during the absorption of the reversing forces.
[0029] To exert an axial pressure to the sealing plate 13 via the pressure plate 14 a , a pressure tube 16 is used, which surrounds the entire assembly of tension elements 3 within the anchor body 10 and which is longitudinally slidable in relation to the anchor body. The length of this pressure tube 16 is calculated in such a way that it projects beyond the outer surface of the abutment ring 9 by the size of the compacted sealing plate 13 at installation of the anchoring. As a result of the positioning of the anchor plate 6 during the tensioning process, it is pressed against the sealing plate 13 , whereby the sealing plate is compacted accordingly. Due to an activation of a transverse deformation of the sealing plate 13 , the hollow space inside the anchor body 10 is sealed off to the PE sheaths 5 of the strands as well as to the inner wall of the anchor body 10 .
[0030] In addition, as a result of the chosen arrangement of the pressure plate 14 a —sealing plate 13 — perforated disk 12 , and steel plate 14 b as the case may be, as well as the dimensioning of the perforated disk 12 , the disadvantage frequently occurring with conventional anchorings is avoided, namely, that the tension elements 3 , particularly when arranged out of order, become dislocated in a transverse direction during the tensioning process thus causing leakages.
[0031] To keep the PE sheaths 5 of the strands 4 from penetrating the bores of the anchor plate 6 in front of the wedges 7 during the installation or tensioning processes, thus possibly blocking the subsequent interposition with corrosion-resistant material, a retensioning plate 17 made of steel is arranged on the inside of the anchor plate 6 . This retensioning plate 17 has bores, which just allow passage of the bare strands 4 , whereas the PE sheaths 5 surrounding the strands are held back by a stop on the retensioning plate 17 ( FIG. 1 b ).
[0032] In order not to block the subsequent interposition of the hollow spaces with corrosion-resistant material, the retensioning plate 17 must be kept at a certain, although marginal distance from the interior of the anchor plate 6 by spacers. It is beneficial to provide the retensioning plate 17 with additional bores so that the corrosion-resistant substance can penetrate the bores of the anchor plate 6 and the slits between the parts of the ring wedges to insure reliable protection of the strands 4 from corrosion.
[0033] Installation of the anchoring structure of this invention is illustrated in FIG. 3 . At a structure-side installation of the tension member 2 , the anchor body 10 is connected to a sheathing 18 that is cut to a suitable length and installed in the encasing of the corresponding concrete structure. The tension elements 3 , that is, the strands 4 surrounded by PE sheaths 5 , are pulled or pushed in in a conventional fashion before or after the mortar is added.
[0034] To guarantee the desired exchangeability of the strands in the area of the seal, the individual strands 4 are surrounded by tubes 23 in the area of the sealing plate 13 , which insure the sealing off to the outside but at the same time allow the strands to be pulled through. With simple extruded strands, telescopic tubes can be slid onto the strands' ends from the open air side, which penetrate the sealing plate 13 . In either case, the tubes 23 find an abutment on the retensioning plate 17 ( FIG. 1 b ).
[0035] When twice-extruded strands are used, that is, strands with two PE sheaths, a certain length of the outer PE sheath must be separated and removed from the end of the strand on the clamping side. Part of the inner PE sheath is then removed so that after tensioning, it ends in the area 19 of the anchoring, which is to be filled in with corrosion-resistant material. The outer PE sheath that was previously removed is re-attached and trimmed to a length such as to integrate it at installation with the area 19 , which is to be filled in with corrosion-resistant substance.
[0036] After all strands are installed, the perforated disk 12 , or, if necessary, before the steel plate 14 b , the sealing plate 13 , the pressure plate 14 a and the pressure tube 16 as well as the retensioning plate 17 are installed. Due to the fact that all these parts only have to be slid onto the tension elements 3 and into the anchor body 10 , no screwing processes are necessary, which allows a simple and time-saving installation. Further simplification of the installation can be achieved by combining the pressure plate 14 a and the pressure tube 16 in a pot-shaped unit. Lastly, the anchor plate 6 is threaded onto the protruding ends of the strands.
[0037] In this state of installation, the anchor plate 6 , which extends somewhat into the anchor body 10 , and thus finds a guide on its inner wall, is positioned at a slight distance to the abutment ring 9 , however, its inner surface rests against the pressure tube 16 , which in turn presses onto the pressure plate 14 a . This distance corresponds with the compactability of the sealing plate 13 , which is being activated in this way, when the anchor plate 6 penetrates the anchor body 10 during the tensioning of the strands 4 at a corresponding distance until it stays on the abutment ring 9 —with insertion of an intermediate spacer 22 .
[0038] After tensioning the tension elements 3 through the bores in the anchor plate 6 , through which an injection tool can be inserted, the interposition of the hollow space 19 between the sealing plate 13 and the anchor plate 6 with corrosion-resistant material is then carried out in a conventional manner. Lastly, the abutment ring 9 of the anchor body 6 is provided with a cover 20 so that by pressing in corrosion-resistant material, the anchor plate 6 with the wedge anchorings of the strands 4 are also protected against corrosion.
[0039] The tension channel, that is, the hollow space between the tension elements 3 and the sheathing 18 , usually remains unobstructed to simplify a possible replacement of individual strands and/or the entire bundle. If a fill-in is desired, in order to avoid penetration of water, for example, a non-hardening material, for example, bentonite, or a material with a low degree of hardening, for example, mortar mixed with a plastic additive, for example, polystyrene, which is easily removed if need be, can be pressed in. For this purpose, conventional venting and injection openings are provided in the anchor body 10 . In tension channels without fillings, these openings can be used for water drainage.
[0040] The intermediate ring 22 arranged between the anchor plate 6 and the abutment ring 9 is used when individual strands are being replaced, which necessitates a tension decrease, to avoid a dual wedge grip during the retensioning of the strands. The thickness of the intermediate ring 22 , which is removed prior to the retensioning of the strands, corresponds with the distance of the “new” wedge grip as compared to the “old” wedge grip. In this case, to reactivate the seal through the sealing plate 13 , an anchoring pipe 16 shortened by the thickness of the intermediate ring 22 is installed.
[0041] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
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A corrosion-resistant tension member, particularly a tendon for prestressed concrete, comprising a bundle of tension elements arranged inside a sheathing, has at its ends anchoring devices each with an anchor plate. On the side of the anchor plate facing away from the open air side, a seal having tension elements running through it and having a sealing plate are arranged, the sealing plate being fixed in place on the side facing away from the anchor plate opposite the anchor body against longitudinal displacement. Between the anchor plate and a pressure plate butting against the sealing plate, pressure-transferring means, for example, a pressure tube, are provided, having a length calculated in such a way that a longitudinal displacement of the anchor plate that occurs when the tension elements are being tensioned, actuates the exertion of surface pressure to the sealing plate for activating the seal.
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FIELD OF THE INVENTION
This invention relates to a reusable device for securing palletized materials. In particular, the pallet wrapper of this invention can be used for stabilizing a cluster of articles on a pallet, which will be transported on a vehicle such as a cart, lift truck, truck, trailer or railcar.
BACKGROUND OF THE INVENTION
In commercial and industrial establishments a cluster of boxes, cartons or other objects must be transported from one location to another. For example, in warehouse situations a large number of articles such as cartons stacked on a pallet are transported on a fork lift truck from a storage area to a shipping area or directly onto a truck, trailer or railcar for further distribution. In addition, pallet wrappers can be used extensively in retail stores where a large number of articles such as boxes are transported on a hand pushed cart from a storage area to various locations in the store where the individual items will be placed on display for customers.
When a fully loaded pallet is transported, turning the cart or truck too rapidly or bumping into shelving or walls results in the articles falling off of the pallet. During transportation on a truck, trailer or railcar, pallet loads tend to move and shift with the movement of the vehicle. In addition, there are occasions when simply running the cart or truck over a rough surface in a warehouse, causes the load of articles to fall off of the pallet. A collection of differently shaped or irregularly shaped articles can be especially unstable.
PRIOR ART
As a result of this need to keep clusters of articles from falling off a pallet during transportation many pallet wrapper devices have been proposed.
For example, in U.S. Pat. No. 4,868,955 issued on Sep. 26, 1989, a device for stabilizing a cluster of articles is disclosed. This invention describes a wrapper for palletized material made of a resilient fabric such as nylon having a large sheet of Velcro (Trademark) on one end thereof. The invention also discloses variations in which the wrapper is constructed of two parts joined by straps and buckles. The straps are sewn to the body material.
U.S. Pat. No. 4,876,841 issued on Oct. 31, 1989, describes a similar wrapper for palletized material formed from a flexible sheet with Velcro (Trademark) faces and straps. This invention also shows the straps being sewn to the body material.
Prior art reusable pallet wrappers, as described above, are unsatisfactory because they can cause excessive pressure points on the cartons resulting in damage to the product being wrapped. This can occur because the straps are sewn or directly attached to the material body. The pressure on the cartons being retained by the wrapper tend to be in line with the tightened straps thereby causing the cartons or boxes in line with the straps to be subjected to excessively large forces that may cause damage to the product in the cartons. This localized pressure is caused by the unequal distribution of force along the width of the wrapper.
In addition, when the wrapper is in place, particularly on uneven loads prior art wrapper material tends to buckle or bulge in the tightening area, possibly allowing small pieces to fall off the pallet. This is particularly evident in cases where the pallet contains a stack of relatively small items that are not packed in larger cartons.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a reusable pallet wrapper that can be used on regular, irregular and variable sized loads. The pallet wrapper will be installed easily with a series of straps and buckles where the tension of the wrapper is evenly distributed across the width of the pallet to eliminate any pressure points on the cartons disposed on the pallet. In addition, the wrapper will provide a rigid line across the width of the wrapper to prevent any buckling or bulging of the wrapper material.
A further object of the present invention is to provide a device for securing palletized material, which is efficient in operation, simple in construction and durable in use.
To reduce the problem of pressure points on wrapped material and bulging of the wrapper material, the present invention provides a reinforcing rod disposed at two opposing ends of the pallet wrapper with a series of straps and buckles attached to the rods.
In accordance with an aspect of this invention there is provided a device for use in stabilizing a cluster of articles, comprising a wrapper panel of flexible material having a first and second end and an upper and lower edge extending over the length of said wrapper panel, a first rigid reinforcing means disposed along said first end, a second rigid reinforcing means disposed along said second end, at least one attachment strap means having a free end and a fixed end, said fixed end being attached to said first reinforcing means, at least one strap receiving means having a free end and a fixed end, said fixed end being attached to said reinforcing means, and wherein said free end of said attachment strap means is engaged with said free end of said strap receiving means with said wrapper panel being adapted to be positioned around said cluster of articles resulting in an even tension across the width of said wrapper panel by said first and second reinforcing means.
A more detailed description of preferred embodiments of the new reusable pallet wrapper will now be set forth in reference to the drawings.
DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like numerals of reference indicate corresponding parts in the various figures, in which:
FIG. 1 is a perspective view of a stack of palletized materials having a reusable pallet wrapper of the present invention positioned in place thereon;
FIG. 2 is a plan view of the reusable pallet wrapper of the present invention;
FIG. 3 is sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is sectional view taken along line 4--4 of FIG. 2; and
FIG. 5 is a perspective view of a stack of palletized materials having a modified version of the reusable pallet wrapper of the present invention positioned in place thereon.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a pallet 20 having a horizontal platform 22 and a plurality of elongated upstanding ribs 24, which support platform 22 in spaced relation above a supporting surface. Supported on platform 22 are a plurality of cartons or packages designated generally by numeral 26. The cartons or packages 26 are piled up on one another to form a stack 28. The cartons 26 in stack 28 shown in FIG. 1 are regular in shape, however the particular shape and size of the containers can vary without detracting from the invention.
Surrounding stack 28 of cartons 26 in FIG. 1 is a pallet wrapper 1 having a flexible primary wrapper panel 2 and a wrapper flap 5. The wrapper panel 2 has an upper edge 30, a lower edge 32 and opposite ends 34-35 as shown in FIG. 2. The wrapper flap 5 has an upper edge 40, a lower edge 42, a free end 44 and a fixed end 45 attached to end 35 of panel 2. Flap 5 can be either an extension of panel 2 or a separate add-on portion. Flap 5 could also extend from end 34 or both ends 34 and 35 of panel 2.
Flap 5 is used in cases where the perimeter of stack 28 exceeds the length of wrapper panel 2. Flap 5 is used to cover exposed cartons 26 between ends 34-35 of panel 2 when panel 2 is wrapped around stack 28 thereby permitting use of the pallet wrapper 1 on variable sized pallet loads, i.e. the perimeter distance of stack 28 may vary and still be accommodated by pallet wrapper 1.
It is not necessary that panel 2 have a width between the upper and lower edges 30-32 sufficient to cover the entire height of stack 28. For example, it would be sufficient for the height between edges 30-32 to be between approximately one-third and one-half of the height of the entire stack 28. In particular, the width of panel 2 depends on the product being wrapped and on the customer's needs. In some instances, the top two tiers of a properly cubed pallet need only be wrapped, whereas a pallet load of onions, or similar product, in bags or sacks will require the width of panel 2 to between approximately three-quarters and the full height of pallet stack 28.
In addition, flap 5 does not necessarily have to be as wide as panel 2. Minor variations in the width of flap 5 with respect to the width of panel 2 can be made without detracting from the invention.
Panel 2 and flap 5 may be made of any material of sufficient strength such as woven polypropylene, canvas or nylon.
A strap sleeve 15 is formed along end 35 of panel 2. Sleeve 15 has a plurality of strap slots 17 approximately the same length as the width of a tightening strap 11.
A buckle sleeve 16 is similarly formed along end edge 34 of panel 2. Sleeve 16 has a plurality of buckle slots 18 approximately the same length as the width of a buckle strap 9.
Rods 13 are disposed within sleeves 15 and 16 and are used to retain a plurality of tightening straps 11 and a corresponding plurality of buckle straps 9. Rods 13 could be of any suitable configuration, such as round, square or rectangular. Rods 13 are approximately as long as the width of panel 2 and made of any suitable rigid material, such as plastic, wood or metal.
A plurality of buckles 7 are attached to one end of each of the plurality of buckle straps 9, which have loop ends 10 formed at the other end thereof. The loop ends 10 of buckle straps 9 are engaged around rod 13 at end 34 of wrapper panel 2, see FIG. 3. A small portion of each of the buckle straps 9 with buckles 7 attached thereto project from buckle slots 18 of buckle sleeve 16. Rod 13 is retained in buckle sleeve 16 by closing the open ends at upper and lower edges 30-32 of sleeve 16 by sewing or other means.
Tightening straps 11 of suitable length are provided having free ends 12 and loop ends 10. The loop ends 10 of straps 11 are engaged around rod 13 at end 35 of wrapper panel 2, see FIG. 4. The free ends 12 of straps 11 project from strap slots 17 of strap sleeve 15. Rod 13 is retained in sleeve 15 by closing the open ends at upper and lower edges 30-32 of sleeve 15 by sewing or other means. The tightening straps 11 and buckle straps 9 can be made from a suitable material such as polyester, nylon or polypropylene.
Buckles 7 and tightening straps 11 perform the function of retaining and holding the tension on wrapper panel 2 when pallet wrapper 1 is in place and tightening straps 11 have been inserted through buckles 7 and tightened. Other tightening devices such as Velcro (Trademark) straps can also be used to maintain the required tension of panel 2 without detracting from the invention.
The number of buckles 7 and corresponding tightening straps 11 is dependent largely on the width of panel 2. It is necessary that a sufficient number of buckles and straps be provided to ensure that an even tension force can be applied across the width of panel 2. Therefore, for relatively small pallet wrappers one buckle 7 and tightening strap 11 located in the center of rods 13 would be sufficient. However, for very large pallet wrappers it may be necessary to provide three or more buckles 7 and a corresponding number of tightening straps 11 attached to rods 13 spaced along the width between the upper and lower edges 30-32 of panel 2.
The reusable pallet wrapper 1 of this invention is used by wrapping panel 2 around the perimeter of stack 28. Flap 5 extends from end 34, 35 or both ends 34-35 of panel 2 under tightening straps 11 and buckles 7, i.e. flap 5 rests against cartons 26. In some cases flap 5 can be tucked under panel 2 against cartons 26. Flap 5 can be either an extension of panel 2 or a separate portion attached to panel 2. Flap 5 is used to protect material that would otherwise be exposed through the gaps between straps 11 and buckles 7 connecting ends 34-35 of panel 2. The free ends 12 of tightening straps 11 are then placed through the corresponding buckles 7.
When tension is applied with tightening straps 11 the rods 13 cause an even tension across the width of panel 2 thereby eliminating pressure points on cartons 26. In addition, pallet wrapper 1 maintains a rigid line across the width of panel 2 thereby preventing buckling or bulging of wrapper panel 2.
In this arrangement it is possible to transport pallet 20 with stack 28 thereon in such a manner that cartons 26 are not damaged and items do not fall off pallet 20 when cartons 26 are properly stacked in a tight configuration.
Although the wrapper panel 2 shown in the figures is substantially rectangular, panel 2 could also be trapezoidal or any other shape that may be required to accommodate irregular pallet stacks 28. The rods 13 would still reinforce the ends of panel 2 no matter what its shape.
Referring to FIG. 5, a modified form of the invention is shown holding stack 28 of cartons 26. In some circumstances it is desirable to protect the top of stack 28 of cartons 26. The modified form of the pallet wrapper is designated as numeral 100. Pallet wrapper 100 includes a top or hood 110 that is sewn or otherwise attached to upper edge 30 of panel 2. This hood will provide additional security and protection to cartons 26. The other components of this modified pallet wrapper 100 are identical to those previously described.
Although preferred embodiments of the invention have been described in detail, such description is intended to be illustrative rather than limiting, for some of the components of the wrapper can be variously modified so the scope of the invention is to be determined only by interpreting the claims.
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The present invention relates to a reusable pallet wrapper used to secure palletized cartons stacked onto a pallet. The wrapper includes a flexible panel with rigid reinforcement at two ends. Straps are attached to one rigid end of the wrapper, and buckles are attached to the other rigid end of the wrapper. When the straps are inserted through the buckles and tension applied the wrapper panel will be secured around a stack of palletized objects with even tension across its width. This wrapper reduces the amount of damage to articles being wrapped.
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This invention relates to a method of controlling call traffic in a telecommunication system and more particularly a method of dynamically altering the rate at which offered calls are accepted, so as to control the volume of calls of a particular type allowed to continue to their destination thereby reducing the tendency of such types of traffic to cause congestion of switching routes and/or switching systems.
BACKGROUND OF THE INVENTION
Communications switching and signalling networks are subject to congestion and overload when the offered traffic is above the capacity of the network to handle the load and various techniques have been developed to control such overload and congestion for particular situations. One such control system which utilizes a call-gapping algorithm to control traffic volume in the system is disclosed in U.S. Pat. No. 5,060,258 entitled "Call Traffic Control" by Peter M. D. Turner, to which the reader is directed for reference. For further details on the application of this algorithm, as well as an excellent review of two prior algorithms, the reader is directed to a paper entitled "A New Call Gapping Algorithm for Network Traffic Management" by P. M. D. Turner and P. B. Key, 13th International Teletraffic Congress, Copenhagen (1991) volume 14, pp. 121-126. The contents of both of these documents are incorporated herein by reference.
In these existing call-gapping algorithms, the volume of calls allowed through the system, is always at or below the volume limit with very high offered traffic. However, it is desirable in some cases within operating communications networks to be able to firmly limit call volumes under conditions of heavy overload, while still allowing some greater volume when the degree of system overload is smaller. Such cases can arise, for example, when the network of a different service provider is interconnected to allow an exchange of calls. The expected traffic volumes may not be well estimated and it is desirable to carry as much of the traffic as reasonable. Under heavy overload, however, it is desirable to firmly limit the accepted traffic to achieve better fairness in the completion of calls from different sources. With the methods of the prior art, the operators of the communications system would have to change the control parameters as the volume of offered traffic varies in order to achieve this end.
SUMMARY OF THE INVENTION
The present invention provides a method of controlling call traffic which will limit the volume of accepted traffic when the offered load is much greater than the predetermined limit, while allowing a greater volume when the offered traffic is only slightly above this limit.
Thus in accordance with the present invention there is provided a method of controlling call traffic in a telecommunication system by dynamically altering the rate at which offered calls are accepted, characterised by the steps of: successively determining the offered call rate; and accepting calls from the offered calls, at a lower rate whenever said offered call rate exceeds a load threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
An example embodiment of the invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a graph illustrating accepted call rate versus offered call rate for a call-gapping algorithm described in the prior art;
FIG. 2 is a graph illustrating accepted call rate versus offered call rate for a call-gapping algorithm in accordance with the present invention;
FIG. 3 is a schematic representation of gapping intervals which are dynamically selected to control the accepted call rate under varying offered call rates (ie: traffic loading conditions), as illustrated in the graph of FIG. 2; and
FIG. 4 is a block schematic diagram of a control circuit which forms part of a telecommunication system, for generating the call-gapping algorithm of the invention, so as to dynamically control the accepted call rate, which is determined during successive load evaluation periods, as illustrated in the graph of FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 illustrates a graph of accepted call rate versus offered call rate, utilizing the call-gapping algorithm in the above referenced prior art patent and the paper by Turner et al. While the Turner method does not necessarily force a time gap between successive messages, common industry usage applies the term "gapping" to the general process of load control characterised by rejecting some offered messages and not others.
The horizontal portion of the solid line in the graph illustrates an accepted call rate of one accepted call per gapping interval. The Turner patent describes an embodiment which permits an allowance for unused gapping intervals to be carried forward (subject to defined limits) to subsequent intervals, so that the accepted call rate can have a transient rise above one accepted call per gapping interval. However, once the carry forward allowance is exhausted, as encountered during sustained overload conditions, the accepted call rate reverts back to one accepted call per gapping interval, and the balance of the offered calls during each gapping interval, are rejected. In another embodiment, the Turner algorithm also limits the maximum number of accepted calls in any one gapping interval, regardless of the number of unused gapping intervals carried forward.
The Turner algorithm provides little deviation from the ideal call acceptance rate for varying offered call rates. However, in some cases as, for example, with interconnecting telecommunications systems, it is desirable to accept as many calls as possible, even more than the engineered design level, as long as this extra acceptance is not too great. Under heavy overload there is still the need to strictly limit allowed calls so that network integrity can be maintained. It is this aspect of the Turner algorithm that the present invention seeks to address.
Referring to FIG. 2 and FIG. 3, the call-gapping algorithm of the present invention will be described with reference to a typical example. In this example, the accepted call rate during sustained overload conditions is set at an average of 8 calls per second, yielding a gapping interval T2=125 milliseconds. Under light overload conditions the accepted call rate is allowed to exceed the long term rate by 25%. The accepted call rate is then 10 calls per second, with a gapping interval T1=100 milliseconds, yielding a peaking factor PF=1.25 (ie: T2/T1). The load representing the transition between light and heavy overload is selected as being a rate 2.5 times the accepted call rate under heavy overload. This results in a dropping factor DF=2.5. A load evaluation period P is selected as 20 times the gapping interval T1 during light loads, or P=2 seconds. A load threshold LT used in the load evaluation, is defined by the following equation:
LT=20×DF/PF
to yield a threshold value LT=40 incoming calls per load evaluation period P.
Offered calls are accepted or rejected using the technique described by Turner, with the gapping interval parameter of the Turner algorithm modified as a result of the load evaluation process. When the incoming call rate is determined at the expiry of a load evaluation period P as being below the threshold level LT defined by the dropping factor DF, the call-gapping algorithm uses the gapping interval T1. When the load is at or above the level LT determined by the dropping factor, the gapping interval is changed to the value T2.
Hence when light overload conditions exist, as shown in the left hand portion of FIG. 2, the call acceptance rate is greater than the design maximum for heavy overloads, as shown in the right hand portion of the FIG. The key advantage of this call-gapping algorithm is that it allows the acceptance of more offered calls under light loads, while maintaining the designed allowance for offered calls when a major overload to the system is encountered.
While this example selects one of two gapping interval values based on the offered call count determined during successive load evaluation periods P, this could be extended to allow a selection of one of a plurality of gapping interval values, depending on that count.
Also, while this example utilizes the Turner algorithm for a basic call-gapping process, the method of this invention may also be applied to vary the gapping interval parameters of other gapping algorithms such as those outlined in Turner's description of the prior art.
The call-gapping algorithm will be manifest by reference to the control circuit of FIG. 4. In the control circuit, offered call signals connected to its input 10, are coupled to the down input D of a load evaluation threshold counter 12, that is reset to the load threshold LT=40 every load evaluation period P=2 seconds, in response to an evaluation period signal P from a clock generator 14. Each offered call signal that is received by the control circuit, decrements the counter 12 by 1 until it reaches 0, whereupon its output, initially LO, goes HI signalling that at least 40 calls have been received during the current load evaluation period P. The output value at the end of the load evaluation period P is stored in a holding register 15 for the duration of the next load evaluation period. This is repeated during each successive load evaluation period P so that the output of the register 15 dynamically tracks the average call traffic. During light incoming call traffic conditions, when less than 40 calls per period P are received, the control signal from the output of the register 15 stays LO. This enables AND gate 16 through its inverted input, so that the gapping interval control signal T1=100 milliseconds from the clock 14, is coupled through the AND gate 16 to one input of OR gate 20. Conversely, when heavy incoming call traffic is present and more than 40 calls per evaluation period P are received, the output from the register 15 goes HI thereby disabling the AND gate 16 and enabling AND gate 18, so as to couple the gapping interval control signal T2=125 milliseconds from the clock 14 to the other input of the OR gate 20.
Hence, depending upon the density of the incoming call signals, either gapping interval signal T1 or gapping interval signal T2, is coupled through the OR gate 20 to the incrementing input U of an up/down counter 22, thereby incrementing the counter 22 by 1 each call-gapping interval until its upper limit of 40 is reached. The maximum value of the counter 22 represents the "Global Counter" described in Turner's paper. Conversely each incoming offered call signal from the input 10, is coupled through one input of an AND gate 11 to the decrementing input D of the counter 22. Each incoming call signal decrements the counter 22 by 1 until its lower limit of 0 is reached, whereupon the counter's output, otherwise LO, goes HI. The counter 22 never exceeds its upper or lower limits, but moves between the two values. The HI output from the counter 22, when coupled through OR gate 24 to the inverted input of AND gate 26, disables the gate 26 so that any additional incoming call signals are blocked or rejected during the current gapping interval.
Incoming call signals from the input 10 are also coupled to the decrementing input D of a limit counter 28 which is reset to 4, at the beginning of each gapping interval, by either the gapping signal T1 or T2 coupled from the output of the OR gate 20. The limit counter 28 represents the limit of the call attempts in one interval identified as the "Local Counter" in the Turner paper. Once reset, each incoming call signal decrements the counter 28 by 1 until 0 is reach where it remains until again reset at the beginning of the next gapping interval. Whenever the counter 28 reaches 0, its output, otherwise LO, goes HI which disables the AND gate 26 in a similar manner to that of the counter 22. Thus, when either of the control signals from the counters 22 or 28 are HI, incoming call signals are blocked or rejected.
In this example of the preferred embodiment, the timers T1 and T2 will be synchronous with expiry of the timer P. In other embodiments when this is not so, the circuit should be arranged so that when the register 15 makes a transition from one output state to another, an appropriate signal is sent to the clock 14. On reception of this signal, the clock 14 will reset the timer output (T1 or T2) which will be used for the next load evaluation period in synchronism with the other timer (which is in current use) so that a clean transition is made between the two clock rates.
This will be further manifest with reference to FIG. 3 in which the upper waveform illustrates the decrementing of the load threshold counter 12 by the incoming call signals during a typical load evaluation period P. The middle waveform illustrates incoming accepted calls at the output 30 of the control circuit, during light loading conditions for several gapping intervals under control of the clock signal T1.
The lower waveform in FIG. 3 illustrates, in more detail, an example of call control in accordance with the call-gapping algorithm. Initially, assume the system has been running for some time and the up-down counter 22 has been incremented to 8 by either or both of the gapping interval signals T1 or T2. At the beginning of each interval, the limit counter 28 is reset to 4. As each incoming call is accepted, both counters 22 and 28 are decremented by 1 until the second gapping interval signal, when the up-down counter 22 is incremented by 1 to a value of 7 while the limit counter 28 is reset to 4.
During the second gapping interval, the counter 28 is decremented to 0 by incoming call signals whereupon the output of the counter 28 goes HI thereby blocking the AND gate 26, so that the further two incoming call signals during the gapping interval are rejected. The output of the counter 28 also controls the decrementing input D to the counter 22 through the inverting input to the AND gate 11, so that the counter 22 is not decremented by incoming calls that are blocked by the limit counter 28.
During the subsequent interval both counters 22 and 28 are decremented to 0 by incoming call signals and the subsequent three calls are rejected. Next, the counter 28 is again reset to 4 while the counter 22 is incremented by 1 to a value of 1. As a result only one call signal is accepted before the counter 22 is decremented to 0 and all further calls during the interval are rejected. This condition will continue as long as there is heavy incoming call traffic, thereby limiting the maximum average accepted call signal to one per gapping interval. When the heavy traffic subsides with less than 40 incoming calls per load evaluation period P, the system will revert to the gapping interval T1 so that up to an additional 25% of the incoming call signals can be accepted.
In the illustrated embodiment, the limit counter 28 limits the accepted calls to a maximum of 4 per gapping interval regardless of whether it is currently being controlled by the gapping interval signal T1 or T2. It will be evident that this restriction could be removed simply by disabling the output of the counter 28.
As described, up to 40 unused gapping intervals can be stored in the up-down counter 22 and thus carried forward to subsequent intervals as described in the Turner paper. However, this number can be readily increased or decreased simply by altering the limits of the counter 22 and in the extreme, limiting the number of accepted calls to one per gapping interval with none carried forward to subsequent intervals.
In the illustrated embodiment, the load evaluation period is set at 20 times the value T1. However, this number can be readily increased or decreased simply by altering the interval set by the clock output P and adjusting the initial value of the counter 12 in a proportionate manner.
While the call-gapping algorithm has been described utilizing a hardware implementation, it could also be readily implemented in software to achieve the same result. Likewise, while the gapping algorithm of this invention has been described in relation to offered calls, it may also be applied to limit other manifestations such as messages within a signalling system. Consequently, in the appended claims, the term "calls" should be interpreted as embracing such other manifestations.
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A method of controlling call traffic in a telecommunication system by dynamically altering the rate at which offered calls are accepted includes the steps of successively determining the offered call rate, and accepting calls from the offered calls, at a lower rate, as the offered call rate increases. For accepting the offered calls, at least two call-gapping intervals are used. The method includes selecting the shorter gapping interval whenever the offered call rate is below a threshold value and the longer gapping interval whenever it is above that value.
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FIELD OF THE INVENTION
This invention relates to a method and article for improving the storage of materials subject to deterioration by water vapor absorption or solvents or absorption of gases such as SO 2 or ozone. It particularly relates to storage of raw photothermographic films.
BACKGROUND OF THE INVENTION
The ability to store processed and unprocessed photographic film without change in the properties of the film is important to maintaining exposed and developed films, as well as maintaining consistent performance of unexposed films. The archival keeping properties of photographic films are expected to be measured in decades. The properties of unexposed films are intended to remain stable over many months of storage in various conditions.
It is common practice to use hermetically sealed containers of plastic or metal, or to seal in metal coated polymer bags to prevent moisture access to films. It is also desirable to protect films from gases such as SO 2 and ozone. Other materials such as food also need sealed and protective packaging. This is commonly referred to as Modified Atmosphere Packaging (MAP). This is where you create a specific ambient condition within a package different than typical ambient atmospheric condition.
Further, it has been disclosed in U.S. Pat. No. 5,215,192--Ram et al that particulate materials such as molecular sieve zeolites may be placed in film storage containers for exposed films to improve their storage properties. Desiccants also have been proposed for package insert or coating material for a package for film or cameras in U.S. Pat. No. 4,036,360--Deffeyes.
It has been proposed in U.S. Pat. No. 5,189,581--Schroder that desiccants be placed within video cameras in order to dry the cameras.
U.S. Pat. No. 5,789,044--Ram et al discloses the use of zeolite molecular materials to form a part of a structure that is utilized for storing or holding film.
It is disclosed in U.S. Pat. No. 5,633,054--Hollinger, Jr., U.S. Pat. No. 5,525,296--Hollinger, Jr., and U.S. Pat. No. 5,683,662--Hollinger, Jr. that materials such as hydrophobic molecular sieve materials may be incorporated into fiber materials. The molecular sieve materials are crystalline, hydrated metal aluminosilicates which are either made synthetically or naturally occurring minerals. Such materials are described in U.S. Pat. Nos. 2,882,243; 2882,244; 3,078,636; 3,140,235; and 4,094,652.
In packaging of unexposed photothermographic films, there has been found to be particular difficulty in that present packaging methods for such films utilized in the health care business do not result in good storage properties even though sealed in plastic film bags having a metalized layer. There is a need for improved packaging materials for such films.
However, the above systems for placing desiccants into a package suffers of from disadvantages. The desiccant packs may be difficult to dispose of. Further, the packs contain polymers which are expensive and may inhibit absorption gases to the zeolite or other humiditants. Further, they cause an inconvenience and expense in packaging in that a separate item must be added to the package, and such external elements may induce pressure sensitization of films.
PROBLEM TO BE SOLVED BY THE INVENTION
There remains a need for a method of providing packages for photothermographic films with improved desiccant and gas absorbing protection. Further, there is a need for a better method of providing photothermographic film packaging with desiccant protection.
SUMMARY OF THE INVENTION
An object of the invention is to overcome disadvantages of prior methods and articles.
A further object of the invention is to provide improved moisture protection for photographic articles.
An additional object is to provide improved storage qualities and container for storing photothermographic film materials.
These and other objects of the invention generally are accomplished by a method of improving raw stock keeping of silver containing imaging material comprising providing a package of said material and providing in said package a fiber board containing zeolite.
ADVANTAGEOUS EFFECT OF THE INVENTION
The invention provides packaging that provides moisture protection without the need for a separate package of desiccant which presents a disposal problem, as well as a packaging problem. The method of the invention further provides an integral structure that is both a structural part of the packaging, as well as providing desiccant protection. The method and articles of the invention are low in cost and provide improved film properties by allowing storage of photothermographic film materials without deterioration.
DETAILED DESCRIPTION OF THE INVENTION
The invention has the advantage that photothermographic films are generally packaged with stiffener, commonly cardboard or paperboard liners to prevent damage to the film during handling and shipping by bending or edge deterioration. The packaging method of the invention utilizes these paper fiber linerboards as the medium for carrying zeolite which will both protect the film from deterioration due to humidity changes and absorption of other gases, while also protecting the film from damage by bending and edge deterioration from handling. Therefore, the use of linerboards of the invention does not increase the packaging load of the product but utilizes a packaging material already present to also provide the added advantage of better raw stock keeping of the material in the package. Even when moisture or solvent saturation of the molecular sieves of the. invention occurs, the structural products will maintain their integrity, as well as being conductive and providing static protection to the materials. The invention also has the advantage that the reduction in moisture during storage will improve the raw stock keeping of a photographic film by increasing the glass transition temperature of the gelatin emulsion due to the reduced moisture content. These and other advantages will be apparent from the description below.
The zeolites utilized in the invention may be added to any suitable paper or fiber that will provide sufficient strength to the package. Further, the paper should be nonphotographcally active and not give off any materials that would be harmful photographically. The paper preferably is free or substantially free of ligand and sulfur. It preferably is a pH with neutral alkaline range and contains an alkaline buffer such as calcium carbonate. It may be preferable when protein based materials are to be stored in or maintained next to the layer that alkaline buffers not be on the surface. The zeolite of the invention is mixed with the paper fibers and may be formed in any conventional paper or linerboard forming machine in which a slurry of fibers is placed onto a foraminous member such as a fourdrinier wire to drain, and then the sheet is subject to further water removal steps between felts and dryer drums. The paper may be formed in a machine with the head box that releases multiple streams for formation of a paper that has a different surface structure from the interior.
In the storage of photographic materials, it is important that the relative humidity be maintained at a low percent of moisture content, as the gelatin which contains the image materials exhibits a variety of glass transition temperatures depending on the amount of retained moisture due to the surrounding relative humidity of the air in equilibrium. Photothermographic films, particularly in the large size sheets of 14"×17" where these materials are used, are also subject to humidity differences across the transverse direction of the sheet. It is desirable that the moisture content at the edges be close to that at the center of the sheet. Having constant humidity decreases sensitivity of this film to temperature. Temperature sensitivity will result in different photographic performance depending on the temperature humidity relationship. The moisture and solvent absorption by the zeolites will increase the glass transition temperature of the poly(vinyl butyral) polymer. The resulting increase in glass transition temperature will prevent rapid deterioration of the film performance due to hydrolysis. By hydrophilic zeolite, it is meant that the zeolite will absorb between 18 and 24% its weight in water. Further, hydrophilic zeolites of the invention will absorb between about 15 and about 35% of their weight in acids. Further, they also will have solvent absorption properties of about 15 and 30 percent by weight.
Any suitable hydrophilic molecular sieve zeolite such as, for example, Type A, Type L, Type X, Type Y, and mixtures of these zeolites may be used in this invention. In the practice of this invention the two hydrophilic types, A and X, are preferred. Molecular sieve, zeolites contain in each crystal interconnecting cavities of uniform size, separated by narrower openings, or pores, of equal uniformity. When formed, this crystalline network is full of water, but with moderate heating, the moisture can be driven from the cavities without changing the crystalline structure. This leaves the cavities with their combined surface area and pore volume available for absorption of water or other materials. The process of evacuation and refilling the cavities may be repeated indefinitely under favorable conditions.
With molecular sieves, close process control is possible because the pores of the crystalline network are uniform rather than of varied dimensions, as is the case with other adsorbents. With the large surface area and pore volume, molecular sieves can make separations of molecules, utilizing pore uniformity, to differentiate on the basis of molecular size and configuration.
Molecular sieves are crystalline, metal aluminosilicates with three dimensional network structures of silica and alumina tetrahedra. This very uniform crystalline structure imparts to the molecular sieves properties which make them excellent desiccants, with a high capacity even at elevated temperatures. The tetrahedra are formed by four oxygen atoms surrounding a silicon or aluminum atom. Each oxygen has two negative charges and each silicon has four positive charges. This structure permits a sharing arrangement, building tetrahedra uniformly in four directions. The trivalency of aluminum causes the alumina tetrahedron to be negatively charged, requiring an additional cation to balance the system. Thus, the final structure has sodium, potassium, calcium or other cations in the network. These charge balancing cations are the exchangeable ions of the zeolite structure.
In the crystalline structure, up to half of the quadrivalent silicon atoms can be replaced by trivalent aluminum atoms. Zeolites containing different ratios of silicon to aluminum ions are available, as well as different crystal structures containing various cations.
In the most common commercial zeolite, Type A, the tetrahedra are grouped to form a truncated octahedron with a silica or alumina tetrahedron at each point. This structure is known as sodalite cage.
When sodalite cages are stacked in simple cubic forms, the result is a network of cavities approximately 11.5 Å in size, accessible through openings on all six sides. These openings are surrounded by eight oxygen ions. One or more exchangeable cations also partially block the face area. In the sodium form, this ring of oxygen ions provides an opening of 4.2 Å in diameter into the interior of the structure. This crystalline structure is represented chemically by the following formula:
Na.sub.12 [(AlO.sub.2).sub.12 (SiO.sub.2).sub.12 ]×H.sub.2 O
The water of hydration which fills the cavities during crystallization is loosely bound and can be removed by moderate heating. The voids formerly occupied by this water can be refilled by adsorbing a variety of gases and liquids. The number of water molecules in the structure (the value of X) can be as great as 27.
The sodium ions, which are associated with the aluminum tetrahedra, tend to block the openings, or conversely may assist the passage of slightly oversized molecules by their electrical charge. As a result, this sodium form of the molecular sieve, which is commercially called 4 A, can be regarded as having uniform openings of approximately 4 Å diameter.
Because of their base exchange properties, zeolites can be readily produced with other metals substituting for a portion of the sodium.
Among the synthetic zeolites, two modifications have been found particularly useful in industry. By replacing a large fraction of the sodium with potassium ions, the 3 A molecular sieve is formed (with openings of about 3 Å). Similarly, when calcium ions are used for exchange, the 5 A (with approximately 5 Å openings) is formed.
The crystal structure of the Type X zeolite is built up by arranging the basic sodalite cages in a tetrahedral stacking (diamond structure) with bridging across the six-membered oxygen atom ring. These rings provide opening 9-10 Å in diameter into the interior of the structure. The overall electrical charge is balanced by positively charged cation(s), as in the Type A structure. The chemical formula that represents the unit cell of Type X molecular sieve in the soda form is shown below:
Na.sub.86 [(AlO.sub.2).sub.86 (SiO.sub.2)lO.sub.6 ]XH.sub.2 O
As in the case of the Type A crystals, water of hydration can be removed by moderate heating and the voids thus created can be refilled with other liquids or gases. The value of X can be as great as 276. A value of X between 10 and 35 is preferred for good solvent and water absorption.
A prime requisite for any adsorbent is the possession of a large surface area per unit volume. In addition, the surface must be chemically inert and available to the required adsorbate(s). From a purely theoretical point of view, the rate at which molecules may be adsorbed, other factors being equal, will depend on the rate at which they contact the surface of adsorbent particles and the speed with which they diffuse into particles after contact. One or the other of these factors may be controlling in any given situation. One way to speed the mass transfer, in either case, is to reduce the size of the adsorbent particles.
While the synthetic crystals of zeolites are relatively small, e.g., 0.1 μm to 10 μm, these smaller particles may be bonded or agglomerated into larger shapes. Typical commercial spherical particles have an average bonded particle size of 1000 μm to 5000 μm (4 to 12 mesh). Other molecular sieve shapes, such as pellets (1-3 mm diameter), Rashig rings, saddles, etc., are useful.
The molecular sieve should be employed as received from the manufacture which is in the most dry conditions. If the molecular sieve has been exposed to the atmosphere, it is preferred that it be reactivated according to manufacturer's recommendations.
The molecular zeolite generally is in powder form when incorporated into the wood fibers. However, there might be instances when a molecular sieve may be somewhat larger than powder such as pellets.
The molecular sieve material may be incorporated in any suitable amount. Generally when the molecular sieve zeolite of a particle size of between 0.1 and 10 μm average diameter is utilized, the zeolite material can be present in any effective amount up to about 4 percent by weight of the paperboard and still provide adequate structural properties for use in photographic. A suitable amount of molecular sieve material is between 20 and 40 weight percent of the total weight of the paperboard. The amount can be varied depending on the mechanical requirement of the paperboard member. A preferred amount of zeolite incorporation is between about 25 and 35 percent by weight of the paperboard for good absorption of water vapor and other vapors with preservation of the properties of the photothermographic film.
The fiber boards of the invention typically will have a basis weight of between about 0.7 kg/m 2 and 0.3 kg/m 2 A preferred basis weight is between 0.44 and 0.52 kg/m 2 for structural properties that will protect the film in the package, as well as providing sufficient zeolite to maintain humidity control. Typically the fiber board having between 25 and 35 percent of zeolite by weight is utilized in an amount such that the fiber board utilized in packaging has a weight of between about 3 and 8 percent of the weight of the photographic material. Typically the liner board utilized in the invention is in the form of a folder such that it is slightly larger than the stack of sheets of film being packaged and has a protective sheet on the top and bottom, as well as extending along one side. This provides adequate protection without complicated packaging or waste of material.
It has been found that the materials of the invention result in exceptionally uniform humidity control of the materials being packaged. Even in the center of the package, the sheets are of a humidity and solvent content similar to those at the edges near the zeolite containing paperboard of the invention. Film packaged without a solvent and humidity controlling hydrophilic zeolite paperboard will have different moisture and solvent contents vertically and horizontally within the package of the film leading to nonuniform photographic performance.
The paper or paperboard containing zeolite of the invention also may be provided with other active materials. The paper may also contain activated charcoal, activated carbon, or other similar carbon-containing absorbent materials. It is also possible to use an inorganic absorbent such as silica, activated alumina, or clay. The addition of these materials will aid in absorption of other materials which may be present in the packaging. As the photothermographic film contains a polymer matrix in which the photoactive ingredient is present, the polymer may give off solvents which can be absorbed both by the zeolite, clay, and activated charcoal. While the invention has been discussed with respect to film that is packaged in a plastic bag, the materials of the invention also could be utilized with photothermographic films that are packaged in materials such as plastic-lined boxes and canisters. Such film also could be packaged with the linerboard to both protect it from physical damage, as well as deterioration by changes in humidity or solvent deterioration.
The fiber board of the invention containing hydrophilic zeolite is generally stable and, therefore, does not significantly shed fibers or zeolite particles which will become contaminants on the film and have a deleterious effect upon images formed on the photothermographic film.
The following examples illustrate the practice of this invention. They are not intended to be exhaustive of all possible variations of the invention. Parts and percentages are by weight unless otherwise indicated.
EXAMPLES
A Molecular Sieve Type 4A hydrophilic zeolite was obtained from UOP--Molecular Sieve Division, Inc. The zeolite has a chemical composition of sodium aluminosilicate and has an average particle size of about 5 μm. A hydrophobic zeolite with a [particle size] 5 μm was also obtained from FiberMark, Inc., 44 Old Princeton Road, Fitchburg, MA 01420. Three samples are then formed, one utilizing the molecular sieve type 13X hydrophilic zeolite, another utilizing the hydrophobic zeolite of the prior art, and a third not containing zeolite. Samples (1) without zeolite, (2) with hydrophobic zeolite, and (3) with hydrophilic zeolite were then compared to see their effect upon photothermographic film during storage. Sample 4 is the control for no aging and is tested prior to incubation. Samples 1, 2, and 4 are controls, and Sample 3 is the invention. The sheets are prepared by forming a slurry of wood fiber of alkaline paper, and dispersing the slurry in water. The diluted and dispersed slurry was then placed in a sheet mold. This sheet mold had a wire mesh screen at its base. The slurry in the sheet hold was mildly agitated, and the sheet mold was then drained. As the water drained through the wire mesh screen, the fiber and the adsorbent and/or buffer was collected as a mat on the screen. Next, a blotter was placed on the resulting wet fiber mat in order to remove excess water. The blotter was then used to peel the fiber mat away from the wire mesh screen. Next, the mat was sandwiched between two cloth felts and mechanically pressed to remove water. The pressed mat was then dried on a dryer can to form a sheet having a moisture content of between 5 and 10 percent. The two samples having the zeolite were prepared according to the above procedure. Each of the samples containing zeolite contain 30% by weight of the zeolite. These boards have a basis weight of about 0.52 kg/m 2 . A sheet of each of the prepared materials was utilized and packaging in a standard pack of photothermograpahic medical imaging film. The pack is vacuum sealed, foil trade pack of 100 14"×17" sheets of silver behemite type photothermograhic medical imaging film. Three packs are formed with the cardboard on the top and bottom of the stack, as well as along one edge. The sealed trade packs were then incubated for two weeks at 100° F. (38° C.) temperature. They were then given a laser sensitometry exposure and processed on a drum type thermal processor to access changes in imaging response brought by incubation. The boards did not show any photo activity detrimental to the films. The Table 1 below illustrates the results of testing. Table 1 shows the 5 results of 2-week Incubation of 2 packages of each sample at 70° F. (21° C.) It also shows a Control Sample 4 tested prior to any incubation. Each sample was divided prior to packaging and one part preconditioned 72 hours at 70° F. (21° C.) and at 15%, relative humidity, and the second part at 60% relative humidity at 70° F. (21° C.) for 72 hours. The samples were then packaged and tested. After incubation, exposure and processing Gross Fog, Upper scale contrast, Upper density point and speed were measured for sheets 1, 20, 50, and 90 of each pack. The average of the number for the measured sheets appears in Table 1.
TABLE 1______________________________________ *Sample At 15% RH At 60% RH Sensitometric Features No. 100° F. (38° C.) 100° F. (38° C.)______________________________________Gross Fog 4 0.433 0.478 Upper Scale Contrast 4 2.100 2.030 Upper Density Point 4 3.660 3.650 Speed 4 97 91 Gross Fog 1 0.448 0.512 Upper Scale Contrast 1 1.74 -0.520 Upper Density Point 1 3.4l0 2.85 Speed 1 89 70 Gross Fog 2 0.453 0.444 Upper Scale Contrast 2 1.78 -.490 Upper Density Point 2 3.43 2.410 Speed 2 84 54 Gross Fog 3 0.442 0.487 Upper Scale Contrast 3 1.730 1.880 Upper Density Point 3 3.400 3.5200 Speed 3 88 85______________________________________ *Samples 1, 2, and 4 are Controls
As the review data in Table 1 show, the hydrophilic zeolites of the invention method exhibited properties close to the material of Sample 4 that were not incubated. Properties of films stored with the Example 3 hydrophilic zeolite linerboards of the invention after two weeks' storage as compared with both the plain stiffener board and the hydrophobic zeolite stiffener board of the prior art were much better. Particularly, in the instance of the high humidity conditioned film, the properties were much improved as compared with the control examples. The invention exhibits less advantage with film that is low humidity conditioned prior to storage.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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The invention relates to a method of improving raw stock keeping of silver containing imaging material comprising providing a package of said material and providing in said package a fiber board containing zeolite.
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BACKGROUND OF THE INVENTION
The invention herein described is designed to enhance the operation of oil pick-up devices which are called upon to operate in freezing temperature environments in which pieces of ice as well as fluid surface areas are found to be coated with undesirable fluids such as oil or the like. The invention is designed to enhance and operate in combination with a Fluid Separation Device of the type described in Yates U.S. Pat. No. 3,576,257, wherein a drum-like member is described which provides a means to pick up oil or other immiscible liquids from a fluid environment. The device described in U.S. Pat. No. 3,576,257 operates by utilizing an inherent characteristic of oil to selectively adhere to an oleophilic surface rotated through the oil while picking up a relatively negligible amount of water or other substance from which the oil is desired to be removed.
While the invention operates most desirably in concert with a Yates type recovery device, it should be understood that it has similar utility in connection with other oil pick-up devices, inter alia those described in U.S. Pat. No. 3,702,297, "Oil Skimming Device and Method" and 3,865,730 "Oil Spill Cleanup", and so-called "endless belt" type devices.
As man's quest for oil becomes more intense, his activities in prospecting and drilling lead into increasingly hostile environments and it has been found necessary to provide oil-pick-up devices which will operate to quickly contain and pick up oil spills so as to minimize ecological damage and commercial losses that might otherwise be sustained, since oil recovered in most instances is industrially usable. By way of background, and to further illustrate the prior art of which applicants are aware, the following patents are cited:
U.s. pat. No. 3,536,199 (Cornelius) "Fire Extinguishing Oil Slick Separator"
U.s. pat. No. 3,358,838 (Kosar) "Oil Skimming Device"
U.s. pat. No. 2,474,018 (Verner) "Oil Skimming Device"
U.s. pat. No. 3,096,278 (Francom) "Scraper Assembly for Filters"
U.s. pat. No. 3,338,414 (Lefke) "Liquid Skimming Device
U.s. pat. No. 3,614,873 (Cole) "Freezing Oil Spills"
U.s. pat. No. 3,702,296 (Maksim) "Oil Skimming Device and Method"
U.s. pat. No. 3,314,540 (Lane) "Removal of Oil Films from Water"
It is apparent to applicants that none of the devices disclosed in the aforementioned patents utilize and describe an effective and efficient means for operating in an ice-clogged environment where part or substantially all of the surface of water contains a mixture of oil and broken oil-covered ice.
DESCRIPTION OF THE INVENTION
As utilized herein the terms "oil" and "water" are utilized representatively to include any type of relatively immiscible fluids at least one of which will display oleophilic characteristics to materials immersed therein. Similarly, the term "ice" is intended to encompass wood, plastic, or other debris to which "oil" may adhere. While many of the aforementioned devices provide, to some degree, a means of separating oil from water, it should be recognized that they provide minimal, if any, capability of removing oil from the surface of ice chunks which are often found floating in an oil/water mixture. For example, a pick-up device of the type described in U.S. Pat. No. 3,576,257, operating alone, would effectively remove most of the oil from water which passes relative to it, but would not effectively remove oil from the surface of pieces of ice passing under it. Accordingly, applicants have provided a means to provide a further "jarring" to the ice pieces while at the same time propelling them back away from the oil pickup means, the ice chunks being then upwardly propelled along the inclined surface of a perforated inclined throughput barrier which allows oil jarred from the ice to rise through the barrier and toward the surface of the water. The oil is contained and, in fact, "built up" in thickness above the throughput barrier as a result of its being contained between the side support members of the structure supporting the pick-up device, the pick-up device itself, and a rear " back stop".
Our invention is highly transportable, including air transportable, on short notice, to the scene of a pollution problem and provides a means preventing oil pollution remaining in an environment where oil covered ice is encountered.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be more easily understood from the following description and accompanying drawings in which:
FIG. 1 is a perspective view, partially broken away to show interior structures of an apparatus constructed in accordance with the teachings of the instant invention, and
FIG. 2 is a side elevational view of the unit shown in FIG. 1.
DESCRIPTION
In accordance with the above, the invention is described in detail in combination with the attached drawings. Turning first to FIG. 1, an oil pick-up means 1 is shown to be mounted between two generally parallel side support members 11. It is noted that these side support members may be the sides of a "well" in a boat hull, the sides of pontoons affording a catamaran type structure, or between other channel forming supports with which the pick-up device is adapted to be suspended. While details of the oil pick-up means 1 are not shown, it is understood that they may be substantially as shown and described in the aforementioned U.S. Pat. No. 3,576,257. Briefly, oil pick-up means 1 comprises a drum formed essentially by parallel and generally horizontal vane members 2 which are slanted toward the interior of the pick-up unit and which peripherally surround a plurality of substantially vertical and parallelly placed discs such as shown at 3 (the interior discs extending through the center portion of the drum) in the manner taught in U.S. Pat. No. 3,576,257, the discs rotate around a hollow trough axle and are provided with wipers which remove oil adhering to the disc surfaces and allow it to drop into the axle trough to be transported to a storage reservoir. Ice chunks shown generally at 13 in FIG. 2 encounter the oil pick-up means and are, by its rotation and/or the relative flow of water forced beneath pick-up means 1. While a portion of oil adhering to the ice surface is removed by this jarring action, a particularly more severe jarring is provided as ice encounters tumbler bar 15 which rotates in a direction identical to that of oil pick-up means 1. In practice, applicants have found that the rotational speed of the tumbler 15 and the pick-up drum 1 is such that the peripheral velocity of the drum is less than that of the tumbler. This like manner of rotation has a two-fold purpose of preventing ice from being crushed between tumbler bar 15 and drum pick-up means 1 which might damage either or both members, and providing an impetus to the chunks of ice to send them backward and into contact with the inclined under surface of perforated inclined throughput barrier 20.
With further reference to tumbler bar 15, it is noted that this member is preferably square in cross section and may be a simple extrusion or other suitably formed member. Tumbler bar 15 is mounted by and adapted to rotate about an axle 16 which may be journalled in side support members 11. It is preferable to provide power for both pick-up means 1, and tumbler bar 15, the motive force for which may be, for example, a hydraulic motor 17 which allows the speed of rotation of the tumbler bar to be easily varied. While applicants have chosen a square cross-sectional shape tumbler bar, it is understood that it could be of other cross-sectional shapes, for example, rectangular or circular, either of which may be provided with a plurality of continuous, or broken, "fins" or spikes extending essentially radially outwardly from the surface thereof.
A perforated, inclined, throughput barrier 20 is preferably journalled between side support members 11 by a pivot pin 18 as shown in FIG. 2. Preferably, pivot pin 18 is located so that the lower end of throughput barrier 20 is at or above the lowermost portion of tumbler bar 15 as it rotates about axle 16. Throughput barrier 20 is preferably formed of a heavy duty, one-inch mesh, screen which will readily allow oil jarred from the surface of ice to pass therethrough. Desirably, the throughput barrier screen may be strengthened by a plurality of essentially parallel bars 19 which are "T" shaped in cross section and secured to throughput barrier 20 on the flat or cross surface of the "T" by welding or other suitable means. The upper surface of throughput barrier 20 may preferably be strengthened by angle bars 21 which have their lower angle surface secured to throughput barrier 20 in a manner similar to that utilized in securing T bar 19 to throughput barrier 20. The upstanding sides of angle bars 21 are preferably inclined at approximately a 45° angle to the throughput barrier 20 in a manner to provide for a flow of fluid therethrough at a similar angle. It should be understood that throughput barrier 20 as described in this preferred embodiment is a large mesh screen (e.g. of one inch square openings). This barrier may also be formed of expanded metal or of essentially solid material with holes of appropriate size extending therethrough. However, the more perforate the member, the less resistance to the flow of rising oil will be presented. Pieces of ice as they are propelled along the under surface of barrier 20 are continually jarred and rotated thus further enhancing the removal of oil from the surface of the ice. It has been found in tests that the angle of throughput barrier 20 may vary from approximately 0° to approximately 30° above or below the horizontal though this may vary within a broad range and still be within the scope contemplated by the present invention.
Hingedly mounted at the aft end of throughput barrier 20 is a containment backstop 25, which is mounted to barrier 20 by means of, for example, a hinge pin 26. Backstop 25 is preferably essentially vertical, that is perpendicular, to the mean water surface, and is provided with a backstop adjustment means 27 by which backstop 25 may be selectively raised and lowered. Obviously, the raising and lowering of backstop 25 will provide for a changed angle of inclination of throughput barrier 20 in a manner desired to suit the requirements of a given situation taking into consideration relative speed of the device with respect to current, speed of rotation of tumbler and pick-up unit, size of ice pieces, fluid viscosity and the like. In the embodiment shown, adjustment means 27 comprises a clevis-like latch 28 secured to side support members 11 which is adapted to engage and receive the notched strap 29. Suitable hand grips 30 may be provided to accommodate the manual adjustment of the mechanism. Obviously, should it be desirable to do so, other adjustment means may be provided to substitute for the manual means shown, such adjustment means taking the form of cranks, pulleys, worm gear drives, hydraulic cylinders or other mechanisms as will be familiar to one skilled in mechanical arts.
OPERATION
In operation, a relative movement is provided between a surface of fluid which is coated with an oil/ice combination, and oil pick-up means 1. Such movement may be provided by a natural or an artifical impetus to the fluid, and/or by the movement of the pick-up means 1 through the fluid as, for example, by mechanical means in a refinery settling pond, or in a water craft. The oil/ice mixture encountered by pick-up means 1 is processed in such a manner that free oil tends to be accumulated within and picked up by the pick-up device 1, while the oil coated pieces of ice continue under pickup means 1 where they encounter tumbler bar 15 which provides a jarring or "kick". Especially for ice chunks which tend to be other than flat, the rotation of pick-up means 1 would tend to impart a rotation to the pieces of ice as indicated in FIG. 2. Tumbler bar 15 rotates in the same direction as pick-up means 1, and provides an additional "jolt" to ice pieces as they are passed onto throughput barrier 20. While they pass under barrier 20 additional jarring and rotational "scouring" motion is provided which tends to wash the oil from the surface of the ice and allow it, as a result of its inherently lighter specific gravity, to move through the perforations in throughput barrier 20 into the relatively quite "pond" area formed by backstop 25, sidewalls 11, and the pick-up device 1. As oil tends to build up within the pond area, it is increasingly forced into the pick-up means 1 where such buildup enhances its operation. Thus a means has been provided to afford not only a cleaning of oil from the surface of a fluid, but also from pieces of ice (and, inherently, wood and other floating debris) which may be contained on the fluid surface.
In operation, it may be desirable to enhance the pickup of oil in extremely cold environments or where particularly viscous oil is encountered by imparting heat either to the inside of the pickup drum, or to the "ponding" area or both, such heating means, not shown, being well within the skill of one familiar with the art.
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A device for separating, in an ice environment, fluids having differing physical properties which combine an oleophilic pick-up device with a rotating tumbler mechanism which tends to agitate and propel oil coated pieces of ice rearward and along a perforated inclined through-put barrier where oil jarred off the ice chunks is allowed to rise through the perforations and be contained in an area where it can be accumulated and recovered by the pick-up unit.
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FIELD OF THE INVENTION
The present invention is directed to a gel polymer electrolyte for use in rechargeable polymer secondary batteries and a precursor composition thereof. Particularly, the precursor composition can be injected into an aluminum shell of a battery cell, which undergoes in-situ heating polymerization by heating and forms a gel polymer electrolyte penetrating a partition membrane therein.
BACKGROUND OF THE INVENTION
Along with the rapid development and availability of portable electronic products, lithium ion secondary batteries, due to their properties, including light in weight, high voltage, and high energy density, etc., have ever increasing demands in the modern era. Furthermore, the use of polymer electrolytes in the lithium ion secondary batteries has become more and more important and attracted wide attention in research for size reduction and increasing flexibility of the electronic products.
The advantages of using a polymer electrolyte in a lithium ion polymer battery include: free of the risk of leakage of electrolyte, capable of being used to produce a battery with an ultra-thin and large area or with an angle, light in weight, lower vapor pressure and lower auto-discharge rate. These advantages greatly increase the commercial applications of lithium ion secondary batteries.
In order to develop thin type batteries with a flexible and thin shell, there are currently a plurality of gel polymer materials, together with electrolyte compositions, under investigation and study. These gel polymer materials include poly(ethylene oxide) (PEO), poly(methyl methacrylate) (PMMA), Poly(vinylidene fluoride) (PVDF), polyacrylonitrile (PAN), and derivatives or co-polymers thereof. An ordinary process of producing a gel polymer electrolyte for a polymer battery comprises forming a film from the gel polymer electrolyte; removing the solvent from the film; mounting the polymer film between two layers of an active material and stacking the resulting composite or coating the polymer film on the surface of an active material to form a battery core; and injecting a liquid electrolyte into the battery shell and binding the electrode plates. Thus, the laminated structure of electrode plates will have reduced expansion or shrinkage during the association/dissociation of lithium ions in the course of the charge/discharge process. As a result, the batteries produced have a long operation lifespan. However, such a production process is complex.
SUMMARY OF THE INVENTION
A gel polymer electrolyte according to the present invention is free of the problem of electrolyte leakage. Thus, a battery so produced has a better reliability. Furthermore, such a gel polymer material has a good miscibility with the electrolyte; and the resulting bridge structure is capable of keeping the solvent inside the battery, so that the electrolyte retainability is good and the electrolyte has a high solubility to the lithium salt and a high ion conductivity. A polymer precursor formula according to the present invention can be injected into an aluminum shell of a battery cell by an ordinary liquid injection process, thereafter the precursor undergoes in-situ heating polymerization by heating and forms a gel polymer electrolyte penetrating a partition membrane therein, wherein two polymer precursors form cross-linked copolymers. Such a process is simple and convenient.
A polymer electrolyte composition for a lithium polymer secondary battery according to the present invention includes: (A) an electrolyte polymer precursor consisting of (1) a modified-bismaleimide oligomer (2) a polymerizable monomer or oligomer thereof, which can from a copolymer with (1); (B) a mixture solvent containing at least two solvents selected from a first type of solvent having an extremely high dielectric constant and a high viscosity, and a second type of solvent having a lower dielectric constant and a low viscosity, e.g. ethylene carbonate (EC), propylene carbonate (PC) and γ-butyrolactone (GBL) which have an extremely high dielectric constant; (C) a lithium dissociable salt such as LiPF 6 , and LiBF 4 , etc.; (D) a free radical initiator; and (E) additives, such as the common additives including vinylene carbonate, sulfites, sulfates, phosphonates, or derivatives thereof.
The above-mentioned polymer electrolyte precursor formula is injected into an aluminum shell of a battery cell according to an ordinary liquid electrolyte injection process. The battery cell is then sealed and the electrolyte precursor undergoes in-situ heating polymerization by heating and forms a gel polymer electrolyte penetrating a partition membrane therein, wherein the polymerization temperature is at 30˜130° C., and the two monomers/oligomers in the polymer precursors form cross-linked type copolymers. The resulting gel polymer electrolyte will adhere to the positive and negative electrode plates, which renders the manufacturing process easier.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the relationship between the capacity and the number of charge/discharge cycles for the gel polymer lithium secondary battery cells of the present invention and the prior art prepared in Example 6;
FIG. 2 shows the relationship between the capacity and the number of charge/discharge cycles for the gel polymer lithium secondary battery cells of the present invention and of the prior art prepared in Example 7; and
FIG. 3 shows the relationship between the capacity and the number of charge/discharge cycles for the gel polymer lithium secondary battery cells of the present invention prepared in Example 8 at different gelation temperatures.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention include (but not limited to) the followings:
1. A gel polymer electrolyte precursor composition for use in the fabrication of a secondary battery cell, which comprises:
a) a modified bismaleimide oligomer resulting from a reaction of barbituric acid with bismaleimide;
b) one or more acrylic/acrylate type monomer represented by CH 2 ═C(R 0 )C(O)O—(C y H 2y O) m R 1 , wherein y=1˜3, m=0˜9, R 0 is hydrogen or methyl, R 1 is selected from the group consisting of hydrogen, hydroxyl, C1-C6 alkyl, C1-C6 alkoxyl, C2-C6 alkenyl, C3-C6 cycloalkyl and phenyl; one or more nitrile type monomer represented by R 2 —CH═C(R 0 )(CN), wherein R 0 has the same definition as the above, R 2 is selected from the group consisting of hydrogen, hydroxyl, C1-C6 alkyl, C1-C6 alkoxyl, C2-C6 alkenyl, C3-C6 cycloalkyl and phenyl; or an oligomer thereof;
c) a non-aqueous metal salt electrolyte;
d) an aprotic solvent; and
e) a free radical initiator;
wherein, based on the total weight of (a) to (d), (a) constitutes 1-50%; (b) constitutes 1-50%; and (d) constitutes 10-90%, wherein (c) has a concentration of 0.5M to 2M in (d); and (e) is in an amount of 0.1-5%, based on the weight of (b).
2. The gel polymer electrolyte precursor composition as described in Item 1, wherein the ingredient (a) is prepared from one or more of the barbituric acid represented by the following formula:
wherein R′ and R″ independently are —H, —CH 3 , —C 2 H 5 , —C 6 H 5 , —CH(CH 3 ) 2 , —CH 2 CH(CH 3 ) 2 , —CH 2 CH 2 CH(CH 3 ) 2 , or —C(CH 3 )HCH(CH 3 ) 2 .
3. The gel polymer electrolyte precursor composition as described in Item 2, wherein R′ and R″ both are —H.
4. The gel polymer electrolyte precursor composition as described in Item 2, wherein the ingredient (a) is prepared from one or more bismaleimide represented by the following formula:
wherein R 3 is selected from the group consisting of C1-4 alkylene, —CH 2 NHCH 2 —, —C 2 H 4 NHC 2 H 4 —, —C(O)CH 2 —, —CH 2 OCH 2 —, —C(O)—, —O—, —O—O—, —S—, —S—S—, —S(O)—, —CH 2 S(O)CH 2 —, —(O)S(O)—, —CH 2 (C 6 H 4 )CH 2 —, —CH 2 (C 6 H)O—, phenylene, biphenylene, substituted phenylene and substituted biphenylene; and R 4 is selected from the group consisting of C1-4 alkylene, —C(O)—, —C(CH 3 ) 2 —, —O—, —O—O—, —S—, —S—S—, —(O)S(O)—, and —S(O)—.
5. The gel polymer electrolyte precursor composition as described in Item 4, wherein the bismaleimide is selected from the group consisting of N,N′-bismaleimide-4,4′-diphenylmethane, 1,1′-(methylenedi-4,1-phenylene)bismaleimide, N,N′-(1,1′-biphenyl-4,4′-diyl)bismaleimide, N,N′-(4-methyl-1,3-phenylene)bismaleimide, 1,1′-(3,3′dimethyl-1,1′-biphenyl-4,4′-diyl)bismaleimide, N,N′-ethylenedimaleimide, N,N′-(1,2-phenylene)dimaleimide, N,N′-(1,3-phenylene)dimaleimide, 1,1′-hexanediyl-bis-pyrrole-2,5-dione, N,N′-bis-(2,5-dioxo-2,5-dihydro-pyrrole-1-carboxyl)-methylenediamine, 1,1′-(3,3′-piperazine-1,4-diyl-dipropyl)bis-pyrrole-2,5-dione, N,N′-thiodimaleimid, N,N′-dithiodimaleimid, N,N′-ketonedimaleimid, N,N′-methylene-bis-maleinimid, bis-maleinimidomethyl-ether, 1,2-bis-(maleimido)-1,2-ethandiol, N,N′-4,4′-diphenylether-bis-maleimid, and 4,4′-bis(maleimido)-diphenylsulfone.
6. The gel polymer electrolyte precursor composition as described in Item 1, wherein the modified bismaleimide oligomer (a) is prepared by the reaction of barbituric acid with bismaleimide at 100˜150° C. for 0.5˜8 hours.
7. The gel polymer electrolyte precursor composition as described in Item 1, wherein the ingredient (b) comprises the acrylic/acrylate type monomer represented by CH 2 ═C(R 0 )C(O)O—(C y H 2y O) m R 1 , wherein y=1˜3, m=1˜9, R 0 is methyl, and R 1 is hydrogen.
8. The gel polymer electrolyte precursor composition as described in Item 7, wherein the ingredient (b) further comprises methyl methacrylate monomer.
9. The gel polymer electrolyte precursor composition as described in Item 1, wherein the ingredient (b) comprises methyl methacrylate monomer.
10. The gel polymer electrolyte precursor composition as described in Item 1, wherein the non-aqueous metal salt electrolyte (c) is selected from the group consisting of LiPF 6 , LiBF 4 , LiAsF 6 , LiSbF 6 , LiClO 4 , LiAlCl 4 , LiGaCl 4 , LiNO 3 , LiC(SO 2 CF 3 ) 3 , LiN(SO 2 CF 3 ) 2 , LiSCN, LiO 3 SCF 2 CF 3 , LiC 6 F 5 SO 3 , LiO 2 CCF 3 , LiSO 3 F, LiB(C 6 H 5 ) 4 , LiCF 3 SO 3 and a mixture thereof.
11. The gel polymer electrolyte precursor composition as described in Item 1, wherein the aprotic solvent (d) comprises a mixture solvent of two types of solvents, wherein the first type solvent has a high dielectric constant and a high viscosity, and the second type solvent has a relatively lower dielectric constant and a relatively lower viscosity; wherein the first type solvent is selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, dipropyl carbonate, acid anhydride, N-methylpyrrolidone, N-methyl acetamide, N-methyl formamide, dimethyl formamide, γ-butyrolactone, acetonitrile, dimethyl sulfoxide and dimethyl sulfite; and the second type solvent is selected from the group consisting of ether, ester, and carbonate; wherein the ether is selected from the group consisting of 1,2-diethoxyethane, 1,2-dimethoxyethane, 1,2-dibutoxyethane, tetrahydrofuran, 2-methyl tetrahydrofuran, and propylene oxide; the ester is selected from the group consisting of methyl acetate, ethyl acetate, methyl butyrate, ethyl butyrate, methyl proionate, and ethyl propionate; and the carbonate is selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC).
12. The gel polymer electrolyte precursor composition as described in Item 11, wherein the aprotic solvent (d) comprises ethylene carbonate (EC), propylene carbonate (PC), and diethyl carbonate (DEC).
13. The gel polymer electrolyte precursor composition as described in Item 12, wherein the aprotic solvent (d) comprises, based on volume, 10%-50% of ethylene carbonate (EC), 5%-80% of propylene carbonate (PC), and 3%-75% of diethyl carbonate (DEC).
14. The gel polymer electrolyte precursor composition as described in Item 1, wherein the free radical initiator (e) is selected from the group consisting of ketone peroxide, peroxy ketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester, and azo compound.
15. The gel polymer electrolyte precursor composition as described in Item 1, wherein the free radical initiator (e) is selected from the group consisting of 2,2-azo-bis-isobutyronitrile (AIBN), phenyl-azo-triphenylmethane, t-butyl peroxide (TBP), cumyl peroxide, acetyl peroxide, benzoyl peroxide (BPO), lauroyl peroxide, t-butyl hydroperoxide, and t-butyl perbenzoate.
16. A polymer lithium secondary battery cell, which comprises:
i) a negative electrode capable of electrochemically migrating in/out alkali metal;
ii) a positive electrode including an electrode active material capable of electrochemically migrating in/out alkali metal; and
iii) a gel polymer electrolyte capable of activating the negative electrode and the positive electrode, wherein the gel polymer electrolyte is prepared from a gel polymer electrolyte precursor composition as described in Item 1 by polymerization by heating.
17. The polymer lithium secondary battery cell as described in Item 16, wherein the negative electrode comprises a negative electrode active material selected from the group consisting of mesophase carbon microbeads (MCMB), vapor Grown varbon fiber (VGCF), carbon nano-tube (CNT), coke, carbon black, graphite, acetylene black, carbon fiber, and glassy carbon.
18. The polymer lithium secondary battery cell as described in Item 16, wherein the negative electrode further comprises a fluorine-containing resin binder.
19. The polymer lithium secondary battery cell as described in Item 16, wherein the electrode active material of the positive electrode is a lithium compound selected from the group consisting of oxide, sulfide, selenide, and telluride of vanadium, titanium, chromium, copper, molybdenum, niobium, iron, nickel, cobalt, or manganese.
20. The polymer lithium secondary battery cell as described in Item 17, wherein the positive electrode further comprises a fluorine-containing resin binder.
21. The polymer lithium secondary battery cell as described in Item 17, wherein the positive electrode further comprises an electrically conductive additive selected from the group consisting of acetylene black, carbon black, graphite, nickel powder, aluminum powder, titanium powder, and stainless steel powder, and a mixture thereof.
The present invention can be further understood through the following examples, which are for illustrative purposes only and not for limiting the scope of the present invention.
EXAMPLE 1
Preparation of Modified Bismaleimide Oligomer
Bismaleimide and barbituric acid were mixed in a molar ratio of 3/1˜10/1, and then added with solvents γ-butyrolactone (GBL) or propylene carbonates. The resulting mixture was heated at 100˜150° C. for reaction for 0.5˜8 hours, thereby forming a modified bismaleimide oligomer. In this example, a modified bismaleimide oligomer was prepared at 130° C. according to the composition listed in Table 1.
TABLE 1
Weight
N,N′-bismaleimide-4,4′-diphenylmethane
59.613
g
barbituric acid
2.132
g
γ-butyrolactone, GBL
247.059
g
EXAMPLE 2
Preparation of Gel Polymer
In this example, gel polymers were prepared according to the formulas listed in Table 2 with or without the modified bismaleimide oligomer prepared from Table 1 in Example 1. Table 2 also lists the gelation time for the gel polymer formulas at 25° C. and 80° C., respectively.
TABLE 2
Gelation time (hour)
Formula*
25° C.
80° C.
1) AN: 5 g, PEGMA: 1 g
without gelation
<1
2) MMA: 5 g, PEGMA: 1 g
without gelation
<1
3) M-BMI: 5 g, PEGMA: 1 g
without gelation
<1
4) M-BMI: 25 g, PEGDA: 1 g
without gelation
<0.5
5) M-BMI: 25 g
without gelation
<0.5
*The formulae contain 1% of 2,2-azo-bis-isobutyronitrile (AIBN) free radical initiator, based on the total weight of monomers and oligomers
AN: acrylnitrile
MMA: methyl methacrylate
M-BMI: modified bismaleimide oligomer from Example 1
PEGMA: poly(ethylene glycol) methacrylate
PEGDA: poly(ethylene glycol) diacrylate
The results in Table 2 show that the modified bismaleimide oligomer from Example 1, under heating and the presence of AIBN free radical initiator, can form a gel co-polymer or polymer at a relatively faster reaction rate (0.5˜1 hour).
EXAMPLE 3
Preparation of Gel Polymer Electrolytes, and Ion Conductivities Thereof
This example used a plurality of formulas to prepare gel polymer electrolyte precursors, which were gelled at 80° C. An AC impedance analysis was used to measure the impedance of an ion diffusion segment. The measured value was used in an ion conductivity formula to obtain an ion conductivity, σ=L/A×R, wherein σ is the ion conductivity, L is thickness, A is area, and R is resistance.
A common preparation process included: mixing a lithium salt electrolyte with an aprotic solvent to obtain an electrolyte solution; preparing a mixture of monomer/oligomer/free radical initiator; mixing the electrolyte solution with the mixture to obtain a gel polymer electrolyte precursor; and heating the precursor to form a gel polymer electrolyte.
Table 3 listed the formulae of the conventional liquid electrolytes and gel polymer electrolytes according to the present invention, and the ion conductivity thereof.
TABLE 3 Ion conductivity Gelation at room time temperature Run Formula (hour) (mS/cm) 1.1 M LiPF 6 (3EC/2PC/5DEC) — 7.1 1 M LiPF 6 EC/GBL — 10.1 1 MMA:M-BMI = 1:1 <3 — (polymer precursor):(electrolyte solution)* = 18:82 M-BMI: 9% 2 MMA:M-BMI = 2:1 <3 7.5 (polymer precursor):(electrolyte solution)* = 14:86 M-BMI: 5% 3 MMA:M-BMI = 1:1 <3 9.3 (polymer precursor):(electrolyte solution)* = 10:90 M-BMI: 5% *The electrolyte solution is 1M LiPF 6 in a mixed solvent of EC/GBL = 1/3.
The polymer precursor contains MMA and modified bismaleimide oligomer of Example 1 with 1% AIBN.
The experimental results of Table 3 indicate that the gel polymer electrolyte can be polymerized after being heated at 80° C., and the formula having 10 wt % of the polymer precursor and 5 wt % of the modified bismaleimide oligomer (M-BMI) of the present invention will result in a gel polymer electrolyte having a high ion conductivity of 9.3 mS/cm slightly smaller than 10.1 mS/cm of the conventional liquid electrolyte.
EXAMPLE 4
Preparation Gel Polymer Electrolytes, and Ion Conductivities Thereof
A gel polymer electrolyte was prepared by repeating the steps of Example 3, wherein the modified bismaleimide oligomer (M-BMI) of Example 1 and the poly(ethylene glycol) diacrylate (PEGDA) as a control were separately used in the polymer precursors in order to verify that a gel polymer electrolyte of the invention has a conspicuously improved ion conductivity. The compositions and results are listed in Table 4.
TABLE 4
Ion
Gelation
conductivity
time
at room
(80° C.)
temperature
Run
Formula
(hour)
(mS/cm)
4
MMA:PEGDA = 6:1
<3
1.2
(polymer precursor):(electrolyte
solution)* = 43:57
PGEDA: 6% (EC/GBL)
5
MMA:M-BMI = 6:1
<3
1.6
(polymer precursor):(electrolyte
solution)* = 43:57
M-BMI: 6% (EC/GBL)
6
MMA:PEGDA = 6:1
<3
0.2
(polymer precursor):(electrolyte
solution)* = 43:57
PEGDA: 6% (EC/PC)
7
MMA:M-BMI = 6:1
<3
0.87
(polymer precursor):(electrolyte
solution)* = 43:57
M-BMI: 6% (EC/PC)
*The electrolyte solutions in Run 4 and Run 5 1M LiPF 6 in a mixed solvent of EC/GBL = 1/3. The electrolyte solutions in Run 6 and Run 7 are 1M LiPF 6 in a mixed solvent of EC/PC = 1/1.
The above-mentioned formulae of polymer precursor/electrolyte solution in Runs 4-7, after polymerization by heating at 80° C., form gel polymer electrolytes, wherein the electrolyte solutions in Runs 4 and 5 are 1M LiPF 6 in a mixed solvent of EC/GBL=⅓, and are 1M LiPF 6 in a mixed solvent of EC/PC=1/1 for Runs 6 and 7. In comparison with M-BMI and PEGDA in Runs 5 and 4, the gel polymer electrolytes of the present invention (Runs 5 and 7) have ion conductivities 1.25 and four times higher than those of the controls (Runs 4 and 6), respectively.
EXAMPLE 5
Preparation of Gel Polymer Electrolytes and Ion Conductivities Thereof
Gel polymer electrolytes were prepared by repeating the steps of Example 3, wherein the modified bismaleimide oligomer (M-BMI) of Example 1 and different monomers were separately used in the polymer precursors. Table 5 listed the compositions and results of the formulae used.
TABLE 5
Ion
Gelation
Conductivity
time
at Room
(80° C.)
Temperature
Run
Formula Composition*
(hour)
(mS/cm)
8
TEGEEA:M-BMI = 7:1
<3
4.75
(polymer precursor):(electrolyte
solution)* = 20:80
M-BMI: 3% (EC/GBL)
9
TEGEEA:PEGDMA330 = 7:1
<3
4.57
(polymer precursor):(electrolyte
solution)* = 20:80
PEGDMA: 3% (EC/GBL)
10
TEGEEA:PEGDA258 = 7:1
<3
4.66
(polymer precursor):(electrolyte
solution)* = 20:80
PEGDA258: 3% (EC/GBL)
11
MMA:PEGDA258 = 7:1
<3
3.9
(polymer precursor):(electrolyte
solution)* = 20:80
PEGDA258: 3% (EC/GBL)
*The electrolyte solutions in Runs 8-11 are 1M LiPF 6 in a mixed solvent of EC/GBL = 1/3; TEGEEA: Tri(ethylene glycol) ethyl ether acrylate; PEGDMA: polyethylene glycol dimethacrylate
Among the gel polymer electrolytes prepared in Runs 8 to 11, the one prepared with M-BMI of the present invention has the highest ion conductivity of 4.75 mS/cm.
Preparation and Capacity Properties of Gel Polymer Lithium Secondary Battery Cell
A process for preparing a gel polymer lithium secondary battery cell comprises: preparation of positive and negative electrode plates, partition membrane, and gel polymer electrolyte containing polymer precursor and liquid electrolyte solution.
The positive and negative electrode plates were prepared the same way as in the conventional lithium ion secondary battery cell. The positive electrode slurry included 80˜95% of LiCoO 2 , 315% of acetylene black, and 3˜10% of PVDF binder. The slurry was dissolved in NMP (N-methyl-2-pyrrolidone) solvent to form an ink-like slurry, which was uniformly coated on an aluminum foil sheet 300 m in length, 35 cm in width, and 20 μm in thickness. After being dried, the positive electrode sheet was calendered and striped, and finally, dried in vacuum at 110° C. for 4 hours. The positive electrode active material can be a lithium compound selected from oxide, sulfide, selenide, and telluride of vanadium, titanium, chromium, copper, molybdenum, niobium, iron, nickel, cobalt, and manganese, etc. The fluorine-containing resin binder can be, for example, poly(vinylidene fluoride) (PVDF). The electrically conductive active material can be selected from carbon black, graphite, acetylene black, nickel powder, aluminum powder, titanium powder, and stainless steel powder, etc.
The negative electrode slurry was prepared by dissolving 90 parts by weight of carbon powder with a diameter of 1 μm˜30 μm in 10 parts by weight of a mixed solvent containing PVDF and NMP. After thoroughly mixing, the slurry was coated on a copper sheet 300 m in length, 35 cm in width, and 10 μm in thickness, and dried. The negative electrode sheet was calendered and striped, and finally, dried in vacuum at 110° C. for 4 hours. The negative electrode active material can be selected from mesophase carbon microbeads (MCMB), vapor grown carbon fiber (VGCF), carbon nano-tubes (CNT), coke, carbon black, graphite, acetylene black, carbon fiber, and glassy carbon. The fluorine-containing resin binder can be, for example, poly(vinylidene fluoride) (PVDF). The vacuum-dried positive/negative electrode stripes were placed in a dry environment, e.g. a glove case or a dry chamber.
EXAMPLE 6
Six battery cells were grouped into two sets of experiments. Experiment A used the following polymer precursor compositions: MEMA:M-BMI=7:1, the electrolyte solution was 1M LiPF 6 in a mixed solvent of EC/DEC/PC=3/5/2; and (polymer precursor): (electrolyte solution)=20:80, wherein M-BMI is 2.5 wt %, and MEMA is methoxy tri(ethylene glycol) methacrylate. Experiment B used the following polymer precursor composition: MEMA:PEGDA258=7:1, the electrolyte solution was 1M LiPF 6 in a mixed solvent of EC/DEC/PC=3/5/2; and (polymer precursor): (electrolyte solution)=20:80, i.e. PEGDA258 is 2.5 wt %. An aluminum foil bag of Model No. 383562 was used for the assembly of a polymer battery cell, which was heated at 85° C. for 3 hours so that the polymer precursor was polymerized inside the battery cell. The battery cells were set at a charge/discharge rate of 0.2C. As shown in the charge/discharge cycle of FIG. 1 , the battery cells of Experiment A have an initial capacity of 760 mAh, and still have an capacity of 710 mAh after 50 cycles of charge/discharge. The battery cells of Experiment B have an initial capacity of 710 mAh, which is decreased to 410 mAh after 50 cycles of charge/discharge. The experimental results indicate that the battery cells prepared from the formula containing M-BMI have a better capacity after 50 cycles of charge/discharge, and a longer battery cell liftspan.
EXAMPLE 7
Six battery cells were grouped into two sets of experiments. Experiment C used the following polymer precursor compositions: MEMA:M-BMI=7:1, the electrolyte solution was 1M LiPF 6 in a mixed solvent of EC/GBL=⅓; and (polymer precursor):(electrolyte solution)=20:80, wherein M-BMI is 2.5 wt %, and MEMA is methoxy tri(ethylene glycol) methacrylate. Experiment D used the following polymer precursor composition: MEMA:PEGDA258=7:1, the electrolyte solution was 1M LiPF 6 in a mixed solvent of EC/GBL=⅓; and (polymer precursor):(electrolyte solution)=20:80, i.e. PEGDA258 is 2.5 wt %. An aluminum foil bag of Model No. 383562 was used for the assembly of a polymer battery cell, which was heated at 85° C. for 3 hours so that the polymer precursor was polymerized inside the battery cell. The battery cells were set at a charge/discharge rate of 0.2C. As shown in the charge/discharge cycle of FIG. 1 , the battery cells of Experiment C have an initial capacity of 650 mAh, and still have an capacity of 560 mAh after 50 cycles of charge/discharge. The battery cells of Experiment D have an initial capacity of 730 mAh, which is decreased to 430 mAh after 50 cycles of charge/discharge. The experimental results indicate that the battery cells prepared from the formula containing M-BMI have a better capacity after 50 cycles of charge/discharge, and a longer battery cell liftspan.
EXAMPLE 8
Fifteen battery cells were grouped into five sets of experiments (E to I). Each set of experiment used the following polymer precursor compositions: MEMA:M-BMI=7:1, the electrolyte solution was 1M LiPF 6 in a mixed solvent pf EC/DEC/PC=3/5/2; and (polymer precursor):(electrolyte solution)=20:80, i.e. M-BMI: 2.5 wt %. An aluminum foil bag Model No. 383562 was used for the assembly of the polymer battery cell, which was heated at different temperatures for 3 hours so that the polymer precursor was polymerized inside the battery cell. The heating temperatures for Experiments E, F, G, H and I were, respectively, 75, 85, 90, 95 and 100° C. The battery cells were set at a charge/discharge rate of 0.2C, and the results are shown in FIG. 3 . As shown in FIG. 3 , the battery cells of Experiment G (90° C.) have a better battery lifespan, wherein the initial capacity is 660 mAh, and the capacity after 20 cycles of charge/discharge is 636 mAh.
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The present invention is directed to a gel polymer electrolyte for use in rechargeable polymer secondary batteries and a precursor composition thereof. The precursor composition can be injected into an aluminum shell of a battery cell, which undergoes in-situ heating polymerization by heating and forms a gel polymer electrolyte penetrating a partition membrane therein. The precursor composition contains (meth)acrylic (acrylate) monomers and a modified bismaleimide oligomer resulting from a reaction of barbituric acid and bismaleimide.
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BACKGROUND
[0001] The present invention involves an improved chopper for chopping continuous or very long loose items such as fiber, fiber strands, yarn, wire, string, ribbon, tape and the like by pulling the item(s) into the chopper while the loose items are held tightly against the surface of a rotating backup roll with a rotating idler roll biased against the backup roll and carrying the item(s) on into a nip between a rotating blade roll and the rotating backup roll where they are separated into short pieces. More specifically the present invention involves a chopper having an improved mechanism for biasing the backup roll and the blade roll against each other during the chopping operation.
[0002] It has long been known to chop continuous fibers or fiber strands into short lengths of about 3 inches or shorter. Billions of pounds of such product including chopped glass fibers and fiber strands are produced each year in process and chopping apparatus such as disclosed in U.S. Pat. Nos. 5,970,837, 4,398,934, 3,508,461, and 3,869,268, the disclosures of which are incorporated herein by reference. The choppers disclosed in these patents comprise a blade roll containing a plurality of spaced apart blades for separating the fibers into short lengths, a backup roll, often or preferably driven, which the blades work against to effect the separation and which pulls the fibers or fiber strands and an idler roll to hold the fibers or fiber strands down onto the surface of the backup roll. In the chopped fiber processes disclosed in these patents, the chopper is usually the most productivity limiting equipment in the processes. These processes typically operate continuously every day of the year, 24 hours each day, except during furnace rebuilds every few years. Therefore, improvements in the chopper, which allow the chopper to pull and chop faster and for longer times between maintenance shutdowns, and/or to pull and chop more fibers or fiber strands at a time, have an extremely positive impact on productivity and production costs.
[0003] In the prior art, the backup roll has been mounted and held against the surface of the blade roll in a generally rigid manner such as with a mechanical screw jack and a gear head stepping motor or with a variable force such as a force applied by an air or hydraulic cylinder. A shear pin or equivalent has also been used as a safety feature in the event a thicker stream of fiber strands comes to the chopper, but when the shear pin fails, considerable down time is incurred and production is lost while the shear pin is replaced and the chopper is put back on line.
[0004] The mechanical jack was set up by manually running the gear motor to bias one of the backup roll or blade roll into the other roll until the blades had penetrated the working layer of the backup roll an appropriate amount. If the blades did not penetrate far enough, double cuts or stringers, long strands, would result, an unacceptable result. If the blades penetrated too far, the chopper would chop the strands properly, but the backup roll life would be shortened substantially. Given these options, at least some operators tended to run the jacuator too long in setting up a rebuilt chopper, or if a chopping problem developed, thus reducing backup roll life substantially below what it could be if the choppers are set up properly. This is a costly situation causing this system to be abandoned in favor of using fluid cylinders with or without shear pins.
[0005] Normally several strands such as up to 14 are fed into the chopper, each strand containing 2000 or more fibers. As more fiber strands and fibers are fed into the chopper it becomes more difficult to pull all of the strands and fibers at the same speed, so more pressure is applied to the cylinder pushing the idler roll against the backup roll with more force.
[0006] Occasionally a glass bead from a fiberizing bushing or a wad of fibers will be pulled to the chopper caught up in the multitude of fiber strands. When this happens, it is necessary for one of the backup roll or blade roll to be able to move away from the other roll to allow this thicker anomaly to pass through the nip between the blade roll and the backup roll. If this separation does not occur the chopper will often lock up causing damage to the drives, belts and/or the rolls.
[0007] Although at least one of the rolls is held in position with a fluid cylinder, the fluid is either not compressible or responds too slowly to the sudden problem to protect the chopper from damage and downtime. In the past the shear pin was used to provide such protection. However, when the shear pin shears the blade roll and backup roll are no longer biased together properly requiring that the chopper be shut down to install a new shear pin. This downtime is costly because of the loss of production during the downtime and due to reduced material efficiency for several minutes following restart. Downtime causes forehearth and bushing temperature upsets because hanging fibers do not pull in cooling air that occurs when the chopper is pulling the fibers from the bushings.
[0008] If all of the strands or fibers are not pulled at the same speed, the slower strands and fibers will have a greater fiber diameter which is unacceptable and the bushings of the slower strands frequently will not operate at the proper temperature causing more frequent breakouts and/or additional fiber diameter variations, both of which are unacceptable. Also, fiber slippage can cause some of the fibers to be cut to shorter lengths than desired resulting in an unacceptable product. Therefore, it is very important that the biasing force between the blade roll and the backup roll remain proper and essentially constant.
[0009] As the pulling speed is increased, and/or as the number of strands and fibers are increased, above about 3000-4000 ft./min. (FPM), depending on the product, the present state of the art choppers begin to vibrate and the idler roll begins to allow one or more of the strands to slip some thus reducing the pulling speed of one or more of the strands. Also, if all of the strands are not pressed between the idler roll and the elastomer layer of the backup roll, a strand can slip partially out of the nip leaving some of the fibers unchopped, producing double cuts and stringers in the chopped product and causing the product to be scrapped.
[0010] U.S. Pat. No. 3,731,575 teaches an air cylinder with an adjustable stop to bias the blade roll against the backup roll so that the blades penetrate the backup roll the desired distance and no further. However, with this arrangement, the pressure in the cylinder increases when a wad or bead or other thicker strand set passes through the chopper and forces the backup roll to back away from the blade roll. Also, an air cylinder bias is subject to permitting vibration at high speeds and is therefore not desirable. Finally, this system suffers the same problem as the mechanical jack system in that it requires an operator to set the mechanical stop limiting the distance the blades can penetrate the working layer of the backup roll.
[0011] It would be very desirable for the chopper to have an adjustable, but constant biasing force between the backup roll and the blade roll while having the ability to instantaneously respond to a substantially thicker feed of material to be chopped without requiring any downtime or without causing unnecessary scrap.
SUMMARY OF THE INVENTION
[0012] The present invention is an improved chopper for separating long lengths of one or more unwound items selected from a group consisting of fibers, fiber strands, wires, strings, tape(s), strip(s) and ribbon(s) into short lengths. One or more of, preferably a plurality of, the long lengths of material are pulled into the chopper in an unwound form at speeds exceeding 1,000 FPM, preferably at speeds exceeding 2000 FPM, by the peripheral surface of an elastomer layer on the peripheral surface of a rotating backup roll which carries the item(s) on into a nip between the elastomer layer and a rotating blade roll. The improvement is a biasing assembly that biases, presses, the blade roll and the backup roll together with an adjustable, but substantially constant force. The biasing system comprises a mechanism that will instantaneously allow a slightly thicker portion of the items to pass through the nip of the blade roll and backup roll while allowing the chopper to resume normal chopping quickly without shutting down and without rebounding such that the blades penetrate excessively into the working layer of the backup roll. The item(s) being chopped can be either dry or wet with or without a chemical sizing on the surface of the item(s). Preferably, the mechanism is an adjustable slip clutch.
[0013] The improvement to the chopper comprises an assembly for biasing either the blade roll against the backup roll, the backup roll against the blade roll or both rolls together, the biasing assembly comprising a mechanical jack, a drive for driving the mechanical jack to bias or force one of either of the blade roll or backup roll against the other roll and, in some embodiments, the drive preferably being a stepping motor having a torque that closely matches the desired force on the jack that will drive the blades the desired amount into the backup roll. Some preferred embodiments can use a gear motor in conjunction with a slipping mechanism.
[0014] Another preferred embodiment is similar to that embodiment just described, but the drive is a stepping motor having higher torque. Its method of use is different comprising setting up a program for the stepping motor that advances the stepping motor a specific number of steps according to the diameter of the backup roll on the chopper, which changes as the backup roll is reconditioned. The operator inputs the diameter and the stepping motor automatically advances enough to move the blades of the blade roll into the working surface of the backup roll the desired amount each time and holds them there. This embodiment can optionally use a slipping mechanism located between the stepping motor and the mechanical jack.
[0015] In some embodiments the biasing assembly also includes a slipping mechanism located between the mechanical jack and the drive. In these embodiments the assembly for biasing comprises a slipping mechanism connected between the drive and the mechanical jack that having a desired torque limit that is either fixed or adjustable and that will slip to limit the amount of force exerted by the mechanical jack and that will also could allow the mechanical jack to retract instantaneously to relieve excessive pressure in the nip between the backup roll and the blades or blade roll.
[0016] The invention also includes a method of chopping items as described above using the improved chopper described above having a novel biasing mechanism to bias the blade roll and the backup roll together as described above for separating the items into short lengths while optimizing backup roll working layer and blade lives.
[0017] When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond that so long as the advantages of the invention are realized. Practically, there is rarely the time or resources available to very precisely determine the limits of all the parameters of one's invention because to do so would require an effort far greater than can be justified at the time the invention is being developed to a commercial reality. The skilled artisan understands this and expects that the disclosed results of the invention might extend, at least somewhat, beyond one or more of the limits disclosed. Later, having the benefit of the inventors disclosure and understanding the inventive concept and embodiments disclosed including the best mode known to the inventor, the inventor and others can, without inventive effort, explore beyond the limits disclosed to determine if the invention is realized beyond those limits and, when embodiments are found to be without unexpected characteristics, those embodiments are within the meaning of the term about as used herein. It is not difficult for the skilled artisan or others to determine whether such an embodiment is either as might be expected or, because of either a break in the continuity of results or one or more features that are significantly better than reported by the inventor, is surprising and thus an unobvious teaching leading to a further advance in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is an elevational view of a chopper of the present invention with a portion cut away to show the novel biasing assembly.
[0019] [0019]FIG. 2 is a partial elevational view of the interior of the chopper shown in FIG. 1 showing the support for the backup roll and backup roll spindle and showing a preferred embodiment of the novel biasing system of the present invention.
[0020] [0020]FIG. 3 is a blown up elevational view of the preferred embodiment of the novel biasing system of the present invention.
[0021] [0021]FIG. 4 is a partial side view of one preferred embodiment of the invention shown in FIG. 2.
[0022] [0022]FIG. 5 is a blown up side view of the novel biasing system of the present invention shown in FIG. 4.
[0023] [0023]FIG. 6 is a partial side view of a more preferred embodiment of the invention shown in FIG. 2.
[0024] [0024]FIG. 7 is a blown up side view of the novel biasing system of the present invention shown in FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
[0025] [0025]FIG. 1 shows a front elevation view of a typical prior art chopper 2 used in making chopped strand glass fiber. It comprises a frame and front plate 4 , feet 5 , a blade roll 6 with spaced apart blades 7 contained in slots and projecting from the periphery of a blade holder integrated into the blade roll 6 , a backup roll 8 and an idler roll 13 . The blade roll 6 is mounted on a rotatable spindle 17 and held in place with a large nut 19 . The blade roll 6 is usually made of metal and thermoplastic material such as the blade rolls shown in U.S. Pat. Nos. 4,083,279, 4,249,441 and 4,287,799, the disclosures of which are herein incorporated by reference.
[0026] The backup roll 8 is comprised of a hub and spoke assembly 9 with an integral metal rim 10 on which is cast or mounted a working layer 11 of an elastomer or thermoplastic material such as polyurethane. The backup roll 8 is mounted on a second spindle 18 and held in place with a large nut 20 . To operate the spindle 18 of the backup roll 8 is moved towards the spindle 17 of the blade roll 6 until the blades 7 of the blade roll 6 press into the working layer 11 of the backup roll 8 a proper amount forming a nip 14 to break or separate fiber strands 12 into an array of short lengths.
[0027] One or more, usually eight or more and up to 20 or more strands 12 , such as glass fiber strands, each strand containing 400-6000 or more fibers and usually having water and/or an aqueous chemical sizing on their surfaces, are pulled by the backup roll 8 , in cooperation with a knurled idler roll 13 , into the chopper 2 and the nip 14 . The strands 12 first run under a grooved oscillating, separator and guide roll 16 , preferably with one or two strands in each groove, and upward and over the outer surface of the backup roll 8 . The working surface of the back up roll 8 is typically wider than the oscillating path of the glass fiber strands 12 . The strands 12 then pass under the outer knurled surface of the idler roll 13 , which is pressed against the strands at a desired pressure to enable pulling of the glass fiber strands. The strands remain on the surface of the working layer 11 and next pass into the nip 14 between the backup roll 8 and the blade roll 6 where they are separated with the razor sharp blades 7 wherein the strands are usually cleanly cut or broken into an array of chopped strand 15 having the desired length.
[0028] The improved chopper 2 of the present invention and illustrated in FIGS. 2 - 5 comprises a novel biasing system such as a preferred biasing assembly 24 . The backup roll spindle 18 , in turn holding the backup roll 8 in a rotatable manner, is supported with multiple bearings in a known manner on a pivoting beam 20 that is held in a pivoting manner with a pin 22 . As the pivoting beam 20 is raised, the outer working surface of the backup roll 8 is pressed against the blades 7 . The biasing assembly 24 is attached to the pivoting beam 20 in a manner that will be described later and a mechanical jack 26 is manipulated to bias the backup roll 8 against the blades 7 of the blade roll 6 in the manner shown in FIG. 2.
[0029] FIGS. 3 - 5 show one preferred embodiment of the biasing assembly of the present invention in more detail. The preferred biasing assembly 24 is comprised of a mechanical jack 26 , such as an Acme screw jack called a Jactuator™, having a rotatable input shaft 35 for extending or retracting a rod 34 of the screw jack, a rotating means such as a conventional stepping motor, conventional motor and gear reducer or gearhead motor combination 28 having an output shaft 29 , conventional controls for the gear motor (not shown), a slipping mechanism, such as a slip clutch 50 , for connecting the gear motor 28 to the rotatable shaft 35 , the slipping mechanism 50 providing an adjustable, constant torque to the rotatable shaft 35 of the mechanical jack 26 , and means for securing one end of the screw jack 26 to the frame of the chopper and the other end to the pivoting beam 20 . When a stepping motor is used as the motor 28 , a conventional programmed control can be used allowing the operator to key in the number of steps for the stepping motor to advance or backoff. All motors used are reversable motors.
[0030] This preferred biasing system 24 also comprises a toothed gear 30 attached to a rotatable output shaft 41 of the mechanical jack 26 , a tooth sensor and counter 32 for counting the number of passing teeth of the toothed gear 30 , a bracket 33 for holding the tooth sensor and counter 32 in the proper location, and a mounting plate 27 for mounting the mechanical jack 26 , the gear motor 28 and the bracket 33 .
[0031] The means for securing mechanical extenuating means or screw jack 26 to the pivoting beam 20 preferably comprises a clevis mount 38 having a hole 39 therethrough and an opening for a clevis attached in any known suitable manner to the underneath surface of the outer end of the pivoting beam 20 as shown in FIG. 2. A clevis 36 is rotatably attached to the end of the mechanical jack rod 34 in a known manner. The clevis 36 is then pivotly attached to the clevis mount 38 with a pin 40 in a known manner.
[0032] The means for attaching the mechanical jack means, screw jack 26 and jackscrew-housing 47 for the jackscrew that is the lower portion of shaft 34 is a plate 42 having on one end an integral eye 42 . The other end of the plate 42 is attached to the underneath side of the mounting plate 27 , preferably centered under the body of the screw jack 26 , in any suitable manner, such as with threaded metal bolts whose heads are recessed in the top portion of the mounting plate 27 . The plate 42 has a cutout portion 49 so the plate 42 can straddle the jackscrew housing 47 as shown in FIG. 3. This preferred means for securing the mechanical jack 26 to the frame of the chopper comprises pivotly attaching the eye 45 of plate 42 to a mounting bracket 44 with a bolt 48 having a threaded end that threads into a threaded opening of the mounting bracket 44 as shown in FIG. 5. The mounting bracket 44 can be attached in any known manner, such as by welding, to a lower frame member 46 of the chopper.
[0033] As the gear motor 28 is energized and rotates its output shaft, coupled to the input side of the slipping mechanism, such as the input side of the slip clutch 50 , with any suitable known coupling device, rotates the slip clutch 50 turning an output shaft of the slip clutch 50 unless the external load exceeds the torque limit of the slip clutch 50 . The output side 37 of the slip clutch 50 is coupled to the input shaft 35 of the mechanical screw jack 26 with any suitable coupling device. The slip clutch 50 can one that is adjustable or, if one is concerned with the proper setting being changed for the wrong reason, a slip clutch with a fixed, non-adjustable torque limit, can be used, selecting the proper slip clutch 50 for the desired torque limit.
[0034] To operate the preferred chopper biasing system described above, the operator first either selects a slip clutch 50 having a torque limit that will press the backup roll 8 against the blades 7 with desired amount of force or, if the slip clutch 50 has an adjustable torque limit, sets the torque limit to achieve the same objective. A preferred torque limit for the type of chopper shown in FIG. 1 is one that will allow the screw jack 26 to exert about 1000 pounds force. Then the operator starts the stepping motor with gear head 28 in a direction that will cause the screw jack 26 to raise the jackshaft 34 thus raising the pivoting beam 20 . The screw jack 26 will continue to raise the backup roll 8 into the blades 7 until the resistance of the blades penetrating the elastomer layer of the backup roll 8 reaches level where the torque on the input shaft 35 of the screw jack 26 reaches the torque limit of the slip clutch 50 .
[0035] At that time the gear motor can be reversed to back off the screw jack 26 about 10 teeth on the toothed gear 30 as counted by the tooth counter 32 followed by shutting off the gear motor, but it is preferred that the slip clutch 50 slips continuously during operation to maintain the desired bias or force pressing the backup roll 8 into the blades 7 at all times during resting or during operation until the stepping motor is stopped or reversed. The stepping motor is usually stopped when the chopper is shut down and reversed to back the backup roll 8 away from the blades 7 when it is desired to remove the blade roll 6 and/or the backup roll 8 .
[0036] This preferred biasing system 24 can also comprise a second toothed gear 31 attached to the gear/stepping motor output shaft 29 , a second tooth sensor/counter 52 for counting the number of passing teeth of the toothed gear 31 , a second bracket 53 , attached to the mounting plate 27 , for holding the second tooth sensor/counter 52 in the appropriate location. With the optional second tooth sensor/counter 52 , the operator can quickly determine when the slip clutch 50 is slipping because said second sensor/counter 52 will be showing that the second toothed gear 31 is turning while the first toothed gear 30 is either turning slower or not at all. This tells the operator when to stop trying to advance the gear/stepping motor 28 to bias the blade roll 6 and the backup roll 8 together.
[0037] During operation, if a wad of fibers, bead or other oversize feed comes to the nip between the backup roll 8 and the blades 7 , the high torque transmitted to the slip clutch 50 by the high pressure in the nip will allow the jack shaft 34 to be pushed down into the screw jack 26 and instantaneous relief of the pressure, but will then immediately drive the back up roll 8 back into operating position without the customary recoil impact resulting from prior spring or fluid, air, biasing systems.
[0038] Any kind of mechanical jack can be used in the inventive biasing system, but it is preferred to use one of lower mechanical advantage, i. e. preferably less than about 10:1 to minimize the pressure that can build up in the nip between the backup roll 8 and the blades 7 due to a thicker feed before it is relieved and to reduce the reaction time to relieve the pressure. A preferred screw jack is a Duff-Norton 2-ton Machine Screw Actuator #TM-9002-4, 6:1 ratio with a 4 inch stroke available from the Duff-Norton Co. of Charlotte, N.C.
[0039] The preferred slip clutch is Polyclutch™ #SFS-44-8K-12K with the torque preset to 50 lb. inches available from Custom Products Company of North Haven, Conn., but other types of slipping systems can be used instead of the slip clutch 50 . For example, a magnetic constant torque clutch that uses an adjustable field on granular ferrites to set and maintain the desired torque limit can be used. Other slipping mechanisms that will achieve the disclosed function of this component of the inventive system can also be used.
[0040] [0040]FIGS. 6 and 7 show a more preferred embodiment of a biasing assembly 55 that is identical with the other preferred embodiment described above, but using a different means for limiting the torque on the input shaft 35 of the jack 26 . In FIGS. 6 and 7 the common elements of the biasing assembly are given the same numbers as in FIGS. 4 and 5. This biasing assembly 55 differs from the biasing assembly 24 described above in that it does not use the slip clutch 50 . Instead a carefully sized stepping motor 57 having an output shaft 59 is connected directly to the input shaft 35 of the jack 26 using the conventional coupling 37 . The stepping motor 57 is carefully sized to have a maximum output torque equal to or very near the maximum desired torque on the input shaft 35 of the jack 26 that will drive the blades 7 on the blade roll 6 the desired distance into the backup roll 8 . When this distance is reached, the stepping motor 57 stalls and this can be seen by the operator by noting that the gear sensor/counter 32 is indicating that the toothed gear 30 is no longer rotating.
[0041] To set up the chopper of the present invention having the just described preferred biasing system, after new or reconditioned backup roll and/or a new or reconditioned blade roll have been installed, the stepping motor is jogged, or stepped, by the operator until jogging will no longer turn the element of the mechanical jack. This can be determined with the toothed gear and tooth sensor/counter described above or by watching said element during jogging. At this time the chopper is ready to run. After the chopper has been put into operation chopping, the stepping motor is occasionally jogged, either automatically with a timer or manually by the operator, until the element no longer rotates with the jogging. This controlled bias between the blades and the backup roll results in substantially longer life of the backup roll and improved quality of chopped items.
[0042] In another preferred embodiment of FIGS. 6 and 7, a higher torque stepping motor 57 can be used along with a conventional programmable control (not shown) for the stepping motor. The control is programmed to advance the stepping motor 57 different amounts and to reverse the stepping motor 57 to a common base. The different amounts of advance are exactly the amounts to bring the blades 7 of the blade roll 6 into the same depth of the working layer on backup rolls 8 having different diameters. A new backup roll 8 has the greatest diameter and this would be one diameter programmed in to the controller. Each time a backup roll 8 is removed from a chopper and dressed to produce a new smooth surface on the working layer, the diameter is decreased by a fixed amount. The controller is also programmed for a diameter after one dressing, after two dressings, and so on. After an operator installs a new backup roll 8 onto the chopper, he measures the diameter of the backup roll 8 and keys in the diameter. When the chopper 8 is ready to be put into operation, the operator pushes the biasing start button and the stepping motor 57 advances the programmed number of steps needed to properly position the blades 7 of the blade roll 6 with respect to the working layer of the backup roll 8 automatically. Although not necessary, the slip clutch 50 can also be used with this embodiment as a safety measure for the times when the operator might key in the wrong diameter.
[0043] Other embodiments employing the concept and teachings of the present invention will be apparent and obvious to those of ordinary skill in this art and these embodiments are likewise intended to be within the scope of the claims. The inventor does not intend to abandon any disclosed inventions that are reasonably disclosed but do not appear to be literally claimed below, but rather intends those embodiments to be included in the broad claims either literally or as equivalents to the embodiments that are literally included.
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A method and apparatus for chopping long unwound items like fiber, fiber strands, yarn, etc. The chopper has a backup roll, a blade roll and a biasing system for forcing the backup roll and the blade roll together at a desired force during set up and operation. The biasing system contains a mechanism such as a slip clutch or a limited torque stepping motor for maintaining a substantially constant biasing force at set up and during operation while allowing the rolls to separate slightly to pass a temporary thicker feed without recoil that currently shortens blade and backup roll working layer life.
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This application is a national stage completion of PCT/EP2005/004352 filed Apr. 22, 2005, which claims priority from German Application Serial No. 10 2004 020 569.8 filed Apr. 27, 2004.
FIELD OF THE INVENTION
The invention concerns a control valve arrangement for the control of a start clutch of an automatic transmission of a motor vehicle.
BACKGROUND OF THE INVENTION
In automatic transmissions with automated, wet start clutches, the general practice is to convert a typical mechanical transmission into an emergency operation, for example if following the failure of a transmission control apparatus, which alleviates the failure of power in a transmission in such a manner the start clutch, now unpowered, is caused to disengaging. Especially, in a case of driving in heavy traffic, this strategy can lead to serious results, since the vehicle has become capable of no more than a powerless, forward rolling behavior.
Engagement of the wet start clutch in such a condition of driving, because of technological safety reasons, is also impossible since the shutdown of power remains in force only because of a hydraulic clutch activation pressure. Insofar as the vehicle's drive motor stalls itself upon the diminution of the travel velocity with the engaged clutch, there is still a low residual speed at which the important motor driven co-acting aggregates, such as brake action reinforcement or power steering pumping can no longer properly function.
In a typical automatic transmission with a dry start clutch, during mechanical emergency operation, the clutch is engaged so that the output torque of the vehicle remains in a technological connection with the motor output until the vehicle comes to a standstill. In such a case, it is true that no dangerous, critical conditions of driving exist for the vehicle although, following the standstill, the vehicle can no longer be brought into motion or even pushed into a safer location.
In accordance with the foregoing, obviously there exists a need for a control apparatus for a start clutch of an automatic transmission of a motor vehicle which, in dependency upon the speed of rotation of the motor and/or the speed of rotation of the output drive of the transmission, the power flow in the drive string is first interrupted when a predetermined threshold speed of rotation of the motor and/or transmission output speed of rotation is understepped. In this way, no stalling of the motor of the vehicle occurs, the auxiliary aggregates remain operable and the driver is still given the advantage of removing himself and his vehicle from a possibly dangerous driving zone. Additionally by way of such a control system, even an induced movement of the vehicle, which is then in standstill, is possible since an otherwise movement blocking, power-flow connection between the motor and the transmission is broken.
Based on this background, DE 199 43 939 A1 discloses a hydraulic emergency control for a stepless transmission, wherein a dedicated clutch to the transmission becomes separable and engagable according to the speed of rotation of the vehicle motor. Thereby, in the case of a disturbance, a renewed stalling of the drive motor can be avoided upon the understepping of a defined threshold value of rotation speed and as well, a startup upon the overstepping of the threshold is enabled. According to the design of the emergency control, the possibility exists that the speed of rotation related signal can be engendered, for example as (1) a hydraulic pressure, as (2) a pneumatic pressure or as (3) an electrical voltage; any one of which can be functional.
Additionally, DE 102 38 104 A1 teaches a procedure for controlling an emergency shifting program for an automatic transmission with a start clutch, which is particularly designed to allow a realization of an emergency operation upon the standstill of the vehicle, as well as permitting a by-pass of the lowering of the speed of rotation of the motor to a point below the stalling threshold. In the case of this procedure, provision has been made that the emergency shifting program is controlled by a signal related to the vehicle travel speed and/or to the speed of rotation of the motor, which is computer processed by valve-logic and acts in such a manner that the motor operation is interrupted only in the compression stage in order to prevent the motor from stalling.
Accordingly, the purpose of the invention is the creation of a control valve arrangement for controlling of a start clutch of an automatic transmission where, during an emergency control operation, the start clutch can be disengaged if the speed of rotation of the motor and/or the output speed of rotation of the transmission, i.e., the travel speed of the vehicle, falls below a predetermined threshold value. The purpose encompasses the fact that this valve arrangement is to be economical in manufacturing costs, simple in design and reliable under emergency conditions.
SUMMARY OF THE INVENTION
The invention is based on a control valve arrangement for controlling a starting clutch of an automatic transmission, where a clutch control valve for controlling at least one clutch activation apparatus which, in the normal operation of the transmission, diverts a provided source of pressure to the direct control of the clutch activation apparatus and does so in relation to a pilot pressure or to an electrical signal.
Additionally, this control valve arrangement is for the realization of an emergency operation of the transmission. Upon the failure of pilot pressure or electrical signal, an activation pressure can be conducted to the clutch control valve, whereby this valve is held in its engaged position as long as a specified speed of rotation lies above a predetermined speed of rotation threshold. The pilot alarms can be induced by the following, individually or in common: motor speed of rotation; transmission output speed of rotation; motor torque; transmission input torque; transmission input speed of rotation; transmission output torque, and the driving load.
By way of this valve arrangement, a control apparatus for emergency operation of a vehicle with an automatic transmission can be created, which can be manufactured at low cost and is reliable in its function. The control apparatus would be activated, for example if an electronic transmission control system and/or an electrically controlled clutch control valve dropped out of service. A controlling pressure, which would be related to the speed of rotation of the vehicle's driving motor and/or to the transmission output speed of rotation, would provide assurance that a start clutch of the automatic transmission remains operative for the transfer of torque through the automatic transmission as long as the driving speed and the speed of rotation of the drive motor do not fall below such a stalling speed of rotation that the driving motor would lose its internal combustion process.
Insofar as the driving speed, during such an emergency operation, actually drops below such a functional value with an engaged start clutch, the driver would be obliged to contend with stalling of the motor, the control pressure, which is related to the speed of rotation, disengages the start clutch. This start clutch, up to this time, has been transferring the full motor torque. Stalling of the motor is thereby avoided, so that important vehicle components, such as a brake pressure reinforcing way and/or a power steering auxiliary pump, can also be continuously operated.
In the embodiment of these principles of the invention, the proposal is made that the activation pressure of a self-operating pressure, retention valve can be conducted directly to the clutch activation apparatus by way of an activation valve leading to a clutch control valve, or alternately through a bypass, if available, directly to the clutch activation apparatus. This would take place if a speed of rotation dependent control pressure is applied to the self-activating check valve and this pressure is greater than the applicable pressure threshold value. As this occurs, this pressure threshold value characterizes that the previously mentioned motor speed of rotation, below which the motor will stall.
According to another component of such a control valve arrangement, provision has been made that a pilot pressure in normal operation, can be exerted on the self-activating check valve and on the activation valve. Deviating therefrom, provision can also be made to the effect that, first, at the self-activating, pressure retention valve and, second, at the activation valve during normal operation, the control pressure, which defines the normal operation or yet, third, during emergency operation at the activation valve, a control pressure is established which defines the emergency operation.
With regard to the advantageous clutch control valve, notice should be given that it is possible to design this valve, which is capable of governing the pressure means or, in some embodiments, activating a solenoid operator. The defined chosen mode of construction for the self-operating pressure, retention valve is, however, not of decisive importance for the result to be achieved by the invention.
A pilot pressure controlled clutch control valve advantageously incorporates two axial, successively placed slide valves which, as is the case with all other slide valves here described, are advantageously inserted into a slide valve body of a hydraulic transmission control apparatus to move with axial motion thereby aligning complementary flow ports.
Belonging to the two slide valves of the pilot pressure controlled clutch control valve, in accord with an advantageous embodiment example, is to be found a shorter slide valve which, on its oppositely situated end surface is pressure-loaded by activation pressure, that is to say, by the pilot pressure, while the pilot pressure can be applied against an axial end face of a longer slide valve.
According to another embodiment of the control valve arrangement, the slide valve of the activation valve can be subjected to the activation pressure and to the pilot pressure. In addition, provision has been made that the slide valve of the self-operating pressure, retention valve can accept activation and pilot pressures.
Beyond this, it is a characterization of a control valve arrangement of invented design in that the slide valve of the self-operating pressure, retention valve and the slide valve of the activation valve exhibit on a first axial end, respectively, a control piston against which a reset spring abuts, while the pilot pressure can act upon that second axial end of a control piston, which is remote from the reset spring.
In a circumstance when pilot pressure fails and a pressure based on speed of rotation exists, which lies below the specified threshold value by way of the above measures, assurance is given that the slide valve of the self-operating pressure, retention valve is pushed so far axially by a reset spring that even a renewed increase of the speed of rotation related pressure is no longer enabled to close the start clutch. From a technological standpoint of safety, this is of exceptional value since the vehicle drive-motor is now in a state of standstill with the start clutch necessarily open. In this operation, the motor, for example, for trial, could be run up to a high rate without the danger that thereby an undesired start of the vehicle would result.
Further, it could be seen as advantageous if the axial end faces of both slide valves located in the pilot pressure controlled, clutch control valve are subjected to the mentioned pilot pressure. In this condition, provision is made in that the end surface, which is remote from the end surface loaded with the pilot pressure, of the axially longer slide valve of the clutch control valve be subjected to the force of a reset spring.
A typical reset spring abuts itself on a piston of the axially longer slide valve of the clutch control valve in such a manner that both end faces of the piston can be loaded by the controlled clutch activation pressure.
In the case of an activation valve, the co-acting reset spring provides assurance that, by a defection of the pilot pressure of the slide valve of this valve, without any auxiliary support, the piston of the valve is pushed into that position where the provided activation pressure from the self-operating pressure, retention valve can be conducted through the clutch control valve, which is now activated by pilot pressure.
Considering the clutch activation apparatus, it is preferable that this apparatus possess an operative piston in a cylinder, which the piston receives force from an axially aligned, piston-encompassing reset spring. By way of this construction, upon a defection of the pilot pressure, that is to say, upon the failure of another control pressure or a dropout of an electric operative signal, as well as entering a lower state of a control pressure based on speed of rotation, this piston would be so far retracted in its cylinder that a clutch, which has previously been disengaged within the circumstances of emergency operation, remains in the same disengaged state.
A further embodiment of the invention provides, that the supply pressure, which is delivered to the clutch control valve, possesses the same level of pressure as the activation pressure. If this is the case, it becomes advantageously possible that, first, the same pressure source is being relied upon and, second, the start clutch will be subjected to the same slip-free, clutch-engaging force as is conventionally used in normal operation when the activation pressure is conducted directly (possibly bypassing a clutch control valve) to the clutch activation apparatus.
In this connection, mention is made that according to another embodiment of the invention, provision could be made so that the activation pressure can be acquired from that very high pressure hydraulic fluid flow, which is employed in normal operation for the clutch slip operation of at least one start clutch.
Since it can be advantageous that the described self-restraining, operational function of the control valve arrangement acts to prevent a shifted-into, reverse vehicle travel, another embodiment of the invention prevents the enablement of the transmission from performing the reverse travel during an emergency operation.
For the realization of this controlling function, another provision can be that the end-face of a piston of a slide valve, which piston forms an abutment for the reset spring of the self-operating pressure, retention valve, is loaded with a reversal-prevention pressure, the degree of which pressure is so selected that, in spite of the control pressure, dependent on speed of rotation, exerted on this self-operating pressure, retention valve, any forwarding of the activation pressure is prevented. At the same time, since the pilot pressure or the electrical control signal is no longer being applied on the clutch control valve then, in the emergency operational state in a case of shifted-into reverse travel, the start clutch is disengaged by way of the clutch activation apparatus by the action of the force of the assigned reset spring.
A special embodiment of an invented design for the control valve arrangement provides that, in normal operation of the transmission, a separate control signal, i.e., a separate control pressure for the activation of the activation valve as well as the self-operating pressure, retention valve is employed, while only the clutch control valve is loaded by the pilot pressure.
According to this embodiment, it is possible that a conduction of pressure can only be directed against that end face, which is remote from the reset spring of the axially longer, slide valve as well as against the opposite end face of the shorter slide valve of the clutch control valve. Moreover, the self-operating pressure, retention valve as well as the activation valve on their ends, which are remote from the reset springs, are pressurized by that control pressure which is characteristic of normal operation of the transmission. In a case of a defection of this control pressure for realization of the transmission emergency operation, a switching of the activation pressure onto the clutch control valve is possible. Thereby the clutch activation apparatus, upon the defection of the pilot pressure, will be held in its engaged position until the speed of rotation related, control pressure at the self-operating pressure, retention valve drops below the preselected pressure threshold value.
Another embodiment of the control valve arrangement provides that the clutch control valve and the self-operating pressure, retention valve can be subjected to the pilot pressure, while the activation valve is loaded with a converted starting pressure, which acts upon the reset spring-loaded end of the slide valve of this valve.
Accordingly, provision is made so that pilot pressure can be applied against that end face, which is remote from the reset spring, of the slide valve of the self-operating pressure, retention valve and to that end face, which is remote from the reset spring of the longer slide valve of the clutch control valve and so that activation pressure can be applied against that end which is remote from the reset spring of the slide valve of the activation valve, as well as a pressure chamber of the activation valve, so that an emergency control pressure can be applied against the end face, which is subjected to the force of the reset spring of the slide valve of the activation valve to bring about the release of an emergency operation of the transmission and so that activation pressure from the activation valve can be diverted to the clutch control valve following a defection of the pilot pressure.
By way of this construction mode, the clutch activation apparatus is held in its engaged position until the speed of rotation related control pressure at the self-operating pressure, retention valve drops below the predetermined threshold of level of pressure.
The invention does not limit itself to the activation arrangement for the start clutch. Thus a provision is possible that with the control valve arrangement in accordance with the invention, two mutually separate, controllable start clutches can be present in an emergency operation of the transmission. In the described case which follows during the emergency operation of the transmission, one of the two start clutches is held just so long in its engaged position until the speed of rotation control pressure lies above the specified pressure threshold.
Thus a control valve arrangement is provided wherein a first pilot pressure of that end surface, which is remote from the reset spring of a spring-loaded, slide valve of a first clutch control valve and a second pilot pressure of that end surface which is remote from the reset spring of a spring-loaded, slide valve of a second clutch control valve, allow both respective clutch control valves to exert pressure upon one of two clutch activation apparatuses with respective one clutch activation pressure and where the two pilot pressures can be directed to one switchover valve by way of which that end surface, which is remote from the reset spring of the slide valve of the activation valve and of the self-operating pressure, retention valve are alternatingly subjected to the higher of the two pilot pressures.
In accordance with the failure of the pilot pressure, as well as in the presence of a sufficiently high speed of rotation related control pressure on the self-operating pressure, retention valve, the activation pressure from the self-operating pressure, retention valve can be forwarded to a selection valve, by way of which and dependent upon its set position, this pressure can be again forwarded to that end face, which is remote from the reset spring of the shorter slide valve of the first clutch control valve or to that end face, which is remote from the reset spring of the shorter slide valve of the second clutch control valve.
Thereby a clutch activation apparatus is held in its engaged position until the speed of rotation control pressure understeps the predetermined pressure threshold, while the second clutch activation apparatus is brought into an open-position or, if already open, is continued to be held in that position.
In the case of such a control valve arrangement, it is possible that provision can be additionally made, to the effect that the reset remote end face of the slide valve in the selection valve can be subjected to the regulated clutch activation pressure of the first clutch control valve so that, under this circumstance, if this controlled clutch activation pressure understeps a predetermined pressure value then the slide valve of the selection valve can be brought into its axial second position in which the activation pressure from this selection valve is directed to that end face, which is remote from the reset spring of the shorter slide valve of the second clutch control valve.
Accordingly, the shorter slide valve acts upon that end face, which is remote from the reset spring of the spring-loaded slide valve of this second clutch control valve so that a supply pressure is delivered as a clutch activation pressure to the emergency operational positioning, i.e., holding, of the second clutch activation apparatus in the direction of closure of the same.
Another embodiment of a control valve arrangement, designed according to the invention, emphasizes the actual control function. This is carried out in that two respective clutch activation apparatuses can act upon one of two start clutches where, for the realization of an emergency operation of the transmission that actuation apparatus, i.e., that clutch would be retained in its engaged position, which clutch has been already activated in the engaged direction.
Provision is made for a control valve arrangement, where a first pilot pressure against that end face, which is remote from the reset spring of the spring-loaded slide valve of a first clutch control valve, as well as a second pilot pressure against that end face, which is remote from a reset spring of a spring-loaded slide valve can be so forwarded, that the two clutch control valves subject one of two clutch activation apparatuses with one clutch activation pressure, so that the two pilot pressures are conducted to a switchover valve, by way of which the end face, which is remote from the reset spring of the slide valve of the activation unit, can be alternately subjected to the pressure of the greater of the two pilot pressures.
Additionally, this control valve arrangement provides that a speed of rotation related, control pressure can be sent to the slide valve of the self-operating pressure, retention valve that following the failure of the two pilot pressures, as well as in the presence of a predetermined speed of rotation related control pressure at the self-operating pressure, retention valve, the activation pressure from the self-operating pressure, retention valve by way of the activation valve can be forwarded to a selection valve (which lacks a reset spring) by way of the activation pressure, which latter is, in accordance with its setting, applied to that end face, which is remote from the reset spring, of the shorter slide valve of the first clutch control valve or to the end face, which is remote from the reset spring, of the shorter slide valve of the second clutch control valve.
Further, care has been taken that an end face of the slide valve in the selection valve is subjected to the controlled clutch activation pressure of the first clutch control valve while, at the same time, the other end face is subjected to the controlled clutch, activation pressure of the second clutch, control valve so that, in case of an emergency, failure of the two pilot pressures which were held at the closure pressure of the clutch activation apparatus until the speed of rotation related control pressure at the self-operating, valve understeps the predetermined pressure threshold value.
As already mentioned, the technological result attributed to the invention is not due to the construction mode of one or more control valves of the control valve arrangement. In this matter, additional embodiments of the invention provide control valve arrangements, which can be equipped with at least one solenoid, proportionally controllable clutch control valve.
In one embodiment with a solenoid, effective clutch control valve, provision has been made to the effect that the end face, which is remote from the reset spring of the slide valve of the activation valve, as well as the self-operating pressure, retention valve are pressure loaded with that pressure which characterizes a normal operating control pressure, so that clutch activation pressure emanating from the clutch control valve is conducted, without interference, by way of the activation valve to the clutch activation apparatus. Further, the self-operating pressure, retention valve becomes loaded with the speed of rotation related control pressure, whereby, upon the failure of the solenoid clutch valve, as well as upon the failure of the control pressure, which characterizes normal operation for the realization of an emergency operation, an activation pressure from the self-operating pressure, retention valve, by way of the activation valve, can be transferred to the clutch activation apparatus. Thereby the clutch activation apparatus will be held in its engaged position until the speed of rotation, control pressure at the self-operating pressure, retention valve understeps the predetermined pressure threshold.
A constructive diversion from the embodiment now offers the provision, that the clutch control valve is indeed designed as an solenoid, proportionally controllable valve, however, the control regulates the activation valve for the realization of an emergency operation of the clutch activation apparatus by way of a control pressure, which can be directed upon the spring-loaded side of the slide valve of the activation piston of this activation valve.
Thus care has been exercised to the effect that the end face, which is remote from the reset spring of the slide valve of the activation valve as well as the self-operating pressure, retention valve, when in normal operation, can be subjected to the controlled clutch, activation pressure from the solenoid clutch, control valve and that the clutch activation pressure, again, in normal operation, which emanates from the clutch control valve, can be directed by way of the activation valve without interference to the clutch activation apparatus, and that for the activation of an emergency operation of the transmission, an emergency control pressure can be applied to the reset spring-loaded, end face of the slide valve of the activation valve.
This design allows that, after the failure of the solenoid clutch, control valve, the activation pressure from the self-operating pressure, retention valve can be applied, by way of the activation valve, onto the clutch activation apparatus, where the clutch activation apparatus is then held it its engaged position until the speed of rotation, control pressure at the self-operating pressure, retention valve understeps a predetermined pressure threshold.
Another control valve arrangement for the activation of two start clutches, which also function as emergency activation clutches, provides that in an emergency operation of the transmission, the start clutch is held in its engaged position, which clutch was last activated into that engaged position. This control valve arrangement encompasses two clutch activation valves, which can be solenoidally activated for the purpose of activation-control of two clutch activation apparatuses, one self-operating pressure, retention valve, an activation valve, a selection valve, a switchover valve as well as a pressure conversion control valve.
In the normal operation of the transmission, provision is made to the effect that a higher controlled, clutch activation pressure present, respectively in one of the two clutch control valves, by way of a switchover valve, acts alternately against that end face of the slide valve which is remote from the reset spring and/or against the activation valve.
In addition, the controlled clutch, activation pressure of the one clutch control valve can be conducted, by way of a first reversal control valve to a first clutch activation apparatus, as well as to an end face of a slide valve of the selection valve, while the controlled clutch, activation pressure of the second clutch, control valve, by way of a second reversal valve, can be conducted to the second clutch, activation apparatus and, further the second end face of the slide valve at the selection valve can be subjected to this clutch activation pressure.
Moreover, provision is made that, in a case of failure of the two solenoid clutch control valves, an emergency operation of the transmission is assured by way of a pressure, which is dependent upon the speed of rotation, which so acts upon the self-operating pressure, retention valve with a rotational velocity which is above the predetermined threshold of speed of rotation value in such a manner, that an activation pressure from the self-operating pressure, retention valve can be applied by way of the activation valve onto the selection valve, where this activation pressure can be relayed from the selection valve to one of the two reversal valves.
Additionally, provision is made that the two reversal valves can be brought into such an operative setting by way of the activation pressure in which setting the activation pressure can be transferred directly to the assigned clutch activation apparatus, whereby the subject clutch activation apparatus is held in its engaged position until the speed of rotation control pressure understeps the predetermined pressure threshold value.
A further embodiment of this named control valve with two solenoid control valves allows that the selection valve has been so designed, that in an emergency operation of the transmission, specifically that one of the two clutch activation apparatuses is held in an engaged position, which activation apparatus was last set into an engaged position.
This situation can be further revised in that alternative to the loading of the self-operating pressure, retention valve and the activation valve with the controlled clutch, activation pressure, a control pressure, equal to that which is characteristic to normal operation of the transmission, can be applied to that end face, which is remote from the reset spring of the slide valve of these two valves.
Considering the design-oriented formulation of the self-operating pressure, retention valve, it could be advantageously assumed that, if this were so constructed that the speed of rotation-related, control pressure could be conveyed to two separate pressure chambers of the self-operating pressure, retention valve, which chambers were separated by way of at least one control piston of the correlated control slide valve.
In accordance with yet other embodiment of the self-operating pressure, retention valve, provision can be made that the mentioned reversal travel, prevention pressure can easily be directed to the spring-loaded end face of the slide valve of the self-operating pressure, retention valve and that the speed of rotation-related, control pressure can be directed to that pressure chamber of the self-operating pressure, retention valve by way of a one-way valve, which is placed axially, directly beside the pressure space for the acceptance of the reset spring and is located for application with the reversal travel, prevention pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a control valve arrangement with a clutch control valve, wherein a pilot pressure for the control valve is employed as a control pressure for an activation valve as well as for a self-operating, check valve;
FIG. 2 is a control valve arrangement with clutch control valve with which a separate control pressure for the control of the activation valve is used;
FIG. 3 is a control valve arrangement with clutch control valve with which a separate control pressure is used for a converted control of the activation valve;
FIG. 4 is a control valve arrangement with two clutch control valves with which alternate to one another, the pilot pressure for the two control valves are used both as a control pressure for an activation valve and for a self-operating pressure, retention valve, as well as one of two clutch, activation apparatuses, which are held in their engaged position while in an emergency operation of the transmission;
FIG. 5 is a control valve arrangement, as in FIG. 4 , in the case of which however, one of two clutch activation apparatuses, in the emergency operation of the transmission, is held in the engaged position, which one clutch activation apparatus had already been placed in its engaged position;
FIG. 6 is a control valve arrangement with an solenoid clutch valve with which a separate control pressure for the control of the activation valve is used;
FIG. 7 is a control valve arrangement with an solenoid clutch control valve with which a separate control pressure for inverse control of the activation valve is employed;
FIG. 8 is a control valve arrangement with two electromagnetic clutch valves with which a separate control pressure for inverse controlling of the activation valve is used, whereby one of two clutch activation apparatuses in an emergency operation of the transmission is held in its engaged position, but wherein the valve was preliminarily placed in its engaged position;
FIG. 9 is a constructive assembly of a self-operating pressure, retention valve as in an aforementioned control valve arrangement, and
FIG. 10 is a variation to the self-operating pressure, retention valve in accord with FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 displays an assembled and comparatively simple embodiment of a control valve arrangement, according to the invention, and which is of a low manufacturing cost. This control valve arrangement encompasses one self-operating pressure, retention valve 1 , an activation valve 2 for emergency operation, (in the following, designated as “activation valve 2 ”), a clutch control valve 3 as well as a clutch activation apparatus 4 . The clutch activation apparatus 4 consists of a cylinder 5 in which is to be found a piston 6 . The piston 6 stands within a co-axial helical, reset spring 7 which acts counter to the activation pressure. A pressure application against an end face of the piston 6 , which face is remote from the reset spring 7 , causes the piston 6 to slide in a closing direction so that a clutch of the transmission for torque transfer is likewise engaged.
The subject clutch (not shown here), but would be known as present to the expert, belongs to an automatic transmission, which can be designed to operate on the basis of a planetary transmission to function as a ratio changing transmission operating in a stepless manner or as a load-shifting, automated simple transmission. In such a case, wherein a control valve arrangement for a double clutch transmission is to be designed then, preferably, two control valves as well as two clutch activation apparatuses should be used, which will be discussed below.
The named valves, i.e., 1 , 2 and 3 are disposed in a smooth cylindrical enclosure (not shown) of a hydraulic control apparatus for the transmission, whereby each valve possesses at least one slide valve, which can be axial movable for opening pressure chambers; for disengaging and/or engaging by hydraulic pressure, and also a helical piston, encompassing reset, spring force.
In the case of all following presented embodiments, the self-operating pressure, retention valve 1 and the activating valve 2 are generally identically designed. Thus the self-operating pressure, retention valve 1 comprises one slide valve 30 , which is located in a valve boring 36 and is axially movable. The slide valve 30 includes, as part of itself, spaced control pistons namely 20 , 21 and 22 , whereby the free end face of the control piston 20 is loaded by force from a reset spring 31 . Against the axially opposite, located end face of the slide valve 30 , a pilot pressure P_VST acts, which is introduced into a pressure chamber 38 by way of a feed-in, pressure line 8 .
Additionally to a pressure chamber 39 on the self-operating pressure, retention valve 1 , located between the control piston 21 and the control piston 22 , a control pressure P_D can be delivered by way of a line 11 , the intensity of the pressure thereof being dependent upon the speed of rotation of the drive motor of the vehicle and/or being dependent upon the speed of rotation of the output shaft of the transmission.
Further, an activation pressure P_A is delivered to the self-operating pressure, retention valve 1 to a pressure chamber 70 between the control pistons 20 and 21 . The delivery is effected through a line 12 which, when in an emergency operation, takes care that a torque transferring clutch of the transmission remains engaged in accordance with a speed of rotation.
Finally, there is also placed in the self-operating pressure, retention valve 1 , a pressure chamber 71 which holds within the reset spring 31 which, by way of a line 13 , can be loaded with a reverse travel, prevention pressure P_RV. This arrangement will be further discussed below.
In regard to the assembly of the activation valve 2 , it must be mentioned that this valve possesses a slide valve 29 with two control pistons 23 , 24 , which are mutually spaced away from one another and the piston 23 is axially and slidingly inserted into a boring 63 of the slide valve enclosure. In this specific case, the free end face of the control piston 24 can be loaded by the force of a reset spring 32 .
The pilot pressure P_VST in a pressure chamber 78 is delivered to the axial, oppositely situated end face of the slide valve 29 by way of a line 9 . A line 14 additionally connects the pressure chamber 70 (or 143 ) of the self-operating pressure, retention valve 1 with a pressure chamber 72 of the activation valve 2 , whereby this pressure chamber 72 , by way of the control piston 23 , which is remote from the reset spring 7 , can be engage or made to communicate with a pressure chamber 73 on the activation valve 2 .
The clutch valve 3 encompasses an axial longer, control slide valve 19 with three control pistons 26 , 27 and 28 , as well as with an axially shorter, control slide valve 34 , which is axially and slidingly located in borings 64 , 65 of the slide valve enclosure. Further, in this matter, the axially longer, control slide valve 19 can be loaded on the free end of the control piston 28 by the restoration force of a reset spring 33 .
The axially shorter, control slide valve 34 includes a slide valve 25 , the end face of which is proximal to the other slide valve 19 , which can be loaded by the pilot pressure P_VST. Correspondingly, this pilot pressure P_VST is available from a pressure chamber 74 on the clutch control valve 3 by way of a line 10 . On the oppositely situated end face of the piston 25 , the activation pressure P_A can be delivered through a line 15 , which is connected with the pressure chamber 73 on the activation valve 2 .
The axially longer, control slide valve 19 of the clutch control valve 3 possesses, as part of its construction, three control pistons 26 , 27 , 28 , where two pistons 26 , 27 are placed immediately next to one another. The free end face and the oppositely situated end of the axially shorter, control slide valve 34 of the slide valve 26 are likewise subject to the pilot pressure P_VST emanating from the pressure chamber 74 while that end face, which is remote from the reset spring of the control piston 28 communicates with a pressure chamber 75 , which itself is subjected to the pressure from a system source or a supply pressure P_V 1 .
By way of an appropriate control of the clutch control valve 3 , this pressure chamber 75 can be connected with a neighboring pressure chamber 76 through the pilot pressure P_VST, so that a controlled clutch pressure P_K can function in the pressure chamber 76 through the control piston 28 . By way of a line 16 , the pressure chamber 76 is additionally connected with the cylinder 5 of the clutch activation apparatus 4 as well as with a pressure chamber 77 on the clutch control valve 3 , which also houses the reset spring 33 .
The method of operation, i.e., the functionality, of the control valve arrangement, according to FIG. 1 , is outlined below.
In normal operation, the pilot pressure P_VST is so adjusted in that the slide valve 30 on the self-operating pressure, retention valve 1 is axially pushed against the force of the spring 31 to the extent that the control piston 20 opens a path for the activation pressure P_A from the pressure chamber 70 , through the pressure chamber 143 and the line 12 , to gain access to the pressure chamber 72 of the activation valve 2 .
Additionally, the pilot pressure P_VST acts in the pressure chamber 78 of the activation valve 2 in such a manner that the slide valve 29 is pushed against the force of the reset spring 32 to take its place so far into the boring 63 that the pressure chamber 73 is separated from the pressure chamber 72 .
Beyond this, the axially longer, control slide valve 19 of the clutch control valve 3 is loaded with the pilot pressure P_VST through the line 10 ; that a rim of the control piston 28 more or less frees up the pressure chamber 75 on the clutch control valve 3 . In this way, with a dependency on the intensity of the pilot pressure P_VST, a supply pressure P_V 1 is regulated to serve as a clutch activation pressure P_K, with which the clutch activation apparatus 4 can finally be brought into a position for opening or closing the attached clutch. Obviously, it is possible that interposed positions can be adjusted to in which the clutch would be slipwise operated.
Should it occur, for example, that by a disturbance in the transmission control equipment, the pilot pressure P_VST drops out, or at least reduces itself drastically, then the speed of rotation dependent control pressure P_D at the self-operating pressure, retention valve 1 becomes activated. Insofar as the motor speed of rotation or, alternately, the speed of rotation of the output shaft of the transmission is so high that a stalling of the motor need not be expected, then even this controlling pressure P_D will be so high that this is in a situation where it can hold the slide valve 30 of the self-operating pressure, retention valve 1 in a position in which the activation pressure P_A can be conducted through pressure chambers 70 and 143 , as well as through the line 14 to the pressure chamber 72 of the activation valve 72 .
The function of the self-operating pressure, retentive valve 1 is extinguished if the speed of rotation related control pressure P_D drops below a predetermined value. This pressure threshold characterizes the stalling speed of rotation of the motor. In this case, the slide valve 30 , by the force of the reset spring 31 , is axially moved in the direction of the pressure chamber 38 , so that the activation pressure supply to the activation valve 2 is interrupted.
In an emergency operation, the pilot pressure P_VST drops to zero in the pressure chamber 78 of the activation valve 2 or is at least significantly reduced, so that the slide valve 29 , by way of the force of the reset spring 32 , is so displaced in the direction of the pressure chamber 78 , that the pressure chamber 72 and the pressure chamber 73 become bound together. Thereby, the activation pressure P_A is conducted through the line 15 to a pressure chamber 80 on the clutch control valve 3 , at which point this pressure then acts upon the axially shorter, control slide valve 34 . As a result of this, an axial section 35 of the slide valve 34 exerts pressure upon the free end face of the piston 26 of the axially longer, control slide valve 19 , whereby this is axially pushed against the force of the reset spring 33 . For this reason, in spite of the failing pilot pressure P_VST, the connection between the pressure chamber 75 and the pressure chamber 76 is held in the open state.
By way of this method of operation, it is possible that, even in a case of the failure of the pilot pressure P_VST by way of a line 18 , the pressure chamber 75 , 76 , as well as the line 16 , a clutch activation pressure P_K, which holds the clutch activation apparatus 4 in its engaged position, can be conducted to the same.
Should the motor speed of rotation or the transmission speed of rotation drop to such an extent that stalling of the motor must be reckoned with, then too, the related speed of rotation related pressure P_D is correspondingly also lowered. This leads, finally, to a break in the emergency operation of the transmission, since under these circumstances, the force of the reset spring 31 on the self-operating pressure, retention valve 1 , without pressure obstruction, becomes sufficient to push its slide valve 30 so far in an axial direction, that the activation pressure connection between the pressure chamber 70 on the self-operating pressure, retention valve 1 and the pressure line 14 can no longer sustain itself.
As a result of this, even the shorter, control slide valve 34 becomes, of the clutch control valve 3 is no longer pressurized with the activator pressure P_A, while the longer, control slide 19 , driven by the force of the reset spring 33 , is pushed into such a position, where the connection between the pressure chambers 75 , 76 are interrupted. Thereby, also the clutch activation pressure in cylinder 5 of the clutch activation apparatus 4 declines to the extent that its piston 6 , driven by the force of the reset spring 7 , is pushed into its open state.
As is made clear in FIG. 1 , it is possible that the clutch activation apparatus 4 , upon a resurgence of the speed of rotation related pressure P_D, in accordance with an emergency operation, cannot be immediately brought into its engaged position so that an advantageous safety precaution is made to exist, so that, for example in a repair-shop, the motor speed of rotation may be driven so high for test purposes, without causing an increase of the speed of rotation dependent pressure P_D and, automatically, an adjustment to closure in the automatic transmission might be made.
Additionally it is obvious that the end face, which is proximal to the reset spring 33 of the control piston 28 of the control slide valve 19 , by way of the pressure chamber 76 and lines 16 and 17 may, likewise, be loaded with the controlled clutch activation pressure P_K, i.e., with the activation pressure P_A.
Finally, FIG. 1 shows that, in a case of a selected reverse travel direction, the pressure chamber 71 , which contains the reset spring 31 of the self-operating pressure, retention valve 1 may be subjected to the pressure of a reverse travel protection pressure P_RV where, in a case of a deficiency of the pilot pressure P_VST, the slide valve 30 , by the force of the spring 31 combined with the pressure P_RV will be axially transported so far that the pressure chamber 39 becomes engaged, as well as that the pressure loading of the control piston 21 is provided with the speed of rotation related control pressure P_D. The reverse travel prevention pressure P_RV, when the control pistons 20 , 21 have equal diameters, can be selected to be greater than the speed of rotation related control pressure P_D.
The illustrated control valve arrangement in FIG. 2 differentiates itself from the above explained embodiment, essentially in that in normal operation, the pilot pressure P_VST is exclusively directed to act upon the clutch control valve 3 , while the pressure chamber 38 of the self-operating pressure, retention valve 1 and the pressure chamber 78 of the activation valve 2 are loaded by a control pressure P_NOR, which characterizes normal operation.
The pressure P_NOR, upon the failure of drastic reduction of the pilot valve P_VST for the realization of the described emergency operation, can be likewise diverted so that when the speed of rotation related control pressure P_D lies above the pressure threshold, the activation pressure P_A, can be forwarded by way of the self-operating pressure, retention valve 1 , the line 14 , the pressure chambers 72 , 73 of the activation valve 2 and the line 15 at the end face, which is remote from the reset spring 31 , of the control piston 25 of the shorter, control slide valve 34 of the clutch control valve 3 .
Thereby the possibility exists, as has already been described in connection with FIG. 1 , the slide valve 34 acts axially on the control slide valve 19 , in the result of which action, the supply pressure P_V 1 can be forwarded by way of the pressure chambers 75 , 76 as well as by the line 16 to the cylinder 5 of the clutch activation apparatus 4 . In this way, the clutch, which is activated by the clutch activation apparatus 4 , even during a failure or drastic diminution of the pilot pressure P_VST is held engaged so that, in the emergency operation of the transmission, a forward motion of the vehicle can be managed.
The control valve arrangement, presented in FIG. 3 as an embodiment example, differentiates itself only comparatively and slightly from the embodiments shown in FIG. 1 and FIG. 2 . Thus, in this case, the pilot pressure P_VST can be conducted into the pressure chamber 38 of the self-operating pressure, retention valve 1 as well as into the pressure chamber 74 of the control valve 3 . Additionally, the activation pressure P_A is directed, not only to the pressure chamber 70 at the self-operating pressure, retention valve 1 , but also to the pressure chamber 78 , which is remote from the reset valve at the activation valve 2 . Finally, in order to realize an emergency operation, a control pressure P_NS, which characterizes this particular emergency, can be directed to a pressure chamber 79 , which contains the reset spring 32 of the activation valve 2 .
Insofar that, because of an operational disturbance, the pilot pressure P_VST drops out or is severely reduced, it is true that by way of a sufficiently higher speed of rotation of the motor or, correspondingly, a higher speed of rotation of the output of the transmission by way of the speed of rotation related control pressure P_D of the control slide valve 30 , then the self-operating pressure, retention valve 1 will be retained specifically in that position, shown in FIG. 3 . However, the activation pressure P_A, which is also present in the pressure chamber 78 of the activation valve 2 , so acts that its slide valve 29 also remains in the depicted position. Only under such a circumstance which characterizes the emergency operation, a control pressure P_NS becomes active in the pressure chamber 79 of the activation valve 2 , can the slide valve 29 be pushed in the direction of the pressure chamber 78 , so that the pressure chamber 72 is brought into communication with the pressure chamber 73 .
When this occurs, then the activation pressure P_A of the pressure chamber 73 , by way of the line 15 becomes open to the pressure chamber 80 of the clutch control valve 3 , so that the axially shorter, control slide valve 34 acts in such a manner upon the control piston 26 of the longer, control slide valve 19 , allowing the latter to be axially moved, against the force of the reset spring 33 and the pressure chamber 75 to be bound to the pressure chamber 76 . Now, in an already described manner, the clutch activation pressure P_K communicates over the line 16 to the cylinder 5 of the clutch activation apparatus 4 and, as an ensuing result, this remains in its engaged position until the speed of rotation control pressure P_D understeps the predetermined pressure threshold.
In the case of the embodiment, illustrated in FIG. 4 , this is an embodiment of a control valve arrangement designed within the framework of the invention. In total, there are two clutch activation apparatuses 4 and 40 , which are of use for an emergency operation of the transmission. These two apparatuses 4 , 40 are for two start clutches, for example, provision for a double clutch gear train, wherein the first clutch activation apparatus 4 , oppositely situated the second clutch activation apparatus 40 , is advantageously retained in its engaged state.
Also, this control valve arrangement includes the self-operating pressure, retention valve 1 and the activation valve 2 , which two valves, by way of a selection valve 42 , for the purpose of relaying the already multiply mentioned activation pressure P_A, bind themselves together in a pressure-technological manner with a first clutch, control valve 3 or a second clutch, control valve 41 .
Especially noted is the fact that in the functionality of this control valve arrangement, a switch-over valve 43 can be subjected to pressure, by way of a line 45 or as well by a line 61 with two pilot pressures P_VST 1 , P_VST 2 . These two pressures can be delivered over lines 46 or 60 to the pressure chamber 74 or 105 of the longer, control slide valve 19 or 90 of the two clutch, control valves 3 and 41 . The respective immediately larger pilot pressure P_VST 1 or P_VST 2 acts in normal operation of the transmission by way of lines 66 and 67 to act upon the pressure chamber 38 of the self-operating pressure, retention valve 1 and upon the pressure chamber 78 of the activation valve 2 .
Further, FIG. 4 clarifies that the activation pressure P_A of the self-operating pressure, retention valve 1 can be continually transferred over the activation valve 2 as well by way of two lines 93 , 94 to pressure chambers 81 , 82 of the selection valve 42 . In relation to the selection positioning of a control slide valve 44 of the selection valve 42 in a first operational position, this activation pressure P_A of the pressure chamber 82 and a pressure chamber 83 is directed by selection valve 42 by way of a line 95 to that pressure chamber 80 on the end face, which is remote from the reset spring of the shorter, control slide valve 34 of the first clutch, activation valve 3 . In a second operational positioning of the selection valve 42 , the activation pressure P_A is forwarded through the pressure chamber 81 and a pressure chamber 84 as well as by way of a line 96 to a pressure chamber 91 , which is located in the area of that end face and which is remote from the reset spring of a shorter, control slide valve 92 on the second clutch, control valve 41 .
Finally, it is a specific design feature of the control valve arrangement, according to FIG. 4 , that the control slide valve 44 of the selection valve 42 is subjected to the application of a restoration force on one of its end faces, by way of a reset spring 97 and further that the oppositely controlled clutch activation pressure P_K 1 of the first clutch, control valve 3 over a line 68 . The latter pressure emanates from a pressure chamber 85 on the selection valve 42 .
Giving consideration to the above operational possibilities of the control valve arrangement, according to FIG. 4 , the following method of functioning is possible.
In the normal operation of the transmission, at least one of the two pilot pressures P_VST 1 or P_VST 2 acts through the switch-over valve 43 to load the pressure chambers 38 and 78 , respective of the self-operating pressure, retention valve 1 and of the activation valve 2 . In this way, the control slide valve 29 of the activation valve 2 is so positioned that an activation pressure P_A from the self-operating pressure, retention valve 1 cannot be delivered over the line 14 to the selection valve 42 . Additionally, at least one of the two clutch activation apparatuses 4 or 40 are activated by way of the pilot pressure P_VST 1 or P_VST 2 to reach an engaged position.
To the extent that the two pilot pressures P_VST 1 , P_VSR 2 fail or are drastically reduced, then the control slide valve 29 on the activation valve 2 is pushed so far from the assigned reset spring 32 in the direction of the pressure chamber 78 , that the two pressure chambers 72 , 73 on the activation valve 2 are bound together in a pressure-technological manner.
Insofar as the speed of rotation related control pressure P_D, which acts upon the pressure chamber 39 on the self-operating pressure, retention valve 1 is intense enough, then the control slide valve 30 is retained in a position shown in FIG. 4 , so that the activation pressure P_A of the self-operating pressure, retention valve 1 can be conducted through the line 14 and through the pressure chamber 72 or 73 on the activation valve 2 to the selection valve 42 . The activation pressure P_A thus appears in this way in the pressure chamber 81 of the selection valve 42 .
In a case of failure of the pilot pressure P_VST 1 to act upon the first clutch control valve 3 , since the control slide valve 44 of the selection valve 42 remains in its depicted position, due to the presence of the still existing clutch activation pressure P_K 1 from the pressure chamber 76 of the first clutch, control valve 3 by way of the line 68 to the pressure chamber 85 on the selection valve 42 in FIG. 4 . Thus, in this emergency operation, a path is made free for the activation pressure P_A from the pressure chamber 73 of the activation valve 2 though the line 93 , the pressure chamber 82 and through the pressure chamber 83 as well as by way of the line 95 to the pressure chamber 80 on the shorter, control slide valve 34 of the first clutch, control valve 3 .
In this way, it is possible that the shorter, control slide valve 34 can establish an axial force upon the longer, control slide valve 19 of the first clutch, control valve 3 which force, in spite of failure of the pilot pressure P_VST 1 , will hold this longer, control slide valve 19 in a position open to the pressure chamber 75 . Thus, the supply pressure P_V 1 , by way of the pressure chambers 75 , 76 , as well as through the line 16 gains access to the cylinder 5 of the first clutch, activation apparatus 4 for the purpose of holding this apparatus in the engaged position.
By way of an exact fitting design of the diameter of a control piston 69 , which is remote from the reset spring of the control selection valve 42 as well as the restoration force of its reset spring 97 , it is possible that this control valve arrangement, according to FIG. 4 , can also be constructed to function effectively, so that upon the failure of the two pilot pressures P_VST 1 , P_VST 2 , a control piston 86 of the control slide valve 44 of the selection valve 42 remains in its second shifted position.
In this second shifted position, the activation pressure P_A of the pressure chamber 73 of the activation valve 2 is conducted through the line 94 to the pressure chamber 81 of the selection valve 42 and from there, by way of the pressure chamber 84 and the line 96 to the pressure chamber 91 of the second clutch control valve 41 . At that location, the shorter, control slide valve 92 acts in the already mentioned manner on the longer, control slide valve 90 , in such a manner that the control piston, which is loaded with a reset valve releases the connection between two pressure chambers 87 , 88 . There the supply pressure P_V 2 is directed to the cylinder 5 of the second clutch, activation apparatus 40 where, in spite of the failure of the pilot pressure P_VST 2 , this is held just so long in its engaged position until the speed of rotation related control pressure P_D at the pressure chamber 39 of the self-operating pressure, retention valve 1 has fallen below the predetermined threshold pressure.
FIG. 5 shows a further embodiment of the inventive control valve arrangement, by way of which one of two clutch activation apparatuses 4 and 40 , are held in their engaged position during an emergency operational phase, which was the last position in which they were formerly placed.
Exhibiting a difference to the control valve arrangement according to FIG. 4 , in this case it is first provided that a selection valve 47 possesses no reset spring. Additionally, in the case of this selection valve 47 , the two control pistons 69 and 99 at the axial ends of the control slide valve 44 are subjected to the control pressure P_K 1 and P_K 2 . Deviating from the control valve arrangement, according to FIG. 4 , in this case, the controlled clutch, activation pressure P_K 2 of the second clutch, control valve 41 is directed from its pressure chamber 88 , over a line 98 to the pressure chamber 89 on the end face side of the control piston 99 of the selection valve 47 .
For the activation of the emergency operation of the transmission, the pilot pressures P_VST 1 and P_VST 2 become inoperable or very much diminished. Additionally, the speed of rotation related control pressure P_D acts upon the pressure chamber 39 on the self-operating pressure, retention valve 1 , with a level of pressure which is high enough to keep the control slide valve 30 of the self-operating pressure, retention valve 1 in the activation mode, as is shown in FIG. 5 .
Since both pilot pressure P_VST 1 and P_VST 2 are not enabled to maintain sufficient pressure in the pressure chamber 78 of the activation valve 2 , then its slide valve 29 is displaced in the direction of the pressure chamber 78 by way of the force of the reset spring 32 , so that the pressure chambers 72 and 73 of the activation valve 2 are bound together within the technology of pressure. Thereby, the activation pressure P_A is conducted by way of the self-operating pressure, retention valve 1 and the activation valve 2 to the pressure chamber 81 and 82 of the selection valve 47 . Insofar as the clutch activation valve which, in an immediately prior time, was in its engaged position, was actually the second clutch, activation apparatus 40 , then this acts for the direction of the clutch activation pressure P_K 2 from the pressure chamber 88 of the second clutch, control valve 41 by way of the line 98 to the pressure chamber 89 on the selection valve 47 , so that the control slide valve 44 becomes pushed so far in the direction of the pressure chamber 85 ; that the activation pressure P_A from the pressure chamber 81 , by way of the pressure chamber 84 of the selection valve 47 , is conducted through line 96 to that end face, which is remote from the reset spring of the shorter, control slide valve 92 of the second clutch, control valve 41 .
As a result of the above, this shorter, control slide valve 92 acts axially on the longer, control piston 90 , whereby this latter is held in an activation position, in which the control piston 89 , which is subjected to the face of a reset spring, hold the flow connection open between the pressure chamber 87 and pressure chamber 88 . In this manner, it is possible, that from the supply pressure P_V 2 , the clutch activation pressure P_K 2 can be formed which, in this emergency operation, now holds engaged, that clutch activation apparatus 40 , which was most recently in the engaged position. This occurs in the same way as in the case of the other control valve arrangements, however, only during that time that the speed of rotation related control pressure P_D lies above the predetermined pressure threshold.
Due to this knowledge of the described assembly, as well as of the explained functionality, an expert would quickly grasp that when, contrary to the last example, the first clutch, activation apparatus 4 was immediately activated in the engaged position, this being held in the engaged position, due to a failure of the pilot pressures P_VST 1 and P_VST 2 , which brought about the governing emergency operation.
FIG. 6 clarifies a control valve arrangement, according to the invention, which arrangement is in a comparatively well designed manner and of simple assembly, wherein the advantages which are desired to be attained do not lie in the mode of construction. In the depicted embodiment example, the clutch control valve is not controlled by the influence of a pilot pressure. Rather, the depicted construction includes a solenoid operated clutch control valve 37 which, in response to a warning signal S received through an electrical line 146 , so acts as to provide a proportional clutch activation pressure P_K.
For the realization of the desired functionality, this control arrangement includes the self-operating pressure, retention valve 1 and the activation valve 2 with slide valves 29 and 30 which, during normal operation, are loaded at their end faces, which are remote from the reset springs 31 , 32 , by a control pressure P_NOR, which is characteristic of the normal operation. This control pressure P_NOR is introduced to the two valves 1 and 2 through a control pressure line 124 to the end face pressure chambers 38 and 78 .
Moreover, a speed of rotation related control pressure P_D acts, in the already explained manner, on the centrally located control piston 21 of the self-operating pressure, retention valve 1 . Likewise, with the existing control pressure P_NOR, the activation pressure P_A is also brought upon a pressure chamber 70 between the two control pistons 20 and 21 .
This activation pressure P_A is conducted through the line 14 to the pressure chamber 72 on the activation valve 2 , which activation valve 2 is engaged during a normal operational condition by way of the piston 23 of the control slide valve 29 against further extension of the pressure. In this operation, two pressure chambers 73 and 102 , which are located between the two control pistons 23 and 24 are bound together in a pressure-technological manner. This action now permits that a clutch activation pressure P_K, which has been generated by the solenoid operating clutch, control valve 37 from a supply pressure P_V, can now be conducted to the cylinder 5 of the clutch activation apparatus 4 through lines 100 and 101 .
Should the case be that, due to dome defect, the solenoid control valve 37 becomes inoperable, then that pressure P_NOR, which is characteristic of normal operation, is either diverted or so reduced that the control slide valve 29 of the activation valve 2 by the power of the reset spring 32 becomes axially transported in the direction of the pressure chamber 78 . Insofar as the motor or the output speed of the transmission lies above the stalling speed of the motor, then the speed of rotation related control pressure P_D is sufficiently high, so that at the self-operating pressure, retention valve 1 of the control slide valve 30 , in spite of the failure of the pressure P_NOR in the pressure chamber 38 , is still enabled to maintain the position shown in FIG. 6 .
Thereby the activation pressure P_A is conducted from the self-operating pressure, retention valve 1 by way of the line 14 , the pressure chambers 72 , 73 of the activation valve 2 and the pressure line 101 to the clutch activation apparatus 4 . In this way, in spite of the failure of the clutch control valve 37 , the clutch activation apparatus 4 is held as long in the engaged position until the speed of rotation related control pressure P_D lies above a predetermined pressure value and simultaneously above that pressure which represents stalling the motor.
Since the control piston 24 of the control slide valve 29 of the activation valve 2 in this emergency operational phase has engaged the pressure chamber 102 , it is possible that no hydraulic pressure fluid can escape over the line 100 to the solenoid control valve 37 . Note is made, only in the interests of a complete explanation that even in this above described case of the invention, a reverse travel prohibiting pressure P_RV would be conducted to the pressure chamber 71 of the self-operating pressure, retention valve 1 to bring about the desired effect.
FIG. 7 shows an embodiment, according to the invention, which is slightly changed from the foregoing, wherein a differentiation is made to the control valve arrangement of FIG. 6 , in that the pressure chambers 38 and 78 on the self-operating pressure, retention valve 1 or on the activation valve 2 can be pressure loaded through lines 100 and 106 or 107 with the clutch activation pressure P_K which is forwarded from the solenoid control valve 37 .
Additionally, provision here has been made that even the pressure chamber 103 on the activation valve 2 , which can contain the reset spring 32 , can be subjected to pressure from through a line 104 with a control pressure P_NS, which is characteristic of the emergency condition. Within the control valve arrangement of FIG. 7 , insofar as the solenoid clutch valve 37 drops out, then also the clutch activation pressure P_K reduces itself in the pressure chambers 38 and 78 as well as 102 and 73 , which has been acting upon the clutch activation pressure P_K.
At this time, in order to bring the activation valve 2 into its emergency state of operation, the pressure chamber 103 , proximal to the reset spring, is loaded with the control pressure P_NS, whereby the control slide valve 29 is axially pushed so far toward the pressure chamber 78 , that the pressure chambers 72 and 73 become bound to one another. Thereby the path for the activation pressure P_A is made free, which the pressure can now emanate from the pressure chamber 70 of the self-operating pressure, retention valve 1 up to the clutch activation apparatus 4 . The pressure P_A can now hold the clutch activation apparatus in its engaged position until the speed of rotation related control pressure P_D drops below the predetermined pressure threshold value.
The last embodiment example for a control valve arrangement, designed according to the invention, is shown in FIG. 8 . In this control valve arrangement, two solenoidally activated clutch, control valves 48 , 49 are present with which two clutch activation apparatuses 4 , 40 can activate two clutches (not shown). The belonging control valves are, in this case, so constructed and placed that, in an emergency operation of the transmission, that particular clutch activation apparatus 4 or 40 is continually held in its engaged position until the motor or the transmission out speed of rotation drops under that speed which sustains operation without stalling.
Additionally to the two clutch control valves 48 and 49 , this control valve arrangement encompasses a self-operating pressure, retention valve 1 and an activation valve 2 , along with a selection valve 51 and two proportional flow solenoid valves 52 , 53 (hereinafter designated as “conversion valves 52 , 53 ”). The control-technological action of this control valve arrangement will be described by way of a presentation of its normal running condition.
In the normal operation of the transmission and by way of electrical connections 144 or 145 , the control signal S acts upon the solenoid clutch control valves 48 or 49 , from a transmission control apparatus (not shown), by way of which each proportional flow, solenoid valve 52 , 53 provides a pressure loading for the displacement of an assigned control slide valve 127 or 128 . Thereby at the respective pressure chamber 125 and/or 126 , existing supply pressure P_V 1 or P_V 2 is converted to a clutch activation pressure, namely P_K 1 and/or P_K 2 .
In the case of the first solenoid clutch, control valve 48 the immediate clutch activation pressure P_K 1 is conducted over a pressure line 123 to the first conversion valve 52 , from which the valve, this pressure, in the depicted set position, is forwarded over line 118 to the cylinder 5 of the first clutch, activation apparatus 4 so that the piston 6 thereof is, for example, forced into an engaged position.
Moreover, the clutch activation pressure P_K 1 , through a line 116 is conducted to a switch-over valve 54 and from this, directed to the pressure chamber 38 and/or 78 of the self-operating pressure, retention valve 1 and/or to the activation valve 2 .
In the case of the second proportional solenoid valve 49 , the clutch activation pressure thereof, namely P_K 2 , is conducted over a line 122 to the second conversion valve 53 , from which this same pressure, in the illustrated set position of the valve, is conducted through a line 120 to the cylinder 5 of the second clutch, activation valve 40 , so that the piston 6 thereof, for example, is placed in an engaged position.
Moreover, the clutch activation pressure P_K 2 is conducted by way of a line 114 to the already mentioned switch-over valve 54 , from which this pressure is directed to the pressure chamber 38 and/or 78 of the self-operating pressure, retention valve 1 and/or of the activation valve 2 . The switch-over valve 54 forwards only the respective higher of the two clutch activation pressures P_K 1 or P_K 2 to the pressure chamber 38 and/or 78 .
As an alternative to the above, a control pressure P_NORA can be conducted to the named pressure chambers 38 and/or 78 through the line 124 , which is characteristic of operation in a non-emergency operation.
In the normal operation of the transmission, the self-operating pressure, retention valve 1 and the activation valve 2 find themselves in that position, shown in FIG. 8 , so that the activation pressure P_A can actually, by way of the pressure chamber 70 of the self-operating pressure, retention valve 1 and the line 14 to the pressure chamber 72 of the activation valve 2 , the forwarding of which is, however, blocked by the position of the control slide valve 29 of the activation valve 2 . On this account, in normal operation, the two clutch activation apparatuses 4 , 40 are simultaneously at rest or are alternatively activated.
In a case of a disturbance, for example, of the transmission control apparatus, the electrically controlled clutch control valves 48 , 49 do not function. On this account, the control slide valves, respectively, 127 or 128 of these two clutch control valves close the pressure chambers 125 or 126 , so that no clutch control pressure P_K 1 or P_K 2 can be transmitted through the switch-over valve 54 to the pressure chambers 38 and/or 78 of the self-operating pressure, retention valve 1 as well as of the activation valve 2 .
Alternatively or in addition to the above, in such an emergency operation, the possibly operating control pressure P_NORA is not operative or at least very much reduced, so that the control slide valve 29 of the clutch activation valve 2 will be driven by the force of the reset spring 32 in the direction of the pressure chamber 78 . Thereby, in a case of a sufficiently higher motor or transmission output speed of rotation, the speed of rotation control pressure P_D at the self-pressure pressure, retention valve 1 takes care that the slide valve 30 thereof when, in the shown position of FIG. 8 , remains unchanged and the activation pressure P_A is communicated to pressure chambers 110 , 111 by way of the pressure chamber 70 , the line 14 and the now mutually connected pressure chambers 72 and 73 , through a line 119 .
In a case of normal operation, the clutch activation apparatus 4 is in its activated state and the clutch activation pressure P_K 1 therein, which was delivered from the first clutch, control valve 48 , is then conducted through the first conversion valve 52 , subsequently through the line 118 to reach a pressure chamber 108 of the selection valve 51 , then is free to invest that location, where the pressure chamber 108 is placed in the neighborhood of one of the two end faces of a control slide valve 50 .
The clutch activation pressure P_K 2 can indeed be transferred from the second clutch, control valve 49 through the conversion valve 53 and the line 120 to a pressure chamber 113 on the exactly oppositely disposed end face of the control slide valve 50 of the selection valve 51 since, in this depicted embodiment, the clutch activation arrangement 40 was finally not activated, whereby the control slide valve 50 , as shown in FIG. 8 , stands in the depicted shifting position.
In this emergency operation shifting position of the selection valve 51 , the activation pressure P_A, emitted by the pressure chamber 110 through a pressure chamber 109 and a line 117 to pressure chambers 129 , 130 of the first conversion valve 52 . Since the pressure chamber 129 is placed in the neighborhood of that end face, which is remote from the reset spring of a control slide valve 135 , then the activation pressure P_A, which has been hereto introduced, pushes the control slide valve 135 against the force of a reset spring 137 , so that pressure chambers 130 , 131 at the conversion valve 52 become combined. Thereby, the activation pressure P_A becomes available in this emergency operation to the first clutch, activation apparatus 4 through the line 118 . This is then held by the now present pressure P_A in its engaged position, until the speed of rotation related control pressure P_D at the self-operating pressure, retention valve 1 drops below the predetermined pressure threshold.
Under a circumstance, wherein the second clutch, activation valve 49 , during the normal operation of the transmission was finally active in an emergency operation which follows that the control slide valve 50 of the selection valve 51 , because of the clutch activation pressure P_K 2 , which was formerly active through the line 120 to pressurize the pressure chamber 113 now stands in a shifting position, in which the activation pressure P_A from the pressure chamber 111 can free the path of the pressure into a pressure chamber 112 on the selection valve 51 . By way of a line 121 , this activation pressure P_A then is open to a pressure chamber 132 as well as to a pressure chamber 133 of the second conversion valve 53 .
Thereby in the emergency operation, no clutch activation pressure P_K 2 is in force at the second conversion valve 53 , a control slide valve 136 is pushed against the force of a reset spring 138 , so that pressure chambers 133 , 134 of the second conversion valve 53 are pressure-wise, bound together. In this way, the activation pressure P_A is communicated to the cylinder 5 of the second clutch, activation apparatus 40 by way of the pressure line 120 . This apparatus will be held with the activation pressure P_A in its engaged position until the speed of rotation related control pressure P_D at the self-operating pressure, retention valve 1 drops below the predetermined threshold pressure value.
Finally, with the aid of the FIGS. 9 and 10 , the explanation is made clear, that the self-operating pressure, retention valve 1 can be extended into further self-operating pressure, retention valve valves 55 , 56 , wherein three slide pistons 139 , 140 , 147 are designed for and mounted on the control slide valve 30 . In the case of the embodiments, it is immaterial as to whether the pilot pressure P_VST or another pressure, such as the control pressure which characterizes normal operation of the transmission, is delivered to the pressure chamber 38 , which is placed in the area of the end face, which is remote from the reset spring of the control slide valve 30 .
Further, the activation pressure P_A is routed to the self-operating pressure, retention valve 55 or 56 , at the pressure chamber 70 , by way of the line 14 to the activation valve 2 (not shown). Now, the attachment of line 14 to the self-operating pressure, retention valve 55 or 56 , as usual, is done by way of the additional pressure chamber 143 , which is contiguous to the pressure chamber 70 .
In the case of the embodiment example according to FIG. 9 and FIG. 10 , provision is further made in that the speed of rotation related control pressure P_D is directed to two pressure chambers 58 and 59 , which are so placed that each, according to the set position of the control piston 139 , which is remote from the reset spring or the control piston 140 , which is proximal to reset springs 141 , 142 , can be subjected to this speed of rotation related pressure P_D, which is activation-effective.
In the case of the embodiment example according to FIG. 10 , there has been additionally provided in the retention valve 56 for the enhancement of the constructive features of the self-operating pressure, retention valve 55 (as indicated in FIG. 9 ), the advantage that the already mentioned reverse travel prevention pressure P_RV can also be directed to pressure chamber 62 which contains the reset spring 142 and that the conveyance of the speed of rotation control pressure P_D can be sent to the pressure chamber 59 by way of a one-way valve 57 .
By way of the last mentioned measure, assurance is given that the reverse travel prevention pressure P_RV cannot act upon the pressure chamber 58 and again, the assurance is provided in that, in a case of purposeful reverse travel in the emergency operation, the clutch, which up to that time has been engaged, is disengaged and thus the forward drive of the vehicle is interrupted for safety reasons.
The control valve arrangements presented up to this point carry the advantage that the lubrication of a wet start clutch during the slipping normal operation of the transmission is an assured matter. Such a slip-operation is, however, terminated when the start clutch is engaged. This condition is forcefully retained during the emergency operations by way of the presented control valve arrangements, so that no special measures for the lubrication of the clutch need be given consideration.
In this connection, provision can also be made that the activation pressure P_A in the description of the invention is then taken from that specific supply of hydraulic pressure fluid, which during the normal operation, is used for the slip operation of at least one start clutch.
REFERENCE NUMERALS
1 self-operating, retention valve (maintains given pressure)
2 activation valve
3 clutch regulation valve
4 clutch activation apparatus
5 cylinder
6 clutch piston
7 reset spring
8 line, pilot pressure
9 line, pilot pressure
10 line, pilot pressure
11 line, pressure regulated by speed of rotation
12 line to retention valve 1
13 line, reverse travel prevention pressure
14 connection line, retention valve-activation valve
15 connection line, activation valve, clutch regulation valve
16 conn. Line, clutch regulation-valve-clutch activation apparatus
17 conn. Line, clutch regulation valve-clutch activation apparatus
18 line, pressure source
19 reset-spring loaded control slide valve in clutch regulation valve
20 control piston on control slide valve in retention valve
21 control piston on control slide valve in retention valve
22 control piston on control slide valve in retention valve
23 control piston on control slide valve in activation valve
24 control piston on control slide valve in activation valve
25 control piston on control slide valve in clutch regulation valve
26 control piston on control slide valve in clutch regulation valve
27 control piston on control slide valve in clutch regulation valve
28 control piston on control slide valve in clutch regulation valve
29 control slide valve in activation valve
30 control slide valve in self-operating pressure, retention valve
31 reset spring in self-operating, retention valve
32 reset spring in activation valve
33 reset spring in clutch regulation valve
34 shorter control slide valve in clutch regulation valve
35 axial section on shorter slider of the clutch regulation valve
36 valve boring of the self-operating, retention valve
37 solenoid operated clutch regulation valve
38 pressure chamber at the self-operating, retention valve
39 pressure chamber at the self-operating, retention valve
40 clutch activation apparatus
41 clutch regulation valve
42 selection valve
43 switch-over valve
44 control slide valve in selection valve
45 line P_VST 1
46 line P_VST 1
47 selection valve
48 solenoid operated clutch regulation valve
49 solenoid operated clutch regulation valve
50 control slide valve at selection valve
51 selection valve
52 proportional flow solenoid valve (conversion of pressure)
53 proportional flow solenoid valve (conversion of pressure)
54 switch-over valve
55 self-operating pressure, retention valve
56 self-operating pressure, retention valve
57 one way block valve
58 pressure chamber for RPM dependent control pressure
59 pressure chamber for RPM dependent control pressure
60 line P_VST 2
61 line P_VST 2
62 pressure chamber for reverse travel prevention pressure
63 boring for control slide valve in the activation valve
64 boring for long control slide valve in the clutch regulation valve
65 boring for short control slide valve in the clutch regulation valve
66 line for exchange valve-self-operating pressure, retention valve
67 line for exchange valve-activation valve
68 line for selection valve-clutch regulation valve
69 control piston on the selection valve
70 pressure chamber on the self-operating pressure, retention valve
71 pressure chamber on the self-operating pressure, retention valve
72 pressure chamber on the activation valve
73 pressure chamber on the activation valve
74 pressure chamber on the first clutch regulation valve
75 pressure chamber on the clutch regulation valve
76 pressure chamber on the clutch regulation valve
77 pressure chamber on the clutch regulation valve
78 pressure chamber on the activation valve
79 pressure chamber on the activation valve
80 pressure chamber on the clutch regulation valve
81 pressure chamber on the selection valve
82 pressure chamber on the selection valve
83 pressure chamber on the selection valve
84 pressure chamber on the selection valve
85 pressure chamber on the selection valve
86 control piston on the selection valve
87 pressure chamber on the second clutch regulation valve
88 pressure chamber on the second clutch regulation valve
89 pressure chamber on the second clutch regulation valve
90 longer control slide valve on the second clutch regulation valve
91 pressure chamber on the second clutch regulation valve
92 shorter control slide valve
93 line
94 line
95 line
96 line: selection valve to second clutch regulation valve
97 reset spring on the selection valve
98 line: selection valve to the second clutch regulation valve
99 control piston on the selection valve
100 line
101 line
102 pressure chamber on activation valve
103 pressure chamber on activation valve
104 line for pressure P_NS
105 pressure chamber on second clutch regulation valve
106 line
107 line
108 pressure chamber on selection valve 51
109 pressure chamber on selection valve 51
110 pressure chamber on selection valve 51
111 pressure chamber on selection valve 51
112 pressure chamber on selection valve 51
113 pressure chamber on selection valve 51
114 line
115 line
116 line
117 line
118 line
119 line
120 line
121 line
122 line
123 line
124 line
125 pressure chamber on clutch regulation valve 49
126 pressure chamber on clutch regulation valve 48
127 control slide valve on clutch regulation valve 49
128 control slide valve on clutch regulation valve 48
129 pressure chamber on conversion valve 52
130 pressure chamber on conversion valve 52
131 pressure chamber on conversion valve 52
132 pressure chamber on conversion valve 52
133 pressure chamber on conversion valve 52
134 pressure chamber on conversion valve 52
135 control slide valve on conversion valve 52
136 control slide valve on conversion valve 53
137 reset spring
138 reset spring
139 control piston
140 control piston
141 reset spring
142 reset spring
143 pressure chamber on self-operating pressure, retention valve
144 electrical control cable
145 electrical control cable
146 electrical control cable
147 control piston
P_A activation pressure
P_D speed of rotation dependent control pressure
P_K clutch activation pressure
P_K 1 clutch activation pressure
P_K 2 clutch activation pressure
P_NOR normal operational characterizing control pressure
P_NORA normal operational characterizing control pressure
P_NS emergency operational pressure
P_RV reverse travel prevention pressure
S electrical pre-signal
P_V 1 supply pressure
P_V 2 supply pressure
P_VST pilot pressure
P_VST 1 pilot pressure
P_VST 2 pilot pressure
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A control valve arrangement for controlling a start coupling of an automatic gearbox comprising a clutch control valve ( 3, 37, 41, 48, 49 ) for controlling at least one clutch actuating device ( 4, 40 ) which, during normal operation of the gearbox, converts a supply pressure input (P_V 1 , P_V 2 ) into a clutch actuation pressure (P_K, P_K 1 , P_K 2 ) according to a pre-control pressure or an electric pre-control signal in order to control the clutch actuation device. An activating pressure (P_A) can be supplied to the clutch control valve or directly to the clutch activation device in the event of a discontinuation of the pre-control pressure or pre-control signal according to the engine and gearbox output speed, whereupon the clutch actuation device is maintained in a closed position as long as the above mentioned speed remains above a predetermined limit.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for forming Ti--TiN laminates and a magnetron cathode suitable for continuously forming laminated layers of Ti (titanium) and TiN (titanium nitride) on the surface of a substrate.
2. Description of the Related Art
Conventionally, Ti--TiN laminates are used as ground barrier layers underlying aluminum films for wiring in semiconductor devices. With increases in the integration density of semiconductor devices, it has become necessary to improve the uniformity of the thicknesses of the Ti and TiN films. Additionally, there has been a problem of dust particles which are produced when TiN film adheres to an inner wall of the chamber and peels off in the TiN film formation process. These dust particles result in reductions in the yield of semiconductor devices.
Ti--TiN laminates are generally formed by first forming a Ti thin film by magnetron sputtering using a Ti target and then forming a TiN thin film by reactive magnetron sputtering by introducing a mixture of argon gas and nitrogen gas into the same chamber. However, a disadvantage of this process is that it is difficult to achieve good thickness distributions in both films when they are both formed in the same chamber with the same magnetron cathode.
Accordingly, the process for forming the Ti film and the process for forming the TiN film have been carried out in separate chambers having magnetron cathodes that can achieve good thickness distributions. In the Ti--TiN laminates formation process, it is suitable to use a multi-chamber system provided with a chamber for the Ti film formation process and a chamber for the TiN film formation process.
In order to form Ti--TiN laminates with the multi-chamber system, first a substrate is transferred into a first chamber for the Ti film formation process by a robot and a Ti film is formed by magnetron sputtering. After that, the substrate is transferred into a second chamber for the TiN film formation process and a TiN film is formed on the Ti film by reactive magnetron sputtering. However, fine dust particles, which are harmful to the devices being manufactured, increase as the formation process of the TiN film is continuously repeated in the chamber for the TiN film formation process. Through continuous repetition of the TiN film formation process, the TiN film deposited on the inner wall of the chamber becomes thicker and then peels off due to high internal stresses in the TiN film. The TiN which peels off the walls of the chamber becomes a source of particulate contamination.
One possible solution for preventing the dust particles from being produced is the technique of periodically coating the unwanted TiN film adhered to the inner wall of the chamber with a Ti film, for example one Ti coating per processing of 100 substrates, by Ti sputtering. Although this method allows fixing of the TiN film, with the Ti coating, it lowers the yield because the continuous production of Ti and TiN films is interrupted.
OBJECTS AND SUMMARY
Accordingly, it is an object of the present invention to solve the aforementioned problems by providing a method for forming Ti--TiN laminates which is adapted to reduce dust particles harmful to semiconductor devices and to achieve good thickness distributions in the Ti and TiN films. It is also an object to provide a magnetron cathode which is suitable for use in the method.
A preferred embodiment of the present invention involves a method for forming Ti--TiN laminates in a multi-chamber system having at least two chambers for magnetron sputtering processes. Each of the chambers comprises a magnetron cathode having a Ti target, a circular band magnet truncated by two parallel straight lines and a trapezoidal magnet disposed within the circular band magnet. A process for forming a Ti film is carried out within one of the chambers by magnetron sputtering and a process for forming a TiN film is carried out within the other chamber by reactive magnetron sputtering. The process comprises the steps of:
(1) carrying out the TiN film formation process on a substrate after carrying out the Ti film formation process thereon;
(2) alternating the TiN film formation process and the Ti film formation process within each chamber before the TiN film adhered to an inner wall of the chamber, where the process for forming TiN film is being carried out, reaches a thickness great enough to cause the peeling thereof; and
(3) shifting the position of a trapezoidal magnet at the alternation so that the thickness distributions of the films are uniform.
The process in each chamber is alternated before the TiN film adhered to the inner wall of the chamber reaches 30 microns thick at which point the amount of dust particles may become unacceptably high. The TiN film reaches a thickness of 30 after the process of TiN coating is performed on about 300 substrates. Therefore, according to a preferred embodiment of the process, the process in each chamber is alternated when the number of substrates on which the process for forming the Ti--TiN laminates is implemented reaches 100.
A trapezoidal magnet of the preferred embodiment is disposed inside a circular band magnet on a sliding plate so that the longer side thereof faces one of the chords of the circular band magnet which is of greater band thickness than the other chord. A middle point of the longer side of the trapezoidal magnet sits on the axis of symmetry of the truncated circular band magnet, and the trapezoidal magnet shifts along this axis of symmetry.
The trapezoidal magnet shifts when alternating between the Ti and TiN film formation processes so that the thickness variations of the Ti and TiN films are less than 5%. The trapezoidal magnet moves over a range such that the distance between the longer side of the trapezoidal magnet and the thicker chord portion of the truncated circular band magnet preferably varies from about 34 mm to about 42 mm. The distance between the longer side of the trapezoidal magnet and the thicker chord portion of the truncated circular band magnet is preferably about 34 mm during the Ti film formation process and preferably about 42 mm during the TiN film formation process.
A magnetron cathode which is suited for the method for forming the films described above includes a target, a holder for holding the target, a magnet assembly as described above, a main shaft for transmitting a rotary motion to rotate the magnet assembly, and a rotating mechanism for rotating the main shaft. A cylinder is formed within the main shaft. Passages for fluid to flow in and out through the shaft are connected to the ends of the cylinder. The cylinder contains a piston to which the sliding plate is linked in order to move the trapezoidal magnet when alternating between the Ti and TiN formation processes.
According to the present invention, the formation of the Ti film or TiN film is alternated every time or after a plurality of times within one chamber. Therefore, the unwanted TiN film on the inner wall of the chamber which causes dust particles is coated periodically with a Ti coating and is prevented from peeling off without the continuous production of Ti--TiN laminates being interrupted.
The uniformity of thicknesses of the Ti and TiN films may be improved by changing the distribution of the magnetic field over the target in each magnetron sputtering process. The distribution of the magnetic field is changeable through movement of a magnet in the magnetron cathode.
The manner in which the foregoing and other objects of the present invention are accomplished will be apparent from the accompanying specification and claims considered together with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a section view of a magnetron cathode;
FIG. 1b is a diagram of a multi-chamber system;
FIG. 1c is a side view of a magnetron cathode showing the relationship between a target holder and a substrate holder;
FIG. 2a is a bottom plan view of a magnetic assembly according to a first embodiment of the invention;
FIG. 2b is a section view along line A--A of the magnetic assembly of FIG. 2a;
FIG. 3a is a bottom plan view of a magnetic assembly according to a second embodiment of the invention; and
FIG. 3b is a section view along line B--B of the magnetic assembly of FIG. 3a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, a preferred embodiment of the present invention will be explained.
FIGS. 1a through 1c show a preferred embodiment of a magnetron cathode of the present invention, wherein a magnet assembly 1 for the magnetron cathode is provided within a target holder 2. A main shaft 3 is mounted on the back of a yoke plate 9 of the magnet assembly 1. The main shaft 3 protrudes out through the housing of the chamber. A bevel gear 4 on the end of the main shaft 3 meshes with a bevel gear 6 on the end of the shaft of a driving motor 5. The magnet assembly 1 is rotated by transmission of rotary motion from the shaft of the driving motor 5 to the main shaft 3. Cooling water 7 circulates within the target holder 2 to cool down a Titanium (Ti) target 8.
The magnet assembly 1 for the magnetron cathode is made up of the yoke plate 9, an N pole permanent magnet 10 and an S pole permanent magnet 11 as shown in FIG. 2. The magnet 10 is a circular band magnet truncated by two parallel straight chords. The outside edges of these two parallel straight chords are equidistant from the center point O of the circular magnet 10. The thicknesses of the two chords are different. The Y chord comprises two separate parallel parts Ya and Yb. Therefore, the total thickness of the band of the chord Y is greater than that of the band of the chord X. The circular Land magnet 10 is symmetrical about a straight line A--A.
As shown in FIGS. 2a and 2b, the magnet 11 is trapezoidal with four corners which are rounded. The trapezoidal magnet 11 is disposed within the circular band magnet 10 and is positioned so that the longer side Z thereof faces the chord Y of the circular band magnet 10 and the middle point P of the bottom side Z sits on the axis of symmetry A--A of the circular band magnet 10. However, the trapezoidal magnet 11 does not overlap the center point 0 of the circular band magnet 10. If the trapezoidal magnet 11 were to overlap the center point 0, dust particles would be generated because the central region of the target 8 would not be subjected to sputter etching due to there being no magnetron plasma over the central region. Then particles (atoms) of the sputtered target would adhere to the region not sputter etched, depositing a film. Dust particles would be produced when the deposited film on the region is peeled off.
According to a preferred embodiment of the magnetic assembly, shown in FIGS. 2a and 2b the trapezoidal magnet 11 is disposed in a position such that the distance between the bottom side Z of the trapezoidal magnet 11 and the chord Y of the circular band magnet 10 is about 34 mm without the trapezoidal magnet 11 overlapping the center point 0. Ferrite or rare earth magnets may be used for the magnets 10 and 11. The trapezoidal magnet 11 is mounted on a sliding plate 12 so that the trapezoidal magnet 11 can move on the yoke plate 9. The sliding plate 12 is disposed in a recess 40 in the yoke plate 9 and moves within the recess 40.
A cylindrical cavity 13 is isolated by the sliding plate 12 from the space within the target holder 2 even when the sliding plate 12 moves to the upper or lower edge of the recess 40. The sliding plate 12 is connected to a piston 14 through a space 42 communicating between the recess 40 and the cylindrical cavity 13. When the piston 14 moves in the direction of arrow 41 within the cylindrical cavity 13, the trapezoidal magnet 11, together with the sliding plate 12, moves along the axis A--A in the direction of arrow 15.
Spaces 13a and 13b are formed by the partitioning of the space in the cylindrical cavity 13 by the piston 14. The spaces 13a and 13b communicate respectively with passages 16 and 16' formed within the main shaft 3. Circular channels 20 and 21 are formed in the inner wall of an outer cylinder 19 at the same heights as openings 17 and 18 of the passages 16 and 16' in the side wall of the main shaft 3. Pressurized air, oil or some other pressurized fluid may be introduced into the space 13a or 13b of the cylinder 13 via the circular channels 20 and 21 and the passages 15 and 16 from pipes 22 and 23. The piston 14 is moved by creating differences between the pressures in the spaces 13a and 13b. The traveling distance of the trapezoidal magnet 11 may be adjusted by adjusting the pressure of the pressurized fluid. However, even if the trapezoidal magnet 11 can be moved through the center point 0 of the circular band magnet 10, it is preferably not set on the center point 0 in order to prevent dust particles from being generated. The reference numeral 24 denotes packings such as 0-rings which are used to seal the various fluid cavities.
In an alternative embodiment of the magnetic assembly, as shown in FIGS. 3a and 3b , the magnet 111 is preferably fixed and the portion of the chord Yb' is mounted on the sliding plate 112. The sliding plate 112 is disposed in the recess 140 in the yoke plate 109 and moves within the recess. This embodiment operates in a similar manner as the embodiment shown in FIGS. 2a and 2b. The magnet chord Yb' can be shifted along the axis of symmetry B--B of the circular band magnet 10. The shifting of the chord Yb' is performed when alternating between the Ti and TiN film formation processes so that the thickness variations of the Ti and TiN films are less than 5%
FIG. 1b shows a multi-chamber system used in a preferred embodiment of the invention. A substrate loading chamber 27, a substrate unloading chamber 28 and processing chambers 29, 30, 31, 32 and 33 are connected through gate valves 34 to a main chamber 26 in which a transferring robot 25 is disposed. A vacuum pump (not shown) is connected to each chamber to allow each chamber to be evacuated separately. The transferring robot 25 is provided with an arm 37 having degrees of freedom, for example in the directions of arrows 35 and 36 and in the direction normal to the plane of the drawing.
A substrate to be processed is transferred by the transferring robot 25 from the substrate loading chamber 27 to processing chambers 29 through 33 and the substrate is subjected to the film formation and other processes in the processing chambers 29 through 33. In chamber 33 the substrate is heated to release unwanted molecules such as H 2 O molecules absorbed on the substrate surface. Then the substrate is transferred to chamber 29 where the impurities naturally growing on the surface of the substrate such as SiO 2 are shaved off by Ar plasma etching. After the preliminary processing of the substrates in chambers 29 and 33 the substrates are transferred to chambers 30 and 31 where Ti and TiN films are formed. The substrates are then transferred to chamber 32 where an Al film for wiring is deposited on the Ti--TiN laminates. The processed substrate is then transferred to the substrate unloading chamber 28 by the robot 25. A transferring robot and transferring method suitable for the multi-chamber system are disclosed in U.S. Pat. No. 5,288,379, the subject matter of which is incorporated herein by reference.
A magnetron cathode provided with the magnet assembly 1 described above is provided in each of the two processing chambers 30 and 31. The substrate is placed on a substrate holder 38 shown in FIG. 1c by the robot 25. Pipes (not shown) for introducing argon gas and a mixture of argon gas and nitrogen gas are connected to the processing chambers 30 and 31 to enable implementation of both the magnetron sputtering process for forming Ti film and the reactive magnetron sputtering process for forming TiN film. The diameter D of the Ti disc target 8 is preferably about 314mm and the distance L between the target 8 and the substrate holder 38 is preferably about 60 mm. Further, the dimension (a) of the magnet assembly 1 shown in FIG. 2a is preferably about 248mm and the dimension (b) is preferably about 352 mm. The distance (l) between the trapezoidal magnet 11 and the chord Y of the circular band magnet 10 is preferably from 34 mm to 42 mm and the trapezoidal magnet 11 can move within that range.
In forming the Ti--TiN laminates on the surface of the substrate in the multi-chamber system described above, the TiN film formation process is commenced in chamber 30 while the Ti film formation process is carried out in chamber 31. After about 100 substrates have been processed the chambers are alternated and the TiN film formation process commences in chamber 31 while the Ti film formation process is carried out in chamber 30. The chambers are repeatedly alternated between Ti and TiN preferably every 100 executions but not more than every 300 executions.
In this way, the TiN film adhered to the inner wall of the processing chambers 30 and 31 (including a shield for preventing the film from adhering to the inner wall) is periodically covered with a Ti film and the peeling of the TiN film having high internal stresses is prevented. As a result, formation of dust particles is greatly reduced.
Specifically, the number of dust particles on the Ti--TiN laminates may be reduced to less than 10/300 cm 2 by this process. When the TiN film deposited on the inner wall of the processing chamber reaches 30, the peeling of the TiN film becomes marked and the number of dust particles on a 6 inch wafer reaches more than 50. The maximum allowable number of dust particles on a substrate from the aspect of quality control of the semiconductor devices is 50 per 6 inch wafer. The thickness of the TiN film on the inner wall reaches 30 microns when the TiN film formation process has been performed on about 300 substrates. Accordingly, it is necessary to alternate from one film formation process to the other film formation process in both processing chambers before the TiN film formation process is performed on 300 substrates.
One problem experienced when Ti and TiN films are formed using the same magnetron cathode is that even thickness distributions cannot be achieved for both films. According to the present embodiment this problem is solved by providing an adjustable magnet. The position of the trapezoidal magnet 11 of the magnet assembly 1 is adjusted by means of the piston 14 by adjusting the pressurized air within the spaces 13a and 13b. The distance (l) between the trapezoidal magnet 11 and the circular band magnet 10 is preferably set at about 34 mm when a Ti film is to be formed and set at about 42 mm when a TiN film is to be formed. As a result, a thickness variation of less than 5% can be achieved for both the Ti films and the TiN films.
EXAMPLE 1
The thickness variation of a Ti film was 1 to 1.5% when the Ti film was formed by setting the pressure of argon gas (the process gas) at 4 mTorr, the power applied to the Ti target 8 at 5 kW and the distance (l) at 34 mm. The thickness variation of the Ti film was 10 to 15% when the distance (l) was set to 42 mm and the other conditions were the same.
EXAMPLE 2
The thickness variation of a TiN film was 7 to 10% when the TiN film was formed by using a mixture of argon gas and nitrogen gas as the process gas (flow ratio (sccm) argon gas : nitrogen gas =15 : 85) and by setting the pressure of the mixture at 4.5 mTorr, the power applied to the Ti target 8 at 6 kW and the distance (l) at 34 mm. The thickness variation of the TiN film was 3 to 4% when the distance (l) was set to 42 mm and the other conditions were the same.
Instead of shifting the trapezoidal magnet 11, it is also possible to move the circular band magnet 10. It is the relative position of the circular band magnet 10 and the trapezoidal magnet 11 which is important. Further, while the magnets in the above preferred embodiment were permanent magnets, it is within the scope of the invention to use electromagnets and change the exciting current of the electromagnets to change the distribution of the magnetic field.
As described above, according to the present invention, two chambers comprising magnetron cathodes in which the position of a magnet can be changed are used to periodically alternate the Ti film formation process in one chamber and the TiN film formation process in the other chamber, so that dust particles may be prevented from forming and good thickness distributions in the Ti and TiN films can be achieved. As a result, the productivity of the process and the quality of the semiconductor devices produced are improved.
While a preferred embodiment has been described, variations thereto will occur to those skilled in the art within the scope of the present inventive concepts which are delineated by the following claims.
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A method for forming Ti--TiN laminates adapted to reduce the formation of dust particles harmful to semiconductor devices without detriment to productivity, and a magnetron cathode for performing the method are provided. Ti films and TiN films are formed through sputtering of a Ti target using a multi-chamber system comprising at least two chambers each having a magnetron cathode in which a magnet can be moved to accommodate different films. The type of film being formed in each chamber is periodically alternated to prevent a buildup of TiN film adhered to the inner walls of the chambers which peels and causes dust particles.
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TECHNICAL FIELD
The present application is generally related to calibration of a vector network analyzer (VNA).
BACKGROUND
FIG. 1 depicts VNA 100 according to a conventional design. As shown in FIG. 1 , VNA 100 comprises switch 101 to switch between VNA ports A through D to establish a path to a single reference receiver 102 . When the RF signal path switch 101 changes position, the termination of the test port also changes. The change in termination causes the source match term to be different from the load match term. In a multiport VNA (more than two test ports), it is possible that each test port has multiple different load match terms. During calibration, each of the load match terms needs to be characterized and treated in the same manner as a two-port VNA. The difference between source and load match is referred to as the “switch error.” The standard 12-term VNA error model (or multiport equivalent) derives the load match term from the through connection.
The TRL family or group of calibrations is based on the 8-term error model which only factors in a single match term at each testport. The TRL family usually requires two receivers for each test port to factor out any port match variation through additional measurements and to obtain the necessary data to determine the VNA's systematic error terms. The TRL family of calibrations includes all calibration algorithms that are based on having a constant match defined for each test port independent of switching. The TRL family includes but is not limited to TRL, TRM, LRL, LRM, and Unknown Thru algorithms. Subsequent references to TRL calibration as used herein applies to the entire family of calibration and not to a specific algorithm. Because two receiver requirement, the traditional TRL calibration method cannot be applied to VNA 100 . To address this issue, a two-tier calibration process has been developed. In the two-tier process, the short, open, load, through (SOLT) calibration method is initially performed to obtain the switch error correction terms. After the initial calibration and with error correction turned “on,” the second tier is performed by applying the TRL calibration process. The multi-tier calibration essentially doubles the amount of time required to calibrate a VNA as compared to the calibration time associated with a VNA having a reference receiver for each port.
SUMMARY
Some representative embodiments enable calibration procedures to be applied to a VNA that only possesses a single reference receiver in an efficient manner. In some representative embodiments, a SOLT calibration is performed as an initial calibration tier. The SOLT calibration is used to calculate parameters associated with the switch error correction terms of the VNA. The calculated parameters are stored. Upon subsequent re-calibration of the VNA, some representative embodiments omit the necessity of repeating the SOLT calibration tier. In particular, some representative embodiments proceed directly to the TRL calibration process. A switch error correction matrix is calculated using the stored parameters and the measurement data from the TRL calibration process. The switch error correction matrix is applied to the measurement data and the error terms are calculated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a single reference receiver VNA according to a conventional design.
FIGS. 2 and 3 depict forward and reverse eight-error term models.
FIG. 4 depicts a flowchart including calibration operations performed on a VNA having only one reference receiver according to one representative embodiment.
FIG. 5 depicts a VNA according to one representative embodiment.
DETAILED DESCRIPTION
To facilitate the discussion of the mathematical basis associated with some representative embodiments, the 8-term error model 200 is shown in FIG. 2 . Given a VNA with two receivers per test port that can measure the incident and reflected signals, when the switch is placed in the forward position and power is applied to the port- 1 side, the following equations are obtained:
b 0 f =S 11m a 0 f +S 12m a 3 f
b 3 f =S 12m a 0 f +S 22m a 3 f (1)
FIG. 3 depicts the eight-term error model 300 where power is applied to the port- 2 side. When power the switch is placed in the reverse side and power is applied to the port- 2 side, the following equations are obtained:
b 3 r =S 21m a 0 r +S 22m a 3 r b 0 r =S 11m a 0 r +S 12m a 0 r (2)
Because the system is not perfect, caused by L 1 and L 2 , the a 3 f and a 0 r terms are not zero and must be addressed. Re-arranging equations (1) and (2) into the following form:
b 0 f a 0 f = S 11 m + S 12 m a 3 f a 0 f b 0 r a 3 r = S 11 m a 0 r a 3 r + S 12 m b 3 f a 0 f = S 21 m + S 22 m a 3 f a 0 f b 3 r a 3 r = S 21 m a 0 r a 3 r + S 22 m [ S R ] = [ b 0 f a 0 f b 0 r a 3 r b 3 f a 0 f b 3 r a 3 r ] = [ S 11 R S 12 R S 21 R S 22 R ] ( 3 )
Let
[ S m ] = [ S 11 m S 12 m S 21 m S 22 m ] ; [ M sc ] = [ 1 a 0 r a 3 r a 3 f a 0 f 1 ] = [ 1 L r L f 1 ] ( 4 )
Then
[S R ]=[S m ]*[M sc ] and [ S m ]=[S R ]*[M sc ] −1 (5)
Solving equation (5) results as follows:
S
11
m
=
b
0
f
a
0
f
-
b
0
r
a
3
r
a
3
f
a
0
f
Δ
S
12
m
=
b
0
r
a
3
r
-
b
0
f
a
0
f
a
0
r
a
3
r
Δ
S
21
m
=
b
3
f
a
0
f
-
b
3
r
a
3
r
a
3
f
a
0
f
Δ
S
22
m
=
b
3
r
a
3
r
-
b
3
f
a
0
f
a
0
r
a
3
r
Δ
,
where
Δ
=
1
-
a
3
f
a
0
f
a
0
r
a
3
r
(
6
)
It is noted that two extra measurements a 3 f and a 0 r are used to solve [S m ]. However, for a VNA with only one reference receiver, these terms cannot be determined.
To solve the switch error correction terms from a different perspective, the L f and L r terms can be rewritten as follows:
L
r
=
a
0
r
a
3
r
=
b
0
r
a
3
r
a
0
r
b
0
r
=
S
12
m
L
1
;
L
1
=
a
0
r
b
0
r
L
f
=
a
3
f
a
0
f
=
b
3
f
a
0
f
a
3
f
b
3
f
=
S
21
m
L
2
;
L
2
=
a
3
f
b
3
f
(
7
)
Equation (7) can be substituted back into equation (6) as follows (this method is equivalent to adding an imperfect termination to the respective error box):
S
11
m
=
b
0
f
a
0
f
-
b
0
r
a
3
r
b
3
f
a
0
f
L
2
Δ
′
S
12
m
=
b
0
r
a
3
r
-
b
0
f
a
0
f
b
0
r
a
3
r
L
2
Δ
′
S
21
m
=
b
3
f
a
0
f
-
b
3
r
a
3
r
b
3
f
a
0
f
L
2
Δ
′
S
22
m
=
b
3
r
a
3
r
-
b
3
f
a
0
f
b
0
r
a
3
r
L
1
Δ
′
,
where
Δ
′
=
1
-
L
1
L
2
b
3
f
a
0
f
b
0
r
a
3
r
(
8
)
If L 1 and L 2 can be determined and saved, the values can be retrieved and used in equation (6). From FIGS. 2 and 3 , the following equations may be derived:
E
LF
=
e
22
+
e
32
e
33
L
2
1
-
e
33
L
2
E
LR
=
e
11
+
e
10
e
01
L
1
1
-
e
00
L
1
(
9
)
Solving for L 2 and L 1 gives:
L
2
=
E
LF
-
e
22
e
32
e
23
+
e
33
(
E
LF
-
e
22
)
L
1
=
E
LR
-
e
11
e
10
e
01
+
e
00
(
E
LR
-
e
11
)
(
10
)
Comparing equation (8) to equation (6), it is seen that:
a 3 f =b 3 f L 2 and a 0 r =b 0 r L 1 (11)
Based upon the preceding mathematical derivations, it is observed that the parameters L 1 and L 2 can be determined using a calibration process based upon the twelve term error model (e.g., the SOLT method). In VNAs with dual reflectometers at each port, a 3 f and a 0 r are directly measured. In VNA systems without dual reflectometers, the terms a 3 f and a 0 r cannot be determined directly by calibration methods that use the eight term error model. However, if a VNA is sufficiently stable with time and temperature, it may be assumed that the parameters L 1 and L 2 will remain relatively constant (at least over the “short” term). Accordingly, instead of directly measuring the terms a 3 f and a 0 r upon each calibration, these terms can be calculated from the terms b 3 f and b 0 r and the parameters L 1 and L 2 .
In view of the ability to accurately estimate the terms a 3 f and a 0 r using stored parameters, an efficient method of calibrating a VNA having only one reference receiver can be achieved as shown in FIG. 4 . The portions of the flowchart of FIG. 4 may be implemented using suitable logic (e.g., software or integrated circuitry) on a VNA or an associated processing platform (e.g., a personal computer). This is also applicable to a VNA with more than one reference receiver. Some reference receiver designs do not measure the a 3 f and a 0 r terms correctly.
In step 401 , a calibration method (e.g., the SOLT method) based upon the twelve error term model is applied to a VNA. In step 402 , the parameters L 1 and L 2 , as defined above, are calculated and stored.
In step 403 , a TRL calibration is performed to generate calibration data. In step 404 , a switch error correction matrix is formed using the calculated terms a 3 f and a 0 r . In step 405 , the switch error correction matrix is formed and, in step 406 , the switch error correction matrix applied to the calibration data. In step 407 , the corrected calibration data is then used to calculate the eight systematic error terms using standard TRL techniques. In step 408 , device testing occurs using the calibrated VNA.
In some embodiments, the SOLT calibration process is repeated from time to time to maintain long term accuracy of the stored parameters L 1 and L 2 . Additionally, the stored parameters L 1 and L 2 preferably include sufficient data points to reduce interpolation errors.
FIG. 5 depicts VNA 300 according to one representative embodiment. VNA 500 that includes a minimum of one reference receiver. VNA 500 comprises SOLT calibration software 502 that calculates parameters L 1 and L 2 and stores the parameters in data file 501 . VNA 500 further includes TRL calibration software 304 that calculates terms a 3 f and a 0 r using data file 501 , generates a switch error correction matrix, and calculates eight systematic error terms using switch error corrected calibration data. Preferably, TRL calibration software 304 performs interpolation of parameters L 1 and L 2 for frequencies not explicitly represented in data file 501 . Although software is shown in FIG. 5 to perform calibration operations, other suitable logic could alternatively be employed such as integrated circuitry.
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In one embodiment, a method comprises storing parameters that are related to switch error correction terms of a vector network analyzer (VNA), and applying a calibration process of a TRL group of calibration processes to the VNA to generate calibration measurements, wherein the calibration process generates calibration measurements, calculates a switch error correction matrix using the stored parameters and a subset of the calibration measurements, and applies the switch error correction matrix to calibration measurements before solving for eight-systematic error terms associated with the calibration process.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a process for preparing solutions with additives and surfactants and, more particularly, to a process effective in preparing such solutions where one or more additives have a tendency to gel.
[0002] Numerous industrial processes require additives for various purposes. These additives may be provided commercially at high concentrations, and are then typically diluted with a liquid base such as water to the desired concentration for use.
[0003] However, simple dilution of such additives are not always effective since some additives have a tendency to gel when directly mixed with water. Such additives have a gelling temperature profile, and gelling is particularly problematic when the mixture is carried out below the gelling temperature.
[0004] Surfactants are one type of additive, for example as can be used to manufacture emulsions and the like, which has a tendency to gel when mixed with water below the gelling temperature of the surfactant. This makes difficult the use of such additives in industrial processes and poses a problem for which a solution is needed.
[0005] It is therefore the primary object of the present invention to provide a process for effectively mixing a liquid additive with a liquid base without gelling.
[0006] It is a further object of the present invention to provide such a process which utilizes inexpensive and reliable equipment, and which can be readily installed in various industrial locations.
[0007] Other objects and advantages of the present invention will appear hereinbelow.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, the foregoing objects and advantages have been readily attained.
[0009] According to the invention, a process is provided for preparing a solution of a liquid additive in a liquid base wherein the liquid additive tends to gel when mixed with the liquid base at temperatures less than a gelling temperature T G , which process com rises the steps of providing a stream of said liquid base at a temperature T C which is greater than ambient temperature and less than said gelling temperature T G ; feeding said stream to a mixer having a mixer inlet so as to impart energy to said stream; and adding said liquid additive to said stream downstream of said inlet, whereby said liquid additive mixes with said liquid base and said energy inhibits gelling of said liquid additive.
[0010] This process is particularly effective for preparing solutions of surfactants in water, wherein the surfactant has a tendency to gel at typical ambient temperatures. One such surfactant is ethoxylated nonylphenol, among others.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A detailed description of preferred embodiments of the present invention follows, with reference to the attached drawings, wherein:
[0012] [0012]FIG. 1 schematically illustrates a process in accordance with the present invention;
[0013] [0013]FIG. 2 illustrates the gel temperature profile for a typical surfactant material at different concentrations in water;
[0014] [0014]FIG. 3 illustrates a heat-only process that can be used to avoid gelling;
[0015] [0015]FIG. 4 illustrates a preferred embodiment of the present invention wherein some heat is applied, and mixing energy is used to avoid gel formation; and
[0016] [0016]FIG. 5 schematically illustrates a preferred mixture in accordance with the present invention, along with preferred placement of an additive injector.
DETAILED DESCRIPTION
[0017] The invention relates to a process for preparing solutions of additives and surfactants wherein heating and a static mixer are used to avoid gel formation of the additives.
[0018] As set forth above, numerous additives are provided at high concentration and, when diluted or added to water or other liquid bases, such additives have a tendency to form gels which interfere with effective mixing.
[0019] [0019]FIG. 1 schematically illustrates a process wherein several additives 10 , 12 , 14 are to be added to a stream 16 of water. In accordance with this embodiment of the present invention, additives 10 and 14 are water soluble, and do not gel, and can therefore be added at any convenient point.
[0020] Additive 12 , however, is an additive which tends to gel if mixed with water at ambient temperature. Stream 16 is therefore fed to a heater 18 to increase the temperature of stream 16 from ambient temperature to a temperature T C which is greater than ambient temperature, and which is preferably less than the maximum gelling temperature T G of additive 12 . The heated stream 20 is then fed to a static mixer 22 , through a static mixer inlet 24 , to impart energy to the stream. Once at least some energy has been imparted to the stream, additive 12 is then added to static mixer, preferably at an additive inlet 26 which is schematically illustrated in FIG. 1.
[0021] Phe energy imparted to stream 20 within mixer 22 has advantageously been found to be sufficient to prevent gel formation of additive 12 , despite the fact that the temperature of stream 20 has not been heated to a temperature above the gelling temperature T G .
[0022] Stream 28 exiting static mixer 22 advantageously comprises a substantially homogeneous and gel-free mixture of water 16 and additive 12 , along with any other additives 10 and the like which may have been provided as desired.
[0023] As set forth above, additives 30 and 14 are water soluble, and can be added at any point. Thus, in the embodiment illustrated in FIG. 1, additive 10 is added to stream 16 upstream of heater 18 and static mixer 22 , while additive 14 is added downstream of mixer 22 .
[0024] Still referring to FIG. 1, stream 28 can itself be fed, at temperature T C , to further processing steps such as an emulsion forming step or the like, particularly when such process is effective at temperature T C . This is advantageous since the heat used to form the solution can be used again in such emulsion preparation, thereby enhancing process efficiency.
[0025] For other processes, wherein lower temperatures are required, stream 28 can be fed to a cooler 30 as schematically illustrated so as to reduce the temperature to a temperature T P which is more suitable to the desired process.
[0026] Referring to FIGS. 2 - 4 , FIG. 2 shows a typical gel temperature profile for a liquid additive having gelling tendencies, and shows the gelling temperature T G at concentrations of the additive in water. As shown, at high concentrations the additive is liquid at substantially any temperature. As should also be clear, however, if such material is merely added to water, so as to reduce concentration at a low temperature, the additive will certainly gel and cause various problems.
[0027] One class of additives which has a gelling profile as illustrated in FIG. 2 are surfactants for use in making oil/water emulsions. For example, ethoxylated nonylphenol (NPE) has a profile as illustrated. NPE is typically provided commercially having a concentration in water of at least about 80% nd typically about 90% or higher, which generally corresponds to point 32 shown in FIG. 2. It is typical to use such surfactant at a concentration of less than about 1%, and preferably about 0.2%, which corresponds to point 34 shown on FIG. 2. In accordance with the present invention, the process provided allows for dilution from point 32 to point 34 without the need to heat in excess of temperature T G , and without the formation of gel. Other examples of similar additives that tend to gel include tridecyl ethoxylated alcohols, polymers that are soluble in water, and the like.
[0028] [0028]FIG. 3 illustrates the heating and cooling that would be necessary to go from ambient temperature to a processing temperature while heating to a temperature above T G . While this would avoid formation of gel, it should readily be appreciated that the heating and cooling costs would be substantial.
[0029] Turning now to FIG. 4, the preferred process of the present invention is shown wherein the additive is diluted with water at a temperature that is heated to a temperature T C that is greater than ambient temperature, but less than the highest temperature for gel existence T G . This moves the additive sufficiently high on the gel formation profile that energy imparted from the static mixer can successfully prevent formation of gel and allow effective mixture with the liquid base or water as desired.
[0030] It should readily be appreciated that the heating and cooling costs in the process of the present invention are substantially reduced as compared to that in FIG. 3. Further, a static mixer which is used to provide the energy desired is likewise efficiently operated, reliable and inexpensive.
[0031] Turning now to FIG. 5, a preferred placement of additive inlet is illustrated. FIG. 5 schematically shows a static mixer wherein mixer 22 has a series of swirling flow imparting element 36 each having a length L m corresponding to a 90° rotation along mixer 22 . Mixer 22 and elements 36 also have a diameter d o . In accordance with the present invention, a surfactant or additive inlet 38 , or preferably a plurality of inlets 38 , are advantageously positioned downstream at the beginning of the third swirling flow imparting member 36 by a distance L b which is preferably approximately equal to L m /4. Furthermore, inlet or inlets 38 advantageously extend inwardly into mixer 22 by a distance h which is preferably equal to about d o /4. This advantageously injects the additive into the stream at a point where sufficient swirling energy has been imparted that gel formation can be avoided at temperatures less than the gel formation temperature. This advantageously provides for the excellent results obtained in accordance with the present invention.
[0032] It should readily be appreciated that the process provided can be carried out in a continuous manner, and provides for manufacture of downstream products such as viscous hydrocarbon in water emulsions with a high degree of quality since surfactant concentration is homogeneously distributed through the water phase. Furthermore, it should readily be appreciated that this process provides such excellent results with a minimum amount of energy used for heating and/or cooling, and utilizing a miser which requires a minimum amount of maintenance.
[0033] The following examples demonstrates the excellent results obtained in accordance with the present invention.
EXAMPLE 1
[0034] In this example, a Kenics™ mixer having 3 inch×12 elements was used to mix an ethoxylated nonylphenol with water at a temperature of 35° C. This water had been heated to 35° C. from ambient temperature. Mixing was carried out at various water flow rates and additive flow rates, with mixing energy imparted by the static mixer being determined based upon the materials fed to the mixer, the process temperature and specifics of the mixer. Table 1 below sets forth the amounts of dissolution obtained in each case.
TABLE 1 Water Flow Additive Flow Mixing Energy Dissolution Degree (l/s) (ml/min.) (W/Kg) (grs dissolved/total grs) 0.42 303 199 0.99 0.33 240 104 0.98 0.24 180 40 0.94 0.12 84 4 0.78
[0035] As shown, excellent dissolution was obtained at mixing energy of 40 W/Kg and above for the flows shown. At a mixing energy of only 4 W/Kg only 78% dissolution was obtained. Thus, the mixing energy provided by the static mixer in accordance with the present invention clearly helps to avoid gel formation and enhances complete dissolution of the additive.
EXAMPLE 2
[0036] In this example, a Sulzer™ mixer SMX, with 1.5 inch×8 elements, was used to mix water at 35° C. with the same surfactant as it Example 1. Table 2 below sets forth the water flow, additive flow, mixing energy and dissolution degree obtained.
TABLE 2 Water Flow Additive Flow Mixing Energy Dissolution Degree (l/s) (ml/min.) (W/Kg) (grs dissolved/total grs) 1.42 1052 341 0.92 1.24 894 231 0.94 0.92 666 99 0.69 0.57 408 85 0.63
[0037] As shown, dissolution with this mixer was not as effective as with the mixer of Example 2. Thus, the geometric configuration of the mixing elements of the mixer, which are different in both commercial mixers, is important.
EXAMPLE 3
[0038] In this example, a stream of heated water was mixed with surfactant in three different locations along the mixer in order to demonstrate the advantageous position of injectors for the additive.
[0039] In the first instance, the additive was injected at the entrance to the mixer, along with the water. In the second evaluation, the additive was injected through a single injector at a point as selected according to the illustration of FIG. 5. Finally, in a third evaluation, additive was injected through two injectors positioned at a point as illustrated in FIG. 5.
[0040] With the additive introduced at the entrance to the mixer, only 72% dissolution was obtained. With additive introduced through a single injector downstream of the inlet, 80% dissolution was obtained. With the additive injected through two Injectors downstream of the inlet as illustrated in FIG. 5, 94% dissolution was obtained. This, positioning of the injector or inlet for the additive in accordance with the present invention provides for enhanced dissolution as desired.
[0041] It is to be understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modification of form, size, arrangement of parts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims.
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A process for preparing a solution of a liquid additive in a liquid base wherein the liquid additive tends to gel when mixed with the liquid base at temperatures less than a gelling temperature T G includes the steps of providing a stream of the liquid base at a temperature T C which is greater than ambient temperature and less than the gelling temperature T G ; feeding the stream to a mixer having a mixer inlet so as to impart energy to the stream; and adding the liquid additive to the stream downstream of the inlet, whereby the liquid additive mixes with the liquid base and the energy inhibits gelling of the liquid additive.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority benefit of Italian Patent Application No. MI2013A000750, filed May 9, 2013, and which application is hereby incorporated by reference to the maximum extent allowable by law.
BACKGROUND
Technical field
The present disclosure relates in general to data acquisition and processing for real time diagnostic and/or control of the functioning of a spark ignition internal combustion engine through evaluation of operating parameters and in particular to “sensorless” evaluation of the pressure in the combustion chamber from waveform feature data of the sensed ionization current.
Discussion of the Related Art
In the last decades, ionization current diagnostics has proven itself to be an effective approach in investigating the mechanism of fuel combustion and optimizing spark-ignition (SI) engine control.
Monitoring of ionization current waveform in SI engines fueled with gasoline or different fuels and sophisticated calibrations are currently used for online diagnosis of misfirings and knock detection, cam phase determination, air/fuel ratio estimation, cylinder pressure estimation and peak cylinder pressure position estimation [1-5].
Most SI engines function with an inductive ignition system. However, large ignition discharge currents can mask ionization current at the beginning of propagation of the combustion (during a so-called front flame phase of the combustion process). During initial flame propagation the ionization current that is significantly masked by the spark discharge current remains hardly detectable if the discharge current of the inductance of the spark plug circuit persists long after ignition starts. How to discriminate the interference of ignition discharge current from the ionization current has been and a key issue for a long time in the ionization current measurement technical field.
Filtration by the so-called “Blind Source Separation” (BSS) method of monitored current, in which the independent original signal can be extracted from the statistically independent source signals, may be a way to discriminate the ignition spark discharge current from ionization current, however the effort may be ineffective in case of significantly corrupted current signals. In any case for achieving reliable analytic diagnosis and/or indirect assessment of important characteristics of the combustion process complex independent component analysis methods should be used [1].
It is observed that high frequency components of the current may hardly circulate both in the primary or secondary windings of the ignition coil, thus they tend to flow through parasitic capacitances towards the supply node of the first spark electrode and then to ground and/or are dissipated as waste heat in the magnetic core of the ignition coil. Therefore, potentially useful information derivable from sensed current data gathered during the crucial ignition and the flame-front phases remains unexploited.
Detection of the low frequency current circulating in the primary circuit of the HV coil is an approach followed in known Delphi and Bosch systems, however the approach allows only the detection of the post spark ion current and requires the use of auxiliary components as HV diodes, capacitors, resistors and/or a DC supply [2].
Reportedly, monitoring of the ionization current “during initial spark phases” has been achieved with additional electrodes inside the combustion chamber.
In the prior Italian patent application No. MI2001A001896, the present applicants disclosed an effective device and circuit arrangement for significantly reducing shortcomings of traditional sensing schemes and related hardware to sense ionization current (sometimes called ion current) during the first two phases, namely the ignition phase and the flame-front phase.
As described in the above cited prior application, the problem is alleviated by providing a resistive element connected to the ground electrode of the spark plug, such that when the spark plug is mounted in a SI engine combustion chamber, the ground electrode of the spark plug becomes electrically connected to the engine body through a resistive element interposed therebetween in the flow path of the ionization current. Moreover, according to a disclosed embodiment, the ground electrode of the spark plug is provided with an appendix adapted to constitute an accessible current sense terminal outside the combustion chamber or wired to it. In this way, it is made possible to detect with enhanced discrimination the ionization current even during the ignition and flame-front phases by sensing the voltage between the integrated sensing terminal and the ground node constituted by the engine body. The whole content of the above cited Italian patent application is incorporated herein by express reference.
SUMMARY
The ability of sensing the current flowing to ground from the ground electrode of a spark plug on a current sensing resistance, processing the voltage signal to filter out high frequency noise and disturbances caused by the spark discharge across the gap, and A/D converting the filtered signal for temporarily storing the data on an appropriate memory (for example a RAM) has enabled the inventors to achieve a clear definition of the waveform of the ionization current even at the ignition instant and flame-front phases of the combustion process.
Extensive laboratory tests on a static mock-up spark plug ignition chamber (for eliminating interactions among spark discharge, ignition and flame propagation mechanisms in a real engine cylinder), equipped with pressure and temperature sensors, confirmed the existence of exploitable correlations between the pressure in the combustion chamber (CCP) and instrumentally detectable or calculable features of the ionization current waveform, such as:
a) the time delay (TD), from the instant of generation of a ignition triggering signal by an engine controller to the instant the sensed current signal of pre-ionization of the gas mixture swings down from a typical latency plateau (corresponding to a pre-ionization phase of the gas mixture being ignited) to the instant of ignition of the gas mixture, initiating a first cycle of a typical decaying oscillatory full ionization current phase, due to the reactive electrical characteristics of the spark plug circuit; b) the asymptotic value of the ionization current; c) the amplitude of the first ringing (or 1 st harmonic) peak, I_rng FFT (calculated by Fast Fourier Transform algorithm) of the decaying oscillatory part of the ionization current waveform; d) the amplitude of detected peaks (or envelope function) of the decaying oscillatory part of the ionization current waveform.
The correlation between the delay time TD and the charge pressure (of the compressed gas mixture being ignited) is explainable in terms of the relation between the breakdown voltage, V bd , gas pressure P, gas temperature T, and electrode gap distance d, as described by the Paschen's law Vbd≈(α·P·d)/T+β·√(P·d/T), where constants α and β substitute the actual numerical constants used in Paschen's equation as it was originally derived for a spark discharge into dry air and not into a fuel/air mixture (which might also contain moisture) [4], [5]. Since the spark plug high voltage increase rate mostly depends on the characteristics of the HV electrical inductive ignition system, the applicants conceived that a noted dependence of the TD/CCP correlation on the actual temperature (T) of the gas mixture compressed into the test combustion chamber could be accounted for by parameterizing in some manner a TD/CCP correlation characteristic in terms of temperature by repeating the TD measurements at various CCP values for different temperatures, covering the expected range of variability of the charge temperature and that, in a real engine context, wherein many other environmental parameters and/or engine control settings, such as the actual composition of a ambient air and gasified fuel mixture, its moisture content, crank angle, RPM, etc. play a role in the ignition and flame front expansion process that affects the pressure profile, a way of correlating, in real time, data extracted from an effectively monitored ionization current waveform with other environmental parameters and/or settings in order to generate estimated values of pressure of enhanced reliability and optionally even of other important operation parameters could be feasible.
According to the method of this disclosure, similar parameterizations of the TD/CCP correlation are reliably established, besides for temperature, also for many other variable environmental parameters or differently expressed parameters, other than temperature, such as air/fuel ratio (briefly AFR) or throttle position, manifold pressure, crank angle, RPM of the engine, etc., by generating, through a calibration campaign of tests conducted on a real combustion chamber of identical geometry and characteristics of the engine cylinders (most preferably on a test engine purposely equipped with pressure, AFR, temperature sensors and/or of actual engine control settings), a specific matrix (or look-up table) of time invariant correlation coefficients, covering the respective ranges of variability of the various parameters and/or settings.
Such a trimming of time invariant correlation coefficients has revealed itself as a very effective way of accounting for parameters and settings that influence the estimation of CCP on the basis of measured and/or calculated features of the monitored ionization current waveform.
The utter complexity of accounting for every single parameter that may affect the TD/CCP correlation as well as other useful correlations with other important parameters and/or engine control settings derivable from the detectable and/or real time calculable features of the ionization current waveform, is generally overcome by exploiting the fact that certain electrical and physical characteristics of the spark plug ignition and combustion system of an engine may be considered to remain substantially constant when the engine is running (being due to its mechanical construction, frictional forces, electrical system, etc.).
According to an embodiment, a mathematical model of the electrical and physical spark plug ignition system and combustion chamber accounting for these time invariant parameters is refined through a calibration campaign of tests conducted on a test engine purposely equipped with pressure, AFR, temperature sensors and/or of the actual engine control settings. Accordingly, the time invariant correlation coefficients of said specific matrix (or look-up table), covering the respective ranges of variability of the various parameters and/or settings, are progressively adjusted by “trial-and-error” process, iteratively testing their interactive “performance” when used as coefficients of the various terms of the expression of the mathematical model of the electrical and physical spark plug ignition system and combustion chamber that generates an estimated pressure value in function of a current set of variable parameters and/or control settings of the test engine (i.e. the terms of the mathematical expression), by comparing it with the real pressure value as measured by the sensor. Iterative and/or heuristic (e.g. genetic algorithms) are generally usable for interactively refining the time invariant coefficients.
When the mismatch between the estimated pressure value generated by the mathematical model is finally reduced to be within an admitted maximum spread (tolerance), the set of time invariant correlation coefficients is permanently stored in said matrix or look-up table.
According to an embodiment, such a matrix (TI) of correlation coefficients compiled at a calibration stage of the ionization current data acquisition set-up conducted on a given type of engine purposely equipped with pressure, temperature, AFR and eventually other sensors and/or readers of actual control settings, running on a test-bench, represents a time invariant (or substantially so) correlation tool that, embedded in an on-board combustion chamber pressure monitoring system, replicating the ionization current monitoring and data acquisition/real time processing structures used for the calibration campaign and post-processing means using the same mathematical model of the real engine, the current instantaneous value of the pressure and optionally even an averaged pressure value over a given number of engine cycles are output.
Therefore, combustion chamber pressure and optionally even other important variable parameters, like the AFR and crank angle, are made monitorable without deploying specific sensors, from detected and/or calculated features of the monitored ionization current waveform. Such reliably assessed values of basic variable operation parameters may be fed to a common engine controller.
Besides the measurable ignition delay time TD, several calculable features of the filtered ionization current waveform, such as the asymptotic value the peak amplitude, or oscillatory decay envelope function, of the monitored ionization current, and in particular the first harmonic frequency and the FFT first harmonic frequency peak amplitude, offers an enhanced discrimination, moreover, differently from the TD/CCP correlation, FTT data (first ringing frequency and related peak amplitude in the frequency domain) appears to be practically unaffected by the charge temperature (T) and less corruptible by disturbances (spurious sample data). These options of feed data of the sensed ionization current, usable for producing estimated values of the pressure by correlation, offer innumerable possibilities of enhancing robustness of the data processing.
1. A method of real-time evaluation of at least the pressure in the combustion chamber of an electronically controlled spark plug ignition engine by sensing the ion current flowing through the spark, comprising the steps of:
refining a mathematical model of the electrical and physical spark plug ignition system and combustion chamber of the engine through a calibration campaign of tests conducted on a test engine purposely equipped with specific sensors of combustion chamber pressure, ambient temperature, air/fuel ratio or correspondent throttle setting, and of other engine control settings, covering the respective ranges of variability of said parameters and/or settings, by iteratively testing the interactive performance of correlation coefficients of related terms of a mathematical expression of said model and comparing the expressed pressure value with the real pressure value as measured by a sensor; storing in a matrix or look-up table a set of time invariant correlation coefficients of said terms when the residual mismatch between the estimated pressure value generated by the mathematical model compared with the measured value remains within a maximum spread; and sensing the ionization current in the running engine, measuring or calculating at least one or more significant features of the waveform of the sensed ionization current and processing any or more measured or calculated feature values together with said matrix of time invariant coefficients and with a set of actual values of said parameters other than pressure and/or of said control settings of the running engine for producing an evaluated value of the combustion chamber pressure.
2. The method of real-time evaluation of the combustion chamber pressure according to claim 1 , wherein said significant features of the waveform of the sensed ionization current signal belong to the group composed of the time delay of the beginning of an oscillatory decay phase of the monitored ionization current from an electronically controlled generation of a trigger signal of the spark plug discharge, the calculated amplitude of the first ringing frequency peak in the FFT domain, the calculated asymptotic current value, the calculated amplitude of resonance peaks or envelope function and the time width of current peaks of said oscillatory decay phase of the ionization current.
3. The method of real-time evaluation of the combustion chamber pressure according to claim 2 , wherein the measured significant feature of the waveform of the sensed ionization current signal is the time delay of the beginning of an oscillatory decay phase of the monitored ionization current subsequent to said trigger signal of a spark plug discharge and further comprising the step of defining the length of a data acquisition time interval, following said delayed instant, from which calculating any or all said features of the monitored portion of the ionization current waveform.
4. The method of real-time evaluation of the charge pressure according to claim 1 , further comprising the steps of
processing of the acquired data of the ionization current signal over a programmable data acquisition time interval for outputting instantaneous values of any or all said features of the monitored portion of the ionization current waveform; averaging over a given number of engine cycles any or all of said measured or calculated features for selectively outputting the instantaneous and the averaged values of any or all said features; to produce continuously updated vectors of values of said calculated features of the monitored portion of the ionization current waveform for a given number of engine cycles; feeding said selected instantaneous or averaged values of any or all said features together with said matrix of time invariant coefficients and with a set of actual values of said parameters other than pressure and/or of said control settings of the running engine to a correlator embedding said mathematical model of the electrical and physical spark plug ignition system and combustion chamber of the engine, for generating on respective outputs correspondingly evaluated instantaneous and averaged values of the combustion chamber pressure.
5. The method of real-time evaluation according to claim 1 , wherein a one or more spark discharges are purposely commanded after ignition has taken place for gathering multiple estimated instantaneous values of the pressure in the combustion chamber over a complete ignition-flame propagation-full combustion-exhaust process.
BRIEF DESCRIPTION OF THE DRAWINGS
Non-limiting and non-exhaustive embodiments are described with reference to the following drawings, wherein like labels refer to like parts or variables throughout the various views unless otherwise specified. One or more embodiments are described hereinafter with reference to the accompanying drawings in which:
FIG. 1 illustrates the typical spark plug circuit and the associated timing diagram of the idealized waveforms of the significant electrical signals;
FIG. 2 illustrates the modeled electrical spark plug circuit of FIG. 1 further including a current sense resistor in series with the ground electrode of the spark plug in the current path toward the circuit ground node and the basic current-voltage characteristic;
FIG. 3 a is a simulated waveform of the voltage drop on a 50Ω current sensing resistor for a combustion chamber of the model considered in FIG. 2 ;
FIG. 3 b shows the decaying oscillatory ionization current signal, sensed during a full ionization phase of the combustion process;
FIG. 3 c shows in a logarithmic scale the main ringing peak of the sensed ionization current in the Fourier transform domain;
FIG. 4 is an oscillograph of the voltage drop on a 50Ω.current sensing resistor, monitored during a full ionization phase of the ignition process within a mock-up test combustion chamber, showing features that have been found to have a direct correlation with the pressure of the gas mixture introduced (charge pressure) in the chamber;
FIG. 5 shows the detected ionization current traces at three different charge pressures of the gas mixture to be ignited and the correlation the traces have with the delay time (TD) of ignition;
FIG. 6 shows the correlation with first harmonic frequency and with the amplitude of the first ringing peak in the Fourier Transform frequency domain of the ionization current with the pressure of the gas mixture ignited;
FIG. 7 shows an experimentally determined characteristic curve of correlation between the ignition delay time and the charge pressure of the gas mixture;
FIG. 8 shows an experimentally determined characteristic curve of correlation between the amplitude of the main ringing frequency peak in the Fourier transform frequency domain of the sensed ionization current and the charge pressure of the gas mixture;
FIG. 9 shows several experimentally determined correlation curves of the ignition delay time and pressure at different charge temperatures of the gas mixture into the combustion chamber;
FIG. 10 is an exemplary embodiment of suitable measurement set-up and calibration flow chart for a specific real engine adapted to generate a matrix (look-up table) of time invariant correlation coefficient values;
FIG. 11 illustrates a scheme of ionization current data acquisition, ignition time delay measurement and real time data processing for producing estimated instantaneous and averaged values of charge pressure value, according to a first embodiment;
FIG. 12 illustrates a circuit diagram for real time measurement of the ignition delay time and of a time interval following the ignition instant, setting the duration of a sample data acquisition window of the monitored ionization current signal and a time diagram or the related signals, according to a first embodiment;
FIG. 13 illustrates an embodiment of ionization current data acquisition, calculation of features of the monitored current waveform and real time data processing for producing estimated instantaneous and averaged values of charge pressure value, according to an embodiment;
FIG. 14 illustrates a circuit diagram for setting the duration of a sample data acquisition window of the monitored ionization current signal and a time diagram or the related signals, adapted for the embodiment of FIG. 13 .
DETAILED DESCRIPTION
A typical spark plug circuit and the associated timing diagram of the idealized waveforms of the significant electrical signals and typical signal amplitudes are shown in FIG. 1 , whilst a simplified correspondent analytical model of the electrical spark plug circuit of FIG. 1 further including a current sense resistor in series to the ground electrode of the spark plug and the basic current-voltage characteristic are shown in FIG. 2 . FIG. 3 a is a simulated waveform of the voltage drop on a 50Ω current sensing resistor of the analytical model considered of FIG. 2 .
FIG. 3 b shows a portion of the simulated decaying oscillatory ionization part of the current signal during a full ionization phase of the combustion process.
FIG. 3 c is a logarithmic scale illustration of spectral contents in the frequency domain of the simulated decaying oscillatory ionization part of the ionization current calculated by Fast Fourier Transform.
A typical waveform (filtered from high frequency disturbances) of the ionization current flowing to ground from the ground electrode of the spark plug during the initial phases of discharge of the ignition coil, of ignition of the gas mixture and of the flame front propagation process is reproduced in FIG. 4 .
Features that have been found to have a direct correlation with the pressure of a given gas mixture introduced in the chamber and compressed therein and thence of the burning mixture are recalled by self-explaining labels: TD, PPE, NPE and AICV, and by the first harmonics ringing peak amplitude in the FFT domain.
The delay TD is the latency between the instant the spark plug ignition of the compressed gas mixture in the combustion chamber is triggered and the instant at which a substantially full ionization across the spark gap is achieved (spark) causing an abrupt negative swing of the sensed ion current amplitude from a modest negative current plateau reached during an initial phase of progressive ionization of gas molecules not jet ignited in the spark gap region. The significantly reactive electrical characteristics of the spark plug circuit cause the ionization current to have a decaying oscillatory waveform.
Repeated laboratory tests on a mock-up spark plug ignition test system of geometry identical to that of the real engine cylinder (to avoid interactions with gas mixture combustion and/or the gas discharge phase of the real engine) have indicated a direct correlation between the charge pressure (pressure of the gas mixture being ignited) of precisely defined air-fuel gas mixtures inside the test combustion chamber and the ignition delay time TD.
FIG. 5 shows the detected ionization current traces for three different charge pressures of a given gas mixture of a certain air-to-fuel ratio (AFR) being ignited and it is clearly observable the evident correlation the traces have with the respective delay times TD highlighted by the arrows.
The reactive characteristic of the spark plug circuit causes the ionization current to have a decaying oscillatory waveform of a well-defined frequency and sampled current data of several cycles of oscillation may be processed by Fast Fourier Transform to determine the spectral contents within the observed/selected time interval, in particular the main ringing frequency (first harmonic) and amplitude of the relative peak. In the FFT frequency domain, the frequency of the first harmonic peak as well as its amplitude have a clear correlation with the charge pressure of the gas mixture being ignited. FIG. 6 shows traces of the main ringing frequency peaks for the indicated nine different values of charge pressure.
From collected experimental values, all obtained at the same temperature of the charge gas mixture of same AFR, were obtained the curves of correlation shown in FIG. 7 and in FIG. 8 , for the detected TD and for the main ringing frequency peak amplitude, respectively. Though of lesser resolvability, distinct correlation characteristics were found also between the pressure and the amplitude of the ionization current peaks or of negative and positive envelope, NPE and PPE respectively, and the asymptotic value AICV of the oscillatory decaying waveform of the ionization current.
The effect of the charge temperature has been investigated in the range from 30° to 100° C. and found to have a non-negligible effect on the delay time of ignition and a practically negligible effect on main ringing frequency peak amplitude. FIG. 9 shows how the characteristic of correlation of TD with charge pressure is affected by varying the charge temperature.
An exemplary embodiment of suitable measurement set-up and of a flow chart of calibration based on the definition of a mathematical model of the electrical and physical spark plug ignition system and combustion chamber of a real engine adapted to generate a matrix (look-up table) of substantially time invariant correlation coefficient values is illustrated in FIG. 10 .
The electrical signal data being acquired with the measurement set up are the ignition trigger signal and the ionization current signal. The sensed signals are filtered and converted into digital sampled data and the ionization current data are temporarily stored in a work RAM.
According to the embodiment considered, the calibration flowchart comprises a data processing block of the stored sampled ionization current data Is(t) of a test engine running on a laboratory bench, purposely equipped with specific sensors of the actual pressure inside the engine cylinders. Besides measuring the ignition delay TD and defining a time window of sampled ionization current data analysis following the ignition instant, the Data Processing block may selectively perform a plurality of operations on the data Is(t) read from the temporary data storage support, including: digital noise filtering, anti-aliasing filtering and calculation of specific feature values of the waveform of the ionization current within said defined time window of sampled ionization current data analysis, following the ignition instant, such as PPE, NPE, AICV and FFT features.
A full set of variable operating parameters and/or settings values of the test engine (S 1 , S 2 , . . . Si, . . . , Sn), corresponding to ambient temperature (Z 1 ), the load on the engine shaft (Z 2 ), the ignition timing or crank angle (Z 3 ), the actual air/fuel ratio (AFR) or throttle (Z 4 ), etc. (Zm), for a given operation condition (or mission) profile of the test engine (as precisely acquired though a suitable interface of an engine controller or directly determined by specific sensors) are fed together with the calculated ionization current waveform features Y(t) produced by the Data Processing block, to a I/O Data block and eventually to an Electrical/Physical mathematical model of the electrical and physical spark plug ignition system and combustion chamber of the test engine. Accordingly, the set of input data Y(t) and Z 1 , Z 2 , . . . Zm will generate an estimated value of the pressure CCPest on the basis of respective weighting coefficients b/a, c/a, d/a, e/a, . . . , n/a of the variable parameters and/or settings of the considered profile.
These coefficients a, b, c, d, e, . . . n that tie the parameters and/or settings Zi for a given mission profile to the pressure inside the engine cylinders (CCP) and that should ensure a match of the mathematical model with the real engine, are individually established through successive iterations during which the Zi values are changed by the engine controller. The minimum number of iterations depends by the number of correct coefficients to be searched, plus one.
At every cycle of iteration, the generated estimated value of the pressure CCPest is compared with the actual pressure CCPmeas measured by the pressure sensor and the mismatch between the two values is checked with a threshold of admissible spread (target tolerance) for the particular coefficient being searched.
If in the course of the iterations one or more coefficients remain constant, the degree of complexity of the matrix TI of dimension K being generated will be reduced because of a broader validity of those coefficients upon the variation of one or more of the parameters and/or settings Zi fed to the model. In general terms, Y(t) represents the information extracted (by measurement or calculation) from Is(t) to be correlated to the pressure CCP, for example TD, FFT 1 st ringing peak amplitude, or other feature of the ionization current waveform that, during the calibration campaign, shows to be well correlated to CCP and comparably the least sensitive to other parameters.
Supposing Y(t) to be the measured ignition delay TD found to vary linearly with CCP according to the relationship traced in FIG. 9 and that TD is found to be substantially insensitive to other parameters and settings apart ambient temperature Troom. In this case the number of parameters Si to be processed will be equal to 1. Supposing to divide in 10 intervals the contemplated range of CCP in order to have an acceptable precision and that to stay within the admitted spread 5 different values of ambient temperature should be considered, the dimension of the matrix TI to be produced will be K=10*5=50. The dimension K increases rapidly with the number of parameters Si that have a non negligible effect on the correlation between the selected feature of the ionization current waveform and CCP.
Once the trimming process of the correlation coefficients to be written in the output matrix TI is completed, that is when acceptability of the coefficients has been verified for every set of control variable parameters and/or settings (mission profile) fed to the mathematical electrical/physical model, the thus established coefficients of correlation will constitute the correlation matrix TI, to which the on board sensor-less system of real time estimation of the CCP value of this disclosure will access for correlating the measured or calculated feature value of the monitored ionization current waveform to a correspondent pressure value using the same mathematical electrical/physical model defined during the calibration campaign.
FIG. 11 illustrates a system of real time combustion chamber pressure evaluation, according to a first exemplary embodiment of this disclosure, based on TD/CCP correlation.
The on-board data acquisition set-up for monitoring the ignition trigger signal and for measuring the ignition delay ionization current signal may be substantially a replica of that used for the calibration campaign of laboratory tests on a test engine equipped with pressure sensors illustrated in the block diagram of FIG. 10 .
The block TD Evaluation detects the ignition trigger signal and measures the actual ignition delay TD of the air/fuel compressed gaseous mixture within the combustion chamber, for example by iteratively incrementing the width of an initial blanking pulse until its width is made to coincide with the ignition delay time TD or equivalent technique.
The measured values TD(t) may optionally be averaged over a given number of engine cycles as depicted by the block Time AVG TD.
The measured TD(t) value is fed together with the current set of Environmental Variable Data and the Time Invariant Data Matrix to the block CCP-TD Correlator embedding the same Electrical/Physical Model of the electrical and physical spark plug ignition system and combustion chamber of the engine used in the calibration campaign of tests for generating and making available on respective outputs, instantaneous and averaged values of real time estimated CCP pressure.
An exemplary circuit diagram of a hardware implementation of the block TD Evaluation of the embodiment of the method of evaluation of the combustion chamber pressure of FIG. 11 is shown in FIG. 12 , together with relevant time diagrams of the circuit signals.
The voltage signal V(Isense), proportional to the voltage drop on a sense resistance, is filtered by the high pass filter that removes the DC component. Fast transients in the first microseconds following the ignition trigger Tr switching instant are blanked by a switch that remains open for a programmable time interval WT 1 generated by a first Delay Generator (interval of time corresponding to a first part of the pre-ignition phase where a first moderate downward (negative) step of the ionization current signal is observed.
When the filtered signal V(Isense) swings down reaching its first negative peak (the symbolically indicated DC reference of comparison may be of the order of about −1V to −2V) of the oscillatory part of the ionization current, coinciding with the ignition instant of the compressed gaseous mixture, a second Delay Generator generates a second programmable time interval in form of the pulse signal WT 2 that controls the switches of the block “Peak and Hold”. The latter block outputs a voltage signal V(Intg_is) at which charges an integrating capacitor during the programmed time interval WT 2 . Once the time interval WT 2 is elapsed, the system stores on the capacitor the last value assumed by V(Intg_Is) that is proportional to the asymptotic value of the current Is. Thus, the stored value of V(Intg_Is) of an n−1 cycle remains available for the successive n th ignition cycle. Practically, the generated comparison value, assumed at the end of the time interval WT 2 of a cycle V(Intg_Is) n−1 is proportional to the asymptotic value of the ionization current and remains stored in the capacitor for the successive cycle, becoming the comparison value of V(Isense) n . Eventually, the digital signal Td-ioniz, during a n th cycle will assume a logic state “1” for V(Isense) n =V(Intg_Is) n−1 and reset the counter that had been activated by the trigger signal Tr.
Therefore, the pulse count appearing on the Pulse Counter before reset, will be proportional to the duration of TD, from the trigger signal instant Tr to V(Isense) n =V(Intg_Is) n−1 . Scaling factor and resolution of TD will depend from the circuit clock frequency value. The time diagrams resume the TD evaluation circuitry behavior wherein gross signal disturbances of V(Isense) are blanked-out during a blanking WT 1 delay time, before the signal is fed to the voltage comparator. The Peak-and-Hold block assures availability of V(Intg_Is) n−1 at the comparator input before acquiring the new V(Intg_Is) n value to be used for next cycle, through the analog time averaging process of V(Isense) during the WT 2 time window. WT 2 starts as soon as the filtered V(Isense) signal falls below a constant negative voltage VDC, usually set in the range −1÷−2V for Rsense=50Ω.
The mixed analog/digital exemplary embodiment of FIG. 12 is depicted as a possible example of hardware implementation, although the algorithm may obviously be alternatively implemented in different circuital forms and with alternative analog and/or digital circuits.
An alternative system of real time combustion chamber pressure evaluation, according to a different embodiment of the method of this disclosure, based on the correlation between CCP and one or more real time calculated features of the oscillatory part of the waveform of the sensed ionization current waveform, is illustrated in FIG. 13 .
According to this embodiment, the on-board system, instead of employing the TD Evaluation block of the embodiment described with reference to FIGS. 11 and 12 , uses a Data Processing Block for calculating in real time at least one of a plurality of feature values of the oscillatory decay part of the ionization current waveform, namely: the first harmonics value of the Fast Fourier Transform, substantially proportional to the peak amplitude of the 1 st ringing frequency cycle (briefly FFT), the negative and positive peak envelopes (briefly, NPE and PPE) and pulse length. Calculations are performed on digital sample values of the monitored ionization current within a programmable time window WT 3 of waveform data acquisition, starting from the ignition instant and lasting for a programmable time.
According to this embodiment, the calculated feature value Y(t) selected among the many calculated (FFT, NPE, PPE, Pulse length) by setting a Parameter Selector, eventually averaged in the block Time AVG over a number of engine cycles, is fed together with the current set of Environmental Variable Data and the Time Invariant Data Matrix to the block CCP-TD Correlator embedding the same Electrical/Physical Model of the electrical and physical spark plug ignition system and combustion chamber of the engine used in the calibration campaign of tests for generating and making available on respective outputs, instantaneous and averaged values of real time estimated CCP pressure.
An exemplary circuit diagram of a hardware implementation of the block Data Processing of the embodiment of the method of evaluation of the combustion chamber pressure of FIG. 13 , together with relevant time diagrams of the circuit signals is depicted in FIG. 14 .
As depicted in the timing diagrams of FIG. 12 , the time window of ionization current values acquisition starts from the instant at which the ionization current waveform swings down towards its maximum negative peak value, determined by the comparison of the filtered signal V(Isense) with the symbolically indicated DC reference that may be of the order of about −1V to −2V) and its duration may WT 3 .
A given number M of ionization current sample digital data output by the A/D Converter thus obtained (e.g. 10-20 bits per sample) form a characteristic vector of the discharge current in the chosen interval of time. In order to untie from cycle-to-cycle variability of the spark discharge and disturbances inevitably present in such an electrically highly noisy environment, the ionization current data acquisition in a fixed time window is repeated for N successive engine cycles. Therefore, digitized information is temporarily stored in a Isense Data Matrix that will have a M×N size.
In the processing DSP unit, dedicated calculation structures, such as the depicted FTT algorithm; Peak detection, PPE, NPE detection, output the peak amplitude of the 1 st ringing frequency (first harmonic) peak in the Fast Fourier Transform domain, the negative and positive peak envelope functions PPE and NPE, respectively, and the selected waveform feature data Y(t) are finally fed to the CCP-Y(t) Correlator block of FIG. 13 .
Preferably, the real time data acquisition system of this disclosure is made to operate over innumerable engine cycles. For a new set of values relative to the new n+1 th cycle to be stored, the cycle n−(n−1) out of the n vectors contained in the Isense Data Matrix will be replaced by the n−(n−2) one, for example through a simple “back Shift” of the stored data.
The method and embodiments of the on board combustion chamber pressure estimation system from the monitored ionization current data of this disclosure may contemplate even the possibility of purposely commanding one or more “service” spark plug discharges following ignition, that is during the phase of flame propagation inside the engine cylinder, in order to gather information on CCP at selected instants following the pre-ionization phase and the ignition instant, using substantially the same method and on board system for real-time data processing and pressure evaluation.
Availability of data related to a large number of samples per cycle and for n cycles in succession, continuously updated by a “rolling acquisition process”, provides an outstandingly effective instrument for a precise and reliable estimation of instantaneous values of a basic physical parameter of operation of the running engine as well as of time-based averages thereof.
In addition, through a comparative analysis of available sample values, the system may autonomously reduce the read noise by recognizing when a particular set of acquired data is statistically irrelevant, i.e. falling outside a min-max range of data values acquired during calibration process.
The circuital arrangement and means for sensing the ionization current flowing through the spark plug may be different from the mentioned resistive layer connected to the ground electrode of the plug, described in the cited prior patent application of the same applicants. The current may be sensed alternatively on the high voltage secondary coil terminal side, for example by using a transformer, with or without a magnetic core for coupling the high voltage supply cable of the spark plug to a sense resistor referred to ground, or a double resistive voltage divider in a Wheatstone bridge configuration, a Hall sensor and equivalent sensing means.
The various embodiments described above can be combined to provide further embodiments. The embodiments may include structures that are directly coupled and structures that are indirectly coupled via electrical connections through other intervening structures not shown in the figures and not described for simplicity. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
REFERENCES
[1] “ Investigation on characteristics of ionization current in a spark - ignition engine fueled with gas - hydrogen blends with BSS de - noising method ”, Zhongquan Gao, et al., International Journal Of Hydrogen Energy-35 (2010), pages: 12918-12929;
[2] “ Method of Ion Current Detection for HCCI Combustion on SI/HCCI Dual Mode Engine ”, Guagyu Dong, et al., 978-1-4244-3504, 03/2009 IEEE;
[3] N. A. Henein, W. Bryzik, A. Abdel-Rehim and A. Gupta, “ Characteristics of Ion Current Signals in Compression Ignition and Spark Ignition Engines ” SAE, Warrendale, Pa., Tech. Rep. 2010-01-0567, 2010.
[4] A. A. Martychenko, J. K. Park, Y. S. Ko, A. A. Balin, J. W. Hwang, J. O. Chae, “ A Study on the Possibility of Estimation of In - Cylinder Pressure by Means of Measurement of Spark Gap Breakdown Voltage ”, SAE, Warrendale, Pa., Tech. Rep. 1999-01-1115, 1999.
[5] G. A Noble, C. R. Morganti, “Misfire detection in a spark ignition engine”, U.S. Pat. No. 5,492,007, 1995.
Having thus described at least one illustrative embodiment of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention is limited only as defined in the following claims and the equivalents thereto.
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The pressure in the combustion chamber of an electronically controlled spark plug ignition engine may be estimated in real time mode without specific sensors by processing sensed ionization current data to calculate features of the current waveform proven to be correlated to the pressure inside the engine cylinders and correlating them on the basis of a look up table of time invariant correlation coefficients generated through a calibration campaign of tests on a test engine purposely equipped with sensors. A mathematical model of the electrical and physical spark plug ignition system and combustion chamber of the engine is refined during calibration by iteratively testing the interactive performance of correlation coefficients of related terms of a mathematical expression of the model and comparing the expressed pressure value with the real pressure value as measured by a sensor.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan applications serial no. 90117176 and 90213278, filed Jul. 13, 2001 and Aug. 6, 2001.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a liquid crystal display (LCD) panel. More particularly, the present invention relates to a liquid crystal display panel with an esthetic design by printing a pattern on back and the fabricating method.
2. Description of Related Art
The LCD monitor has been a usual device equipped with a personal computer due to its small volume, light, low power consumption, and non-irradiation. Like the various commercial products, the personal computer requires more convenient and more humanistic function but also requires that the space be small and weight be light and even the appearance be more beautiful and rich in diversity of pattern. Since the plastic material is easy to be formed into desired shape, very plastic, and light, the plastic material is commonly used to form a housing of appliances. For a LCD panel, the house is usually also made of plastic material.
Referring to FIG. 1 and FIG. 2 , FIG. 1 is a front perspective view, illustrating a conventional LCD monitor. FIG. 2 is a back perspective view, illustrating the conventional LCD monitor in FIG. 1 . The conventional LCD monitor 100 basically includes a LCD panel 102 , such as the thin film transistor (TFT) LCD panel that currently is a main tendency. It has a front housing 104 and a back housing 106 to cover thereon. The front side of the LCD panel 102 has a displaying portion and the back side of the LCD panel has a portion of reflector or back light The front housing 104 does not only expose the displaying portion but also include multiple buttons 108 , so as to adjust the parameters, such as brightness and contrast. A voice hole (not shown) may even be included to allow the output of voice. The back housing 106 includes multiple thermal dissipation holes 112 , which can have the slit structure or circular holes. Usually, the front housing 104 and the back housing 106 include plastic material. Under the consideration of thermal dissipation, the back housing 106 has dissipation holes 112 and also needs to contain a part of wires. Thus, its shape is not regular and it is not easy to make the pattern by printing. As a result, the appearance cannot be beautified. The front housing 104 , the back housing 106 and the LCD panel 102 are installed on a base 110 . However, even though the plastic product can be easily fabricated, it is very difficult and complicated to beautify the housing by forming an esthetic pattern on its surface due to the appearance is not regular. In addition, the plastic housing cannot provide any protection of electromagnetic interference and would also affect the quality of the LCD monitor.
If a pattern is desired to be printed on a curving or concave surface of the plastic product, the conventional manner has to take processes of shifting printing, thermal transferring printing, or gluing a cover film. These manners have common disadvantages that the yield is low, fabrication process is complicated crinkle easily occurs, the printing net is not easy to be steadily located, and overdyeing is also difficult. It is quite difficult to apply the manners to the product needing a complicated color effect or pattern. For the commonly accepted product of LCD monitor, consumers always desire to have a specific pattern with colorful design. However, for this kind of need, the product currently has not been declared in the market. It is also in short for the corresponding fabricating process to solve the issues. In other words, the fabrication processes have to face the problems of high fabrication cost, low yield, limitation of color and style.
SUMMARY OF THE INVENTION
An objective of the invention is to provide an esthetic LCD monitor with a back cap on the backside of the LCD monitor, and allowing its surface to be designed with desired patterns. As a result, the appearance of the LCD monitor can be rich in design variety, so as to satisfy the designing trend in the future with a personal style.
Another objective of the invention is to provide an esthetic LCD monitor with metal back cap, so as to shield the electromagnetic interference, and also effectively maintain the thermal dissipation effect.
Further another objective of the invention is to provide a printing method on a sheeting element, which can be used on fabrication of a back cap of LCD monitor or a housing of personal computer. The sheeting element can be printed with various colorful patterns.
To at least achieve the foregoing objective, the invention provides an esthetic LCD monitor, including a liquid crystal display (LCD) panel having a. first surface and a second surface again to the first surface, in which the first surface includes a displaying portion. A front housing covers the first surface of the LCD panel and expose the displaying portion. A back housing covers the second surface of the LCD panel. A base is engaged with the back housing by, for example, a butt hinge, such that the angle of the LCD panel with respect to the base can be adjusted. A back cap has a generally planar outer surface. The back cap is disposed on the back housing, where the back cap includes a metallic material.
The back cap includes a plate body and a sidewall. The plate body has an outer appearance about conformal to the LCD panel and the about planar outer surface. The plate body includes metallic material. The sidewall abuts the rim of the plate body and is about perpendicular to the plate body, and is further suitable for use in connecting with an outer rim of the LCD monitor.
According to the preferred embodiment of the invention, the plate body and the sidewall are integrated in one body. The sidewall and the corresponding outer rim of the LCD monitor are respectively formed with a buckle connection structure. The plat body and/or the sidewall further includes at least one screw hole, suitable for affixing the back cap to the LCD monitor by a screw. The back cap includes aluminum, aluminum alloy, or magnesium alloy.
An outer surface of the back cap has a pattern. The pattern is formed by a surface printing method. The pattern can also be formed by an etching process to pattern the surface or a sand jet process to pattern the surface. The back cap of the LCD monitor of the invention can further include a plastic transparent cover, enclosing the outer surface of the back cap.
To at least achieve the foregoing objective, the invention provides a printing method on a sheeting element, which method can be applied to a screen back cap, an electric appliance housing, metal packaging housing, and housing for anti-radiation of electric appliance. The printing method on a sheeting plate includes providing a metal plate. A surface printing process is performed to form a pattern on the surface of the metal plate. Then, a protection film is adhered on the surface of the pattern of the metal plate. A drawing process is performed to draw the metal plate into a desired housing shape as a sheeting element.
According to a preferred embodiment of the invention, before the step of surface printing process, the invention further includes a surface film treatment. The surface film treatment includes performing sand jet treatment or etching treatment. Moreover, the metal plate includes aluminum, aluminum alloy, or aluminum-magnesium alloy. The protection film includes polyurethane (PU). The pattern with various colors can be achieved by performing a few steps of the plate printing process with respect to different colors.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
FIG. 1 is a front perspective view, illustrating a conventional LCD monitor;
FIG. 2 is a back perspective view, illustrating a conventional LCD monitor in FIG. 1 ;
FIG. 3 is an explosive drawing in perspective view, schematically illustrating an LCD monitor with esthetic back design, according to one preferred embodiment of this invention;
FIG. 4 is a back perspective view for the LCD monitor in FIG. 3 , according to one preferred embodiment of this invention; and
FIG. 5 is a process diagram, schematically illustrating the fabrication process to form a back cap for the LCD monitor, according to one preferred embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 3 and FIG. 4 , FIG. 3 is an explosive drawing in perspective view, schematically illustrating an LCD monitor with esthetic back design, according to one preferred embodiment of this invention. FIG. 4 is a back perspective view for the LCD monitor in FIG. 3 . The LCD monitor 200 include a screen body 210 and-a base 208 . The screen body 210 includes a front housing 202 , an LCD panel 204 , and a back housing 206 . The base 208 is engaged to the base by, a butt hinge 209 to form a holding part. The LCD panel 204 includes, for example, a thin film transistor (TFT) LCD panel. The front side 212 , which is the first surface, has a displaying portion 214 . The driver device 218 is located at the peripheral region of the-displaying portion 214 . The back side 216 , which is the second surface, has a portion for installing back light and reflector. The front housing 202 encloses the front side 212 of the LCD panel 204 but exposes the displaying portion 214 . The front housing 202 also includes multiple adjusting button 220 , used to adjust the screen setting parameters, such as brightness or contrast, or also installed with voice hole (not shown), used for exporting voice. The back housing 206 encloses the back side 216 of the LCD panel 204 and includes multiple thermal dissipation holes 222 like a slit hole, as shown in FIG. 3 or circular holes. The base 208 is engaged to the back housing 216 by, for example, a hinge or a multi-direction connector. This arrangement allows the adjustment of the screen body 210 with respect to the base 208 . The foregoing front housing 202 , back housing 206 and base 208 usually are made of plastic material.
The esthetic LCD monitor of the invention includes a back cap 230 , which includes a plate body 232 and a sidewall 234 , covers on the back housing 206 . The shape of the plate body 232 is designed according to the appearance of the screen body 210 conformal to the screen body 210 . The outer surface of the plate body 232 is generally planar, and forms the esthetic back, such as a printed color pattern 238 . The plate body 232 and the sidewall 234 can be formed by a metal with an integrated one body. It can also provide a good protection against electromagnetic interference. The back 230 is affixed to the screen body 210 by an affixing device. For example, screw holes 240 can be formed on the plate body 232 and/or the sidewall 234 . The back cap 230 is then affixed on the screen body by screws. Alternatively, the inner side of the sidewall 234 can be formed with a protruding part, and the rim of the back housing 206 can be formed with a concave part, whereby a buckle mechanism is achieved. Moreover, the protrusion structure can also be formed on the rim of the back housing 206 and the concave part is formed on the inner side of the sidewall 234 , whereby the purpose of the buckle mechanism is achieved. In addition to the affixing device, the skilled artisans should known that it still has many other affixing method, such as using rivets or bonding. The affixing method is not limited to the foregoing methods.
Further still, the back cap 230 can be additionally covered with transparent protection cover 250 , which can protect the pattern 238 on the back cap 230 from being scratched. Some other manners of semi-transparent or partial transparent portion can be applied to improve the esthetic view for the back pattern of the LCD monitor. The transparent protection cover 250 includes, for example, plastic material, which can be formed by drawing process.
However, to achieve the foregoing design for the esthetic back, the invention introduces a fabrication method for forming a back cap of the LCD monitor. FIG. 5 is a process diagram, schematically illustrating the fabrication process to form a back cap for the LCD monitor. In FIG. 5 , the back cap of the LCD monitor is formed by a metal plate with work. In step 300 , a metal plate is provided to serve as a substrate. The metal plate can include, for example, aluminum, aluminum alloy, or other metallic material. In step 302 , a surface film treatment is optionally performed. That is, a surface work as needed is performed on the surface of the metal plate desired to have the printed pattern, such as etching or sand jet treatment to obtain the more 3-dimensional view and more diversity for the pattern in the subsequent process. Alternatively, the surface film treatment can be optionally performed according to the actual design and need. The surface film treatment can even be omitted. Instead, a printing process is performed in the subsequent process on the clean surface of the metal plate.
Then, in step 304 , a surface printing process is performed on the metal plate. Since the surface of the metal plate is about planar in the current step, it is very suitable for performing the surface printing to directly print the patterns on the surface of the metal plate. If the color pattern is chosen, it can be achieved by performing multiple surface printing processes. For example, it can takes red, blue, yellow surface printings. After the color overdyeing, various color patterns can be obtained. Usually, the desired pattern is de-coupled in color into several basic colors, such as three or five, or even more, according to the actual color variation. The surface printing for each color is then performed and then the overdyeing printing is performed. As a result, a colorful pattern is achieved. Since the overdyeing in surface printing technique can be precisely controlled, the yield can be quite high. In addition, the formation of plate and the printing speed are fast, the cost is small. It is quite suitable for massive production. Moreover, due to the color separation, formation of plate, overdyeing all takes only a short time, it is also quite suitable for a small production but with variety.
Furthermore, in step 306 , a protection film can be optionally glued on the metal surface, on which a colorful pattern has be formed. The protection film includes, for example, polyurethane (PU) or other organic films. The purpose of the protection film is to protect the already printed pattern from being damaged in the subsequent process. Of course, the step 306 can associate with the surface printing results and the mold designs to decide whether or not the protection film is needed. Therefore, the step for adhering the protection film can be skipped. After then, in step 308 , a drawing process for formation is performed. The metal plate is drawn in formation to have the desired shape for the back cap of the LCD monitor. In step 310 , the final product is achieved. The drawing forming process can include one or more molds to perform drawing processes, according to the complexity of the LCD monitor. In addition, several needed assembling holes can also be formed, such as the screw holes. Moreover, in the step of surface plating process, the aligning marks used by the overdyeing operation cam also be used as the alignment point in the drawing forming process. This can assure the production yield to be high.
Even though the foregoing example uses the back cap of the LCD monitor as an example, the skilled artisans should know that the technique can be applied to any plate element, which can include aluminum, aluminum alloy, aluminum magnesium alloy, and so on. The application scope can be generally applied to the back cap of LCD monitor, housing of electric appliance, housing of personal computer, electric packaging box, or house for shielding electromagnetic interference (EMI). The method of the invention can be applied to related products with appearance design in more variety.
In summary, the invention at least includes the advantages as follows:
1. The LCD monitor with esthetic back additionally includes the back cap, which can be formed with various patterns on the surface by the surface printing associating with drawing formation. As a result, the LCD monitor can have various designs, so as to satisfy the trend for the personalized design in the future.
2. The LCD monitor with esthetic back additionally includes a metal back cap, which can provide the better protection of the electromagnetic interference, also and improve the practical and esthetic effect. Due to the good thermal conductivity for the metal material, and low thermal yield from the LCD monitor, the thermal dissipation can remain at a proper condition.
3. According to the fabrication method of the invention, the surface printing process can be performed before the sheeting plate is formed, whereby it improve the work ability for printing the pattern on the sheeting plate. At the same time, the invention also takes the surface printing, which can improve the production yield, reduce the fabrication cost, and be fabricated by massive production.
4. According to the fabrication method of the invention, after the pattern is printed on the metal plate, the protection film is adhered before performing drawing process. This manner can assure the pattern not to be damaged and can be applied to various appearance of the sheeting plate.
5. The invention with respect to various houses in different appliance provides a various choice of design in fabrication techniques. This can satisfy the trend of need of personal design in the future.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention covers modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
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An esthetic LCD monitor, including a liquid crystal display (LCD) panel having a first surface and a second surface against to the first surface, in which the first surface includes a displaying portion. A front housing covers the first surface of the LCD panel and expose the displaying portion. A back housing covers the second surface of the LCD panel. A base is engaged with the back housing in a butt hinge manner, such that the LCD panel with respect to the base in angle can be adjusted. A back cap has a about planar outer surface. The back cap is disposed on the back housing, where the back cap includes a metal material.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to surprisingly effective antimicrobial compositions suitable for use in the protection of paints, paint films, wood, wood composite products, leather, metal working fluids, mineral slurries, inks, dispersions and other products.
[0003] 2. Background of the Invention
[0004] Materials which can be degraded by microorganisms such as fungi, yeast, bacteria and algae include, for example, coatings, surfactants, proteins, inks, emulsions, resins, stuccoes, concretes, stones, woods (including wood-plastic composites), adhesives, caulks, sealants, and leathers. Aqueous latex paints; polymer dispersions containing polyvinyl alcohol, polyacrylates or vinylpolymers; thickener solutions containing cellulose derivatives, clay and mineral suspensions; and metal working fluids are also prone to degradation by the action of microorganisms. The degradation may produce, among other things, discoloration, odors, changes in pH values, and/or changes in rheological properties.
[0005] Generally, a composition in a smaller amount that provides the same antimicrobial activity is a superior product, as compared to other antimicrobial compositions. Ideally, these superior compositions should protect against a wide variety of problem microorganisms and remain effective for an extended period of time, without adversely affecting the product to be protected, the health of people who make or use the product, or the environment.
[0006] One approach to formulating compositions that require a smaller amount to provide the same antimicrobial activity is to employ biologically active ingredients which exhibit a synergistic effect when acting together. For example, U.S. Pat. No. 6,197,805, issued to Roger Errol Smith and assigned to the assignee of the present application, teaches that when 3-iodo-2-propynyl butyl carbamate and 2-(methoxycarbonylamino) benzimidazole are combined as active ingredients in a ratio which is greater than about 2 parts of the benzimidazole to about 1 part of the iodopropynyl compound, they form antimicrobial compositions which can exhibit synergy between the two active ingredients. U.S. Pat. No. 6,197,805 is hereby incorporated in its entirety, and particularly for its teachings regarding the use of 3-iodo-2-propynyl butyl carbamate and 2-(methoxycarbonylamino) benzimidazole as antimicrobial ingredients.
[0007] U.S. Pat. No. 6,416,789, issued to Brian Marks et al., describes a wood treatment material containing a synergistic combination of fungicides. The combination of the '789 patent is said to include boron-containing compounds such as zinc borate, organo-iodine compounds such as 3-iodo-2-propynyl butyl carbamate, and amine-oxides such as N-alkyl-N,N-dimethylamine oxide. The '789 patent reports that wood treated with the combination resists decay, mold and mildew. The '789 patent is silent regarding the use of 2-(methoxycarbonylamino) benzimidazole as a synergistic active ingredient.
[0008] U.S. Pat. No. 6,884,811, issued to Kazuhide Fujimoto, describes an industrial antifungal composition comprising synergistically effective amounts of iodo-2-propynyl butyl carbamate, 2-(methoxycarbonylamino) benzimidazole, and 4,5-dichloro-2-octyl-isothiazolin-3-one. The '805 patent reports that the composition is particularly useful when applied to wood and to paint. However, isothiazolin-3-ones are known to act as chemical sensitizers under some conditions. For this and other reasons, alternatives to the antifungal composition of the '811 are still needed.
[0009] Borates have long been used as broad-spectrum wood preservatives. They are effective against many types of fungi, termites and wood-boring beetles, and exhibit low acute mammalian toxicity and low environmental impact. Soluble borates such as boric acid, borax and disodium octaborate tetrahydrate are known as aqueous-based preservative systems for treating solid wood products for use in protected environments, such as interior building applications and painted external joinery. However, because they are readily leached from treated wood when exposed to moisture, soluble borates are not generally suitable for exterior or ground contact applications. Water-insoluble borate compounds which have been used as wood preservatives include zinc borate, calcium silicate borate, sodium silicate borate, aluminum silicate borate, hydroboracite, aluminum borate, copper borate, magnesium borate, and iron borate.
[0010] No single organic antimicrobial compound can provide protection against all microorganisms or is suitable for all applications. Chemical stability, toxicological profile, regulatory considerations, environmental concerns, physical properties or other characteristics may render a particular ingredient unsuitable for a particular use. Accordingly, there is a need to constantly develop new antimicrobial compositions that offer broad spectrum protection for a variety of needs.
SUMMARY OF THE INVENTION
[0011] The invention is an antimicrobial mixture comprising iodo-2-propynyl-butyl carbamate; 2-(methoxycarbonylamino)-benzimidazole; and a metal borate. Carriers may be employed to deliver the antimicrobial mixtures in liquid or pellet form. The invention is also a method for inhibiting microbial growth which employs the antimicrobial mixtures.
[0012] In a preferred aspect, the invention is a synergistic antimicrobial composition comprising 3-iodo-2-propynyl butyl carbamate, 2-(methoxycarbonylamino) benzimidazole, and a metal borate as biologically active ingredients. These active ingredients are present in the composition in proportions effective for three-component synergy. A resin carrier such as, for example, a porous polypropylene resin carrier, can serve as a convenient vehicle in pellet form for delivering the compositions.
[0013] The antimicrobial compositions of the invention exhibit biological activity for inhibiting the growth of fungus, such as Aspergillus niger, Aureobasidium pullulans, Alternaria alternata and Penicillium sp., among others. Against these and other fungi, the antimicrobial composition exhibits a relatively favorable minimum inhibitory concentration, as compared to that of the individual active ingredients, and as compared to that of pairs of the active ingredients.
[0014] In another preferred aspect, the invention is a three-component synergy antimicrobial mixture comprising iodo-2-propynyl-butyl carbamate, 2-(methoxycarbonylamino)-benzimidazole, and zinc borate, which exhibits a minimum inhibitory concentration of less than about 4 ppm against various fungi.
[0015] In other preferred aspects, the invention is a method for protecting a substrate (such as a wood, a metal working fluid, a paint or a dry film coating) from fungal infestation, and a method for making polymeric materials and wood-plastic composites that are resistant to fungal infestation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a triangular coordinate graph showing the mass proportions of 3-iodo-2-propynyl butyl carbamate (IPBC), 2-(methoxycarbonylamino) benzimidazole (BCM) and zinc borate (ZB) which exhibit minimum inhibitory concentrations (MIC) of less than 1 ppm, equal to 1 ppm, and greater than 1 ppm against a fungus known as Aspergillus niger ; and
[0017] FIG. 2 is a triangular coordinate graph showing the mass proportions of IPBC, BCM and zinc borate which exhibit MIC of less than 4 ppm, equal to 4 ppm, and greater than 4 ppm against Aspergillus niger.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] When one or more propynyl carbamates such as 3-iodo-2-propynyl butyl carbamate (hereinafter referred to as “IPBC”) is combined with one or more benzimidazoles such as 2-(methoxycarbonylamino) benzimidazole (hereinafter referred to as “BCM”) and one or more metal borates such as zinc borate (hereinafter referred to as “ZB”) in proportions effective for biological multi-component synergy, a surprisingly effective antimicrobial composition is produced. The effective proportion for each of the components is determined against microbes of interest by methods which are described below.
[0019] IPBC, BCM and ZB compositions of the invention offer a number of advantages which are both novel and unexpected in a variety of applications. It has been found that IPBC, BCM and ZB complement one another in these compositions in ways that could not have been anticipated.
[0020] The antimicrobial compositions of the invention provide a desirable level of activity over a useful period of time. Under certain conditions, the antimicrobial compositions of the invention exhibit activity that is hereinafter referred to as three-component synergy. For the present purposes, “three-component synergy” means the property of a composition having three biologically active ingredients that enables the composition to achieve a given biological effect using less of the three ingredients than would be expected based on the amounts of the individual ingredients separately required to produce the biological effect.
[0021] The three-component synergy of the invention makes it particularly effective against various fungi which are encountered indoors and outdoors. In practice, anti-fungal compositions are often called upon to protect against one or more unidentified fungus that are encountered in a particular application. To the extent that fungal growth as a whole is inhibited in the particular application, the antifungal composition is considered successful. The identity of the inhibited fungi may remain undetermined.
[0022] The invention has been found effective against a number of precisely identified fungi in the laboratory, and effective against unidentified microbes in tests conducted outdoors. Without intending to limit the scope of the invention in any way, it is expected that the invention will inhibit the growth of Aspergillus niger, Aureobasidium pullulans and Penicillium sp. (widely spread surface fungi and indoor contaminants); Gleophyllum trabeum, Poria placenta, Coniophora puteana , and Lentinus lepideus (associated with brown rot); Serpula lacrymans and Poria incrassate (associated with dry rot); and Coriolus versicolor and Pleurotus ostreatus (associated with white rot).
[0023] IPBC is a widely used fungicide/antimicrobial known as a preservative in paint, adhesives, emulsions, metal cutting fluids, oil recovery drilling mud/packer fluids, plastics, textiles, inks, paper coatings, and wood products. It is also used in residential settings as a wood preservative stain to combat wood rot/decay, and as a preservative in paints. IPBC is also applied to heating, ventilation, and air conditioning ducts and equipment to control mold and fungi.
[0024] The iodopropynyl compounds of the invention are known and generally referred to as iodopropynyl carbamates or carabamic acid esters of the following formula:
[0000]
[0025] wherein R may have one to three linkages corresponding to n and is selected from the group consisting of hydrogen, substituted and unsubstituted alkyl groups having from 1 to 20 carbon atoms, substituted and unsubstituted aryl, alkylaryl, and aralkyl of from 6 to 20 carbon atoms or cycloalkyl and cycloalkenyl groups of from 3 to 10 carbon atoms, and
m and n are independently integers from 1 to 3.
[0027] Particularly preferred are formulations of these iodopropynyl carbamates where m is 1 and n is 1, and which have the following formula:
[0000]
[0028] Suitable R substituents include alkyls such as methyl, ethyl, propyl, n-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, and octadecyl; cycloalkyls such as cyclohexyl; aryls, alkaryls and aralkyls such as phenyl, benzyl, tolyl, and cumyl; halogenated alkyls and aryls, such as chlorobutyl and chlorophenyl; and alkoxy aryls such as ethoxyphenyl and the like.
[0029] Especially preferred are such iodopropynyl carbamates as 3-iodo-2-propynyl propyl carbamate, 3-iodo-2-propynyl butyl carbamate, 3-iodo-2-propynyl hexyl carbamate, 3-iodo-2-propynyl cyclohexyl carbamate, 3-iodo-2-propynyl phenyl carbamate, and mixtures thereof. The preferred and most widely used among these compounds is 3-iodo-2-propynyl butyl carbamate (IPBC).
[0030] Examples of compounds which may be used as the iodopropynyl compound of the invention are reported in U.S. Pat. Nos. 3,923,870; 4,259,350; 4,592,773; 4,616,004; 4,719,227; and 4,945,109, which are hereby incorporated by reference in their entirety, and in particular for their teachings regarding the manufacture and use of iodopropynyl carbamates such as 3-iodo-2-propynyl butyl carbamate.
[0031] BCM is a widely used broad-spectrum benzimidazole fungicide. The IUPAC name for BCM is methyl N-(1H-benzoimidazol-2-yl)carbamate. It has a CAS Registry Number of 10605-21-7. BCM is also known as Mercarzole or Carbendazole. The chemical formula of BCM is:
[0000]
[0032] As a third component, the compositions of the invention include have a fungicidal boron compound which may be, for example, an alkali metal borate, an alkali metal borate, an amine borate, a boric acid, or a boric ester. Of these fungicidal boron compounds, metal borates are preferred. More preferably, the third component is calcium silicate borate, sodium silicate borate, aluminum silicate borate, hydroboracite, aluminum borate, copper borate, magnesium borate, iron borate, or zinc borate. Copper borate, iron borate and zinc borate are most preferred for use as the third component, and zinc borate is especially preferred.
[0033] For the present purposes, “metal borate” means a fungicidal metal borate compound selected from the group consisting of metal borate, the corresponding basic, dibasic, tribasic and polybasic metal borate(s), and mixtures thereof. For example, “zinc borate” means a fungicidal zinc borate compound selected from the group consisting zinc borate (ZnB 4 0 7 ), any of its the corresponding basic zinc borates (such as monobasic zinc borate of the structure Zn(OH).B 4 0 7 , dibasic basic zinc borate of the structure 2Zn(OH) 2 .B 4 0 7 , tribasic zinc borate of the structure 3Zn(OH) 3 .B 4 0 7 ) and the like), and mixtures thereof. As another example, “copper borate” means a fungicidal copper borate compound selected from the group consisting copper borate (CuB 4 0 7 ), any of its the corresponding basic copper borates (such as monobasic copper borate of the structure Cu(OH).B 4 0 7 , dibasic basic copper borate of the structure 2Cu(OH) 2 .B 4 0 7 , tribasic copper borate of the structure 3Cu(OH) 3 .B 4 0 7 ) and the like), and mixtures thereof. The metal borate may include more than one metal.
[0034] In the invention, the antimicrobial mixture can be a component of a final formulation for use in applications such as paints, coatings, exterior insulation and finish systems, stucco, wood preservative coatings, wood-plastic composites, adhesives, mineral slurries, leather finishes, wet blue hides, dispersions, emulsions, aqueous materials, optical brighteners, oil field chemicals, inks, caulking, sealants, textiles, and the like, in a broad range from about 0.004 mass % to 10 mass % active concentration. The final formulation can be prepared from more highly concentrated compositions of the active ingredients by appropriate dilution. The preferred range for combined active ingredients in the final formulation range is about 0.01 mass % to about 4 mass %, more preferably about 0.1 mass % to about 2 mass %. The final formulation can protect aqueous substrates against microbial growth for extended periods of time
[0035] Compositions of the invention will generally be formulated by mixing or dispersing the active ingredients in selected proportions with a liquid vehicle for dissolving or suspending the active components. The vehicle may contain a diluent, an emulsifier and a wetting-agent. The compositions of the invention may be provided as wettable powders; liquid mixtures such as dispersions, emulsions, microemulsions; or any other suitable form.
[0036] In a preferred embodiment of the invention, a resin carrier such as, for example, a porous polypropylene resin carrier, can serve as a convenient vehicle in pellet form for delivering the antifungal composition. The resin carrier may be utilized in solid or liquid form. Other materials which may be employed as the resin carrier include acrylic polymers, vinyl ether polymers, polystyrene-butadiene polymers, polyesters (including polyesters modified with fatty acids), polyureas, and ethylene vinyl alcohol copolymers, among others. The resin carrier and antifungal composition of the invention may be extruded as part of a process for manufacturing wood-plastic composites or other polymer-containing or polymeric products.
[0037] When preparing formulations of the invention for specific applications, the composition may include adjuvants conventionally such as organic binding agents, additional fungicides, auxiliary solvents, processing additives, fixatives, plasticizers, UV-stabilizers or stability enhancers, water soluble or water insoluble dyes, color pigments, siccatives, corrosion inhibitors, anti-settling agents, anti-skinning agents and the like.
[0038] Treating substrates with a composition of the invention can protect them from microbial attack. The protective treatment may involve mixing the composition with the substrate, coating the substrate with the composition, or otherwise contacting the substrate with the composition. In a preferred aspect, the invention is a method for protecting a substrate from fungal infestation. The method includes treating the substrate with a fungicidally inhibiting amount of a composition comprising (a) 3-iodo-2-propynyl-N-n-butylcarbamate, (b) 2-(methoxycarbonylamino) benzimidazole, and (c) zinc borate. Components (a), (b), and (c) are present in the composition in a proportion that exhibits three-component synergy.
[0039] In still another preferred embodiment, the invention is a method for inhibiting the growth of fungi in a metal working fluid. In the method, (a) 3-iodo-2-propynyl-N-n-butylcarbamate, (b) 2-(methoxycarbonylamino) benzimidazole, and (c) zinc borate are added to a metal working fluid. The resulting combination is a protected metal working fluid in which components (a), (b) and (c) are present in a proportion that exhibits a three-component synergy. If one or more fungi are subsequently permitted to contact the protected metal working fluid, the growth of the fungi will be inhibited.
[0040] In yet another preferred aspect, the invention is a method for making a polymeric material that is resistant to the growth of fungi. Components (a) 3-iodo-2-propynyl-N-n-butylcarbamate, (b) 2-(methoxycarbonylamino) benzimidazole, and (c) zinc borate are incorporated in the polymeric material. For example, the components may be adsorbed, absorbed, or dissolved in a resin carrier, and that the resin carrier containing the components may be is co-extruded with a selected polymer. The resulting polymeric material contains (a), (b) and (c) in proportions which enable the material to exhibit three-component synergy.
[0041] Alternatively, the selected polymer and the resin carrier containing the active components can be co-extruded on wood and with wood particles to produce a wood-plastic composite. The wood-plastic composite so produced includes 3-iodo-2-propynyl-N-n-butylcarbamate, 2-(methoxycarbonylamino) benzimidazole, and zinc borate in proportions effective for three-component synergy and resists fungal growth.
[0042] In still yet another preferred aspect, the invention is a method for inhibiting the growth of fungi in a dry film coating. The method includes adding (a) 3-iodo-2-propynyl-N-n-butylcarbamate, (b) 2-(methoxycarbonylamino) benzimidazole, and (c) zinc borate to a film-forming coating precursor. The coating precursor is exposed to an oxygen-containing gas to form a dry film coating. The dry film coating contains (a), (b), and (c) in proportions that enable the dry film coating to exhibit three-component synergy.
[0043] In any of the embodiments or aspects of the invention described above, the three-component synergy composition may be delivered in a resin carrier, preferably a carrier in solid pellet form. Most preferably, the resin carrier is composed of polypropylene polymers, acrylic polymers, vinyl ether polymers, polystyrene-butadiene polymers, polyesters (including polyesters modified with fatty acids), polyureas, and ethylene vinyl alcohol copolymers, among others. The resin carrier and the three-component synergy composition may be extruded as part of a process for manufacturing wood-plastic composites or other polymer-containing or polymeric products.
[0044] A method for assessing synergy of a multi-component mixture having biologically active components is described in a technical article by M. C. Berenbaum entitled “Synergy, additivism and antagonism in immunosuppression”, which was published in the Journal of Clinical Experimental Immunology. See Clinical Exp. Immunol. 28, p. 1-18 (1977). The method is appropriate for quantitatively demonstrating the three-component synergy of the invention.
[0045] In the method, the dose of each agent which provides a synergistic or antagonistic effect in the overall biological effect of a mixture against a particular organism is expressed as a fraction of the dose that causes the effect when the respective agent is tested alone (hereinafter referred to as “dose of X/X e ”, “Fractional Inhibitory Concentration of agent X” or “FIC X ”). If the sum of the FIC X 's for a combination of active ingredients in a mixture is 1, the combination is additive in its effect. If the sum is less than one, the combination is synergistic. If the sum is greater than one, the combination is antagonistic. The general relationship (which may be an equality or an inequality) expressed for multi-component mixtures of biologically active components is herein designated Equation 1, as follows:
[0000]
dose
of
A
/
A
e
+
dose
of
B
/
B
e
+
dose
of
C
/
C
e
+
...
dose
of
X
/
X
e
=
{
<
1
for
synergy
1
for
additivism
>
1
for
antagonism
[0046] In order to apply the Berenbaum method to compositions of the invention, mixtures of fungicidal agents are prepared. The fungicidal activity of each of the mixtures is determined and expressed in terms of a minimum inhibitory concentration, which is just sufficient to inhibit the growth of a given microbe (hereinafter referred to “MIC”) for each of the mixtures. These MICs are subsequently used to calculate FIC X for each agent X of a particular mixture. All of the FIC X 's for each mixture (also known as the doses of X/X e for the mixture) are summed, and the criteria for synergism, additivism and antagonism (as set forth above in Equation 1) are used to assess the mixture.
[0047] Practitioners will appreciate that experimental data, such as the data described above with respect to Equation 1 above, may also be employed as input data for polynomial mixture models which mathematically interpolate and extrapolate the experimental data for the purpose of predicting biological effects associated with the various mixtures of the biologically active components. Known methods of experimental design are employed to be certain that sufficient information is input to support a reliable mixture model prediction. For example, methods of experimental design are described in a technical article by Ronald D. Snee entitled “Design and Analysis of Mixture Experiments”, which was published at pages 159-169 of the Journal of Quality Technology Vol. 3, No. 4, October 1971.
[0048] The following examples are presented to explain the invention, and are not intended to limit the scope of invention in any way. Unless otherwise indicated, all references to parts and percentages are based on mass.
EXAMPLES
Example 1
Preparation of Wood-Plastic Composite Panels Including Biocides
[0049] Several candidate biocides were tested in a typical WPC formulation, which is presented below in Table I.
[0000]
TABLE I
Formulation of Wood-Plastic Composite
Ingredient
Description
mass %
Petrothene ® LB 0100-00 Plastic
high density polyethylene
35.4
from Equistar.
Ponderosa Pine Wood Flour
60 mesh
60.0
from American Wood Fiber
Glycolube ® WP 2200 Lubricant
amide-based,
2.0
from Lonza
stearate-free
Tinuvin ® 783 FDL
oligomeric Hindered
0.3-0.34
from Ciba
Amine Light Stabilizer
Grey Pigment 191130
none
1.0-2.0
From Ampacet
Irganox 1010 and Irganox
thermal stabilizers
0.3
Antioxidants
present in 2:1 ratio
from Ciba
Biocide
see Table II, below 2
0.22-5.5 1
Note 1:
Total of ingredients in formulation is 100 mass %. Differences in the mass of an additive ingredient or a biocide ingredient in a particular formulation are compensated by varying Plastic and Wood Flour proportionally.
Note 2:
The biocide ingredients are described below in Table II.
[0050] WPC panels for evaluation were prepared by blending the above ingredients in a drum mixer for 30 to 35 minutes at 30 to 40 rpm and then processing the resulting mixture through a Tek Milacron extruder. This extruder is a twin-screw counter rotating conical unit having four temperature zones, for a total heated length of ten feet (3.0 m), and a 3.38 inch (86 mm) die at the exit. The temperature of extrusion was in the range of 340 to 350 degrees F. (171 to 177 degrees C.) and the WPC boards so produced had dimensions of about 5 feet (152 cm)×5½ inches (14 cm)×1 inch (2.5 cm). The WPC boards were subsequently cut into panels of one foot (30 cm) length.
Example 2
Outdoor Testing of Wood-Plastic Composite Panels Including Biocides
[0051] Wood-plastic composite panels incorporating various biocides were prepared in accordance with the procedure set forth above in Example 1. The panels were evaluated for mildew growth by being exposed to the weather outdoors in Miami, Fla. for one year under a protocol publicly known as ASTM D 3274-94 of ASTM International (originally known as the American Society for Testing and Materials).
[0052] For the purposes of this evaluation, any biocide or combination of biocides which prevents moderate (or worse) mildew growth for an outdoor exposure period of at least 9 months is considered to have passed the weathering test. The results of the evaluation are shown below in Table II.
[0000]
TABLE II
Outdoor Exposure Evaluation Results
Mass %
Biocide
(Mass
Mildew Growth 1
Eval.
%
3
6
9
12
No.
Biocide
Active)
Months
Months
Months
Months
1
Blank (no
0 (0)
10
8
6
6
biocide)
2
8.3% IPBC 2
5.34
10
9
2
5
(0.44)
3
40% IPBC
0.5
7
0
2
2
(0.2)
4
98% BCM 3
0.2
5
1
2
4
(0.2)
5
99% Zinc Borate
4.0
8
2
6
5
(4.0)
6
Captan
0.22
9
1
2
4
(0.22)
7
Chlorothalonil
0.2
9
2
0
3
(0.2)
8
Folpet
0.23
10
2
0
0
(0.23)
9
Irgaguard F-3000
0.2
8
2
2
2
(0.2)
10
10% IPBC + 75%
0.28
9
6
3
4
BCM
(0.23)
11
10% IPBC + 67%
0.53
9
1
0
4
ZB
(0.41)
12
15% IPBC + 50%
0.8
10
2
2
6
ZB
(0.52)
13
75% BCM + 25%
0.22
2
2
0
5
ZB
(0.22)
14
75% BCM + 25%
0.29
8
5
4
4
Chorothalonil
(.29)
15
4% IPBC + 50%
0.82
10
9
8
9
BCM + 25% ZB
(0.65)
16
4% IPBC + 50%
1.63
10
10
10
10
BCM + 25% ZB
(1.29)
Note 1: The extent of Mildew Growth on each of the panels was visually assessed by applying the following criteria.
10 - No mildew growth
9 - Very slight growth
8 - Slight (very good)
7 - Some growth (good)
6 - Moderate growth (considered a failure)
4 - Pronounced growth
2 - Severe growth
0 - Very severe growth
Note 2: IPBC means 3-iodo-2-propynyl n-butylcarbamate
Note 3: BMC means methyl-N-benzimidazol-2-ylcarbamate
Note 3: ZB means zinc borate
[0053] Inspection of Table II reveals that, when tested individually at the indicated doses, all of the biocides failed to meet the goal of preventing moderate (or worse) mildew growth for at least 9 months outdoors. Additionally, the results of Evaluations 10-14 in Table II demonstrate that all of the pairs of biocides tested at the indicated doses failed to meet this goal.
[0054] In contrast, the panels protected by biocides containing 4% IPBC+50% BCM+25% ZB (designated Evaluations 15 and 16 in Table II) were consistently assessed as “10—No mildew growth”, “9—Very slight growth” or “8—Slight (very good)” throughout twelve months of outdoor exposure to Florida weather. The data in Table II demonstrates that a combination of IPBC, BCM and ZB provides effective and long-lasting protection against microbial growth.
Example 3
Synergistic Effects with Respect to Fungus Aspergillus niger
[0055] Minimum Inhibitory Concentrations (hereinafter referred to as “MIC”) for various mixtures of biocides were determined against spore suspensions of the fungus Aspergillus niger , also known as ATCC 6275 (hereinafter referred to as “ A. niger ”). The determinations were performed with the aid of an Autoplate 4000 spiral plater, which is commercially available from Spiral Biotech, Inc. of Norwood, Mass.) and appropriate spiral gradient endpoint software (hereinafter referred to as “SGE software”). The spiral plater and SGE software are not a part of the invention nor are they essential for demonstrating its utility. The spiral plater and SGE software conveniently facilitate the performance of a well-known serial dilution method for determining MICs.
[0056] Spore suspensions for the test fungus were prepared by growing Aspergillus niger on a Difco malt agar slant in an incubator for one week at 28 degrees C. Spores were loosened by adding a small amount of buffer solution at pH 7.0 and scraping with a sterile nichrome wire loop. This process was repeated twice. The buffer solution included phosphate buffer and magnesium chloride, and was obtained commercially from Thomas Scientific Company, as Lot # 023-0703.
[0057] Loosened spores were removed from the slant by aseptically pouring them into a sterile bottle containing 30 ml of the buffer solution and a volume of approximately 40 ml of 6 mm diameter borosilicate glass beads. The bead bottle was shaken to disperse the spores and adjusted to a final liquid volume of 50 ml. For use as a test inoculum, spore density was adjusted in distilled water blanks to that of a 0.5 McFarland nephelometer standard.
[0058] The Autoplate 4000 automatically applied 54.3 micro-liters of each biocide mixture to the surface of 150 MM malt agar plates using an exponential application gradient. Fungicide concentration was heaviest near the center of the Petri plates and decreased toward the edges. Fungicide gradients were allowed to air dry at room temperature for 1 to 4 hours at 23° C. before inoculation with fungi. Spiral gradient plates were inoculated by streaking with sterile cotton swab applicators that had been soaked in test fungus spore suspension. These streaks were applied in a radial pattern, using a paper template generated by the SGE software to guide the application. Four radii were inoculated per Petri plate. Each radius is considered as one replicated observation and is referred to herein as a “replication”. Four plates were tested in each evaluation, for a total of twelve of twelve replications per evaluation.
[0059] Inoculated spiral gradient plates were incubated for 48 hours in an incubator at 28° C. Visible growth of the test fungus developed along the radial streaks and ended where the concentration of biocide was sufficient to prevent growth. This growth endpoint value (expressed in mm as measured from center point of the Petri plate) was used by the instrument's computer software to determine MIC for the test mixture, expressed as parts per million (ppm) of active fungicide.
[0060] Twelve biocide mixtures, each including IPBC, BCM and/or zinc borate, were prepared for MIC determination with respect to A. niger . In those of the mixtures which required a solvent, dimethyl sulfoxide, dimethylformamide (also known as N,N-dimethylmethanamide) or DBE-2 was included as the solvent. “DBE-2” means a dibasic ester fraction, commercially available from Invista, which includes dimethyl adipate and dimethyl glutarate and is essentially free of dimethyl succinate. These solvents were shown by other procedures to have no inhibiting effect on A. niger.
[0061] The proportions of biologically active material in the twelve mixtures, each corresponding to a unique Mixture No. and hereinafter referred to as an “evaluation”, are presented below in Table III. The proportions are set forth in units of mass percent active material, based on the total active material in the biocide mixture. The MIC listed for each of the Mixtures in Table III is the concentration which is just sufficient to produce the effect of inhibiting growth of A. niger , based on the mean average of twelve replications. In order to demonstrate reproducibility, some of the evaluations have the same active material proportions as others of the evaluations.
[0000]
TABLE III
Biocide Mixtures for Determining MIC against A. niger
IPBC mass %,
BCM mass %,
ZB mass %,
based on
based on
based on total
MIC ppm,
total active
total active
active
average of
Mixture
material in
material in
material in
spiral plater
No.
the mixture
the mixture
the mixture
replications
1
100
0
0
0.7
2
0
100
0
3.5
3
0
100
0
1.7
4
0
0
100
12
5
0
50
50
2.0
6
50
0
50
0.7
7
50
50
0
1.3
8
66.7
16.7
16.7
0.8
9
16.7
66.7
16.7
1.9
10
16.7
16.7
66.7
1.9
11
33.33
33.33
33.33
1.0
12
33.33
33.33
33.33
0.6
[0062] Inspection of Table III indicates that the MICs for pure IPBC, BCM and ZB are 0.7 ppm (Mixture No. 1), 2.6 ppm (average of values for Mixtures No. 2 and 3) and 12 ppm (Mixture No. 4), respectively. The MICs for binary mixtures including equal mass of BCM and ZB (Mixture No. 5), IPBC and ZB (Mixture No. 6), and IPBC and BCM (Mixture No. 7) are 2.0 ppm, 0.7 ppm, and 1.3 ppm, respectively. While Mixtures No. 1-7 are not of the invention, their MICs and those of Mixtures No. 8 through 12 (which are of the invention) were used to establish whether a particular mixture is synergistic, additive or antagonistic, in accordance with criteria set forth in a technical article by M. C. Berenbaum which was published in the journal of Clinical & Experimental Immunology, Volume 28, pages 1-18 (1977).
[0063] As explained above, “multi-component synergy” means synergy which enables a composition having three or more mutually synergistic ingredients to achieve an effect that is greater than the additive effect of the individual ingredients.
[0064] For mixtures having three active materials, the above described Equation 1 reduces to the following the relationship (which may be an equality or an inequality), herein designated Equation 2, as follows:
[0000]
dose
of
A
/
A
e
+
dose
of
B
/
B
e
+
dose
of
C
/
C
e
=
{
<
1
for
synergy
1
for
additivism
>
1
for
antagonism
where A e , B e and C e are the doses of samples A, B and C which respectively produce the same effect (also known as “equi-effective doses”).
[0066] In the following Examples, the effect is inhibition of fungal growth and IPBC e , BCM e and ZB e are the doses of samples of IPBC, BCM and ZB, respectively, which are just sufficient to inhibit fungal growth. Modifying Equation 2 to reflect these circumstances produces Equation 3, as follows:
[0000]
dose
of
IPBC
/
IPBC
e
+
dose
of
BCM
/
BCM
e
+
dose
of
ZB
/
ZB
e
=
{
<
1
for
synergy
1
for
additivism
>
1
for
antagonism
[0067] For convenience, the “dose IPBC/IPBC e ” will hereinafter be referred to as the “Fractional Inhibitory Concentration of IPBC” and written as “FIC IPBC ”. Similarly, the “dose of BCM/BCM e ” will be written as “FIC BCM ”, and the “dose of “ZB/ZB e ” will be written as FIC ZB .
[0068] By way of illustration, the calculation of FIC IPBC for Mixture No. 8 follows.
[0069] 1) The definition for “dose of IPBC/IPBC e ” is expressed in mathematical form and hereby designated Equation 3:
[0000] dose of IPBC/IPBC e =(IPBC mass % of Mixture No. 8)(concentration of Mixture No. 8 required to achieve inhibition effect)/(100 mass %) (concentration of IPBC sample required to achieve inhibition effect)
[0070] 2) MIC (also known as Minimum Inhibitory Concentration) is defined as the concentration of a particular mixture which is just sufficient to inhibit growth of a given microbe. In the special case of a mixture which contains IPBC as the only biologically active ingredient, MIC IPBC for that mixture is equal to IPBC e .
[0071] 3) By inspection of Table III, (IPBC mass % of Mixture No. 8) is (66.7 mass %) and MIC of Mixture No. 8 is (0.8 ppm). Because IPBC is the only active ingredient in Mixture No. 1, IPBC e has the same value as the MIC for Mixture No. 1, which Table III shows as 0.7 ppm.
[0072] 4) Inserting these values from Table III into Equation 3 produces:
[0000]
dose
of
IPBC
/
IPBC
e
=
(
66.7
mass
%
)
(
0.8
ppm
)
(
100
mass
%
)
(
0.7
ppm
)
=
0.763
[0073] 5) In accordance with popular practice, “dose of IPBC/IPBC e ” will hereinafter be referred to as “Fractional Inhibitory Concentration of IPBC” or “FIC IPBC ”. For example, Table IV below shows FIC IPBC as 0.763, which is the value calculated above for the dose of IPBC/IPBC e .
[0000]
TABLE IV
Synergy of Biocidal Mixtures against A. niger
Sum of FIC's
Synergistic,
for the
Additive or
Mixture No.
FIC IPBC
FIC IPBC
FIC IPBC
mixture
Antagonistic
8
0.763
0.051
0.011
0.825
Synergistic
9
0.453
0.487
0.026
0.966
Synergistic
10
0.453
0.122
0.106
0.681
Synergistic
11
0.471
0.127
0.028
0.626
Synergistic
12
0.283
0.076
0.017
0.376
Synergistic
[0074] Mixtures No. 8 through 12 of Table IV are mixtures of the invention. Table IV quantitatively communicates the effect of these mixtures on A. niger . Inspection of Table IV confirms that mixtures of the invention exhibit a three-component synergy between IPBC, BCM and ZB against A. niger.
Example 4
Mixture Ratios of Equal MIC Against Aspergillus niger
[0075] The data of Table III and Table IV, above, is utilized as input to a commercially available computer program which calculates the mass proportions of three-active component systems consistent with various MIC values. Triangular coordinate graphs of the three-active component system IPBC-BCM-ZB with isograms indicating proportions of equal MIC against A. niger are generated from the data by the program.
[0076] FIG. 1 and FIG. 2 of the drawings depict triangular coordinate graphs having isograms which indicate mixture ratios consistent with 1 ppm MIC and 4 ppm MIC, respectively, against A. niger . In these triangular coordinate graphs, the proportions are based on the total mass of 3-iodo-2-propynyl butyl carbamate, 2-(methoxycarbonylamino) benzimidazole, and zinc borate. The proportions of these actives ingredients total 100 mass %. Additional, inert ingredients are also present in the compositions.
[0077] Inspection of FIG. 1 reveals that the proportions of 3-iodo-2-propynyl butyl carbamate, 2-(methoxycarbonylamino) benzimidazole, and zinc borate for compositions of the invention having MIC of about 1 ppm or less against A. niger are within a parabolic-shaped isogram. These proportions are generally within the interior of triangle A-B-C, which is shown in FIG. 1 . The vertices of triangle A-B-C correspond to the following proportions: A is 100 mass % 3-iodo-2-propynyl butyl carbamate, 0 mass % 2-(methoxycarbonylamino) benzimidazole, and 0 mass % zinc borate; B is 0 mass % 3-iodo-2-propynyl butyl carbamate, 72 mass % 2-(methoxycarbonylamino) benzimidazole, and 28 mass % zinc borate; and C is 47 mass % 3-iodo-2-propynyl butyl carbamate, 0 mass % 2-(methoxycarbonylamino) benzimidazole, and 53 mass % zinc borate. All of the points within the interior of triangle A-B-C correspond to highly preferred compositions of the invention.
[0078] For the present purposes, “proportion” with respect to one of the biologically active materials of the invention means the mass of the biologically active materials divided by the sum of the masses of all of the biologically active materials, expressed in units of mass %.
[0079] Inspection of FIG. 2 , in light of the data shown Table III and Table IV, reveals that the isogram for MIC approximates a straight line from D to E. D corresponds to the proportions 0% IPBC, 33% BCM and 67% ZB. E corresponds to the proportions 28 IPBC, 0 BCM and 72% ZB. Therefore, that MIC is about 4 ppm or less against A. Niger for various compositions of the invention in which the proportion of zinc borate is less than about 67 mass %. These compositions are very preferred embodiments of the invention.
[0080] For the present purposes, “the proportion of zinc borate” means the mass of zinc borate by the sum of the masses of 3-iodo-2-propynyl-N-n-butylcarbamate, 2-(methoxycarbonylamino) benzimidazole, and zinc borate, expressed in units of mass %.
Example 5
Synergistic Effects with Respect to Fungus Aureobasidium pullulans
[0081] The procedure for determining MICs, as set forth above in Example 3, was performed again except that this time spore suspensions of the fungus Aureobasidium pullulans , also known as ATCC 9348 (hereinafter referred to as “ A. pullulans ”) were utilized instead of A. niger.
[0082] Twelve biocide mixtures, each including IPBC, BCM and/or zinc borate, were prepared for MIC determination with respect to A. pullulans . The proportions of biologically active material in the twelve mixtures, each corresponding to a unique Mixture No. and referred to as one evaluation, are presented below in Table V. The MIC listed for each of the Mixtures in Table III is the concentration which is just sufficient to produce the effect of inhibiting growth of A. pullulans , based on the mean average of twelve replications. As explained above, some of the evaluations have the same active material proportions as others of the evaluations in order to demonstrate reproducibility.
[0000]
TABLE V
Biocide Mixtures for Determining MIC against A. pullulans
IPBC mass %,
BCM mass %,
ZB mass %,
based on
based on
based on
MIC ppm,
total active
total active
total active
average of
Mixture
material in
material in
material in
spiral plater
No.
the mixture
the mixture
the mixture
replications
1
100
0
0
0.35
2
0
100
0
2.03
3
0
100
0
1.63
4
0
0
100
>1000
5
0
50
50
1.7
6
50
0
50
1.63
7
50
50
0
1.87
8
66.7
16.7
16.7
0.68
9
16.7
66.7
16.7
0.78
10
16.7
16.7
66.7
1.47
11
33.3
33.3
33.3
0.53
12
33.3
33.3
33.3
0.53
[0083] While Mixtures No. 1-8 of Table V are not of the invention, their MICs and those of Mixtures No. 9 through 12 (which are of the invention) were used to determine whether a particular mixture is synergistic, additive or antagonistic using the mathematical method set forth above. The results of this determination are set forth below in Table VI.
[0084] Mixture No. 4 in Table V, which contains zinc borate as its only biologically active material, exhibited little or no inhibition against A. pullulans . The MIC of “>1000” shown above in Table V for Mixture No. 4 is intended to convey that a mixture having concentration of 1000 ppm of zinc borate did not inhibit the growth of A. pullulans in a manner that could be detected in the spiral plater replications described above.
[0000]
TABLE VI
Synergy of Biocidal Mixtures against A. pullulans .
Sum of FIC's
Synergistic,
for the
Additive or
Mixture No.
FIC IPBC
FIC BCM
FIC ZB
mixture
Antagonistic
8
1.333
0.062
<0.0001
1.395
Antagonistic
9
0.383
0.284
<0.0001
0.667
Synergistic
10
0.717
0.133
<0.001
0.850
Synergistic
11
0.514
0.096
<0.0002
0.610
Synergistic
12
0.514
0.096
<0.0002
0.610
Synergistic
[0085] Mixtures No. 9 through 12 of Table VI are mixtures of the invention. Table IV quantitatively communicates the effect of these mixtures on A. pullulans . Inspection of Table VI proves that mixtures of the invention exhibit a three-component synergy between IPBC, BCM and ZB, and can provide more efficient protection against A. pullulans.
[0086] As set forth above, Mixture No. 4 (consisting of zinc borate at a concentration of 1000 ppm in an inert carrier) exhibited little or no inhibition against A. pullulans . Therefore, MIC for Mixture No. 4 in Table V is shown as >1000. When this inequality is utilized as the denominator in calculating FIC ZB for various mixtures, the calculated FIC ZB values are inequalities. For example, in Mixture No. 12 of Table VI:
[0000] FIC ZB =(33.3 mass %)(0.53 ppm)/(100 mass %)(>1000)<0.0002.
[0087] Taken together, the data of Table VI and Table VI indicate that compositions of the invention can be prepared which have MIC of about 2 ppm or less against A. pullulans.
Example 7
Synergistic Effects with Respect to Fungus Penicillium sp
[0088] The procedure for determining MICs, as set forth above in Example 3, was performed again except that this time spore suspensions of the fungus Penicillium sp., also known as ATCC 12667, were utilized instead of A. niger.
[0089] The biologically active material proportions of twelve biocide mixtures are presented below in Table VII, as mass percent based on the mass of the total active material in the biocide mixture. The MIC against Penicillium sp. determined for each of the evaluations as the mean average of twelve replications is shown in Table VII.
[0000]
TABLE VII
Mixtures for Determining MIC against Penicillium sp.
IPBC mass %,
BCM mass %,
ZB mass %,
based on
based on
based on
MIC ppm,
total active
total active
total active
average of
Mixture
material in
material in
material in
spiral plater
No.
the mixture
the mixture
the mixture
replications
1
100
0
0
0.27
2
0
100
0
0.26
3
0
100
0
0.23
4
0
0
100
>1000
5
0
50
50
0.16
6
50
0
50
0.49
7
50
50
0
0.30
8
66.7
16.7
16.7
0.26
9
16.7
66.7
16.7
0.18
10
16.7
16.7
66.7
0.30
11
33.33
33.33
33.33
0.20
12
33.33
33.33
33.33
0.23
[0090] Mixtures No. 8 through 12 of Table VII are mixtures of the invention. Mixtures No. 1 through 7 of Table VII are not mixtures of the invention. All of the MIC values shown in Table VII were analyzed in accordance with the Berenbaum criteria described above in order to determine whether particular mixtures are synergistic, additive or antagonistic against Penicillium sp. The results of this determination are set forth below in Table VIII.
[0000]
TABLE VIII
Synergy of Biocidal Mixtures against Penicillium sp.
Sum of FIC's
Synergistic,
Mixture
for the
Additive or
No.
FIC IPBC
FIC BCM
FIC ZB
mixture
Antagonistic
8
0.642
0.181
<0.00004
0.823
Synergistic
9
0.111
0.500
<0.00003
0.611
Synergistic
10
0.186
0.209
<0.0002
0.395
Synergistic
11
0.259
0.291
<0.00007
0.550
Synergistic
12
0.284
0.319
<0.00008
0.603
Synergistic
[0091] Mixtures No. 8 through 12 of Table VIII are mixtures of the invention. Table VIII quantitatively communicates the effect of these mixtures on Penicillium sp. The results shown in Table VIII demonstrate that mixtures of the invention exhibit a three-component synergy between IPBC, BCM and ZB, and can provide efficient protection against Penicillium sp.
[0092] Taken together, the data of Table VII and Table VIII indicate that compositions of the invention can be prepared which have MIC of about 0.5 ppm or less against Penicillium sp.
[0093] While the invention has been described in terms of specific embodiments and examples, its scope is limited only by the scope of the following claims.
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A broad spectrum antimicrobial composition comprising a mixture of an iodopropynyl compound in combination with a benzimidazole and a metal borate is disclosed. The composition can be used to protect industrial systems against microbial growth and, more particularly, to protect substrates such as paints, coatings, stucco, concrete, stone, cementaceous surfaces, wood, wood-plastic composites, caulking, sealants, textiles, leather, wood, preservatives, metal working fluids, drilling muds, clay slurries, glazes, optical brighteners, carpet backing, and pigments against microbial growth. The composition can be used as a preservative for aqueous products.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to new and improved buoys for indicating the position of a sunken vessel and more particularly to said buoys as are normally resident in a receptacle which is attached to the superstructure or upper decks of a vessel, which is designed to be released upon submersion of the vessel, and which is useful in locating the vessel after it has sunk.
2. Description of the Prior Art
It is well known in the art of buoys to place a buoy in a receptacle on the upper deck of a vessel, attached to the vessel by a line, so that it will float free of the vessel and, subsequently floating on the surface of the water, mark the location of the vessel after it has sunk.
It is additionally known in the art of buoys to place both a buoy and the line connecting the buoy to the vessel in a housing or receptacle on an upper deck of the vessel to float free of the vessel, in case of the vessel's sinking.
It is further known in the art of buoys to provide a buoy which is and/or supports a visual indicator on the surface of the water above a sunken vessel of the vessel's position.
It is also well known to provide a drum or winding mechanism to contain the line and/or control the feed of the line connecting the buoy to the vessel.
The following patents indicate the state of the art in buoys designed to indicate the position of a sunken vessel.
A. J. Hebert, U.S. Pat. No. 1,070,253 discloses a buoy with a support which contains the buoy's connecting line to the vessel, mounts on a topside deck of the vessel, and provides spring retaining arms to retain the buoy in place within the support.
E. H. W. Crossley, U.S. Pat. No. 1,250,807 discloses a buoy in combination with a spring loaded means for mounting said buoy which acts to project the buoy clear of the vessel in the event of submersion or assumption of a dangerous angle.
J. Hlvaty, Jr., U.S. Pat. No. 1,352,000 discloses a buoy in combination with a drum upon which the line connecting the buoy to the vessel is wound and a casing having a plurality of compartments, one of which compartments normally contains the buoy and provides a pair of spring-impelled lever arms adapted to hold the buoy in position until such time as the rising water level in another of the compartments causes a float therein to rise and trip a lever disengaging the spring-impelled lever arms holding the buoy whereby the buoy is allowed to float free.
J. J. Higgins, U.S. Pat. No. 1,517,158 discloses a can buoy with receptacle, which buoy supports a visual indicating signal which is held in an upright position irrespective of the wave action on the buoy. The receptacle provides storage for the line and/or chain connecting the buoy to the vessel, is designed to be attached to the vessel's upper deck, and allows the buoy to float free when the vessel sinks.
H. Tomic, U.S. Pat. No. 1,566,934 discloses a buoy and buoy anchorage housing with means for locking the buoy on the housing. The housing provides an annular seat for the spherical buoy and the buoy has a cylinder which extends up into the buoy which cylinder is open at the bottom end. Additional means are provided to, moveably within the cylinder, release the locking means when the water rises into the cylinder of the buoy.
S. V. Clyde, U.S. Pat. No. 1,615,108 discloses a buoy, a drum to hold the line connecting the buoy to the vessel, and a support for the buoy which, when holding the buoy, is positioned directly above the drum, but when the buoy floats free swings clear of the drum to avoid entangling the line.
L. H. Roeth, U.S. Pat. No. 1,839,001 discloses a buoy which sits atop a funnel pipe which extends to the bottom of the vessel where a drum sits with line coiled, which line connects the buoy through the funnel pipe to the bottom of the vessel. The drum provides means for controlling the pay out of the line such that the drum rotates and line is paid out only during those times when the buoy is submerged.
B. W. Allen, U.S. Pat. No. 3,225,368 discloses a buoy which is cored and normally rests on a spindle which is part of a buoy holder having resilient and flexible fingers from which the buoy floats free upon submersion in water. The line connecting the buoy to the vessel is wound upon either a portion of the spindle beneath the buoy or a separate drum.
SUMMARY OF THE INVENTION
The primary object of the invention is to provide a low-cost, reliable buoy with radio beacon that will serve to locate sunken vessels.
It is another object of the invention to provide a buoy with storage space internal to the buoy for the line connecting the buoy to the vessel.
It is yet another object of the invention to provide a buoy with a line guide integral to the buoy to avoid line fouling.
It is stil another object of the invention to provide a buoy having compartments suitable for the placement of a radio transmitter, a battery or power source, and a radio transmitter antenna.
It is further an object of the invention to provide a receptacle suitable for storage of the buoy when not in use and suitable, further, for reliable buoy flotation should the vessel to which the buoy is attached become submerged.
It is finally an object of the invention to provide a buoy which may be opened for servicing of the battery, radio transmitter, or line and which may be easily restored to a watertight condition.
These and other objects are accomplished as described in the accompanying drawings and the following description of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic lateral view showing the invention installed on the superstructure of a vessel.
FIG. 2 is a lateral sectional view of the invention.
FIG. 3a is a downward vertical view of the exterior of the top half of the buoy.
FIG. 3b is an upward vertical view of the interior of the top half of the buoy.
FIG. 4 is a perspective view, partly in section, of the bottom half of the buoy.
FIG. 5a is a horizontal elevation, partly in section, of the detail of the pull-key switch contained within the buoy.
FIG. 5b is a vertical elevation, partly in section, of the detail of the pull-key switch contained within the buoy.
FIG. 6 is a sectional vertical elevation of the detail of the connection and seal of the upper part of the buoy to the lower part of the buoy.
DESCRIPTION OF THE INVENTION
Referring in detail to the drawings, the invention 10 is shown in FIG. 1 as attached to the superstructure 14 of the vessel 20. The invention 10 is shown only in an external view in FIG. 1 where the invention 10 may be seen to comprise a buoy 15 inside a receptacle 11, which receptacle 11 provides a mounting bracket 16 for attachment of the invention 10 to the superstructure 14 with fastener means 17. Additionally, the receptacle 11 provides an orifice 13 through which pass a line 12 and a pull-key chord 19. The line 12 attached to the buoy 15 on one end and attaches to the superstructure 14 on the other end by means of the fastener means 18. The pull-key chord 19 attaches to a pull-key shaft 41 within the buoy 15 on one end and attaches to the superstructure 14 on the other end by means of the fastener means 18 as shown in FIG. 1.
Referring to FIG. 2, the buoy 15 can be seen in its usual at rest position within the receptacle 11. The buoy 15 is seen to comprise, in its major separate physical components, an upper shell 35, a lower shell 34, and a center plate 26. The upper half 25 of the buoy 15 is, in the preferred embodiment, a hollow, hemispherical upper shell 35 containing or providing various components hereinafter described. The lower half 24 of the buoy 15 is, in the preferred embodiment, a hollow, hemispherical lower shell 34 containing or providing various components hereinafter described.
The lower shell 34 of the buoy 15 is shown in FIG. 4 of in the drawings as hemispherical with a cylindrical tube 21 extending through its surface. Within the lower shell 34, and in the lower regions thereof, is placed a ballast 23 which is attached to the lower shell 34 by fastener means 39 and which is intended to assist in maintaining a correct top-bottom orientation of the buoy when it is floating free of the receptacle 11. Also within the lower shell 34 is coiled the line 12 which connects the buoy 15 to the superstructure 14 of the vessel 20. The line 12 is coiled around the cylindrical tube 21 within the lower shell 34. The cylindrical tube 21 serves both as a guide to pay out the line 12 and as a means to keep water from rushing into the buoy 15 when it is afloat. Note that the draft of the buoy 15 may not be greater than the length of the cylindrical tube 21 and that the greatest draft is possible if the cylindrical tube 21 is oriented such that its long axis is perpendicular to the surface of the water when the buoy 15 is afloat. The line 12 may be connected by the fastener means 22 to the cylindrical tube 21 as shown in FIG. 2 or to any portion of the lower shell 34 as shown in FIG. 4.
The upper shell 35 of the buoy 15 is depicted in the drawings as hemispherical with an access port through its surface. The access port is shown in FIG. 2, FIG. 3a and FIG. 3b as being covered by the access port cover 36. Said access port cover 36 provides a handle 38 and is in sealed connection 37 with the upper shell 35. The sealed connection 37 may be understood to be an O ring washer or seal if the access port cover 36 is threadably engaged with the upper shell 35. Additionally, the upper shell 35 has attached to its interior surface a radio antenna 32. Accordingly, it is expected that the upper shell 35 will be contructed of materials that are transparent to radio frequency transmissions. The means by which the radio antenna 32 is attached to the upper shell 35 are varied and may range from glue, to fasteners, to actual imbedding of the radio antenna 32 in the material of the upper shell 35.
FIG. 2 shows the arrangement of the radio transmitter 30, the power source 33, and the pull-key mechanism 51 on the center plate 26. The radio transmitter 30 and the pull-key mechanism 51 are contained within a housing 40 which also serves as a support for the power source 33. The housing 40 is attached to the center plate 26 and together with the center plate 26 completely envelopes the radio transmitter 30 and the pull-key mechanism 51, save only the pull-key shaft 41 which extends through the center plate 26. The housing 40 additionally is formed in such fashion as to provide lateral restraints on the movement of the power source 33 while providing physical support for the weight of the power source 33 and allowing easy vertical access to the power source 33 from above through the access port cover 36. As shown in FIG. 2 and FIG. 5b, the center plate 26 also provides an orifice 29 which allows the pull-key shaft 41 to extend through the center plate 26 and provides sealed fastener means 27 whereby the upper shell 35 is sealably fastened to the center plate 26 and to the lower shell 34, and the lower shell 34 is sealably fastened to the center plate 26 and to the upper shell 35.
Detail of the pull-key mechanism 51 is shown in FIG. 5a and FIG. 5b. Said detail shows that the pull-key mechanism 51 is enclosed within a shaft housing 49 which has attached thereto a plunger housing 46. Together the shaft housing 49 and the plunger housing 46 form a watertight enclosure around the pull-key mechanism 51 which is in sealed connection 52 with the center plate 26 such that the pull-key shaft 41 protrudes through the orifice 29 in the center plate 26. The pull-key mechanism 51 is comprised of a shaft housing 49, a plunger housing 46, a spring 45, a plunger 42 having an end cap 44 which is conductive to electron flow, an annular seating plate 43 against which the end cap 44 rests when the spring 45 is allowed to extend from its normally compressed state within the plunger housing 46, a plunger bore 48 through which the plunger 42 slideably moves into the shaft housing 49 when the pull-key shaft 41 is withdrawn from the pull-key mechanism 51. O ring seals 47 are provided within the plunger bore 48 to slideably engage the plunger 42 and provide a watertight seal.
As shown in FIG. 5a, the annular seating plate 43 of the pull-key mechanism 51, which annular seating plate 43 is constructed of electron flow insulator material, provides, on its surface facing away from the plunger bore 48 to which it is attached, two electrical contacts 50 which comprise an open circuit until such time as the spring 45 is extended and pushes the plunger 42 into the plunger bore 48 sufficiently to bring the end cap 44 into contact with the annular seating plate 43 at which time a closed circuit is formed. The electrical contacts 50 are electrically connected such that one of the electrical contacts 50 is electrically connected to the positive output of the power source 33 and the other of the electrical contacts 50 is electrically connected to the positive power input of the radio transmitter 30.
The pull-key mechanism 51 is thus able to turn on the radio transmitter 30 when the pull-key shaft 41 is withdrawn allowing the plunger 42 to extend into the shaft housing 49. As shown in FIG. 2, the radio transmitter 30 output has an electrical connection 31 to the radio antenna 32 whereby when the radio transmitter 30 is activated a radio frequency signal is transmitted from the radio antenna 32.
In FIG. 6 the connection of the upper shell 35 to the center plate 26 and to the lower shell 34 is shown in detail. While the connection made by the sealed fastener means 27 may comprise any watertight fitting, the preferred embodiment makes the connection as shown in FIG. 6 by providing a flange 60 at the circumference of the upper shell 35 and a flange 61 at the circumference of the lower shell. Each of said flanges 60 and 61 is drilled and tapped with threads to receive a screw 66 which, when tightened, pulls the upper shell 35 and the lower shell 34 together. The flange 60 provides a groove 62 suitable to receive the O ring seal 63 between the upper shell 35 and the center plate 26. The flange 61 provides a groove 65 suitable to receive the O ring seal 64 between the lower shell 34 and the center plate 26. When the screw 66 is tightened, the upper shell 35 and the lower shell 34 are pulled together and squeezeably engage the center plate 26 compressing said O ring seals 63 and 64 forming a watertight seal between the upper shell 35 and the center plate 26 and between the lower shell 34 and the center plate 26.
In operation, the buoy 15 floats free of the receptacle 11 when the vessel 20 sinks and the pull-key chord 19 pulls the pull-key shaft 41 free of the pull-key mechanism 51 which then switches on electricity from the power source 33 to the radio transmitter 30. As the buoy 15 floats free of the vessel 20, the line 12 is paid out through the cylindrical tube 21 thus avoiding entanglements of the line 12 and allowing the buoy 15 to float on the surface of the water above the vessel 20 providing a visual indicator of the location of the vessel 20 at the same time that the radio transmitter 30 is transmitting a radio signal for location of the vessel 20 by radio direction finding techniques.
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An improved buoy which provides for internal storage of the line securing the buoy to the vessel, internal placement of a radio transmitter with power source and electrical switch, and a receptacle for attachment to the superstructure of a vessel.
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BACKGROUND OF THE INVENTION AND PRIOR ART
This application is a continuation-in-part of application Ser. No. 429,719, filed Oct. 31, 1989 now abandoned.
This invention relates to pressure-sensitive adhesives for application to substrates or carrier layers to provide laminates having positionable-repositionable properties and to methods of adhering laminates to mounting or application surfaces to provide such properties.
The pressure-sensitive adhesives and laminates of interest herein are characterized by low initial tack and adhesion properties which enable the laminate to be adhered with pressure to a mounting surface and removed therefrom before any appreciable build-up in adhesion occurs. The laminates are initially removable without damage to the substrate or transfer of adhesive to the mounting surface. Preferably, the pressure-sensitive adhesive permits repeated application of the laminate to the surface and removal therefrom during an initial time period of 15 to 30 minutes or longer. Further, the layer of pressure-sensitive adhesive should not stick to itself during such initial time period.
Upon passage of time, the adhesion build-up should be sufficient to secure the laminate to the mounting or application surface in accordance with its intended purpose. For example, permanent bond systems result in a maximum or ultrimate adhesion which prevents removal of the laminate from the mounting surface without laminate damage such as tearing or distortion. The development of maximum or ultimate adhesion build-up may take about one week at room temperature.
In many applications, it is preferable that adhesion build-up may also be achieved by application of heat. This enables the development of the ultimate adhesion to be expedited.
The laminates may be used in a wide range of decorative or protective applications. For example, the laminates may be used in signs, tapes and vehicle marking such as decorative decals and fleet marking and in architectural applications such as service station canopy decoration. The laminates may be used in the form of tapes, sheets or roll stock. The substrate or carrier layer may comprise a facestock material which can be printed, coated or over-laminated to provide desired indicia.
The term positionable or positionability is used herein to indicate a sufficiently low degree of tack to allow a laminate having its adhesive surface in contact with a mounting surface to be slid across the mounting surface without sticking or grabbing. An illustrative test includes the manual sliding of a 3"×8" laminate test sample along a clean aluminum surface without contact pressure other than the weight of the sample. Positionability is indicated by a smooth sliding movement of the test sample without damage to the specimen or removal of adhesive.
A quantitative test for measurement of pressure-sensitive adhesive tack is set forth in ASTM D 2979-88. Herein, positionability is considered to be achieved by pressure-sensitive adhesives having tack values ranging up to about 90 g. using a Polyken brand tester in accordance with the test procedure.
Adhesion build-up may be quantitatively measured by means of the 180° peel test as set forth in PSTC Test Method No. 1. Herein, 180° peel test values are determined at time intervals ranging from one minute to thirty minutes after the application of the pressure-sensitive adhesive to a mounting surface in order to further characterize tack and adhesion build-up characteristics. Peel values are also measured after one week following the application of the pressure-sensitive adhesive to a surface in order to determine the maximum or ultimate peel strength and degree of adhesion build-up.
Repositionable or repositionability is used herein to indicate the ability to install a laminate with pressure to the mounting or application surface in a final manner and to remove it therefrom repeatedly prior to a build-up of adhesion during an initial time period and without damage to the laminate. Therefore, repositionability is also a function of the strength of the substrate or facestock material. In addition, the laminate also retains its positionability characteristics after removal from the mounting surface. The mounting surface may be a metallic surface, a painted surface or other suitable surface cleaned for adhesive application.
The use of solid particles disposed along the adhesive surface of a pressure-sensitive adhesive layer and partially embedded therein to space the adhesive surface from the mounting or application surface to enable positionability is disclosed in U.S. Pat. No. 4,556,595. A wide variety of particles are disclosed including calcium carbonate, aluminum hydroxide and silica. The particle size is indicated to be less than 10 microns and in the range of 0.001 micron to 3 microns. Upon application of sufficient installation pressure to the laminate, the particles are embedded in the adhesive so as to no longer interfere with the adhesion. Thus, the laminate is not repeatedly positionable.
Japanese Patent No. 52133339, dated Nov. 8, 1977, is reported to disclose a multi-layered acrylic pressure-sensitive adhesive having silica acid powder of less than 0.1 micron particle size concentrated at the surface thereof. A solvent solution of the adhesive containing dispersed particles is evaporated to form a film which is more than 15 microns thick. It is indicated that release paper is not required, positioning may be done at low pressure and final bonding is achieved at high pressure.
The prior art also discloses a variety of laminate materials having a pressure-sensitive adhesive layer including micro-balloons disposed therein to aid the positionability of the laminate. U.S. Pat. No. 3,331,729 discloses the use of thin-walled fragile micro-balloons which are randomly distributed over and partially embedded in the surface of the adhesive layer. The micro-balloons space the adhesive from the surface to allow positionability of the laminate. Thereafter, sufficient pressure is applied to crush the micro-balloons and permit the adhesive to adhere to the substrate. The laminate is thereby fully installed and not capable of further movement. U.S. Pat. No. 4,376,151 also discloses the use of micro-balloons which allow positionability until a threshold pressure is applied to displace the micro-balloons.
U.S. Pat. No. 3,314,838 discloses a monolayer of micro-balloons covered with a thin film of adhesive which provides a slidable pebbled surface prior to the application of pressure. Upon installation, sufficient pressure is applied to crush the micro-balloons and cause the adhesive to contact the application surface.
The prior art also discloses the addition of particles and micro-balloons to pressure-sensitive adhesives for other purposes. For example, U.S. Pat. No. 4,415,615 discloses the use of of thixotropic agents such as fumed silica in its microbubble-filled cellular adhesive layers. Increased cohesiveness is indicated in U.S. Pat. No. 4,710,536 by the addition of hydrophobic silica.
SUMMARY OF INVENTION
It has now been discovered that a positionable-repositionable pressure-sensitive adhesive may be provided by incorporation of a detackifying resin and a detackifying particulate or filler in an adhesive base resin. Optionally, a tackifier may be used in a conventional manner. The detackifying resin and particulate cooperate to temporarily reduce the tack and peel characteristics of the pressure-sensitive adhesive and to allow positionability and repositionability.
As used herein, detackifying resin and detackifying particulate refer to non-tacky thermoplastic resins and insoluble solid particles which interact to reduce the tack and suppress adhesion build-up of a normally tacky adhesive base resin and any tackifier present. The detackifying resin is believed to act as a mechanical compatibilizer between the particulate and the adhesive which increases the effectiveness of the particulate in reducing the adhesive contact efficiency. Because less particulate is required to reduce the adhesive contact efficiency to enable positionability-repositionability, the reduction in ultimate peel strength due to the particulate is also less.
The pressure-sensitive adhesives of the invention are substantially non-tacky and positionable. Accordingly, laminates may be slid easily along surfaces to which they are to be applied with the mounting surface and outer adhesive surface in contact. Upon application of an installation pressure, such as that resulting from hand pressing or the use of hand tools to install a laminate, the pressure-sensitive adhesive adheres with a peel strength which is sufficient to retain the laminate in its installed position. This peel strength may range up to 3.0 lb./linear inch or higher depending upon the strength of the substrate.
In contrast with the prior art use of surface disposed particles to physically isolate the adhesive and mounting surfaces as by forming spaces or barriers therebetween, the particulate of the present invention is blended with the adhesive components for interaction therewith, and not concentrated at an outer surface of the pressure-sensitive adhesive layer. Accordingly, the pressure-sensitive adhesives disclosed herein do not require preparation or adhering techniques which are limited to specific surface treatments or surface handling procedures. Further, the inventive adhesives are not characterized by a threshold pressure for final installation, but rather, adhesion builds with the passage of time or application of thermal energy.
The preferred detackifying resins comprise non-tacky thermoplastic resins or polymers having a molecular weight in the range of from about 3,000 to about 350,000. The resins are solid at room temperature and they are also characterized by sites for interaction with the detackifying particle and at least one moiety which is compatible with or interacts with the adhesive base resin or tackifier. Polycaprolactone polymers are preferred detackifying resins for use with acrylic adhesives. As disclosed in U.S. Pat. No. 3,892,821, these polymers are characterized by containing a major molar amount of the following recurring structural linear unit I: ##STR1## wherein each R, individually, is selected from the class consisting of hydrogen, alkyl, halo and alkoxy; A is the oxy group; x is an integer from 1 to 4; y is an integer from 1 to 4; z is 0 or 1; with the provisos that (a) the sum of x+y+z is at least 4 and not greater than 7, and (b) the total number of R variables which are substituents other than hydrogen does not exceed 3. Illustrative R variables include methyl, ethyl, isopropyl, n-butyl, sec-butyl, t-butyl, hexyl, chloro, bromo, iodo, methoxy, ethoxy, n-butoxy, n-hexoxy, 2-ethylhexoxy, dodecoxy, and the like. The preferred polycaprolactone polymers may be characterized by recurring unit I and up to a minor molar amount of the following recurring structural unit II: ##STR2## wherein each R 1 is selected from the class consisting of, individually, hydrogen, alkyl, cycloalkyl, aryl and chloroalkyl, and, together with the ethylene moiety of the oxyethylene chain of unit II, a saturated cycloaliphatic hydrocarbon ring having from 4 to 8 carbon atoms. The recurring linear unit I is linked by the oxy group with the carbonyl group of the linear unit II. The most preferred polycaprolactone polymers are characterized by the oxypentamethylenecarbonyl chain of the following recurring structural unit III: ##STR3## wherein each R 1 is hydrogen and water is used as the polymerization initiator to result in hydroxyl termination at both ends of the molecule.
The detackifying particle should be a solid at room temperature and insoluble in the pressure-sensitive adhesive. The average particle size should be in the range of from about 0.01 micron to about 4 microns. The particle should have hydrophilic characteristics capable of hydrogen bonding with the preferred detackifying resin. Such particles often have polar surfaces as are provided by the presence of OH groups. Fumed silica is a preferred particle.
The adhesive base resin is an acrylic adhesive such as those which are composed of homopolymers, copolymers or cross-linked copolymers of at least one acrylic or methacrylic component, for example acrylic esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, undecyl acrylate or lauryl acrylate, and optionally as a comonomer, a carboxyl-containing monomer such as (meth)acrylic acid [the expression "(meth)acrylic" acid denotes acrylic acid and methacrylic acid], itaconic acid, crotonic acid, maleic acid, maleic anhydride or butyl maleate, a hydroxyl-containing monomer such as 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate or allyl alcohol, an amido-containing monomer such as (meth)acrylamide, N-methyl(meth)acrylamide, or N-ethyl-(meth)acrylamide, a methylol group-containing monomer such as N-methylol(meth)acrylamide or dimethylol(meth)acrylamide, an amino-containing monomer such as aminoethyl(meth)acrylate, dimethylaminoethyl(meth)acrylate or vinylpyridine, or a non-functional monomer such as ethylene, propylene, styrene or vinyl acetate; mixtures thereof; and adhesives containing at least one such adhesives as a main component.
Rubber based adhesives can also be used as the pressure-sensitive adhesive. They may require a detackifying resin which has moieties which are compatible with the rubber based adhesive.
Preferred acrylic adhesive base resins comprise multi-polymers based upon a mixture of monomers and typified as being composed of lower glass transition temperature esters. Such acrylic adhesives provide sufficient viscoelastic flow to assure adequate build-up of adhesion. Upon passage of time and/or application of thermal energy, the ultimate peel value may be equal to about 90% or more of the value achieved by the base resin and any tackifier without detackifying resin and particle.
The use of a tackifier is optional. Conventional tackifiers such as hydrogenated rosin esters may be used. The use of a tackifier enables achievement of increased levels of adhesion and peel value, but its use is not necessary to recovery of available peel. Since 90% recovery is achieved in most cases, the use of a tackifier is determined by the need to increase the overall level of adhesion and peel strength.
Pressure-sensitive adhesives in accordance with the invention may include from about 1 to about 30% detackifying resin on a dry weight basis and, more preferably, from about 4% to about 20%. (Unless otherwise indicated, all weight percentages are on a dry weight basis of the final pressure-sensitive adhesive.) The detackifying particle may be used in amounts ranging from about 1% to about 15% by weight and, more preferably from about 3% to about 12%. If a tackifier is used, it may be added in amounts ranging up to about 30% by weight and, more preferably, up to about 20% by weight. The tackifier may be used in the pressure-sensitive adhesives of the present invention to increase the ultimate adhesion or peel strength in the same manner as used in conventional pressure-sensitive adhesives. The adhesive base resin forms the remainder of the pressure-sensitive adhesive and it ranges in amount from about 25% to about 98% by weight. If a tackifier is not used, the adhesive base resin ranges from about 45% to about 98% by weight of the pressure-sensitive adhesive.
The substrate is not critical to the invention and may be formed of a wide variety of materials in accordance with the intended application. The substrate thickness may range from about 0.5 mil or less to about 20 mils. The substrate may comprise plastic film, paper material, metal foil or other suitable sheet or web material. The substrate may be a facestock material suitable for display of indicia applied thereto in conventional manners such as printing or coating.
The pressure-sensitive adhesive may be applied to the substrate by knife-coating, roll-coating and other conventional techniques. Alternatively, the pressure-sensitive adhesive may be applied to a liner or carrier web and then joined to the substrate. The thickness of the pressure-sensitive adhesive is not critical to the invention and conventional application thicknesses in the range of from about 0.5 to about 4 mils may be used.
It is also within the scope of the invention to use the pressure-sensitive adhesive as an exterior or overcoat layer on a layer of compatible adhesive which does not have positionable-repositionable properties. For example, such compatible adhesive may comprise a pressure-sensitive adhesive of the same base resin but without the detackifying resin and particle. Successive coatings may be used to provide such a combined adhesive construction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of a laminate including a substrate layer and a pressure-sensitive adhesive layer in accordance with the invention;
FIG. 2 is a schematic sectional view similar to FIG. 1 showing the laminate partially applied to a wall of a vehicle;
FIG. 3 is a graph showing the effect on peel strength of pressure-sensitive adhesives containing varying amounts of two different detackifying resins; and
FIG. 4 is a graph showing the effect on peel strength of pressure-sensitive adhesives containing varying amounts of detackifying resin and varying amounts of detackifying particle.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a laminate 10 is shown comprising a substrate or carrier layer 12 secured to a pressure-sensitive adhesive layer 14. A conventional release liner 16 having a low energy surface of silicone or the like may be applied to the outer surface 14a of the adhesive layer 14 to protect it from contamination when the laminate 10 is in sheet form or to allow the laminate to be wound in roll form. The laminate 10 may be self-wound without the use of a liner 16 depending upon the composition of the substrate layer 12.
Referring to FIG. 2, the laminate 10 is shown partially applied or installed to an exterior sidewall 18 of a vehicle body and, more particularly, to a mounting or application surface 18a of the wall 18. In such applications, the laminate 10 is typically applied by hand using a flexible blade squeegee and stiff bristle brush to conform the laminate with the contour of the application surface. In order to obtain register of indicia and/or improve conformity, the laminate may be adhered to the surface with full installation pressure and removed several times. The pressure-sensitive adhesives of the present invention enable such installation procedures. In such applications, the pressure-sensitive adhesives also provide a permanent bond suitable for use in vehicle applications and fleet marking.
The adhesive products of the present invention are illustrated in the following examples. Unless otherwise indicated, the pressure-sensitive adhesives are applied to plastic film substrates to produce laminates suitable as facestock material. The facestock materials are repeatedly positionable-repositionable, and the pressure-sensitive adhesive develops a permanent bond.
An acrylic resin sold by Ashland Chemical Company under the designation A 1930 is used as the adhesive base resin in the pressure-sensitive adhesive of Example 1. The adhesive base resin is an acrylate multi-polymer typified by lower glass transition temperature esters. The adhesive base resin is solvent borne and cross-links during cure.
The detackifying resin is a polycaprolactone polymer sold by Union Carbide Corporation under the designation Tone 300. This is a linear polymer having an oxypentamethylenecarbonyl chain of recurring structural unit III as indicated above. The recurring ester groups along the molecule provide a dipole distribution believed to allow interaction with the detackifying particle and/or adhesive base. The polycaprolactone polymer has a molecular weight range of 3,000 to 90,000 and weight mean of 10,000.
The detackifying particulate is silica sold under the designation Cab-O-Sil M-5 by Cabot Corporation. This is a fumed silica having an average particle size of about 0.012 micron. The particles are hydrophilic and are believed to undergo hydrogen bonding with the detackifying resin and may nucleate the crystallization of the polycaprolactone.
A tackifier sold by Ashland Chemical Company under the designation PS 293 was used. Alternatively, a hydrogenated rosin ester sold by Hercules Chemical Company under the designation Foral 85 may be used.
On dry weight basis, 116 parts of the adhesive base resin, 20 parts of the detackifying resin and 30 parts of the tackifier are blended in a toluene and hexane solvent mixture. The mixture is heated sufficiently to assure that the detackifying resin is dissolved or dispersed. For example, the mixture may be heated to temperatures in the range of about 140° F. A smooth homogeneous mixture is obtained with sufficient heating and mixing. Thereafter, 13.4 parts of the detackifying particle is added to the mixture and uniformly dispersed with further mixing. The pressure-sensitive adhesive is drawn-down on a release sheet and then transfer laminated after cure to a two mil thick vinyl plastic film substrate. The coat weight of the adhesives is 33 g/m 2 ±2 g/m 2 .
Using the procedures and components of Example 1, comparative Examples 1C through 6C were prepared to evaluate deletion and concentration variation of detackifying resin and particulate components. The compositions are summarized in Table I below.
TABLE I______________________________________ BASE DETACK DETACK TACKI-NUMBER ADHESIVE RESIN PARTICLE FIER______________________________________1C 116 0 13.4 302C 116 20 0 303C 116 0 0 304C 116 10 6.7 305C 116 40 0 306C 116 0 26.8 30______________________________________
Example 1 and Comparative Examples 1C-6C were tested for tack using a Polyken tester. Also, the 180° peel values were tested at one minute and 20 minute intervals following installation. (All peel tests were performed using a stainless steel mounting surface.) The maximum peel values were tested one week after installation. The results of these tests are set forth in Table II.
TABLE II______________________________________ PEEL (lb./LINEAR INCH)NO. TACK(g) 1 Min. 20 Min. 1 Week______________________________________1 59 ± 12 2.97 ± .03 3.47 ± .35 5.70 ± .101C 170 ± 20 2.70 ± .00 3.57 ± .15 6.27 ± .062C 289 ± 73 3.28 ± .16 4.33 ± .29 6.67 ± .423C 369 ± 71 3.80 ± .17 4.50 ± .00 6.30 ± .204C 129 ± 38 2.93 ± .29 4.27 ± .12 6.53 ± .405C 270 ± 53 2.53 ± .25 3.60 ± .00 6.00 ± .176C 62 ± 24 1.90 ± .10 2.93 ± .06 4.67 ± .06______________________________________
As shown in Table II, both the detackifying resin and particle are required to achieve an adequate reduction in tack to enable positionability. Comparative Example 3C is considered to represent the base system since it contains neither detackifying resin nor detackifying particle, the relative percent performance of the other examples and comparative examples may be measured against it. Thus, Example 1 has a one week peel value of 5.70 lb./linear in. which is equal to 90% of the one week peel value of Comparative Example 3C.
Comparison of Example 1 with Examples 5C and 6C indicates that the detackifying resin and particulate interact to reduce tack and suppress adhesion build-up in a manner such that neither component alone is required in an amount which will also result in an excessive reduction of peel strength. The use of detackifying resin alone in increased amounts does not enable satisfactory tack values and excessive reductions in the ultimate peel strength occur. Although detackifying particles used alone in increased amounts enable satisfactory tack values, excessive reductions in peel strength also occur.
The compositions of Examples 1, 1C, 2C, 3C and 6C were further examined to better characterize the interaction between the detackifying resin and particulate. Samples of the compositions were drawn-down on a silicone release sheet and dried as described above in Example 1 to form adhesive layers of the various compositions.
Each of the surfaces of the adhesive layers of the compositions of Examples 1 and 1C was examined by X-ray photoelectron spectroscopy. The examination did not detect any sign of silicon characteristic of that found in the silica particulate in the outer 50 angstroms of the layers. This indicates the detackification obtained is not due to any preferential concentration of the particulate at the adhesive surfaces as was required in some prior art techniques.
The compositions of Examples 1, 1C, 2C, 3C and 6C were also examined using dynamic mechanical spectroscopy. The dynamic shear storage modulus (G 1 ) of an adhesive, measured at a frequency corresponding to the time scale of bonding, indicates the softness and conformability or contact efficiency of the adhesive. The higher the value of G 1 at the frequency of 1-0.01 rad/sec (corresponding to a bonding time scale of 1-100 seconds) the less flowable the adhesive and the lower the tack or quick-stick, e.g. a lower Polyken tack and better positionability are obtained. Carl Dahlquist has proposed a contact efficiency criteria which translates to the proposition that pressure-sensitive adhesives are contact efficient if G 1 at 1 rad/sec is less than 3×10 6 dynes/cm 2 .
Referring to Table IIA below, the dynamic shear storage moduli (G 1 ) at 0.01 rad/sec and 1 rad/sec are reported for the compositions of Examples 1, 1C, 2C 3C and 6C. All modulus measurements were made in accordance with ASTM D 4065-82 using a Rheometrics Mechanical Spectrometer (RMS 800) with parallel plate specimen mounting and a forced constant amplitude-torsional oscillation frequency scan at a constant temperature of 23° to 25° C.
TABLE IIA______________________________________ G.sup.1 × 10.sup.5 (dynes/cm.sup.2)NUMBER 0.01 rad/sec 1 rad/sec______________________________________1 28.1 74.81C 3.2 14.82C 1.2 5.73C 1.2 7.16C 21.8 43.5Dahlquist 30Criteria______________________________________
The addition of inert particulate or filler to a pressure-sensitive adhesive will stiffen the adhesive and raise its G 1 value so as to make it less contact efficient. This is shown by comparing the increasing G 1 values at 1 rad/sec for Examples 3C, 1C and 6C which respectively contain 0, 13.4 and 26.8 parts of particulate and no detackifying resin. Unexpectedly, the addition of detackifying resin in combination with 13.4 parts of particulate in Example 1 raised the G 1 value to 74.8 even though the addition of the resin by itself in Example 2C lowered the G 1 value to 5.7 as compared with the G 1 value of 7.1 in Example 3C which contains neither detackifying resin or particulate.
The unexpected increase in the G 1 value and positionability of Example 1 as shown in Table IIA result from the detackifying resin and particulate interaction. More particularly, the polycaprolactone detackifying resin is compatible with the adhesive and interacts with the surface of the silica particulate thereby acting as a mechanical compatibilizer between the adhesive and the silica particles. This increases the effectiveness of the particles in raising the dynamic shear storage modulus of the adhesive.
The addition of inert particulate or filler to a pressure-sensitive adhesive tends to decrease its ultimate peel strength. This is shown by comparing the decreasing one-week peel strength for Examples 3C, 1C and 6C which respectively contain 0, 13.4 and 26.8 parts of particulate and no detackifying resin. The final peel force achieved with pressure, time and/or thermal energy is a function of the level of mechanical dissipation of the volume of polymeric material in the adhesive that can contribute to the mechanical dissipation in the time scale of debonding. The inert particulate or fillers do not contribute to the debonding as they do not deform under the applied peel stress. Accordingly, the enhancement of the particulate effectiveness in achieving positionability by the detackifying resin enables a reduced amount of particulate to be used and a lesser reduction of the ultimate peel strength as compared with a similar laminate except for the omission of the detackifying resin. Similarly, for a given amount of particulate consistent with a desired ultimate peel strength, the detackifying resin may be used to enable positionability and achievement of the desired peel strength.
The adhesive base resin of the pressure-sensitive adhesive and tackifier of Example 1 were aged for a one week period before repeating the preparation of a corresponding series of laminates. Referring to Table III, the test results are reported for the aged samples. The coaction of the detackifying resin and particles is again demonstrated by the data.
TABLE III______________________________________ PEEL (lb./LINEAR INCH)NO. TACK(g) 1 Min. 20 Min. 1 Week______________________________________ 2 40 ± 13 2.87 ± .06 3.57 ± .06 5.27 ± .21 7C 208 ± 32 2.37 ± .06 3.57 ± .06 5.97 ± .25 8C 212 ± 67 3.43 ± .06 4.07 ± .25 5.57 ± .12 9C 452 ± 39 3.60 ± .20 4.63 ± .15 5.70 ± .2010C 288 ± 64 3.10 ± .35 3.60 ± .10 6.13 ± .3111C 208 ± 32 2.67 ± .15 3.57 ± .12 5.60 ± .1712C 85 ± 26 2.03 ± .21 2.87 ± .15 4.70 ± .00______________________________________
Using the procedure and formulation of Example 1, Example 3 was prepared in accordance with the invention as a standard for comparison with similar adhesives containing varying amounts of detackifying resin. More particularly, Examples 3-1 to 3-6 were prepared by varying the amount of detackifying resin, Tone 300, between 35% and 160% of the amount used in Example 3 without varying the other components. The twenty minute peel strength of Example 3 was 2.17 lb./linear inch. The peel strength of Examples 3-1 to 3-6 are reported below in Table IV.
TABLE IV______________________________________ Example Number 3-1 3-2 3-3 3-4 3-5 3-6______________________________________Relative Amount +60 +40 +20 -45 -55 -65of Detack Resin20 Minute Peel 1.53 1.33 1.63 2.27 1.87 1.90______________________________________
In a manner similar to that described immediately above, Example 4 was prepared as a standard using the procedure and formulation of Example 1 except for the replacement of Tone 300 with a higher molecular weight detackifying resin, Tone 700. This resin is similar to Tone 300, but it has a molecular weight range of 11,000 to 342,000 and a weight mean of 40,000. The twenty minute peel strength of Example 4 was 2.67 lb./linear inch. As also described above, Examples 4-1 to 4-3 were prepared and tested for twenty minute peel strength. The results are reported below in Table V.
TABLE V______________________________________ Example Number 4-1 4-2 4-3______________________________________Relative Amount -40 -60 -80of Detack Resin20 Minute Peel 2.90 3.05 3.00______________________________________
Referring to FIG. 3, the results reported in Tables IV and V are graphically shown using regression analysis. Curve 3-1 corresponds with the data of Table IV for Tone 300 and curve 3-2 corresponds with the data of Table V for Tone 700. (A low adhesion aluminum mounting surface was used for these tests so as to result in lower one week peel values than obtained with stainless steel or painted aluminum mounting surfaces.) As indicated, a unit variation in the amount of either detackifying resin causes a similar effect on peel strength.
The effect of varying the amount of detackifying resin or varying the amount of detackifying particle is demonstrated with reference to a standard pressure-sensitive adhesive, Example V, prepared in accordance with the procedures and formulation of Example 1. In a first series of Examples 5-1 to 5-4, the amount of detackifying resin (Tone 300) was varied between 45% and 140% of the amount used in Example 5 without varying the amounts of other components. In a second series of Examples 5-5 to 5-10, the amount of detackifying particle (Cab-O-Sil M-5) was varied between 35% and 160% of the amount used in Example 5 without varying the amount of the other components. The one week peel strength of Examples 5 was 3.8 lb./linear inch. The one week peel strength of each of Examples 5-1 to 5-10 is reported in Table VI. (A low adhesion aluminum mounting surface was used for these tests so as to result in lower one week peel values than obtained with stainless steel or painted aluminum mounting surfaces.)
TABLE VI______________________________________ RELATIVE RELATIVE AMOUNT AMOUNTEXAMPLE DETACK DETACK 1 WK.NO. RESIN (%) PARTICLE (%) PEEL______________________________________5-1 No Change +40 2.775-2 No Change +20 2.975-3 No Change -45 4.605-4 No Change -55 4.935-5 +60 No Change 3.075-6 +40 No Change 2.905-7 +20 No Change 2.805-8 -45 No Change 3.775-9 -55 No Change 3.77 5-10 -65 No Change 4.47______________________________________
Employing regression analysis, the data of Table VI are graphically shown in FIG. 4 as curve 4-1 for variation of detackifying resin concentration and curve 4-2 for variation of detackifying particle concentration. As shown in FIG. 4, a greater change in peel strength occurs for a given change in the amount of detackifying particle than occurs for a corresponding change in the amount of detackifying resin for the examined system.
The procedures of Example 1 were used to prepare the following pressure-sensitive adhesives shown in Table VII.
TABLE VII______________________________________ ADHESIVE DETACKEXAMPLE BASE DETACK PAR- TACK-NUMBER RESIN RESIN TICLE.sup.2 IFIER______________________________________6 116.sup.3 20 13.4 07 116.sup.4 20 13.4 30.sup.58 116.sup.4 20 13.4 0______________________________________ .sup.1 Tone 300 sold by Union Carbide Corporation .sup.2 CabO-Sil M5 sold by Cabot Corporation .sup.3 An acrylic polymer sold by Ashland Chemical Company under the designation Aroset 1877 .sup.4 An acrylic polymer sold by Monsanto Chemical Company under the designation Gelva 1753 .sup.5 Tackifier sold by Ashland Chemica1 Company under the designation P 293
The pressure-sensitive adhesive of Examples 6-8 were transfer laminated onto two mil vinyl substrates to provide laminates useful as positionable-repositionable facestock materials. The tack of Example 6 was 36±28 g. as measured using a Polyken tester. The 20 minute peel values are reported in Table VIII.
TABLE VIII______________________________________ Peel (lb./LINEAR INCH)EXAMPLE 20 Minute______________________________________6 2.75 ± .077 2.30 ± .008 2.20 ± .00______________________________________
Repositionability is indicated for Examples 6, 7 and 8 by 20 minute peel values less than 2.75 lb./linear inch. After 3 days, the peel values for each of the examples exceeded 3.0 lbs./linear inch.
Using laminates prepared in accordance with Example 1, the increase in adhesion build-up with the application of heat was evaluated at temperatures ranging from 110° F. to 150° F. in 10 degree increments for incremental time intervals up to a total of 30 minutes. Each laminate was applied to a stainless steel test surface by hand using a plastic squeegee to firmly position the laminate and then heated for the indicated time and temperature. Following heating, the laminate and test surface were allowed to cool at room temperature and then tested for peel strength. The results are reported below in Table IX.
TABLE IX______________________________________ TEMP 5 10 15 20 30EXAMPLE (°F.) MIN. MIN. MIN. MIN. MIN.______________________________________ 9 110 2.63 ± 2.87 ± 2.97 ± 3.20 ± 3.20 ± .06 .15 .15 .10 .1010 120 2.80 ± 3.10 ± 3.23 ± -- 3.73 ± .13 .15 .15 .1511 130 2.93 ± 3.47 ± 3.50 ± 3.97 ± 3.93 ± .15 .20 .20 .15 .2312 140 3.30 ± 3.47 ± 3.50 ± 3.83 ± 3.93 ± .1 .17 .17 .15 .1213 150 4.03 ± 4.40 ± 4.63 ± 4.17 ± 4.60 ± .25 .25 .25 .06 .26______________________________________
As shown in Table IX, the rate of adhesion build-up of the pressure-sensitive adhesives in accordance with the invention increases with temperature. Temperatures in the range of 150° F. for relatively short intervals of time such as 5 to 10 minutes achieve substantial adhesion build-up as compared with the use of lower temperatures for longer time periods.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
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A positionable-repositionable pressure-sensitive adhesive may be repeatedly applied to a surface and removed during an initial installation time period. The adhesive contains an adhesive base resin and coacting detackifying resin and particulate components which temporarily reduce the tack and peel strength of the adhesive. Upon passage of time and/or application of thermal energy, adhesion build-up occurs to a maximum value. The pressure-sensitive adhesive may be used as an adhesive layer in a laminate for tapes, signs and decorative and protective applications including vehicle marking and architectural installations.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent Application No. 2004-99281, filed on Nov. 30, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of modulating transmission data and demodulating received data. More particularly, the present invention relates to a method of modulating and demodulating data represented in two types, that is, high and low.
[0004] 2. Description of the Related Art
[0005] Generally, a transmitting end of a communication system, which sends out signal to a receiving end, carries out certain predetermined processes to reduce error of signal transmission. Therefore, the transmitting end carries out modulation with respect to the transmission data, and the receiving end carriers out demodulating processes with respect to the received data to recover to the initial data.
[0006] FIG. 1 shows a general data (signal) transmission in a conventional communication system, and FIGS. 2A to 2 H show the waveforms of the signal being processes in the transmitting and receiving nodes of the communication system. As follows, the process of modulating and demodulating data in a general communication system will be described in detail with reference to FIG. 1 , and FIGS. 2A to 2 H.
[0007] In FIG. 1 , a communication system includes a transmitting node A, a transmitting node B, and a receiving node C. Other elements may be included in the communication system. However, FIG. 1 only shows the above-mentioned elements for easier understanding.
[0008] The transmitting node A generates data (a) to transmit to the receiving node C. The transmitting node B generates data (b) to transmit to a node other than the receiving node C.
[0009] When the data to transmit is ‘1’, the data is expressed as ‘-1’, and when the data for transmission is ‘0’, it is expressed as ‘1’. As illustrated in FIG. 2A , the data (a) is ‘101’, and according to FIG. 2C , the data (b) is ‘110’.
[0010] The transmitting node carries out modulation with respect to the data for transmission. Accordingly, the transmitting node spreads data for transmission by using orthogonal codes. By the orthogonal code expansion, error rate of the data in the transmission channel can be reduced, The transmitting node spreads the transmission data by using the orthogonal code as allocated to the receiving node. The orthogonal code may include Walsh code.
[0011] Accordingly, the transmitting node A spreads transmission data by using the orthogonal code which is allocated to the receiving node C. In FIG. 1 , the receiving node C is allocated with the orthogonal code ‘w0’. With reference to FIG. 2B , the code ‘w0’ is ‘0101’, and through data expansion as illustrated in FIG. 2E , the code ‘w0’ is spread to ‘1010 0101 1010’. The transmitting node A sends out the spread data over the antenna.
[0012] The transmitting node B spreads transmission data by using the orthogonal code which is allocated to the receiving node. With reference to FIG. 1 , the orthogonal code ‘w1’ is allocated to the receiving node. With reference to FIG. 2D , the code ‘w1’ is ‘0011’, and through the data expansion as shown in FIG. 2F , the code ‘w1’ is spread to ‘1100 1100 0011’. The transmitting node B sends out expansion data over the antenna.
[0013] The receiving node C receives the spread data from the transmitting node A and from the transmitting node B. Accordingly, the receiving node C needs to extract data which is transmitted from the transmitting node A. The process by the receiving node C of extracting the data of the transmitting node A, will now be described below.
[0014] FIG. 2G shows the data received at the receiving node C. With reference to FIG. 2G , the receiving node C receives summation data of the data of the transmitting node A and the transmitting node B. For the convenience of explanation, the receiving node C therefore receives data of ‘-2 0 0 2 0-2 2 0 0 2-2 0’.
[0015] The receiving node C reverse-spreads the received data with the orthogonal code it is allocated. More specifically, the receiving node has allocated with the orthogonal code of ‘0101’, which is converted to ‘1-1 1-1’ for use in the modulation and demodulation process. Therefore, the receiving node reverse-spreads the received data ‘-2 0 0 2 0-2 2 0 0 2-2 0’ by using ‘1-1 1-1’.
[0016] With reference to FIG. 2H , the receiving node C obtains ‘-2 0 0-2 0 2 2 0 0-2-2 0’ by carrying out the reverse-expansion.
[0017] The receiving node C segments the obtained data in the unit of orthogonal code length, and averages the segmented data. More specifically, the receiving code C obtains an average ‘-1’ with respect to ‘-2 0 0-2’, obtains an average ‘1’ with respect to ‘0 2 2 0’, and obtains an average ‘-1’ with respect to ‘0-2-2 0’. As the receiving node C obtains ‘-1 1-1’, the transmitting node A can obtains transmission data ‘101’.
[0018] However, because the transmission data is expressed in three types, that is, ‘-1’, ‘0 (no data)’, ‘1’, the data range for reception at the receiving nodes increases as the number of transmitting nodes increases. In other words, when there are five transmitting nodes, the receiving node needs to receive data of ‘-5’ to ‘5’. Accordingly, bits increase to receive the data, and subsequently load also increases to process the increased data.
[0019] Furthermore, the above-explained method is not suitable for a communication system which transmits data in two types, that is, high and low. Accordingly, a method of data modulation and demodulation, which can be used in a communication system that expresses data in high and low type, is required.
SUMMARY OF THE INVENTION
[0020] Accordingly, it is an aspect of the present invention to provide a data modulation and demodulation method which can be used in a communication system transmitting data in two types, that is, ‘high’ and ‘low’ data types.
[0021] Another aspect of the present invention is to provide a method for reducing required load for reception data demodulation, by providing a communication system which transmits data in two data types, that is, ‘high’ and ‘low’ types.
[0022] The foregoing and/or other aspects of the present invention are achieved by providing a method of data modulation and demodulation for a communication system which has a transmitting end modulating a data and a receiving end demodulating the transmitted data from the transmitting end, the data being represented by two types including ‘high’ and ‘low’, and the method of data modulation and demodulation including receiving at least one data which comprises at least one code-word spread by a unique orthogonal code, and adding up the received data in the unit of code-word, subtracting the length of the orthogonal code from a value which is obtained by doubling the sum of the code-word, when the code-word of the orthogonal code is ‘0’, and averaging the result after the subtraction in the unit of orthogonal code length and extracting the result.
[0023] Additionally, the value, which is obtained by doubling the sum of the code-word, is subtracted from the length of the orthogonal code, when the code-word of the orthogonal code is ‘1’. The communication system may be a system-on-chip (SoC).
[0024] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
[0026] FIG. 1 is a view illustrating a conventional communication system modulating and demodulating data;
[0027] FIG. 2 is a view illustrating conventional waveforms of signals being processed in respective steps of the communication system of FIG. 1 ;
[0028] FIG. 3 is a view illustrating the structure of a SoC;
[0029] FIG. 4 is a view illustrating the operation of a transmitting IP according to an embodiment of the present invention; and
[0030] FIG. 5 is a view illustrating the operation of a receiving IP according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.
[0032] First, a SoC using modulation and demodulation according to the present invention will be described.
[0033] Digital information devices such as mobile phones, personal digital assistants (PDA), digital TVs, smart phones, require various semiconductor chips such as microprocessor, network chip and memory, in order to achieve efficient Internet access or computing. As the information devices get more complex and varied, incorporation of different information devices is expected to accelerate, and more chips will be subsequently needed in a single information device.
[0034] System on a chip, or SoC, is a technology suggested to incorporate not only semiconductor chips, but also all the separate components in a single chip by integrating various components in one chip. The SoC usually includes computational element, I/O, logic, and memory. Being compact and highly integrated, SoC of high performance and low power consumption is expected to be applied to a wide range of information communication devices. An intellectual property (IP) is used for efficient design of semiconductor chips. IPs refer to design blocks which are developed for application in corresponding chips.
[0035] Many studies are seeking for the techniques to realize the SoC, and especially, an efficient way of connecting several IPs of the chip, is one of the most important matters. Currently, using a bus structure and a network structure are available as a way to connect IPs. Using the bus structure almost reached a limit due to the increase of data volume transmitted between IPs, because a bus cannot be used by other IPs if any one of IPs is using the bus. In other words, one IP exclusively uses the bus.
[0036] Furthermore, the bus structure does not sufficiently support for the expansion characteristic. Due to the fixed characteristic of the bus structure, expansion of IPs in the chip is not supported. Using the network structure has been suggested in an attempt to overcome the shortcoming of the way of using bus structure. The network structure has a less power consumption than the bus structure.
[0037] FIG. 3 illustrates a SoC which transmits data to the neighboring IPs. In FIG. 3 , a star topology is illustrated in which at least two IPs share one switch. More specifically, FIG. 3 illustrates eight IPs that share one switch. The eight IPs include IP(0) to IP(7). Each IP is allocated a unique orthogonal code. Allocation of orthogonal code to each IP will be described below.
[0038] It is assumed that data is generated for IP(0) to send to IP(3), and another data is generated for IP(6) to send to IP(7). The IP(0) spreads generated data by using the orthogonal code allocated to IP(3). The IP(0) transmits the spread data to the switch. The IP(6) spreads the generated data by using the orthogonal code allocated to the IP(7). The IP(6) transmits the spread data to the switch. The switch adds up the received data and broadcast to the neighboring connected IPs. In other words, the switch transmits the sum of received data to IP(0) through IP(7).
[0039] The IP(0) through IP(7) de-spreads the received data by using the allocated orthogonal code. By the de-spreading, the IP(3) receives the data from the IP(0), and the IP(7) receives the data from the IP(6).
[0040] The process of the transmitting IP transmitting data will now be described with reference to FIG. 4 . As mentioned above, an IP of a SoC transmits data in two representation, that is, transmits data in high and low data types. For the convenience of explanation, the high data will be expressed as ‘1’, and the low data will be expressed as ‘0’.
[0041] At operation 400 , the transmitting IP stores an orthogonal code in length L, which is allocated to the IPs of a SoC. When it is assumed that seven IPs constitute the SoC, the following table 1 lists orthogonal codes which are 8 in length, respectively, and allocated to the respective IPs of the SoC:
TABLE 1 IP Allocated orthogonal code IP(0) 0101 0101(w1) IP(1) 0011 0011(w2) IP(2) 0110 1001(w3) IP(3) 0000 1111(w4) IP(4) 0101 1010(w5) IP(5) 0011 1100(w6) IP(6) 0110 1001(w7)
[0042] In this embodiment, ‘w0’ is not allocated to the IPs, but used when there is no data.
[0043] At operation 402 , the transmitting IP generates data, and spreads the generated data at operation 404 , by using the orthogonal code which is allocated to the destination IP. The transmitting IP transmits the spread data to the switch at operation 406 .
[0044] FIG. 5 illustrates the operations of a receiving IP. The operations of the receiving IP according to an embodiment of the present invention will now be described with reference to FIG. 5 .
[0045] At operation 500 , the receiving IP stores orthogonal codes in length ‘L’ to the respective IPs. The orthogonal code stored at the receiving IP at operation 500 is identical to the orthogonal code stored at the transmitting IP at operation 400 .
[0046] At operation 502 , the receiving IP receives at least one data. In other words, when there are two transmitting IPs, the receiving IP receives two data. At operation 504 , the receiving IP adds up the received data to code-word unit (word-wise unit) and obtains S[i]. The code-word unit will be explained below.
[0047] At operation 506 , the receiving IP determines whether the code-word of the orthogonal code is ‘0’ or not. If the code-word of the orthogonal code is ‘0’, the operation continues to operation 508 , while if it is ‘1’ the operation moves to operation 510 .
[0048] At operation 508 , the receiving IP doubles the sum of operation 504 and subtracts the length of the orthogonal code (2S[i]−L). At operation S 510 , the receiving IP subtracts the doubled value of the summed result of operation 504 from the length of the orthogonal code (L−2S[i]).
[0049] At operation 512 , the receiving IP averages the data of operation 508 or operation 510 , and subsequently obtains the data from the transmitting IR The operation of the receiving IP, which is illustrated in FIG. 5 , can be performed at an output port of the switch.
[0050] The characteristics and aspects of the present invention will be described mainly with reference to one exemplary embodiment of the present invention.
[0051] It is assumed that the IP(1) intends to send data ‘10’ to the IP(2). It is also assumed that the IP(3) intends to send the data ‘11’ to the IP(4). In order to transmit the data ‘10’, the IP(1) spreads the data ‘10’ by using the orthogonal code allocated to the IP(2). The orthogonal code allocated to the IP(2) is ‘0110 1001’. Accordingly, the IP(1) generates spread data of ‘1001 01100110 10001’. In order to transmits the data ‘11’, the IP(3) spreads the data ‘11’ by using the orthogonal code allocated to the IP(4). The IP(4) is allocated with the orthogonal code of ‘0101 1010’. Therefore, the IP(3) generates spread data of ‘1010 0101 1010 0101’. The IP(1) and the IP(3) transmit the generated data to the switch. The above operations can be carried out at the input port of the switch, instead of the IP(1) and IP(3).
[0052] The IP(2) and the IP(4) respectively add up the data from the IP(1) and the IP(3) in the unit of code-word, and receive the data. In other words, the IP(2) and the IP(4) receive data S[i] of ‘2011 0211 1120 1102’ (i=code word). The IP(2) and the IP(4) double the received S[i] to, ‘4022 0422 2240 2204’.
[0053] The IP(2) and the IP(4) perform operation 508 when the code-word of the allocated orthogonal code is ‘0’, and perform operation 510 when the code-word of the allocated orthogonal code is ‘1’.
[0054] The following table 2 lists the operations of the IP(2), and the following table 3 lists the operations of IP(4).
TABLE 2 2S[i] 4 0 2 2 0 4 2 2 2 2 4 0 2 2 0 4 L 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 Allocated orthogonal code 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 D[i] −4 8 6 −6 8 −4 −6 6 −6 6 4 −8 −6 6 −8 4
[0055]
TABLE 3
2S[i]
4 0 2 2 0 4 2 2 2 2 4 0 2 2 0 4
L
8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8
Allocated orthogonal code
0 1 0 1 1 0 1 0 0 1 0 1 1 0 1 0
D[i]
−4 8 −6 6 8 −4 6 −6 −6 6 −4 8 −6 6 8 −4
[0056] The IP(2) adds up the D[i] of Table 2 in the unit of orthogonal code length and averages the result. In other words, the IP(2) obtains an average ‘1’ of ‘-4 8 6-6 8-4-6 6’, and obtains an average ‘-1’ of ‘-6 6 4-8-6 6-8 4’. Based on the assumption that the transmission data is ‘1’ when the average is ‘1’, and the transmission data is ‘0’ when the average is ‘-1’, the IP(2) can obtain ‘10’ transmitted from the IP(1).
[0057] The IP(4) adds up the D[i] of Table 3 in the unit of orthogonal code length and averages the result. In other words, the IP(4) obtains an average ‘1’ of ‘-4 8-6 6 8-4 6-6’, and obtains an average ‘-1’ of ‘-6 6-4 8-6 6 8-4’. Based on the assumption that the transmission data is ‘1’ when the average is ‘1’, and the transmission data is ‘0’ when the average is ‘-1’, the IP(4) can obtain ‘11’ transmitted from the IP(3).
[0058] The above examples shows transmission of only two IPs. However, the present invention is equally applicable to a case where all of the IPs of the SoC transmit data. Of course, the length of the allocated orthogonal codes increases as the number of IPs of the SoC increases.
[0059] Although FIGS. 3 to 5 shows the operations at IPs and the switch of SoC, it should not be construed as limiting. In other words, any system that can transmit and receive data in ‘high’ and ‘low’ data types may equally utilize the technical idea of the present invention in transmitting and receiving data.
[0060] As described above in a few exemplary embodiments of the present invention, a system transmits and receives data in two data types, that is, ‘high’ and ‘low’, in modulating and demodulating the data. Compared to a conventional system, which modulates and demodulates data in three data representation types, a smaller range of reception is provided to a receiving end and therefore, load to the receiving end reduces. More specifically, in a system which has five transmitting nodes, and modulates and demodulates data in three representation types, a receiving node needs to express ‘-5’ to ‘5’. On the contrary, in the system employing the present invention, a receiving node is only required to express ‘0’ to ‘5’.
[0061] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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A method of modulating data, which is represented by two data types of ‘high’ and ‘low’, and demodulating the modulated data, is disclosed. In a method of data modulation and demodulation for a communication system which has a transmitting end modulating a data and a receiving end demodulating the transmitted data from the transmitting end, the data is represented by two types including ‘high’ and ‘low’, and the receiving end receives at least one data which consists of at least one code-word spread by a unique orthogonal code. The receiving end adds up the received data in the unit of code-word, and subtracts the length of the orthogonal code from a value which is obtained by doubling the sum of the code-word, when the code-word of the orthogonal code is ‘0’. The receiving end then averages the result after the subtraction in the unit of orthogonal code length and e-tracts the result, and therefore obtains the data from the transmitting end.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. divisional application filed under 37 CFR 1 . 53 ( b ) claiming priority benefit of U.S. Ser. No. 12/379,759 filed in the United States on Feb. 27, 2009, which claims earlier priority benefit to Korean Patent Application No. 10-2008-0112362 filed with the Korean Intellectual Property Office on Nov. 12, 2008, the disclosures of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to a printed circuit board (PCB) having a flow preventing dam and a manufacturing method thereof, and more particularly to a PCB having a flow preventing dam, in which the flow preventing dam is provided on the peripheral area of the PCB so as to prevent the outflow of an underfill solution which is introduced between the PCB and a semiconductor chip which is flip chip bonded thereto.
[0004] 2. Description of the Related Art
[0005] With the recent advancement of electronics industries, there is a demand for increasing performance and functionality of electronic components and reducing the size thereof. Accordingly, high integration, slimness and fine circuit patterning are also required on a substrate for surface mounting components, such as SIP (System in Package), 3D package, etc.
[0006] In particular, in techniques for mounting electronic components on the surface of a substrate, a wire bonding process or a flip chip bonding process is utilized for electrical connection between an electronic component and a substrate.
[0007] The wire bonding process includes bonding an electronic component having design circuits to a PCB using an adhesive, connecting a lead frame of the PCB to a metal terminal (i.e., pad) of the electronic component using a metal wire to transmit and receive information therebetween, and molding the electronic component and the wire with thermosetting resin or thermoplastic resin.
[0008] The flip chip bonding process includes forming an external connection terminal (i.e., bump) having a size of tens of μm to hundreds of μm on an electronic component using a material such as gold, solder or another metal, and flipping the electronic component having the bump so that the surface thereof faces the substrate and is thus mounted on the substrate, unlike the mounting operation based on the wire bonding.
[0009] Although the wire bonding process has higher productivity compared to other packaging processes, it needs wires for connection to the PCB, and thus the size of a module is increased and an additional procedure is required. Hence, the flip chip bonding process is mainly employed.
[0010] FIGS. 1 and 2 are views showing a process of packaging a flip chip semiconductor package according to a conventional technique.
[0011] As shown in FIGS. 1 and 2 , the flip chip bonding according to the conventional technique is performed in a manner such that solder balls 16 are attached to the connection pads 14 of a PCB 12 and a semiconductor chip 18 is mounted on the PCB 12 by means of the solder balls 16 .
[0012] In this way, however, when the semiconductor chip 18 is mounted on the PCB 12 , a gap G is formed between the semiconductor chip 18 and the PCB 12 due to the height of the solder balls 16 attached to the connection pads 14 of the PCB 12 , undesirably weakening the ability to support the semiconductor chip 18 and causing cracks around the soldering portion of the solder balls 16 . In particular, in the case where a temperature change occurs, the coefficient of thermal expansion between the semiconductor chip 18 and the PCB 12 is different, and thus thermal stress is applied to the solder balls 16 , thereby causing cracks on the solder balls 16 .
[0013] Hence, with the goal of stably supporting the semiconductor chip 18 , an underfill solution 22 of a liquid material is introduced into the gap G between the semiconductor chip 18 and the PCB 12 using a dispenser 20 .
[0014] The underfill solution 22 is introduced in a small amount between the semiconductor chip 18 and the PCB 12 and thus functions as an adhesive for holding the chip and plays a role in protecting the chip from the external environment, unlike a conventional semiconductor molding material (EMC) for packaging the entire semiconductor chip 18 .
[0015] However, in the course of introducing the underfill solution 22 using the dispenser 20 , part of the underfill solution 22 which is introduced into the gap G between the semiconductor chip 18 and the PCB 12 may undesirably overflow the outer edge of the PCB 12 from the position where the dispenser 20 is located, causing defects.
[0016] In order to solve this problem, there have been proposed methods of forming a dam on the peripheral area of the PCB using a dispensing process.
[0017] However, the dispensing process which is used to form a linear dam through linear extrusion of epoxy resin from a dispensing nozzle is problematic in that the width of the dam may be non-uniform, and the shape of the dam may become winding due to frictional force at the end of the dispensing nozzle.
[0018] Further, an additional dispensing apparatus is required to form the dam, and a process for forming the dam should be additionally carried out.
SUMMARY
[0019] Accordingly, the present invention has been made keeping in mind the problems encountered in the related art and the present invention provides a PCB having a flow preventing dam, which is able to prevent the outflow of an underfill solution, and a manufacturing method thereof.
[0020] In addition, the present invention provides a PCB having a flow preventing dam, in which the flow preventing dam is formed using a dry film resist for forming a solder bump without a need for an additional dispensing apparatus or dispensing process, and a manufacturing method thereof.
[0021] According to a preferred embodiment of the present invention, a PCB having a flow preventing dam includes a base substrate having a solder pad, a solder bump formed on the solder pad of the base substrate, and a flow preventing dam formed on the peripheral area of the base substrate using a dry film resist.
[0022] As such, a solder resist layer having an opening for exposing the solder pad may be formed on the base substrate.
[0023] The flow preventing dam may include the dry film resist which is attached in a state of being overcured through excessive exposure to the solder resist layer.
[0024] Also, a semiconductor chip which is flip chip bonded to the base substrate by means of the solder bump formed on the solder pad of the base substrate may be further included.
[0025] The flow preventing dam may be provided to protrude from the base substrate along the outer edge of the semiconductor chip, in order to prevent the outflow of an underfill solution which is introduced into a gap between the semiconductor chip and the base substrate.
[0026] The flow preventing dam may be formed to be lower than the upper surface of the semiconductor chip which is flip chip bonded to the base substrate and to be higher than the gap between the semiconductor chip and the base substrate.
[0027] The flow preventing dam may be provided between the outer edge of the base substrate and the outer edge of the semiconductor chip.
[0028] In addition, according to another preferred embodiment of the present invention, a method of manufacturing a PCB having a flow preventing dam includes (A) applying a dry film resist on a base substrate having a solder pad, and then primarily exposing the dry film resist to light, (B) secondarily exposing the primarily exposed dry film resist formed on a peripheral area of the base substrate to light, thus forming a flow preventing dam, (C) removing the unexposed dry film resist to expose the solder pad, thus forming an opening, (D) printing the opening with a solder paste and then forming a solder bump through a reflow process, and (E) removing the primarily exposed dry film resist.
[0029] After (E) removing the primarily exposed dry film resist, (F) flip chip bonding a semiconductor chip to the base substrate by means of the solder bump formed on the solder pad of the base substrate may be further included.
[0030] After (F) flip chip bonding the semiconductor chip, (G) introducing an underfill solution into a gap between the semiconductor chip and the base substrate may be further included.
[0031] The flow preventing dam may be provided to protrude from the base substrate along the outer edge of the semiconductor chip, in order to prevent outflow of an underfill solution which is introduced into the gap between the semiconductor chip and the base substrate.
[0032] The flow preventing dam may be formed to be lower than an upper surface of the semiconductor chip which is flip chip bonded to the base substrate and to be higher than the gap between the semiconductor chip and the base substrate.
[0033] The flow preventing dam may be provided between the outer edge of the base substrate and the outer edge of the semiconductor chip.
[0034] Also, a solder resist layer having an opening for exposing the solder pad may be formed on the base substrate.
[0035] The features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.
[0036] Further, the terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept implied by the term to best describe the method he or she knows for carrying out the invention
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIGS. 1 and 2 are views showing a process of packaging a flip chip semiconductor package according to a conventional technique;
[0038] FIG. 3 is a cross-sectional view showing a PCB having a flow preventing dam according to a preferred embodiment of the present invention;
[0039] FIG. 4 is a cross-sectional view showing the PCB having a flow preventing dam according to the preferred embodiment of the present invention, to which a semiconductor chip is flip chip bonded;
[0040] FIG. 5 is a top plan view of FIG. 4 ; and
[0041] FIGS. 6 to 13 are cross-sectional views showing the process of manufacturing the PCB having a flow preventing dam according to the preferred embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0042] The features and advantages of the present invention will be more clearly understood from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In the description, the terms “first”, “second” and so on do not indicate any particular amount, sequence or importance but are used only to distinguish one element from another element. Throughout the drawings, the same reference numerals refer to the same or similar elements, and redundant descriptions are omitted. In order to make the characteristics of the invention clear and for the convenience of description, a detailed description pertaining to the other known techniques may be omitted.
[0043] Hereinafter, a detailed description will be given of the preferred embodiment of the present invention, with reference to the accompanying drawings.
[0044] PCB having Flow Preventing Dam
[0045] FIG. 3 is a cross-sectional view showing the PCB having a flow preventing dam according to the preferred embodiment of the present invention. With reference to this drawing, the PCB 100 having a flow preventing dam according to the preferred embodiment of the present invention is described below.
[0046] As seen in FIG. 3 , the PCB 100 having a flow preventing dam according to the present invention includes a base substrate 102 having solder pads 104 , solder bumps 116 formed on the solder pads 104 , and a flow preventing dam 110 c formed on a peripheral area thereof.
[0047] The base substrate 102 is configured such that the solder pads 104 are formed on either or both surfaces thereof and a solder resist layer 106 having openings for exposing the solder pads 104 is formed.
[0048] The flow preventing dam 110 c is composed of a dry film resist which is attached in a state of being overcured through excessive exposure to the solder resist layer 106 .
[0049] FIGS. 4 to 5 are a cross-sectional view and a top plan view showing the PCB having a flow preventing dam according to the preferred embodiment of the present invention, to which a semiconductor chip is flip chip bonded;
[0050] As shown in FIGS. 4 and 5 , the semiconductor chip 118 is flip chip bonded to the base substrate 102 by means of the solder bumps 116 formed on the solder pads 104 of the base substrate 102 , and an underfill solution 120 is introduced between the semiconductor chip 118 and the base substrate 102 .
[0051] The flow preventing dam 110 c is provided to protrude from the base substrate 102 along the outer edge of the semiconductor chip 118 , thus preventing the outflow of the underfill solution 120 .
[0052] The flow preventing dam 110 c is provided between the outer edge of the base substrate 102 and the outer edge of the semiconductor chip 118 , and is formed to be higher than the gap G between the base substrate 102 and the semiconductor chip 118 and to be lower than the upper surface of the semiconductor chip 118 , in order to prevent the outflow of the underfill solution 120 .
[0053] Method of Manufacturing PCB having Flow Preventing Dam
[0054] FIGS. 6 to 13 are cross-sectional views showing the process of manufacturing the PCB having a flow preventing dam according to the preferred embodiment of the present invention.
[0055] With reference to FIGS. 6 to 13 , the method of manufacturing the PCB having a flow preventing dam according to the present invention is described below.
[0056] As shown in FIG. 6 , a dry film resist 110 is applied on the baser substrate 102 having solder pads 104 .
[0057] The base substrate 102 is configured such that the solder pads 104 are formed on one surface thereof and the solder resist layer 106 having openings 108 for exposing the solder pads 104 is formed on the base substrate 102 .
[0058] The dry film resist 110 includes a photoresist in a film form, a mylar film formed on one surface of the photoresist to impart flexibility thereto, and a cover film formed on the other surface thereof.
[0059] The dry film resist 110 is applied in a state of peeling off the cover film using a typical dry film laminating apparatus.
[0060] The dry film resist 110 may be formed to a predetermined thickness in consideration of the size of the solder bumps 116 and the height of the flow preventing dam 110 c.
[0061] Next, as shown in FIG. 7 , the portion of the dry film resist 110 , other than the portion of the dry film resist 110 applied on the solder pads 104 , is subjected to a primary exposure process.
[0062] The primary exposure process is performed by exposing the portion of the dry film resist 110 , other than the portion thereof applied on the solder pads 104 , to UV light, using a mask (not shown) having a predetermined pattern.
[0063] The primarily exposed dry film resist 110 b , other than the unexposed dry film resist 110 a applied on the solder pads 104 , is cured through polymerization in the primary exposure process.
[0064] Next, as shown in FIG. 8 , the primarily exposed dry film resist 110 a formed on the peripheral area of the base substrate 102 is subjected to a secondary exposure process, thus forming the flow preventing dam 110 c.
[0065] As such, the secondarily exposed dry film resist, which forms the flow preventing dam 110 c , is overcured through excessive exposure and is thus more firmly attached to the solder resist layer 106 . Accordingly, the dam is not removed in a subsequent dry film resist stripping process.
[0066] Next, as shown in FIG. 9 , the unexposed dry film resist 110 a is removed through a development process to expose the solder pads 104 , thus forming openings 112 .
[0067] The development process is performed by dissolving and removing the uncured portion other than the cured portion due to UV exposure, and thus the unexposed dry film resist 110 a is removed using a developer such as sodium carbonate (Na2CO3) or potassium carbonate (K2CO3).
[0068] Next, as shown in FIG. 10 , the openings 112 are printed with a solder paste.
[0069] The solder paste 114 is printed through a screen printing in a manner such that the base substrate 102 is disposed on a printing table, a mask having a plurality of openings is placed on the base substrate, and the solder paste is pressed into the openings of the mask using a squeegee.
[0070] Next, as shown in FIG. 11 , the printed solder paste 114 is subjected to a reflow process, thus forming solder bumps 116 .
[0071] The solder paste 114 printed in the openings 112 of the dry film resist 110 is formed in a round shape through a reflow process to be lower than the flow preventing dam 110 c . In the case where the semiconductor chip 118 is mounted on the solder bumps 116 , the gap G between the base substrate 102 and the semiconductor chip 118 is lower than the flow preventing dam 110 c , and therefore the flow preventing dam 110 c can prevent the outflow of the underfill solution which is introduced into the gap G.
[0072] As shown in FIG. 12 , the primarily exposed dry film resist 110 b is removed.
[0073] The primarily exposed dry film resist 110 b may be stripped using a stripping solution such as NaOH or KOH.
[0074] In the course of bonding the OH— of the stripping solution with the carboxyl group (COOH+) of the dry film resist, the primarily exposed dry film resist 110 b gets loose and thus is stripped. Because the secondarily exposed dry film resist, namely, the flow preventing dam 110 c , is attached in a state of being overcured through excessive exposure to the solder resist layer 106 , it is not removed by the stripping solution.
[0075] As shown in FIG. 13 , the semiconductor chip 118 is flip chip mounted on the base substrate 102 by means of the solder bumps 116 , and the underfill solution 120 is introduced into the gap G between the base substrate 102 and the semiconductor chip 118 , thus completing a flip chip package.
[0076] The flow preventing dam 110 c is provided to protrude from the base substrate along the outer edge of the semiconductor chip 118 , and is formed to be higher than the gap between the base substrate 102 and the semiconductor chip 118 and to be lower than the upper surface of the semiconductor chip 118 , thereby preventing the outflow of the underfill solution.
[0077] As described hereinbefore, the present invention provides a PCB having a flow preventing dam and a manufacturing method thereof. According to the present invention, the flow preventing dam is provided, thus preventing the expansion and outflow of an underfill solution.
[0078] Also, according to the present invention, the flow preventing dam is formed through excessive exposure of a dry film resist used in the course of forming solder bumps, thus obviating a need for additional material, apparatus, and process.
[0079] Also, according to the present invention, the flow preventing dam can be formed with the dry film resist, and thus the height and width thereof are uniform.
[0080] Also, according to the present invention, the outflow of the underfill solution is prevented, thus improving the overall package reliability.
[0081] Although the preferred embodiment of the present invention regarding the PCB having a flow preventing dam and the manufacturing method thereof has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible within the scope of the invention.
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A method of manufacturing a printed circuit board having a flow preventing dam, including: applying a dry film resist on a base substrate having a solder pad, and then primarily exposing the dry film resist to light; secondarily exposing the primarily exposed dry film resist formed on a peripheral area of the base substrate to light, thus forming a flow preventing dam; removing the unexposed dry film resist to expose the solder pad, thus forming an opening; printing the opening with a solder paste, and then forming a solder bump through a reflow process; and removing the primarily exposed dry film resist
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to pulling, pushing, or lifting of materials, including objects, on penetrable terrain and more particularly to an apparatus which uses multi-directional anchoring to react the forces generated in performing various material handling tasks.
2. Description of the Related Art
The present invention is directed to providing a more efficient alternative to tractor-type vehicles. Vehicles of this type pull or push work-performing implements or objects, by developing high tractive forces through friction with the surface of the ground on which they operate. The total pulling or pushing force generated by a tractor is most dependent upon, and proportional to, the weight of the vehicle. An upper bound for pulling or pushing ability is usually taken to be equal to the weight of the vehicle. For requirements in the range of tens of thousands of pounds, the required tractor is large, expensive, and in need of frequent maintenance and a skilled operator.
Caterpillar Tractor Co. Model Nos. 528 and 508 relate to "skidders" which are vehicles which handle material through the use of a vehicle mounted winch. The weight of these vehicles and their frictional effect with the ground, through contact patches of their wheels, determines the maximum pulling force available. U.S. Pat. No. 4,093,034, issued to Curley et al., assigned to Caterpillar Tractor Co., entitled "Vehicle Supported Winch" discloses a winch system applicable to the above-identified model numbers.
U.S. Pat. No. 3,613,816 issued to W. Gutbrod, entitled "Self-Propelled Multipurpose Vehicle" discloses a utility vehicle of the two-axle type which is designed to fulfill general and cross country transportation requirements and which may include towing or hoisting operations. The power take-off accessory or, capability of the vehicle can be used as a built on or hung on work performing accessory. The '816 device uses a system of belts, clutches and gears which constitute the power take-off facility. Likewise, the hoisting facility, built onto the vehicle is provided by a separate series of clutches and gears.
U.S. Pat. No. 4,202,453, issued to Wilkes Jr. et al, entitled "Articulated Mine Service Vehicle", discloses a hydraulic powered vehicle which performs lifting tasks by means of a winch and boom crane mounted to the vehicle. The vehicle's primary purpose is to lift and carry extremely heavy loads. Like other utility vehicles, this device is dependent upon its own weight to provide the friction necessary for proper operation as a tractor.
OBJECTS AND SUMMARY OF THE INVENTION
It is a principal object of the present invention to pull, push or lift materials, including objects, in a manner that does not rely on the frictional characteristics between the equipment and the surface on which equipment operates.
It is another object of the present invention to reduce the amount of hardware required to do heavy pulling, pushing and/or or hoisting tasks.
Yet another object of the present invention is to provide a means of anchoring a material handling apparatus to a penetrable surface for reacting the pulling, pushing or lifting forces.
Still another object is to provide a system for handling and transporting material relative to a penetrable surface.
Still another object of the present invention is to provide an efficient extraterrestrial material handling and transporting vehicle for construction and mining applications in low gravity environments.
These and other objects are achieved by the present invention which, in its broadest aspects, comprises a chassis, anchoring means retained in the chassis and material handling means secured to the chassis. The anchoring means provides multi-directional anchoring of the chassis onto a penetrable surface upon which the apparatus rests. The anchoring means comprises a pair of counter-rotating shafts whose lower ends comprise left and right-hand helical augers, respectfully. The upper ends of the shafts are drivingly connected to a means of rotation. The material handling means pulls, pushes or lifts the material being handled. The anchoring means is so retained in the chassis to react the operating forces of the material handling apparatus.
Use of this multi-directional anchoring mechanism obviates the requirement for massive, traction based devices, which presently perform large material handling tasks.
The present invention is distinguished from the winch systems disclosed by Caterpillar Tractor Company. It provides a more secure, active means of anchoring and generating a high winching capability (by use of the anchoring mechanism) rather than relying on mere friction effects produced by wheel contact patches.
The term "penetrable" as used herein refers broadly to any surface in which helical augers may penetrate. Thus, for example, a penetrable surface may include natural terrain on earth, the lunar surface or other extraterrestrial surfaces.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of the material handling apparatus of the present invention.
FIG. 2 is a top plan view of the FIG. 1 apparatus, taken along line 2--2 of FIG. 1.
FIG. 3 is a top plan view of the counter-rotating mechanism of the shafts, taken along line 3--3 of FIG. 1.
FIG. 4 is a side elevation view of an alternate embodiment of the material handling apparatus, illustrating a dual function motor for alternatively operating the anchoring means and the material handling means of the present invention.
FIG. 5 is an end view of the FIG. 4 embodiment, taken along line 5--5 of FIG. 4.
FIG. 6 is a side elevation view of the material handling apparatus mounted on a vehicle to form a system for handling and transporting material.
The same elements or parts throughout the figures are designated by the same reference characters.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and the characters of reference marked thereon, the material handling apparatus of the present invention is designated generally as 10 in FIG. 1. The apparatus 10 may be placed on a vehicle (as will be described below) or may be manufactured in either sufficiently small size or/and weight to be hand carried. A chassis, designated generally as 12, retains the operating portion of the apparatus and reacts to forces generated during operation of the apparatus 10. (The chassis 12 illustrated in FIG. 1 may be disassembled for ease of stowage. Or, if preferred, the chassis may be constructed as a unitary structure.) Chassis 12 includes a triangular framework of tubular elements. Lower, triangular elements 14 connect to a fairlead assembly 16 at a forward end of the tubular framework. Upper diagonal tubular elements 18 also connect to this fairlead assembly 16. The rear end of the tubular elements 18 are connected to fixed joints 20. Each diagonal stabilizing element 22 is supported between a fixed joint 20 and a pin joint 24 at the rear of the tubular element 14. As can be seen in FIG. 2, the fixed joints 20 are connected by a lateral tubular element 26.
At the rear end of the chassis 12, are side plates 28 which attach at their lower ends, to the lower pin joints 24 and, at their upper ends, to upper pin joints 30. Upper pin joints 30 attach to the end of rear, upper diagonal tubular elements 32. An upper cradle 34 is connected at the upper end of the side plates 28 and a lower cradle 36 is connected at the lower end of the side plates 28. Upper cradle 34 and lower cradle 36 have semi-circular cutout portions 38 (see FIG. 2) for maintaining the position of the rotating shafts and for transmitting the forces induced by these large diameter shaft, as will be discussed below. Both the upper and lower cradles 34, 36 have similar cutouts. The two side plates 28 are connected by an end plate 40. Upper shaft retainer 42 and lower shaft retainer 44 hold the shafts in the cutouts 38.
As noted, two large diameter shafts 46, 48 are retained by the cutouts 38 in the cradles 34, 36. The shafts 46, 48 are free to move vertically within their respective cradles so as to submerge or retract the shafts into or out of the penetrable surface in which the apparatus is operating. The lower ends of the pair of shafts 46, 48 include left and right-hand helical augers 50, respectively. The upper ends of shafts 46, 48 each transition to a narrow diameter 52 which rests in upper and lower bearings 54, 56.
In addition to the shafts, the anchoring means, designated generally as 58, for providing multi-directional anchoring of the chassis 12, includes a mechanism for providing high torque, counter-rotating motion to the shafts. Referring now to FIG. 3, this high torque counter-rotating mechanism comprises a rectangular box structure 60, gear motor 62, and chain drive assembly designated generally as 64. This counter-rotating mechanism includes upper and lower shaft bearings 56, 54, as identified previously. The required counter-rotating motion of the shafts is created by the gear motor 62 which operates a system of chains and sprockets. A drive sprocket 66 on the gear motor 62 drives a small sprocket 68 (via chain 69) on one of the shafts. Another small sprocket is driven on the same chain on lay shaft 70 to reverse the direction of rotation for the opposite large shaft 48 via chain 72.
The material handling means, designated generally as 74, is secured to the chassis 12 for pulling material to be handled. Material handling means 74 includes a winch assembly 76. Winch assembly 76 includes a cable 78 and a hook 80. Winch assembly 76 is bolted to the end plate 40.
Power control of gear motor 62 is provided by electric leads 82. Power and control of winch assembly 76 is provided by electric leads 84. The winch assembly and/or gear motor may be operated by electric, hydraulic or pneumatic means.
During operation the user places the device on the surface of the ground. The user operates gear motor 62 with a switch on his controller to operate the gear motor 62 and counter-rotating drive mechanism, the helical augers 50 of the shafts being in contact with the surface of the ground. The augers 50 pull their respective anchor shafts into the ground. The user deactivates the gear motor 62 when the auger shafts have submerged to their maximum depth.
At this point, the mechanism is anchored to the surface of the ground and the user takes the cable hook from the winch assembly 76 and attaches it to the material to be moved. The user then activates the switch for the winch assembly 76 and the material is drawn toward the material handling device, horizontally along the surface of the ground. When the desired movement of the material is achieved, the user stops the winch action, activates the gear motor 62 in reverse for the anchor shaft counter-rotation and the helical ends of the anchor shafts push the anchor shafts upward out of the ground.
When the helical augers 50 have reached the surface of the ground, the device is ready to be relocated in a different position if the material is to be moved another distance. Once the device is relocated, the entire operation is repeated a number of times sufficient to move the material from its initial position to its desired position.
Instead of, or in addition to, the winch assembly 76, a jack screw assembly or hydraulic cylinder may be used to provide a means for pushing or pulling material to be handled. Such a jack screw assembly is illustrated in phantom as general numeral designation 86. During the operation of the material handling device, using the jack screw assembly for pushing and pulling, the operator would position the apparatus 10 on the surface of the ground and anchor the apparatus using the gear motor switch to lower the anchor shafts, as was described previously. The horizontal tubular elements on the jack screw assembly 86 are adjustable and are used to position the end of the jack screw. The end of the jack screw assembly consists of a fitting which is accommodated by a corresponding receptable on the material or object to be pulled or pushed. After the horizontal positioning elements have been fixed at a position at which the receptacle and fitting on the material to be moved are coincident, and the device is securely anchored to the surface of the ground, a switch for the jack screw assembly gear motor is activated and the material to be moved is either pushed or pulled.
An alternate embodiment of the device consists of a combined winch assembly and counter-rotation gear motor unit, which can be alternatively selected using a selector on the unit. FIGS. 4 and 5 illustrate such an alternate arrangement. Referring now to these figures the winch assembly 88 is located above the shaft bearing holder 90. The winch assembly 88 has a dual mode selector mechanism, 91, which allows it to function as either a winch or as the gear motor to counter-rotate the shafts. The shaft rotation mechanism includes the rotation of a jack screw 92 which aids in raising and lowering the anchoring means 94. Pulley 96 changes the direction of winch cable 98 from horizontal to vertical, since in the alternative embodiment, winch 88 resides atop the apparatus.
The present invention was developed to perform extraterrestrial construction and mining tasks, particularly for the lunar surface. For such tasks on the lunar surface where the gravitational pull is only approximately 1/6 that of the earth, use of conventional pushing, pulling and lifting techniques are problematic because these tasks are normally dependent on the ability to generate traction relative to the surface on which the equipment is resting. By supplying a more secure means of anchoring to the surface, more effective construction and mining equipment is attained.
Referring now to FIG. 6, it can be seen that the apparatus 10 can be readily adapted to an extraterrestrial construction and mining vehicle, designated generally as 100. Vehicle 100 comprises a vehicle chassis 102 from which material handling apparatus 10 may be suspended and lowered to the extraterrestrial surface. Alternatively, apparatus 10 can be built into the vehicle and the vehicle's wheels can be retracted to lower the apparatus to the ground. The vehicle nominally consists of four driven and steered wheels to provide the required mobility. Robotic control of the vehicle 100 is accomplished through the use a video camera system 104 and associated communication link (not shown). The attachment and detachment of material handled by vehicle 100 is assisted by a remotely controlled arm 106.
During the operation of material handling system on the vehicle for a pulling application, the user, located at a remote site, would maneuver the vehicle using the camera system to a point where the material to be handled is within reach of manipulator arm 106. Arm 106 would be used to place the hook of the material handling apparatus 10 on the material to be moved. The user would then maneuver the vehicle away from the material to be handled a distance compatible with the length of the cable or the terrain between the two objects. When the proper distance is achieved, the operator would stop the vehicle 100 and lower the material handling apparatus 10 to the surface of the ground and use his control to operate the gear motor on the anchoring shaft to submerge the anchor shafts into the ground to their maximum depth. Once the vehicle is properly anchored, the user would switch to the winch operation and draw the material to be handled to the vehicle using the winch and cable. When that sequence is finished, the user would retract the anchoring system by operating the gear motor in reverse he would then raise the material handling device off the surface to provide ground clearance and he would advance vehicle 100 to a new location to reset the anchor. This process would be repeated until the material was moved the required distance.
During the operation of vehicle 100 in a pushing or lifting mode, the operator would, again, maneuver the vehicle using the remote camera system, to the proper proximity with the object to be moved. In this operation, however, the operator would be using the jack screw assembly located on the front of the vehicle and would position the jack screw in the retracted position at the proper distance away from the object to be pushed or lifted. From this position, the user would lower the material handling device 10 to the surface and again submerge the anchoring device to its maximum depth. From this configuration, the operator would operate the jack screw assembly to either push or pull the object to be moved to its new location. Once the desired position is achieved, the anchoring system would be retracted, the material handling apparatus would be withdrawn from the surface and the vehicle would be positioned at a new point.
Obviously, 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 material handling apparatus comprises a chassis, an anchoring mechanism retained in the chassis and a material handling mechanism secured to the chassis. The anchoring mechanism provides multi-directional anchoring of the chassis onto a penetrable surface upon which the apparatus rests. The anchoring mechanism comprises a pair of counter-rotating shafts whose lower ends comprise left and right-hand helical augers, respectfully. The upper ends of the shafts are drivingly connected to a means of rotation. The material handling mechanism pulls, pushes or lifts the material being handled. The anchoring mechanism is so retained in the chassis to react the operating forces of the material handling apparatus. Use of this multi-directional anchoring mechanism obviates the requirement for massive, traction based devices, which presently perform large material handling tasks.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Division of U.S. Ser. No. 11/721,256, filed Sep. 16, 2008, which is a National Phase conversion under 35 U.S.C. §371 of PCT/ES2005/000068, filed Feb. 10, 2005, which claims benefit of priority from Spanish Application No. ES200400424, filed Feb. 11, 2004, the disclosure of which are each incorporated herein by reference. PCT International Application was published in the Spanish language.
FIELD OF THE INVENTION
[0002] The invention involves the use of P substance antagonists, specifically non-peptide NK1 receptor antagonists, in the treatment of human cancers, explicitly on melanoma, neuroblastoma, glioma, Hodgkin's-KM-H2 lymphoma, lymphoblastic leukemia, Rhabdomyosarcoma, breast cancer, Burkitt's lymphoma, lung cancer, Ewing's sarcoma and human osteosarcoma.
BACKGROUND OF THE INVENTION
[0003] Substance P is a natural undecapeptide from the Tachykinins family and is used for its rapid stimulant action on smooth muscle tissue. More specifically, Substance P is an active pharmacological neuropeptide that is produced in mammals. It was originally isolated in the intestine and possesses an amino acid sequence that has been described by D. F. Veber, in the patent U.S. Pat. No. 4,680,283. The implication of Substance P, like in other Tachykinins, is seen in the physiopathology in a large number of illnesses that are well demonstrated in the bibliography.
[0004] Substance P receptor is a member of the super family of G-protein-coupled receptors. The neuropeptide receptor of Substance P (NK-1) is well distributed in the nervous system of mammals (especially in the cerebrum and spinal cord) the circulatory system and in the peripheral tissues (especially in the duodenum and in the jejunum) and is involved in the regulation of diverse biological processes.
[0005] The central and peripheral action of the Tachykinins in mammals have been associated with various inflammatory conditions such as migraines, rheumatoid arthritis, asthma, and intestinal inflammatory disease, as well as in the mediation of nauseous reflexes, and the regulation of CNS central nervous system disorders such as Parkinson's disease. (Neurosci. Res., 1996, 7, 187-214), anxiety (Can. J. Phys.; 1997, 612-621) and depression (Science, 1998, 281, 1640-1645).
[0006] In the article titled “Tachykinin Receptor and Tachykinin Receptor Antagonists”, by J. Auton, in Pharmacol.; 1993, 13, 23-93, the use of antagonists of Substance P have been evidenced in the treatment of headaches, especially migraines, Alzheimer's disease, multiple sclerosis, attenuation of the syndrome in the absence of opiates, cardio vascular changes, edemas, such as those provoked by burns, in chronic inflammatory illnesses like rheumatoid arthritis, asthma, hyperactive bronchials, and other respiratory illnesses including allergic rhinitis, etc.
[0007] Also, U.S. Pat. No. 5,972,938 describes a method for the treatment of a psychoimmunological disorder or psychomotor by way of the administration of an NK1 receptor antagonist.
[0008] The article published in Nature, 2000, 405 (6783), 180-183 details the activity in rats lacking NK-1 receptors and shows a decrease in the beneficial effects of morphine. Consequently, the NK-1 antagonist receptors can be used in the treatment of breaking certain drug addition habits such as those associated with opiates, nicotine as well as in the reduction of abuse and abstinence from the drugs.
[0009] The article in Life Sci.; 2000, 67(9), 985-1001 describes the Astrocytes express functional receptors for various neurotransmitters in the reception of Substance P. The cerebral tumors of malignant glials derived from Astrocytes unchain under the action of the Tachykinins mediating the NK-1 receptors in the secretion of soluble mediators that augment the speed of reproliferation. Consequently, the selective antagonists of NK-1 can be very useful therapeutic agents in the treatment of malignant gliomas and for the treatment of cancer.
[0010] Additionally, the New Journal of Medicine, 1999, 340, 190-195, states that the use of a selective NK1 receptor induces the reduction of vomiting by employing cisplatin.
[0011] In the article published in the International Journal of Cancer by Antal Orosz et al. 1995, 60, 82-87, the use of diverse peptide antagonists in Substance P (SP) is described in the inhibition of the proliferation of lung cancer cells. (Ex. in designated cells NCI-H69). Equally as important is the article published in Cancer Research, 1994, 54, 3602-3610, describing another antagonist of Substance P (SP) as well as other peptides capable of the inhibition of the growth of various in-vitro lines in cancerous lung cells (ex. Designated cells NCI-H510, NCI-H345, and SHP-77).
[0012] The patent EP 773026 (Pfizer) states the use of non-peptide NK1 receptor antagonists in the treatment of breast cancer, particularly in the treatment of small lung cancers in APUdoma, neuro endocrinic tumors, and small extra lung carcinomas.
[0013] Additionally in the WO 2001001922 patent the use of NK1 receptors in the treatment of adenocarcinoma is described, most specifically in prostatic carcinomas. Giardina, G.; Gagliardi S. and Martinelli M. review the most recent patents about the NK1, NK2 and NK3 receptors in “Antagonists at the neurokinin receptors-Recent patent literature” (IDrugs 2003; 6(8): 758-772). The authors describe the action of the molecules of the most important world producers with a specific indication of the most noteworthy possible applications being used in the treatment of: depression, inflammation, anxiety, vomiting, Ulcerative colitis and other illnesses.
SUMMARY OF THE INVENTION
[0014] The objective of the current invention is the use of non-peptide NK1 receptor antagonists and Substance P for the production of apoptosis in breast cancer tumors. The tumor cells that the antagonists act on present a number of NK1 receptors that is superior to those in non tumor cells, composed of between 400% and 500% of the normal number of non tumor cells.
[0015] The tumor cells that the antagonists act on are selected from the group consisting of:
[0016] invasive primary and invasive malignant melanomas;
[0017] metastatic melanoma cells;
[0018] cells localized in ganglion lymph nodes—glioma cells—human breast cancer cells;
[0019] Acute lymphoblastic leukemia B cells;
[0020] Acute lymphoblastic leukemia T cells;
[0021] primary neuroblastoma cells—astrocytoma cells;
[0022] Burkitt's lymphoma cells;
[0023] Hodgkin's lymphoma cells;
[0024] Rhabdomyosarcoma cells;
[0025] small lung cancer cells;
[0026] Ewing's sarcoma cells; and
[0027] osteosarcoma cells.
[0028] They indicated the continuation in specific cells acted upon by the non-peptide NK1 receptor antagonists and substance P.
[0029] The tumor cells related to human melanoma on which the current antagonists act in cell lines are COLO 858 [ICLC, Interlab Cell Line Collection—CBA—Génova), MEL HO [DSMZ, Deutsche Sammlung von Mikroorganismen and Zellkulturen] and COLO 679 [DSMZ].
[0030] The tumor cells related to the human glioma and the human neuroblastoma to which the antagonists act on in cell lines are the GAMG [DSMZ] and SKN-BE (2) [ICLC].
[0031] The tumor cells related to lymphoblastic leukemia which the current antagonists act on are human lymphoblastic leukemia cells B SD1 [DSMZ] and human lymphoblastic leukemia cells TBE-13 [DSMZ]. The tumor cells related to Burkitt's lymphoma on which the antagonists act in cell lines are CA-46 [DSMZ]. The tumor cells related to Hodgkin's lymphoma on which the antagonists act are KM-H2 [DSMZ]. The tumor cells related to human rhabdomyosarcoma on which the antagonists act in a cell line form are A-204 [DSMZ]. The tumor cells related to small human lung cancer cells on which the antagonists act in a cell line are COLO-677 [DSMZ]. The tumor cells related to human breast cancer on which the antagonists act in a cell line are MT-3 [DSMZ].
[0032] The tumor cells related to Ewing's sarcoma on which the current antagonists act in a cell line are MHH-ES-1 [DSMZ].
[0033] The tumor cells related to human osteosarcoma on which the current antagonists act in a cell line are MG-63 [ICLC].
[0034] One of the antagonists used is (2S,3S) 3-{[3,5-Bis(trifluoromethyl)phenyl]methoxy}-2-phenylpiperidine, commercially known as L-733060 (Sigma-Aldrich) and used in concentrations composed of between 5 μM and 50 μM.
[0035] Other compounds of antagonist non-peptide receptors NK1 and Substance P that can be used include:
[0036] vofopitant6GR-205171 (Pfizer);
[0037] eziopitant 6 CJ-11974 (Pfizer);
[0038] CP-122721 (Pfizer);
[0039] Aprepitant 6 MK 869 6 L-754030 (MSD);
[0040] L-758298 (MSD);
[0041] TAK-637 (Takeda/Abbot);
[0042] GW597599 (GSK);
[0043] GW679769 (GSK); and
[0044] R673 (Roche).
[0045] Lastly, the other objective on the current invention is the use of the non-peptide NK1 receptor and Substance P antagonists, such as the aforementioned indicators in the creation of a pharmaceutical composition for the treatment of cancer.
[0046] It is therefore an object to provide for the use of non-peptide NK1 receptor and Substance P antagonists to induce apoptosis in tumor cells of mammals.
[0047] It is also an object to provide for the use of non-peptide NK1 receptor and Substance P antagonists to induce apoptosis in tumor cells of mammals characterized in that the tumor cells that the antagonists act on present between 400% and 500% of the number of NK1 receptors as compared to those present in non-tumor cells.
[0048] It is a further object to provide for the use of non-peptide NK1 receptor and Substance P antagonists to induce apoptosis in tumor cells of mammals, characterized in that the tumor cells that the antagonists act on are selected among: invasive primary and invasive malignant melanomas; metastatic melanoma cells; cells localized in ganglion lymph nodes; glioma cells—human breast cancer cells; Acute lymphoblastic leukemia B cells; Acute lymphoblastic leukemia T cells; primary neuroblastoma cells; astrocytoma cells; Burkitt's lymphoma cells; Hodgkin's lymphoma cells; rhabdomyosarcoma cells; small lung cancer cells; Ewing's sarcoma cells; and osteosarcoma cells.
[0049] The antagonists act, for example, on tumor cells related to any of:
[0050] human melanoma cell lines COLO 858 [ICLC, Interlab Cell Line Collection—CBA—Génova), MEL HO [DSMZ, Deutsche Sammlung von Mikroorganismen undZelikulturen] and COLO 679 [DSMZ];
[0051] human glioma and neuroblastoma cell lines GAMG [DSMZ] and SKN-BE (2) [ICLC];
[0052] lymphoblastic leukemia cell lines B SD1 [DSMZ] and TBE-13 [DSMZ];
[0053] Burkitt's lymphoma cell line CA-46 [DSMZ];
[0054] Hodgkin's lymphoma cell line KM-H2 [DSMZ];
[0055] rhabdomyosarcoma cell line A-204 [DSMZ];
[0056] small cell lung cancer cell line COLO-677 [DSMZ];
[0057] breast cancer cell line MT-3 [DSMZ];
[0058] Ewing's sarcoma cell line MHH-ES-1 [DSMZ]; and
[0059] osteosarcoma cell line MG-63[ICLC].
[0060] It is a further object to induce apoptosis in tumor cells of mammals using of the antagonist (2S,3S) 3-{[3,5-Bis(trifluoromethyl)phenyl]methoxy}-2-phenylpiperidine, commercially known as L-733060 (Sigma-Aldrich). The antagonist L-733060 may be used in concentrations of between 5 μM and 50 μM.
[0061] It is a still further object to induce apoptosis in tumor cells of mammals by uses of a antagonist that is selected among some of the following compounds: vofopitant 6 GR-205171 (Pfizer); eziopitant 6 CJ-11974 (Pfizer); CP-122721 (Pfizer); Aprepitant 6 MK 869 6 L-754030 (MSD); L-758298 (MSD); TAK-637 (Takeda/Abbot); GW597599 (GSK); GW679769 (GSK); and R673 (Roche).
[0062] It is also an object to use non-peptide NK1 receptor and Substance P antagonists for the development of a pharmaceutical compound for the treatment of cancer.
BRIEF DESCRIPTIONS OF THE FIGURES
[0063] FIGS. 1A and 1B : variation in the time of the concentration of the cells SKN-BE (2) to growing concentrations of L-733,060 ( 1 A) in the cellular growth inhibition of SKN-BE (2) ( 1 B).
[0064] FIGS. 2A and 2B : variation in the time of the concentration of the cells COLO 858 to growing concentrations of L-733,060 ( 2 A) in the cellular growth inhibition of COLO 858 ( 2 B).
[0065] FIGS. 3A and 3B : variation in the time of the concentration of the cells MEL HO to growing concentrations of L-733,060 ( 3 A) in the cellular growth inhibition of MEL HO ( 3 B).
[0066] FIGS. 4A and 4B : variation in the time of the concentration of the cells COLO 679 to growing concentrations of L-733,060 ( 4 A) in the cellular growth inhibition of COLO 679 ( 4 B).
[0067] FIG. 5 : variation in the time of the concentration of the cells SD1 to growing concentrations of L-733,060 ( 5 A) in the cellular growth inhibition of SD1 ( 5 B).
[0068] FIGS. 6A and 6B : variation in the time of the concentration of the cells KM-H2 to growing concentrations of L-733,060 ( 6 A) in the cellular growth inhibition of KM-H2 ( 6 B).
[0069] FIGS. 7A and 7B : variation in the time of the concentration of the cells MT-3 to growing concentrations of L-733,060 ( 7 A) in the cellular growth inhibition of MT-3 ( 7 B).
[0070] FIGS. 8A and 8B : variation in the time of the concentration of the cells MHH-ES-1 to growing concentrations of L-733,060 ( 8 A) in the cellular growth inhibition of MHH-ES-1 ( 8 B).
[0071] FIG. 9 : variation in the time of the concentration of the cells MG-63 to growing concentrations of L-733,060 ( 9 A) in the cellular growth inhibition of MG-63 ( 9 B).
[0072] FIGS. 10A and 10B : variation in the time of the concentration of the cells GAMG to growing concentrations of L-733,060 ( 10 A) in the cellular growth inhibition of GAMG ( 10 B).
DETAILED DESCRIPTION OF THE INVENTION
[0073] In addition, a detailed explanation of how the activity was carried out was based on the current invention of each tested in cell lines. The following examples are provided only in order to illustrate the invention and thus they should not be construed as limiting.
Example 1
Cell Lines Related to Neuroblastoma
[0074] A Cell line of human neuroblastoma SKN-BE (2)(ICLC Interlab Cell Line Collection—CBA—Génova) was used.
[0075] This line was maintained in a culture of RPMI 1640 (GIBCO-BRL) supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0076] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half was refreshed every two days and the cells were treated with trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37 C in humidified (95% air/5% CO 2 ).
[0077] Treatment with the NK1 receptor antagonists: The solutions of antagonist NK1 receptors (2S,3S)3-([3,5Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060) (Sigma-Aldrich, U.K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 20 μM) were studied with the objective of determining the IC 50 .
[0078] The proliferation of cells was tested using the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium]method, following the instructions established by (Cet) Titer 96 Aqueous One Solution Cell Proliferation Assay, Promega, (USA).
[0079] Methods of cellular proliferation: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0080] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0081] In T 0 , 20 μl of MTS reagent was immediately added to the wells and the wells were read 90 minutes later. T 1 and T 2 were treated with different concentrations of (2.5 μM to 20 μM) of L-733,060 and were incubated during a period of 30 hrs. (first cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0082] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by testing the optical density, being directly proportional to the number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on an adequate curve based on the parameters.
[0083] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0084] Results: The results shown in FIG. 1A represent the variation in time of the concentration of cells SKN-BE (2) at growing concentrations of L-733,060.
[0085] FIG. 1B shows the percentage of inhibition of cellular growth of SKNBE (2) (at 30 hrs. and 72 hrs.) after the addition of growing concentrations of L-733,060 (2.5, 5, 10, 20 μM), at the first and second duplication times of the incubation. The non-continuous lines represent IC 50 at 30 and 72 hrs. The points on the graph represent the average value/typical deviation.
Example 2
Cell Lines Related to Melanomas
[0086] Cell lines related to melanomas COLO 858 (ICLC Interlab Cell LineCollection—CBA—Génova), MEL HO and COLO 679 (DSMZDeutsche Sammlung von Mikroorganismen and Zellkulturen) were used.
[0087] These cell lines were maintained in a culture of RPMI 1640 (GIBCOBRL) supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC, the ICLC and the DSMZ.
[0088] The cell lines were cultivated in 75 ml flasks (Falcon, Germany).
[0089] Half was renewed every two days and the cells were treated with trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at 37 C in humidified (95% air/5% CO 2 ).
[0090] The NK1 receptor antagonist, (2S,3S)3-([3,5Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine (L-733,060)(Sigma-Aldrich, U. K.) was dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. With the objective of determining the IC 50 , different concentrations (2.5 μM to 50 μM) were studied.
[0091] The cellular proliferation was evaluated using the MTS method 1344,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], according to the instructions of use established by (Cet) Titer 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0092] Cellular Proliferation Method: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0093] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0094] 20 μl of MTS reagent was immediately added to the T 0 wells and they were read 90 minutes after. T 1 and T 2 were treated with different concentrations (2.5 μM to 50 μM) of L-733,060 and were incubated during a varying period in cell lines.
[0095] Line COLO 858: 48 h. (first cellular duplication) (T 1 ) and 96 hrs. (second cellular duplication) (T 2 ).
[0096] Line MEL HO: 24 hrs. (cellular duplication) (T 1 ) and 48 hrs. (second cellular duplication) (T 2 ).
[0097] Line COLO 679: 30 hrs. (cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0098] To study the cellular proliferation, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the plate samples with the (TECAN Spectra Classic) 492 nm. The quantity of MTS reagent was determined by measurement of the optical density, being directly proportional to the number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentrations to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on a curve suited to the parameters.
[0099] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0100] Results: The results are shown in FIGS. 2A , 2 B (COLO 858), FIGS. 3A and 3B (MEL HO) and FIGS. 4A and 4B (COLO 679).
[0101] FIG. 2A represents the variation in the time of the concentration of cells COLO 858 to growing concentrations of L-733,060 (from 2.5 to 20 μM).
[0102] FIG. 3A represents the variation in the time of the concentration of cells MEL HO to growing concentrations of L-733,060 (from 10 to 30 μM).
[0103] FIG. 4A represents the variation in the time of the concentration of cells COLO 679 to growing concentrations of L-733,060 (from 20 to 50 μM).
[0104] In FIG. 2B , the inhibition of cellular growth is shown from COLO 858 (at 48 and 96 hrs.) after the addition of growing concentrations of L-733,060 (2.5, 5, 10, 20 μM). The discontinuous lines represent the IC 50 for 48 and 96 hrs. The points on the graph represent the value of the average value/typical deviation.
[0105] In FIG. 3B the inhibition of cellular growth is shown from MEL HO (at 24 and 48 hrs.) after the addition of growing concentrations of L-733,060 (10, 20, 25, and 30 μM). The discontinuous lines represent the IC 50 for 24 and 48 hrs. The points on the graph represent the average value/typical deviation.
[0106] In FIG. 4B the inhibition of cellular growth is shown from COLO 679 (at 30 and 72 hrs. after the addition of growing concentrations of L-733,060 (20, 30, 40, and 50 μM). The discontinuous lines represent the IC 50 for 30 and 72 hrs. The points on the graph represent the average value/typical deviation.
Example 3
Cell Lines Related to Lymphoblastic Leukemia
[0107] Cell lines related to human lymphoblastic leukemia were used, BSD1 (DSMZ) and T BE-13 (DSMZ).
[0108] These cell lines were maintained in a culture of 1640 supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0109] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO 2 ).
[0110] Treatment with antagonist NK1 receptors: The solutions of the antagonist NK1 receptors (2S,3S) 3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060) (Sigma-Aldrich, U.K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 25 μM) were studied in order to determine the IC 50 .
[0111] The cellular proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0112] Method of Cellular Proliferation: The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0113] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0114] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes later. T 1 and T 2 were treated with different concentrations (2.5 μM to 25 μM) of L-733,060 and were incubated during a period of 30 hrs. (cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0115] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 180 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by optical density, being directly proportional in number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated with a curve suited to the parameters.
[0116] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0117] Results: The results shown in FIG. 5 represents the variation in time of the concentration of cells BSD1 to growing concentrations of L-733,060.
[0118] In FIG. 5 , the inhibition of cell growth BSD1 is represented (at 30 and 72 hrs.) after the addition of growing concentrations of L-733,060 (2.5, 5, 10, 25 μM). The percentage of the inhibition for the first and second time of the duplication of the incubation is shown. The discontinuous lines represent the IC 50 at 30 and 72 hrs. The points on the graph represent the average value/typical deviation.
Example 4
Cell Line Related to Burkitt's Human Lymphoma
[0119] Linear cells related to human Burkitt's lymphoma were used with CA-46 (DSMZ).
[0120] This cell line was maintained in a culture of RPMI 1640 and supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0121] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days and the cells were treated with trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO 2 ).
[0122] Treatment with NK1 receptor antagonists: The solutions of the antagonist NK1 receptors (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060) (Sigma-Aldrich, U. K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 25 μM) were studied to determine the IC 50 .
[0123] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0124] Method of Cellular Proliferation: The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates called T 0 , T 1 and T 2 .
[0125] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0126] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes later. T 1 and T 2 were treated with different concentrations (2.5 μM to 25 μM) of L-733,060 and were incubated during a period of 35 hrs. (cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0127] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by optical density, being directly proportional in number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (ICso) with L-733,060 was calculated on a curve suited to the parameters.
[0128] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0129] Results: At the highest concentrations, inhibition in cellular growth was produced and at the maximum dose, apoptosis.
Example 5
Cell Lines Related to Human Hodgkin's Lymphoma
[0130] A cell line related to human Hodgkin's lymphoma.KM-H2 (DSMZ) was used.
[0131] This cell line was maintained in a culture of RPMI 1640 and supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0132] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO 2 ).
[0133] Treatment with NK1 receptor antagonists: The solutions of the NK1 receptor antagonists (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060)(Sigma-Aldrich, U. K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 20 μM) were studied to determine the IC 50 .
[0134] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0135] Method of Cellular Proliferation: The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0136] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both, T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0137] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes later. T 1 and T 2 were treated with different concentrations of (2.5 μM to 20 μM) of L-733,060 and were incubated during a period of 48 hrs. (cellular duplication) (T 1 ) and 96 hrs. (second cellular duplication) (T 2 ).
[0138] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 180 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by optical density, being directly proportional in number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on a curve suited to the parameters.
[0139] The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0140] Results: The results shown in FIG. 6A represent the variation in the time of the concentration of the cells KM-H2 with growing concentrations of L-733,060.
[0141] In FIG. 6B the inhibition of cell growth KM-H2 is represented (at 48 and 96 hrs.) after the addition of growing concentrations of L-733,060 (2.5, 5, 10, 20 μM). The percentage of the inhibition for the first and second time of the duplication of the incubation. The discontinuous lines represent the IC 50 at 48 and 96 hrs. The points on the graph represent the average value/typical deviation.
Example 6
Cell Lines Related to Human Rhabdomyosarcoma
[0142] A cell line related to human rhabdomyosarcoma A-204 (DSMZ) were used.
[0143] This cell line was maintained in a culture of Mc—Co— supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0144] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days and the cells were treated with Trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO 2 ).
[0145] Treatment with antagonist NK1 receptors: The solutions of the antagonist NK1 receptors (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060)(Sigma-Aldrich, U. K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 25 μM) were studied to determine the IC 50 .
[0146] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0147] Method of Cellular Proliferation: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0148] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0149] In T 0 , 20 μl of MTS reagent was immediately added to the wells and were read 90 minutes later. T 1 and T 2 were treated with different concentrations (2.5 μM to 20 μM) of L-733,060 and were incubated during a period of 36 hrs. (first cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0150] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by testing the optical density, being directly proportional to the number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on an adequate curve based on the parameters.
[0151] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0152] Results: Cellular growth is inhibited at the highest concentrations and at the maximum dose, apoptosis.
Example 7
Cell Lines Related to Small Cell Lung Cancer
[0153] A cell line related to small cell lung cancer COLO-677 (DSMZ) was used. This cell line was maintained in a culture of RPMI 1640 supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0154] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days and the cells were treated with Trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO2).
[0155] Treatment with antagonist NK1 receptors: The solutions of the antagonist NK1 receptors (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060)(Sigma-Aldrich, U. K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 25 μM) were studied to determine the IC 50 .
[0156] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0157] Method of Cellular Proliferation: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0158] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0159] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes later. T 1 and T 2 were treated with different concentrations (5 μM to 20 μM) of L-733,060 and were incubated during a period of 40 hrs. (first cellular duplication) (T 1 ) and 96 hrs. (second cellular duplication) (T 2 ).
[0160] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by testing the optical density, being directly proportional to the number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on an adequate curve based on the parameters.
[0161] Statistical Analysis The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0162] Results: Cellular growth is inhibited at the highest concentrations and at the maximum dose, apoptosis.
Example 8
Cell Lines Related to Human Breast Cancer
[0163] A cell line related to human breast cancer MT-3 (DSMZ) was used. This cell line was maintained in a culture of RPMI 1640 supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0164] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days and the cells were treated with Trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO2).
[0165] Treatment with NK1 receptor antagonists: The solutions of the NK1 receptor antagonists (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060) (Sigma-Aldrich, U. K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 20 μM) were studied to determine the IC 50 .
[0166] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0167] Method of Cellular Proliferation: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0168] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0169] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes later. T 1 and T 2 were treated with different concentrations (2.5 μM to 20 μM) of L-733,060 and were incubated during a period of 30 hrs. (first cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0170] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by optical density, being directly proportional in number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on a curve suited to the parameters.
[0171] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0172] Results: The results shown in FIG. 7A represent the variation in the time of the concentration of cells MT-3 at growing concentrations of L-733,060.
[0173] In FIG. 7B , the inhibition of cell growth MT-3 is represented (at 30 and 72 hrs.) after the addition of increasing concentrations of L-733,060 (2.5, 5, 10, 20 μM). The percentage of the inhibition for the first and second time in the duplication of the incubation. The discontinuous lines represent the IC 50 at 30 and 72 hrs. The points on the graph represent the average value/typical deviation.
Example 9
Cell Lines Related to Ewing's Human Sarcoma
[0174] A cell lines related to Ewing's human sarcoma MHH-ES-1 (DSMZ) was used. This cell line was maintained in a culture of RPMI 1640 supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0175] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days and the cells were treated with Trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO2).
[0176] Treatment with NK1 receptor antagonists The solutions of the NK1 receptor antagonists (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060) (Sigma-Aldrich, U.K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 25 μM) were studied to determine the IC 50 .
[0177] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0178] Method of Cellular Proliferation: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0179] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0180] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes later. T 1 and T 2 were treated with different concentrations (5 μM to 20 μM) of L-733,060 and were incubated during a period of 30 hrs. (first cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0181] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by optical density, being directly proportional in number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on a curve suited to the parameters.
[0182] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0183] Results: The results shown in FIG. 8A represent the variation in the time of the concentration of cells MHH-ES-1 at growing concentrations of L-733,060.
[0184] In FIG. 8B the inhibition of cell growth MHH-ES-1 is represented (at 30 and 72 hrs.) after the addition of growing concentrations of L-733,060 (5, 10, 15, 20, μM). The percentage of the inhibition for the first and second time of the duplication of the incubation. The discontinuous lines represent the IC 50 at 30 and 72 hrs. The points on the graph represent the average value/typical deviation.
Example 10
Cell Line Related to Human Osteosarcoma
[0185] A cell line related to human osteosarcoma MG-63 (ICLC) was used.
[0186] This cell line was maintained in a culture of MEN supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0187] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days and the cells were treated with Trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO2).
[0188] Treatment with NK1 receptor antagonists: The solutions of the NK1 receptor antagonists (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060) (Sigma-Aldrich, U.K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 25 μM) were studied to determine the IC 50 .
[0189] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0190] Method of Cellular Proliferation: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0191] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0192] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes after. T 1 and T 2 were treated with different concentrations (2.5 μM to 25 μM) of L-733,060 and were incubated during a period of 30 hrs. (one cellular duplication) (T 1 ) and 72 hrs. (second cellular duplication) (T 2 ).
[0193] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by optical density, being directly proportional to the number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on a curve suited to the parameters.
[0194] Statistical Analysis: The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0195] Results: The results shown in FIG. 9A represent the variation in the time of the concentration of cells at growing concentrations of L-733,060.
[0196] In FIG. 9B the inhibition of cell growth MG-63 is represented (at 30 and 72 hrs.) after the addition of growing concentrations of L-733,060 (2.5, 5, 10, 20 and 25 μM). The percentage of the inhibition for the first and second time of the duplication of the incubation. The discontinuous lines represent the IC 50 at 30 and 72 hrs. The points on the graph represent the average value/typical deviation.
Example 11
Cell Lines Related to Glioma
[0197] A cell line related to human glioma GAMG (DSMZ) was used.
[0198] This cell line was maintained in a culture of MEN supplemented with 10% fetal bovine serum according to the established cellular culture conditions of the ATCC.
[0199] The cell line was cultivated in 75 ml flasks (Falcon, Germany). Half were renewed every two days and the cells were treated with trypsin (0.05% and 0.02% EDTA without Ca 2+ and Mg 2+ ) every six days. The cells were incubated at a temperature of 37° C. in humidified (95% air/5% CO2).
[0200] Treatment with NK1 receptor antagonists: The solutions of the NK1 receptor antagonists (2S,3S)3-([3,5-Bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine, (L-733,060) (Sigma-Aldrich, U.K.) were dissolved in distilled water containing 0.2% dimethyl sulfoxide (DMSO) before treating the samples. Different concentrations of (2.5 μM to 25 μM) were studied to determine the IC 50 .
[0201] The cell proliferation was evaluated using the MTS method [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) 2-(4-sulfophenyl)-2H-tetrazolium], following the manufacturer's instructions for use (CellTiter 96 Aqueous One Solution Cell Proliferation Assay, Promega, USA).
[0202] Method of Cellular Proliferation: During the experiment, the cultivated cells were broken apart every 4-5 days by way of trypsinization and to test the cell viability the trypan blue method was used. The cells were quantified and cultured in plates of 96 wells each. Each experiment included three plates termed T 0 , T 1 and T 2 .
[0203] T 0 contained wells without cells (0 cells/0.1 ml) termed white wells and wells that contained cells (10 4 cells/0.1 ml) were termed control wells. Both T 1 and T 2 included white wells (0 cells/0.1 ml), control wells (10 4 cells/0.1 ml) and control wells treated with L-733,060.
[0204] In T 0 , 20 μl of MTS reagent was immediately added to the wells and they were read 90 minutes later. T 1 and T 2 were treated with different concentrations (2.5 μM to 25 μM) of L-733,060 and were incubated during a period of 48 hrs. (first cellular duplication) (T 1 ) and 96 hrs. (second cellular duplication) (T 2 ).
[0205] To study the proliferation of the cells, 20 μl of MTS reagent was added to each well (T 1 , T 2 ) 90 min before reading the samples with the plate reader (TECAN Spectra Classic) at 492 nm. The quantity of MTS reagent was measured by optical density, being directly proportional in number of live cells. Each plate (white, control, and control treated with different concentrations of L-733,060) was performed in triplicate. The experiment was repeated on three different occasions. The concentration to inhibit fifty percent of the cells (IC 50 ) with L-733,060 was calculated on a curve suited to the parameters.
[0206] Statistical Analysis. The data obtained was evaluated using the Student's T Test, with a significance level of p<0.05.
[0207] Results: The results shown in FIG. 10A represent the variation in the time of the concentration of cells at growing concentrations of L-733,060.
[0208] In FIG. 10B the inhibition of cell growth GAMG is represented (at 48 and 96 hrs.) after the addition of growing concentrations of L-733,060 (10, 15, 20 and 25 μM). The percentage of the inhibition for the first and second time of the duplication of the incubation. The discontinuous lined represent the IC 50 at 30 and 72 hrs. The points on the graph represent the average value/typical deviation.
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Substance P antagonists and, in particular, non-peptidic NK1 receptor antagonists are useful for the treatment of cancer and, more specifically, human melanoma, neuroblastoma, glioma, human Hodgkin's lymphoma KM-H2, lymphoblastic leukemia, human rhabdomyosarcoma, human breast carcinoma, human Burkitt's lymphoma, human lung carcinoma, human Ewing's sarcoma, human glioma and human osteosarcoma.
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RELATED APPLICATION DATA
This application claims priority from U.S. provisional application Ser. No. 60/577,047, “Managing An Investment Vehicle,” filed Jun. 4, 2004, herein incorporated in its entirety by reference.
BACKGROUND
This invention relates to the practice, administration, or management of an enterprise, or the processing of financial data.
Investment vehicles obtain investments from investors, and then invest the proceeds in assets that will generate cash flows. Some portion of the cash flows from the assets is then paid to the investors.
SUMMARY
In general, in a first aspect, the invention features a method for managing an investment vehicle. The investment vehicle issues multiple debt instruments to a plurality of investors. The debt instruments have different liability characteristics. The proceeds of the debt instruments are invested in assets. From time to time, liabilities on the debt instruments and the credit quality of the assets are reevaluated, to ensure that the cash flows generated by the portfolio, disregarding fair market value of the assets, will be sufficient to pay timely principal and interest on the liabilities based on evaluation criteria of two different rating agencies. In response to the reevaluating, the capital structure of the investment vehicle is adjusted to maintain a desired agency rating for the debt instruments.
In a second aspect, the invention features a method for managing an investment vehicle. The investment vehicle issues multiple debt instruments to a plurality of investors. The debt instruments have different liability characteristics. The proceeds of the debt instruments are invested in assets. From time to time, liabilities on the debt instruments and the credit quality of the assets are reevaluated, to ensure that the cash flows generated by the portfolio, disregarding fair market value of the assets, will be sufficient to pay timely principal and interest on the liabilities. In response to the reevaluating, the capital structure of the investment vehicle is adjusted to maintain a desired agency rating for the debt instruments.
In a third aspect, the invention features a method for managing an investment vehicle. The investment vehicle issues multiple debt instruments to a plurality of investors. The debt instruments have different liability characteristics. The proceeds of the debt instruments are invested in assets. From time to time, liabilities on the debt instruments and the credit quality of the assets are reevaluated, to ensure that the cash flows generated by the portfolio will be sufficient to pay timely principal and interest on the liabilities based on evaluation criteria of two different rating agencies. In response to the reevaluating, the capital structure of the investment vehicle is adjusted to maintain a desired agency rating for the debt instruments.
In a fourth aspect, the invention features method for investing. At least one debt instrument from an investment vehicle is purchased, and payment is received from the investment vehicle. The investment vehicle issues multiple debt instruments to a plurality of investors. The debt instruments have different liability characteristics. The proceeds of the debt instruments are invested in assets. From time to time, liabilities on the debt instruments and the credit quality of the assets are reevaluated, to ensure that the cash flows generated by the portfolio, disregarding fair market value of the assets, will be sufficient to pay timely principal and interest on the liabilities. In response to the reevaluating, the capital structure of the investment vehicle is adjusted to maintain a desired agency rating for the debt instruments.
In a fifth aspect, the invention features method for investing. At least one debt instrument from an investment vehicle is purchased, and payment is received from the investment vehicle. The investment vehicle issues multiple debt instruments to a plurality of investors. The debt instruments have different liability characteristics. The proceeds of the debt instruments are invested in assets. From time to time, liabilities on the debt instruments and the credit quality of the assets are reevaluated, to ensure that the cash flows generated by the portfolio will be sufficient to pay timely principal and interest on the liabilities based on evaluation criteria of two different rating agencies. In response to the reevaluating, the capital structure of the investment vehicle is adjusted to maintain a desired agency rating for the debt instruments.
Embodiments of the invention may include one or more of the following features. The reevaluating of liabilities may include calculating estimated default rates for the debt instruments, simulating default and interest rate scenarios, and/or determining a required capital structure for maintaining the desired agency rating. The debt instruments may differ from each other in maturity date, issue date, payment seniority, or agency rating. The debt instruments may be issued through a public offering or through a private placement, or a private placement to qualified investors. The reevaluation may be performed essentially each business day, on some other periodic, fixed, schedule, when a credit support aspect of the portfolio changes, when new debt instruments are issued or retired.
The above advantages and features are of representative embodiments only. It should be understood that they are not to be considered limitations on the invention as defined by the claims. Additional features and advantages of the invention will become apparent in the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an investment vehicle.
FIG. 2 is a flow chart of determining capital structure requirements.
DESCRIPTION
I. Overview
Referring to FIG. 1 , investment vehicle 100 may offer debt instruments 122 of one or more classes (e.g., in a public offering or by private placement) secured by a portfolio of collateral 102 . Particularly in cases where the amounts due on debt instruments 122 fluctuates over time (because of rolling issue and retirement of debt instruments 122 , currency fluctuations, differing amounts, etc.), the liabilities of investment vehicle 100 to repay debt instruments 122 may change over time. Similarly, the quality (including credit quality, among other features) of a given asset in portfolio 102 may change over time, and the assets in collateral portfolio 102 may change as investments are bought or sold out of portfolio 102 by the fund managers. Debt instruments 122 issued by investment vehicle 100 may be issued and retired, and assets in portfolio 102 may be purchased from and sold on market 110 . Thus, the estimated default and loss risk of the entire transaction may change over time. To support a given rating from one of the credit rating agencies (Standard & Poor's, Moody's Investor Services or Fitch Ratings, Inc.) for one or more of debt instruments 122 , investment vehicle 100 may analyze its portfolio 102 from time to time, for example daily, to assess capitalization 104 needed to maintain the desired rating. For example, a computer model of collateral portfolio 102 may determine a default ratio of portfolio 102 , and that model may be run with a number of differing assumed scenarios. Using the result of that model under the scenarios, capitalization 104 of investment vehicle 100 may be managed to maintain a funding level, asset level, and/or asset credit quality to support a desired default profile and/or credit rating under all (or a selected fraction) of the assumed scenarios. In other alternatives, portfolio 102 may be managed so that the total portfolio 102 maintains the desired default profile or rating level.
Credit support provider or guarantor 130 may transfer capital 104 in and out of investment vehicle 100 as necessary to maintain the desired credit rating.
Investment vehicle 100 may be managed based on the cash flows generated by those assets and/or based on the fair market value of the assets. In an investment vehicle managed solely for the cash flows of the assets, the credit quality of an asset may be evaluated based on the cash flows generated by the asset. For example, the spread on a particular asset may change due to a macro event such as a terrorist attack, but the credit quality of the asset may not be affected, leaving its rating unaffected. Such an asset may be valuable collateral in a cash-flow managed investment vehicle, and less valuable in a investment vehicle managed based on fair market value. Generally, the cash flow of a given asset is less subject to rapid fluctuations than its fair market value.
This structure may be used in investment vehicle 100 that does not have a fixed capitalization structure. For example, investment vehicle 100 may offer debt instruments 122 to investors, and in turn invest the proceeds in securities 102 . Investment vehicle 100 may require additional capital to be contributed as needed from credit support provider 130 , in order to maintain a capitalization 104 or over-collateralization ratio that supports the desired rating for debt instruments 122 . This allows the capitalization structure of investment vehicle 100 to be managed over time as investment vehicle 100 's asset portfolio and liabilities change. This management may allow capital to be employed more efficiently, which may increase returns to investors.
Debt instruments 122 issued by investment vehicle 100 may vary from each other in a number of respects. For example, debt instruments 122 may be issued at different dates, bear differing maturities, or the cash flows may be tranched among debt instruments 122 at differing priorities. Debt instruments 122 may bear different interest rates, some of which may be fixed, while others may be floating, while others may have a step-up yield or other variable yield characteristic. Debt instruments 122 may be denominated in differing currencies. Investment vehicle 100 may adjust its capitalization 104 according to its portfolio makeup, which is dynamic. In some cases, investment vehicle 100 may issue a single class of debt instruments 122 to all investors.
The form of investment vehicle 100 may include a collateralized bond obligation, a collateralized debt obligation, a collateralized loan obligation, or other structured investment vehicle. Credit support provider 130 may be a sponsor of investment vehicle 100 , a guarantor, or other source of capital.
II. Collateral and Capitalization
The investment fund may invest in securities as specified by the agreements between the investment vehicle 100 and its investors 120 . Depending on any limits specified in agreements between investment vehicle 100 , guarantor 130 and investors 120 , investment vehicle 100 may invest in fixed income instruments (including, but not limited to, corporate loans and bonds, Government bonds, leases, Mortgage Backed Securities (MBS), Commercial Mortgages, Commercial Mortgage Backed Securities (cmbs), Asset backed securities (abs), Equipment Trust certificates (ETC, EETC), Collateralized Loan Obligations (CLO), Collateralized Debt Obligations (CDO), and default swaps), equities, real estate, derivatives, insurance contracts, or any other asset. These agreements may require investment vehicle 100 to maintain its funding level and capital at a certain level. That level may be stated, for example, as the portfolio balance+cash−liabilities, or as the ratio of that value to the portfolio balance.
As the credit quality of the assets in the portfolio changes, and as the liabilities on debt instruments 122 change, credit support provider or guarantor 130 may be required to contribute further capital so that investment vehicle 100 maintains a “safety margin,” so that investment vehicle 100 as a whole can withstand a specified default profile or expected loss rate in order to maintain a specified credit rating. This safety margin may generally be set out in an indenture between investment vehicle 100 , its investor 120 and credit support provider 130 , and may be stated in terms of a computer model calculation based on default ratio or expected loss rates (see §III, below), and/or an over-collateralization ratio. Conversely, the credit quality of the assets and the liabilities on debt instruments 122 may change so that capital may be withdrawn from investment vehicle 100 while maintaining the safety margin required to meet the specified credit rating, allowing capital to be used more efficiently.
Generally, portfolio 102 may be managed so that the cash flows generated by portfolio collateral 102 will be aligned with the maturities of debt instruments 122 .
Capital 104 may be supplied by the credit support provider 130 as equity, subordinated debt, a guarantee, or in other forms.
III. Computer Models and Analyses
In one implementation, the following four software components may be used to run a daily analysis of required capitalization:
Fund Manager: A database system, in this case called “Fund Manager,” may maintain information on the collateral underlying portfolio 102 . This database may be updated continually on a real time basis to track (a) the contents of the underlying collateral portfolio 102 , and (b) the respective interest rates, maturities, amortization schedules, ratings, S&P Industry Sectors, portfolio break-down by asset type and the market price for each asset in portfolio 102 . CDO Evaluator: A financial model provided by Standard & Poor's (S&P) for the purpose of estimating the default risk of collateral portfolio 102 (securing a “collateralized debt obligation,” or “CDO”), as it may be modified by S&P in connection with its confirmation of the ratings of debt instruments 122 , and as may be further modified from time to time by S&P. The CDO evaluator is available to any client that contracts S&P to rate a product (see www.securitization.net/pdf/sp_cdo — 111502.pdf). The CDO Evaluator calculates an SDR (“scenario default rate”) for a specific portfolio of collateral 102 . The SDR states the percent of default in portfolio 102 but does not calculate the timing of defaults or the loss severity associated with a default. The following components are used to evaluate varying timing and severity assumptions:
Dynamic Capital Optimizer (DCO): The DCO determines the required funding consistent with the desired rating for any class of debt instruments 122 for which investment vehicle 100 has a targeted rating (for example S&P “AAA” for the senior debt instruments, and lower ratings, or ratings by other agencies, for other debt instruments). The DCO may calculate and simulate different default and interest-rate trend scenarios using the SDR from the CDO evaluator and the Cash Flow Model, varying (i) the timing with which the defaults occur, (ii) the prepayment speed of the underlying collateral and (iii) interest rates. The DCO uses actual collateral portfolio 102 as of any point in time and the actual debt instruments 122 that exist on any day taking into account the terms of each debt instrument 122 outstanding. The DCO calls the Cash Flow Model (see next paragraph) iteratively in order to calculate the capital or required funding needed in order to pass each scenario. The highest required funding from any scenario becomes the required funding amount, which investment vehicle 100 is required to maintain on any given day in order to reduce any amortization of the transaction. Cash Flow Model: A conventional cash flow model that generates the principal and interest cash flows from collateral portfolio 102 , and applies the cash flows to the liabilities, both their principal and interest, in order to satisfy that the principal and interest on each debt instrument 122 will be paid on a timely basis when due.
As shown in FIG. 2 , the required funding level may be calculated as follows:
Step 1—Run Fund Manager 200 in order to generate tables that describe collateral portfolio 102 and respective data for a specific day.
Inputs: Data in the database that includes descriptive information on the terms of each piece of collateral and daily trading information. Outputs: (FMT 1 (“Fund Manager Table”)) Table that has every individual principal payment that contractually is required to be made as well as the Security, Rating, Industry, Timing associated with the payment. (FMT 2 ) Table that has aggregated principal payments going out over time for collateral portfolio 102 grouped into subportfolios based on whether the collateral is (i) fixed or floating rate; loans, bonds, Mortgage Backed Security, Asset Backed Security or synthetics; Secured or Unsecured; and Senior or Subordinated. (FMT 3 ) Table that has the total amounts in each subgrouping above as well as the percentage of the total collateral portfolio 102 and the respective weighted average interest rate.
Step 2—Run the S&P CDO Evaluator 210 .
Inputs: FMT 1 Process: S&P CDO Evaluator 210 performs the functions described above. Outputs: Table of SDRs 212 for different rating levels going up to AAA
Step 3—Run DCO 220 .
Inputs: (1) FMT 2 (2) FMT 3 (3) A table that specifically describes each debt instrument 122 currently outstanding or to be issued by the investment vehicle 100 . For example, this table may describe the amount, coupon, maturity, amortization, and other attributes of each debt instrument 122 . This table may be generated manually, and maintained as debt instruments 122 are issued or retired. (4) The SDR generated in step 2 for the given rating being sought. Process: DCO 220 evaluates a number of default scenarios and interest rate scenarios, for example twenty combinations, that assume different timing for defaults and different interest rate trends to the SDR calculated in Step 2. The default scenarios are described in paragraph [0025] below, and the interest rate scenarios are described in paragraph [0026].
Within each default-rate scenario combination, the DCO iteratively calls Cash Flow Model 222 to evaluate the level of capital required to pass the scenario. Each iteration applies Cash Flow Model 222 to the collateral portfolio, “Input Table (3)” from the above list (the descriptions of the debt instruments 122 ), and a given level of capitalization. One each iteration, Cash Flow Model 222 determines whether that level of capitalization passes the scenario. The iterative calls of Cash Flow Model 222 continue until the amount of capital required to pass the scenario has been determined within a specified tolerance. After DCO 220 has finished all the required scenarios it then determines which needs the highest amount of capital. The maximum capital becomes the required amount. DCO 220 finishes by calculating how much capital can be taken out of investment vehicle 100 , or how much has to be put in, to have optimal capitalization 104 . Capital may be taken out as cash.
Outputs: Table 230 that has
(a) the required capital for each scenario. (b) the minimum required capital for investment vehicle 100 to pass all scenarios and thereby maintain the desired ratings. This minimum required capital is the maximum capital computed by the iterative application of the scenarios. (c) the amount of capital that can be taken out of investment vehicle 100 by credit support provider 130 if there is too much capital or the amount of capital that must be put into investment vehicle 100 if there is too little capital.
Recall that the SDR (“scenario default rate”) does not state the timing of defaults. Currently, to give an “AAA” rating, S&P supplies four default timing scenarios that make varying assumptions of this timing. S&P requires that these scenarios be applied to the SDR, and passed, in order to achieve the AAA rating. S&P's current example set of scenarios is as follows, though others may be applicable in other circumstances:
Default Patterns Percent of SDR to be applied Scenario 1 Scenario 2 Scenario 3 Scenario 4 Year 1 40% 25% 15% 20% Year 2 30% 25% 30% 20% Year 3 20% 25% 30% 20% Year 4 10% 25% 15% 20% Year 5 10% 0% 10% 20%
For example, scenario 1 assumes that 40% of all defaults that will occur over the entire life of the portfolio occur in year 1, 30% in year 2, 20% in year 3, etc. (Note that each scenario column sums to 100%.). In a fifth scenario (not supplied by S&P), there are 0% defaults and 0% prepayments in each year. This fifth scenario protects against liabilities on notes 122 that come due before cash flows mature from collateral 102 .
Each of these Default patterns is tested with the portfolio and SDR four times, each time with a different LIBOR assumption. The four LIBOR vectors are—LIBOR Up, LIBOR Down, LIBOR Up/Down, LIBOR Forward. Hence there are altogether twenty (five default patterns×four LIBOR vectors) different scenarios that are tested.
In another implementation, investment vehicle 100 agrees with investors 120 to maintain a credit rating specified by a rating agency other than S&P, using a portfolio credit evaluation model 260 for rating collateral portfolio 102 specified by that agency. For example, the rating agency, or an investment bank, may have developed a function for a set of variables 250 (the values of which are based upon data from collateral portfolio 102 ) that determines a minimum level of capital 270 necessary to maintain a desired credit rating. For example, capitalization 270 may be a function 260 of the average rating of the individual assets in portfolio 102 , diversity of those assets, weighted average life, weighted average recovery rate, average loss severity, and/or net margin. As another example, a rating agency may have developed a map of values from a set of variables 250 to a capitalization value, so that a “best fit” search of the map based on collateral portfolio 102 specifies the minimum level of capital 270 . Once the minimum level of capital 270 is determined, capital may then be added or removed from investment vehicle 100 to meet the minimum capital requirements.
In yet another implementation, rating methods of two or more agencies may be combined to calculate the amount of required capital. For example, investment vehicle data may be processed through S&P CDO Evaluator 210 and DCO 220 to determine the capitalization necessary to maintain a desired S&P rating. Similarly, investment vehicle data may be processed through the financial model 260 of another rating agency to determine the capitalization necessary to for investment vehicle 100 to maintain a desired credit rating for that agency. Capitalization 104 of investment vehicle 100 may then be adjusted based on the higher of the two capitalization determinations.
For the convenience of the reader, the above description has focused on representative samples of all possible embodiments, a sample that teaches the principles of the invention and conveys the best mode contemplated for carrying it out. The description has not attempted to exhaustively enumerate all possible variations. Other undescribed variations or modifications may be possible. For example, where multiple alternative embodiments are described, in many cases it will be possible to combine elements of different embodiments, or to combine elements of the embodiments described here with other modifications or variations that are not expressly described. Many of those undescribed variations, modifications and variations are within the literal scope of the following claims, and others are equivalent.
A portion of the disclosure of this patent document contains material that is protected by copyright. The copyright owner has no objection to the facsimile reproduction of the patent document or the patent disclosure as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights whatsoever.
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A method for managing an investment vehicle. The investment vehicle issues multiple debt instruments to a plurality of investors. The debt instruments have different liability characteristics. The proceeds of the debt instruments are invested in assets. From time to time, liabilities on the debt instruments and the credit quality of the assets is reevaluated, to ensure that the cash flows generated by the portfolio, disregarding fair market value of the assets, will be sufficient to pay timely principal and interest on the liabilities. In response to the reevaluating, the capital structure of the investment vehicle is adjusted to maintain a desired agency rating for the debt instruments.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a laundry treatment apparatus, such as a washing machine, clothes dryer or washer-dryer with a drum with mounted for rotations about an at least approximately horizontal axis and with a drive motor arranged on the shaft of the drum and structured as a synchronous motor energized by a permanent magnet the stator of which is provided with a winding energized by a converter, the winding being structured as a single pole winding and the number of stator poles being different from those of the magnet poles.
2. The Prior Art
Washing machines of the kind referred to are generally known from WO-A-98/00902. Washing machines are also known from DE 3,819,651 A1 in which the laundry drum is driven directly without the use of the customary intermediate transmission (drive belt, pulley). In such drives the rotor constitutes the component for transmitting rotational movement to the drum of the washing machine. Furthermore, DE 3,819,861 A1 proposes to use an asynchronous motor with a squirrel-cage rotor. Such a motor is characterized by a relatively quiet movement, but it suffers from the drawback that because of the prevailing marginal conditions, such as, for instance, the large air gap and high pole construction in an asynchronous motor, good efficiency cannot be achieved. Yet in connection with a frequently operated household appliance an ecologically friendly, i.e. energy-saving operation, is desirable.
A motor for directly driving the drum has been described in DE 4.341,832 A1. That motor is structured as a synchronous motor fed by a converter. No further statements are made as regards the type of motor.
Furthermore, washing machines are known which are provided with directly driving motors structured as external rotor motors (DE 4,335,966 A1; EP 413,915 A1; EP 629,735 A2). The rotor may be manufactured as a deep-drawn component, such as a plastic bell or as a compound structure. The structure of a deep-drawn component is advantageous since in it, the iron forms the magnetic yoke and a hub may be integrated for receiving the bell. Among others, such a structure also constitutes an arrangement typical of venting motors.
Direct current motors without collectors are used in the above-mentioned direct drives for washing machines. See, for instance, WO-A-98/00902. The stator winding there described may be structured either as a conventional three-phase current winding with a winding pitch over several stator teeth or as a single pole winding with a winding around a stator pole. In this type of motor, commutation is performed by power semi-conductors. In such an arrangement, individual strands of the stator winding are energized by a d.c to a.c. converter in dependence of the stator position so that the excitation field rotates with the motor. In a treble stranded excitation winding current for the generation of torque flows at any given time in two strands only, the third strand remaining unenergized. The temporal current flow in the individual strands is block shaped or trapezoidal. For that reason, when switching the individual windings on and off, large current change velocities occur which generate noises at the motor. Such noises are undesirable, however, in laundry treatment apparatus of the kind sometimes installed in living facilities (kitchen, bathroom).
In electronically commutated d.c. motors, Hall sensors, magnetic transducers or optical sensors are utilized for sensing the rotor position. The mounting of such sensors and their appurtenant signal lines involves additional costs. Moreover, sensors and lines are subject to malfunctioning. A further drawback is that operating with field weakening is not easily accomplished in such self-controlled motors energized by permanent magnets. The large spread of torque and revolutions between washing and spinning operations necessary in washing machines usually results in large motor current spreads. For that reason, it is necessary to install switchable or tapped windings, or else the motor winding and the power semiconductors have to be sized for the largest possible current.
Synchronous motors sinusoidally energized and controlled by a converter are already known as servo-motors. They are utilized where precise positioning is required. In known servo-motors the stator winding is a conventional three-phase current winding, and the number of rotor and stator poles is identical. While the three-phase current winding is characterized by conventional and known winding techniques, the large amount of copper in the winding heads is a disadvantage as it not only increases manufacturing costs but also the structural depth of the motor. The latter aspect would, in washing machines with a housing of predetermined depth, reduce the volume of the drum. Moreover, for a controlled operation servo-motors require very accurate and expensive sensors for sensing the rotor position.
A further disadvantage of all previously mentioned motors with permanent magnet excitation is their lack of field weakening, since the magnetic flux of the motor essentially depends upon the field of the permanent magnets and is, therefore, constant. For washing machine drives such motors are, therefore, rather unsuited since a large spread of torque and revolutions between washing operations and spinning operations would entail a large spread of the motor current. The motor winding and the power semiconductors of the frequency converter would, therefore, have to be dimensioned for the largest current and would be very expensive. As an alternative, the windings could be tapped which would, however, require installing additional lines from the motor to the electronic components. Also, expensive switching relays would be required.
OBJECT OF THE INVENTION
Therefore, it is the the object of the invention is to optimize, in a laundry treatment machine of the kind mentioned hereinbefore to optimize the motor in respect of energy consumption, low noise development and costs.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a laundry treatment apparatus having a drum rotationally mounted on a substantially horizontal axle and a synchronous motor with permanent magnets and a stator including winding strands energized by a frequency converter the output voltage of which is set such that continuous currents are generated in all strands.
In contrast to hitherto known direct drives for washing machines with d.c. motors without commutators, all three winding strands of the three-phase excitation winding are continuously energized in the drive concept here described, with the frequency of the excitation field being determined by the electronic control. In this case, the motor is operated as an externally controlled synchronous motor. In connection with a synchronous motor with permanent magnet excitation this method ensures that the noise developed is very low.
By utilizing a single pole winding, copper consumption is less than in a conventional three-phase current winding; the volume of copper of the winding heads is markedly less. Accordingly, the entire drive becomes smaller and more compact. Because of the smaller amount of copper and as a result of the lower copper losses higher degrees of efficiency can be achieved at the same motor size.
It is advantageous to structure the rotor as an external rotor. In this manner, the most compact structural shapes may be obtained because the torque generating radius of the air gap is located near the outer radius.
Furthermore, it is of advantage to utilize a control device which regulates the output voltage of the frequency converter by a control such that a minimum sinusoidal current is derived as a function of the load torque. Sinusoidal currents affect a very quiet motor movement and a reduction in losses resulting from current ripples. This is particularly true where the output voltage is set as a sinusoidal pulse width modulation. Moreover, the torque-dependent current control ensures an optimum degree of efficiency at each load point.
In synchronous motors with single pole windings the number of magnet poles characteristically deviates from the number of stator poles. A ratio of rotor poles to stator poles of 2 to 3 or of 4 to 3 is favorable in a treble stranded arrangement and continuous energization or in a rotational magnetomotive force of the stator winding. In these two cases only does the vectorial addition of the voltages induced in the individual pole windings yield a maximum and optimum degree of efficiency.
At a pole ratio of 4 to 3, the use of thirty stator poles is favorable in order to cover the required range of revolutions from 0 to 2,000 min. The selected number of poles ensures a definite start-up at an external control, low torque ripples and a large spread of revolutions.
Aside from this, it is advantageous to base the control device for controlling the motor current upon a mathematical model of the motor and to energize the winding strands without rotor position transducers. Since motor current and voltage at the motor may be detected at the frequency converter, there is no need for sensors at the motor.
In an advantageous embodiment of a control without sensors the mathematical model may be calibrated either as required or continuously. Motor-specific parameters such as winding resistance, motor inductance and the constant of the induced voltage may be detected by means of the current sensors and microprocessor control present in the frequency converter and the mathematical model may be adjusted on the basis of the measured values.
The essential advantage of the laundry treatment apparatus structured in accordance with the invention derives from the possibility of dimensioning the number of windings of the stator windings such that the level of the induced voltage or of the synchronous generated voltage for high revolutions is higher than the maximum output voltage of the frequency converter. Such a winding design makes possible a field weakening operation of the synchronous motor in the range of higher revolutions. The advantage of such a winding design is a marked reduction of the motor current in the washing mode. It may be selected in such a manner that the motor may be operated with the same current in the washing and spinning modes. Owing to the lower motor current smaller and less expensive power semiconductors may be utilized. Moreover, the losses in the power semiconductors are reduced so that the overall degree of efficiency of motor and power electronics is higher than in comparable drives utilizing the same quantity of copper. In order also to utilize field weakening when using a control with rotor position transducers, it is advantageous not to evaluate them at higher revolutions. At higher revolutions, large and short-term load deviations do not occur so that controlling the motor current is not absolutely necessary. In that case, the motor is operated with external controls with voltage and frequency being determined by the converter regardless of the position of the rotor field. The motor current will in such circumstances adjust itself within limits as a function of the load torque. In order to prevent an overload and an asynchronization of the motor, it will suffice to monitor the level of motor current as a function of the frequency of the rotational field.
Furthermore, It is also possible by field weakening to achieve good efficiency with high pole synchronous motors with permanent magnet excitation at high revolutions as the losses resulting from magnetic hysteresis are reduced as a result of field weakening.
Operation of d.c. motors without collectors with field weakening is possible only at great complexity as in such arrangements it would be necessary to change the position of the rotor position transducer or mathematically to shift the instants of commutation. For the above reasons, field weakening operation of servomotors is not known.
DESCRIPTION OF THE SEVERAL DRAWINGS
The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, in respect of its structure, construction and lay-out as well as manufacturing techniques, together with other objects and advantages thereof, will be best understood from the following description of preferred embodiments when read in connection with the appended drawings, in which:
FIG. 1 is a schematic view in section of a washing machine built in accordance with the invention;
FIG. 2 is a partial section of the rear portion of a washing water container, a drum and their drive motor;
FIG. 3 is a perspective presentation of the support cross of a washing machine;
FIG. 4 shows an individual laminate of a stator of the drive motor;
FIG. 5 is a perspective presentation of a permanent magnet rotor;
FIG. 6 depicts a block circuit diagram of the structure of the controlled drive with three-phase current synchronous motor and rotor position transducers; and
FIG. 7 depicts a block circuit diagram of the structure of the drive controlled without sensors with three-phase current synchronous motor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The washing machine shown in FIG. 1 is provided with a housing 1 within which a wash water container 2 is suspended by springs 3 for oscillating movements. To dampen the oscillations relative to the bottom of the housing 1 , it is supported by friction dampeners 5 . Within the wash water container 2 a drum 6 for receiving laundry (not shown) is rotatably supported. Drum 6 , wash water container 2 and the front housing wall 1 a are provided with aligned openings through which the laundry may be put into the drum 6 . The openings may be closed by a door 7 arranged on the front housing wall 1 a. Latching the door 7 is carried out by an electromagnetic latching device 8 . The door latching has only been shown schematically in the drawing. Construction and function of an electromagnetic latching device 8 as such is known from the above-mentioned DE-OS 1,610,247 or from DE 3,423,083 C2 and will, therefore, not be described in detail. In the upper portion of the front wall 1 a of the housing there is provided an operations panel in which a rotary switch serves to select washing programs. As is known, the washing programs include a washing cycle and a rinsing cycle subsequent thereto. The washing revolutions in household washing machines are between 20 and 60 per minute, the spinning revolutions, particularly at the final spinning toward the end of the rinsing operation should be as high as possible. It is upwardly limited by the extent to which the oscillating system consisting of the wash water container 2 , suspension 3 , drive motor 10 , drum 6 may be loaded, the limits being at present at about 1,600 revolutions per minute.
FIG. 2 depicts a partial section through the rear portion of a wash water container 2 , a drum 6 and their drive motor 10 . A four-armed support cross 11 shown in FIG. 3 is affixed to a marginal abutment 2 a formed by the circumferential wall 2 b of the wash water container 2 and a crimped portion of its bottom 2 c. A bearing hub 12 having two radial roller bearings 13 a, b inserted therein is provided in the center of the support cross 11 . The roller bearings 13 a, b, in turn, serve to receive a drive shaft 14 which is affixed to the bottom 10 of the drum. The rear end of the drive shaft 14 protrudes from the bearing hub 12 . A permanent magnet rotor 15 structured as an external rotor is mounted thereon and, therefore, drives the drum 6 directly. The stator 16 of the drive motor 10 is affixed to the support cross 11 .
The laminated stator core 17 including the stator windings 18 is of substantially annular configuration. For mounting the laminated stator core 17 on the support cross, the individual laminates 17 a are provided with fastening eyelets arranged at the internal peripheral surface and provided with through-bores 19 . Fastening screws (not shown) are seated in these through-bores 19 and threaded into threaded bores 26 in the support cross 11 . The bores 26 are arranged concentrically with respect to the bearing hub 12 . Their free ends are provided with support surfaces 20 for the frontal surface of the laminated stator core 17 . The laminated stator core 17 is centered by radially formed reinforcement ribs 21 .
The rotor 15 consists of a pot-shaped deep-drawn component or an injection molded aluminum component 15 a provided with a hollow cylindrical section 15 b containing the iron magnetic yoke 22 and, as rotor poles, the permanent magnets 23 mounted thereon (see also FIG. 5 ). Furthermore, the rotor 15 is provided with a hub 24 which is keyed and, therefore rigidly connected, to the free end 14 a of the drive shaft 14 by a threaded bolt 25 and splines (not shown).
The drive motor is structured as a three-phase current synchronous motor excited by permanent magnets. A treble-stranded single pole winding (tooth winding) is housed in the stator 16 , the strands being connected in a star connection (see FIGS. 5, 6 ). The windings of a strand on each tooth 27 are series connected. Hence, the drive motor is structures as a modular permanent magnet machine. The ratio of rotor poles a to stator poles 27 is 4 to 3 at thirty stator poles 27 .
FIG. 6 is a block circuit diagram of the structure of the controlled drive with a three-phase current synchronous motor 10 . The number of revolutions of the motor 10 is preset at a desired value by the program control of the washing machine ST 101 as a function of a program selected by means of the dial switch 9 (see FIG. 1 ). In order to influence the number of motor revolutions it is necessary to adjust the frequency of voltage and current as well as the level of the voltage in the stator windings 18 . To control the motor the motor current is additionally set in dependence of the load torque. To this end, at least two strand currents I 1 and I 2 are measured by current sensors 103 a, b.
The adjustment of the previously mentioned parameters is performed by the frequency converter 104 . For this purpose, network voltage is initially converted to d.c. by a rectifier 105 and is smoothed by a buffer capacitor 106 . The d.c. voltage is converted by a three-phase inverter 107 the output of which is connected to the stator winding 18 . Since the buffer voltage is constant, the voltage at the motor 10 will be set by way of pulse width modulation. The effective value of the voltage may then be set by way of the pulse width. A pulse pattern will be chosen which will lead to sinusoidal currents within the stator winding 18 of the motor 10 . This is referred to as sinusoidal pulse width modulation. The sinusoidal currents provide for very quiet running of the motor 10 as well as for reduced losses otherwise caused by current harmonics. To affect the pulse pattern, a microprocessor control 108 with an integrated control 109 and a valve control 110 is associated with the inverter 107 .
Calculation of the control signals for the transistors of the inverter 107 is performed on the basis of the position of the rotor at any given time in order to set the optimum orientation and force of the rotary field and thus to ensure sufficient torque at the rotor 15 . A continuous and precise recognition of the rotor position are required because of the sinusoidal current supply of the synchronous motor 10 and the torque dependent current control. Resolvers or analog Hall sensors 111 may be used for this purpose. Hall sensors 111 are preferred because of their lower prices. In both cases, the measuring systems are absolute and furnish exact data about the absolute position of the rotor 15 relative to the stator 16 immediately upon being turned on. Where two Hall sensors 111 are used they will generate two signals which are phase-shifted by 90°, with the assistance of the rotor magnets. The rotor angle may be determined on the basis of these two signals by the mathematical function β=arctan(a/b).
Where analog Hall sensors 111 are used their self-calibration is recommended since because of deviations between different sensors in respect, for instance, of sensitivity, offset, temperature drift and so forth the analog output signals of different Hall sensors 111 in a magnetic field are not necessarily identical. A precise recognition of the rotor position thus requires the output signals to be corrected. The correction aims at identical output signals in a magnetic field from the used Hall sensors 111 . Such a correction may be carried out by storing the analog output signals of both Hall sensors 111 during a rotor revolution in a correction device 112 integrated in the microprocessor control and by thereafter deriving from the stored values the mean value as well as maximum and minimum values. Once the mean value is known, any offset may be corrected, whereas sensitivity and temperature drift may be corrected on the basis of the maximum and minimum values. It is not necessary to consider the influence of temperature on the remanence induction of the magnets 23 since in that case the output signals of both Hall sensors 111 are changed in the same manner and to the same extent. Where the rotor angle is calculated on the basis of the mathematical formula β=arctan(a/b) the quotient (a/b) will remain constant at temperature induced changes of the magnetic field.
FIG. 7 is a block circuit diagram of the structure of a control in which sensors for the recognition of the rotor position may be dispensed with. When controlling the synchronous motor 10 with a continuous, especially sinusoidal current supply the position of the rotor must be calculated by the microprocessor 108 . This is carried out on the basis of a mathematical model 103 of the motor 10 stored in the control in which the characteristic parameters of the motor such as winding resistance, motor inductance and induced voltages must be known. The motor currents I 1 and I 2 and the motor voltage U —w are continually registered vectorially, i.e. according to amount and phase position, whereby the currents are measured by the sensors and the voltage is known from the pulse pattern generated by energization of the valve control 110 . In this manner, the operational point of the motor 10 at any given instant may be precisely defined, and the motor 10 may be operated at the minimum current required for the load torque. Since motor current and voltage at the motor 10 are detected in the frequency converter 104 no further sensors are necessary at the motor 10 .
In an advantageous embodiment of the control without sensors the parameters of the mathematical model 113 are adjusted either as required or continuously. Such an adjustment may become necessary if the motor-specific parameters (winding resistance, motor inductance and induced voltage) change as a result of the motor 10 heating up during operation. The winding resistance and the induced voltage in particular are parameters strongly dependent upon temperature. By briefly feeding d.c. current into the stator winding 18 from the frequency converter 104 , preferably during the reversing pauses in the washing mode, the instantaneous winding resistance (and, hence, the temperature of the motor) as well as the motor inductance may be determined provided the voltage at the motor is known and the current is measured by the sensors 103 a, b in the frequency converter 104 .
The winding resistance R may be derived from the relation R=U/I and the inductance L from the time constant T=L/R, it being necessary continuously to measure the current in order to determine the time constant T.
Since the machine is being operated as an externally controlled synchronous motor 10 a low output frequency of the frequency converter 104 at start-up of the motor 10 is important. Typical switch-on frequencies are from 0.1 to 1 Hz. In connection with the high number of poles of the motor 10 this ensures a definite start-up without bucking, even under a load.
The number of windings of the stator winding 18 is calculated such that at higher revolutions the synchronous generated voltage and the induced voltage of the synchronous motor 10 are higher than the output voltage or the buffer voltage of the frequency converter 104 . Such an arrangement allows an operation with field weakening at higher revolutions. The field weakening makes it possible to operate the motor 10 at about the same motor current in two different working conditions at different revolutions and different torques, for instance in the washing and spinning modes.
In this context, field weakening is to be understood as a weakening of the field generated by the permanent magnets 23 of the rotor 15 in the air gap by a field of corresponding force and phase position generated in the stator 16 . At the occurrence of field weakening the synchronous generated voltage and the motor current are not in phase; rather, the current in the strands is ahead of the synchronous generated voltage. At field weakening, the angle between the stator magnetomotive force and rotor field exceeds 90° (electrically). In addition to its force generating component in the transverse axis the current has a negative longitudinal component in the stator which is opposing the rotor field. The current in the strands may be vectorially divided into a force generating and into a field generating component with the force generating component being in phase with the synchronous generated voltage and the field generating force opposing and weakening the rotor field.
In a controlled operation the torque generating component of the current in the transverse axis and the longitudinal current component in the stator may be adjusted separately from each other by means of the current sensors 103 a, b which will detect the strand current in at least two phases. Hence, the drive may be operated at minimum current and optimum efficiency even in the field weakening range. Sensing and controlling the motor current in a field weakening operation are recommended since at too large a negative longitudinal current component in the stator the magnets may become irreversibly weakened by the field generated by the magnetomotive force.
In a sensorless control the rotor position or the position of the rotor field is calculated on the basis of the measured strand currents and the mathematical model 113 the motor 100 . The rotor position may thus be defined only as long as the motor is energized. For that reason, it is advantageous in a sensorless control to maintain the motor 10 energized even during its phase of deceleration from the washing revolutions or from the spinning revolutions to complete stoppage. During this process the rotary field defined by the frequency converter 104 is continuously reduced in frequency and amplitude until complete stoppage has been reached. If the winding strands of the motor 10 are at least partially energized even during stoppage, thereby to maintain the position of the rotor 15 , the next start-up into the defined direction may commence immediately and without bucking. If Hall sensors are utilized, deceleration may take place without control or without feeding of current.
The described drive makes possible reversals without any or no more than a short reversing pause. In washing machines equipped with a drive belt as an intermediate drive this would not be possible without some difficulties. The drives usually utilized in such washing machines are universal motors which decelerate without controls and without braking. After switching off such a motor the washing drum will slow down or cease oscillating. To prevent increased wear and noises of the drive belt it is necessary following switching off to wait until the drum has come to a definite stop before the motor can be switched on again. In washing machines with drive belts these stopping intervals typically last 2 to 4 seconds. By eliminating these hitherto customary and needed pauses during reversing operations washing cycles of reduced duration will result.
A further advantageous embodiment of a laundry treatment apparatus is provided with a device for evaluating the voltage induced by the deceleration of the rotor 15 . The revolutions at any given instant may be deduced from this voltage. As long as the motor 10 is rotating a voltage will be induced in the stator winding 18 of the motor 10 . Level and strength are in proportion to the number of rotations. The induced voltage may be utilized to sense drum rotation. In a washing machine with an electromagnetically or electromechanically latched door the induced voltage may be used to operate the latching device. It is thus possible in a simple manner to provide for safe latching of the door 7 without use of additional revolution sensors. Such an application is possible in general in washing machines provided with rotors excited by permanent magnets and is thus not limited to the embodiment in accordance with the invention.
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The invention relates to a laundry treatment apparatus like washing machines, laundry dryers or a washer-dryers with a rotatably mounted drum ( 6 ) with an at least approximately horizontal axle and with a drive motor ( 10 ) structured as a synchronous motor ( 10 ) energized by permanent magnets arranged on the drum ( 6 ) shaft, the stator ( 16 ) of the motor ( 10 ) being provided with a winding ( 18 ) which is energized by a converter. In order to optimize the motor in such machines in respect of energy consumption, noise development and costs it is proposed to design the winding ( 18 ) as a single pole winding, whereby the number of stator poles ( 27 ) and of the magnet poles ( 23 ) is different, and to utilize a frequency converter ( 104 ) as the converter the output voltage of which being set such the continuous currents are generated in all winding strands.
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This application claims the benefit of Provisional No. 60/145,767 filed Jul. 27, 1999.
FIELD OF THE INVENTION
The present invention is related in general to the field of semiconductor devices and processes and more specifically to structures, materials and fabrication of substrates to be used in surface mount assembly of semiconductor devices.
DESCRIPTION OF THE RELATED ART
In order to successfully attach a leaded semiconductor surface mount device onto a board by soldering, all the device leads have to touch the board surface simultaneously, or at least be within a certain small distance from that surface; they have to exhibit “coplanarity”. The coplanarity is a function of the lead pitch. As an example of industry practice, for a lead pitch of 0.65 mm, the acceptable coplanarity is 0.1 mm, representing a tolerance window of ±0.05 mm. For a lead pitch of 0.3 mm, the acceptable coplanarity is only 0.05 mm (for comparison, the diameter of a human hair falls into the 0.1 to 0.3 mm range).
With the advent of the Ball Grid Array (BGA) package for semiconductor devices, the coplanarity of leaded devices is no longer an issue, since the leads are replaced by solder “balls” for surface mount assembly. However, in plastic BGA's, the overall packages are usually somewhat flexible, since they are composed of flexible materials. There is typically a significant difference in the coefficients of thermal expansion between the silicon chip, the plastic substrate used for chip mounting, and the encapsulation material (commonly a plastic molding compound). Consequently, in processes at elevated temperatures, the package may slightly warp and then represent, as a whole package, coplanarity problems in subsequent assembly processes. Due to the warping and coplanarity problem, only a limited number of solder balls attached to the warped package surface will contact the board in assembly, while a substantial number of solder balls will not contact the board surface and will not be able to form solder joints in solder reflow attach processes.
Typically, assembly and packaging processes at elevated temperatures include:
Transfer molding at 175° C. in less than 1 minute.
Polymerization of the molded device at 175° C. for up to six hours in “cure” ovens.
Reflow of attached solder balls or bumps. Typically, solder bumps are reflowed in chain type furnaces at temperatures dependent on the melting of the solder mixture (typically between about 150 and 250° C.).
After these temperature treatments, plastic BGA packages may exhibit warping to the extent that uniform solder ball attachment onto substrates is difficult, if not outright impossible. The resultant coplanarity problems are particularly pronounced for BGA packages using plastic films or other thin plastic materials as supporting parts. As a consequence, serious yield losses and reliability problems have been encountered in board attach processes of plastic BGA's.
The proposal to remedy the coplanarity problem by using an array of solder balls having different diameters dependent on the location on the package, is completely impractical; in addition, the degree of warping varies with device type, size and materials of packages, thermal process history, and so on. As an example, in BGA's having a convex warping, this proposal would require smaller diameter solder balls for the center portion of the package and larger diameter balls for the peripheral portions—a proposition which mass manufacturing would have great difficulties in handling.
An urgent need has therefore arisen for a low-cost and reliable approach, involving both package and board structures and the assembly fabrication method, to provide uniform board attachment of warped plastic Ball Grid Array packages, with the goal of assembling the plastic BGA device substantially parallel to the substrate. The structure of the substrate and the assembly method should be flexible enough to be applied for different semiconductor product families and a wide spectrum of design and assembly variations, and should achieve improvements towards the goals of enhanced process yields and device reliability. Preferably, these innovations should be accomplished using the installed equipment base so that no investment in new manufacturing machines is needed.
SUMMARY OF THE INVENTION
According to the present invention for a semiconductor integrated circuit (IC) assembly, a Ball Grid Array (BGA) package with the solder balls arrayed on a warped surface can be attached substantially parallel onto a flat substrate when the substrate has contact areas featuring at least one distributed characteristic to cause the solder balls to become thinner during reflow. One such distributed characteristic may be the size of the contact areas. Another such feature may be the metallic thickness of the areas. Most frequently, the warped surface has an outward concave contour, but the invention applies also to convex BGA surface contours.
The present invention is related to high density ICs packaged as plastic BGA's, especially those having high numbers of inputs/outputs, and also to low end, low cost devices. These ICs can be found in many semiconductor device families such as standard linear and logic products, digital signal processors, microprocessors, digital and analog devices, high frequency and high power devices, and both large and small area chip categories.
It is an aspect of the present invention to provide a substrate with solder contact areas having at least one characteristic which exploits the wetting of solder on metallic surfaces, the dissolving strength of liquid solder, and the self-aligning feature of liquid solder surfaces based on surface tension.
Another aspect of the present invention is to design these characteristics so that certain categories of substrates match certain BGA package types having their known statistical degree of warping.
Another aspect of the invention is to reach these goals without cost of equipment changes and new capital investment and using the installed fabrication equipment base.
Another aspect of the invention is to teach guidelines for designing the substrate contact areas in order to match the corrective characteristic to the statistical coplanarity distribution of the BGA-to-be-assembled.
These aspects have been achieved by the teachings of the invention concerning the structure, geometries and material selection of the substrates, and the assembly methods suitable for mass production. Various modifications have been successfully employed.
In the first embodiment of the invention, the sizes of the metallic substrate areas are modified to accommodate a BGA package with concave warping of its solder ball surface. The resultant lowering of the solder joint heights and resolved coplanarity problem are illustrated.
In the second embodiment of the invention, the metallic thickness and solder-dissolving characteristic of the substrate contact areas are modified to accommodate a BGA package with concave warping of its solder ball surface. The resultant lowering of the solder joint heights and resolved coplanarity problem are illustrated.
The technical advances represented by the invention, as well as the aspects thereof will become apparent from the following description of the preferred embodiments of the invention, when considered in conjunction with the accompanying drawings and the novel features set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic and simplified cross section of a BGA device with coplanarity problem, to be attached to a substrate.
FIG. 2 is a schematic and simplified cross section of a BGA device with coplanarity problem and its assembly, substantially parallel, onto a substrate.
FIG. 3 is a mathematical description of the conditions for assembly of a BGA with coplanarity problem, substantially parallel to a flat substrate.
FIG. 4 lists mathematical equations expressing the interrelation of the parameters in FIG. 3 .
FIGS. 5 to 7 illustrate schematically the first embodiment of the invention.
FIG. 5 is a simplified cross section through a portion of a substrate characterized by metallic contact areas of various sizes.
FIGS. 6A and 6B are simplified cross sections through the contact areas of FIG. 5 before and after solder ball reflow.
FIG. 7 lists numerical examples of BGAs featuring the first embodiment of the invention.
FIGS. 8 to 10 illustrate schematically the second embodiment of the invention.
FIG. 8 is a simplified cross section through a portion of a substrate characterized by metallic contact areas of various thicknesses.
FIGS. 9A and 9B are simplified cross sections through the contact areas of FIG. 8 before and after solder ball reflow.
FIG. 10 lists numerical examples of BGAs featuring the second the second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated in FIG. 1, the invention relates to the assembly of an integrated circuit (IC), packaged in a plastic Ball Grid Array (BGA) package 100 , onto a flat substrate 110 in solder reflow process. Because of the mismatch of the coefficients of thermal expansion of the semiconductor chip and the mostly plastic parts (including carrier 101 and encapsulant 102 ) of the package, the BGA package frequently deviates from a flat shape and may, for instance, exhibit a convex surface curvature 103 .
As defined herein, the difference in elevation between BGA solder “balls” touching the substrate surface and BGA “balls” not touching the surface due to package warping, is called BGA “coplanarity”. In FIG. 1, solder balls 105 touch the substrate surface at places 111 ; however, solder balls 106 do not touch the substrate surface. In devices having a warping problem with a convex surface, the coplanarity reaches a maximum value C, designated 104 in FIG. 1, for solder balls positioned at the BGA perimeter.
As defined herein, the term “ball” is used to refer to a finite body of material. In addition, it may often but by no means always have the additional connotation of approximately spherical shape. When used in conjunction with solder material after reflow, this finite body of material may rather have the shape of a half-dome, a truncated cone, or a cylinder with straight, concave or convex outlines. It is still referred to as a “ball”.
The present invention relates to methods of assembling by solder reflow a warped BGA 200 in FIG. 2, having the maximum coplanarity 204 , onto a flat substrate 210 . During assembly, all solder balls have to undergo reflow and will have to result in different solder joint heights dependent on the position of the solder ball on the warped BGA surface. In the warped BGA of FIG. 2 having a convex surface, balls 205 show a lower solder joint height compared to balls 206 around the perimeter of the package.
By way of example, BGAs with small outlines (for instance, μ*BGA™), have square shape of 12×12 mm and solder balls numbering 100 , 128 , 144 , or 180 ; square shape of 15×15 mm and solder balls numbering 176 or 196 ; solder ball diameter after reflow typically 450 μm. In other devices, solder ball diameters may be smaller, as in the diameter range of about 100 to 120 μm, or may be considerably larger.
Using the warped BGA after solder reflow of FIG. 2 as a guideline, FIG. 3 derives the mathematical relations between coplanarity C and the extreme cases of solder ball distribution in order to accommodate the device warping. Solder ball cases with tall solder joint height (designated 206 in FIG. 2 ), are indicated in FIG. 3 by subscripts “o”: Solder ball of height Ho and radius Ro for contact length Lo over contact depth Do. Solder ball cases with low solder joint height (designated 205 in FIG. 2 ), are indicated by subscripts “1”: Solder ball of height H1 and radius R1 for contact length L1 over contact depth D1. In FIG. 3, the warped surface is indicated by heavy line 301 .
The results of the mathematical model are summarized in FIG. 4 based on two relations which characterize BGA solder reflow operations: First, solder volumes Vo and V1 are identical, since no material is lost or created in the assembly process (equation (1)). Second, the taller solder height Ho is the sum of the smaller solder height H1 plus the coplanarity C (equations (3a) and (3b)), expressing the goal of substantially parallel assembly of BGA and substrate. Further, the volume of any solder ball is expressed in equation (2) in terms of solder ball radius and contact length and depth. For ease of calculations, the tacit assumption is made that the solder contacts on the substrate surface are identical.
In the actual assembly process, the solder contacts at the package joints are identical and the contacts on the substrate surface are variable. This does not affect the modeling results. As a consequence, the embodiments of the invention start with the design of the minimum length and minimum depth of the substrate contact areas. Based on typical fabrication practice, it is reasonable to let these minima be Lo and Do, as is also suggested by FIGS. 2 and 3. Fixing the minima and using equation (1) delivers equation (4). Consequently, the remaining variables are R1, L1, and D1. When L1 and D2 are designed, R2 will be determined as a consequence of equation (1). Designing L1 leads to the first embodiment of the invention; designing D1 leads to the second embodiment.
First Embodiment of the Invention: Discrete
Lengths L1, L2, . . . , Ln
FIGS. 5 to 7 illustrate structure, materials and processes of the first embodiment of the present invention. The embodiment is based on variable sizes of the discrete metallic contact areas 500 of the substrate 510 . The substrate is preferably made of electrically insulating organic material selected from a group consisting of polyimide, polymer strengthened by glass fibers, FR- 4 , FR- 5 , and BT resin. The substrate has a generally flat surface. Another option is a thermally conductive substrate (for instance, metal such as copper) with an insulating layer on top. Deposited on the surface, or inset in the surface, are contact areas 500 , usually consisting of copper with a flash of gold. However, if metal interdiffusion with the solder is to be kept at a minimum, a thin layer of refractory metal (titanium or titanium-tungsten alloy, 40 to 700 nm thick, preferred 50 nm) may be deposited over the copper layer, followed by a layer of platinum or platinum-rich alloy (200 to 800 nm thick, preferred 500 nm). Other materials for the contact areas may be selected from a group consisting of aluminum, tungsten, or alloys thereof, overlaid by palladium or gold.
FIG. 5 schematically shows a portion of substrate 510 with three discrete metallic substrate areas of lengths L1, L2, and L3, respectively. Length L1 has the smallest value, length L3 the largest. The number of areas and the actual lengths are designed based on the model of FIGS. 3 and 4 in relation to the number of BGA solder balls and the degree of surface warping of the BGA to be assembled (see examples in FIG. 7 for a typical values L1).
FIGS. 6A and 6B display schematically the attachment of solder balls 601 (of approximately equal diameter) to the discrete substrate areas on substrate 510 , the reflow of the solder balls 601 and the effect of the invention on the heights of the resulting solder joints. Solder balls 601 are selected from a group consisting of tin/lead, tin/indium, tin/silver, tin/bismuth, solder pastes, and conductive (for instance, silver-filled) adhesives. The solder alloy is selected based on its melting temperature convenient for the device application, and its capability to wet the contact surface completely. As FIG. 6A shows, the solder balls 601 are preferably of identical size, with the diameter varying widely dependent on device type and application; typical diameters are about 250 to 500 μm, other examples are quoted above.
FIG. 6B illustrates the fact that the solder balls of originally equal size spread at the reflow temperatures across the surface of the substrate contact areas and create solder joints of unequal heights H1, H2, H3. The tallest height H1 is related to the smallest length L1, the smallest height H3 to the longest length L3. Since the length of the substrate contact area is the characteristic variable in the first embodiment of the invention, this result indicates that higher amounts of the characteristic cause the solder balls to become thinner during solder reflow, relative to the thickness of the remaining solder joints. This, in turn, causes lower solder joint heights relative to the heights of the remaining solder joints.
FIG. 7 tabulates typical results based on two actual μ*BGA™ geometrical data. The quoted values for L1 are averages over many L1, L2, . . . , Ln.
The heights H1, H2, . . . , Hn have been structured according to the empirical warping of the plastic BGA to be assembled on the board. Using the invention for the characteristics of substrate and reflow solder balls, warped semiconductor BGA packages can be accommodated.
Second Embodiment of the Invention: Discrete
Depths D1, D2, . . . , Dn
FIGS. 6 to 10 illustrate structure, materials and processes of the second embodiment of the present invention. The embodiment is based on variable depths of the discrete metallic contact areas 800 of the substrate 810 . The substrate is preferably made of electrically insulating organic material selected from a group consisting of polyimide, polymer strengthened by glass fibers, FR- 4 , FR- 5 , and BT resin. The substrate has a generally flat surface. Another option is a thermally conductive substrate (for instance, metal such as copper) with an insulating layer on top. Inset into the surface are contact areas 800 of various depths D1, D2, D3, . . . , Dn. FIG. 8 shows these contact areas filled flat to the substrate surface with a material somewhat spongy (such as gold-clad aluminum sponge) or containing voids intended to be filled with solder. FIG. 9A shows these contact areas recessed to various depths, with a metal layer deposited in each recess (such as copper with a flash of gold). Other materials for the contact areas may be selected from a group consisting of aluminum, tungsten, or alloys thereof, overlaid by palladium, gold, platinum, or platinum-rich alloy.
FIGS. 8 and 9A schematically show a portion of substrate 810 and 910 , respectively, with three discrete metallic substrate areas of depth D1, D2, and D3, respectively. D1 has the smallest value, D3 the largest. The number of areas and the actual depths are designed based on the model in FIGS. 3 and 4 in relation to the number of BGA solder balls and the degree of surface warping of the BGA to be assembled (see examples in FIG. 10 for typical values D1).
FIGS. 9A and 9B display schematically the attachment of solder balls 901 (of approximately equal diameter) to the discrete substrate areas on substrate 810 and 901 , respectively, the reflow of the solder balls 901 and the effect of the invention on the heights of the resulting solder joints. The solder alloy is selected based on its melting temperature convenient for the device application, and its capability to penetrate the contact depths fully. Solder balls 901 are selected from a group consisting of tin/lead, tin/indium, tin/silver, tin/bismuth, solder pastes, and conductive (for instance, silver-filled) adhesives. The diameter of solder balls 901 may vary widely dependent on device type and application; typical diameters are about 250 to 500 μm.
FIG. 9B illustrates the fact that the solder balls of originally equal size penetrate at the reflow temperatures into the depth of the contact areas and create solder joints of unequal heights H1, H2, H3. The tallest height H1 is related to the shallowest depth D1, the smallest height H3 to the deepest depth D3. Since the depth of the substrate contact area is the characteristic variable in the second embodiment of the invention, this results indicates that the higher amounts of the characteristic cause the solder balls to become thinner during solder reflow, relative to the thickness of the remaining solder joints. This, in turn, causes lower solder joint heights relative to the heights of the remaining solder joints.
FIG. 10 tabulates typical results based on two actual μ*BGA™ geometrical data. The quoted values for D1 are averages over many D1, D2, . . . , Dn.
The heights H1, H2, . . . , Hn have been structured according to the empirical warping of the plastic BGA to be assembled on the board. Using the invention for the characteristics of substrate and reflow solder balls, warped semiconductor BGA packages can be accommodated.
While this invention has been described in reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. As an example, the material of the semiconductor chip may comprise silicon, silicon germanium, gallium arsenide, or any other semiconductor material used in manufacturing. As another example, the BGA may have an encapsulation made by overmolding or another technique, or may have no encapsulation at all. The IC chip may be wire bonded or solder flip processed. It is therefore intended that the appended claims encompass any such modifications or embodiments.
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A substrate for solder ball assembling a semiconductor device substantially parallel onto said substrate, said device having a plurality of terminals arrayed on a warped surface, comprising an electrically insulating surface including a plurality of discrete metallic areas; said areas having locations matching the locations of said device terminals, and further being suitable for solder ball attachment in surface mount reflow operation; and said areas further having at least one characteristic suitable for accommodating said device warping in solder reflow operation, whereby areas having higher amounts of said characteristic cause said solder balls to become thinner during reflow, resulting in lower solder joint heights, relative to the heights of the remaining solder joints.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
Inherent or unique vibrations occur with a yarn guide disposed on a ring spinning frame when the yarn quide comes into contact with spinning yarns. This invention relates to an apparatus having a piezo-electric element disposed at a yarn guide for sensing the vibrations, a yarn guide installation lappet and electrical connections leading out the output of the piezo-electric element, for the purpose of detecting broken yarns.
2. Description of the Prior Art
In ring frames or other similar spinning machines, early inspections of yarn breaks are of great importance to increase production, minimize refused yarns and prevent failures in advance.
To this end several broken yarn detectors are well known: the photoelectric tube type whereby movements of a flier in contact with yarns due to breaks in the yarns are sensed; the dielectric constant type, etc. Those detectors are divided into two types; those wherein detectors sense yarn breaks in the progress of travelling along spinning yarn lines and those wherein the counterparts are disposed on individual spinning parts.
However, the former or moving type needs a device to move and guide the detectors and in particular substantial expenditures in applying the detectors to the conventional frames. The latter is therefore more desirable. Moreover, the above described photoelectric tube type or dielectric constant type is expensive and it is almost impractical to dispose the detectors at the individual spinning parts, from an economic point of view. There is a requirement that those detectors be disposed at the individual spinning parts and easily applicable to the conventional frames.
Conveniently, yarn guides are disposed on the ring frames for guiding spinning yarns onto bobbins and cause vibrations when coming into contact with the spinning yarns. Another approach which is well known is to sense the vibration for detecting broken yarns through the utilization of a piezo-electric element. It is also well known that the vibrations due to contact with the spinning yarns are discriminated from that accompanying mechanical vibrations of the ring frames in indicators of breaks in yarns.
Nevertheless, no system is suggested which picks up collectively the electromotive forces of piezo-electric elements disposed on a multiplicity of yarn guides and detects their unique vibrations. In addition, there is no suggestion on a specific structure of lappets for leading out signals developed from the piezo-plectric elements.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a yarn break detector in which vibration sensing yarn guides are easily applicable to the conventional ring frames or the like. It is another object of the present invention to provide a lappet structure for installation of vibration sensing yarn guides and a means for leading electric signals out from lappet bars.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will be more full appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompany drawings, wherein like reference characters designate like or corresponding parts throughout the several views, and wherein:
FIG. 1 is a cross sectional side view of a ring frame embodying the present invention;
FIG. 2 is an enlarged view of a lappet illustrated in FIG. 1;
FIG. 3 is a plan view of FIG. 2 illustrating only two divided lappet bars;
FIG. 4 is a rear view, partly in cross section, of the lappet;
FIG. 5 is an exploded perspective view of the lappet illustrated in FIGS. 2 and 4;
FIG. 6 is a cross sectional view taken on the lines A--A and B--B of FIG. 2;
FIG. 7 is an explanatory diagram of an amplifier and detector section for a piezo-electric element;
FIG. 8 is a perspective view of circuit boards secured in front of a lappet bar;
FIG. 9 is a partly enlarged view of FIG. 8;
FIG. 10 is a perspective view of electrical connections on the circuit boards;
FIG. 11 is a plan view of a bearing surface of a coupling board;
FIG. 12 is a bottom view of FIG. 11;
FIG. 13 is a perspective view of another preferred form of the present invention;
FIG. 14 is a circuit diagram showing the operating principle of a signal detector;
FIG. 15 is a circuit diagram of a signal detection and transmission circuit;
FIG. 16 is a block diagram of the signal detection and transmission circuit;
FIG. 17 is a timing chart;
FIG. 18 is a side view of another form of the lappet used according to the present invention;
FIG. 19 is a right side view of FIG. 17;
FIG. 20 is a cross sectional view of a yarn guide mounting section shown in FIG. 18 and a lappet mounting section;
FIG. 21 is an exploded perspective view of the lappet shown in FIG. 17; and
FIG. 22 is an explanatory diagram of a part of FIG. 21.
DETAILED DESCRIPTION OF INVENTION
Referring now to FIG. 1, there is illustrated a representative example of a ring spinning frame in which spinning yarns Y are drawn out from a pair of front rollers 1, 1' and wound up on a bobbin 8 while being guided by a yarn guide 2. The spinning yarns Y are twisted and wound up to form a cup 7 during rotation of the bobbin 8 since the yarns are wound about the bobbin 8 via a link ring 5 movable up and down on a ring rail 4 and a rotatable traveller 6. An anti-node ring is labeled 9. The yarn guide is mounted on a lappet 3 which in turn is supported on a lappet bar 10. The yarn guide 2 is adjustable in position on the lappet 3, while the lappet bar 10 is slidable up and down along a spindle of the bobbin 8.
The present invention successfully utilizes as a yarn break detector the above described structure of the yarn guide 2. A piezo-electric element 12 is secured on part of the yarn guide 2, the output of the piezo-electric element 12 being led out for yarn break detecting purposes. It will be noted that high frequency vibrations occur in the yarn guide 2 on its contacting the spinning yarns Y. Such vibrations are mixed with mechanical vibrations of the ring frame. The mechanical vibrations occur at about 1 KHz, while the yarn guide, in fact, vibrates at about 15 KHz. It has been found that the latter are vibrations inherent to the yarn guide and substantially independent of the pressure of contact with the spinning yarns Y and the rate of the traveling yarns Y. Accordingly, breaks in yarns can be detected by discriminating the inherent or unique vibrations from the mechanical vibrations. As a vibration sensing measure, a piezo-electric element is employed of the type in which the electromotive force is measured in sensing the unique vibrations. The yarn guide embodying the present invention is, therefore, provided with a piezo-electric element of which the electromotive force is easily led out for detecting purposes. It is required that the yarn guide 2 be adjustable with respect to and detachable from the lappet 3 and the lappet 3 be also detachable from the lappet bar 10. The lappet 3 is usually of the spring hinge type which always holds the yarn guide 2 at a fixed level. As noted earlier, the present invention provides a vibration detector which fulfills these requirements.
FIG. 2 is a cross sectional view in which the yarn guide 2, the lappet 3 and signal leading means are mounted on the lappet bar 10 according to the present invention. The lappet 3 is secured on the lappet bar 10 via an insulator board 16 and a circuit board 15 on the rear of the insulator board 16. The lappet 3 is of the hinge shape on a lappet bracket 13. The yarn guide 2 is adjustably mounted on the front side of the lappet 3. The piezo-electric element 12, as indicated in FIG. 4, has a flat side bonded to the yarn guide 2 via an adhesive. Conveniently, the yarn guide 2 used with the present invention is springily held on a holder 21 as denoted by 11. The holder 21 is of a cylindrical shape as shown in FIG. 5 having two slots 22 one of which is not shown. Leads from the piezo-electric element 12 are connected to an electrically conductive plate 121 received within the slots 22. The yarn guide 2 is exchangeable together with the holder 21. A slide hole or slot receptor 32 is formed in the bottom of the lappet 3 for urging the yarn guide holder 21 downwardly. A "U" shaped member 40 is inserted into the slide slot receptor 32 from the rear. The holder 21 and the "U" shaped member 40 both are made of insulating material. Slots 42 are formed inside fingers 41 of the "U" shaped member 40, respectively. The fingers 41 pass through the slots 42. An aperture at the tip thereof is labeled 43.
Electrically conductive wires 46 are inserted into the slots 44 and the aperture 43, the wire consisting of a coil section 44, a terminal section 14 and a contact section 47 springily folded inwardly from the slot 42. The wires 46 are also inserted into the slots 42 and the aperture 43 beginning with the contact section 47 thereof. Electrically insulating collar rings are disposed on both sides of the coil sections 44 via necks 35 of an electrically insulating cylinder 34. A stopper 45 is formed on the rear side of the "U" shaped member 40 for limiting the insertion positions.
The bracket 13 of the lappet 3 carries two hinge pivots 131 and lappet holding arms 133. An installation screw hole is labeled 132. The lappet 3 has hinge pivots 31 at its rear end. The "U" shaped member 40 is inserted into the slide slot receptor 32, the cylinder 34 is disposed between the pivots 131 of the bracket 13 and the pivots 31, the bracket hinge pivots 131 and the cylinder 34 of the lappet 3 are connected by a shaft 33, thereby completing assembly of the lappet 3. The yarn guide holder 21 is inserted into the slide slot receptor 32 in the lappet 3 as indicated in FIG. 4 and the leads of the piezo-electric element 12 are connected to the terminal sections 14 via the wires 46.
In installing the yarn break detecting lappet 3 on the conventional lappet bar 10, care should be taken that the respective terminals 14 be surely electrically connected and the lappet 3 be exchangeable and adjustable in installation position to a certain degree. Since approximately 200 lappets are disposed on both sides of the frame in precise ring spinning machines, it is necessary that the insulating plate 16 and the circuit board 15 be divided for 4-8 weight use and it is favorable that these boards be of the same size. Moreover, it is inconvenient to dispose a multiplicity of lead wires in the vicinity of the lappet bar 10 from a productivity point of view. The present invention, therefore, provides a new structure for the circuit boards which are designed to pick up and transmit signals on the individual yarn guides. As viewed from FIG. 3, the circuit boards 15 are disposed closely to one another and electrical connections are formed on both sides of the circuit boards in such a way that the coupling boards 17 carrying junctions with the insulating board 16 are held in contact with the lappet bars 10 under pressure by the action of the adjacent lappets. As is clear from FIG. 8, the circuit boards 15 are disposed on the lappet installation side (the front face) of the lappet bars 10 and sandwiched between the insulating boards 16 by means of lappet installing bolts and nuts. By the nuts 102 (FIG. 2) the lappet installing bolts (not shown) are fastened to run through the hole 132 (FIG. 5) in the lappet bracket 13, a hole 162 formed in the insulating board 16, a hole 151 in the circuit board 15 and an installing hole 101 in the lappet bar 10. Each circuit board 15 carries a printed circuit pattern on one major surface of an electrically insulating material. Although the drawings illustrate these circuit boards 15 and insulating boards for six-weight use, it is obvious that they are equally applicable to four-to eight-weight uses. Electrical connections 18 leading to the terminals 14 are disposed above the installing holes 151 in the circuit boards 15, respectively. Above the installing hole 162 in the insulating board 16 there is formed an elongate slot 161 through which the terminals 14 extending backwardly from the lappet 3 run. When the lappets are installed as stated above, the terminals are in contact with the connections 18 to establish electrically conductive paths via the elongate slot 161.
The circuit board 15 is electrically connected as depicted in FIG. 6 taken on the lines A--A and B--B of FIG. 2. The circuit board 15 carries electrically leading symmetric regions 19 at the both ends thereof. Each of the insulating boards 16 is shorter than the full length of the circuit boards 15 and held in contact with the circuit boards 15 except for the lead regions of the circuit boards 15. The coupling board 17 is disposed about the lead regions of the circuit boards 15 and the lead regions 19 of the circuit boards 15 are electrically connected to each other. As indicated in FIG. 10, connectors 173, with the number thereof corresponding to the number of the stepwise lead regions, are disposed at the back of the coupling board 17. As indicated in FIGS. 11 and 12, a longitudinal slot 171 and a lateral slot 172 are formed in each connector 173 for holding the connector. Projections 174 are formed on the slot forming side of the coupling board 17 and inserted into holes 152 (FIG. 6A) formed in the proximity of the lead regions 19 of the circuit board 15 for defining the position of the coupling board 17. Portions of both sides of each respective connector 173 are folded to extend from the surface of the coupling board 17 and contact electrically the lead areas 19 by the pressing action of the coupling board 17. As already described with respect to FIG. 3, the coupling board 17 is held on the lappets 3.
In FIG. 7, there is illustrated a schematic diagram of a signal detector 50 operatively associated with the piezo-electric transducer 12 on the yarn guide 2. Two leads from the piezo-electric element 51 are connected to a band-pass amplifier 52 which picks up the inherent vibration frequency component within the signals from the piezo-electric element. The inherent vibration component is then amplified up to a definite level through an amplifier 53. A rectifying filter 54 converts alternating current signals into direct current signals. A voltage comparator 55 is adapted to decide a voltage region wherein normal operation is guaranteed and provide logic signal outputs 56.
However, it is rather difficult to dispose such a detector 50 for each of the respective lappets because of an increase in cost of equipment. It is therefore desirable to detect and indicate the vibrations in a collective fashion. The piezo-electric elements 12 on approximately 200 yarn guides should be scanned for a brief period of time for detecting their unique vibrations. It is also necessary to detect approximately 400 signals since the lappets are disposed on both sides of the ring frame.
The present invention provides a means for selecting and transmitting a number of alternating current electric signals. FIG. 14 shows a unit circuit of the basic signal transmission circuitry which includes a positive voltage source 60, a load 61, an output terminal 62, switches 63, 65, a source 64 of alternating current signals and an OV voltage source 66. With such an arrangement, when the switch 65 is closed and the switch 63 remains opened, the output of the alternating current signal source 64 is short-circuited so that no signal is transmitted therefrom. If the switch 63 is closed and the switch 65 is opened, then the output of the alternating current signal source 64 enables alternating current to flow to the load 61 via the switch 63 and an alternating current signal voltage is developed between the voltage source and the output terminal 62, the resulting signal voltage being useful for the purpose of detecting the vibrations. The switches 63, 65 may be implemented similarly with semiconductor switches, preferably, MOS (field effect mode) transistors having excellent leak and cut-off properties. FIG. 15 depicts a circuit construction in which a number of the alternating current signal sources 64 are connected. When semiconductor switches 67-1, 67-2, . . . 67-n and 68-1, 68-2, . . . 68-n are switched ON and OFF if necessary, the alternating current sources 64-1, 64-2, 64-n are selected to convey any signals to the output terminal 62 via the selected signal sources. FIG. 16 is a circuit diagram of an implementation of the circuit of FIG. 15 by means of a C-MOS type digital IC shift register. This circuit further includes the positive voltage source 60 and the load 61 of a transformer of which the secondary output is labeled 611. The shift register has a data input terminal 67 and a clock pulse input terminal 68. Each of the latch type flip flops 70 has a D input 671, a clock input 681 and an output. A timing chart associated with the shift register construction is illustrated in FIG. 17, which depicts the developments of the data output 67 and the outputs 71, 71-1, 71-2, 72-n of the shift register clock 68 which comprises a semiconductor switch circuit as in FIG. 16. When the clock output is at a high level, the signals are transmitted from the alternating current signal sources 64, 64-1, 64-2, 64-n into the positive voltage line 60 and when the same is at a low level all the signals are short-circuited. Accordingly, the alternating current signal sources 64, 64-1, 64-2, . . . 64-n are selected in sequence by the shift register data input 67 and the shift register clock pulses 68 so that the various signals from the alternating current signal sources may be transmitted onto a common bus line by the shift register scanning. In installing these circuit elements on the circuit boards 15, as indicated in FIG. 9, holes 152 are formed at the center of the circuit boards 15 and surrounded by the lead areas. The C-MOS type digital IC shift register 153 is secured within the hole 152 with its terminals connected to the lead areas of the circuit board 15. Since the circuit boards 15 used with the present invention are those having a major surface overlaid with copper, the IC shift register 153 is secured by means of a jumping connector 154.
The above structure makes it easy to select and transmit the signals of the multiplicity of alternating current signal sources for the purpose of detecting the individual alternating current signals. In addition, in the case where the yarn break detector is applied to the ring frame, an indicator may be provided for one side or both sides of the frame or for each block of the frame. This eliminates the need for the operator or supervisor to carry out time-consuming yarn jointing operations.
Although in the foregoing description the circuit boards 15 and the insulating board 16 are disposed at the front surface of the lappet bar 10, they may be installed inside the lappet bar 10 for the purpose of the present invention. In this case an aperture 102 is formed in the installing surface of the lappet bar 10 for receiving the terminals 14 of the lappet and the coupling board 17 is disposed on the rear surface of the lappet bar. Other forms of the lappet 3 may be available as long as the leads of the piezo-electric element 12 on the yarn guide 2 extend backwardly. FIGS. 18 through 22 represent examples of the other forms of the lappet 3. The whole of a lappet 30 is made of plastic material except for the yarn guide 2. The yarn guide 2 and its installing means are similar to that in FIG. 15. The lappet 30 has a slot receptor 307 for insertion of the yarn guide holder 21 and further two slots 305 for receiving flexible contact arms 306. In the illustrated example, the lappet 30 carries no spring and a bracket 300 is of a hinge shape. It is thus difficult to form terminals 310 extending toward the back side of the bracket 300 integrally with the contact arms 306. For this reason a hinge pivot 312 is made of electrically conductive material for connecting the flexible contact arms 306 and terminal leaves 310. The terminal leaves 310 have holes 311 on their one side, the holes 311 being not completely formed in such a way that the tip of the pivot 312 is flexibly inserted thereto. The terminal leaves 310 are inserted into slots 304 formed in the bracket 300.
The contact arm 306 is shaped as shown in FIG. 21 and 22 and disposed as in FIG. 20. The contact arm 306 has a hole 309 at its one end to normally electrically connect a body of the pivot 312. Moreover, the contact arm 30 is disposed in agreement with the hole 313 which runs through the hinge section 301 formed on the top of the bracket 300, by means of a concealing member 308 closing the rear side of the slot receptor 307. The pivot 312 is secured to penetrate inserting holes 314 on both sides of the rear edge of the lappet 30, the hole 309 in the contact arm 306, the hole 313 in the bracket and the hole 311 in the terminal 310. In this way, the contact arms 306 are electrically connected to the terminals 310 via the pivot 312, respectively. Both leads of the piezo-electric element 12 are also connected to the terminals 310 as viewed from FIG. 22 by inserting the yarn guide holder 21 into the slot 307 in the lappet 30.
The above discussed plastic lappet 30 is electrically nonconductive and thus suitable to hold the break detecting yarn guide 2 of the present invention.
Obviously, 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 herein.
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Apparatus is disclosed herein which detects breaks in spinning yarns in ring spinning frames or the like and in particular senses vibrations inherent to a yarn guide disposed on a bobbin when the yarn guide comes into contact with the spinning yarns. The apparatus achieves quick inspection of whether breaks occur with the spinning yarns by the presence and absence of the vibrations, thereby monitoring joints in the spinning yarns and the operating state of the spinning machine.
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BACKGROUND OF THE INVENTION
The instant invention relates generally to portable work ladders, and more particularly to a relatively small portable ladder that is especially suitable for use by welders for welding a vertical seam on metal structures.
Numerous different types of portable ladders especially designed for use by welders for welding upright or vertical seams on metal structures are available in the prior art today. In most designs of such ladders, it is necessary that the welder be positioned adjacent one of the rails or side stanchions whereby he can gain access to a vertical seam to be welded on a metal structure, for example, a seam on the hull of a ship. By the very nature of their design many of these ladders are relatively unsafe in that they do not provide any form of cage to prevent the welder from falling backwards. In addition, many of these ladders require that the welder be located to either one side or the other of the ladder whereby the ladder itself is placed somewhat off-balance with the net result that quite often the ladder is not employed under stable working conditions. Additionally, besides the welder being uncomfortable in the above regards, the welder is generally welding on the seams slightly from an angle rather than from directly over the seam. In any event, these various types of conventional portable welding ladders offer much to be desired and among the objects of the present invention is to provide a unique portable welding ladder which has the combination of safety and efficient working features and advantages that makes it very attractive and perhaps mandatory from a safety viewpoint.
The above together with other features and advantages of the instant invention will be apparent to one skilled in the art in light of the details of construction and operation of the present welding ladder as shown in the drawing and described in the ensuing detailed disclosure of its preferred embodiment which is particularly pointed out in the appended claims.
DESCRIPTION OF THE DRAWING
For a better understanding of the nature and objects of the invention, reference should be had to the following drawing, taken in conjunction with the detailed description thereof. In the drawing, synonomous reference numerals are employed throughout in the various views to refer to identifal components.
FIG. 1 in the drawing depicts a front elevational isometric view of the present light-weight portable welder's ladder, however, with the safety cage feature removed.
FIG. 2 in the drawing illustrates a side elevational view of the present ladder.
FIG. 3 in the drawing illustrates a plan view of the embodiment of FIG. 2 of the drawing.
FIG. 4 in the drawing illustrates another preferred embodiment of the specific rung design which can be employed in lieu of the specific design illustrated in FIG. 1 of the drawing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawing, the present unique design of portable ladder 10 comprises the elongated side member rails or stanchions 11 which in turn can constitute any suitable design of shape or configuration of an appropriate construction material, however, the side rails 11 and 12 are preferably constructed of aluminum channel members. The members 11 and 12 can be made of any given length as desired, as well as spaced apart any specific width as long as they are sufficiently spaced apart to accomodate the average width of a human being, however, they are preferably spaced wider than a human being to allow full access and the use of various tools before and after a welding operation, e.g., a grinder to dress the welds.
The side stanchions 11 and 12 are rigidly affixed to each other by virtue of the lower rung or connecting step member 13 at their bottom end and at their top end by virtue of the solid connecting rods or bars 14. Of course, the bars 14 can be replaced with a single member connecting the top portions of the rails 11 and 12 which is a matter of choice of design. A distinguishing feature of the present design of ladder is embodied in the additional steps or rungs 15 which can comprise any number as desired. In the embodiment of FIG. 4, the ladder 10 comprises the four interior rungs 15 and the bottom rung 13, the four interior rungs 15 being identical in design. The rung 13, as well as the bars 14 and the interior rungs 15 are welded to the rail members 11 and 12, the rungs also being preferably fabricated of a light-weight metal such as aluminum.
The indevidual interior rungs 15 are designed such that an interior portion thereof can be readily relocated or removed in the manners as shown in FIGS. 1 and 4 of the drawing. Referring specifically to FIG. 1 of the drawing, each individual rung or step member 15 further comprises the left hand portion 16 which is rigidly affixed to the side hand rail member 11 and the opposite portion 17 rigidly affixed to the right hand rail member 12. The member 16 and 17 are located essentially on a parallel plane, that is, the various steps or rungs 15 all being essentially parallel to each other and perpendicular to the hand rail members 11 and 12. In other words, they form in essence the design of a conventional ladder in which the various steps 15 are spaced apart more or less on 12 inch centers. Each respective rung 15 further comprises the center removable portion 18 which as shown in FIG. 1 of the drawing, specifically the top most rung, is hinged such that it can be flipped upwards and away out of position to thereby provide the open gap 19. The center portion 18 is held in a horizontal position and prevented from swinging downwards by virtue of the extended clip member 20 which is welded to the under side of the right hand portion 17. Each of the individual rungs 15 in the embodiment as shown in FIG. 1 is designed the same, the lower most three interior rungs being shown in their as closed position.
By virtue of the above structure, a welder can thus readily remove the center portion 18 by swinging it upwards towards the left so as to expose the center gap portion or area 19 such that upon placing the ladder assembly 10 over a seam such that the gap area 19 spans a seam to be welded on a metal structure located behind the ladder, then a welder can readily flip the center portion 18 out of the way and weld downwards while being positioned directly in the middle of the ladder. This unique feature and advantage thus becomes apparent as far as what it offers to the welding art, viz. much greater safety, ease of working, and a considerable improvement in the speed of welding is thus realized. The center portion 18 of a given rung assembly 15 can be hinged to the left hand portion 16 in any conventional manner, such as a conventional hinge assembly welded to the underside of both those members (not shown). Of course, the member 18 could be hinged at the right hand side opposite from that is shown in FIG. 1 of the drawing. The various components 16, 17, and 18 also preferably made of a light-weight material such as aluminum, in fact, it is especially preferred to make the entire ladder out of aluminum or the like light-weight material, however, any type of material of construction can be employed, e.g., steel or the like.
For purposes of illustration only, the arrangement depicted in FIG. 1 of the drawing is shown as including only one solid rung which is the lower most rung 13, however, from a practical viewpoint, a given ladder design would include somewhere between two to four rungs located at the bottom most position as a welder standing upon the lower most rung 13 would probably not attempt to descend or extend welding a seam beneath the height of his chest, but rather, would employ a lower extending ladder or lower the present ladder.
Referring to FIG. 4 of the drawing, the embodiment of the rung assembly 21 illustrated therein performs the same function as that of the rung assembly 15 illustrated in FIG. 1 of the drawing. In that embodiment, the rung assembly 21 further comprises the right hand portion 22 and the left hand portion 23 which in turn are rigidly affixed to the respective side rail members 11 and 12. The portions 21 and 23 comprise a hollow elongated tubular member wherein the sliding member 24 fits, that is, the center portion member 24 bayonets within the portion 22 wherein it can be recessed when gaining access to a welding seam located behind the rung 21, and conversely, is retracted and slid into the open end portion of the left hand portion 23 of the rung assembly 22 when the rung assembly is employed during a non-welding operation, that is, as a conventional ladder. Suitable stops (not shown) are provided on the sliding center portion 24 for preventing it from sliding all of the way out of the right hand portion 22.
Referring to FIG. 2 of the drawing, the top most portion 25 of each respective hand rail 11 and 12 is provided with some suitable means for attaching the present ladder assembly 10 upon a structure upon which it is being employed, generally a storage tank. For that reason, the top portion 25 of the present welding ladder preferably comprises an arcuate shaped portion fitting over the side rail of the rim of a tank during which type of construction the present ladder is preferably utilized and generally mainly required for use in welding seams toward the top of the tank where the greatest problem is encountered in regard to welding from a safety viewpoint. That is, the seams along the bottom portion of the tank can be more safely handled from the ground level and generally, the upper seams present the greatest problem from a safety viewpoint. For that reason, the present ladder assembly 10 also preferably comprises the cage assembly 26 which is conventional in design, further comprising in turn the horizontal circular struts 27 which are welded at their respective end to each respective hand rail member 11 and 12, being spaced apart at suitable structural distances. The struts 27 are interconnected by the vertically oriented struts 28 so as to define the cage assembly 26 which functions so as to prevent a worker from falling backwards off of the ladder 10. As is well known in the art, generally most workers upon falling from a ladder by losing control and falling backwards, have virtually no chance to grab hold of anything whereby the net result is the fact that they suffer considerable head injuries, as compared to a worker who slips straight down on a ladder whereby he has a chance to grab and hang on an additional rung as he is falling. Thus, among the distinguishing features of the present invention is the fact that the present welding ladder allows the use of a safety cage assembly since the welder need not work to one side or the other of the ladder, but rather, can confine his work space within the side hand rails of the ladder. The net result is a trememdous improvement in safety operating conditions.
The bottom spacer member 29 which is affixed to any suitable portion of the bottom of each respective side hand rail members 11 and 12 is provided for maintaining the ladder assembly 10 a suitable distance away from the structure on which the present ladder has been mounted for use. The spacer member 29 provides a suitable spacing so that the worker can let his foot extend across a respective rung 15 for safety reasons, that is, so that he need not go up and down the ladder with his weight being supported on the front part or ball of his foot under which conditions he would be more apt to slip. Additionally, the spacing member 29 provides a more convenient operating distance between the welder and the particular surface upon which he is working. The length of the spacing member 29 would naturally be determined by the particular working and operating conditions of any given application.
It will be apparent to one skilled in the art that various changes and modifications can be made in the above device, as well as in its mode of use, without departing from the true scope and spirit of the present invention. For example, the present ladder can be produced in different sections and suitably connected together during operations rather than making it in one long extended assembly. For that matter, a telescoping arrangement can be employed as in a conventional ladder. The particular details of the removable center portion of the various rung designs can be varied, for example, in the case of the rung design 15, the center portion 18 can comprise two separate portions, each half of which would be connected to the side member 16 and 17. Various structural details can be elaborated upon so as to improve the structural strength of the present ladder, for example, knee braces can be positioned under the rung side members 16 and 17 so as to strengthen their supporting capability. Additionally, the particular mode or manner of attaching the present ladder assembly 10 to the structure upon which it is to be employed can be varied considerably, that is, the top portion 25 of the hand rails 11 and 12 need not be curved as shown but rather, could be provided with hooks or the like for attaching it to the particular structure upon which the present ladder assembly 10 is being employed.
Other refinements can be made without departing from the intent of the present invention such as providing a gripping material on the rungs 15 so as to insure a sure footing. The spacing member 29 can also be varied in design by making it adjustable so that a worker can readily provide the particular working distance he desires in spacing the ladder assembly 10 from the surface upon which it is being employed.
The various sizes or widths of the portions 16, 17, and 18 of the embodiment of FIG. 1 can vary, however, it is preferred to make the center folding portion 18 of a rung equal in length to that of the rung portion 16 over which it folds so that the portion can fold back flat thereon. Moreover, in the case of the embodiment of FIG. 4, it is preferred to size the portions 21 and 23 such that the sliding rung portion 24 need not have to protrude out of the side of the stantion 12 as shown in FIG. 4.
In light of the above, it can be appreciated by one skilled in the art that many varying and different embodiments may be made within the scopy of my inventive concept as disclosed herein, and accordingly, since many such modifications may be made in the embodiments as disclosed in detail herein, in accordance with the descriptive requirements of the law, it is to be understood that the details of my inventive concept are to be interpreted as illustrative and not in a limited sense. Therefore, what I intend to encompass within the ambit of my invention is that as set forth and particularly pointed out in the appended claims.
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The present invention provides a portable light-weight ladder for use in connection with welding metal plates together positioned in an upright or vertical position comprising a main frame portion having extended side rails or stanchions which are rigidly affixed to each other by connecting rungs at each respective end of the side rails as in the manner of a conventional ladder. The side rails are further joined to each other by interconnecting rungs which in turn are provided with a removable portion at approximately the center thereof which portion can be swung or relocated out of position to provide access to an area immediately behind the particular rung, e.g., to gain access to a seam to be welded. One end of the present ladder is provided with an attachment for securing the ladder against a structure upon which the present ladder is to be employed.
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CROSS-REFERENCES TO RELATED APPLICATION
The application claims priority to U.S. Provisional Patent Application No. 61/809,799 filed Apr. 8, 2013, entitled “Hip Apparatus”, the entire contents of which is incorporated herein by this reference.
FIELD OF INVENTION
The present invention relates to an apparatus for supporting a woman's hip and, more particularly, an apparatus designed to support the hip of a pregnant woman who often experiences hip pain associated with her pregnancy to help relieve this pain.
BACKGROUND OF THE INVENTION
It is well known that abdominal distention due to excess weight causes pain. Though not limited to pregnancy, abdominal distention is especially encountered during pregnancy. In this respect, it is known that there is substantial weight gain during pregnancy, especially during the latter 20 gestational weeks. Weight increase during pregnancy may often reach 40 pounds or more with the largest amount of the increase occurring during the last 20 gestational weeks.
It is also well known that during pregnancy, the joints, ligaments and muscle structure of the pelvis and spine are particularly lax to increase the joint laxity and elasticity to accommodate the shape of the fetus.
Hip and pelvic pain is a very common aliment for both men and women. However, these symptoms are usually worse during a pregnancy. There are several reasons for the hip pain symptoms to be worse during a pregnancy. One reason is that during pregnancy the body of a woman releases a hormone called Relaxin. This hormone relaxes and softens joints and muscle tissue to accommodate the baby moving through the birth canal during delivery.
Unfortunately, this hormone can also increase the risk for joint injury and can cause hip pain during pregnancy. Second, as the pregnancy progresses, the uterus becomes larger. As previously stated above, pregnant women also gain weight. The added pressure on the pelvis from the gravid uterus with an unborn fetus developing inside of it and weight gain can aggravate hip and pelvic pain. Lastly, a pregnant woman is instructed to sleep on her side with the left side being more optimal than the right side. This recommendation is usually given after 20 weeks gestation. This positioning helps to optimize placental perfusion with the least amount of stress on the mother's cardiovascular system. However, sleeping in this position causes added strain on the hips and thus leading to more hip pain.
Unfortunately, treatment options for the hip pain are limited due to safety restrictions in pregnancy. There are some treatment recommendations to counter this hip and pelvic pain as listed below but usually these steps supply minimal to moderate relief:
1) Bending legs, not crossing the legs while sleeping 2) Body pillows 3) Heating pads 4) Proper mattresses 5) Hip exercises and stretches 6) Swimming/water aerobics 7) Yoga/Pilates 8) Perinatal massages 9) Maternity belt iliac brace used when woken up & about—not for sleeping 10) BELLA BANDS® 11) Analgesics such as TYLENOL® 12) Sitz baths
Therefore, what is really needed to help alleviate the hip pain is added support across the joint to counter the reasons listed above. This is exactly what the apparatus of the present invention accomplishes. The apparatus of the present invention securely holds the ball in the socket of the hip joint while sleeping and therefore lessens the strain across the joint and thus lessens the possible hip pain during a woman's pregnancy.
SUMMARY OF THE INVENTION
The apparatus of the present invention incorporates a unique design to women leggings. The leggings may be made from stretch cotton, a modal fabric that resists pilling and still holds its shape for extended wear during pregnancy. The leggings may have a comfortable midrise to go with a slim elastic waistband that offers an easy fit for pregnant women that generally is ankle-length but the leggings may be shorter or longer in length depending upon the circumstances. So the leggings may be made from a mix of cotton, modal, and small percentage of SPANDEX®. Of course other materials like polyester, rayon and nylon or any combination thereof that is normally used for clothing leggings is a fine material too. Also, leather or rubberized leggings might also be material suitable for the hip support hip apparatus.
So the general stretch cotton leggings of various sizes and colors include fabric hook-and-loop fastener sewn along the inner and outer leg of the leggings or approximately in opposing position with respect to one another.
A belt with fabric hook-and-loop fastener sewn along the inside and outside is also a component part of the apparatus used in combination with the leggings to provide the structure that helps to alleviate hip pain when attached in a number of different ways. A back pillow comprised of a generally foam material inside with a cloth material on the outside includes openings generally at either end of the pillow cloth enclosure thereof to allow the VELCRO® belt to slip through the openings to use the pillow as a cushioned support when engaging the back of a pregnant lady using the support apparatus.
An alternate structure is where 1) the padding is now sewn into the pants; 2) the leg straps of fabric hook-and-loop fastener are sewn into the padding and exit from a slit on the outside of the legs; and 3) the strap is 2 inches thick with a fabric hook-and-loop fastener along the length.
Therefore, the present invention comprises generally cotton leggings of various sizes and colors with Velcro straps sewn along the inner and outer leg of the leggings, a belt with a fabric hook-and-loop fastener sewn along the inside and outside surfaces of the belt, a back support pillow including a foam core and cloth exterior pillow ease includes openings at opposite ends of the pillow case enclosing the foam core wherein the openings in the pillow case receive the belt there through to have the pillow slide onto the belt with opposing ends of a predetermined length of the belt with fabric hook-and-loop fastener hang out of the pillow case to engage the fabric hook-and-loop fastener straps along the inner and/or outer leg of the leggings, a foam thigh support pillow with a fabric hook-and-loop fastener attached thereto for fastening to the belt or to the inner fabric hook-and-loop fastener strap sewn on the inner leg of the legging, and a foam ankle support pillow with a fabric hook-and-loop fastener strap to keep the pillow in place between the ankles on the pregnant woman.
DRAWINGS
FIG. 1 shows a front view of leggings made in accordance with the present invention;
FIG. 2 shows a side view of the leggings of FIG. 1 ;
FIG. 3 show a frontal view of a foam core pillow enclosed by a cloth pillow case having openings at opposing ends in accordance with the present invention;
FIG. 4 shows a cloth belt having predetermined strips of fabric hook-and-loop fastener along its length.
FIG. 5 shows a front view of the cloth belt having a portion of the belt attached to a foam core back support pillow within a cloth pillow case in accordance with the present invention;
FIG. 6 shows a back view of a cloth belt attached to a foam core back support pillow within a cloth pillow case of FIG. 3 ;
FIG. 7 shows a side view of a foam thigh support pillow in accordance with the present invention having fabric hook-and-loop fastener in the concave portion thereof;
FIG. 8 shows a side view of a foam ankle support pillow with a fastening strap;
FIG. 9 shows a side view of the leggings on a person in accordance with the present invention;
FIG. 10 shows the support pillow around the waist and one end of the belt attached to the outside fabric hook-and-loop fastener on the leg of the legging in accordance with the present invention; and
FIG. 11 shows both the thigh and ankle from pillows of FIGS. 7 and 8 , respectively.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIGS. 1 and 2 , a hip apparatus or system made in accordance with the present invention comprises a leggings 10 having two legs 12 and 14 with a strap 16 having fabric hook-and-loop fastener 18 on at least one side over generally the length of the exposed strap 16 . As shown in FIGS. 1 and 2 , one end of the strap 16 is sewn into the upper portion of the leggings or garment 10 . Also, the leggings or garment includes a hook-and-loop strips 20 or the like running down the inside and outside of each leg 12 and 14 a predetermined distance for attachment to the hook-and-loop fastener 18 on the strap 16 or to a belt 22 hanging down from either end of a back support pillow 24 as shown in FIGS. 3, 5, 6 and 10 with a pair of openings 26 on generally opposing ends of the pillow 24 for receiving the belt 22 with a hook-and-loop fastener 28 running generally the length of the belt 22 for attaching to the hook-and-loop fastener 28 to the hook-and-loop fasteners 20 on the outside of the legs 12 and 14 , respectively. The pillow 24 is made of a foam block or any other suitable material that is generally solid or slightly flexible but generally holds it shape.
As shown in FIGS. 7 and 11 , a thigh support pillow 30 of similar material to pillow 24 includes opposing concave portions 32 and 34 , respectively, with opposing hook-and-loop fasteners 36 and 38 therein that is placed between the thighs of a pregnant woman 40 sleeping on her left side is further attached to either the belt 22 or to the fasteners 20 on inside of the each leg 12 and 14 of the leggings 10 .
As shown in FIGS. 8 and 11 , an ankle support pillow 42 having an opening 44 therethrough for receiving a belt 46 through the opening 44 and having a hook-and-loop fastener 48 generally running the length of the belt 46 is placed between the ankles of a pregnant woman 40 and the fabric hook- and loop fastener 48 or the like to hold the pillow 42 in place between the ankles.
The combination of the leggings 10 of various sizes and colors, hook-and-loop fabric straps or belts 16 sewn into leggings and extending through the pillow 24 within the leggings 10 and having the inner and outer length of each leg 12 and 14 over a predetermined distance with hook-and-loop strips 20 to engage the hook-and-loop fasteners 18 of the belts 16 provide a back support for the pregnant woman 40 .
The back support pillow 24 with the opposing openings 26 at either longitudinal end thereof allowing the belt 22 to slide through the openings 26 and then hang down a predetermined distance from either side of the pillow 24 to engage the hook-and-loops strips 20 on the outside of each leg 12 and 14 , the thigh support pillow 30 attaching to the inner side of each leg on the leggings 10 and the ankle support pillow 42 attached via hook- and loop strap 46 attached thereto or other fastener are all elements comprising the overall apparatus and system for relieving hip pain in the pregnant women 40 while trying to sleep.
Although the invention has been shown and described with reference to a specific structural embodiment, it is understood certain elements are widely variable in composition of materials and design and that the materials shown do not limit the field of practical application or the substitution of similar materials to achieve the same result. Therefore many modifications and changes are possible without deviation from the scope of the attached patent claims.
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An apparatus and system for designed for supporting a hip of a pregnant woman who often experiences hip pain associated with her pregnancy to help relieve this pain including a leggings with hook-and-loop belts, straps and strips associated with pillows for the thigh and ankles.
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FIELD OF THE INVENTION
This invention relates to a powdery hydrophobic filler, based on at least one substance which lowers the freezing point of water, for bitumen-bonded traffic surfaces.
STATEMENT OF RELATED ART
It is known that road surfaces containing substances which reduce the freezing point of water can be prepared in order to prevent ice from forming, particularly at ambient temperatures varying around 0° C., and to facilitate snow clearing operations. For example, DE-OS 24 26 200 describes a bituminous or asphalt-containing preparation for the production of a road surface that inhibits ice formation and melts snow, containing alkaline earth metal halide and alkali metal hydroxide particles incorporated in the structure of the mineral and protected by a water-tight coating of a drying oil or a plastic from the group consisting of polyvinyl acetate, polyvinyl alcohol, epoxy resin or acrylic resin. The thawing effect of these particles, which have a particle size of up to 7 mm, is brought into action after destruction of the oil or plastic coating by the usual abrasion of the road surface by traffic. However, this known preparation has the major disadvantage that the relatively large particles are difficult to disperse uniformly in the other constituents of the road surface, so that the thawing effect obtained is not uniform over the entire area of the road surface. In addition holes in the road surface can be formed by the dissolving out of these large particles and have to be subsequently repaired.
EP 153 269 describes the use, for road surfaces, of a fine particle mixture, with a particle size below 0.2 mm, which, in addition to sodium chloride, contains polyurethane, perlite and optionally carbon black as a hydrophobicizing component. In the fine particle mixture, the percentage content of the hydrophobicizing component is between 5 and 75% by weight of the percentage content of the hydrophilic components.
It is desirable to keep the percentage filler content based on a substance which reduces the freezing point of water in an asphalt mixture relatively low because, on the one hand, minimum quantities of other fillers which do not reduce the freezing point of water, for example mineral powder, are often required although, on the other hand, the permitted total quantity of filler is limited by the particular technical specification. Accordingly, there is an interest in highly effective fillers based on a substance which reduces the freezing point of water. This means that the percentage content of substances reducing the freezing point of water in fillers such as these should be as high as possible. The higher the percentage content of substances which reduce the freezing point of water (hydrophilic substances), the lower the percentage availability of substances which hydrophobicize the hydrophilic substances. However, for the absolutely essential long-term effect of a filler incorporated in a traffic surface, premature leaching of the substances which reduce the freezing point of water must be avoided, i.e. a low extraction rate has to be guaranteed by particularly good hydrophobicization. In addition, such fillers should be stable even at temperatures above 250° C. so that they may readily be incorporated, for example, in bituminous mastic concrete.
DESCRIPTION OF THE INVENTION
Object of the Invention
Accordingly, the problem addressed by the present invention was to provide a filler for bitumen-bonded traffic surfaces which, even in small quantities, would enable such traffic surfaces to be protected much more effectively against freezing over, even in the long term, by comparison with known fillers.
SUMMARY OF THE INVENTION
It has been found that the stringent requirements which a filler of the type in question is expected to meet are satisfied by a powder-form filler based on at least one substance which reduces the freezing point of water and which contains hydrophobicized amorphous silicon dioxide in quantities of 0.1 to 10% by weight.
Accordingly, the present invention relates to a powder-form hydrophobic filler for bitumen-bonded traffic surfaces based on one or more substances which reduce the freezing point of water, the diameter of the filler particles being between >0 and 200 μm, characterized in that the filler contains:
______________________________________60 to 95% by weight of one or more substances which reduce the freezing point of water,0 to 39.9% by weight of mineral powder and0.1 to 10% by weight of one or more hydrophobicized amorphous silicon dioxide.______________________________________
DESCRIPTION OF PREFERRED EMBODIMENT
A preferred filler contains:
______________________________________60 to 95% by weight of one or more substances which reduce the freezing point of water,0 to 39.5% by weight of mineral powder and0.5 to 5% by weight of one or more hydrophobicized amorphous silicon oxide.______________________________________
A particular preferred filler contains:
______________________________________80 to 95% by weight of one or more substances which reduce the freezing point of water,0 to 19.5% by weight of mineral powder and0.5 to 5% by weight of one or more hydrophobicized amorphous silicon dioxide.______________________________________
With a filler according to the invention which may contain up to 95% by weight of one or more substances which reduce the freezing point of water, bitumen-bonded traffic surfaces, more particularly road pavements and airport runways, can be far more effectively protected against icing and hoarfrost. In addition, the extraction rate of the substances reducing the freezing point of water is distinctly reduced by a filler according to the invention, in comparison with a known filler having the same content of substances reducing the freezing point of water, thus lengthening the protection of traffic surfaces against freezing over.
Chlorides and/or sulfates of alkali metals and/or alkaline earth metals and/or urea are particularly suitable for use as the substances which reduce the freezing point of water. Chlorides of alkali metals are particularly preferred. Examples of suitable chlorides and/or sulfates are sodium, potassium, magnesium and/or calcium chloride and/or sodium, potassium and/or magnesium sulfate.
Suitable hydrophobicized amorphous silicon dioxide are hydrophobicized amorphous silicon dioxide precipitated from aqueous solution and hydrophobicized, amorphous fumed silicon dioxide. Hydrophobicized, amorphous silicon dioxide precipitated from aqueous solution are preferred. The hydrophobicized silicon dioxide have a primary particle size of 5 to 100 μm and preferably 8 to 30 μm and a specific BET surface of preferably 50 to 300 m 2 /g and more preferably 50 to 200 m 2 /g.
To produce a filler according to the invention, the substances reducing the freezing point of water are first ground in such a way that up to 15% by weight of the particles have a diameter of >90 μm. The ground substances reducing the freezing point of water are then homogeneously mixed with one or more hydrophobicized amorphous silicon dioxide and optionally mineral powder. The mineral powder used may be for example, limestone flour, marble flour, lava flour, basalt flour, silica flour and/or slate flour. Limestone flour is preferably used as the mineral powder. In a filler according to the invention, the percentage of particles larger than 90 μm in diameter, as determined by sieving in an air jet sieve, is preferably between 5 and 20% by weight and more preferably between 10 and 15% by weight.
A filler according to the invention is processed in known manner with sand, chips, mineral powder and bitumen to form rolled asphalt or other bitumen-containing mixtures, such as bituminous mastic concrete or mixtures for the treatment and particularly for the repair of road surfaces. The filler content in rolled asphalt is at most 14% by weight and, in other bitumen-containing mixtures, at most 30% by weight.
By virtue of its particle size and its heat resistance up to 280° C., a filler according to the invention can be homogeneously distributed in bitumen-containing mixtures, for example bituminous mastic concrete, in exactly the same way as a mineral powder filler. In addition, a filler according to the invention is stable in storage at temperatures of -20° C. to +60° C. and under high contact pressures, shows high fluidity, is vibration-resistant and does not separate, for example, in pneumatic conveyors.
EXAMPLES
Production of powdery fillers for bitumen-bonded traffic surfaces
The particle sizes of the fillers, the sodium chloride, the lava powder and the limestone stone powder were determined by sieving in an air jet sieve.
Production Example 1
900 g of sodium chloride were ground in a laboratory mill until only 13% by weight of the particles were larger than 90 μm in diameter. The sodium chloride was then homogeneously mixed with 80 g of lava powder (82% by weight of the particles were smaller than 90 μm in diameter) and 20 g of Aerosil®972 (a product of Degussa AG; fumed hydrophobicized silica, primary particle size 16 nm, specific BET surface 110 m 2 /g). 13% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Production Example 2
A filler containing 20 g of Sipernat®D 17 (a product of Degussa AG; hydrophobicized amorphous precipitated silica, primary particle size 28 nm, specific BET surface 110 m 2 /g) instead of 20 g of Aerosil®972 was produced under the conditions described in Production Example 1. 13.4% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Production Example 3
A filler containing 20 g of an amorphous fumed silicon dioxide (specific BET surface 105 m 2 /g) hydrophobicized with methyl hydrogen polysiloxane and dioctyl tin dilaurate in a ratio by weight of 10:1 instead of 20 g of Aerosil®972 was produced under the conditions described in Production Example 1. 13% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Production Example 4
A filler containing 20 g of an amorphous precipitated silicon dioxide (specific BET surface 77 m 2 /g) hydrophobicized with methyl hydrogen polysiloxane and dioctyl tin dilaurate in a ratio by weight of 10:1 instead of 20 g of Aerosil®972 was produced under the conditions described in Production Example 1. 11.7% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Production Example 5
A filler was produced from 600 g of sodium chloride, 380 g of lava powder and 20 g of an amorphous precipitated silicon dioxide (specific BET surface 77 m 2 /g) hydrophobicized with methyl hydrogen polysiloxane and dioctyl tin dilaurate in a ratio by weight of 10:1 under the conditions described in Production Example 1. 14.7% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Production Example 6
A filler containing 380 g of limestone flour (82% of the particles were smaller than 90 μm in diameter) instead of 380 g of lava flour was produced under the conditions described in Production Example 5. 14.7% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Production Example 7 (Prior Art)
600 g of sodium chloride were ground in a laboratory mill until only 15% by weight of the particles were larger than 90 μm in diameter. The ground sodium chloride was then homogeneously mixed with 280 g of lava flour (82.8% by weight of the particles were smaller than 90 μm in diameter), 100 g of rigid polyurethane foam (25% by weight of the particles were smaller than 90 μm in diameter) and 20 g of carbon black (92.8% by weight of the particles were smaller than 90 μm in diameter). 20.6% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Production Example 8 (Control)
600 g of sodium chloride were ground in a laboratory mill until only 13% by weight of the particles were larger than 90 μm in diameter. The sodium chloride was then homogeneously mixed with 400 g of lava flour (82% by weight of the particles were smaller than 90 μm in diameter). 14.1% by weight of the particles in the filler obtained were larger than 90 μm in diameter.
Determination of the hydrophobic properties of the filler
The hydrophobic properties were determined in accordance with ISO 7202, 01.06.1987 Edition (Fire Protection--Fire Extinguishing Media Powder § 12.6) after 45 minutes. A "positive" evaluation means that the requirements of ISO 7202 were satisfied after 45 minutes; a "negative" evaluation means that the requirements of ISO 7202 were not satisfied after 45 minutes. In addition, the time taken by water droplets to disappear completely was determined. The results are set out in Table 1.
Determination of the quantity of chloride extracted by water from asphalt test specimens (Marschall specimens)
A Marschall test specimen was made from
360 g of basalt chips (particle size 8 to 11 mm)
120 g of basalt chips (particle size 8 to 5 mm)
180 g of basalt chips (particle size 2 to 5 mm)
444 g of basalt screenings (particle size 0.09 to 2 mm)
TABLE I__________________________________________________________________________ Determination of Quantity of Chloride Extracted Hydrophobic Properties After 48 Hr. After 192 Hr.Filler According Droplet Min. for Complete As % by As % byto Production Drainage Disappearance of Weight of Weight ofExample after 45 Water Total TotalNo.: min. Droplet In mg. Chloride In mg. Chloride__________________________________________________________________________1 Positive 270 1210 2.2 2660 4.92 Positive 240 1150 2.1 2050 3.73 Positive 270 1350 2.5 2880 5.34 Posifive 300 1220 2.2 2270 4.25 Positive 270 700 1.9 1590 4.46 Positive 270 720 2.0 1300 3.67(Prior Negative 105 1150 3.1 2200 6.1art)8(Control) Negative 1 1310 3.6 2560 7.1__________________________________________________________________________
36 g of limestone flour (particle size 0 to 0.09 mm)
60 g of a filler according to the invention and
72 g of bitumen B 80
in accordance with DIN 1996. The Marschall test specimen was placed in 2 liters of distilled water and the water containing chloride ions was replaced at regular intervals by distilled water. After 48 and 192 hours, the chloride content of the waters containing chloride ions was determined by precipitation of silver chloride. The smaller the amount of chloride extracted, the longer the expected duration of the freezing-over protection of the Marschall test specimens. The results are set out in Table 1.
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The invention concerns a powdery, hydrophobic filler for bituminized traffic surfaces, including at least one substance that lowers the freezing point of water.
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FIELD OF THE INVENTION
The disclosure relates to the transdermal sampling of extracellular fluid. The present disclosure provides an apparatus and process for the enhanced transdermal transport of drugs or other substances using ultrasound standing waves.
BACKGROUND OF THE INVENTION
Conventional sampling methods for collecting body fluids typically involve invasion of the organism (e.g., physical disruption of the skin). Such invasive processes are both painful and messy. The difficulty and pain involved with the process provides a disincentive to the patient to perform the procedure.
Several techniques have been reported that involve little or minimal invasion of the skin. Exemplary such techniques are sonophoresis, iontophoresis and vacuum.
The use of iontophoresis requires using electrodes containing oxidation-reduction species as well as passing electric current through the skin. Iontophoresis has also been used to increase skin permeability. Despite the effective use of iontophoresis for skin permeation enhancement, there are problems with irreversible skin damage induced by the transmembrane passage of current.
Vacuum has been reported to draw fluid transcutaneously while avoiding the complications of invasive procedures. The use of vacuum to extract fluid across the skin is limited because of the relative impermeability of the stratum corneum.
The art discloses methods of using ultrasound traveling waves to enhance the rate of permeation of a drug medium into a selected area of contact of an individual or to enhance the rate of diffusion of a substance through the area of contact of an individual. The use of ultrasound traveling waves may induce localized skin heating.
Thus, there continues to be a need to provide a process and apparatus for sampling extracellular fluid across the skin of an animal.
The present disclosure provides ultrasonic standing waves to enhance permeation and mass transport through skin. While prior art techniques use ultrasonic traveling waves to enhance permeation of the skin, traveling waves do not enhance mass transport of the interstitial fluids. Standing waves on the other hand may promote permeation as well as mass transport. High velocity gradients exhibited by a standing wave sound field can provide enhanced mass transport specifically at boundary layer and at air-fluid interfaces within the structures of skin.
Furthermore, standing waves differ from traveling waves in radiation force. As understood in the art, radiation force is the time-average force exerted on a rigid spherical object immersed in a sound field over a number of cycles. In other words, the radiation force of a traveling wave is the gradient of the kinetic energy density minus the gradient of the potential density plus a phase factor. In contrast, the sum of the kinetic and potential energy density of a standing wave is independent of distance, and so their gradients are equal in magnitude but opposite in sign. The phase factor equals zero since it is constant with distance. Thus, the force for the standing wave is a constant times the gradient of the potential energy density whose maximum is equal to twice the potential energy density.
For example, in a traveling wave of pressure amplitude A, a particle is acted on by a small steady state force in the direction of the wave. If the wave is uniform, then the force is the same independent of the particle's position. However, in a standing wave the total pressure amplitude varies in space or position. The maximum amplitude is 2A and occurs in planes spaced at a half-wavelengths apart. The radiation force on the particle varies in both magnitude and direction. The force reverses direction every quarter wavelength.
The ratio of the maximum standing wave radiation force to the traveling wave value is approximately (1/kR) 3 , where R is the particle radius and k is 6.28 divided by the wavelength. The wavelength in soft tissue is about 1.5/f millimeters, where f is the frequency in MHz (e.g. at 1 MHz the wavelength is 1.5 millimeters). If the radius of a particle is 0.01 mm and the wavelength is 1.5 mm, one obtains 0.042 for kR, 0.000073 for (kR) 3 , and 13,600 for (1/kR) 3 . As is apparent, the radiation force produced by a standing wave relative to a traveling wave is significant. While the radiation force is calculated for rigid spherical particles, the relationship is applicable to small biological particles such as blood cells, intracellular bodies such as chloroplasts, and mitochondria, as these cells and organelles exist in vivo, since these structures in which they are located are comparable to a suspending medium. Thus, the radiation force is applicable to biological structures existing within animal skin.
There are several advantages to the use of standing waves in enhancing skin permeability and mass transport for diagnostic sampling. First, the energy required for diagnostic sampling is less than that required for traveling wave techniques. This is evident with the fact that the radiation force generated by a standing wave is larger in comparison to a traveling wave of the same energy. Second, a standing wave using significantly less intensity but effectively producing the necessary permeability and, in addition mass transport effects, would alleviate the danger of bioacoustic effects. In addition, acoustic sources of low energy typically require less electrical power and are more amenable to miniaturization. Finally, the acoustic effect of standing waves can be localized within the stratum corneum, which is the rate-limiting barrier to transport in skin, while low frequency traveling waves tend to penetrate deeply into skin significantly beyond the stratum corneum. This can potentially cause undesirable bioeffects at bone-tissue interfaces that produce discomfort to a subject undergoing treatment, e.g., drug delivery or extracellular-fluid-extraction for diagnostic purposes.
The present disclosure provides, in part, a surface-acoustic-wave (SAW) device to generate standing waves within the stratum corneum region as a means for enhancing permeability and mass transport of analytes across the skin. A SAW device provides safe-coupling of sound field adjacent to skin since the electrodes needed to excite the waves are mounted on the opposite side of the acoustic device away from skin.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which form a portion of the specification:
FIG. 1 illustrates one embodiment of an apparatus of the invention for the transdermal transport of extracellular fluid.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a process of sampling extracellular fluid across the skin of an animal comprising establishing an ultrasonic standing wave across the skin and collecting fluid transudate.
In a preferred process of the invention, the standing wave is generated by a surface acoustic wave device.
In alternate processes of the invention, the standing wave is established by generating an ultrasonic wave of a given wavelength from an ultrasound transducer located at a first position on the external surface of the skin and reflecting that wave from an ultrasound reflector located at a second position on the surface of the skin, wherein the half-trip distance of ultrasonic wave travel between the first and second location is equal to integer multiple number of half-wavelengths. Optionally, the pressure on the surface of the skin in the vicinity of the ultrasonic standing wave may be reduced, preferably by applying a partial vacuum to the surface of the skin.
The invention further provides an apparatus for the transdermal sampling of extracellular fluid. In a preferred apparatus of the invention, the standing wave is generated by a surface acoustic device and includes means for collecting transudate.
In alternate embodiments, the apparatus includes means for generating an ultrasonic wave through the skin of an animal, means for reflecting the ultrasonic wave sonically aligned with the means for generating the wave such that when the apparatus is positioned on the skin the half-trip distance of ultrasonic wave travel between the means for generating and the passive reflector is equal to integer multiple number of half-wavelengths, and means for collecting transudate. Optionally, the pressure on the surface of the skin in the vicinity of the ultrasonic standing wave may be reduced, preferably by applying a partial vacuum to the surface of the skin.
In preferred embodiments of this aspect of the invention, the reflector may be a passive reflector sonically aligned with the transducer such that, when the apparatus is positioned on the skin, the half-trip distance of wave travel between the transducer and the passive reflector is equal to integer multiple number of half-wavelengths. In other preferred embodiments, the reflector is a second transducer, sonically aligned with the first transducer such that, when the apparatus is positioned on the skin, the half-trip distance of ultrasonic wave travel between the two transducers satisfies the multiple number of half-wavelength resonant condition.
DETAILED DESCRIPTION
The present disclosure provides an apparatus and process for enhancing permeability and mass transport through skin, preferably the skin of a human. The apparatus comprises a device suitable to produce standing waves within the region of the stratum corneum. The process includes steps of establishing standing waves within skin and transport of compounds contained in fluid transudate to appropriately positioned sensors for detection and/or analysis of the compounds.
Any compound which can be delivered to the body through the skin or can be sampled from the body via the skin is suitable for use or detection by the processes and devices disclosed herein. Among such compounds well known in the art are compounds of clinical and/or therapeutic significance, such as glucose, cholesterol, insulin, estradiol, and other hormones or proteins, potassium, sodium, calcium, etc. The preferred compound is glucose.
As used here, the term "ultrasound" means ultrasonic radiation of a frequency above 20 kHz. Ultrasound used for most medical purposes employs frequencies ranging 50 kHz to 100 MHz.
The term "standing wave" means that acoustic wave forms exhibited within a medium remain fixed in position while the amplitude of the waves fluctuate repetituously from maximum to minimum over the total operating distance of the wave. The distance between adjacent nodes or antinodes is equal to integer multiples of half-wavelength. The phases of wave forms between two nodes or antinodes are constant.
In contrast, traveling waves have amplitudes that remain constant. A traveling acoustic wave can be characterized by a parameter of intensity. Intensity is the average power transported per unit area and is defined in a traveling acoustic wave. The intensity in a standing wave is zero.
In accordance with the present invention, ultrasound frequencies greater than 20 kHz and less than 300 MHz are preferable. The most preferable frequencies are those which, when converted to wavelengths, are comparable to single or multiples of cellular dimensions. Such frequencies will provide oscillation and mechanical motions within the fine-structure of cells and lipid-bilayers that influence movements or fluid motions within the stratum corneum.
The time period during which the standing wave is generated is typically from about 30 milliseconds to 60 minutes, more preferably from about 10 seconds to 20 minutes. The most preferred time is 30 seconds to 3 minutes.
Any type of device can be used to administer the ultrasound, which can be pulsed or continuous. The ultrasound is preferably continuous at lower frequencies and pulsed at very high frequencies to dissipate generated heat.
The preferred intensity of the applied ultrasound is less than about 5.0 W/cm 2 , more preferably from about 0.2 to about 5.0 W/cm 2 , and most preferably from about 0.1 to about 0.03 W/cm 2 .
In the process of the invention, the standing wave is established by generating an ultrasonic standing wave of a given frequency and distributing the wave over the surface of the skin. The "foot print" of the ultrasonic standing wave is not critical to the invention and is typically in the form of a circular or rectangular surface area.
An ultrasonic standing wave can be established in a number of ways. One preferred apparatus capable of establishing a standing wave is a surface-acoustic-wave (SAW) device. SAWs are commercially available and are well suited for enhancing the permeation of the stratum corneum since the surface waves travel parallel to the surface and do not penetrate the skin to any significant degree, e.g., at most to about 100 micrometers. A SAW device is compact and can constructed so as to eliminate direct electrical contact with the skin by placing the electrical contacts on a side of the device away from the skin. A SAW device is typically characterized by an electrically excited surface acoustic wave in a piezoelectric single-crystal plate substrate by use of a metallic (e.g. aluminum) interdigital transducer (IDT) structure. As is understood in the art, an IDT structure comprises a row of metallic electrodes laying parallel and adjacent, but not touching each other. Each electrode has an alternating applied voltage potential. Typical substrates are quartz, lithium niobate, and lithium tantalate, but other substrate materials are known and are suitable for use in the invention, e.g., piezoceramics such as lead-zirconate-titanate (PZT), zinc oxide (ZnO), and polyvinylidene-fluoride (PVDF). The specific operating characteristics of these materials, such as direction of particle displacement of the wave, is defined by the cut of the substrate. The anisotropy of the piezoelectric crystals allows different angles of cut with very different properties.
An alternate method of providing a standing wave is a transverse vibrating wire. The wire is secured at each end as to satisfy the standing wave resonant condition and is caused to vibrate at a desired frequency. The device is applied parallel to the skin and the field emanating from the side of the wire is used as previously described, e.g., to enhance permeation and mass transport. Structures resembling wires can also be fabricated from silicon or other suitable materials using microfabrication techniques well known in the electronic industry. Such structures can be made to operate analogous to metallic wires and can be incorporated and operated in a similar manner previously described for mating and extraction with skin.
In further embodiments, a combination of ultrasonic transducers and reflectors is arranged on the surface of a patient extremity such that the necessary spacing of multiple number of half-wavelength of ultrasonic wave to establish a standing wave is satisfied.
Single transducers can be positioned perpendicularly to the interface of different layers of skin or at the tissue-bone plane. Multiple transducers and reflectors can be positioned on the same plane. In one embodiment of a process of the invention, a transducer and a passive reflector are utilized to establish the standing wave.
In yet another embodiment of the invention, a second transducer can be used as a reflector. The two emitting transducers establish the standing wave when they are operated at the same frequency and are positioned, as is well known in the art, to satisfy the multiple number of half-wavelength resonant conditions.
As is well known in the art, the location of the transducer with respect to the reflector depends on the frequency of excitation needed to establish a standing wave via the interior of the skin. The half-trip distance of ultrasonic wave travel between the transducer and reflector should be equal to integer multiple number of half-wavelengths.
A sinusoidal voltage at a given frequency is applied to the transducer to produce an ultrasonic wave that propagates from the face of the transducer. The wave travels through the interior of the skin and exits at the reflector of the same diameter but is reflected back to the source transducer.
The half-trip distance between the transducer and reflector causes the wave to resonate and be confined between the transducer and reflector. The amplitude of the wave is controlled by the amplitude of the sinusoidal voltage signal.
As is well known, the oscillation of the transducer can be stabilized to compensate for drift using the current-voltage phase relation occurring at the resonant response of the transducer.
By changing the phases of the signals applied to each transducer, complex movement of tissues and microcirculation between tissues can occur creating more fluid flux through the skin (transudation). The transudate can then be analyzed using appropriate sensors and/or detectors. In preferred embodiments., an absorbent pad or material receives the fluid from which the content of fluid can be analyzed using appropriate sensors.
In the processes and apparatus of the invention, impedance mismatches can be reduced by applying a coupling agent to the surface of the transducer and reflector.
The coupling agent should have an absorption coefficient similar to that of water, be non-staining, non-irritating to the skin, and slow drying. It is clearly preferred that the coupling agent retain a paste or gel consistency during the time period of ultrasound administration so that contact is maintained between the ultrasound source and the skin.
Exemplary and preferred coupling agents are mixtures of mineral oil, glycerin, and propylene glycol, oil/water emulsions, and a water-based gel. A solid-state, non-crystalline polymeric film having the above-mentioned characteristics can also be used.
The description and operation of a particular embodiment of the invention maybe understood with reference to FIG. 1. As shown in FIG. 1, the device 10 includes a housing 20 which surrounds the internal mechanism and provides one or more attachment sites 180 (two shown) for fixing the device 10 to the patient's skin 200. The device 10 is configured to fit snugly on the surface of the skin. Within the device 10 is located the ultrasound source, e.g., fabricated from a thin PZT-5A piezoelectric crystal substrate 110. Typically, it is anticipated that the ultrasonic source 110 will be operating in the region of 1 to 3 MHz. Thus the thickness of a device operating at 1 MHz is approximately 0.4 mm thick. A representative area of a substrate 100 is 1 cm by 1 cm. Pairs of opposing metal electrodes 120 are deposited on the top surface of the PZT substrate. The distance between the electrodes 120 is determined by the operating frequency, in this example multiples of 2.26 mm. The metal electrodes 120 can be approximately 1 micron wide and approximately 1 mm long. Alternatively, multiple finger-interdigital electrodes (not shown) can also be utilized. In such, embodiments, the electrode fingers are typically spaced at fractions of the operating wavelength from each other and two opposing IDTs are excited by sinusoidal inputs from a function generator and power amplifier. A battery 170 powers an electronic chip 140 capable of providing memory and control functions. In addition, the electronic chip 140 can provide sinusoidal outputs amplified in an appropriate manner as an alternative to the individual generator and amplifier. A display 160 provides means by which the operation of the device, its functioning and results are provided to the user. Optionally, the device can include a port (not shown) allowing connection to an external computer and thus allowing the health care provider the ability to more closely monitor the patient's condition.
The excitation frequency of the SAW device might drift due to external conditions and operating environments. Therefore the electronic chip should contain a close-loop portion such a Phase-Lock-Loop (PLL). Since the SAW has two opposing IDTs, one of them can provide the feedback sensing input to the PLL. The chip 140 is also capable of providing a variety of other excitation functions such as square pulses. The chip 140 can also provide different modulation and phase shift functions to the SAW device. These modulation and phase shifts can provide additional bioeffects to the stratum corneum regions of the skin 200. By providing excitation to the IDTs 120, an acoustic beam is caused to propagate between the IDTs and a resulting wave is established within the region. The opposite side of PZT substrate is coated with a thin layer typically equivalent to about a one-quarter wavelength of material, typically glass 100, to maximize coupling to a coupling agent 150 between the substrate 110 and skin 200.
The coupling agent also functions as a means for transporting extracted fluids containing the compound of interest (metabolites, diffusing species, etc.) to a sensor for detection. Permeation through the coupling membrane can take place by two mechanisms; viscous flow and diffusive flow. The viscous flow mechanism can facilitate the movement of extracted transudate and the diffusive flow can facilitate the diffusion of metabolites. A hydrated polymeric membrane or hydrogel can be formulated as to have the capacity to absorb more fluid in proportion to the solid proportion of the hydrogel. A specific volume of extracted transudate can then be transported to the hydrogel for subsequent analysis by appropriate detection means. As stated above, the coupling agent medium should have a similar impedance with skin when placed between the sound source and skin in order to provide efficient transfer of acoustic energy into skin. Since the acoustic impedance of skin is similar to the impedance of water, it is assumed that the acoustic wave is propagating in water and therefore the optimal configurations and characteristics of the extraction apparatus is designed to operate with a water interface.
Optimally, the components of the device are housed in a thin molded plastic device 20, e.g., a patch. As shown in FIG. 1, the excitation or control electronic chip 140 and the batteries 170 are preferably stored within a separate compartment or layer 190 of the patch. In this way the functional elements and the control electronics can be physically separated such that the sound source is attached to the skin and the electronics are contained in small package, similar to a electronic paging devices, that can be located elsewhere near or on the body, e.g., attached to a belt. Optionally, the excitation of a SAW device 110 can be performed in a wireless fashion since the SAW is capable of receiving an excitation wave from a wave propagating through free space at specific wavelengths. In this embodiment, a separate sending unit containing electronic controls and transmitter provides the excitation wave. Preferably, the sending unit is located near the vicinity of the SAW-containing patch so as to minimize transmission requirements. The patch is attached to the surface of the skin via one or more attachment sites 180 using bioadhesives. In addition or alternatively, the patch can be further secured to the skin in the form of a bracelet or watch.
When a standing wave from the sound source is applied to the surface of skin it is physically transferred into the skin through the glass 100 and coupling agent 150 layers. While not wishing to be bound by any one theory, the penetration of the wave into the skin is limited to within a few wavelengths beyond the thickness of the stratum corneum, which is approximately 15 micrometers. It is believed that the deepest penetration is approximately 100 micrometers. As exhibited in any standing waves, cells and their constituents such as lipid-bilayers will migrate toward pressure nodes. The amplitude of displacement is determined by the elastic nature of the fine-structure of the stratum corneum. The stratum corneum will exhibit dense regions as well as regions sparse in materials. The cells in the stratum corneum such as keratenocytes that are asymmetric in shape, being long in one axis and short in another axis, will rotate to align with the preferred axis of the standing wave to minimize energy with the acoustic field. The lipid-bilayer channels between corneocytes provide regions capable of producing acoustic microstreaming near boundary layers. The microstreaming generate high velocity gradients which enhance mass transport of compounds within the extracellular fluid (ECF). The effect of the standing wave is thus to create transient intercellular pores through the stratum corneum. In conjunction with the surface standing wave, secondary standing waves are produced within the corneocytes. These secondary waves arise from flexural coupling modes of the corneocytes. Corneocytes contain approximately half water and half keratin and thus have boundaries defined by differences in densities. As material density is a parameter of the propagation of acoustic waves, velocity gradients are produced within the corneocytes which provide enhanced mass transport of ECF and subsequent intracellular permeation. The combined effect of the surface standing wave and the secondary standing wave is to produce a region of skin which exhibits enhanced permeability and convective transport of molecular species and fluids from one side of the stratum corneum to the other.
The extracellular fluid (ECF) is extracted and diffuses through the transport medium. The transport medium is then analyzed for the presence or amount of the compound of interest. Of course, the particular analytical technique utilized will be selected depending on the compound of interest, ease of use, sensitivity, etc., and other factors well known to the clinician or diagnostician. The detection and analysis can be accomplished in situ or some or all of the transport medium can be removed from the device for analysis. Several different methods are know which are suitable for use in the method and apparatus of the invention, e.g., amperometric and optical detectors.
Alternatively, a SAW device is used in the form of a mass sensor. A layer of the SAW substrate is coated with biologics, such as receptors or antibodies, reactive to ECF compounds or metabolites, and the presence of the compound is detected by changes in the SAW generated, e.g., a shift in the resonance frequency, a phase shift of the acoustic wave, or a shift in the amplitude of an acoustic wave. Since the preferred embodiments utilize a SAW device to extract ECF, it is advantageous to incorporate a portion of the substrate within a region capable of providing detection. In this embodiment, another pair of IDTs can be incorporated onto the SAW substrate in combination with a detection portion of the fluid transport/coupling medium. This portion of the fluid transport medium is coated with biologics providing specificity to the metabolites of interests. A separate set of electronic controls provides excitation of the second set of IDTs as well as detection of the frequency, phase, or amplitude shifts due to the presence of the analytes. The extraction and detection functions can operate at the same frequency or at combinations of frequencies. The spacing arrangements of the detection IDTs with respect to the operating surface provides optimal extraction and detection means. When appropriate electronics are included, the SAW device can detect the presence of increase or decrease in fluid flow by a mass sensing region and then compensate by the excitation region. Thus, such a SAW device can provide a complete system capable of controlling fluid extraction and feedback to as to optimize the ECF extraction.
Further alternate embodiments include a transducer 210, e.g., PZT sandwiched between two thin isolated electrodes, and a Reflector 220. Any passive reflector can be used in conjunction with the transducer to establish an ultrasonic standing wave. The passive reflector is positioned in the apparatus such that, when the apparatus is contacted with skin, the half-trip distance of ultrasonic wave travel between the transducer and reflector is equal to multiple of a half-wavelength.
The size of the reflector contacting the skin is preferably the same as the size of the transducer that contacts the skin.
In another embodiment, the reflector is a second transducer. The second transducer is stimulated at the same frequency as the first transducer to create a standing ultrasonic wave. The position of the second transducer in the apparatus is such that, when the apparatus is contacted with the skin, the distance separating the transducers satisfies the multiple number of half-wavelength resonant condition. Procedures for establishing such a distance are well known in the art. Of course, these embodiments also include coupling agents/fluid transport medium as previously described. Optionally, the pressure on the surface of the skin in the vicinity of the ultrasonic standing wave may be reduced, preferably by applying a partial vacuum 230 to the surface of the skins.
The present invention has been described with reference to preferred embodiments. Those embodiments are not limiting of the claims and specification in any way. One of ordinary skill in the art can readily envision changes, modifications and alterations to those embodiments that do not depart from the scope and spirit of the present invention.
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A process for the sampling of extracellular fluid across the skin of an animal involves establishing an ultrasonic standing wave across the skin and collecting fluid transudate. Sampling can be enhanced by combining the use of ultrasound with the application of a partial vacuum to the surface of the skin. An apparatus includes an ultrasonic transducer, a reflector and an absorbent material for collecting transudate. The apparatus can further include a pressure component for reducing hydrostatic pressure on the skin surface.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to industrial straight lock stitch sewing machines, especially to a thread trimming device for a sewing machine in which an upper thread and a lower thread are subject to being caught by a thread catcher and trimmed by cutter blades after the termination of the sewing operation.
2. Description of the Prior Art
A thread trimming device of this class is disclosed, for example, in U.S. Pat. No. 3,921,554, patented Nov. 25, 1975 in which a first partial gear fixedly secured to a first shaft connected to a hook shaft meshes with a second partial gear disposed on a second shaft which is operably connected to a thread catcher through a clutch against the action of a spring to move the second shaft for thread trimming operation. However, high compressive pressure is applied between a holder of the thread catcher and a metal bearing for the shaft by virtue of trimming pressure applied when trimming the thread, thereby precluding smooth sliding of the second partial gear during the trimming operation and further swivel of the thread catcher and the holder thereof returning to the original position after the termination of the thread trimming operation.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a thread trimming device for a sewing machine in which the swivel of the thread catcher and the holder thereof returning to the original position after the termination of the thread trimming operation is ensured.
According to the present invention, there is provided a thread trimming device which achieves the foregoing objective. This device includes a first shaft rotatably driven by a main shaft of the sewing machine. A first ratchet means having a first partial gear, a first cam surface, a first radial projection, and blank surfaces formed on both sides of the first radial projection on the periphery thereof is disposed on the first shaft and rotatable therewith. A stationary blade means is fixedly secured to the framework of the sewing machine. A second shaft is disposed parallel to the first shaft. Pivotably movable blade means are connected to the second shaft. A second ratchet means having a second partial gear, radial projection, and a second cam surface therebetween on the periphery thereof is disposed on the second shaft and is axially movable relative thereto so as to selectively engage the first ratchet means. Electrically operable means are provided for moving the second ratchet means along the second shaft so as to engage the first ratchet means. Upon actuation of the electrically operable means, the toothed portions of the first and second partial gears are engaged with each other, causing rotation of the second shaft. Rotation of the second shaft causes pivotal movement of the movable blade means to an operable position relative to the stationary blade means. Thereafter, the first cam surface comes into sliding contact with the second partial gear. Interaction of the first cam surface and the second partial gear slowly rotates the second movable blade means to cooperate with the stationary blade means to perform the thread trimming operation. Next, the first radial projection comes into sliding contact with the second radial projection and the second cam surface to rotate the second ratchet means in a direction reverse to the direction of the thread trimming job after the termination of the thread trimming operation.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same become better understood from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts through the several views and wherein:
FIG. 1 is an inverted plan view of essential parts of the thread cutting device according to the present invention from the bottom side of the machine bed.
FIG. 2 is a perspective view of the essential parts of the thread cutting device according to the invention.
FIG. 3 is a front elevation of the thread cutting device when seen from the front side of the machine bed.
FIG. 4 is perspective view of a tension release mechanism cooperating with the thread cutting device.
FIG. 5 is partial sectional elevation of a needle bar together with a part of the machine arm, specifically illustrating a timing mark provided on the needle bar.
FIG. 6 is an enlarged detail side view of a pair of partial gears employed in the thread cutting device shown at a timing in coincidence of that of the needle bar shown in FIG. 5.
FIG. 7 is a partial sectional front view of a thread catcher cooperating with a conventional rotary hook, the timing being such that the thread catcher is beginning to catch the sewing thread.
FIG. 8 is a view similar to FIG. 6 wherein, however, the timing is the same as in FIG. 7.
FIG. 9 is a view similar to FIG. 7, wherein, however, the thread catcher has caught the sewing yarn.
FIG. 10 is a view similar to FIG. 6, wherein, however, the timing corresponds to that in FIG. 9.
FIG. 11 is a view similar to FIG. 7, wherein, however, the timing is such that the thread cutter has just cut the thread.
FIG. 12 is a view similar to FIG. 6, wherein, however, the timing corresponds to that in FIG. 1.
FIG. 13 is a view similar to FIG. 6, wherein, however, the timing is such that the thread catcher has begun to rotate in a direction reverse to the direction in which the catcher catches the sewing yarn.
FIG. 14 is an isometric drawing of the thread catcher.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following, a preferred embodiment of the invention will be described in detail by reference to the accompanying drawings.
In FIGS. 1-3, numeral 1 denotes schematically and partly in phantom manner a machine bed, a mounting frame 2 being fixedly attached on a lower surface of the bed by means of set screws 3 and 4. A shaft 6 having a rigid operating lever portion 5 is mounted rotatably on the frame 2. The shaft 6 is further provided rigidly with an enlarged flange 7 attached thereto by means of a set screw 8. As seen, especially from FIG. 2, the shaft 6 is formed with a shoulder 9 for the prevention of occasional axial shift of the shaft 6 in one direction. The flange 7 serves to prevent axial shift of the shaft 6 in the other direction.
A coil spring 10 is mounted on the shaft 6 between a part of the frame 2 and a radial projection 7a of the flange 7. As will be recalled, the flange 7 is fixed to the shaft 6, and the coil spring 10 accordingly does not have an axial biasing function. Instead, it biases the shaft 6 in the counterclockwise direction in FIG. 2. When the thread trimming device is in its off-service position (shown in FIG. 1), the coil spring 10 keeps the radial projection 7a in engagement with a stationary stop 11 mounted on the frame 2. The stop 11 is fixedly positioned by being threaded through a portion of the frame 2.
Numeral 12 represents a follower partial gear toothed only at 100 and mounted loosely on the shaft 6. The follower partial gear 12 has a radial projection 100' and a cam portion 100" between the teeth 100 and the radial projection 100' as shown in FIG. 6. The follower partial gear 12 also has an axially projecting boss 12a which in turn has an axial slot 14 formed in its periphery. The axial slot 14 slidably receives an axial projection 13 which projects rigidly from the solid flange 7. Follower partial gear 12 is slidable axially on the shaft 6, but its rotation is made in unison therewith by virtue of the fixed mounting of the flange 7 on the shaft 6.
Arm member 15 is mounted loosely on the shaft 6. The loose mounting of the arm member 15 permits it both to move axially on the shaft 6 and to rotate relative to the shaft 6. The arm member 15 has a recess 16 which receives the tip end of plunger 19 of thread-cutter solenoid 18. Thread-cutter solenoid 18 is fixedly mounted on a part 2a of the frame 2 by means of a plurality of horizontal set screws 17. A stationary member 103 is fixed on the upper surface of the part 2a of the frame 2 by vertical set screws (not shown) which pass through holes 17' in stationary member 103. Therefore, the arm member 15 normally cannot rotate with the shaft 6 when the latter is caused to rotate.
It will be seen from the foregoing that, when solenoid 18 is energized by supply of electric current thereto from a current source (not shown) for the execution of a thread-cutting job, plunger 19 is caused to advance leftwards in FIG. 1. When the plunger 19 advances leftwards in FIG. 1, it pushes the arm member 15 and the partial gear 12 in the same direction against the action of a coil spring 20 provided between the partial gear 12 and the flange 17.
Numeral 22 represents a thread-release cable passing through a small hole 21 formed in one end of the arm member 15 and fixedly attached thereto by a pair of fixing elements 23. A flexible cable sheath 102 slidably guides the thread-release cable 22 and is attached fixedly as its one end to the stationary 103 by means of a clip 104.
Number 24 represents part of a conventional hook shaft which is supported rotatably at the one end shown by a bearing 25. The bearing 25 is press fit in position into the bed 1, as shown in FIG. 1.
A pivotable holder 26 is provided in close proximity to the left end of the bearing 25, FIG. 1. Leftward axial movement of the pivotable holder 26 is prevented by a stop ring 27 mounted on the hook shaft 24. The holder 26 and the operating lever portion 5 are pivotably connected to each other by a link member 28 and stepped screws 29 and 30.
A stationary cutter blade 32 and a thread guide plate 33 are fixedly attached to the bed 1 by means of a set screw 31. The stationary cutter blade 32 is arranged in opposition to a thread catcher 35 (shown in FIG. 14) which is fixedly attached to the pivotable holder 26 by a set screw 34. The stationary cutting edge 41 formed on the tip end of the stationary cutter blade 32 and the movable cutting edge 40 formed on thread catcher 35 can be brought into a shearing relationship for performing a thread cutting job, as will be described later more fully.
The free end portion of thread guide plate 33 has an arc-shape in its side view, the arc being designed and arranged concentrically with a conventional rotary hook 36. The thread guide plate 33 is arranged to occupy an intermediate position when seen in the radial direction of the rotary hook, as most clearly seen from FIGURE &. The thread guide plate 33 is further provided with an opening 97 adapted for passage of the sewing thread so as to keep the sewing thread in coincidence with the center of the needle.
The thread catcher 35 comprises as its effective portion an arc-shaped portion made concentric to the rotary hook 36. The thread catcher 35 also has a pointed end portion 37. Behind the pointed end portion 37 is a thread-engaging portion 38, and behind the thread-engaging portion 38 is a longitudinally grooved portion 39 terminating in the movable cutting edge 40. The movable cutting edge 40 is adapted for cooperating with the stationary cutting edge 41 formed on the tip end of the stationary cutting blade 32 for performing a thread cutting job, as will be more fully described hereinafter.
A driving partial gear 42 is attached fixedly to the hook shaft 24 by means of a set screw 43. The driving partial gear 42 has drive teeth at 98. In succession to the drive teeth 98, the partial gear 42 has on its outer periphery a cam portion 92 having a gradually increasing radius of curvature. In further succession to the cam portion 92, the partial gear 42 has a radial projection 98' and blank peripheral surfaces 99, 99 on both sides of the radial projection 98'. The blank peripheral surfaces 99, 99 terminate at the teeth 98 in one direction and at the cam portion 92 in the other direction. The radius of curvature of the blank peripheral surfaces 99, 99 are equal to or less than the radius of the bottom circle of the drive teeth 98.
The driving partial gear 42 rotates in idle and in unison with the hook shaft 24 during the normal sewing operation of the machine. However, when the solenoid 18 is energized for initiating a thread cutting job, the follower partial gear 12 is caused to slide on the shaft 6 as explained previously so that the follower partial gear 12 is brought into lateral registration with the companion driving partial gear 42. As will be further explained hereinafter, the two partial gears 12 and 42 are adapted for engagement with each other during the rotational movement of the hook shaft 24.
As shown in FIG. 4, a tension-release lever 45 and a pivotable member 46 are both pivotably mounted on a conventional machine arm 44 by means of a common pivot pin 47, although the set position has been omitted from the drawing. Tension release lever 45 is formed with a cam surface 48 which is adapted for acting upon a pin or tension stud 49 when the tension release lever 45 is rotated. When the tension stud 49 is moved, the tension of the upper thread at a thread tension disc unit 50 of a known structure is released, as in the commonly known way.
The cable guide sheath 102 is fixedly attached at one end of the solenoid mounting plate 103 as shown and described hereinbefore in connection with FIG. 1. The opposite end of the cable guide sheath 102 is fixedly attached to the machine arm 44, although not specifically shown. The cable 22 slidable in and along the sheath 102 has its one end fixedly attached to the upper or motion-receiving end of the tension release lever 45 as shown in FIG. 4. A tension spring 51 is connected between the tension release lever 45 and the cable guide sheath 102 (which, as previously mentioned, is attached to the machine arm 44), biasing the tension release lever 45 in the counterclockwise direction in FIG. 4. By the sliding movement of arm member 15 caused by energization of the solenoid 18 in the previously described manner, the tension-release lever 45 is pulled by the cable 22 against the spring action of the tension spring 51 so that the tension release lever 45 is caused to pivot in the clockwise direction in FIG. 4 about the pivot pin 47 for the execution of the tension-releasing job, as was described hereinbefore. On the contrary, when the solenoid 18 is de-energized, the tension in the cable 22 is released, allowing the accumulated energy in the tension spring 51 to pivot the tension release lever 45 in the counterclockwise direction in FIG. 4. When the tension release lever 45 pivots in the counterclockwise direction, the cam surface 48 is disengaged from contact with the motion-receiving end of the pin or tension stud 49.
When a commonly known lifting plate 52 is lifted by means of knee lifter, as an example, the pivotable member 46 is caused to pivot in the clockwise direction in FIG. 4 by virtue of the fork joint between a pin 53 on the lifting plate 56 and a fork 54 on the pivotable member 46. The pivotal motion of the member 46 causes it to push a pointed projection 55 of the thread tension release lever 45, in turn causing the thread tension release lever 45 to pivot in the clockwise direction. As previously described, clockwise rotation of the thread tension release lever 45 releases upper thread tension.
As shown in FIG. 5, a conventional needle bar 94 is disposed in the machine arm 44. The needle bar 94 carries a needle 94a and is reciprocated by a crank mechanism (not shown) actuated by the rotation of a conventional upper or arm shaft (not shown). The needle bar 94 is given a timing mark shown at 95 which is selected at a predetermined position on the needle bar 94. In the present case, when the timing mark 95 is brought into coincidence with the lower end of needle bar bearing 96 as shown, the needle bar 94 will occupy a position of about 55 degrees in advance of the upper dead point of the needle bar 94.
As is commonly known, and although not specifically shown, the thread tension disc unit 50 is mounted on the front side of the machine arm 44 in close proximity to the free end extremity of the machine arm 44.
The general operation of the thread trimming device so far shown and described is as follows.
When the operation for a thread cutting job is started, the trimming solenoid 18 is energized. Accordingly, the plunger 19 operates to push the arm member 15 and the partial gear 12 axially in the previously described manner, bringing the partial gear 12 into registration with its companion partial gear 42 ready for mutual engagement. When the hook shaft 24 rotates to the point where the needle bar 94 is about 55 degrees in advance of its upper dead point, the driven partial gear 42 is brought into engagement with the follower partial gear 12, as shown in FIG. 6. Thus, rotation is transmitted from the driving partial gear 42 to the follower partial gear 12 against the resilient force of the coil spring 10. This motion is further transmitted through flange 7, shaft 6, lever 5 and link member 28 to pivotable holder 26. Thus, the pivotable holder 26 begins to pivot, causing the thread catcher 35 to initiate a thread trimming operation.
Next, the two partial gears 12 and 42 rotate to positions shown in FIG. 8. When the partial gears 12 and 42 are in the positions shown in FIG. 8, the pointed end portion 37 of thread catcher 35 is thrust into the loop of upper thread N formed by the rotary hook 36, as schematically shown in FIG. 7. At the same time, the thread-engaging portion 38 of thread catcher 35 begins to engage thread B extending from a bobbin case 91, housed as is conventional within the rotary hook 36.
At a still further advanced timed phase of the mutually engaging partial gears 12, 42 as shown in FIG. 10, the partial gears 12 and 42 have completed a partial revolution due to the meshing of their gear teeth. At this time, the upper thread N is subjected to an upwardly directed drawing action by a conventional thread take-up lever (not shown). However, the upper thread N is held by the thread-engaging portion 38 of the thread catcher 35, so as to leave a proper end length of the thread N--enough to avoid a slip-out of the thread from the thread eyelet (not shown) of the needle 94a at the commencement of the next sewing job. At this stage, the lower thread B, together with a part of the upper thread N which lies close to the sewing material (not shown), runs in and along the groove in the grooved portion 39 of the thread catcher 35. In this position, both threads are spaced in the leftward, or counterclockwise direction from the stationary cutting edge 41 of stationary cutter blade 32. Therefore, a proper length of the lower thread B as necessary for later use after thread trimming and upon initiation of a new sewing job can be drawn out from the bobbin case 91 and preserved in position.
As the timing of the operational stage shown in FIGS. 9 and 10 corresponds to 60°-70° in advance of the arrival of the upper dead point of the thread take-up lever, a considerable difficulty will occur due to the imposition of an excess upward pulling of the trimmed upper thread N by the upward movement of the thread take-up lever towards its upper dead point if the upper thread is trimmed directly after the completion of the aforementioned thread catching operation. In fact, the excess upward pulling of the trimmed upper thread N may even cause the thread N to slip off the needle 94a, thereby making the next succeeding sewing operation impossible. On the other hand, if the thread catcher 35 is moved over a substantial distance after the execution of the thread catching operation, it is necessary to overcome a considerable amount of resistance provided by the part of the upper thread N extending from its supply source to the thread catcher 35 even if the thread tension at the thread tension disc unit 50 has been released. Even if the upper thread N is not broken unintentionally in this case, the thread trimming device will require a considerably large amount of driving force when operating under these conditions. According to the present invention, these otherwise unavoidable conventional drawbacks can be substantially obviated.
In the design and arrangement of the thread trimming device according to this invention, such excess drawing-out of the upper thread N can be effectively avoided by bringing the gear teeth 98, 100 of the partial gears 12, 42, respectively, into mutual engagement so that the movable cutting edge 40 of the thread catcher 35 and the stationary cutting edge 41 of the stationary cutter blade 32 may be brought rapidly together directly after the arrival of the specific operational timing stage shown in FIG. 10. Accordingly, the occurrence of the thread trimming operation is brought as close as possible to the time of the upper dead point of the thread take-up lever. After it has reached the position shown in FIG. 10, the drive partial gear 42 rotates in such a way that the cam portion 92 formed in succession to the gear teeth 98 thereon keeps in sliding contact with the last one of the teeth 93 on the follower partial gear 12. By this operation, the cutting edges 40, 41 are brought into cooperation with each other, as shown in FIGS. 11 and 12, for simultaneous trimming of the threads N and B. Until the trimming job has been completed, the thread catcher 35 continues to pivot at a rather low speed due to the gradually increasing radius of curvature of the cam portion 92.
Upon execution of the thread trimming job and after further slight rotation of the driving partial gear 42, the engagement of cam portion 92 of the driving partial gear 42 and the gear tooth 93 on the follower partial gear 12 is released. After release of the follower partial gear 12, the thread catcher 35 pivots in the opposite direction under the resilient force of the coil spring 10 until the radial projection 7a of the flange is brought into contact with stationary stop 11. Just after release of the engagement between the two partial gears 12 and 42, the radial projection 98' formed on the periphery of the driving partial gear 42 comes into contact with the radial projection 100' and the cam portion 100" formed on the periphery of the follower partial gear 12. The engagement of the radial projection 98' with the radial projection 100' and the cam portion 100" assists reverse swivel of the follower partial gear 12 as well as the thread catcher 35. After completion of this step, a known position sensor (not shown) acts to sense the upper stop position of the thread take-up lever, which is close to its upper dead point. When the position sensor senses that the thread take-up lever has reached its upper stop position, an electrical instruction signal for the interruption of electric current supply is delivered to the trimming solenoid 18. In this way, the follower partial gear 12, the arm member 15, and the plunger 19 are caused to return to their starting positions by the resilient resetting action provided by the coil spring 20.
Under these conditions, therefore, the thread trimming device is kept ineffective and ready for the next trimming operation when the sewing machine is caused to run for its next sewing job.
When the plunger 19 pushes the arm member 15 to the left in FIG. 1 for the execution of the thread trimming job, movement of the arm member 15 pulls the cable 22 to the left in FIG. 1. As previously explained, that motion of the cable 22 pivots the tension release lever 45, FIG. 4, thereby pushing the tension stud 49 towards the thread take-up disc unit 50 by means of cam surface 48 on the lever 45, resulting in the release of tension in the thread at the unit. Therefore, the thread N will be delivered from its supply source in a smooth manner after the thread take-up lever has begun its thread pull-up operation after successful catch of the upper thread N by the thread catcher 35, as schematically shown in FIG. 9.
After completion of the thread trimming job and upon interruption of current supply to solenoid 18, the tension release lever 45 will be caused to swivel in the opposite or counterclockwise direction in FIG. 4 under the action of return spring 51, so as to bring the thread take-up disc until 50 into its operating position for applying tension to the upper thread N.
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A thread trimming device comprises a first ratchet disposed on a first shaft having a first partial gear, a first cam surface, a first radial projection, and blank surfaces on its periphery. A second ratchet disposed on a second shaft has a second partial gear, a second radial projection, and a second cam surface on its periphery. A stationary blade is secured to a framework. A pivotably movable blade is connected to the second shaft. A solenoid moves the second ratchet along the second shaft such that, upon actuation of the solenoid, the toothed portion of the first and second partial gears are engaged with each other to rotate the movable blade to an operable position relative to the stationary blade. Thereafter the first cam surface comes into contact with the second partial gear to slowly rotate the movable blade to cooperate with the stationary blade to perform the thread trimming operation. Afterwards, the first radial projection comes into sliding contact with the second radial projection and the second cam surface to rotate the second ratchet in the reverse direction after the termination of the thread trimming operation.
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TECHNICAL FIELD
[0001] The present invention relates to a relay cell system, especially to a system and method for transmitting a downlink schedule in a WiMax/WiBro relay system.
BACKGROUND
[0002] In a conventional WiMax/WiBro system, it is necessary for a BS to transmit a schedule in a header of each frame so that users may receive or transmit data at some location. In general, this schedule should be decoded by any user even the user with worse channel quality in a cell. Thus, the schedule is processed with lower level of modulation and encoding scheme and retransmitted for several times.
SUMMARY OF THE INVENTION
[0003] With introduction of relay, a space multiplexing scheme is mostly adopted between relay stations to make full use of the system's frequency resource, i.e., several relay stations may simultaneously transmit or receive data, as shown in FIG. 2 . In this way, several data or control messages are transferred in a cell at some time. Therefore, items of the schedule in each frame increases with the increasing of relays. Since a schedule is usually processed with lower level of modulation and encoding scheme and retransmitted for several times, it occupies more system frequency resources than data transmission. It is necessary to adopt a more effective method to transmit the schedule so as to reduce the resource increased for transmitting the schedule with the increasing of relays.
[0004] A system and method for transmitting a schedule in a WiMax/WiBro relay system is provided in present invention. In this method, a task of transmitting the schedule is dispersed from the BS to both of BS and RSs so that several RSs may transmit the schedule items simultaneously and therefore the resource of the system is saved.
[0005] To achieve the object mentioned above, a system for transmitting a schedule in a WiMax/WiBro relay system comprising:
[0006] a relay scheduling function information module in a BS, for receiving relay scheduling function information transmitted from a relay scheduling function transmitting module in a RS with or without a function of scheduling, the information indicating whether a RS bears the function of scheduling or not;
[0007] a transmission location information transmitting module in the BS, for transmitting the transmission location information on a schedule for the next frame to a transmission location information receiving module of the RS with or without the function of scheduling;
[0008] a user information transmitting module in the BS, for transmitting the user information to the RS with the function of scheduling;
[0009] an item calculating module in the BS for calculating schedule items for all links except for the links between the RSs with the function of scheduling and the relay user in the cell;
[0010] a schedule item calculating module in the RS with the function of scheduling for calculating items needed to be transmitted in the next frame to user;
[0011] a schedule item transmitting module in the BS for transmitting the schedule items from the RS to a RS without function of scheduling in the next frame to users of the RS without the function of scheduling;
[0012] wherein the BS, schedule item declaration modules with or without the function of scheduling simultaneously transmit their own schedule items to users, in frequency domain, the BS transmits the schedule items via some sub-channels and a plurality of RSs transmit schedule items via other sub-channels.
[0013] In present invention, the task of transmitting the schedule is dispersed from the BS to both of the BS and RSs so that several RSs may transmit the schedule items simultaneously and therefore the resource of system is saved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates a process that BS, the RSs with or without the function of scheduling cooperatively implements the transmission of schedule effectively;
[0015] FIG. 2 illustrates space multiplexing for RSs resulted from that several RSs simultaneously transmit data to users;
[0016] FIG. 3 illustrates a conventional mode in transmitting a downlink schedule;
[0017] FIG. 4 illustrates a high effective mode in transmitting a downlink schedule;
[0018] FIG. 5 illustrates a message flow in the process that BS, the RSs with or without the function of scheduling cooperatively implement the transmission of schedule effectively.
DETAILED DESCRIPTION
[0019] In the structure of present invention, the relay end without the function of scheduling includes following modules:
[0020] Transmission location information receiving module 101 that receives a transmission location information message from a BS. With this message, the RS obtains where (for example, in which one of the OFDMA time frequency grid) the schedule items are transmitted in the next frame. After the RS receives this message, it records the transmission location for subsequent frames in the transmission of schedule items. Before this message indicating the next transmission location is not received, the transmission location is kept unchanged;
[0021] Schedule item receiving module 102 that receives the schedule item message sent from the schedule item transmitting module 302 in the BS. This message indicates the schedule needed to transmit in the next frame for this RS;
[0022] Schedule item declaration module 103 that transmits the schedule item message received by the relay schedule item receiving module 102 in the previous frame via the recorded transmission location;
[0023] Relay scheduling function transmitting module 104 that transmits the information to the BS, indicating that it has no function of scheduling.
[0024] The relay end with the function of scheduling includes following modules:
[0025] Transmission location information receiving module 201 that receives the transmission location information from BS. With this message, the RS obtains where (for example, in which one of the OFDMA time frequency grid) the schedule items are transmitted in the next frame. After the RS receives this message, it records the transmission location for subsequent frames in the transmission of schedule items. Before the message indicating the next transmission location is not received, the transmission location is kept unchanged;
[0026] Module 202 that can receive and buffer user information, which receives the messages indicating a destination address from the BS for the relay user, and then buffers them;
[0027] Schedule item calculating module 203 that calculates the schedule items that are necessary to transmit to users according to the buffered messages;
[0028] Schedule item declaration module 204 that transmits the schedule items obtained by the schedule item calculating module 203 via the recorded transmission location;
[0029] Relay scheduling function transmitting module 205 that transmits the information to BS, indicating that it bears function of scheduling.
[0030] BS includes following modules:
[0031] Schedule item calculating module 301 that calculates the schedule items for all links except for the links between the RSs with the function of scheduling and the relay user in the cell;
[0032] Schedule item transmitting module 302 that can transmit the schedule items which from the RS without the function of scheduling to the user of the relay in the next frame to the RS in the current frame;
[0033] Schedule item declaration module 303 that transmits the schedule items in current frame to RSs and the users;
[0034] Relay scheduling function information receiving module 304 that receives the scheduling function information from RSs so as to know whether the RS has the scheduling function or not;
[0035] Transmission location information transmitting module 305 that transmits the transmission location message of the relay schedule to the RS. In this message, the location (i.e., in which one of the OFDMA time frequency grid) is specified in the next frame for transmitting the schedule items;
[0036] User information transmitting module 306 that transmits the user information on the destination address to the RS. These messages are forwarded to the users through the RS.
[0037] The user end includes following modules:
[0038] Schedule item receiving module 401 that receives the schedule items via the locations specified in the system.
[0039] Based on the structure above, high effective transmission of downlink schedule is implemented cooperatively by BS and RS, as shown in FIG. 1 .
[0040] FIG. 5 illustrates an example message transmission process.
[0041] In one example, there are one BS and two RSs (for example, RS1 and RS2) in a cell, in which RS1 includes the function of schedule and RS2 does not include a scheduling function; and two users (for example, user1 and user2). Detailed steps that high effective transmission of downlink schedule is implemented cooperatively by BS and RS, as shown in FIG. 5 :
[0042] Step 1. in the first frame, the relay scheduling function transmitting module 205 in RS1 transmits the scheduling function message to the BS, indicating that RS1 has the function of scheduling;
[0043] Step 2. in the first frame, the relay scheduling function information receiving module 304 in the BS receives the scheduling function message from RS1 to know that RS1 has the function of, scheduling;
[0044] Step 3. in the first frame, the relay scheduling function transmitting module 104 in RS2 transmits the scheduling function message to the BS, indicating that RS2 has no function of scheduling;
[0045] Step 4. in the first frame, the relay scheduling function information receiving module 304 in the BS receives the scheduling function message from RS2 to know that RS2 has no function of scheduling;
[0046] Step 5. in the first frame, the transmission location message transmitting module 305 in the BS transmits the message indicating the transmission location of schedule in the next frame to RS1 and RS2;
[0047] Step 6. in the first frame, the transmission location message receiving module 201 in RS1 receives the transmission location message from BS and records it;
[0048] Step 7. in the first frame, the transmission location message receiving module 101 in RS2 receives the transmission location message from BS and records it;
[0049] Step 8. in the first frame, the user information transmitting module 306 in the BS transmits the user information to RS1;
[0050] Step 9. in the first frame, the user information receiving and buffering module 202 in RS1 receives the transmission user information from BS and buffers it;
[0051] Step 10. in the first frame, the schedule item calculating module 301 in the BS calculates the schedule items (in the next frame, for example, the second frame) for all links except the ones between the RSs which bear function of scheduling and the relay user in the cell;
[0052] Step 11. in the first frame, the schedule item calculating module 203 in RS1 calculates the schedule items needed to be transmitted to users via the next frame (for example, the second frame);
[0053] Step 12. in the first frame, the schedule item transmitting module 302 in the BS transmits the schedule items (from RS2 to the users of RS2) to RS2 via the next frame (for example, the second frame);
[0054] Step 13. in the first frame, the schedule item receiving module 102 in RS2 receives the schedule items (from RS2 to the users of RS2) from BS via the next frame (for example, the second frame) and records them;
[0055] Step 14. in the second frame, the schedule item declaration modules (i.e., 301 , 204 and 103 ) in the BS, RS1 and RS2 simultaneously transmits their own schedule items, where the location (for example, the OFDMA time frequency unit grid) of the broadcast schedule item of RS1 or RS2 is the one recorded in the first frame;
[0056] Step 15. in the second frame, the schedule item receiving module 401 of user1 receives the schedule items from both BS and RS1 so as to obtain the schedule items in current frame;
[0057] Step 16. in the second frame, the schedule item receiving module 401 of user2 receives the schedule items from both BS and RS2 so as to know about the schedule items in current frame.
[0058] In an illustrative example a cell has one BS, three RSs (for example, RS1, RS2 and RS3) and three users (for example, user1, user2 and user3). Three messages should be transmitted from BS to user1, user2 and user3 respectively on the premise that the message to user1 should be relayed by RS1 the message to user2 by RS2 and the message to user3 by RS3. In this case, it is necessary for the BS to broadcast six (6) schedule items: (1) BS->RS1; (2) BS->RS2; (3) BS->RS3; (4) RS1->user1; (5) RS2->user2; (6) RS3->user3.
[0059] FIG. 3 shows a PDU structure of MAC of the conventional mode in transmitting the downlink schedule with a dash part indicating that the transmission is not implemented. In this figure, all six (6) schedule items should be transmitted by the BS. Meanwhile, all users have received the PDU that contains the six (6) schedule items.
[0060] FIG. 4 shows a process of transmitting the schedule items with the high effective transmission method according to present invention. Here, FIG. 4A shows the content that BS needs to transmit. It should be noted that BS transmits only the MAC header and the three schedule items which are from BS to RSs. FIGS. 4B through 4D respectively show the transmission content of RS1, RS2 and RS3. Each RS transmits the corresponding schedule items to users. Different sub-channels are adopted by BS and RSs to transmit the schedule items. The three RSs share the same sub-channels to transmit the schedule items. Since the three RS are told apart spatially, the PDUs received by user1, user2 and user3 are illustrated in FIGS. 4E through 4G respectively.
[0061] From the comparison between FIG. 3 and FIGS. 4A-4G , it will be seen that each user in FIG. 3 has received the same PDU of six (6) schedule items, and each user in FIGS. 4A-4G has received PDUs (which are partially consistent) of four (4) schedule items. Suppose one OFDMA time frequency grid is used for the MAC header and one schedule item, seven OFDMA time frequency grids are needed to transmit the schedule in the conventional method, while only five (5) OFDMA time frequency grids are needed in the high effective transmission method. In practice, with the increment of schedule items occupied by RSs, more system resource will be saved by the high effective transmission method.
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A system and method for transmitting downlink schedule in a WiMax/WiBro relay system is proposed in present invention. In present invention, the task of transmitting the schedule is dispersed from the BS to both of the BS and RS so that several RS may transmit the schedule items simultaneously and therefore the resource of the system is saved.
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TECHNICAL FIELD
[0001] The present invention relates to a numerically-controlled machine tool such as a machining center, a horizontal boring machine or a double column piano milling machine.
BACKGROUND ART
[0002] A numerically-controlled machine tool such as a machining center, a horizontal boring machine or a double column piano milling machine has heretofore been configured to determine a machining start point, an inclination of a reference plane, and the like prior to machining by measuring a position of a predetermined portion of a workpiece fixed and supported onto a table, and the like by use of a contact sensor such as a touch probe.
CITATION LIST
Patent Literatures
[0000]
Patent Literature 1: Japanese Patent Application Publication No. Hei 6-055407
Patent Literature 2: Japanese Patent Application Publication No. 2009-163414
Patent Literature 3: Japanese Patent Application Publication No. 2010-108292
SUMMARY OF INVENTION
Technical Problem
[0006] In the meantime, when a contact sensor such as a touch probe is used in an attempt to three-dimensionally measure a shape of a workpiece, a moving speed (a feeding speed) of the contact sensor such as a touch probe cannot be set very fast in the light of accuracy and significant time is wasted as a consequence.
[0007] In view of the above, an object of the present invention is to provide a numerically-controlled machine tool which is capable of quickly measuring an actual three-dimensional condition of a workpiece attached onto a table via a jig or the like.
Solution to Problem
[0008] A numerically-controlled machine tool of the present invention for solving the above problem is characterized in that the machine tool comprises: a main spindle to which a tool is detachably attached and which is configured to rotate the tool; a table configured to fix and support a workpiece; tool measuring means for measuring a length and a diameter of the tool attached to the main spindle; workpiece measuring means for measuring a three-dimensional shape, a position, and an orientation of the workpiece fixed and supported onto the table in a non-contact manner; and controlling means for finding a position of a machining start point and an inclination of a reference plane on the basis of information from the workpiece measuring means, then controlling an action of at least one of the main spindle and the table in such a manner as to perform machining on the workpiece on the table on the basis of an inputted machining program while using information from the tool measuring means and the workpiece measuring means as well as the position of the machining start point and the inclination of the reference plane, and controlling an action of at least one of the main spindle and the table in such a manner as to move the tool relatively to the workpiece at a faster speed than a relative moving speed of the tool defined in the machining program when the tool is located in a non-machining region where the tool moves relatively to the workpiece without being in contact with the workpiece.
Advantageous Effect of Invention
[0009] According to a numerically-controlled machine tool of the present invention, the three-dimensional shape, the position, and the orientation of the workpiece fixed and supported onto the table are measured with the workpiece measuring means in a non-contact manner. Thus, an actual three-dimensional condition of the workpiece attached onto the table via a jig or the like can be quickly measured.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a schematic configuration diagram of a main embodiment of a numerically-controlled machine tool according to the present invention.
[0011] FIG. 2 is a control block diagram of principal part of the main embodiment of the numerically-controlled machine tool according to the present invention.
[0012] FIG. 3 is a control flowchart of the principal part of the main embodiment of the numerically-controlled machine tool according to the present invention.
DESCRIPTION OF EMBODIMENTS
[0013] An embodiment of a numerically-controlled machine tool according to the present invention will be described below with reference to the drawings. It is to be noted, however, that the present invention is not limited only to the embodiment described with reference to the drawings.
Main Embodiment
[0014] A main embodiment of a numerically-controlled machine tool according to the present invention will be described with reference to FIGS. 1 to 3 .
[0015] As shown in FIG. 1 , a numerically-controlled machine tool 100 of this embodiment includes: a main spindle 102 to which a tool 101 can be detachably attached and which is configured to rotate the tool 101 ; a table 103 configured to fix and support a workpiece 1 ; a tool measuring sensor 104 serving as tool measuring means for measuring two-dimensional shapes, namely, a length and a diameter of the tool 101 attached to the main spindle 102 ; and workpiece measuring sensors 105 serving as workpiece measuring means for measuring a three-dimensional shape of a combination of a jig and the workpiece 1 fixed and supported onto the table 103 in a non-contact manner with a laser beam or the like.
[0016] In addition, as shown in FIG. 2 , the tool measuring sensor 104 and the workpiece measuring sensors 105 are electrically connected to an input unit of a control device 106 serving as controlling means. Moreover, an input device 107 serving as inputting means for inputting various machining conditions including a machining program and the like is electrically connected to the input unit of the control device 106 .
[0017] In the meantime, an output unit of the control device 106 is electrically connected to each of a drive motor 108 which is configured to rotate the tool 101 attached to the main spindle 102 ; drive motors 109 to 111 which are configured to move the main spindle 102 and the table 103 in such a manner as to move the tool 101 and the workpiece 1 relatively in X, Y, and Z axis directions; and a display device 112 serving as information displaying means such as a speaker or a monitor for displaying a variety of information in the form of sounds or images. The control device 106 is capable of controlling actions of the motors 108 to 111 on the basis of information from the sensors 104 , 105 and information inputted from the input device 107 , and of displaying the variety of information on the display device 112 (to be described later in detail).
[0018] Next, actions of the numerically-controlled machine tool 100 of this embodiment will be described.
[0019] First, various machining conditions including the machining program are inputted to the control device 106 by using the input device 107 (S 1 in FIG. 3 ). When the tool 101 is attached to the main spindle 102 , the control device 106 activates the motors 109 to 111 and thereby moves the tool 101 and the tool measuring sensor 104 relatively in the X, Y, and Z axis directions (S 2 in FIG. 3 ) in such a manner as to measure the two-dimensional external sizes including the length and the diameter of the tool 101 with the tool measuring sensor 104 .
[0020] Thus, the control device 106 determines the actual two-dimensional external sizes of the tool 101 including a length between an end of the main spindle and a tip of the tool 101 , a diameter on the tip side, and the like on the basis of the information from the tool measuring sensor 104 .
[0021] Subsequently, when the workpiece 1 is fixed and supported onto the table 103 via the jig, the control device 106 activates the motors 109 to 111 and thereby moves the workpiece measuring sensors 105 and the workpiece 1 relatively in the X, Y, and Z axis directions (S 3 in FIG. 3 ) in such a manner as to measure the three-dimensional external shape, a position, and an orientation of the combination of the jig and the workpiece 1 on the table 103 with the workpiece measuring sensors 105 .
[0022] Thus, the control device 106 determines the actual three-dimensional external shape, position, and orientation of the combination of the jig and the workpiece 1 on the table 103 on the basis of the information from the workpiece measuring sensors 105 .
[0023] Next, the control device 106 determines compliance between the inputted machining program and the workpiece 1 on the basis of the actual external shape of the tool 101 and the actual external shape, position, and orientation of the workpiece 1 determined as described above.
[0024] Specifically, the control device 106 first compares a shape of the workpiece assumed in the machining program inputted from the input device 107 with the actual shape of the workpiece 1 on the table 103 on the basis of the actual external shape of the workpiece 1 , and determines whether or not a content of machining to be carried out complies with the workpiece 1 to be machined (S 4 in FIG. 3 ). When the shape of the workpiece assumed in the machining program does not comply with the shape of the workpiece 1 on the table 103 , namely, when the content of machining to be carried out does not conform to the workpiece 1 to be machined, the control device 106 warns an operator by displaying such a fact on the display device 112 (S 5 in FIG. 3 ).
[0025] When the shape of the workpiece assumed in the machining program complies with the shape of the workpiece 1 on the table 103 , namely, when the content of machining to be carried out conforms to the workpiece 1 to be machined, the control device 106 subsequently finds machining reference values including a position of a machining start point, an inclination of a reference plane, and the like on the basis of the position and orientation of the workpiece 1 (S 6 in FIG. 3 ).
[0026] Then, the control device 106 determines whether or not the actual position and orientation of the workpiece 1 on the table 103 comply within normal ranges (S 7 in FIG. 3 ) by comparing the actual machining reference values including the position of the machining start point, the inclination of the reference plane, and the like thus found with assumed machining reference values including the position of the machining start point, the inclination of the reference plane, and the like which are assumed in the inputted machining program. When the actual machining reference values do not comply with the assumed machining reference values, namely, when the actual position and orientation of the workpiece 1 on the table 103 are misaligned, the control device 106 warns the operator by displaying such a fact on the display unit 112 , and displays the information indicating the position and orientation of the non-compliant workpiece 1 (S 8 in FIG. 3 ).
[0027] When the actual machining reference values comply with the assumed machining reference values, namely, when the actual position and orientation of the workpiece 1 on the table 103 are compliant, the control device 106 performs simulation of machining the actual workpiece 1 inclusive of the jig on the table 103 to an intended final shape (S 9 in FIG. 3 ) on the basis of the various machining conditions including the inputted machining program and the like, the measured actual two-dimensional shapes including the length and the diameter of the tool 101 , the measured actual three-dimensional shape of the workpiece 1 , and the found actual machining reference values including the position of the machining start point, the inclination of the reference plane, and so forth.
[0028] Presence of any of the following machining problems is checked (S 10 in FIG. 3 ) by carrying out the machining simulation of the actual workpiece 1 to the intended final shape:
[0000] (1) Presence of interference of the workpiece 1 side inclusive of the jig or the like with the tool 101 side such as a slide (a ram);
(2) Presence of a machining load equal to or above a prescribed value (a machining allowance of a size equal to or above the prescribed value); and
(3) Presence of a portion of the workpiece 1 left unmachined.
[0029] Here, if there is any of the above-mentioned problems, the control device 106 warns the operator by displaying such a fact on the display device 112 , and displays details (position, magnitude, and the like) of such a problem (S 11 in FIG. 3 ).
[0030] On the other hand, when there are none of these problems, the control device 106 starts control of the actions of the motors 108 to 111 in order to perform actual machining on the workpiece 1 on the table 103 in a similar manner to the machining simulation (S 12 in FIG. 3 ).
[0031] Then, the control device 106 continues the actual machining on the basis of the machining simulation. In a machining region where the tool 101 is in contact with the workpiece 1 (S 13 in FIG. 3 ), the control device 106 controls the actions of the motors 109 to 111 (S 14 in FIG. 3 ) in such a manner as to relatively move the main spindle 102 and the table 103 according as defined in the machining program. On the other hand, in a non-machining region where the tool 101 moves without being in contact with the workpiece 1 , the control device 106 controls (overrides) the actions of the motors 109 to 111 (S 15 in FIG. 3 ) in such a manner as to move the tool 101 relatively to the workpiece 1 at a higher speed than the moving speed such as the feeding speed of the tool 101 defined in the machining program.
[0032] Then, the actual machining on the workpiece 1 is terminated as the machining program is terminated (S 16 in FIG. 3 ).
[0033] In other words, the numerically-controlled machine tool 100 of this embodiment is configured to find the actual three-dimensional shape of the workpiece 1 inclusive of the jig or the like by using the workpiece measuring sensors 105 which perform measurement in a non-contact manner with a laser beam or the like.
[0034] Accordingly, the numerically-controlled machine tool 100 of this embodiment can quickly measure the actual three-dimensional condition of the workpiece 1 attached onto the table 103 via the jig or the like. In addition, the following advantageous effects can be achieved as well.
[0000] (1) It is possible to considerably simplify a conventional operation so-called a debugging operation, in which the machining program is executed while moving the main spindle 102 away before machining is actually performed on the workpiece 1 ; meanwhile, the operator visually checks a relation concerning an acting position (such as the presence of the interference, the degree of fluctuation of the machining allowance or the presence of the portion left unmachined) of the main spindle 102 with the workpiece 1 and the operator performs adjustment so as to reflect a result of the check in the actual machining. Thus, a burden on the operator can be significantly reduced and fluctuation attributed to an experience level of the operator can be eliminated.
(2) The moving speed such as the feeding speed of the tool 101 is overridden when the tool 101 is in the non-machining region in the course of the actual machining. Thus, processing time can be significantly reduced.
Other Embodiments
[0035] The foregoing embodiment has described the case of providing the workpiece measuring sensors 105 configured to measure the three-dimensional shape and the like of the workpiece 1 in a non-contact manner with a laser beam or the like. Instead, as another embodiment, it is possible to provide a CCD camera configured to shoot the three-dimensional shape and the like of the workpiece 1 , for example.
[0036] Meanwhile, in the foregoing embodiment, the tool measuring sensor 104 configured to measure the shapes including the length, the diameter, and the like of the tool 101 , and the workpiece measuring sensors 105 configured to measure the three-dimensional shape and the like of the workpiece 1 in a non-contact manner are provided. Instead, as another embodiment, it is possible to provide measuring means for measuring the shapes including the length, the diameter, and the like of the tool 101 and measuring the three-dimensional shape and the like of the workpiece 1 in such a manner as to serve as both of the tool measuring sensor 104 and the workpiece measuring sensors 105 , for example.
[0037] Meanwhile, in the foregoing embodiment, the interference of the workpiece 1 side inclusive of the jig or the like with the tool 101 side such as the slide (the ram) is checked in the machining simulation prior to the actual machining. Instead, as another embodiment, it is possible to conduct machining while performing simulation of a state ahead of a point of machining (such as 5 seconds ahead) during the actual machining, for example. Here, when occurrence of the interference of the workpiece 1 side inclusive of the jig or the like with the tool 101 side such as the slide (the ram) is predicted, the controlling means is caused to warn the operator by displaying such a fact on the displaying means, to display a position of the interference, and to suspend the machining. In other words, the controlling means can be provided with a crash prevention function (see PTL 1, for example).
[0038] In the meantime, the foregoing embodiment has described the case of checking the presence of both the machining problems of the machining load equal to or above the prescribed value (the machining allowance of a size equal to or above the prescribed value) and the portion of the workpiece 1 left unmachined. However, depending on various conditions such as accuracy associated with a manufacturing history of the workpiece 1 , it is possible to check the presence of only one of the machining problems of the machining load equal to or above the prescribed value (the machining allowance of a size equal to or above the prescribed value) and the portion of the workpiece 1 left unmachined.
[0039] In addition, the present invention is applicable as described in the foregoing embodiment to a numerically-controlled machine tool such as a machining center, a horizontal boring machine or a double column piano milling machine.
INDUSTRIAL APPLICABILITY
[0040] A numerically-controlled machine tool according to the present invention is capable of quickly measuring an actual three-dimensional condition of a workpiece attached onto a table via a jig or the like, and is therefore extremely useful in metal processing industries and the like.
REFERENCE SIGNS LIST
[0000]
1 workpiece
100 numerically-controlled machine tool
101 tool
102 main spindle
103 table
104 tool measuring sensor
105 workpiece measuring sensor
106 control device
107 input device
108 to 111 drive motor
112 display device
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Provided is a numerically-controlled machine tool ( 100 ) provided with: a tool measuring sensor ( 104 ) that measures the length and diameter of a tool ( 101 ); a workpiece measuring sensor ( 105 ) that measures the three-dimensional shape, and position and orientation of a workpiece ( 1 ) in a non-contact manner by laser beam etc.; and a control device ( 106 ), which, after determining the position of the machining starting point and the slope of a reference plane on the basis of information from the workpiece measuring sensor ( 105 ), on the basis of an inputted machining program, controls the movement of a main axis ( 102 ) etc. such that the workpiece ( 1 ) is machined from the information from the sensors ( 104, 105 ), and the position of the machining starting point and the slope of the reference plane, and controls the movement of the main axis ( 102 ) etc. in such a manner that the tool ( 101 ) is made to travel more quickly than the tool ( 101 ) travel speed in the machining program, in a non-contact manner, when the tool ( 101 ) is positioned in a non-machining region.
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FIELD OF THE INVENTION
1. FIELD OF THE INVENTION
[0001] My invention relates to games and more particularly to a sales-inducement business method provided by merchants for their customers to play for having charges paid by the customers for goods and services refunded by the merchant if the customers win the game.
BACKGROUND OF THE INVENTION
[0002] Most people like to gamble, even though a night of gambling usually ends by the gambler losing money, especially if the gambling is done in a professional gambling casino. People who like to gamble look for a way to gamble without losing money, but to date there is no such thing on the market.
SUMMARY OF THE INVENTION
[0003] My invention is a play-free game that is played at a cashier's counter in any commercial establishment such as a restaurant, motel or gasoline station where a person pays by cash or credit card for their meal, lodging or gasoline. Sitting on the cashier's counter is a miniature roulette wheel that is preferably mounted on an attractive teak frame about twelve inches in diameter.
[0004] The roulette wheel has a ball and 38 spherical depressions numbered 1 to 36 + 0 + 00 into one of which a spinning ball rests at the end of the game.
[0005] The game begins by the cashier's asking a customer who has paid for their goods or services if they would like to play a game that costs nothing, but if they win, the full amount of the charges they just paid except tax and tips would be refunded.
[0006] If the customer wants to play, as they usually do for a no-loss game, the customer calls out a number from 0 -to - 36 and vigorously turns the roulette wheel to spin the ball around a circular track until the ball slows and finally comes to rest in one of the 37 depressions. If the ball rests in the numbered depression called out by the customer, the customer is paid back in cash the amount of their bill less tax and tips or a voucher for the next visit. If the ball rests in any other depression, the customer loses, but it has cost him nothing to play.
BRIEF DESCRIPTION OF DRAWINGS
[0007] This invention is described by appended claims in relation to description of a preferred embodiment with reference to the following drawings which are explained briefly as follows:
[0008] [0008]FIG. 1 is a block diagram of the game business method:
[0009] [0009]FIG. 2 is a top view of a horizontal miniature roulette wheel for the gambling game;
[0010] [0010]FIG. 3 is a partially cutaway side view of the FIG. 2 illustration;
[0011] [0011]FIG. 4 is a front elevation view of a vertical miniature roulette wheel;
[0012] [0012]FIG. 5 is a partially cutaway side view of the FIG. 4 illustration; and
[0013] [0013]FIG. 6 is a partially cutaway top view of the FIG. 2 illustration with a slot-machine ball ejector.
DESCRIPTION OF PREFERRED EMBODIMENT
[0014] Listed numerically below with reference to the drawings are terms used to describe features of this invention. These terms and numbers assigned to them designate the same features throughout this description.
[0015] 1. Sale to customer
[0016] 2. Customer pays bill
[0017] 3. Merchant offers play
[0018] 4. Customer accepts
[0019] 5. Customer plays
[0020] 6. Customer wins
[0021] 7. Merchant refunds bill
[0022] 8. Customer loses
[0023] 9. No refund
[0024] 10. Merchant gains
[0025] 11. Customer declines
[0026] 12. No game
[0027] 13. Horizontal roulette wheel
[0028] 14. Horizontal roulette table
[0029] 15. Ball depression
[0030] 16. Roulette ball
[0031] 17. Ball rail
[0032] 18. Rotator handle
[0033] 19. Central shaft
[0034] 20. Ball ejector
[0035] 21. Vertical roulette wheel
[0036] 22. Vertical roulette table
[0037] 23. Sleeve ball depressions
[0038] 24. Horizontal sleeve
[0039] 25. Horizontal axis
[0040] 26. Transparent window
[0041] Referring to FIG. 1, this game business method is started when a merchant makes a sale of goods and/or services to a customer 1 , followed by the customer paying the bill as indicated by customer pays bill 2 . The merchant then makes an offer for the customer to play a game for refund of the paid bill as indicated by merchant offers play for refund 3 . Preferably, the game is an attractive miniature roulette game positioned convenient and obvious to the customer, preferably near a cash register, in order to tempt the customer to play it.
[0042] Usually, the customer accepts 4 and plays the game 5 . If the customer wins 6 , the merchant refunds the payment of the bill to the customer 7 . If the customer losses the game 8 , there is no refund 9 .
[0043] This is a win-win situation in that the merchant gains customer base with tax-deductible refund and game costs from either win or loss by the customer 10 . Even if the customer declines 11 and there is no game 12 , the merchant wins public favor and increased customer base for merely making the game available at a low cost which can be passed onto customers with their knowledge, acceptance and appreciation for making the win-win game available.
[0044] Referring to FIGS. 2 - 3 and 6 , the miniature roulette game can have a horizontal roulette wheel 13 that is rotatable centrally on a horizontal roulette table 14 having 37 or more ball depressions 15 placed circumferentially proximate an outside perimeter of the horizontal roulette wheel 13 . The ball depressions 15 are articulated to contain a bottom portion of a roulette ball 16 to be hurled radially from the ball depression 15 by rotation of the horizontal roulette wheel 13 at a predetermined speed of rotation.
[0045] The horizontal roulette table 14 is tapered predeterminedly downward and inward to proximate the outside perimeter of the horizontal roulette wheel 13 . The horizontal roulette wheel 13 is tapered predeterminedly downward and outward from a central position on the horizontal roulette wheel 13 to proximate the ball depressions 15 . The horizontal roulette wheel 13 is also tapered predeterminedly downward and inward from the outside perimeter of the horizontal roulette wheel 13 to the ball depressions 15 . The horizontal roulette table 14 has a ball rail 17 with a circumferential inside periphery having a height to prevent radial escape of the roulette ball 16 from being hurled from the ball rail 17 by the speed of the rotation of the horizontal roulette wheel 13 . Circumferentially intermediate the ball depressions 15 , the horizontal roulette wheel 13 is arched upwardly to prevent resting of the roulette ball 16 between the ball depressions 15 . A wheel rotator which can include a rotator handle 18 on a central shaft 19 is provided for rotating the horizontal roulette wheel 13 .
[0046] Referring to FIG. 6, the horizontal roulette table 14 can include a slot-machine ball ejector 20 to hurl the roulette ball 16 against the ball rail 17 in addition to or in lieu of rotation of the horizontal roulette wheel 13 .
[0047] Referring to FIGS. 4 - 5 , the miniature roulette game can have a vertical roulette wheel 21 that is rotational proximate a center of a vertical roulette table 22 . The vertical roulette wheel 21 has eleven or more sleeve ball depressions 23 in an inside periphery of a horizontal sleeve 24 that is concentrically outward radially from a horizontal axis 25 on which the vertical roulette wheel 21 is rotatable on the vertical roulette table 22 .
[0048] The sleeve ball depressions 23 are articulated to allow the roulette ball 16 to come to rest in a bottommost sleeve ball depression 23 when the vertical roulette wheel 21 is not rotating.
[0049] A transparent window 26 on a front end of the horizontal sleeve 24 provides visibility of the roulette ball 16 tumbling circumferentially in the horizontal sleeve 24 and coming to rest in a bottommost sleeve ball depression 23 when the vertical roulette wheel 21 is not rotating.
[0050] The roulette ball 16 for the vertical roulette wheel 21 is preferably a ball made of wood, plastic or metal.
[0051] The miniature-roulette game having the horizontal roulette wheel 13 is played by choosing a numbered ball depression 15 into which the roulette ball 16 will come to rest after the horizontal roulette wheel 13 stops rotating or when it is not rotating after only hurling or spinning the roulette ball 16 about the inside periphery of the ball rail 17 . In most cases, the horizontal roulette wheel 13 and the roulette ball 16 are rotated simultaneously. After waiting for the roulette ball 16 to come to a rest and it settles in a ball depression 15 , the customer wins only if the chosen ball depression is the one in which the roulette ball 16 comes to rest. Otherwise, the customer loses.
[0052] The miniature-roulette game having the vertical roulette wheel 21 is played by making a section of a number of the bottommost sleeve ball depression 23 in which the roulette ball 16 will come to rest after the vertical roulette wheel 21 is rotated and stops. A win results from resting of the roulette ball 16 in the chosen sleeve ball depression 23 .
[0053] The miniature roulette games having horizontal roulette wheels 13 and vertical roulette wheels 21 can both be played by merely rotating the respective roulette wheels 13 and 21 because the roulette ball 16 stops automatically in a ball depression 15 or sleeve ball depression 23 from which the roulette ball 16 is removed by rotation of the particular roulette wheel.
[0054] The rotator handle 18 shown in FIGS. 2 - 6 is optional to an electrical or other mechanical rotator. Either are foreseeable and intended.
[0055] Also intended and foreseeable is placement of the ball depressions 15 either radially inside of the numerals 1 -to- 36 or more on the horizontal roulette wheel 13 as shown in FIGS. 2 - 3 and 6 or outside next to its outside perimeter.
[0056] Preferably but not necessarily, the miniature roulette game will have a diameter of about a foot and the roulette balls 16 a size of approximately ½ inch..
[0057] The ball depressions 15 can have a depth of about twenty-five-to-100 percent of a diameter of the roulette balls 16 in order to allow the roulette balls 16 to be hurled from the ball depressions 15 by fast rotation of the horizontal roulette wheel 13 . This will be sufficient for some uses, but is not as reliable for achieving desired spin or fast travel of the roulette ball 16 against the ball rail 17 as by use of the ball ejector 20 shown in FIG. 6 or by hand throwing the roulette ball 16 tangentially against the ball rail 17 , either of which are intended and foreseeable options.
[0058] A new and useful game business method and device having been described, all such foreseeable modifications, adaptations, substitutions of equivalents, mathematical possibilities of combinations of parts, pluralities of parts, applications and forms thereof as described by the following claims and not precluded by prior art are included in this invention.
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A sales-inducement business method which preferably uses a roulette wheel provided by merchants for their customers to play for having charges paid by the customers for goods and services refunded by the merchant if the customers win the game. Described as preferred games are miniature roulette games having horizontal roulette wheels 13 rotatable in horizontal roulette tables 14 and optionally vertical roulette wheels 21 rotatable in vertical roulette tables 22.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 14/100,728, filed Dec. 9, 2013 now U.S. Pat. No. 8,821,629 B2; which is a continuation-in-part of U.S. patent application Ser. No. 13/832,753, filed Mar. 15, 2013 now U.S. Pat. No. 8,623,133; which is a continuation-in-part of U.S. patent application Ser. No. 13/563,902, filed Aug. 1, 2012 now U.S. Pat. No. 8,419,852; which is a continuation-in-part of U.S. patent application Ser. No. 13/330,763, filed Dec. 20, 2011, now U.S. Pat. No. 8,252,108 which is a continuation-in-part of U.S. patent application Ser. No. 13/168,412, filed Jun. 24, 2011, now U.S. Pat. No. 8,101,017 which is a continuation-in-part of U.S. patent application Ser. No. 12/945,941, filed Nov. 15, 2010, now U.S. Pat. No. 7,967,908.
This application is related to U.S. Pat. No. 7,468,102 titled, “LIGHT-WEIGHT COMPOSITION FOR MASONRY, MORTAR AND STUCCO,” inventor Jorge G. Chiappo.
FIELD OF THE INVENTION
This invention relates to the field of cement and more particularly to a light-weigh composition of pre-mixed cement mix and sand.
BACKGROUND OF THE INVENTION
Mortar and stucco normally consists of the combination of cement and sand in a ratio of approximately three (3) parts sand to one (1) part cement. Directions for specific brands of cement usually call for from 2.25:1 to 3:1 sand to cement ratios. The cement is generally mixed at the job-site in a gasoline or electric powered mortar mixers. Often, the sand is delivered in bulk, while the cement mix is delivered in bags weighing either 78 or 80 pounds. Due to the weight of the bags, they are often delivered on palates and lifted with fork lifts and/or cranes. One bag of cement mix is mixed with approximately three cubic feet of sand. Water is added to achieve a consistency that allows good workability. While the term sand is used throughout this disclosure for ease of discussion, those skilled in the art will recognize that sand may include other heavy aggregates, such as gravel, crushed stone and the like.
Pre-mixed mortar, stucco or masonry mix is a form of concrete that is pre-mixed at the manufacturing site and typically delivered to the job site in packages such as bags. The package (e.g. bag) contains a mixture of sand and concrete and, optionally, other aggregates. Typically, the pre-mixed mortar, stucco or masonry is used by adding water and applying to the job site.
The weight and volume of these bags of pre-mix mortar, stucco or masonry create several problems. During storage, the weight and volume relate to the total storage space required and the cost of transporting within the warehouse. During transportation, the volume and weight affect the total number of bags that fit within a given truck and the fuel consumption required to transport the bags to the construction site. At the construction site, the weight becomes more of an issue since individual bags are often lifted by a worker and many bags are lifted per day, the 78-80 pound bags cause fatigue and are the cause of many stress-related ailments. For home use, smaller bags (e.g. 60 pound bags) are often sold since many homeowners find it difficult to lift 80 pounds.
U.S. Pat. No. 5,718,758 to Breslauer recognizes that mortars of the prior art create problems due to weight, leading to worker injury during carrying of the mortar, etc.
Other cement compositions disclosed in U.S. Pat. No. 6,840,996 to Morioka, et al, U.S. Pat. No. 7,070,647 to Fujimori, et al, and U.S. Pat. No. 7,148,270 to Bowe describe various cement compositions, none of which provide a light-weight ready-mix composition.
U.S. Pat. No. 7,468,102 to Jorge G. Chiappo describes a light-weight cement mix, but not a pre-mixed composition comprising sand.
Existing pre-mixed compositions have a substantial effect on the environment. For example, in Florida alone, around 25 million bags of pre-mix were consumed in 2008, or approximately 1 million tons of material that had to be mined, shipped, hauled and used. By reducing the per-bag weight by 18 percent while producing an equivalent yield 820 million tons of material would be mined, shipped, hauled and used to create the same amount of finished product that previously contributed to 1 million tons of material that had to be mined, shipped, hauled and used. That means, 180M tons less in raw materials mined, significantly less transportation costs, less wear and tear on vehicles, less fossil fuel used in transportation, less structure for storage, reduced personal injury from strain, etc.
What is needed is a light-weight, pre-mixed mortar, stucco or masonry mix ready for adding water at the job site.
SUMMARY OF THE INVENTION
In one embodiment, a pre-mixed mortar, stucco or masonry composition is disclosed including from 70 to 80 percent sand and from 20 to 30 percent of a light-weight cement mix composition that comprises either slag cement, Gypsum or a combination of slag cement and gypsum; Portland cement; silicon dioxide; calcium stearate; and metakaolin.
In another embodiment, a pre-mixed mortar, stucco or masonry composition is disclosed comprising approximately 75 percent sand and approximately 25 percent of a light-weight cement mix composition that includes from 1 to 10 percent silicon dioxide; 0.5 to 2 percent calcium stearate; 1 to 10 percent metakaolin; up to 20 percent slag cement; and from 60 to 91 percent Portland cement.
In another embodiment, a pre-mixed mortar, stucco or masonry composition is disclosed comprising approximately 75 percent sand and approximately 25 percent of a light-weight cement mix composition that includes from 1 to 10 percent silicon dioxide by weight; 0.5 (½) to 1 percent calcium stearate by weight; 1 to 10 percent metakaolin by weight; up to 20 percent slag cement by weight; and up to 91 percent Portland cement by weight.
The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the presently preferred embodiments of the invention. Although the disclosed pre-mixed mortar, stucco or masonry mixture is ideal for use in masonry, mortar and stucco, there is no limitation to the application of the mortar, stucco or masonry mix of the present invention.
Prior to the present invention, pre-mixed mortar, stucco or masonry mix is typically delivered to the job site in bags weighing 78 or 80 pounds. The weight of these bags often causes stress and strain injuries to the workers. Additionally, transporting and storage of these bags utilizes more space and energy than is needed. The pre-mixed cement of the present invention provides the same resulting volume of cement with the strength and consistency of the prior art cement mixtures at a per-bag weight of approximately 65 pounds, saving energy and storage space and reducing worker stress and strain. Although 65 pound bags are used as an example, it is known and anticipated to produce the claimed product in any size bag or container including an 80 pound bag that will produce a greater resulting volume than an 80 pound bag of the prior art cement mixtures.
The mortar, stucco or masonry mix of the present invention is mixed with water as the prior mortar, stucco or masonry mixes. Mixing a 65 pound container of the pre-mixed cement mix of the present invention with water, results in a volume is similar to that of an 80 pound container of a pre-mixed cement mix of the prior art. Therefore, a 65 pound bag of the mortar, stucco or masonry mix of the present invention produces a similar amount (volume) of mortar, stucco or masonry when mixed with water as did an 80 pound bag of the prior art.
In some embodiments, the pre-mixed mortar, stucco or masonry mix of the present invention consists of approximately 75% sand and a light-weight cement mix composition of from 35% to 90% cement by weight (either slag cement, Portland cement or hydraulic cement), from 2% to 10% fly ash or hydrous magnesium sulfate by weight, from 1% to 3% sodium tall oil (e.g., a wood pulp by-product) by weight, from 1% to 2% sodium stearate by weight, from 1% to 2% sodium C 14-16 Alpha Olefin by weight, from 1% to 3% linear alkyl benzene by weight and from 10% to 20% silicon dioxide SiO 2 (also known as silica or silox) or fly ash by weight. Silicon dioxide SiO 2 is often derived from fly ash which is a byproduct of coal combustion. Fly ash also consists of aluminum oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ).
In some embodiments, the pre-mixed mortar, stucco or masonry mix of the present invention consists of approximately 75% sand and a light-weight cement mix composition of from 35% to 90% of either slag cement, Portland Cement and/or Gypsum, from 2% to 10% ground granulated blast furnace slag (GGBFS) by weight, from 1% to 3% sodium tall oil (e.g., a wood pulp by-product) by weight, from 1% to 2% sodium stearate by weight, from 1% to 2% sodium C 14-16 Alpha Olefin by weight, from 1% to 3% linear alkyl benzene by weight and from 10% to 20% silicon dioxide SiO 2 (also known as silica or silox) by weight. Silicon dioxide SiO 2 is often derived from fly ash which is a byproduct of coal combustion. Fly ash also consists of aluminum oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ).
In some embodiments, the pre-mixed mortar, stucco or masonry mix of the present invention consists of approximately 75% sand and a light-weight cement mix composition of from 60% to 91% of Portland Cement by weight, from zero to 20% Slag Cement by weight, from 4% to 20% ground plastic, preferably polystyrene by weight, from 0% to 20% Perlite or Mica by weight, and from 5% to 10% clay by weight.
In some embodiments, the pre-mixed mortar, stucco or masonry mix of the present invention consists of approximately 75% sand and a light-weight cement mix composition of up to 91% of Portland Cement, preferably from 60% to 91% of Portland Cement by weight, from zero to 20% Slag Cement by weight, from 1% to 10% silicon dioxide by weight, from 1% to 2% calcium stearate, and from 1% to 10% metakaolin by weight.
Although any type of clay is anticipated, a silicate material known as Kaolin is preferred, for example, AS 2 H 2 .
Although any type of plastic is anticipated, including, but not limited to, polystyrene, ABS, acrylic, fiberglass, latex powder, and vinyl acetate; polystyrene is preferred.
Although any form of polystyrene is anticipated, it is preferred that the polystyrene be in the form of a fine powder, between 75 to 375 mesh, preferably between 350 and 375 mesh. One method of producing polystyrene is a fine powder of around 350 to 375 mesh is by dry freezing the polystyrene, and pulverizing and/or grinding the polystyrene to an approximately 350-375 mesh. In some embodiments, the polystyrene is recycled polystyrene, such as from packing material.
When a 65 pound bag of pre-mixed cement mix of the present invention is mixed with aggregate and water, it produces, for example, a similar amount of product as a 78 or 80 pound bag of pre-mixed cement of the prior art. Therefore, less weight is transported to the job site, less strain is placed upon the workers, yet the same amount of resulting mix is derived. Equivalent and proportional results are achieved with smaller or larger sized bags or containers.
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.
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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A pre-mixed mortar, stucco or masonry composition includes from 70 to 80 percent sand and from 20 to 30 percent of a light-weight cement mix composition. The light-weight cement mix composition comprises either slag cement, gypsum or a combination of slag cement and gypsum; Portland cement; silicon dioxide; calcium stearate; and metakaolin.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic transmission having a planetary gear unit, in particular, a compact automatic transmission preferably applicable to a vehicle of front engine, front drive (F--F) type. More specifically, the invention relates to the structure of a planetary gear unit with improved steps between gear ratios of transmission ranges.
2. Description of the Prior Art
Hitherto the present applicant has invented an automatic transmission having a planetary gear unit comprising a combination of a simple planetary gear and a double pinion planetary gear as described in Japanese Patent Application Laid Open No. 62-93545 and 7-19297. As illustrated in FIGS. 6 and 8, a planetary gear unit 1 of the automatic transmission has a sun gear S and a carrier CR commonly provided for a simple planetary gear 2 and a double pinion planetary gear 3. A first pinion P1/P2 engages the sun gear S and comprises a long pinion common for the both gears 2 and 3 while a second pinion P3 of the double pinion gear 3 engages the first pinion P1/P2. An input shaft 7 rotated by motive power from an engine (not shown) transmitted via a torque converter 5 or a lock-up clutch 6 is coupled to a ring gear R1 of the simple planetary gear 2 via a forward (first) clutch C1 as well as to the sun gear S via a direct (second) clutch C2. Further, a counter drive gear 9 comprising the output portion of the gear unit is coupled to the carrier CR. The sun gear S can be stopped by a first brake B1 or can be stopped against reverse rotation via a second brake B2 and a first one-way clutch F1 permitting free rotation in the direction in which driving force/rotation is transmitted from the engine to the wheels (hereafter described as positive drive or positive rotational direction). The ring gear R2 of the double pinion planetary gear 3 is stopped against reverse rotation by a second one-way clutch F2 permitting free rotation in the positive drive or positive rotational direction and can be stopped against any rotation by a third brake B3.
As shown in the operation table of FIG. 7, a main transmission system 10' comprising the above-mentioned planetary gear unit 1 itself provides three forward gear ranges and one reverse gear range. In the first gear range or state (1ST), the forward clutch C1 is connected and the second one-way clutch F2 operates so as to prevent reverse rotation of the ring gear R2 of the double pinion planetary gear 3. In this state, rotation of the input shaft 7 is transmitted to the ring gear R1 of the simple planetary gear 2 via the forward clutch C1, and the ring gear R2 of the double pinion planetary gear is in the stopped state to set the orbiting speed of pinions P1/P2 and P3 to rotate the common carrier CR at a drastically reduced rate in the positive direction while the sun gear S idles in the reverse direction so as to obtain reduced rotational rate from the counter drive gear 9.
In the second gear range or state (2ND), the second brake B2 is operated in addition to the forward clutch C1 to switch one-way operation from the second one-way clutch F2 to the first one-way clutch F1. In this state, reverse rotation of the common sun gear S is stopped by the second brake B2 and the first one-way clutch F1, and thus rotation of the ring gear R1 of the simple planetary gear 2 is transmitted from the input shaft 7 via the forward clutch C1 and orbiting pinion P1/P2 to rotate the carrier CR in the positive direction at a reduced rate relative to the input shaft 7 while idling the ring gear R2 of the double pinion planetary gear in the positive direction so as to obtain a reduced rotational rate but which is greater than the rotational rate of the first gear range from the counter gear 9.
In the third gear range or state (3RD), the direct clutch C2 is engaged in addition to the forward clutch C1. In this state, rotation of the input shaft 7 is transmitted both to the common sun gear S as well as to the ring gear R1 so that the pinion P1/P2 of the simple planetary gear 2 and the carrier CR rotate integrally with the ring gear R1 and sun gear S to transmit lock-up rotation to the counter drive gear 9.
In the reverse gear range or state (REV), the direct clutch C2 and the third brake B3 are engaged. In this state, since rotation of the input shaft 7 is transmitted to the sun gear S via the direct clutch C2 and the ring gear R2 of the double pinion planetary gear is maintained in the stopped state by the third brake B3, the pinions P1/P2, P3 are orbited in the reverse direction to rotate the carrier CR in the reverse direction while the ring gear R1 of the simple planetary gear idles in the reverse direction so as to obtain reverse rotation from the counter gear 9.
As to the operation of the engine brake, the operating state is indicated by triangle marks (Δ) as shown in FIG. 7. In the first gear range or state, the third brake B3 is engaged and the ring gear R2 of the double pinion planetary gear is maintained in the stopped state to prevent forward rotation of the ring gear R2 otherwise permitted by the second one-way clutch F2 when the brake B3 is not engaged and the speed of the output gear exceeds the input speed reduced by the first gear ratio. In the second gear range or state, the first brake B1 is engaged and the common sun gear S is maintained in the stopped state to prevent forward rotation of the common sun gear S otherwise permitted by the one-way clutch F1 if the brake B1 is not engaged while brake B2 is engaged.
A gear ratio λ of the above-mentioned gear ranges can be calculated as follows with Z indicating the number of the teeth of the gear and a subscript indicating the gear range: as to the first range, λ 1 =1+(Z R2 /Z R1 ); as to the second range, λ 2 1+(Z S /Z R1 ); as to the third range, λ 3 =1; and as to the reverse range, λ R =1-(Z R2 /Z S ).
In an automatic transmission system 10' comprising the above-mentioned planetary gear unit 1, torque from the input shaft 7 is transmitted to the ring gear R1 which has a diameter larger than that of the sun gear S; thus, the tangential force applied to the engaged portion of the pinion P1/P2 is smaller compared with the case in which input torque is applied through the sun gear such as a gear unit of a Ravigneaux type, so that bearing and bending stresses acting upon the engaged portions of the gears are smaller. Accordingly, the automatic transmission of FIGS. 6-8 enables obtaining sufficient durability without broadening the width of the teeth. Additionally, the need for an additional motive power transmitting member between the two planetary gears is eliminated since the sun gear is common to both the simple and double planetary gears and the carriers are integrally coupled to each other, consequently reducing the axial dimension to achieve a more compact structure.
On the other hand, the gear ratio λ 2 of the second gear range (2ND) in the above-mentioned planetary gear unit 1 is determined by the number of teeth of the sun gear S and the ring gear R1 of the simple planetary gear 2, that is, λ 2 =1+(Z S /Z R1 ). Accordingly, a smaller number of teeth of the sun gear S, that is, a smaller diameter of the sun gear, or a larger number of teeth of the ring gear R1, that is, a larger diameter of the ring gear is required in order to obtain a second range gear ratio λ 2 of a smaller value. However, a smaller diameter of the sun gear cannot be achieved since the input shaft passes through the inner diameter of the sun gear. Further a larger diameter of the ring gear R1 would enlarge the radial dimension of the automatic transmission and thus decrease the compactness thereof. Therefore, in the above-mentioned prior art, the gear ratio in the second range is comparatively large so as to achieve a compact structure of the planetary gear unit.
In the third gear range or state (3RD), since the planetary gear unit rotates integrally, the gear ratio λ 3 is equal to 1.0, and the setting cannot be changed, the proportion of the gear ratio λ 2 to the gear ratio λ 3 (λ 2 /λ 3 ), which will be described hereafter as the gear ratio step between the second range and the third range, becomes larger if the gear ratio λ 2 is comparatively large as mentioned above. In general, a large gear ratio step between two high gear ranges may cause so-called "busy shift", i.e., frequent shifting while driving at a high speed.
That is, when a moderate uphill slope is encountered while driving at a high speed in the third range and the third gear range cannot provide a sufficient motive power, the vehicle slows down so that a shift-down to the second gear range becomes necessary in order to maintain the high speed driving. With a large gear ratio step as in the prior art, the second gear range has a motive power state larger than the motive power sufficient to achieve the high speed driving of the vehicle. Then the vehicle speeds up to a certain high speed driving state causing a shift up to the third range. However as mentioned above, the third range provides insufficient motive power as mentioned above to maintain a certain high speed driving and a down shift to the second range occurs. By repeating such operations, the busy shift occurs.
On the contrary, it would be desirable to have a small gear ratio step so that the motive power does not increase as much as in the above-mentioned prior art when a down shift to the second gear range is carried out and so that the motive power in the second gear range is only sufficient to maintain a certain high speed driving without an increase to a higher speed state so as to avoid an up shift to the third gear range; thus, the above-mentioned busy shift can be prevented and smooth driving of the vehicle can be obtained.
SUMMARY OF THE INVENTION
Therefore a first object of the present invention is to provide a compact automatic transmission which achieves a smaller gear ratio step when shifting between higher gear ranges to prevent busy shift while driving at a high speed to ensure smooth driving of the vehicle.
A second object of the present invention is to provide an automatic transmission wherein the gear ratio relationship between the first range and the reverse range is not ruined by reducing the gear ratio step between higher gear ranges.
The above-mentioned problems are solved by the present invention summarized in an automatic transmission having a planetary gear unit with a plurality of gear states connecting an input member to an output member wherein the planetary gear unit includes first and second planetary pinions wherein the first pinion has a diameter smaller than the second pinion and the first and second pinions are connected so as to rotate integrally. The first pinion engages a first ring gear while the second pinion engages a third pinion which in turn engages a second ring gear. A first sun gear engages the second pinion. A carrier is connected to the output member and supports the first, second and third pinions. A first gear range of the planetary gear unit is achieved by transmitting rotation of the input member to the first ring gear and by stopping the second ring gear. A second gear range is achieved by transmitting rotation of the input member to the first ring gear and by stopping the first sun gear. A third gear range is achieved by rotating the planetary gear unit integrally with the input member.
In a further aspect, the planetary gear unit further includes a second sun gear engaging the first pinion and which can rotate relatively with respect to the first sun gear. A reverse range is achieved by transmitting rotation of the input member to the second sun gear and by stopping the second ring gear.
In a still further aspect the transmission achieves its gear states by including a first clutch interposed between the input member and the first ring gear, a second clutch interposed between the input member and the second sun gear, a first device capable of selectively stopping the first sun gear, and a second device capable of selectively stopping the second ring gear.
In a further embodiment there is provided a sub-automatic transmission system having three forward ranges. The combination of the sub-automatic transmission system with the above-mentioned automatic transmission system achieves five forward ranges and one backward range.
According to the above-mentioned construction in forward gear states, torque from the input member is transmitted to the first ring gear of the planetary gear unit which is selectively set to one of a plurality of the gear ratios to determine the transmission ratio. The torque is transmitted via the carrier to the output member.
In the second gear range or state with the first pinion having a diameter smaller than that of the second pinion and with the first and second pinions being coupled integrally together, the gear ratio (λ 2 ) of the second range can be described as 1+(Z S2 /Z R1 )×(Z P1 /Z P2 ) with Z indicating the number of teeth of each gear. As (Z P1 /Z P2 ) is made less than 1, the gear ratio is made smaller without enlarging the diameter of the first ring gear drastically (i.e., without enlarging Z R1 ).
In the third gear range or state with the planetary gear unit rotating integrally, the gear ratio is equal to 1.0. As the above-mentioned gear ratio of the second gear range becomes smaller, the gear ratio step between the second range and the third range becomes smaller.
The first range gear ratio (λ 1 ) can be described as 1+(Z R2 /Z R1 )×(Z P1 /Z P2 ) which is smaller compared with the prior art because of the multiplication by (Z P1 /Z P2 ) which is less than 1.0. Further, the reverse range gear ratio (λ R ) can be described as 1-(Z R2 /Z S1 )×(Z P1 /Z P2 ), the absolute value of which is similarly smaller because of the multiplication by (Z P1 /Z P2 ) which is less than 1.0. Since a smaller diameter of the first pinion results in a larger second sun gear (that is, Z S1 becomes larger), (Z R2 /Z S1 ) becomes smaller, further making the reverse range gear ratio (λ R ) smaller.
Accordingly, in general, the smaller a gear ratio difference between the lowest forward range and the reverse range is, the more controllable the automatic transmission becomes. As mentioned above, by making the gear ratio step smaller between higher gear ranges, a first range gear ratio, which is the lowest forward range gear ratio, becomes smaller. Therefore, the absolute value of the reverse range gear ratio step becomes smaller.
Further, although the gear ratio width becomes smaller by making the gear ratio step smaller between higher gear ranges, a gear ratio of sufficient width can be ensured as a whole by providing five forward ranges with a sub-transmission system having three forward ranges. Thus a desirable gear ratio step is obtained in the entire automatic transmission from the lowest range to the highest range.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating an automatic transmission system of the present invention.
FIG. 2 is a sectional view of the automatic transmission system as shown in FIG. 1.
FIG. 3 is a table showing the operation of the automatic transmission system of FIG. 1.
FIG. 4 is a schematic diagram illustrating an automatic transmission having five forward ranges and one reverse range according to the present invention.
FIG. 5 is a table showing the operation of the automatic transmission of FIG. 4.
FIG. 6 is a schematic diagram illustrating an automatic transmission system of the prior art.
FIG. 7 is a table showing the operation of the automatic transmission system of FIG. 6.
FIG. 8 is a sectional view of the automatic transmission system of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
A main automatic transmission system 10 according to one embodiment of the present invention is illustrated in FIGS. 1 and 2 and is aligned with an engine output shaft. The transmission 10 has an input shaft 7 to which the engine motive power is transmitted via a torque converter 5 having a lock-up clutch 6. On the input shaft 7, there are arranged in order from an oil pump 11 adjacent to the torque converter 5 to the axial rear end, a brake portion 12, an output portion 13, a planetary gear unit portion 1 and a clutch portion 16. These portions are enclosed by an axle case 17 and a rear cover 19 integrally joined.
The planetary gear unit portion 1 comprises a simple planetary gear 2 and a double pinion planetary gear 3. The simple planetary gear 2 comprises a (second) sun gear S1, a first ring gear R1, and a carrier CR supporting a first pinion P1 engaging the gears S1, R1, while the double pinion planetary gear 3 comprises a (first) sun gear S2, a second ring gear R2, a second pinion P2 in engagement with the sun gear S1 and a third pinion P3 in engagement with the ring gear R2 wherein the carrier CR supports the pinions P2, P3 in such a manner that both the pinions P2, P3 are in mutual engagement. The sun gear S1 of the simple planetary gear 2 and the sun gear S2 of the double pinion planetary gear 3 are rotatably supported respectively by the first and second hollow shafts 20, 21 which in turn are supported by the input shaft 7. A thrust bearing 22 is interposed between the both hollow shafts 20, 21 to allow the both shafts 20, 21 to rotate relative to each other. The carrier CR is provided for the both planetary gears 2, 3 in common, the above-mentioned first pinion P1 and the second pinion P2 engaging the sun gears S1, S2 respectively are connected so as to rotate integrally, and the first pinion P1 has a diameter smaller than that of the second pinion P2, namely, a smaller number of teeth Z P1 . Accordingly, the sun gear S1 of the simple planetary gear 2 engaging the first pinion P1 has a diameter larger than that of the sun gear S2 of the double pinion planetary gear 3 engaging the second pinion P2, that is, (Z S1 >Z S2 ).
In the brake portion 12, a first one-way clutch F1, a first brake B1 and a second brake B2 are arranged in order from the radially inner side to the radially outer side. Further hydraulic servos 25, 26 for operating the respective brakes B1, B2 are arranged parallel in the radial direction and are provided adjacent to the brakes B1, B2 respectively in a case 17a which is integrally coupled to the case enclosing the oil pump 11. The first brake B1 is interposed between a flange portion 21a at the edge of the second hollow shaft 21 and an edge portion extending from the pump case 17a. The second brake B2 is arranged between a flange portion 27 extending from an outer race of the first one-way clutch F1 and an edge portion extending from the pump case 17a. The first one-way clutch F1 is arranged between the second hollow shaft 21 and the second brake B2.
The output portion 13 has a counter drive gear 9 supported by bearings 29 on a partition 17b formed on the axle case 17, and the gear 9 is coupled to the carrier CR via a spline. Further, an outer race portion of the bearings 29 extending axially is non-rotatably fixed to the partition 17b. A second one-way clutch F2 is interposed between the fixed extending race portion of the bearing 29 and a coupling portion for coupling the one-way clutch F2 integrally to the ring gear R2 of the double pinion planetary gear 3. Further, a third brake B3 is interposed between the outer periphery of the ring gear R2 and the axle case 17. A hydraulic servo 30 is arranged on one side of the partition 17b and has a piston axially extending like teeth of a comb to control the third brake B3 with a return spring 31 arranged in the teeth-of-a-comb portion.
The clutch portion 16 comprises a forward clutch C1 and a direct clutch C2 located at the edge of the main automatic transmission system 10 extending into a trans-axle rear cover 19 which forms a portion of an integral case. Further, a flange portion 7a is coupled integrally to the input shaft 7 and rotatably mounted on a boss portion 19a formed on the cover 19 for rotatably supporting one end of the input shaft 7. A movable member 32 is fitted in the flange portion 7a, and further, a movable piston member 33 is fitted in the movable member 32. The movable member 32 forms a piston for an oil chamber 35 formed between the peripheral portion of the member 32 and the flange portion 7a. The outer peripheral portion of the movable member 32 is coupled to the flange portion 7a to prevent relative rotation and is opposed to the forward clutch C1 with a slight gap therebetween to form a hydraulic servo for the forward clutch C1. Within the member 32, an oil chamber 36 is formed between the piston portion 33 and the movable member 32. The other side of the piston portion 33 is opposed to the direct clutch C2 to form a hydraulic servo for the direct clutch C2. Further, a spring 39 is located between the piston member 33 and a ring 37 bonded to the input shaft 7 in a compressed state, the spring 39 comprises a return spring commonly provided for the piston members 32, 33 of both hydraulic servos. The forward clutch C1 is interposed between the inner periphery of the radially outer portion of the flange portion 7a and the outer periphery of the ring gear R1 of the simple planetary gear 2, and the direct clutch C2 is interposed between the inner periphery of the movable member 32 and the flange portion 20a connected to the edge of the first hollow shaft 20.
The above-mentioned automatic main transmission system 10 operates in accordance with the operation table as shown in FIG. 3.
In the first gear range or state (1ST), the forward clutch C1 is connected, and the second one-way clutch F2 operates to hold the ring gear R2 of the double pinion planetary gear 3 stopped against reverse rotation. In this state, since rotation of the input shaft 7 is transmitted to the ring gear R1 of the simple planetary gear 2 via the forward clutch C1 and since the ring gear R2 of the double pinion planetary gear 3 is stopped against reverse rotation, the carrier CR rotates at a drastically reduced rate while idling both sun gears S1, S2 in the reverse direction, and the reduced rotation is output by the counter drive gear 9. The gear ratio λ 1 in the first range state can be described (with Z indicating the number of the teeth of each gear) as 1+(Z R2 /Z R1 )×(Z P1 /Z P2 ), which in one example produces a value of 2.07.
In the second gear range or state (2ND), the second brake B2 is in operation in addition to the forward clutch C1 to switch operation from the second one-way clutch F2 to the first one-way clutch F1. In this state, the sun gear S2 of the double pinion planetary gear 3 is stopped against reverse rotation by the second brake B2 and the one-way clutch F1. Thus, rotation of the ring gear R1 of the simple planetary gear 2 transmitted from the input shaft 7 via the forward clutch C1 causes the carrier CR to rotate at a reduced rate in the positive direction while idling the ring gear R2 of the double pinion planetary gear 3 and the sun gear S1 of the simple planetary gear 2 in the positive direction. As a result, the reduced rotation is output by the counter gear 9. The gear ratio λ 2 in the second range state can be described as 1+(Z S2 /Z R1 )×(Z P1 /Z P2 ), which in the one example produces a value of 1.30. In this case, since the first pinion P1 has a diameter smaller than that of the second pinion P2 (Z P1 <Z P2 ) and both pinions rotate integrally, the gear ratio λ 2 can be made smaller than the second gear ratio of the prior art without enlarging the diameter of the ring gear R1 of the simple planetary gear 2 (the number of teeth Z R1 ) because of the multiplication by the term (Z P1 /Z P2 ), which is less than one.
In the third gear range or state (3RD), the direct clutch C2 is engaged in addition to the forward clutch C1. In this state, rotation of the input shaft 7 is transmitted to the sun gear S1 as well as to the ring gear R1 of the simple planetary gear 2, causing the gear unit 1 comprising the single and double pinion planetary gears 2, 3 to rotate integrally so that the lock-up rotation is transmitted to the counter drive gear 9 producing a gear ratio λ 3 equal to 1. Since the above-mentioned second range gear ratio λ 2 is smaller than in the prior art, the gear ratio step between the second range and the third range becomes smaller accordingly. The example value of the gear ratio step in this case is 1.3, which is smaller than 1.4, a step value in a conventional transmission. Thus, while holding the enlargement of the diameter of the simple planetary gear 2 at the minimal level, the gear ratio step between the two highest gear ranges can be made smaller.
In the reverse gear or state (REV), the direct clutch C2 and the third brake B3 are engaged. In this state rotation of the input shaft 7 is transmitted to the sun gear S1 of the simple planetary gear 2 via the direct clutch C2 and the ring gear R2 of the double pinion planetary gear 3 is stopped by the third brake B3 to idle the ring gear R1 of the simple planetary gear 2 in the reverse direction and the sun gear S2 of the double pinion planetary gear 3 in the positive direction and to rotate the carrier CR in the reverse direction. Thus, the reverse rotation is output by the counter gear 9. The gear ratio λ R in the reverse range state can be described as 1-(Z R2 /Z S1 )×(Z P1 /Z P2 ), which in the example produces a value of -1.41.
In general, it is preferable in terms of controllability that the reverse gear range ratio should be equivalent to or less than the first gear ratio. (Since the reverse gear ratio is negative, the comparison should be made as to their absolute values). Since the above-mentioned first gear ratio λ 1 described as 1+(Z R2 /Z R1 )×(Z P1 /Z P2 ) includes multiplication by the term (Z P1 /Z P2 ) which is smaller than 1.0, it becomes smaller than the first gear ratio in the prior art. Accordingly, if rotation is input to the sun gear S2 of the double pinion planetary gear 3 during driving in REV as in the prior art, the gear ratio is described as 1-(Z R2 /Z S2 ). Since the first range gear ratio has become smaller because of the term (Z P1 /Z P2 ), the above-mentioned relationship between the first range gear ratio and the reverse range gear ratio is not maintained.
Therefore, by separating the sun gears S1, S2 of the both planetary gears 2, 3 from each other and inputting rotation to the sun gear S1 of the simple planetary gear 2 while driving in reverse, the absolute value of the reverse range gear ratio λ R , as well as the first gear ratio, can be made smaller owing to the above-mentioned multiplication by (Z P1 /Z P2 ), which is smaller than 1.0. Further, since the sun gear S1 of the simple planetary gear 2 can be formed larger by providing a first pinion P1 with a smaller diameter, (Z R2 /Z S1 ) becomes smaller, further making the reverse range gear ratio smaller.
The operating state of the engine brake is denoted by triangle marks as shown in FIG. 3. That is, in the first gear range or state, the third brake B3 is engaged and the ring gear R2 of the double pinion planetary gear 3 is maintained in the stopped state. If the third brake is released, the ring gear R2 can be rotated in the positive direction by the transmission output rotation driven by the vehicle motion exceeding the output rotation produced by operation of the second one-way clutch F2. In the second range state, the first brake B1 is engaged and the sun gear S2 of the double planetary gear 3 is maintained in the stopped state. If the brake B1 is not engaged, the sun gear S2 permitted to rotate in the forward direction by the first one-way clutch F1.
As illustrated in another embodiment in FIG. 4, a five forward gear range automatic transmission U in accordance with the invention is formed by combining the above main automatic transmission system 10 and a three range sub-transmission system 40.
The sub-transmission system 40 is arranged on a second shaft (under-drive shaft) 43 located parallel to the first (input) shaft 7. When viewed from their ends, the first and second shafts along with a third shaft position occupied by differential shafts (left and right axles) 45l, 45r form a triangle-like configuration. The sub-transmission system 40 comprises first and second simple planetary gear arrangements 41, 42 including respective carriers CR3, CR4, a ring gear R4 of the second simple planetary gear 42 connected integrally with the carrier CR3 of the first simple planetary gear 41, and sun gears S3, S4 coupled integrally to form a Simpson type gear line. Further, the ring gear R3 of the first simple planetary gear 41 is connected to a counter driven gear 46 meshing with the counter gear 9 to form an input portion to the sub-transmission system, and the carrier CR3 of the first single planetary gear 41 and the ring gear R4 of the second simple planetary gear 42 are coupled to a reduction gear 47, which provides an output portion. Further, an under-drive (UD) direct clutch C3 is interposed between the carrier CR3 of the first planetary gear 41 and the integral sun gears S3, S4, and the integral sun gear S3, S4 can be selectively stopped by the fourth brake B4, while the carrier CR4 of the second single planetary gear 42 can be selectively stopped by the fifth brake B5. Accordingly, the sub-transmission system 5 can provide three forward ranges.
A differential device 50 in the third corner of the triangular configuration is provided with a differential case 51 on which is fixed a gear 52 engaging the above-mentioned reduction gear 47. Differential gears 53 and left and right side gears 55, 56 are mutually engaged and rotatably supported inside the differential case 51 with the left and right axles 45l, 45r arranged to extend from the left and right side gears 55, 56. Accordingly, rotation from the gear 52 is distributed to the left and right wheels via the left and right axles 45l, 45r according to the loaded torque applied to the wheels.
Operation of the five range automatic transmission U is explained with reference to the operation table as shown in FIG. 5. In the first gear range or state (1ST), the forward clutch C1, the second one-way clutch F2 and the fifth brake B5 are engaged. Accordingly, the main transmission system 10 is brought into the first gear range or state, and the reduced rotational rate is transmitted to the ring gear R3 of the first simple planetary gear 41 in the sub-transmission system 40 via the counter gears 9, 46. The sub-transmission system 40 is in its first gear range or state with the carrier CR4 of the second simple planetary gear 42 stopped by the fifth brake B5, and the above-mentioned reduced rotational rate of the main transmission system 10 is further reduced by the sub-transmission system 40 to be transmitted to the axles 45l, 45r via the gears 47, 52 and the differential device 50.
In the second gear range or state (2ND), the second brake B2 is engaged in addition to the forward clutch C1, and operation is switched from the second one-way clutch F2 to the first one-way clutch F1 smoothly. Then, the main transmission system 10 is brought into the second range state as mentioned above. Further, the sub-transmission system 40 is in its first gear range or state owing to the engagement of the fifth brake B5, and the combination of the second gear range or state or the main transmission system 10 and the first gear range or state of the sub-transmission system 40 provides the second gear range or state in the automatic transmission U as a whole.
In the third gear range or state (3RD), the main transmission system 10 is in its second gear range or state with the forward clutch C1, the second brake B2 and the first one-way clutch F1 engaged, and the sub-transmission system 40 is in its second gear range or state with the fourth brake B4 in engagement. Then, the sun gears S3, S4 of the first and second simple planetary gears 41, 42 are fixed, and rotation from the ring gear R3 of the first simple planetary gear 41 is output from the carrier CR3 as the second range rotation. As a result, the combination of the second gear range or state in the main transmission system 10 and the second gear range or state in the sub-transmission system 40 provides the third gear range or state in the automatic transmission U as a whole.
In the fourth gear range or state (4TH), the main transmission system 10 is in its second range with the forward clutch C1, the second brake B2 and the first one-way clutch F1 engaged, and the sub-transmission system 40 is in its third gear range or state with the fourth brake B4 released and the UD direct clutch C3 engaged. In this state, the clutch C3 locks the carrier CR3 to the sun gears S3, S4 which in turn locks the ring gear R3 of the first simple planetary gear 41 and to the carrier CR3 and output gear 47 to provide lock-up rotation, namely, to cause both planetary gears 41, 42 to rotate integrally. Accordingly, the combination of the second gear range or state in the main transmission system 10 and the lock-up or third state of the sub-transmission system 40 provides the fourth gear range or state in the automatic transmission U as a whole.
In the fifth gear range or state (5TH), the forward clutch C1 and the direct clutch C2 are engaged, and rotation of the input shaft 7 is transmitted to the ring gear R1 of the simple planetary gear and the sun gear S1 so that the main transmission system 10 is brought into its lock-up or third state, causing the gear unit 1 to rotate integrally. Further, the sub-transmission system 40 is also in its lock-up or third state with the UD direct clutch C3 engaged. Thus, the combination of the third gear range or state (lock-up) of the main transmission system 10 and the third gear range or state (lock-up) of the sub-transmission system 40 provides the fifth range gear range or state in the automatic transmission U as a whole.
In the reverse gear range or state (REV), the direct clutch C2 and the third brake B3 are engaged as well as the fifth brake B5 is engaged. In this state, in the main transmission system 10, reverse rotation is output as mentioned above. In the sub-transmission system 40, the carrier CR4 of the second planetary gear 42 is stopped by the engagement of the fifth brake B5 and the sub-transmission system 40 is maintained in its first gear range or state. Accordingly, the combination of the reverse rotation of the main transmission system 10 and the first gear range of the sub-transmission system 40 provides reduced rotational output in the reverse direction.
In FIG. 5, as in FIG. 3, the operating state of the engine brake is denoted by triangle marks. That is, in the first range state, the third brake B3 is engaged to fix the ring gear R2 of the double pinion planetary gear 42 instead of the second one-way clutch F2. In the second, third, and fourth range states, the first brake B1 is engaged to fix the sun gear S2 of the double pinion planetary gear 42 instead of the first one-way clutch F1.
Since the fourth and fifth range gear ratio steps are obtained by shifting the main transmission system 10 between its second and third gear ranges, gear ratio steps as shown in FIG. 5 are small as mentioned above, and a smaller gear ratio step between higher gear ranges provides a small gear ratio width. However, by compensating such gear ratio width with the combination of the sub-transmission system 40 which increases the number of forward gear ranges up to five, a desirable gear ratio steps are maintained from the lowest gear range to the highest gear range in the automatic transmission U as a whole. Gear ratios and steps are not limited to the values as shown in the Tables, but can be adjusted within any desired range.
The planetary gear unit does not need to include the sun gear S1 (the second sun gear) of the simple planetary gear if the above-mentioned desirable gear ratio can be disregarded for driving in reverse. In this case, the direct clutch C2 is interposed between the input shaft 7 and the sun gear S2 (the first sun gear) of the double pinion planetary gear so that rotation is input to the sun gear S2 during reverse driving.
The sub-transmission system is not limited to the above-mentioned Simpson type but can be realized in the form of a different shifting gear system. Also, it is not limited to those providing three forward ranges but can be realized in the form of a sub-transmission system providing two forward ranges in combination with the main automatic transmission system, thus achieving a four range automatic transmission as a whole. Further it is also possible to provide a sub-transmission system exclusively for reduction.
As heretofore mentioned, since the carrier is connected to the output member and torque from the input member is input to the first ring gear in driving forward, a compact structure can be achieved as in the prior art. On the other hand, a smooth driving of the vehicle can be realized without causing busy shift in driving at a high speed by providing a small gear ratio step at a higher range side based on the structure that a first pinion has a diameter smaller than that of a second pinion having a small gear ratio in the second range state.
Further, in spite of the fact that the gear ratio in the first range state becomes smaller by providing a smaller gear ratio in the second range state and since torque from the input member is input to the second sun gear in the reverse range state, the first and second sun gears can be separated from each other to allow relative rotation thereof and the reverse range gear ratio can be set at a small value. Thus the gear ratio relationship between the first range and the reverse range is not ruined so as not to deteriorate controllability.
Further, by achieving an automatic transmission providing five forward ranges and one backward range as a whole by using a combination with a sub-transmission system having three forward ranges, a smaller gear ratio step is obtained between the higher gear ranges as mentioned above. Thus, the entire gear ratio steps can be improved, compensating for gear ratio widths which are too small.
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Smooth driving of a vehicle is achieved by eliminating busy shift by providing a small gear ratio step between the two highest gear ranges while maintaining structural compactness of the transmission. In the second highest gear range or state, a first pinion P1 has a diameter smaller than that of a second pinion P2, both pinions P1 and P2 being coupled integrally and at least partially determining the second highest gear ratio. The gear ratio λ 2 in the second highest gear range is described as 1+(Z S2 /Z R1 )×(Z P1 /Z P2 ). Since (Z P1 /Z P2 ) is always equal to 1.0 or less, the gear ratio can be made smaller without enlarging the diameter of the ring gear R1 significantly to decrease the gear ratio step to the highest gear range.
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BACKGROUND OF THE INVENTION
This invention relates generally to the construction environment and more particularly to a construction process to simulate a desirable appearance, particularly stone.
Methods for simulating a desirable appearance are common in the area of construction. A simulated surface that has the appearance of a natural solid medium is much less expensive and is often more practical. The prior art has therefore disclosed various methods of simulating a desirable appearance, especially to simulate a natural stone appearance.
U.S. Pat. No. 2,618,815 discloses a method for applying a plaster or cement coating to a wall by using a stone-shaped mold coated on its interior with a waxy solution and using small stone or stone-like particles. U.S. Pat. No. 2,810,180 also discloses a mold for applying stone-like materials to a wall. U.S. Pat. No. 4,146,599 discloses a method for applying exposed aggregate comprising loading the aggregate on a resilient facing material.
While all of these prior art techniques perform well for their intended purpose, room exists for further improvement in the art.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a novel construction process to simulate a desirable appearance.
It is another object of the present invention to provide such a construction process that simulates the appearance of a solid stone structure with a natural weathered appearance.
It is still another object of the present invention to provide a building structure simulating the appearance of a weathered stone structure.
These as well as other objects are accomplished by a construction process utilizing a construction frame to support an external facade, affixing a construction medium simulating the appearance of a solid stone to the construction frame, and then applying stucco around the construction medium and to the construction frame to give the appearance of the construction medium having been exposed due to the natural weathering of the stucco.
Other objects and a fuller understanding of the invention will become apparent from the following description given with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a house having corners with a surface section, of a construction medium simulating the appearance or solid stone affixed thereto.
FIG. 2 is a perspective view of a construction frame having a surface section of a construction medium simulating the appearance of solid stone affixed thereto in accordance with this invention.
DETAILED DESCRIPTION
In accordance with this invention it has been found that a construction process can be provided which produces a structure simulating a desired appearance. It has also been found that such a construction process can produce a structure simulating the appearance of a solid stone structure with a weathered appearance. Further advantages and features will become apparent from a reading of the following description given with reference to the various figures of drawing.
FIG. 1 is a perspective view of a house with corners 10 having the appearance of weathered solid stone resulting from the construction process according to the present invention. As shown, the corners 10 comprise an exposed area of a construction medium 12 which simulates the appearance of solid stone. The construction medium 12 is affixed to and supported by a construction frame (not shown). Stucco 14 is shown applied around the construction medium 12 and to the construction frame to give the appearance of the construction medium 12 being exposed due to natural weathering of the stucco 14. This construction process is particularly suitable for corners 10, as illustrated in FIG. 1, but would also be appropriate on flat surfaces adjacent to doors, windows or other architectural features where investigation reveals that natural weathering and subsequent peeling of stucco to reveal underlying construction material would be most likely to occur.
As seen in FIG. 2, the construction process in accordance with this invention includes the use of a construction frame 16. This construction process also includes placement of a surface section of a solid stone-simulating construction medium 12 simulating the appearance of solid stone to the construction frame 16. In a preferred embodiment, coquina is used as the construction medium 12. Construction frame 16 can be constructed of various conventional materials such as lumber, plywood, durock or particle board. The surface section of a construction medium simulating the appearance of solid stone can be applied by use of a man-made backing such as fiberglass to form an exposed area or areas of stone-simulating structure. FIG. 2 illustrates only one assembly of a construction frame 16 with a construction medium 12 affixed to it. It is also contemplated within this invention that various shapes of construction frames 16 can be used, and various methods for affixing a construction medium 12 to a construction frame 16 may be utilized.
The construction process in accordance with this invention comprises providing a construction frame 16 (shown in FIG. 2) and affixing a surface section of a construction medium 12 simulating the appearance of solid stone to the construction frame 16. Referring to figure stucco 14 is then applied around the construction medium 12 without totally covering the construction medium 12. This gives the appearance of the construction medium 12 being exposed due to the natural weathering of the stucco 14. This produces a structure 10 that has every outward appearance of being constructed of solid stone and being naturally weathered. The corners 10 are an example of only one shape and size, as this construction process can provide structures of various sizes and shapes which can be used as building structures.
It is thus seen that the invention provides a novel construction process for simulating a desirable appearance. It is further seen that the present invention provides a construction process for simulating the appearance of a stone structure with a natural weathered appearance. The construction process according to this invention also produces such a structure which can be used as a building structure for construction. Many variations are apparent to those of skill in the art, and such variations are embodied within the spirit and scope of the present invention as measured by the following appended claims.
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A construction process and product thereof are provided which include affixing a construction medium simulating the appearance of solid stone to a construction frame to simulate a desirable appearance.
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BACKGROUND OF THE INVENTION
The present invention relates to drilling apparatus and more particularly to mechanism for vibrating the core receiving tube as the drill string is being rotated.
At times, during core drilling operation, greater resistance to the core receiving tube slipping axially inwardly along the core as the cut is being cut is encountered than is desirable. Also, at times, during core drilling operation and more particularly when drilling in broken earth formations and sandy and/or gravel type formations, the core will become more packed along the inner peripheral wall of the core receiving tube than at the radial central part of the tube and/or the radial outer part of the tube will fill up while the central part of the tube is not filled.
U.S. Pat. No. 4,279,315 to Tibussek discloses a wire line core barrel inner tube assembly that includes a latch body mounting latches for movement into a latch seat to retain said assembly adjacent to the drill bit, and clutch dogs movable into grooves in the drill string to rotate the latch body with the drill string. The latch body is rotatable relative to the core receiving tube and as the latch body rotates, a hammer strikes an anvil to impart striking force that is applied to the core receiving tube.
U.S. Pat. No. 3,194,326 to Bodine discloses a coring tool for obtaining a core underwater and subjecting the tube to sonic vibrations for providing a force that, during the half cycle of elastic elongation of the elastic stem, results in the core receiving tube moving downwardly in the earth formation. Herbold, U.S. Pat. No. 3,049,185, discloses a link pivotally connected between spaced magnetic disks and the core receiving tube. The magnetic disks are magnetically attached to the radial inner surface of a drilling tube to be eccentric to the central axis of the drilling tube and are rotated to generate centrifugal forces that are said to decrease frictional resistance to drilling.
In order to make improvements in core drilling apparatus to facilitate the collection of a core sample, this invention has been made.
SUMMARY OF THE INVENTION
A drilling assembly that is movable in a drill string to the inner end portion thereof for being latchingly retained therein for collecting a core sample and which includes a latch body with retractable latches for releasably retaining the core receiving tube adjacent to the core bit and when in a latch seated position, the drill string, in rotating, imparts a rotary motion to the latches and therethrough to the latch body. The latch body in rotating imparts a rotational movement through a spindle subassembly to a vibrational subassembly which converts rotational movement to axial movement. This axial movement is imparted to the core receiving tube to axially reciprocate the core receiving tube while not rotating the core receiving tube, even though the latch body and drill string are rotating, in order to facilitate core moving into the core receiving tube and the filling of the tube with the core.
One of the objects of this invention is to provide new and novel vibrational core feeder means for facilitating the entry of core into a core receiving tube while collecting a core sample in an earth formation. Another object of this invention is to provide new and novel means for imparting axial vibrations to a core receiving tube without rotating the core receiving tube to facilitate the collection of a sample from an earth formation. Still another object of this invention is to provide new and novel means for imparting reciprocal axial movement to a core receiving tube while a latch body of a core barrel inner tube assembly is rotating and the core receiving tube has core entering thereinto.
A different object of this invention is to provide in core drilling apparatus, new and novel means for imparting movement to a core receiving tube to facilitate movement of a core receiving tube over a core to enhance the likelihood of the core receiving tube being completely filled adjacent to the inner peripheral wall of the receiving tube over that adjacent to the radial central part of tube and/or while decreasing the likelihood of increased packing of the core more closely adjacent to the receiving tube inner peripheral wall than the central part of the tube, particularly when drilling in a broken earth formation or a sandy gravel formation. Still another object of this invention is to provide new and novel means operated by the rotation of the drill string to mechanically impart axial reciprocal movement to a core receiving tube as the core receiving tube remains rotationally stationary.
For purposes of facilitating the description of the invention, the term "inner" refers to that portion of the drill string, or of the assembly, or an element of the assembly being described which in its position "for use" in, or on, the drill string is located closer to the drill bit on the drill string (or bottom of the hole being drilled) than any other portion of the apparatus being described, except where the term clearly refers to a transverse circumferential, direction, or diameter of the drill string or other apparatus being described. The term "outer" refers to that portion of the drill string, or of the assembly, or an element of the assembly being described which in its position "for use" in, or on, the drill string is located axially more remote from the drill bit on the drill string (or bottom of the hole being drilled) than any other portion of the apparatus being described, except where the term clearly refers to a transverse circumferential, direction, or diameter of the drill string or other apparatus being described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 one arranged above the other with the axial center lines aligned and lines A--A of FIGS. 1 and 2 aligned, and lines B--B of FIGS. 2 and 3 aligned, form a composite longitudinal section through the drilling apparatus of this invention with the latches being in a latch seated locked position and an axial intermediate portion of FIG. 3 broken away;
FIG. 4 is an enlarged, longitudinal section of the vibrational subassembly;
FIG. 5 is fragmentary view of part of the vibrational subassembly that is taken at generally right angles to that shown in FIG. 4 with part of the cap screw being broken away;
FIG. 6 is a transverse cross sectional view generally taken along the line and in the direction of the arrows 6--6 of FIG. 5;
FIG. 7 is a transverse cross sectional view generally taken along the line and in the direction of the arrows 7--7 of FIG. 5; and
FIG. 8 is a transverse cross sectional view generally taken along the line and in the direction of the arrows 8--8 of FIG. 7;
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in particular to FIGS. 1-3, there is illustrated a hollow drill string 10 which is made up of a series of interconnected hollow drill rods (tubes). Even though illustrated as extending horizontally, the drill string 10 is in a downwardly extending bore hole 11 drilled in rock or other types of earth formations by means of an annular core bit 12. The pump apparatus indicated by block 84 pumps fluid under pressure through line 85 into the axial outer end of the drill string 10 in a conventional manner, the illustrated part of the drill string 10 in FIG. 1 being located just axially inwardly of the bit in the bore hole 11 and may be at a considerable depth below the formation surface.
The portion of the drill string attached to or extended below the pipe (rod) section 10b is commonly referred to as a core barrel outer tube assembly, generally designated 13, the core barrel outer tube assembly being provided for receiving and retaining the wire line core barrel inner tube assembly, generally designated 15. Details of the construction of the core barrel radial outer tube assembly of the general nature used in this invention may be such as that disclosed in U.S. Pat. Nos. 3,120,282 and 3,120,283. The outer tube assembly 13 includes an adaptor coupling 21 that is threadedly connected to the core barrel outer tube 18 to provide a recess in which a landing ring (drill string landing shoulder) 23 is mounted, a reaming shell 19 connected to the inner (lower) end of tube 18 and an annular drill (core) bit 12 at the inner (lower) end of the reaming shell for drilling into the earth formation from which the core sample is taken. The outer (upper) end of the assembly 13 includes a locking coupling 20 that connects the adaptor coupling to the adjacent pipe section 10a of the drill string. At the opposite end of the coupling 20 from the pipe section 10a, the locking coupling in conjunction with the annular recess of the coupling 21 form a latch seat 21b inside of the surface of the adaptor coupling against which the latches 47, 48 are seatable for removably retaining the core barrel inner tube assembly, generally designated 15, adjacent to the core bit. The inner end portion of the locking coupling has a conventional projection flange 20b which extends as a partial cylindrical surface more closely adjacent to the core bit than to the main part of said coupling. This flange (or other structure) bears against a latch to cause the latches, the latch body and other portions of the inner tube assembly to rotate with the drill string when the latches are in a latched position, as is conventional.
The core barrel inner tube assembly 15 includes a latch body, generally designated 25, having a main body portion 44 with a conventional annular, axially inwardly facing shoulder 30 seatable on the landing ring 23 and a fluid bypass channel 28 to permit fluid flow to bypass the landing ring when the shoulder 30 is seated on the ring 23. That is, the portion of the inner tube assembly from the shoulder 30 and axially inwardly thereof is of a smaller diameter than at least the axial part of the main body outwardly of and adjacent to the shoulder while the channel has a port opening exterior of the latch body outwardly of the shoulder and a second port opening exterior of the latch body inwardly of the shoulder. Suitable valving (not shown) may be provided for blocking flow through the channel, for example of the type referred to in U.S. Pat. No. 3,103,981 to Harper or U.S. Pat. No. 4,800,969 to Thompson.
The assembly 15 also includes a core receiving tube 31, an inner tube cap 33 threaded into the outer (upper) end of the core receiving tube, a vibrational subassembly, generally designated 40, having an axial inner end threadedly connected to the tube cap and a spindle and bearing subassembly, generally designated 40, connecting the outer (upper) end of the vibrational subassembly to the inner (lower) end portion of the latch body. The core receiving tube has a replaceable core lifter case 34 and a core lifter 35, the structure and function of which may be generally the same as set forth in U.S. Pat. No. 2,829,868. A fluid passageway 39 formed in the cap 33 opens through a valve subassembly 38 to the interior of the outer end of the core receiving tube and at the opposite end to the annular clearance space 37 between the inner tube assembly 15 and the outer tube 18 that forms a part of the annular fluid channel 37 to, in conjunction with the bypass channels, permit fluid to bypass the inner tube assembly when in a core taking position such as illustrated in FIG. 1-3.
The core barrel inner tube assembly also includes a latch assembly L having a pair of latches 47, 48 with their lower end portions pivotally mounted in a latch body slot 25b by a pivot member 51 that is mounted by the latch body, and a spring 50 for constantly resiliently urging the latches to pivot to their latch seated positions. A latch retractor (release) tube 54 is mounted by the latch body for limited axial movement relative thereto for retracting the latch assembly from its latch seated position and alternately, for permitting the latch assembly moving to its latch seated position when the latches are adjacent to the latch seat, a pin 58 being mounted in an axial fixed position relative to retractor tube and extended through axially elongated slots 53 in the latch body to function in a conventional manner. A pin 55, which is mounted in a fixed position relative to the latch release tube, mounts the overshoot coupling member (spearpoint) 59 to the latch release tube for moving the latch release tube axially outwardly to retract the latches when the overshoot coupling member is moved axially outwardly by a conventional overshot assembly (not shown).
The core barrel spindle subassembly 41 includes an axially elongated spindle bolt 42 having an axial outer end threadedly connected to the inner end portion of the latch body with a lock nut 71 threaded on the bolt 42 to abut against the latch body. Inwardly of the lock nut an annular member 72 is mounted on the non-threaded part of bolt 42 in a fixed axial position relative to the bolt while axially intermediate an annular member 57 and member 72 there is mounted a shut off valve 73 to function in a manner similar to the valve members 47-49 of U.S. Pat. No. 3,333,647 to Karich. A spindle bearing 74 is mounted on the spindle bolt to abut against the member 57. Provided on the spindle bolt is a coil spring 78 that at one end abuts against a nut 87 threaded on the inner end of the spindle bolt while the opposite end of the spring abuts against a spacer 77 to resiliently urge the spacer to remain in abutting relationship to the axially inwardly facing shoulder 42b formed by the inner end and intermediate diameter portions of the spindle bolt while permitting the spindle bolt being moved axially outwardly a limited amount relative to the spacer while compressing the spring 78.
An axially elongated spring housing 75 has an axially elongated, outwardly opening bore 81 with the inner end of the spindle bolt together with the coil spring and spacer located therein. The adjacent end portions of the spindle bearing and spring housing are threadedly connected. A cut out is provided on the spindle bolt to form an axially elongated flat 79 that extends axially from the spacer 77 and outwardly to a location adjacent the annular member 72 while a key 80 is mounted by the spindle bearing to extend in abutting relationship to the flat to prevent the spindle bearing and thereby the spring housing from rotating relative to the spindle bolt while permitting axial movement of the spindle bearing relative to the spindle bolt. Annular members 74, 57 are axially movable relative to the spindle bolt to permit the annular member 57 being moved axially to compress the shut off valve between members 57, 72 to a radial expanded condition for blocking fluid bypass flow in the annular space 37, i.e. to prevent fluid bypass in the outer tube 18.
The outer end of the vibrational assembly 40 is threadedly connected to inner threaded end of the spring housing 75. Referring to FIG. 5, the vibrational assembly includes an axially elongated bearing tube T having a bore X extending axially therethrough, the bore including an axially outer bore portion 90 threadedly connected to the spring housing. The bore X also includes a reduced diameter bore portion 98 that has an axially outer threaded end part that opens to bore portion 90 and an opposite end part that opens to reduced diameter bore portion 92 to form an axially outwardly facing shoulder 93. Opposite shoulder 93, the bore includes a larger diameter bore portion 94 while the inner end of portion 94 opens to a further enlarged diameter portion 97 to form an axially inwardly facing shoulder 95. Bore portion 97 is of a constant diameter other than for an axial intermediate, annular recess 99 which is of a larger diameter.
The central axes of all of the bore portions of bore X, other than for bore portions 98, coincides with the central axis C--C of the core barrel inner tube assembly while the central axes of bore portion 98 is inclined relative to central axis C--C as indicated by line 110 by an angle of for example one degree while the planes of the annular shoulder 93 is at right angles to axis 110.
A cylindrical roller bearing 102 is mounted in the inner part of bore portion 98 and is retained in abutting relationship to shoulder 93 by a cap nut 100 that is threaded in the outer part of bore portion 98. A bearing spindle B has a semi-cylindrical portion 104 and a semicircular disk portion 105 that is of a much smaller axial dimension than portion 104. Portions 104, 105 are located in bore portion 94 and radially spaced from the internal wall defining said bore portion. The combination of portions 104, 105 are circular when looking axially inwardly and are of a diameter to leave an annular clearance space between them and the radial inner peripheral wall defining bore portion 94. The spindle subassembly also includes a cylinder portion 103 integrally formed with portions 104, 105 to extend axially outwardly through bore portion 92 and into the cylindrical roller bearing 102 while a reduced diametric cylindrical portion 101 is joined to and extends outwardly of portion 103. An annular retainer 108 has a diametric portion abutting against the axial outer, transverse surface of the intermediate race of bearing 102 to, in combination with the cap bolt 109 extended through retainer 108 and threaded into the vertical threaded bore 111 in the cylindrical portion 101, 103, to retain the axial outer transverse surface of the bearing spindle in abutting relationship to the axial inner transverse surface of the intermediate race of the thrust bearing while permitting relative rotation between the bearing spindle and the bearing tube.
The generally planar chordal face 104b of cylindrical portion 104 contains a straight line extension of the central axis of the bore portion 98 while the threaded aperture 107 in the cylindrical portion extends perpendicularly to the chordal face. A pivot member (cap screw) 112 is threaded into the transverse bore 107 in the semi-cylindrical portion 104 to have a pivot axis E--E that extends at right angles to axis 110 to intersect the central axis C--C at the intersection of axis 110 with axis C--C. The pivot member 112 mounts a spherical bearing member 113 that is pivotal in the partial spherical recess in the eye rod 114 to permit spherical pivotal movement of the eye rod relative to the bearing spindle, the spherical bearing being pivotable in the eye rod. The eye bolt is threaded into an aperture 117 in the enlarged diametric portion 118 of the cap shaft R, the shaft having a reduced diameter portion 121 threaded into the axial outer reduced diameter portion 33b of the cap 33 which extends into and axially inwardly of the bearing tube.
The cap shaft includes a first intermediate diameter portion 119 extending inwardly of portion 118 to form an axially inwardly facing shoulder for abutting against the axial outer annular surface of the inner race (not shown) of a conventional bearing 123 which permits axial slidable movement of the bearing tube and thus, for convenience, will be referred to as a "slide bearing" while the axial opposite surface of the slide bearing abuts against the axial outer transverse surface of the cap reduced diameter portion 33b. The axial outer annular surface of the outer race (not shown) of the bearing 123 is in abutting relationship to the bearing tube shoulder 95. The slide bearing 123 retains the cap radially centered relative to the bearing tube such that the cap central axis is coextensive with the central axes of the bearing tube and the core receiving tube. An annular fluid seal 124 extends radially between the inner peripheral wall defining bore portion 97 and the outer peripheral surface of the cap reduced diameter portion, and axially between the bearing 123 and the radially slit retainer ring 125 that is mounted in the recess 99.
The cap reduced diameter portion is integrally joined to the cap main body portion 33c which advantageously is of the same outer diameter as the outer diameter of the bearing tube. Further, cap 33 is movable a limited axial amount relative to the bearing tube. The cap shaft is mounted by the slide bearing 123 for limited axial movement relative to the bearing tube, while the cap shaft is in a fixed axial and angular position relative to the cap.
In view of the threaded connection between the spindle bolt and the latch body, the threaded connections between the spindle bearing, the spring housing and the spring housing and the bearing tube, and the flat on the spindle bolt and the key mounted by the spindle bearing, these members are retained in fixed angular relationship to one another and their central axes, other than for the key, are coextensive with one another and with the central axis of the inner tube assembly, including with the core receiving tube and the core bit when said assembly is in its latch seated position in the drill string.
In using the apparatus of this invention, for example, the core barrel inner tube assembly 15, the assembly 15 is inserted into the outer end of the drill string and is lowered by a wire line overshot assembly, or allowed to free fall through the drill string until the latch body shoulder seats on the landing ring. Now as conventional, the latches seat in the latch seat and upon rotating the drill string, the flanges 20b abuts against the latches to cause the latches, the latch body, the spindle subassembly 41 and the bearing tube to rotate therewith. Likewise, as the drill string is rotated, an axial inward force is transmitted through the latches, the latch body, the spindle subassembly and the bearing tube which results in the core receiving tube moving axially inwardly to have core extending thereinto. Usually, the core in the core receiving tube prevents the core receiving tube from rotating as the drill string is rotated, the vibrational subassembly permitting the core receiving tube remaining stationary while the spindle subassembly rotates.
As the bearing tube is rotated, the core receiving tube, core lifter case and core lifter are moved a limited amount axially inwardly and outwardly relative to the bearing tube. This movement results due to the plane of the annular surface of the shoulder 93 of the bearing tube being inclined relative to the central axis of the inner tube assembly, and accordingly the central axis 110 of the bearing 102 and the cylindrical portions of the bearing spindle are similar inclined. Desirably the axis 110 intersects the inner tube assembly central axis C--C at the intersection of the spherical bearing axis E--E with the central axis C--C. Since, as the bearing tube rotates, the eye rod 114 mounts the spherical bearing to pivot relative thereto and be axially move and the bearing spindle does not rotate with the bearing tube, the bearing spindle is moved such that axis 110 traces a substantially conical path around axis C--C with the cone apex being adjacent to the intersection of axes 110, C--C and E--E, and pivot member 112 and thereby axis E--E is moved about the intersection mentioned in the preceding sentence. Thus, as the bearing tube rotates relative to the bearing spindle, the central axis of the bearing spindle central portion is angularly varied relative to the bearing tube and inner tube assembly axis C--C as a generatrix of a cone. This movement of the pivot member 112 results in the spherical bearing moving relative to the eye bolt and axially moving the eye rod. Thus the spherical bearing pivots in the eye rod so that the eye rod is only moved axially (axially reciprocate) as long as the core receiving tube is not rotated as the latch body is rotating about the central axis C--C. It is noted that the center of curvature of the spherical surface of bearing 113 is transversely offset from the inner tube assembly central axis C--C, the semi-cylindrical portion 104 and the above mentioned intersections of axes.
The axial movement of the eye bolt correspondingly moves the cap shaft and thereby the cap 33 and core receiving tube. The slide bearing permits such axial movement, the bearing tube rotating relative to the slide bearing and retaining the cap shaft centered relative to the bearing tube. As a result of providing the bearing 102 with its axis offset from the central axis C--C and the bearing spindle, for each 360° cycle of revolution of the bearing tube, the core receiving tube is axially reciprocated (axially vibrates) through one cycle. As an example, the axis 110 may be inclined at an angle of about one degree relative to the central axis C--C and the core receiving tube is first moved about 0.25 mm axially toward the bearing tube and then 0.25 mm axially away from the bearing tube.
As a result of axially reciprocating the core receiving tube when collecting core, particularly in broken earth formations and sandy gravel formation, the entire core receiving tube can be filled. This is in contrast to only rotating and moving the core receiving tube axially inwardly in such formation as the core receiving tube is moved axially over the core wherein usually there is a tendency to have the radial outer part of the tube packed while the radial central part of the tube would not be filled. Further, as a result of the core receiving tube being axially reciprocated, the core receiving tube more easily moves over the core without substantially increasing the amount of fracturing of the core being collected. Upon the core receiving tube being filled, the core barrel inner tube assembly can be retracted in a conventional manner. Upon the filling of the core receiving tube, the continued downward force on the latch body results in the drill string moving downwardly relative to the core receiving tube and the spindle bolt moving downwardly relative to the spindle bearing such that the shut valve is operated to its fluid flow blocking condition to provide a high pressure signal at the drilling surface. The spindle subassembly in being connected through the vibrational subassembly to the cap shaft, blocks spindle housing and thereby the spindle bearing being moving downwardly with the spindle bolt.
Even though the invention has been described with reference to a core barrel inner tube assembly that is used for drilling in a downward direction, it is to be understood the vibrational subassembly may be used with inner tube assemblies that are fluidly propellable to the bit end of the drill string, including in bore holes that extend vertically upwardly from the drilling surface as long as the latch body is rotated with the drill string and can rotate relative to the core receiving tube. Further, the mechanism for latching the latch body to the drill string and/or the spindle subassembly may be varied as long as the bearing tube is rotated with the drill string as core is being drilled and can be rotated relative to the core receiving tube.
It is to be understood that the combination of the spindle assembly and the vibrational subassembly of this invention together with an appropriate length core receiving tube and core cap may be sold as a conversion kit to replace a conventional spindle assembly, the core cap and core receiving tube, for example such as described in U.S. Pat. Nos. 3,340,939 or 3,346,059 or 5,267,620 or 5,325,930.
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A drilling tool, for example a core barrel inner tube assembly, includes a latch body mounting latches for movement into a latch seat to removably retain the assembly adjacent to a drill string bit end and to impart rotary movement to the latch body as the drill string is rotated. A spindle subassembly is connected to the axial inner end of the latch body, to in turn, mount a vibrational subassembly for imparting axial reciprocal movement to a core receiving tube as the drill string is rotated to facilitate entry of core into the tube. The vibrational assembly converts rotary motion of the spindle subassembly to axial reciprocal movement of the core receiving tube while the core receiving tube is not being rotated but is moved axially inwardly over the core.
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This application is a divisional of Ser. No. 08/900,560, filed Jul. 25, 1997, now U.S. Pat. No. 6,133,597.
BACKGROUND OF THE INVENTION
The present invention relates to semiconductor circuits, and more particularly to wells used in semiconductor circuits.
Some semiconductor circuits use wells biased at a predetermined voltage to obtain needed functionality or performance characteristics. For example, biased wells can be used to isolate transistors from each other. Thus, in some dynamic random access memories (DRAMs), NMOS transistors of DRAM cells are formed in a P-well formed in a biased deep N well (DNW) that isolates the P well from the P doped substrate. The P well itself is biased at a lower voltage than the substrate. Hence, the body regions of DRAM cell transistors in the P well are biased at a lower voltage that the body regions of NMOS transistors of read/write circuitry (for example, of sense amplifiers) that are fabricated in the substrate. The lower bias voltage in the P well reduces the leakage current through the DRAM cell transistors. The leakage current through these transistors is of concern because it could discharge the cells. At the same time, the lower bias voltage is not suitable for read/write NMOS transistors because the lower bias voltage would make these transistors slower. (Of note, the leakage current is not as big a concern for the read/write transistors as for the DRAM cell transistors.) The biased DNW isolates the DRAM cell transistors from the read/write transistors.
In order to improve the electrical contact between a voltage source biasing the DNW and the DNW itself, the DNW is provided with a low-resistance, heavily-doped N+ contact region located at the substrate surface. The N+ contact region is formed in a separate N well which itself is formed in the DNW. The reason for the separate N well is as follows.
One of the DRAM fabrications steps is a channel stop implant. The channel stop implant is a P-type implant performed into the NMOS transistor active areas and into field isolation regions. The purpose of the channel stop implant is to increase the punch-through voltages of NMOS transistors and the punch-through and threshold voltages of parasitic field transistors. The channel stop implant is blocked from N wells in which PMOS transistors are formed. To simplify mask generation, the mask for the channel stop implant is made to be a reverse of the mask used for the N-type implant that creates the N wells. Thus, the channel stop implant is implanted precisely into those areas which are blocked from the N-well implant.
Besides the N wells containing the PMOS transistors, the channel stop implant is also blocked from the N+ contact region used to bias the DNW. This is done to prevent the channel stop P-type dopant from impeding electrical contact between the N+ contact region and the DNW. In order to enable the channel stop implant mask to be the reverse of the N well mask and still to block the channel stop implant from the N+ contact region, the N+ contact region is formed in the separate N well which is formed with the same N well mask as used for the N wells containing-the PMOS transistors.
It is desirable to reduce spacings associated with wells in the integrated circuit. Of note, a minimal spacing is typically required between a well and transistors outside the well. For example, in DRAMs a minimal spacing is required between the DNW and read/write circuitry transistors. It is desirable to reduce such spacings.
SUMMARY OF THE INVENTION
According to the present invention, integrated circuit spacing requirements are reduced. In some embodiments, spacing requirements between wells and transistors outside the wells are eliminated. Therefore, the integrated circuit size can be reduced.
More particularly, in some embodiments, the separate N wells containing the N+ contact regions in the DNWs are eliminated. This is made possible by modifying the channel stop mask not to be a reverse of the N well mask.
Further, spacing requirements between wells and transistors outside the wells are eliminated as follows. When transistors outside the well (e.g., a DNW) are laid out, the transistor placed adjacent to the well is a transistor that can be used to bias the well. This transistor couples a predetermined voltage from one of its electrodes to the other. For example, in a DRAM, this transistor can be a precharge transistor that couples a predetermined voltage to a bit line to precharge the bit line before a memory access (e.g., a memory read operation). The predetermined voltage is also suitable to bias the well. The transistor electrode that receives the predetermined voltage is at least partially inside the well, biasing the well to the predetermined voltage. Therefore, the minimal spacing requirement between the well and the transistor is eliminated.
In some DRAM embodiments, the channel stop implant mask blocks at least a portion of an area in which the DNW overlaps the precharge transistor drain region. Hence, the channel stop P dopant is prevented from impeding the electrical contact between the DNW and the drain region.
In some embodiments, P and N conductivity types are reversed.
Other features of the invention are described below. The invention is defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a DRAM according to the present invention.
FIG. 2 shows a cross-section of a portion of the DRAM of FIG. 1 .
FIGS. 3A, 3 B are a circuit diagram of a portion of the DRAM of FIG. 1 .
FIGS. 4A, 4 B are a top layout view of the portion of the DRAM of FIG. 1 .
FIGS. 5 and 6 are cross-section illustrations of the DRAM of FIG. 1 in the process of fabrication.
FIG. 7 is a cross-sectional view showing drawn dimensions in some embodiments of FIG. 1 .
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows an integrated DRAM 110 . Memory arrays 120 . 1 , 120 . 2 in DRAM 110 alternate with read/write (R/W) circuitry blocks 130 . 1 , 130 . 2 , 130 . 3 along the horizontal direction in FIG. 1 (the memory column direction). Each memory array 120 is surrounded on the left and right by R/W circuitry blocks 130 . Each memory array 120 is an array of memory cells. Each cell includes an NMOS transistor 210 (FIG. 2 ). Source regions 210 S and drain regions 210 D of transistors 210 of each memory array are formed in one or more P wells 216 . Each P well 216 is formed in a corresponding deep N well (DNW) 220 .
Drain 210 D of each transistor 210 is connected to a bit line BL (or a complimentary bit line not shown in FIG. 2 ). Source 210 S is connected to a memory capacitor 226 which is also connected to a reference voltage VREF. P well 216 is biased to a negative voltage, −1.0V in some embodiments in which VCC=3.3V, to reduce leakage through transistors 210 . Deep N well 220 is biased to a positive voltage HVCC (half VCC) to isolate the P well 216 from P substrate 230 . VCC is 3.3V or 5.0V in some embodiments.
In an adjacent read/write circuitry block 130 on the right of memory array 120 in FIG. 2, the transistor adjacent to DNW 220 is a bit line precharge transistor 236 . Drain 236 D of transistor 236 is connected to the same voltage source HVCC that biases the deep N well 220 . Source 236 S is connected to a bit line BL (or {overscore (BL)}). Gate 236 G receives an equalization signal EQ. Signal EQ is asserted high before a memory access operation to precharge the bit lines to HVCC.
A portion of drain 236 D is inside DNW 220 so that the DNW overlaps the drain 236 D. Therefore, no minimal spacing is required between the R/W circuitry block 130 and the deep N well.
Similarly, in R/W block 130 on the left of the memory array (not shown in FIG. 2 ), a bit line precharge transistor has a drain region overlapping DNW 220 . The drain region is connected to HVCC. Therefore, no minimal spacing is required.
In some embodiments, the drains of the bit line precharge transistors 236 are the only N+ contact regions in the DNW that connect the DNW to HVCC.
As seen in FIG. 1, DRAM 110 includes four boundaries between memory arrays 120 and R/W circuitry blocks 130 . Hence, four minimal spacings are eliminated. The number of spacings eliminated increases with the number of memory arrays. Some 4 Mb DRAMs include 16 memory arrays, and hence 32 boundaries between memory arrays and read/write circuitry blocks. Significant size reduction is therefore achieved.
In FIG. 1, memory columns and their respective bit lines BL, {overscore (BL)}, extend horizontally. Memory rows and their respective word lines WL extend vertically. Each memory array 120 .i is subdivided into a number of identical memory blocks M. (A circuit diagram of block M- 1 . 2 is shown in FIG. 3A.) Each memory block M-i.j is a single column of memory array 120 .i. Each word line WL of memory array 120 .i runs through all blocks M-i.j of the array. Only one pair of bit lines BL, {overscore (BL)} runs through any given memory block M-i.j.
The bit line pair BL, {overscore (BL)} of block M-i.j is connected to a read/write block RW-k.j (FIGS. 1-3) in an adjacent R/W circuitry block 130 .k (where k=i or k=i+1) in a staggered fashion. Thus, the bit lines of memory block M- 1 . 1 are connected to read/write block (RW block) RW- 1 . 1 on the left of memory array 120 . 1 . The bit lines of memory block M- 1 . 2 are connected to RW block RW- 2 . 2 on the right of memory array 120 . 1 , and so on. Block RW- 2 . 2 is also connected to memory block M- 2 . 2 . Additional details of this staggered architecture are described in U.S. patent application “DRAM With Staggered Shared Bit Line Sense Amplifier Architecture”, attorney docket number M-3880 US, filed by Li-Chun Li et al. on Dec. 3, 1996 and incorporated herein by reference.
In memory block M- 1 . 2 (FIG. 3 A), and hence in every memory block M-i.j, a memory cell is located at the intersection of bit line BL with every other word line WL, and at the intersection of bit line {overscore (BL)} with each of the remaining word lines. The gate of each memory cell transistor 210 is connected to a respective word line WL, and the drain is connected to a respective bit line BL or {overscore (BL)}.
All memory cell transistors 210 of a single memory array 120 are formed in the same P well 216 located in the same deep N well 220 (FIG. 2 ).
As shown in FIGS. 3A, 3 B, RW block RW- 1 . 2 includes: (1) precharge block 310 (FIG. 3A) for precharging the bit line segments running through memory block M- 1 . 2 ; (2) sensing block 314 (FIG. 3B) including a sense amplifier 320 ; and (3) precharge block 326 for precharging the bit line segments of memory block M- 2 . 2 . All the RW blocks RW-i.j are identical to each other, except that the leftmost blocks RW- 1 .j omit the precharge block 310 , and the rightmost blocks RW- 3 .j omit precharge block 326 .
In precharge block 310 , precharge transistor 236 (FIGS. 2, 3 A) has its drain connected to a metal- 1 line HVCC-M 1 running vertically (in the plan view of FIGS. 1, 3 A) through all the RW blocks in the R/W circuitry 130 . 2 (i.e. through blocks RW- 2 . 2 , RW- 2 . 4 ). This metal- 1 line HVCC-M 1 carries the constant voltage HVCC. The source of transistor 236 is connected to bit line BL. The gate is connected to a metal- 1 line EQ-M 1 . This line carries equalization signal EQ. Metal line EQ-M 1 runs vertically through all the RW blocks of R/W circuitry 130 . 2 .
Metal line EQ-M 1 is connected also to the gate of NMOS equalization transistor 330 interconnecting the bit lines BL, {overscore (BL)}.
NMOS transistors 334 , 340 connect bit line segments BL, {overscore (BL)} of memory block M- 1 . 2 to respective bit line segments BL, {overscore (BL)} of sensing block 314 (FIG. 3 B). Similar NMOS transistors 344 , 350 connect the bit line segments of sensing block 314 to respective bit line segments of memory block M- 2 . 2 . The gates of transistors 334 , 340 receive signal SS 1 distributed on a vertical metal- 1 line SS 1 -M 1 . The gates of transistors 344 , 350 receive signal SS 2 distributed on a vertical metal- 1 line SS 2 -M 1 . Lines SS 1 -M 1 , SS 2 -M 1 run through all the RW blocks of R/W circuitry 130 . 2 . When signal SS 1 is asserted high, sense amplifier 320 amplifies the signals from memory block M- 1 . 2 . When signal SS 2 is asserted high, sense amplifier 320 amplifies signals from memory block M- 2 . 2 . At most one of signals SS 1 , SS 2 is high at any given time.
In sensing block 314 , bit line BL is connected to a source/drain region of NMOS pass transistor 354 . The other source/drain region of pass transistor 354 is connected to data bit output line {overscore (DB)} . Bit line {overscore (BL)} is connected to a source/drain region of pass transistor 360 whose other source/drain region is connected to complimentary data bit output line DB. The gates of transistors 354 , 360 receive a column select signal YS. Data lines {overscore (DB)}, DB are metal- 1 lines running vertically through all the RW blocks of R/W circuitry 130 . 2 .
PMOS transistors 364 , 370 and NMOS transistors 374 , 380 form two cross-coupled latches which form sense amplifier 320 . Bit line BL is connected to the gates of transistors 364 , 374 , and the drains of transistors 370 , 380 . Bit line {overscore (BL)} is connected to the gates of transistors 370 , 380 , and the drains of transistors 364 , 374 . The sources of PMOS transistors 364 , 370 are connected to a vertical metal- 2 line SLP. The sources of NMOS transistors 374 , 380 are connected to a vertical metal- 2 line SLN. Lines SLP, SLN run through all the RW blocks of R/W circuitry 130 . 2 . During amplification, line SLP is connected to a positive voltage, and line SLN is connected to ground. During precharge, both lines SLP, SLN are connected to the same precharge voltage HVCC. The sense amplifier operation and timing are described in U.S. patent application “Charging a Sense Amplifier”, serial number 08/760,121, now U.S. Pat. No. 5,768,200 filed Dec. 3, 1996 by L. Liu et al. and incorporated herein by reference.
Precharge block 326 is similar to block 310 . In particular, block 326 includes NMOS equalization transistor 381 connected between the bit lines BL, {overscore (BL)} and NMOS precharge transistor 383 connected to bit line BL. The drain of transistor 383 is connected to a vertical metal- 1 line receiving the voltage HVCC and running through all the RW blocks of circuitry 130 . 2 . The gates of transistors 381 , 383 receive equalization signals EQ provided on a vertical metal- 1 line running through all the RW blocks of circuitry 120 . 2 . The drain of transistor 383 overlaps with the deep N well (not shown) of memory block M- 2 . 2 .
FIGS. 4A, 4 B are a layout view showing tasks used to manufacture the blocks 310 , 314 . DRAM 110 includes four polysilicon layers and two metal layers over the polysilicon layers. Bit lines BL, {overscore (BL)} are formed from the fourth polysilicon layer (“poly 4 ”). The bit line boundaries are shown by dashed lines.
Stippled areas are mask openings through which N+ or P+ implants are performed into substrate 230 . Stippled region 210 S is the N+ source region of transistor 210 of the rightmost memory cell of memory block M- 1 . 2 . See also FIG. 2 . In capacitors 226 (FIG. 2 ), the capacitor plates connected to memory call transistors 210 are formed from the second polysilicon layer (not shown). The capacitor plate connected to voltage VREF is formed from the third polysilicon layer (not shown). This plate is shared by a number of memory blocks in a memory array. This poly- 3 plate is interrupted between some memory blocks M-i.j of the array to allow metal- 1 word lines WL to contact poly- 1 word lines WL (each word line WL includes a metal- 1 line running over a poly- 1 line).
Stippled region 410 (FIG. 4A) includes N+ drain 236 D of precharge transistor 236 .
Metal- 1 line HVCC-M 1 contacts drain region 236 D in contact region 418 . (In region 418 , line HVCC-M 1 contacts a doped poly- 4 region. The poly- 4 region contacts the drain region.)
Metal- 1 line EQ-M 1 contacts a poly- 1 line EQ-P 1 in region 422 . Poly- 1 line EQ-P 1 provides the gates for transistors 236 , 330 (FIG. 3 A).
Poly- 1 line SS 1 -P 1 provides the gates of transistors 334 , 340 . Line SS 1 -P 1 contacts metal line SS 1 -M 1 in region 426 . Bit lines BL, {overscore (BL)} contact the source/drain regions of transistors 334 , 340 in contact regions 430 .
Poly- 1 line YS-P 1 provides the gates of pass transistors 354 , 360 . Poly- 1 line YS-P 1 contacts a metal- 1 region in contact region 434 . The metal- 1 region contacts a metal- 2 region which provides Y-select signal YS. Stippled region 440 includes source and drain regions of transistor 360 . (Region 440 is a mask opening through which the dopant is implanted. This implant is also masked by poly- 1 line YS-P 1 , causing the source and drain regions to be spaced from each other.) A source/drain region of transistor 360 contacts the metal- 1 line DB in region 444 .
Similarly, stippled region 450 includes the source and drain regions of transistor 354 of RW block RW- 2 . 2 and of transistor 354 of the next RW block RW- 2 . 4 . Poly- 1 line YS 2 -P 1 provides the gates of the pass transistors of RW block RW- 2 . 4 . The common source/drain region of transistors 354 of the two RW blocks contacts the data line {overscore (DB)} in contact region 454 .
Bit lines BL, {overscore (BL)} contact the source/drain regions of transistors 360 , 354 in contact regions 455 .
In FIG. 4B, poly- 1 line 364 -P 1 extending essentially directly below the bit line {overscore (BL)} provides the gate of transistor 364 . Poly- 1 line 370 -P 1 extending essentially directly below the bit line BL provides the gate of transistor 370 . Stippled region 460 includes the P+ sources and drains of the two PMOS transistors. Line 370 -P 1 contacts bit line {overscore (BL)} in contact region 464 . Poly- 1 line 364 -P 1 contacts bit line BL and the drain of transistor 370 in contact region 468 . Bit line {overscore (BL)} contacts the drain of transistor 364 in contact region 472 . Metal- 2 line SLP (not shown in FIG. 4B) contacts the common source of transistors 364 , 370 in contact region 476 .
Poly- 1 line 374 -P 1 provides the gate of transistor 374 . Poly- 1 line 380 -P 1 provides the gate of transistor 380 . The two poly- 1 lines extend between the bit lines essentially in parallel with the bit lines. Poly- 1 line 380 -P 1 contacts bit line {overscore (BL)} in contact region 480 . Poly- 1 line 374 -P 1 contacts bit line BL in contact region 482 .
Stippled region 484 includes the sources and drains of transistors 374 , 380 . Bit line BL contacts the drain of transistor 380 in contact regions 486 . Bit line {overscore (BL)} contacts the drain of transistor 374 in contact regions 490 . Metal- 2 line SLN (not shown) contacts the common source of transistors 374 , 380 in contact region 494 .
Bit lines BL, {overscore (BL)} contact the source/drain regions of transistors 344 , 350 (FIG. 3B) in contact regions 430 (FIG. 4 B). Transistors 344 , 350 are not shown in FIG. 4 B.
FIG. 5 shows the beginning stages of fabrication of DRAM 110 . Wafer 230 doped with boron has a doping concentration of 3×10 15 cm −3 . Initial silicon dioxide layer 510 is grown by thermal oxidation to a thickness of 300 to 1000 nm. Oxide 510 is patterned by standard photolithographic techniques to expose a region 520 into which dopants will be implanted for P well 216 and DNW 220 .
A protective silicon dioxide layer 530 is grown by thermal oxidation to a thickness of 30 to 300 nm (100 nm in some embodiments). Phosphorous is implanted into region 520 at the energy 180 keV to create DNW 220 . The ion dose is 1 to 9 times 10 13 atoms/cm 2 (1.5×10 13 atoms/cm 2 in some embodiments.)
Phosphorous is driven in by heating the wafer in nitrogen atmosphere at a temperature of 1150° C. for 510 to 1000 minutes (950 minutes in some embodiments). The deep N well diffuses laterally and downward as shown in FIG. 6 .
A blanket etch removes protective oxide 530 and a small portion of oxide 510 . Protective silicon dioxide 610 is grown thermally to a thickness of 30 to 300 nm (100 nm in some embodiments) by wet oxidation performed at 950° C. for 10 to 60 minutes. Boron is implanted at an energy of 30 to 180 keV (60 keV in some embodiments) to form P well 216 . The ion dose is 1×10 13 to 9×10 13 cm −2 (2×10 13 cm −2 in some embodiments).
Then oxide layers 510 , 610 are removed. A protective 100 nm layer of silicon dioxide (“third protective oxide”, not shown) is grown by wet oxidation performed at 950° C. for 10 to 60 minutes. Photoresist (not shown) is deposited and patterned to expose N well regions 620 (FIG. 2) in which the PMOS transistor 370 and other PMOS transistors will be formed. Phosphorous is implanted at an energy of 30 to 180 keV to form the N wells. The ion dose is 1×10 13 to 9×10 13 cm −2 (1.2×10 13 cm −2 in some embodiments). Then a well drive-in step is performed at a temperature of 1150° C. for 200 to 800 minutes (250 minutes in some embodiments). The resulting depth of DNWs 220 is about 5 μm. The depth of P wells 216 is 2 μm. The depth of N wells 620 is 3 μm. The distance dw between the right edge of P well 216 and the right edge of respective DNW 220 is 2 μm.
The third protective oxide is removed 470 nm thick field oxide regions 630 are grown between transistor active areas by LOCOS oxidation performed at 1000° C. for 90 minutes using methods known in the art.
A 30 nm sacrificial layer of silicone dioxide (not shown) is grown by wet oxidation performed at 850° C. for 40 minutes. Blanket ion implantation of BF 2 is performed through this sacrificial oxide at an energy of 70 keV to adjust transistor threshold voltages. The ion dose is 3.2×10 12 cm −2 .
Then a deep P type implant (channel stop implant) is performed into NMOS transistor active regions to enhance the P type dopant concentration under the NMOS transistors and the field oxide regions. The resulting P-channel stop regions are shown at 640 . Regions 640 increase the punch-through voltages of NMOS transistors and parasitic transistors formed under field oxide 630 . Regions 640 also increase the parasitic transistor threshold voltages. Regions 640 are formed by implanting boron at the energy 120 keV The ion dose is 8×10 12 atoms/cm 2 . The implant mask protects N wells 620 during this implant. The implant mask also protects regions CN of equalization transistor drains 236 D. Each region CN overlaps an area in which the respective drain 236 D meets the respective DNW 220 . Protecting the regions CN from the channel stop implant serves to improve the electrical contact between drains 236 D and DNWs 220 .
In some embodiments, the channel stop implant mask is the reverse of the N well 620 mask except that the channel stop implant mask also covers regions CN.
Each region CN is spaced from the respective gate 236 G. This spacing allows a portion 640 . 1 of channel stop region 640 to extend under the drain 236 D, thus increasing the punch-through voltage of transistor 236 . Each region CN is also spaced from the edge of the respective drain 236 D where the drain meets field oxide 630 (the left edge of drain 236 D in FIG. 2 ). This spacing allows a portion 640 . 2 of channel stop region 640 to extend from under the field oxide to a region under the drain 236 D. This helps to improve the punch-through voltage and the threshold voltage of the field transistor formed at the location of oxide 630 .
In some embodiments, after formation of the implant mask used to form channel stop regions 640 , but before the boron implantation forming the channel stop regions, another boron implant is performed through the sacrificial oxide at an energy of 30 keV to adjust the threshold voltages of NMOS transistors. The ion dose of this implant is 2×10 12 cm −2 .
After the channel stop implant, the sacrificial oxide is removed.
Gate oxide (not shown) is grown to a thickness of 5 to 18 nm (8 nm in some embodiments) by oxidizing the structure at 700 to 1000° C. (850° C. in some embodiments) for 10 to 60 minutes. Polysilicon or polycide gates of transistors 210 , 236 , 370 , and other transistors, are formed by known techniques. Phosphorous is ion-implanted at 25 keV to form LDD regions of NMOS transistors. The ion dose a 2×10 13 cm −2 . Then pocket ion implantation of boron is performed at an angle of 25° and an energy of 60 keV into regions underlying NMOS sources and drains, to increase the NMOS punch-through voltages. The pocket implant ion dose is 1.2×10 13 cm −2 . These two implants—NMOS LDD and P-type pocket—are performed using the same photoresist mask (“NMOS LDD mask”, not shown) patterned by standard photolithographic techniques. The mask covers regions LN one of which is shown in FIG. 2 . Each region LN covers the region CN and extends to the adjacent field oxide region 630 separating the respective drain 236 D from the respective P well 216 . By covering the regions LN, the mask blocks the pocket-implant boron from areas in which the drain regions 236 D meet the respective DNWs 220 . Thus, the mask helps to improve the contact between drain regions 236 D and DNWs. At the same, the mask exposes a portion of the drains 224 D adjacent the respective gates 236 G and also exposes the source regions 236 S.
Pocket implants are described in U.S. Pat. No. 5,618,740 entitled “Method of Making CMOS Output Buffer with Enhanced ESD Resistance”, issued Apr. 8, 1997 to T. Huang and incorporated herein by reference.
BF 2 is implanted to form LDD regions of PMOS transistors such as transistor 370 . A pocket implant of phosphorous is performed into the PMOS transistor regions to increase their punch-through voltages. A 100 nm layer of silicone nitride (not shown) is deposited by LPCVD and etched to form spacers on transistor gate sidewalls. The silicon nitride deposition temperature is 780° C., and the deposition time is 40 mins. A 20 nm layer of silicone dioxide (not shown) is grown at 875° C. on exposed silicone surfaces. Arsenic and BF 2 are implanted in successive ion implantation steps. The arsenic implant forms heavily doped portions of NMOS source/drain regions. The BF 2 implant forms heavily doped portions of PMOS source/drain regions and also forms one or more P+ contact regions (not shown) in each P well 216 . The P+ contact regions will contact a voltage source that will bias the P-wells. In some embodiments the mask used in the BF 2 implant is the reverse tone of the NMOS LDD mask, except that both the NMOS LDD mask and the BF 2 mask block the regions LN.
Remaining fabrication steps are known in the art.
The dopant concentration in DNWs 220 is 1×10 16 atoms/cm 3 . The dopant concentration in drains 236 D is 1×10 20 atoms/cm 3 . The higher dopant concentration in the drain regions improves the electrical contact between DNWs 220 and doped poly-4 regions (not shown) contacting the drains 236 D and also contacting the metal- 1 lines HVCC-M 1 .
FIG. 7 illustrates some drawn mask dimensions in the cross section of FIG. 2 . The lateral distance d 1 between the right edge of the rightmost source region 210 S in a P well 216 and the right edge of the respective DNW 220 /P well 216 mask opening (corresponding to the left edge of oxide 510 in FIG. 5) is only 0.45 μm. This spacing is small due to elimination of a separate N+ contact region in the DNW and of a separate N well containing the N+ contact region. The distance d 2 between the right edge of the DNW mask opening and the left edge of the mask opening for drain region 236 D is 1.5 μm. The drawn distance d 2 between the left edge of the region 236 D and the left edge of the region CN is 0.4 μm. The width d 4 of each region CN is 3.1 μm. The distance d 5 between the right edge of the region CN and the left edge of gate 236 G is 1.0 μm.
The distance d 6 between the left edges of region LN and drain 236 D is 1.0 μm. The rights edges of regions LN, CN coincide.
In this embodiment, DNW 220 diffuses laterally after implantation by 75-80% of the DNW depth. Thus, if the DNW depth is 5 μm, the DNW diffuses laterally by 3.75 μm to 4 μm. The minimal photolithographic line width is 0.5 μm, and the maximum alignment error is 0.6 μm. The minimal spacing between the DNW mask and the gate of the nearest transistor is only d 2 +d 3 +d 4 +d 5 =6 μm.
The above embodiments illustrate but do not limit the invention. In particular, the invention is not limited by any particular dimensions, fabrication techniques, temperatures, energies, or other process parameters, or by layer compositions or layout. The invention is not limited to DRAMs or any other particular circuitry. Other embodiments and variations are within the scope of the invention as defined by the following claims.
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Dynamic Random Access Memory (DRAM) cells are formed in a P well formed in a biased deep N well (DNW). PMOS transistors are formed in N wells. The NMOS channels stop implant mask is modified not to be a reverse of the N well mask in order-to block the channels stop implant from an N+ contact region used for DNW biasing. In DRAMS and other integrated circuits, a minimal spacing requirement between a well of an integrated circuit on the one hand and adjacent circuitry on the other hand is eliminated by laying out the adjacent circuitry so that the well is located adjacent to a transistor having an electrode connected to the same voltage as the voltage that biases the well. For example, in DRAMs, the minimal spacing requirement between the DNW and the read/write circuitry is eliminated by locating the DNW next to a transistor precharging the bit lines before memory accesses. One electrode of the transistor is connected to a precharge voltage. This electrode overlaps the DNW which is biased to the same precharge voltage. This electrode provides the DNW N+ contact region.
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The present invention relates to dispensers or guns for mixing and dispensing two-part or--component bonding, casting and similar resins, such as epoxies using catalysts silicones, polyurethanes and the like, sealants, adhesives and other compounds, all hereinafter referred to generically as "fluids"; being more particularly directed to pre-loaded fluid-filled cartridges, often containing fluids of widely varying viscosities and other properties, and to their accurate and programmable controlled dispensing.
BACKGROUND
Prior two-part fluid dispensers of this character have inherently operated with dispensing problems and limitations, including requirements for expensive bulk meter mix dispensing apparatus (MMD) that demands costly cleanup and maintenance procedures and involves operator exposure to toxins in the fluids, and with conventional two-part fluid cartridge dispenser systems lacking sufficient accuracy for controlled applications. In addition, such cartridge systems are subject to cartridge and/or piston deformation in use; and, with their monitoring of the air volume required to dispense, have shot size affected by variation in air pressure, fluid viscosities and humidity, among other factors. They are not adapted, furthermore, for two-part fluids of widely different viscosities and for widely variable ratio mixing and dispensing cartridge arrays. Prior apparatus of this type, moreover, are frequently subject to lead/lag, oozing, drooling or dripping difficulties causing users often to continue with manual mixing and dispensing operations despite their poor reliability, high labor costs, waste, and personnel exposure to materials and solvents.
Among the major inherent problems with prior cartridge systems is the fact that especially when dealing with ratios other than 1:1, the viscosities of the resin and the catalyst are very far apart. Almost always, the catalyst viscosity is close to water, while the resin can be like molasses or even thick paste. This has two effects. Because the resin is thicker, the pressures in the resin cartridge is much higher. The cartridges are constructed out of plastic with thin walls and may be of different diameters. The required dispensing pressures cause a very significant expansion of the cartridge diameters, and because of the difference of viscosities in the two materials, as well as the difference in cartridge sizes, the cartridges expand differently, creating an error in the dispensing ratio which often exceeds the normally allowed tolerances; for urethanes, for example, of the order of about 2%.
A second major problem is the inequality of the dispensing forces required by the two parts due to the mismatch in viscosity. This puts a severe bending stress on the dispensing mechanism resulting in faster feeding of one part then the other. This is known as the lead/lag effect. Prior to the present invention, the mechanisms that are available do not have the required rigidity to overcome this problem.
The present invention is directed to obviating significantly the above-described limitations and difficulties through a novel combination of the accuracy of bulk MMD procedures through the use of static mixers with vastly improved low-cost cartridge dispenser apparatus.
OBJECTS OF INVENTION
The principal object of the invention, accordingly, is to provide a new and improved two-fluid cartridge dispensing system and method, remarkably void of prior art problems and limitations, including those above described, and that enable low-cost, low maintenance, increased productivity and small foot-print disposable cartridge operation, adapted for both low and high viscosity and even widely different viscosity fluid materials, including highly reactive or abrasive systems, and particularly adapted for semi-automatic and computer-controlled highly accurate dispensing, with a wide selectable and adjustable range of mixing and dispensing ratios.
A further object is to provide such a new system and technique that have increased reliability and reduced waste, and of such relatively small size as to be readily integrated into production lines or other limited spaces, and easily programmable and simple to operate.
Still a further object is to provide a novel apparatus wherein all contact components are dispensable, ranging from economical large capacity cartridges to simple static mixers, with no valves to wear out, no internal parts to clean, and minimal material waste.
Other and further objects will be explained hereinafter and are more particularly delineated in the appended claims.
SUMMARY
In summary, however, from one of its viewpoints, the invention embraces a two-part fluid dispenser apparatus having, in combination, a housing into which a pair of pre-loaded cartridges respectively containing the two fluid parts is received and provided with compressed air-actuated push rod plungers for compressing the fluid parts in the cartridges; a static mixer connected to receive and mix the fluids as they are compressed out of the cartridges; a flexible pinch tube connected to receive the mixed fluids from the static mixer and to dispense the same; and a pinch valve disposed variably to pinch off the pinch tube to control the mixed fluid dispensing.
Preferred and best mode designs and techniques for the practice of the invention are later presented.
DRAWINGS
The invention will now be explained with reference to the accompanying drawings,
FIG. 1 of which is a longitudinal sectional view of preferred mixing and dispenser apparatus for the practice of the method underlying the invention; and
FIG. 2 is a similar but enlarged view of the preferred fully adjustable pinch valve particularly adapted for use in the novel apparatus of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1, the dispenser of the invention is illustrated as a cylinder 1 bounded by top and bottom end plates 3 and 5 and intermediately housing a pair of parallel spaced longitudinally extending push rods 7 and 9 guided through an intermediate planar guide plate connected by an axially extending tension translator cable 13 connected to the inner surface of the top plate 3. The push rods 7 and 9 are held by a push rod brace 15 disposed between the top plate 3 and the guide plate 11 and carrying a rotary encoder 21.
At their lower ends, FIG. 1, the push rods 7 and 9 are terminated in respective push pads 17 and 19, shown for illustrative purposes to demonstrate the wide flexibility of the invention, as of smaller and larger diameters and volumes, respectively, for engaging the respective plungers 2 1 and 4 1 of smaller and larger fluid material disposable flexible cartridges 2 and 4 as of plastic, inserted side-by-side and containing respective fluids PART B and PART A therein as fed into openings 2 11 and 4 11 , depending centrally through an opening O in the dispenser bottom plate 5, from a later-described static mixer 23. The cartridge 2 and its plunger 2 1 , for example, may be for a 300 cc volume unit, whereas the cartridge 4 and its plunger 4 1 may be for a 750 cc, volume, inserted side-by-side at the bottom of the dispenser 1, with the push rod 7 centrally engaging the plunger 2 1 and the pushrod 9 engaging the plunger 4 1 , offset to the right to accommodate the larger cartridge 4.
At their upper ends, the push rods 7 and 9 pass through corresponding openings in the dispenser top plate 3 and terminate on opposite sides of a pneumatic piston 6 disposed within a cylindrical pneumatic cylinder 8 carried on top of the dispenser top plate 3. The pneumatic piston 6 is moved upwardly and downwardly in the cylinder 8 along an axially disposed tye rod 10 secured between the center of the dispenser top plate 3 and a cylinder cap 10 1 in response to downwardly and upwardly directed compressed air or similar fluid inputs 12 and 12 1 , respectively disposed at the top and bottom of the pneumatic cylinder 8. The air is derived from a compressed air source A through a pressure regulator 16 and a cylinder direction switch 14 as, for example, of the foot-pedal or other type, driving the push rods 7 and 9 simultaneously downwardly to exude the cartridge materials into the static mixer 23 to dispense for use at E under the control and regulation of a pinch valve V having cooperative pressure elements V 1 and V 11 acting upon a flexible pinch tube 25, as of plastic. The pinch valve V, in turn, is operated by the switching action of a solenoid SV under programmable microprocessor control at M, as initiated at 21 1 from the before-mentioned rotary encoder 21, controlling the compressed air fed from the source A to operate the later-described piston 20 of the pinch valve V, FIGS. 1 and 2.
The mechanism described herein operates in the following manner. The pre-loaded plastic cartridges 2 and 4 are placed in a confining metal sleeve S, such as two sleeve halves, then bolted into place, clampingly securing the cartridges in a rigid side-by-side assembly, and with the metal sleeve very closely fitting the overall cartridge diameter. The plastic tube 25 is attached to the tip of the static mixer 23 and is inserted through the pinch valve mechanism V 1 --V 11 which controls the flow of material. Pressure is applied to the air cylinder 8 which then applies a dispensing force through the push pad rods, 7-17 and 8-19.
With the pinch valve V closed, material is unable to flow. This causes the plastic cartridges 2 and 4 to expand against the constraining sleeves S and thereby obtain a controlled and precise dimension. This pressure remains constant during the entire dispensing process, thereby insuring that the correct volume ratio is maintained in the cartridges.
In order to prevent the before-described lead/lag problems, the solid cross brace 15 is used intermediately to hold the two push rods 7 and 9 together to prevent any possibility of lead/lag motion of the rods. The guide plate 11 and the cover or top plate 3 force the push rods to travel straight and take up the bending stresses. The guide plates, as well as the sleeves and bottom plate 5 are bolted to the enclosure 1, combining into a very rigid structure which absorbs bending forces and allows the maintenance of the proper dispensing ratios.
Dispensing is controlled by the opening and closing of the pinch valve V. This can be accomplished either manually or automatically.
In the manual mode, the pinch valve V will be opened and closed by the operator. In the automatic mode, control is implemented by the programmable microprocessor M, receiving an input from the rotary encoder 21 that measures the movement of the push rods 7 and 9, and from that, calculates the dispensed volume. Linear motion is translated to rotary by wrapping the before-mentioned tensioned translator cable 13 around the shaft of the rotary transducer. Once pressure is applied to the system, all the mechanical tolerances are taken up, and this pressure is maintained throughout the dispensing cycle, ensuring constant and even stresses on the dispensing mechanism and thus permitting accurate measurement and control of the dispensed quantities.
Advantage in the use of static mixer 23 is that it is capable of thoroughly mixing materials of highly different viscosities without introducing any air, thus eliminating the need for degassing. and enabling immediate dispensing that greatly improves material flow. This is especially important with urethanes and the like where moisture contained in the air causes chemical bubble formation.
The static mixer shown at 23 is in the form, preferably, of a spiral mixer, such as, for example, that of TAH Company, having a series of left-hand and right-hand helical elements, as shown, that progressively divide and recombine the pumped fluids and provide a uniform output.
A preferred form of fully adjustable pinch valve mechanism V-V 1 -V 11 is shown in more detail in FIG. 2, having a cylindrical body 30 within which a longitudinally extending pinch rod 32 may drive the piston 20, against the action of a return spring 34, to compress the transversely extending pinch tube 25 between the clamping surface V 1 carried by and at the end of the pinch rod, and an opposing tube retainer surface V 11 , before mentioned, to apply the desired and precise degree of control of flow of the mixed fluids from the static mixer 23 as dispensed at E. Retainer thumb screws are shown at 36, a spring closure adjustment nut at 38, and opening adjustment pins at 40 carried in the back plate 42.
The principle of this valve V is that the tube 25 through which material flows is pinched off to stop the flow of material. The pinching action is removed to restore material flow, Adjustment of the opening of the valve permits precise sizing of the open cross sectional area of the tube 25, helping to obtain additional precision in controlling minute amounts of the fluids of low viscosity.
The closing adjustment of the valve provides the precise adjustment needed for the closure force such that it is sufficient to prevent material flow but such that it will not damage the tube. This provides for a long work life that produces thousands of operations before tube replacement is needed.
The tube retainer V 11 captures the tube 25 extending transversely of the longitudinal pinch rod 25 and keeps it from moving when the tube is pinched. It is normal for the end of the tube to be contaminated with dripping material. If this tube is then pulled out of the pinch valve, the dripping material will contaminate the pinch valve causing it to eventually to malfunction. To prevent this from happening, the retainer V 11 is made removable, as shown, so as to open the pinch valve for tube removal without contaminating the valve.
Compressed air enters the valve body 30 through the commutation hole in the push rod 32, and the piston 20 is press-fitted onto the pinch rod. The compressed air causes the piston to move forward and pinch off the tube 25. The before-mentioned closure adjustment nut 38 stops the forward motion of the pinch rod when it comes up against the back plate 42 which is threaded into the body 30.
The position of the back plate determines how far the pinch tube 25 is allowed to open. The return spring 34 will move the pinch rod 32 as far back as the backplate 42 will allow when the compressed air is removed.
A typical set of specifications for a successfully constructed apparatus constructed as in FIGS. 1 and 2, is as follows:
______________________________________WORKING PRESSURE 20-100 PSIMAXIMUM CARTRIDGE VOLUME 750 CCMAXIMUM DISPENSING VOLUME 1500 CCDISPENSING RATIOS 1:1 2:1 2.5:1 4:1 5:1 10:1DISPENSING ACCURACY +/-.25 CCFLOW CONTROL PINCH VALVEPINCH VALVE SPECIFICATIONS:MINIMUM PRESSURE 20 PSIMAXIMUM PRESSURE 100 PSIMAXIMUM TUBE DIAMETER 3/8 INCHPINCH STOP ADJUSTABLE TO MATCH DISPENSING TUBE______________________________________
In the computer-controlled mode of operation, once the operator has programmed a volume to be dispensed, the system allows the correct dispensed deposit with each depression of the foot pedal or other switch 14, as previously described.
For a semi-automatic single shot mode, the dispensing occurs for so long as the foot pedal or other type switch is pressed. The total amount of mixed fluid dispensed may be indicated on a commercial display, schematically represented at D, resettable back to zero between deposits.
In a semi-automatic cumulative mode, on the hand, the operation is similar to the before-described manual mode, but the display does not reset with each deposit, thus registering a cumulative total.
Further modifications will also occur to those skilled in this art, and such are considered to fall within the spirit and scope of the invention as defined in the appended claims.
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A novel two-part fluid dispensing and technique using fluids of similar or widely different viscosities and in flexible plastic or similar cartridges of a similar or different volumes, and with adjustable dispensing ratios by forcing the fluids out of their respective cartridges in response to variable air pressure into a static mixer, and thence along a dispensing flexible pinch tube, the opening and closing of which is controlled by a pinch valve operated in response either to manual or micro-processor-controlled control.
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[0001] The invention lies in the field of microbiology, more particularly in the field of (food) preservation and testing of viability of microbiological spores.
[0002] Since the development of pasteurisation no real break-through has been achieved in the field of food preservation. The most common preservation process is heat treatment and the effectiveness of preservation is nowadays determined by a trial and error method. Thus, present preservation methods are directed to a ‘worst case’ scenario, in which the most infected sample is taken as standard for subsequent preservation treatments. One of the reasons for this is that a detailed insight in the process of preservation lacks: current methodologies are not capable of a reliable and quick assessment of the micro-organisms and their viability in relation to the preservation process. Hitherto, the inactivation of contaminating micro-organisms is measured indirectly: by determining the growth of surviving micro-organisms after heat treatment. This method has two large disadvantages:
[0003] it is very time consuming (often results are only available after more than two days);
[0004] if no survivors are measured, it cannot be determined whether the applied treatment was just barely sufficient or meant an overkill.
[0005] The worst case scenario in practice means that often more energy is used for the heat treatment than would have been necessary, because either the contamination was less than expected or the micro-organisms in the sample were more heat-sensitive than those on which the treatment was based. It will be understood that any surplus heat treatment of the product will affect its quality.
[0006] Thus, there is a large need for rapid microbiological testing of (heat) treated samples to assess the quality and effect of the preservation treatment.
[0007] In the last couple of years genomic techniques have enabled a relatively rapid and specific approach to microbiological assaying. With these techniques it is possible to detect even small amounts of (micro)organisms within a sample, and it has become possible to discriminate between micro-organisms on a species or subspecies level. However, especially in heat (or other stress) treated food, the most important safety challenge is formed by the spores. Spores are formed by spore-forming micro-organisms under growth limiting (stress) conditions. Spore-forming micro-organisms, such as Bacillus and Clostridium , determine for a major part the shelf-life of heat-preservation treated food. One spore is formed from one vegetative bacterium. Each spore is composed of a protoplast, a protoplast membrane, cortex and multiple coat layers (Turnbill, 1996). This multilayered outer shell excludes macromolecules. An additional heat and chemical resistant component in the cortex, peptidoglycan, increases the spore's resiliency (Turnbill, 1996). Bacillus spores central protoplast contains dipicolinic acid, (DPA), the component necessary for high temperature tolerance (Turnbill, 1996). Slieman et al. (2001) found that approximately 10 percent of a spore's dry weight is DPA. DPA exists as a calcium complex. Rosen et al. (1997) developed a terbium chloride assay to identify and quantify endospore concentrations utilizing this DPA-Ca++ complex. The reaction between the calcium dipicolinic acid complex and terbium chloride results in a terbium (III) anion. This terbium anion is photoluminescent when in the presence of the DPA-Ca++ complex and is easily recognized. As mentioned above, the protoplast is enveloped by the cortex, followed by three protein coats (Turnbill, 1996). However, members of the B. cereus group, which includes, B. anthracis , have an additional protective layer, the outer-most exosporium. These multilayered outer structures, which can make up half of the spore's weight, provide protection for the spores from chemical, physical and enzymatic degradation (Turnbill, 1996).
[0008] Several species of Bacillus and Clostridium are important to human and animal health. B. anthracis , the agent of anthrax, is a zoonotic disease which primarily affects grazing animals and can also be a dangerous pathogen to humans. B. anthracis spores are known to survive along livestock trails in the United States causing frequent outbreaks in states from Texas to South Dakota (CDC, 2001). Members of the B. cereus group can cause food poisoning in humans and related forms (eg. B. thuringiensis ) are used in biological control of insect pests. C. perfringens and C. botulinum are commonly known food-contaminating bacteria. C. perfringens is a Gram-positive square-ended anaerobic (microaerophilic) bacillus classified in Group III of the Family Bacillaceae. This non-motile member of the clostridia forms oval, central spores rarely seen in culture unless grown in specially formulated media, although the spores are produced readily in the intestine. Capsules may be seen in smears from tissue. Sugar reactions (acid and gas) may be irregular. Nitrate is reduced and lecithinase (alpha-toxin activity) can be demonstrated in egg yolk medium (Nagler reaction). Food poisoning from C. perfringens gives rise to abdominal pain, nausea and acute diarrhea 8-24 h after the ingestion of large numbers of the organism, a proportion of which survive the acid conditions of the stomach (Sutton & Hobbs, 1971). The illness is usually brief and full recovery within 24-48 h is normal. However, death occasionally occurs in the elderly or otherwise debilitated patients, e.g. in hospitals or institutions (Smith, 1998). The symptoms of the disease are caused by an enterotoxin. C. perfringens is grouped into 5 types A-E according to the exotoxins (soluble antigens) produced. Types A, C and D are pathogens for humans, types B, C, D and E, and possibly A also, affect animals. The enterotoxin produced by types A and C is distinct from the exotoxins and is responsible for the acute diarrhea that is the predominant symptom of C. perfringens food poisoning. The beta-toxin of type C appears to be the necrotic factor in the disease enteritis necroticans jejunitis (“pig-bel”). Type A strains are responsible for gas gangrene (myonecrosis), necrotizing colitis, peripheral pyrexia, septicaemia as well as food poisoning.
[0009] Clostridium botulinum neurotoxin (BoNT) has the capacity to cause disease in essentially all vertebrates. Symptoms may appear in a few hours or take several days to appear. Initial symptoms such as weakness, fatigue and vertigo, are usually followed by blurred vision and progressive difficulty in speaking and swallowing. In type E botulism nausea and vomiting often occur early in the illness and probably contribute to its lower mortality than types A and B. Disturbed vision and difficulty in speaking and swallowing are due to neurological implications involving extra-ocular and pharynx muscles. Weakening of diaphragm and respiratory muscles also occurs and death is usually due to respiratory failure. Specifically neurotransmission of the peripheral nerve system is blocked. The mortality rate has fallen due to early diagnosis, prompt administration of antitoxin, and artificial maintenance of respiration. The illness is serious and full recovery usually takes many months.
[0010] C. tetanus causes one of the major diseases still present in developing countries, tetanus. Tetanus has been known to take up to ten years to manifest, but normally, incubation period is a few days to a few weeks. The first signs of the disease include mild muscle contractions at the site of infection as the infection gradually spreads along nerve fibers to the spinal cord and brain stem. Trismus (lockjaw) ensues with continued rigidity and spasms of the extremities. Death occurs when spasms interfere with respiration.
[0011] There are several reliable assays used to characterize and identify spores. Genetic identification relies on PCR-DNA sequencing to identify the species by their nucleotide sequences (Hansen, B., Leser, T., Hendriksen, N. 2001. Polymerase chain reaction assay for the detection of Bacillus cereus group cells. FEMS Microbiology Letters 202: 209-213; Kolbert, C., Persing, D. 1999. Ribosomal DNA sequencing as a tool for identification of bacterial pathogens. Microbiology 2:299-305; Lindstrom, M. et al., 2001. Multiplex PCR assay for detection and identification of Clostridium botulinum types A, B, E, and F in food and fecal material. Appl. Environm. Microbiol. 67:5694-5699; US 2003/0203362). Phenotypic identification relies on physiological profiling such as the Sherlock Microbial Identification System (MIDI Inc., Newark, Del.), and BIOLOG, (Biolog, Inc., Hayward, Calif.). The MIDI system utilizes fatty acid analysis of the bacterium, and assigns a numerical value to the results, called a similarity index. This similarity index is then compared to an internal library which chooses the most similar identities for the microbes in question. BIOLOG is a cell-based test for utilization of carbon sources. It requires a 96-well plate with multiple carbon sources from which color changes are compared to a Biolog library to determine the identification of the bacterium. Steady-state fluorescence is a powerful tool for distinguishing differences in molecules and macromolecules and the technique may prove useful in examining spores. Fluorescence spectroscopy utilizes emission peaks to characterize spores. It is a sensitive technique because excitation is performed at a single wavelength. The resulting emission data are recorded at a longer wavelength. Bronk and Reinisch (1993) concluded that initial microbial identification could be generated using fluorescence spectroscopy. All spore assays are influenced by environmental contaminants (Kuske, et al., 1998, Balser, et al. 2002, Gamo et al. 1999) and each would benefit from isolation, concentration and purification.
[0012] One technique that may aid in spore isolation and concentration from environmental samples is to use partitioning into hexadecane or some similar hydrophobic material whereby hydrophobic spores would partition into the hydrocarbon and hydrophilic spores would remain in the aqueous phase.
[0013] Thus spores are commonly more heat-resistant than the cells of the micro-organism, also because they do not require an active metabolism during the spore stage. Yet, on return of favourable conditions the spores can develop into colonizing micro-organisms and then are able to cause enormous health-risks. Until now no genomics-based techniques have been developed to assay the amount and viability of spores after preservation treatment without the requirement of pregermination of the surviving spores.
SUMMARY OF THE INVENTION
[0014] The invention now provides for an easy and reliable assay to measure the viability and/or detonation (e.g. by damaging) of spores during or after preservation treatment. The assay uses biomarkers, comprising RNAs, more especially ribosomal RNAs (rRNAs) and messenger RNAs (mRNAs). It has now been found that preservation treatments such as a heat treatment or pressure degrades these RNAs and also that the sensitivity towards degradation varies within these ribonucleotides
[0015] Thus, the invention provides a method to measure viability of bacterial spores, which have been subjected to a preservation treatment, such as heat, pressure, radiation or combinations of these, chemicals like hypochlorite, benzoates, nitrites and sulphites, and pEF (pulsed electric fields, comprising measuring the degree of degradation of RNA by said treatment in said spores, particularly wherein the RNA is either ribosomal RNA (rRNA), messenger RNA (mRNA) or both, more particularly wherein the treatment is heat treatment.
[0016] Another embodiment of the invention is a method to assay the effect of heat preservation methods by performing a method as described above.
[0017] Alternatively, the invention provides a method to assay bacterial contamination after heat or radiation preservation by performing a method according to the invention.
[0018] The invention also provides a heat preservation method comprising
[0000] a) maintaining a sample at a certain temperature for a certain time;
b) performing a method according to the invention.
[0019] Another embodiment of the present invention is formed by the use of RNA in microbial spores as a biomarker for viability.
LEGENDS TO THE FIGURES
[0020] FIG. 1 shows survival of B. subtilis 168 spores after heat treatment at the indicated temperatures during the time period depicted on the X-axis. The Y-axis indicates logarithmically the number of colony forming units (cfu).
[0021] FIG. 2 shows a Bioanalyzer pseudogel of RNA isolated from B. subtilis 168 spores treated at three different temperatures (90° C., 98° C. and 105° C.) each during four different time periods (2, 5, 10 and 20 minutes), indicating the integrity of the RNA. The left lane represents molecular weight control.
[0022] FIG. 3 shows the results of survival counts of two B. subtilis strains (168 and A163) which have been heat treated at the indicated temperatures (X-axis) during a period of 5 minutes. Y-axis as in FIG. 1 .
[0023] FIG. 4 shows a Bioanalyzer pseudogel of RNA isolated from the spores. Treatments identical as in FIG. 3 .
[0024] FIG. 5 Shows a heat map of spore mRNAs (in duplo, indicated on the right) measured during germination. Red color indicates presence of transcript, green color indicates absence.
[0025] FIG. 6 shows ethidium bromide stained gels of three PCR products (Bs-2 (=coxA), Bs-4 (=ykzE) and Bs-7 (=sspE) obtained through RT-PCR from the spore mRNA. In each panel the left lane shows the molecular weight marker.
[0026] FIG. 7 indicates survival of B. subtilis 168 spores after heat treatment at 98° C. for the indicated time periods (X-axis). Y-axis as in FIG. 1 .
[0027] FIG. 8 depicts the results of the quantitative analysis of degradation of spore rRNAs and mRNAs. The bars indicate the 10 log value of the decrease in RNA concentration measured in treated spores in comparison with untreated spores. Spores and treatments in FIG. 7 .
[0028] FIG. 9 shows a Bioanalyzer pseudogel of RNA isolated from C. botulinum spores treated at three different temperatures (80° C., 105° C. and 110° C.), the last two during three different time periods (5, 10 and 15 minutes), indicating the integrity of the RNA. The left lane (M) represents molecular weight control. Lane 1 is untreated, Lane 2 is treatment at 80° C. for 10 minutes. Lanes 3, 4 and 5 is treatment at 105° C. for 5, 10 and 15 minutes respectively. Lanes 6, 7 and 8: ibid for 110° C.
[0029] FIG. 10 Top panel: Ethidium bromide stained gels showing denaturation products of RNA of B. licheniformis ATCC 14580 after heat treatment at 90° C. for 0, 2, 5, 10 and 20 minutes. Bottom panel: viability counts.
[0030] FIG. 11 Top panel: Effect of duration of ultra high pressure treatment on viability of B. subtilis spores. Bottom panel: Bioanalyzer pseudogel. Lanes represent the following treatments:
[0000] M: molecular size marker
1: RNA from control sample (untreated spores)
2: RNA from spores subjected to high pressure (600 MPa) for 2 minutes
3: RNA from spores subjected to high pressure (600 MPa) for 10 minutes
4: RNA from spores subjected to high pressure (600 MPa) for 30 minutes
DETAILED DESCRIPTION OF THE INVENTION
[0031] The presence of messenger RNA is microbial spores has been disputed. Some old literature indicates that spores contain mRNAs (Aronson A. J., 1965, Mol. Biol. 13:92-104; Jeng Y. H. and Doi R. H., 1974, J. Bacteriol. 119:514-521), while other authors report an absence (Halvorson H O, Vary J C, Steinberg W. J, (1966). Developmental changes during the formation and breaking of the dormant state in bacteria. Annu Rev Microbiol 20:169-88; R. H. Doi and R. T. Igarashi (1964) RIBONUCLEIC ACIDS OF BACILLUS SUBTILIS SPORES AND SPORULATING CELLS. Bacteriol. February; 87(2): 323-328). However, nowhere in the art identification of spores on basis of mRNA or other RNA sequences is taught.
[0032] It has now appeared that Bacillus subtilis spores contain ribosomal RNAs (more particularly the 16S and 23S rRNAs) and also mRNAs for about 20 gene products. The latter finding is surprising, since it was generally thought that only de novo transcription takes place in spores (during germination). This small group of mRNAs is generated during the last phase of sporulation and is in general rapidly degraded during germination. The function of these transcripts and why they are maintained in the spore is as of yet unclear. A list of the mRNAs that are found in spores is given in Table 1.
[0000]
TABLE 1
List of spore mRNA found in spores of B. subtilis 168.
Gene Details
Gene name
BG14189
yozQ
BG14179
sspN
BG14174
sspJ
BG13937
ytzC
BG13861
ythQ
BG13859
ythC
BG13782
coxA
BG13430
ymfJ
BG13334
ykzF
BG13333
ykzE
BG13008
yhdB
BG12879
yfhD
BG11921
sspP
BG11920
sspO
BG11806
tlp
BG11670
yqfX
BG11600
yhcV
BG11595
yhcQ
BG11592
yhcN
BG10789
sspE
BG10108
sspF
[0033] The presence of both rRNA and mRNA enables using molecular biological techniques to study survival and/or heat resistance in spores during radiation and heat treatment (e.g. for preservation). One of the findings of this invention is that both rRNA and mRNA are being degraded during heat treatment, which degradation coincides with the loss of viability of the spores. Degradation predominantly depends on the type of micro-organism: in spores of a more heat resistant micro-organism the degradation of the RNA starts at higher temperatures. Thus, the degradation of RNA is an excellent parameter for determination of the viability and/or (sublethal/postmortal) damage of the spores.
[0034] Molecular biological assays for the detection of RNA and/or determination of the length of the RNA fragments can now be used to assess the viability of spores in (food and other) samples. This is not only useful during development of preservation methods on basis of heat treatment, but these assays can also be applied in the regular testing of the condition of food samples, e.g. by the commodity inspection department.
[0035] Typically, for the molecular biological methods of the invention, first the RNA of the spores has to be isolated from the sample. To enrich the sample for spores, methods which are well known to a person skilled in the art can be used (e.g. Vaerewijck, M. J. M. et al. (2001) J. Appl. Microbiol. 91:1074-1084). Then, spores are lysed and RNA is extracted using commonly known techniques. RNA isolation from spores can, for instance, be done through a commercially available kit, such as the BIO101-FASTRNA Pro Blue kit (QBIOGENE cat no 6025-050). To remove superfluous DNA from the RNA, the extracted sample can be treated further with a DNAse1, such as present in the TURBO DNA-free kit (AMBION, cat no 1907).
[0036] Determination of the length of the RNAs can be performed on normal gels, such as denaturing agarose gels, but it is also possible to analyse the integrity of the RNA on a bioanalyzer RNA chip, such as a RNA 6000 Nano LabChip (Agilent Technologies cat no 5065-4476) using a 2100 bioanalyzer (Agilent Technologies, cat no G2940CA). The integrity of the isolated RNA samples is normally derived from the relative intensity of the bands for the ribosomal subunits (16S and 23S). When the RNA is intact the ratio between 23S and 16S is about 2:1. On RNA degradation this ratio shifts usually in favour of 16S RNA and increasingly RNA debris is found.
[0037] In order to make detection more sensitive the nucleotides in the sample can be amplified, e.g. through an RNA amplification kit, such as Nucleic Acid Sequence Based Amplification (NASBA). Alternatively, it is also possible to convert the RNA into DNA by using a reverse transcriptase and then to amplify the DNA by PCR techniques. Methods of the invention can in principle be performed by using any nucleic acid amplification method, such as the Polymerase Chain Reaction (PCR; Mullis 1987, U.S. Pat. No. 4,683,195, 4,683,202, en 4,800,159) or by using amplification reactions such as Ligase Chain Reaction (LCR; Barany 1991, Proc. Natl. Acad. Sci. USA 88:189-193; EP Appl. No. 320,308), Self-Sustained Sequence Replication (3SR; Guatelli et al., 1990, Proc. Natl. Acad. Sci. USA 87:1874-1878), Strand Displacement Amplification (SDA; U.S. Pat. Nos. 5,270,184, en 5,455,166), Transcriptional Amplification System (TAS; Kwoh et al., Proc. Natl. Acad. Sci. USA 86:1173-1177), Q-Beta Replicase (Lizardi et al., 1988, Bio/Technology 6:1197), Rolling Circle Amplification (RCA; U.S. Pat. No. 5,871,921), Cleavage Fragment Length Polymorphism (U.S. Pat. No. 5,719,028), Isothermal and Chimeric Primer-initiated Amplification of Nucleic Acid (ICAN), Ramification-extension Amplification Method (RAM; U.S. Pat. Nos. 5,719,028 and 5,942,391), LATE-PCR (Sanchez, J. A. et al (2004) PNAS USA 101:1933-1938) or other suitable methods for amplification of DNA.
[0038] For quantitative assays a Real Time-PCR or a semi-RT-PCR can be used. All of these amplification techniques are known by the person skilled in the art, and application of those can be found in the Examples, hereunder.
[0039] The detection of the amplification products can in principle be accomplished by any suitable method known in the art. The detection fragments may be directly stained or labelled with radioactive labels, antibodies, luminescent dyes, fluorescent dyes, or enzyme reagents. Direct DNA stains include for example intercalating dyes such as acridine orange, ethidium bromide, ethidium monoazide or Hoechst dyes. Alternatively, the DNA fragments may be detected by incorporation of labelled dNTP bases into the synthesized DNA fragments. Detection labels which may be associated with nucleotide bases include e.g. fluorescein, cyanine dye or BrdUrd.
[0040] Amplification can be used to detect the integrity of the RNA sequences because amplification primers can be chosen in such a way that only (nearly) complete, i.e. not yet degraded sequences will be amplified. A suitable way to accomplish this is by choosing a forward amplification primer which corresponds with a sequence at the 5′ end of the sequence which needs to be amplified. Consequently, the backward or reverse primer should be chosen to correspond with a sequence at the 3′ end of the sequence to be amplified. Only if forward and reverse primer anneal to one and the same (intact) RNA stretch amplification will occur; if the target sequence has been degraded by heat or radiation treatment a fragment will at the utmost only contain the recognition site for one of the set of primers and no amplification will take place. Further, a quantitative determination of the amplicons at the 3′ end and the 5′ end gives an indication of the amount of fragmentation of the target nucleic acid.
[0041] The term “primer” as used herein refers to an oligonucleotide which is capable of annealing to the amplification target allowing a DNA polymerase to attach thereby serving as a point of initiation of DNA synthesis when placed under conditions in which synthesis of primer extension product which is complementary to a nucleic acid strand is induced, i.e., in the presence of nucleotides and an agent for polymerization such as DNA polymerase and at a suitable temperature and pH. The (amplification) primer is preferably single stranded for maximum efficiency in amplification. Preferably, the primer is an oligodeoxy ribonucleotide. The primer must be sufficiently long to prime the synthesis of extension products in the presence of the agent for polymerization. The exact lengths of the primers will depend on many factors, including temperature and source of primer. A “pair of bi-directional primers” as used herein refers to one forward and one reverse primer as commonly used in the art of DNA amplification such as in PCR amplification.
[0042] If the nucleotide sequences from the sample are subjected to amplification for the detection of RNA integrity, it is a prerequisite that from each micro-organism (i.e. from each spore) at least one sequence is amplified. Therefore, primer sets should be chosen which recognise all possible micro-organisms present. This can be achieved by identifying conserved sequences, which are shared by all the micro-organisms. Since it is sometimes impossible to cover all micro-organisms with one and the same primer set, it is envisaged that more than one pair of bidirectional primers is needed to be present in de amplification reaction mixture to enable amplification of at least one sequence from all possibly present micro-organisms. Luckily, the 16S and 23S rRNA are rich in stretches of conserved sequences. Alternatively, or in addition to that, it is also possible to use degenerated primers, i.e. primers which do not or less suffer from any mismatches between the primer sequence and the target sequence on the gene to be amplified, thereby allowing for hybridisation of the primer to a target sequence with a lower homology.
[0043] Another method to determine the viability and/or amount of damage to the spores is to assess for the ratio of intact DNA versus intact RNA. As already mentioned in the introduction, the spores also contain DNA, which has other temperature sensitivity than RNA (see e.g. Setlow, P. 1995. Mechanisms for the prevention of damage to DNA in spores of Bacillus species. Annu. Rev. Microbiol. 49:29-54; and Setlow, P. 1999. Bacterial spore resistance, p. 217-230. In G. Storz, and R. Hengge-Aronis (ed.), Bacterial stress responses. American Society for Microbiology, Washington, D.C). In a control experiment it can be determined for a particular bacterial strain how the ratio of DNA:RNA develops when the spores are subjected to heat treatments, and at which ratio the spores are lethally damaged or lost their viability. A simple detection of the amounts of DNA and the amounts of RNA can then be used to determine viability and/or damage.
[0044] Use of the methods of the invention can of course be found in the food-industry. Not only detection of contamination of actual foodstuffs can be performed through the methods of the invention, these methods also are a useful tool in the development of (new) preservation methods for different types of samples (predominantly food). The methods enable monitoring of preservation processes and quick feedback on the results thereof. Also, as a result of better preservation techniques, next to a decrease of product loss also savings of energy and water can be obtained.
[0045] Besides the food industry, the present invention can also be applied in other areas where preservation treatments, such as heat and/or radiation and/or pressure, chemicals, such as hypochlorite, benzoates, nitrites and sulphites, and pEF (pulsed electric field) are used for sterilisation (i.e. killing of micro-organisms). An example of such an area is in the medical environment where surgical instruments, hospital consumables, such as bandages and surgical gloves, and also patient waste material require sterilisation.
EXAMPLES
Example 1
Heat Inactivation of Bacillus subtilis Spores
[0046] Spores of Bacillus subtilis 168 [ Bacillus genetic stock center: http://www.bgsc.org/BGSCID:] were generated by culture in synthetic MOPS medium (1.32 mM K 2 HPO 4 , 0.4 mM MgCl 2 , 0.276 mM K 2 SO 4 , 0.01 mM FeSO 4 , 1.36 mM CaCl 2 , 80 mM MOPS (morpholinepropane sulfonic acid), 4 mM tricine, 3 nM (NH 4 ) 6 Mo 7 O 24 , 0.4 μm H 3 BO 3 , 30 nM CoCl 2 , 10 nM CuSO 4 , 10 nM ZnCl 2 , 0.1 mM MnCl 2 , 20 mM glucose and 10 mM ammoniumchloride). The thus obtained spores were purified with 10 steps of washing with demineralised water at 4° C. The purity of the spores was monitored with a phasecontrast microscope (>99% phase bright). Heat treatment of the spores was done according to Kooiman et al. (“The screw cap tube technique: A new and accurate technique for the determination of the wet heat resistance of bacterial spores”. In: Spore Research, ed: Barker, A. N., Gould G. W. and Wolf, J., 1973, Academic Press, London, pp. 87-92). Survival was counted by plating serial dilutions of the samples in a peptone saline solution on TSA (tryptric soy agar, DIFCO, the Netherlands).
[0047] Results are shown in FIG. 1 . It appears that spores of B. subtilis 168 were able to survive heat treatment of 90° C., but that survival declines at temperatures of 98° C. and higher.
Example 2
Degradation of rRNA
[0048] From the heat treated spores of Example 1 the RNA was isolated with a BIO101-FASTRNA Pro Blue kit (QBiogene #6025-050) according to the manufacturer's instructions, with the modification that the spores were processed 3 times 40 seconds in the FastPrep apparatus (QBiogene #6001-220) on setting 6 with 2 minutes of cooling on ice in between the lysis steps. After precipitation the RNA was treated with the TURBO DNA-free kit (AMBION #1907) according to the manufacturer's instructions. The integrity of the RNA was analysed on a RNA 6000 Nano LabChip (Agilent Technologies #5065-4476) with a 2100 bioanalyzer (Agilent Technologies #G2940CA).
[0049] At relatively low temperature treatments two clear bands are visible on the Bioanalyzer pseudogel, which indicate the presence of 16S and 23S rRNA, in a about 1:1.8 ratio ( FIG. 2 ). The intensity of the bands becomes weaker at higher temperatures and/or longer treatment times. This coincides with the appearance of RNA material of low molecular weight.
[0050] To investigate whether the degradation of RNA in the spores is dependent on the heat resistant properties of the spores, also the spores of a micro-organisms with a known higher heat resistance were tested. For this spores of the isolate B. subtilis A163 (Kort R, O'Brien AC, van Stokkum I H, Oomes S J, Crielaard W, Hellingwerf K J, Brul S. Assessment of heat resistance of bacterial spores from food product isolates by fluorescence monitoring of dipicolinic acid release. Appl Environ Microbiol. 2005 July; 71(7):3556-64). were chosen. Spores were generated and heat treated in the same way as the B. subtilis 168 spores of Example 1. The results are shown in FIGS. 3 and 4 . While the viability of B. subtilis 168 spores decreases by 1 log after treatment at 98° C. for 5 minutes, there is no indication of loss of viability in B. subtilis A163 spores after this treatment. A comparable loss of viability in the latter spores only has been demonstrated at a temperature of 115° C. The integrity of the rRNA from B. subtilis 168 remained intact at 80° C., but degradation was observed at temperatures of 90° C. and higher (in concordance with the previous experiment). In contrast, the integrity of the RNA isolated from B. subtilis A163 appeared intact after treatments up to 98° C. With the 105° C. treatment degradation of the RNA was observed, predominantly of the 23S rRNA. Increasing degradation was observed at higher temperatures.
Example 3
Detection of mRNA in B. subtilis Spores
[0051] Using microarray analysis germination of B. subtilis spores has been studied. Hereto, a B. subtilis oligonucleotide library (Sigma-Genosys #BACLIB96) was spotted onto Corning GAPSII slides (Corning, #40003) according to standard protocols. Cy-labeled cDNA of spore RNA was made by direct incorporation of cy-labeled dUTP according to standard protocols. Hybridisation and washing of the micro-arrays was performed on an automated slide processor (Agilent) and scanning of the micro-array slides was done in an automated slide scanner (Agilent) according to the manufacturer's instructions.
[0052] This showed (see FIG. 5 ) that a small group of mRNA molecules was present (about 20), of which the majority rapidly disappears during germination. Only sspE appeared to be present during the whole germination period. According to the fluorescence intensities of the hybridisation signals of the spore mRNA transcript levels were relatively high.
Example 4
Heat Degradation of mRNA
[0053] a. RT-PCR
[0054] To determine the stability of mRNA after heat treatment the spores were generated and treated as described in Example 1. RNA isolation was performed as described in Example 2. The isolated RNA was subjected to reverse transcription PCR(RT PCR) using Ready-to-Go RT-PCR Beads (Amersham Biosciences #27-9266-01) according to the manufacturer's instructions. Template concentration was between 10 and 200 ng. The primers used (determining 9 of the 20 transcription products) are indicated in Table 2.
[0000]
TABLE 2
RT-PCR Primer sequences
Gene
Primer forward
Primer reverse
TLP
TATCAGCAGCCTAATCCTG
CGTTTTGTCTCGCTGCAG
YHCV
GAGTTCAGTTAAAGATAC
ATACGAGTTCTGTTGACATC
YFHD
GGGCAGAAATCATATCC
CGCTCTGTTGTCGGCTG
YKZE
AACCGTCATAGCAGAGAC
TCAGGCTTGGTGACTTcc
SSPN
ATGGGAAACAACAAGAAAAAC
TCGCCTTTTGTCTGCATG
SSPE
GCTAACTCAAATAACTTCAGC
CAGCAGATTGGTTTTGCTG
COXA
GATACGCGCAATAACGGC
ATATGTTCCGTCAGTTGCC
YQFX
GAAGGTGGCAAACGATTAC
TGATGGACAAGGCTAAAGC
[0000]
TABLE 3
qPCR Primer and probe sequences. The dashes
indicate superbases added for stability of
the probe/primer, see http://www1.qiagen.
com/Products/Pcr/QuantiTect/CustomAssays.
aspx for details
Gene
Forward
Reverse
FAM-labeled
Name
Primer
Primer
Probe
ykzE
GCAGAGACA
CAT*T*GT*
AGGTGCTGGAG
TGCAAAATCA
AAT*CCCCG
GAAGAA
TAA
AGTT
coxA
ATAGACAGG
TCGTCAGCA
TAACCGAAACA
GAGACGGAA
GTAACAC
CCACGA
GGT
16s
GGTCATTGG
CTACGCATT
GAAGAGGAGAG
rRNA
AAACTGGGA
T*CACCG
TGGAA
CTA
23s
CAGGTAACA
TTT*CGGAG
GATGAGGTGT
rRNA
CTGAATGGA
AGAACGAGC
GG*GTAG
TAT
[0055] Products were analysed with agarose gel electrophoresis using staining with ethidium bromide ( FIG. 6 ). In untreated B. subtilis 168 spores for all transcription products, except for Tlp, amplification products could be detected. In untreated B. subtilis A163 spores a clear amplification product was obtained with primers for coxA, ykzE, yhcV, yfhD, and yqfX. A weak signal was obtained with sspE primers and no product was formed using Tlp and sspN primers. Possibly these transcripts do not occur in spores of this B. subtilis strain, or the primer sequences, which have been designed for B. subtilis 168 sequences, would not be suited for the A163 isolate.
[0056] In many cases in heat treated spores, a decrease in the amount of product was observed with increasing treatment temperatures ( FIG. 6 ), which indicates degradation of mRNA. In spores of the A163 strain a similar decrease was observed, but starting at higher temperatures. For Bs-2 (the coxA transcript) no transcripts were detected in 168 spores at treatments temperatures of 98° C. and higher, while for A163 spores a decrease was only observed at temperatures of 115° C. Bs-4 (ykzE) did not show a clear decrease in the amount of product, which may be an indication that this transcript is less sensitive to heat treatment. Alternatively, the effect could be caused by the quantitative character of the RT-PCR experiment. To investigate this further for a limited set of RNAs a quantitative PCR (qPCR) was performed.
[0057] b. qPCR
[0058] B. subtilis 168 spores were heat treated at 98° C., the survival was measured by plating and culturing, and the spore RNA was isolated as described above. Reverse transcription of the spore RNA was performed using a RETROscript kit (Ambion, #1710) according to the manufacturer's instructions. Quantitative PCR was performed using a QuantiTect Multiplex PCR kit (Qiagen, #204543) on a 7500 Real-Time PCR System (Applied Biosystems). Primers and probes (see Table 2) were designed using the QuantiProbe Design Software (http://customassays.qiagen.com/design/inputsequences.asp). Two primer-probe sets were used to study the effects on the rRNA (16S and 23S). Two primer-probe sets were directed against the ykzE and coxA spore transcripts. In this type of experiments, the number of amplification cycles (C t ) required to reach a certain threshold level, is used to calculate the original amount of template. A titration curve with genomic DNA was used to calibrate. A ten times reduction in template concentration appeared to increase the number of cycles necessary to reach the threshold by three. This calibration was used to interpret the differences in Ct values between the treated and untreated spores.
[0059] FIG. 7 shows the survival of heat treated spores according to the classical plating and culturing assay. FIG. 8 shows the results of the qPCR. It is clear that heat treatment results in a reduction of both the rRNAs and the mRNAs (which is in concordance with the earlier results on basis of gel electrophoresis). It also appears from this more sensitive qPCR that ykzE, which was deemed to be unresponsive in the RT-PCR assay, indeed degrades as a result of the heat treatment.
Example 5
Heat Inactivation of Clostridium botulinum Spores
[0060] Spores of C. botulinum strains NCTC 2916, 7272, 7273, 3806 and 10381 [Health Protection Agency: National Collection of Type Cultures Centre for Emergency Preparedness and Response: http://www.hpa.org.uk/srmd/div_cdmssd_nctc/default.htm] were generated by anaerobic cultivation in complex medium containing bacto peptone (50 g/ltr), trypticase peptone (5 g/ltr), K 2 HPO 4 (1.25 g/ltr), NaHCO 3 (0.75 g/ltr), pH 7.2. The thus obtained spores were purified with 10 steps of washing with demineralised water at 4° C. The purity of the spores was monitored with a phasecontrast microscope (>99% phase bright). Heat treatment of the spores was done according to Kooiman et al. (“The screw cap tube technique: A new and accurate technique for the determination of the wet heat resistance of bacterial spores”. In: Spore Research, ed: Barker, A. N., Gould G. W. and Wolf, J., 1973, Academic Press, London, pp. 87-92). Survival was counted by plating serial dilutions of the samples in a peptone saline solution on Schaedler Anaerobic Agar (tritium microbiologie, the Netherlands http://www.tritium-microbiologie.nl/eindex.htm) Spores (10 7 spores/ml) were heat treated by heating them for 5, 10 or 15 minutes at a temperature of 80° C., 105° C. or 110° C.
[0061] Survival of the spores at these temperatures is indicated in Table 1.
[0000]
TABLE 1
Survival of C. botulinum spores at different heat treatments
Treatment
5 minutes
10 minutes
15 minutes
untreated
10 7
80° C.
10 7
105° C.
58
0
0
110° C.
0
0
0
Example 6
Degradation of rRNA
[0062] From the heat treated spores of Example 5 the RNA was isolated with a BIO101-FASTRNA Pro Blue kit (QBiogene #6025-050) according to the manufacturer's instructions, with the modification that the spores were processed 3 times 40 seconds in the FastPrep apparatus (QBiogene #6001-220) on setting 6 with 2 minutes of cooling on ice in between the lysis steps. After precipitation the RNA was treated with the TURBO DNA-free kit (AMBION #1907) according to the manufacturer's instructions. The integrity of the RNA was analysed on a RNA 6000 Nano LabChip (Agilent Technologies #5065-4476) with a 2100 bioanalyzer (Agilent Technologies #G2940CA).
[0063] At relatively low temperature treatments clear bands are visible on the Bioanalyzer pseudogel, The intensity of the bands becomes weaker at higher temperatures and/or longer treatment times. This coincides with the appearance of RNA material of low molecular weight.
[0064] Results are shown in FIG. 9 . It appears that spores of C. botulinum were able to survive heat treatment of 80° C., but that survival declines at temperatures of 105° C. and higher.
Example 7
Degradation of RNA Isolated from Heat Treated B. licheniformis ATCC 14580 Spores
[0065] B. licheniformis ATCC 14580 (www.atcc.org) spores were treated for 2, 5 10 and 20 minutes at 90° C. Plate counts were used to establish the inactivation rate. Briefly, dilution series of spore suspensions were prepared in 0.1% peptone-0.85% NaCl and added to Trypticase soy agar pour plates. The number of colonies was counted after 4 days of incubation at 37° C. All heat inactivation experiments and viability counts were carried out in duplicate. RNa was isolates an the integrity was examined by denaturing agarose gel electrophoresis (Sambrook J, Fritsch E F, Maniatis T. 1989 Molecular Cloning, A Laboratory Manual, Second Edition. Cold Spring Harbour Laboratory Press). Spore viability decreased with the treatment time resulting in a decrease in viability counts. In parallel, RNA integrity was found to decrease during the thermal treatment of the spores. (see FIG. 10 ).
Example 8
Effects of UHP Treatment on Integrity of B. subtilis Spore RNA
[0066] B. subtilis 168 spores were treated for 2, 10 and 30 minutes at 600 MPa at an initial temperature of 50° C. Upon pressurization, the temperature adiabatically increased to approximately 6° C. Plate counts were used to establish the inactivation rate. Briefly, dilution series of spore suspensions were prepared in 0.1% peptone-0.85% NaCl and added to Trypticase soy agar pour plates. The number of colonies was counted after 4 days of incubation at 37° C. All heat inactivation experiments and viability counts were carried out in duplicate. RNA was isolated and the integrity was examined by Bioanalyzer (Agilent).
[0067] For results, see FIG. 11 . Spore viability decreased with the treatment time resulting in a decrease in viability counts. In parallel, RNA integrity was found to decrease during the thermal treatment of the spores. The thermal treatment without an increase in pressure did not result in spore inactivation or loss of integrity of spore RNA.
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The invention lies in the field of microbiology, more particularly in the field of (food) preservation and testing of viability of microbiological spores. It is shown that measurement of the integrity of both rRNA and mRNA in spores is an accurate indicator of viability. Nucleotide assays then form a significant improvement over the state of the art assays for viability.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns fuel-efficient vehicles, and more particularly relates to automotive vehicles powered by both an electric motor and an internal combustion engine, popularly known as “hybrid” vehicles.
2. Description of the Prior Art
Hybrid vehicles have been developed to improve the fuel efficiency of motor vehicles. They are powered by both an internal combustion engine and an electric motor energized by rechargeable storage batteries. The combined power of both power sources is used when maximal power is needed, such as for acceleration, towing heavy loads or climbing steep grades. The engine is generally used for cruising, and is usually severely down-sized to achieve fuel efficiency. The electric motor can be used alone but only for relatively short distances because of the limited power capacity of the batteries which soon become discharged and lose their power. Consequently, the electric motor is usually simply used to augment the power of the engine for some fairly short duty cycles such as to quickly accelerate the vehicle from a standing start and for passing. Performance can deteriorate for longer heavy duty cycles such as when climbing long grades or towing heavy loads when the down-sized engine may have to toil alone without assistance from the electric motor after the batteries become discharged.
Some hybrid vehicles have been modified to increase the cruising range of the electric motor by adding substantial numbers of storage batteries to the vehicle, and then by charging these batteries overnight using household electricity. Although such vehicles can travel as much as 60 miles between charges, and with little use of gasoline, the cost of the extra batteries is considerable. The batteries also have limited life expectancy, and the added weight of the batteries adversely affects the vehicle's fuel efficiency.
Examples of hybrid vehicles involving an internal combustion engine and one electric motor are found in the following U.S. Pat. Nos.
5,513,719
5,788,003
6,044,922
6,209,672
6,328,671
6,668,954
6,706,789
6,712,165
6,958,549
6,995,480
7,004,273
7,028,796
Hybrid vehicles involving a single internal combustion engine in exemplified or suggested association with two or more electric motors are disclosed in the following U.S. Pat. Nos.
5,343,971
6,717,281
6,856,035
6,959,237
6,962,224
6,965,173
7,044,255
Hybrid vehicles have high initial and maintenance costs due to the need for an especially down-sized engine, batteries of high amperage capacity, and the associated specialized control components. These requirements make it difficult to apply current hybrid technology as after-market modifications for converting current standard automotive vehicles into fuel-efficient hybrid vehicles.
The present invention provides cost-effective solutions to the problems cited above.
Firstly, it enables the vehicle to cruise for long distances powered by an electric motor without the need for a substantially increased number of high-capacity batteries. Instead, the electric motor is energized by an on-board generator powered by a fuel-efficient internal combustion engine. This permits the vehicle to cruise over long distances with maximal fuel-efficiency using mainly the power from its electric motor. The weight of the added equipment need not significantly affect the fuel economy of the vehicle, and the cost should compare favorably with that of current hybrid vehicles.
Secondly, this invention achieves the desired fuel economy for long distance cruising without sacrificing the vehicle's performance, particularly in acceleration, load-bearing, towing and hill-climbing. This is done through the use of a separate auxiliary “accelerator” engine to add to the power of the electric motor whenever more power is needed. Since the accelerator engine is usually operated only for short periods of time, and is usually not operated while the vehicle is traveling over long distances at cruising speed, its size, power and fuel consumption need not substantially impact the over-all fuel efficiency of the vehicle. Hence, the operator can enjoy the comfort and confidence of having as much power as he desires under the hood and yet, with properly prudent driving technique, cruise with high fuel-efficiency over long distances.
This invention further permits great versatility in the choice of both the generator engine and accelerator engine. For example, the generator engine can be a small diesel engine, powerful enough to keep the batteries fully charged, and the accelerator engine can be a powerful gasoline engine, such as a Wankel rotary engine, for quick throttle response and lively performance.
The power train aspect of the present invention is easily adaptable for use as an add-on after-market modification of some existing motor vehicles which are thereby converted into fuel-efficient hybrid vehicles in a cost-effective manner.
It is accordingly a primary object of this invention to provide a hybrid vehicle capable of cruising for long distances using power from an electric motor without the need for high storage battery capacity.
It is an additional object of the present invention to provide a hybrid vehicle capable of cruising for long distances with maximal fuel-efficiency, without sacrifice of acceleration, hill climbing, and load-carrying capabilities.
It is another object of this invention to provide a fuel-efficient hybrid power train which can be installed into an existing automotive vehicle as an after-market add-on modification requiring minimal changes in said vehicle.
In one aspect of the present invention, a conventional non-hybrid vehicle having a regular engine with a horsepower in the range of about 100 to 350, a 12 volt battery, and a generator that is belt-driven by the vehicle's drive shaft is converted into a hybrid vehicle by the introduction of the following features:
a) an electrically actuated motor of about 50 to 120 horsepower which serves as the main source of power to maintain the vehicle at cruising speed for long distance travel, b) a relatively small, fuel-efficient second internal combustion engine of about 50 to 120 horsepower henceforth referred to as a “generator” engine that drives said generator, and c) control means causing said regular engine, henceforth referred to as the first or “accelerator” engine, to operate only when the vehicle requires additional power, as for acceleration, hill climbing, and carrying heavy loads.
In effect, such converted hybrid vehicle utilizes said motor as its primary source of power for cruising travel, and employs the accelerator engine simply as an auxiliary engine to be used only when additional power is needed. The ratio of the horsepower of the accelerator engine to the horsepower of the generator engine is preferably in the range of 1.5:1 to 3:1.
For ease of operation, the generator engine can be programmed to run automatically whenever the battery needs to be charged and to stop automatically when the battery is fully charged. For added fuel-efficiency, the electric motor can be configured as a motor/generator to charge the battery through regenerative braking, a technology which is well known in the art. For further ease of operation, the accelerator engine can be caused to start automatically whenever the gas pedal is depressed beyond what is needed to run the electric motor at full power, and to be automatically coupled to the output shaft of the electric motor, when its power is needed, through a suitable automatic clutch mechanism such as an overriding sprag clutch. Further savings in fuel consumption can be achieved if the accelerator engine is configured to be automatically shut down, namely deprived of fuel whenever the vehicle is being maintained at cruising speed by the electric motor alone. This may be controlled by the degree to which the gas pedal is depressed. Alternatively, start-up, shut down, engagement and disengagement of the accelerator engine may be controlled through the vehicle cruise control system in response to input signals from speed sensors and/or load sensors associated with the driving wheels.
In a further aspect of the present invention, a hybrid automotive vehicle is provided having a power train comprised of:
1) a first internal combustion “accelerator” engine, 2) speed change transmission means having an input shaft which receives power from said first engine, 3) an electric motor having sufficient power to maintain said vehicle at an acceptable cruising speed and delivering said power in a manner to controllably receive additional power from said first engine, and 4) an electrical supply system comprised of a) a second internal combustion “generator” engine of lesser power than said first engine, b) an electrical generator driven by said second engine, and c) a rechargeable storage battery interactive between said generator and motor.
In preferred embodiments, releasable coupling means are interactive between said accelerator engine and transmission means, enabling controlled automatic transfer of power to said transmission means. Suitable coupling means include free wheeling devices such as an overriding sprag clutch.
Said conveyance of power serves to accelerate said vehicle from a standing start to cruising speed by the combined power of said electric motor and said accelerator engine, and then, when the operator partially releases the gas pedal to stop the acceleration and to simply maintain the vehicle at cruising speed by using power from the electric motor alone, the fuel supply to said accelerator engine is diminished then stopped, causing said accelerator engine to slow down and stop, and as said accelerator engine slows down below the speed of said electric motor, said engine is automatically decoupled from said transmission input shaft through the function of said sprag clutch. Then, if or when the operator depresses the gas pedal again to provide more power than that produced by said electric motor, said accelerator engine is automatically restarted and speeded up to match the speed of said electric motor, causing said accelerator engine to be automatically coupled to said transmission input shaft through the action of said sprag clutch.
The aforesaid hybrid vehicle of this invention achieves four desirable results, namely:
a) It enables said electric motor, powered by said electric generator assembly, to maintain the vehicle at cruising speed with reduced fuel consumption per unit of distance traveled. b) It enables the vehicle to accelerate quickly to cruising speed through the combined power of the electric motor and the accelerator engine. c) It enables the power train, including said accelerator engine, to remain ready to be activated whenever increased power is needed. and d) It enables the operator to selectively control the operation of said motor and said accelerator engine, including the automatic engagement and disengagement of said accelerator engine by simply depressing or releasing the gas pedal in the same manner as would have been required if he were operating a standard non-hybrid motor vehicle.
Said releasable coupling means may be a friction clutch such as the type used with standard manual transmissions, a fluid torque converter of the type generally used with automatic transmissions, a centrifugal clutch, electromagnetic clutch, or other suitable types of releasable coupling means.
In an alternative embodiment, the accelerator engine is coupled to the speed change transmission in the conventional manner (i.e., via a friction dry plate clutch in the case of a manual transmission, or via a fluid torque converter in the case of an automatic transmission) and the vehicle is accelerated from a standing start to cruising speed by power from the accelerator engine alone. After the vehicle reaches cruising speed, the speed change transmission is shifted to neutral and the vehicle is placed in a free-wheeling state.
The electric motor may be coupled to a pinion drive of a differential, completely bypassing the speed change transmission, using a power transfer means which may be an endless chain connected to sprockets, or spur gears, or combinations thereof. For added speed flexibility, a continuously variable torque converter may be installed between the electric motor output shaft and said power transfer means.
BRIEF DESCRIPTION OF THE DRAWING
With these and other advantages in view, the invention is disclosed in the following description which will be more fully understood when read in conjunction with the following drawings in which:
FIG. 1 is a schematic top view, partly in section, of an embodiment of the hybrid vehicle of this invention equipped with an automatic transmission.
FIG. 2 is a magnified fragmentary view of a portion of FIG. 1 .
FIG. 3 is a schematic top view, partly in section, of a first alternative embodiment of this invention equipped with a manual transmission.
FIG. 4 is a magnified fragmentary view of a portion of FIG. 3 .
FIG. 5 is a schematic top view of a second alternative embodiment of this invention.
FIG. 6 is a schematic top view of a third alternative embodiment of this invention.
FIG. 7 is a schematic top view of a fourth alternative embodiment of this invention.
FIG. 8 is a schematic top view of a fifth alternative embodiment of this invention.
For clarity of illustration, details which are not relevant to the invention, such as engine mounts, electrical circuits, transmission mounts, internal parts of the speed change transmission, differential, transaxle, sprag clutch and continuously variable torque converter, etc., have been omitted from the aforesaid drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the above drawings wherein one character designates one part of the vehicle, FIG. 1 shows the vehicular chassis 11 connected to the front bumper 12 and rear bumper 13 , and supported by front wheels 14 and rear wheels 15 .
Accelerator engine 16 , mounted on chassis 11 , has flywheel 17 and output shaft 18 interactive with releasable coupling means in the form of sprag clutch 20 , whose inner race 19 is fixedly mounted upon output shaft 18 . Outer race 21 of sprag clutch 20 is fixedly mounted within the hub 40 of the armature 22 of electric motor 23 so that armature 22 is freely rotatable on output shaft 18 in one direction, particularly when armature 22 is spinning faster than output shaft 18 , but would be fixedly locked to output shaft 18 if shaft 18 were to tend to spin faster than armature 22 . Field coils 24 of electric motor 23 are mounted on bell housing extension 25 which is fixedly bolted to accelerator engine 16 , and upon which bell housing 26 of automatic transmission 27 is in turn fixedly bolted.
Armature 22 is connected to electric motor output shaft 28 which extends through rear wall 29 of bell housing extension 25 and is supported by bearings 30 mounted on rear wall 29 . Electric motor output shaft 28 terminates in a motor flywheel 31 which supports the driving vanes 32 of fluid torque converter 33 whose output shaft 34 extends rearward to become the input shaft 35 of automatic transmission 27 .
Electric motor 23 is energized by electricity generated by generator 36 from power produced by generator engine 37 , and supplemented by electricity stored in battery 38 .
To start the vehicle, the operator depresses the accelerator (or “gas”) pedal which activates a rheostat that controls how much electricity will be allowed to flow from battery 38 and generator 36 to electric motor 23 which then begins to spin armature 22 , output shaft 28 and driving vanes 32 of fluid torque converter 33 . Generator engine 37 may be configured to start running as soon as a substantial amount of current begins to flow from battery 38 to motor 23 or it may be programmed to automatically start as soon as the battery 38 is discharged to a predetermined degree. When the gas pedal is depressed far enough for full power to be produced by electric motor 23 , the gas pedal also closes a start switch for the accelerator engine 16 , turns on the ignition and begins to open the gas supply so that accelerator engine 16 starts running, initially at “idle” speed. The transmission 27 may then be shifted to “drive” or “reverse.” When the gas pedal is depressed further the accelerator engine 16 will run faster and eventually match the rotational speed of electric motor 23 . At this point the inner race 19 and other race 21 of sprag clutch 20 will automatically lock together and couple output shaft 18 to armature 22 so that combined power from both the accelerator engine 16 and electric motor 23 will be transmitted to fluid torque converter 33 thence to automatic transmission 27 , and thence to differential 34 and rear wheels 15 .
When the vehicle has reached the desired speed, the operator simply eases up on the gas pedal until the accelerator engine 16 slows down and stops, and then maintains slight pressure on the gas pedal to regulate power from the electric motor 23 to maintain the cruising speed of the vehicle. When more power is needed to accelerate or climb a grade the operator needs only to depress the gas pedal to generate more power from electric motor 23 , and if necessary depress it further to restart and run accelerator engine 16 to supply added power. These are exactly the same maneuvers that the operator would have had to do were he driving a currently standard vehicle similarly equipped with an automatic transmission.
Turning now to FIG. 3 , there is shown the first alternative embodiment of the invention applied to a front-engine/rear-wheel drive vehicle with manual transmission. Accelerator engine 41 has an output shaft 42 upon which is fixedly mounted the inner race 43 of sprag clutch 44 . The outer race 45 of sprag clutch 44 is fixedly mounted on the hub 46 of the armature 47 of electric motor 48 . When both accelerator engine 41 and electric motor 48 are in operation, they rotate coaxially in the same direction. Sprag clutch 44 permits electric motor 48 to rotate freely in its operational direction relative to output shaft 42 , but not in reverse, so that if said output shaft 42 were to tend to rotate faster than electric motor 48 , sprag clutch 44 will lock the two together, causing them to turn at the same speed and transmit their combined power through electric motor output shaft 49 to friction clutch 50 which is a standard dry plate clutch operated through a clutch foot pedal.
To operate the vehicle, the accelerator engine is started and run initially at idle speed, causing the sprag clutch to engage so that both engine 41 and electric motor 48 are running at the same speed. The clutch is depressed, the transmission is shifted to first gear, and the accelerator pedal is depressed to feed current to electric motor 48 and, if depressed further, to feed fuel to engine 41 , whereupon the clutch pedal is gradually released to engage the clutch 50 and move the vehicle on the combined power of accelerator engine 41 and electric motor 48 . The transmission 51 is shifted through the gears in the usual manner, and when cruising speed is reached the operator eases on the accelerator pedal to cause accelerator engine 41 to slow down to idle speed and yet allow electric motor 48 to produce enough power to maintain the vehicle at cruising speed. The accelerator pedal is calibrated in such a way that when it is depressed one-third of the way down only a rheostat which controls power from the electric motor 48 is operated, and then when the pedal is depressed further, increasing amounts of fuel are fed to accelerator engine 41 . When the accelerator engine slows below the speed of electric motor 48 , the sprag clutch 44 automatically disengages the output shaft 42 of engine 41 from the hub 46 of electric motor 48 , thereby disengaging accelerator engine 41 from transmission 51 . The vehicle then cruises solely on power from electric motor 48 which draws current from battery 52 which is kept fully charged by generator 53 powered by generator engine 54 .
FIG. 5 illustrates a second alternative embodiment adapted to be more easily retro-fitted to a standard front-engine/rear wheel drive vehicle. Accelerator engine 55 is the stock regular engine of the vehicle, mated to a standard transmission 56 which may be manual or automatic, transmitting power through propeller shaft 57 , pinion 58 and differential 59 to drive (rear) wheels 60 . Electric motor 61 supplies power through splined short propeller shaft 62 , jack shaft 63 , drive chain 64 , sprockets 65 and 66 , and thence to pinion 58 . Generator engine 69 powers generator 68 which keeps battery 67 fully charged, and also supplies additional power to electric motor 61 as needed.
The vehicle is accelerated from a standing start to cruising speed by power from the accelerator engine in the usual manner. The transmission is then shifted to neutral and the vehicle is placed in a free wheeling state. Electric motor 61 is then speeded up to provide power for cruising. Meanwhile accelerator engine 55 is on standby to produce additional power as needed. As explained above, this vehicle can travel at cruising speed with less fuel consumption per distance traveled by using the electric motor/electric generator system as compared to traveling long distances on the larger regular (accelerator) engine which consumes more fuel to travel the same distance.
FIG. 6 illustrates a third alternative embodiment of the invention adapted to be easily retro-fitted to a front engine/rear wheel drive vehicle modified to give the electric motor more flexibility of operation at a wider range of speeds and having more torque flexibility as well. Accelerator engine 70 is the regular engine of the vehicle, mated to a standard transmission 71 which may be an automatic transmission or a manual transmission connected to propeller shaft 72 , pinion 73 , differential 74 and wheels 75 . The vehicle is accelerated to cruising speed with power from accelerator engine 70 through speed change transmission 71 in the usual manner. When cruising speed is reached, transmission 71 is shifted to neutral, placing the vehicle in a free wheeling state, and fuel flow to engine 70 is cut off. Electric motor 76 is speeded up to deliver power through drive pulley 77 , drive belt 78 and driven pulley 79 of a movable sheave continuously variable ratio torque converter, thence through splined short propeller shaft 80 , jack shaft 81 , sprockets 82 and 83 and endless chain 84 , thence to pinion 73 to maintain the vehicle at cruising speed. Battery 85 supplies power to electric motor 76 . Generator 86 , powered by generator engine 87 , supplies electricity to battery 85 to keep it fully charged at all times.
FIG. 7 shows how the invention may be fitted or retro-fitted to a front engine/front wheel drive vehicle. Accelerator engine 88 is a regular engine mated to a transaxle 89 which drives half-shafts 90 and front driving wheels 91 . The vehicle is accelerated to cruising speed by power from engine 88 , coursed through transaxle 89 and wheels 91 . After cruising speed is reached, the transaxle is shifted to neutral, placing the vehicle in a free wheeling state. Electric motor 92 is then speeded up to transmit power through splined short propeller shaft 93 to jack shaft 94 , sprockets 95 and 96 and endless chain 97 , thence to pinion 98 , differential 99 and wheels 100 , to maintain the vehicle at cruising speed for economical long distance travel. Battery 101 supplies power to electric motor 92 . Electric generator 102 , powered by generator engine 103 supplies electric current to battery 101 to keep it fully charged at all times, and to supply additional current to electric motor 92 whenever necessary.
FIG. 8 illustrates a fifth alternative embodiment of the invention which uses an electromagnetic power clutch 115 or any similarly suitable clutch means, instead of a sprag clutch. Electric motor 110 is coupled to speed change transmission 111 which is connected to propeller shaft 112 , thence to differential 113 and drive wheels 114 in the usual manner. Electromagnetic power clutch 115 is fixedly mounted on the output shaft 116 of accelerator engine 117 . The output shaft of electromagnetic power clutch 115 is coupled to the main shaft of the rotor of electric motor 110 , which is in turn coupled to said speed change transmission 111 . Accelerator engine 117 can therefore be selectively coupled to speed change transmission 111 via electromagnetic clutch 115 and the main shaft of electric motor 110 .
To accelerate the vehicle, power from both the accelerator engine 117 and electric motor 110 are used. To cruise economically, accelerator engine 117 is decoupled through electromagnetic clutch 115 and stopped and the vehicle is kept at its cruising speed by power from electric motor 110 alone. Electric generator engine 119 drives electric generator 120 which supplies current to electric motor 110 and also charges battery 118 . Electric motor 110 can be configured to be a motor/generator so that it can charge battery 118 through regenerative braking. Battery 118 need not be of high capacity since electric motor 110 can be powered continuously for long distance cruising operation by generator 120 . Battery 118 is only useful to supply supplemental current to electric motor 110 and to supply current to accessory electrical devices in the vehicle, such as the radio, gauges and lights.
Other types of releasable couplings can be used instead of electromagnetic power clutch 115 , and may be selected from a group which includes centrifugal clutches, single disc or multiple disc clutches, cone clutches, toroidal torque converters, pawl and ratchet freewheeling clutches, sprag clutches or any combination thereof.
While particular examples of the present invention have been shown and described, it is apparent that changes and modifications may be made therein without departing from the invention in its broadest aspects. The aim of the appended claims, therefore, is to cover all such changes and modifications as fall within the true spirit and scope of the invention.
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A drive-train for a fuel-efficient wheeled vehicle includes a first internal combustion engine and a second internal combustion engine of lesser power adapted to drive a generator. An electric motor is adapted to drive the vehicle primarily during cruising mode operation. The first engine is employed primarily to provide maximal power to the vehicle for acceleration, hill-climbing and towing. The power from both the motor and first engine can be selectively combined for varied conditions of operation of the vehicle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application relates to and claims the priority of U.S. Provisional Patent Application Ser. No. 61/521,417 filed Aug. 9, 2011 by Charles Kelderhouse and entitled “CO2 Model Car Launcher”, the entire contents and substance of which are hereby incorporated in total by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention comprises an apparatus for launching a plurality of CO2 propelled model cars simultaneously.
[0004] 2. Description of the Prior Art
[0005] The use of pressurized carbon dioxide gas (“CO2”) cartridges to propel model racing cars has been known for a long time. The cartridges used are of the type known to pressurize seltzer bottles and the like. The following prior art devices are typical of relevant model vehicle launchers.
[0006] U.S. Pat. No. 5,711,695 discloses a gas-propelled toy with an exhaust nozzle for a gas cartridge. A plug terminal on the toy prevents the release of the gas from the cartridge and may be pierced by a firing pin. The firing pin may be mounted to a stationary blast wall, or a moveable support, such as a board, or, alternatively, the firing pin may be unattached. Once the plug terminal is pierced, the pressurized gas exits the cartridge through the neck outlet resulting in the creation of thrust.
[0007] U.S. Pat. No. 3,950,889 discloses a pressurized gas driven vehicle and method for launching a group of them where the vehicles are positioned in line with all other vehicles by a starting positioner in the form of a movable barrier pivoted on a hinge and are attached to their respective guide cables. A pressure chamber is mounted in the vehicles and a nozzle, mounted on the rear of the body to enclose the pressure chamber, is provided with a jet outlet passage, through which pressurized gas is released. When released at high velocity through the jet outlet passage, pressurized gas effects a leftward action which, in reaction, propels the car rightward.
[0008] U.S. Pat. No. 5,141,467 discloses a powered toy utilizing explosive caps to drive the toy vehicle from a launcher, the toy having an open-ended detonating chamber portion as a part of the connector portion, which is structured to receive a piston portion or ram portion. The piston portion is affixed to the vehicle and is assembled with the chamber portion to confine a cap of the type used in toy cap guns. When the cap is detonated the sudden expansion of combustion gases in the chamber increases the pressure, causing the piston to be driven from the chamber which rapidly propels the vehicle.
[0009] U.S. Pat. No. 2,803,922 discloses a toy vehicle and launching device therefore, the launching device being operated by pulling back on a plunger rod to compress and place an actuating spring under tension. The car is then placed on the platform with its rear extremity abutting the front wall of the housing and the projection extending through the opening so that its end is located in a predetermined position, after which the plunger rod is released causing the hammer to strike the projection with considerable force to project the car forwardly.
[0010] U.S. Pat. No. 3,844,557 discloses a rocket motor driven model racing vehicle having a reaction engine providing between 12 and 38 newtons of thrust. The racing vehicle is tethered to a monofilament plastic line.
[0011] U.S. Pat. No. 4,690,654 discloses a toy vehicle carrying case and launcher where depression of a firing button causes a projection to contact a firing lever moving a latch out of a vehicle cavity allowing an impact plate to propel the vehicle forwardly by the force of a launching spring.
[0012] U.S. Pat. No. 4,291,878 discloses a starting gate for a multiple-track toy vehicle racing set where the base of the starting gate includes two plate-shaped projections to which the respective ends of tracks can be connected. The base also includes two depressions, each of which constitutes a bay in which a respective charged toy vehicle can be accommodated prior to the beginning of the race.
[0013] U.S. Pat. No. 5,499,940 entitled “Fluid Powering and Launching System for a Toy Vehicle” describes in FIGS. 11 and 12 a manual compressed air system for launching two vehicles simultaneously.
[0014] U.S. Pat. No. 7,601,068 discloses a slot car system for simultaneously launching at least two vehicles at the same time.
[0015] U.S. Pat. No. 4,605,229 entitled “Toy Drag Strip and Starting Tower” describes another device which permits multiple cars to be raced simultaneously side by side.
[0016] In conclusion, the prior art appears to disclose the launching of multiple compressed air devices in at least U.S. Pat. Nos. 3,950,889 and 5,499,940. The launching of multiple model race cars having different forms of propulsion is described at least in the following U.S. Pat. Nos. 3,844,557; 4,291,878; 4,605,299; and, 7,601,068.
[0017] It is very important that any CO2 launcher launch all model vehicles in a totally fair and consistent manner so that the winner of the race is determined by the skill of the model maker and not the launch mechanism.
[0018] While there do appear to be devices for launching two or more vehicles simultaneous, they don't appear to have caught on commercially because they are believed to be expensive to manufacture and relatively unreliable and balky. In contrast, the present invention is inexpensive to manufacture and can be easily assembly by youngsters and safely used. It was in the context of the above prior art that the current invention arose.
SUMMARY OF THE INVENTION
[0019] Briefly described, the present invention comprises an apparatus for simultaneously launching two or more CO2 propelled model racing cars in a safe and consistent manner. The launcher includes a base plate that supports two towers which in turn support two launch modules. A trigger plate is also supported by grooves in another pair of vertical supports attached to the base plate. Each launch module includes a firing pin mechanism that comprises: a rod, a sharp tip at one end of the rod, a knob at the second end of the rod, and a disc located intermediate the knob and the sharp tip. The disc has a short side and a long side so that when properly rotated it can pass through one of the two slots in the trigger plate. The launcher is armed, or cocked, by pulling outwardly on the knob and rotating it so that the disc can pass through one of the two respective slots in the trigger plate then rotated again so that the long, or fat, part of the disc engages the plate itself and is held in that position by the force of a spring inside the launch module. The CO2 Model cars are then placed into the launch modules so that the frangible CO2 exhaust nozzle comes into contact with the sharp end of the firing pin. Pulling sidewise on the trigger plate causes the fat parts of the discs to simultaneously disengage from their respective slots thereby allowing the spring to slam the sharp end of the firing pin into the frangible end of each CO2 cartridge releasing both at the same time so that a fair race can take place. The invention also includes features that allow the launch modules to adjust for model cars of differing heights and also includes a feature that allows launchers to be ganged together so that more than two race cars can be simultaneous launched.
[0020] The invention will be more fully understood by reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 illustrates a typical model race car track according the preferred embodiment of the invention where two cars may be simultaneously launched and race down guide wires towards a stop block at the far end.
[0022] FIG. 2 is a front perspective view of the present invention according to the preferred embodiment thereof.
[0023] FIG. 3A is a front elevation view of the launcher of FIG. 2 .
[0024] FIG. 3B is a left side elevation view of the launcher of FIG. 2 .
[0025] FIG. 3C is a right side elevation view of the launcher of FIG. 2 .
[0026] FIG. 3D is a rear elevation view of the launcher of FIG. 2 .
[0027] FIG. 3E is a top plan view of the launcher of FIG. 2 .
[0028] FIG. 4A is a side cross-sectional view of an individual launch module showing the firing pin mechanism in the post launch position immediately prior to cocking.
[0029] FIG. 4B shows the first step in the cocking process in which the knob is pulled back against the bias of an internal spring.
[0030] FIG. 4C shows the next step in the cocking process in which the knob is rotated so that the disc can pass through the slot in the trigger plate when the trigger plate is in its first prelaunch position.
[0031] FIG. 4D shows the next step in the launch process where the knob is further rotated after the disc passes through the slot.
[0032] FIG. 4E shows the next step in the launch process where pressure on the knob is relaxed so that the long side of the disc contacts the trigger plate and is held there under spring pressure in the pre-launch mode.
[0033] FIG. 4F shows next step in the launch process where the trigger plate is moved sideways so that the discs are no longer held by the trigger plate and so that the discs move through their respective slots under the influence of their internal spring.
[0034] FIG. 4G illustrates the last step in the launch process and comprises a side cross-sectional view of an individual launch module showing the firing pin mechanism puncturing the frangible nozzle of a CO2 cartridge in the released, or fully launched, mode.
[0035] FIG. 5A illustrates a launch module mounted on a tower and shown in a low position.
[0036] FIG. 5B shows the launch module of FIG. 5A moved to a higher position to launch a taller model vehicle.
[0037] FIG. 6 illustrates two launchers attached at the base plate and also shows the use of a dog bone shaped clip to connect two trigger plates together so that four or more model cars can be launched simultaneously.
[0038] FIG. 7A illustrates an alternative embodiment of the invention where the model vehicles comprise a pair of CO2 propelled model boats.
[0039] FIG. 7B illustrates another alternative embodiment of the invention where the model vehicles comprise a pair of CO2 propelled model rockets.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] During the course of this description like numbers will be used to identify like elements according to the different drawings that illustrate the invention.
[0041] FIG. 1 illustrates a typical model race car track according to the preferred embodiment of the invention ( 10 ) wherein a first model car ( 14 ) and a second model car ( 16 ) may be simultaneously launched by a launcher ( 12 ). Model cars ( 14 , 16 ), supported by wheels ( 22 ), are guided respectively by wires ( 18 , 20 ) which are anchored at one end by launcher ( 12 ) and the other end by a stop block ( 84 ). Model cars ( 14 , 16 ) are respectively propelled by CO2 cartridges ( 24 , 26 ) which are simultaneously punctured by moving trigger plate ( 46 ) sidewise in a manner described below.
[0042] The launcher ( 12 ) is shown in a front perspective view in FIG. 2 . FIGS. 3A , 3 B, 3 C, 3 D, and 3 E also show the launcher ( 12 ) from the front, from the left side, from the right side, from the rear, and from a top plan view. The major features of launcher ( 12 ) are a relatively flat launcher base plate ( 28 ), a first and a second tower ( 30 , 32 ), a first and a second launch module ( 34 , 36 ) attached respectively to towers ( 30 , 32 ), and a trigger plate ( 46 ) supported by a first and a second support means ( 70 a , 70 b ). Towers ( 30 , 32 ) each have a first and a second adjustment fin ( 38 a , 38 b ). Each of the fins ( 38 a , 38 b ) include, respectively, a first bead ( 40 a ) and a second bead ( 40 b ) along the edges thereof. Launch modules ( 34 , 36 ) each include a first and a second groove ( 42 a , 42 b ) which terminate at a first and a second enlarged opening ( 44 a , 44 b ). The first fin ( 38 a ) with its corresponding bead ( 40 a ) is received in the first groove ( 42 a ) so that the bead ( 40 a ) is held by the first enlarged opening ( 44 a ). Similarly, the second fin ( 38 b ), with its corresponding beaded edge ( 40 b ), is received in the second groove ( 42 b ) with its enlarged opening ( 44 b ) accepting the bead portion ( 40 b ). Beads ( 40 a , 40 b ) are secured by the enlarged openings ( 44 a , 44 b ) so that the launch modules ( 34 , 36 ) do not disengage from the fins ( 38 a , 38 b ). The important and unique aspect of this arrangement is that it permits the launch modules ( 34 , 36 ) to move up and down, vertically, along the height of the towers ( 30 , 32 ) so that the launch modules ( 34 , 36 ) can be paired up with cars ( 14 , 16 ) in which the wheels ( 22 ) may be of different heights or, wherein the location of the CO2 cartridge ( 24 , 26 ) is at a different height from car to car. The engagement is a friction fit and the height adjustment is made simply by pulling up or pushing down on the appropriate launch module ( 34 , 36 ).
[0043] FIG. 4A is a side cross-sectional view of an individual launch module ( 34 , 36 ) showing the firing pin mechanism ( 48 ) in the post launch position immediately prior to cocking.
[0044] FIGS. 4B-4G illustrate the steps necessary to cock and then release the firing pin mechanism ( 48 ).
[0045] The firing pin mechanism ( 48 ) is housed within a cavity ( 62 ) of each of the launch modules ( 34 , 36 ). It comprises a rod ( 50 ) having a sharp point ( 52 ) at a first end of the rod ( 50 ) and a pull knob ( 54 ) located at the second end of the rod ( 50 ) distal from the sharp point ( 52 ). A disc ( 56 ) is located on rod ( 50 ) intermediate the pull knob ( 54 ) and the sharp point ( 52 ). Disc ( 56 ) has a long side, or big radius ( 60 ) and a short side, or small radius ( 58 ). The term “long” is used to indicate that the radius of the disk ( 56 ) is greater from the rod ( 50 ) to the long side ( 60 ) than it is to the short side ( 58 ). The interior cavity ( 62 ) inside of launch modules ( 34 , 36 ) includes a return spring ( 64 ) that biases the firing pin rod ( 50 ) towards the forward position.
[0046] The trigger plate ( 46 ) is received at each end thereof in vertical grooves ( 72 a , 72 b ) located in the first and second trigger support means ( 70 a , 70 b ). Vertical grooves ( 72 a , 72 b ) face each other and include just enough depth in them so that the trigger plate ( 46 ) can be moved sideways from a first pre-launch ( 74 ) to a second post-launch ( 76 ) position without slipping out of the grooves ( 72 a , 72 b ). Trigger plate ( 46 ) includes a handle grip hole ( 68 ) which permits the user to readily grab onto the trigger plate ( 46 ) so that the trigger plate ( 46 ) can be moved from side to side. Trigger plate ( 46 ) also includes a first and a second slot ( 66 a , 66 b ) that permits the rod portions ( 50 ) of the firing pin mechanism ( 48 ) of each of the launch modules ( 34 , 36 ) to pass there through.
[0047] FIGS. 4A and 4G show the launcher ( 12 ) in the fired, or discharged, or post-launch, position ( 76 ).
[0048] FIGS. 4B-4F illustrate the steps necessary for cocking and simultaneously triggering the launch of model vehicles ( 14 , 16 ).
[0049] The first step in the cocking process, as shown in FIG. 3 , is to begin to pull the knob ( 54 ) backwards against the bias of spring ( 64 ) as shown in FIG. 4B .
[0050] In the next step, as shown in FIG. 4C , the knob ( 54 ) is rotated so that the disc ( 56 ) can pass through slots ( 66 a or 66 b ) of trigger plate ( 46 ).
[0051] According to the next step, as shown in FIG. 4D , the knob ( 54 ) is further rotated so that the long, or big radius, side ( 60 ) of the disc ( 56 ) is directly opposing a land portion of trigger plate ( 46 ).
[0052] In the next step, as show in FIG. 4E , pressure on the knob ( 54 ) is relaxed so that the long, or big radius, side ( 60 ) of the disc ( 56 ) contacts land on the trigger plate ( 46 ). In this position the firing pin rod ( 50 ) is held in the pre-launch mode ( 74 ) by the pressure of the disc ( 56 ) on the trigger plate ( 46 ).
[0053] The pre-launch steps as shown in FIGS. 4B-4E are repeated as many times as necessary to set up whatever number of model cars ( 14 , 16 ) are being raced.
[0054] The next, and final step, shown in FIG. 4F is to move the trigger plate ( 46 ) sidewise so that the discs ( 56 ) slip through the respective slots ( 66 a , 66 b ) of the trigger plate ( 46 ). The current invention ( 10 ) permits both firing pin mechanisms ( 48 ) to be released substantially simultaneously thereby ensuring a fair start to the race and minimizing the effects of the launch on the ultimate performance of the model vehicle ( 14 , 16 ). This is very important because the winner of the race should be determined by the skill of the model car maker rather than by the unpredictability of the launch mechanism ( 12 ). According to FIG. 4F the trigger plate ( 46 ) is shown moving from its pre-launch position ( 74 ) towards its fired or disengaged position ( 76 ).
[0055] Lastly, as shown in FIG. 4G , the sharp point ( 52 ) of the firing pin rod ( 50 ) punctures the frangible nozzle end of a CO2 cartridge ( 24 , 26 ) thereby respectively propelling model cars ( 14 , 16 ) down guides wires ( 18 , 20 ) towards stop block ( 84 ).
[0056] As previously discussed, the height of the launch modules ( 34 , 36 ) can be adjusted. Prior to launch and firing, it is desirable to adjust the launch modules ( 34 , 36 ). For example, FIG. 5A illustrates a launch module ( 34 , 36 ) mounted on a tower ( 30 , 32 ) and shown in a low position to accommodate a model car ( 14 , 16 ) which is low to the ground. Conversely, FIG. 5B illustrates a launch module ( 34 , 36 ) of FIG. 5A moved to a higher position in order to launch a taller model vehicle ( 14 , 16 ) which is higher off the ground. This further ensures the fairness of the race by eliminating any bias that the launch mechanism might have towards taller or shorter vehicles.
[0057] Another unique embodiment of the invention ( 10 ), shown in FIG. 6 , is that it is possible to gang, or couple, several launchers ( 12 ) together so that four ( 4 ) or more model race cars ( 14 , 16 ) might be launched simultaneously. To accomplish this, each base plate ( 28 ) includes engaging elements ( 86 ) along its edge so that the base plates ( 28 ) do not slip pass each other and are perfectly aligned. A dog bone shaped clip ( 80 ), which normally sits in a cavity ( 82 ) in the launcher base plate ( 28 ), includes grooves that couple a pair of trigger plates ( 46 ) to each other. Accordingly, the base plates ( 28 ) are perfectly aligned and the trigger plates ( 46 ), in addition to being perfectly aligned, are also rigidly connected to each other, so that actuation of one trigger plate ( 46 ) will actuate two or more trigger plates ( 46 ) simultaneously thereby launching more than two vehicles ( 14 , 16 ) at the same precise moment.
[0058] The preferred embodiment of the invention ( 10 , 12 ) has been described with regard to model race cars ( 14 , 16 ) but it is possible to propel other vehicles in a similar manner.
[0059] FIG. 7A illustrates an alternative embodiment of the invention where the vehicles comprise a pair of CO2 propelled model boats ( 90 ).
[0060] FIG. 7B illustrates another alternative embodiment of the invention where the vehicles comprise a pair of CO2 propelled model rockets ( 92 ).
[0061] The present invention has a number of advantages over prior art efforts to achieve similar results. First, and foremost, the basic launcher ( 12 ) is relatively inexpensive and safe to use. The use of a sliding trigger plate ( 46 ) and a virtually fool-proof firing mechanism ( 48 ) ensures that two or more model cars ( 14 , 16 ) can be launched simultaneously thereby leaving the results of the race primarily to the skill of the model car builder rather than to any other factor. Being able to adjust the firing mechanism ( 48 ) vertically further increases the fairness of the competition so as to eliminate any bias towards taller or shorter vehicles.
[0062] Lastly, the invention's unique ability to gang, or connect, launchers ( 12 ) together in such a way that the base plates are perfectly aligned and the trigger mechanisms are rigidly connected together further ensures that more than two model vehicles ( 14 , 16 ) can be launched fairly and safely simultaneously.
[0063] While the invention has been described with reference to the preferred embodiment thereof it will be appreciated by those of ordinary skill in the art that modifications can be made to the parts of the basic invention and the basic concept without department from the scope and spirit of the invention as a whole.
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A CO2 gas-propelled model car launcher permits two or more model vehicles to be launched substantially simultaneously. Launching of the vehicles is achieved by moving a trigger plate sidewise which disengages a disc and thereby releases a firing pin whose forward movement punctures the CO2 cartridge. A height adjustment feature permits the launcher to accommodate model cars of different sizes. Multiple launchers may be ganged together and their trigger plates rigidly connected in such a way that sidewise movement of one trigger plate launches all of the model vehicles.
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BACKGROUND OF THE INVENTION
This invention relates generally to pressure activated seals, and more particularly relates to a pressure activated seal between two adjacent surfaces, such as between pipes or tubes arranged coaxially one within the other, or adjacent substantially parallel surfaces of two plates, for example.
Seals and gaskets such as O rings are commonly used to seal two adjacent surfaces of pipes or tubes arranged coaxially one within another. Such seals or gaskets are commonly used to seal the outside surface of an inner, relatively smaller diameter tube and the inside surface of an outer, relatively larger diameter tube disposed over the smaller tube, or two flat surfaces. In the case of two adjacent pipes or tubes arranged coaxially one within another, the smaller tube usually has a groove on the outside circumferential surface in which an O ring is inserted. The outside diameter of the O ring is typically slightly larger than the inside diameter of the outer tube, causing a slight compression of the O ring when the outer tube is slipped over the smaller tube, and forming a “seal” that stops liquid or air from passing between the two pipes or tubes. In some cases the inside diameter of the outer tube can become enlarged, for many reasons, particularly if one or both of the inner or outer tubes is eccentric (i.e., not round), or expands, because it made of expandable materials such as plastic, or due to heating, for example. Similarly, spacing between adjacent substantially parallel surfaces of two plates can become enlarged or distorted, such as due to warping of either of the plates, wear, or heating, for example.
It would be desirable to provide a pressure activated seal that can provide a seal between two adjacent surfaces, such as between inner and outer pipes or tubes arranged coaxially, or adjacent substantially parallel surfaces of two plates, for example, to overcome eccentric inside diameters, expanding tubing and other odd shapes, such as oval, square, hexagon or other similar shapes of pipes or tube, as well as warping of adjacent substantially parallel surfaces of adjacent plates having flat or curved shapes. The present invention meets these and other needs.
SUMMARY OF THE INVENTION
Briefly and in general terms, the present invention provides for a pressure activated seal including a main body with a main wall having a main outer sealing surface and first and second ends. First and second side walls are connected to the first and second ends of the main wall, with first ends of the first and second side walls connected to the first and second ends of the main wall, and second ends of the first and second side walls extending away from the main wall. First and second flexible flaps are connected to the second ends of the first and second side walls, respectively, and the main wall, the side walls, and the first and second flexible flaps define a main chamber configured to receive fluid pressure for activating the pressure activated seal, to bias the main outer sealing surface outwardly from the main chamber, and to bias the first and second flexible flaps outwardly from the main chamber. In a presently preferred aspect, the first and second flexible flaps extend generally perpendicular to and inwardly from the first and second side walls. In another presently preferred aspect, each of the first and second flexible flaps of the pressure activated seal gradually narrow from the connection of the first and second flexible flaps to the side walls to a relatively thin edge. In another presently preferred aspect, each of the first and second flexible flaps of the pressure activated seal are formed to have a surface extending at an outside angle of about 15 degrees with respect to the main wall, and a surface extending inwardly at an inside angle of about 60 degrees with respect to the main wall.
Accordingly, in a first presently preferred embodiment, the present invention provides for a combination of a pressure activated seal disposed between an inner tube and an outer tube, for providing a seal between the inner tube and the outer tube. The inner tube has an outside diameter smaller than the inside diameter of the outer tube, and is disposed within the outer tube. The inner tube includes an inner tube wall, and a radially outer channel defined in the inner tube wall, with one or more orifices defined in the inner tube wall, with the one or more orifices extending into and connected in fluid communication with the radially outer channel. A pressure activated seal is disposed radially within the outer tube and radially outside of the inner tube in the radially outer channel of the inner tube. The pressure activated seal has a generally annular body including a radially outer main wall with a radially outer sealing surface, and first and second radially inwardly projecting side walls connected to first and second ends of the radially outer main wall, respectively. The first and second radially inwardly projecting side walls have first and second radially inner ends, respectively, and first and second radially inner flexible flaps are connected to the first and second radially inner ends of the first and second radially inwardly projecting side walls. The radially outer main wall, radially inwardly projecting side walls, and radially inner flexible flaps of the generally annular body of the pressure activated seal define a main chamber of the pressure activated seal, and the one or more orifices defined in the inner tube wall allows fluid pressure to enter the main chamber of the pressure activated seal through the one or more orifices to activate the pressure activated seal to form a seal between the inner tube and the outer tube.
In a presently preferred aspect of the first embodiment, the first and second radially inner flexible flaps extend generally perpendicular to and inwardly from the first and second radially inwardly projecting side walls. In another presently preferred aspect of the first embodiment, each of the first and second radially inner flexible flaps of the pressure activated seal gradually narrow from a relatively thick connection of the first and second radially inner flexible flaps to the first and second radially inner ends of the first and second radially inwardly projecting side walls to a relatively thin edge. In another presently preferred aspect of the first embodiment, each of the first and second radially inner flexible flaps of the pressure activated seal have a radially inner surface extending radially inwardly at an outside angle of about 15 degrees with respect to the radially outer main wall, and a radially outer surface extending radially inwardly at an inside angle of about 60 degrees with respect to the radially outer main wall, causing a decrease in wall thickness of the first and second radially inner flexible flaps from the relatively thick connection of the first and second radially inner flexible flaps to the first and second radially inner ends of the first and second radially inwardly projecting side walls to a relatively thin edge. In another presently preferred aspect of the first embodiment, one or more auxiliary tubes are provided in the inner tube, and a first end of the one or more auxiliary tubes is connected to a corresponding one of the one or more orifices, respectively, while a second end of the one or more auxiliary tubes is connected to an outside source of fluid pressure, so that fluid pressure can enter the main chamber of the pressure activated seal and activate the radially outer sealing surface of the pressure activated seal.
In a second presently preferred embodiment, the present invention provides for a combination of a pressure activated seal disposed between an inner tube and an outer tube, for providing a seal between the inner tube and the outer tube. The inner tube has an outside diameter smaller than the inside diameter of the outer tube, and is disposed within the outer tube. The outer tube includes a radially inner channel defined in the outer tube wall and one or more orifices defined in and extending through the outer tube wall and connected in fluid communication with the radially inner channel of the outer tube. A pressure activated seal is disposed radially within the outer tube and within the radially inner channel of the outer tube. The pressure activated seal has a generally annular body with a radially inner main wall providing a radially inner sealing surface. First and second radially outwardly projecting side walls are connected to first and second ends of the radially inner main wall, respectively, and first and second radially outer flexible flaps are connected to first and second radially outer ends of the first and second radially outwardly projecting side walls, respectively, The radially inner main wall, the radially outwardly projecting side walls, and the radially outer flexible flaps of the generally annular body define a main chamber, so that the one or more orifices defined in the outer tube wall allows fluid pressure from outside the outer tube to enter the main chamber of the pressure activated seal through the one or more orifices of the outer tube, to activate the pressure activated seal to form a seal between the inner tube and the outer tube.
In a presently preferred aspect of the second embodiment, the first and second radially outer flexible flaps extend generally perpendicular to and inwardly from the first and second radially outwardly projecting side walls. In another presently preferred aspect of the second embodiment, each of the first and second radially outer flexible flaps of the pressure activated seal gradually narrow from a relatively thick connection of the first and second radially outer flexible flaps to the first and second outer ends of the first and second radially outwardly projecting side walls to form a relatively thin edge. In another presently preferred aspect of the second embodiment, each of the first and second radially outer flexible flaps of the pressure activated seal have a radially outer surface extending radially outwardly at an outside angle of about 15 degrees with respect to the radially inner main wall, and a radially inner surface extending radially outwardly at an inside angle of about 60 degrees with respect to the radially inner main wall, causing a decrease in wall thickness of the first and second radially outer flexible flaps from the relatively thick connection of the first and second radially outer flexible flaps to the first and second radially outer ends of the first and second radially outwardly projecting side walls to a relatively thin edge.
In a third presently preferred embodiment, the present invention provides for a combination of a pressure activated seal disposed between first and second adjacent plates having substantially parallel adjacent exterior surfaces. The first plate has a sealing side with an exterior surface, and the second plate is disposed adjacent to the first plate, with a sealing side of the second plate having an exterior surface facing the exterior surface of the sealing side of the first plate. The first and second plates are preferably placed adjacent to each other in spaced apart relation with the exterior surface of the sealing side of the second plate preferably substantially parallel to the exterior surface of the sealing side of the first plate. The second plate includes a wall on the sealing side and one or more channels defined in the wall on the sealing side of the second plate, one or more orifices formed in and extending through the wall of the second plate and connected in fluid communication with the one or more channels. A pressure activated seal is disposed between the sealing side of the first plate and the sealing side of the second plate within the one or more channels defined in the wall of the second plate. The pressure activated seal includes a main body with a main wall having a main outer sealing surface, and first and second side walls connected at first ends of the first and second side walls to the first and second ends of the main wall, with opposing second ends of the first and second side walls extending away from the main wall. The first and second side walls also include first and second inner flexible flaps connected to the second ends of the first and second side walls. The main wall, the side walls, and the flexible flaps of the main body of the pressure activated seal define a main chamber, and the one or more orifices extending into the one or more channels of the second plate allowing fluid pressure from outside the second plate to enter the main chamber of the pressure activated seal, for activating the pressure activated seal, to bias the main outer sealing surface outwardly from the main chamber, and to bias the first and second flexible flaps outwardly from the main chamber, so as to form a seal between the first and second plates.
In a presently preferred aspect of the third embodiment, the first and second flexible flaps extend generally perpendicular to and inwardly from the first and second side walls. In another presently preferred aspect of the third embodiment, each of the first and second flexible flaps of the pressure activated seal gradually narrow from the connection of the first and second flexible flaps to the side walls to a relatively thin edge. In another presently preferred aspect of the third embodiment, each of the first and second flexible flaps of the pressure activated seal are formed to have a surface extending at an outside angle of about 15 degrees with respect to the main wall, and a surface extending inwardly at an inside angle of about 60 degrees with respect to the main wall.
These and other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments in conjunction with the accompanying drawings, which illustrate, by way of example, the operation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective diagram of a first embodiment of the pressure activated seal of the present invention in combination with inner and outer tubes.
FIG. 2 is an end view of the pressure activated seal of FIG. 1 .
FIG. 3 is a cross-sectional view of the pressure activated seal taken along line 3 - 3 of FIG. 2 .
FIGS. 4-7 is a cross-sectional view of a portion of the pressure activated seal as shown in FIG. 3 , illustrating variations of the pressure activated seal of FIG. 1 .
FIG. 8 is a schematic perspective diagram of a variation of the first embodiment of the pressure activated seal of the present invention in combination with inner and outer tubes.
FIG. 9 is a schematic perspective diagram of a second embodiment of the pressure activated seal of the present invention in combination with inner and outer tubes.
FIG. 10 is a schematic perspective diagram of a third embodiment of the pressure activated seal of the present invention in combination with adjacent plates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, which are provided by way of example, and not by way of limitation, in a first preferred embodiment, illustrated in FIGS. 1-8 , the present invention provides for a pressure activated seal 10 having generally annular body 12 including radially outer main wall 14 having a thickness and a radially outer sealing surface 18 . The main wall has first and second ends 20 , 22 , and first and second radially inwardly projecting side walls 24 , 26 , are connected to the first and second ends of the radially outer main wall, respectively. The first and second radially inwardly projecting side walls project radially outwardly a distance generally determining a thickness 27 of the pressure activated seal, and have first and second radially inner ends 28 , 30 , respectively, and first and second radially inner edges or flexible flaps 32 , 34 , that are connected to the first and second radially inner ends of the first and second radially inwardly projecting side walls.
Referring to FIG. 1 , in the first embodiment, the pressure activated seal is configured to be disposed radially within an outer tube 36 having an inside diameter 38 , and radially outside of an inner tube 40 having an outside diameter 42 smaller than the inside diameter of the outer tube, and within a radially outer channel or groove 44 defined in a wall 46 of the inner tube, to provide a pressure activated seal between the inner tube and the outer tube. As is illustrated in FIGS. 1 and 3-8 , the first and second radially inner edges or flexible flaps can extend generally perpendicular to and inwardly from the first and second radially inwardly projecting side walls, for example, or can be any similar suitable form so as to facilitate forming a seal against the groove. The radially outer main wall, radially inwardly projecting side walls, and radially inner edges or flexible flaps of the generally annular body define a main chamber 48 . The thickness 50 of the radially outer main wall can be varied as desired according to the desired use of the pressure activated seal, and the desired hardness, rigidity, and flexibility of the pressure activated seal.
The sealing surface of the main wall of the pressure activated seal can be flat, as shown in FIGS. 1, 3 and 4 , or can be angled, radiused or rounded 51 as shown in FIG. 6 . The sealing surface may also be provided with various designs of protrusions, such as protruding rounded bumps 52 , or sharply angular protruding bumps 54 , as shown in FIG. 5 , for example.
In another aspect, each of the first and second radially inner edges or flexible flaps of the pressure activated seal preferably gradually narrow or taper from the relatively thick connection of the first and second radially inner edges or flexible flaps to the first and second radially inner ends of the first and second radially inwardly projecting side walls to a relatively thin radius, feather edge or intersecting point 56 . In another aspect, each of the first and second radially inner edges or flexible flaps of the pressure activated seal are preferably formed to have a radially inner surface extending radially inwardly at an outside angle 58 of about 65 degrees with respect to the adjacent radially inwardly projecting side wall, or of about 15 degrees with respect to the radially outer main wall, and a radially outer surface extending radially inwardly at an inside angle 60 of about 60 degrees with respect to the radially outer main wall, for example, causing a decrease in wall thickness of the first and second radially inner edges or flexible flaps from the relatively thick connection of the first and second radially inner edges or flexible flaps to the first and second radially inner ends of the first and second radially inwardly projecting side walls to a relatively thin radius, feather edge or intersecting point. As is illustrated in FIG. 7 , the first and second radially inner edges or flexible flaps of the pressure activated seal alternatively may terminate in squared ends 62 , or rounded ends 64 , or ends of similar suitable desirable shapes.
The pressure activated seal is inserted into the radially outer channel or groove of the inside tube in a manner similar to the way an O ring is installed. The depth of the radially outer channel or groove is determined by the inside diameter 66 and the outside diameter 68 of the pressure activated seal. The outside diameter of the pressure activated seal may be equal to, slightly bigger or slightly smaller than the outside diameter 70 of the radially outer channel or groove. When the pressure activated seal is installed in the radially outer channel or groove, the first and second radially inner edges or flexible flaps collapse radially inwardly and lay horizontally in the radially outer channel or groove. The pressure activated seal is not stretched on the outside diameter, as the first and second radially inner edges or flexible flaps collapse.
One or more orifices 72 are formed through the wall of the inner tube extending into the radially outer channel or groove, allowing fluid pressure 74 from inside the smaller tube to enter the main chamber of the pressure activated seal. As the fluid pressure inside the inner tube increases, the radially outer main wall and radially outer sealing surface of the pressure activated seal can expand outwardly and exert fluid pressure on the inside surface 76 of the outer tube creating a seal. The fluid pressure in main chamber of the pressure activated seal is equally spread to the entire inside walls of main chamber of the pressure activated seal, also exerting fluid pressure to the first and second radially inwardly projecting side walls and the first and second radially inner edges or flexible flaps of the pressure activated seal, causing a complete seal between the inner and outer tubes. If for any reason the inside diameter of the outer tube is “out of round” or eccentric, the radially outer sealing surface of the pressure activated seal will take this form and cause a seal. For example, if the inner tube and outer tube were to have a square cross-sectional configuration, the pressure activated seal could be made square. When fluid pressure is communicated to the main chamber of the pressure activated seal from the inner square tube, the pressure activated seal will expand and seal the inside of the outer square tube.
The shape of the main chamber located on the inside diameter of the pressure activated seal can be made in any desired shape, such as curved, radius, square or rectangular shapes, depending on the desired pressure calculations and sealing method desired. The outside diameter of the pressure activated seal can be made to be bigger than the inside diameter of the outer tube to cause a seal when no fluid pressure is present. Alternatively, the outside diameter of the pressure activated seal can be smaller, which can allow a “flushing” action to occur when fluid pressure is introduced in the inner tube, as it may be desirable for fluid to flow past the seal until a certain fluid pressure is attained in the system for the pressure activated seal to form a seal between the inner tube and the outer tube.
In some instances the pressure activated seal may be activated by an outside source of fluid pressure. For example, in a variation of the first embodiment, one or more small auxiliary tubes 78 can be inserted into or formed in the inner tube and connected to the corresponding one or more orifices, respectively, extending through the wall of the inner tube extending into the radially outer channel or groove, as shown in FIG. 8 . An outside source of fluid pressure can then enter the main chamber of the pressure activated seal and activate the radially outer sealing surface of the pressure activated seal.
In a second presently preferred embodiment illustrated in FIG. 9 , the pressure activated seal can be used to form a seal between inner and outer tubes by activation from an outside source of fluid pressure, such as may be suitable for use when the wall thickness of an inner tube is too thin to install a groove for activation of the pressure activated seal. In the second embodiment, a pressure activated seal 110 has a generally annular body 112 with a radially inner main wall 114 having a thickness and a radially inner sealing surface 118 having first and second ends 120 , 122 . First and second radially outwardly projecting side walls 124 , 126 are connected to the first and second ends of the radially inner main wall, respectively. The first and second radially outwardly projecting side walls have first and second radially outer ends 128 , 130 , respectively, and first and second radially outer edges or flexible flaps 132 , 134 , are connected to the first and second radially outer ends of the first and second radially outwardly projecting side walls. The first and second radially inner edges or flexible flaps can extend generally perpendicular to and inwardly from the first and second radially outwardly projecting side walls, for example, or can be any similar suitable form so as to facilitate forming a seal against the groove. The thickness of the radially inner main wall can be varied as desired according to the desired use of the pressure activated seal, and the desired hardness, rigidity, and flexibility of the pressure activated seal.
The pressure activated seal is configured to be disposed radially within an outer tube 136 having an inside diameter 138 , and radially outside of an inner tube 140 having an outside diameter 142 smaller than the inside diameter of the outer tube, within a radially inner channel or groove 144 defined in a wall 146 of the outer tube to provide a pressure activated seal between the inner tube and the outer tube. The radially inner main wall, radially outwardly projecting side walls, and radially outer edges or flexible flaps of the generally annular body define a main chamber 148 .
The sealing surface can be flat, angled, radiused or rounded as discussed above. The sealing surface may also be provided with various designs of protrusions, such as protruding rounded bumps, or sharply angular protruding bumps, for example. In a presently preferred aspect, each of the first and second radially outer edges or flexible flaps of the pressure activated seal preferably gradually narrows or tapers from the relatively thick connection of the first and second radially outer edges or flexible flaps to the first and second radially outer ends of the first and second radially inwardly projecting side walls to a relatively thin radius, feather edge or intersecting point 156 . In a presently preferred aspect, each of the first and second radially outer flexible flaps of the pressure activated seal preferably are formed to have a radially outer surface extending radially outwardly at an outside angle of about 15 degrees with respect to the radially inner main wall, and a radially inner surface extending radially outwardly at an inside angle of about 60 degrees with respect to the radially inner main wall, for example, causing a decrease in wall thickness of the first and second radially outer flexible flaps from the relatively thick connection of the first and second radially outer flexible flaps to the first and second radially outer ends of the first and second radially outwardly projecting side walls to a relatively thin radius, feather edge or intersecting point. As discussed above, the first and second radially inner edges or flexible flaps of the pressure activated seal alternatively may terminate in squared ends, or rounded ends, or ends of similar suitable desirable shapes.
The pressure activated seal is inserted into the radially inner channel or groove of the outer tube in a manner similar to the way an O ring is installed. As previously described, the depth of the radially inner channel or groove is determined by the inside diameter and the outside diameter of the pressure activated seal. The inside diameter of the radially inner channel or groove may be equal to, slightly bigger or slightly smaller than the inside diameter of the pressure activated seal. When the pressure activated seal is installed in the radially inner channel or groove, the first and second radially inner edges or flexible flaps collapse radially outwardly and lay horizontally in the radially inner channel or groove. The pressure activated seal is not stretched on the inside diameter, as the first and second radially outer edges or flexible flaps collapse.
One or more orifices 172 are formed through the wall of the outer tube extending into the radially inner channel or groove, allowing fluid pressure 174 from outside the smaller tube to enter the main chamber of the pressure activated seal. As the fluid pressure outside the inner tube increases, the radially inner main wall and radially inner sealing surface of the pressure activated seal can expand inwardly and exert fluid pressure on the outside surface 176 of the inner tube creating a seal. The fluid pressure in main chamber of the pressure activated seal is equally spread to the entire inside walls of main chamber of the pressure activated seal, also exerting fluid pressure to the first and second radially outwardly projecting side walls and the first and second radially outer edges or flexible flaps of the pressure activated seal, causing a complete seal between the inner and outer tubes.
The shape of the main chamber located on the inside diameter of the pressure activated seal can be made in any desired shape, such as curved, radius, square or rectangular shapes, depending on the desired pressure calculations and sealing method desired. The inside diameter of the pressure activated seal can be made to be smaller than the outside diameter of the inner tube to cause a seal when no fluid pressure is present. Alternatively, the inside diameter of the pressure activated seal can be larger, which can allow a “flushing” action to occur when fluid pressure is introduced in the outer tube, as it may be desirable for fluid to flow past the seal until a certain fluid pressure is attained in the system for the pressure activated seal to form a seal between the inner tube and the outer tube.
In a third presently preferred embodiment, the present invention provides for a pressure activated seal 210 that can be used for providing a seal between two or more plates or flat surfaces put together as is illustrated in FIG. 10 , such as for use in cooling channels or other fluid flow channels, for example. The pressure activated seal includes a main body 212 including a main wall 214 having a thickness, and a main outer sealing surface 218 having first and second ends 220 , 222 . First and second side walls 224 , 226 have first ends 228 connected to the first and second ends of the main wall, and second ends 230 that extend away from the main wall. First and second inner edges or flexible flaps 232 , 234 , are connected to the second ends of the first and second side walls.
The pressure activated seal is configured to be disposed between a first plate 236 and a second plate 240 , within one or more channels or grooves 244 defined in a wall 246 of the second plate to provide a pressure activated seal between the first and second plates. The first and second edges or flexible flaps typically extend generally perpendicular to and inwardly from the first and second side walls, for example, or can be any similar suitable form so as to facilitate forming a seal against the channel or groove. The main wall, side walls, and edges or flexible flaps of the main body of the pressure activated seal define a main chamber 248 .
The thickness of the main wall can be varied as desired according to the desired use of the pressure activated seal, and the desired hardness, rigidity, and flexibility of the pressure activated seal. The sealing surface can be flat as shown in FIG. 10 , or can be angled, or radiused or rounded, for example. The sealing surface may also be provided with various designs of protrusions, such as protruding rounded bumps, or sharply angular protruding bumps, as discussed above.
In a presently preferred aspect, each of the first and second edges or flexible flaps of the pressure activated seal preferably gradually narrows or tapers from the relatively thick connection of the first and second edges or flexible flaps to the side walls to a relatively thin radius, feather edge or intersecting point as described above. In another presently preferred aspect, each of the first and second edges or flexible flaps of the pressure activated seal preferably are formed to have a surface extending at an outside angle of about 15 degrees with respect to the main wall, and a surface extending radially inwardly at an inside angle of about 60 degrees with respect to the main wall, for example, causing a decrease in wall thickness of the first and second edges or flexible flaps from the relatively thick connection of the first and second edges or flexible flaps to the ends of the first and second side walls to a relatively thin radius, feather edge or intersecting point. The flexible flaps of the pressure activated seal alternatively may terminate in squared ends, or rounded ends, or ends of similar suitable desirable shapes.
The pressure activated seal is inserted into the channel or groove of the second plate in a manner similar to the way a gasket is installed. The depth of the channel or groove is determined by the thickness of the main wall and length of side walls of the pressure activated seal. One or more orifices 272 are formed through the wall of the second plate extending into the one or more channels or grooves, respectively, allowing fluid pressure 274 from outside the second plate, such as through a cooling channel 275 , for example, to enter the main chamber of the pressure activated seal. As the fluid pressure increases, the main wall and sealing surface of the pressure activated seal can expand and exert fluid pressure on the surface 276 of the first plate creating a seal. The fluid pressure in main chamber of the pressure activated seal is equally spread to the entire inside walls of main chamber of the pressure activated seal, also exerting fluid pressure to the first and second side walls and the first and second edges or flexible flaps of the pressure activated seal, causing a complete seal between the first and second plates.
The shape of the main chamber located on the inside diameter of the pressure activated seal can be made in any desired shape, such as curved, radius, square or rectangular shapes, depending on the desired pressure calculations and sealing method desired. If for any reason the two surfaces are not securely fastened to one another the sealing surface would be activated by the fluid pressure and move against the plate causing a seal. If the surfaces of the first and second plates were not perfectly parallel, the sealing surface of the pressure activated seal would expand more in the area needed to seal.
As has been demonstrated, the pressure activated seal of the present invention is activated by fluid pressure. The sealing surfaces can vary to make up inconsistencies in surfaces, diameters and irregular shapes to form a seal. The softer the material is for making the pressure activated seal the more small irregularities in the surface can be sealed. Activation of the pressure activated seal by application of fluid pressure in the chamber of the pressure activated seal forces a sealing surface of the pressure activated seal to seal against any adjacent surface of a tube or plate, having a round, flat, angled or any other similar shape, for example, to attain a seal.
It will be apparent from the foregoing that while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
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A pressure activated seal includes a main wall, side walls connected to the ends of the main wall, and flexible flaps connected to the side walls. The main wall, side walls, and flexible flaps define a main chamber adapted to receive fluid pressure for activating the pressure activated seal to form a seal between opposing adjacent surfaces. The pressure activated seal can be placed between concentric tubes or between adjacent plates, with one of the tubes or plates including one or more orifices leading to the main chamber to allow fluid pressure to activate the pressure activated seal to form a seal between the opposing adjacent surfaces of the tubes or plates.
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BACKGROUND OF INVENTION
This invention relates generally to methods and systems for medical treatment of the human body, and more specifically relates to a method and system usable in treating the blood supply of a human subject for the purpose of reducing the functioning lymphocyte population in the blood supply of such subject.
In a number of highly significant human diseases, including certain forms of leukemia, the population of certain types of leucocytes, including especially lymphocytes, increases inordinately in comparison to the other populations of nucleated cells in normal blood. While the excessive population of such lymphocytes represents a result of, rather than the underlying cause of the disease, the excessive lymphocyte population brings direct adverse effects to the patient if steps are not taken to reduce same. Complications thus rapidly develop which impair function of bodily organs, and eventually a life-threatening situation is presented.
It should also be appreciated that excessive increase in the lymphocyte population of the blood supply can occur in other human maladies, in addition to lymphocytic leukemias. Thus, for example, such results can obtain in consequence of severe allergic reactions to administered agents, including drugs or the like, or in many other lymphocyte-mediated diseases.
In addition to the development over the years of pharmaceutical agents and the like, which may nonspecifically reduce the lymphocyte population, e.g. by altering the underlying production rate of same, various techniques have from time to time been used in an effort to directly attack the problem, as for example by mechanically removing such lymphocytes from the blood supply. It is thus known, for example, to pass the blood supply through a continuous centrifuge, whereat one seeks to selectively remove lymphocytes to reduce the population of the latter in the thereby processed blood supply. In general, however, this method tends to be very inefficient, in part because the density differences between the blood fractions including the undesired lymphocytes and fractions which include desired blood components, is insufficient to assure that high percentages of the former are removed while retaining high proportions of the latter.
It is also well-known to treat diseases such as leukemia with high energy electromagnetic radiation, including in the X-ray region. While such treatment is often directed at internal bodily organs whereat the blood cells are being generated, it has also been known to irradiate the blood supply with x-radiation at a point external to the body (the blood having first been withdrawn), whereby the radiation is not rendered directly incident on the body or internal organs of same. This method, while powerful, is indiscriminate, in that the intensely disruptive energy, in addition to destroying undesirable cells, disables or destroys components of the blood which are desired to be retained in vital status.
For many years, it has been known that certain heterocyclic furocoumarins possess photoactive properties that render same useful in the treatment of certain human diseases. A noteworthy example of this occurs in certain recently reported methods for treatment of psoriasis.
The photoactive compounds referred to are all members of a group of coumarin derivatives which are commonly referred to as "psoralens", the basic member of which is the (photoactive) compound psoralen, having the structure: ##STR1##
The remaining compounds of interest for this invention (as will be discussed in greater detail hereinbelow) are all derivatives of psoralen, i.e. of structure (1). In accordance, however, with accepted terminology in the nomenclature of the pertinent chemical art, the phrase "psoralen" or "a psoralen" will be used at places in this specification to refer to certain derivatives of structure (1) which include "psoralen" in their accepted name, such as 8-methoxypsoralen, 5-methoxypsoralen, etc.
In an article appearing in the New England Journal of Medicine, Volume 291, No. 23 for Dec. 5, 1974, John A. Parrish, M.D. et al, thus report a method involving oral administration of 8-methoxypsoralen (8-MOP) to a patient who is thereafter treated by exposure to a high intensity longwavelength ultraviolet light source, i.e. to a source of ultraviolet radiation in the UVA wavelength region, and preferably in the wavelength range between about 3200 and 4000 Angstroms, with a peak emission at about 3650 Angstroms. The highly successful treatment is deemed to be effective by interrupting the disease process in psoriasis, a disorder characterized by an accelerated cell cycle and rate of DNA synthesis. The treatment acts to inhibit DNA synthesis by formation of C-4 cyclo-addition products between the pyrimidine bases of the nucleic acids and psoralen molecule. Since the 5,6 double bond of the pyrimidine can photoreact with the psoralen molecule at either the 3,4 double bond of the pyrone ring or at the 4',5' double bond of the furan ring, two types of photoadducts are possible. In consequence formation of photo-induced DNA cross-links is enabled.
In this sequence of treatment thus employed in the treatment of psoriasis, it has been common to place the patient following administration of the psoralen, in a light box or other environment whereat the high intensity illumination is effected. It has come to the attention of investigators that a side effect resulting from the cited treatment, can occasionally be the destruction of certain nucleated blood cells. Investigation appears to establish that such result obtains because the incident UV radiation has sufficient penetrating power, to induce some bonding between the psoralen introduced into the bloodstream and the nucleic acid of the nucleated blood cells such as the lymphocytes. In consequence the metabolic processes of such modified lymphocytes are detrimentally affected, eventually leading to the inactivation and ultimate destruction of same. This type of phenomenon has been studied in vitro, and among other places, is reported in an article by G. Lischka et al appearing in Archives for Dermatological Research, 259, 293-298 (1977). Of interest for present purposes is that the reported phenomenon is regarded as an undesirable side effect, which is incident to the beneficial results otherwise achieved during treatment of psoriasis.
SUMMARY OF INVENTION
Now, in accordance with the present invention, a method and system has been found which enables safe and effective reduction of the functioning lymphocyte population in the blood supply of a human subject. According to the method of invention, blood requiring such treatment, is withdrawn from the subject and irradiated with UVA radiation in a preferred wavelength range of from about 3200 to 4000 Angstroms, in the presence of from about 1 nanogram to 100 microgram per ml of blood of a dissolved psoralen of the type capable of forming photoadducts with DNA, to thereby effect covalent bonding between the psoralen and the nucleic acid of the lymphocytes present in the blood. The said nucleic acid is thereby altered to inhibit the metabolic processes of the said lymphocytes, after which the irradiated blood is returned to the human subject.
The withdrawn blood can be treated in batch, but preferably is formed into an extracorporeal stream and passed through a treatment station whereat the irradiation is effected. Such treatment station may take the form of an extended flattened tubular passageway, the walls of which are substantially transparent to the incident long-wave UV energy (UVA) used to activate the psoralen. Typical radiation doses range from about 0.1 to 100 joules per cm 2 of blood surface where the process is carried out on a continuous or discontinuous basis, and typical flow rates through the irradiation station can be in the range of from about 10 to 75 ml/min.
Following treatment, the entire batch, or irradiated flow of diverted blood, can be returned to the patient with all blood components intact. The lymphocytes, however, by virtue of the treatment, have been so altered that their metabolic functioning is rapidly impaired, and especially the ability of same to divide, in consequence of which destruction of the impaired lymphocytes rapidly occurs. Moreover, the impairment and destruction tends to be selective in certain diseases such as leukemia, to the cells most sought to be reduced, by virtue of the fact that it is such cells which are undergoing the most intense metabolic activities to begin with, whereby they are the cells most subject to disablement by the present process.
A preferred psoralen for use in the process of the present invention is 8-methyoxypsoralen (8-MOP, also known as methoxsalen). Other photoactive psoralens useful in practice of the present invention include psoralen itself, i.e. structure (1), and 4,5',8-trimethylpsoralen. Less preferred, but still useful photoactive psoralens for use in the invention include 5-methoxypsoralen, 4-methylpsoralen, 4,4-dimethylpsoralen, 4,5'-dimethylpsoralen, and 4',8-dimethylpsoralen.
Further discussion of these photoactive psoralens may be found in the tutorial article entitled Photobiology and Photochemistry of Furocoumarins (Psoralens) by M. A. Pathak et al, which article appears as Chapter 22 of the work Sunlight and Man, edited by Thomas B. Fitzpatrick et al, University of Tokyo Press (1974). This article observes (which is appropriate for present purposes) that the most effective photoactive psoralens include the compound psoralen proper, i.e. structure (1), and derivatives of structure (1) wherein methyl or methoxy groups are substituted at one or more of the 4,4',5' and 8 positions, as for example in the aforementioned 8-MOP, which has the structure: ##STR2## and 4,5',8-trimethylpsoralen, which has the structure: ##STR3##
As aforementioned, the reactive sites of the nucleic acids are considered to be the pyrimidine bases, and it is believed that the photoinduced reaction of the present invention involves the activated psoralen and one or more of the pyrimidine bases normally present in nucleic acids, such as thymine, cytosine, uracil or so forth. A C4 cyclo-addition takes place; the pyrimidine bases always react with their 5,6 double bond, while the psoralens can react with either their 3,4 double bond or with their 4',5' double bond. In consequence two types of photo-adducts can be obtained. This ability to bond at two regions of the linear psoralen structure enables the said structure upon photo-activation to link to one pyrimidine base, or to two pyrimidine bases which engage both of the reactive double bonds of the psoralen structure. Where this double linking occurs, cross-linking can be effected between the two strands of DNA, which is particularly effective in inhibiting the metabolic functions of the associated nucleated cells, such as the lymphocytes.
BRIEF DESCRIPTION OF DRAWINGS
The invention is diagrammatically illustrated, by way of example, in the drawings appended hereto, in which:
FIG. 1 is a schematic flow diagram illustrating a preferred embodiment of a system operating in accordance with the present invention;
FIG. 2 is a schematic elevational view of the irradiation station portion of the FIG. 1 system;
FIG. 3 is a plan view, schematic in nature, of one embodiment of the irradiation station of FIG. 2; and
FIGS. 4 and 5 are cross-sectional views, taken along the lines 4--4 and 5--5 of FIG. 3, and illustrate the configurations of the flow passageway and the output passage for the FIG. 3 device.
DESCRIPTION OF PREFERRED EMBODIMENT
In FIG. 1 herein a schematic diagram appears of a system 10 in accordance with the present invention. Except for the irradiation station, the bulk of the components of system 10 are per se conventional and known in the art; and hence it is not deemed appropriate or necessary to vastly detail same.
As indicated in the Figure, blood may initially be withdrawn from the human subject, as at 12. Typically the blood is withdrawn via a donor needle, which may e.g. be emplaced at the right antecubital vein. In the showing of FIG. 1, it is assumed that the processing of blood pursuant to the invention is conducted on a continuous basis, i,e. for purposes of the present discussion the flow may be regarded as continuous from withdrawal at 12, to final return of the blood to the subject at 14. Such return 14 is typically effected via a recipient needle positioned in the left antecubital vein. Where the flow is indeed continuous in this manner, a typical blood flow utilizable in practice of the invention is in range of from about 10 to 75 ml/min, with a more preferred range being from about 40 to 50 ml/min. The indicated flow rates are effected by means of a pump 16, which is positioned in the extracorporeal blood flow stream generally indicated at 18, and may comprise one of numerous types of pumps used for blood flow treatment purposes, including such pumps as those available from Haemonetics Corp. under Model Designation 30.
As is known in the pertinent medical art, anti-coagulants are preferably injected into the extracorporeal blood flow stream at 20, i.e. close to the point of blood withdrawal. Such anti-coagulants can comprise solutions of acid citrate dextrose and/or of heparin, or of other known compositions useful for this purpose.
An occluded vein sensor 22 is preferably provided in stream 18 for purposes, as known in the art. Such sensor basically comprises a reservoir or buffer volume, the object of which is to prevent or inhibit generation or continued existence of bubbles in the blood flow stream.
Pursuant to a preferred mode of practicing the present invention, the photoactive psoralen is preferably added to the blood of the human subject external to such subject; and thus as shown in the system 10 of FIG. 1, may be provided to the flowing blood downstream of pump 16, and just upstream of where the blood enters the irradiation station 24.
As has been discussed under the "Summary of Invention" the preferred psoralen for use in the process of the invention is 8-methoxypsoralen (8-MOP). As also discussed, other photoactive psoralens as previously described, are also utilizable in the method of the invention. The basic technique used in introducing the psoralen, is to disolve same in an isotonic solution, which thereafter is directly injected into the flowing blood stream, as at 26. The psoralen is injected at a rate in comparison to the blood flow rate, as to achieve a concentration in the blood thereafter passed to irradiation station 24, of from about 1 nanogram to 100 micrograms of dissolved psoralen per ml of blood.
In the foregoing connection it should be appreciated that the primary objective of the operations thus far described is one of achieving the desired dissolved concentration of the photoactive psoralen prior to introduction of the blood to the irradiation station. In accordance with a further aspect of the invention, it will therefore be appreciated that the said photoactive compound need not necessarily be directly introduced by injection into the extracorporeal blood stream 18 flowing in FIG. 1. Rather, it is also acceptable to achieve the desired psoralen concentration levels by orally or otherwise administering the compound directly to the patient.
Indeed, in those instances of the prior art which have been heretofore discussed, wherein 8-MOP has been utilized in treatment of psoriasis, it has been usual for the psoralen to be orally administered. Where, pursuant to the invention, the psoralen is thus orally administered, it can be provided in oral dosages of from about 0.6 to 1.0 mg per kg of body weight. The desired concentration range in the blood used for practice of the invention, is then achieved in about two hours from oral administration.
However, it is preferred to introduce the psoralen to the extracorporeal stream (or to an extracorporeal batch volume) in order to achieve more exact concentration levels; and further, to avoid or minimize possible side effects and the like, which can occur from administration of any drug directly to the body system.
At irradiation station 24, consisting of an irradiation chamber 28 and radiation source 30, the blood now carrying in solution the desired psoralen concentration, is subjected to ultraviolet radiation in the UVA portion of the spectrum. Such UVA portion of the spectrum includes primarily wave lengths in the range from about 3200 to 4600 Angstroms. For present purposes it is preferred to use a radiation source having the bulk of its spectral components in the 3200 to 4000 Angstrom range, with peak intensities at about 3600 to 3700 Angstroms. Such radiation passes readily through conventional clear plastic tubing.
In FIG. 2, a schematic elevational view appears of an irradiation station 24 of a type suitable for use with the invention. Such station consists of a blood treatment or irradiation chamber 28, having an inlet 31 and an outlet 32, enabling blood flow through the chamber, and a spaced source 30 of UVA radiation. The chamber 28 can take various forms, with the principal requirement for same being that the wall 34 of same opposed to source 30, be substantially transparent to the incident UVA radiation. The said chamber (or at least wall 34) can therefore typically be comprised of various substantially UVA-transparent plastics, as are commonly used in tubing constructed for administration of standard intravenous solutions, such as polyvinyl chloride and the like.
In one embodiment of chamber 28, the said device can comprise a simple envelope, i.e., the central void 36 is substantially of thin rectangular cross-section. Where, however, the blood is to be treated as preferred, on a continuous basis, superior flow characteristics and better control of the exposure time can be achieved where blood treatment chamber 28 has a configuration as shown in FIGS. 3, 4 and 5. In this instance a tubular coil 38, which in cross-section (FIG. 5) is flattened to a very elongated elipse, is fixedly maintained in or upon a support plate 40. The blood flow inlet 30 to the coil is of circular cross section, and in terms of FIG. 1 is at a point downstream of pump 16. The feed-in for the psoralen compound is schematically depicted at 26. The highly flattened cross-section of the coil enables good flow for the blood passing through the coil, but, more importantly, enables good exposure of the flowing blood to the incident UVA radiation. The outlet 32 is again returned to a circular cross-section.
UVA source 30 may comprise one or a plurality of side-by-side or otherwise arranged UVA light sources 41, each of which may be backed by a reflector 42. The UVA sources can comprise commercially available lamps, numerous types of which are known in the art.
By way of example, source 30 can comprise a single 1000 watt Hg lamp of the type available from Oriel Corporation of Stamford, Conn., under Model designation 6287. When used with appropriate filters this source provides a good relatively continuous spectrum of high intensity radiation between 3200 and 4000 Angstroms, with a peak emission at about 3650 Angstroms. The said lamp with a suitable reflector can be positioned approximately 5 to 30 cm from chamber 28. With the flow rates utilized in accordance with one aspect of the invention, such a source will provide absorbed energy in the flowing blood within the range of interest for practicing the method of the invention.
The blood flow from irradiation station 24 proceeding as shown in FIG. 1 via outlet 32, can be directly returned to the subject at 14. Under these circumstances, the modified lymphocyes, i.e. wherein bonding of nucleic acid to the photo-activated psoralen compounds has been effected, are impaired in their metabolic processes, in consequence of which the said lymphocytes will be rapidly broken down and destroyed by normal processes occurring in the subject. Since further, and as already discussed, the metabolic processes in the abnormal lymphocytes associated with disease conditions are usually accelerated, the breakdown in functioning, and the destruction of such abnormal lymphocytes, is accelerated beyond the corresponding effects on rate of normal lymphocytes, thereby contributing to the destruction of the abnormal lymphocyte population in the blood supply of the subject.
The burden placed upon the body's organ system, however, can be further alleviated, by utilizing in conjunction with the present system, a continuous centrifuge 44, which device serves several functions.
It is to be noted that continuous centrifuges of the type here utilized, have been long employed in blood flow processing systems commercially available from several manufacturers, including Haemonetics Corporation of Braintree, Mass., and the IBM Corporation, Medicals Products Division, of Monsey, N.Y. In the prior art systems in which such devices have been utilized all elements of FIG. 1 have been present, with the singularly important exception of the irradiation station 24. The function of the continuous centrifuge in such prior art systems has been one of separating excess lymphocytes or other blood components of interest. Where so used, a detriment of such system was the inefficiency of same, i.e. the centrifuging process can at best remove about 40 to 50% of the lymphocytes, and unfortunately also removes numerous components which are in fact desired to be retained.
In the system 10 of the present invention, two functions can be performed by the continuous centrifuge 44. One of these, is removal of lymphocytes, as previously discussed. Because the present invention, however, relies primarily on impairment of function of the lymphocytes to ultimately reduce the functioning population of same, the centrifuge 44 need not be relied upon to the extent that same has been in the aforementioned prior art arrangements. From a mechanical viewpoint, this implies that one need not work as close to the specific gravity interface between the lymphocyte fraction of the blood and the desirable fractions of the blood which one seeks to retain. Thus one can avoid undue separation of those desired fractions of the whole blood.
The continuous centrifuge 44, may further be utilized for an additional important purpose. In particular, some or virtually all of the blood plasma may be removed at 46 and replaced with fresh plasma at 48. This washing technique enables one to effectively withdraw the excess psoralen compounds which may be present in the blood plasma, replacing the plasma at 46 with psoralen-free isotonic fluid. Thus, when the blood is returned to the subject at 14, it is substantially free of any excess psoralens, i.e. other that those which have combined with the nucleic acid components of the lymphocytes in the manner desired.
It should also be reemphasized that while the preferred mode of practicing the present invention, as illustrated in FIG. 1, contemplates a continuous operation, the blood treatment pursuant to the invention can be effected by batched techniques. Thus for example a distinct, fixed quantity of blood may initially be withdrawn from the subject. Such quantity or batch, may already have present therein the desired quantities of disolved psoralen, i.e. by prior adminstration to the patient; or the said psoralen may be admixed externally with the withdrawn blood. The said blood batch bearing the psoralen may then be provided to an irradiation station, where the desired quantity of UVA energy is rendered incident upon same. During this process the batch of blood can be flowed through the station as previously discussed, or if the quantity of blood is appropriate and the blood treatment chamber 28 of appropriate dimensions, the batch can simply be treated under static conditions until the desired energy has been dissipated. Thereafter, the treated blood is taken from the irradiation station, and either centrifuged as above discussed, or directly returned to the subject.
While the present invention has been particularly described in terms of specific embodiments thereof, it will be understood in view of the present disclosure, that numerous variations upon the invention are now enabled to those skilled in the art, which variations yet reside within the scope of the present invention. Accordingly, the invention is to be broadly construed, and limited only by the scope and spirit of the claims now appended hereto.
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A method and system are disclosed for externally treating human blood, with the objective of reducing the functioning lymphocyte population in the blood system of a human subject. According to the method, blood is withdrawn from the subject and passed through an ultraviolet radiation field in the presence of from about 1 nanogram to 100 micrograms per ml of blood, of a dissolved psoralen capable of forming photoadducts with DNA, to thereby effect covalent bonding between the psoralen and the nucleic acid of the lymphocytes, thereby altering the said nucleic acid and inhibiting the metabolic processes of the lymphocytes; and thereupon returning the irradiated blood to the subject. The withdrawn blood may be formed into an extracorporeal stream and flowed through a treatment station whereat the irradiation is effected, as for example by exposure to UV energy in the wave length range of from about 3200 to 4000 Angstroms; and such flow process may be conducted on a continuous basis. If desired, at least portions of the treated blood may then be separated, as for example by a continuous centrifuge, before returning the remaining diverted blood to the subject.
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BACKGROUND OF THE INVENTION
The present invention is directed to a telescopic flashlight, and, in particular, to such a telescopic flashlight disclosed in U.S. Pat. No. 7,510,295, which patent is incorporated by reference herein, and which discloses a telescopic, collapsing flashlight having an extensible stem with a retractable and bendable flexible member, which allows for hard-to-reach areas and locations to be illuminated. The illuminating structure or device of the flashlight is attached to, and located at, the distal end of the flexible member, and includes a power button. At the distal end of the illuminating body, there is also provided a magnetic collar for use in attracting and holding a metal object during use of the flashlight.
In U.S. Pat. No. 5,951,142 there is disclosed an adjustable illuminating apparatus having an adjustable lighting unit, and which is also provided with an adjustable reflecting mirror unit mounted at the end of the apparatus, with the light from the lighting unit impinging on the mirror and being reflected thereby. The reflecting mirror unit is mounted to the end of the apparatus via mating threaded parts.
In published U.S. Application Number US2005/0201085, there is disclosed a telescopic flashlight apparatus having at one end thereof a pivotal mirror unit for reflecting the light emanating from the lighting unit to various locations. This mirror unit is cumbersome, and difficult to attach and remove.
SUMMARY OF THE INVENTION
It is the primary objective of the present invention to provide a telescopic, collapsible flashlight apparatus that includes a universally adjustable inspection mirror unit for reflecting the light of the lighting unit over a universal range, which mirror unit is readily and easily attached and detached from the distal end of the flashlight apparatus via a mounting collar having an annular metallic mounting ring that is magnetically retained by means of an annular magnet affixed to the distal end of the apparatus where the lighting or illuminating device is located, which mounting collar itself is rotatable relative to the distal end of the flashlight apparatus in order to provide two degrees of freedom of rotational motion of the mirror proper.
It is also the primary objective of the present invention to provide such a telescopic flashlight apparatus with a distal, adjustable mirror unit that is itself removably detachable, such that the mirror proper may be attached and re-attached to the mounting collar at will, so that when the mirror proper is not needed for directing the light from the lighting unit to hard-to-see or get-at places or locations, it may be removed from the metallic mounting collar, so that it does not interfere with the normal and average use of the flashlight apparatus.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be more readily understood with reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of the telescopic flashlight device with universally-adjustable mirror unit of the invention;
FIG. 2 is a perspective view of the universally-adjustable mirror unit of the flashlight device of FIG. 1 and showing various positions it may be assume in a first plane;
FIG. 3 is a perspective view similar to FIG. 3 but showing the universally-adjustable mirror unit pivoted to various positions via a first pivot in a second plane;
FIG. 4 is a perspective view similar to FIG. 3 but showing the universally-adjustable mirror unit pivoted to various positions via a second pivot in the second plane;
FIG. 5 is an assembly view, in perspective, showing the telescopic flashlight device with universally-adjustable mirror unit of FIG. 1 ;
FIG. 6 is an assembly view of the universally-adjustable mirror unit of the invention; and
FIG. 7 is a transverse cross-sectional view of the assembled universally-adjustable mirror unit.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in greater detail, the telescopic flashlight device with universally-adjustable mirror unit is indicated generally by reference numeral 10 . The basic telescopic flashlight is that disclosed in U.S. Pat. No. 7,510,295, which patent is incorporated by reference herein. The telescopic, collapsing flashlight 10 includes a main, hollow, cylindrical handle, body portion or casing 12 , used for gripping the flashlight, and in which is received a series of collapsing, hollow, telescoping elements or sections 14 , 16 , 18 , 20 , and 22 . Each telescopic element 14 , 16 , 18 , 20 , and 22 is collapsible into the immediate-adjacent element closer to the main body portion or housing 12 , in the manner depicted in FIG. 1 , for storage, and for removal therefrom for expansion and use. The degree to which the telescoping elements are pulled out is variable so that the flashlight may be used in all environments. The end of the main body portion is provided with a enlarged head or section 12 ′, to which is secured a magnet for attracting and holding metal objects.
At the end of the telescopic section 22 there is provided a flexible, bendable member or section 26 which is collapsible into the telescopic section 22 , and to the end of which is attached or mounted an illuminating or lighting unit or device 30 . The illuminating device 30 comprises a hollow main housing 32 serving as a battery or power-cell compartment, a push-button switch 34 , or the equivalent thereof, and a removable bulb-fixture 38 ( FIG. 5 ) containing one or more halogen lighting bulbs or LCD's. The distal end 38 ′ of the removable bulb-fixture 38 also mounts a forwardly-facing, annular magnet, such as magnet-ring 40 , by which objects may be picked up and held.
The annular magnet 40 is used to removably, temporarily and mutably mount a universally-pivotal reflection mirror unit 44 . The universally-pivotal reflection mirror unit 44 is comprised of a removable mounting collar or annular ring-element 46 , defining an inner, circular main portion 48 defining an exteriorly-located or outer annular surface section, which is substantially circular in shape that defines an outer or outwardly-facing opening 50 . To the interior-facing portion of the exteriorly-located or outer annular surface section is mounted an annular element or ring 54 made of magnetic material, such as ferrous metal, which is attracted to, and held by the annular magnet 40 . The inner or inwardly-facing opening 56 of the annular ring-element 46 has a diameter slightly larger than the diameter of the distal end of the removable bulb-fixture 38 , so that the annular ring-element 46 may be telescopingly mounted thereover, and held removably in place thereat, by means of the annular magnet 40 magnetically retaining the annular ring-element 46 via the metallic ring or annular element 54 , whereby the entire universally-pivotal reflection mirror unit 44 is rotatable in a first degree of rotational motion about the end of the flashlight. It is noted that the central or inner opening of the annular ring-element 46 has a diameter less than the diameter of the distal end of the removable bulb-fixture 38 , whereby the interior-facing portion of the metallic annular ring 54 abuts against the annular end-surface distal end 38 ′ of the removable bulb-fixture 38 in facto-face contact with the annular magnet 40 to allow for the mounting thereto. The material from which the annular ring element 46 is made is preferably plastic providing a low coefficient of friction, which readily allows the rotation thereof about the distal end 38 ′ of the illuminating device 30 , which is also made of plastic having a low coefficient of friction. The facing and contacting surfaces of the annular magnet 40 and the metallic annular ring 54 also offer a low coefficient of friction, whereby no obstruction to the rotation of the mounting annular ring-element 46 exists. Alternatively, the annular ring 46 may be made entirely of a low-coefficient-of-friction magnetic material, such as ferrous metal, which obviates the need for the metallic annular ring 54 .
The removable mounting collar or annular ring-element 46 is also provided with an eccentric or protruding section 58 defining a through-opening or hole 60 . The opening 60 has a first outer portion 60 ′ that is preferably hexagonal in shape for part of the depth of the opening 60 , and a second inner portion 60 ″ that is circular in shape for the remainder of the depth thereof. Mounted in the circular portion 60 ″ is a circularly-shaped magnetic rod or post-element 64 , as best seen in FIGS. 6 and 7 .
The universally-pivotal reflection mirror unit 44 also consists of the main mirror-portion 68 , which contains the mirror-element proper 70 , which is preferably circular in shape. The circular-shaped mirror 70 has a mounting eccentric or ear 72 defining a bottom pivot shaft or post 72 ′ that is pivotally mounted at one end 76 ′ of a mounting bracket 76 , in a conventional manner; the mirror unit is allowed a second degree of rotational motion different from the first degree of rotational motion provided by the annular ring-element 46 . To the other end 76 ″ of the mounting bracket 76 is pivotally mounted a metallic mounting pin or shaft 80 , made of ferrous metal or the like, which defines a hexagonally-shaped main shaft portion 80 ′ which is partially receivable in the first, outer hexagonally-shaped portion 60 ′ of the opening 60 , whereby the metallic mounting pin or shaft 80 , and thus the mirror-element proper 70 , are removably mounted to the mounting collar or annular ring-element 46 , and where the mirror unit is also allowed additional degrees of rotational motion via the spherical or ball joint at the upper end of the pin 80 . Thus, the universally-pivotal reflection mirror unit 44 is removable from the illuminating or lighting unit or device 30 in two ways or sections. The first by means of the metallic collar, or an annular element or ring 46 , by which the entire mirror unit 44 is removable, and the second by means of the metallic mounting pin or shaft 80 , by which part of the mirror unit 44 is removable, whereby differently-shaped or sized mirrors 70 may be mounted to the illuminating device. For example, a prism mirror, disclosed in U.S. Pat. No. 6,210,009, may be attached to the illuminating apparatus, which prism mirror displays a non-inverted image of the object or objects, being viewed in the proper sense and handedness.
While the universally-pivotal reflection mirror unit 44 has been disclosed for use and removable attachment to a telescopic, collapsing flashlight, it may be used in all types of flashlights incorporating an annular magnet at the distal end of the lighting unit itself, or at the distal of another section of the flashlight. Moreover, the universally-pivotal reflection mirror unit 44 may incorporated into other lighting devices not considered to be a flashlight, as long as it incorporates a magnetic ring or magnetic, in a manner equivalent to the mounting of the universally-pivotal reflection mirror unit 44 .
It is also noted that instead of the forwardly-facing annular magnet 40 located on the front surface of the illuminating device 30 , a collar-magnet that circumferentially surrounds the end 38 ′ thereof may be used, in which case the annular element or ring 46 would be located or mounted to interior annular rim-surface thereof for face-to-face contact with the collar-magnet.
While a specific embodiment of the invention has been shown and described, it is to be understood that numerous changes and modifications may be made therein without departing from the scope and spirit of the invention.
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A telescopic flashlight that includes a universally adjustable mirror unit for reflecting the light of the lighting unit over a universal range, which mirror unit is readily and easily attached and detached from the distal end of the flashlight apparatus via a metallic mounting collar that is magnetically retained by means of an annular magnet affixed to the distal end of the apparatus, which mounting collar itself is rotatable relative to the distal end of the flashlight apparatus in order to provide two of the three degrees of freedom on motion of the mirror proper.
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This is a continuation of application Ser. No. 07/729,423, filed Jul. 12, 1991, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates generally to the recognition and interpretation of the operational and control signals used by a computer system microprocessor, by its peripheral chips, and, more specifically, to providing peripheral chips that operate with several different types of microprocessors having various signaling protocols.
For several years after first making, in the mid-1970s, a complete microprocessor ("MPU") on a single integrated circuit chip, semiconductor manufacturers attempted to provide a complete family of peripheral circuit chips to be used with their microprocessors. Such peripheral chips typically function to provide parallel input-output, serial input-output, interface with system memory, memory management, direct memory access ("DMA") control, event counting and timing circuits, high speed numerical processing, and various other similar functions that need to be provided along with the MPU in order to form a complete computer system. In the beginning of microprocessor-based system technology, semiconductor manufacturers designed their own techniques and signal protocols for controlling operation of the peripheral circuits from the microprocessor. Although these techniques had many common aspects, they also had many differences that prevented a peripheral circuit of one semiconductor manufacturer from working with a microprocessor of another, or at least without the addition of translation or "glue" logic between them.
Over time, as the number of types of peripheral circuits being provided increased dramatically, along with an increasing number of microprocessor types, it became impossible for any single semiconductor manufacturer to provide a full line of peripherals for all of its own microprocessors. Also, as certain peripheral parts became popular because of better designs and more complete functions, computer system designers began to use peripheral devices of one semiconductor manufacturer family with a microprocessor of another. The trend lately has been for semiconductor manufacturers to design both microprocessors that can be more easily interfaced to an increasing number of peripheral devices, and to also design peripheral devices that can be more easily used with a variety of microprocessors from different manufacturers.
Each popular microprocessor still has its own particular interfacing requirements, including specific signal protocols, but there is a considerable commonality between them and the differences are now well defined. Examples of such differences include the use by some microprocessors of an 8-bit wide data bus and use by others of a 16-bit wide data bus. In the case of a 16-bit wide data bus, some microprocessors use the least significant address line (A0) to designate which half of the bus is being used to transfer a single byte of data, along with a single data strobe to transfer that byte, while other microprocessors use separate data strobes for transferring bytes on the lower and upper byte data bus lines. Further, microprocessors that so utilize the A0 line do so with different polarities.
Another example difference among microprocessors in communicating with peripheral devices is in designating whether data is to be written from the data bus to the peripheral device or read from it. In one arrangement, separate read and write strobe signals are provided. In another arrangement, one signal is provided to designate whether a read or write operation is to take place, and another signal acts as a data strobe to implement that operation. In the latter protocol, microprocessors also differ in the polarities used to designate the read-write control signal.
Another difference in control signal protocols among microprocessors is in the way they match the speed of their operation to that of the peripheral device. A peripheral circuit often needs to delay and slow down the operation of the microprocessor to allow the peripheral enough time to capture write data or provide read data asked of it by the microprocessor. Typical situations where this occurs is when the peripheral device is unable to provide read data to the microprocessor within the time required to maintain full speed operation of the microprocessor, or when the peripheral device is unable to accept and capture write data provided by the microprocessor quickly enough to allow the microprocessor to move on to its next operation at its full speed. Two alternative techniques have emerged for allowing the peripheral device to slow down the microprocessor in such circumstances. One method is for the peripheral device to emit a WAIT signal as soon as it recognizes that it is not going to be able to complete its designated task before the microprocessor will want to move on to its next operation. An alternative technique is for the peripheral device to emit an acknowledge (ACK) signal when it begins to perform an operation requested of it by the microprocessor and then terminate that signal when the task has been completed. Some microprocessors utilize one of these protocols, and others utilize the other protocol.
One early technique to provide a peripheral device to operate with microprocessors using any of such different signaling protocols was to provide a separate pin for each different signal and protocol, circuits then being provided as part of the peripheral device to utilize any of them. A given microprocessor was then connected with the appropriate pins of the peripheral device depending upon the microprocessors control signals and their protocols. Because higher pin counts and larger packages increase costs, such an approach requiring provision of redundant, unused pins is not often used.
Another technique currently used in peripheral devices for adapting them to various microprocessors utilizes a control register having fields whose bits determine which among various signaling protocols is to be used on a group of control signal pins. The control register is loaded each time the computer system in which the peripherals are used is initialized or reset. This technique is limited in its flexibility in that the operation of loading the control register is itself accomplished using at least some of the control signals being defined.
It is a primary object of the present invention to provide a technique that allows a peripheral device to automatically adapt to various types of microprocessor control signals and protocols, thereby to avoid having to use separate, redundant pins and avoiding the necessity of programming control register fields for this purpose.
SUMMARY OF THE INVENTION
This and additional objects are realized by the various aspects of the present invention wherein, briefly and generally, a peripheral device includes several control signal pins that are each connectable to different types of control signals and protocols used by various microprocessors, circuits being provided as part of the device to automatically recognize which signals and protocols are being used by the microprocessor. This is done by monitoring the signals during the first few operations performed by the microprocessor after initialization or reset of the computer system. After this initialization learning process is completed, the recognized one of the various different signals and protocols that can be connected to these pins is automatically converted within the peripheral circuit to a common protocol and set of signals. This protocol and signals are then utilized to control operation of the peripheral device circuitry, including, for example, control of its data bus configuration and transfers of data over it and a designation of the type of speed matching signaling that is to be utilized.
In the example peripheral circuit described below with respect to the drawings, a plurality of latches are connected through appropriate logic to a number of control signal pins including those which are designed to operate with different signal protocols. The state of several of these latches is set upon observing the types of signals used by the microprocessor during its first operations after initialization. Examples of such latches include one for determining whether the data bus is 8 or 16 bits wide, whether the A0 address line is utilized, and which read/write control signal protocol is used. The states of another set of latches observing many of the same microprocessor signals are set upon the first access by the microprocessor to the specific peripheral chip, specific constraints being set on the nature of the first access. Examples of information stored in this second set of latches is the polarity convention of the A0 signal, if used, and the polarity convention of a read/write signal, if used. A logic system receives the outputs of these latches and other incoming control signals to generate internal control signals that have the same protocol for any of the microprocessor signals that may be connected to the multipurpose control signal pins. Yet another latch learns whether the wait or acknowledge speed matching protocol is used by the microprocessor, and the information stored there connects either a wait logic circuit or an acknowledge logic circuit to a common pin.
Additional objects, features and advantages of the various aspects of the present invention will become apparent from the following description of its preferred embodiments, which description should be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in very general terms a portion of a computer system having a microprocessor and a peripheral connected to operate together;
FIG. 2 is a block diagram of the peripheral circuit of FIG. 1;
FIG. 3 is a circuit diagram of one of the blocks shown in FIG. 2;
FIG. 4 is a circuit diagram of one of the blocks shown in FIG. 3;
FIGS. 5(A) and 5(B) provide waveforms to illustrate one existing read-write signaling protocol;
FIGS. 6(A) and 6(B) provide waveforms to illustrate another existing read-write protocol;
FIG. 7 is a set of waveforms that illustrates a wait control signal protocol;
FIG. 8 is a set of waveforms that shows an acknowledge signal protocol; and,
FIG. 9 is a circuit diagram illustrating another of the blocks of the circuit of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a portion of a typical computer system is shown as background to explaining implementation examples of the various aspects of the present invention. A microprocessor integrated circuit device 11 is illustrated to be of a type that utilizes a data bus 13 that is separate from an address bus 15, although the invention can be used with a multiplexed address/data bus by simply capturing the state of address line 0 in a demultiplexing latch, the output of which is then connected to the A0 signal shown in the drawings. A peripheral integrated circuit device 17 is shown to be connected to those same busses. A number of system control and status lines 19 are also connected to each of the microprocessor 11 and peripheral 17, as is a voltage supply line 21. Of course, a complete computer system will include a number of additional peripheral integrated circuit devices, memories, timing circuits and the like, not shown in FIG. 1.
It is the different types of signals and signal protocols communicating over the system control and status lines 19 between the microprocessor 11 and the peripheral circuits, including circuit 17, to which the peripherals are desirably designed to automatically adapt according to the present invention. Referring to FIG. 2, an example of such a peripheral is shown in a general schematic diagram. A primary portion 23 of the peripheral circuit performs the functions for which the circuit is utilized, such as a parallel input-output device, serial input-output device, memory interface, and the like. Any such circuit 23 may be connected through a plurality of package pins 25, in this case seven, to the system address bus, designated in this example as A0-A6, or it may be connected to the outputs of a plurality of demultiplexing latches that capture address information.
Similarly, the circuit portion 23 is connectable to a system data bus which may or may not also carry multiplexed addresses. Since one of the capabilities of a peripheral device using the present invention is to transfer data 16 bits at a time, circuit 23 includes an internal data bus that is 16 bits wide, and is divided into two 8-bit groups INT D15-8 and INT D7-0. One set of 8 device pins 27 is provided for connecting to an 8-bit system data bus D7-0 or to 8 lines of a system data bus that includes 16 or more data lines. Another set of 8 device pins 29 is provided for connecting to 8 more lines of a system data bus that includes 16 or more data lines. If the device is configured for 8-bit data only, the pins 29 can be used for other functions. In the initial commercial embodiment, they are used for "modem control signals". The data bus pins are connected to the INT D15-8 and INT D7-0 through a plurality of gated directional buffer amplifiers (drivers and receivers). An amplifier 31, when gated on by the output of an AND-gate 33, drives the state of the D7-0 pins onto INT D7-0 during a write operation. Similarly, such a buffer 35 drives, in response to the output of an AND-gate 37, the state of INT D7-0 onto the D7-0 pins during a read operation. Likewise, a write buffer 39, gated by an output of an AND-gate 41, and a read buffer 43, gated by an output of an AND-gate 45, control transfers between INT D15-8 and the D15-8 pins. Another set of such buffers 47 and 49 are gated from the outputs of respective AND-gates 51 and 53 for transferring between INT D15-8 and the D7-0 pins, which is required when the external system data bus is only 8 bits wide. The inputs to the controlling AND-gates just mentioned are described below.
In addition to the address and data buses, the primary functional circuit portion 23 will likely have a plurality of lines 55 that are connected to separate pins, a number depending upon the function of the circuit portion 23. For example, if it is a serial input-output device, lines 55 may be connected to another computer system, a printer, or a display terminal. For proper operation, the circuit also requires connection with at least a majority of the control and status lines 19 of the computer system. A pin 57 is designated for receiving a RESET* signal from the microprocessor 11. Similarly, a pin 59 is designated for receiving a chip select (CS*) signal from external address-decoding logic. Both of the pins 57 and 59 are connected directly to the main circuit portion 23. (The asterisk (*) used after the signal names herein is intended to identify those signals that are active when in their low voltage state.) Also, of course, at least one pin 61 needs to be provided for a voltage supply V CC ,
The main functional circuit portion 23 likely requires connection with a number of the other system control and status lines 19 in order to operate, and certainly control signals are required from the microprocessor in order to direct the flow of data over the data bus by appropriately gating the various buffer amplifiers that are provided in the path of the data bus, as described above. Three pins 63, 65 and 67 are designated for connecting with three additional of the system control and status lines 19. But each of these three pins is intended to be connected to different control signals depending upon the type of microprocessor 11 with which the peripheral circuit is being used. Therefore, before signals from these pins are utilized within the peripheral circuit, they are passed through circuits indicated by a block 69. A primary purpose of the circuits 69, which are described below with respect to FIG. 3, is to recognize the types and protocols of the control signals from the microprocessor on pins 63, 65 and 67, as well as the protocol of the signal on an A0 address line 71, and then convert those signal protocols into a common set of data transfer control signals on lines 73-77. That is, the circuits 69 are able to recognize various different microprocessor control signals related to transfers of data over the data bus and translate those control signals into a form on lines 73-77 which is the same no matter which of the various microprocessor control signal protocols is being utilized. In addition to these internal control signal lines 73-77 being connected to the various data bus controlAND-gates 33, 37, 51, 53, 41 and 45, they will also be used by the main circuit functional portion 23, to provide read data on, and capture write data from, the INT D15-8 and/or INT D7-0 lines.
Additionally, it should be noted that each of the data bus AND-gates 33, 37, 51, 53, 41 and 45 receive as an input a chip select (CS) signal in a line 79, a result of an inverter 81 receiving the CS* signal from the pin 59. This then limits any data transactions on the data bus to occur only when the microprocessor addresses this particular circuit for operation. As is usual, the chip select signal (CS*) is received at pin 59 from an external logic circuit that decodes the peripheral's address from the system address bus.
An example of the bus adaptation circuit 69 is shown in FIG. 3. The different protocols of control signals which may be connected to the pins 63, 65 and 67 will first be explained. Pins 63 and 65 are designed for connection with the two control lines in the microprocessor 11 which designate whether the peripheral is to be read from or written to. There are two well-known read/write control protocols to which the circuit 69 adapts. One is illustrated in FIG. 5. In this case, one of the control signals is a read (RD*) signal and the other is a separate write (WR*) signal. As shown in FIG. 5(A), a read operation occurs when the read (RD*) control signal goes low while the write (WR*) signal remains high. The reverse occurs during a write operation, as indicated in FIG. 5(B). With this protocol, the RD* control signal from the microprocessor is connected to the pin 63, while the WR* signal is connected to the pin 65.
In the second type of read-write signaling, illustrated in FIG. 6, the control signals are a direction line, which may be designated R/W or W/R, and one or more data strobes, designated DS* or UDS* and LDS*. According to this protocol, as shown in FIG. 6(A), a signal designated R/W remains high when a read operation is occurring, and, as shown in FIG. 6(B), drops low when a write operation is occurring. The data strobe signal(s) DS* or UDS* and LDS* work(s) the same in either a read or write operation, simply to designate when one or the other function is to be executed. In the adaptation circuit 69, the R/W signal from a microprocessor utilizing this protocol is connected to a pin 63, while the DS* or LDS* signal is connected to the pin 65. It will also be noted from FIG. 3 that a W/R signal is also indicated as an alternative to be connected to the pin 63. The W/R notation indicates an reverse polarity of the R/W signal, which is a variation of the protocol illustrated in FIG. 6. This variation is also detected and the circuit adapted to it, in the manner explained below.
Before proceeding to describe the operation of the adaptation circuits of FIG. 3, the microprocessor control signals which may be connected with the pin 67 will be explained. If the system in which the peripheral is being used only has an 8-bit data bus, pin 67 is then connected permanently to a high voltage such as V CC . If a 16-bit data bus, any one of the control signals indicated in FIG. 3 that is utilized by the microprocessor of the system is connected to the pin 67. These three signals are the upper data strobe (UDS*), a strobe for the D15-8 data bus pins, the bus high enable (BHE*), a control signal that is low if data is to be transferred on the data bus portion D15-8, or byte/word select (B/W), a control signal that is low if 16 bits of data are to be transferred. One of these standard control signals, possibly in conjunction with the A0 address pin 71, specifies how bytes of data are transferred on the lower and upper byte data bus portions when a 16-bit wide system bus is being used.
Similarly, if the system in which the peripheral is being used includes an A0 line, it should be connected to the pin 71, otherwise pin 71 should be connected to a fixed logic level (e.g., V CC or ground).
In order to detect the protocols of the control signals received at pins 63, 65 and 67, and on address line A0, a bus type detection circuit 83 and polarity adaptation circuit 85 are provided (FIG. 3). Circuit 83 learns about the system control signal protocols being utilized during the first cycles of operation of the system after initialization or reset, which are typically directed to system read-only-memory (ROM) and random-access-memory (RAM). Circuit 85 learns more about the system control signal protocols from the first cycle directed to this peripheral 17, which needs to be one in which the microprocessor writes a byte to the peripheral on the D7-0 data bus pins.
The bus type detection circuits 83 include three latches 87, 89, and 91. All three latches are cleared/reset when the RESET* signal becomes active. This occurs at the beginning of any system initialization cycle, and places the latches of the circuit 83 in an initial state. The latch 87 will remain reset, giving a signal in an output line 93 that indicates an 8-bit bus is being utilized, unless the signal on the pin 67 goes active low. In the latter case, the latch 87 is set and the signal in the line 93 indicates that a 16-bit bus is being utilized.
The second latch 89 is clocked by any rising transition that might occur on the A0 line 71, which causes the voltage V CC to be latched and presented at an output 95 if there is any activity on the A0 line. If there is, that indicates that microprocessor uses the A0 line and the signal in the line 95 provides that information. If not, the latch 89 remains in a cleared state and its output in line 95 indicates that.
The third latch 91 is set by the signals on the pins 63 and 65 both being active, as detected by the gate 97. If both signals are active at the same time, the state which is latched and presented on the signal 99 indicates that a direction line and one or more data strobes are being utilized as in FIG. 6, since only in FIG. 6(B) do both of the signals on those pins become active at the same time. If the signals at the pins 65 and 63 are never simultaneously low, this indicates that separate read and write strobes are being utilized as in FIG. 5, and the state of the latch 91 remains reset and provides an indication of that in the line 99.
The polarity adaption circuit 85 learns more about the protocols being used. Another latch 101 is enabled through an AND-gate 103, the first time after a Reset that the signal levels on the pins 63 and 65 are both low, to latch the voltage level in the A0 address line 71 and give an indication in line 105 as to whether A0 was high or low in said first cycle. Since this is occurring during a write operation to this peripheral using the lower data byte D7-0 of the data bus, the polarity of the A0 signal that designates the lower byte is thus captured. In microprocessor systems that use the A0 line to control whether the upper or lower data bus bytes are being used, the polarity protocol to designate each is thus learned.
Another latch 107 is similarly enabled and latches the voltage state of the pin 63 and presents that at an output 109. Since the first cycle is known to be a write, a low voltage level so latched indicates that if the read/write protocol of FIG. 6 is being utilized, the polarity on the pin 63 to indicate a write is low, as indicated in FIG. 6(B). However, if that voltage is high, it indicates a W/R signal, rather than an R/W signal, is connected to the pin 63, so that a write operation is indicated by a high and a read operation by a low.
Finally, with respect to the polarity adaption circuits 85, another latch 111, connected to be cleared when a system RESET* signal is asserted low, is connected to disable the AND-gate 103 after the first write cycle directed toward this peripheral, thereby assuring that the state of the latches 101 and 107 is not altered during subsequent operation of the peripheral.
To summarize the state of the signals for various protocols being detected, the following are the states learned by the latches 87, 89, 91, 101 and 107 respectively:
______________________________________D16 (line 93) true/high for a 16-bit data bus (false/low for an 8-bit bus)USEA0 (line 95) true/high if A0 is being used (false/low for UDS*-LDS* system)DIRDS (line 99) true/high for a system with a direction line and a common data strobe (false/low for separate read and write strobes)FirstA0 (line 105) the state of A0 as of the first cycle with this device after a Reset, which must be an 8-bit write on the D7-0 linesFirstDir (line 109) the state of RD*-R/W-W/R as of the first cycle with this device after a Reset, which must be an 8-bit write on the D7-0 lines.______________________________________
Outputs of the learning latches, in lines 93, 95, 99, 105 and 109, as well as connections from the pins 63, 65 and 67, and from the address A0 line 71, are all combined in a logic circuit 113 to provide the internal control signals 73-77 which have a common protocol no matter which of the various control signal protocols discussed above is being used by the system microprocessor 11. The logical function to be executed by the circuit 113 is given by the following equations; wherein the symbol "!" is used to indicate logical negation (inversion), the symbol "+" is used to indicate logical inclusive ORing, and the symbol "&" is used to indicate logical ANDing:
______________________________________DHi = !UDS*-BHE*-B/W + (D16 & USEA0 & XA0)DSwap = !D16 & XA0DLo = (!WR*-DS*-LDS* & !USEA0) + (!D16 &!XA0) + (USEA0 &!XA0) + USEA0 & !UDS*-BHE*-B/W & !A0RD = (!RD*-R/W-W/R & !DIRDS) + (R/W & DS)WR = (!WR*-DS*-LDS* & !DIRDS) + (!R/W & DS)______________________________________
The logic terms used in the above equations are those included in FIG. 3 to identify various signals, along with intermediate terms which are defined as follows:
______________________________________XA0 = A0 xor FirstA0R/W = RD*-R/W-W/R xor FirstDirDS = (!WR*-DS*-LDS* & DIRDS) + (!UDS*-BHE*-B/W & !USEA0)______________________________________
This results in output signals in lines 73-77, which, through their connections as inputs to the AND-gates 33, 37, 51, 53, 41 and 45, control data transfer between the external data bus pins 27 and 29 and an internal data bus connected with the functional circuit portions 23, as follows:
______________________________________DHi (line 75) true/high if the D15-8 pins should be connected to the INT.sub.-- D15-8 busDSwap (line 74) true/high if the D7-0 pins should be connected to the INT.sub.-- D15-8 busDLo (line 73) true/high if the D7-0 pins should be connected to the INT.sub.-- D7-0 busRD (line 76) true/high for a Read cycleWR (line 77) true/high for a Write cycle______________________________________
An example of a logic circuit for the block 113 of FIG. 3, which implements the logic equations given above and provides the foregoing outputs in response to the learned states held in the various latches, is given in FIG. 4.
Referring again to FIG. 2, another learning capability is provided by circuits indicated as a block 121 which operate separately from the bus type adaption circuit 69. The circuits 121 provide the capability of learning in a first cycle, directed to a memory or another peripheral device, which of two microprocessor/peripheral speed matching signaling protocols is used. The circuits adapt a single pin 123 to operate with either the standard wait protocol indicated in FIG. 7 or the standard acknowledge protocol indicated in FIG. 8. An example implementation of the circuit 121 is given in FIG. 9. The circuit automatically adapts to either of the wait or acknowledge protocols by asserting the appropriate signals in a single pin 123 that is connected to provide signals to the speed matching pin of the microprocessor. No separate pins are required for this peripheral chip to learn the correct protocol, nor need any register be loaded as part of the initialization process. No extra circuits are required outside of the peripheral device to accomplish this learning function. The circuit simply observes the nature of the speed matching signal generated from memory or some other peripheral in the system in response to a read or write command to it by the microprocessor and adjusts its operation to match that observed to be performed by the memory or other peripheral.
Central to the learning capability of the circuit 121, as illustrated in FIG. 9, is a latch 125 that is initially preset to the "one" state by a RESET* signal that is made active at the beginning of any computer initialization process. An OR-gate 127 generates in a line 129 a "cycle strobe" signal that is active when either a read or write operation is occurring somewhere in the computer system, by having lines 76 and 77 as inputs. The rising (trailing) edge of the speed matching signal observed at pin 123 causes the latch 125 to capture at its output 131 the state of the cycle strobe signal in line 129 at that instant. As can be seen by comparing FIGS. 7 and 8, a rising edge 133 of the wait signal occurs during an active cycle strobe in line 129, and thus leaves the output 131 in its "one" state as after Reset. If the signal received at the pin 123 is the acknowledge type, as shown in FIG. 8, a rising edge 135 occurs after termination of the cycle strobe in line 129 and thus forces the output 131 of the latch 125 to its "zero" state. The timing of the alternative wait or acknowledge signals from a memory or another peripheral in the system exists as a result of one of those standards being used and is simply being observed by the circuits 121 in order to set itself to operate in accordance with that standard. The selection of the WAIT* signal alternative when RESET* is asserted is significant in that a WAIT* signal may not be asserted during the initial cycles in a system using that protocol, but an ACK* signal is always asserted for each cycle in such a system.
Once the latch 125 has learned which standard is being employed by the system, its output 131 sets a switch (multiplexer) 137 to connect the input of a driver 139 to an output of either a wait logic circuit 141 or an acknowledge logic circuit 143. The driver 139 makes its output low while the selected signal is active. The wait logic circuits 141 cause the driver 139 to drive its output low as indicated in FIG. 7 for the WAIT* signal. Similarly, the acknowledgement logic circuit 143 makes the driver 139 generate the ACK* pulse of FIG. 8. The selection of one of those circuits causes the appropriate speed matching signal to appear at the pin 123 when a read or write operation is occurring and the current peripheral is selected by a CS* signal at the pin 59.
Although the various aspects of the present invention have been described with respect to the preferred embodiments, it will be understood that the invention is protected within the full scope of the appended claims.
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By monitoring various combinations of control signals generated by a microprocessor in a computer system in the first operational cycles after it is reset, a peripheral circuit sets itself to respond appropriately to control signals from the microprocessor according to any of several different protocols. For example, an instruction from the microprocessor to write to or read from the peripheral circuit is implemented over two control lines with one of several possible protocols. The circuit determines which protocol is being used each time the system is initialized and thereafter knows when a read or write operation is being performed. Another example is the different wait or acknowledge protocols that various microprocessors use. The peripheral circuit can thus be used with a variety of microprocessors without having to provide sets of pins dedicated to each signal protocol used by available microprocessors, and without the necessity to load a configuration register in the peripheral circuit by the microprocessor as part of the initialization process.
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BACKGROUND OF INVENTION
Hunting or bird dogs are trained to locate game birds, as pheasants, partridges, and grouse, in the outside environment or field. The field usually has irregular terrian and vegetation, such as brush, grass, or cultivated crops, as corn. The terrain and vegetation can obscure the dog, preventing visual contact by the dog handler or the hunter. The hunter will signal the dog to return to a location where the dog can be observed. Occasionally, the hunter spends considerable time locating the dog. Bells and signaling devices have been mounted on dog collars to provide an audio signal providing the hunter with information as to the location of the dog. These signaling devices generate the same signals when the dog is moving or is stationary, or no signal when the dog is stationary. A stationary dog, such as a dog on point, cannot be located with silent signaling devices.
SUMMARY OF INVENTION
The invention is directed to an audio signal device carried by the collar of a hunting dog to provide a first audio signal when the dog is moving and a second audio signal when the dog is stationary. The first and second signals are different distinguishable sounds used as an aid in locating the dog and provide information as to whether the dog is moving or stationary. The audio signal device has an audio indicator electrically coupled to electronic circuitry operable to energize the audio indicator to produce the audio signals. When the dog stops moving, the electronic circuitry withholds electric power from the audio indicator for a variable period of time; for example, five seconds, to provide a silent period to allow the dog and handler to coordinate instructions.
The audible sound is produced by an electrically operated audio indicator means having means, such as a piezo-electric transducer operable to provide accoustic energy within the frequency range of the human ear. The electronic circuitry is electrically connected to the audio indicator means to drive the audio indicator means so as to produce an audible sound. An electric power source, such as a battery, is connected to the electric circuit means through an on-off switch means. The on-off switch means is manually operated to complete the electric circuit connecting the power source and the circuit means. Support means, such as a casing or encapsulating plastic body, is used to contain the circuit means, power source, and switch means. In one embodiment, the switch means is located within a tube encapsulated in a plastic body. The tube has an open end providing access to an actuator for the switch means allowing the switch means to be manually operated. The plastic body has a central cavity to accommodate a battery power source. The electronic circuitry has means responsive to movement of the dog to provide electric power to the audio indicator means whereby the audio indicator means produces first audio signals providing the handler with audio information that the dog is moving. The means of the electronic circuitry is also responsive to a stationary condition of the dog to withhold the electric power to the audio indicator means for a limited period of time making the audio signal device inoperative. The electronic circuitry then is operative to provide electric power to the audio indicator means whereby the audio indicator means produces a second audio signal, such as intermittent sound signals, have an initially reduced volume and different rate than the first sound signals so that they are readily discernible by the handler indicating the stationary or point condition of the dog.
The electronic circuitry utilizes a pair of mercury switches connected to provide or withhold power to the audio indicator when the dog is moving. Transistor means are used to energize the audio indicator means when the dog is stationary. A time delay resistor capacitor arrangement holds the base voltage of the transistor means below the turn-on point for a predetermined period of time to withhold power to the audio indicator means thereby providing a limited silent period as soon as the dog stops. This allows the dog and handler to coordinate their activities. The silence is also a signal to the handler that the dog has stopped and may be on point.
The audio signal device is light in weight, sturdy in construction, and durable in use. A casing or body is used to support and protect the electronic circuitry, on-off switch, and the power source. The casing, being mounted on the dog collar, does not interfere with or inhibit the activities of the dog. The on-off switch is manually operated, allowing the handler to turn off the audio signal device without removing the device from the dog. The power source, such as a battery, can be conveniently removed from the audio signal device and replaced with a new power source. These and other objects and advantages of the audio signaling device are set out in the audio signal devices hereinafter described.
IN THE DRAWINGS
FIG. 1 is a perspective view of a dog provided with a collar carrying the audio signal device of the invention;
FIG. 2 is an enlarged sectional view taken along the line 2--2 of FIG. 1 of the collar and audio signal device;
FIG. 3 is an enlarged sectional view taken along the line 3--3 of FIG. 1;
FIG. 4 is a circuit diagram of the audio signal device;
FIG. 5 is a view similar to FIG. 2 of a modification of the audio signal device;
FIG. 6 is a modified circuit diagram of the audio signal device; and
FIG. 7 is a sectional view similar to FIG. 3 of a modification of the audio signal device of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a hunting dog or bird dog 10 in a field 11 providing an environment for one or more birds 12, such as a pheasant, partridge, grouse, and the like. A conventional dog collar 13 is located around the neck of dog 10. As shown in FIG. 2, a releasable connector 14, such as a buckle, snap, or pin, retains collar 13 about the dog's neck. An audio signal device indicated generally at 16 is secured to a lower portion of collar 13 with a plurality of fasteners 17. Fasteners 17 are shown as short flat-headed bolts. Other fastening means, such as bands, cables, ties, tape, screws, and rivets, can be used to attach audio signal device 16 to collar 13.
As shown in FIG. 3, audio signal device 16 has a cylindrical casing or body 18 having an open end and a closed end wall 19. End wall 19 has a central circular opening 21. A cap or disc 22 is snapped into the open end of casing 18. An audio signal generator or beeper unit 23 is located in casing 18 adjacent wall 19. Signal generator or audio indicator unit 23 has a cylindrical horn or projection 24 that fits through the opening 21. Preferably, signal generator 23 has an audio frequency of 1000 to 3000 cycles per second. Other audio frequencies can be used. The sound frequency range is within the sound range detectable by the human ear. Signal generator 23 is a commercial unit constructed according to the audible alarms disclosed in U.S. Pat. Nos. 3,277,465 and 3,331,970. The subject matter of these patents is incorporated herein. The signal generator has a piezo-electric transducer that is electrically driven to produce an audible sound.
Signal generator 23 has a pair of electrical terminals 26 and 27 connected to electronic circuitry or circuit means indicated generally at 28. Electronic circuitry 28 is connected with a ground line 30 to terminal 26 and an output signal line 31 to terminal 27. The electronic circuitry 28, lines 30 and 31, and terminals 26 and 27 are encapsulated in a plastic body 29. Plastic body 29 is a plug that protects and retains signal generator 23 in engagement with casing end wall 19.
An input power line 32 connects terminal 27 to an on-off switch 33. A screw 34 secures switch 33 to casing 18. Additional screws or fasteners can be used to retain or anchor switch 33 on casing 18 or cap 22. Switch 33 can be secured to body 29. Switch 33 has an actuator or button 35 that is manually moved to turn the switch on and off. Actuator 35 projects through a hole in cap 22 so that the outer end thereof can be pressed with the fingers of the hunter or dog handler. A line 36 connects switch 34 to a battery 37, such as a 9-volt D.C. battery. A ground line 38 connects battery 37 to terminal 26. The battery 37 is located within casing 18 and is surrounded with a padding 39, such as fibers or foam plastic. Cap 22 can be removed from casing 18 to allow replacement of battery 37. This is accomplished by snapping cap 22 off of casing 18 and removing lines 36 and 38 from the battery terminal. After the battery has been replaced, cap 22 is snapped back into the open end of casing 18.
Referring to FIG. 4, electronic circuitry 28 controls the power supplied to signal generator 23. Electronic circuitry 28 has a first mercury switch 41 connected with line 42 to a power input line 32 and line 43 to ground line 30. Switch 41 is normally open when the audio signal device 16 is in its normal horizontal position. When dog 10 walks or runs, the mercury in switch 41 moves to intermittently make and break electrical contact whereby switch 41 is intermittently on and off. Mercury switch 41 is a dog motion detection switch. A series connected resistor 44 and capacitor 46 are located in power line 32. Line 42 is connected between resistor 44 and capacitor 46. A second mercury switch 47 is connected with line 48 to power line 32 and line 49 to terminal line 31. Switch 47 is normally off when the audio signal device is in its horizontal position and the dog is stationary. When dog 10 moves, the mercury in switch 47 causes the switch 47 to complete the circuit to signal generator 23. Mercury switch 47 is a motion detector. Mercury switch 41 functions to discharge capacitor 46. The time delay, resistor 44-capacitor 46, provides for delaying application of voltage to signal generator 2, causing an inactive or silent period.
A first transistor 51 and second transistor 54 are operable to provide the current requirements for signal generator 23. A line 52 connects the base of transistor 51 to the power line 32. A line 53 connects the collector of transistor 51 to line 48. The emitter of transistor 51 is connected with a line 56 to the base of transistor 54. Line 53 is also connected to the collector of transistor 54. The emitter of transistor 54 is connected to a line 57 joined to terminal 27 of signal generator 23.
Referring to FIG. 5, there is shown a modification of the audio signal device. The audio signal device is mounted on an animal or dog collar 60 having a releasable connector 61, such as a pin, buckle, clasp, or the like. A cylindrical casing or body 62 is connected to a lower portion of collar 60 with a plurality of bands 63. Casing 62 houses the electronic circuitry 28 and battery 37. An audio signal generator or beeper unit 64 is secured by fasteners, such as bolts or screws 65 to the top of collar 60. A cable or line 66 connects the electronic circuitry 28 in casing 62 to signal generator 64. A switch (not shown) is used to disconnect the electronic circuitry and signal generator from the battery.
Referring to FIG. 6, there is shown a modification of the audio signal device indicated generally at 68. The device has electronic circuitry which operates the piezo-ceramic beeper buzzer unit 69. Buzzer unit 69 is a commercial unit having a piezo-ceramic transducer electrically energized to produce an audio signal or sound. Buzzer unit 69 has three terminals 71, 72, and 73 that are coupled to the electronic circuitry. Terminal 71 is connected to the drive line 126. Terminal 72 is connected to a feedback line 127. Terminal 73 is connected to common or ground line 78. The circuitry includes a mercury switch 74 connected with a line 76 to a power line 82. A second line 77 connects mercury switch 74 to ground line 78. A resistor 79 and capacitor 81 are connected in series to power line 82. Power line 82 is connected via an on-off switch 83 to a power source 84, such as a 9-volt battery.
The electronic circuitry includes a second mercury switch 86 connected with line 87 to power line 82. A pair of transistors 88 and 89 are located in parallel with mercury switch 86. A line 91 connects the base of the transistor 88 to power line 82 between transistor 79 and capacitor 81. Line 93 connects the collectors of transistors 88 and 89 to line 87. The emitter of transistor 88 is connected with line 94 to the base of transistor 89. A line 96 connects the mercury switch 86 to the emitter of the transistor 89 which is connected via a resistor 97 to the collector of a transistor 98. The emitter of transistor 98 is connected with a line 99 to ground line 78. The base of transistor 98 is connected with a line 101 to a line 102. A resistor 103 and capacitor 104 are coupled to line 102. Capacitor 104 is also connected to ground line 78. Transistors 106 and 107 are connected in the circuit with transistor 98. The collector of transistor 98 is connected with a line 108 to the base of transistor 106. The collector of transistor 106 is connected with a line 109 to the base of transistor 107. A resistor 111 is interposed in line 109. Line 102, having a resistor 110, is connected to line 109. The emitter of transistor 106 is connected with line 112 to ground line 78.
A capacitor 113 located in line 114 is connected to line 109 and ground line 78. The collector of transistor 107 is connected to line 116 which leads to line 101. The emitter of transistor 107 is connected with a line 117 to ground line 78.
A line 118 is connected to line 108 and a resistor 119 which in turn is connected to the beeper unit terminal 72. Another transistor 121 is connected with a line 122 having a resistor 123 to the line 118. A line 124 connects the emitter of transistor 121 to ground line 78. Line 122 is connected with line 126 to a terminal 71 of beeper unit 69. The base of transistor 121 is connected with a line 127 having a resistor 128 to the terminal 72. Resistors 123, 119, and 128 and transistor 121 provide the drive and feed-back circuits to operate the piezo-ceramic beeper buzzer unit 69. The circuitry consisting of the resistors 103, 97, 110, and 111, capacitors 104 and 113, and transistors 98, 106, and 107 provide an oscillator with a component value chosen to provide an output having a nominal period of one second and a 50 percent duty cycle. This circuitry provides the characteristic pulsing tone output of a device when signal generator units, other than a Mallory pulsed signal generator unit, are used.
Referring to FIG. 7, there is shown a modification of the audio signal device, indicated generally at 200. Audio signal device 200 has an audio signal generator or beeper unit 201 having terminals 202 and 203. Beeper unit 201 has a cylindrical casing or housing 204 and a cylindrical projection or horn 206 attached to one side of the casing. Examples of beeper units are disclosed in U.S. Pat. Nos. 3,277,465 and 3,331,970. The subject matter of these Patents is incorporated herein. The beeper unit, when energized, produces an audible sound. Preferably, the frequency of the sound is about 1000 to 3000 cycles per second. Other frequencies can be used to provide the audio signals which inform the hunter of the location of the dog and indicate if the dog is moving or stationary.
Electronic circuitry 207 is connected to terminal 203 and a line 208 leading to terminal 202. The circuit diagram of electronic cicuitry 207 is shown in FIG. 4. A power input line 209 connects electronic circuitry 207 with an on-off switch 211. A line 212 connects switch 211 with one terminal of a battery 213, such as a Union Carbide No. 522 9-volt battery. The other terminal of battery 213 is connected to a line 214 joined to beeper unit terminal 202. A releasable cap or connector 216 connects lines 212 and 214 to the battery terminals.
Switch 211 has a movable actuator or button 217 located in a passage 218 of a tube 219. Passage 218 has an open end providing access to actuator 217 to linearly move the actuator thereby selectively turning the switch on and off. The actuator 217, being located in passage 218, is protected from damage and unwanted actuation.
The electronic circuitry 207, tube 219, and lines 208, 209, 212, and 214 are encapsulated with a cylindrical rigid plastic body 221. The plastic of body 221 is, preferably, a polyurethane encapsulating compound. Body 221 is bonded to casing 204 of beeper unit 201 whereby beeper unit 201 and body 221 comprise a one-piece structure. The center of body 221 has a rectangular cavity 222 accommodating battery 213. Cavity 222 has dimensions such that battery 213 has a tight or friction fit relative to body 221 so that in use battery 213 remains assembled with body 221. Battery 213 can be removed from cavity 222 and replaced with a new or recharged battery. Body 221 protects the battery 213, switch 211 and electronic circuitry from external objects, water, and impact damage.
In terms of a method of providing audio information to a dog handler or hunter as to the movement or stationary conditions of a dog, the audio signal device 16 operates to provide a first audio signal responsive to movement of the dog. The first signal informs the handler that the dog is moving. If the handler cannot visually observe the dog, the first signal will also provide the information as to the location of the dog in the field. This is done by ascertaining the signal direction. As soon as the dog stops or is in a stationary condition, the first audio signal is terminated for a limited period of time. This silences the audio signal device and enables the handler to instruct the dog.
A second audio signal is then provided in response to the stationary condition of the dog. This signal informs the handler that the dog is stationary and may be on point. This signal also provides information as to the location of the dog in the event that the dog is not within sight. The first and second signals are intermittent sounds having a frequency range that can be detected by the human ear. The first and second signals are distinguishable from each other, as they have different beats or rates. For example, the first audio signal can have a beat of 10 signals per second, while the second audio signal can have a beat of about 1 signal per second. The second signal starts at a reduced level and rises to the volume level of the first signal. The signals emanating from the audio signal device are ascertainable at a range from 0 to 1/2 mile maximum. The range of the audio signal device will vary in accordance with the background noise and the environmental conditions, as terrain and vegetation.
While there has been disclosed and described several audio signal devices for use with a hunting dog, it is understood that changes in the structure and circuits of the audio signal devices may be made by those skilled in the art without departing from the invention. Also, the audio signal device can be used with other animals to provide information as to the moving and stationary condition of the animals. The invention is defined in the following claims.
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An audio signal device is used as an aid in locating a hunting dog and providing audio information as to whether the dog is moving, or is stationary. The signal device has an audio signal generator or beeper unit connected to electronic circuitry, an on-off switch, and a battery. The electronic circuitry has mercury switches responsive to movement of the dog to supply the signal generator with power so as to produce a first output sound. The electronic circuitry functions to energize the signal generator to produce different audio signals when the dog is moving, or is stationary. When the dog stops moving, the electronic circuitry withholds electric power from the signal generator for a limited period of time to allow the dog to locate the handler or receive instructions. Thereafter, with the dog stationary, the signal generator is energized to produce a second output sound that is different from the first output sound.
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BACKGROUND OF THE INVENTION
The present invention relates to an improved stonework crusher, and more particularly relates to improvements in a shape memory alloy type crusher used for crushing stoneworks such as big stones, rocks and building structures made of stones or concretes.
Such a shape memory alloy (SMA) type stonework crusher is highly appreciated in the field of stonework construction because of its easy handling and relatively quick operation when compared with crushing via water expansion. Its safety in handling and operation is also highly welcomed in practice in particular in comparison with explosion type crushing which often endangers workers and ambient inhabitants and, as a consequence, is limited in application, due to its dangerous nature.
Some SMA type crushers are proposed in Japanese Patent Openings Sho. No. 60-115794 and Sho No. 61-169600. In construction of the crushers of these earlier proposals, a heating element situated at the center of a crusher is surrounded by a cylindrical shell made of SMA. In operation, the crusher is inserted into a bore or a groove naturally or artificially formed in a stonework and the cylindrical shell is heated by the heating element so that thermal deformation of the shell should apply a crush force to the walls of the bore or the groove to crush the stonework.
In the case of such a SMA type crusher, the cylindrical shell expands in all radial directions during the thermal deformation. In other words, the cylindrical shell expands into directions not contributing to enlargement of the bore or the groove and, as a consequence, the thermal deformation of the cylindrical shell cannot be fully utilized for generation of the crush force. In addition, thermal deformation of the cylindrical shell enlarges the space between the central heating element and the surrounding shell, thereby lowering efficiency in heat transmission to the shell. In particular when two or more stonework crushers are used in combination, variation in thermal deformation caused by such enlarged space between the heating element and the shell tends to impair concerted action of these crushers, thereby leading to unsuccessful crushing of the stonework.
In an attempt to measure the magnitude of a force necessary for successfully crushing a stonework, a series of experimental tests were conducted using rectangular concrete columns of various square sections. The height of each column was 200mm and the side length of the square was changed. A SMA rod of 10mm diameter and 20mm length was sued as a crusher. The rod had a built-in curvature about the middle of its length. After insertion into a vertical bore of 10mm diameter and 120mm. depth formed in the top face of the concrete column, the rod was heated to restore its built-in curvature. As a result of the test, it was confirmed that the concrete columns could be successfully crushed only when the side length of the square section was 1/3 or smaller than the length of the SMA rod. This results indicates the fact that, in order to crush a big stonework, crusher rods have to be arranged in a bore or groove in the stonework at an interval of about 2 times as large as the diameter of the rod whilst necessitating great deal of labour and time. From these experimental data, it is well understood that a large force is necessary to crush a stonework.
For these reasons, most of the conventional SMA-type crushers have not been widely used in practice. Even when used, it is inevitably accompanied with increased labour, time and cost.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a practical SMA-type crusher of stoneworks which can exhibit a large crush force with high and uniform heat transmission.
In accordance with the basic concept of the present invention, at least one insert head is made of SMA and a pair of abutments are attached to opposite outer faces of the insert head.
Most preferably, the pair of abutments are spaced apart from each other in the direction of thermal deformation of the insert head.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of one embodiment of the stonework crusher in accordance with the present invention,
FIG. 2 is an end view of the crusher shown in FIG. 1,
FIG. 3 is a perspective veiw of one example of the insert head used for the crusher shown in FIGS. 1 and 2,
FIG. 4 is a transverse sectional view of another embodiment of the crusher in accordance with the present invention,
FIGS. 5 and 6 are side sectional and end views of another embodiment of the stonework crusher in accordance with the present invention,
FIG. 7 is a perspective view of one example of the insert head used for the crusher shown in FIGS. 5 and 6,
FIGS. 8 and 9 are partly sectional side and end views of the other embodiment of the stonework crusher in accordance with the present invention, and
FIG. 10 is a partly sectional side view of the other embodiment of the stonework crusher in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the stonework crusher in accordance with the present invention is shown in FIGS. 1 and 2, in which the crusher is comprised of three insert heads 1 made of SMA, a pair of abutments 2 sandwiching the insert heads 1 and a proper heating means. Each abutment 2 is provided with a convex outer face 2a and a flat inner face 2b and a hollow 2c is formed in the inner face 2b for reception of the insert heads 1. The curvature of the outer face 2a of the abutment 2 is preferably selected so as to match that of the wall of a bore or a groove into which the crusher is to be inserted in operation.
In the case of this example, each insert head 1 is given in the form of a circular cylinder such as shown in FIG. 3 which is designed to increase its axial length by thermal deformation. More specifically in FIG. 3, the insert head 1 is deformed from the shape shown with solid lines to the shape shown with chain lines by application of head. The insert heat 1 may be given in other forms such as, for example, a rectangular cylinder as long as it increases the axial length by thermal deformation. The insert head 1 may be made of a shape memory alloy which restores its built-in shape by change in temperature but does not restore its usual shape when the temperature resumes its normal level. The insert head 1 may also be made of a shape memory alloy which restores its built-in shape by change in temperature and again restores its usual shape when the temperature resumes its normal level.
The insert heads 1 are assembled with the abutments in an arrangement such that both longitudinal ends 1a of each insert head 1 should be placed in contact with the hollows 2c in the abutments 2. In other words, the abutments 2 are spaced apart from each other in the direction of thermal deformation of the insert heads 1. Sandwiching the insert heads 1 in such an arrangement, the abutments 2 may act as a housing of the crusher. Though not illustrated, the crusher is further provided with a proper heating means.
The abutments 2 are connected to each other by means of a plurality of elastic connectors 3 so that they can change the intervening distance following thermal deformation of the insert heads 1. When the shape memory alloy restores its usual shape after removal of the change in temperature, use of these elastic connectors 3 expedites restoration of the initial position of the abutments 2. Tension springs are used for the elastic connector 3 in the case of the illustrated example. Other materials such as rubber bands may be used to this end too.
In one preferred embodiment of the heating means, the abutments 2 are given in the form of electrodes connected to a given power source. In such a case, the elastic connectors 3 are preferably electrically insulated from the abutments 2 so as to prevent formation of short circuits. Conversely the elastic connectors 3 may be made of an alloy of high resistance such as tungsten alloys for additional heating of the insert heads 1.
Another embodiment of the crusher in accordance with the present invention is shown in FIG. 4 in which the crusher is two-directional in operation. The crusher includes two groups of insert heads 21 and 22, each group being accompanied with a pair of abutments 2. More specifically, the direction of thermal deformation of an insert head 1 of one group is substantially normal to that of an insert head 1 of the other group. Preferably, the insert heads 1 of one group and the insert heads 1 of the other group are arranged at alternate positions. The crusher of this two-directional type is particularly suited for use in a bore.
When the abutments 2 are expected to act as the heating means rather than as contact faces, they may be spaced apart from each other in a direction different from the direction of thermal deformation of the insert heads 1. Such an example is shown in FIGS. 5 and 7. In this case, the insert head 1 is deformed from the shape shown with solid lines to the shape shown with chain lines in FIG. 7. In other words, the abutments 2 are spaced apart from each other in a direction substantially normal to the direction of thermal deformation of the insert head 1. Further, the pair of abutments 2 are connected to each other by the insert head 1 to which the abutments are secured via set screws.
The other embodiment of the stonework crusher in accordance with the present invention is shown in FIGS. 8 and 9 in which, as in the case of the first embodiment shown in FIG. 1, juxtaposed insert heads 1 are sandwiched by a pair of abutments 2 connected to each other via elastic connectors 3 in the form of tension springs. The outer face 2a of at least one of the abutments 2 is sloped in the direction of juxtaposition of the insert heads 1. More specifically, the outer face 2a is given in the form of a slope which has an uprising gradient from the inserting end (the left end in the illustration) to the tail end (the right end in the illustration) of the crusher. In combination with this sloped outer face 2a of the abutment 2, the crusher is further provided with a wedge 30. This wedge 30 is provided with an elongated grove 33 having a sloped bottom 31 tightly engageable with the sloped outer face 2a of the abutment 2. Near the inserting end of the crusher, the wedge 30 is provided with a pair of projecting skirts 34 on both sides of the groove 33 as best seen in FIG. 9. In other words, the wedge 30 embraces the abutment 2 near the inserting end of the crusher.
When the inserting end of the crusher of this construction is inserted into a bore H shown with two dot chain lines in FIG. 9, the tail end of the crusher projects outside the bore H for convenience in forced insertion of the crusher into the bore H.
Preferably, parallel corrugations are formed in the outer face 2a of the abutment 2 and the bottom 31 of the groove 33 in the wedge 30 whilst extending in the direction of the juxtaposition of the insert heads 1 so that, at forced insertion of the crusher into the bore H, no lateral slippage should occur between the abutment 2 and the wedge 30.
The other embodiment of the crusher in accordance with the present invention is shown in FIG. 10 in which the heating means is given in the form of a built-in type heater unit 6. More specifically, the heater unit 6 includes a block interposed between the pair of abutments 2 and provided with through holes 62 for accommodating the insert heads 1. Healing coils 63 are embedded in the block 61 whilst surrounding the holes 62. The heating coils 63 are connected to a given power source (not shown) via conductors 64. Each abutment 2 is provided at each end of the crusher with a pin 2d projecting into a space between the abutments 2. The block 61 is provided, in the vicinity of the pin 2d on the abutment 2, with a tongue 65 which is provided with a through hole for passage of the pin 2d. The pin 2d is idly inserted into the hole in the tongue 65, the length of the pin 2d is larger than the thickness of the tongue 65 and the pin 2d is provided, at its distal end, with a snap ring so that the abutments 2 should be separably connected to the block 61.
In accordance with the present invention, there is no space between the heating means and the insert head or heads made of SMA and, as a consequence, the distance between the heating means and the insert heads remains unchanged even after thermal deformation of the insert heads, thereby mitigating change and variation in heat transmission. In particular when two or more crushers are used in combination, the uniform heat transmission assures effective and efficient crushing of stoneworks. When the abutments are spaced apart from each other in the direction of thermal deformation of the insert heads, crush force generated by the thermal deformation of the insert heads can be most effectively utilized for crushing operation.
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In construction of a stonework crusher utilizing thermal deformation of shape memory alloy, heating means is coupled to one or more insert heads made of shape memory alloy without leaving any space there between so that thermal deformation of the insert heads should pose no substantial influence upon heat transmission from the heating means. In particular when several crushers are used in combination, uniform heat transmission at different crushers allows concerted generation of crush force by the combined crushers for effective and efficient crushing of stoneworks.
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BACKGROUND OF THE INVENTION
The invention pertains to internal combustion engines, and in particular, to four cycle internal combustion engines operating on the Otto cycle or the Diesel cycle, the former being a constant volume combustion cycle and the latter being a limited pressure combustion cycle.
There are several variations to these basic cycles. Two that are of particular importance are the Atkinson cycle and the Miller cycle. In the basic theory of a naturally aspirated Otto cycle engine, compression occurs from bottom dead center to top dead center with the valves closed. Ignition occurs at top dead center. With ignition the pressure within the cylinder increases and the piston retreats back to bottom dead center. The exhaust valve opens and the exhaust is dumped as the piston again moves to top dead center. The exhaust valve closes and the intake valve opens with the piston now moving back toward bottom dead center to draw in a fresh charge.
In an actual engine, the theoretical valve timing of the Otto cycle is modified substantially to take advantage of inertia effects of the moving intake air and exhaust gases. In an actual engine, the intake valve is closed after bottom dead center and during the initial portion of the compression stroke to take advantage of the inertia effects of the intake air and thereby increase the trapped intake charge resulting in higher engine power. Similarly, the exhaust valve is open before bottom dead center allowing exhaust blow down and thereby returning the cylinder pressure to near atmospheric before the piston moves from bottom dead center to top dead center pushing the exhaust from the cylinder. Slightly before top dead center the intake valve opens to allow the intake charge to begin flowing and slightly after top dead center, the exhaust valve closes. In the naturally aspirated Otto cycle engine, the cylinder pressure within the cylinder during the intake stroke is normally below atmospheric pressure. However, at wide open throttle and high speed, toward the end of the intake stroke, the pressure within the cylinder of a well designed engine may exceed atmospheric pressure due to inertial effects.
Turbo supercharging of the Otto cycle engine assures that the cylinder pressure during the intake stroke from top dead center to bottom dead center is always above atmospheric pressure and the intake manifold pressure is almost always above the cylinder pressure during the exhaust stroke from bottom dead center to top dead center. Only at extremely low speeds is the cylinder pressure of the exhaust cycle likely to equal or exceed the intake manifold pressure. The cylinder pressure during the exhaust stroke from bottom dead center to top dead center is greater than atmospheric pressure.
The naturally aspirated Diesel cycle engine operates substantially similar to the naturally aspirated Otto cycle, however, the constant volume burning at top dead center is followed by constant pressure burning as the piston descends toward bottom dead center on the expansion stroke. During intake from top dead center to bottom dead center, the cylinder pressure during the intake is closer to atmospheric at all loads because the naturally aspirated Diesel engine does not utilize throttling for the intake air. With turbo charging of the Diesel engine, the cylinder pressures during the intake and exhaust strokes of the diesel engine behave in a manner similar to the cylinder pressures of the turbocharged Otto cycle engine.
The Atkinson cycle comprises a modification to either the Otto cycle or Diesel cycle. The Atkinson cycle comprises a cycle in which the expansion stroke is much longer and larger than the compression stroke (Combustion Engine Processes, Lester C. Lichty, 1967, McGraw-Hill p. 10). In the true Atkinson cycle engine, a special crank shaft linkage causes the expansion stroke to be longer than the compression stroke. In the modified Atkinson engine, the intake valve closing is either substantially earlier or substantially later than otherwise, either of which leads to an artificially shortened compression stroke (Effects of Intake-Valve Closing Timing On Spark-Ignition Engine Combustion, SAE 850074).
The Miller cycle can also be applied to the Otto cycle or Diesel cycle engine and borrows the Atkinson cycle principle of a larger expansion stroke than compression stroke (A New Type Of Miller Supercharging System For High Speed Engines Part 2--Realization Of High BMEP Diesel Engines, SAE 851523). In addition, the Miller cycle consists of an increased charging pressure over that feasible without the use of the Atkinson principle and a variation in the intake valve timing while the engine is running.
In essence, the Miller cycle is directed to shifting the intake valve closing to an earlier time before bottom dead center as the load on the engine increases. To compensate for the decreased intake flow because of the early closure of the intake valve, the boost pressure on the turbocharger is increased to provide an intake air charge of essentially the same mass. The pressure volume diagram of the Miller cycle appears like a turbocharged Otto or Diesel cycle engine with the early intake valve closing of the Atkinson cycle. In order to achieve the high levels of turbocharger boost necessary to operate the engine on the Miller cycle, most such engines use a two-stage turbocharger and usually include air coolers for the intake charge. The primary purpose of the Miller cycle is to increase thermal efficiency while maintaining high specific output through high boost pressure.
However, the complex mechanical components necessary to vary the valve timing have lead to the following variants of the Miller cycle. First, is the auxiliary intake control rotary valve (ICRV) (A New Type Of Miller Supercharging System For High Speed Engines Part 1--Fundamental Considerations And Application To Gasoline Engines, SAE 851522, SAE 851523).
In the ICRV concept, an auxiliary rotary control valve is positioned upstream of a normal intake valve. The timing of the intake valve is near bottom dead center. The timing of the rotary valve is adjusted while running to close off the intake channel prior to the closing of the intake valve. The closed timing of the rotary valve is dependent on speed and load (boost pressure) which results in a pressure volume relationship that simulates a normal Miller cycle engine (SAE 851522, p. 3).
The Miller cycle engine suggests that the intake valve can be closed before or near bottom dead center and power can be maintained by utilizing extremely high boost pressures (3.5-5.5 bar) (A New Type Of Miller Cycle Diesel Engines, Sakai et. al. p. 1 & FIG. 6, JSAE Vol. 9, no. 2, Apr. 19, 1988). Thus, the principal of the Miller cycle is to increase the charge density without increasing the maximum pressure in the cylinder. The ratio of the exhaust back pressure to the inlet boost pressure for maximum efficiency should be close to 1; however, in practice, 0.67 is normally used (The Internal Combustion Engine In Theory And Practice, Vol. 1: Thermodynamics, Fluid Flow, Performance, Charles F. Taylor, Fifth Printing Second Edition 1982, MIT Press, p. 384 and example 10-4).
The other variant of the Miller cycle for Diesel engines is provided by the exhaust leak-down method disclosed in U.S. Pat. No. 4,424,790. In the exhaust leak-down method, the intake valve closes near bottom dead center. The exhaust leak-down concept controls the cylinder pressure, and hence the compression stroke by bleeding off cylinder pressure by two alternate and equivalent means. One means is to hold the exhaust valve slightly open throughout the intake stroke. In this way, a portion of the boost pressure is continually blown out the exhaust valve. In the other approach, the exhaust valve is opened immediately after the intake valve has closed allowing the cylinder pressure to escape through the exhaust valve. The amount of pressure bled off the cylinder is automatically controlled by the difference between the boost pressure provided by the turbocharger required in the Miller cycle and the exhaust back pressure created by the turbocharger. As a result, the pressure-volume relationship is modified from the Miller cycle by moving the intake cylinder pressure from the boost pressure towards the average steady flow exhaust pressure (as defined by Taylor, p. 382) during the time the auxiliary exhaust leak is opened.
U.S. Pat. No. 4,424,790 thus discloses an exhaust pressure modulated bleed-off of the boost pressure to achieve a Miller cycle engine. This patent shows that volumetric efficiency and trapping efficiency for the cycle disclosed therein, the Miller cycle, and the Atkinson cycle go down with increasing load. Further, the reference claims that holding the exhaust valve partially open throughout the intake cycle is equivalent to closing the exhaust at the normal time and then reopening the exhaust valve after the intake valve is closed.
To summarize, the momentum effects of a high-speed four cycle Otto or Diesel cycle engine that does not employ the Miller or Atkinson principles, must, in the valve timing, delay the closing of the intake substantially beyond bottom dead center to obtain reasonable power. Generally, the higher the speed or the higher the specific output desired, the later intake valve closing occurs (Taylor, p. 193; Internal Combustion Engines And Air Pollution, Edward F. Oberth, Harper & Row 1973, p. 471-474).
Empirically observed pressure waves or pulses in exhaust pipes are discussed along with computer simulations in a publication entitled "Gas Flow in the Internal Combustion Engine", W. J. D. Annand and G. E. Roe, G. T. Foulis & Co., Ltd., 1974, Sparkford, Yeovil, Somerset, England. Discussed are compression, rarefaction and reflected compression waves. As described, the compression wave is a positive pressure wave occurring when a valve opens and the high upstream cylinder pressure escapes into the exhaust pipe or system. This phenomenon is described by Taylor (p. 382) in terms of the blow-down portion of the exhaust cycle. The rarefaction wave described by Annand and Roe is a "negative pressure" wave transmitted upstream. A reflected compression wave is also described and is a positive pressure wave transmitted upstream which is commonly termed a "plugging pulse". The plugging pulse can prevent the overshoot of intake gases into the exhaust pipe at the end of scavenging during valve overlap (four cycle engine) or the loss of cylinder pressure (two cycle engine).
Annand, et al. describe the effect of the exhaust pipe geometry on the timing and magnitude of compression and rarefaction waves in the exhaust system. The geometry discussed includes constant diameter (straight pipe), divergent, and expansion box pipes. The expansion box disclosed includes a divergent section followed by a convergent section usually with a constant diameter section therebetween. Both the divergent exhaust pipe and the expansion box have a smooth transition between the upstream exhaust pipe (usually constant diameter) and the entrance to the divergent section.
According to Annand, et al. in the straight pipe a rarefaction wave occurs from the sudden expansion of gases at the end of the pipe, the rarefaction wave then traveling upstream in the pipe. Generally an almost imperceptible reflected compression wave ("plugging pulse") also occurs from a straight pipe. In the divergent pipe the rarefaction wave is stronger and more ordered than in the straight pipe. The reflected compression wave also appears as a small but ordered plugging pulse.
The expansion box through the divergent section also produces rarefaction waves moving upstream, however, due to the geometry of the divergent-convergent sections, the strength and general order of the reflected compression wave (plugging pulse) transmitted upstream is much greater than in either the straight pipe or the divergent pipe.
Four cycle engines predominately use an open end constant diameter exhaust pipe or straight pipe. Very rarely is a divergent exhaust pipe used with a four cycle engine, and the expansion box per se is never applied to a four cycle engine. In a four cycle engine with a straight pipe the blow down pulse creates a rarefaction wave that travels upstream and can cause a lower pressure in the cylinder during the exhaust stroke. In a well designed exhaust system, the cylinder pressure during the exhaust stroke can be below atmospheric pressure which increases the scavenging of the exhaust from the cylinder. Subsequently, a pressure wave or plugging pulse is reflected upstream, in particular, when multiple straight pipes are connected to a pulse convertor or collector. In a well designed system, the plugging pulse will arrive at the cylinder in time to prevent the intake charge from exiting through the exhaust valve to the exhaust pipe system. During the early portion of the intake stroke, both the intake and exhaust valve are simultaneously opened (valve overlap) and absent the plugging pulse, the intake charge can exit into the exhaust system.
In contrast, two cycle engines use the plugging pulse or reflected pressure wave in an entirely different manner for a different purpose. The exhaust system of a two cycle engine is typically designed to draw a significant amount of the intake charge into the exhaust system (which includes an expansion box) due to the rarefaction wave following the onset of the blowdown period, since at the time both the exhaust ports and the intake transfer ports are open. Properly designed, the expansion box causes the reflected pressure wave to force the re-entry of some of the intake charge drawn into the expansion box back into the cylinder after the intake transfer ports or passageway leading thereto are closed thereby increasing the trapped charge.
The current approach and design of an expansion box for a two cycle engine is not simply transferable to a four cycle engine, the reason being the reflected pressure wave within the expansion box arrives much too early for the proper effect since the four cycle engine is still on the exhaust stroke. Furthermore, if the reflected pressure wave is delayed to arrive at an equivalent point in the compression stroke of a four cycle engine as compared to a two cycle engine, then the reflected pressure wave arrives to impact the closed exhaust valve. A recent article (Circle Track Magazine, P. Saueracker, January 1989, pp. 68-72) discusses why a reflected compression wave is very undesirable and detrimental to power production in a four cycle engine. Saueracker further describes various techniques that automobile racers are currently using to prevent or attenuate the reflected compression wave as it moves upstream.
Most common are stepped design exhaust headers comprising a series of different diameter straight pipes with sudden transitions between pipes, the pipes decreasing in diameter in the upstream direction. Another approach comprises an anti-reflection chamber ("anti-reversionary chamber") having a diverging section joined to a converging section by an outer constant diameter pipe. But, unlike an expansion box, in the anti-reflection chamber the inlet exhaust pipe extends at constant diameter substantially into the chamber. As taught by Saueracker a zone between the extended internal pipe and the divergent section traps the reflected compression wave before further movement upstream.
U.S. Pat. No. 1,952,881 discloses method and apparatus for reintroducing exhaust gases into the combustion chamber of an engine. The reintroduction of the exhaust gases is accomplished by modifying the cam for the exhaust valve to retain the exhaust valve open during the period of time that the cylinder pressure is less than the pressure in a common log exhaust manifold of a multicylinder engine, thereby allowing the exhaust gases to flow back into the cylinder from the common log manifold. The purpose for the reintroduction of the exhaust gases is to reduce detonation in the cylinder thereby lowering the required octane value of the fuel.
Another relatively early U.S. Pat. No. 2,131,958 discloses a two cycle fuel injected engine cylinder equipped with a crank shaft driven rotary exhaust valve downstream of the exhaust port and a reflection delay device comprising an expansion box with an internal swirl generator. This disclosure is directed to the reintroduction of exhaust gases into the cylinder by the timing of the rotary valve and by additionally delaying the reflected pressure pulse in the exhaust system.
U.S. Pat. No. 2,476,816 discloses two cycle multi-cylinder engines with an exhaust manifold system of constant diameter pipes configured to cause the pressure wave or pressure pulse of blowdown from one cylinder to arrive at another cylinder just prior to the closure of the exhaust at the second cylinder. The result is a sudden charging pressure introduced into the second cylinder just prior to the closure of the exhaust port to the second cylinder. The result is claimed to be more effective in a multi-cylinder two cycle engine than attempting to reintroduce the reflected pressure pulse from a constant diameter pipe into the same cylinder.
More recently, U.S. Pat. No. 3,298,332 disclosed the application of the above blowdown pressure pulse with constant diameter pipes in a multi-cylinder engine to a four cycle engine. The exhaust system disclosed is used in conjunction with a specified intake system consisting of a series of constant diameter pipes. Furthermore, the exhaust system disclosed is limited to connection of cylinders that are 360° apart in the firing order. Thus the blowdown pulse from one cylinder travels through the mutually connected exhaust system so configured that the pulse arrives at the exhaust valve of second cylinder 360° away just prior to the closure of the second cylinder. The disclosure does include the re-entry of any intake air that has escaped into the exhaust manifold thereby improving the volumetric efficiency of the engine.
SUMMARY OF THE INVENTION
The principal object of the new exhaust recharging cycle disclosed below is to increase the power of four cycle internal combustion engines by maximizing the trapping efficiency in the cylinder primarily under full power conditions. The invention is equally applicable to both spark ignition (Otto cycle and its variants) and compression ignition (Diesel cycle and its variants) four cycle engines.
The invention relies upon the use of an expansion chamber or expansion box in the exhaust conduit downstream from the exhaust valve sized to produce a reflected exhaust pressure wave timed to the auxiliary reopening of the exhaust valve after the intake valve has substantially closed. The reflected exhaust pressure wave or pulse causes the re-entry into the cylinder of a quantity of intake charge (which has previously purposely been drawn into the expansion chamber) or intake charge diluted with exhaust gases subsequent to the effective filling of the cylinder with fresh air or fuel-air mix through the intake valve. The result is a boost in cylinder charge and pressure on the compression stroke of the piston. At engine design speed the power output of the engine is substantially improved over the power without the boost in cylinder charge and compression stroke pressure.
Only by combining the intake charge purposefully drawn into the exhaust system with an expansion box and the correctly timed auxiliary opening of the exhaust valve in the four cycle engine can the benefit of increased cylinder charge and trapping efficiency be obtained by using the reflected exhaust pressure wave. The energy contained in this reflected exhaust pressure wave is thus captured rather than lost out the exhaust. Thus, it is the purpose of the expansion box to promote the upstream movement of the reflected compression wave.
At design speed the auxiliary or second opening of the exhaust valve occurs well after bottom dead center (BDC) of the piston stroke and after the intake valve has closed sufficiently to prevent back flow through the intake valve. Thus, the intake valve is effectively closed and cylinder filling through the intake valve not substantially affected. Where an individual cylinder includes two or more exhaust valves, the second opening may optionally be applied to only one valve.
The invention is applicable to both single cylinder and multicylinder four cycle engines. Depending upon the exhaust conduit configuration, the boost can result from a reflected pressure wave from the same cylinder exhaust or from another cylinder exhaust. Thus, expansion chambers can be separately provided for each cylinder or single expansion chambers can be connected to a plurality of cylinders.
The invention is applicable to naturally aspirated engines, supercharged engines and turbo charged engines that are predominantly operated at full power design speed or design speed with maximum power output per unit of fuel. Thus, the invention is most applicable to automotive race cars and dragsters, and to piston engine aircraft. However, the invention is applicable to stationary engines normally continuously operated at design speed under design load or maximum load.
The invention has a particular advantage in piston aircraft engines because the blow down pulse changes little with altitude. Thus, the reflected pressure wave changes little with altitude, however, the intake charge is less dense. Therefore, the reflected pressure wave is able to pack additional charge back into the cylinder. As a result, the reflected pressure wave provides a means of self compensating power regulation with increasing altitude.
As an option to permit the effective length of the expansion box to be adjusted to engine speed over a range of engine speeds, the expansion box may be physically alterable or the thermodynamic properties of the exhaust gases alterable within the expansion box. Means to change the interior length of the expansion box may be employed as further disclosed below, or the gas constant, temperature, density, or ratio of specific heat at constant pressure to specific heat at constant volume of the exhaust gases can be altered as they pass into and through the expansion box. In this manner the effective length of the expansion box may be adjusted over a range of engine speeds.
DESCRIPTION OF THE DRAWINGS
FIGS. 1a, 1b and 1c illustrate by comparison the conventional Otto cycle, the new cycle applied to a conventional Otto cycle and the new cycle applied to a turbo supercharged Otto cycle in terms of engine pressure-volume diagrams;
FIG. 2 illustrates valve opening area versus timing for a single cylinder of an engine;
FIG. 3 is a schematic of an exhaust reflection chamber;
FIGS. 4a, 4b and 4c schematically illustrate the application of expansion chambers to multiple cylinder engines;
FIGS. 5a, 5b, 5c, 5d, and 5e schematically illustrate cam and follower mechanisms to provide auxiliary opening of a valve;
FIG. 6 schematically illustrates a cam and follower mechanism to operate a second valve as an auxiliary valve;
FIG. 7 schematically illustrates a physically adjustable expansion box;
FIG. 8 schematically illustrates means to adjust exhaust gas density and gas constant within the expansion box;
FIG. 9 illustrates supercharging means to add air to the expansion box;
FIG. 10 illustrates non-supercharging means to add air to the expansion box; and
FIG. 11 illustrates means to change the effective length of an exhaust header.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrated in FIG. 1a is a typical pressure-volume diagram for a naturally aspirated Otto or spark ignition four cycle engine. Beginning with the compression stroke 20, followed by ignition 22 substantially at top dead center (TDC) causing a sudden constant volume pressure increase 24, an expansion stroke 26 completes the first half of the full four cycles. The expansion stroke 26 is followed after bottom dead center (BDC) by an exhaust stroke 28 to TDC and an intake stroke 30 to BDC to complete the full four cycles. As shown cylinder pressure during exhaust 28 is slightly above atmospheric pressure (P atm ) and during intake 30 is slightly below P atm . However, with suitable exhaust devices such as "headers", the cylinder pressure during exhaust 28 may be below the atmospheric pressure.
Also indicated in FIG. 1a is the typical valve timing as a function of cylinder volume. Normal exhaust opening (NEO) is at 32 and normal exhaust closing (NEC) is at 34. Normal intake opening (IO) is at 36 and normal intake closing (IC) is at 38. As indicated in the diagram, the openings and closings may overlap and may begin or end earlier or later over a range as is well known. The intake closing (IC) is shown at a single location in FIGS. 1a, 1b, and 1c for clarity.
Illustrated in FIG. 1b is a pressure-volume diagram for a naturally aspirated spark ignition engine modified by exhaust recharging of the compression stroke 20. At approximately the intake close (IC) 38 auxiliary exhaust opening (AEO) is effected by means disclosed below causing a sudden increase 40 in compression. This increase in compression results in a higher compression carried through the compression stroke 20', ignition 22', pressure increase 24' and expansion stroke 26'. The power output and thermal efficiency are thereby enhanced without the addition of mechanical boost.
However, the exhaust recharging of the compression stroke can be applied to a spark ignition engine with boost as illustrated in FIG. 1c. Turbocharger boost results in an exhaust stroke 28" above P atm and intake stroke 30" at boost pressure (P boost ). As is well known the boost pressure raises the pressure in the cylinder through all four cycles. The exhaust recharging modification at approximately IC by an auxiliary exhaust opening AEO causes a sudden increase 40' in compression. This increase in pressure on the compression stroke 20" carries through the expansion stroke 26" as above thus further increasing engine power and thermal efficiency. The dotted lines 20"' and 26"' are to emphasize the instantaneous cylinder pressure in compression and expansion with boost but absent exhaust recharge.
Illustrated in FIG. 2 is a diagram of valve opening area versus valve timing. Line 42 indicates opening and closing of the exhaust valve and line 44 indicates opening and closing of the intake valve. Lines 42 and 44 overlap between the exhaust stroke and intake stroke as indicated at TDC. Line 46 indicates the reopening of the exhaust valve for recharging when the intake valve is effectively closed. As shown the amount of exhaust area open 46 between AEO and AEC is considerably less than the full openings shown by lines 42 and 44. The timing of the AEO is critical and determined by arrival of a reflected compression wave in the exhaust conduit downstream from the exhaust valve.
FIG. 3 illustrates a single exhaust reflection chamber 48 having a head pipe 50 immediately downstream of the exhaust valve 52, a diverging cone or section 54, a center section 56, a converging reflection cone 58 and an outlet 60 for the exhaust. The size of the reflection chamber 48, in particular, its length is carefully specified to produce a reflected compression wave in the exhaust that arrives back at the exhaust valve 52 as the AEO occurs, thereby causing an amount of intake charge or charge diluted with exhaust gases residing in the chamber 48 to be forced back into the cylinder after the effective closing of the intake valve IC. The mass of intake charge and compression in the cylinder is thereby suddenly increased. Before this extra charge and compression can be dissipated, the exhaust valve recloses (AEC). As an alternative outlet 60 can be attached to the center section 56 with no outlet from the reflection cone 58.
The reflection chamber 48 configuration is a function of exhaust temperature and other gas dynamic properties at design load and the speed of the engine at full power. The reflected wave as indicated schematically by 62 is produced by the reflection off converging cone 58 of the sudden rush of exhaust. The sudden rush of exhaust forward from the exhaust valve 52 through the chamber 48 occurs when the exhaust valve first opens during the exhaust stroke 28 of the engine.
The reflection chamber 48 may be applied to a single cylinder engine or separate chambers 48 may be applied to each cylinder in a multicylinder engine 64 as shown schematically in FIG. 4a. As applied to race car engines the reflection length may be about 60 inches depending on engine speed and is therefore applicable but cumbersome. The length is required because of the two revolutions per compression stroke of the engine.
FIG. 4b illustrates a means of shortening the reflection chamber 48 by leading the head pipes 50 and 50' from two separate cylinders into one reflection chamber 48. As a result, the reflected exhaust compression wave from one cylinder arrives back at the other cylinder timed for auxiliary exhaust opening AEO and the reflection distance is substantially halved in length. Thus, by carefully sizing the reflection chamber and head pipes two or more cylinders may be serviced by a single reflection chamber sized as a function of degrees of crankshaft rotation and head pipe length between cylinder AEO's.
In FIG. 4c the outlets 60 from two or more reflection chambers 48 can be merged downstream into one outlet 60' as shown to meet certain racing rules or to otherwise limit the number of tail pipes extending from the vehicle.
FIGS. 5a through 5e illustrate schematically a number of means to effectuate auxiliary exhaust opening. In FIG. 5a a camshaft 66 includes a large lobe 68 for causing normal valve push rod 70 movement to open the exhaust valve and a second smaller lobe 72 to cause AEO. The configuration of camshaft 66 with a large lobe 68 and a small lobe 72 can also be applied to conventional valve opening mechanisms used in overhead camshaft designs. In FIG. 5b a primary overhead camshaft 74 includes a large lobe 76 that moves a rocker arm 78 in turn opening the valve 80. A second smaller overhead cam 82 with a smaller lobe 84 also engages the rocker arm 78. The camshafts and valve in FIG. 5b are all to one side of the rocker arm fulcrum 86.
In FIG. 5c the valve 88 is located opposite (about the fulcrum 90) to overhead camshafts 92 and 94 both being located beneath the rocker arm 96. Both the primary camshaft 92 and auxiliary camshaft 94 are equipped with lobes 98 and 100 respectively. In FIGS. 5d and 5e a single overhead camshaft 102 is shown operating a valve 104 about a fulcrum 106. The camshaft 102 includes a primary lobe 108 and auxiliary lobe 110 displaced axially along the camshaft 102. The rocker arm 112 is bifurcated with separate arms engaging the primary lobe 108 and auxiliary lobe 110.
FIG. 6 illustrates the use of a single cam 114 on a single camshaft 116 to operate both the primary exhaust valve 118 and an auxiliary separate exhaust valve 120. The separate valve 120 is actuated by a rocker arm 122 about a fulcrum 124. The separate valve 120 can be much smaller in opening area and differently positioned in the head of the engine cylinder.
The embodiments of FIGS. 5b and 5c offer the possibility of relatively simple timing adjustment relative to the primary cam by adjusting the rotational position relative to the timing belt or chain of the engine. Alternatively, means to deactivate the auxiliary cam can be similar to the means used to deactivate individual cylinders in engines designed to operate on 4, 6 or all 8 cylinders. Thus, the AEO can be selectively used only when the engine is at design speed and load or the timing of the AEO can be adjusted over a range of engine speeds and loads.
Illustrated in FIG. 7 is an expansion box 248 having a movable reflection cone 259 located toward the downstream end of the box. While a variety of means may be employed to move the reflection cone 259 within the expansion box 248, a tubing sleeve 261 is shown attached to the reflection cone at 263 and extending within the tubular exhaust outlet 260. A slot 265 formed in the tubular exhaust outlet 260 and a bolt 267 engaging the tubular sleeve 261 permit the reflection cone 259 to be moved the length of the slot 265 and set as desired to time to engine speed. In the alternative, the center section 256 may be formed in two telescopically engaged portions to change the length between the exhaust valve 252 and converging cone 258 thereby obviating the need for the internal movable cone 259 and inner sleeve 261. Or, the headpipe 250 can be formed in two telescopically engaged sections to change the length between the exhaust valve 252 and the converging cone 258. A dynamic actuator responsive to changes in speed or load may be used in place of the bolt 267 to adjust the position of the reflection cone 259, or to adjust the telescopically engaged sections.
In FIG. 8 an air pump 269 is employed to provide a stream of fresh air through a conduit 271 in communication with the interior of the expansion box 248. The fresh air being substantially more dense and at a temperature considerably below the exhaust temperature mixes with the hot exhaust gases thereby changing the gas dynamic properties of the gaseous mixture in the expansion box 248. The speed of the pulse and, in particular, the reflected pressure wave being a function of specific heat ratio, temperature, and gas constant, thereby may be adjusted downward by increasing the proportion of fresh air to exhaust. The flow of fresh air from the air pump may be a continuous function of engine speed or power output thereby permitting the benefit to apply to a range of engine operating conditions as a vehicle is driven. An orifice or control valve 253 may be used to control the flow rate of air from the air pump 269. The conduit 271 is provided with a check valve 257 to prevent backfire through the conduit 271.
Or, a pressurized source of air or other relatively cool inert gas such as carbon dioxide, argon or Halon may be admitted to the expansion chamber.
In FIG. 9 the source of the bleed air to the expansion box or chamber 348 comprises a conduit 349 from the turbocharger or supercharger outlet 351 to a proportional control valve 353 or orifice. From the proportional control valve a conduit 355 divides to provide bleed air to each expansion box 348. The divided conduits 355 are provided with check valves 357 to prevent back fire through the conduits 355 and proportional control valve 353. In a manner similar to the air pump above noted, the quantity of bleed air provided through the proportional control valve 353 may be a function of engine speed or engine load.
In non-turbo or supercharged engines the bleed air may be supplied to each expansion box 448 through a reed valve 449 operated by the vacuum or rarefraction pulses in the exhaust as shown in FIG. 10. A control valve or orifice 451 is incorporated to control the quantity of bleed air admitted and a check valve 453 prevents back fire through the reed valve 449.
The bleed air or other gas admitted to the exhaust can be injected at any location upstream of the convergent reflection cone in FIGS. 8, 9 and 10.
FIG. 11 illustrates the use of bleed air into the exhaust stream to achieve the same "effective" header lengths in an exhaust configuration with differing header lengths leading to an expansion box 548. A physically long header 549 leading from one cylinder parallels a physically short header 551 leading from another cylinder. The short header 551 is equipped with a conduit 553 communicating through a check valve 555, control valve or fixed orifice 557 and reed valve 559 to provide cool bleed air directly into the hot exhaust in the short header. The speed of sound in the short header 551 is effectively slowed thereby slowing the reflected wave in the short header 551 relative to the reflected wave in the long header 549. This change in effective header length can also permit a changed crankshaft angle between the firing-sequence of the cylinders in communication with the same expansion box 548. Clearly, the means to admit air or other gas disclosed in FIGS. 8 or 9 could applied to effectively equalize the header lengths.
In addition to the above means of altering the exhaust gas dynamic properties within the expansion chamber or reflection means to alter the speed of the reflected pressure wave, other means not requiring the addition of a cool gas can be applied to alter the exhaust gas properties. In substitution for the gaseous material, another foreign material such as a liquid in the form of finely divided droplets or a finely comminuted powder may be injected as a spray to absorb sensible heat and otherwise alter the gas properties of the exhaust gases flowing through the exhaust conduits and expansion chamber.
The outlet 60 in FIG. 3 from the expansion chamber 48 can be restricted in flow area, extended in length or other means taken to alter the backpressure on the engine. An increase in backpressure increases the pressure and temperature within the expansion chamber by retaining hot exhaust therein for a longer time period. The result is an increase in reflected pressure wave speed. Thus, a reduction in backpressure tends to lower expansion chamber pressure and reflected wave speed.
The exhaust temperature can also be altered by adding fixed or movable protuberances and internal 455 or external fins to the expansion chamber. Variation of the instant the exhaust valve is opened during the normal exhaust cycle will also affect the exhaust temperature and reflected wave speed. Thus, a multiplicity of means to adjust and tune the arrival of the reflected pressure wave can be applied to a single or multicylinder engine.
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In a spark ignition or compression ignition four cycle internal combustion engine, an exhaust expansion chamber is sized to produce a reflected exhaust pressure wave timed to an auxiliary reopening of the exhaust valve after the intake valve has effectively closed. The reflected exhaust pressure wave causes the re-entry into the cylinder of a quantity of intake charge (which has previously been drawn into the expansion chamber) subsequent to the effective filling of the cylinder through the intake valve, the result being a boost in cylinder charge and pressure on the compression stroke of the piston. At engine design speed, the power output of the engine is substantially improved over the power output without the boost in cylinder charge and in compression stroke pressure. The particular exhaust expansion chambers and valve re-opening timing is adaptable to single and multiple cylinder four cycle engines. With respect to multiple cylinder engines the reflected wave can be timed to feed into another cylinder exhaust valve re-opening.
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This is a continuation of application Ser. No. 503,335, filed June 10, 1983, now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 206,142, filed Nov. 12, 1980, now abandoned, and a continuation-in-part of U.S. patent application Ser. No. 458,432, filed Jan. 17, 1983, now U.S. Pat. No. 4,518,459 which is in turn a continuation of U.S. patent application Ser. No. 93,744, filed Nov. 13, 1979, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to methods of decontaminating secondary (i.e., not virgin or primary) cellulosic fiber or fiber sources during repulping. More particularly, the present invention relates to methods of substantially removing contaminants such as waxes, adhesives, and the like from secondary fiber, dispersing them in the aqueous repulping medium, and removing the repulping medium from the pulp.
The present invention provides nearly complete removal of contaminants from the secondary fiber, and sufficiently permanent dispersion of them to prevent their deposition within the newly formed sheets or on production equipment. These contaminants, commonly referred to as "stickies", encompass a wide variety of substantially thermoplastic organic resinous water-insoluble contaminants such as waxes, hot melt adhesives, pressure sensitive adhesives, vinyl acetate-type coatings, SBR resins, latex adhesives, and others. Inks and the above substantially organic resinous water-insoluble contaminants form a broad category of deposits commonly referred to as "stickies and tackies".
These contaminants which can remain the secondary fiber after repulping or can later reagglomerate in the paper production waters can create a variety of series problems for the paper making industry, particularly in the liner board and corrugated industries. The contaminants typically form deposits on all types of paper making equipment, including the press roll and wet end of corrugating machines, press section calendars, dryer surfaces, wires, press felts, and the like. As a result, production time is lost and machine efficiency reduced due to sheet breaks at the breaker stacks, wrinkles at the rewinder, limited machine speeds due to wire filling, down time for deposit cleanup, and the like. Further these deposits typically require significant amounts of solvents and manpower for their removal, further contributing to their undesirability. Additionally, the stickies and tackies generally contaminate the paper sheets themselves, forming deposits which result in sheet defects such as holes, deposits, specks, and low brightness. In corrugated medium mills, frequently the product comprising secondary fibers will have poor absorbency because of the incorporated contaminants. This is a problem because absorbency is required for proper glue penetration of the corrugated products.
Many types of paper making utilize repulped secondary fibers. The paper products comprising such fibers include tissue, toweling, specialties grades, liner board, corrugated medium, boxboard and so on. Particularly the corrugated medium mills and liner board mills have turned to secondary fiber obtained from pre-used corrugated as a low cost fiber substitute. However, the ratio of secondary fiber to virgin fiber which can be utilized has been limited, due to the problems associated with stickies deposits in the system and sheets.
Until recently, the major form of control for stickies and tackies has been mechanical. Pressure screens, reverse cleaning systems and flotation loops have been used to remove these contaminants from secondary fiber stock flows in processes such as tissue, toweling, corrugating board, and secondary liner board manufacture. Chemical approaches to the problem have incorporated talc, polymers, dispersants, and so on, but with little success. In the manufacture of corrugating and liner board, steam and asphalt dispersion units are sometimes used in an attempt to control these deposits. However, these machines are typically expensive to purchase and even more expensive to operate on a continual basis. Further, even where contaminants may appear to have been dispersed by known methods of controlling contaminants, these methods do not appear to prevent the contaminants from re-agglomerating, for example when the repulped paper fibers are being used to form a paper product. When the contaminants reagglomerate, the above-described problems of deposition will typically occur. Frequently the paper-making process is a continuous process from the repulping of secondary fiber until the new product is dried. Typically the production waters are redistributed or re-used through the system. Consequently, dispersed contaminants which are not sufficiently dispersed or which do not remain dispersed ultimately can cause problems as the process waters are recirculated through the system.
Accordingly, use of repulped secondary fiber originally containing contaminants such as wax and adhesives continues to be a significant source of lost production and expense due to the tendency of these contaminants to form deposits within the paper making system and on the sheets.
The present invention provides substantially reduced (if not eliminated) deposition of objectionable contaminants on processing machinery and in the sheets themselves where secondary fiber is utilized in a paper making process. Secondary fiber processed according to this invention will generally allow for increased production, less down time for deposit removal, faster machine speeds due to elimination of web breaks caused by sticky felt and rolls, improved drainage, faster drying, and the like.
SUMMARY OF THE INVENTION
The present invention provides a method in which a combination of particular nonionic surfactants and dispersants provide both foam control (e.g., defoaming effects), high deinking efficiency where required, enhanced handsheet brightness and unexpected increased contaminant removal from fiber and dispersion resulting in restriction of contaminant deposition.
The present invention is a method of substantially removing and dispersing contaminants from contaminant-containing secondary fiber during repulping. The method involves use of an aqueous repulping medium comprising contaminant-containing secondary fiber, a sufficient amount of a substituted oxyethylene glycol nonionic surfactant and a contaminant-dispersing amount of a water soluble, low molecular weight polyelectrolyte dispersant at a temperature above the melting point of a contaminant to be removed from the secondary fiber. This method achieves unexpected control of stickies and tackies as well as foam control, enhanced handsheet brightness, and high deinking efficiency where any of these latter properties may also be desirable.
For purposes of the present invention, the following terms shall be defined:
"Washing-type" or "washing" methods shall mean methods for producing substantially dispersed secondary fiber contaminants, comprising suspending the contaminated secondary fiber in an aqueous medium, allowing the contaminants to disperse into the aqueous medium, and substantially separating the decontaminated fiber from the contaminant-containing aqueous medium by means of washing-type steps.
"Substituted oxyethylene glycol surfactants" herein shall mean nonionic surfactants comprising oxyethylene glycol chain wherein one terminal hydroxyl of the chain has been replaced with an aliphatic or alkylaromatic ether group, and the other terminal hydroxyl has been replaced with a polyoxypropylene group or a benzyl ether group.
"Low molecular weight" herein shall mean having a molecular weight in the range of 500 to 50,000.
"Water soluble" as the term is intended herein means any material that substantially dissolves in water at room temperature to form a solution.
DETAILED DESCRIPTION OF THE INVENTION
In the usual practice of the process of this invention, contaminated secondary fiber is blended with water, a substituted oxyethylene glycol surfactant and a dispersant, thereby causing contaminants to separate from the fiber and become distributed or dispersed in a very stable condition throughout the aqueous fiber slurry or medium. To achieve this the components are preferably heated, or if already at the required temperature due for example to the heat of the system, maintained, at a temperature above the melting point of the contaminant to be removed or dispersed. Generally the required temperature will be in the range of about 25° C. to 85° C., or, due to the nature of the frequently-encountered contaminants, more typically in the range of about 35° C. to 60° C.
The decontaminated fiber is then substantially separated or isolated from the contaminated aqueous medium, e.g., by centrifuging, decanting, filtering, or preferably, screening. Screening involves the deposition of the fiber pulp onto a foraminous surface capable of retaining the fiber while the aqueous medium drains through the holes in this surface. If desired, the separation or recovery of the decontaminated fiber from the aqueous medium can be preceded by a concentration or dilution step and can be followed by washing-type steps, e.g., dilution and/or screening, which steps can be accompanied by agitation of dilute fiber slurries.
It is particularly preferred in this invention that the contaminant control begin with the repulping of the secondary fiber, i.e., that the surfactant and dispersant used in this invention be present during the repulping process. However, the present surfactants and/or dispersants can also be added downstream from the repulping including sidehill washer stages and/or to the caustic extraction stage of a bleaching system. It can be advisable to select an addition point ahead of a system exit, or ahead of a problem location such as a dilution step or a point where pH or temperature changes occur which would lead to the deposition of contaminants.
Where decontaminated secondary fiber is utilized, contaminant build-up on paper processing machinery has been experienced particularly where the decontaminated fiber was obtained from papers having increased water resistance, for example, wax coated papers such as cold cups, or corrugated board products such as cartons or boxes. In this type of contaminant environments, contaminant deposition was found to occur even when the advantageous substituted oxyethylene glycol surfactants of U.S. Ser. No. 093,744, filed Nov. 13, 1979, discussed hereinafter, were utilized.
In a practice of the present invention, the addition of a water soluble, low molecular weight polyelectrolyte dispersant and a substituted oxyethylene glycol to the repulping milieu produced a completely unexpected and unpredicted improved dispersion of the contaminants into the processing medium.
This improved dispersion of the contaminants into the aqueous repulping medium resulted in substantially reduced deposition of the objectionable materials on processing machinery as the paper making process continued after repulping, thus reducing machinery down time. Where the secondary fiber processed according to this invention is later used in the manufacture of paper products, generally the result will be significantly reduced deposition of stickies and tackies on machinery and on the sheets themselves, thus increasing machine efficiency.
Further, the polyelectrolyte dispersants herein tend to prevent (by preferential complexation) the formation of certain insoluble reaction products formed between ions of metals such as calcium and magnesium and the organic materials commonly present in secondary fiber such as fatty acids (a major constituent of printing inks), resin, casein and starch. Such insoluble, hard water reaction products are analogous to the familiar bath tub or hard water deposit.
The present invention involves use of a nonionic surface active agent or surfactant. The surfactant comprises an oxyethylene glycol chain, wherein one terminal hydroxyl of the chain has been replaced with an ether group selected from the group consisting of an aliphatic ether group and an alkylaromatic ether group, and the other terminal hydroxyl of the chain has been replaced with an ether group selected from the group consisting of a polyoxypropylene group and a benzyl ether group. A typical formula for preferred surfactants of this invention would be as follows: ##STR1## wherein a is zero or 1,
Ar represents an aromatic residue, preferably monocyclic,
R represents an aliphatic group,
n has a value from about 3 to about 50,
m has a value from about zero to about 50, and
Y is selected from the group consisting of hydroxy and benzyl ether and is benzyl ether when m equals 0.
The R group is typically saturated and contains at least 6 carbons. When a equals zero, R contains from 6 to 24 carbons; when a equals 1, R normally contains no more than 18 carbon atoms. In short, the R(Ar) a group contains at least 6 aliphatic carbon atoms and up to a total of 24 carbon atoms.
A preferred foam-suppressing surface active agent for use in the present method is of the formula:
R--(AR)--(OC.sub.2 H.sub.4).sub.n --(OC.sub.3 H.sub.6).sub.m --Y
wherein R is a monovalent higher aliphatic group containing from 6-24 carbon atoms, AR represents an aromatic residue, n is about 6-15, m is about 12-48; n:m is less than 1, and Y is hydroxyl or benzyl ether.
The foregoing structural formula can be considered to encompass two major classes of surfactants, i.e. (a) alkylene oxide adducts of alkylphenols, and (b) alkylene oxide adducts of higher (greater than C 5 aliphatic alcohols. These surfactants are described in detail in commonly assigned U.S. patent application Ser. No. 093,744 filed Nov. 13, 1979 on behalf of of Richard E. Freis, James E. Maloney and Thomas R. Oakes, entitled "Methods of Deinking Secondary Fibers", the entire disclosure of which is incorporated by reference herein. A continuation of U.S. Ser. No. 093,744 (now abandoned) was filed on Jan. 17, 1983, and has been assigned U.S. Ser. No. 458,432 now U.S. Pat. No. 4,518,459.
The invention of U.S. Ser. No. 093,744 relates to washing methods of deinking and decontaminating secondary fiber and to the use of substituted oxyethylene glycol nonionic surfactants in such washing-type deinking and decontamination methods. Washing methods of deinking are distinguished from flotation methods which are more technically involved and which generally require more capital investment. The substituted oxyethylene glycol nonionic surfactants described and claimed in U.S. Ser. No. 093,744 provide enhanced deinking and decontaminating performance (vis-a-vis, conventional washing methods) with unexpected low foaming throughout wide variation in processing temperature.
The method of the present application, as well as U.S. Ser. No. 093,744, also contemplates the avoidance or mitigation of the drawbacks of conventional washing-type repulping methods while obtaining the advantages of those methods, particularly as compared to the more complicated, more capital-intensive, and more sensitive flotation methods. This invention is based upon the discovery of a particular class of dispersants which unexpectedly enhance the performance of the substituted oxyethylene glycol surfactants of U.S. Ser. No. 093,744, primarily in decontamination.
In the context of this invention, the present dispersants provide nearly complete removal and sufficiently permanent dispersion of secondary fiber resinous contaminants to prevent their deposition within the sheets or on production.
The present invention also involves the use of polyelectrolyte dispersants. A "polyelectrolyte dispersant" as the term is intended herein means any homo, co, ter, etc., polymer of the structure: ##STR2## wherein R 1 , R 2 , R 4 and R 5 are independent and can be hydrogen, C 1 -C 4 lower alkyl, alkylcarboxy (e.g., --CH 2 COOH) or mixtures thereof; R 3 and R 6 can be hydrogen, carboxy, alkylcarboxy, or mixtures thereof, and X can be carboxy (including salts or derivatives thereof, e.g., amide), acetyl, or hydrocarbon moieities commonly attached to free radical polymerizable monomers (e.g., --C 6 H 5 in styrene); a+b having a value in the range of 15 to about 1,000.
Examples of materials within the scope of the above formula include polymaleic acid, polyacrylic acid, polymethacrylic acid, polyacrylic acid/itaconic acid copolymers, polyacrylic acid/hydrolyzed maleic acid copolymers, polymaleic acid/itaconic acid copolymers, hydrolyzed polymaleic acid/vinyl acetate copolymers, polyacrylic acid/acrylamide copolymers, polyacrylic acid/methacrylic acid copolymers, styrene/maleic acid copolymers, sulfonated styrene/maleic acid copolymers, polymaleic acid/methacrylic acid copolymers, maleic acid telomers, maleic/alkyl sulfonic copolymers.
A particularly prefered class of water soluble polyelectrolytes for use in the practices of the present invention is the polyacrylate compounds. The polyacrylate compounds comprise polymers and copolymers of the structure: ##STR3## and their derivatives, wherein R 2 , R 5 , X, a and b are defined as above.
In a most preferred practice of the present invention, X is --COOZ, wherein Z is H, or a monovalent cation, e.g. Na + , K + , or HN 4 + . Thus, typical most preferred polyelectrolytes of the present invention are polyacrylic acid (e.g. GOODRITE K732 available from B. F. Goodrich Company), polymethacrylic acid (e.g., TAMOL 850, available from Rohm & Haas), and copolymers of acrylic acid/methacrylic acid (e.g., AQUATREAT available from ALCO Chemical).
The polyelectrolytes of this invention must be water soluble. Generally speaking, to be water soluble, the polymer must contain sufficient polar groups (e.g., COOH) for the molecule to interact with the polar water molecules. This means that in copolymers, terpolymers, tetramers, etc., with unsaturated monomers which are predominantly or entirely hydrocarbon (e.g., styrene) there must be sufficient polar functional groups for the polymer to dissolve in room temperature or below water. Generally, at least about 10 mole percent of the monomers comprising the polymer must contain polar functionality (e.g., ##STR4## to provide the required water solubility.
The low molecular weight polyelectrolytes of present invention generally have molecular weights of less than about 50,000 with preferred molecular weights in the range of about 500 to 25,000, most preferably of 750 to 5,000. Thus, the sum of a+b above, generally falls in range of 5 to 1,000, preferably 10 to 500 and most preferably 12 to 450. One skilled in the art will recognize that the materials within the above molecular weight ranges are generally of lower molecular weight than polymers generally referred to in the art as flocculants which may have molecular weights in the range of several million or more. Flocculants perform function of agglomerating suspended particles opposite the desired function of dispersion described herein. Thus, these high molecular weight materials operate in a manner effectively opposite that of the materials described herein. The lower molecular weight materials of the present invention are generally referred to in the art as "dispersants".
Functionally speaking, the polyelectrolytes of this invention should be present in the aqueous surfactant mixture to the extent necessary to prevent deposition of contaminants (e.g., pigments, coatings, fillers, adhesives, etc.) onto processing equipment. Generally, the concentrations of the present polyelectrolytes falls in the range of about 5 to about 500 parts per million, with concentrations in the range of about 10 to about 75 ppm being preferred.
Another area where the present invention is found to be particularly effective is in the area of decontaminating secondary fiber having photocopying inks therein, (i.e., recycled photocopies). Photocopies are made on coated or uncoated papers, the coated papers having various materials thereon (and therein) to enhance the ability of the paper to accept and permanently retain Xerographic imaging powders. Photocopy paper coatings and sizes and the imaging powder itself tend to be suspended during the repulping step (i.e., to be held in the solution primarily by physical agitation of the liquid) only to be deposited on processing machinery as a result of eventual coagulation or as the aqueous processing stream cools and/or is less aggressively agitated. Use of the polyelectrolytes described herein (in conjunction with the substituted oxyethylene glycols) tends to reduce or substantially eliminate such deposition.
Yet another area where the present invention finds utility is the deinking and decontamination of newsprint. Recycled newsprint is distinguishable from other secondary fiber sources because the printing ink used in printed directly or uncoated fiber. In other secondary fiber sources the print is on a coated fiber (i.e., not directly on the fiber itself). The difficulty with deinking of newsprint is increased by the fact that newsprint can be up to 12% to 14% by weight printing ink which is essentially all relatively hard-to-disperse carbon black. Given the quantity and availability of recycled newsprint, efficient newsprint deinking and decontamination methods are a desideratum of the secondary fiber industry of the highest order.
The improvement of the present invention optionally contemplates the use of various well-known water soluble solvents or cosolvents, along with the dispersants and surfactants. Particularly preferred examples of such solvents include tetrahydrofuran, tetrahydrofurfural alcohol, and ethoxylated and propylated derivatives thereof.
The following non-limiting examples are intended to illustrate the practice of the present invention and should not be used to limit its scope.
EXAMPLE I
The deinking and decontamination of wax coated paper consumer "cold cups" or drink cups to produce handsheets was accomplished on a laboratory scale using the standard deinking formula of Table IA. Repulping of cold cups was accomplished in a pulper (under moderate agitation) at 160° F. (71° C.) for 60 minutes.
TABLE IA______________________________________Material Amount______________________________________Water 250 mlFiber stock (to be deinked and decontaminated) 18.8 gChlorine dioxide (10%) 1.9 mlNaOH (50% aqueous solution) 0.4 mlSubstituted oxyethylene glycol (10%)* 1.9 mlSolvent 0.4 ml______________________________________ *C.sub.10-14 alcohol(ethylene oxide).sub.20 --CH.sub.2 --C.sub.6 H.sub.5
Various solvents were employed as listed in Table IB.
TABLE IB
Solvents
1. 50 weight percent kerosene and 50 weight percent aromatic naphtha with a nonylphenol-(EO-- 6 --OH emulsifier.
2. butyl "CARBITOL" (diethylene glycol monobutylether).
3. "PENTOXONE" (4-methoxy-4 methyl-pentanone available from Shell Chemical Co.).
4. tetrahydrofuran (available from Quaker Oates Chemical Company).
5. mono ethoxylated tetrahydrofurfuryl alcohol (also available from Quaker Oates Company).
Handsheets prepared from the deinked and decontaminated cold cups were found to have improved brightness but were found to generate a heavy colored wax buildup on the equipment (i.e., on the inside of the glass beakers). It was then decided that solvent number 1 (vis., the mixture of kerosene and aromatic naphtha) would be employed and various dispersants would be added to the deinking composition at the level of 12 parts per million. The dispersants employed are listed in Table IC. Dispersants in Table IC numbered 1a, 2a and 3a are within the scope of the present invention.
TABLE IC
Dispersants
1a. Aqueous solution of 15 weight percent "DEQUEST 2054" (see 5 below), 12 weight percent of 50/50 mole percent copolymer of hydrolyzed maleic anhydride and vinyl acetate having a molecular weight of about 3,000.
2a. 50/50 mole percent copolymer of hydrolyzed maleic anhydride and vinyl acetate having a molecular weight of about 3,000 (50% active).
3a. Polyacrylic acid having a molecular weight of about 3,000 (e.g., GOODRITE K732, commercially available from B. F. Goodrich Co.) (50% active).
4a. Ethylene diamine tetraacetic acid, sodium salt aqueous solution, 40% active (e.g. VERSENE 100 available from Dow Chemical Co.).
5a. Hexamethylenediamine tetramethylenephosphonate, hexapotassium salt aqueous solution, 36% active (e.g., "DEQUEST" 2054 available from Monsanto Company).
Handsheets were prepared utlizing the above compositions, their Hunter brightness being determined. The results of this evaluation appear in Table ID. Table ID indicates that the best combination of solvent and dispersant within the scope of this invention (i.e., the combination which provides the best reduction of wax deposit and brightnes enhancement) is the tetrahydrofurfuryl alcohol solvent (straight and 9EO) used in conjunction with polyacrylic acid dispersant having molecular weight of about 3,000.
TABLE ID______________________________________ BRIGHTNESS (HUNTER) WHITE- NESS OR Wax DELTA Disper- De- WHITE- WHITE-Solvent sant posit Y XZ NESS NESS______________________________________1 None Heavy 81.9 81.1 84.0 66.4 25.05 None Heavy 84.7 83.5 89.7 72.0 19.42 None Heavy 84.0 83.4 88.4 70.7 20.83 None Heavy 83.5 83.0 87.5 69.8 21.74 None Heavy 85.0 83.6 89.9 71.9 19.61 1a None 83.3 83.0 88.2 71.6 19.51 5a Heavy 84.7 83.7 90.4 73.3 18.11 2a None 83.4 81.4 87.9 70.8 20.71 4a Some 87.3 85.2 93.8 75.9 15.61 3a None 85.1 84.2 91.7 75.2 16.2THFA 3a None 87.7 85.7 95.6 78.4 13.19EO*THFA** 3a None 86.6 84.6 93.8 77.0 14.5______________________________________ *Tetrahydrofurfural alcohol with 9 moles of ethylene oxide (EO) condensed thereon. **Tetrahydrofurfural alcohol.
EXAMPLE II
Secondary fiber having Xerographic ink and/or electrostatic coatings thereon were deinked and decontaminated and handsheets prepared therefrom, the brightness values of the resulting handsheets being shown in Table II. The family of substituted oxyethylene glycols indicated in Table II are the nonyl phenol-polyethylene (EO) oxide nonionic surfactants, there being an average of 9.5 moles of ethylene oxide per mole of nonylphenol. Additionally, various amounts of propylene oxide (PO) were condensed on the ethylene oxide chain to provide substituted oxyethylene glycol nonionic surfactants with different deinking properties. The remainder of the composition used to obtain the brightness values for the handsheets indicated in Table II was 250 milliliters water, 15 grams Xerographic coated paper stock, 0.09 grams 50% NaOH. The substituted oxyethylene glycol was added to the extent of 0.04 ml and the co-solvent (where added) was added to the extent of 0.4 ml (two handsheets were prepared for each example, the brightness values indicated being an average for the two sheets).
Table II indicates that the nonylphenol ethoxylates are good deinkers of Xerographic grade secondary fiber. Those nonylphenol ethoxylates with more propylene oxide were found to be slightly better in their performance than those with less. Further, polyacrylic acid dispersant having a molecular weight of about 3,000 was found to provide enhanced deinking and decontamination performance, vis-a-vis, the same composition without such a dispersant. Lastly, in contrast with the paper grades having wax coatings thereon, deinking of Xerographic grade papers were enhanced only slightly by the addition of a co-solvent.
TABLE II______________________________________ HUNTER REFLECTOMETERSubstituted BRIGHTNESSOxyethylene Co- VALUESGlycol Dispersant Solvent X Y Z______________________________________nonylphenol None None 77.8 78.4 91.9(EO).sub.9.5 --OHnonylphenol None None 78.8 80.1 92.6(EO).sub.9.5 --(PO).sub.6 --OHnonylphenol None None 79.4 80.4 94.6(EO).sub.9.5 --(PO).sub.12 --OHnonylphenol None None 80.0 80.6 95.0(EO).sub.9.5 --(PO).sub.24 --OHnonylphenol 2a None 80.7 81.4 97.3(EO).sub.9.5 --(PO).sub.24 --OHnonylphenol 3a None 82.4 83.1 99.6(EO).sub.9.5 --(PO).sub.24 --OHnonylphenol 3a butyl 82.6 83.3 99.4(EO).sub.9.5 -- carbitol(PO).sub.24 --OHnonylphenol 3a tetrahy- 81.8 82.5 99.7(EO).sub.9.5 -- drofur-(PO).sub.24 --OH furyl alcohol______________________________________
EXAMPLE III
Newsprint was deinked and decontaminated using various combinations of deinking surfactant, dispersant and cosolvent. The newsprint was repulped as described in Example I. The standard deinking/decontaminating/repulping medium employed was as follows:
______________________________________Water 500 mlSodium metasilicate 0.5 gNewsprint 25.0 gmSubstituted oxyethylene glycol 0.4 gmDispersant 25 ppmCosolvent (when added) 0.3 gm______________________________________
The brightness (Hunter Reflectometer values) of handsheets prepared from the deinked newsprint are shown in Table III.
TABLE III______________________________________Substituted BrightnessOxyethylene (Hunter ZGlycol Dispersant Cosolvent Value)______________________________________nonylphenol None None 58.8(EO).sub.9.5 --OHnonylphenol None None 54.6(EO).sub.9.5 --(PO).sub.6 --OHnonylphenol None None 51.7(EO).sub.9.5 --(PO).sub.24 --OHnonylphenol 2a None 55.5(EO).sub.9.5 --(PO).sub.6 --OHnonylphenol 3a None 52.7(EO).sub.9.5 --(PO).sub.6 --OHnonylphenol 3a butyl 56.1(EO).sub.9.5 -- carbitol(PO).sub.6 --OHnonylphenol 3a THFA 54.2(EO).sub.9.5 --(PO).sub.6 --OHnonylphenol 3a THFA--EO--OH 53.8(EO).sub.9.5 --(PO).sub.6 --OH______________________________________
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The method of substantially removing and dispersing resinous or waxy contaminants from contaminant-containing secondary fiber during repulping, is disclosed. The method includes combining the contaminant-containing secondary fiber in an aqueous repulping medium with a substituted oxyethylene glycol nonionic surfactant, and a water soluble, low molecular weight polyelectrolyte dispersant, at an elevated temperature.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a printing machine, such as a flexographic printing machine, of the type comprising a plurality of inking units, a plurality of plate cylinders and at least one impression cylinder which, during a printing operation, is driven by a central gear in mesh with plate cylinder gears. The plate cylinders are mounted on plate cylinder carriages, on tracks included in the machine frame, and which extend in approximately tangential to radial directions relative to the central gear. The plate cylinders are movable into engagement with the impression cylinder for the printing operation and are movable away from the impression cylinder. The inking units comprise halftone rollers, which carry halftone roller gears in mesh with the plate cylinder gears, and the halftone rollers are movable by inking unit carriages on tracks of the plate cylinder carriages. The machine also has means for aligning the teeth of the central gear with the teeth of the plate cylinder gears when the latter have been moved to pushed-in positions, datum marks provided on the plate cylinder gears and feelers, secured to the carriages for cooperating with the datum marks, for ensuring that the plate cylinders are properly aligned or adapted to be aligned for printing in register.
2. Description of the Prior Art
In a flexographic printing machine, the plate cylinders generally must be changed after each print job and the printing format may also have to be changed. The number of plate cylinders to be changed will depend on the number of colors to be printed. For each print job the plates of the plate cylinders must be properly adjusted relative to each other so that a web moving through the machine will be printed in register. To ensure printing in register, it is necessary to establish accurate meshing between the plate cylinder gears and the central gear. It is also desirable that printing be resumed after as short as possible a change-over time and that prolonged downtimes of expensive printing machines be avoided to the extent possible.
In a printing machine of the kind hereinbefore described and disclosed, for example, in published German Pat. Application No. 34 37 216, the need for expensive adjusting work after a changeover of the printing machine is substantially eliminated. A certain amount of adjusting work however, must still be performed by hand in the known machine, because the gears for driving the plate cylinders must be rotated by hand until the feeler, consisting of a lever, snaps into the associated datum mark, which is constituted by a setting bore.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a multicolor printing machine of the kind described with register preadjusting means for adjusting the machine for printing in register with high accuracy substantially without errors and without the need for manual adjustments.
In accordance with the invention, a respective plate cylinder gear is adapted to be coupled to a gear which is connected to a servomotor for moving the plate cylinder gear to a position in which the feeler senses the datum mark.
The servomotor may be controlled by a control device, which causes the servomotor to operate until the feeler has detected the mark. This can be accomplished in two ways. The mark may either define the proper position for the plate cylinder gear for printing or may alternatively define a zero position from which the plate cylinder gear must be rotated by the servomotor through an appropriate angle to position the plate cylinder in the proper position for printing.
If the mark is itself to define the proper position of the plate cylinder for printing, the mark must be provided after the machine has been set up and the plates have been secured. If the mark is to define the proper printing position of the plate cylinder, care must be taken during a change-over or adjusting operation always to install each plate cylinder in the appropriate print unit, because the plate cylinders should not be interchanged in this case.
On the other hand, if the mark only defines the zero position, so that the mark is aligned with the plate in a predetermined manner, the plate cylinders can be installed in any one of the print units, and when a plate cylinder has been adjusted to its zero position, the associated plate cylinder gear is rotated to move the plate cylinder to the proper position for printing. For this reason, according to a further feature of the invention, the servomotor may be controlled by an electronic computer, which causes the servomotor to operate until the plate cylinder concerned has been moved from the zero position, defined by the mark, to the proper position for printing. This feature eliminates the need for additional change-over times because it is not necessary during a change-over to take care that a respective plate cylinder will be installed into a specific print unit. The computer-controlled servomotor will first effect a movement to the zero position, in which the feeler detects the mark, and in accordance with a program entered into the computer, the plate cylinder gear is then rotated through an appropriate angle to position the plate cylinder gear in the proper meshing position relative to the central gear.
In accordance with a further feature of the invention, the gear for driving the plate cylinder gear from the servomotor may be the halftone roller gear or ink roller gear, and the ink roller shaft may be adapted to be coupled to the servomotor.
A further consideration resides in that the gears of the ink roller and of the plate cylinder should be adjusted relative to each other in such a manner that the top lands of their respective teeth will not strike against each other, but rather that the gears will properly mesh with each other when the inking unit carriage is moved toward the plate cylinder.
In accordance with a further feature of the invention, a synchronizing gear is mounted on the ink roller shaft beside the ink roller gear. The synchronizing gear has teeth which are axially aligned with the teeth of the ink roller gear, and the addendum circle of the synchronizing gear is larger than the addendum circle of the ink roller gear. The synchronizing gear is radially movable against spring means from a position in which the synchronizing gear is concentric with the ink roller shaft. For an adjustment of the ink roller gears and plate cylinder gears, these gears are moved toward each other to a position in which their addendum circles are slightly spaced apart. In that position, the teeth of the synchronizing gear will either mesh with the teeth of the plate cylinder gear or the teeth of the synchronizing gear will strike against the teeth of the plate cylinder gear. In the latter case, the ink roller shaft is rotated through a small angle to cause the teeth of the synchronizing gear to snap into mesh between the teeth of the plate cylinder gear. Alternatively, the plate cylinder gear will be rotated through the small angle when the synchronizing gear has meshed with the plate cylinder gear. As a result, an adjustment is effected by a rotation through a small angle so that a second step may be performed in which the gears are moved toward each other until their teeth properly mesh with each other.
The plate cylinder gear is desirably axially slidably mounted on the plate cylinder shaft and means may be provided for displacing the plate cylinder gear between positions in which the plate cylinder gear is in mesh and out of mesh, respectively, with the synchronizing gear. In this case, it is simple to move the synchronizing gear to its effective and ineffective positions.
The feeler may suitably consist of a clearance-measuring proximity sensor. By axial displacement of the plate cylinder gear, the proximity sensor is moved to an activated position, in which the proximity sensor is responsive to marks provided on the plate cylinder gear and which suitably consist of bores. A marking bore is suitably provided on an end face of the plate cylinder gear within the dedendum circle, so that the bore can be properly detected.
The feeler or the proximity sensor is suitably mounted in a fixed position on the ink roller carriage.
The proximity sensor is suitably in its sensing position when the halftone roller gear has been displaced to a position in which it is in mesh with the plate cylinder gear, which position corresponds to the so-called impression-off position of the printing machine.
In accordance with a further feature of the invention, the ink roller gear may be adapted to be coupled by a clutch to a gear which is freely rotatably mounted on the ink roller shaft and which is operatively connected to the servomotor by a pinion or by gears. Before a printing operation is initiated, after the plate cylinder has been adjusted, the freely rotatable gear is uncoupled from the ink roller gear so that the former gear can rotate freely on the ink roller shaft while the servomotor is at a standstill.
In a further embodiment of the invention, gears provided with free-wheels are rotatably mounted on both stub shafts for the ink roller. One of the gears on each stub shaft is the halftone roller gear, adapted to be coupled to the respective stub shaft by a clutch. That one of the gears which is opposite to the halftone roller gear meshes with the output pinion of the servomotor directly or by means of idler gears. In this embodiment, the servomotor may be used to effect the required adjustment and in a second mode of operation, when the gears provided with the free-wheels have been coupled and uncoupled, respectively, the servomotor may be used to continue the drive of the ink roller in intervals between printing operations.
The clutches by which the gears provided with free-wheels are adapted to be coupled to the stub shafts carrying the halftone roller may consist of friction clutches, which are actuated by fluid-operably piston-cylinder units.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagrammatic side elevational view of a flexographic printing machine having multiple printing and inking units;
FIG. 2 is a plan view of the printing unit and inking unit shown in the top right-hand part of FIG. 1, with the plate cylinder gears and ink roller gears shown in an out-of-mesh position for clarity of illustration;
FIG. 3 is an enlarged view of the encircled portion labelled III in FIG. 7;
FIG. 4 is an enlarged view of the encircled portion designated IV in FIG. 2;
FIG. 5 is an enlarged view of the encircled portion designated V in FIG. 2;
FIG. 6 is a side elevational view of an inking unit provided with a proximity sensor; and
FIG. 7 is a plan view of the inking unit.
DESCRIPTION OF PREFERRED EMBODIMENTS
Illustrative embodiments of the invention will now be described in detail with reference to the drawings.
FIG. 2 shows an inking unit of the printing machine shown in FIG. 1, the inking unit being provided with a newly installed plate cylinder 1 and an associated plate cylinder gear 2. In its outer end face the plate cylinder gear 2 is formed within its dedendum circle with a bore 3, with which a proximity sensor 4 cooperates. The sensor 4 is secured to a holder 5, which is screw-connected to an ink roller bracket 6. An axial adjusting device 7 is provided, which is known per se and for this reason is not described in detail, and is operable axially to adjust the plate cylinder gear 2 relative to the plate cylinder 1 to such an extent that the plate cylinder gear 2 can be spaced an exactly defined distance from the proximity sensor 4. Such adjustable spacing corresponds to an activated position of the proximity sensor 4, i.e., to that position thereof in which the sensor 4 is able to detect the bore 3. To move the proximity sensor 4 to its active position, the bracket 6 mounting the ink roller 9 must be moved sufficiently closely to the plate cylinder 1, that the proximity sensor 4 laterally overlaps the gear 2 to a predetermined extent. Such overlap should be sufficiently large that the proximity sensor 4 radially protrudes over the root of the gear 2 but is not disposed on the radius on which the bore 3 is disposed. If the sensor is adjusted to reach the radius of the bore 3, the proximity initiator 4 may be exactly in the register, in dependence on the angular position, so that the depth of the bore may be effective to prevent a detection of the exact axial spacing.
An axial adjustment of the plate cylinder 1 is prevented by known means, not shown in detail, so that the plate cylinder gear 2 is axially displaced.
The radial distance left between the proximity sensor 4 and the marking bore 3 when the sensor is in the active position described above, corresponds to a so-called impression-off position of the printing machine, in which the pitch circle of the plate cylinder gear 2 is spaced from the pitch circle of a gear 8 for driving the ink roller 9. Thus the proximity sensor 4 will not be disposed on the radius of the bore 3 when the teeth of the plate cylinder gear and of the ink roller gear are loosely in mesh in a position which corresponds to the impression-off position.
As described above, a new plate cylinder 1 provided with an associated drive gear 2 has been installed into a bearing bracket 39 shown in FIG. 1. Also, the ink roller 9 and the ink, roller bracket 6 have been moved toward the plate cylinder 1 to such an extent that the proximity sensor 4, which is connected to the ink roller bracket 6 by the holder 5, overlaps the drive gear 2 to a predetermined extent. It is assumed that the drive gear 2 has been axially adjusted relative to the proximity sensor 4 by the adjusting means 7. By means of a motor 40, shown in FIG. 1, the ink roller bracket 6 is moved toward the plate cylinder 1 to such an extent that the addendum circles of the ink roller gear 8 and of the plate cylinder gear 2 are still slightly spaced from each other. A synchronizing gear 29 is mounted on a stub shaft 10 carrying the ink roller and is coaxial to the ink roller gear 8. Gear 29 has the same number of teeth as gear 8 but has an addendum circle which is larger than the addendum circle of gear 8. In an axial direction the teeth of the synchronizing gear 29 are so positioned relative to the teeth of the ink roller gear 8 that the teeth are mutually aligned. By known coupling and bearing means, the synchronizing gear 29 is mounted on the stub shaft 10 in such a manner that the gear 29 is non-rotatably connected to the stub shaft 10 but is radially displaceable.
When the ink roller gear 8 and the plate cylinder gear 2 are in the position which has been described above in which the addendum circles of the gears do not yet contact each other, the teeth of the synchronizing gear 29 will either mesh with the teeth of the plate cylinder gear 2, or else the top lands of the teeth of the synchronizing gear 29 will engage the top lands of the teeth of the plate cylinder gear 2. When the top lands of the respective teeth engage each other, the synchronizing gear 29 is radially shifted against the force of compression springs 30 (FIG. 5) of a mounting means which is known and therefore not described in detail. When this position is reached, two free-wheel assemblies 16, 16', shown in FIGS. 4 and 5, which normally allow gears 8, 8' to rotate on stub shafts 10, 33, are locked in that pressure fluid supplied compressed air is supplied through air supply passages 25, 25' to force clamping cones 22, 22' against the conical rings 26, 26', overcoming the action of springs 21, 21' which abut on plates 20, 20'. Cones 22, 22' are non-rotatably connected to stub shafts 10, 33 and rings 26, 26' are secured to gears 8, 8' so that a rigid connection is formed between the ink roller gears 8, 8', on the one hand, and the stub shafts 10, 33 and the ink roller 9, on the other hand. Cones 22, 22' are moved by pistons 24, 24' on which the compressed air acts. Thereafter, a stepping motor 36, shown in FIG. 2, is started for a first time to rotate shafts 10, 33 as will be described, so that the teeth of the synchronizing gear 29 are brought into mesh with the teeth of the plate cylinder gear 2 even when their top lands have previously engaged each other.
When the top lands of the gears 2 and 29 engage each other, the compression spring 30 included in the means for mounting the synchronizing gear 29 will exert on the latter only such a small force that the pressure applied by the synchronizing gear 29 to the teeth of the plate cylinder gear 2 is not sufficient for rotation of the plate cylinder 1 by friction. Also, even when the teeth of the synchronizing gear 29 already are properly in mesh with the teeth of the plate cylinder gear 2, this will not be harmful, because in that case the operation of the stepping motor 36 will rotate only the plate cylinder 1 to a certain extent. After a short actuation of the stepping motor 36, the synchronizing gear 29 will reliably be in mesh with the teeth of the plate cylinder gear so that the teeth of the ink roller gear 8 will be properly positioned relative to the teeth of the plate cylinder gear 2. As a result, the motor 40 shown in FIG. 1 can be used to move the ink roller bracket and the ink roller 9 toward the plate cylinder 1 to such an extent that the teeth of the ink cylinder gear 8 are brought loosely into mesh with the teeth of the plate cylinder gear. In that so-called impression-off position, the marking bore 3 of the plate cylinder 2 is disposed on the same radius as the proximity sensor 4. The bore 3 may then assume any desired angular position relative to the proximity sensor 4.
In the illustrative embodiment described above, a reference edge, i.e., leading edge of a block which has been adhered to the plate cylinder 1, lies in an axial plane with the marking bore 3. Thereafter, the stepping motor 36 is operated to rotate the plate cylinder 1 and the plate cylinder gear 2 until the proximity sensor 4 is adjacent to and detects the marking bore 3 of the plate cylinder gear 2. Because the several plate cylinders of each printing unit must assume a predetermined angular position relative to each other, the plate cylinder must be rotated further through a corresponding angle from the zero position defined by the marking bore. The extent through which a plate cylinder 1 must be rotated to assume the correct position in mesh with the central gear is controlled by an electronic computer. In accordance with a suitable program, the correct extent of the adjustment is stored in the computer, so that the latter controls the motor 36 for a rotation of the plate cylinder gear 2 and the plate cylinder to the correct position. The motor 36 suitably consists of a stepping motor so that the rotation of the plate cylinder 1 is then effected by a suitable number of steps. When said steps have been performed, the plate cylinder 1 is in the associated proper angular position relative to the impression cylinder 41. Previously, the impression cylinder 41 has been moved to a predetermined initial position by means not shown because they are known per se. The motor 42 shown in FIG. 1 is then operated to move the carriage 39 and the plate cylinder 1 together with the ink roller 9 toward the impression cylinder 41 and toward the central gear 43 associated with the impression cylinder 41 to such an extent that the teeth of the plate cylinder gear 2 loosely mesh with the teeth of the central gear 43 so that they are in the impression-off position. During the adjusting movement, the two annular pistons 24, 24' may be vented so that they are moved to their initial position by the springs 21, 21'. To ensure that the synchronizing gear 29 is not always in mesh with the plate cylinder gear 2, the latter is moved by axial adjusting means 7 toward the plate cylinder 1 until the synchronizing gear 29 is disposed beside the plate cylinder gear 2.
When all printing units have been properly adjusted, the main drive for the central gear 43 can be started. The rotation of the central gear 43 will be transmitted to the plate cylinder gears 2 and from the latter to the ink roller drive gears 8, which are connected by the free-wheels 16 to the stub shafts 10 to rotate the ink roller 9. That stub shaft 33 for the ink roller 9 which is opposite to the stub shaft 10 does not rotate with the latter. The free-wheel 16' ensures that the rotation is not transmitted to the gear 8', which is in mesh via an idler gear 35 with a pinion 38 of the stepping motor 36. In such state, the printing machine rotates in the so-called impression-off position. As the plate cylinder 1 is moved closer to the impression cylinder 41 and the ink roller 9 is moved closer to the plate cylinder 1, the impression-on position is assumed, i.e., the printing machine is now in its operating position. When a print job has been completed, the printing machine returns to its impression-off position and the main drive for the central gear 43 is turned off. In that position, care must be taken to continue the rotation of the ink roller 9 so that the ink will not dry. To that end, the stepping motor 36 is turned on again to rotate via its pinion 38 the idler gear 35, the gear 8', the free-wheel 16', and the stub shaft 33 so that the ink roller is kept in motion. In that case, the free-wheel 16 mounted on the stub shaft 10 ensures that the rotation of the stub shaft 10 is not transmitted to the drive gear 17. It is apparent that the respective free-wheel devices 16 and 16' can be actuated independently of one another dependent on which form of operation of the machine is required.
It is further apparent from the foregoing description that the stepping motor is used for effecting an exact positioning of the plate cylinder 1 and for effecting a continued rotation of the ink roller 9 when the printing machine is in the impression-off position. Because stepping motors can generally be operated at different speeds, this will afford the advantage that the continued rotation imparted to the ink rollers in the impression-off position can be effected at a speed which involves the smallest abrasion at the interface between a doctor blade and the ink roller.
In the apparatus which has been described above and shown in FIGS. 2, 4 and 5, the two stub shafts 10 and 33 carrying the ink roller are provided each with an adjusting device. In the embodiment shown in FIG. 3, a plate cylinder 1 can be adjusted 15 and an adjusting device 45 can be provided only on the right-hand stub shaft 10 carrying the ink roller 9.
FIG. 7 shows a portion of FIG. 2 in an embodiment which has been modified in accordance with FIG. 3. It is apparent that a difference from FIG. 2 resides in that the ink roller bracket 6 is connected on the right to a stepping motor 46, a pinion 47 of which is in mesh via an idler gear 48 with a gear 49. The gear 49 is mounted by means of bearings 50 on sleeve 51. The flange 52 of the gear 49 is embraced by an intermediate ring 53, which is held against the end face of the gear 49 by means of a retaining ring 54, inserted into an annular recess of the flange 52, and with a thrust bearing 54' interposed. The intermediate ring 53 has a recess 55, which receives an annular piston 56, which by means of the bearing 57 bears on a clamping cone 58, which in an initial position is urged against the flange 52 of the gear 49 by a plurality of springs 59, which are spaced around the circumference. On that side opposite to the cone 58, the springs 59 bear on plate 60, which is supported by a disk 61 on a flange of the sleeve 51. A conical ring 62 is associated with the clamping cone 47, and corresponds to the two conical rings 26 and 26' shown in FIGS. 4 and 5. Because the design corresponds in other respects to that of the adjusting device 34 shown in FIG. 5, further details of the design of the adjusting device shown in FIG. 3 will not be described.
Regarding the operation of the embodiment described with reference to FIGS. 3 and 7, it is assumed that a new plate cylinder 1 has been installed and that the ink roller and the plate cylinder 1 have been moved toward each other to such an extent that the sensor 4 laterally overlaps the plate cylinder gear 2. This displacement operation is performed like that described hereinbefore with references to FIGS. 2, 4 and 5. When the spacing of the several cylinders and rollers has been adjusted, the plate cylinder 1 must be adjusted. To that end, compressed air is forced into the cylinder chamber 55 through the air supply line 25, so that the annular piston 56 and the bearing 57 effect a frictional coupling between the conical clamping cone 58 and the conical ring 62. The conical ring 62 is secured by screws 63 to the drive gear 17. The stepping motor 46 is then operated so that the adjusting operation is effected in the manner described with reference to FIGS. 2, 4 and 5. In the embodiment shown in FIGS. 3 and 7 the required continued rotation of the ink roller 9 in the impression-off position is not effected by the stepping motor but by a separate motor, not shown.
FIG. 6 is a side elevation showing on an enlarged scale an inking unit and indicates the position and arrangement of the sensor 4.
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A printing machine, such as a flexographic printing machine has a plurality of inking units and a plurality of plate cylinders. A central gear drives an impression cylinder and during a printing operation meshes with plate cylinder gears. The plate cylinders are mounted on plate cylinder carriages on tracks included in the machine frame and which are movable towards the impression cylinder for a printing operation. Halftone ink roller gears are associated with halftone rollers of the inking units and mesh with the plate cylinder gears. The halftone rollers are movable on inking unit carriages on tracks on the plate cylinder carriages. The teeth of the central gear are to be aligned with the teeth of the plate cylinder gears when the latter teeth are moved to pushed-in positions. The plate cylinder gears are provided with datum marks with which sensors fixed to the inking carriage cooperate so that the plate cylinders can be aligned for printing in register. To ensure that an adjustment for printing in register can be effected with high accuracy, without errors and without a need for manual work, each plate cylinder gear is equipped with a servomotor which rotates the plate cylinder gear to a position in which the respective sensor detects the respective datum mark.
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This is a nationalization of PCT/NZ00/00139 filed Jul. 27, 2000 and published in English.
TECHNICAL BACKGROUND
The invention relates to apparatus useful in a method of assessing pulp, paper or wood from the stem of a felled tree (e.g., so as to be determinate of possible destinies of logs to be cut from the stem), such as stiffness of sections of wood cut from the stem, or wood fibre characteristics such as fibre length or the strength of pulp produced from the wood.
BACKGROUND ART
The timber industry faces a need to efficiently utilise its rather variable forest resource. Timber classification, for example machine stress grading, is currently done at the end of the production chain. This process results in wastage from processing which ultimately proves to have been inappropriate. Clearly, it would be more efficient to measure log properties early in the chain and process the logs accordingly.
In our New Zealand Patent Specification Nos. 331527 (filed Aug. 1998) and NZ333434 filed Dec. 17, 1998 there are disclosed procedures in respect of the testing of felled tree stems or logs with a view to determining a destiny for that tree stem or log or logs to be cut from the tree stem.
New Zealand Patent Specification 331527 is directed to the selection of wood according to fibre characteristics so as to determine materials appropriate for the pulp and paper industry whilst, New Zealand Patent Application 333434 is directed to timber or lumber cutting determinations but with the prospects of directing inappropriate tree stems or logs to the pulp and paper industry.
DISCLOSURE OF THE INVENTION
The present invention is directed to apparatus sufficiently portable and effective in usage which will allow the adoption of such aforementioned methods in the field.
It is therefore an object of the present invention to provide such apparatus and the use of such apparatus in the field for such tree stem or log assessment purposes. As used herein MOE is the dynamic modulus of elasticity derived by the product of (A) the square of the velocity of an appropriate wave propagation between the ends of a felled tree stem or a log (V 2 ) and (B) the specimen density ρ.
In one aspect the invention consists in an apparatus for providing an indicator of or from which stiffness can be estimated for elongate timber, logs or felled tree stems (hereafter “logs”) of known length L or measurable length L, said apparatus comprising or including
sensing means capable of being placed in contact with or in close proximity to a log end to detect the impulse and echoes thereof resulting from a striking of the other or that same log end,
processing means to derive using an echo or echoes sensed by said sensing means a said indicator, and
display means to display said indicator or any derivative thereof received from said processing means,
wherein said processing means tests algorithmically frequency transformed data derived from time based echo data with a view to deriving a measure or good estimate of fundamental frequency f 0 ,
and wherein L is or can be entered into said processing means,
and wherein said processing means derives said indicator by reference to both f 0 and L.
Preferably said processing means tests all spectral peaks of the echo data for membership of a series from which a best value of fundamental frequency f 0 can be derived and related to the plane wave speed V and specimen length L by V=2L/f 0 rather than by reliance on the identification of any single resonance peak.
Preferably said processing means recognises that the characteristic frequencies may be shifted significantly from a harmonic series f 0 , 2f 0 , 3f 0 . . . . . set and recognises that a better indication of the fundamental frequency f 0 , from which the speed V can be found is obtained from higher harmonics.
Preferably said processing means recognises that a better indication of the fundamental frequency f 0 than an attempted direct measure of f 0 itself is from at least the second harmonic.
Preferably said processing means recognises that whilst the natural resonance frequencies of stems and logs may be far from harmonic (principally on account of the asymmetry introduced by their taper or loading eg; when stacked) they may be transformed to a harmonic series by applying a correction which decreases as the harmonic number increases.
Preferably said processing means can transform observed resonant frequencies f n into multiples of a “true” fundamental frequency f 0 from which a plane wave velocity can be derived by reliance upon the relationship (f n =n f 0 )/f n =kc −n .
Preferably said the fractional deviation falls in geometric progression with ratio approximately 2.7.
Preferably the relationship is f n /nf 0 −1=k/n 2 .
Preferably said processing means discriminates against noise spikes in the spectra, peaks from unwanted modes inadvertently excited, or any other signals which differ from the spectral peaks sought and which have the desired relationship by using a comb filter comprising a number of frequencies (“centre” frequencies) which match the sought relationship, which can themselves be harmonic or have some other relationship, the comb filter having passbands wide enough to allow small derivations about each centre frequency.
forming the sum of the products of the actual spectral peaks and the comb filter, and
identifying as the sequence or filter which accounts for most spectral power, and, where necessary.
deciding between two filters which produce equal power sums on the basis of the comb which produces the least frequency offset between the actual spectral peaks and the filter centre frequencies.
Preferably said processing means uses such transforms to convert a harmonic series with a defined base frequency f 0 to a non-harmonic series, thereby defining the centre frequencies of a comb filter with which the actual series may be compared, without the need for all members of the actual series to be present.
Preferably said processing means can calculate a confidence number to be displayed by said display means to indicate the likelihood that the indicated velocity is correct or whether a re-measure is advisable based on the amount of power in the spectral peak series identified with a base value off 0 , compared with spectral power not accounted for, e.g. that assumed to be in spurious noise spikes or non-longitudinal resonances inadvertently excited.
Preferably said indicator is V or V 2 or a function of V or a function of V 2 .
Preferably said indicator is V 2 or a function of V 2 derived from a value or function of V, V having been determined by V=2L f n .
Preferably said display means displays V 2 or an indicator or indicators of the one or more properties being assessed, such as MOE or an approximation of MOE derived from MOE=ρV 2 where ρ has been approximated (e.g. as near 1000 kg/m 3 for green felled logs).
Preferably said sensing means and/or processing means includes amplification means to ensure a sufficient gain to ensuing echoes in use.
Preferably said sensing means is adapted to be placed in contact with said log end.
Preferably said sensing means carries a switch for said processing means conducive, when activated, of good log/sensing means contact.
Preferably said sensing means is compliantly mounted by a sensing head to be physically pressed by a user against the log surface to be tested.
Preferably the compliant mounting of said sensing means within the means to be handled by a user i.e. the sensing head, is compliantly mounted by use of silicone rubber.
Preferably said sensing means is in a sensing head connected by flexible means to apparatus carrying said processing means and said display means.
Preferably said sensing means is or includes a piezo-style accelerometer.
Preferably said processing means has analog signal acquisition means, means for digitization and processing into a characteristic spectrum of the acquired analog signal data of the echoes and further software algorithms to interpret the data.
Preferably, with a view to power saving, said display means is a small low power display.
Preferably said sensing means is in a sensing head capable of one handed manipulation by a user and whereby the apparatus is adapted to minimise power consumption by allowing initiation of the measurement sequence by finger pressure on a push switch immediately prior to the striking of a log to be tested, such pressure on such a push switch encouraging positive contact between the head and the log surface.
Preferably said processing means is adapted to threshold the signal from said sensing means and immediately to apply an exponentially increasing amplification of the signal to compensate for absorption of the signal in the log so increasing the time over which acoustic signals can be useful digitalised and to increase spectral resolution.
Preferably the apparatus is such that power consumption is adapted to be minimised by allowing operation under the control of PLDs which remain in low current mode until enabled by an initiation switch after which there is a powering up, at least as needed, of analogue functions of said processing means with respect to signal acquisition, powering up and analysis of such signals and a sending results to the display means before being subsequently powered down after a time period or time periods.
Preferably there is provided a keyboard through which data entries can be made into said processing means.
Preferably preset information for data entry is selected from the class any one or more of
(i) velocity class codes e.g. colours to be painted on a log after its speed group is determined,
(ii) log length codes,
(iii) information analysis purposes,
(iv) information for instrument configuration purposes, and/or
(v) to control the sending of spectral information via a serial port to an external computer for graphical display or archiving.
Preferably, if desired, the apparatus can be externally controlled e.g. by connecting an external device via a serial port to the instrument power controllers and its microprocessor.
Preferably the apparatus has a hardware architecture substantially as herein described with reference to the accompanying drawings and which is operable in a manner substantially as herein described with reference to any one or more of the accompanying drawings.
Preferably said sensing means is adapted to be placed at or in close proximity to the same log end as that to be struck to provide said impulse.
In another aspect the invention is a method of providing an indicator of or from which stiffness, fibre characteristics or other properties can be estimated, which method involves an operative use of apparatus of the present invention.
Preferably said method is performed substantially as herein described with or without reference to any one of the accompanying drawings.
In still a further aspect the invention consists in a method of providing an indicator of or from which stiffness, fibre characteristics, or other properties can be estimated for a felled log of known or measurable length L, said method comprising or including the steps of
striking an end of the felled log whilst having sensing means of the previously defined apparatus in contact with or in close proximity to a log end to detect at least one echo of the impulse resulting from the striking of that same or the other log end,
processing the output of at least said sensing means in said processing means to derive, using an echo or echoes sensed by said sensing means, a said indicator, and
displaying on or by said display means said indicator or any derivative thereof received from said processing means,
optionally thereafter appropriately marking or otherwise indicating the fate of the log on the basis of the displayed indicator,
said process being further characterised in that said processing means tests frequency transformed data derived from time based echo data with a view to deriving a measure or good estimate of fundamental frequency f 0 , L is or can be entered into said processing means, and said processing means derives said indicator by reference to both f 0 and L.
Preferably said indicator is an estimation of MOE for a green felled log on the basis of an estimation of its density at or about 1000 kg/m 3 .
In another aspect the invention is the use of apparatus of the present invention for use in a method of the present invention.
In still another aspect the invention is a method of generating and displaying an indicator of stiffness or fibre characteristics of wood within an elongate wooden structure (e.g. a log) which comprises or includes
(i) presenting an accelerometer based sensing means compliantly to an end of the elongate wooden structure,
(ii) impacting that said end of the structure so as to generate an impulse capable of reflection from the other end thereof,
(iii) passing the analogue signal detected by said compliant sensing means to a processing means,
(iv) processing the input data in said processing means to generate said indicator, and
(v) passing to the display means the generated indicator from said processing means for display,
wherein the architecture of the apparatus is such that said sensing means is a sensing head in which said accelerometer is compliantly mounted and is connected by a flexible link to a housing carrying said processing means and said display means.
Preferably said sensing head has a switch capable of being initiated by applying pressure which is conducive to compliant contact of said accelerometer with the end of said wooden structure.
Preferably said apparatus is apparatus as previously defined.
In another aspect the invention is a method of cutting a stem into logs of predicted speeds based upon the stem speed using the fact that the wave or acoustic speed along a stem has a characteristic variation by
(i) establishing an expression, the speed function, which represents the nature of the speed variation with distance along the stem, characteristic for a species and a locality, with one adjustable parameter to allow the variation along individual stems, to be matched,
(ii) measuring the average speed along the stem by a method as previously defined and converting this to a stem transit time,
(iii) integrating the wave travel time along the stem using the speed function, and altering the adjustable parameter until the integrated time equals the measured stem transit time, and
(iv) using the speed function thus established to compute the likely speed at points along the stem, to mark and route logs accordingly.
The present invention in another aspect consists in apparatus for providing an indicator of or from which stiffness can be estimated for a felled log of known length L or measurable length L, said apparatus comprising or including
sensing means capable of being placed in contact with a log end to detect the impulse and echoes thereof resulting from a striking of that same log end,
processing means to derive using an echo or echoes sensed by said sensing means a said indicator, and
display means to display said indicator or any derivative thereof received from said processing means,
wherein said processing means tests frequency transformed data derived from time based echo data with a view to deriving a measure or good estimate of fundamental frequency f 0 ,
and wherein L is or can be entered into said processing means,
and wherein said processing means derives said indicator by reference to both f 0 and L.
Preferably said indicator is V or V 2 or a function of V or a function of V 2 .
Preferably said indicator is V 2 or a function of V 2 derived from a value or function of V, V having been determined by V=2L f 0 .
Preferably said display means displays V 2 or an indicator or indicators of the one or more properties being assessed, such as MOE or an approximation of MOE derived from MOE=ρV 2 here ρ has been approximated (e.g. as near 1000 kg/m 3 for green felled logs).
Preferably said sensing means and/or processing means includes amplification means to ensure a sufficient gain to ensuing echoes (preferably logarithmic amplification of subsequent echoes).
Preferably said sensing means carries a switch conducive, when activated, of good log/sensor contact.
The present invention is reliant upon any of the processing procedures hereinafter described with or without reference to any one or more of the accompanying drawings and/or with or without reference to any of the algorithmic processes hereafter described.
Preferably the apparatus with a view to power savings in the field includes hardware incorporating analog signal acquisition means, means for digitization and processing into a characteristic spectrum of the acquired analog signal, further software algorithms to interpret the data, and preferably means to provide a small low power display rather than the full screen of a computer.
Preferably such display is of a MOE or wood fibre characteristics indicator.
Preferably said sensing head (preferably a piezo-style accelerometer) is compliantly mounted on a body, e.g.; using a pad of silicone rubber, and capable of being brought into contact with a tree stem end or log end.
Preferably said sensing head is flexibly connected to the processing means and display means.
Preferably said sensing head includes a test commencement switch or the like.
Preferably said sensing means is substantially as hereinafter described with reference to FIG. 1 of the accompanying drawings.
In a further aspect the present invention consists in a method of providing an indicator of or from which stiffness, fibre characteristics, or other properties can be estimated, which method involves an operative use of apparatus as previously set forth.
In still a further aspect the present invention consists in a method of providing an indicator of or from which stiffness, fibre characteristics, or other properties can be estimated for a felled log of known or measurable length L, said method comprising or including the steps of
striking an end of the felled log whilst having sensing means of the previously defined apparatus in contact with the log end to detect at least one echo of the impulse resulting from the striking of that same log end,
processing the output of at least said sensing means in said processing means to derive, using an echo or echoes sensed by said sensing means, a said indicator, and
displaying on or by said display means said indicator or any derivative thereof received from said processing means,
optionally thereafter appropriately marking or otherwise indicating the fate of the long on the basis of the displayed indicator,
said process being further characterised in that said processing means tests frequency transformed data derived from time based echo data with a view to deriving a measure or good estimate of fundamental frequency f 0 , L is or can be entered into said processing means, and said processing means derives said indicator by reference to both f 0 and L.
Preferably said indicator is an estimation of MOE for a green felled log on the basis of an estimation of ρ=1000 kg/m 3 .
DETAILED DESCRIPTION OF THE INVENTION
Preferred forms of the present invention will now be described with reference to the accompanying drawings in which:
FIG. 1 shows a measuring instrument including an accelerometer sense head as it is preferable used against a log end in conjunction with a hammer and data interpretation devices to yield such as result to be used,
FIG. 2 illustrates schematically the types of spectra derived from long and short stems, where the harmonic or overtone frequencies f N (normalised to N times the fundamental frequency f 0 which relates to wave speed within the log), are plotted against harmonic or overtone number, N,
FIG. 3 illustrates how whole stem velocity information, combined with a knowledge of typical velocity profiles along a stem, can predict velocities within logs subsequently cut from the stem,
FIG. 4 shows echo decay,
FIGS. 5 and 6 shows two preferred sensing heads,
FIG. 7 shows a preferred control panel
FIG. 8 shows a flow chart of the measuring operation,
FIG. 9 is a block diagram of the preferred electronic hardware,
FIG. 10 is an illustration of the operation of a comb filter on a power spectrum, and
FIGS. 11 to 15 are graphs referred to further below in the description of a trial carried out to determine wood fibre characteristics using the instrument of the invention.
Measurements carried out by us on wood as it is dried from the green to dry state have shown that there is good agreement between the static bending modulus and the so-called dynamic MOE found from the formula
MOE=ρV
2
where V is the velocity of longitudinal waves along the log or beam and ρ is the mass density of the wood, including its water content. This agreement is possibly because the effective measurement frequency is low (hundreds of Hz) rather than in the ultrasonic range often reported in the literature. Ultrasonic measurements show a water-dependent modulus. The low frequency agreement has profound significance for the log or timber industry; since the density of green wood is known to be about 1000 kg/m 3 , regardless of the dry density. The modulus can therefore be estimated from a green velocity measurement alone. The dry value can be estimated as being perhaps 15% above this as the wood cellulose dries from saturation to equilibrium water content.
This document deals with three elements required in combination to make a fast yet portable field instrument by identification of impact-induced resonances found by Fourier analysis. Accurate measurement of the sonic velocity of logs or stems can be made in a time of a second from these resonances and a good estimate of the stiffness modulus found. The three elements are the measuring head, the signal acquisition and processing hardware, and the algorithms needed to interpret the resonance data.
In this respect see FIG. 1 .
General Instrument Requirements
The requirements for a portable, hand-held tool for log assessment, able to be used by a single operator in a yard or forest are
Low right and small size
Ease of operation in obtaining the measurement
Fast processing and display of answer, e.g. a second.
Low battery drain, e.g. operation for at least one shift on a battery
Rugged construction with a degree of waterproofing.
Robust processing algorithms able to handle variable quality data
Low cost if many units are to be deployed by technically unskilled operators
Some of these requirements are potentially contradictory, such as ruggedized but lightweight construction, fast processing but small current drain. In particular, though small “laptop” style computers are available, it is unlikely that waterproofing, full shift operation and low cost can be easily achieved. It is generally more efficient to use dedicated hardware which incorporates the analogue signal acquisition, its digitization and processing into a characteristic spectrum, further software algorithms to interpret the data, and a small, low power display rather than the full screen of a computer. Such a configuration allows major savings of power, as will be described.
Sensing Head
FIGS. 6 and 7 show two sensing heads (1), comprising a piezo-style accelerometer 8 mounted on a body 9 which contains a cable entry 10 for the wires to the accelerometer 8 , and an enabling switch 11 . The accelerometer is of a type which responds only to accelerations along the axis of the body. The wires are further protected mechanically by flexible tubing 12 which also prevents water ingress to the head 1 and which extends to the electronic unit ( 4 , 5 , 6 ) to be described.
The frequency response of the accelerometer may be chosen for the nature of the log expected. For normal forest work, a frequency response of 10 to 3000 Hz is adequate, but wider ranges may be advantageously used, particularly if the instrument is to be used in research applications.
It is preferable that the accelerometer incorporates a charge amplifier, since connection to the electronic unit may then be made through a cable of any length. The purpose of the switch 11 is to activate the signal acquisition circuits immediately prior to striking the log under test. It is desirable that the accelerometer is compliantly mounted on the body, for example on a pad of silicone rubber 13 , as this enables the operator to press the head against the timber face of a log or stem end (e.g. of log 2 ) and maintain good contact independently of any hand movement. If the accelerometer mount is rigid, spurious acceleration signals may be generated if the flat face of the accelerometer is inadvertently rocked against the timber. In FIG. 5, a thin cap 14 of material such as neoprene rubber is fixed over the end of the head so as to be in contact with the accelerometer end face. The purposes of this is to provide some protection for the accelerometer against inevitable build up of debris such as resin from the logs under test. The cap may be cleaned or replaced. Tests have shown that 1 mm of a hard rubber only slightly impairs collection of acoustic signals from logs.
In FIG. 6, maximum sensitivity is gained at the cost of debris protection by replacing the cap 14 with a rigid tube 14 a, within which the sensor 8 is directly mounted.
To take a measurement, it is sufficient to press the assembly against the end face of the log 2 , depress the switch 11 (an action designed to encourage pressure contact with the timber) and strike the timber clearly but not forcefully with a mallet or hammer 3 . Pressure contact must be maintained for up to half a second while the sound waves within the log decay.
Signals may be collected reliably with this head 1 regardless of the nature of the cross-cut face; for example, the deep ridges produced by the hydraulic saws in automatic harvesters such as the WARRATAH™ GENERATE signals no different from more even surfaces. It is not necessary to embed the detector in the wood to achieve coupling, a fact that considerably speeds up the sounding operation. Experience has shown that neither placement of the head or the blow is critical. This is understandable since the system analyses many tens of reflections of the acoustic pulse in modes which incorporate the entire log, so the precise nature of the initial shock becomes unimportant. This is in clear distinction from so-called stress wave testers, where a single transit time of an acoustic pulse is measured. Clearly, for stress wave testers, the initial development of the pulse from a hammer-generated, localised, near spherical disturbance, to a mode filling the log may be a significant fraction of the first transit. Nevertheless, good practice seems to be to place both the head and position the blow perhaps a quarter of the distance from the log centre to the bark. Peripheral blows tend to encourage non-longitudinal oscillations of the sample, while are not wanted.
Experience shows that unskilled operators have the unshakeable belief that if modest blows produce results, then Herculean strikes must be even more effective. This tendency can be controlled by issuing a hammer of appropriate weight for the task. For logs and stems, a weight of 400 gm is adequate. For lighter samples, such as sawn and dried framing timber, lighter mallets can be used. Only on very short logs of exceptionally large diameter have heavy hammers been beneficial in exciting clean resonances.
Electronic Unit
The electronic unit is shown by reference to function in FIG. 1 as including the processing means (a combination of means 4 to electronically measure and control and means 5 to process using algorithms) and display means 6 .
The two dominating considerations of this electronic unit are the high rate of decay of the signal coming from the wood, and the need to reduce power consumption as much as possible so that effectively continuous operation on small batteries for at least one shift is possible. Consideration of currents drawn by processors capable of performing the functions required here show that some automatic form of power saving is necessary.
Measurements of the attenuation of acoustic signals in wet wood show that the signal can fall by 60 dB in 0.1s, in an approximately exponential fashion. The process of Fourier analysis in this application can be thought of as a simple way of averaging the echo times of many reflections, since the fundamental frequency f 0 found by Fourier analysis is the inverse of the echo time T. (FIG. 4 ). The reception of many echoes leads to an accurate average. It is for this reason that resonance-type instruments produce more consistent answers than single transit stress-wave times. However the echo time in a long stem is typically 10 ms. To detect 20 echoes necessitates detecting signal for 200 ms, and clearly by this time the amplitude will be very low if the attenuation is 60 dB/100 ms.
To obtain useful signals for a duration of 0.1 to 0.4s, the gain of the analogue amplifier is made to increase at a constant exponential rate, for example 20 to 60 dB, over the course of the event to partially offset the natural attenuation. Amplifier offset voltages must be carefully controlled with such a strategy to prevent dc contamination of the final spectrum. In conjunction with this, high resolution A/D converters, typically 14 bits, are used so that useful resolution can still be obtained where the signal has fallen into the microvolt range (but is still above the noise background). If the initial acoustic signal is converted to a 3V amplitude signal, the level 100 ms after this might be 3 mV, which would give some resolution on a 14 bit converter set to 3V scale, since the least significant bit is 0.19 mvolt. However, signals beyond the 100 ms time frame would quickly fail to be digitized.
The provision of time-dependent gain is vital to extend the period over which signals can be usefully digitized. 20 dB of gain over the 100 ms described above would raise the signal at that time to 30 mv, enabling the time of useful digitization to be considerably extended.
FIG. 7 shows a possible layout of the controls seen by the operator. Upon turn on, the results from the analysis of the last log are shown in the display. Should new control information be required, it is entered via the keyboard in conjunction with the Function keys F 1 to F 3 . The most common user-information needed is a new log length if this is different from the already displayed, and this is achieved by pressing F 1 and entering the new length via the key pad. The key F 2 is used to select predefined log lengths to speed up entry when a few fixed lengths are expected. These lengths can have been pre-loaded into the device (using F 3 ), and are selected by pressing F 2 followed by the one of keys 0 - 9 . The F 3 key is used less frequently and in conjunction with particular key pad numbers, for example by supervisors to set up various defaults such as the maximum velocity expected, to download information to another device, read battery voltage, set default log lengths, or to allow the instrument to be controlled from an external computer.
The display shows the current length, the grade or code for the log based on its velocity, and the actual velocity. The bottom line indicates a “c” or confidence value, summarized as “*good*” or “*rehit*” based on the value. In the absence of a visual display of the spectrum, or indeed a skilled operator capable of judging from such a display that the automatically extracted velocity is the correct one, some indicator of how well the data collected fits expectations is very important. How the parameter c is calculated is described later. The value of c at which the display changes from “good to “rehit” can be changed using the F 3 key.
The display shows instrument status in the top left corner. When the enable switch 11 on the head is depressed, the symbol “!” appears when the device is ready. This changes to “{circumflex over ( )}” when a hit has been detected, and calculation is proceeding. The symbol “*” is used to indicate that data is being downloaded to an external device, making the instrument temporarily unavailable for new measurement.
The operator flow described above is summarised in FIG. 8 .
A more detailed understanding if the invention comes from the block diagram of the electronic hardware drawn in FIG. 9 . The accelerometer 15 is coupled to an analogue amplifier 16 which incorporates a gain control function. The state of the entire instrument is controlled by two programmable logic devices numbered 18 (the event controller) and 19 (the intelligent power controller). When powered up, only parts of these PLDs are operative, and since they are not switching, standing current is very low. When the enable switch 20 on the head is closed the PLD 18 ( a ) turns on the Analogue section 16 and the A/D converter 17 , and digitized samples from the accelerometer are fed to the signal register 18 ( b ) in the PLD. If the signal exceeds a threshold, the event detector 18 ( c ) assumes that the log or sample has been struck. The event starts the logarithmic increase in the analogue amplifier gain, and initiates the Intelligent Power Controller PLD 5 , which powers up the microprocessor 21 .
The microprocessor 21 records a number of digitized values over an ensuing time. Typically, 2048 readings will be taken over 400 ms, following which the analogue amplifier and A/D converter are turned off. The data are then Fourier transformed following appropriate windowing and filtering. The particular data record described combination will yield a maximum frequency of 2.5 kHz with a resolution of 2.5 Hz, which suits forest applications, but could be changed to suit other needs.
The power spectrum is then analysed by the processor 21 using algorithms discussed in the next section to extract a fundamental resonance f 0 , and an answer displayed in the liquid crystal unit 22 . This can consist of a single value for velocity, (assuming a prior log length has been entered into the unit), using the formula
V= 2 f 0 L
where L is the length, or the value can be converted to a speed class, and the code for that class displayed, for example “green” to indicate a colour marker to be used.
Having initiated the display, the microprocessor returns to hibernation mode to save current, and reactivates after a time of for example 30s to turn the display off under the control of the intelligent power controller 19 .
It is necessary to manually enter some information, for example new log lengths. Operation of the key pad 23 is detected by the power controller PLD 19 , which activates the processor 21 long enough to store the new data.
The unit is configured to deliver the minimum necessary information to operating crews, but clearly the full detail of spectral information, which may be required for R and D operations, is potentially available. The logic of the controller 19 is configured so that by keyboard entries, it is possible to send the spectral information via serial port 24 to an external computer for graphical display or data recording. Conversely, data received at the serial port activates the power controller and thence the processor, so that the serial port can be used to control the operation of the device from an external computer.
Spectrum Interpretation
It is well known that exciting a beam or log of wood into longitudinal oscillation produces a disturbance which can be Fourier analysed into a series which is harmonic, and in which the speed of sound in the wood is given by
V= 2 Lf 0
V is the speed of longitudinal compressional motions along the member, and since the lateral boundaries are stress free, is given by the well known relation
V
2
=E/ρ
where E is Young's modulus, and ρ the material density.
In samples of regular cross section, particularly where the these are slender, higher resonances are closely harmonically related to the fundamental. Extraction of the modulus using the two equations above is simple since the fundamental is easily identified. The number of harmonics detected depends on the frequency characteristics of the exciting impulse. Wet wood is soft. Typically a hammer is arrested in a time of the order of a millisecond and the spectra cannot be expected to contain harmonics greatly in excess of the inverse of this time, i.e. greatly above 1 kHz. However, modelling studies we have made show that slenderness of the beam is a factor also. Thin beams or logs encourage the excitation of high harmonics, while short fat beams or logs do not.
In practice, there is a variety of circumstances where this picture requires modification to extract reliable values of the modulus.
In field use, samples may not be slender—a four metre saw log with a diameter of 50 cm is considerably “fatter” than a sawn beam 100 by 50 mm, and because of the excitation spectrum and the log shape, few harmonics will be detected in the log compared with the sawn wood. A decision on which frequency should be identified as the fundamental may be less clear for the log. We have found that this can be exacerbated by the presence of unwanted noise spikes in the spectrum, or unwanted resonances arising from less than optimum hammer blows. Situations of poor spectra have been found to be inevitable in some physical locations, for example when obtaining spectra from the logs of cross-cut stems, when the log faces are relatively inaccessible. In development work, it is possible to repeatedly take a spectrum until by chance it is “clean”. In a production tool, a high success rate in analysis must be available, and a built-in indication of the confidence in the answer is desirable.
It is also recorded in the literature that spectra from logs in stacks may differ from harmonic. We have observed that the fundamental can be typically 5% higher than the value expected from the resonance identified as the second harmonic, and values of 10% have been seen. Calculating MOE based on the fundamental or the second harmonic in this case would have a discrepancy of 20%, which is unacceptable.
Tests done on logs measured first in a stack and then unstacked on bearers show that it is the fundamental which is shifted most. The second harmonic is affected by about 1% by stacking effects, and higher harmonics, where seen, are approximately unchanged. As a rough guide, the second harmonic is a more reliable estimate of stiffness than the fundamental. Always, any frequency shift of the fundamental is positive.
However, some short logs, measured in isolation on bearers, still show a small but measurable departure from a harmonic series, usually with the higher harmonics at frequencies below what would be expected.
In the case of stems, the departure can be enormous. Since stems are “slender” many harmonics can be excited in the region below 1000 Hz, and the lowest member of the series, if the fundamental, has been observed to be as much as 40% above the value implied by the higher harmonics. This would lead to a difference of two in the predicted value of stiffness.
All the foregoing situations must be allowed for in the analysis software.
Finite Element modelling of the eigenmodes of the logs and stems has been carried out to gain an understanding of the factors involved in departures from harmonic series.
The results show that for a cylindrical log, the lowest resonance frequencies are closely harmonic. This remains true when the anisotropic elasticity of wood is included. The frequency of the fundamental mode is only slightly affected by the value chosen for Poisson's Ratio, which is fortunate since this parameter is ill-defined in wood. Further, no evidence was found that radial structure in logs, approximated by an inner core of low stiffness surrounded by a stiffer outer cylinder produced other than some average spectrum of the two; i.e. such internal structure is not responsible for anharmonic effects.
At a frequency when the wavelength across the log approaches the wood diameter, the longitudinal frequencies become lower than expected i.e. a harmonic pull-down of the kind described earlier i seen. Due to the fact that the sound speed across the log is of the order of one tenth the longitudinal speed, this condition may be reached at what may be surprisingly low harmonic numbers in “fat” logs. Model results showed that ill-defined body resonances prevailed at higher frequencies. In other words, the spectra of short fat logs might be expected to show a small lowering of higher harmonics compared to the fundamental, but few harmonics will be seen. This roughly accords with our observational experience. The theory shows that for non-tapering logs, not stacked, the best indication of stiffness comes from the fundamental.
The situation for stems is different because of their taper. Taper is the only parameter found which causes the resonances following the fundamental to be sharply lowered in frequency. However, the modelling shows that it is the low harmonics which are raised above the value expected from the wood modulus, while the high harmonics still indicate stem stiffness. As with non-tapered logs, when the transverse wavelength of a resonance frequency approaches the stem diameter, the harmonic frequency tends to fall lower than expected. Because for stems, the frequency at which this is predicted to occur is high, the effect is unlikely to be seen and indeed we have not observed it.
Tapered-log modelling shows that it is the taper per wavelength which is important. The imbalance or asymmetry occurring in the oscillating mass and spring forces about each node in the log is the underlying cause of frequency shift. Thus the fundamental mode, where the stem is half a wavelength long, can be strongly affected. The taper per wavelength in the N th harmonic is only 1/N of that in the fundamental. The higher harmonics are much less affected by the taper and yield the correct stiffness. Modelling shows, and our experience confirms, that to a reasonable approximation, if the fundamental resonance frequency is raised by a factor ke −1 over its value expected on the basis of the stem length and stiffness, the N th harmonic will be raised by a factor ke −N over its harmonic value. Resonances therefore fairly quickly reach their harmonic values. Other expressions which express the deviation of the overtones from a harmonic series can be derived.
We believe that the cause of the rise in the fundamental resonance of stacked logs noted earlier also lies in asymmetry similar to the case of the tapered stem. Now, the effect is that a log may be pinned to its neighbour in only two or three places. For low harmonics, this can produce a major elastic asymmetry and consequent lifting of the fundamental. Most of the nodal sections of the higher harmonics will not see the pinning points and their frequencies will be little affected.
The various cases described are illustrated in FIG. 2, where f N is the frequency of the N th member of the actual resonance series, and f 0 is the “true” fundamental, or lowest member of the series, from which the velocity and stiffness can be found. The lowest member f 1 coincides with f 0 if the long is slender and non-tapered, but there may be no resonance energy seen at f 0 , for example with stem spectra.
This background of observation and modelling results provides the basis of the algorithms used to analyse spectra. While a velocity can be judged by an operator from a screen display of spectra, an automatic system needs to allow for noise peaks, non harmonic effects, and perhaps most confusing to an automatic process, missing spectral peaks which confuse the identification of a series.
The algorithm must reject occasional noise peaks in the spectrum, which means that as many as possible of the resonant peaks should be identified, since random noise spikes will not occur in harmonics ratios. It must allow for the fact that frequencies may be non-harmonic to a small extent in short logs and greatly so in stems and it should not require all members of a series to be present.
The identification system first considers only spectral signals above a threshold, for example those within 20% of the power of the largest spectral peak. It may be advantageous to smooth data in the frequency domain before doing this if signals are noisy to limit the number of peaks to be considered.
Given the length of a log and a likely range of sound speed, the possible range of frequencies for a fundamental is calculated and spectral peaks sought within the that range. The search is done within velocity windows whose ranges are less than 2:1. Within such a window, the range of possible fundamental frequencies cannot overlap the consequent second harmonics range, and so allows fundamental and second harmonic to be distinguished. If no successful identification is ultimately made within this window, subsequent searches are made within modified velocity windows. This is generally not required. Most green P. radiata logs have velocities between 2.5 and 4 km/s which fulfills the velocity criterion.
For each potential candidate for a fundamental resonance, a filter comb is constructed. For example, if the peak to be tested had a frequency of 300 Hz, a comb consisting of 300, 600, 900, Hz is constructed, and the energy measured within that comb by adding the power at the comb frequencies. For short logs, a deviation of a few percent is allowed, i.e. energy is considered to be part of the comb if it falls within a predetermined band about the expected centre, to take account of the effects described earlier which are encountered in practice.
A useful variation of this procedure, which takes into account the stacking effect, is to base the comb search on the second harmonic, since this is relatively little affected by stacking, and to allow deviations from harmonic to fall mainly at the fundamental frequency. The velocity, and modulus, are then calculated from the second harmonic by assuming that this is the frequency 2f 0 .
This procedure is repeated for all peaks which are candidates for the fundamental within its allowed frequency range. The preferred identification is that spectral peak whose comb accounts for the greatest quantity of spectrum power. A numerical confidence measure which follows from this procedure is the ratio of the power accounted for in the peaks within the comb to the sum of power in other peaks plus the background noise level.
In the search to identify harmonic members, no power is considered in peaks which fall at frequencies which would lead to impossibly low velocities. The reason for this is that such peaks can be generated by moving the accelerometer head during the course of recording data. Nevertheless, their inclusion in the confidence measure gives operator warning that such an event might have happened.
It will be occasionally found, particularly with short “fat” logs, that only one resonance is seen. In that case, provided it produces a plausible velocity, it must be assumed to be the fundamental.
The procedure is modified for stems where taper is important resulting in a grossly non-harmonic series. A range of fundamental frequencies is sought as before, but the comb generated is considerably modified. Because the procedure is more complex and suits the presence of many harmonics, it is only applied to logs above a preset length, for example 12 m.
It f 0 is as before the “true” fundamental from which the speed in the tapered log can be found and the modulus calculated, the exponential deviation from a harmonic series described earlier can be expressed as
( fN−Nf 0 )/ fN=ke −N
Here fN is the frequency of the N th harmonic, and k is a constant between 0 and 1, which must be determined. Other expressions are possible. One such alternative expression has the form
f N /Nf 0 −I =(constant)/ N 2
When for example using the former expression, having identified one peak as a possible fundamental (i.e. N=1), for a given value of k, a value of f 0 is defined, and a comb of frequencies can then be generated at which the other harmonics should fall. The power falling within the comb is summed as before, and the procedure repeated with different values of k to find the optimum match for that presumed fundamental mode.
The comb filter process is illustrated in FIG. 10, with reference to the analysis of a stem, using the exponential expression above to analyse the spectrum sketched in FIG. 10 panel (c). This spectrum shows a noise floor, from which a genuine resonance sequence occurs near the frequencies f 1 , f 2 , f 4 and f 5 , but the member f 3 is missing and there is a noise pulse or unwanted resonance mode between f 1 and f 2 . To test whether f 1 is indeed the first member of series, value f 0 is chosen, which defines the harmonic series nf 0 in FIG. 10 ( a ) and the value of k. This frequency f 0 is that which, together with the stem length, defines the true wave propagation speed sought. A series of displaced frequencies f 1 , f 2 . . . which are the centre frequencies of the comb filter can now be generated from the exponential expression. Passbands for the filter are created by opening narrow windows about these centre frequencies, thus defining the comb filter shown in FIG. 10 ( b ). The power spectrum in FIG. 10 ( c ), minus a threshold representing the noise floor, is multiplied by the filter to yield the output of FIG. 10 ( d ), which is the spectral power falling in the windows of the comb. The sum of the power coming through the filter is a measure of how well the original harmonic series describes the actual spectrum. A range of values of f 0 and k are tested to find the combination which produces the best fit. Note that the noise spike between f 1 and f 2 is ignored, and the absence of the third overtone is merely regrettable, not catastrophic, in generating a fit.
This procedure will sometimes yield two values of k which generate equal summed powers. A second measure is therefore taken at each value of k to express how closely the comb is fitted. This is the sum of the deviations of each peak from its comb centre frequency. The choice is made on the basis of the most power and the best comb fit.
The next candidate resonance for the fundamental is then tested, and classed as a better identification or not on the basis of both the resonance power accounted for, and the closeness of fit to the comb. With a fast processor, computation time is acceptably short.
In effect, a transformation is being done to best fit the given resonance to a harmonic set, and does not require all member of a series to be present. It could begin by generating a comb by assuming that a particular peak was the N th harmonic and generating a comb from that. In fact, the algorithm does this, testing each peak in turn to be a particular harmonic of an assumed series, and finding the goodness-of-fit for each combination. This is useful since some stem signatures have an ill-defined fundamental frequency.
The complexity of these procedures is frequently not needed because many resonance spectra have an obvious interpretation. Their need is in the general case, when a reliable answer is needed in a high percentage of cases from less than perfect data, and the data itself must be used to indicate to unskilled operators whether or not the answer is reliable.
Stem average velocities can be advantageously used to more intelligently break stems into logs. We have found that the velocity varies along stems in a broadly similar way and can be predicted.
It can be represented by a sum of a cubic expression involving the position along the stem and a constant term. With reference to FIG. 3, a constant term in the cubic can be adjusted by calculation so that the transit time derived by integrating the speeds from the cubic expressions along an actual stem equals the time found from the averaged velocity V along the stem. For example, A× 3 +B× 3 +C×+D where × is the distance along the stem and A, B, C and D are constants.
The curve drawn is the resulting prediction of speed along that stem. Also shown in FIG. 3 as the stepped line are speeds subsequently measured in the sequence of logs made from that stem. Clearly in this example, a combination of reference information and stem-average measurement has enabled a considerable improvement to be made in velocity or stiffness estimation along the stem prior to making cuts.
A better non cubic predictive model might be of the form
V / VT =aL b M (1 −L M ) a +d
where
a, b, c and d are constants,
V is velocity of the log
V τ is velocity of the tree stem from which the log is to be derived, and
L M is the mid-point relative length of the log.
Data such as that in FIG. 3 gives confidence in the comb filter technique. Generally, the transit time deduced for a stem based on a determination of f 0 agrees within about 1 to 2% with the sum of the transit times in each log cut from that stem, each of which has been analysed by a comb filter. This agreement is very satisfactory. A speed based on the lowest resonant frequency in a stem, and simple interpretations of the log spectra, could not approach such accuracy.
Stiffness measurement is a parameter which has had recent prominence, both in regard to log and timber stiffness and the implications it has for the basic constituent fibres of the wood. Measurement of stiffness using so-called stress wave timers, that is to say electronic instruments which detect the time of flight of a sonic impulse along or across a piece of wood have been in use for many years. While it is generally accepted that they measure a quantity indicative of mechanical stiffness, for forest use, they tend to be of marginal accuracy, and relatively insensitive (due their inherent broadband nature) and therefore difficult or impossible to apply to long logs. Their fatal flaw is that they require double ended operation, i.e. detectors need to be placed at each end of the log under test. Logistically, this is unacceptable in forest use.
In 1986, Sobue demonstrated the excitation of longitudinal resonances from a log or beam which had been struck by a hammer, their detection by a single sensor, and their identification by Fourier analysis. However this process was well understood as a general analysis method in material analysis prior to that time. This development however demonstrated that single-ended testing of logs to obtain an indication of stiffness modulus was possible. In general, subsequent developments have used commercial elements such as spectrum analysers, or standard computers, which mean that true field-portability has not been achieved and it has not been possible to survey production quantities of timber.
The following describes a trail carried out to test use of the instrument of the invention for determining wood fibre characteristics. The objective of the trail was to segregate 5000 pulp logs into three classes and process each through a commercial continuous digester and evaluate the properties of the pulp which is produced.
Trial Description
5000 pulp logs were tested for sound speed transmission using the instrument of the invention described above. The logs were separated into three different classes based on sound speed:
Slow: velocity <2.80 km/s
Medium: 2.80 ≦velocity <3.30 km/s
Fast: velocity ≦3.30 km/s
The logs in each class were then chipped and processed through a 800 tonne/day Kamyr continuous digester. The three classes were processed sequentially through the digester.
Dried pulp samples were collected every 20 minutes from the Pulp Dryer while the trail was in progress. Samples of chips from the exit of the chipping plant were also collected as each sound class was being processed.
Length Weighted Fibre Length (LWFL) was measured with a Kajaani FS200 fibre analyser. Pulps were refined in the PFI Mill for 1000 revolutions and standard hand sheets prepared according to appropriate Appita standard methods. Wet Zero Span Tensile Strength (WZST) was measured with a Pulmac TS100 Tensile Tester and other hand sheet properties were measured according to Appita standards. The basic density of the chips was also measured according to the Appita standard.
Results:
The average characteristics of the three log classes and the pulps made from each are shown in Table. FIG. 11 gives a cumulative frequency distribution for sound speed, showing that the data are normally distributed. FIG. 8 plots average pulp properties (fibre length and WZST strength) for each log class against average class sound speed. Chronological plots of fibre length, WZST strength, and Tear Index are given in FIGS. 12 to 14 .
TABLE 1
Average Characteristics of the Three Log Classes and the Pulp Made from Each
Average
Average
Average
Average
Class
Basic
Log Distribution
Weight/
Average
WZST
Velocity
Density
by Class
Log
LWFL
Strength
Class
(km/s)
(kg/m 3 )
% by no.
% by wt.
(tonnes)
(mm)
(km)
Slow
2.59
389
23
34.2
0.72
2.38
13.5
Medium
3.05
400
45
43.7
0.49
2.49
14.8
Fast
3.80
429
32
22.1
0.33
2.72
16.0
Several features are apparent in these data:
average log size decreased as sound speed increased. This is an unexpected result, since small log diameter is often thought to indicates low wood density;
there is a strong relationship between average fibre length and WZST strength and average class sound speed;
average basic density correlated reasonably well with average sound speed, suggesting that when measurements for large numbers of logs are averaged, sound speed can be related to basic density;
the pulp properties obtained from the three log classes are distinctly different, which indicates that three log sorts will be commercially useful;
pulp properties are very consistent within each sound class.
Thus, log segregation has provided a useful separation of a mixed quality log supply into three, more homogeneous log groups. The pulps obtained from each log class would be suitable for different end-use applications.
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Apparatus (preferably portable) enabling a felled tree stem or log to have its stiffness characterized. The analysis is performed with best fit recognition procedure or one that emphasizes high harmonics to determine a fundamental frequency related to acoustic speed, which is indicative the stiffness characteristics of the tree stem or log. The apparatus uses a compliantly mounted accelerometer pressed against one end of the tree stem to defect reflections from the other end after impacting the first end. Also disclosed is a method of cutting a stem into logs by establishing a function that represents the nature of speed variation with distance along the stem characteristic for a species and locality. The average speed along a stem and the speed function are used to compute the likely speed at points along the stem, and then the stems are routed for cutting according to their speed.
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BACKGROUND OF THE INVENTION
The invention relates to a quick mounting system for use with a work light. More specifically, the invention relates to a mount which releasably affixes a light housing to a support structure such as stand, clamp, or other support means.
SUMMARY OF THE INVENTION
In the work light field, there are many types of halogen work lights with several common ones, being a stand light, a portable floor light, and a clamp light. A stand light, as the name suggests, uses a stand to elevate a light housing, in most instances, several feet off the ground for use. A portable floor light, on the other hand, is often placed upon a floor through the use of a base or legs which typically elevate the light no more than several inches off of the floor. A clamp light has a light housing affixed to a clamp which, in turn, may be affixed to a wide variety of objects.
The present invention provides a mounting system which allows a typical light housing to be quickly and easily mounted to any number of different support structures such as a stand, base, legs, clamp, and the like. The mounting system does this by providing a post which has a groove on the support structure. The light housing, in turn, includes a bracket which has a catch. The catch is adapted to releasably engage the post for ease of mounting and dismounting.
DESCRIPTION OF THE DRAWINGS
The novel features which are characteristic of the present invention are set forth in the appended claims. However, the invention's preferred embodiments, together with further objects and attendant advantages, will be best understood by reference to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of one embodiment of the present invention.
FIG. 2 is an exploded perspective view of the embodiment shown in FIG. 1 with the post detached from the mount.
FIG. 3 is a cross-sectional view showing the roller engaging the post.
FIG. 4 is a cross-sectional view showing how the roller is disengaged from the post.
FIG. 5 is an exploded perspective view.
FIG. 6 shows an alternate embodiment of the present innovation in which the groove is located in the catch and the roller on the post.
FIG. 7 shows the engagement between the groove and rollers for the embodiment shown in FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Set forth below is a description of what are currently believed to be the preferred embodiments or best examples of the invention claimed. Future and present alternatives and modifications to the preferred embodiments are contemplated. Any alternates or modifications in which insubstantial changes in function, in purpose, in structure or in result are intended to be covered by the claims of this patent.
As shown in FIG. 1, the present invention provides a bracket or frame 10 to which a light housing 12 (shown partially in phantom) may be secured by fasteners 14 . Also included on frame 10 is a catch 20 which is adapted to releasably engage a post 30 which is located on a support 32 which may be a pole which extends upwardly from stand (not shown), a clamp, a support base, or some other suitable support to which the light housing may be affixed. Post 30 includes a groove 34 .
Catch 20 includes a cap 21 , interior spring 22 , and outer housing 23 defining a sleeve 24 having bore 25 and inwardly directed finger 45 . Coaxially located within bore 25 is second sleeve 26 which defines a second bore 27 which is adapted to receive post 30 . Sleeve 26 is mounted to bracket 10 and includes an aperture 40 in which roller 42 rests.
In use, light housing 12 is mounted to support 32 by inserting post 30 into bore 27 located in catch 20 . As shown in FIG. 3, post 30 is inserted until roller 42 , which is urged inwardly by finger 45 , engages groove 34 . The engagement is maintained by spring 22 which is urged against cap 21 and finger 45 and maintains finger 45 in the proper spatial relationship with respect to roller 42 . Roller 42 only partially extends through wall 47 of sleeve 26 and is prevented from passing through aperture 40 since the inner diameter of aperture 40 is sized to be less than the diameter of roller 42 .
By urging roller 42 against and into groove 34 , axial movement is prevented by the coaction between the roller and groove while rotational movement is still allowed for the positioning of the light on an object to be illuminated. In addition, a plurality of rollers may be used as well for ease of rotational movement.
To disengage worklight 12 from support 32 , roller 42 is released from its engagement with groove 34 . To do this, outer sleeve 23 is actuated in a manner to remove finger 45 from its engagement with roller 42 . This causes roller 42 to travel downwardly on sloped surface 50 away from and out of groove 34 . Once roller 42 clears groove 34 , the light may be disengaged from the support.
As shown in FIGS. 6 and 7, the location of the groove and roller may be switched. As shown, catch 60 defines a bore 64 in which groove 62 is located. Post 70 , on the other hand, may include thereon rollers 72 and 74 which partially extend from the post and are adapted to be depressed into post 70 . In use, coaction between groove 62 and rollers 72 and 74 is similar to the groove/roller engagement described above. As post 70 is inserted into bore 64 , rollers 72 and 74 are urged inwardly until they coact with groove 62 . Then, the rollers spring outwardly to inhibit any further axially movement while permitting rotational movement as described above.
It should be understood that various changes and modifications to the preferred embodiments described would be apparent to those skilled in the art. Changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is, therefore, intended that such changes and modifications be covered by the following claims.
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A worklight mounting system having a post extending from a support and a light having a catch. The post is insertable into the catch and is releasably secured within the catch by the coaction between a groove and at least one roller. The coaction there between prevents axial movement while permitting rotational movement there between.
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FIELD OF THE INVENTION
The present invention is directed to an electrical generator for a gas turbine engine, and more particularly to a high-speed generator with high pole count.
BACKGROUND OF THE INVENTION
A gas turbine engine generally includes one or more compressors followed in turn by a combustor and high and low pressure turbines. These engine components are arranged in serial flow communication and disposed about a longitudinal axis centerline of the engine within an annular outer casing. The compressors are driven by the respective turbines and compressor air during operation. The compressor air is mixed with fuel and ignited in the combustor for generating hot combustion gases. The combustion gases flow through the high and low pressure turbines, which extract the energy generated by the hot combustion gases for driving the compressors, and for producing auxiliary output power.
The engine power is transferred either as shaft power or thrust for powering an aircraft in flight. For example, in other rotatable loads, such as a fan rotor in a by-pass turbofan engine, or propellers in a gas turbine propeller engine, power is extracted from the high and low pressure turbines for driving the respective fan rotor and the propellers.
It is well understood that individual components of turbofan engines, in operation, require different power parameters. For example, the fan rotational speed is limited to a degree by the tip velocity and, since the fan diameter is very large, rotational speed must be very low. The core compressor, on the other hand, because of its much smaller tip diameter, can be driven at a higher rotational speed. Therefore, separate high and low turbines with independent power transmitting devices are necessary to drive the fan and core compressor in aircraft gas turbine engines. Furthermore since a turbine is most efficient at higher rotational speeds, the lower speed turbine driving the fan requires additional stages to extract the necessary power.
Many new aircraft systems are designed to accommodate electrical loads that are greater than those on current aircraft systems. The electrical system specifications of commercial airliner designs currently being developed may demand up to twice the electrical power of current commercial airliners. This increased electrical power demand must be derived from mechanical power extracted from the engines that power the aircraft. When operating an aircraft engine at relatively low power levels, e.g., while idly descending from altitude, extracting this additional electrical power from the engine mechanical power may reduce the ability to operate the engine properly.
Traditionally, electrical power is extracted from the high-pressure (HP) engine spool in a gas turbine engine. The relatively high operating speed of the HP engine spool makes it an ideal source of mechanical power to drive the electrical generators connected to the engine. However, it is desirable to draw power from additional sources within the engine, rather than to rely solely on the HP engine spool to drive the electrical generators. The LP engine spool provides an alternate source of power transfer, however, the relatively lower speed of the LP engine spool typically requires the use of a gearbox, as slow-speed electrical generators are often larger than similarly rated electrical generators operating at higher speeds.
However, extracting this additional mechanical power from an engine when it is operating at relatively low power levels (e.g., at or near idle descending from altitude, low power for taxi, etc.) may lead to reduced engine operability. Traditionally, this power is extracted from the high-pressure (HP) engine spool. Its relatively high operating speed makes it an ideal source for mechanical power to drive electrical generators that are attached to the engine. However, it is desirable at times to increase the amount of power that is available on this spool, by transferring torque and power to it via some other means.
Many solutions to this transformation are possible, including various types of conventional transmissions, mechanical gearing, and electromechanical configurations. One such solution is a turbine engine that utilizes a third, intermediate-pressure (IP) spool to drive a generator independently. However, this third spool is also required at times to couple to the HP spool. The means used to couple the IP and HP spools are mechanical clutch or viscous-type coupling mechanisms.
U.S. Pat. No. 6,895,741, issued May 24, 2005, and entitled “Differential Geared Turbine Engine with Torque Modulation Capacity”, discloses a mechanically geared engine having three shafts. The fan, compressor, and turbine shafts are mechanically coupled by applying additional epicyclic gear arrangements. The effective gear ratio is variable through the use of electromagnetic machines and power conversion equipment.
High-speed electric machines are almost always manufactured with low pole counts, lest the magnetic materials experience excessive core losses at higher frequencies that results in an inefficient motor design. This is primarily related to the fact that the soft material used in the vast majority of present motors is a silicon-iron alloy. It is well known that losses resulting from changing a magnetic field at frequencies greater than about 400 Hz in conventional silicon-iron based materials causes the material to heat, frequently to a point where the device cannot be cooled by any suitable means.
SUMMARY OF THE INVENTION
The present invention relates to a new system and apparatus for high-speed generators that can rotate mechanically up to a very high speed but generate electrical power based on a lower rotational speed. Usually one of the key limitations for the design of high-speed generators is the number of magnetic poles because it determines the fundamental electrical frequency and hence the power converter PWM frequency. The PWM frequency cannot exceed a certain limit in order to keep the converter switching losses within acceptable ranges. The number of magnetic poles has a significant effect on the size of the stator and rotor back iron and hence the size and weight of the generator. A generator with a high number of magnetic poles must be small and light-weight to stay within the frequency limit imposed by the converter operation. In addition, a high number of magnetic poles allows the use of tooth winding configuration that is fault-tolerant, which is a key issue in several applications especially the aerospace applications. If a machine operating at a wide speed range (in a direct-drive configuration) is only required to generate power over a narrower portion of its wide speed range, it is suggested to gear up the speed so that the number of magnetic poles are only limited by the frequency at the top speed for power generation. The machine can still mechanically rotate up to the maximum speed. Gearing up the speed will help reduce the size of the machine. Limiting the frequency at a much lower speed will allow the use of a higher number of magnetic poles, which will have a significant effect on reducing the size and weight of the machine. This machine can be of any type, e.g. switched reluctance, permanent magnet etc. Also it can be combined with other machines in the form of double-sided dual-rotor generators or single-stator dual-rotor generators for further reduction of overall system size and weight. This machine can either be a radial-flux or an axial-flux machine.
Another source of power within the engine is the low-pressure (LP) spool, which typically operates at speeds much slower than the high-pressure (HP) spool, and over a relatively wider speed range. Tapping this low-speed mechanical power source without transformation typically results in impractically large generators. The LP spool has a wider operating speed range, typically 1100-4500 rpm, however, the LP generator may require electrical power generation corresponding to about 2200 rpm during idle-descent, even though it will still be spinning up to 4500 rpm since it cannot be disengaged from the LP spool. One means of reducing the size of the generator is by stepping up the speed range, e.g., using a gear box, so that the machine is sized for a smaller torque for the same power. Since an active power converter controls the generator, practical limitations are imposed on the converter PWM frequency in order to reduce the converter switching losses and hence achieve good overall system efficiency. This limitation on the PWM frequency defines a limitation on the maximum machine fundamental frequency that in turn defines the number of magnetic poles. If this limitation is imposed at a lower speed, the machine can have a higher number of magnetic poles, resulting in a thickness reduction in the back iron of the stator and rotor portions. Hence, the overall machine size and weight is reduced, a critical parameter for aerospace applications.
The present invention is directed to a system for generating supplemental electrical power from the low-pressure (LP) turbine spool of a turbofan engine. The system includes a high-speed, high magnetic pole count, generator, a gearbox, a controller and a power converter. The LP turbine spool is mechanically coupled to the generator portion by the gearbox for driving the generator portion. The controller portion has a speed-sensing element for sensing the LP turbine speed. The controller portion disables the power converter when the generator exceeds a predetermined speed, and enables the power converter when the generator portion is less or equal to the predetermined speed. The effective load on the generator is reduced to approximately zero when the LP turbine spool exceeds the predetermined speed, permitting the generator to be electrically bound up to the predetermined speed and mechanically bound in excess of the predetermined speed.
The present invention is also directed to system for generating supplemental electrical power from the low-pressure (LP) turbine spool of a turbofan engine, the system having a generator portion for generating electrical power having a stator back iron portion and a rotor back iron portion, the stator back iron portion and the rotor back iron portion having significantly reduced thickness relative to low magnetic pole count generators. The system also includes a gearbox for driving the generator portion, a controller portion for controlling an output of the generator, a power converter for converting generator power to power a load and the LP turbine spool being mechanically coupled to the generator portion by the gearbox for driving the generator portion. Further the system includes the controller portion in electrical communication with a speed-sensing element for sensing a speed of the LP turbine spool. During operation of the engine, the controller portion is configured to disable the power converter in response to the speed of the generator portion exceeding a predetermined speed, and to enable the power converter when the speed of the generator portion does not exceed the predetermined speed, such that the effective load on the generator portion is reduced to approximately zero when the LP turbine spool exceeds the predetermined speed.
An advantage of the present invention is the use of a number of magnetic poles that is greater than conventional related devices that make feasible concentrated and isolated armature windings that exhibit increased fault tolerance. For even further reduction of overall generator weight, the high-speed generator can be combined with other HP spool generators in the form of double-sided dual-rotor or single-stator dual-rotor configurations.
Another advantage is the ability to extract electrical power from the LP spool and combination of HP and LP generators, to provide significant weight and size reduction in the generator.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view schematic illustration of an exemplary aircraft turbofan gas turbine engine.
FIG. 2 is a diagrammatic representation of the generator drive train of the present invention.
FIG. 3 is a diagram of the active and passive speed ranges of the generator.
FIG. 4 is a schematic representation of a low-pole count prior art permanent magnet machine.
FIG. 5 is a schematic representation of a high-pole count permanent magnet machine of the present invention.
FIG. 6 is a schematic representation of a low-pole count prior art permanent magnet machine with distributed overlapping windings.
FIG. 7 is a schematic illustration of a high-pole count permanent magnet machine of the present invention having concentrated non-overlapping windings.
FIG. 8 is an alternate embodiment of the high speed, high pole count generator configured in combination with another generator driven by the HP turbine.
DETAILED DESCRIPTION OF THE INVENTION
Shown in FIG. 1 is an exemplary turbofan engine 10 having a generally axially extending axis or centerline 12 generally extending in a forward direction 14 and an aft direction 16 . The bypass turbofan engine 10 includes a core engine 18 (also called a gas generator) which includes a high pressure compressor 20 , a combustor 22 , and a high pressure turbine (HPT) 23 having a row of high pressure turbine blades 24 , all arranged in a serial, axial flow relationship. High-pressure compressor blades 64 of the high-pressure compressor 20 are fixedly connected in driving engagement to the high pressure turbine blades 24 by a larger-diameter annular core engine shaft 26 which is disposed coaxially about the centerline 12 of the engine 10 forming a high pressure spool 21 .
A combustor 22 in the core engine 18 mixes pressurized air from the high-pressure compressor 20 with fuel and ignites the resulting fuel and air mixture to produce combustion gases. Some work is extracted from these gases by the high-pressure turbine blades 24 causing the blades 24 to rotate, and by this rotation driving the high-pressure compressor 20 . The combustion gases are discharged from the core engine 18 into a power turbine or low-pressure turbine (LPT) 27 having a row of low-pressure turbine blades 28 . The low-pressure turbine blades 28 are fixedly attached to a smaller diameter annular low-pressure shaft 30 that is disposed coaxially about the centerline 12 of the engine 10 within the core engine shaft 26 forming a low-pressure spool 29 . The low-pressure shaft 30 rotates axially spaced-apart first and second stage fans 31 and 33 of an engine fan section 35 . The first and second stage fans 31 and 33 include first and second stage rows of generally radially outwardly extending and circumferentially spaced-apart first and second stage fan blades 32 and 36 , respectively.
A fan bypass duct 40 circumscribes the second stage fan 33 and the core engine 18 . Core discharge airflow 170 is discharged from the low pressure turbine 27 to mix with a bypass airflow 178 discharged from the fan bypass duct 40 through a rear variable area bypass injector (VABI) 53 . Mixing takes place in a tail pipe 69 in which exhaust flow is formed, which is discharged through a variable area exhaust nozzle 122 . An optional afterburner 130 may be used to increase the thrust potential of the engine 10 .
Referring next to FIG. 2 , an electromagnetic generator 50 of the present invention is coupled with a gearbox 44 through a connecting shaft 46 . The gear box 44 is driven by LP spool 30 through a power take-off (PTO) 42 . The ratio of the gear box 44 is designated as (x). The ratio x is normally a multiplier in the range of five to ten, although the range may be higher or lower for specific applications if so required. The electromagnetic generator is designed to rotate mechanically at speeds up to 4500×revolutions per minute (rpm). During idle descent of an aircraft, when the engine 10 is operating in a range of 1100 rpm to 2200 rpm, the generator 50 is required to generate electrical power up to 2200×rpm. During normal flight operation the engine 10 operates in a higher speed range of 2200 rpm to 4500 rpm.
When the generator 50 is driven by gearbox 44 at speeds in excess of 2200×rpm, a generator controller 52 disables a power converter 54 connected to the generator output, for example, by using contactors or by disabling gate signals to semiconductor devices within the power converter, effectively reducing the load 56 on the generator 50 to zero. This allows the machine to operate at high speeds while at the same time having a high number of magnetic poles, and thereby preventing the generator 50 from exceeding the fundamental frequency limit at 2200×rpm. The fundamental frequency limit is imposed by the maximum practical pulse width modulated (PWM) frequency that can be achieved in the electrical active power converter. Depending on the power level, the limit on the PWM frequency is set based on the switching capabilities of the semiconductor devices used as well as the available thermal management of the power converter. The switching losses increase in proportion to the PWM, thus affecting the power converter and system efficiencies. Also, higher PWM frequency generates more heat, and thus requires greater cooling capacity. The high number of magnetic poles allows the use of concentrated isolated armature windings that are fault-tolerant in nature.
FIG. 3 is a diagram showing the speed range in which there is active generation versus the speed range in which the generator 50 is in a passive mechanical rotation mode. The active speed range 200 preferably occurs between 100× and 2200×, which as indicated above, is the normal operating range of the engine 50 during idle descent. The passive speed range 202 is above 2200×, up to about 4500×, which is the engine speed during normal flight.
In the embodiment shown in the figures the generator 50 is a permanent magnet, but this generator 50 may be any type of suitable generator such as, but not limited to, e.g., switched reluctance, permanent magnet, wound-field, and other configurations, as well as a radial-flux or axial-flux machine. Also the generator 50 can have any number of phases.
Referring next to FIGS. 4 and 5 , which respectively show a prior art stator and rotor, and the stator and rotor of the present invention, the reduced size of the stator and rotor back iron is illustrated. In FIG. 4 , a low-pole count machine 60 is shown having twelve slots 62 and four poles 64 . The slots are defined by adjacent tooth portions 67 . The poles 64 are affixed to the rotor back iron 68 a , and the slots 62 receive pole windings (not shown), which are coiled around stator tooth portions 67 . The tooth portions 67 extend radially inward from stator back iron 68 a . By contrast, in FIG. 5 , a high-pole count generator 50 of the present invention has twelve slots 62 and ten poles 64 . The stator back iron 66 b and the rotor back iron 68 b are significantly reduced in thickness in the high-pole count generator 50 , relative to low-pole count generator 50 . The reduced size is achievable due to the inverse relationship between the number of poles and the magnetic flux per pole, i.e., as the number of poles gets higher, the magnetic flux/pole gets lower. The lower flux/pole requires less back iron to accommodate the same magnetic flux density.
Referring next to FIGS. 6 and 7 , an example of a prior art machine and a high pole count generator are shown for comparison purposes. In the low-pole count machine of FIG. 6 , distributed overlapping windings of prior are shown and the distributed overlapping windings of the present invention are shown. Phase windings designated A, B and C are shown as overlapping one another. For example, phase winding A is connected between slots (s 1 ) and (s 4 ); phase winding B connected between slots (s 2 ) and (s 11 ); and phase winding C connected between slots (s 3 ) and(s 6 ). Since each phase is connected between non-adjacent slots, there is overlap in the flux paths circulating in the respective stator back iron 66 and tooth portions 67 . By contrast, FIG. 7 illustrates the high-pole count machine 50 . The phase windings in generator 50 are concentrated with phase windings A, B and C connected between adjacent slots, and thus providing non-overlapping, fault-tolerant stator windings. The non-overlapping, concentrated phase windings A, B and C improve the machine fault-tolerance because there is minimum coupling between the various phases. For example, in case of a fault in phase A, phases B and C will not be significantly affected, and the machine can still continue to produce a useful level of power, and the machine could produce the rated power if the machine phases were rated above the actual rated power. Referring to FIG. 8 , the high-speed LP generator 50 can be part of a combination machine 80 , having one or more HP spool generators 82 in the form of double-sided dual-rotor or single-stator dual-rotor configurations. The double-sided dual rotor configuration permits significant reduction in the overall frame size and cooling equipment sizes, as well as reduced weight. Further reduction in the size and weight of the shared stator yoke may be achievable, depending on the vector summation of the magnetic fluxes present in the dual machine configurations.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
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A system for generating supplemental electrical power from the low-pressure (LP) turbine spool of a turbofan engine includes a high-speed, high magnetic pole count, generator, a gearbox, a controller and a power converter. The LP turbine spool is mechanically coupled to the generator portion by the gearbox for driving the generator portion. The controller portion has a speed-sensing element for sensing the LP turbine speed. The controller portion disables the power converter when the generator exceeds a predetermined speed, and enables the power converter when the generator portion is less or equal to the predetermined speed. The effective load on the generator is reduced to approximately zero when the LP turbine spool exceeds the predetermined speed, permitting the generator to be electrically bound up to the predetermined speed and mechanically bound in excess of the predetermined speed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to loading dock equipment and in particular to dock levelers that are used to span the distance between a loading dock and the bed of a vehicle. Specifically, it deals with an improved mechanical latch for the lip of a dock leveler.
2. Prior Art
A conventional dock leveler has a deck assembly which typically stores in a position level with the dock floor, and has a pivoting lip assembly which extends outward to rest on the vehicle which is being loaded. The lip must hinge downward approximately 90 degrees for the lip to be removed from the vehicle and to store the dock leveler with the lip hanging in a pendant position. To move the dock leveler from the stored position to the operative position, the leveler is raised, the lip is extended from the pendant position and the leveler is then lowered until it is supported by the lip resting on the transport vehicle. The use of various mechanisms as a mechanical latch to hold the lip in the extended position until it rests on the transport vehicle is well known in the industry. U.S. Pat. No. 2,974,33 discloses a pawl mounted to the dock leveler engaging a lug on the lip. U.S. Pat. No. 3,249,956 discloses a releasable lip latch that is supported by a spring which will yield to allow the lip to fold if it is inadvertently struck by a backing truck. Both U.S. Pat. No. 3,662,416 and U.S. Pat. No. 4,398,315 show over-center toggle mechanisms as a latch which is yieldable to allow the lip to fold if it is inadvertently subjected to an excessive downward load.
U.S. Pat. No. 4,937,906 discloses a lip counterbalance spring attached to the frame instead of the deck as is conventional in this technology. The purpose is to provide extra force to extend the lip. The advantage of this system is that the lip is at least partially counterbalanced throughout the operating range of the leveler. Another more complicated system is disclosed in U.S. Pat. No. 6,112,353 disclosing a yieldable lip latch.
A major limitation of prior art mechanical lip latches has been that the lip latch does not automatically disengage and allow the lip to fall to the pendant position if the lip is extended when a transport vehicle is not present and when safety legs or cross traffic legs are engaged. Safety legs or cross traffic legs are well known in the dock leveler industry and are used to limit the distance that the deck will fall if the transport vehicle inadvertently pulls away when the leveler is supported by the lip resting on the vehicle. However the presence of safety legs can cause problems for prior art mechanical lip latches. Several designs including U.S. Pat. No. 3,662,416 and U.S. Pat. No. 5,475,888 disclose a means to release the lip latch when the dock leveler descends to its lowest position. However when safety legs or cross traffic legs are engaged, the dock leveler is prevented from descending to its lowest position and the latch will remain engaged until the lip is manually lifted to allow the latch to release. A second problem with mechanical lip latches is referred to in the industry as “stump out” and occurs when the bed of the transport vehicle is lower than the lip when the safety legs engage the frame of the leveler. Unless the dock operator notices the problem and retracts the safety legs, the lip will be supported by the lip latch and not by the bed of the vehicle. A fork truck driven over the lip will force it down and cause severe damage to the lip latch.
One attempt to address this problem has been the use of a viscous damper commonly referred to as a “hydrashock” to replace the lip latch. Such a device is shown in U.S. Pat. No. 5,323,503. The lip is able to freely extend but the rate of fall of the lip is retarded by the viscous resistance of the damper. Thus if the lip is left extended without the support of a transport vehicle, the lip slowly falls by gravity. While eliminating some of the problems associated with mechanical lip latches, the viscous damper has its own significant limitations. The viscosity of the oil in the damper changes with temperature. As the viscosity decreases in warm weather the rate of fall of the lip increases and the lip may not remain extended long enough to properly engage the bed of the transport vehicle. Conversely as the viscosity increases in cold weather, the rate of fall of the lip may be so slow that it impedes the ability to move the leveler from the transport vehicle to the stored position with the lip pendent. Most dock levelers with such devices provide multiple mounting positions of the damper so that the force resisting lip falling may be modified for large changes in ambient temperature.
Another attempt to provide a yieldable latch is set forth in U.S. Pat. No. 4,398,315. The configuration disclosed is a latch that releases by buckling within the link to the lip rather than by a latch mounted to the dock leveler. Another proposed solution is found in U.S. Pat. No. 6,112,353 which employs a yieldable lip latch with a compensating link supporting the lip bellcrank.
Dock levelers use various means to raise the deck and extend the lip. Dock levelers which are upwardly biased with springs are typically “walked down” from the elevated position by dock worker placing his weight on the deck and the rate of decent is relatively rapid. Dock levelers which use powered means such as an electric actuator, hydraulic cylinder or inflatable bag to raise the leveler have a slower rate of decent. While the viscous damper may provide satisfactory performance for a “walk-down” type of mechanical leveler, it is much less suitable for use with power actuated levelers having a slower rate of descent. If the viscous damper were stiff enough to hold the lip extended until the leveler lowered the lip to the transport vehicle then an unacceptably long time would be required to allow the lip to fall while restoring the leveler.
SUMMARY OF THE INVENTION
This invention is a mechanical lip latch that automatically disengages at multiple positions of deck height depending on whether the safety legs are engaged. The latch is disengaged at the lower limit of downward travel of the dock leveler. The lower limit is determined by whether the safety legs are engaged or retracted. The latch also has multiple positions of engagement to ensure that the lip is supported even if it is not fully extended. The latch is also designed to yield and disengage to protect it from damage if excess force is applied to the lip.
The first preferred embodiment has a lip extension structure suited for the faster activation speed of an upwardly biased “walk down” dock leveler. The second preferred embodiment has a lip extension method better suited for the slower activation speed of a powered up, a downwardly biased dock leveler. In each of these embodiments the ability to vary the lip tension is a significant benefit. For example the ability to increase the tension may be limited so that the lip can fall when the leveler is raised from a high truck.
In the third preferred embodiment a single lip spring is attached to the deck to maintain support for the lip and additionally is releasably attached to the frame. This spring is engaged to the frame only when the lip nearly fully pendant and therefore the spring tension may be increased as the deck is raised to extend the lip without the necessity of using a lip cam as in the second preferred embodiment. This embodiment also uses a lip latch which is biased toward the release position only when the deck is lowered to the working position. Thus a second spring to overcome the release spring when the deck is raised is unnecessary.
In the first and second preferred embodiments the lip spring tension is varied but the increase in tension has a limit or else the lip may not fall when the leveler is raised from the bed of a truck that is high. In the third embodiment a single lip spring is employed, attached to the deck to maintain support for the lip. It is releasably attached to the frame. The spring is engaged with the frame only during the period of time when the lip is nearly fully pendant and therefore the spring tension may be sufficiently increased as the deck is raised to extend the lip without requiring the lip cam of the second embodiment. The third embodiment also has a lip latch which is biased toward to release position only when the deck is lowered to the operative position and thus does not require a second spring to overcome the force of the release spring.
In accordance with this invention there is a provision for a multi-position latch trip. This allows the release of a mechanical lip latch at multiple positions of deck height as a function of the deployment state of the safety legs.
This invention will be described more completely by reference to the drawing and the description of the preferred embodiments that follow.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional side view of the first preferred embodiment of this invention with the leveler raised and the lip in the pendant position;
FIG. 2 is a sectional side view of the first preferred embodiment of this invention with the leveler raised and the lip held by the lip latch in a partially extended position;
FIG. 3 is a sectional side view of the first preferred embodiment of this invention with the leveler raised and the lip held by the lip latch in a fully extended position;
FIG. 4 is a sectional side view of the first preferred embodiment of this invention with the leveler lowered to an operative position and the lip latch deflected by an external force on the lip;
FIG. 5 is an exploded view showing the safety legs, lip latch trip rod and trip bar;
FIG. 6 is a sectional side view of the first preferred embodiment of this invention with the leveler lowered to rest on the safety legs and the lip latch disengaged;
FIG. 7 is a sectional side view of the first preferred embodiment of this invention with the safety legs retracted and the leveler almost fully lowered;
FIG. 8 is a sectional side view of the first preferred embodiment of this invention with the leveler fully lowered and the lip latch disengaged;
FIG. 9 is a partial sectional side view of the second preferred embodiment of this invention with the leveler raised and the lip in the pendant position;
FIG. 10 is an enlarged partial sectional view of the latch assembly of the second preferred embodiment of this invention;
FIG. 11 is a partial sectional side view of the second preferred embodiment of this invention with the leveler raised and the lip held by the lip latch in a partially extended position;
FIG. 12 is a partial sectional side view of the second preferred embodiment of this invention with the leveler fully lowered and the lip latch disengaged;
FIG. 13 is a sectional side view of the third preferred embodiment of this invention with the lip extended and resting on a transport vehicle;
FIG. 14 is an enlarged view of the latch bar;
FIG. 15 is an enlarged view of the hook assembly for the lip spring;
FIG. 16 is a sectional side view of the third preferred embodiment of this invention with the deck raised to remove the lip from the transport vehicle;
FIG. 17 is a partial sectional side view of the third preferred embodiment of this invention with the lip latch forcing the hook into engagement with the frame;
FIG. 18 is an enlarged view of the latch release rod;
FIG. 19 is a partial sectional side view of the deck raised and the hook providing increased tension for the lip spring;
FIG. 20 is a sectional side view of the third preferred embodiment of this invention with the leveler lowered to an operative position and the lip latch deflected by an external force on the lip;
FIG. 21 is a partial sectional side view of the third preferred embodiment of this invention with the leveler fully lowered and the lip latch disengaged.
FIG. 22 is a perspective view of the lip latch of the fourth preferred embodiment of this invention;
FIG. 23 is a sectional side view of the fourth preferred embodiment of this invention with the leveler raised and the lip held by the lip latch in an extended position; and
FIG. 24 is a sectional side view of the fourth preferred embodiment of this invention with the with the leveler lowered to the working range, the lip held by the lip latch in an extended position, and the lip latch spring biased toward the disengaged position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 through 8 the essential components of the first preferred embodiment of this invention will be described, it being understood that a typical dock leveler has other constructional features, not illustrated. A loading dock is shown with a driveway approach 1 , a dock face 2 , and a dock floor 3 with a recessed pit 4 . A transport vehicle 5 is shown in front of the dock. The dock leveler 10 is typically mounted in the pit 4 . A frame has horizontal members 14 and a vertical brace 15 both of which rest in the pit. The leveler frame also has stop blocks 16 and lip keepers 17 at the forward end of the horizontal members 14 . A trip plate 18 , shown in broken lines in FIG. 1, is attached to the far side of one horizontal member 14 at a predetermined distance below the top of the stop block 16 . The leveler 10 has a deck 20 which has a top plate 21 , a plate 22 that forms a front header and a plate 23 that forms a rear header. Deck beams 24 attached to the top plate and header bars provide structural strength to the assembly. The deck 20 is pivoted to the frame at pivot 25 .
A lip 30 is pivoted to the deck on a pin 26 inserted in hinge tubes 27 attached to the front header bar 21 and hinge tubes 32 attached to the lip plate 31 . Control arms 33 are attached to the lip plate 31 . Although not illustrated, the leveler is held horizontal in the stored position with the lip 30 in the pendant position and retained in the lip keepers 17 . The lifting of the dock leveler to the position shown in FIG. 1 may be accomplished by any means including mechanical linkage and springs, electric actuator, hydraulic cylinder or inflatable bag. Such is not material to the functioning of this invention.
Two pairs of brackets 29 are attached to the front header plate 22 to carry the safety legs 70 on pivot pins 76 . As shown in FIG. 5 the safety legs comprise two vertical bars 71 . Each bar 71 is attached to a pivot boss 73 by an arm 72 . A cross bar 74 joins both vertical bars 71 to ensure that they move in and out of engagement together. One bar 71 carries a pin 75 to control the lip trip mechanism that will be described later. When in the forward position the vertical bars 71 are placed between the front header plate 22 and the stop blocks 16 to limit the downward travel of the deck 20 as shown in FIG. 6 . The safety legs 70 are urged forward to the operative position by a spring, not illustrated. To allow the deck to fall lower the safety legs must be manually retracted, typically by the operator pulling on a chain that is also not illustrated.
The deck 20 also carries a support bar 27 with a pivot pin 28 . A crank assembly 35 pivots on the pin 28 and carries pins 36 and 37 . A bar 40 is attached at one end to the pin 36 and at the other end to the lip control arms 33 by a pin 38 . A spring 41 is attached to the pin 37 on the crank assembly 35 by an adjusting bolt 44 and a nut 45 . The other end of the spring 41 is attached to two chains 42 and 43 which are attached to the deck 20 and a vertical frame brace 15 respectively.
As shown in FIG. 4, when the leveler is lowered to an operative position, near horizontal, the chain 43 is slack and the spring 41 is held by chain 42 attached to the deck 20 . The adjusting bolt 44 is positioned by the nut 45 to tension the spring 41 so that most of the weight of the lip 30 is counterbalanced. The tension of the spring must allow the lip to fall by gravity to the pendent position for storing.
Referring now to FIGS. 1, 2 and 3 , rotation of the deck 20 to the raised position causes the chain 43 to increase the tension of the spring 41 and thereby provide greater assistance in rotating the lip 30 to the extended position.
Referring now to FIGS. 1 through 8 the operation of the first preferred embodiment of the lip latch and extension mechanism will be described. As shown in FIG. 1, a latch bar 50 pivots on the pin 36 of the crank assembly 35 . One end of the latch bar 50 has a notch that provides two engagement surfaces 51 and 52 . The other portion of the latch bar 50 carries a release arm 53 and a pin 54 . A latch bracket 55 is attached to the deck and has a slotted opening which guides the end of the latch bar 50 yet allows some limited vertical travel. A latch plate 60 is attached to the latch bracket 55 by a bolt 56 , nut 57 and spring 61 . A chain 65 has one end attached to the bar 40 and the other end to a spring 66 which is then attached to the frame member 14 . A spring 67 has one end attached to the chain 65 and the other end attached to the pin 54 on the latch bar 50 . As the dock leveler is lifted toward the position shown in FIG. 1 the chain 65 is stretched taut and pulls the front of the bar 40 against the pin 38 , causing the lip 30 to rotate rapidly towards the extended position. The spring 66 stores energy and limits the force exerted on the chain 65 . The chain 65 and spring 66 also limit the upward travel of the deck 20 . Because the latch bar 50 heavier than the control arm 53 gravity urges the latch bar to fall out of engagement. The spring 67 is pulled taut by the chain 65 and causes the latch bar 50 to rotate clockwise into engagement with the latch plate 60 .
As the lip 30 approaches the extended position shown in FIG. 2 the line of the force exerted on the pin 38 moves much closer to the lip pivot pin 26 and the rotational moment exerted by the chain on the lip is greatly reduced. The lip 30 is urged toward the fully extended position by rotational inertia and by the force exerted on the lip bar 40 by the lip spring 41 acting on the crank assembly 35 . Because resistance to extension of the lip is dependent on the factors such as wear, debris and lack of lubrication, the energy available may not always be sufficient to fully extend the lip. FIG. 2 shows the lip 30 almost fully extended with the surface 51 of the latch bar 50 engaging the latch plate 60 . Although not fully extended, the lip 30 is still held in a position where it can properly engage the bed of a transport vehicle. Without the alternate latch position provided by the surface 51 , the lip would fall back to the pendant position as the deck is lowered. FIG. 3 shows the lip 30 fully extended with the surface 52 of the latch bar 50 engaging the latch plate 60 . Because the tension of the spring 41 is increased when the deck 20 is fully raised, the weight of the lip 30 may not be sufficient to overcome the spring 41 and hold the latch bar 50 in contact with the latch plate 60 .
The spring 67 maintains the latch bar 50 in the engaged position. As the deck 20 is lowered and the tension of both springs 41 and 67 is reduced and gravity urges the latch bar 50 to fall out of engagement with the latch plate 60 . The weight of the lip 30 acting on the bar 40 holds the end of the latch bar 50 against the latch plate 60 and the lip 30 is prevented from falling. When the deck 20 lowers and the lip 30 is supported by a transport vehicle, the load is removed from the latch bar 50 and it falls out of engagement with the latch plate 60 allowing the lip to fall when the dock leveler is stored.
FIG. 4 illustrates the dock leveler with the lip 30 extended and an external force “F” exerted essentially horizontally on the end of the lip. The spring 61 has sufficient compression to withstand the force exerted on the latch bar 50 by the weight of the lip 30 . When the force on the latch bar 50 exceeds the compression load of the spring 61 the spring will deflect and allow the latch plate 60 to rotate. The end of the latch bar 50 will then slip out of engagement with the latch plate 60 and the lip 30 will fall pendent.
The components that automatically disengage the lip latch 50 will now be described. As shown on FIG. 5 a trip bar 80 has a formed member 81 with its rearward end attached to a pivot boss 82 . An angle bracket 83 is attached near the forward end of the member 81 . A control surface 84 is formed into the middle part of the member 81 . FIG. 5 also shows a trip bar 85 that has a pivot hole 86 and an elongated hole 87 . As shown in this exploded view, the end of the rod 81 engages the hole 86 to carry the trip bar 85 . The pin 75 on the safety leg assembly 70 engages the elongated hole 87 in the trip bar 85 .
As illustrated in FIGS. 1, 2 and 3 the trip rod pivots on pin 28 . The forward end of the trip rod 80 is supported by the trip bar 85 which is supported at the top of the elongated hole 87 by the pin 75 on the safety legs 70 .
FIG. 6 illustrates how the lip latch is automatically disengaged as the deck 20 is lowered and the safety legs 70 rest on the stop blocks 16 . In FIGS. 1 through 4 the vertical position of the stop bar 85 is determined by the pin 75 on the safety legs 7 supporting the top of the elongated hole 87 . FIG. 6 has the stop block 16 cut away to show the stop plate 18 attached to the frame member 14 .
As the deck 20 falls the lower end of the trip bar 85 rests on the trip plate 18 . Thus the forward end of the trip rod 80 is held at a predetermined height above the trip plate 18 as the deck 20 is lowered to rest on the safety legs 70 . As the deck 20 moves down the trip rod 80 rotates upward relative to the deck 20 . The control surface 84 on the trip rod 80 engages the pin 54 on the latch bar 50 forcing the control arm 53 upward and the end of the latch bar 50 downward and out of engagement with the latch plate 60 . The lip 30 is now free to fall to the pendent position.
FIG. 7 illustrates the condition where the dock leveler with the safety legs moved to a retracted position. The pin 75 on the safety legs 70 causes the trip bar 85 to rotate rearward and expose the angle bracket 83 . Thus, as the deck 20 falls to the fully lowered position shown in FIG. 8, the trip bar 85 does not engage the trip plate 18 and the lip latch does not disengage prematurely. However when the deck 20 is fully lowered the angle bracket 83 engages the trip plate 18 and this causes the lip latch 50 to disengage from the latch plate 60 as described herein.
A second preferred embodiment of the invention is illustrated in FIGS. 9, 10 , 11 and 12 . This embodiment is better suited for a powered dock leveler where the rate of lifting the deck is much slower and there is insufficient rotational inertia of the lip to ensure that it is fully extended. With the exception of the lip latch and release components, the dock leveler has the same components as the first preferred embodiment.
FIG. 9 shows a roller 88 on the pin 28 . A latch bar 90 pivots on the pin 38 . The latch bar 90 has a cam surface 91 , a stop surface 92 and a latch surface 93 . The chain 65 is attached to the latch bar 90 rather than to the lip bar 40 as in the first preferred embodiment. The trip rod 180 is similar to the trip rod 80 of the first preferred embodiment except for having a different formed shape.
In FIG. 10 the latch housing 95 and spring housing 96 are mounted to the deck 20 . A latch assembly 100 has an adjustable bolt 101 , flange 102 and latch block 103 which is free to move axially in the latch housing 95 . A latch spring 97 is supported in the spring housing 96 and acts against a nut 98 to urge the flange 102 of the latch assembly 100 against the end of the latch housing 95 . The latch housing 95 also carries a latch release spring 99 .
When the lip is in the pendent position as shown in FIG. 9, tension in the chain 65 acts on the latch bar 90 to pull down on the pin 38 and cause the lip 30 to rotate. As the lip approaches the extended position shown in FIG. 11 the line of force exerted on the pin 38 moves much closer to the lip pivot pin 26 and the rotational moment exerted by the chain 65 on the lip 30 is greatly reduced. The lip 30 is urged toward the fully extended position shown in FIG. 11 by force exerted on the lip bar 40 by the lip spring 41 acting on the crank assembly 35 and by the cam surface 91 bearing on the roller 88 . Any increase in resistance to extension of the lip caused by factors such as wear, debris and lack of lubrication may be overcome by increasing the tension on the chain 65 . The lip 30 is fully extended when the stop surface 92 of the latch bar 90 contacts the roller 99 . The stop surface 92 also deflects the latch release spring 99 . The latch surface 93 is positioned against the end of the latch block 103 .
As in the first preferred embodiment, in this embodiment, the weight of the lip 30 may not be sufficient to overcome the spring 41 and hold the latch bar 90 in contact with the latch block 103 . The spring 67 maintains the latch bar 90 in the engaged position until the deck 20 has lowered. The tension of the spring 41 decreases and the weight of the lip 30 is sufficient to hold the latch surface 93 against the end of the latch block 103 . When the deck 20 lowers and the lip 30 is supported by a transport vehicle, the load is removed from the latch bar 90 . Because forward travel of the latch block 103 is limited by the flange 102 bearing against the end of the housing 95 , the latch bar 90 moves away from the latch block 103 . The release spring 99 lifts the end of the latch bar out of engagement and the lip is free to fall. The latch spring 97 has sufficient compression to withstand the force exerted by the weight of the lip 30 acting on the latch bar 90 . However an external force exerted on the end of the lip will cause the latch spring 97 to deflect. The cam surface 91 acting on the roller 88 will cause the latch arm 90 to be lifted out of engagement with the latch block 103 and the lip will be free to fall.
FIG. 12 illustrates how the lip latch is automatically disengaged as the deck 20 is lowered and the safety legs 70 rest on the stop blocks 16 . As in the first preferred embodiment, in this embodiment, the lower end of the trip bar 85 contacts the trip plate causing the trip rod 80 to rotate upward as the deck 20 is lowered. The trip rod 80 engages the bottom surface of the latch bar 90 forcing the end of the latch bar out of contact with the latch block 103 and allowing the lip 30 to fall by gravity. As in the first embodiment, when the safety legs 70 are retracted the pin 75 on the safety legs 70 causes the trip bar 85 to rotate rearward and expose the angle bracket 83 . Thus as the deck 20 falls to the fully lowered position the angle bracket 83 engages the trip plate 18 and causes the lip latch 50 to disengage from the latch plate 60 as described previously.
A third preferred embodiment of the invention is illustrated in FIGS. 13 through 21. This embodiment is also suited for a powered dock leveler where the rate of lifting the deck is much slower and there is insufficient rotational inertia imparted to the lip 30 by the lip chain 65 to ensure that the lip is fully extended. FIG. 13 shows a dock leveler with the lip 30 resting on a transport vehicle 5 . The frame member 15 carries an anchor pin 19 . The deck 20 has a bracket 105 having a slotted hole 106 . A pair of link bars 107 are attached to the bracket 105 by a pin 108 . FIG. 15 shows a hook assembly 110 having a hook 111 and attachment holes 112 and 113 . A lever arm 114 projects upward and carries a cantilevered spring 115 . The hook assembly 110 is attached to the end of the link bars 118 by a pin 109 passing through the hole 112 . The spring 41 has one end attached to the hook assembly 110 through the hole 113 and the other end to the pin 37 on the crank 35 with the adjusting rod 44 and nut 45 . The rod 44 is adjusted so that most of the weight of the lip 30 is counterbalanced by the tension of the spring 41 while still allowing the lip to fall by gravity when the deck 20 is raised from the transport vehicle 5 . As shown in FIG. 13 the spring 41 pulls the hook assembly 110 into alignment between the end of the bracket 105 on the deck 20 and the pin 37 . The hook assembly 110 is thus held so that the hook 11 is positioned above the pin 19 on the frame member 15 .
When the deck 20 is raised to allow the lip to fall as shown in FIG. 16, the hook 111 does not engage the pin 19 . Consequently, the tension of the spring 41 is not increased as the deck 20 is raised.
FIG. 17 illustrates an enlarged partial view of the dock leveler in the stored position. A latch housing 120 has a latch plate 121 and is pivoted on the deck with a pin 122 . A bracket 123 is anchored to the deck 20 and the latch housing 120 is held in a forward position by the spring 61 , bolt 56 and nut 57 . The latch bar 125 , shown in FIG. 14, has two latch surfaces 126 and 127 . The latch bar 125 is attached to the pin 36 on the crank 35 and passes through the latch housing 120 . As shown in FIG. 13, when the lip is extended the latch bar 125 is moved forward away from the arm 114 on the hook assembly 110 . Because the lip is supported on the transport vehicle there is no load on the latch bar 125 and the spring 115 urges the latch bar 125 upward to lift the latch surfaces 126 and 127 out of engagement with the latch plate 121 . FIG. 16 shows the end of the latch bar 125 moving closer to the lever arm 114 of the hook assembly 110 as the lip 30 rotates toward the pendent position.
FIG. 17 shows the dock leveler in the stored position. When the lip 30 is fully lowered the end of the latch bar 125 contacts the lever arm 114 to rotate the hook assembly 110 and force the hook 111 to a position where it will engage the pin 19 when the deck 20 is raised.
FIG. 19 shows the deck fully raised with the hook 111 engaging the pin 19 . The deck 20 has rotated forward relative to the hook assembly 110 and the end of the spring 41 has been pulled rearward relative to the bracket 105 . The pin 108 has moved in the slotted hole 106 to allow the link bars 108 to move rearward with the spring 41 and hook assembly 110 . Thus the tensional force of the spring 41 may be increased to exceed the weight of the lip 30 so that the lip can be fully extended by the force of the spring 41 . As the lip 30 is extended the latch bar 125 moves forward and out of contact with the spring 115 allowing the latch bar to fall with the latch surface 127 placed to engage the latch plate 121 as shown in FIG. 19 .
As described in the second preferred embodiment, in this embodiment the alternate latch position 126 will allow the latch to engage even if the lip does not full extend. The cantilever spring 115 will not engage the end of the latch bar 125 until the deck 20 has lowered to a position where the hook assembly 110 no longer exerts extra tension on the spring 41 . Thus the latch bar 125 will remain in the engaged position until the weight of the lip 30 forces the latch surface 127 into contact with the latch plate 121 and the lip will remain extended. There is no requirement for a spring 67 attached to the chain 65 to hold the latch in the engaged position as in the first and second embodiments. Because the lever arm 114 is not in contact with the end of the latch bar 125 , the hook 111 will disengage the pin 19 when the deck is lowered to a working position as shown in FIG. 13 .
FIG. 20 illustrates how an external force exerted on the end of the lip 30 will cause the latch plate to disengage the latch bar 125 . The bolt 56 and nut 57 can be adjusted so that the compression of the spring 61 will support the lip 30 in the extended position. An excessive force on the lip will cause the spring 61 to deflect and allow the latch housing 120 to rotate about the pin 123 . The latch bar 125 will then be supported by the rear edge of the latch plate 121 . The front edge of the latch plate will rotate downward to disengage the latch surfaces 126 and 127 and the lip 30 will be allowed to fall.
FIG. 20 also illustrates a third embodiment of this invention that will release the lip latch 125 in multiple positions of the deck 20 depending on the position of the safety legs 70 . A latch release rod 130 is shown in FIG. 18 with a pivot boss 131 , a guide loop 132 and a contact bar 133 . FIG. 20 shows a latch trip angle 135 with a vertical leg 136 and horizontal leg 137 mounted on the frame member 14 . The release rod 130 is carried by the boss 131 mounted on the pin 75 of the safety legs 70 and the guide loop 132 carried by the latch bar 125 . When the safety legs 70 are forward in the engaged position the latch release rod 130 is held in a forward position with the contact bar 133 above the vertical leg 136 of the angle 135 . As the deck 20 lowers to bring the safety legs 70 into contact with the stop blocks 16 , the contact bar 133 will engage the vertical leg 136 and cause the release rod 130 to lift the latch bar 125 out of engagement with the latch plate 121 .
FIG. 21 shows the safety legs 70 retracted so that the deck 20 can be fully lowered. The latch release rod 130 is moved to a rearward position where the contact bar 133 will not engage the vertical leg 136 of the angle 135 . As the deck 20 reaches the fully lowered position the contact bar 133 will engage the horizontal leg 137 and cause the release rod 130 to lift the latch bar 125 out of engagement with the latch plate 121 and allow the lip 30 to fall pendent.
A fourth preferred embodiment of the invention is illustrated in FIGS. 22 through 24. This embodiment is also suited for a powered dock leveler where the rate of lifting the deck is much slower and there is insufficient rotational inertia imparted to the lip 30 by the lip chain 65 to ensure that the lip is fully extended. FIG. 22 shows the latch bar 190 having a cam surface 91 and a stop surface 92 . A latch surface 193 is recessed slightly from the cam surface 91 . A trip bar 195 projects horizontally from the side of the latch bar 190 and has a trip rod 196 attached at a downward angle.
FIG. 23 shows the deck 20 in the fully raised position and the lip 30 fully extended. The latch bar 190 has engaged the roller 88 on the pin 28 . FIG. 23 also shows a latch release spring 160 attached at the front end to a pivot bushing 161 mounted on the front header bar 22 . The rear of the latch release spring 160 is supported by a chain 162 attached to the upper lip spring chain 42 . Because the chain 42 is slack when the deck 20 is raised the latch release spring 160 does not engage the trip bar 195 on the lip latch bar 190 .
As in the first and second preferred embodiments, in this embodiment the tension of the spring 41 increases as the deck 20 is raised and the weight of the lip 30 may not be resting on the latch bar 190 . However in this embodiment the latch bar falls by gravity to the engaged position and there is no need of a spring 67 to hold the latch bar engaged as shown in FIG. 11 .
In operation, as the deck lowers the latch bar remains engaged by gravity and there is no danger that the latch bar will release accidentally even though the weight of the lip 30 may not be urging the latch surface 193 into contact with the roller 88 . As the deck 20 continues to lower the chain 43 attached to frame 15 causes the tension of the spring 41 to decrease until the spring is supported by the chain 42 attached to the deck 20 . FIG. 23 shows the deck 20 lowered to the working range. As the chain 43 is slackened the chain 42 is tightened and the rear of the latch release spring 160 is raised until it engages the trip bar 195 on the lip latch bar 190 . Because the weight of the lip 30 is resting on the latch bar 190 , the force of the latch release spring 160 cannot lift the latch bar 190 from the engaged position. However as the deck continues to lower and the end of the lip 30 is supported on the bed of the transport vehicle 5 then the spring 160 will lift the lip latch bar 190 from the engaged position and the lip 30 will fall when the deck 20 is raised. If no transport vehicle is in position as the dock 20 is lowered with the lip 30 held extended then the end of the trip bar 196 will engage the floor of the pit 4 and cause the lip latch bar 190 to disengage and allow the lip 30 to fall.
While this invention has been described with respect to the preferred embodiments, it will be apparent to those skilled in this art that modifications of this invention may be practiced without departing from the scope of the invention.
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A dock leveler having a frame and a deck pivotably mounted at one end thereof to the frame. A lip is pivotably mounted to the deck at another end thereof. A lip latch and lip extension mechanism are mounted to the leveler and comprises a lip latch pivotably connected to the deck by a crank mechanism and a latch bar pivotably connected to the crank mechanism. The latch bar has one end selectively engaging a latch bracket mounted to the deck. A bar is connected at one end to the crank mechanism and another end is operably connected to the lip. A first spring is operably connected to the crank mechanism and the frame. A second spring is operably connected to the bar and the frame. A third spring operably couples another end of the latch bar to the second spring. Upon upward movement of the deck the first spring urges the crank mechanism in a first direction to move the bar so that the lip is raised from a pendant position to an extended position and the latch bar moves based on movement of the crank mechanism and engages the latch bracket at a first point to hold the lip in the extended position and is maintained in engagement by the third spring.
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BACKGROUND OF THE INVENTION
The present invention relates to arthroplastic reconstruction of the human joints and more particularly to flexible implant resection arthroplasty of the wrist joint.
In recent years, silicone implants have been successfully employed for the restoration of function of the joints of the hand affected with rheumatoid arthritis and similar conditions. The procedures developed have generally been found to be more successful than prior attempts to restore motion by soft tissue arthroplasties and by the use of metal implants. Due to the shortcomings of prior conventional operational procedures to correct deformities of the wrist joint, flexible implants for this specific joint were developed. Proper function of the wrist joint is necessary for proper function of the hand. A stable and mobile joint is necessary for the proper transmission of muscle forces and for the normal moving and grasping of objects by the hand encountered in normal activities.
Aseptic necrosis and/or arthritis of the carpal bones, either primary or secondary to trauma, is a frequent cause of disability of the wrist joint. Surgical treatment of conditions of the wrist joint have included intercarpal fusion, wrist fusion, local resection, proximal row carpectomy, bone grafting, radial styloidectomy, radial shortening or ulnar lengthening, and soft tissue interposition arthroplasty. Fusion procedures do not provide optimum results since the stability, power and mobility of the wrist is affected even though pain is relieved. Local resection procedures, which involve the removal of an irreversibly pathological bone, are complicated by migration of adjacent carpal bones in the space left by the resection. This results in instability in the wrist joint. Metallic and acrylic implants for the replacement of carpal bones were not satisfactory due to problems relating to progression of the arthritic process, migration of the implant, breakdown of the material and absorption of bone due to hardness of the material inserted.
As a result of the shortcomings of such operative procedures, intramedullary stem silicone rubber implants were developed to replace the lunate bone of the carpal row. The implants were designed to act as articulating spacers capable of maintaining the relationship of adjacent carpal bones after excision of the lunate while preserving mobility of the wrist.
An initial attempt to develop a lunate implant resulted in an implant having essentially the same anatomical shape as the bone being replaced. This implant was developed through exhaustive anatomical shaping and sizing of cadaver bones and roentgenographic studies of a variety of hands. The lunate implant was provided in progressive sizes and concavities were more pronounced then the lunate bone replaced in an attempt to increase stability. A stabilizing stem was formed integral with the implant and fitted into the intramedullary canal of the triquetrum bone.
A second form of lunate implant was developed having a deeper concavity at the distal surface of the implant in an attempt to obtain a better fit around the head of the capitate and therefore obtain increased stability. This increased concavity was not totally satisfactory since impingement with the ligaments of the carpace resulted. Initial silicone implants were essentially anatomically reproduced equivalents to the bones being replaced. These implants included multifaceted and angled and curvilinear surfaces which represented mean averages of approximately 72 different measurements made on each of over one hundred lunate bones. It was believed that an anatomically correct implant including a deeper concavity on the distal surface which articulates with the capitate bone, would result in the most stable arthroplastic reconstruction.
SUMMARY OF THE INVENTION
In accordance with the present invention a lunate implant is provided which results in increased stability and which is not a multifaceted, complexly surfaced implant mimicking the bone replaced. Essentially, the unique lunate implant includes a planar triquetrum face having a generally U-shape in plan and including outwardly angled lateral edges, a curvilinear proximal edge and a curvilinear distal edge having a radius of curvature greater than the radius of curvature of the proximal edge and astabilizing stem extending outwardly from and perpendicular to the planar triquetrum face which is adapted to be inserted within the intramedullary canal of the triquetrum bone. The body further includes a planar scaphoid face having a configuration similar to the planar triquetrum face but having an overall length less than the length of the triquetrum face. The scaphoid face is adapted to articulate with the scaphoid bone and defines with the triquetrum face an included, acute angle from the distal to the proximal edges. A cupped, concave, smooth distal surface is adapted to articulate with the head of the capitate bone to stabilize the implant. The distal surface is less pronouncely cupped than with the prior lunate implants and includes lateral edges defined by the distal edges of the triquetrum and scaphoid faces. A proximal surface has a smooth convex shape and joins the proximal edges of the triquetrum and the scaphoid faces. The proximal surface has a decreasing or double radius between the triquetrum and the scaphoid faces.
Generally planar, dorsal and palmar surfaces extend between the dorsal lateral edges of the triquetrum and scaphoid faces and the palmar lateral edges of the triquetrum and scaphoid faces, respectively. Both the dorsal and palmar surfaces have straight distal edges and curved proximal edges smoothly joining with the proximal surface of the body. The body of the implant is substantially symmetrical about a longitudinal centerline passing through the distal and proximal surfaces and along the longitudinal centerlines of the scaphoid and triquetrum faces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, anterior view of a wrist joint showing the distal and proximal carpal rows;
FIG. 2 is a posterior view of a wrist joint showing a lunate implant in accordance with the present invention;
FIG. 3 is an elevational view showing the posterior or dorsal surface of the implant;
FIG. 4 is a perspective view of the scaphoid or lateral surface of the implant;
FIG. 5 is a plan view illustrating the distal surface of the implant;
FIG. 6 is an elevational view showing the anterior or palmar surface of the implant;
FIG. 7 is a perspective view showing the triquetrum or medial surface of the implant;
FIG. 8 is an elevational view of the triquetrum surface of the implant;
FIG. 9 is an elevational view showing the scaphoid surface of the implant; and
FIG. 10 is a plan view showing the proximal surface of the implant.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, FIG. 1 illustrates an anterior view of a wrist. The bones that make up the wrist joint include a proximal carpal row 12. The proximal carpal row is adjacent the radius 14 and the ulnar 16 of the arm and includes a scaphoid bone 18 and a lunate bone 26, a triquetrum bone 22 and the pisiform bone 24. The joint of the wrist extending along the proximal carpal row of the wrist between the distal radius is referred to as the radiocarpal joint. The wrist joint further includes a distal carpal row 28. The distal carpal row includes a trapezium bone 30, a trapezoid bone 32, a capitate bone 34 and a hamate bone 36. A midcarpal joint 38 of the wrist extends between the distal and proximal carpal rows.
Wrist movement is divided between the radiocarpal and midcarpal joints of the wrist in a relatively complex manner. Displacement of the carpal bones is necessary for bone motion. The configurations of each row of bones changes according to the position of the hand. Flexion and extension movements are fairly equally divided between the proximal and distal rows of carpal bones while ulnar and radial deviation movements occur mostly at the radiocarpal joint. Anatomical distortion of the carpal bones or loss of integrity of their ligaments or secondary stiffness affects the joints and results in wrist disability.
The carpal bones are held together by short interosseous ligaments. Ulnar collateral and radial collateral ligaments provide lateral support of the wrist. Palmar radiocarpal and dorsal radiocarpal ligaments maintain support of the carpal area. The fibers of the palmar radiocarpal ligament extend distally and obliquely from the radius, the triangular fibrocartilage and styloid process of the ulna. These ligaments define a symmetrical pattern due to insertions into the scaphoid, lunate, triquetrum and capitate bones. It is important that the integrity of the radiocarpal and ulnocarpal bands of ligaments be maintained in carpal bone surgery and that these ligaments not be interferred with or impinged on by the implant.
The lunate bone 26 articulates proximally about the radius, distally about the capitate and hamate bones, laterally about the scaphoid bone and medially about the triquetrum bone. The lunate bone has a deeply concave and crescent outline and is situated in the center of the proximal row of the carpus. The bone distal surface is deeply concave and articulates with the head of the capitate by a long narrow facet separated by a ridge from the general surface of the hamate bone. The dorsal and palmar surfaces are rough and serve as points for attachment of the ligaments. The lateral surface includes a narrow, flat, semilunar facet for articulation with the scaphoid and the medial surface includes a smooth, quadrilateral facet for articulation with the triquetrum.
Initial attempts to provide a lunate implant involved detailed empirical studies of an excess of l00 lunate bones and resulted in a series of graduated implants which were anatomically very similar to the bone replaced. While being successfully employed in arthroplastic reconstruction of the wrist joint, the stability obtained did not as closely approach that normally present in a non-defective wrist joint as was desired. In an attempt to obtain a more stable implant, the distal surface, which articulates around the capitate, was more deeply cupped. Although increasing the stability of the implant at the capitate head, this deeper cupping resulted in impingement on the ligaments and therefore did not provide a completely satisfactory solution to the problems encountered.
As illustrated in FIG. 2 and explained in detail below, the present invention provides a lunate implant generally designated 40, which is surgically positioned to articulate with the capitate bone 34, the triquetrum bone 22, the scaphoid bone 18 and the radius 14.
As seen in FIGS. 3-6, the lunate implant 40 includes a posterior or dorsal surface 42, a triquetrum face or medial surface 44, a scaphoid face or lateral surface 46, a proximal surface 48, a distal surface 50 and an anterior or palmar surface 51. Extending outwardly from and perpendicular to the triquetrum or medial surface 44 is a stabilizing stem 52. The scaphoid face 46 and the triquetrum face 44 are flat or planar and are angularly related. The surfaces 44, 46 opening from the distal surface 50 to the proximal surface 48 define an acute included angle designated a. The surfaces 44, 46, are adapted to abut against and articulate with the triquetrum and the scaphoid bones, respectively. The flat or planar surfaces, it is believed, result in an unexpected increase in the stability of the implant when compared with prior implants.
As seen in FIGS. 7 and 8, the triquetrum surface 44 has a general U-shape in plan and includes outwardly angled edges 56, 58. The edges 56, 58 define an included angle extending outwardly from a proximal edge 60 of the face to a distal edge 62 which is designated b. The proximal edge 60 of the face 44 is curved and has a radius of curvature less than the radius of curvature of the distal, curved edge 62. The stabilizing stem 52 extends outwardly from the face 44 generally perpendicular thereto and is in the shape of a truncated, tapered rectangle. The stem extends outwardly offset along the vertical centerline of the face 44, as seen in FIG. 8, towards the distal edge 62. The stem 52 is dimensioned and adapted to be inserted within the intramedullary canal of the triquetrum bone. It is presently preferred that the stem 52 be positioned on the triquetrum face since the interface between the triquetrum and the lunate has the least amount of movement in the carpal row.
As seen in FIGS. 4 and 9, the scaphoid face 46 has the same general configuration as the triquetrum face 44. However, the vertical height or longitudinal dimension of the face 46 is less than that of the face 44. The face 46 is similarly flat or planar, has a general U-shape in plan and includes lateral edges 64, 66 which extend outwardly from a proximal edge 68 to a distal edge 70. The distal edge 70 is curvilinear and has a radius of curvature greater than the curvilinear proximal edge 68. The edges 64, 66 lie in substantially the same perpendicular plane as the lateral edges 56, 58 of the triquetrum face. The scaphoid face 46 is adapted to abut and articulate with the scaphoid bone 18 as shown in FIG. 2.
As seen in FIGS. 4, 5, 6 and 7, the distal surface 50 of the implant 40 is concave and smoothly cupped in shape. The surface 50 is adapted to engage the head of the capitate bone 34 to stabilize the implant. The surface 50 has a sufficient concavity so as to provide stability but is not so deep as to impinge upon ligaments. The surface 50 includes a transverse curvature having a radius designated c and a longitudinal curvature having a radius designated d. The concavity defined by the surface 50 is substantially less than that provided by prior lunate implants. The lateral edges 72, 74 of the distal surface 50 are curvilinear in shape and are defined by the distal edges 62, 70 of the triquetrum face 44 and the scaphoid face 46, respectively. The posterior or dorsal edge and the anterior or palmar edge 76, 78 of the dorsal surface 50 are substantially straight edges.
As seen in FIGS. 3 and 4, the dorsal surface 42 of the implant is generally planar and joins the dorsal edges of the triquetrum surface and the scaphoid surface 46. The surface 42 has the shape of a truncated V in plan and smoothly joins into the proximal surface 48 of the implant.
As seen in FIGS. 6 and 7, the lunate implant body also defines a palmar or anterior surface 51 which is the mirror image of the dorsal surface 42. This surface similarly possesses a generally truncated V-shape in plan, is generally planar or flat, and smoothly joins into the proximal surface 48 of the implant body.
As best seen in FIGS. 3, 9 and 10, the proximal surface 48 is smoothly curvilinear in shape and includes a decreasing radius curve defined by two radii from the triquetrum face 44 to the scaphoid face 46. This surface includes a first radius designated e and a second smaller radius designated f. Also, as seen in FIG. 9, this surface is defined by a third, transverse radius designated g. extending between the dorsal and palmar surfaces of the implant body. Radius g is the same as the radius of curvature of the proximal edge 60 of face 44. The proximal surface 48 articulates with the radius bone 14.
In a presently existing embodiment of the lunate implant in accordance with the present invention, the angle a included by the triquetrum face and the scaphoid face is approximately 30°. The angle b included by the lateral edges 56, 58 of the triquetrum face 44 is approximately 28°. The longitudinal distance h from the proximal edge 60 of the triquetrum face 44 to the dorsal edge 62 is approximately 0.4 inches. The distance i from the proximal edge 68 to the dorsal edge 70 along the vertical centerline, as seen in FIG. 9 of the scaphoid face 46, is approximately 0.3 inches. The distance W shown in FIG. 9, which represents the length of the dorsal surface 50, is approximately 0.630 inches. The maximum distance or overall length of the implant (FIG. 3) from the dorsal surface 50 to the highest point on the proximal surface 48 along a single plane is approximately 0.53 inches.
The transverse distance between the proximal edge of the triquetrum face 44 and the proximal edge of the scaphoid 46, designated y in FIG. 3, is approximately 0.52 inches. The stabilizing stem 52 has a length of approximately 0.32 inches and tapers from a square width at its juncture with a triquetrum face of approximately 0.10 inches to a square width of approximately 0.075 inches. The radius d (FIG. 9) is approximately 0.39 inches and the radius c (FIG. 6) is approximately 0.2 inches. The radius f (FIG. 3) is approximately 0.43 inches and the radius g (FIG. 9) is approximately 0.26 inches. A plurality of implants of graduated size are preferably provided to insure a stable fit with the individual patient. Each of these implants are graduated to have the same general proportions as the preferred embodiment illustrated. For example, the ratio of the longitudinal length of the scaphoid face and the triquetrum face is approximately 0.75, the ratio of the transverse radius c to the longitudinal radius d of the distal surface is approximately 0.55. The included angle b would remain at 28° and the included angle a would remain at 30°. The ratio of the overall width w to the overall length x would be approximately 1.29. This ratio may be varied within the range of 1.08 to 1.29 and acceptable results will be obtained. The ratio of radius d to radius g may decrease within the range of 1.48 to 1.2 as the overall length increases from 0.55 inches to 0.73 inches and acceptable results will be obtained.
The implant in accordance with the present invention results in an improved fit and is firmly supported on all sides by adjacent bones. The implant in situ is analogous to a ball bearing in function and must be surrounded by a "housing". Therefore, a tight capsuloligamentous structure must be insured. When used to correct a collapsed deformity of the wrist, instability will continue unless the ligamentous structures are repaired. The stem 52 is included primarily to provide stability during the early postoperative phase.
Insertion of a lunate implant is indicated for avascular necrosis or in the case of longstanding dislocation. The implant should not be employed when the arthritic involvement is not localized in the lunate articulation if complete relief of pain is sought. In the case of longstanding dislocations and advance cases of avascular necrosis, the space for the lunate implant may be substantially reduced in size, resulting in fitting problems. Also, loss of integrity of the capsular structures due to fracture dislocation or collapsed deformity of the wrist may be a contra-indication to the implant procedure unless the carpal bone relationship is reestablished and ligaments are repaired.
A surgical procedure for implantation of the lunate involves either a dorsal, a volar or palmar incision. If a dorsal longitudinal incision is used, the wrist capsule is transversely incised between the third and fourth dorsal compartments and carefully preserved. The extensor pollicis longus tendon is retracted radially and the dissection is carried downward radial to the compartment of the extensor digitorum communis tendons. The capsule is then incised over the lunate and dissected close to the radius of the underlying carpal bones. The lunate bone is removed en bloc or piecemeal. Care must be exercised to avoid injury to the palmar, radiocarpal and ulnocarpal ligaments. The integrity of the interior capsuloligamentous structures is verified and the ligament structures are brought together with sutures to assure a firm, palmar capsulous support. An implant sizing set is then used to determine the correct size of the implant. The implant should be selected so that it will comfortably fit in the space of the resected lunate. A small curet or drill is used to make a hole in the triquetrum to accept the stem of the implant. This hole should not be larger than the stem and minimal trauma to the triquetrum bone should be allowed. The hole should be directed such that the stem placement will orient the implant in accurate anatomical relationship to the contingeous bones.
The dorsal capsule is then tightly sutured by means of an inverted knot technique. A strip of extensor retinaculum can be used to reinforce the dorsal carpal ligaments. The tendon compartments are then brought back into position so that there will be no adherence to the underlying structures. The wound is closed in layers and a small silicone, rubber drain is placed subcutaneously.
The lunate implant in accordance with the present invention is easily and relatively inexpensively manufactured with conventional molding techniques from medical grade silicone rubbers. The implant is employed with a relatively simple surgical procedure that has the potential of permitting wrist motion with increased stability from that heretofore obtained, mobility and freedom from pain. The above description should be considered as that of the preferred embodiment. The true spirit and scope of the present invention may be determined by reference to the appended claims.
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A flexible implant for replacement of the lunate bone of the wrist includes a one-piece body of resilient material defining a planar triquetrum face having a general U-shape in plan and further including a stabilizing stem extending outwardly from and perpendicular to the planar triquetrum face and a planar scaphoid face having a generally U-shape in plan extending at an angle with respect to the triquetrum face. The body further includes a cupped, concave, smooth distal surface adapted to articulate with the head of the capitate bone. The body defines a proximal surface having a smooth convex shape and extending between the proximal edges of the triquetrum and scaphoid faces. Generally planar palmar and dorsal surfaces extend between the dorsal lateral edges and the palmar lateral edges of the triquetrum and scaphoid faces.
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RELATED APPLICATION
This application claims priority to and the benefit of United Kingdom patent application number 0208480.4, filed on Apr. 11, 2002, which application is herein incorporated by reference in its entirety.
BACKGROUND
The present invention generally relates to building components and, more particularly, but not exclusively, relates to building components for roofing, in the form of inflatable cushions.
Inflatable cushions comprise two or more layers of a plastics foil material such as ETFE (ethylene tetra flouro ethylene) inflated with low pressure air. The ETFE foil cushion is restrained in a perimeter frame usually manufactured from extruded aluminium, which in turn is fixed to a support structure. As the ETFE foil cushion is inflated, the ETFE is put under tension and forms a tight drum like skin. ETFE foil cushions are sold under a number of trade names, for example Texlon. ETFE cushions of this kind are fixed to a support structure to form a cladding and are used to enclose atria or other enclosed spaces to provide a transparent or translucent roof or facade to the enclosure, as an alternative to and in a similar way to glass. A number of buildings have been built using this technology most notably the Eden project in Cornwall, England.
Whenever a space is enclosed by a cladding system, due consideration needs to be given to the acoustic properties of the cladding system and how it affects the ambience of the enclosed space. ETFE foil cushions are acoustically fairly transparent having a sound reduction index of approximately 8 dBA. This is generally beneficial to the perceived acoustics of an enclosed space as the ETFE foil cushions act as acoustic absorbers to internally generated noise in that they only reflect a small proportion of the sound energy generated back into the enclosure. When it rains, however, the rain drums on the external surface of the inflated ETFE foil cushion and generates a loud noise, which can be obtrusive to the occupants.
SUMMARY OF THE INVENTION
It is the object of the present invention to reduce the amount of noise generated by rain falling on an ETFA foil cushion.
According to the invention there is provided a building component in the form of an inflatable cushion, comprising two or more sheets of plastics foil and a relatively rigid frame surrounding and supporting the foil sheets, and liquid retaining means associated with one of the sheets. Preferably, the frame is manufactured from a metal, e.g., extruded aluminium, which in turn is fixed to a support structure. Preferably, the sheets are made from ethylene tetra flouro ethylene (ETFE). Thus, the ETFE foil cushion is fitted with a device which reduces the effects of rain generated noise by reducing the vibration of the external layer of the inflated ETFE foil cushion by dampening it with a liquid. In addition, the sound reduction index of the inflated ETFE foil cushion is increased due to the increased mass of the ETFE foil cushion due to the addition of the liquid. Preferably, two of the sheets define a space between them which is inflated with air and the frame restrains the sheets about their perimeters, thereby forming the cushion.
In one exemplary embodiment, the liquid retaining means comprises means applied to the outer most sheet of the cushion, arranged to retain rain water on the surface of the outermost sheet. The liquid retaining means may comprises a woven material, a net, or a sheet which is holed, cut, textured or embossed. Alternatively, the liquid retaining means may comprise a further sheet of plastics material overlying the outermost sheet of the cushion thereby defining a fluid-tight compartment between the further sheet and the outermost sheet, the compartment being fillable with a liquid. Preferably, the further sheet is partially fixed to the outermost sheet. The fixing may be by means of welding, gluing or stitching. The sheets may be fixed together along lines, thereby defining the compartment as a continuous channel or at individual points.
Two exemplary ways of fitting the rain suppressor to the ETFE foil cushion are also described. Firstly, an open weave fabric, net, holed or textured material is patterned or shaped to fit over the outer surface of the cushion. When it rains, water gathers on the surface of the cushion which reduces the effects of rain drumming by damping, and increases the sound reduction index of the cushion by the increase of mass through the addition of water. Secondly, the outer skin of the cushion is effectively made up of two layers of ETFE foil welded together in places to form a continuous pipe or chamber. Water is introduced between the layers of foil, which reduces the effects of rain drumming by damping and increases the sound reduction index of the cushion by the increase of mass through the addition of water.
The invention also extends to a cladding system for a building, particularly a roof, comprising a plurality of building components as described, the frames of which are attached to a structure.
A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth illustrative embodiments which are indicative of the various ways in which the principles of the system and method may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference may be had to preferred embodiments shown in the following drawings in which:
FIG. 1 is a plan view of an exemplary ETFE cushion constructed in accordance with the present invention;
FIG. 2 is a perspective cross section through the assembly of FIG. 1 ;
FIG. 3A to 3 D show four different variants of covering;
FIG. 4 is a view similar to FIG. 1 showing an alternative, exemplary embodiment;
FIG. 5 is a cross section through the assembly of FIG. 4 ;
FIG. 6 is a three dimensional view of the embodiment of FIGS. 4 and 5 ;
FIG. 7 is a section on the line A—A in FIG. 6 ;
FIG. 8 is a view similar to FIG. 4 showing another alternative, exemplary embodiment; and
FIG. 9 is a cross section through the assembly of FIG. 8 .
DETAILED DESCRIPTION
Turning now to the figures, where like reference numerals refer to like elements, FIGS. 1 and 2 illustrate an exemplary embodiment of an ETFE cushion constructed in accordance with the invention. The cushion 11 comprises three rectangular ETFE foil sheets 12 , 13 , 14 , a support frame 15 and a plenum 16 . The frame 15 is located about the perimeter of the sheets 12 , 13 , 14 and incorporates a rain suppressor. The space between the sheets 12 , 13 , 14 is inflated with air via the plenum 16 . Although shown as being rectangular, the cushion 11 could be of any convenient shape.
The illustrated rain suppressor 17 is in the form of an open weave material stretched over the outside surface of the cushion 11 . This is shown in more detail in FIG. 3 A.
The variant shown in FIG. 3B is a film or extruded material 27 with punched holes 28 , that would be stretched over the cushion 11 . The holes 28 would typically be between 0.5 mm and 3 mm across, though other sizes would be possible.
The variant shown in FIG. 3C consists of a film or extruded material 37 with small parallel cuts 38 made in it in a diamond pattern. The material is stretched to form a netlike material and then stretched over the outside surface of the cushion 11 .
The fixing may be by means of welding, gluing or stitching. The sheets may be fixed together along lines, thereby defining the compartment as a continuous channel or at individual points.
The variant shown in FIG. 3D consists of a film or extruded material 47 , which has a textured or embossed surface and which is stretched over the outside face of the cushion 11 . The function of the textured or embossed surface is to slow the passage of rain water over the surface of the cushion and clearly many textures and embossed patterns could perform this function.
The preferred material for all the variants in FIGS. 3A to 3 D is ETFE due to its long life but clearly other films woven or extruded materials are possible.
The exemplary embodiment shown in FIGS. 4 to 7 consists of a frame 55 holding an ETFE foil cushion 51 which is inflated by air via a plenum 56 and which incorporates a rain suppressor 57 as is the case in the previous embodiment and its variants. In this case, however, the rain suppressor 57 consists of a further sheet 52 of an extruded material which is partially fixed by welding, gluing or stitching to the uppermost ETFE sheet 12 to form a fluid tight compartment 53 between the two sheets 12 , 52 . The fluid tight compartment 53 is filled via a hose 59 with a distilled water.
When it rains or when the cushion 51 is required to form an acoustic barrier between two areas, fluid is introduced between the two sheets 12 , 52 to increase the mass of the cushion 51 and to damp the surface with fluid. Any fluid can be used although ideally it should be distilled water to ensure no residue is left in the compartment 53 . The fluid should be pumped although alternative methods of introducing fluid in to the rain suppressor are possible, including gravity feed, fed by rainwater, etc.
FIGS. 6 and 7 show one possible way of fixing the two sheets 12 , 52 of material together. The fluid compartment 53 takes the form of a continuous channel 58 as the two sheets 12 , 52 are fixed together on the lines indicated at 61 .
FIGS. 8 and 9 show a further exemplary embodiment similar to that of FIGS. 4 to 7 . FIG. 8 shows a frame 75 holding an ETFE foil cushion 71 which is inflated by air via a plenum 76 . The rain suppressor 77 again consists of a further sheet 72 of an extruded material but in this case, it is partially fixed by spot welding, gluing or stitching to the uppermost sheet 11 of the ETFE cushion 71 to form a fluid tight compartment 73 between the two layers. The fluid tight compartment 73 is filled via a hose 79 with distilled water.
While various embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, it will be understood that the particular arrangements and procedures disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any equivalents thereof.
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A building component for forming a roof. The component includes an ETFE foil cushion comprising sheets of ETFE foil which are held in a frame about their periphery, and which are inflated. The cushion includes a liquid retaining means to suppress rain noise.
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BACKGROUND
[0001] An optical sensor is used to identify particular materials carried on a conveyor belt. The material is launched off the end of the conveyor and travels along a trajectory path into a far bin. Particular objects identified by the optical sensor are knocked out of their normal trajectory into a different near bin via a blast of air from a high pressure air nozzle.
SUMMARY
[0002] A cross-flow air separation system comprises a conveyor configured to project material out over an end of the conveyor generally along a trajectory path into a far receiving bin. An optical sensing system is configured to identify particular objects in the projected material. The primary air ejection system, which operates perpendicular to the material flow, is configured to eject identified objects from the trajectory path into the near receiving bin. A second cross air current system is configured to generate a second airstream parallel to the material flow that reduces air resistance for the materials projected along the trajectory path. The second airstream reduces certain aeronautic phenomena that would cause some of the projected materials to unintentionally fall into the wrong receiving bin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a side view of an optical air separation system used for separating plastic containers from other objects in a material stream.
[0004] FIG. 2 shows some of the problems associated with the optical air separation system shown in FIG. 1 .
[0005] FIG. 3 is an isolated side view of a cross flow air separation system.
[0006] FIG. 4 is a more detailed side view of the cross flow air separation system shown in FIG. 3 .
[0007] FIG. 5 is another side view showing how the cross flow air separation system reduces air resistance and reduces collision friction for projected materials.
[0008] FIG. 6 shows a pneumatic transport system used in combination with the cross flow air separation system.
[0009] FIG. 7 shows another embodiment of the pneumatic transport system that uses a venturi system to compensate for downward air pressure.
DETAILED DESCRIPTION
[0010] FIG. 1 shows a schematic diagram of an optical air separation system 12 . A conveyor 24 carries different materials 26 that, in one example, may comprise Municipal Solid Waste (MSW) or may comprise primarily recyclable materials 26 referred to generally as a single stream. The single stream may include plastic, aluminum, steel, and glass containers and objects and may also include paper and Old Corrugated Cardboard (OCC). The MSW may contain these recyclable materials as well as other materials such as textiles, food waste, yard debris, wood, concrete, rocks, etc. Any MSW stream, single stream, or any other materials that may need to be separated are referred to generally below as a material stream.
[0011] It may be desirable to separate certain objects or materials from the material stream 26 . For example, plastic, aluminum, steel, and glass objects may need to be separated from other recyclable or non-recyclable materials, such as paper, Old Corrugated Cardboard (OCC), textiles, food waste, yard debris, wood, concrete, rocks, etc. Further, the different plastic, aluminum, steel, and glass objects may all need to be separated. In one example described below, polyethylene terephthalate (PET) and/or high density polyethylene (HDPE) objects 28 are separated from other materials in material stream 26 . Of course, any variety of different objects 28 may need to be separated from the rest of material stream 26 .
[0012] Theoretically based on gravity and conveyor speed, all the materials 26 would be projected from conveyor 24 at the same speed and travel generally along the same trajectory path 34 . With this information a computer system (not shown) attached to optical sensor 14 can detect and calculate the location of different objects 28 after being projected through the air off the end of the conveyor 24 .
[0013] The speed of conveyor 24 is selected so that all of the materials 26 are launched out over the end of conveyor 24 into a far bin 30 B and onto a conveyor 32 B. The optical sensor 14 is programmed via software in the computer system to detect the shape, type of material, color or levels of translucence of particular objects 28 . For example, the computer system connected to optical sensor 14 may be programmed to detect the type of plastic material associated with plastic bottles.
[0014] Any objects 28 having the preprogrammed types of materials are detected by the optical sensor 14 when passing through a light beam 16 . The computer system connected to the optical sensor 14 sends a signal activating a high pressure ejection air nozzle 20 . The ejection nozzle 20 releases a blast of air 22 that knocks the detected objects 28 downward out of normal trajectory path 34 into near bin 30 A and onto conveyor 32 A. The other materials 28 continue to travel along trajectory path 34 into the far bin 30 B and onto conveyor 32 B.
[0015] Referring to FIG. 2 , theoretically, all of the materials 26 should move along the same trajectory path 34 . However, in reality different materials 26 “fly” off of the conveyor 24 differently for several different reasons. For example, pieces of paper, cardboard, or Styrofoam 26 C may have aerodynamic characteristics that due to air resistance cause those objects to flip upward, flip downward, or just generally drift downward after being launched from conveyor 24 . The air resistance experienced by these objects (lack of aerodynamics), causes the paper, cardboard, or Styrofoam 26 C to deviate from the normal trajectory path 34 and fall short into the near bin 30 A.
[0016] The projection of objects 26 and/or air blasts 22 may also create air turbulence 42 that alters the normal trajectory path 34 of other objects 26 B. For example, the air disturbance 42 may push down, raise up, or tumble relatively light objects 26 B. This air disturbance 42 causes the objects 26 B to deviate out of the normal trajectory path 34 and unintentionally drop into the near bin 30 A.
[0017] Other objects may collide into each other while being launched from conveyor 24 . For example, an object 26 A may run into or slightly attach onto bottle 28 A while being projected from conveyor 24 . The frictional force created when object 26 A comes in contact with the bottle 28 A may cause object 26 A to deviate out of trajectory path 34 and unintentionally drop into near bin 30 A.
[0018] The optical air separation system 12 may also use large bins 30 A and 30 B to catch the different separated materials 28 and 26 , respectively. One possible disadvantage of large bins is that slight variances in the normal trajectory path 34 can cause objects to fall into the wrong bins. Accordingly, any of the trajectory disturbances described above are more likely to cause material to fall into the wrong bin.
Cross Flow Air Separation
[0019] FIG. 3 shows a cross air current system 48 that improves the consistency of material separation. The cross air current system 48 includes an air nozzle 52 , alternatively referred to as an “air knife,” that creates a cross air current 50 in a direction generally along the trajectory path 34 . The cross air current 50 reduces at least some of the air resistance that material 26 normally experiences after being projected from the conveyor 24 ( FIG. 2 ). The positive airstream provided by the cross air current helps material 26 travel along the desired trajectory path 34 , thus counteracting some of the trajectory deviation problems described above.
[0020] As described above, one cause of trajectory path deviation is the different aerodynamic characteristics of the different materials 26 . The cross air current 50 prevents these projected materials from having to fight dead air, which equates to wind resistance or lack of aerodynamics. As previously shown in FIG. 2 , dead air resistance caused certain objects such as paper, cardboard, or Styrofoam 26 C′ to flip vertically upward, flip vertically downward, or simply run out of speed after being projected off the end of conveyor 24 ( FIG. 2 ). The increased air resistance caused these objects 26 C to lose speed and incorrectly drop into near bin 30 A.
[0021] However, the cross air current 50 shown in FIG. 3 removes at least some of this dead air resistance and as a result, the paper, cardboard, Styrofoam, etc. 26 C is less likely to flip and/or run out of speed after being projected from conveyor 24 . Instead, the cross air current 50 allows the paper, cardboard, or Styrofoam 26 C to maintain theoretical aerodynamic characteristics and continue along trajectory path 34 into the correct far bin 30 B.
[0022] In certain embodiments, the speed of material 26 coming off of conveyor 24 and the corresponding speed of cross air current 50 may both be between 7-12 feet per second (FPS). It has been discovered that approximately 10 FPS on the infeed material conveyor 24 provides good separation of material into a single layer as the material 26 is being carried and launched off of conveyor 24 . The 10 FPS projection speed also provides controlled launching of the material 26 along trajectory path 34 . Of course other conveyor speeds and cross air current speeds may be used depending on the material being separated and the configuration of the cross air current system 48 .
[0023] In one embodiment, the air knife 52 generates a cross air current 50 that is either substantially parallel to the trajectory path 34 , in line with the trajectory path 34 , or possibly in a slightly upward intersecting direction with trajectory path 34 . The air nozzle 52 can be rotated or moved so that the cross air current 50 is aligned in a variety of different directions with respect to trajectory path 34 . The alignment of air current 50 in relationship to trajectory path 34 may be changed according to the type of materials 26 that need to be separated, the speed of conveyor 24 , the height of the conveyor 24 above bins 30 , the size of bins 30 , etc.
[0024] In one embodiment, the mid-range airspeed of cross air current 50 is approximately equal to the mid-range travel speed of material 26 . The location 27 of the mid-range airspeed is approximately half way between the air bar 22 where the ejection air nozzle 20 blasts downward air pressure and the splitter plate 31 that separates the first near bin 30 A ( FIG. 4 ) from the far bin 30 B ( FIG. 4 ).
[0025] The speed of air, coming off the face of the air knife 52 is much faster than 10 FPS. This is required due to the compressibility of air which creates exponential reduction in speed compared to distance off the air knife face. It has been discovered that air speeds of 20,000 to 30,000 FPS with air knife system pressures of 25-35 inches of water provide the necessary force and speeds to properly interface with the material traveling at 10 FPS off the end of the conveyor. Thus the air speed off the face of the air knife may have to be faster than the mid-range air speed, in order to obtain the desired air speed at location 27 . Of course, these speeds and pressures can vary in different embodiments according to the types of materials that need to be separated.
[0026] Referring to FIG. 4 , in this example, the cross air current system 48 separates polyethylene terephthalate (PET) and/or high density polyethylene (HDPE) bottles, jugs, containers, etc. 28 from other objects in material stream 26 or comingled recyclable material stream. However, it should again be understood that the cross air separation system 48 can be used to separate any detectable object from a material stream.
[0027] Another trajectory issue described above in FIG. 2 relates to air turbulence created by the air 22 blasted out of air ejection nozzle 20 and created by objects projected out from conveyor 24 . As described above in FIG. 2 , there was previously very little continuous air flow around the ejection area at the end of conveyor 24 . As a result, the projection of materials 26 and the air blasts 22 created a substantial amount of air turbulence 42 . This air turbulence 42 disrupted the normal trajectory path 34 of some lighter materials 26 B and caused those materials to incorrectly fall into the near bin 30 A.
[0028] The cross air current 50 creates a layer of continuously flowing air that effectively blazes a path through the air turbulence 42 allowing the material 26 B to continue along trajectory path 34 into the correct far bin 30 B. The cross air current 50 effectively carries away some of the air turbulence 42 resulting in more surgical, higher precision blasts of air 22 from ejection air nozzle 20 . An analogy would be throwing a rock into a quiet pond versus throwing a rock in a swift river. The rock creates large wide spreading ripples in the quiet pond. However, the rock creates much less noticeable disturbance in the swift river.
[0029] The air blasts 22 generated by the ejection air nozzle 20 have more force than the cross air current 50 . Therefore, the air blasts 22 can still blast through the cross air current 50 and push certain detected objects 28 A downward into the near bin 30 A. At the same time, the material 26 around the ejected object 28 A is more insulated from the air blasts 22 by the layer of cross air current 50 and is therefore less likely to deviate out of trajectory path 34 .
[0030] FIG. 5 shows how cross air current 50 compensates for “friction forces” that might exist between different projected materials 26 . For example, as previously described in FIG. 2 , a projected object 26 A might run into bottle 28 A, lose velocity, and incorrectly drop into near bin 30 A.
[0031] The cross air current 50 offsets these friction forces by helping all of these objects to flow e along the trajectory path 34 A at the same speed. The cross air current 50 in FIG. 5 also provides more separation of material launched off the conveyor 24 . For example, the cross air current 50 may blow the object 26 A off of bottle 28 A thus helping the object 26 A continue along trajectory path 34 into the desired far bin 30 B.
Pneumatic Transfer
[0032] FIG. 6 shows a pneumatic transfer system 60 used for transporting the PET and/or HDPE objects 28 , such as plastic bottles, from the cross air current separation system 48 to a storage bin 61 . The pneumatic transfer system 60 includes a blower 68 , air flow controller (venturi) 64 , and a series of air chambers (pipes) 62 . The air flow controller 64 in one embodiment is a metal plate or door that can be either rotated about the side of the pipe 62 and/or slid back and forth inside of air chamber 62 .
[0033] The plastic bottles 28 A are blasted down into near bin 32 A by the ejection air nozzle 20 as described above. Attached to the bottom of the near bin 32 A is a vertical air chamber 62 A. This air chamber transports the material via gravity and potentially other pneumatic forces depending on how the system is tuned, down to the main horizontal air chamber # 62 D. Once the objects 28 A transfer into air chamber 62 D, the air 86 A from blower 68 carries the objects 28 A up through air chamber 62 B into bin 61 .
[0034] Due to the nature of the pneumatic transfer system 60 , the air flow 86 A going through the venturi 64 can create a vacuum in vertical air chamber 62 A. The downward air flow 86 B created by the vacuum can undesirably draw relatively light material down into the near bin 30 A. The cross air current 50 offsets some of this downward air flow 86 B further allowing material to travel over near bin 30 A and drop into far bin 30 B.
[0035] FIG. 7 shows an alternative pneumatic transfer system 80 that provides more balanced air flow. The pneumatic transfer system 80 includes a second air flow controller (venturi) 88 located at the L-shaped horizontal to vertical elbow section between air chamber 62 D and air chamber 62 B. Depending on the nature of material and air flow characteristics, the second air flow controller 88 can be located in other locations in air chamber 62 B. Air flow controller 88 in one embodiment is a metal plate or door that rotates between air chamber 62 D and air chamber 62 B.
[0036] The two air flow controllers 64 and 88 control the amount of air allowed to pass through air chambers 62 A, 62 B, and 62 D respectively, by varying the size of the opening in the air chambers 67 and 65 , respectively. The second air flow controller restricts air flow 86 C through the air chamber 62 B causing back pressure back up into air chamber 62 A. The back pressure eliminates some or all of the previous downward air flow 86 B ( FIG. 6 ) previously created by the vacuum in air chamber 62 A.
[0037] The combination of air flow controllers 64 and 88 can further be arranged so that a positive upward air flow 86 E blows back up through air chamber 62 A into the near bin 30 A. This positive upward air pressure 86 E can work separately, or in combination with cross air current 50 , to help carrying light material over near bin 30 A and into the far bin 30 B. As the opening 65 between air chamber 62 D and air chamber 62 B is made smaller by air flow controller 88 , more back pressure air flow 89 E is created in air chamber 62 A. Additional positive upward air flow 86 E can be created by further reducing the size of the opening 65 with air flow controller 88 and/or increasing the size of the opening 67 in air chamber 62 A with the air flow controller 64 .
[0038] In another embodiment, another air chamber (pipe) 62 C taps off of pipe 62 B at the main outlet of the blower 68 and provides the air flow for the cross air current 50 output by the air knife 52 . A third air flow controller (venturi) 82 is located in pipe 62 C and is used for controlling the amount of cross air current 50 output by air knife 52 .
[0039] The same blower 68 can be used for providing the cross air current 50 to air knife 52 and for generating the air flows 86 in air chambers 62 A 62 B and 62 D. Using the same air supply from blower 68 self balances the different air flows 50 , 86 A, 86 B, and 86 C.
[0040] For example, it is easier to adjust or synchronize multiple different air flows when they all originate from a common air supply 68 . Since there is one common air supply used for all of these air flows, increasing the cross air current 50 coming from air knife 52 , for example, will correspondingly reduce some of the air flow 86 A. This in turn can reduce the upward air flow 86 E in air chamber 62 A. Similarly, reducing the amount of air allowed into air chamber 62 C can increase the amount of positive air flow 86 E moving vertically up from air chamber 62 A. Accordingly, the entire air control system self balances to provide more predictable material trajectory and transfer control.
[0041] Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention may be modified in arrangement and detail without departing from such principles. I/we claim all modifications and variation coming within the spirit and scope of the following claims.
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A cross-flow air separation system comprises a conveyor configured to project material out over an end of the conveyor generally along a trajectory path into a far receiving bin. An optical sensing system is configured to identify particular objects in the projected material. A first air ejection system is configured to generate a first airstream that ejects the identified objects from the trajectory path into a second near receiving bin. A second cross air current system is configured to generate a second airstream that reduces air resistance for the materials projected along the trajectory path. The second airstream reduces certain aeronautic phenomena that would cause some of the projected materials to unintentionally fall into the wrong receiving bin, thus creating a higher purity/less contaminated materiel stream into the near bin.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. provisional patent application Ser. No. 61/162,487 filed on Mar. 23, 2009, the entire contents of which are incorporated herein by reference.
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to nanoparticles. In particular, this invention relates to nanoparticles that are clinically applicable for diagnostic and/or therapeutic uses.
[0004] Medical imaging is used to collect information about a subject. In some types of imaging, a contrast agent is administered to the subject. The contrast agent selectively binds to a bioparticle or other structure of interest in the subject. This contrast agent is then detected using a medical imaging device and the collected information is used to develop an image or the like.
[0005] Although much information can be gathered from even a single medical image, multiple imaging techniques are necessary to provide comprehensive quantitative diagnostic information having high spatial and temporal resolution, high sensitivity of detection, and tomographic capability. In the past, this has often meant that multiple contrast agents would need to be administered to a single subject for each performed modality.
[0006] Multimodal contrast agents have been developed that are suitable for detection by various types of modalities. These multimodal contrast agents typically include multiple entities that are each detectable by a separate modality. The multiple entities are typically joined together using chemical linkers to make particles that each contain all of the respective multiple entities. However, the chemical linkers often have varying stabilities in cells and tissues or across time, meaning that some of the entities could separate, thus degrading the quality and usefulness of these contrast agents.
[0007] To avoid the problems of chemically linking multiple entities together, some have attempted to form contrast agents having a core-shell structure. However, to date, there have been significant problems developing a core-shell structure that can be clinically applied. The currently available particles either require the use of toxic chemicals during synthesis that limit the use of the resultant contrast agent in the human body or possess a morphology that prevents the particles from being effectively functionalized with targeting moieties.
[0008] Hence, a need exists for a multimodal contrast agent that is clinically applicable and efficiently functionalized.
SUMMARY OF THE INVENTION
[0009] Multimodal nanoparticles and a method of making these nanoparticles are disclosed. Given their structure and the method in which they are made, these nanoparticles may be clinically applicable and efficiently functionalized. The synthesized nanoparticles may facilitate multiple imaging methods and, in some instances, may be used in therapeutic treatment.
[0010] A method of forming gold-coated iron oxide nanoparticles is disclosed. The method comprises contacting dextran-coated iron oxide nanoparticles with a gold donating reagent in a citrate solution to form the gold-coated iron oxide nanoparticles.
[0011] In some forms, the gold donating reagent may be chloroauric acid.
[0012] In other forms, a gold shell may be formed on each of the dextran-coated iron oxide particles to provide gold-coated iron oxide nanoparticles.
[0013] In still other forms, the method may further include forming gold nanoparticles from chloroauric acid. At least some of the gold nanoparticles may be deposited onto a surface of the dextran-coated iron oxide nanoparticles to form gold nanoparticle conjugated iron oxide nanoparticles. Additional gold chloride ions may be reduced on the surface of the gold nanoparticle conjugated iron oxide nanoparticles to form the gold-coated iron oxide nanoparticles. Hydroxylamine may used to reduce the additional gold chloride ions. The gold nanoparticle conjugated iron oxide nanoparticle may be separated by magnetic column prior to reducing additional gold chloride ions on the surface of the gold nanoparticle conjugated iron oxide nanoparticle.
[0014] The gold-coated iron oxide nanoparticles may be clinically applicable and may be substantially free of toxins. The gold-coated iron oxide nanoparticles may be MRI active due to the iron oxide and may be CT active due to an amount and morphology of gold surrounding the iron oxide.
[0015] The method may also include functionalizing the gold-coated iron oxide nanoparticles with at least one of a Raman spectroscopy active dye and a targeting moiety. By functionalizing the nanoparticles with a Raman spectroscopy active dye, such as DTTC, the nanoparticles may be made SERS active.
[0016] A gold-coated iron oxide nanoparticle may be manufactured by the methods described herein.
[0017] A nanoparticle is also disclosed which includes an iron oxide core, a dextran layer surrounding the iron oxide core, and a gold coating formed on the dextran layer.
[0018] The iron oxide core may be superparamagnetic.
[0019] The nanoparticle may have a diameter in a range of about 60 nanometers to about 120 nanometers.
[0020] The nanoparticle may have many uses. The nanoparticle may be clinically applicable and may be substantially free of toxins. The nanoparticle may be adapted for use as a contrast agent, for use in a therapeutic application, or for both.
[0021] In some forms, the gold coating of the nanoparticle may be functionalized with targeting moieties. The gold coating may be functionalized with a Raman spectroscopy active dye, such as DTTC, or a targeting moiety. The gold coating may be a gold shell surrounding the dextran layer and the iron oxide core.
[0022] A method of imaging a subject is also disclosed. The method includes introducing the nanoparticles described herein into a subject and performing at least two modes of imaging in the subject using the nanoparticles as a contrast agent for modes of imaging. The modes of imaging may include two or more of magnetic resonance imaging, CT imaging, and Raman spectroscopy.
[0023] A method of providing a therapeutic treatment to a subject is also disclosed. The method includes introducing nanoparticles as described herein into a subject and applying an energy source to raise a temperature of the nanoparticles in the subject. As the temperature of the nanoparticles is increased, a therapeutic treatment is provided to the subject. In some forms, the energy source may be an alternating magnetic field or an infrared light.
[0024] Furthermore, the methods of imaging and treatment may be combined as a single method. The nanoparticles used to perform these methods may be manufactured by the methods described herein.
[0025] These and still other advantages of the invention will be apparent from the detailed description and drawings. What follows is merely a description of some preferred embodiments of the present invention. To assess the full scope of the invention the claims should be looked to as the preferred embodiments are not intended to be the only embodiments within the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a process diagram showing the formation of a gold-coated iron oxide nanoparticle;
[0027] FIG. 2 is a transmission electron microscope (TEM) image of 13 nm gold nanoparticles (AuNP);
[0028] FIG. 3 is a TEM image of a mono-dispersed superparamagnetic iron oxide nanoparticle (MN);
[0029] FIG. 4 is a TEM image of AuNP conjugated MNs;
[0030] FIG. 5 is a dynamic light scattering graph of AuNP conjugated MNs indicating the size of the particles;
[0031] FIG. 6 is a diagram showing the absorbance of gold-coated iron oxide nanoparticles (AuMN), gold nanoparticles (AuNP), and iron oxide nanoparticles (MN);
[0032] FIG. 7 is a TEM image of a gold-coated iron oxide nanoparticle;
[0033] FIG. 8 is a dynamic light scattering graph of the gold-coated iron oxide nanoparticle;
[0034] FIG. 9A is a process diagram showing the synthesis of an AuMN-DTTC nanoparticle;
[0035] FIG. 9B is dynamic light scattering graph of the AuMN-DTTC and control probes;
[0036] FIG. 9C are pictures of AuMN-DTTC and control probe suspensions in cuvettes;
[0037] FIG. 9D are pictures of TEM images of AuMN-DTTC;
[0038] FIG. 9E is a chart of relaxivity values of the probes;
[0039] FIG. 9F is a chart of elemental analysis of the probes;
[0040] FIGS. 10A-10F are graphs of the stability of AuMN-DTTC compared to AuNP under various conditions;
[0041] FIG. 11A is an in vitro T2 weighted MR image of AuMN-DTTC and the control probes in water;
[0042] FIG. 11B is a chart showing calculated T2 values;
[0043] FIG. 11C is a Raman spectra of AuMN-DTTC and control probes in water;
[0044] FIG. 12A is a schematic indicating the in vivo injection sites of AuNP and AuMN-DTTC in a test specimen;
[0045] FIG. 12B is a T2 weighted MR image of AuMN-DTTC and AuNP in the injected test specimen;
[0046] FIG. 12C is a chart showing calculated T2 values;
[0047] FIG. 12D is a photo of the specimen undergoing Raman spectroscopy;
[0048] FIG. 12E is a Raman spectra of AuMN-DTTC and control probes in deep muscle injection; and
[0049] FIG. 13 is an image of in vitro CT values of AuMN-DTTC and the control probes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] Referring first to FIG. 1 , a process for forming a gold-coated iron oxide nanoparticle is shown. According to this process, a dextran-coated iron oxide nanoparticle 10 is provided (the dextran coating being indicated by the lines surrounding the sphere in FIG. 1 ). The dextran-coated iron oxide nanoparticle 10 is exposed to a gold donating reagent in a citrate solution. In one form, and according to the particular process shown in FIG. 1 , the gold donating reagent is chloroauric acid (HAuCl 4 ) and the citrate solution is sodium citrate.
[0051] Given the conditions in the solution, which may include the application of heat, stirring, or the like as will be described in more detail in the example below, the gold donating reagent forms gold nanoparticles 12 in solution, such as those seen in the TEM of FIG. 2 .
[0052] While in the citrate solution, some of the formed gold nanoparticles 12 further get deposited onto the dextran-coating on the iron oxide nanoparticle 10 , serving as seeds for the formation of a gold nanoparticle conjugated iron oxide nanoparticle 20 upon reduction by citrate. Such attachment or conjugation through dextran is notable because the pairing of magnetic particles, such as iron oxide nanoparticles, with gold has been deemed difficult given the dissimilar nature of the two surfaces.
[0053] Next, the gold nanoparticle conjugated iron oxide nanoparticles 20 are separated from the excess of unconjugated gold nanoparticles in the solution. In one form, this separation of the gold nanoparticle conjugated iron oxide nanoparticles 20 from the unconjugated gold nanoparticles is performed by magnetic column. This is possible because of the differing magnetic properties of the unconjugated gold nanoparticles from the gold nanoparticle conjugated iron oxide nanoparticles in the solution.
[0054] In the next step, gold ions are reduced on the surface of the separated gold nanoparticle conjugated iron oxide nanoparticles to form a gold shell about the dextran-coated iron oxide nanoparticle. This is done by the subsequent addition of a gold donating reagent (in the form shown, chloroauric acid) and a reducing agent (in the form shown, hydroxylamine, NH 2 OH). Gold ions from the gold donating reagent are deposited on the surface of the conjugated nanoparticle, beginning the growth of a gold shell around the dextran coated iron oxide nanoparticle. As the deposition continues, a gold-coated iron oxide nanoparticle 30 is formed.
[0055] Again, the gold-coated iron oxide nanoparticles 20 are separated from the solution by using a magnetic column technique or the like.
[0056] The resultant gold-coated iron oxide nanoparticle 30 has an iron oxide core 32 , a surrounding gold shell 34 that substantially surrounds the iron oxide core 32 , and an intermediate dextran T-10 layer 36 . In one form, the iron oxide core 32 is a mixture of magnetite and maghemite and has a 3-5 nm size. Including the dextran layer 36 , the diameter of the dextran-coated iron oxide nanoparticle is in a range of 10-30 nm. After the deposition of gold onto the surface to form the gold shell 34 , the final diameter is in the range of 30-120 nm. These values are merely representative of some of the size ranges of the gold-coated iron oxide nanoparticle 30 and its associated elements. By altering the processing variables, it is contemplated that different sizes of nanoparticles could be formed.
[0057] The iron oxide core 32 is superparamagnetic, meaning that the core as a whole is not magnetized unless it is subjected to an external magnetic field, and can be detected during, for example, magnetic resonance imaging and the like.
[0058] The gold shell 34 is well adapted for functionalization with targeting moieties such as RGD peptides, aptamers, molecular probes, and the like. It is well known in the art that gold serves as a preferred surface for receiving such targeting moieties. By producing gold-coated iron oxide nanoparticles 30 having a gold shell 34 that entirely or substantially covers the iron oxide core 32 , the exposed gold surface area for functionalization is maximized meaning the nanoparticles can be efficiently functionalized. In comparison, a particle morphology in which the exposed surface of the particle was not entirely gold would exhibit unpredictable or inefficient attachment of targeting moieties.
[0059] As to the applications of the nanoparticle, the gold-coated iron oxide nanoparticle 30 can be detected using three separate imaging modalities—magnetic resonance imaging, computed tomography, and Raman microscopy without the conjugation of additional imaging labels for each of the modalities. This means that the multimodal properties of the gold-coated iron oxide nanoparticle are innate.
[0060] The gold-coated iron oxide nanoparticle 30 can also act as a therapeutic agent. When the gold-coated iron oxide nanoparticle 30 is exposed to infrared light and/or an alternating magnetic field, the nanoparticle 30 generates heat and can mediate thermally-mediated cytotoxicity. If the nanoparticle 30 has been functionalized with an appropriate biomolecule, the application of this heat can be targeted at an area of interest in the subject to which the nanoparticle 30 has been administered for thermotherapy.
[0061] It is observed that the various chemicals used to form the gold-coated iron oxide nanoparticle 30 do not compromise the ability of gold-coated iron oxide nanoparticle 30 to be used in the human body. Sodium citrate is a safe, clinically applicable reagent, routinely used by the pharmaceutical and food-production industries. Hydroxylamine is routinely used by the pharmaceutical industry for the synthesis of analgesics, antibiotics, tranquillizers, and the like. By using these chemicals, or other non-toxic chemicals with similar reactivities that will not limit the use of the resultant gold-coated iron oxide nanoparticle 30 in the human body, a clinically applicable particle is provided that is substantially free of toxins.
[0062] As used herein, “substantially free of toxins” means that the resultant gold-coated iron oxide nanoparticles have no toxins or levels of toxins, either individually or in aggregate, that are low enough to have little, and preferably no, short-term or long-term effects on the health of the individual to which the nanoparticles have been administered. Factors such as the weight, the body chemistry, and the like of the individual to whom the nanoparticles are administered may need to be taken into account in the determination of how much of a toxin is safe for the individual.
[0063] To date, the formation of gold shell—magnetic core structures has required the use of chemicals that rendered the resulting particle unfit for use in humans.
[0064] Yet, using the chemicals and the process described herein, the resultant particle is clinically applicable. The use of chloroauric acid, sodium citrate, and hydroxylamine does not restrict the clinical use of the resultant nanoparticle. The dextran layer is also non-toxic and, further, has a stabilizing effect on the iron oxide core and has the potential to act as an additional reducing agent.
[0065] Thus, the gold-coated iron oxide nanoparticle 30 represents a versatile platform with an array of potential applications. By functionalizing the gold-coated iron oxide nanoparticle 30 with a targeting moiety specific for chosen cells, tissues or biological processes, one can design many diagnostic and/or therapeutic agents. To the best of our knowledge, this is the first clinically relevant trimodal MRI/CT/optical contrast agent that can be functionalized.
[0066] Specific examples of the processes used to form a gold-coated iron oxide nanoparticle are provided below. These examples are offered for illustrative purposes only, and are not intended to limit the scope of the present invention in any way. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and the following examples and fall within the scope of the appended claims.
Example I
[0067] According to one specific example, gold-coated iron oxide nanoparticles were prepared in the following manner.
[0068] First, 2 mL of 1% sodium citrate were added into 20 mL of boiling distilled water to form a boiling citrate solution. The solution was stirred in an Erlenmeyer flask on a hot plate to achieve uniformity of the citrate solution. 400 microliters of 50 mM chloroauric acid (HAuCl 4 ) solution and 300 microliters of previously prepared mono-dispersed superparamagnetic iron oxide nanoparticles (9.3 mg/ml of iron) were added to the citrate solution.
[0069] Upon the addition of the chloroauric acid and the iron oxide nanoparticles to the citrate solution, the color of the solution changed from colorless, to black, and finally to red. The red color was indicative that gold nanoparticles had formed in the solution. Separation of by magnetic column was then performed to separate the gold nanoparticle conjugated iron oxide nanoparticles from the excess unconjugated gold nanoparticles. The separated conjugated nanoparticles had a reddish-brownish color.
[0070] FIG. 2 shows an image made by a transmission electron microscope of the prepared gold nanoparticles and FIG. 3 shows an image of the iron oxide nanoparticle core before conjugation. As visually shown in FIG. 2 and further supported by dynamic light scattering results, the size of the formed gold nanoparticles alone are approximately 13 nm. The size of the iron oxide nanoparticle with the dextran coating is approximately 30 nm and the iron oxide core alone is approximately 5 nm based on the TEM image of FIG. 3 .
[0071] It is believed that after citrate stabilization occurs, the gold nanoparticles begin to attach to the dextran-coated surfaces of the iron oxide nanoparticle. As seen in FIG. 4 , a TEM image of the separated gold nanoparticle conjugated iron oxide nanoparticles indicates that the resultant conjugates are approximately 40 nm in size. This image shows numbers of gold nanoparticles attaching to the surface of the dextran coated iron oxide nanoparticle, increasing its size. Gold particle conjugation is further supported by the dynamic light scattering results shown in FIG. 5 which reveal an average particle size in the separated conjugated nanoparticles of 42 nm.
[0072] Next, chloroauric acid and hydroxylamine (NH 2 OH) were introduced to the separated conjugated nanoparticles to further reduce gold ions onto the surface of the conjugated nanoparticle and deposit gold ions to form a gold shell around the iron oxide core. According to the specific process, 2 mL of the gold nanoparticle conjugated iron oxide nanoparticles was mixed with 75 microliters of 1% chloroauric solution. This mixture is stirred at room temperature. Then 150 mM of the hydroxylamine was slowly added in a dropwise fashion to the stirred solution. The color of the solution shifted from the reddish-brownish color to a dark red. After the color change was complete, the dropwise addition of hydroxylamine was halted and the resulting nanoparticle solution was purified by magnetic column against distilled water.
[0073] A red colored suspension was recovered from the magnetic column separation. This red color is indicative of a gold surface for the formed particles. However, as the particles were separated by magnetic column, it is clear that the particles were also magnetic.
[0074] Referring now to FIG. 6 , absorbance of the resulting suspension was determined by UV-vis spectroscopy. This spectrum was compared to known absorbance spectra of the iron oxide nanoparticles and the gold nanoparticles. The measured spectrum of the resulting suspension had a gold nanoparticle plasmon resonance peak, strongly suggesting that the resultant nanoparticle contained gold nanostructures.
[0075] Referring now to FIGS. 7 and 8 , the resultant nanoparticles of the suspension were imaged using TEM and measured using dynamic light scattering. Each of these reveal that the resultant nanoparticle size is in the range of 100 to 120 nanometers.
[0076] Given the above-collected data, nanoparticles having a gold-shell, iron-oxide core with an intermediate dextran layer were formed. Although a specific example has been provided, it is contemplated that the processing variables could be altered to modify one or more of the characteristics of the resultant particle. For example, it is contemplated that an increase or reduction in the amount of chloroauric acid presented in the reduction step could alter the thickness of the gold shell and the size of the final nanoparticle. Likewise, the temperature of the various solutions could be altered to change the reaction kinetics and resultant nanoparticle structures created therefrom.
Example II
[0077] According to another example, multilayered nanoparticles AuMN-DTTC, which can be used as a MRI-SERS-CT active contrast agent were also prepared. AuMN-DTTC includes (1) iron oxide, which makes it MRI active-gold, which makes it CT active (2) DTTC (diethylthiatricarbocyanine, a Raman active dye) and (3) gold nanostructures, which makes it SERS active material.
[0078] Referring now to FIG. 9A , a schematic representation of the multi-step synthesis of the contrast agent is illustrated. The process steps are similar to those shown in FIG. 1 , but with the addition of DTTC and PEG-SH (polyethylene glycol-thiol or sulfhydryl) during the second step. As can be seen in the resultant product, during the second step, additional gold is reduced on the surface of the gold-conjugated nanoparticles and the DTTC and PEG-SH are attached to the growing Au-nanoparticles. In the form shown, less than a full shell of gold is formed around the magnetic nanoparticle.
[0079] FIG. 9B shows the absorbance spectra of AuMN-DTTC, AuNP (gold nanoparticles), and MN (iron oxide nanoparticles) in water. AuMN-DTTC has a surface plasmon resonance peak at 530 nm which is similar to surface plasmon resonance peak at 520 nm of AuNP. MN does not have a corresponding peak, which suggests that the resonance peak in the AuMN-DTTC must be due to presence of gold nanostructures. The dark red color of the AuMN-DTTC in FIG. 9C and the TEM images in FIG. 9D also suggest that the gold nanostructures are present in the composition of the probe.
[0080] With additional reference to FIG. 9E , the relaxivity (R 1 and R 2 ) values indicate that the validity of AuMN-DTTC as an MRI contrast agent is not too different than the MN, which is a clinically approved MRI contrast agent. As shown in FIG. 9F , elemental analysis on AuMN-DTTC confirms the presence of iron and gold in the composition of the probe.
[0081] Stability of the multifunctional contrast agent in biological conditions is important because the agent should remain relatively stable from injection though imaging. Referring now to FIGS. 10A through 10F , the stability of AuMN-DTTC is compared to that of AuNP at in various conditions. FIGS. 10A through 10C illustrate before and after absorbance spectra of AuNP in 0.4 M NaCl and 1×PBS (phosphate buffered saline), AuMN-DTTC in 0.4 M NaCl and 1×PBS, and AuMN-DTTC in fetal bovine serum, respectively. The change in optical density of selected wavelengths (520 nm and 610 nm) over time is illustrated in FIGS. 10D through 10F , with the conditions of FIG. 10A corresponding to FIG. 10D , FIG. 10B corresponding to FIG. 10E , and FIG. 10C corresponding to FIG. 10F .
[0082] FIGS. 10A and 10D illustrate the stability of the citrate-stabilized AuNP. FIG. 10A shows the absorbance spectrum of AuNP before and 20 minutes after the addition of 0.4 M NaCl and PBS (phosphate buffered saline). The AuNP aggregate in the presence of the 0.4 M NaCl and PBS, which is observed as a surface plasmon resonance shift from 520 nm to higher wavelengths.
[0083] Referring now to FIGS. 10B and 10E , under similar environmental conditions (i.e., 0.4 M NaCl and 1×PBS), AuMN-DTTC is protected against aggregation by the PEG coating. Therefore, an aggregation of the particles is not observed in the presence of 0.4 M NaCl and PBS. Likewise, FIGS. 10C and 10F illustrate the stability of AuMN-DTTC in fetal bovine albumin.
[0084] Having established stability under biological conditions, the following experiments were performed to establish that the synthesized probe was MRI, SERS (surface enhanced Raman spectroscopy), and CT active.
[0085] Referring to FIG. 11A , a T2 weighted MRI scan was performed on AuMN-DTTC along with the control probes in water. The T2 values from the images were also calculated and are shown in FIG. 11B . As seen in these figures, the AuMN-DTTC and AuMN has similar brightness as MN (the only difference of AuMN from AuMN-DTTC is that DTTC is not added during the synthesis of AuMN), but AuNP is significantly different than MN and close to the brightness of the blank solution PBS. This establishes that the AuMN-DTTC is valid as an MRI contrast agent in terms of signal capacity. The calculated T2 results also support this conclusion.
[0086] Tests were also performed to see if the synthesized AuMN-DTTC is SERS active. Referring to FIG. 11C , Raman spectra of AuMN-DTTC and control probes in water were collected. The control probes include AuMN (which does not include the Raman reporter DTTC dye), AuNP, and DTTC. As seen in FIG. 11C , AuMN-DTTC has identifiable peaks in its spectrum, whereas the other control samples such as AuMN and AuNP do not. These results suggest that AuMN-DTTC is SERS active.
[0087] In vivo MRI and SERS experiments were performed in a test specimen. AuMN-DTTC was injected into the right gluteal muscle of a mouse and AuNP into the left gluteal muscle, as shown schematically in FIG. 12A . As seen in FIG. 12B , the AuMN-DTTC in the right muscle has a dark signal in comparison to the surrounding tissue and in comparison to the left muscle. As shown in FIG. 12C , T2 values were calculated on the image and the AuMN-DTTC injected tissue has a significantly lower T2 value compared to tissue injected with AuNP.
[0088] As shown in FIG. 12D , the SERS spectra in the injected areas were obtained from the living specimen. As seen in FIG. 12E , the tissue containing AuMN-DTTC has the same SERS peaks as AuMN-DTTC in silica. However, AuMN injected tissue or skin does not exhibit clearly identifiable SERS peaks. The tissue was also excised and monitored and SERS was observed in the excised tissue as well. These results indicate that the AuMN-DTTC contrast agent is not only MR active, but is also SERS active.
[0089] In order to monitor if the compound creates change in CT signal due to gold content, a phantom of the AuMN-DTTC probes and control probes was made. The AuMN-DTTC was compared to PBS. As seen in FIG. 13 , the 10× concentrated AuMN-DTTC has a CT signal higher than PBS but relatively lower than iodine, which is a CT contrast agent.
[0090] It should be appreciated that various other modifications and variations to the preferred embodiments can be made within the spirit and scope of the invention. Therefore, the invention should not be limited to the described embodiments. To ascertain the full scope of the invention, the following claims should be referenced. All patents, applications, and publications cited herein are incorporated by reference in their entirety for all purposes.
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A gold-coated iron oxide nanoparticle, method of making thereof, and method of using thereof is disclosed. The nanoparticle is substantially toxin free (making it clinically applicable), easily functionalized, and can serve as a contrast agent for a number of imaging techniques, including imaging a subject in at least two distinct imaging modes. Further, the nanoparticle is well-suited for therapeutic uses.
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BACKGROUND OF THE INVENTION
This invention relates to a process for the purification of 1,3-dihalobenzenes, particularly 1,3-dichlorobenzene, and their separation from a mixture of corresponding 1,4- and 1,3-dihalobenzenes. The purification of 1,3-dihalobenzene is accomplished by selectively removing the 1,4-isomer as a complex with polyethylene glycol. The process according to the invention produces 1,3-dihalobenzenes in high purity.
1,3-dichlorobenzene is a commercially important intermediate compound which serves as a building block in the synthesis of many products that are important to both the pharmaceutical and agricultural industries. The direct synthetic routes to produce 1,3-dichlorobenzene are limited and are economically unfeasible. Normally, 1,3-dichlorobenzene is co-produced along with other dichlorobenzenes by the chlorination of benzene. Similarly, dichlorobenzenes can be isomerized to a mixture containing predominantly 1,3-dichlorobenzene.
The recovery of 1,3-dichlorobenzene from mixtures of other dichlorobenzenes, particularly 1,4-dichlorobenzene, is one of the most difficult separations in aromatic chemistry. Normally, the separation and/or purification of these organic chemicals is carried out by distillation or crystallization. In the case of 1,3- and 1,4-dichlorobenzene, separation via the distillation route is practically impossible due to their narrow difference in the boiling points (less than 0.2° C. apart from one another). Similarly, the purification of 1,3-dichlorobenzene from a mixture of 1,4- and 1,3-dichlorobenzenes by crystallization is also impossible due to the formation of an eutectic mixture where both compounds freeze at the same temperature. The eutectic point for 1,4- and 1,3-dichlorobenzene mixture is approximately -29.4° C. and consists of approximately 88% 1,3-dichlorobenzene and 12% 1,4-dichlorobenzene. Up to or closer to the eutectic point, 1,4-dichlorobenzene can be removed from the mixture in high purity by crystallization. However, in the proximity of the eutectic point, removal of 1,4-dichlorobenzene by crystallization becomes difficult and therefore the purity of 1,3-dichlorobenzene can not be improved further. At eutectic point and lower temperatures, both 1,4- and 1,3-dichlorobenzene freezes together. If the composition changes such that the mixture contains more than 88% 1,3-dichlorobenzene, the crystallization at or above -29.4° C. will yield pure 1,3-dichlorobenzene. But to achieve the concentration of 1,3-dichlorobenzene required for its purification through crystallization is very difficult.
Because of the difficulty in the separation and purification of 1,3-dichlorobenzene, several complicated and expensive options have been suggested and commercially practiced to produce high purity 1,3-dichlorobenzene. For example, the reaction of metachloronitrobenzene with SOCl 2 (Beilstein V-243, V1-(129), metabenzenesulfonic acid with SOCl 2 (Beilstein XI-68, XI1-(21), and metabromonitrobenzene with PCl 5 (Beilstein V-248, V1-(131) have been described.
U.S. Pat. No. 3,170,961 describes a process of extracting 1,3-dichlorobenzene from a mixture of 1,4- and 1,3-dichlorobenzenes by a bromination route. In this process, during the bromination step, the 1,3-isomer is selectively reacted to form 1-bromo-2,4-dichlorobenzene which is separated from the 1,4-dichlorobenzene by distillation. The bromodichlorobenzene is debrominated in a second step in the presence of a bromine acceptor, e.g. benzene, and aluminum chloride as the catalyst. This process is complicated and expensive and produces undesirable by-products such as hydrogenbromide gas and bromobenzene.
Other purification processes, such as the one described in U.S. Pat. No. 2,958,708, include the physical separation of the 1,3-isomer with various agents, such as a molecular sieve. While this process provides the desired purity of 1,3-dichlorobenzene, the regeneration of the molecular sieve is very difficult. This process is also not cost effective.
Japanese patent JP 89,313,446 (application JP 01,313,446) describes a process to purify 1,3-dichlorobenzene by forming an inclusion complex between this isomer and a host compound, such as 9,9'-bianthracene, and distillation of the complex from 1,4-dichlorobenzene at a temperature lower than the decomposition point of the complex. This process has several shortcomings, such as requiring the handling of toxic compounds and lack of cost effectiveness.
U.S. Pat. No. 4,996,380 describes another process for separating 1,3-dichlorobenzene from a mixture of dichlorobenzenes using the selective absorption characteristics of certain zeolites. While high purity 1,3-dichlorobenzene can be produced by the use of this technique, this process becomes expensive since the zeolites can not be used indefinitely. Also, an additional solvent (which needs to be removed subsequently through distillation) is required to extract the absorbed 1,3-dichlorobenzene.
Another method to separate 1,3-dichlorobenzene from a mixture of 1,4- and 1,3-dichlorobenzenes is described in German patent 2,855,940. It uses combination of distillation and crystallization. In this process the crude dichlorobenzene mixture is distilled to first increase the concentration of the 1,3-dichlorobenzene to approximately 90%. The distillate is then subjected to a crystallization to extract the pure 1,3-dichlorobenzene. After the separation of the 1,3-dichlorobenzene, the mother liquor is recycled to the distillation stream to further increase its purity to 90%. Even though this method produces high purity 1,3-dichlorobenzene, it requires a distillation column with a large number of stages. Therefore, this process becomes very difficult to practice and economically unattractive.
Belgium patent BE 897,296 describes a process for the concentration of 1,4-dichlorobenzene using a thin film (100-u) of very high molecular weight (5×10 6 ) glycols to increases its concentration to 70%. However, high purity 1,3-dichlorobenzene is not produced. Moreover, such high molecular weight thin film glycols are not commercially available.
German patent 23 32 889 and European patent application 0 451 720 describe methods to separate 1,3-dichlorobenzene from a mixture containing 1,3- and 1,4-dichlorobenzenes. Both processes use an extractive rectification technique using different extractants. For instance, the German patent uses hexamethyl phosphoric acid triamide and the European patent uses alkylene carbonates. Various other compounds, such as dimethyl sulfoxide, n-ethyl pyrolidone and dibutyl sulfoxide, have been described as possible extractants for this process. However, some of these substances are toxic, corrosive, unstable, and their boiling points unfavorable for high temperature distillation.
In view of the deficiencies of the aforementioned prior art processes, it is highly desirable to provide a new process for the purification and commercial production of high purity 1,3-dihalobenzenes from a mixture containing its corresponding 1,4-disubstituted isomer.
SUMMARY OF THE INVENTION
The present invention relates to a process for separating 1,3-dihalobenzene from a mixture of 1,4-dihalobenzene and 1,3-dihalobenzene, comprising treating the mixture with a polyethylene glycol to form a complex of polyethylene glycol and 1,4-dihalobenzene. The complex is separated from the reaction mixture by vacuum filtration. This process is repeated until the concentration of 1,3-isomer in the filtrate reaches a predetermined amount. The filtrate is then distilled to recover the 1,3-dihalobenzene and remove any residual polyethylene glycol.
The process of the present invention can be performed on any dihalobenzene with the preferred dihalobenzenes for treatment being dichlorobenzene and dibromobenzene.
The purity of the 1,3-dihalobenzene obtained by the treatment of polyethylene glycol ranges from 95 to 97%. This is sufficiently pure for the normal commercial use. For special applications, where higher purity is required, the product can be further purified to up to 99.95% by a selective solidification using a static crystallizer.
The polyethylene glycol used in the process may be recovered and reused. Normally, the polyethylene glycol is recovered by distillation.
The process of the present invention can also be used to purify 1,3-dihalobenzene from a mixture of 1,2-dihalobenzene, 1,3-dihalobenzene and 1,4-dihalobenzene.
Additionally, the present invention is directed to a composition consisting of the complex of polyethylene glycol and 1,4-dihalobenzene.
DETAILED DESCRIPTION OF THE INVENTION
In the process of the present invention, 1,3-dihalobenzene is selectively isolated from an isomeric mixture containing 1,3- and 1,4-dihalobenzenes by the use of polyethylene glycol.
The polyethylene glycol can be in the form of fine particles (as powder), pellets, or granules. While the ultimate absorption of the 1,4-dihalobenzene during the process is not affected by the form (especially in processes involving dihalochlorobenzene), the powder needed less reaction time. preferred molecular weight of the polyethylene glycol is 5,000 to 10,000 although PEG with a molecular weight of 500-50,000 can be used. The molecular weight of the PEG normally is not independently determined. The supplier certifies the molecular weight and grade of PEG when purchased. The grade of polyethylene glycol has little effect in the overall process.
For an effective removal of the 1,4-dihalobenzenes from mixture of 1,3- and 1,4-dihalobenzene, a sufficient amount of the polyethylene glycol must be added to the mixture. The required purity determines the amount of polyethylene glycol used. For example, to raise the purity of 1,3-dichlorobenzene from 80% to 90% in a mixture of 1,4- and 1,3-dichlorobenzenes or bring the dichlorobenzene mixture away from the eutectic point for further processing elsewhere, a minimum amount of polyethylene glycol is used. Normally, the polyethylene glycol required for this purpose varies from 20 to 60% in weight, preferably 30 to 40%, in relation to the amount of 1,4-dichlorobenzene present in the mixture. To achieve higher purity for the 1,3-dichlorobenzene, the amount of the polyethylene glycol used should be equal in weight to that of the 1,4-dichlorobenzene in the mixture. This is the amount normally used in the process.
The complexing step is carried out in batch operation. Immediately upon the addition of the polyethylene glycol to the mixture of dihalobenzenes, the temperature is raised to about 45° C. For optimum complex formation, the temperature range is 15° to 65° C., preferably 35° to 45° C. The dihalobenzene mixture is kept at the optimum temperature for about 30 minutes under agitation. The time required for the complex formation at the optimum temperature is from about 15 minutes to 1 hour, preferably from about 25 to 35 minutes.
At the end of complex formation, the material is cooled to room temperature. For an efficient and complete complex formation of polyethylene glycol with the 1,4-dihalobenzene, the cooling cycle may require sub-ambient temperatures. A normal temperature range for the cooling cycle for 1,4- and 1,3-dichlorobenzene mixture is -15° to 25° C., preferably about 12° to 18° C., and more preferably about 15° C. Depending on the dihalobenzenes, the optimum temperature ranges may vary during the complexing and cooling cycles.
During the complex formation cycles, the reaction mixture requires continuous agitation. The agitation speed must be controlled such that an optimum complex formation can be achieved. Controlled agitation is also particularly important during the cooling cycles when the complex material starts to precipitate. Excessive agitation increases the fine particles which are formed and thereby results in the inefficient removal of the 1,4-isomer.
The requirement for the final purity of the 1,3-dihalobenzene is critical in determining how the purification steps need to be carried out. If the expected purity is below 92%, a one step process can be implemented. If the purity requirement exceeds 92%, multiple treatments of polyethylene glycol are useful. Carrying out the reaction in different steps and cooling the reaction mixture to -5° C. prior to filtration provides higher purity 1,3-dichlorobenzene as compared to the one step reaction. However, attempts to increase the purity of the 1,3-dihalobenzenes above 96% using this process considerably reduces its efficiency due to poor yield.
After formation of the complex, it must be separated from the 1,3-dihalobenzene by filtration under vacuum. The preferred mode of filtration employs 10 μM or 25 μM filter paper and a vacuum at about 150 mm of Hg.
The filtrate is then distilled to recover the 1,3-dihalobenzene in the overhead and to remove any residual polyethylene glycol.
If it is desired to produce 98 to 99.9% pure 1,3-dihalobenzene, a combination of the polyethylene glycol process axed a final purification step using a static crystallizer should be considered. In such cases, the polyethylene glycol treatment should be limited to increasing the purity of the 1,3-dihalobenzene above the eutectic point and then subjecting the material to a crystallization process.
A static crystallizer is preferred for the crystallization of the 1,3-dihalobenzene due to its crystal characteristics and for better yield. To improve the purity and yield of the process, a two or three stage crystallization is preferred. The crystallization preferably takes place in 20m 3 vats. The first stage requires very low temperature to initiate the crystallization. For the crystallization of 1,3-dichlorobenzene from a mixture of 1,4- and 1,3-dichlorobenzenes, a temperature of -33° to -38° C. is preferred during the first stage of the process. The feed material containing the dichlorobenzene isomers is kept at -33° to -35° C. for a period of 1 to 9 hours depending on the size of the crystallizer. At the end of the crystallization cycle, the material is subjected to a melt cycle preferably to about -15° C. for 1,3-dichlorobenzene) and the product and the reject are separated. Normally the melt cycle is carried out very slowly. Preferably the time required to reach the desired temperature is 1 to 12 hours. The first cycle crystallization can be carried out in one crystallizer or in multiple crystallizers, in parallel.
The 1,3-dihalobenzene from the first cycle normally has a purity of 97 to 98%. This can be further improved to 99% by using a second stage crystallization. The second stage crystallization is normally carried out at slightly higher temperature, preferably very close to the melting/freezing point of the 1,3-dihalobenzene. For 1,3-dichlorobenzene isomer, a temperature of -28° C. is ideal for the second stage crystallization. If the reject material from the crystallizer is below the eutectic point, it is then subjected to another polyethylene glycol treatment to improve the 1,3-isomer content before being fed to the crystallizer.
The polyethylene glycol used during the complex formation can be recovered and reused. Typically the spent polyethylene glycol is distilled under very high vacuum, preferably less than 10 mm of Hg, to recover the absorbed organic matter from the polyethylene glycol. Once the organic matter is removed, the polyethylene glycol is suitable for another round of selective absorption. It is not essential that the recovered polyethylene glycol from the distillation be collected as an overhead product. It also can be transferred from the still bottom directly to another selective reaction system.
In the case of dichlorobenzene, if the mixture contains any 1,2-dichlorobenzene, it will not be significantly affected by the polyethylene glycol treatment and will be collected in the filtrate. This may be removed by distillation to achieve high purity for 1,3-dichlorobenzene.
The following examples are illustrative of the present invention, however, it will be understood that the invention is not limited to the specific details set forth therein.
EXAMPLE 1
In this example, a mixture of dichlorobenzenes containing 1,4-, 1,3- and 1,2-dichlorobenzene isomers is used to illustrate the ability of polyethylene glycol to remove 1,4-dichlorobenzene (p-DCB) selectively from a mixture containing both 1,2- and 1,3-dichlorobenzenes. This also illustrates the effect of polyethylene glycol loading in the removal of p-DCB. In this example, a 50% loading of polyethylene glycol with a molecular weight of 8,000 is used.
The reaction was carried out in a round bottom flask. Dichlorobenzene (250 grams) with a composition of 53.61% 1,3-dichlorobenzene, 21.70% 1,4-dichlorobenzene and 24.18% 1,2-dichlorobenzene was charged into the reaction flask. Powdered polyethylene glycol (27.12 grams) with a molecular weight of 8,000 was added to the reaction flask. The material was slowly heated to 50° C. while stirring for a period of 20 to 25 minutes. When all the polyethylene glycol dissolved in the reaction mass, the heating and the stirring was discontinued and the material was slowly cooled down to room temperature (18° to 20° C). The cooled reaction mass was filtered through a 10 μM filter paper using a vacuum at about 150 mm of Hg.
The results obtained in Example 1 are summarized in Table 1.
EXAMPLES 2-4
Examples 2-4 were carried out as described in Example 1, using the same starting material and reaction conditions, except increasingly higher loading of polyethylene glycol was used in each subsequent example. The amount and percentage of polyethylene glycol loading, as well as a summary of results obtained in each example, is set forth in Table 1. These four examples illustrate the effect of increasingly higher loading of polyethylene glycol in the removal of 1,4-dichlorobenzene. As shown in Table 1, the higher the loading of the polyethylene glycol used in the method, the purer the 1,3-dichlorobenzene obtained in the final product.
TABLE 1__________________________________________________________________________EFFECT OF INCREASED PEG LOADINGEXAMPLES 1 THROUGH 4__________________________________________________________________________FEED WEIGHT OF PEG % WEIGHT 1,3 DCBEXAMPLE ADDED PEG OF FEED % % % SELECTIVITYNUMBER (Grams) LOADING.sup.3 (Grams) 1,3 DCB 1,4 DCB 1,2 DCB %__________________________________________________________________________1 27.12 50 250 53.61 21.7 24.18 71.192 40.69 75 250 53.61 21.7 24.18 71.193 54.25 100 250 53.61 21.7 24.18 71.194 67.8 125 250 53.61 21.7 24.18 71.19__________________________________________________________________________ PRODUCT WEIGHT OF % % % 1,3 DCB 1,3 DCB EXAMPLE PRODUCTS 1,3 1,4 1,2 SELECTIVITY.sup.1 YIELD.sup.2 NUMBER (Grams) DCB DCB DCB % %__________________________________________________________________________ 1 193 62.2 9.95 27.85 86.21 89.56 2 161 66.1 6.15 27.19 91.48 79.4 3 122 68.5 4.9 26.6 93.32 62.35 4 82 68.7 4.8 26.5 93.46 42.03__________________________________________________________________________ NOTE: ##STR1## either the % or the weight in gm may be used ##STR2## .sup.3 PEG loading is based on the amount of 1,4dichlorobenzene present i the feed.
EXAMPLE 5
This example illustrates the effect of polyethylene glycol to remove 1,4-dichlorobenzene from a mixture containing only 1,3- and 1,4-dichlorobenzenes. Polyethylene glycol, in a powdered form and having a molecular weight 8,000, was loaded to 100% by weight to that of 1,4-dichlorobenzene. The reaction was carried out as a one step process as described in the previous examples.
Dichlorobenzene (250 grams) with a composition of 75% 1,3-dichlorobenzene and 25% 1,4-dichlorobenzene was charged into a two liter round bottom flask. A powdered form of polyethylene glycol (62.5 grams) having a molecular weight of 8,000 was charged into the reactor. The reaction mixture was heated to approximately 55° C. and stirred with a mechanical stirrer. The heating and stirring was discontinued (after 25 minutes) once the polyethylene glycol was completely dissolved in the dichlorobenzene mixture. The reaction mixture was cooled to room temperature (18° to 20° C.) and filtered using a 10 μM filter paper under vacuum. The collected filtrate (150 grams) consisted of 92% 1,3-dichlorobenzene and 8% 1,4-dichlorobenzene.
1,3-dichlorobenzene in the starting material: 75%
1,3-dichlorobenzene in the product: 92%
Yield of 1,3-dichlorobenzene: 73.6%
Charge of polyethylene glycol: 100% by weight of 1,4-dichlorobenzene
EXAMPLE 6
This example illustrates the ability of polyethylene glycol to remove 1,4-dichlorobenzene from a mixture containing 1,3- and 1,4-dichlorobenzene, as described in Example 5, with the exception that the polyethylene glycol was added in equal amounts, in two different steps. A powdered form of polyethylene glycol having a molecular weight of 8,000 was used for this reaction.
Step 1: Dichlorobenzene (250 grams) with a composition of 75% 1,3-dichlorobenzene and 25% 1,4-dichlorobenzene was charged into a two liter reaction flask. Polyethylene glycol (31.25 grams) having a molecular weight of 8,000 was added to the reactor and the mixture was heated to 50° C. during a 20 minute period under stirring. During the heating cycle, the polyethylene glycol completely dissolved in the dichlorobenzene mixture. The reaction mixture was then cooled down to room temperature (18° to 20° C.) and filtered using a 10 μM filter paper. The collected filtrate (200 grams) consisted of 86% 1,3-dichlorobenzene and 14% of 1,4-dichlorobenzene.
1,3-dichlorobenzene in the starting material: 75%
1,3-dichlorobenzene in the product: 86%
Yield of 1,3-Dichlorobenzene in Step 1: 91.73%
Charge of polyethylene glycol in Step 1: 50% by weight of 1,4-dichlorobenzene
Step 2: The filtrate (200 grams) obtained from Step 1 was further treated with polyethylene glycol as described in Step 1. The material was transferred to a two liter round bottom flask and polyethylene glycol (31.25 grams) was added and processed as described in Step 1. The collected filtrate (153 grams) consisted of 93% 1,3-dichlorobenzene and 7% 1,4-dichlorobenzene.
1,3-dichlorobenzene in the starting material: 86%
1,3-dichlorobenzene present in the product: 93%
Yield of 1,3-dichlorobenzene in Step 2: 82.73%
Over-all yield of 1,3-dichlorobenzene: 75.89%
EXAMPLE 7
This example illustrates the improved performance of polyethylene glycol at low temperatures in removing 1,4-dichlorobenzene from a mixture of 1,3- and 1,4-dichlorobenzenes.
Dichlorobenzene (250 grams) with a composition of 75% 1,3-dichlorobenzene and 25% 1,4-dichlorobenzene was charged into a two liter round bottom reaction flask containing powdered polyethylene glycol (62.5 grams) having a molecular weight of 8,000. The reaction flask was heated slowly to dissolve the polyethylene glycol in the dichlorobenzene mixture. This was achieved at about 50° C. after a 20 minute period, under mechanical stirring. The molten material is then allowed to cool down to around -5° C. in a refrigerated bath. The resultant slush was filtered under vacuum using a 25 μM filter paper. The collected filtrate (46.5 grams) had a composition of 95% 1,3-dichlorobenzene and 5% 1,4-dichlorobenzene.
1,3-dichlorobenzene in the starting material: 75%
1,3-dichlorobenzene in the product: 95%
Yield of 1,3-dichlorobenzene: 23.56%
Polyethylene glycol loading: 100% by weight to that of 1,4-dichlorobenzene
Filtration temperature: -4° to 2° C.
EXAMPLE 8
This example illustrates that a higher yield is achieved by carrying out the polyethylene glycol treatment in two steps, instead of one step. This example was carried out as described in Example 7, except two steps were used.
Step 1: Dichlorobenzene (250 grams) containing 75% 1,3-dichlorobenzene and 25% 1,4-dichlorobenzene was charged into a two liter reaction flask containing of powdered polyethylene glycol (31.25 grams) having a molecular weight of 8,000. The reaction flask was heated slowly for about 20 minutes (to about 50° C.) under mechanical stirring to dissolve the polyethylene glycol in the dichlorobenzene mixture. At the end of the heating cycle, the stirring was discontinued and the material was slowly cooled down to around -5° C. in a refrigerated bath. The resultant slurry was filtered under vacuum using a 25 μM filter paper. The filtrate (130 grams) consisting of 88% 1,3-dichlorobenzene and 12% 1,4-dichlorobenzene was collected as the product.
1,3-dichlorobenzene in the starting material: 75%
1,3-dichlorobenzene in the product: 88%
Yield of 1,3-dichlorobenzene in Step 1: 61%
Polyethylene glycol loading in Step 1: 1/2 of 100% by weight to that of 1,4-dichlorobenzene
Filtration temperature in Step 1: -4° to 2° C.
Step 2: The filtrate (130 grams) collected from Step 1 was further treated with polyethylene glycol using the procedure as described in Step 1. A fresh loading of polyethylene glycol (31.25 grams) was used during this step. The collected filtrate (72 grams) consisted of 96.5% 1,3-dichlorobenzene and 3.5% 1,4-dichlorobenzene.
1,3-dichlorobenzene in the starting material: 88%
1,3-dichlorobenzene in the product: 96.5%
Yield of 1,3-dichlorobenzene in Step 2: 60.73%
Polyethylene glycol loading in Step 2: 1/2 of 100% by weight to that of starting 1,4-DCB
Filtration temperature in Step 2: -4° to 2° C.
Overall yield for 1,3-dichlorobenzene: 37.06%
EXAMPLE 9
This example illustrates the efficacy of carrying out the reaction with polyethylene glycol at lower temperature and the ability to recover the organic matter from the spent glycol.
Step 1: Use of polyethylene glycol at lower temperature
Dichlorobenzene (100 grams) with a composition of 51.0% 1,3-dichlorobenzene, 25.9% 1,4-dichlorobenzene and 22.9% 1,2-dichlorobenzene was charged in to a one liter round bottom flask containing powdered polyethylene glycol (26 grams) having a molecular weight of 8,000. The reaction mass was kept at around 25° C. under mechanical agitation for 2 hours. The reaction mass was then filtered at room temperature under vacuum using a 10 μM filter paper. The filtrate (51 grams) with a composition of 63.6% 1,3-dichlorobenzene, 6.59% 1,4-dichlorobenzene and 29.18% 1,2-dichlorobenzene was collected as the product. The wet residue (65.8 grams) was also collected from this step.
1,3-dichlorobenzene in the starting material: 51% (51 grams)
1,3-dichlorobenzene in the product: 63.6% (32.44 grams)
1,4-dichlorobenzene in the starting material: 25.9% (25.9 grams)
1,4-dichlorobenzene in the product: 6.59% (3.36 grams)
Selectivity of 1,3-DCB in the product on the basis of 1,4- and 1,3-DCB's only: 90.6%
Selectivity of 1,3-DCB in the starting material on the basis of 1,4-and 1,3-DCB: 66.31%
Step 2: Recovery of organic matter from the spent polyethylene glycol
The residue (65.8 grams) obtained from Step 1 was transferred in to a 250 ml round bottom three neck flask connected with a vacuum distillation head, condenser, a 200 ml collection flask and a thermometer. The distillation flask was heated to around 85° C. under a vacuum of 5 mm of Hg. The absorbed dichlorobenzene from the polyethylene glycol was distilled off (vapor temperature 65° C.) and collected in the collection flask. The collection was continued until an increase in the distillation temperature was noticed. Heating was then discontinued and samples were collected from the still bottom and the product for analysis of chlorobenzene content. The details of the analysis are given below:
______________________________________Starting II III IVmaterial Product Distillate Residuestep 1 step 1 step 2 step 2% gms % gms % gms % gms______________________________________1,3-DCB 51.00 51.00 63.60 32.40 35.82 12.31 36.36 3.801,4-DCB 25.90 25.90 6.59 3.36 49.89 17.14 29.18 3.051,2-DCB 22.40 22.40 29.18 11.42 14.29 4.91 34.45 3.60Total 100.00 47.18 34.36 10.45(grams)______________________________________ Total starting material (Column I): 100 grams Total recovered materials (Columns I, II, III and IV): 91.99 % Recovery of organics: 91.99% Total polyethylene glycol recovered: 20.9 grams % Recovery of polyethylene glycol: 80%
EXAMPLE 10
This example illustrates the efficacy of reusing the recovered polyethylene glycol in the selective absorption of 1,4-dichlorobenzene from a mixture of 1,3- and 1,4 dichlorobenzenes.
Dichlorobenzene (80 grams) with a composition of 75% 1,3-dichlorobenzene and 25% 1,4-dichlorobenzene was charged into a one liter round bottom flask containing the recovered polyethylene glycol from Step 2 of Example 9 (equal to 20.9 grams polyethylene glycol). The reaction mass was slowly heated to around 50° C. during a period of 25 to 30 minutes under mechanical stirring and the polyethylene glycol was dissolved in the organic mass. The reaction mass was then cooled down to room temperature 18° to 20° C.) and the precipitated polyethylene glycol was filtered under vacuum using a 10 μM filter paper. Dichlorobenzene (52 grams) was recovered having a composition of 92% 1,3-dichlorobenzene and 8% 1,4-dichlorobenzene.
1,3-dichlorobenzene in the starting material: 75% (60 grams)
1,4-dichlorobenzene in the starting material: 25% (20 grams)
Polyethylene glycol used: effective 20.9 grams as recycled
1,3-dichlorobenzene in the product: 92% (47.8 grams)
EXAMPLE 11
This example illustrates the efficacy of combining the polyethylene glycol process and a low temperature crystallization process to improve the purity of 1,3-dichlorobenzene to above 98%.
Step 1: Treatment with polyethylene glycol
Dichlorobenzene (250 grams) with a composition of 75% 1,3-dichlorobenzene and 25% 1,4-dichlorobenzene was charged into a two liter reaction flask containing powdered polyethylene glycol (62.5 grams) having a molecular weight of 8,000. The reaction mixture was heated to 50° C. under mechanical stirring to dissolve the polyethylene glycol in the dichlorobenzene mixture. The heating and stirring was discontinued after 30 minutes, when all at the polyethylene glycol dissolved in the dichlorobenzene mixture. The reaction mixture was cooled to around 18° to 20° C. and the precipitate polyethylene glycol was filtered under vacuum using a 10 μM filter paper. The collected filtrate (145 grams) consisted of 92% 1,3-dichlorobenzene and 8% 1,4-dichlorobenzene.
% of 1,3-dichlorobenzene in the starting material: 75% (187.5 grams )
% of 1,3-dichlorobenzene in the product after treatment with polyethylene glycol: 92% (133.4 grams)
Yield of 1,3-dichlorobenzene in Step 1: 71.1%
Step 2: Low temperature crystallization
The dichlorobenzene obtained from Step 1 was transferred to a laboratory microcrystallization apparatus capable of cooling the charge below -35° C. The crystallizer charge was kept between -30° to -38° C. for around 3 hours. At the completion of the freezing cycle, the temperature of the frozen material was slowly raised to -25° C. and the mother liquor obtained during the process was withdrawn from the crystallizer unit. The frozen material was melted uniformly by increasing the temperature of the crystallizer to around -15° C. The steps involved in the crystallization were repeated for a total of three times. The product (13 grams) collected in the final step had a purity of 99.1% 1,3-dichlorobenzene.
EXAMPLE 12
This example illustrates the efficacy of using polyethylene glycol in the selective removal of 1,4-dibromobenzene from a mixture of 1,4- and 1,3-dibromobenzenes.
A synthetic mixture (30 grams) of 1,3- and 1,4-dibromobenzene with a composition of 67% and 33% respectively was charged into a 250 ml reaction flask containing powdered polyethylene glycol (4 grams) having a molecular weight of 8,000. The reaction mixture was heated to around 60° C. and the polyethylene glycol was dissolved in the dibromobenzene mixture. The material was slowly cooled down to around 20° to 25° C. and filtered through a 10 μM filter paper under vacuum. The product (12.5 grams) having a composition of 86% 1,3-dibromobenzene and 14% 1,4-dibromobenzene was collected as the product.
1,3-dibromobenzene in the starting material: 67% (20.1 grams)
1,4-dibromobenzene in the starting material: 33% (9.9 grams)
1,3-dibromobenzene in the product: 86% (10.75 grams)
1,4-dibromobenzene in the product: 14% (1.75 grams)
Amount of polyethylene glycol used: 40% by weight to that of 1,4-dibromobenzene (4 grams).
EXAMPLE 13
This example shows the use of a polyethylene glycol with a higher molecular weight to remove 1,4-dichlorobenzene from a mixture containing 1,3- and 1,4-dichlorobenzene.
Dichlorobenzene (100 grams) with a composition of 55.31% 1,3-dichlorobenzene, 21.71% 1,4-dichlorobenzene and 22.30% 1,2-dichlorobenzene was charged into a two liter round bottom flask. Granulated polyethylene glycol (22 grams) having a molecular weight of 35,000 was added into the reactor. This constitutes a weight ratio of the polyethylene glycol to 1,4 DCB of 1:1. The reaction mixture was heated to about 80° C. under mechanical stirring. The heating was discontinued (after 25 to 30 minutes) when all of the polyethylene glycol was dissolved in the chlorobenzene mixture. The reaction mixture was then cooled to 18° C. and filtered through a 10 μM filter paper under vacuum. The collected filtrate (48.5 grams) consisted of 69.26% 1,3-dichlorobenzene, 4.27% 1,4-dichlorobenzene and 26.5% 1,2-dichlorobenzene.
Selectivity of 1,3-DCB in starting material (excluding 1,2-DCB): 71.80%
Selectivity of 1,3-DCB in the product (excluding 1,2-DCB): 94.19%
Yield of 1,3-DCB: 60.73%
EXAMPLE 14
Characteristics of Polyethylene glycol DCB complex
The polyethylene glycol complex with dichlorobenzene (mainly 1,4-dichlorobenzene) is a gelantious solid as it separates out in the chlorobenzene mixture. When the complex is filtered and separated from the dichlorobenzene which is not part of the complex, a material is recovered which is a grayish white powder at room temperature. The properties of the complex vary, depending on the molecular weight and the loading of polyethylene glycol in the dichlorobenzene mixture. The following properties were observed for complexes formed by the reacting equal weights of polyethylene glycol having molecular weights of 4,000 and 35,000, respectively, with 1,4-dichlorobenzene.
______________________________________ PEG Complex PEG Complex______________________________________PEG Molecular weight 4,000 35,000Color Off White Off White (cream) (cream)Appearance Powder PowderMelting point; °C. 72-77 75-80Bulk density; gm/cc 1.0385 1.105DCB content; (wt/wt) % ˜45 ˜45______________________________________
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1,3-dihalobenzene, particularly 1,3-dichlorobenzene, is produced in high efficiency from a mixture containing the subject compound and its corresponding 1,4-isomer by a special process in which the dihalobenzene mixture is treated with polyethylene glycols of varying molecular weight and the resulting slurry is filtered to remove a complex of 1,4-dihalobenzene and polyethylene glycol as a solid and the 1,3-dihalobenzene as the filtrate.
The 1,4-dihalobenzene complexed with the polyethylene glycol can be recovered by a flash distillation under vacuum and the residue containing the polyethylene glycol can be recycled.
The purity of the 1,3-dihalobenzene obtained by this process can further be improved by subjecting the product obtained after the polyethylene glycol treatment to a low temperature crystallization process where 1,3-dihalobenzene can be selectively crystallized to a purity of above 99%.
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RELATED APPLICATIONS
This is a divisional application of application Ser. No. 13/099,592 filed on May, 3, 2011 which is a continuation of application Ser. No. 12/448,839 having a filing date of Feb. 16, 2010 which claims priority to PCT/GB2008/000079 having an International filing date of Jan. 9, 2008, and are herein incorporated by reference.
BACKGROUND OF THE INVENTION
Traditionally there are two types of beverage dispensers, those which dispense a beverage into an open drinking receptacle and those which dispense a pre-closed container of beverage, for example a can, commonly known as beverage vending machines.
Beverage dispensers which produce a beverage from a concentrate and a diluent are advantageous in that they require only shipping of concentrate, not of diluted beverage. These type of dispensers are known to dispense a variety of beverages from different concentrates. These machines typically either have one dispense nozzle per beverage or have a single nozzle and the user manually places a cup under said nozzle.
In some circumstances it is desirable to locally produce a beverage, package it in a closed container, and then dispense the container containing the beverage. Such machines are generally limited to a single product, e.g. water, and do not offer the variety of product demanded by customers. To do so would either require a complex positional mechanical solution to place a packet under the desired dispense nozzle or alternatively use a common nozzle. Any miss alignment of package and nozzle will result in spillages inside the machine where they are not visible and could possibly sit for some time before being cleaned. Furthermore, the use of a common nozzle is undesirable due to cross contamination of flavours.
In addition, in such a vending machine application the parts of the machine used to produce the beverage are not easily cleaned as they are generally enclosed within the machine which is only opened by a service engineer resulting in a machine that is hard to maintain in a clean and safe condition.
It is the purpose of the present invention to provide a sanitary beverage dispenser for filling and dispensing containers of different flavoured beverage.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided an apparatus for introducing a selected beverage into a container, sealingly closing said container and dispensing said closed container, the apparatus comprising:
a housing adapted to, in use, accept a plurality of containers of beverage concentrate each container having a concentrate pump and flexible conduit, terminating in a nozzle, associated therewith, a plurality of drivers adapted to drive said concentrate pumps; a means of, in use, introducing diluent to the pumped concentrate to produce a beverage; a multiple dispense head for accepting the plurality of nozzles; a means for, in use, selecting a flexible pouch and bringing it into alignment with a nozzle in a filling position where it is filled via an opening therein; and a means for, in use, sealingly closing said opening and dispensing said filled sealed flexible pouch from said apparatus, wherein the filling position is a fixed position and, in use, said nozzles are movable relative to the filling position such that any of said plurality nozzles can be presented at said filling position.
The pump and drive and driver constructions are set forth and shown in PCT/GB2008/000080 having an International filing date of Jan. 9, 2008 and for which a National Stage application was filed on the same date as the present application and which PCT and U.S. National Stage application is hereby incorporated by reference as if fully set forth herein.
Preferably, in use, the multiple dispense head maintains the nozzles in an array.
In a first preferred arrangement, in use, the multiple dispense head maintains the nozzles in a linear array and the apparatus is provided with means for linearly indexing said multiple dispense head so as to, in use, present the nozzle associated with the required beverage above the opening in the flexible pouch.
According to a second preferred arrangement, in use, the multiple dispense head maintains the nozzles in a circular or radial array and the apparatus is provided with means for radially indexing said multiple dispense head so as to, in use, present the nozzle associated with the required beverage above the opening in the flexible pouch.
According to a third preferred arrangement, in use, the nozzles associated with each mixed beverage are maintained in a horizontal array, and the apparatus is provided with means to move each nozzle in both the horizontal and vertical axis from its stored position to the filling position.
In all three arrangements the apparatus preferably further comprises means for, in use, bringing into selective co-operation the opening of the flexible pouch and the required nozzle. Preferably the means for bringing into selective co-operation the opening of the flexible pouch and the required nozzle comprises providing relative vertical movement between said pouch and said nozzle thereby bringing them into contact with one another.
In one preferred arrangement the apparatus has a single fixed filling position to which the pouches are presented and at which the opening of the flexible pouch and the required nozzle are brought into selective co-operation.
Preferably, the apparatus comprises at least one source of diluent which may include a valve controlling flow of diluent from the source. In a preferred arrangement the apparatus comprises at least two sources of diluent, at least one of which is carbonated and one of which is un-carbonated. Preferably the apparatus includes a carbonator to carbonate one source of diluent.
In one preferred arrangement the means of introducing the diluent to the concentrate introduces said diluent immediately downstream of the concentrate pump.
In an alternative preferred arrangement the means of introducing the diluent to the concentrate introduces said diluent immediately prior to the nozzle.
Preferably, the apparatus further comprises a means for receiving a cartridge or bandolier containing a plurality of flexible pouches. More preferably the apparatus comprises means for receiving a plurality of cartridges or bandoliers containing a plurality of flexible pouches. Preferably the flexible pouches are interlinked so as to form a chain.
Preferably, flexible pouches from each cartridge or bandolier are fed to the filling position. In one preferred arrangement each bandolier or cartridge has its own fixed filling position. Preferably the filling positions are adjacent each other and the array of nozzles are movable such that each nozzle can be presented at any one of said fixed filling positions.
Preferably the apparatus comprises a means for opening a closure in said pouch prior to it being filled. In one preferred arrangement the means opening a closure comprises removing the cap from an opening in the pouch, preferably by unscrewing it. In an alternative preferred arrangement means for opening a closure comprises rotating or moving a first part of the closure respective a second part of the closure, the relative movement opening a flowpath therethrough.
According to a second aspect of the invention there is provided an apparatus in accordance with the first aspect of the invention in combination with a plurality of concentrate reservoirs, each having a concentrate pump and flexible conduit, terminating in a nozzle, associated therewith.
Preferably the concentrate pump, conduit and nozzle are disposable.
Preferably the concentrate pump, conduit and nozzle comprise a unitary component.
According to a third aspect of the invention there is provided an apparatus in accordance with the first or second aspect of the invention in combination with at least one cartridge or bandolier of flexible pouches.
Preferably each flexible pouch has a rigid spout comprising a mixing element. More preferably the mixing elements extend into the pouch.
In one preferred embodiment of the third aspect of the invention, the apparatus further comprising a controller, the controller configured to control the loading of a concentrate reservoir into the apparatus by driving the apparatus in the following steps:
a) controlling the apparatus to arrange a flexible pouch at the filling position; b) operating the driver to couple it with the concentrate pump; c) operating the driver to draw fluid into the concentrate pump to substantially fill pump cavities therein; d) continuing to operate the driver to pump fluid through the concentrate pump, flexible conduit and nozzle to substantially eliminate any air or other gasses from any of the cavities therein, the pumped fluid emitting into the flexible pouch; e) controlling the apparatus to sealingly close the flexible pouch; and f) releasing the flexible pouch for disposal.
In another preferred embodiment of the third aspect of the invention, the concentrate pump comprises at least one barrel having an inlet valve and an outlet valve associated therewith and a piston, movable within the barrel to change the enclosed volume of the barrel between a minimum and a maximum volume to draw fluid into, and pump fluid from, said barrel via said inlet valve and outlet valve respectively, and further comprises a controller, the controller configured to control the disengagement of a concentrate pump from the apparatus by driving the apparatus in the following steps:
a) controlling the apparatus to arrange a flexible pouch at the filling position; b) operating the driver to return each piston to its position wherein the enclosed volume of the barrel is substantially at its minimum thereby ejecting any fluid contained within the enclosed volume into the flexible pouch to substantially empty said concentrate pump; and c) operating the driver to de-couple the drive mechanism from the removable concentrate pump to allow for its removal.
Preferably the controller is further configured to:
d) operate the apparatus to sealingly close the flexible pouch; and e) release said flexible pouch for disposal.
In yet another preferred embodiment of the third aspect of the invention the concentrate pump comprises at least one barrel having an inlet valve and an outlet valve associated therewith and a piston, movable within the barrel to change the enclosed volume of the barrel between a minimum and a maximum volume to draw fluid into, and pump fluid from, said barrel via said inlet valve and outlet valve respectively, and further comprises a controller, the controller configured to control the changing of a concentrate reservoir driving the apparatus in the following steps:
a) operating, the apparatus to arrange a flexible pouch at the filling position; b) operating the driver to return each piston of a first concentrate pump to its position wherein the enclosed volume of the barrel is substantially at its minimum thereby ejecting any fluid contained within the enclosed volume into the flexible pouch to substantially empty said first concentrate pump; c) operating the driver to de-coupling itself from the first concentrate pump and associated concentrate reservoir enabling it to be removed and a concentrate reservoir and associated second concentrate pump to be inserted; d) operating the drive mechanism to couple the drive mechanism to the second concentrate pump; e) operating the drive mechanism to draw fluid into the second concentrate pump to substantially fill the cavities therein; f) operating the drive mechanism to pump fluid through the second concentrate pump to substantially eliminate any air or other gasses from the cavities therein, the fluids expelled from the second concentrate pump collecting in said flexible pouch; g) operating the apparatus to sealingly close the flexible pouch; and h) releasing the flexible pouch from the apparatus for disposal.
Preferably, subsequent to coupling the drive mechanism to the second concentrate pump and prior to sealingly closing the flexible pouch the controller is further configured to simultaneously operate the driver to pump concentrate through the concentrate pump to substantially eliminate any air or other gasses from the cavities therein, and control the diluent valve to add diluent into the pumped concentrate such that the downstream of the pump cavities, the flexible conduit and nozzle becomes primed with a diluted mixture of concentrate and diluent.
Preferably the controller is configured to operate the diluent valve such that sufficient mixture of concentrate and diluent are passed through the concentrate pump and into the flexible pouch such that the flexible conduit and nozzle are primed with a substantially homogeneous mixture of diluent and concentrate at a required concentrate:diluent ratio.
Preferably the removable concentrate pump has a diluent inlet downstream of its outlet valves and the controller is further configured to control the diluent valve such that, once both pistons are returned to the position wherein the enclosed volume of the barrels is substantially at its minimum, diluent is passed through the concentrate pump to substantially flush the concentrate from the flexible conduit and nozzle, downstream of the diluent inlet, into the flexible pouch.
In a further preferred embodiment of the third aspect of the invention, wherein the dispenser has a supply of carbonated diluent and a supply of non carbonated diluent, the controller is configured to control dispense of a carbonated beverage into a flexible pouch in the following steps:
a) controlling the apparatus to arrange a flexible pouch at the filling position; b) operating the driver to pump fluid through the concentrate pump; c) introducing carbonated diluent to the concentrate flow downstream of the concentrate pump and upstream of the flexible conduit, such that the pouch is filled; via the flexible conduit, with a diluted carbonated beverage; d) prior to completion of the dispense, controlling the apparatus to stop the flow of carbonated diluent and to start a flow of non-carbonated diluent such that at least the flexible conduit becomes filled with non carbonated diluted concentrate; e) controlling the apparatus to stop the flow of concentrate and non carbonated diluent; f) controlling the apparatus to sealingly close the flexible pouch; and g) releasing the flexible pouch.
In this way, after dispensing a carbonated beverage into the pouch, the residual fluid left in the flexible conduit is non carbonated. This helps to prevents drips from the nozzle as, were the flexible conduit left with residual carbonated fluid therein, over time the dissolved gasses would break out of the fluid and expand in volume thereby forcibly ejecting fluid out of the nozzle.
According to a fourth aspect of the invention there is provided a method of loading a concentrate reservoir into the apparatus according to the third aspect of the invention comprising the steps of:
a) aligning the nozzle of the concentrate reservoir with the filling position; b) arranging a flexible pouch at the filling position; c) coupling the drive mechanism to the concentrate pump; d) operating the driver to draw fluid into the concentrate pump to substantially fill pump cavities therein; e) pumping fluid through the concentrate pump, flexible conduit and nozzle to substantially eliminate any air or other gasses from cavities therein; f) collecting any fluids expelled from the nozzle in said flexible pouch; g) sealingly closing the flexible pouch; and h) disposing of said flexible pouch.
Preferably the concentrate pump has a diluent inlet downstream of the pump cavities and the method further comprises the step of, simultaneously operating the drive mechanism to pump concentrate through the concentrate pump to substantially eliminate any air or other gasses from the cavities therein, adding diluent into the pumped concentrate such that, downstream of the pump cavities, the flexible conduit and nozzle becomes primed with a diluted mixture of concentrate and diluent.
Preferably sufficient mixture of concentrate and diluent is passed through the concentrate pump and into the flexible pouch such that the flexible conduit and nozzle are primed with a substantially homogeneous mixture of diluent and concentrate at a required concentrate:diluent ratio.
According to a fifth aspect of the invention there is provided a method of disengaging a concentrate pump from an apparatus according to the third aspect of the invention, the concentrate pump comprising at least one barrel having an inlet valve and an outlet valve associated therewith and a piston, movable within the barrel to change the enclosed volume of the barrel between a minimum and a maximum volume to draw fluid into, and pump fluid from, said barrel via said inlet valve and outlet valve respectively, said method comprising the steps of:
a) aligning the nozzle associated with the concentrate pump with the filling position; b) arranging a flexible pouch at the filling position; c) returning each piston to its position wherein the enclosed volume of the barrel is substantially at its minimum thereby ejecting any fluid contained within the enclosed volume into the flexible pouch to substantially empty said concentrate pump; d) de-coupling the drive mechanism from the concentrate pump; and e) removing the substantially empty concentrate pump from the drive mechanism.
In a preferred arrangement the method further includes the steps of:
f) sealingly closing the flexible pouch; and g) disposing of said flexible pouch.
Preferably the concentrate pump has a diluent inlet downstream of its outlet valves and the method further comprises the step of, once both pistons are returned to the position wherein the enclosed volume of the barrels is substantially at its minimum, passing diluent through the concentrate pump to substantially flush the pumped fluid from the flexible conduit and nozzle, downstream of the diluent inlet, into the flexible pouch.
According to a sixth aspect of the invention there is provided a method of changing a concentrate pump of the third aspect of the invention, the concentrate pump comprising at least one barrel having an inlet valve and an outlet valve associated therewith and a piston, movable within the barrel to change the enclosed volume of the barrel between a minimum and a maximum volume to draw fluid into, and pump fluid from, said barrel via said inlet valve and outlet valve respectively, said method comprising the steps of:
a) aligning the nozzle of the concentrate reservoir with the filling position; b) arranging a flexible pouch at the filling position; c) returning each piston to its position wherein the enclosed volume of the barrel is substantially at its minimum thereby ejecting any fluid contained within the enclosed volume into the flexible pouch to substantially empty said first concentrate pump; d) de-coupling the drive mechanism from the first concentrate pump; e) removing the substantially empty first concentrate pump from the drive mechanism; f) inserting a second concentrate pump into the drive mechanism; g) coupling the drive mechanism to the second concentrate pump; h) operating the drive mechanism to draw fluid into the second concentrate pump to substantially fill the cavities therein; i) operating the drive mechanism to pump fluid through the second concentrate pump to substantially eliminate any air or other gasses from the cavities therein; j) collecting any fluids expelled from the second concentrate pump in said flexible pouch; k) sealingly closing the flexible pouch; and l) disposing of said flexible pouch.
Preferably the concentrate pump has a diluent inlet downstream of the outlet valves and the method further comprises the step of, once both pistons are returned to the position wherein the enclosed volume of the barrels is substantially at its minimum, passing diluent through the concentrate pump to substantially flush any concentrate downstream of the concentrate pump through the flexible conduit and nozzle and into the flexible pouch.
Preferably the concentrate pump has a diluent inlet downstream of the outlet valves and the method further comprises the step of, simultaneously to operating the drive mechanism to pump concentrate through the concentrate pump to substantially eliminate any air or other gasses from any the cavities therein, adding diluent into the pumped concentrate such that, downstream of the diluent inlet, the pump, flexible conduit and nozzle become primed with a diluted mixture of concentrate and the diluent.
Preferably sufficient mixture of concentrate and diluent is passed through the concentrate pump and into the flexible pouch such that the flexible conduit and nozzle are primed with a substantially homogeneous mixture of diluent and concentrate at the required diluent:concentrate ratio.
By operating in the method as described in relation the fourth, fifth and sixth aspects of the invention, a reservoir of concentrate, together with its associated concentrate pump, flexible conduit and nozzle, can be removed and/or inserted ready for use in a manner in which any waste fluids emitted from the apparatus as a result thereof are captured in a flexible pouch which is then sealed and disposed of. In this manner a reservoir of concentrate, together with its associated concentrate pump, flexible conduit and nozzle can be changed in a clean manner.
According to a seventh aspect of the invention there is provided a flexible pouch for containing a liquid comprising at least two sides of flexible material, sealed along their edges to form a pouch and a rigid spout in an opening of the container, wherein said spout comprises a mixing element to assist the mixing of any fluid entering said flexible pouch via said spout.
Preferably the mixing element extends into said pouch.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described in detail, by way of example, with reference to the following drawings in which:
FIG. 1 is a perspective view of the apparatus with the door open;
FIG. 2 is a perspective view of the apparatus showing detail of the nozzle block;
FIG. 3 is a perspective view of the apparatus with the door open showing how the bandolier of flexible pouches are loaded.
FIG. 4 is an exploded view of a pump cartridge for use in the invention without the flexible conduit;
FIG. 5 is a perspective view of a pump cartridge for use in the invention; and
FIG. 6 is a pouch according to the seventh aspect of the invention.
DETAILED DESCRIPTION
Referring to the FIGS. 1 and 2 a dispenser 2 is shown comprising an enclosure 4 containing two bandoliers 6 of flexible pouches 8 , the bandoliers 6 are led so as to present the flexible pouches 8 at a pick up point. The bandoliers 6 may contain the same sized pouches 8 or alternatively the bandoliers 6 may each contain pouches 8 of a different size. Also within the enclosure are a plurality of concentrate containers 10 containing different flavoured beverage concentrates and attached to each container is a removable pump 12 which is advantageously disposable. Each disposable pump has a water inlet and a mixer attached thereto, the water being added to the pumped concentrate and mixed therewith in the mixer. Leading from each disposable pump 12 is a flexible conduit 14 terminating in a nozzle through which the mixed beverage can be dispensed. The pump, mixer, flexible conduit and nozzle are all disposable. Each disposable pump 12 has associated therewith a pump driver 16 which is a permanent part of the dispenser. The pump driver 16 operates at the required speed to create a ratiometric mix of concentrate to water to dispense a beverage of the required concentration. The water flow through the machine has a control valve to control the flow of water and a flow sensor to measure the flow of water thereto. The signal, indicative of the water flow, is used to control the speed of the pump driver 16 to achieve the required concentrate:diluent ratio.
Each flexible pouch has an opening therein containing a rigid spout having a removable screw cap thereover. A mechanical arm 18 grips the rigid spout, detaches a flexible pouch from the bandolier, and moves it to a location where the cap is gripped and unscrewed. The pouch, without its top may then be moved to a filling position. The filling position and the cap removal location may be one and the same; this removes the necessity of moving a full pouch without a cap on between the two and therefore reduces the risk of contamination due to spills.
The dispenser has a nozzle block 20 which receives the nozzles from the various concentrate containers, the nozzles forming an array. The nozzle block 20 is movable so as to enable the required nozzle to be moved adjacent the open top of the spout of the flexible pouch 8 . As shown the nozzle block 20 forms a three by two array and is indexable in two directions X, Y. The nozzles protrude through the base of the nozzle block 20 so when the required nozzle is positioned above the flexible pouch 8 in its filling position, the pouch 8 can be moved so that its spout abuts the end of the nozzle such that when the pouch is filled via the nozzle the beverage only contacts the nozzle and the pouch, not any non disposable parts of the dispenser. In this way a sanitary dispenser can be achieved. Different arrays, e.g. four by two, six by one or rotary may of course be substituted for the array shown in FIG. 2 without departing from the invention.
When the pouch and nozzle are abutting one another the pump actuator pumps beverage concentrate and the water valve opens to dilute the concentrate. The diluent and concentrate pass through the mixer and flexible conduit 14 and exit the nozzle directly into the flexible pouch 8 . The flexible pouches 8 are stored with their sides flat against one another on the bandolier 6 and open when the beverage enters via the spout. In this manner there is negligible air within the pouch prior to filling and as such no venting of the pouch is required as it fills with beverage. When the pouch 8 is full the water control valve shuts and the pump actuator stops thereby halting the flow of beverage into the pouch. The pouch is then either moved to the lid-off station where the lid is replaced on the spout and screwed so as to form a seal, or alternatively, if the lid-off station and filling station are one and the same, the nozzle block 20 is moved clear of the top of the pouch and the lid replaced. Once the full pouch has been sealed by replacement of the lid it can be dispensed from the dispenser 2 via a chute.
The concentrate reservoir, pump, mixer, flexible conduit and nozzle form one unit which is placed in the machine. The pump assembly comprising pump, mixer, conduit and nozzle forms one integral disposable part which is disposed of each time the concentrate reservoir is changed. The pump assembly and the concentrate reservoir may be supplied as one unitary piece or alternatively may be attached to one another before being inserted into the dispenser. The pump may be of a known type, for example a diaphragm pump or alternatively may be a piston pump as described below.
Referring to FIG. 3 , when the door 22 is open a slide 24 enables the bandolier 6 of pouches 8 to be slid forwards out of the enclosure 4 . The bandolier 6 is then simply slid off an axis 26 on which it is held and a replacement slid on. The slide 24 is then pushed back into the enclosure 4 and the end of the bandolier 6 of pouches 8 is fed into a guide 28 from which one can be selected to be filled.
Referring to FIG. 4 an exploded view of a removable pump unit 12 is shown. The unit 12 is manufactured of a number of parts: a body section 32 , a cover section 34 (which may be integral to the body section moulding), two pistons 36 , 38 and valve closures (omitted for clarity). The body section 32 is a simple plastics moulding of a suitable material, for example low density polypropylene or medium or low density polyethylene (alternative longer lasting materials, for example metal could be used in situations where the pump was intended to be reusable but not removable). The cover 34 is ultrasonically welded to the body section 32 so as to enclose an open face thereof. The body section comprises an inlet 40 connected in use to a reservoir containing the substance to be pumped. The inlet 40 opens into an inlet valving chamber 42 from which two inlet valves 44 , 46 lead into the end faces of the barrels 48 , 50 of the pump unit 12 . The pump barrels 48 , 50 each have a piston 36 , 38 therein. At the highest most position on the end face of each barrel 48 , 50 is situated an outlet valve 52 , 54 leading from the barrels 48 , 50 into an outlet valve chamber 56 . By placing the outlet valves 52 , 54 at the very top of the barrels and having them situated above the inlet valves 44 , 46 the system is essentially self bleeding as any air within the barrels 48 , 50 will rise to the top of the barrel and be expelled therefrom via the outlet valves 52 , 54 and dead space in which air can collect at the top of the barrels is avoided. As the volume of air trapped in any dead space will vary from use to use, and even from stroke to stroke, good priming and eliminating dead space enables a highly repeatable pump to be effected. The inlet valves 44 , 46 and the outlet valves 52 , 54 are umbrella or flap type check valves and allow flow in the direction from the inlet 46 to the outlet 58 but not in the reverse direction. The pump unit 12 has a diluent inlet 60 to which diluent can be supplied. Situated in the mouth of the diluent inlet 60 is a diluent check valve 62 to prevent flow of concentrate from the barrels 48 , 50 into the diluent inlet. In addition the check valve operates to prevent drips from the pump via the diluent inlet when the pump is disconnected from the machine. The fluid being pumped, i.e. the beverage concentrate, and the diluent mix in the outlet valve chamber 56 and pass together through a static mixer 64 before exiting the pump unit 30 via the outlet 58 .
Referring to FIG. 5 a pump 12 with a unitary flexible conduit 66 and nozzle 68 is shown. The pump is suitable for use in the dispenser shown in FIGS. 1 to 3 and the nozzle is adapted to fit into a multiple dispense head as shown in FIG. 3 .
Referring to FIGS. 1 to 5 , when it is required to load a concentrate reservoir 10 with associated pump 12 , flexible conduit 14 and nozzle 68 onto the dispenser 2 then the dispenser places a flexible pouch 8 at the filling position for alignment with the nozzle. The concentrate reservoir 10 is placed in situ and the concentrate pump 12 and nozzle 68 are located in their desired positions. It will be noted that the flexible pouch 8 may be located at the filling point prior to, or after, the nozzle 68 of the concentrate reservoir 10 is located in the nozzle block 20 .
The pump driver 16 is then operated to engage the concentrate pump 12 and to reciprocate the pistons 36 , 38 thereof such that fluid is drawn into the pump barrels 48 , 50 via the inlet valves 44 , 46 at the bottom of the end face of the piston barrels 48 , 50 and ejected via the outlet valves 52 , 54 at the top of the pump barrels 48 , 50 . In this manner any air trapped in the barrels will rise to the top and be ejected via the outlet valves 52 , 54 thereby priming the concentrate pump 12 . Prior to use for dispensing a volumetric amount from the concentrate pump 12 , the pistons 36 , 38 are reciprocated sufficiently to substantially eliminate all the air from the pump bands 52 , 54 and valve areas. Any concentrate that passes through the pump 12 during this priming process passes through the flexible conduit 14 and nozzle 68 and is collected in the flexible pouch 8 positioned at the filling position. During this priming process diluent is supplied into the concentrate pump 12 via the diluent inlet 60 to admix with the concentrate. Sufficient concentrate and diluent are passed through the concentrate pump 12 in the priming process that any fluid retained in the pump 12 , flexible conduit 14 or nozzle 68 , downstream of the diluent inlet 60 , is substantially at the required ratio of concentrate to diluent. Again any fluid passing through the concentrate pump 12 , flexible conduit 14 and nozzle 68 to achieve this is collected in the flexible pouch 8 . In this manner when the flexible pouch 8 is removed, the dispenser 2 is ready to pump the required product at the required ratio without the inclusion of any substantial amounts of air.
When it is required to remove an empty or partially empty concentrate reservoir 10 , with associated pump 12 , flexible conduit 14 and nozzle 68 , from the dispenser then a flexible pouch 8 is presented at the filling position for alignment with the nozzle 68 prior to the disengagement of the pump driver 16 from the piston 36 , 38 .
The pump driver 16 is then operated to disengage from the concentrate pump 12 . As the pistons 36 , 38 are driven forward during the disengagement process an amount of concentrate contained in the pump will be driven out of the pump barrels 48 , 50 , down the flexible conduit 14 and out the nozzle 68 to be collected in the flexible pouch 8 . Prior to removal of the concentrate pump 12 from the dispenser 2 , diluent is pumped through the diluent inlet 60 and into the flexible pouch 8 via the flexible conduit 14 and nozzle 68 to flush any concentrate therefrom. This process removes any concentrate from the concentrate pump 12 , conduit 14 and nozzle 68 leaving them containing diluent which, in case of drips, is easier to clean. After the concentrate pump 12 has been removed the flexible pouch 8 may be sealed, removed and disposed of. Alternatively if the removed concentrate reservoir 10 and associated pump 12 , conduit 14 and nozzle 68 are being replaced, flexible pouch 8 may be left in position and the same flexible pouch 8 used to collect any fluids passing through the new concentrate pump during the engagement and priming process as described above. The apparatus has a controller (omitted for clarity) of a known type, for example a micro-controller, associated with it programmed to control the various components of the apparatus, both during normal operation and to perform the apparatus functions during the steps of loading and unloading of concentrate reservoirs.
Referring to FIG. 6 a pouch 600 is shown comprising first 602 and second 604 panels made of a flexible material. The panels are attached to one another around their peripheral edges to form a pouch. During the forming process, spout 606 is inserted between the edges of the panels so as to become fixed therebetween. Traditional fixing methods such as heat welding are used to attach the panels. The spout 606 has a mixing element 608 extending therefrom into the interior of the pouch 600 , when formed. The mixing element 608 comprises a channel having a torturous flowpath therein causing turbulence of fluid entering the pouch via the spout. The two panels may comprise sections of a single panel attached along one edge.
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A method of dispensing a beverage includes the steps of: providing a housing having a plurality of reservoirs of beverage concentrate each reservoir having a concentrate pump and flexible conduit terminating in a nozzle; providing a plurality of drivers driving said concentrate pumps; providing diluent to the pumped concentrate to produce a beverage; providing a multiple dispense head accepting the plurality of nozzles; selecting a flexible pouch and bringing it into alignment with a nozzle in a filling position where it is filled via an opening; closing said opening and dispensing said filled sealed flexible pouch; wherein the filling position is a fixed position and wherein said nozzles are movable relative to the filling position such that any one of said plurality of nozzles can be presented at said filling position.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a through type capacitor used for various electric and electronic equipment.
(2) Description of the Prior Art
FIGS. 1a and 1b illustrate a conventional through type capacitor having two capacitor units which is used for a magnetron circuit of a microwave oven or the like. FIG. 1a shows a partial cross section and FIG. 1b an equivalent circuit.
This conventional through type capacitor comprises two capacitor units 2, each having a through hole extending throughout the axial length thereof, through which a through terminal 3 is inserted. Each capacitor unit 2 comprises a cylinder, formed of such a dielectric material as ceramic, having an electrode on both ends thereof. An electrode on one end of the capacitor unit 2 is electrically connected with the through terminal 3, and another electrode on the other end of the capacitor unit 2 is electrically connected with a grounding plate 5. A resin cover 6a is placed around the outer peripheral surface of the capacitor unit 2, and another resin cover 6b is inserted into the grounding plate 5. A resin 7 injected from both ends A and B fills the space. between the resin cover 6 and the capacitor unit 2, in order to securely insulate the electrode on the above other end of the capacitor unit 2 from the through terminal 3.
As shown in FIG. 1b, noise currents i 1 and i 2 flow from the A end of the through terminal 3 and pass from one end of the capacitor unit 2 to the other end, until it is bypassed to the grounding plate 5.
Such noise currents inevitably generate a large residual inductance. Practically, if the through type capacitor has a capacitance of approx. 200 pF, a residual inductance of 7 to 10 nH is generated. With such a capacitor, resonance occurs at around 100 MHz,
15 and an impedance of approx. 30 Ω is generated at around 500 MHz. The capacitor absorbs a noise current of only up to 300 MHz max., but does not effectively absorb a noise current having a higher frequency.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a through type capacitor which has a small residual inductance and is useful in a high frequency range.
Another object of the present invention is to provide a through type capacitor which reduces the residual inductance in a high frequency range, by making effective use of the skin effect, which is occurred when a noise current has a high frequency.
The above objects are fulfilled by a through type of capacitor formed of a capacitor unit inserted through a grounding member by a through terminal, comprising a through terminal having conductivity and the shape of a rod; a capacitor unit having a first electrode on a first end, a second electrode on a second end of the axial length thereof, and a through hole extending throughout the capacitor unit, through which the through terminal is inserted; a connecting member for electrically connecting the through terminal inserted through the capacitor unit and the first electrode of the capacitor unit; and a grounding member having a connecting portion for being connected with the second electrode of the capacitor unit, a prolonged portion extending up to the first end of the capacitor unit, and a grounding portion at the tip of the prolonged portion.
A first insulating member may be interposed between the through terminal and the through hole of the capacitor unit, and a second insulating member may be interposed between an outer peripheral surface of the capacitor unit and the prolonged portion of the grounding member.
The prolonged portion of the grounding member may have a cylindrical shape for covering the capacitor unit.
The prolonged portion of the grounding member may have at least half the axial length of the capacitor unit.
In a preferred embodiment of the present invention, a male thread ridge is formed on an outer peripheral surface of the prolonged portion of the grounding member.
In the above construction, a noise current makes a U-shape flow, which counteracts the residual inductance. Practically, the residual inductance is reduced to 1/10 or less of a conventional capacitor and the through type capacitor according to the present invention is useful in a frequency range of up to 3 GHz. Consequently, the through type capacitor absorbs a noise current having a higher frequency.
Moreover, if the grounding member comprises a metal tube, it has a shielding effect as a metal case.
In the above construction, the grounding member is wrapped around the capacitor unit with the second insulating member, which is a sheet, therebetween. With such a construction, the high frequency current flowing through the capacitor unit is very close to the current flowing through the grounding member, owing to the skin effect. Also, the current flows through the capacitor unit in a direction opposite to the current flowing through the grounding member. Because of these facts, a magnetic field generated by the current flowing through the capacitor unit and another magnetic field generated by the current flowing through the grounding member counteract each other, and as a result, reduce the residual inductance as much as possible.
The residual inductance may be reduced utilizing the skin effect of a high frequency current by a through type capacitor formed of a capacitor unit inserted through a grounding member by a through terminal, comprising a through terminal having conductivity and the shape of a rod; a capacitor unit consisting of an inner capacitor portion and an outer capacitor portion, each having a first electrode on a first end and a second electrode on a second end of the axial length thereof, wherein the inner capacitor portion is axially longer than the outer capacitor portion, wherein the inner capacitor portion has a through hole through which a through terminal is inserted, and wherein the outer capacitor portion covers the inner capacitor portion; a connecting member for electrically connecting the through terminal inserted through the capacitor unit and the first electrode of the capacitor unit; and a grounding member having a connecting portion for being connected with the second electrodes of the capacitor unit, a prolonged portion extending up to the first end of said capacitor unit, and a grounding portion at the tip of the prolonged portion.
According to the above construction, the outermost capacitor unit, to which the high frequency current is attracted, has a short axial length and a small capacitance. Such a construction realizes a through type capacitor which has a smaller residual inductance and is useful in a higher frequency range.
The objects of the present invention may also be fulfilled by a through type capacitor formed of a capacitor unit inserted through by a through a grounding member terminal, comprising a through terminal having conductivity and the shape of a rod; a capacitor unit having a first electrode on a first end, and a second electrode on a second end of the axial length thereof, and a through hole extending throughout the capacitor unit, through which the through terminal is inserted; a connecting member for electrically connecting the through terminal inserted through the capacitor unit and the first electrode of the capacitor unit; and a return path forming member for leading the current flowing through the capacitor unit to a grounding point, wherein a current flows in the opposite direction to the current flowing from the first electrode to the second electrode of the capacitor unit.
The return path forming member may be an outer capacitor unit for covering the capacitor unit, one end of the outer capacitor unit may be connected with the second electrode of the capacitor unit covered with the outer capacitor unit, and another end of the outer capacitor unit may be connected with the ground.
In the above construction, the noise current flows through the inner capacitor unit and makes a Uturn to flow through the outer capacitor unit in the opposite direction. Consequently, the residual inductance in the inner capacitor unit and the outer capacitor unit counteract each other to be reduced to 1/5-1/10 of that of a conventional through type capacitor. Therefore, the attenuation characteristic shown by the insertion loss - frequency curve is flatter, which realizes a through type capacitor absorbing and restricting enough noise for practical use in a higher frequency range.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrate a specific embodiment of the invention. In the drawings:
FIG. 1a is a partial cross sectional view of a conventional through type capacitor,
FIG. 1b, is an equivalent circuit diagram of the
FIG. 2a is a partial cross sectional view of an embodiment according to the present invention,
FIG. 2b is an equivalent circuit diagram of the
FIG. 3 is a figure showing a detailed construction of a capacitor unit,
FIG. 4a is a partial cross sectional view of another embodiment according to the present invention,
FIG. 4b is an end view of the same,
FIG. 5a is a partial cross sectional view of still another embodiment according to the present invention,
FIG. 5b is an end view of the same,
FIG. 6a is a partial cross sectional view of still another embodiment according to the present invention,
FIG. 6b is an end view of the same,
FIG. 7 is an equivalent circuit diagram of the embodiment illustrated in FIG. 5,
FIG. 8 is an equivalent circuit diagram of the embodiment illustrated in FIG. 6,
FIG. 9 is a line graph showing the relationship between insertion loss and frequency of the embodiments illustrated in FIGS. 5 and 6,
FIG. 1a is a is a partial cross sectional view of still another embodiment according to the present invention,
FIG. 10b is an end view of the same,
FIG. 11 is an equivalent circuit diagram of the embodiment illustrated in FIG. 10,
FIGS. 12a and 12b are end views of still another embodiment according to the present invention,
FIG. 13 is an equivalent circuit diagram of the same,
FIGS. 14 and 15 respectively show an inner capacitor unit and an outer capacitor unit of the embodiment illustrated in FIG. 10, and
FIG. 16 is a line graph showing the relationship between insertion loss and frequency of the embodiments illustrated in FIGS. 10 and 12.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 2a and 2b illustrate an embodiment according to the present invention. FIG. 2a shows partial cross section and FIG. 2b an equivalent circuit of a through type capacitor 20 employing two capacitor units 21.
As illustrated in FIG. 3, each capacitor unit 21 comprises a first dielectric film 212 and a second dielectric film 214, both of which are tapes having approximately the same width throughout their length and also with each other. The first dielectric film 212 has a capacitor electrode 211 formed on one main surface thereof, and the second dielectric film 214 has another capacitor electrode 213 formed on one main surface thereof. The above capacitor electrode 213 formed on the second dielectric film 214 is superposed on the other main surface of the first dielectric film 212, and the obtained layers of film is wound into a cylindrical shape around an insulator S.
The capacitor electrode 211 of the first dielectric film 212 and the capacitor electrode 213 of the second dielectric film 214 are both formed by evaporating or sputtering aluminum (Al) or zinc (Zn). The capacitor electrode 211 covers the above one main surface of the dielectric film 212 except a certain width of margin 215 along one side thereof. The capacitor electrode 213 covers the above one main surface of the dielectric film 214 except a certain width of margin 216 along the side thereof facing to the other side of the dielectric film 212. In this way, the capacitor electrode 211 is exposed on one end of the capacitor unit 21, and the capacitor electrode 213 is exposed on the other end of the capacitor unit 21.
The capacitor unit 21 has a metallicon electrode (FIG. 5a) formed on both ends thereof by applying a molten metal. One metallicon electrode is electrically connected with the capacitor electrode 211 of the first dielectric film 212, and the other metallicon electrode with the capacitor electrode 213 of the second dielectric film 214.
A through terminal 22 inserted through the capacitor unit 21 is electrically connected with the electrode on one end thereof. The through terminal 22 is covered with an insulation tube 23, to be insulated from the electrode on the other end of the capacitor unit 21. A grounding casing 24 comprises a metal tube having a cylindrical part 24c which is big enough for the capacitor unit 21 to be inserted into axially. The grounding casing 24 is folded inwardly at one end and outwardly at the other end so as to form a cup-like shape. The inwardly folded part 24a is electrically connected with the far end of the inserted capacitor unit 21. The outwardly folded part 24b is folded at an angle to be connected with such a part as the housing of an equipment. A resin cover 25 is inserted between the grounding casing 24 and the capacitor unit 21, and the space enclosed by the resin cover 25 is filled with a resin 26.
In the foregoing embodiment, a noise current flows through the through terminal 22, the capacitor unit 21 and the grounding casing 24 to the ground. The current flows through the capacitor unit 21 in the opposite direction to the current flowing through the grounding casing 24 around the capacitor unit 21. In other words, the current flows in a U shape as shown with i 1 or i 2 in FIGS. 2a and 2b. Such a U-shape current flow causes the counteracting of the residual inductance to reduce it to 1/10 or less than that of a conventional through type capacitor. In this embodiment, a cylindrical part 24c of the grounding casing 24 acting as a return path is longer than the axial length of the capacitor unit 21, but they are preferably of the same length. However, it has been confirmed by an experiment that a return path having at least half the axial length of the capacitor unit 21 reduces enough residual inductance for practical use.
The grounding casing 24, moreover, has a shielding effect because it covers the capacitor unit 21 as a metal case.
FIGS. 4a and 4b illustrate another embodiment according to the present invention. FIG. 4a shows a partial cross section and FIG. 4b an end view seen in the direction of an arrow A. The through type capacitor illustrated in these figures is a modification of the embodiment in FIG. 2 and employs one capacitor unit. In this embodiment, a noise current flows in the direction of an arrow B. The construction is almost the same as the embodiment in FIG. 2 except for the grounding casing 24. The grounding casing 24 in this embodiment does not have the outwardly folded part 24b but has a male thread ridge 28 on the outer peripheral surface thereof. On condition that a housing 27 has a female thread ridge, the above construction facilitates attaching and detaching of the through type capacitor to and from the housing 27 with a smaller attaching area. Further, the grounding casing 24, comprising a metal case, covers the capacitor unit 21 as is the embodiment in FIG. 2, and so has a shielding effect. Moreover, if the metal case has a hexagon head as shown in FIG. 4b, it can be attached to the housing 27 by such a tool as wrench, which realizes easier and stronger attachment.
FIGS. 5a and 5b illustrate still another embodiment according to the present invention. FIG. 5a shows a cross section and FIG. 5b an end view of a through type capacitor employing a single capacitor unit 31.
The above through type capacitor comprises a cylindrical capacitor unit 31 employing a resin film as a dielectric, a through terminal 32 to be inserted through the axis of the capacitor unit 31, a collector 34 to electrically connect the through terminal 32 and the terminal electrode 33 of the capacitor unit 31, a grounding casing 35 to cover the capacitor unit 31, a first insulator 36 to electrically insulate the capacitor unit 31 from the through terminal 32, and the second insulator 37 to electrically insulate the capacitor unit 31 from the grounding casing 35.
The capacitor unit 31 has the same construction as the one in FIG. 3, and so the detailed explanation is omitted here.
A capacitor electrode of the capacitor unit 31 is connected with a terminal electrode 33 formed on one end of the capacitor unit 31. Another capacitor electrode, which produces a capacitance together with the above capacitor electrode, is connected with another terminal electrode 38 formed on the other end of the capacitor unit 31.
The through terminal 32 is partially covered with the insulating tube 36 comprising an insulating resin, and is inserted through the axis of the capacitor unit 31. Then, the through terminal 32 is inserted through a hole 34a at the center of the collector 34, which is obtained by punching a metal plate into a disc. The collector 34 is conductively adhered to the through terminal 32 and to the terminal electrode 33 of the capacitor unit 31 by such a method as soldering.
The grounding casing 35 comprises a metal case having an opening at one end thereof and a cylindrical part 35a for covering approximately the whole length of the capacitor 31. The other end 35b of the grounding casing 35 is a plain surface and has a hole 39 at the center thereof, through which the through terminal 32 is loosely inserted. The end surface 35b of the grounding casing 35 is conductively adhered to the terminal electrode 38 of the capacitor 31 by such a material as solder provided through the hole 39 and another hole 40, which is formed if necessary.
The second insulator 37 comprises an insulating resin sheet. The capacitor unit 31 is covered with the second insulator 37 and is inserted into the grounding casing 35. The second insulator 37 has an axial length which is long enough to partly project from the opening of the grounding casing 35.
The grounding casing 35 has a flange 41 around the opening thereof, which has four mounting holes 42 for fixing the through type capacitor on the chassis or the case of an electronic equipment. Though not shown here, the grounding casing 35 may have a male thread ridge on the outer peripheral surface thereof for screwing the through type capacitor into the chassis or the case of an equipment.
The foregoing through type capacitor in FIGS. 5a and 5b has distributed constants as shown by the equivalent circuit in FIG. 7. The above equivalent circuit indicates that series circuits, each consisting of a capacitance Ck (k=1, 2, . . . , n) and an inductance Lk (k=1, 2, . . . , n), are formed between the collector 34 and the grounding casing 35. The above series circuits are accumulated in the radial direction of the through terminal 32, and each of them is placed with a distance dk (k=1, 2, . . . , n) from the through terminal 32. It is known that, provided the distance between the through terminal 32 and the cylindrical part 35a of the grounding casing 35 is d, the inductance Lk is in proportion to
log d/dk (1)
This means that the bigger k becomes, namely, the closer inductance Lk is to the cylindrical part 35a of the grounding casing 35, the smaller the inductance Lk becomes.
A high frequency current flows through the through terminal 32, the above-mentioned circuit of the capacitance and the inductance in the capacitor unit 31, and the cylindrical part 35a of the grounding casing 35 until it is bypassed to the flange 41. The high frequency current has a tendency that the higher the frequency is, the more distance it keeps from the through terminal 32. In other words, the higher the frequency is, the smaller the current i 1 is which is flowing through the series circuit of the capacitance C 1 and the inductance L 1 , and the bigger the current i n is which is flowing through the series circuit of the capacitance C n and the inductance L n . This means that when the frequency is high, the current is attracted to flow through the outermost series circuit of the capacitance C n and the inductance L n . Here, when k=n, d/dk is minimum (1.2 to 1.05). Because the inductance Lk is in proportion to (1), L n , namely, the residual inductance of the through type capacitor, is minimum. The above is also apparent from the fact that, because the high frequency current flows through the series circuit of the capacitance C n and the inductance L n , which is closest to the grounding casing 35, a magnetic field generated by the above high frequency current flowing through the above series circuit and another magnetic field generated by the high frequency current flowing in the opposite direction through the grounding casing 35 effectively counteract each other.
The relationship between insertion loss and frequency of the through type capacitor in FIG. 5 was examined, and the result is shown with a dashed line h 1 in FIG. 9. A solid line h 3 shows the above relationship of a conventional through type capacitor. According to these results, the through type capacitor in FIG. 5 has 20 dB bigger insertion loss than the conventional one at 1,000 MHz.
FIGS. 6a, 6b and 8 illustrate still another embodiment according to the present invention. FIG. 6a shows a vertical cross section, FIG. 6b an end view, and FIG. 8 an equivalent circuit of the embodiment.
The through type capacitor illustrated in these figures is a modification of the embodiment in FIG. 5. The capacitor unit 31 is radially divided at least into two capacitor units 31a and 31b, and the length l 2 of the outer capacitor unit 31b, which is closer to the grounding casing 35, is shorter than the length l 1 of the inner capacitor unit 31.
Because the high frequency current tends to flow through the circuit closest to the grounding casing 35, it flows a shorter path and so reduces the residual inductance.
FIGS. 6a and 6b employ the identical numbers as the corresponding parts in FIGS. 5a and 5b, and the explanation is omitted here where otherwise would be repeated.
A two-dot chain line h 2 in FIG. 9 shows the relationship between insertion loss and frequency of the through type capacitor in FIG. 6. This capacitor has approximately 10 dB bigger insertion loss at 1,000 MHz.
FIGS. 10a and 10b illustrate still another embodiment according to the present invention. FIG. 10a shows a partial cross section and FIG. 10b an end view of a through type capacitor 51 for high voltage use.
The through type capacitor 51 for high voltage use comprises three capacitor units C 0 , C 1 and C 2 , two through terminals 52a and 52b, insulating tubes 53, insulating sheets 54, a grounding plate 55 and a resin mold 56. The grounding plate 55 has four mounting holes 57.
The capacitor units C 0 , C 1 and C 2 have cylindrical shapes as shown in FIGS. 14a, 14b, 15a and 15b, and comprise dielectric films. They have metallicon electrodes connected with both ends thereof. The first capacitor units C 1 and C 2 both have a 50 to 100 times bigger capacitance (0.01 to 0.5 μF) than the second capacitor unit C 0 and both have a withstand voltage of approx. 100 V. The second capacitor unit C 0 has a capacitance of approx. 200 to 500 pF and a withstand voltage of approx. 5 kV. The capacitor unit C 0 is wound into an elliptic cylinder with a hole in the center thereof so that it may cover the capacitor units C 1 and C 2 arranged in parallel in the same axial direction.
The capacitor units C 1 and C 2 have through terminals 52a and 52b inserted therethrough, respectively. The through terminals 52a and 52b are soldered with metallicon electrodes 59E on the ends of the capacitor units C 1 and C 2 closer to the grounding plate 55, and are insulated from electrodes 59F on the other ends by the insulating tubes 53.
The capacitor units C 1 and C 2 are individually covered with insulating sheets 54, are arranged in parallel in the same axial direction, and are inserted into the capacitor unit C 0 . The electrodes 59F, which are insulated from the through terminals 52a and 52b, are soldered on the whole surface of an electrode 59G of the capacitor unit C 0 on the end facing the electrodes 59F. An electrode 59H on the end of the capacitor unit C 0 closer to the grouding plate 55 is insulated from the metallicon electrodes 59E on the same ends of the capacitor units C 1 and C 2 by the insulating sheets 54. The electrode 59H is soldered with a grounding plate 55. The resin mold 56 covers the outer surface of the capacitor unit C 0 .
FIG. 11 is an equivalent circuit diagram of the through type capacitor 51 for high voltage use. Noise currents 1 1 and i 2 flow in the directions of the arrows.
The noise currents i 1 and i 2 respectively flow through the through terminals 52a and 52b and the capacitor units C 1 and C 2 until they make a U-turn to flow through the capacitor unit C 0 . Here, the currents flow through the capacitor units C 1 and C 2 in the opposite direction to the currents flowing through the capacitor unit C 0 , to cause the counteracting of the residual inductance. The relationship between insertion loss and frequency of the through type capacitor 51 for high voltage use is shown with the thick dashed line in FIG. 16. As shown here, resonance is restricted until 700 to 800 MHz, and the insertion loss characteristic is flatter than that of a conventional one, shown with the solid line, in which there is no counteracting of residual inductance.
The conventional through type capacitor for high voltage use has several resonance points over 100 MHz, which reflect the resonance between residual inductance and floating capacitance generated when the lead wires are taken out or when the capacitor is mounted.
In FIG. 10b, the grounding plate 55 has only four mounting holes 57 on the corners thereof. With this setting, the center of the grounding plate 55 and the housing of an equipment are incompletely connected with each other to make the current flow an extra distance. As a result, big local inductances L p1 and L p2 of 3 to 5 nH are generated on the grounding plate 55. When this is considered a serious problem, the grounding plate 55 can be modified as follows.
As shown in FIG. 12a, two more mounting holes may be made on the center of the longer sides of the grounding plate 55. Or, as shown in FIG. 12b, the grounding plate 55 may be spot-welded at the same positions as the above six mounting holes in FIG. 12a. By these methods, the capacitor units C 1 and C 2 are mounted on the housing almost coaxially, which reduces local inductances L p1 and L p2 in FIG. 11. The result is shown in the equivalent circuit in FIG. 13. Practically, the total residual inductance of the capacitor units C 0 , C 1 and C 2 is reduced to 1/5 to 1/10, the local inductance on the grounding plate 55 to 1/2 to 1/3, and the floating capacitance to a neglectable value. The insertion loss - frequency curve in this case, shown by the thin dashed line in FIG. 16, is 20 to 30% flatter than that of the embodiment in FIG. 10.
In the above embodiment, the capacitor units C 0 , C 1 and C 2 comprise films. If the desirable characteristic is to be obtained with no need for considering weight, manufacturing cost, capacitance fluctuation, or the like, dielectrics such as ceramic may be employed. As for the number of mounting holes, a required number to obtain the desirable characteristic, if more than six, can be made.
Although the present invention has been fully described by way of embodiments with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.
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A through type capacitor formed of a capacitor unit (or capacitor units) inserted through by a through terminal (or through terminals). The above through type capacitor mainly comprises a through terminal, a capacitor unit, a connecting member and a grounding member. The above grounding member is formed in the manner that the current flowing therethrough flows in the opposite direction to the current flowing through the capacitor unit. The above construction causes the counteracting of the residual inductance to reduce it as much as possible, which realizes a through type capacitor useful in a high frequency range.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an automated system for appraising value to consumers of a life insurance or annuity product, and more particularly, to a computer-based value appraising system.
[0003] 2. Discussion of the Related Art
[0004] The financial services industry consists of industry segments such as insurance and banking. In turn, the insurance industry consists of industry segments such as life insurance, health insurance, and property and casualty insurance.
[0005] The life insurance industry includes product markets such as term life insurance, life insurance, variable life insurance, annuities, joint products, viatical settlements, preneed insurance, and long-term care insurance. Insurance carriers sell life insurance products through various distribution channels such as captive agents, independent agents, banks, affinity groups, and financial planners.
[0006] The present life insurance product markets for both insurance product proposals and in-force insurance products are inefficient. For insurance product proposals, the problem stems from: (1) an inadequate exchange of information between consumers and insurers during the selling process and, (2) the absence of a real-time auction market in which to price life insurance product proposals. Inefficient product markets for in-force insurance products stem from the absence of a system for measuring an insurance product's performance while that product is in-force.
[0007] An inadequate exchange of relevant and available information between consumers and insurers during the selling process is a significant source of product market inefficiency. Typically, consumers often do not receive relevant and available information necessary to make an informed purchase decision. Also, insurers frequently do not receive relevant and available information on the consumer and current market pricing necessary to tailor their proposals for optimal product performance and pricing. Such inefficient transmission of information results in product market inefficiency. Such product market inefficiency in the insurance industry adversely affects consumers and insurance companies.
[0008] Moreover, many life insurance products have complex features that consumers do not understand. Consumers' lack of insurance product knowledge opens the door to misleading sales practices such as twisting, churning, and vanishing premiums. Product “gimmickry,” such as lapse basing, preys on a consumer's inability to detect its existence. Recent, widely publicized accounts of race-based underwriting indicate that market conduct problems can go undetected for years by consumers, insurance company managements, and insurance industry regulators. Insurance industry regulators have attempted to enforce market conduct standards. Insurance companies have sought to curtail sales abuses. Their efforts have not solved the problem.
[0009] Market conduct problems occur regardless of an insurance company's financial strength. Favorable financial ratings are no indication of an insurer's compliance with market conduct standards. Independent rating firms evaluate an insurer's claims paying ability. They do not rate the products sold by insurers. The life insurance industry has no product rating system that appraises a proposed insurance product's total value to the consumer.
[0010] These and other market conduct problems point to the need for a system that assists the consumer in appraising a proposed insurance product's value.
[0011] The absence of a real-time auction market in which to price life insurance product proposals is a source of product market inefficiency. Currently, whether life insurance products are sold on the Internet or sold offline, the products are sold in a “fixed-priced” market. Typically, during the sales process, consumers and insurers cannot obtain real-time, market pricing information for products that are tailored to individual consumer needs. Thus, both consumers and insurers are deprived of opportunities to improve pricing before the sale closes. Consequently, some insurance products may be priced too high. In other cases, product prices may be too low.
[0012] Some insurers presently post fixed pricing information for standard products on the Internet, making it easier for consumers to compare prices for certain products. The Internet has made available more pricing information to consumers than ever before. However, while price comparisons allow the consumer to seek the lowest price for such fixed-price products, these price comparisons provide no other information to allow for an appraisal of the total value proposition.
[0013] Similarly, existing policyholders have no means for evaluating the performance of their in-force insurance policies. No system exists in the marketplace for appraising an in-force product's continuing value to the consumer.
[0014] Moreover, price is only one element in appraising an insurance product's total value proposition. No available systems provide consumers with information other than price to facilitate informed purchase decisions. Consumers need a system that appraises the total value proposition of life insurance product proposals. Such a system would lead to stronger product market efficiency.
[0015] In addition, even though present systems allow for price shopping on the Internet by consumers, from the insurer's perspective, such price shopping commoditizes insurance products. Thus, insurers are forced to compete on price alone and cannot differentiate products that provide other “non-price” value for consumers. Consequently, the attractiveness of the industry's structure declines, competitor rivalry increases, weak product substitutes proliferate, and entry barriers become lower across product markets. These structural changes squeeze margins and erode industry-wide profitability.
SUMMARY OF THE INVENTION
[0016] Accordingly, the present invention is directed to an evaluating system for a life insurance or annuity product that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
[0017] An advantage of the present invention is to provide an on-line, real-time system for evaluating a proposed life insurance or annuity product.
[0018] An advantage of the present invention is to provide an on-line, real-time system for evaluating an in-force life insurance or annuity product.
[0019] An advantage of the present invention is to provide an on-line, real-time system for evaluating a replacement life insurance or annuity product.
[0020] Another advantage of the present invention is to provide a system that creates efficient product markets for the benefit of the life insurance industry and its customers.
[0021] Another advantage of the present invention is to provide a system that enables insurance companies and insurance distribution channels to better serve their customers and to improve industry-wide profitability
[0022] Another advantage of the present invention is to provide a system to improve product pricing by pricing insurance products in an auction-style market.
[0023] Another advantage of the present invention is to provide a system for evaluating the current performance of an in-force life insurance or annuity product.
[0024] Additional features and advantages of the invention will be set forth in the description which follows, 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 hereof as well as the appended drawings.
[0025] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method of appraising a life insurance or annuity product includes the steps of receiving a request for a life insurance or annuity product and information about a party requesting the product; preparing a bid solicitation for the product based on the request and information and transmitting the bid solicitation to a plurality of product carriers; at least one of the plurality of product carriers providing a proposal for providing the life insurance or annuity product; automatically generating a numerical rating corresponding to each proposal and providing the numerical rating to the corresponding product carrier; allowing the plurality of product carriers to revise the proposals based on the numerical rating; the product carriers providing a final proposal; and generating an appraisal for each of the final proposals.
[0026] 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
[0027] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
[0028] In the drawings:
[0029] [0029]FIG. 1 is a block diagram that illustrates a preferred embodiment of the present invention.
[0030] [0030]FIG. 2 is a block diagram that illustrates parties involved in a business transaction according to the preferred embodiment of the present invention.
[0031] [0031]FIG. 3 is a block diagram that illustrates an embodiment of the present invention appraising the continuing value proposition to the policyholder of an in-force life insurance policy or annuity.
[0032] [0032]FIG. 4 is a block diagram that illustrates an embodiment of the present invention for a policyholder to query a product value appraisal system without the aid of a distribution channel.
[0033] [0033]FIG. 5 is a block diagram that illustrates an embodiment of the invention appraising the value proposition for replacing an in-force life insurance policy or annuity.
[0034] [0034]FIG. 6 is a block diagram that illustrates an embodiment of the present invention for a policyholder to query a product value appraisal system for rating an in-force life insurance policy or annuity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0036] The present invention relates to an evaluating system for a life insurance or annuity product under consideration for purchase, the ongoing value of a life insurance or annuity product already owned, or replacing a life insurance or annuity product. In addition, either as a separate process or in conjunction with this process, the product value appraisal system of the present invention enables an on-line, real-time auction process for pricing life insurance and annuity products. The present invention provides a system for appraising a life insurance or annuity product's total value proposition to the consumer. The product value appraisal system operates preferably via the Internet, but may be configured to work off-line or via a closed network or Intranet. The system is configured to support all categories of insurance transactions including, business-to-business, business-to-consumer, and business-to-employee. The system appraises life insurance product and annuity proposals as well as life insurance and annuity products that are in-force and replacement product proposals.
[0037] The present invention is applicable to a number of financial products within the life insurance industry, as well as annuities. Within the market for life insurance, there are a variety of products for which a system for appraising value is most useful. Term life policies provide a death benefit for a limited number of years after which they expire without value. They may insure the life of one person, or provide protection on the lives of two people (Joint Term policies). Joint Term policies are of two types: those that pay the death upon the first death to occur and those that pay upon the second death during the term.
[0038] Term products may have non-guaranteed premium structures (participating policies that pay dividends or “indeterminate premium” plans that feature a guaranteed maximum premium scale, but provide for the opportunity to pay a lower current premium based on current experience of the insurer) or fully guaranteed premiums that never change (non-participating plans). Term plans that provide a death benefit that is a constant amount over the term period may be renewable at the end of the term (e.g., Annually Renewable Term, 5-Year Renewable Term, etc.). A subset of renewable term plans is Reentry Term, which provides the opportunity for a lower renewal premium than otherwise available if the insured can provide evidence of continuing good health. Non-renewable term plans include 20-Year Term and Term to Age 65. Term plans that provide a death benefit that decreases over the term period are generally non-renewable and are purchased to insure a specific need. Mortgage Protection Term, often sold in connection with new residential home loans is a good example.
[0039] Ordinary life insurance plans are conceptually designed to provide death protection for the insured's entire lifetime. Unlike term life, they commonly provide for the accumulation of cash values that are available to the insured should the policy need to be terminated prior to death. Premiums for Ordinary Life can be structured to be payable for life or some finite number of years. Single Premium Life forms are even available. All Ordinary Life plans are generally available in joint life insurance (first-to-die) and joint and last survivor insurance forms in addition to single life forms. In order of decreasing guarantees (increasing risk) to the purchaser, these plans fall into the following types: nonparticipating whole life, indeterminate premium whole life, participating whole life, interest sensitive whole life, universal life insurance, variable whole life and variable universal life.
[0040] Nonparticipating whole life provides for guaranteed level premiums and a guaranteed death benefit with fully guaranteed cash values. The insurer assumes all risks and the purchaser does not participate in experience more favorable than the insurer's guarantees.
[0041] Indeterminate premium whole life insurance is a version of nonparticipating whole life insurance with indeterminate premiums, which is discussed above with regard to term life insurance.
[0042] Participating whole life insurance is similar to nonparticipating whole life, but offers the opportunity to receive annual dividends from the insurer if experience is more favorable than guarantees.
[0043] Interest sensitive whole life insurance is a version of nonparticipating whole life insurance under which the insurer credits excess interest over and above the policy's guarantee to the policy's cash values as current conditions warrant.
[0044] Universal life insurance is a version of nonparticipating whole life under which the insurer provides guarantees as to maximum charges for expenses and the mortality risk and minimum interest rates, but the amount of premium is based on current charges and interest rates. Thus, the insured is assuming a fair amount of risk with respect to future experience, primarily concerning interest rates. Considerable flexibility is provided for changes in the amount and timing of premium payments and the amount of the death benefit as well the ability to make withdrawals from the cash values. There is consequently no guarantee that the policy will be in effect at the insured's death if proper adjustments are not made in the premium payment pattern. This is a significant difference from the four types of Ordinary Life described above.
[0045] Variable whole life insurance is a form of nonparticipating whole life under which the insured assumes substantially all of the investment risk, including the risk of fluctuations in principal value as well as the interest rate risk. Fixed level premiums are provided, but the death benefit and cash values fluctuate with the investment performance of the mutual funds selected by the insured for investment of the premiums. There is a minimum guaranteed death benefit payable whenever the insured's death occurs.
[0046] Variable universal life insurance is a combination of variable whole life insurance and universal life insurance. Variable universal life insurance represents the life product type with the fewest traditional insurer guarantees and thus the greatest assumption of risk by the insured. In return for assuming this risk, the insured has the upside potential of receiving a significant better value in favorable economic environments than under the other product types.
[0047] As shown in FIG. 1, the product value appraisal system of the present invention simultaneously solicits, prices, and rates life insurance and annuity policy proposals. FIG. 1 illustrates a “business-to-business” transaction.
[0048] A party seeking a life insurance or annuity product, the proposed insured 104 , requests a life insurance or annuity product through a distribution channel 108 that sells such products to consumers, as illustrated by step 1 in FIG. 1. The proposed insured 104 also provides the distribution channel 108 with information necessary for the distribution channel to request proposals from carriers who sell that product type. This information includes the risk profile of the proposed insured 104 for the product. Demographic and risk profile data include, for example, the proposed insured's age, sex, smoking habits, amount of insurance or annuity benefit desired, the pattern of premium payments and the pattern of disbursements desired from the product.
[0049] Next, the distribution channel 108 transmits to a product value appraisal system (“PVAS”) 112 information provided by the proposed insured 104 , including the demographic and risk profile information as inputs to the product value appraisal system 112 , as illustrated by step 2 of FIG. 1.
[0050] Then, the product value appraisal system 112 initiates bidding and/or invites proposals from interested product providers or carriers 116 by sending a proposed opening bid or invitation for proposal to a participating insurance carrier 116 , as illustrated by step 3 of FIG. 1. The opening bid provided by the product value appraisal system 112 may include an opening price with a minimum product rating.
[0051] After initiating bidding or inviting proposals, the product value appraisal system 112 proceeds in an on-line, real-time, iterative process with the insurance carriers 116 , as illustrated by step 4 of FIG. 1. Upon receipt of a bid or proposal from a participating insurance carrier 116 , the product value appraisal system 112 reviews each bid or proposal and rates the bid or proposal and the pricing of each bid or proposal.
[0052] With each product proposal, the insurance carrier will transmit information about the price and benefits of its product along with identifying information about itself. This data includes data about the product's proposed benefits and price on both a guaranteed and illustrated basis, and information about the insurance company proposing the product. Product data include the proposed premiums to be paid and the proposed benefits to be provided, both distinguished between guaranteed amounts and illustrated amounts that depend on assumptions about the future. The insurance company information includes data that quantifies the financial strength of the insurance company. The product value appraisal system 112 will use appropriate actuarial assumptions, such as mortality information specific to the end customer's risk profile, and traditional actuarial present value methodology to determine a numeric rating of the benefits offered in light of the proposed price, the Product Value For Money, as represented in FIG. 1. Numeric ratings will also be assigned to other key scoring drivers: the product's performance under less optimistic assumptions about future interest rates and at lower premium levels (Product Stress Tolerance); various company financial information (Management Performance); previous interest rates actually credited to the product's values (Historical Credited Rates); various qualitative measures of customer service (Customer Service Quality); and the financial strength of the product provider (e.g., A.M. Best Rating). The numeric ratings for these six scoring drivers will then be weighed to arrive at an overall rating of the customer value proposition.
[0053] In one embodiment, a universal life insurance product, the first scoring driver, the product value for money, is determined using four metrics. The first and second metrics are based on projections of cash flow for groups of 1,000 policyholders. Each year, the system projects the number of policyholders dying, which is based on mortality tables appropriate for the gender, smoker status, and rating class of the insured, and the number of policyholders surrendering, which is based on lapse assumptions. Cash inflows consist of the premiums paid by survivors, and cash outflows consist of death and surrender benefits paid. The ratio of the present value of cash inflows to the present value of cash outflows is the cash-on-cash Internal Rate of Return (IRR). Two separate IRR calculations are made based on two different assumptions about lapses and surrender rates to provide the first and second metrics that make up the product value for money scoring driver.
[0054] The first IRR calculation is made based on lapse and surrender rates from the 1995 LIMRA life lapse rate study for the age and policy size of the client, i.e., empirical lapse and surrender rates. The second IRR calculation is made based on level lapse and surrender rates.
[0055] The third metric that factors into the product value for money scoring driver is the premium required to achieve the illustrated objective, typically the level premium to endow or to mature the policy at age 100. The fourth metric that factors into the product value for money scoring driver is an index of product flexibility. The index of product flexibility consists of one point for each of the following features: no-lapse guarantees, term riders, penalty-free withdrawals, preferred loans, refunds of cost-of-insurance (COI) charges, and persistency bonuses.
[0056] The next scoring driver, for the embodiment for universal life insurance, product stress tolerance, incorporates three metrics. The first metric is the ratio of the 20-year cash surrender value on mid-point assumptions (halfway between current assumptions and guaranteed assumptions) to the 20-year cash surrender value on current assumptions. Thus, the first metric measures the percentage drop in policy values if interest rates and mortality deteriorate. The second metric used in assessing product stress tolerance is the number of years the policy stays in force at the mid-point assumptions. This second metric measures the adequacy of the planned premium if interest rates and mortality both deteriorate from what was expected. Finally, the system calculates the IRR just as for the product value for money scoring driver, but with premiums cut in half after the third year. This third metric measures the drop in product performance should the policyholder reduce premium payments.
[0057] In the embodiment for universal life insurance products, Management Performance is measured using the following analytical metrics: (1) Five-year average Return on Equity (ROE); (2) ratio of ordinary life expenses to Generally Recognized Expense Table expenses (GRET); (3) five-year average of annual premium growth rate in excess of annual expense growth rate (PEGG); (4) five-year asset compound annual growth rate; (5) maximum earnings deviation from geometric path; (6) ratio of ordinary life expenses to ordinary life premiums; and (7) ratio of ordinary life expenses to ordinary life reserves. Information to support these metrics may be derived from a carrier's annual statutory statements, or if the company is a subsidiary of a larger life insurer, data is taken from the consolidated statutory statement for total U.S. operations for the larger insurer.
[0058] (1) The ROE for each year is net income divided by average of beginning and ending capital & surplus for the carrier.
[0059] (2) Generally Recognized Expense Tables (GRET) are calculated as follows (based on the 1998 Society of Actuaries factors): $65 per policy for new business, plus $33 per policy already issued, plus $1.25 per unit for new business, plus 72% of new business premiums.
[0060] (3) Five-year Average Premium Growth Rate in excess of Expense Growth Rate (PEGG) is the average annual difference between the ordinary life premium growth rate and the ordinary life expense growth rate.
[0061] (4) Five-year Assets CAGR is the compound annualized growth rate for the Assets over the last 5 years.
[0062] (5) Maximum earnings deviation from geometric path is the maximum absolute difference between the net income in each of the previous 5 years and the theoretical net income, if net income had grown at exactly the 5-year net income CAGR, divided by theoretical net income.
[0063] (6) & (7) Ordinary Life Expense is equal to line 22 (General Insurance Expenses), column 3 (Life Insurance) in the Analysis of Operations by Lines of Business. Ordinary Life Premium is the sum of lines 1 & 1A (Premiums and Deposit-type funds), column 3, in the Analysis of Operations by Lines of Business. Reserves are the ordinary life reserves gross of reinsurance (Exhibit 8A) in the annual statement.
[0064] The fourth scoring driver for the embodiment for universal life insurance products, historical credited rates, is a measure of the composite effects of historical rates. As a measure of the composite effect of historical rates, this scoring driver calculates the value of $1,000 at the beginning of each year accumulated at the historical credited rates for five years.
[0065] The fifth scoring driver for the embodiment for universal life insurance products, company service quality, is based on appropriate industry-sponsored surveys of carrier practices. One such survey is conducted by the Life Office Management Association (LOMA), an insurance trade association based in Atlanta, Ga. If this survey were to be used as the basis for this scoring driver, four metrics would emerge. The first metric is number of days between application and the offer of insurance. This metric captures one of the most often cited sources of customer satisfaction or dissatisfaction when applying first for a policy. The second metric is telephone service, which is based on a composite score of the following: (1) days per week that customer service is available; (2) average number of calls per customer service representative per day; (3) number of hours a day that customer service is available; and (4) availability of 800 numbers. The third metric is an index of Internet service, consisting of one point for each of the following features: (1) availability of a web page for the carrier; (2) availability of specific product information on the web page; (3) online quotation availability; (4) online application capability; (5) access to customer account information and policy values; (6) capability to change customer information online (address, beneficiary, etc.); and (7) application status tracking capability. The fourth metric is the number of days to complete standard service functions. This fourth metric is the average of the days to complete each of the following: (1) process a cash loan request; (2) process a cash surrender request; (3) pay an uncontested death claim; and (4) reply to customer correspondence.
[0066] The final scoring driver for the embodiment for universal life insurance products is A.M. Best's Ratings, which represent the opinion of one rating agency, A. M. Best Company, as to the insurer's financial strength and ability to meet ongoing obligations to policyholders.
[0067] The product value rating, the individual driver numeric scores, and the scores for all the metrics are all converted to a “normalized” scale between 0 and 5. The higher the score, the better the product value. The product value rating is the weighted average of the six driver scores. For scoring drivers based on more than one metric, the driver score is the weighted average of the scores for each metric.
[0068] The weights reflect the relative importance of each of the scoring drivers in evaluating life insurance and annuity products. The weights for each driver, and for each metric within the drivers, are shown in Table A for the embodiment for universal life insurance products.
TABLE A Weighting Summary Driver Metric I. Product Value for Money 40% IRR - current assumptions, LIMRA lapses 32.5% IRR - current assumptions, level lapses 32.5% Planned Premium to Achieve Objective 25% Product Flexibility 10% 100% II. Product Stress Tolerance 20% Ratio of 20-year CSV for midpoint: current 60% assumptions Years in force at midpoint assumptions 20% IRR - current assumptions with 50% premium 20% years 4+ 100% III. Management 20% Performance 5-year Average ROE 40% Actual Ordinary Life Expenses/Generally 20% Recognized Expense Table 5-year Average PEGG 10% 5-year Assets CAGR 10% Maximum Earnings Deviation from 10% Geometric Path Ordinary Life Expenses/Ordinary Life 5% Premium Ordinary Life Expenses/Ordinary Life 5% Reserves 100% IV. Historical Credited Rates 10% V. Company Service Quality 5% Average time to offer 60% Telephone service 15% Website capabilities 15% Response time for standard requests 10% 100% VI. Best's Rating 5% Total Weight of Drivers: 100%
[0069] For each metric within a scoring driver, a high point and a low point are set. If that metric for any product exceeds the high point, that product's normalized score is set to 5. If the metric is below the low point, the normalized score is set to 0; if it lies between the high and low points, the normalized score is set by linear interpolation.
[0070] For Best's ratings, the normalizing methodology is approximated by tabulating 407 companies according to Best's ratings. A++ rated companies' normalized scores are set to 5. A+ rated companies are in the 88th percentile, so their normalized scores are set at 4.4 (88% of 5). A rated companies are in the 53rd percentile, so their normalized scores are set at 2.6, etc. Companies with a rating below B+ have their normalized scores set to 0. Companies on review for upgrade or downgrade may be adjusted halfway up or down to the next normalized score.
[0071] Thus, the product value appraisal system 112 simultaneously solicits, prices, and rates, life insurance policy and annuity proposals from insurance carriers. Soliciting, rating and pricing life insurance and annuity policy proposals are conducted in an iterative process. This process is conducted in real-time and preferably continues until optimal product pricing and product ratings have been obtained.
[0072] The product value appraisal system 112 continues to provide feedback to the insurance carriers, including rating information and whether the carrier's current bid or proposal meets the customer's minimum requirements. The insurance carrier can then provide a new bid or proposal, taking into consideration the feedback from the product value appraisal system 112 . If the insurance carrier believes that its proposal is final, e.g., that it cannot submit a more competitive bid, it provides a final bid or proposal to the product value appraisal system 112 .
[0073] Insurance carriers transmit their final product proposals to the product value appraisal system 112 , as illustrated by step 5 of FIG. 1. Proposals received from insurance carriers must meet or exceed minimum product ratings established at the outset by the product value appraisal system 112 . The ratings reflect the product proposal's total value proposition to the proposed insured. The total value proposition of a life insurance or annuity product proposal takes into account, among others, the proposed insured's risk profile together with such detailed information as the insurance product proposal, information on the insurer's financial strength, and information on current market prices.
[0074] The product value appraisal system 112 transmits or outputs rated product proposals to the distribution channel, as illustrated by step 6 of FIG. 1. This output includes an appraisal of the entire value proposition for the proposed insured. The appraisal takes such form as a numerical index, an alphabetic grade, or a descriptive phrase such as “superior,” “above average,” “average,” “below-average,” or “unacceptable.” These results are communicated to the proposed insured by the distribution channel, as illustrated by step 7 of FIG. 1. Appropriate explanatory comments may accompany this information.
[0075] Next, the proposed insured makes a purchase decision and communicates that decision to the distribution channel, as illustrated by step 8 of FIG. 1. The proposed insured's purchase decision flows back to the insurance carriers via the distribution channel and the product value appraisal system, as illustrated by steps 9 and 10 of FIG. 1.
[0076] [0076]FIG. 2 illustrates a more detailed view of the parties involved in the valuation system. Insurance carriers 216 (Ins. Co. A, B, C, D, E, F, . . . ) represent competing insurance carriers available to propose insurance products to meet customer requirements according to the present invention. The product value appraisal system 212 for soliciting, pricing, and rating life insurance and annuity product proposals in a real-time, iterative process is shown. The product value appraisal system 212 way also rate the performance of in-force life insurance policies and annuities and measures the value proposition of replacing in-force insurance policies and annuities. Distribution channels 208 include, among others, aggregators, banks, non-bank institutions, bank trusts, insurance agents, brokers, financial planners and advisors, funeral homes, place of employment, affinity groups and other carriers.
[0077] In addition, another embodiment of the present invention provides a method of valuing in-force life insurance and annuity policies and rates the continuing value proposition to the policyholder. As shown in FIG. 3, the product value appraisal system 312 collects, processes and uses available information on the insurance policyholder, the in-force policy, and the insurance company that issued the in-force policy to rate the performance of the in-force policy.
[0078] Further, if requested by the policyholder, the product value appraisal system 312 determines the value proposition involved in replacing the in-force policy. If a valuation of a replacement policy is requested, the process proceeds in a manner similar to that process described with regard to FIG. 1. For example, the product value appraisal system 312 solicits, auctions and rates replacement life insurance and annuity policy proposals to compare their value proposition to that of the in-force policy. Second, the product value appraisal system 312 calculates whether replacing the in-force policy would create value for the policyholder, particularly in view of the existing in-force policy.
[0079] As shown in FIG. 4, it is possible for an entity including a consumer seeking a life insurance or annuity product to invoke the product value appraisal system 412 without the aid of a distribution channel. As shown in step 1 of FIG. 4, a party seeking such a product, the proposed insured, 404 contacts the product value appraisal system 412 , typically via a website interface. The proposed insured 404 provides to the product value appraisal system 412 information necessary to request proposals for life insurance or annuity products. This information provided by the proposed insured includes demographic information and information for developing a risk profile of the proposed insured 404 for the product to be evaluated. Demographic and risk profile data may include, for example, the proposed insured's age, sex, smoking habits amount of insurance desired, the pattern of premium payments and the pattern of disbursements desired from the product. A knowledgeable proposed insured may also provide information about the insurance policy sought, including the proposed premiums to be paid and the proposed benefits to be provided. The proposed insured may also include information as to preferred carriers.
[0080] Then, the product value appraisal system 412 initiates bidding and/or invites proposals from interested product providers or carriers 416 by sending a proposed opening bid or invitation for proposal to participating insurance carriers 416 , as illustrated by step 2 of FIG. 4. The opening bid provided by the product value appraisal system 412 may include an opening price with a minimum product rating.
[0081] After initiating bidding or inviting proposals, the product appraisal system 412 proceeds in an on-line, real-time, iterative process with the insurance carriers 416 , as illustrated by step 3 of FIG. 4. Upon receipt of a bid or proposal from a participating insurance carrier 416 , the product value appraisal system 412 reviews each bid or proposal and rates the bid or proposal and the pricing of each bid or proposal.
[0082] With each product proposal, the carrier 416 will transmit information about the price and benefits of its product along with identifying information about itself. This data includes data about the product's proposed benefits and price on both a guaranteed and illustrated basis, and information about the insurance company proposing the product. Product data include the proposed premiums to be paid and the proposed benefits to be provided, both distinguished between guaranteed amounts and illustrated amounts that depend on assumptions about the future. The insurance company information includes data that quantifies the financial strength of the insurance company. The product value appraisal system 412 will use appropriate actuarial assumptions, such as mortality information specific to the end customer's risk profile, and traditional actuarial present value methodology to determine a numeric rating of the benefits offered in light of the proposed price (Product Value For Money in FIG. 1). Numeric ratings will also be assigned to the product's performance under less optimistic assumptions about future interest rates and at lower premium levels (Product Stress Tolerance), various company financial information (Management Performance), previous interest rates actually credited to the product's values (Historical Credited Rates), various qualitative measures of customer service (Customer Service Quality) and to the financial strength of the product provider (e.g., A.M. Best Rating). These ratings will then be weighted to arrive at an overall rating of the customer value proposition. Details of these six scoring drivers and the formulas for the product value appraisal system are as described above for the embodiment for universal life insurance.
[0083] Thus, the product value appraisal system 412 simultaneously solicits, prices, and rates, life insurance and annuity policy proposals from insurance carriers 416 . Soliciting, rating and pricing these life insurance and annuity policy proposals are conducted in an iterative process. This process is preferably conducted in real-time and continues until optimal product pricing and product ratings have been obtained. Although each insurance carrier can make one proposal at a time, multiple proposals can also be made by each carrier to generate multiple ratings with multiple prices.
[0084] The product value appraisal system 412 continues to provide feedback to the insurance carriers 416 , including rating information and whether the carrier's current bid or proposal meets the customer's minimum requirements. The insurance carrier can then provide a new bid or proposal, taking into consideration the feedback from the product value appraisal system 412 . If the insurance carrier believes that its proposal is final, e.g., that it cannot submit a more competitive bid, it provides a final bid or proposal to the product value appraisal system 412 .
[0085] Insurance carriers 416 transmit their final product proposals to the product value appraisal system, as illustrated by step 4 of FIG. 4. Proposals received from insurance carriers 416 must meet or exceed minimum product ratings established at the outset by the product value appraisal system 412 . The ratings reflect the insurance or annuity product proposal's total value proposition to the proposed insured 404 . The total value proposition of a life insurance or annuity product proposal takes into account the proposed insured's risk profile together with detailed information about the life insurance or annuity product proposal, information on the insurer's financial strength, and information on current market prices.
[0086] The product value appraisal system 412 transmits rated product proposals to the proposed insured, as illustrated by step 5 of FIG. 4. This output includes an appraisal of the entire value proposition for the proposed insured 404 . The appraisal takes such form as a numerical index, an alphabetic grade, or a descriptive phrase such as “superior,” “above average,” “average,” “below-average,” or “unacceptable.” Appropriate explanatory comments may accompany this information.
[0087] Next, the proposed insured 404 may make a purchase decision and communicate that decision to the product value appraisal system 412 , as illustrated by step 6 of FIG. 4. The proposed insured's purchase decision flows back to the insurance carriers 416 via the product value appraisal system 412 , as illustrated by step 7 of FIG. 4.
[0088] [0088]FIG. 5 illustrates an embodiment of the invention appraising the value proposition for replacing an in-force policy. As shown in FIG. 5, it is possible for the holder of an existing policy to query the policy appraisal system or product value appraisal system 512 to appraise the value of the in-force policy and also appraise the value proposition for replacing the in-force policy. As shown in FIG. 5, step 1 , the policyholder 504 contacts a distribution channel 508 to assist in obtaining such appraisal. The distribution channel then contacts the product value appraisal system 512 , as shown in step 2 .
[0089] The product value appraisal system 512 then collects, processes and uses available information on the insurance policyholder, the in-force policy, and the insurance company that issued the in-force policy to rate the performance of the in-force policy. The product value appraisal system 512 uses appropriate actuarial assumptions, such as mortality information specific to the end customer's risk profile, and traditional actuarial present value methodology to determine a numeric rating of the benefits offered in light of the price (Product Value For Money in FIG. 1). Numeric ratings will also be assigned to the product's performance under less optimistic assumptions about future interest rates and at lower premium levels (Product Stress Tolerance), various company financial information (Management Performance), previous interest rates actually credited to the product's values (Historical Credited Rates), various qualitative measures of customer service (Customer Service Quality) and to the financial strength of the product provider (e.g., A.M. Best Rating). These ratings will then be weighted to arrive at an overall rating of the customer value proposition. Details of these six scoring drivers and the formulas for the product value appraisal system are as described above for the embodiment for universal life insurance products. Information regarding the rating and value proposition are transmitted to the policyholder 504 via the distribution channel 508 .
[0090] The product value appraisal system 512 also conducts a similar appraisal for a proposed replacement policy. If requested by the policyholder 504 via the distribution channel or by the distribution channel 508 , the product value appraisal system 512 can solicit life insurance and annuity policy proposals from insurance carriers in the iterative processed described with regard to FIG. 1. Similarly, the policyholder 504 may provide information regarding the replacement policy under consideration to the product value appraisal system via the distribution channel 508 , as illustrated by steps 5 and 6 .
[0091] Although FIG. 5 illustrates a policyholder invoking the product value appraisal system via a distribution channel, it is possible for the policyholder to contact the product value appraisal system directly to conduct an analysis of an in-force policy and appraisal of the value proposition for replacing the in-force policy.
[0092] As shown in FIG. 6, it is possible for the holder of an existing policy to query the product value appraisal system to value the in-force policy without the aid of a distribution channel. As shown in FIG. 6, the policyholder 604 contacts the product value appraisal system 612 , for example, via a website. The product value appraisal system 612 then collects, processes and uses available information on the insurance policyholder, the in-force policy, and the insurance company that issued the in-force policy to rate the performance of the in-force policy.
[0093] Further, if requested by the policyholder, the product value appraisal system 512 determines the value proposition involved in replacing the in-force policy. If a valuation of a replacement policy is requested, the process proceeds in a manner similar to that process described with regard to FIG. 4. For example, the valuation system solicits, auctions and rates replacement insurance policy proposals to compare their value proposition to that of the in-force policy. Second, the invention calculates whether replacing the in-force policy would create value for the policyholder, particularly in view of the existing in-force policy.
[0094] Revenues for use of the product value appraisal system are generated from subscription fees from life insurance product or annuity providers for participation in the auction process, transaction fees from the providers for the processing of bids and appraising the customer value proposition of proposals submitted, transaction fees from the distribution channel to receive the output from valuation system, and data subscription fees from the product providers to access the market intelligence data that will accumulate over time. Moreover, the valuation system may be provided as value-added services to the distribution channels, or to consumers directly, who pay a fee to use the service.
[0095] An example of the valuation system of the present invention is provided. John Consumer is reviewing his estate plan with his personal, fee-based financial advisor. The advisor recommends the purchase of an additional $250,000 of life insurance in an irrevocable trust to replace assets transferred to a Charitable Remainder Trust. Because it is not known when Mr. Consumer will die, a permanent (as opposed to term) form of insurance is recommended. Following some discussions of the various forms of permanent coverage, it is agreed to seek the best available life product to fill the need.
[0096] The financial advisor then goes on-line to the web site which places the financial advisor in contact with the product value appraisal system and commences a search for the best value for his client using the value appraisal system. In this example, the distribution channel is the financial advisor. As the distribution channel, the financial advisor, in response to prompts by the web site interface, enters the following information which is transmitted to the product value appraisal system: (1) risk profile data about John Consumer including, inter alia, his present age (45), sex (male), and smoking status (non-smoker); (2) the purpose of the proposed insurance (asset replacement to preserve his estate); (3) the desired pattern of premium payments (for life); (4) the disbursements desired from the policy (none prior to payment of the death benefit); and (5) face amount and type of product for which proposals are desired ($250,000 of life insurance).
[0097] The website receives the information and invokes the product value appraisal system, which opens an on-line, real-time proposal solicitation process for interested carriers. These proposals include, inter alia, policy illustrations showing the target premiums, guaranteed and illustrated benefits and cash values at select points in the future, and identifying information about the proposing carrier. Proposals are received from four carriers (A, B, C, and D). The product value appraisal system conducts an overall appraisal of the proposals received.
[0098] Product Value for Money
[0099] The cash flow was projected for the group of policyholders, using an industry mortality rate for nonsmokers of this policy size, and lapses (a) according to the LIMRA tables, as shown in Table B and (b) 5%, as shown in Tables C1-C4.
TABLE B Product Value for Money Mortality and LIMRA Lapse rates per 1,000 Du- ra- Mortality Lapse Mortality Lapse Age tion Rate Rate Age Duration Rate Rate 45 1 0.40 59 77 33 40.15 42 46 2 0.59 69 78 34 44.46 42 47 3 0.78 51 79 35 49.29 42 48 4 0.98 65 80 36 54.43 42 49 5 1.24 57 81 37 59.90 42 50 6 1.60 29 82 38 65.32 42 51 7 2.02 42 83 39 70.91 42 52 8 2.49 42 84 40 77.59 42 53 9 2.94 42 85 41 85.53 42 54 10 3.44 42 86 42 95.14 42 55 11 3.85 42 87 43 105.23 42 56 12 4.46 42 88 44 115.29 42 57 13 5.17 42 89 45 124.98 42 58 14 5.63 42 90 46 134.61 42 59 15 6.18 42 91 47 146.21 42 60 16 7.13 42 92 48 159.13 42 61 17 8.07 42 93 49 175.52 42 62 18 9.10 42 94 50 192.61 42 63 19 10.26 42 95 51 207.65 42 64 20 11.35 42 96 52 219.62 42 65 21 12.53 42 97 53 224.00 42 66 22 13.67 42 98 54 230.49 42 67 23 14.81 42 99 55 238.19 761.81 68 24 15.85 42 69 25 16.96 42 70 26 21.03 42 71 27 22.98 42 72 28 25.18 42 73 29 27.60 42 74 30 30.27 42 75 31 33.01 42 76 32 36.25 42
[0100] In each year, the cash flow is:
[0101] Premiums for lives in force at the beginning of the year, less
[0102] Expected deaths in the year multiplied by the Face Amount, less
[0103] Expected surrenders in the year multiplied by the Cash Surrender Value.
[0104] Internal rates of return are then calculated. A commercial software product, such as Microsoft Excel, which has an IRR function, may be used for each product based on the cash flows. Using the LIMRA lapse assumptions, for example, Company D the highest IRR at 6.616%, and Company A has the lowest IRR at 5.073%. The high point is set at 6.5% and the low point at 4.5%. Company D, being above the high point, receives a normalized score of 5. Company A, by interpolation, receives a normalized score of 1.4325, rounded to 1.4. A similar process is used for the flat 5% lapse assumption. The IRR calculations for each of the Companies A, B, C, and D are shown in Tables C1-C4.
TABLE C1 Product Value for Money - Calculation of IRR - LIMRA Lapses Company A Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 2,125 526 0 250,000 2,027.14 5.073% 46 2 2,125 2,002 0 250,000 1,864.09 47 3 2,125 3,566 0 250,000 1,693.07 48 4 2,125 5,223 0 250,000 1,565.67 49 5 2,125 6,959 567 250,000 1,388.14 50 6 2,125 8,827 2,751 250,000 1,205.97 51 7 2,125 10,813 5,064 250,000 1,003.19 52 8 2,125 12,894 7,483 250,000 812.31 53 9 2,125 15,098 10,037 250,000 635.74 54 10 2,125 17,426 12,732 250,000 463.23 55 11 2,125 19,850 16,396 250,000 291.96 56 12 2,125 22,296 19,944 250,000 111.58 57 13 2,125 24,852 23,446 250,000 (65.26) 58 14 2,125 27,524 26,908 250,000 (193.46) 59 15 2,125 30,338 30,338 250,000 (319.55) 60 16 2,125 33,278 33,278 250,000 (469.45) 61 17 2,125 36,352 36,352 250,000 (603.74) 62 18 2,125 39,560 39,560 250,000 (734.97) 63 19 2,125 42,908 42,908 250,000 (865.03) 64 20 2,125 46,398 46,398 250,000 (974.62) 65 21 2,125 50,054 50,054 250,000 (1,079.20) 66 22 2,125 53,858 53,858 250,000 (1,167.40) 67 23 2,125 57,809 57,809 250,000 (1,243.07) 68 24 2,125 61,906 61,906 250,000 (1,299.40) 69 25 2,125 66,140 66,140 250,000 (1,350.62) 70 26 2,125 70,502 70,502 250,000 (1,582.22) 71 27 2,125 74,977 74,977 250,000 (1,647.34) 72 28 2,125 79,545 79,545 250,000 (1,708.99) 73 29 2,125 84,179 84,179 250,000 (1,763.59) 74 30 2,125 88,573 88,573 250,000 (1,808.46) 75 31 2,125 93,055 93,055 250,000 (1,837.56) 76 32 2,125 97,548 97,548 250,000 (1,868.36) 77 33 2,125 102,043 102,043 250,000 (1,902.89) 78 34 2,125 106,540 16,540 250,000 (1,384.83) 79 35 2,125 111,037 111,037 250,000 (1,942.39) 80 36 2,125 115,538 115,538 250,000 (1,939.12) 81 37 2,125 120,047 120,047 250,000 (1,918.18) 82 38 2,125 124,572 124,572 250,000 (1,870.75) 83 39 2,125 129,126 129,126 250,000 (1,805.84) 84 40 2,125 133,719 133,719 250,000 (1,742.95) 85 41 2,125 138,369 138,369 250,000 (1,679.76) 86 42 2,125 143,094 143,094 250,000 (1,616.67) 87 43 2,125 147,917 147,917 250,000 (1,531.49) 88 44 2,125 152,871 152,871 250,000 (1,422.26) 89 45 2,125 158,001 158,001 250,000 (1,293.41) 90 46 2,125 163,372 163,372 250,000 (1,156.21) 91 47 2,125 169,070 169,070 250,000 (1,029.28) 92 48 2,125 175,208 175,208 250,000 (905.19) 93 49 2,125 181,934 181,934 250,000 (792.92) 94 50 2,125 188,913 188,913 250,000 (677.31) 95 51 2,125 197,239 197,239 250,000 (557.51) 96 52 2,125 207,171 207,171 250,000 (442.56) 97 53 2,125 219,020 219,020 250,000 (335.01) 98 54 2,125 233,154 233,154 250,000 (254.31) 99 55 2,125 250,016 250,016 250,016 (595.21)
[0105] [0105] TABLE C2 Product Value for Money - Calculation of IRR - LIMRA Lapses Company B Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 1,953 909 0 250,000 1,855.14 6.185% 46 2 1,953 2,409 0 250,000 1,702.31 47 3 1,953 3,972 0 250,000 1,542.54 48 4 1,953 5,638 663 250,000 1,387.20 49 5 1,953 7,434 2,911 250,000 1,151.34 50 6 1,953 9,465 5,394 250,000 1,024.52 51 7 1,953 11,611 7,992 250,000 794.56 52 8 1,953 13,879 10,713 250,000 604.31 53 9 1,953 16,275 13,561 250,000 429.05 54 10 1,953 18,803 16,541 250,000 258.47 55 11 1,953 21,446 19,637 250,000 110.56 56 12 1,953 24,203 22,847 250,000 (53.52) 57 13 1,953 27,068 26,164 250,000 (218.51) 58 14 1,953 30,045 29,593 250,000 (338.77) 59 15 1,953 33,139 33,139 250,000 (460.29) 60 16 1,953 36,357 36,537 250,000 (612.25) 61 17 1,953 39,699 39,699 250,000 (741.12) 62 18 1,953 43,164 43,164 250,000 (869.93) 63 19 1,953 46,756 46,756 250,000 (997.11) 64 20 1,953 50,474 50,474 250,000 (1,103.34) 65 21 1,953 54,284 54,284 250,000 (1,203.31) 66 22 1,953 58,225 58,225 250,000 (1,286.63) 67 23 1,953 62,293 62,293 250,000 (1,357.18) 68 24 1,953 66,487 66,487 250,000 (1,408.21) 69 25 1,953 70,804 70,804 250,000 (1,454.08) 70 26 1,953 75,241 75,241 250,000 (1,680.31) 71 27 1,953 79,781 79,781 250,000 (1,739.86) 72 28 1,953 84,421 84,421 250,000 (1,796.15) 73 29 1,953 89,158 89,158 250,000 (1,845.76) 74 30 1,953 93,985 93,985 250,000 (1,888.48) 75 31 1,953 98,880 98,880 250,000 (1,914.94) 76 32 1,953 103,828 103,828 250,000 (1,943.12) 77 33 1,953 108,814 108,814 250,000 (1,974.94) 78 34 1,953 113,823 113,823 250,000 (1,996.37) 79 35 1,953 118,843 118,843 250,000 (2,008.32) 80 36 1,953 123,863 123,863 250,000 (2,001.52) 81 37 1,953 128,878 128,878 250,000 (1,976.72) 82 38 1,953 133,890 133,890 250,000 (1,925.18) 83 39 1,953 138,900 138,900 250,000 (1,855.96) 84 40 1,953 143,895 143,895 250,000 (1,788.58) 85 41 1,953 148,866 148,866 250,000 (1,720.70) 86 42 1,953 153,818 153,818 250,000 (1,652.81) 87 43 1,953 158,755 158,755 250,000 (1,562.79) 88 44 1,953 163,689 163,689 250,000 (1,448.82) 89 45 1,953 168,654 168,654 250,000 (1,315.47) 90 46 1,953 173,705 173,705 250,000 (1,174.12) 91 47 1,953 178,990 178,990 250,000 (1,043.56) 92 48 1,953 184,626 184,626 250,000 (916.32) 93 49 1,953 190,769 190,769 250,000 (801.38) 94 50 1,953 197,629 197,629 250,000 (683.83) 95 51 1,953 204,973 204,973 250,000 (562.11) 96 52 1,953 213,158 213,158 250,000 (445.51) 97 53 1,953 222,747 222,747 250,000 (336.72) 98 54 1,953 234,628 234,628 250,000 (255.23) 99 55 1,953 250,248 250,248 250,048 (596.19)
[0106] [0106] TABLE C3 Product Value for Money - Calculation of IRR - LIMRA Lapses Company C Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 2,048 1,044 0 250,000 1,950.14 5.182% 46 2 2,048 2,589 0 250,000 1,791.66 47 3 2,048 4,174 0 250,000 1,625.68 48 4 2,048 5,823 0 250,000 1,501.78 49 5 2,048 7,551 1,227 250,000 1,299.32 50 6 2,048 9,369 3,045 250,000 1,143.55 51 7 2,048 11,288 4,963 250,000 951.70 52 8 2,048 13,313 6,988 250,000 774.27 53 9 2,048 15,446 9,122 250,000 610.78 54 10 2,048 17,688 11,364 250,000 451.10 55 11 2,048 20,031 14,339 250,000 297.40 56 12 2,048 22,451 17,391 250,000 128.44 57 13 2,048 24,934 20,507 250,000 (40.53) 58 14 2,048 27,484 23,689 250,000 (163.93) 59 15 2,048 30,102 26,939 250,000 (287.78) 60 16 2,048 32,752 30,222 250,000 (445.88) 61 17 2,048 35,494 33,596 250,000 (586.89) 62 18 2,048 38,330 37,065 250,000 (723.54) 63 19 2,048 41,265 40,633 250,000 (857.86) 64 20 2,048 44,303 44,303 250,000 (970.67) 65 21 2,048 47,421 47,421 250,000 (1,067.49) 66 22 2,048 50,616 50,616 250,000 (1,147.79) 67 23 2,048 53,904 53,904 250,000 (1,215.79) 68 24 2,048 57,293 57,293 250,000 (1,264.85) 69 25 2,048 60,782 60,782 250,000 (1,309.34) 70 26 2,048 64,369 64,369 250,000 (1,534.93) 71 27 2,048 68,055 68,055 250,000 (1,594.93) 72 28 2,048 71,843 71,843 250,000 (1,652.53) 73 29 2,048 75,734 75,734 250,000 (1,704.32) 74 30 2,048 79,724 79,724 250,000 (1,750.03) 75 31 2,048 83,809 83,809 250,000 (1,780.38) 76 32 2,048 87,983 87,983 250,000 (1,813.30) 77 33 2,048 92,240 92,240 250,000 (1,850.69) 78 34 2,048 96,575 96,575 250,000 (1,878.47) 79 35 2,048 100,987 100,987 250,000 (1,897.52) 80 36 2,048 105,476 105,476 250,000 (1,898.42) 81 37 2,048 110,047 110,047 250,000 (1,881.81) 82 38 2,048 114,711 114,711 250,000 (1,838.75) 83 39 2,048 119,482 119,482 250,000 (1,778.16) 84 40 2,048 124,363 124,363 250,000 (1,719.41) 85 41 2,048 129,360 129,360 250,000 (1,660.10) 86 42 2,048 134,488 134,488 250,000 (1,600.60) 87 43 2,048 139,768 139,768 250,000 (1,518.66) 88 44 2,048 145,231 145,231 250,000 (1,412.29) 89 45 2,048 150,929 150,929 250,000 (1,285.90) 90 46 2,048 156,935 156,935 250,000 (1,150.76) 91 47 2,048 163,342 163,342 250,000 (1,025.55) 92 48 2,048 170,263 170,263 250,000 (902.82) 93 49 2,048 177,843 177,843 250,000 (791.59) 94 50 2,048 186,264 186,264 250,000 (677.00) 95 51 2,048 195,758 195,758 250,000 (557.72) 96 52 2,048 206,617 206,617 250,000 (442.98) 97 53 2,048 219,221 219,221 250,000 (335.47) 98 54 2,048 234,056 234,056 250,000 (254.76) 99 55 2,048 251,745 251,745 251,745 (599.60)
[0107] [0107] TABLE C4 Product Value for Money - Calculation of IRR - LIMRA Lapses Company D Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 1,648 1,387 — 250,000 1,550.14 6.616% 46 2 1,648 2,800 — 250,000 1,415.43 47 3 1,648 4,242 — 250,000 1,275.62 48 4 1,648 5,717 — 250,000 1,169.85 49 5 1,648 7,255 523 250,000 1,020.37 50 6 1,648 8,833 2,435 250,000 864.48 51 7 1,648 10,482 4,430 250,000 684.49 52 8 1,648 12,180 6,487 250,000 517.91 53 9 1,648 13,929 8,609 250,000 366.15 54 10 1,648 15,705 10,772 250,000 219.51 55 11 1,648 17,453 12,923 250,000 96.68 56 12 1,648 19,174 15,062 250,000 (41.58) 57 13 1,648 21,011 17,333 250,000 (183.69) 58 14 1,648 22,969 19,744 250,000 (283.86) 59 15 1,648 25,058 22,308 250,000 (388.04) 60 16 1,648 27,287 25,032 250,000 (530.53) 61 17 1,648 29,664 27,932 250,000 (658.69) 62 18 1,648 32,200 31,012 250,000 (785.00) 63 19 1,648 34,905 34,295 250,000 (911.51) 64 20 1,648 37,790 37,790 250,000 (1,018.82) 65 21 1,648 40,816 40,816 250,000 (1,111.76) 66 22 1,648 43,943 43,943 250,000 (1,188.75) 67 23 1,648 47,230 47,230 250,000 (1,254.51) 68 24 1,648 50,616 50,616 250,000 (1,301.37) 69 25 1,648 54,111 54,111 250,000 (1,343.86) 70 26 1,648 57,657 57,657 250,000 (1,567.12) 71 27 1,648 61,286 61,286 250,000 (1,624.57) 72 28 1,648 65,034 65,034 250,000 (1,679.92) 73 29 1,648 68,893 68,893 250,000 (1,729.66) 74 30 1,648 72,878 72,878 250,000 (1,773.65) 75 31 1,648 76,961 76,961 250,000 (1,802.34) 76 32 1,648 81,159 81,159 250,000 (1,833.87) 77 33 1,648 85,490 85,490 250,000 (1,870.23) 78 34 1,648 89,913 89,913 250,000 (1,897.03) 79 35 1,648 94,450 94,450 250,000 (1,915.25) 80 36 1,648 99,103 99,103 250,000 (1,915.43) 81 37 1,648 103,843 103,843 250,000 (1,898.02) 82 38 1,648 108,731 108,731 250,000 (1,854.28) 83 39 1,648 113,745 113,745 250,000 (1,792.95) 84 40 1,648 118,901 118,901 250,000 (1,733.46) 85 41 1,648 124,220 124,220 250,000 (1,673.43) 86 42 1,648 129,756 129,756 250,000 (1,613.27) 87 43 1,648 135,527 135,527 250,000 (1,530.66) 88 44 1,648 141,585 141,585 250,000 (1,423.60) 89 45 1,648 147,976 147,976 250,000 (1,296.48) 90 46 1,648 154,755 154,755 250,000 (1,160.54) 91 47 1,648 161,991 161,991 250,000 (1,034.44) 92 48 1,648 169,755 169,755 250,000 (910.71) 93 49 1,648 178,135 178,135 250,000 (798.41) 94 50 1,648 187,254 187,254 250,000 (682.68) 95 51 1,648 197,236 197,236 250,000 (562.25) 96 52 1,648 208,253 208,253 250,000 (446.42) 97 53 1,648 220,519 220,519 250,000 (337.94) 98 54 1,648 234,314 234,314 250,000 (256.41) 99 55 1,648 250,002 250,002 250,002 (596.58)
[0108] Calculation of IRR based on a level lapse rate are shown in Tables D1-D4.
TABLE D1 Product Value for Money - Calculation of IRR - Level Lapses Company A Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 2,125 526 0 250,000 2,026.69 4.806% 46 2 2,125 2,002 0 250,000 1,880.59 47 3 2,125 3,566 0 250,000 1,744.08 48 4 2,125 5,223 0 250,000 1,613.06 49 5 2,125 6,959 567 250,000 1,456.88 50 6 2,125 8,827 2,751 250,000 1,231.80 51 7 2,125 10,813 5,064 250,000 1,007.95 52 8 2,125 12,894 7,483 250,000 792.20 53 9 2,125 15,098 10,037 250,000 594.93 54 10 2,125 17,426 12,732 250,000 405.41 55 1 2,125 19,850 16,396 250,000 216.78 56 12 2,125 22,296 19,944 250,000 24.34 57 13 2,125 24,852 23,446 250,000 (159.84) 58 14 2,125 27,524 26,908 250,000 (292.34) 59 15 2,125 30,338 30,338 250,000 (419.27) 60 16 2,125 33,278 33,278 250,000 (563.88) 61 17 2,125 36,352 36,352 250,000 (690.84) 62 18 2,125 39,560 39,560 250,000 (812.29) 63 19 2,125 42,908 42,908 250,000 (930.11) 64 20 2,125 46,398 46,398 250,000 (1,026.55) 65 21 2,125 50,054 50,054 250,000 (1,116.30) 66 22 2,125 53,858 53,858 250,000 (1,189.14) 67 23 2,125 57,809 57,809 250,000 (1,248.93) 68 24 2,125 61,906 61,906 250,000 (1,289.93) 69 25 2,125 66,140 66,140 250,000 (1,325.16) 70 26 2,125 70,502 70,502 250,000 (1,517.01) 71 27 2,125 74,977 74,977 250,000 (1,560.13) 72 28 2,125 79,545 79,545 250,000 (1,598.79) 73 29 2,125 84,179 84,179 250,000 (1,629.99) 74 30 2,125 88,573 88,573 250,000 (1,651.26) 75 31 2,125 93,055 93,055 250,000 (1,658.30) 76 32 2,125 97,548 97,548 250,000 (1,665.94) 77 33 2,125 102,043 102,043 250,000 (1,675.80) 78 34 2,125 106,540 16,540 250,000 (1,146.61) 79 35 2,125 111,037 111,037 250,000 (1,669.07) 80 36 2,125 115,538 115,538 250,000 (1,646.39) 81 37 2,125 120,047 120,047 250,000 (1,609.52) 82 38 2,125 124,572 124,572 250,000 (1,551.99) 83 39 2,125 129,126 129,126 250,000 (1,481.50) 84 40 2,125 133,719 133,719 250,000 (1,413.59) 85 41 2,125 138,369 138,369 250,000 (1,346.42) 86 42 2,125 143,094 143,094 250,000 (1,280.33) 87 43 2,125 147,917 147,917 250,000 (1,198.61) 88 44 2,125 152,871 152,871 250,000 (1,100.39) 89 45 2,125 158,001 158,001 250,000 (989.56) 90 46 2,125 163,372 163,372 250,000 (874.88) 91 47 2,125 169,070 169,070 250,000 (770.06) 92 48 2,125 175,208 175,208 250,000 (669.52) 93 49 2,125 181,934 181,934 250,000 (579.56) 94 50 2,125 188,913 188,913 250,000 (489.22) 95 51 2,125 197,239 197,239 250,000 (398.10) 96 52 2,125 207,171 207,171 250,000 (312.54) 97 53 2,125 219,020 219,020 250,000 (234.19) 98 54 2,125 233,154 233,154 250,000 (175.96) 99 55 2,125 250,016 250,016 250,016 (398.31)
[0109] [0109] TABLE D2 Product Value for Money - Calculation of IRR - Level Lapses Company B Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 1,953 909 0 250,000 1,854.69 6.034% 46 2 1,953 2,409 0 250,000 1,717.26 47 3 1,953 3,972 0 250,000 1,589.02 48 4 1,953 5,638 663 250,000 1,437.51 49 5 1,953 7,434 2,911 250,000 1,222.06 50 6 1,953 9,465 5,394 250,000 997.53 51 7 1,953 11,611 7,992 250,000 775.38 52 8 1,953 13,879 10,713 250,000 561.31 53 9 1,953 16,275 13,561 250,000 366.54 54 10 1,953 18,803 16,541 250,000 180.30 55 11 1,953 21,446 19,637 250,000 20.41 56 12 1,953 24,203 22,847 250,000 (152.05) 57 13 1,953 27,068 26,164 250,000 (321.74) 58 14 1,953 30,045 29,593 250,000 (444.47) 59 15 1,953 33,139 33,139 250,000 (565.64) 60 16 1,953 36,357 36,537 250,000 (712.11) 61 17 1,953 39,699 39,699 250,000 (832.40) 62 18 1,953 43,164 43,164 250,000 (950.64) 63 19 1,953 46,756 46,756 250,000 (1,064.74) 64 20 1,953 50,474 50,474 250,000 (1,156.97) 65 21 1,953 54,284 54,284 250,000 (1,241.18) 66 22 1,953 58,225 58,225 250,000 (1,308.26) 67 23 1,953 62,293 62,293 250,000 (1,362.10) 68 24 1,953 66,487 66,487 250,000 (1,397.02) 69 25 1,953 70,804 70,804 250,000 (1,426.20) 70 26 1,953 75,241 75,241 250,000 (1,612.04) 71 27 1,953 79,781 79,781 250,000 (1,649.05) 72 28 1,953 84,421 84,421 250,000 (1,681.88) 73 29 1,953 89,158 89,158 250,000 (1,707.74) 74 30 1,953 93,985 93,985 250,000 (1,726.57) 75 31 1,953 98,880 98,880 250,000 (1,730.72) 76 32 1,953 103,828 103,828 250,000 (1,735.51) 77 33 1,953 108,814 108,814 250,000 (1,742.48) 78 34 1,953 113,823 113,823 250,000 (1,740.08) 79 35 1,953 118,843 118,843 250,000 (1,729.34) 80 36 1,953 123,863 123,863 250,000 (1,703.06) 81 37 1,953 128,878 128,878 250,000 (1,662.33) 82 38 1,953 133,890 133,890 250,000 (1,600.74) 83 39 1,953 138,900 138,900 250,000 (1,526.07) 84 40 1,953 143,895 143,895 250,000 (1,453.84) 85 41 1,953 148,866 148,866 250,000 (1,382.25) 86 42 1,953 153,818 153,818 250,000 (1,311.68) 87 43 1,953 158,755 158,755 250,000 (1,225.52) 88 44 1,953 163,689 163,689 250,000 (1,123.00) 89 45 1,953 168,654 168,654 250,000 (1,008.15) 90 46 1,953 173,705 173,705 250,000 (889.81) 91 47 1,953 178,990 178,990 250,000 (781.83) 92 48 1,953 184,626 184,626 250,000 (678.58) 93 49 1,953 190,769 190,769 250,000 (586.37) 94 50 1,953 197,629 197,629 250,000 (494.41) 95 51 1,953 204,973 204,973 250,000 (401.70) 96 52 1,953 213,158 213,158 250,000 (314.80) 97 53 1,953 222,747 222,747 250,000 (235.46) 98 54 1,953 234,628 234,628 250,000 (176.61) 99 55 1,953 250,248 250,248 250,048 (398.97)
[0110] [0110] TABLE D3 Product Value for Money - Calculation of IRR - Level Lapses Company C Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 46 1 2,048 1,044 0 250,000 1,949.69 4.891% 46 2 2,048 2,589 0 250,000 1,807.47 47 3 2,048 4,174 0 250,000 1,674.66 48 4 2,048 5,823 0 250,000 1,547.16 49 5 2,048 7,551 1,227 250,000 1,367.56 50 6 2,048 9,369 3,045 250,000 1,161.15 51 7 2,048 11,288 4,963 250,000 955.37 52 8 2,048 13,313 6,988 250,000 755.98 53 9 2,048 15,446 9,122 250,000 574.37 54 10 2,048 17,688 11,364 250,000 399.99 55 11 2,048 20,031 14,339 250,000 231.88 56 12 2,048 22,451 17,391 250,000 52.38 57 13 2,048 24,934 20,507 250,000 (123.22) 58 14 2,048 27,484 23,689 250,000 (250.81) 59 15 2,048 30,102 26,939 250,000 (375.86) 60 16 2,048 32,752 30,222 250,000 (530.52) 61 17 2,048 35,494 33,596 250,000 (665.66) 62 18 2,048 38,330 37,065 250,000 (793.72) 63 19 2,048 41,265 40,633 250,000 (916.72) 64 20 2,048 44,303 44,303 250,000 (1,017.10) 65 21 2,048 47,421 47,421 250,000 (1,098.71) 66 22 2,048 50,616 50,616 250,000 (1,163.41) 67 23 2,048 53,904 53,904 250,000 (1,215.43) 68 24 2,048 57,293 57,293 250,000 (1,249.20) 69 25 2,048 60,782 60,782 250,000 (1,277.90) 70 26 2,048 64,369 64,369 250,000 (1,464.07) 71 27 2,048 68,055 68,055 250,000 (1,502.54) 72 28 2,048 71,843 71,843 250,000 (1,537.73) 73 29 2,048 75,734 75,734 250,000 (1,566.79) 74 30 2,048 79,724 79,724 250,000 (1,589.64) 75 31 2,048 83,809 83,809 250,000 (1,598.64) 76 32 2,048 87,983 87,983 250,000 (1,609.07) 77 33 2,048 92,240 92,240 250,000 (1,622.42) 78 34 2,048 96,575 96,575 250,000 (1,627.09) 79 35 2,048 100,987 100,987 250,000 (1,624.02) 80 36 2,048 105,476 105,476 250,000 (1,605.88) 81 37 2,048 110,047 110,047 250,000 (1,573.63) 82 38 2,048 114,711 114,711 250,000 (1,520.67) 83 39 2,048 119,482 119,482 250,000 (1,454.62) 84 40 2,048 124,363 124,363 250,000 (1,390.89) 85 41 2,048 129,360 129,360 250,000 (1,327.61) 86 42 2,048 134,488 134,488 250,000 (1,265.04) 87 43 2,048 139,768 139,768 250,000 (1,186.48) 88 44 2,048 145,231 145,231 250,000 (1,091.00) 89 45 2,048 150,929 150,929 250,000 (982.52) 90 46 2,048 156,935 156,935 250,000 (869.78) 91 47 2,048 163,342 163,342 250,000 (766.55) 92 48 2,048 170,263 170,263 250,000 (667.26) 93 49 2,048 177,843 177,843 250,000 (578.26) 94 50 2,048 186,264 186,264 250,000 (488.83) 95 51 2,048 195,758 195,758 250,000 (398.17) 96 52 2,048 206,617 206,617 250,000 (312.81) 97 53 2,048 219,221 219,221 250,000 (234.52) 98 54 2,048 234,056 234,056 250,000 (176.28) 99 55 2,048 251,745 251,745 251,745 (401.25)
[0111] [0111] TABLE D4 Product Value for Money - Calculation of IRR - Level Lapses Company D Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 1,648 1,387 0 250,000 1,549.69 6.335% 46 2 1,648 2,800 0 250,000 1,427.63 47 3 1,648 4,242 0 250,000 1,314.04 48 4 1,648 5,717 0 250,000 1,204.85 49 5 1,648 7,255 523 250,000 1,071.27 50 6 1,648 8,833 2,435 250,000 876.42 51 7 1,648 10,482 4,430 250,000 682.52 52 8 1,648 12,180 6,487 250,000 496.22 53 9 1,648 13,929 8,609 250,000 328.63 54 10 1,648 15,705 10,772 250,000 169.71 55 11 1,648 17,453 12,923 250,000 38.09 56 12 1,648 19,174 15,062 250,000 (105.62) 57 13 1,648 21,011 17,333 250,000 (250.46) 58 14 1,648 22,969 19,744 250,000 (351.92) 59 15 1,648 25,058 22,308 250,000 (455.32) 60 16 1,648 27,287 25,032 250,000 (593.21) 61 17 1,648 29,664 27,932 250,000 (714.96) 62 18 1,648 32,200 31,012 250,000 (832.59) 63 19 1,648 34,905 34,295 250,000 (948.10) 64 20 1,648 37,790 37,790 250,000 (1,043.62) 65 21 1,648 40,816 40,816 250,000 (1,122.18) 66 22 1,648 43,943 43,943 250,000 (1,184.43) 67 23 1,648 47,230 47,230 250,000 (1,235.16) 68 24 1,648 50,616 50,616 250,000 (1,267.66) 69 25 1,648 54,111 54,111 250,000 (1,295.26) 70 26 1,648 57,657 57,657 250,000 (1,479.95) 71 27 1,648 61,286 61,286 250,000 (1,516.76) 72 28 1,648 65,034 65,034 250,000 (1,550.58) 73 29 1,648 68,893 68,893 250,000 (1,578.46) 74 30 1,648 72,878 72,878 250,000 (1,600.44) 75 31 1,648 76,961 76,961 250,000 (1,608.63) 76 32 1,648 81,159 81,159 250,000 (1,618.48) 77 33 1,648 85,490 85,490 250,000 (1,631.59) 78 34 1,648 89,913 89,913 250,000 (1,636.04) 79 35 1,648 94,450 94,450 250,000 (1,632.88) 80 36 1,648 99,103 99,103 250,000 (1,614.73) 81 37 1,648 103,843 103,843 250,000 (1,582.35) 82 38 1,648 108,731 108,731 250,000 (1,529.35) 83 39 1,648 113,745 113,745 250,000 (1,463.16) 84 40 1,648 118,901 118,901 250,000 (1,399.27) 85 41 1,648 124,220 124,220 250,000 (1,335.79) 86 42 1,648 129,756 129,756 250,000 (1,273.06) 87 43 1,648 135,527 135,527 250,000 (1,194.30) 88 44 1,648 141,585 141,585 250,000 (1,098.57) 89 45 1,648 147,976 147,976 250,000 (989.76) 90 46 1,648 154,755 154,755 250,000 (876.60) 91 47 1,648 161,991 161,991 250,000 (772.84) 92 48 1,648 169,755 169,755 250,000 (672.90) 93 49 1,648 178,135 178,135 250,000 (583.16) 94 50 1,648 187,254 187,254 250,000 (492.91) 95 51 1,648 197,236 197,236 250,000 (401.41) 96 52 1,648 208,253 208,253 250,000 (315.25) 97 53 1,648 220,519 220,519 250,000 (236.24) 98 54 1,648 234,314 234,314 250,000 (177.40) 99 55 1,648 250,002 250,002 250,002 (399.23)
[0112] In this instance, the objective was to endow at age 100. A planned premium to achieve the objective for each of the example companies A, B, C, and D is shown in Table E.
TABLE E Product Value for Money - Planned Premium to Achieve Objective Company Company Company Company A B C D Planned Premium $2,125 $1,953 $2,048 $1,648 to Achieve Objective
[0113] The premiums to meet this objective are annual premiums, which range from $1,648 for Company D to $2,125 for Company A. The high and low points were set at $1,600 (normalized score of 5) and $2,500 (normalized score of 0) respectively, a range of $900. On this scale, Company D got a normalized score of 4.7 (48/900 of the way between 5 and 0).
[0114] For product flexibility, one point is given for each of the six features. The high point is 5 and the low point is 0. The interpolation here works out so that the normalized score is the number of points for each product, but not more than 5.
[0115] Product flexibility for each of the example companies A, B, C, and D, is shown in Table F.
TABLE F Product Value for Money - Flexibility Company Company Company Company Flexibility (1=Y, 0=N) A B C D No lapse guarantee 1 0 0 1 Term rider 1 1 1 1 Penalty-free 1 0 0 1 withdrawals Preferred loans 0 1 1 1 COI refunds 0 1 0 1 Persistency bonus 1 0 1 0 Total 4 3 3 5
[0116] Finally, the weighted average of the four metrics is calculated, giving effect to the weights from table A.
[0117] Product Stress Tolerance
[0118] A similar process is followed for this scoring driver. For two of the policies, Company A and Company C, the illustration at the midpoint in this example does not produce an IRR because the product failed. I.e., the policyholder group, on average, did not get back as much money as they put in. In those cases, the ratio of 20-year Cash Surrender Values provides a more discriminating metric.
[0119] Calculations for Product Stress Tolerance for each of the example companies is shown in Table G1-G4.
TABLE G1 Product Stress Tolerance - Midpoint Assumptions Company A Current Midpoint Age Duration Premium CSV DB Cash Value Cash Flow IRR 45 1 2,125 0 250,000 0 2,026.69 0.00% 46 2 2,125 0 250,000 0 1,880.59 47 3 2,125 0 250,000 0 1,744.08 48 4 2,125 0 250,000 0 1,613.06 49 5 2,125 567 250,000 0 1,479.89 50 6 2,125 2,751 250,000 43 1,336.05 51 7 2,125 5,064 250,000 1,485 1,138.59 52 8 2,125 7,483 250,000 2,904 950.61 53 9 2,125 10,037 250,000 4,298 783.00 54 10 2,125 12,732 250,000 5,651 625.12 55 11 2,125 16,396 250,000 7,798 469.26 56 12 2,125 19,944 250,000 9,664 309.87 57 13 2,125 23,446 250,000 11,265 159.95 58 14 2,125 26,908 250,000 12,581 62.96 59 15 2,125 30,338 250,000 13,619 (27.83) 60 16 2,125 33,278 250,000 13,867 (135.15) 61 17 2,125 36,352 250,000 13,910 (223.70) 62 18 2,125 39,560 250,000 13,703 (305.59) 63 19 2,125 42,908 250,000 13,199 (382.65) 64 20 2,125 46,398 250,000 12,343 (437.14) 65 21 2,125 50,054 250,000 11,087 (483.63) 66 22 2,125 53,858 250,000 9,359 (512.22) 67 23 2,125 57,809 250,000 7,087 (526.89) 68 24 2,125 61,906 250,000 4,190 (521.98) 69 25 2,125 66,140 250,000 560 (510.49) 70 26 2,125 70,502 250,000 0 (701.52)
[0120] [0120] TABLE G2 Product Stress Tolerance - Midpoint Assumptions Company B Current Midpoint Age Duration Premium CSV DB Cash Value Cash Flow IRR 45 1 1,953 0 250,000 0 1,854.69 0.00% 46 2 1,953 0 250,000 0 1,717.26 47 3 1,953 0 250,000 0 1,589.02 48 4 1,953 663 250,000 0 1,465.86 49 5 1,953 2,911 250,000 975 1,300.63 50 6 1,953 5,394 250,000 3,231 1,080.79 51 7 1,953 7,992 250,000 4,787 892.36 52 8 1,953 10,713 250,000 6,417 709.93 53 9 1,953 13,561 250,000 8,123 544.75 54 10 1,953 16,541 250,000 9,908 386.11 55 11 1,953 19,637 250,000 10,906 276.80 56 12 1,953 22,847 250,000 11,903 151.91 57 13 1,953 26,164 250,000 12,901 26.46 58 14 1,953 29,593 250,000 13,898 (55.26) 59 15 1,953 33,139 250,000 14,896 (138.52) 60 16 1,953 36,537 250,000 15,894 (256.16) 61 17 1,953 39,699 250,000 16,891 (357.65) 62 18 1,953 43,164 250,000 17,889 (455.34) 63 19 1,953 46,756 250,000 18,886 (551.17) 64 20 1,953 50,474 250,000 19,884 (627.54) 65 21 1,953 54,284 250,000 18,249 (656.13) 66 22 1,953 58,225 250,000 16,615 (675.28) 67 23 1,953 62,293 250,000 14,980 (688.59) 68 24 1,953 66,487 250,000 13,345 (689.93) 69 25 1,953 70,804 250,000 11,711 (692.11) 70 26 1,953 75,241 250,000 10,076 (858.28) 71 27 1,953 79,781 250,000 9,068 (889.97) 72 28 1,953 84,421 250,000 8,061 (922.85) 73 29 1,953 89,158 250,000 7,053 (953.88) 74 30 1,953 93,985 250,000 6,046 (982.81) 75 31 1,953 98,880 250,000 5,038 (1,001.76) 76 32 1,953 103,828 250,000 4,030 (1,025.81) 77 33 1,953 108,814 250,000 3,023 (1,056.41) 78 34 1,953 113,823 250,000 2,015 (1,081.81) 79 35 1,953 118,843 250,000 1,008 (1,102.67) 80 36 1,953 123,863 250,000 — (1,111.30)
[0121] [0121] TABLE G3 Product Stress Tolerance - Midpoint Assumptions Company C Current Midpoint Age Duration Premium CSV DB Cash Value Cash Flow IRR 45 1 2,048 0 250,000 0 1,949.69 0.00% 46 2 2,048 0 250,000 0 1,807.47 47 3 2,048 0 250,000 0 1,674.66 48 4 2,048 0 250,000 0 1,547.16 49 5 2,048 1,227 250,000 0 1,417.35 50 6 2,048 3,045 250,000 1,664 1,214.32 51 7 2,048 4,963 250,000 2,712 1,037.53 52 8 2,048 6,988 250,000 3,819 865.63 53 9 2,048 9,122 250,000 4,985 709.95 54 10 2,048 11,364 250,000 6,210 559.91 55 11 2,048 14,339 250,000 6,366 466.00 56 12 2,048 17,391 250,000 7,721 320.96 57 13 2,048 20,507 250,000 9,104 176.13 58 14 2,048 23,689 250,000 10,517 75.84 59 15 2,048 26,939 250,000 11,960 (25.16) 60 16 2,048 30,222 250,000 13,418 (159.36) 61 17 2,048 33,596 250,000 14,915 (276.82) 62 18 2,048 37,065 250,000 16,456 (389.85) 63 19 2,048 40,633 250,000 18,040 (500.38) 64 20 2,048 44,303 250,000 19,669 (590.74) 65 21 2,048 47,421 250,000 18,536 (629.74) 66 22 2,048 50,616 250,000 17,404 (658.18) 67 23 2,048 53,904 250,000 16,271 (679.72) 68 24 2,048 57,293 250,000 15,138 (688.31) 69 25 2,048 60,782 250,000 14,006 (696.82) 70 26 2,048 64,369 250,000 12,873 (868.42) 71 27 2,048 68,055 250,000 8,582 (864.12) 72 28 2,048 71,843 250,000 4,291 (866.25) 73 29 2,048 75,734 250,000 0 (871.43)
[0122] [0122] TABLE G4 Product Stress Tolerance - Midpoint Assumptions Company D Current Midpoint Age Duration Premium CSV DB Cash Value Cash Flow IRR 45 1 1,648 0 250,000 0 1,549.69 0.00% 46 2 1,648 0 250,000 0 1,427.63 47 3 1,648 0 250,000 0 1,314.04 48 4 1,648 0 250,000 0 1,204.85 49 5 1,648 523 250,000 0 1,092.50 50 6 1,648 2,435 250,000 1,055 929.53 51 7 1,648 4,430 250,000 1,920 774.13 52 8 1,648 6,487 250,000 2,812 623.36 53 9 1,648 8,609 250,000 3,731 488.47 54 10 1,648 10,772 250,000 4,669 359.07 55 11 1,648 12,923 250,000 5,281 262.50 56 12 1,648 15,062 250,000 5,892 149.06 57 13 1,648 17,333 250,000 6,504 33.83 58 14 1,648 19,744 250,000 7,116 (38.76) 59 15 1,648 22,308 250,000 7,728 (113.95) 60 16 1,648 25,032 250,000 8,339 (224.52) 61 17 1,648 27,932 250,000 8,951 (319.86) 62 18 1,648 31,012 250,000 9,563 (412.26) 63 19 1,648 34,295 250,000 10,174 (503.62) 64 20 1,648 37,790 250,000 10,786 (576.25) 65 21 1,648 40,816 250,000 8,835 (602.94) 66 22 1,648 43,943 250,000 6,884 (620.69) 67 23 1,648 47,230 250,000 4,933 (633.05) 68 24 1,648 50,616 250,000 2,982 (633.85) 69 25 1,648 54,111 250,000 1,031 (635.87) 70 26 1,648 57,657 250,000 0 (813.04)
[0123] The ratios of 20-Year cash values on midpoint and current assumptions are shown in Table H, and the years in force at midpoint assumptions are shown in Table I.
TABLE H Product Stress Tolerance - Ratio of 20-year Cash Values on Midpoint and Current Assumptions Company Company Company Company A B C D CV 20 MIDPOINT 12,343 19,884 19,669 10,786 CV 20 CURRENT 46,398 50,474 44,303 37,790 Ratio 26.60% 39.39% 44.40% 28.54%
[0124] [0124] TABLE I Product Stress Tolerance - Years in Force at Midpoint Assumptions Company Company Company Company A B C D Years in force at 26 36 29 26 Midpoint Assumptions
[0125] Calculation of IRR premium reduction in years 4 and later for each of the example companies is shown in Tables J1-J4.
TABLE J1 Product Stress Tolerance - Calculation of IRR Premium Reduction in Years 4 and Later Company A Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 2,125 525 0 250,000 2,026.69 2.642% 46 2 2,125 2,001 0 250,000 1,880.59 47 3 2,125 3,564 0 250,000 1,744.08 48 4 1,063 4,147 0 250,000 703.80 49 5 1,063 4,739 0 250,000 616.99 50 6 1,063 5,380 0 250,000 519.02 51 7 1,063 6,057 308 250,000 405.11 52 8 1,063 6,740 1,328 250,000 269.08 53 9 1,063 7,450 2,390 250,000 148.11 54 10 1,063 8,184 3,489 250,000 31.72 55 11 1,063 8,872 5,419 250,000 (86.08) 56 12 1,063 9,452 7,100 250,000 (210.45) 57 13 1,063 10,004 8,599 250,000 (329.38) 58 14 1,063 10,524 9,908 250,000 (399.22) 59 15 1,063 10,986 10,986 250,000 (465.25) 60 16 1,063 11,395 11,395 250,000 (551.58) 61 17 1,063 11,745 11,745 250,000 (622.76) 62 18 1,063 12,018 12,018 250,000 (690.90) 63 19 1,063 12,199 12,199 250,000 (757.83) 64 20 1,063 12,271 12,271 250,000 (805.78) 65 21 1,063 12,234 12,234 250,000 (849.45) 66 22 1,063 12,042 12,042 250,000 (878.51) 67 23 1,063 11,660 11,660 250,000 (896.75) 68 24 1,063 11,050 11,050 250,000 (898.26) 69 25 1,063 10,159 10,159 250,000 (895.97) 70 26 1,063 8,926 8,926 250,000 (1,053.17) 71 27 1,063 7,272 7,272 250,000 (1,064.09) 72 28 1,063 5,100 5,100 250,000 (1,072.71) 73 29 1,063 2,290 2,290 250,000 (1,075.96) 74 30 0 0 0 0 0
[0126] [0126] TABLE J2 Product Stress Tolerance - Calculation of IRR Premium Reduction in Years 4 and Later Company B Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 1,953 909 0 250,000 1,854.69 5.883% 46 2 1,953 2,409 0 250,000 1,717.26 47 3 1,953 3,972 0 250,000 1,589.02 48 4 977 4,669 0 250,000 630.20 49 5 977 5,430 907 250,000 510.34 50 6 977 6,356 2,285 250,000 364.79 51 7 977 7,322 3,704 250,000 218.31 52 8 977 8,330 5,164 250,000 76.80 53 9 977 9,379 6,665 250,000 (48.43) 54 10 977 10,467 8,205 250,000 (168.07) 55 11 977 11,570 9,761 250,000 (264.18) 56 12 977 12,679 11,322 250,000 (375.59) 57 13 977 13,777 12,873 250,000 (486.86) 58 14 977 14,860 14,407 250,000 (553.56) 59 15 977 15,920 15,920 250,000 (621.17) 60 16 977 16,956 16,956 250,000 (712.53) 61 17 977 17,950 17,950 250,000 (787.86) 62 18 977 18,890 18,890 250,000 (859.42) 63 19 977 19,760 19,760 250,000 (929.02) 64 20 977 20,542 20,542 250,000 (978.87) 65 21 977 21,172 21,172 250,000 (1,022.67) 66 22 977 21,672 21,672 250,000 (1,051.35) 67 23 977 22,008 22,008 250,000 (1,068.72) 68 24 977 22,148 22,148 250,000 (1,068.99) 69 25 977 22,048 22,048 250,000 (1,065.22) 70 26 977 21,664 21,664 250,000 (1,220.62) 71 27 977 20,921 20,921 250,000 (1,229.29) 72 28 977 19,756 19,756 250,000 (1,235.71) 73 29 977 18,093 18,093 250,000 (1,237.07) 74 30 977 15,837 15,837 250,000 (1,233.34) 75 31 977 12,854 12,854 250,000 (1,216.73) 76 32 977 8,998 8,998 250,000 (1,202.59) 77 33 977 4,091 4,091 250,000 (1,192.59)
[0127] [0127] TABLE J3 Product Stress Tolerance - Calculation of IRR Premium Reduction in Years 4 and Later Company C Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 2,048 1,098 0 250,000 1,949.69 3.824% 46 2 2,048 2,705 0 250,000 1,807.47 47 3 2,048 4,357 0 250,000 1,674.66 48 4 1,024 5,041 0 250,000 670.85 49 5 1,024 5,740 0 250,000 585.72 50 6 1,024 6,463 138 250,000 484.04 51 7 1,024 7,214 890 250,000 355.73 52 8 1,024 7,996 1,671 250,000 230.54 53 9 1,024 8,804 2,480 250,000 119.89 54 10 1,024 9,633 3,309 250,000 13.37 55 11 1,024 10,469 4,777 250,000 (89.88) 56 12 1,024 11,279 6,219 250,000 (207.41) 57 13 1,024 12,041 7,614 250,000 (323.79) 58 14 1,024 12,750 8,955 250,000 (394.73) 59 15 1,024 13,396 10,233 250,000 (465.71) 60 16 1,024 13,929 11,399 250,000 (568.73) 61 17 1,024 14,402 12,505 250,000 (654.67) 62 18 1,024 14,804 13,539 250,000 (735.86) 63 19 1,024 15,126 14,494 250,000 (814.38) 64 20 1,024 15,356 15,356 250,000 (872.58) 65 21 1,024 15,450 15,450 250,000 (914.24) 66 22 1,024 15,382 15,382 250,000 (941.12) 67 23 1,024 15,123 15,123 250,000 (957.09) 68 24 1,024 14,541 14,641 250,000 (956.37) 69 25 1,024 13,897 13,897 250,000 (952.06) 70 26 1,024 12,851 12,851 250,000 (1,107.57) 71 27 1,024 11,456 11,456 250,000 (1,117.37 72 28 1,024 9,665 9,665 250,000 (1,125.84) 73 29 1,024 7,418 7,418 250,000 (1,130.21) 74 30 1,024 4,643 4,643 250,000 (1,130.51) 75 31 1,024 1,251 1,251 250,000 (1,119.09)
[0128] [0128] TABLE J4 Product Stress Tolerance - Calculation of IRR Premium Reduction in Years 4 and Later Company D Du- ra- Pre- Age tion mium AV CSV DB Cash Flow IRR 45 1 1,648 1,387 0 250,000 1,549.69 6.823% 46 2 1,648 2,800 0 250,000 1,427.63 47 3 1,648 4,243 0 250,000 1,314.04 48 4 824 4,902 0 250,000 499.70 49 5 824 5,572 0 250,000 423.29 50 6 824 6,226 0 250,000 335.25 51 7 824 6,892 839 250,000 211.44 52 8 824 7,541 1,848 250,000 85.87 53 9 824 8,172 2,852 250,000 (23.57) 54 10 824 8,755 3,822 250,000 (126.87) 55 11 824 9,227 4,697 250,000 (205.22) 56 12 824 9,582 5,469 250,000 (297.93) 57 13 824 9,961 6,283 250,000 (394.13) 58 14 824 10,364 7,139 250,000 (449.17) 59 15 824 10,795 8,045 250,000 (508.42) 60 16 824 11,255 9,000 250,000 (604.41) 61 17 824 11,745 10,013 250,000 (686.39) 62 18 824 12,268 11,081 250,000 (766.44) 63 19 824 12,826 12,216 250,000 (846.49) 64 20 824 13,421 13,421 250,000 (908.71) 65 21 824 13,998 13,998 250,000 (956.02) 66 22 824 14,496 14,496 250,000 (988.90) 67 23 824 14,970 14,970 250,000 (1,012.28) 68 24 824 15,332 15,332 250,000 (1,019.21) 69 25 824 15,573 15,573 250,000 (1,022.99) 70 26 824 15,598 15,598 250,000 (1,186.11) 71 27 824 15,423 15,423 250,000 (1,203.39) 72 28 824 15,061 15,061 250,000 (1,219.74) 73 29 824 14,469 14,469 250,000 (1,232.19) 74 30 824 13,629 13,629 250,000 (1,240.86) 75 31 824 12,463 12,463 250,000 (1,237.78) 76 32 824 10,945 10,945 250,000 (1,238.53) 77 33 824 9,043 9,043 250,000 (1,244.89) 78 34 824 6,633 6,633 250,000 (1,244.96) 79 35 824 3,670 3,670 250,000 (1,239.95) 80 36 824 67 67 250,000 (1,222.52)
[0129] Management Performance
[0130] In order to set reasonable high and low points for this scoring driver, a universe of ten companies is examined, and the metrics for each one computed based on recent statutory filings. In this example, statutory filing as of Dec. 31, 2000 were examined. Where a company is a subsidiary of a larger life insurer, consolidated statutory numbers from the NAIC database are used. Management performance statistics for each of the companies A, B, C, and D are shown in Table K.
TABLE K Management Performance Statistics Management Performance Company Company Company Company Company Company Company Company Company Company A B C D E F G H I J 5-year Average ROE 7.1% 11.0% 12.9% 13.6% 1.8% 26.9% 8.9% 18.1% 14.1% 23.3% Ordinary Life Expenses/ 166.3% 608.2% 342.4% 197.5% 206.1% 122.4% 73.7% 372.3% 495.5% 181.9% Generally Recognized Expense Table 5-year Average PEGG 4.2% 8.8% −3.6% 118.1% 157.4% 6.2% −16.5% −3.8% 8.2% −0.3% 5-year Assets CAGR 12.1% 25.5% 6.6% 23.4% 38.8% 8.3% 12.5% 9.5% 24.1% 10.9% Maximum Earnings Deviation 366.5% 108.6% 44.2% 24.4% 162.9% 52.1% 48.4% 125.1% 62.9% 23.1% from Geometric Path Ordinary Life Expenses/ 17.7% 22.7% 22.4% 14.4% 11.6% 6.5% 2.3% 15.1% 12.6% 6.6% Ordinary Life Premiums Ordinary Life Expenses/ 3.6% 2.3% 2.9% 1.6% 9.5% 0.9% 1.1% 2.0% 1.6% 0.9% Ordinary Life Reserves
[0131] Historical Credited Rates
[0132] The high point is set at $6,150 and the low point at $5,800. Company D, being above the high point, receives a normalized score of 5. Historical credit rates are shown in Table L.
TABLE L Historical Credited Rates Company Company Company Company A B C D 1996 8.00% 8.30% 8.40% 8.50% 1997 7.50% 7.60% 7.80% 8.00% 1998 7.00% 6.90% 7.20% 7.50% 1999 6.50% 6.20% 6.60% 7.00% 2000 6.00% 5.50% 6.00% 6.50% $1,000 Accumulated to 2001: $6,098 $6,058 $6,123 $6,188
[0133] Company Service Quality
[0134] Company service quality indicators are shown in Table M for the example companies A, B, C, and D.
TABLE M Company Service Quality Indicators Co. Co. Co. Co. Low High A B C D Score Score Average Time to Offer 60 30 45 15 15 60 Telephone Service - 5.0 4.0 3.5 2.5 Composite Score: Days/week CSRs available 5 5 5 5 5 5 Avg # of calls/day 30 40 50 60 30 60 per CSR Hours/day customer service 8 9 9 10 8 10 available 800 # available (1 = Y, 1 1 1 1 1 1 0 = N) Website Capabilities (1 = Y, 0 = N) Website 1 1 1 1 Specific product 1 1 1 0 information available Quote capabilities 0 0 0 0 Ability to apply online 0 0 0 0 Ability to access account 0 0 0 0 information Ability to change address, 0 0 0 0 beneficiary Application status 0 0 0 0 capabilities Total 2 1 0 0 0 7 Standard Requests - days to process Cash loans 5 4 5 3 Cash surrenders 6 6 5 4 Non-contestable death 5 5 4 3 claims Customer correspondence 6 8 5 4 Average 5.5 5.75 4.75 3.5 3 5
[0135] Best's Rating
[0136] Best's rating for the example companies A, B, C, and D are shown in Table N.
TABLE N Number of companies by Best Ratings Percentile Score A++ 46 11.3% 100.0% 5.0 A+ 147 36.1% 88.7% 4.4 A 123 30.2% 52.6% 2.6 A− 52 12.8% 22.4% 1.1 B++ 22 5.4% 9.6% 0.5 B+ 15 3.7% 4.2% 0.2 E 2 0.5% 0.5% 0.0 Total 407 Company A A Company B A++ Company C A Company D A++
[0137] PVAS Rating
[0138] The PVAS rating is a weighted average of the normalized scores on each of the scoring drivers. This calculation is summarized in Table O.
TABLE O PVAS Calculation Summary Company Company Company Company A B C D PVAS Rating (Out of 5 Points): 1.8 3.6 2.5 4.0 I. Product Value for Money 1.6 3.7 1.8 4.8 II. Product Stress Tolerance 0.3 3.9 3.3 1.6 III. Management Performance 1.9 2.6 2.2 4.0 IV. Product Crediting Rate History 4.3 3.7 4.6 5.0 V. Company Service Quality 2.4 3.5 2.9 3.9 VI. AM Best Rating 2.6 5.0 2.6 5.0 I. Product Value for Money IRR - current assumptions, LIMRA 1.4 4.2 1.7 5.0 lapses IRR - current assumptions, level lapses 0.8 3.8 1.0 4.6 Planned Premium to Achieve Objective 2.1 3.0 2.5 4.7 Product Flexibility 4.0 3.0 3.0 5.0 Score 1.6 3.7 1.8 4.8 II. Product Stress Tolerance Ratio of 20-year CSV for 0.4 3.6 4.8 0.9 midpoint: current assumptions Years in Force at Midpoint Assumption 0.5 5.0 2.0 0.5 IRR - current assumptions with 50% 0.0 3.5 0.0 5.0 premium years 4+ Score 0.3 3.9 3.3 1.6 III. Management Performance 5-year Average ROE 0.0 2.5 3.7 4.1 Ordinary Life Expenses / GRET 3.7 0.0 0.0 2.8 5-year Average Premium Expense 4.4 5.0 0.0 5.0 Growth Gap 5-year Assets CAGR 2.5 5.0 0.8 5.0 Maximum Earnings Deviation from 3.7 5.0 5.0 5.0 Geometric Path Ordinary Life Expenses / Ordinary Life 1.6 0.1 0.2 2.5 Premium Ordinary Life Expenses / Ordinary Life 0.7 2.8 1.9 4.0 Reserves Score 1.9 2.6 2.2 4.0 IV. Historical Credited Rates Score 4.3 3.7 4.6 5.0 V. Company Service Quality Average time to offer 2.0 4.0 3.0 5.0 Telephone service 5.0 4.0 3.5 2.5 Website capabilities 1.4 1.4 1.4 0.7 Response time for standard requests 2.8 2.7 3.3 4.1 Score 2.4 3.5 2.9 3.9 VI. AM Best Rating Score 2.6 5.0 2.6 5.0
[0139] After a purchase decision is made, that information is transmitted back to the value appraisal system to become a part of the market intelligence database and to the “winning” carrier. The value appraisal system will also be able to transmit an on-line application for the selected product to the winning carrier.
[0140] It will be apparent to those skilled in the art that various modifications and variation can be made in the system for appraising a life insurance product of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents
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A method and system of appraising a life insurance or annuity product includes receiving a request for a life insurance or annuity product and information about a party requesting the life insurance or annuity product; preparing a bid solicitation for the life insurance or annuity product based on the request and information and transmitting the bid solicitation to a plurality of product carriers; a plurality of product carriers submitting initial proposals for providing the life insurance or annuity product; generating ratings for the initial proposals, respectively; and generating appraisals for the initial proposals; and informing the product carriers of the decision.
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BACKGROUND
1. Field of the Invention
This invention relates generally to the field of fluid handling and liquid chromatography. In particular, the invention is directed toward a novel sanitizable rotary valve that may be used in conjunction with liquid chromatographic columns and sanitary liquid handling systems to separate and/or purify biological macromolecules of importance to the pharmaceutical industry.
2. Description of the Prior Art
Rotary valves have been used for multiple fluid distribution in many different variations. For instance, U.S. Pat. No. 4,808,317 (Berry et al.) is directed to a method and device including a rotary valve for continuously contacting fluids with solid particulates. The design of this fluid distribution valve also allows simulated moving bed ("SMB") counter-current operation. In general, the device operates as follows. A plurality of inlet conduits are provided at the top of a feed box for the purpose of introducing fluid streams into the device for treatment, and a corresponding plurality of outlet conduits are provided at the bottom of the discharge box for removing treated fluid streams. Separator compartments are located so that they rotate past the fluid ports. In normal operation the separator compartments contain a resin or other adsorbent particulate bed which is then sequentially contacted with each fluid stream through the upper and lower timing crown stator ports. Details of the operation of the rotary valve are presented in the '317 patent's FIGS. 5 and 7 through 9. As can be seen from these figures, the rotor and stator must be fully disassembled for cleaning and no provision has been made for sanitizing the contact faces of the rotor and stator surfaces.
U.S. Pat. No. 2,985,589 (D. B. Broughton et al.) is directed to a process and apparatus for continuous simulated counter-current flow to and from the several inlets and outlet streams in relation to beds of solid sorbent. A rotary valve is described for connecting the inlet and outlet fluid streams to the adsorbent bed columns. The process and apparatus are demonstrated by separating a mixture of normal and isohexanes into a stream of relatively pure N-hexane and a secondary product of isohexane. The apparatus comprises a series of 12 beds containing molecular sorbent. The rotary valve used is not sanitizable, and there is no indication that a sanitizable valve face was contemplated.
U.S. Pat. No. 3,268,604 (D. M. Boyd, Jr.) is directed to a fluid flow control system for simulated moving bed processes which include a rotary valve. A multi-port rotary distributing valve is shown in FIG. 1, which is capable of being connected to 24 fluid transfer lines. The valve does not have any sanitizing feature.
U.S. Pat. No. 4,409,033 (LeRoy) is directed to a simulated moving bed separation process for high capacity feed streams, and incorporates a fluid distribution means comprising a rotary valve. Again, no sanitizable aspects are disclosed.
Known non-rotary sanitizable valves include Mieth, U.S. Pat. Nos. 4,757,834 and 4,687,015; and Dolling 4,191,213. Also known are rotary valves granted to Ringo, U.S. Pat. No. 2,706,532 and Pruett, U.S. Pat. No. 3,451,428. The latter two patents disclose no sanitary flushable design.
U.S. Pat. No. 4,921,015 (Sedy) is directed to a rotary vacuum valve having two annular continuous pressurized chambers formed in the sealed face of the rotor. In each chamber are a pair of annular U shaped elastomeric Teflon™ seals expanded by an expansion spring positioned concentrically within the open sides of the seals. These seal assemblies are known as spring-energized TFE lip seals. The stator and rotor move slightly apart upon the application of high pressure to the stator, the lift being sufficient so that the spring-loaded TFE lip seals have a slight contact with the top of the ring, allowing the seal faces to run dry. Thus the arrangement presents a dry low friction seal between the two valve members. No sanitizable or flushable means are provided.
U.S. Pat. No. 4,625,763 (Shick et al.) is directed to a disc-axial multi-port valve for accomplishing the simultaneous interconnection of a plurality of conduits. The valve is comprised of a stator and a rotor, both being comprised of two sections, one being cylindrical and the other being disc-like. FIG. 1 discloses a peripheral seal element 94 retained in a grove in the rotor discular element and urged against the stator transfer face by springs such as 92t. Any fluid leaking from the transverse volume will be retained by this barrier. In addition, in order to prevent cross contamination among the conduits which are interconnected, a flushing fluid may be passed through the transverse volume. Referring again to FIG. 1, flushing fluid may be provided to transverse volume 90 via conduit 95. However, no arrangement is made for pulling apart the faces of the rotor and stator in order to sanitizably flush the faces.
Aseptic diaphragm valve construction, or sanitary valves, are known in the art. These valves are used for aqueous fluids containing or capable of containing microorganisms, or for handling of foods, beverages, or of materials being made into pharmaceuticals or the like. For example, Hoobyar et al. U.S. Pat. No. 5,152,500 disclose an outlet valve wherein a shaft that moves up or down and is covered by a diaphragm bellows thereby engages or disengages a round inlet opening, thereby closing or opening the valve opening surrounding the inlet. The aseptic nature of the valve involves isolation of contaminants by way of a double axial seal and also its self-draining nature. However, the diaphragm valve does not have a multiple-port capability.
U.S. Pat. No. 5,273,075 (Skaer) discloses a diaphragm-based diverter valve with a single inlet and two outlets. The diaphragm engages a weir to open or close a fluid path. Stems are compressed against the diaphragms to close them against the weirs, or opened to create a fluid flow path. According to the patent, dead legs are eliminated in this design.
It is clear that valve designs for sanitizing slider or rotary valves in place without the need for disassembly have not been described in the prior art. In order for the advantages of rotary valve-based separations to be applied to process-scale manufacture of pharmaceuticals, it is mandatory to provide sanitizing means for ensuring removal of contamination within the wetted surfaces of the valve following use, without the need for disassembly. Therefore, there is a need for sanitizable rotary valves which may be intermittently flushed and cleaned, while maintaining the sterile condition of the process system.
SUMMARY OF THE INVENTION
The inventor has designed a completely new type of valve which combines some elements previously found in the valve art, but in addition adds the unique feature of partial (sealed) separation of the rotor-stator faces to allow flushing across the process fluid-contacting surfaces. The partial separation would normally result in sanitizing fluid leaking out of the valve resulting in non-aseptic operation, but a novel diaphragm-like elastomeric seal has been invented which functions to both seal the two faces together in normal use, and also to retain the sanitizing process fluids when the faces are partially separated for cleaning. This design allows the unique sanitary operation of the valve that is disclosed herein,the ability to sanitize in place ("SIP") without disassembling the valve.
The unique operation of the valve is performed by a new type of slider (or rotary) valve shown specifically in a rotary carousel diaphragm valve which has a thermoplastic elastomeric diaphragm integrally molded to form the multiple sealing ports of the rotor face. Ports or grooves molded into the face of the elastomeric diaphragm are positioned to sealably engage grooves or ports in the stator face, and to form sanitary elastomeric tubular ducts leading through the body of the rotor, terminating as elastomeric flanges. These flanges permit direct connection to sanitary piping flanges within the carousel which lead to and from multiple columns or other solid phase bed segments.
To permit periodic sanitization and cleaning of the port sealing faces of the stator and rotor, the external limit of the elastomeric rotor diaphragm is molded to form a flexible wiping lip seal which maintains fluid-tight sealing engagement with the face of the stator even when the rotor is moved orthogonally away from the stator far enough to permit cross flushing of the port sealing faces.
In the preferred embodiment, the required sealing force is minimized by relieving material from either the surface of the stator or from the rotor diaphragm to form port-sealing ledges and adjoining gutters. The gutters may carry a barrier fluid stream which is used to capture and sweep away any process fluid which escapes from the port seals. This feature prevents accumulation of dried material which may damage the sealing faces, and ensures containment of material which might otherwise constitute an environmental hazard to workers in the area.
The invention is directed to a sliding multi-port diaphragm valve having at least two inner surfaces, comprising: a rotor having a body wherein the inner surface is a stator-facing surface, the rotor body having at least a pair of first and second connection ports in fluid connection with rotor ports located on the stator-facing surface, the rotor having attached to the stator-facing surface a sealing means comprising a diaphragm, the diaphragm having a plurality of rotor port sealing means and at least one diaphragm-integral dynamic wipe sealing lip; a stator having a body wherein the inner surface is a rotor-facing surface, the stator body having at least a pair of first and second connection ports in fluid communication with stator ports located on the rotor-facing surface, the stator ports being fluidly connected to their respective connection ports; means for at least one SIP/barrier gutter located on an inner surface of the valve; orthogonal actuating means for incrementally adjusting the rotor perpendicular to its direction of linear motion; fluid connection means for fluidly connecting stator and rotor connection ports to externally located fluid sources and receivers and chromatographic separation devices; and actuating means for moving the rotor body thereby indexing the ports. The SIP/barrier gutter(s) is(are) located either on the diaphragm or on the face of the stator.
The invention is also directed to a multi-port sliding valve of the type having a linear slider, a stator having a plurality of connection ports and associated channels in liquid communication with external fluid sources and separation means, the improvement comprising: a sealing means comprising a diaphragm, the diaphragm having at least one slider port sealing means;
at least one connection port capable of being in fluid communication with a source of SIP fluid, and ports comprising channels through the stator body fluidly connected to their respective connection ports; and
orthogonal separation means for partially separating the slider body from the stator body thereby allowing flushing of sanitizing fluid across the stator face without loss of fluid to the outside.
This invention is also directed to an insert molding process for forming in place a rotary valve diaphragm seal, comprising the steps of: affixing a mold base to the rotor which provides a negative impression of the desired diaphragm surface; capping the ports of the rotor with flange-forming plugs containing channel-forming cores, the cores extending through the connection port channels to seat in holes in the mold base; affixing injection molding equipment to said capped rotor; injecting the rotor with an elastomer suitable for forming a diaphragm seal; curing the diaphragm seal; and removing the mold and caps, thereby exposing a diaphragm molded in place having the desired surface features.
An object of this invention is to provide a sanitizable slider valve in which the port-sealing faces of the slider and stator may be intermittently flushed and cleaned, while maintaining the sterile condition of the process system.
Another object of this invention is to provide a slider valve having a fluid barrier stream which continually purges the external limits of the port-sealing faces to prevent accumulation of dried material and release to the external environment of the solution being processed, while permitting connection of ducts from the ports in the face of the slider to and from multiple solid phase bed segments mounted in an attached carousel.
A further object of this invention is to provide a simple and reliable elastomeric means of ensuring sealing of all ports in a slider valve which is tolerant of imperfect flatness or parallelism of the stator or slider sealing faces, which is not damaged by particulate contamination in the process solution, and which maintains an acceptable sealing integrity over a useful life at least equal to that of typical chromatographic beds used for pharmaceutical manufacturing purification processes.
A further object of this invention is to provide simple means to remove and remotely store the rotor carousel in a sanitary sealed state, to clean and store the stator in a sanitary sealed state, and to permit sequential operation of different rotor carousels on the same stator actuator assembly.
These and other objects and advantages of the invention will become apparent in the following detailed description of the preferred embodiments, in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a drawing of a bench-scale embodiment of the present invention showing a top view of the stator face with the barrier fluid flowpath illustrated by arrows, with rotor not shown.
FIG. 1B is a transverse sectional view along line AA taken through the valve of FIG. 1A and a pair of inlet and outlet fittings, showing the valve while rotating during normal operation, just as stator and rotor ports are aligned, with the right side showing the stator sump drain port.
FIG. 2A is a drawing of the bench scale embodiment of FIG. 1 showing a top view during SIP mode of the stator port sealing ledges, with rotor not shown.
FIG. 2B is a transverse sectional view along line BB of FIG. 2A through both inner and outer barrier/SIP stator ports.
FIGS. 3A-D are a series of sectional close-projections of the rotor and stator ports through conical planes along line CC of FIG. 1B showing the motion of the rotor ports while the rotor is traversing; process solution flow paths are also shown, as is the make-before-break aspect of the invention.
FIG. 4 is a sectional view of the left half of the preferred embodiment of the present invention showing a pilot scale rotor carousel and stator, with all gutters and grooves also molded into the face of the elastomeric rotor diaphragm.
FIG. 5 is a flow schematic diagram of a 5-segment carousel system illustrating the principle of SMB adsorption and separation.
FIG. 6 is a schematic diagram of the Universal Oil Products Sorbex Cascade system for SMB continuous counterflow fractionation.
FIG. 7 is a flow schematic diagram of an SMB size exclusion fractionation separation system similar to that of FIG. 6 with internal liquid recycle implemented on a carousel valve system according to the present invention, with components being resolved shown pictorially.
FIG. 8 is a flow schematic diagram of an SMB ion exchange fractionation separation system with separate flowpaths for adorption, desorption and stripping implemented on a carousel valve system according to the present invention, with components being resolved shown pictorially.
DETAILED DESCRIPTION OF THE INVENTION
Definitions.
The following terms used throughout the specification shall have the following meaning:
"Diaphragm" is used when referring to a generally elastic sealing surface that is urged against a second surface to effect a seal.
"Dynamic wipe sealing lip" is used to refer to a specific integral construction of an elastomeric lip seal used at the sealing edge of the diaphragm. The lip is dynamic in that it has spring action either from a spring insert or inherently.
"Make-before-break" groove is an area on either the slider or stator sealing surface that channels fluid from one channel located in the slider or stator body to another channel. It comprises a groove or ditch cut into the respective surface and terminates at one end in a port or hole that fluidly connects to the channel through the stator or slider body. Make-before-break grooves are commonly known for alleviating the pressure surges that can otherwise stress piping and pumps when fluid flowing under pressure is suddenly diverted from one conduit into another through a valve which interrupts flow continuity.
"SIP" is an acronym for "sanitize-in-place", which describes the action of partially separating the sealing surfaces of the slider (or rotor) and stator and then flushing sanitizing fluid across the sealing faces of the stator and the diaphragm.
A. Preferred Embodiments of the Invention
FIGS. 1-2 show plan views of the stator 300 and transverse sections through the stator and rotor 200 of a bench scale embodiment of the present invention. Stator 300 incorporates actuating and fluid connecting means connected to the bottom portion of stator body 301, which may be formed from ceramic material, or be machined from stainless steel, preferably 316L alloy for corrosion resistance, or from a variety of engineering plastics such as Kel F (polychlorotriflouroethylene or PCTFE), polyphenylsulfone (PPSU), polyphenylene sulfide (PPS), polythalamide (PPA), polyetheretherketone (PEEK), or other high performance materials having good resistance to abrasion and to sodium hydroxide commonly used for cleaning and SIP. With reference to FIG. 1B, the rotor 200 of this embodiment contains 12 pairs (only 1 pair being shown) of first column connection fittings 210 and second column connection fittings 212 engaging mating threads in holes in first rotor connection port 214 and second rotor connection port 215 in the top face of rotor body 201. Rotor body 201 is not normally wetted, thus it may be machined from aluminum or machined or molded from any high temperature engineering thermoplastic resin which will maintain integrity during brief exposure to a secondary insert molding operation at temperatures from about 120° to about 400° F. Suitable materials might include polysulfone, PEEK, or PPS. The fittings shown are commonly available, made from plastic such as polyethylene or polypropylene, with a 1/4-28 UNF thread machined or molded in. These secure the flanged ends of tubes 213, which may be fashioned from Teflon® or Tefzel® or polyethylene or polypropylene or other suitable thermoplastic tubing, and serve to provide a sanitary means to fluidly connect to the inlets and outlets of a plurality of columns mounted in a carousel attached to the rotor, which is not shown in these closeup views.
In practice, any column or solid phase medium may be used. For instance, functionalized ion exchange, hydrophobic interaction, affinity, metal chelate, or size exclusion resin columns may be used to separate biomolecules such as proteins or peptides. Pharmaceuticals may be separated by ion exchange, chiral, or reverse phase media, etc. The specific type of column or media employed or molecules to be separated are not limiting.
The primary objects of this invention are served by the presence of an elastomeric diaphragm 220, which is fashioned as an integral insert molded part of the base of rotor 200. Suitable materials for the diaphragm are thermoplastic elastomers such as styrene-ethylene/butylene-styrene block coploymers, for example the KRATON™ G rubbers (Shell Chemical Co. Houston, Tex.) such as KRATON G 2705. This is an untilled injection moldable elastomeric rubber made and sold for FDA regulated food contact and pharmaceutical applications which is steam sterilizable, inert to sodium hydroxide, and has passed acute toxicity extractables testing including USP XIX, Class VI (121° C.), and the Cumulative Toxicity Index. Other examples of potentially suitable thermoplastic elastomer materials for sealing of a pharmaceutical valve are discussed by Marecki in "Device for Delivering and Aerosol", WO93/22221, which is included by reference here in its entirety.
Diaphragm 220 has a first diaphragm surface 225 which is in contact with the mating bottom surface of rotor body 201, and a second diaphragm surface 226 which is in direct contact with the fluids passing through the valve, and is in selective sealing contact with portions of stator 300 as described below. As shown in FIG. 1B, diaphragm 220 is molded to provide hollow sleeves 223 which extend upward from first diaphragm surface 225 through rotor body 201 to terminate in integral flange gaskets 224 making sanitary sealing fluid connection to ranged column connecting tubes 213. Sleeves 223 are hollow, each containing a sleeve duct 227 which fluidly connects the bore of ranged column connecting tube 213 with its respective first rotor sealing port 228 or second rotor sealing port 229.
Diaphragm 220 also includes first and second integral dynamic wipe sealing lips 221 and 222, which, along with integral flange gaskets 224, form the physical delimitation between first diaphragm surface 225 and second diaphragm surface 226. The dynamic wipe sealing lips have a flexible vee shape with the point angled inward toward the fluid carrying region of the valve, with the axis of the relaxed vee as molded forming an angle of between about 15 to 45 degrees, preferably 40 degrees from the plane of the stator/rotor seal, and the point of the relaxed vee as molded extending about 0.02 to 0.035 inch, preferably 0.028 inch below the mating surface of the stator when the stator is brought into fluid sealing engagement with rotor sliding sealing ports 228 and 229. The resulting fully flexed sealing engagement of lips 221 and 222 when rotor 200 is sealed to stator 300 is shown in FIG. 1A as shaded first and second barrier sealing zones 361 and 365, respectively.
When forming diaphragm 220 as an integral attachment to the base of rotor body 201 by insert molding, rotor body 201 is mounted to a mold base which has a shape to form second diaphragm surface 226 in the inner and outer circumferential limits of first diaphragm surface 225, and which has a plurality of holes at the desired positions of first and second rotor sealing ports 228 and 229. Hollow threaded plugs with ends shaped to form integral flange gaskets 224 and containing channel-forming cores of diameter to form sleeve ducts 227 are screwed into each rotor connection port 214 and 215 such that the cores engage the holes in the mold base. The molten thermoplastic polymer is then injected through a runner preferably located in the center of rotor body 201. When the elastomer has cooled, the threaded plugs and core wires are removed, the mold is opened, and the central runner is sliced away.
Another embodiment of this invention would place the elastomeric diaphragm seal in the opposite orientation, i.e., instead of the diaphragm being adapted for and adhered to the rotor, it may equally be designed to function on the stator face. This embodiment is not shown in the drawings, but given the teachings above, one of ordinary skill in the art would be able to adapt one specific embodiment to the opposite orientation.
With reference to FIG. 1B, the center of rotor 200 has means provided to connect to an actuator shaft 400. An elongated rotor drive slot 240 extends through the center of rotor 200 and loosely engages matching actuator rotating flats 410 machined into the sides of shaft 400. When shaft 400 is periodically rotated by a pneumatic or electric indexing means not shown, but known to those versed in the art, first and second rotor sealing ports 228 and 229 are caused to move while remaining in sliding sealing engagement with the respective stator first port sealing ledge 350 and second port sealing ledge 352. With reference to FIG. 3, this actuation sequence is shown from an initial indexed position of each first rotor sealing port 228 at one end of its respective stator make-before-break groove 370 in FIG. 3A, through a traversing position of FIG. 3B, to a bridging make-before-break position shown in FIG. 3C in which fluid momentarily flows to or from each stator first connection port 310 to or from two adjoining rotor sealing ports 228, through final indexed position seen in FIG. 3D in which each first rotor sealing port 228 has been advanced by one position to the right along stator first port sealing ledge and zone 350.
Again with reference to FIG. 1B, actuator locking nut 420 is secured to the top of actuator shaft 400 by threads (not shown). Nut 420 has a rounded locking nut engagement shoulder 425 which bears on rotor engagement cone 250 machined into the top surface of rotor 200. These elements provide a simple universal swivel joint coupling whereby downward force applied to actuator shaft 400 is uniformly applied both in order to center rotor 200 and to urge second diaphragm surface 226 into sealing engagement with mating portions of stator 300, as seen in FIG. 1B, without regard to exact perpendicularity to shaft 400 or the planarity of surface 226 or the mating portions of stator 300. Means for orthogonal displacement of actuator shaft 400 (not shown) might include springs, pneumatic or hydraulic cylinders, or motor-driven gears. When actuator shaft 400 is moved upward a controlled distance, for example 0.02 inch as seen in FIG. 2B, integral dynamic wipe sealing lips 221 and 222 are permitted to partially relax and flex downward, thereby elevating rotor 200 and permitting second diaphragm surface 226 to break sealing contact between rotor sealing ports 228 (not shown in FIG. 2B) and the mating top surface of stator 300, while maintaining stator fluid sealing contact by the tips of lips 221 and 222, as indicated schematically by the shaded first and second SIP sealing zones 362 and 366 in FIG. 2A.
The orthagonal adjustability of actuator shaft 400 and rotor 200 in the present invention also permits an optimal balance of negligible loss of process fluid and maximum diaphragm life, in excess of that of the carousel column beds. The greater the downward force applied by actuator shaft 400 to second diaphragm surface 226, the larger will be its sealing footprint with first and second port sealing ledges 350 and 352. This sealing area is represented schematically by the shaded zones 350 and 352 in FIG. 2A. Increased sealing force will minimize or eliminate leakage and loss of process fluid from make-before-break grooves 370 into the adjoining barrier fluid gutters described below. However, use of excessive sealing force will also tend to reduce the lifetime of diaphragm 220, which will eventually need to be replaced as grooves become worn into it by the sliding abrasion of first and second port sealing ledges 350 and 352. Depending on the maximum hydraulic pressure being delivered by the process pumps, a relaxed sealing force during rotation may be programmed which permits only a minute lubricating film loss from the process streams, for example not to exceed 0.1% of the total flowrate, into the first, second and mid-barrier fluid gutters 330, 332, and 333 respectively, during the time that the rotor is being rotated as shown in FIGS. 3A-D, typically 1-2 seconds every 1-5 minutes, and then operation may be returned to the maximum programmed sealing force while the rotor remains in the static indexed position.
Again with reference to FIG. 1B, stator 300 has connecting ports and ducts for all fluids entering and leaving valve 100. A plurality of paired first connection ports 310 and second connection ports 312 may be used to program the sequence of flow through the plurality of rotor carousel beds, for example as illustrated schematically in FIGS. 7 and 8. In the embodiment shown in FIGS. 1-3, stator connection ports 310 are each fluidly connected to one end of a plurality of make-before-break grooves 370 spaced equally about the top surface of first and second sealing port ledges 350 and 352. As seen in FIG. 1 and FIGS. 3A and 3D, rotor sealing ports 228 and 229 are normally in fluid tight sealing engagement with the other end of grooves 370. This insures that in normal operation there is no unswept stagnant fluid volume in the process flowpath, which would otherwise cause undesirable mixing and loss of separation. As shown in FIG. 3C, adjoining grooves 370 are separated by delimiters 371 which are narrower than the diameter of rotor sealing ports 228 or 229, so that as the sealing ports are passing from engagement with one groove to the next, there is no interruption of flow. This make-before-break feature is needed to permit continuous operation of even high flow rate pumps without pump-damaging shock waves when the valve is rotated.
In normal operation, all sliding valves are known to release a film of liquid which wets the surface of the sliding seal. Release of this liquid to the environment, or damaging accumulation of dried salt deposits, is prevented in the present invention by the use of an integral barrier fluid flow path. As shown in FIG. 1A, barrier fluid, which might typically be sterile water for injection, enters valve 100 through first SIP/barrier connection port 320, which is mounted in the wall of stator 300 beyond the field of view. Barrier fluid flows circumferentially in both directions through first SIP/barrier gutter 330, which is a stator conduit between first SIP/barrier sealing ledge 360, first port sealing ledge 350 and second diaphragm surface 226. This stream cleans the inner side of first port sealing ledge 350, which will preferably be operated feeding the bed inlets, since it has a smaller surface area to carry the higher pressure loads. As shown in FIG. 1A, barrier fluid leaves first SIP/barrier gutter 330 and enters mid barrier gutter 333 by means of first barrier gutter connection 323. Mid barrier gutter 333 is a stator conduit between first and second port sealing ledges 350 and 352 and second diaphragm surface 226. Barrier fluid flows circumferentially through this channel, cleaning the outer side of first port sealing ledge 350 and the inner side of second port sealing ledge 352. From there, the barrier stream passes through second barrier gutter connection 324 to enter second SIP/barrier gutter 332. This is a stator conduit between second port sealing ledge 352 and second SIP/barrier sealing ledge 364 and second diaphragm surface 226. Barrier fluid cleans the outer side of second port sealing ledge 352 and then leaves stator 300 through second SIP/barrier connection port 322, to be carried to a kill tank or other appropriate disposal means. The size of all the barrier channels is deliberately larger and the barrier flow deliberately slower than that of the process channels to ensure that fluid pressure in the barrier channels will always be lower than fluid pressure in the process stream grooves 370. This prevents solutes in the slowly flowing barrier stream from subsequently reentering any of the process streams.
Secondary containment means for any liquid escaping under rotor diaphragm integral dynamic wipe sealing lips 221 and 222, which bear on first and second SIP/barrier sealing ledges 360 and 364, is also provided in the present invention by first and second sumps 342 and 344. These are deep channels in the face of the stator which connect to sump drain port 340, which may be also plumbed to the kill tank.
The primary object of the present invention is shown in FIG. 2B, which depicts the means by which the valve may be aseptically cleaned and sanitized. In normal operation, upon completion of continuous SMB processing of a batch, all stator connection ports 310 and 312 (FIG. 1B) might optionally first be flushed with a salt or other stripping buffer which is strong enough to desorb moderately tightly bound contaminants, and then a strong sanitizing agent such as 1-5N NaOH is recirculated through all the rotor carousel beds to clean and desorb bound materials and foulants. Following this, actuator shaft 400 and rotor 200 are moved upward as described above to permit crossflushing of first and second port sealing SIP cleaning paths 351 and 353 with sanitizing agent which may be valved into barrier/SIP connection port 320. This cycle may then be repeated with a sterile storage buffer, and the rotor left for storage either in the elevated or relaxed rotational pressure position. These positions are preferred for storage, as they will prevent or minimize compression setting of the elastomeric diaphragm, which would otherwise tend to emboss the pattern of the stator gutters and grooves into second diaphragm surface 226, and to reduce the effective cross-sectional area for flow.
A second embodiment of the present invention is shown in FIG. 4, which is a half transverse section through a pilot scale valve 600. For convenience, the features of valve 600 have been numbered identically, where possible, to those of valve 100, with 500 added. For brevity, only those features which are different will be commented upon.
First and second column connection fittings 710 and 712 are standard 3/8 inch TriClamp™ sanitary tubing connectors with clamps which axially compress the flanges to make a seal against integral diaphragm elastomeric integral flange gaskets 724. Hollow sleeve 723 has a sleeve duct 727 with an approximate bore of 0.2 inch.
The primary difference between embodiments 100 and 600 is that the larger flow channels of pilot scale valve 600, relative to the practical thickness of the diaphragm, permit first and second SIP/barrier gutters 730 and 732 and mid barrier gutter 733, and make-before break grooves 770 of valve 600 to all be molded directly into second diaphragm surface 726. This saves the cost of machining these details into the stator, as deemed necessary for the finer grooves 370 and gutters 330, 332 and 334, which have been placed on the stator to prevent loss of effective cross-sectional area over time due to wear of the diaphragm.
The other feature included in embodiment 600 is elevating spring 930, which is needed to support the greater weight of the rotor carousel. When actuator shaft 900 is relaxed for rotation or elevated for SIP, spring 930 raises rotor 700 to permit unloading or cleaning of first and second port sealing ledges 850 and 852. The use of a spring to transmit upward displacement of actuator shaft 900 in pilot scale embodiment 600 maintains the universal joining aspects of the rotor-to-actuator shaft linkage taught for bench scale valve 100.
B. A Preferred Application of the Invention.
Liquid chromatography is the process of separating a solute dissolved in a flowing or moving solvent from other solutes in the solvent by the differential interaction of the particular solute with a solid phase bed that is packed within a column structure. A solution of liquid phase and solute is flowed or pumped through the solid phase, and the solutes are retained and become separated based on their degree of interaction with the solid phase bed.
In commercial biotechnology separation schemes, some of the resin materials used as adsorption media may cost up to one million dollars a year per separation step. Thus, getting the highest loading, longest life and highest number of cycles possible out of the resin beds can become a key economic consideration. Therefore, regeneration of the adsorbent by desorbing the bound contaminants is crucial to the commercial success of the process.
The adsorption--desorption cycles may be further complicated by the use of flow reversal. Adsorption is done by flowing the feed solution through the resin bed until just before break-through (the point at which the bed is saturated and adsorbate begins to flow through the column). Regeneration can be done in either the same direction as the feed in the adsorption step or in the opposite direction to the feed. When the regeneration fluid (or eluent) flows in the same direction it pushes the adsorbed material ("adsorbate") through the previously clean end portion of the bed. When regeneration occurs by flowing the regenerant in the opposite direction from the original adsorption flow the clean end of the bed stays clean. Flow reversal elution is also often used for adsorption systems because the adsorbate will leave the column as a very concentrated peak. Thus, adsorption columns can serve as concentrators for dilute streams and may be the cheapest way to concentrate.
The productivity of conventional batch elution column chromatography is actually quite low, and the liquid consumption rate is quite high. These limitations arise because only a fraction of the bed is actually used for separation, and because the lower part of the bed may not be fully loaded without loss of product due to breakthrough of the rising concentration front in the emerging mass transfer zone (MTZ). These shortcomings may be overcome through the use of means which cause the solid phase medium to move in a direction countercurrent or opposite to that of the liquid phase, relative to the points of addition and removal of fluid. Actual recirculation of the solid phase has been tried repeatedly, but suffers from loss of the resin by breakage, loss of efficiency due to the increased void volume, and greater complexity.
The use of multiple beds to simulate counter-current operation dates back to the Shanks carousel system for leaching soda ash introduced in England in 1841. Carousel bed arrays have been applied to single component adsorption and ion exchange for many years. As shown in FIG. 5, multiple bed segments connected in series are used for adsorption. The adsorbed concentration in the first segment rises to near saturation before the rising concentration in the MTZ in the last segment begins to emerge in the product stream. By switching all connection ports upward in the direction of fluid flow in the adsorption zone, the carousel simulates downward movement of the adsorbent. The switching rate is timed to follow the MTZ, ensuring maximal loading of each bed segment, and continual supply of a freshly regenerated segment for optimal final removal from the product stream. The valved co-current movement of the fluid ports simulates counter-current movement of the bed, hence the name simulated moving-bed (or SMB).
The first large scale commercial use of simulated moving bed chromatography for fractionation was by Universal Oil Products, as described in U.S. Pat. No. 2,985,589 (Broughton et al. ), who introduced the Sorbex Cascade process for fractionation of hydrocarbons, and later for fructose enrichment from glucose and polysaccharides in corn syrup. The Sorbex system employs a complex rotary valve to move feed and eluent inlets and raffinate and extract outlets cyclically along a multi-segmented column which carries a continuous recirculation of mobile phase in a direction counter to that of the simulated movement of resin caused by the intermittent rotation of the valve (see FIG. 6). To maintain purity, an additional flush loop is needed to remove feed material remaining in the lines between the valve and column segments prior to their use for removing extract slow product as described in U.S. Pat. No. 3,268,604 (Boyd). Eluent savings result from the reduced flow rate needed for a given contact velocity due to the countercurrent motion of the bed segments (internal reflux). Further savings result if external reflux (liquid recyle) is also used, because the recycled liquid phase is blended with eluent and flowed counter to resin bed movement for efficient removal of the more tightly bound components. Weakly bound ("fast") components are moved along with the liquid phase, and taken off in a raffinate stream.
With particular reference to FIGS. 7-8, a specific application of counterflow simulated moving bed liquid chromatography using a multi-port slider (rotary) valve is described. This separation scheme is depicted in a 12-bed rotating carousel arrangement, whereby the beds are fed by the sanitizable rotary valve previously described, and adapted to provide two inputs (eluent, feed) and two outputs (raffinate, extract), with a substantial portion of the eluent being recycled. Feed liquid containing both slow (represented as dots) and fast (larger circles) components is introduced at the feed port, located schematically in the middle of zones I-II (the "differential migration" zone). Eluent is continuously flowed in a direction counter to that of the movement of the columns. The slow components are carried mainly by the bed packing, typically a size exclusion-type resin, and the fast components are carried mainly by the eluent. Thus, they move in opposite directions from the feed port. At the border of zones I and IV, the raffinate stream (largely comprising fast component) is taken off through the raffinate port and led to waste or solvent recapture. At the border of zones II and III, extract (containing largely product slow component) is taken off through a similar port. Flow rates of the inputs and outputs are controlled by pumps relative to the switching rate of the beds so as to create the separations shown in each zone.
FIG. 8 is a schematic representation of a typical ion-exchange salt gradient separation. Here, the plumbing is more complicated and requires four inputs (eluent, wash, feed, strip) and three outputs (extract, raffinate, waste). Feed containing the desired product and undesirable by-products and process artifacts is introduced through a feed port intermediate to zones I and II and is immediately channeled into the "slow capture" zone I. Slow components are adsorbed in zone I, and fast unbound components are swept along with the liquid to be removed as a raffinate stream. As the carousel turns the beds pass upstream of the feed port into a wash buffer zone II. This wash step allows "rectification" of the slow and fast components, flushing away entrained unbound fast components from the bound slow components. The bound slow product continues to move with the beds past the wash inlet port into desorption zone III. Here product is desorbed by a stronger eluent, which may have a different ionic strength and/or pH, and comes off in the extract stream at the boundary of zones II and III. An even stronger eluent is then optionally introduced in zone IV to strip the column and desorb strongly bound species from the bed before the next adsorption cycle. Some stripping solution migrates into zone I with the rotation of the carousel, but this material is diluted and washed away by the raffinate stream containing unbound contaminants. One of ordinary skill in the an will be able to determine the concentrations of the various eluents needed to optimize a particular step gradient.
Although the foregoing invention has been described by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the following appended claims.
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A sanitary slider valve shown specifically as a rotary carousel diaphragm valve which has a thermoplastic elastomeric diaphragm integrally molded to form the multiple sealing ports of the rotor/stator interface is described. Ports or grooves molded into the face of the elastomeric diaphragm are positioned to sealably engage grooves or ports in the stator face, and to form sanitary elastomeric tubular ducts leading through the body of the rotor or of the stator, terminating as elastomeric flanges. These flanges permit direct connection to sanitary flared piping flanges within the carousel which lead to and from multiple columns or other solid phase bed segments, or to sanitary flared piping flanges connecting the stator to piping interconnecting the multiple carousel columns to each other and to external supply and collection lines. Sanitary operation is made operable by energized flexible diaphragm wiping lip seals which maintain fluid-tight sealing engagement with the opposing face even when the rotor is lifted off the stator far enough to permit cross flushing of the port sealing faces with sanitizing fluid. The valve permits sanitary operation of advanced chromatographic separations of biopharmaceuticals, including simulated moving bed chromatography.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention lies in the field of appliances. More specifically, the invention relates to a front-loading washing machine having a rotatable laundry drum with a casing, and with an axis of rotation in the operating position of the washing machine which deviates from the horizontal such that it slopes upward in the forward direction. The laundry drum has hollow, elongate paddles that are disposed on the inside of the casing. The paddles include liquid inlet openings located such that when located in a lower position as a result of drum rotation are proximate the rear region of the laundry drum. By such arrangement, upon rotation of the drum, the openings provide at the lowermost position admission of liquid into the paddle. A baffle arrangement redirects the liquid within the paddle to be discharged from the paddle through openings located toward the front of the drum when the paddle is in, or around, the upper most region of the drum during a rotation cycle.
[0003] 2. Discussion of Prior Art
[0004] Prior art washing machines have included arrangements where laundry that is to be washed is exposed to washing liquid and moved mechanically to remove soiling on wash items. With drum-type washing machines, that function is performed by a laundry drum that is arranged essential horizontally in a tub. The drum is arranged for receiving the laundry and rotated to move the laundry in its interior. In order to assist in moving the laundry, rib-like paddles are aligned transverse to the movement direction of the laundry-drum casing.
[0005] Other prior art drum-type washing machines exist that position the paddles obliquely to run along a helical line on the inside of the laundry-drum casing. The paddles are arranged obliquely for the purpose of influencing the movement of the laundry. This causes the laundry to be transported by the paddles within the drum as the drum rotates.
[0006] One prior art approach which tends to distribute water throughout the laundry drum and in contact with the wash items involves having paddles arranged to scoop water in the lowermost region of the tub to raise the water as the laundry drum rotates to spray the water from a raised position, through openings onto the laundry located beneath. However, this configuration is such that the scooped quantity of liquid is discharged before the paddles have reached the position in which they are located essentially above the laundry. Such an arrangement slows the wetting process to a considerable degree because the liquid discharge only runs down the inner wall of In an attempt to avoid such an occurrence, U.S. Pat. No. 6,463,767 discloses a front-loading washing machine which includes a laundry drum rotatably mounted around a rotation axis. The rotation axis slopes upward in a direction defined from the rear region to the front region. Hollow elongate paddles are disposed on the interior of the casing of the laundry drum in an oblique arrangement with respect to a direction of rotation. Each of the paddles includes liquid inlets which pass through a rear lower region of the laundry drum as a result of rotation to collect liquid and discharge it through outlets when the paddles are in an upper position within the drum. The drum is cylindrical and includes a casing line. Paddles are fastened on the inner casing of the drum cylinder and the inlets project outside of the casing line, i.e., beyond the drum, for scooping water into the paddles.
[0007] All the prior art discussed fails to address the desirability of directing water collected from the bottom of a rotating drum which is inclined, and redistributing the liquid in a manner consistently wetting laundry items within the drum at a location forward relative to the rear of the drum, such that laundry items towards the front of the drum are also uniformly exposed to washing liquid within the washing machine.
SUMMARY OF THE INVENTION
[0008] It is accordingly an object of the invention to provide a front-loading washing machine having a rotatable laundry drum that overcomes the previously mentioned disadvantages, and improves the wetting of the laundry, and the ability to reach the laundry with washing liquid within the washing machine.
[0009] With the foregoing and other objects in view, there is provided in accordance with one aspect of the invention, a paddle for a laundry drum which includes a hollow body which is open in a direction of a inner surface of a drum casing of the laundry drum when mounted within the laundry drum. A first plurality of openings which includes a distal opening is arranged on the hollow body at a position to pass adjacent the rear and bottom of the laundry drum when mounted on the laundry drum for gathering liquid collected at the rear and bottom of the laundry drum. At least one baffle member is provided within the hollow body which defines a channel within the hollow body for directing liquid gathered within the hollow body toward a position which passes adjacent the front of the laundry drum as the laundry body is moved toward the top of a laundry drum as a result of rotation thereof. A second plurality of openings which includes a proximal opening is provided located toward the front of the laundry drum, when the hollow body is mounted on the laundry drum, at a location for having liquid gathered by the hollow body directed toward the second plurality of openings when the drum is rotated to be located at or near the top, for having the liquid discharged through the second plurality of openings towards clothing located toward the front of the drum.
[0010] In an alternative aspect, the invention involves a laundry drum for a drum-type washing machine. The laundry drum includes a drum casing having an outer surface and an inner surface. At least one paddle is fastened on the inner surface of the drum casing. The paddle is made up of a hollow body open in a direction of the drum casing inner surface. A first plurality of openings on the hollow body is located at a position to pass adjacent a lower rear region of the casing for gathering liquid collected at the lower rear region of the casing. At least one baffle defines a channel within the hollow body for directing liquid gathered therein toward the front of the casing through the hollow body as it is moved toward the top of the laundry drum as a result of rotation thereof. A second plurality of openings is located toward the region of the body for having liquid gathered by the hollow body discharged therethrough toward a front region of the laundry drum, when the hollow body is moved by the drum casing into a position at or near the top.
[0011] In a yet still further aspect, there is provided a front-loading washing machine. The washing machine includes a laundry drum which is rotatably mounted about a rotation axis. The drum includes a drum casing having an outer surface and an inner surface, and a front region and a rear region. The rotation axis of the drum slopes upward in a direction defined from the rear region to the front region. At least one paddle is fastened on the inner surface of the drum casing. The paddle includes a hollow body open in the direction of the drum casing inner surface. A first plurality of openings on the hollow body is located at a position to pass adjacent to the rear region of the drum casing for gathering liquid collected at the rear region at the bottom thereof as a result of drum rotation. At least one baffle defines a channel within the hollow body for directing liquid gathered within the hollow body toward the front region of the drum as the hollow body is moved toward the top of the laundry drum as a result of rotation. A second plurality of openings is located toward the front region of the drum for having liquid gathered by the hollow body discharged therethrough when the hollow body is moved by the drum casing into a position near to or at the top of rotation.
[0012] As a result of the arrangement contemplated herein, the paddles transport quantities of liquid to a higher level than previously possible and direct the liquid towards the front of the laundry drum to ensure that all of the laundry articles within the drum are properly wetted.
[0013] In a more specific aspect, the drum rotates in a clockwise direction with the inlet openings of the first plurality of openings facing the direction of rotation to ensure water or liquid is collected within the paddle, transported upwardly upon rotation and then directed toward the front of the paddles to be discharged through the second plurality of openings at a location toward the front of the drum.
[0014] Other features that are considered as characteristic of the invention are set forth in the appended Claims.
[0015] Although the invention is illustrated and described herein as embodied in a front-loading washing machine having a rotatable laundry drum, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0016] The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of the specific embodiments when read in connection with the accompanying Drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a side view of a front-loading drum type washing machine showing in dashed lines a drum arrangement within the washing machine;
[0018] FIG. 2 is a side cross-sectional view of a subassembly of a washing machine according to the invention, including a tub and laundry drum;
[0019] FIG. 3 is a perspective view of a paddle in accordance with the invention, shown from the hollow side thereof, and indicating liquid flow collected at a bottom location in a rotating drum;
[0020] FIG. 4 is a view similar to FIG. 3 , showing a paddle mounted on a drum at a top location, and showing a liquid flow for discharge therefrom;
[0021] FIG. 5 is a perspective view showing a paddle in accordance with the invention approaching liquid at the bottom of a laundry drum for collecting liquid therein;
[0022] FIG. 6 is a view as in FIG. 5 but showing the paddle after having collected liquid at the bottom of the drum; and
[0023] FIG. 7 is a view showing the paddle rotated into a upward position within the drum, and discharging liquid toward a location at the front of the drum as a result of rotation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Referring now to the figures of the Drawings in detail and first, particularly to FIG. 1 thereof, there is shown a front-loading washing machine 3 having a laundry drum subassembly 11 mounted about a drum axis of rotation 16 which is slightly inclined from rear to front in an upward direction relative to a horizontal line. The washing machine 3 includes a front-loading opening 17 . The drum subassembly 11 is arranged to rotate about the axis 16 .
[0025] The drum subassembly 11 is a rotatable drum and is provided with a plurality of paddles that are described in more detail hereinafter. Each paddle has a body element mountable in a rotatable drum that rotates about the drum axis 16 , a distal opening, and a promixal opening. The body element of each paddle has an interior and the body element has an axial extent bi-sected by a mid-axial line and formed by a distal portion extending from the mid-axial line to a distal axial end and a proximal portion extending from the mid-axial line to a proximal axial end. The body element of each paddle is mountable on an inner surface of the drum subassembly 11 with the distal axial end thereof oriented toward one axial end of the drum subassembly 11 and the proximal axial end thereof oriented toward an opposite axial end of the drum subassembly 11 . The distal opening in the distal portion of the body element of each paddle is operable to receive liquid therethrough for entry of liquid into the interior of the body element. The proximal opening in the proximal portion of the body element is operable for the passage of liquid therethrough such that liquid can exit the interior of the body element. The proximal opening and the distal opening is in communication with one another such that, as the drum subassembly 11 rotates about the drum axis 16 , liquid enters the interior of the body element via the distal opening, flows within the interior of the body element to the proximal opening, and exits the body element via the proximal opening.
[0026] FIG. 2 illustrates in greater detail the drum subassembly 11 which includes a tub 14 and a laundry drum 15 including an outer surface 19 and an inner surface 21 . Paddles 31 in accordance with the invention are located therein and include intake openings 35 shown in dashed lines in the paddle 31 located at the bottom of drum 15 and in solid lines in the paddle 31 located at the top of the drum 15 , and which face in the direction of rotation of the drum 15 , i.e., clockwise for scooping in liquid 41 such as water, detergent or a combination of both, located at the bottom rear portion 39 of the drum 15 . As may be appreciated from the drawing, as the drum rotates, the paddles 31 scoop in the liquid and when the paddle 31 is raised to a position close to or at the top of the drum 15 , the liquid 41 is discharged through discharge openings 33 at a location close to the front 37 of the drum 15 .
[0027] FIG. 3 illustrates a paddle 31 in accordance with the invention, the drawing illustrates liquid or water flow 51 as directed, after intake into the paddle, through baffles 53 and 55 . As may be appreciated, the paddle 31 is illustrated in an upside down arrangement, and because of the view angle the inlet openings 35 are not shown, but the discharge openings 33 are clearly illustrated. In addition, through-holes 49 are provided to facilitate mounting of the paddle 31 , preferably through a stake-welding technique. As will be readily apparent to those of ordinary skill, alternative attachment techniques can be employed, including without limitation screws and the like.
[0028] As further illustrated in FIG. 4 , the paddle 31 is shown attached to the inside surface 21 , in a partial cut away view of laundry drum 15 . As shown therein, it is also appreciated how the liquid 51 flows as guided by the baffles 53 and 55 . More specifically, the liquid as it has been taken into the paddle 31 , due to gravity, is maintained away from the discharge openings 33 until the paddle 31 arrives at a location close to or at the top of the drum 15 rotation.
[0029] FIG. 5 illustrates in greater detail a paddle 31 as the drum 15 is rotated arriving at a location towards the bottom of the washing machine in which the liquid 41 is collected through openings 35 . Thereafter, in the view of FIG. 6 , the paddle 31 is shown after having been passed through the liquid 41 . While the paddle is generally of V-shaped cross-section, it can also include an elongated, flattened section 57 which aids in retaining liquid 41 therein away from discharge openings 33 as the paddle is rotated clockwise upwardly within the washing machine 3 . The paddle 31 then arrives at a location near the top of the washing machine due to the drum 15 rotation, as shown in FIG. 7 , and the liquid 41 is discharged through openings 33 towards the front 37 of the drum 15 , as shown in FIG. 7 .
[0030] The paddles 31 , may be made of a number of different materials. Plastics make manufacturing of the paddles 31 particularly easy through conventional molding or injection processes. In addition, depending on the type of plastics employed, they are advantageously suited for use in wet environments having large temperature variations such as occurs in washing machines.
[0031] In terms of mounting arrangements, the paddle 31 may be mounted transverse to the direction of rotation of the drum 15 . Alternatively, the paddles 31 may be mounted oblique to the direction of rotation with appropriate placement of discharge openings 33 , inlet openings 35 and baffles 51 and 53 to achieve the function described.
[0032] It will be understood that various details of the present invention may be changed without departing from the scope of the present invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the present invention is defined by the claims as set forth hereinafter.
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A washing machine paddle includes a plurality of intake openings for collecting liquid at the bottom and rear of a drum of a front loading washing machine. Discharge openings are located on the paddle toward the front of the drum for discharging liquid therethrough. A baffle arrangement in the paddle directs the liquid collected from the intake openings to the discharge openings upon rotation of the drum to place the paddle into a top location. A drum arrangement and washing machine includes at least one such paddle mounted thereon.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to decking tools, and in particular, to a spacing strap assembly which permits a user to align, space and hold decking boards in position prior to nailing.
[0002] Outdoor decks and patios have become increasingly popular in recent years and kits and do-it-yourself books are available to allow the homeowner as well as the construction professional to construct elaborate wooden decks and patios. The aesthetic appearance of the deck is usually judged by the appearance of the deck boards and their spacing and appearance. The deck boards are the final item normally installed after the deck joists have been positioned and leveled.
[0003] Deck boards are typically spaced apart to leave a gap between adjacent boards so that water can more readily drain from the deck surfaces. Spacing the boards equally along support beams and joists, however, has heretofore proven to be a relatively time consuming and laborious task. Deck boards are typically positioned, spaced and nailed, one-at-a-time. Unless the builder is very skilled, it is not unusual for the deck boards to become gradually out of line, thereby affecting the overall esthetics of the deck, but also in some cases the very structure of the deck.
SUMMARY OF THE INVENTION
[0004] The present invention provides a deck board spacing strap. The strap has a series of spacer bars attached thereto thereby enabling the deck builder to position, space and hold a substantial number of deck boards in place at one time before nailing. This enables the builder to review the deck board configuration before nailing. The present invention also permits the builder to position out-of-line boards in the least disruptive manner. With the deck boards assembled, positioned and properly spaced, nailing time and labor are substantially reduced.
[0005] These together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a top perspective of view the invention.
[0007] [0007]FIG. 2 is a close-up, perspective view, partly in section of the invention.
[0008] [0008]FIG. 3 is a close-up view of an individual spacer bar.
[0009] [0009]FIG. 4 is a side view of a double spacer bar assembly positioned over a first board.
[0010] [0010]FIG. 5 is a side view of the first three spacer bars in place.
DETAILED DESCRIPTION OF INVENTION
[0011] Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown an elongated, generally rectangular spacing strap 10 constructed according to the principles of the present invention. The spacing strap 10 is constructed with two elongated layers, a top layer 11 and a bottom layer 12 . The layers are mirror images of each other. Each layer 11 , 12 is preferably made from a nylon webbing material. Other materials providing comparable strength, toughness, durability and longevity may also be used. The top layer 11 is attached to the bottom layer 12 by stitching 13 . Other means of attachment may also be used. The spacing strap 10 has two opposing, parallel, elongated sides 14 defining the strap width. Applicants have found an approximate width of two to three inches to be preferable. The spacing strap 10 has two ends, a proximal end 15 and a distal end 16 , said ends defining the general longitudinal axis of the strap. Beginning at the proximal end 15 the strap layers form periodic, equidistant, generally cylindrical interstices 17 between each layer, each interstice having an elongated central axis transverse to the longitudinal axis of the spacing strap 10 . Each interstice 17 opens out through both sides 14 . In one embodiment of the invention, specifically adapted to be used with deck boards having an outside diameter width of five and five-eighths inches, the interstices 17 are longitudinally positioned six inches apart on center. In another embodiment of the invention, specifically adapted to be used with porch boards having an outside diameter width of three and five-eighths inches, the interstices 17 are longitudinally positioned four inches apart.
[0012] A U-shaped spacer bar 20 is inserted into each interstice 17 . Each spacer bar 20 has an elongated, straight, intermediate, cylindrical portion 21 interconnecting two opposing, parallel, L-shaped, cylindrical spacer sections 22 . Each spacer section 22 has a nominal diameter of three-sixteenths inches. Each spacer bar 20 is joined to the spacing strap 10 so that each spacer bar intermediate portion 21 is held within an interstice 17 . The spacer bars 20 are preferably made from stainless steel. However, the spacer bars 20 may be made from any other sturdy, weather resistant material. Spacing cylinders 24 may be slid over the spacer sections 22 (See, FIG. 3) to adjust the radial thickness of each spacer section 22 .
[0013] The first two spacer bars 20 , beginning with the proximal strap end 15 , are interconnected by two parallel, position bars 25 , resulting in a double spacer bar assembly 30 . Each position bar 25 interconnects the first spacer bar 20 with the second spacer bar 20 . Each position bar 25 has two ends, a proximal end 26 and a distal end 27 . Each position bar proximal end 26 is attached to the junction 23 of the first spacer bar intermediate portion 21 and a spacer section 22 . The position bar distal ends 27 are attached to the junctions 23 of the second spacer bar intermediate portion 21 and spacer sections 22 .
[0014] In operation, a first deck or porch board 2 is positioned and aligned as desired. The first board 2 is then attached to appropriate joists 5 and/or support beams 6 . The builder then fixes the double spacer bar assembly 30 over the first board 2 keeping the remainder of the spacing strap 10 rolled up and positioned over the first board 2 and double spacer bar assembly 30 as shown in FIG. 4. Each spacer bar 20 is positioned about a board 2 so that the spacer bar intermediate portion 21 lies on the top 3 of a particular board 2 and the bar spacer sections 22 lie along the sides 4 of the board 2 . The builder then assembles a desired number of additional boards 2 ′ unrolling the spacing strap 10 across the boards 2 ′ and inserting and positioning the strap spacer bars 20 between the boards 2 , 2 ′, etc. When all the boards are laid down with deck board spacer bars 20 properly in place, the spacing strap 10 will hold all in position until the builder follows with a screw gun, hammer, nail gun, or the like, securing all boards to the appropriate joists 5 and/or support beams 6 . Typically two straps 10 would be used, however, any number of straps 10 may be used as desired. Separation between boards 2 may be adjusted by means of spacing cylinders 24 slid over the spacer bar spacer sections 22 .
[0015] It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof. Space bars 20 may be made in different sizes and thicknesses. Spacing cylinders 24 may also be provided in different sizes and thicknesses.
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A deck board spacing strap. The strap has a series of spacer bars attached thereto thereby enabling a deck builder to position, space and hold a substantial number of deck boards in place at one time before nailing.
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FIELD OF THE INVENTION
This invention relates generally to a bone reinforcement process and surgical tool for, and more particularly, the present invention relates to an application device for injecting poly methyl methacrylate into a bone matrix through a canulated element through which a screw may subsequently be inserted.
BACKGROUND OF THE INVENTION
The bones and connective tissue of an adult human spinal column consists of an upper portion having more than 20 discrete bones, and a lower portion which consists of the sacral bone and the coccygeal bodies. The bones of the upper portion are generally similar in shape, however, they do vary substantially in size in accordance with their individual position along the column and are, therefore, anatomically categorized as being members of one of three classifications: cervical, thoracic, or lumbar.
These similarly shaped bones vary in size, but are each similarly coupled to the next by a tri-joint complex. The trijoint complex consists of an anterior disc and the two posterior facet joints, the anterior discs of adjacent bones being cushioned by cartilage spacers referred to as intervertebral discs. The posterior portion of the vertebral bone is coupled to the anterior portion by a pair of bone bridges referred to as pedicles, between which the spinal canal is housed.
In its entirety, the spinal column is highly complex in that it houses and protects critical elements of the nervous system which have innumerable peripheral nerves and arterial and veinous bodies in close proximity. In spite of these complexities, the spine is a highly flexible structure, capable of a high degree of curvature and twist through a wide range of motion.
Genetic or developmental irregularities, trauma, chronic stress, tumors, and disease, however, can result in spinal pathologies which either limit this range of motion, or which threaten the critical elements of the nervous system housed within the spinal column. A variety of systems have been disclosed in the art which achieve this immobilization by implanting artificial assemblies in or on the spinal column. These assemblies may be classified as anterior, posterior, or lateral implants. As the classification suggests, posterior implants are attached to the back of the spinal column, generally hooking under the lamina and entering into the central canal, attaching to the transverse process, or coupling through the pedicle bone. Lateral and anterior assemblies are coupled to the vertebral bodies.
The region of the back which needs to be immobilized, as well as the individual patient's anatomy, determine the appropriate surgical protocol and implantation assembly. Because the spine is routinely subject to high loads which cycle during movement, primary concerns of physicians performing spinal implantation surgeries focus on screw pull-out and screw failure. Screw pull-out occurs when the cylindrical portion of the bone which surrounds the inserted screw fails. Screw pull-out often an additional danger in that it often leaves the bone into which the screw was implanted completely useless with respect to continued implant support. This is especially true when the patient suffers from osteoporosis. In such patients the bone matter is often much less structurally supportive and lacks the necessary holding strength to prevent macromotion of the screws which may be implanted therein, thus severely limiting the immobilization potential of the assembly.
The use of artificial materials, such as bone cements and specific organic bone mimicking compounds such as poly methy methacrylate (PMMA), have been taught in the art as being effective in strengthening the osteoporotic bones to effect better immobilization of the screws. Percutaneous insertion of bone reinforcing agents has been successful in many instances, and is generally known as vertebroplasty. This “closed” use of PMMA and/or bone cement is useful in supporting subsiding bone masses in some instances, but is insufficient in those cases in which pedicle screw support is required. One of the failings of vertebralplasty, however, is that the cured PMMA/bone cement is often so much more dense and hard than the surrounding natural bone material that if subsequent screws need to be inserted, the bone drill is confounded by the difference in material properties.
The “open” use of PMMA and/or bone cement has been thought of as an alternative to “closed” use, especially when posterior implants are expected to be utilized. In such an instance, the patient's posterior spine is exposed and a bone drill is used to bore a hole through the pedicles for the posterior assembly to be implanted. Prior to the screws being implanted, however, the surgeon injects a quantity of PMMA/bone cement into the hole. Subsequently, the screw is inserted into the hole with the uncured cement. As the cement harden around the threads of the screw, however, the screw becomes thoroughly incarcerated in the hole, and is thus irretrievable. This presents a significant problem for potential revision surgery as well as being a cumbersome and time sensative process (as the PMMA/bone cement must not dry before the screw is implanted.
It is, therefore, the principal object of the present invention to provide a bone cement injector system for use in spine surgery wherein the surgeon has the ability to assemble the bone cement injectors without the time pressure of inserting the screws exactly after the material has been inserted.
It is also an object of the present invention to provide a bone cement injector system for use in spine surgery wherein the surgeon has the ability to insert the pedicle screws into a dried bone cement cavity which will support, but not incarcerate the screw against removal if necessary.
Other objects of the present invention not explicitly stated will be set forth and will be more clearly understood in conjunction with the descriptions of the preferred embodiments disclosed hereafter.
SUMMARY OF THE INVENTION
The preceding objects are achieved by the present invention, which is a system and method for reinforcing bone in preparation for screw implantation. A system of the invention in one embodiment comprises a threaded cannula having a central bore and a perforated distal end, a cannula applicator that is insertable into the central bore and which achieves a friction fit within the central bore, a plunger that is insertable into the central bore and which achieves an intimate fit within the central bore (the plunger having a guide wire passing through its central longitudinal axis), bone cement, and a cannulated drill bit. A method of the invention in one embodiment comprises drilling and tapping a hole in a vertebral body, inserting the applicator into the central bore of the cannula, screwing the cannula into the tapped hole by rotating the applicator, removing the applicator, injecting the bone cement into the central bore, distributing the bone cement out the holes in the distal end of the cannula and into the surrounding bone using the plunger, letting the bone cement harden, and drilling out the plunger using the cannulated drill following the guide wire. Thereafter, the surgeon can re-tap the hole and insert a bone screw into the reinforced vertebral body.
More particularly, a cannula of the invention has an elongated cylindrical body with a central bore, the body having a proximal end providing access to the bore (especially access by a cannula applicator, plunger, syringe and drill bit of the present invention, as described in greater detail below), and a distal end that is perforated. The outer surface of the cannula is threaded for engagement with threads of a tapped drill hole and to restrict proximal migration of the bone cement, as described in greater detail below. The cannula should be formed from biocompatible material (e.g., poly methyl methacrylate) inasmuch as it will become incarcerated into the target vertebral body in accordance with the procedures described herein. Preferably, the cannula has a radiodense tip that can be used to aid the surgeon in determining the position of the cannula after the cannula has been placed into the target vertebral body.
A cannula applicator of the invention has an elongated cylindrical body and is used to assist the surgeon in threading the cannula into a tapped drill hole and in determining the placement of the cannula in the vertebral body, as described in greater detail below. Accordingly, the applicator is dimensioned so that it can be placed into and removed from the proximal end of the cannula and so that when the applicator is placed into the bore of the cannula, it fits snugly within the bore. The intimate fit enables the applicator to provide structural support for the cannula as the cannula is twisted into the drill hole, and causes the applicator to grip the walls of the bore so that cannula will rotate when the applicator is rotated, so that the cannula will threaded into the drill hole. Preferably, the applicator comprises a radiodense material or is of a radiodense configuration, so that it can be used to determine the position of the cannula as the cannula is threaded into the drill hole.
A plunger of the present invention has an elongated cylindrical body that fits tightly within the bore of the cannula so that it can be used to squeeze bone cement out the holes in the distal end of the cannula as described in greater detail below. Preferably, the body is formed from a material that is softer than the biocompatible material from which the body of the cannula is formed. As described in greater detail below, this difference in material facilitates the drilling away of the plunger after it is used to distribute the bone cement. Also preferably, the plunger is formed from biocompatible material (e.g., poly methyl methacrylate), as some of the plunger may remain after most of the plunger has been drilled away, and the remaining portion would become incarcerated in the vertebral body. Also preferably, the body has a central longitudinal axis and an internal guide wire passing through the central longitudinal axis. As described in greater detail below, this guide wire also facilitates the drilling away of the plunger.
During use of the invention, upon proper preparation of the target vertebral body or bodies in accordance with known and accepted surgical procedures, the surgeon drills a hole in the target vertebral body. Then, the surgeon threads the hole using a tap in a manner known in the art. The surgeon repeats the above procedure for each hole he wishes to drill.
Next, the surgeon inserts into the hole a cannula of the present invention, using an appropriately sized cannula applicator of the present invention. The surgeon inserts the applicator into the proximal end of the cannula and into the bore of the cannula, establishing a tight fit of the applicator against the walls of the bore. Once the applicator is fitted into the bore, the surgeon places the cannula into the tapped hole, and repeatedly turns the applicator to screw the cannula into the hole to the desired position (typically, all the way into the hole). The intimate fit of the applicator in the bore facilitates the rotation of the cannula in response to the rotation of the applicator. The structural integrity of the applicator, in conjunction with the intimate fit of the applicator in the bore, provides structural support for the thin-walled cannula as the cannula is twisted into position. For each drilled hole, the surgeon places a cannula into the drilled hole using an appropriately sized applicator in accordance with the above procedure. The surgeon should leave each applicator in place until it is time to inject the bone cement, as described below. This will keep bleeding to a minimum and will continue to make possible radiographic assessments of the position of each applicator and accordingly each cannula.
Once each drilled hole has been fitted with a cannula, the surgeon prepares the appropriate bone cement mixture and loads one or more syringes with the bone cement, in a manner know in the art. Then, for each installed cannula, one at a time, the surgeon removes the applicator, injects an appropriate amount of the bone cement into the bore using the syringe(s), and applies a plunger of the present invention to distribute the bone cement through the holes of the distal end of the cannula. In order to effect this procedure for each cannula, the surgeon first removes the applicator from the cannula by pulling it from the bore. Next, the surgeon prepares the bone cement, loads the syringe(s), and injects the bone cement into the bore. Then, the surgeon inserts an appropriately sized plunger of the present invention into the distal end of the cannula and into the cannula bore, pushing the plunger down the bore so that the bone cement squeezes out the holes at the distal end of the cannula and into the bone surrounding the cannula. For each cannula, the surgeon leaves the plunger in until each plunger has been applied and the bone cement has set in the surrounding bone. The setting of the bone cement in the surrounding bone strengthens the surrounding bone in preparation for the next steps, which involve re-tapping the target vertebral body for a bone screw.
Once each plunger has been applied and the distributed bone cement has set, the surgeon drills out each plunger using a drill and cannulated drill bit. The surgeon selects a cannulated drill bit having an appropriate outer diameter, sets the drill bit into the drill, passes the drill bit over the guide wire extending from the plunger, and proceeds to drill into the plunger body, following the guide wire to ensure that primarily the plunger body is being drilled away. As noted above, the preferable softness of the plunger body relative to the cannula body facilitates the drilling away of primarily the plunger body. The surgeon repeats this procedure for each installed cannula.
Finally, the surgeon threads each hole that remains after each plunger has been removed, using a tap in a manner known in the art. Once each new hole has been tapped, the surgeon can insert a bone screw of the surgeon's choice into each hole, and complete the operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a , 1 b and 1 c illustrate a cannula of an embodiment of the present invention, with FIG. 1 a showing a side view of the cannula, FIG. 1 b showing a cannula applicator of an embodiment of the present invention, and FIG. 1 c showing a side view of the cannula engaged with the cannula applicator.
FIGS. 2 a and 2 b illustrate a plunger of an embodiment of the present invention, with FIG. 2 a showing the plunger alone and FIG. 2 b showing the cannula of FIG. 1 a engaged by the plunger.
FIGS. 3 a-f illustrate a method of an embodiment of the present invention, with FIGS. 3 a-b illustrating the drilling and tapping of a hole in a target vertebral body, FIG. 3 c illustrating the placement of the cannula of FIG. 1 a in the hole, FIGS. 3 d-e illustrating the filling of the cannula bore with bone cement, and the distribution of the bone cement out the holes in the distal end of the cannula using the plunger of FIG. 2 a , and FIG. 3 f illustrating the drilling out of the plunger body from the cannula bore using the guide wire in the plunger as a guide.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which particular embodiments and methods of implantation are shown, it is to be understood at the outset that persons skilled in the art may modify the invention herein described while achieving the functions and results of this invention. Accordingly, the descriptions which follow are to be understood as illustrative and exemplary of specific structures, aspects and features within the broad scope of the present invention and not as limiting of such broad scope. Like numbers refer to similar features of like elements throughout.
Referring now to FIGS. 1 a , 1 b and 1 c , a cannula 100 of the present invention is shown, with FIG. 1 a showing a side view of the cannula 100 , FIG. 1 b showing a cannula applicator 118 of the present invention, and FIG. 1 c showing a side view of the cannula 100 engaged with the cannula applicator 118 . The cannula 100 has an elongated cylindrical body 102 with a central bore 104 , the body 102 having a proximal end 106 providing access to the bore 104 (especially access by a cannula applicator 118 , plunger 200 , syringe 300 and drill bit 318 of the present invention, as illustrated in other figures and as described in greater detail below), and a distal end 108 that is perforated with holes 110 as shown. The outer surface of the cannula 100 is threaded with outer threads 114 for engagement with inner threads of a tapped drill hole and to restrict proximal migration of the bone cement, as described in greater detail below, and for other reasons. The cannula 100 should be formed from biocompatible material (e.g., poly methyl methacrylate) inasmuch as it will become incarcerated into the target vertebral body in accordance with the procedures described herein.
For example in the illustrated embodiment, the body 102 of the cannula 100 has a length of 70.0 mm, an inner diameter of 4 mm, and an outer diameter of 6.5 mm. It should be understood that the cannula 100 can have other dimensions without departing from the scope of the present invention. For example, in some applications, a useful outer diameter would be 5.5 mm, 7.5 mm, or any measurement between 5.5 mm and 7.5 mm, and any other measurement less than 5.5 mm, or greater than 7.5 mm, as needed depending on the clinical application for which the invention is used, and the corresponding dimensions of the other instruments used with the cannula 100 . For another example, in some applications, a useful cannula length would be shorter or longer than 70.0 mm, as necessary or desirable depending on the depth of the drill hole. The illustrated embodiment has a cannula 100 with a body length of 70.0 mm, inner diameter of 4.0 mm, and outer diameter of 6.5 mm. An inner diameter of 4.0 mm, while not required, is useful for minimizing resistance to flow of the bone cement, as described in greater detail below.
Further preferably, the cannula 100 has a radiodense tip 116 that can be used to aid the surgeon in determining the position of the cannula 100 after the cannula 100 has been placed into the target vertebral body. While any radiodense material or configuration can be used to make the tip 116 radiodense, suitable examples include using metal, wires, beads or barium. Any method know in the art for determining the position of a radiodense mass in a vertebral body can be used to determine the position of the radiodense tip 116 in the target vertebral body.
Referring again to FIGS. 1 b and 1 c , a cannula applicator 118 of the invention is shown, alone in FIG. 1 b and in FIG. 1 c engaged with the cannula 100 . The applicator 118 has an elongated cylindrical body and is used to assist the surgeon in threading the cannula 100 into a tapped drill hole (e.g., by providing structural support for the cannula 100 and allowing purchase of the cannula 100 so that the cannula 100 can be twisted into position) and in determining the placement of the cannula 100 in the vertebral body, as described in greater detail below, and for other purposes. Accordingly, the applicator 118 is dimensioned so that it can be placed into and removed from the proximal end 106 of the cannula 100 and so that when the applicator 118 is placed into the bore 104 of the cannula 100 , it fits snugly within the bore 104 as shown. For example in the illustrated embodiment, the diameter of the applicator 118 is 4.0 mm and its length is 100.0 mm. The intimate fit enables the applicator 118 to provide structural support for the cannula 100 as the cannula 100 is twisted into the drill hole, and causes the applicator 118 to grip the walls of the bore 104 so that cannula 100 will rotate when the applicator 118 is rotated, so that the cannula 100 will threaded into the drill hole.
Also preferably, the applicator 118 comprises a radiodense material or is of a radiodense configuration, so that it can be used to determine the position of the cannula 100 as the cannula 100 is threaded into the drill hole. While any radiodense material or configuration can be used to make the applicator 118 , suitable examples include using metal or barium. Any method know in the art for determining the position of a radiodense mass in a vertebral body can be used to determine the position of the applicator 118 in the target vertebral body.
Referring now to FIGS. 2 a and 2 b , a plunger 200 of the present invention is shown, with FIG. 2 a showing the plunger 200 alone and FIG. 2 b showing the cannula 100 engaged by the plunger 200 . The plunger 200 has an elongated cylindrical body 202 that fits tightly within the bore 104 of the cannula 100 so that it can be used to squeeze bone cement out the holes 110 in the distal end 108 of the cannula 100 as described in greater detail below. For example in the illustrated embodiment, the body 202 has a length of 80.0 mm and a diameter of 4.0 mm. Preferably, the body 202 is formed from a material that is softer than the biocompatible material from which the body 102 of the cannula 100 is formed. As described in greater detail below, this difference in material facilitates the drilling away of the plunger 200 after it is used to distribute the bone cement. Also preferably, the plunger 200 is formed from biocompatible material (e.g., poly methyl methacrylate), as some of the plunger 200 may remain after most of the plunger 200 has been drilled away, and the remaining portion would become incarcerated in the vertebral body. Also preferably, the body 202 has a central longitudinal axis and an internal guide wire 204 (such as, for example, a k wire) or guide rod passing through the central longitudinal axis. As described in greater detail below, this guide wire 204 also facilitates the drilling away of the plunger 202 .
A use of the invention will now be described with reference to FIGS. 3 a-f . As illustrated in FIG. 3 a , upon proper preparation of the target vertebral body or bodies in accordance with known and accepted surgical procedures, the surgeon drills a hole 302 in the target vertebral body 300 , typically using drill bits of increasing diameter (e.g., starting with a 2.5 mm diameter bit and ending with a 4.0 mm diameter bit, in preparation for tapping the hole with a 5.25 mm diameter tap).
Then, as illustrated in FIG. 3 b , the surgeon threads the hole 302 using a tap in a manner known in the art, establishing threads 308 on the walls of the hole 302 . Preferably, a plurality of taps are provided, so that the surgeon can choose from taps with, for example, 5.25 mm, 6.25 mm or 7.25 mm diameters, depending on the size of cannula that the surgeon is planning to use for a particular patient. (For many applications, the use of a tap that is 0.25 mm diameter smaller than the cannula to be used is preferred.) Typically, during the preparation of the tapped hole 302 , the surgeon will use a probe to determine the proper angulation and depth of the hole 302 . The surgeon repeats the above procedure for each hole 302 he plans to drill.
Next, as illustrated in FIG. 3 c , the surgeon inserts into the hole 302 a cannula 100 of the present invention, using an appropriately sized cannula applicator 118 of the present invention. The surgeon inserts the applicator 118 into the proximal end 106 of the cannula 100 and into the bore 104 of the cannula 100 , establishing a tight fit of the applicator 118 against the walls of the bore 104 . It should be noted that the applicator 118 may already be inserted into the bore 104 before the surgeon is provided with the cannula 100 , so that procedural steps to be made by the surgeon can be minimized. Once the applicator 118 is fitted into the bore 104 , the surgeon places the cannula 100 into the tapped hole 302 , and repeatedly turns the applicator 118 to rotate the cannula 100 so that the outer threads 114 of the cannula 100 engage the threads 308 of the hole 302 and the cannula 100 is twisted deeper into the hole 302 to the desired position (typically, all the way into the hole 302 ). The intimate fit of the applicator 118 against the walls of the bore 104 facilitates the rotation of the cannula 100 in response to the rotation of the applicator 118 . The structural integrity of the applicator 118 , in conjunction with the intimate fit of the applicator 118 in the bore 104 , provides structural support for the thin-walled cannula 100 as the cannula 100 is twisted into position. Inasmuch as the applicator 118 is preferably radiodense, the surgeon is able to assess the position of the cannula 100 in a manner known in the art as needed until he is satisfied that the cannula 100 has been placed in the desired position. For each drilled hole 302 , the surgeon places a cannula 100 of the present invention into the drilled hole 302 using an appropriately sized applicator 118 in accordance with the above procedure. The surgeon should leave each applicator 118 in place until it is time to inject the bone cement, as described below. This will keep bleeding to a minimum and will continue to make possible radiographic assessments of the position of each applicator 118 and accordingly each cannula 100 .
As illustrated in FIGS. 3 d-e , once each drilled hole 302 has been fitted with a cannula 100 of the present invention, the surgeon prepares the appropriate bone cement mixture 310 and loads one or more syringes 312 with the bone cement 310 , in a manner know in the art. Then, for each installed cannula 100 , one at a time, the surgeon removes the applicator 118 , injects an appropriate amount of the bone cement 310 into the bore 104 using the syringe(s) 312 , and applies a plunger 200 of the present invention to distribute the bone cement 310 through the holes 110 of the distal end 108 of the cannula 100 . FIG. 3 d illustrates the injection of the bone cement 310 into the cannula bore 104 . FIG. 3 e illustrates the distribution of the bone cement 310 using the plunger 200 . Typically, the appropriate amount of bone cement will be 1.5 cc to 2.0 cc of cement per hole. In order to effect this procedure for each cannula 100 , the surgeon first removes the applicator 118 from the cannula 100 by pulling it from the bore 104 . The engagement of the threads 114 of the cannula 100 with the threads 308 of the drilled hole 302 prevent the cannula 100 from also being removed. Next, the surgeon prepares the bone cement 310 , loads the syringe(s) 312 , and injects the bone cement 310 into the cannula bore 104 . Then, the surgeon inserts an appropriately sized plunger 200 of the present invention into the proximal end 106 of the cannula 100 and into the cannula bore 104 , pushing the plunger 200 down the bore 104 so that the bone cement 310 squeezes out the holes 110 at the distal end 108 of the cannula 100 and into the bone 314 surrounding the cannula 100 . The engagement of the outer threads 114 of the cannula 100 with the inner threads 308 of the drilled hole 302 limit the migration of bone cement 310 out of the drilled hole 302 during the distribution process. For each cannula 100 , the surgeon leaves the plunger 200 in until each plunger 200 has been applied and the bone cement 310 has set in the surrounding bone 314 . The setting of the bone cement 310 in the surrounding bone 314 strengthens the surrounding bone 314 in preparation for the next steps, which involve re-tapping the target vertebral body for a bone screw.
As illustrated in FIG. 3 f , once each plunger 200 has been applied and the distributed bone cement has set, the surgeon drills out each plunger 200 using a drill 316 and cannulated drill bit 318 . The surgeon selects a cannulated drill bit 318 having an appropriate outer diameter (preferably, the outer diameter of the drill bit 318 has the same diameter as the diameter of the cannula bore 104 which in the illustrated embodiment is 4.0 mm), sets the drill bit 318 into the drill 316 , passes the drill bit 318 over the guide wire 204 extending from the plunger 200 , and proceeds to drill into the plunger body 202 , following the guide wire 204 to ensure that only the plunger body 202 material (and in some applications part, e.g., 05.mm, of the cannula 100 ) is being drilled away. As noted above, the preferable softness of the plunger body 202 relative to the cannula body 102 facilitates the drilling away of primarily the plunger body 202 . The surgeon repeats this procedure for each installed cannula 100 .
Finally, the surgeon threads each hole that remains after each plunger 200 has been removed, using a tap in a manner known in the art. Typically, a tap having a diameter of 5.5 mm to 7.5 mm will be useful, preferably matching the diameter of the cannula 100 that has been used. A tap suitable for use in the illustrated embodiment would have a diameter of 6.5 mm. Once each new hole has been tapped, the surgeon can insert a bone screw of the surgeon's choice into each hole, and complete the operation.
While there has been described and illustrated specific embodiments of an intervertebral spacer device, it will be apparent to those skilled in the art that variations and modifications are possible without deviating from the broad spirit and principle of the present invention. The invention, therefore, shall not be limited to the specific embodiments discussed herein.
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A system and method for reinforcing bone in preparation for screw implantation. One system embodiment comprises a threaded and centrally bored cannula with a perforated distal end, a cannula applicator frictionally fitting within the central bore, a plunger translating within the central bore (the plunger having a internal longitudinal guide wire), bone cement, and a cannulated drill bit. One method embodiment comprises drilling and tapping a hole in a vertebral body, inserting the applicator into the central bore, screwing the cannula into the tapped hole by rotating the applicator, removing the applicator, injecting the bone cement into the central bore, distributing the bone cement out the holes in the distal end of the cannula and into the surrounding bone using the plunger, letting the bone cement harden, and drilling out the plunger using the cannulated drill following the guide wire.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Patent Application No. 10-2008-0067628, filed Jul. 11, 2008, entitled “METHOD FOR MANUFACTURING THE HYDRODYNAMICS BEARING”, which is hereby incorporated by reference in its entirety into this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a method of manufacturing a hydrodynamic bearing, and, more particularly, to a method of manufacturing a hydrodynamic bearing in which a metal bearing, which is prepared by sintering metal powder, is internally subjected to chemical etching, such as done by an electrochemical machining process or an etching process, to form hydrodynamic pressure grooves thereon, thus assuring a high-precision and reliable hydrodynamic bearing.
2. Description of the Related Art
The hydrodynamic bearing, which is intended to rotatably support a rotating shaft that is rotated by externally applied electric current, holds a predetermined type of fluid between the rotating shaft and the bearing. In order to assure the smooth rotation of the rotating shaft, fine hydrodynamic pressure grooves, which perform a hydrodynamic pumping action of the fluid, are provided between either the rotating shaft or the hydrodynamic bearing.
An example of the methods of manufacturing such a hydrodynamic bearing is disclosed in Japanese Unexamined Patent Publication No. 2006-316896, which is schematically illustrated in FIGS. 9 and 10 .
As shown in FIG. 9 , the conventional method of manufacturing a hydrodynamic bearing is conducted in such a manner that metal powder M, which is a raw material of a shaft-supporting sleeve, is compressed between an upper punch 14 and a lower punch 13 which are forcedly moved toward each other, and the resulting compressed body Ma is sintered at a predetermined temperature, resulting in a sintered bearing body 15 .
Subsequently, as shown in FIG. 10 , in order to form hydrodynamic grooves on the internal surface of the sintered body 15 , the sintered body 15 is put into a press die 16 , and a core rod 17 , having thereon protrusions corresponding to the desired hydrodynamic grooves, is inserted into the internal space of the sintered body 15 . Thereafter, the external surface of the sintered body 15 is pressed using the press die 16 , with the result that the internal surface of the sintered body 15 is formed with the hydrodynamic grooves.
The core rod 17 is separated from the sintered body 15 , and then the sintered body 15 is separated from the press die 16 , thus producing a desired shaft-supporting sleeve.
However, in the above conventional method of manufacturing a shaft-supporting sleeve, when the core rod 17 is separated from the sintered body 15 , the hydrodynamic grooves of the sintered body may be damaged due to the protrusions of the external surface of the core rod 17 , thus causing uneven hydrodynamic pressure to occur.
Furthermore, since the sintered body 15 must be made of metal powder having a spring back behavior, the raw material of the sintered body 15 is inevitably selected from restricted kinds of materials.
In addition, since the hydrodynamic grooves are formed by pressing the sintered body 15 after the compression and sintering processes of the metal powder M, the compressed structure of the sintered body 15 is not dense, thus deteriorating the durability of the sintered body 15 .
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and the present invention provides a method of manufacturing a hydrodynamic bearing, which is conducted in such a manner that a bearing is prepared by compressing and sintering metal powder at high pressure and temperature, and the bearing is subjected to an electrochemical machining process or an etching process to form hydrodynamic grooves on the internal surface of the bearing, thus providing a hydrodynamic bearing having durability and accuracy superior to those made by conventional methods.
In one aspect, the present invention provides a method of manufacturing a hydrodynamic bearing having an internal space and configured to exert hydrodynamic pressure between fluid and the bearing, including: compressing metal powder that is a raw material of the bearing in a press unit, and sintering the compressed metal powder at a predetermined temperature, thus preparing a sintered bearing; removing foreign substances adhering to the sintered bearing through a deburring process, and pressing the sintered bearing into a desired shape; forming a hydrodynamic groove, configured to generate hydrodynamic pressure, on an internal surface of the shaped bearing using chemical etching; and conducting a post treatment of cleaning the bearing including the hydrodynamic grooves thereon and drying the bearing.
In this method, forming the hydrodynamic groove may be conducted using electrochemical machining (EXM) in a manner that an electrode tool, having an electrode portion corresponding to the hydrodynamic groove, is inserted into the internal space of the shaped bearing, positive current is applied to the shaped bearing while negative current is applied to the electrode tool, and flowing electrolyte between the shaped bearing and the electrode tool.
The electrode tool may be covered with nonconductive insulating layer at a separate portion other than the electrode portion.
In forming the hydrodynamic groove, the shaped bearing may be covered with photoresist at an entire area other than an area at which the hydrodynamic groove is to be formed, and thus the area, at which the hydrodynamic groove is to be formed, is chemically etched.
The photoresist may be positive photoresist that is cured due to exposure to ultraviolet rays.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic flowchart showing a method of manufacturing a hydrodynamic bearing, according to a first embodiment of the present invention;
FIG. 2 is a schematic cross-sectional view showing compression and sintering processes in the method shown in FIG. 1 ;
FIG. 3 is a schematic cross-sectional view showing electrochemical machining of a bearing using an electrode tool, according to the first embodiment of the present invention;
FIG. 4 is a schematic flowchart showing a method of manufacturing a hydrodynamic bearing, according to a second embodiment of the present invention;
FIG. 5 is a schematic cross-sectional view showing compression and sintering processes in the method shown in FIG. 4 ;
FIGS. 6 to 8 are cross-sectional views showing a process of forming hydrodynamic grooves on a bearing using etching, according to the second embodiment of the present invention; and
FIGS. 9 and 10 are schematic cross-sectional views showing a conventional process of manufacturing a hydrodynamic bearing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, embodiments of the present invention will be described in greater detail with reference to the accompanying drawings.
As shown in FIG. 1 , a method of manufacturing a hydrodynamic bearing, according to a first embodiment of the present invention comprises a process (S 110 ) of compressing and sintering metal powder, a process (S 120 ) of shaping the sintered material, a process (S 130 ) of electrochemical machining the shaped material, and a process (S 140 ) of post treatment. The respective processes of the method according to an embodiment of the present invention will now be described with reference to FIGS. 2 and 3 .
As shown in FIG. 2 , metal powder 10 a is compressed and sintered to prepare a bearing 10 of a hydrodynamic bearing.
The metal powder 10 a , which is used in the formation of the bearing 10 , may be essentially composed of copper powder, copper alloy powder or a mixture of copper powder and iron powder, and may have an optional lubricant powder additive such as a stearin additive.
For the compression and molding of the metal powder 10 a , metal powder 10 a is loaded into a hollow space of a press unit 20 which is a combination of an upper press part 21 and a lower press part 22 , and the metal powder 10 a is compressed at a predetermined pressure using the upper press part 21 . Thereafter, the metal powder 10 a is sintered at a proper sintering temperature, thus preparing a sintered bearing 10 .
Subsequently, a shaping process of removing unnecessary portions of the bearing 10 , thus tailoring the bearing to a desired size, is performed. If required, the shaping process may be repeatedly conducted.
Thereafter, a deburring process is conducted in which unwanted portions, such as burrs which may be formed on external and internal surfaces of the sintered bearing 10 , are eliminated using a deburring device. The bearing 10 is fitted in a predetermined mold, and then a predetermined pressure and stroke are applied to the bearing 10 for the process of shaping the bearing 10 . At this point, the diameter of the external surface and the total height of the bearing 10 may be calibrated to the desired dimensions.
In consideration of frictional and cooling properties of the bearing, the shaping process may be conducted after the bearing 10 is dipped into shaping oil. In the case of dipping the bearing into shaping oil, an additional process of clearing away the shaping oil from the bearing 10 using an organic cleaning agent may be required. In the organic cleaning process, an ultrasonic organic cleaning, which is capable of completely removing the shaping oil from the bearing 10 by continuous application of ultrasonic waves to the bearing 10 , may be employed.
After the organic cleaning, in order to eliminate the organic cleaning agent from the bearing 10 , the bearing 10 is put into a separate oven and is sufficiently heated and dried at a temperature of 60° C. or higher for a period of one hour (S 120 ).
Subsequently, as shown in FIG. 3 , the bearing 10 is subjected to an electrochemical machining (ECM) process, which is a kind of chemical etching processes, in order to form hydrodynamic grooves 11 on the external surface of the bearing 10 .
The electrochemical machining (ECM) refers to an etching process of removing a metal oxide which results from electrochemical dissolution of a metal workpiece, thus forming fine grooves on the metal workpiece. More specifically, in order to form fine hydrodynamic grooves 11 at predetermined locations on the bearing 10 , a positive current is applied to the bearing 10 while a negative current is applied to an electrode tool which is provided with a conductive pattern corresponding to the hydrodynamic grooves 11 . Under these conditions, electrolyte is forced to flow between the bearing 10 and the electrode tool 30 , thus forming the hydrodynamic grooves 11 .
In this embodiment, the electrode tool 30 comprises an electrode matrix 31 to which the negative current is applied, and a nonconductive insulating layer 32 surrounding the electrode matrix 31 and having grooves corresponding to the hydrodynamic grooves 11 . In other words, the electrochemical machining does not affect the region of the electrode tool 30 covered with the nonconductive insulating layer 32 but affects only the region of the electrode tool 30 which is exposed through the grooves of the nonconductive insulating layer 32 (S 130 ).
Finally, the bearing 10 , which includes the hydrodynamic grooves 11 formed thereon, is subjected to a post treatment process. In the post treatment process (S 140 ), various successive processes are sequentially conducted, which include a cleaning process of removing electrolyte adhering to the bearing 10 , an antirust process to prevent corrosion of the bearing 10 using antirust agent, a water washing process of removing electrolyte and other substances remaining on the surface of the bearing 10 using water, a vacuum drying process of removing moisture and oil remaining in pores of the bearing 10 by subjecting the bearing to vacuum drying at a temperature of 80° C. or higher, an organic cleaning process of clearing away oil and the like exuding from the surface of the bearing 10 using organic cleaning agent, and a drying process of removing the organic cleaning agent by drying the bearing 10 at a temperature of 60° C. or higher (S 140 ).
As described above, since the method according to this embodiment of the present invention is conducted in such a manner that the bearing is sintered and then the sintered bearing 10 is subjected to the electrochemical machining to form hydrodynamic grooves 11 on the bearing 10 , the method can enhance the durability of the bearing 10 itself and can prevent the breakdown of the hydrodynamic grooves 11 .
As shown in FIG. 4 , a method of manufacturing a hydrodynamic bearing, according to a second embodiment of the present invention comprises a process (S 210 ) of compressing and sintering metal powder, a process (S 220 ) of shaping the sintered material, a process (S 230 ) of etching the shaped material, and a process (S 240 ) of post treatment. The respective processes of the method according to a second embodiment of the present invention will now be described with reference to FIGS. 5 to 8 .
As shown in FIG. 5 , metal powder 10 a is compressed and sintered to prepare a bearing 10 of a hydrodynamic bearing.
The metal powder 10 a , which is used in the formation of the bearing 10 , may be essentially composed of copper powder, copper alloy powder or a mixture of copper powder and iron powder, and lubricant powder such as a stearin additive may be optionally added thereto.
For the compression and molding of the metal powder 10 a , metal powder 10 a is loaded into a hollow space of a press unit 20 which is a combination of an upper press part 21 and a lower press part 22 , and the metal powder 10 a is compressed at a predetermined pressure using the upper press part 21 . Thereafter, the metal powder 10 a is sintered at a proper sintering temperature, thus preparing a sintered bearing 10 .
Subsequently, a shaping process of removing unnecessary portions of the bearing 10 , thus tailoring the bearing to a desired size, is conducted. The shaping process may be repeatedly conducted, if required.
Thereafter, a deburring process is conducted in which unwanted portions, such as burrs, which may be formed on external and internal surfaces of the sintered bearing 10 , are eliminated using a deburring device. The bearing 10 is fitted in a predetermined mold, and then a predetermined pressure and stroke are applied to the bearing 10 for the shaping of the bearing 10 . At this point, the diameter of the external surface and the total height of the bearing 10 may be calibrated to the desired dimensions.
In consideration of frictional and cooling properties of the bearing, the shaping process may be conducted after the bearing 10 is dipped into shaping oil. In the case of dipping the bearing into shaping oil, an additional process of clearing away the shaping oil from the bearing 10 using organic cleaning agent may be required. In the organic cleaning process, an ultrasonic organic cleaning, which is capable of completely removing the shaping oil from the bearing 10 by continuously applying ultrasonic waves to the bearing 10 , may be employed.
After the organic cleaning, in order to eliminate the organic cleaning agent from the bearing 10 , the bearing 10 is put into a separate oven and is sufficiently heated and dried at a temperature of 60° C. or higher for a period of one hour (S 120 ).
Subsequently, as shown in FIGS. 6 to 8 , the bearing 10 is subjected to an etching process, which is a kind of chemical etching processes, in order to form hydrodynamic grooves 11 on the external surface of the bearing 10 .
The etching process refers to an etching process of removing a metal oxide which results from electrochemical dissolution of a metal workpiece, thus forming fine grooves on the metal workpiece. More specifically, in order to form fine hydrodynamic grooves 11 at predetermined locations on the bearing 10 , the bearing is covered with photoresist or a dry film 40 such that regions of the bearing 10 , at which the fine hydrodynamic grooves 11 are formed later, are exposed. The regions of the bearing 10 , at which the hydrodynamic grooves 11 are formed, are etched using etchant.
As shown in FIG. 6 , photoresist is applied to the bearing 10 such that the bearing 10 is completely covered with the photoresist 40 . In this embodiment, the photoresist 40 may be positive photoresist which is cured by exposure to ultraviolet rays. Prior to the exposure to ultraviolet rays, in order to remove the regions of the photoresist 40 , which correspond to the hydrodynamic grooves 11 on the internal surface of the bearing 10 , a masking member 50 is inserted into the internal space of the bearing 10 such that the regions of the photoresist 40 which correspond to the hydrodynamic grooves 11 are not exposed to ultraviolet rays. More specifically, the masking member 50 is configured such that the regions of the masking member 50 , corresponding to the hydrodynamic grooves 11 , remain uncut so as not to allow the regions of the photoresist 40 corresponding to the hydrodynamic grooves 11 to be cured by the exposure to ultraviolet rays whereas the other regions of the masking member 50 are cut away so as to allow the other regions of the photoresist 40 to be exposed to the ultraviolet rays.
As shown in FIG. 7 , after the photoresist 40 is exposed to ultraviolet rays and is thus cured, the regions of the photoresist 40 , corresponding to the hydrodynamic grooves 11 , i.e., the uncured regions of the photoresist 40 are removed, and the entire bearing 10 is completely immersed into etching solution 60 , with the result that the hydrodynamic grooves 11 are formed on the bearing 10 . Subsequently, as shown in FIG. 8 , the bearing 10 , which includes the hydrodynamic grooves 11 formed on the internal surface thereof, is pulled out of the etching solution 60 , and then the photoresist 40 surrounding the entire bearing 10 is removed from the bearing (S 230 ).
Finally, the bearing 10 , which is formed with the hydrodynamic grooves 11 , is subjected to the post treatment. In the post treatment, various successive processes are sequentially conducted, which include a cleaning process of removing electrolyte adhering to the bearing 10 , an antirust process to prevent corrosion of the bearing 10 using antirust agent, a water washing process of removing electrolyte and other substances remaining on the surface of the bearing 10 using water, a vacuum drying process of removing moisture and oil remaining in pores of the bearing 10 by subjecting the bearing to vacuum drying at a temperature of 80° C. or higher, an organic cleaning process of clearing away oil and the like exuding from the surface of the bearing 10 using organic cleaning agent, and a drying process of removing the organic cleaning agent by drying the bearing 10 at a temperature of 60° C. or higher (S 240 ).
As described above, since the method according to this embodiment of the present invention is conducted in such a manner that the bearing is sintered and then the sintered bearing 10 is subjected to the etching to form hydrodynamic grooves 11 on the bearing 10 , the method can enhance the durability of the bearing 10 itself and can prevent the breakage of the hydrodynamic grooves 11 .
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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Disclosed herein is a method of manufacturing a hydrodynamic bearing in which a metal bearing made of sintered metal powder is internally subjected to chemical etching, to form hydrodynamic pressure grooves thereon, thus assuring a high-precision and reliable hydrodynamic bearing. The method includes: compressing metal powder that is a raw material of the bearing in a press unit, and sintering the compressed metal powder at a predetermined temperature, thus preparing a sintered bearing; removing foreign substances adhering to the sintered bearing through a deburring process, and pressing the sintered bearing into a desired shape; forming a hydrodynamic groove, configured to generate hydrodynamic pressure, on an internal surface of the shaped bearing using chemical etching; and conducting a post treatment of cleaning the bearing including the hydrodynamic grooves thereon and drying the bearing.
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CROSS -REFERENCE TO RELATED APPLICATIONS
[0001] Related Patents have attorney docket numbers wakelley01, wakelley02, and wakelley03, wakelley04 and are listed below as Patent A, Patent B, Patent C and Patent D, respectively.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] This patent is not federally sponsored.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] Many processes require a fluid make a transition from gaseous state to liquid and back, or from liquid to gaseous state and back. These include chemical separation, compression, water purification, and power generation. This is an energy intensive process, as simple methods for boiling and condensing both take large amounts of energy. However, the initial state (temperature) and final state of the fluid's are generally the same, or can be. A mechanism capable of boiling a fluid, then saving the energy by boiling a second fluid while liquefying the first allows the same energy to be used to gasify, liquefy, then gasify, or liquefy, gasify, and liquefy, is theoretically possible, as long as the energy quantities are matched.
[0005] Related Patents have attorney docket numbers wakelley01, wakelley02, and wakelley03, wakelley04 and are listed below as Patent A, Patent B, Patent C and Patent D, respectively.
BRIEF SUMMARY OF THE INVENTION
[0006] Two devices are disclosed with similar purpose. One handles discrete quantities of fluid, the other handles continuous flow. Patent A, Patent B, Patent C, and Patent D in combination, can liquefy then gasify the outflow of a steam generator. The systems as is will recycle most of the water and heat. The devices described here use the same principles, but are specifically designed to be able to run as a closed system. This would meet a zero emission requirement. It would also allow steam generation plant to be operated economically in regions where water is scarce. A second class of devices is introduced, with the ability to cycle discrete quantities, and also can run as a fully enclosable system. An example application would be power generation from heated oil or liquid salts from a solar collection plant located in a desert. It could eliminate the need to pipe the heated fluid, as well as reduce the danger exposed when piping extremely hot materials.
[0007] Both devices are capable of cycling a fluid to and from gas state with a hot reservoir, or to and from liquid state with a cold reservoir. In addition, a small heat pump is included which can restore precise beginning conditions of the cold or hot reservoir.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0008] FIG. 1 shows a diagram of a discrete liquefier and gasifier. This device uses 2 paired liquid and vapor chambers, each with opposing pistons, and a 5th expanded vapor chamber.
# 1 Coupling rod for opposing pistons. # 2 d Reservoir Liquid piston, down position. (Full liquid reservoir) # 2 u Reservoir Liquid piston, up position (Empty liquid reservoir). # 3 d Target liquid storage, down position (full). # 3 u Target liquid storage, up position (empty). # 4 d Reservoir Vapor storage, down, emptiest position. Vapor chambers must be larger than liquid chambers. Forces still balance due to identical piston area for vapor and liquid. # 4 u Reservoir Vapor storage, up position, reservoir fully converted to vapor. # 5 d Target Vapor compressed storage, down position, target fluid being liquefied or fully liquefied. # 5 u Target Vapor compressed storage, up position, Target fluid fully vaporized and compressed. # 6 d Simple valve to select between uncompressed vapor storage and compressed vapor storage. # 6 u Simple valve, opposite position. # 7 Heat exchanger insulated container. # 8 Heat exchanger, counter flow heat exchanger, such as low cost counter flow heat exchanger from Patent A. Sized for material, temperature range and flow rate ideally 90+% transference # 9 Target Fluid compressed vapor storage, a cylinder sealed by a piston. # 10 Reservoir Vapor storage, a cylinder sealed by a piston. # 11 Target Liquid Storage, a cylinder sealed by a piston. # 12 Reservoir Liquid Storage, a cylinder sealed by a piston. # 13 All connecting tubing—insulated, temperature and pressure rated for materials in use. # 14 Uncompressed Target Vapor Storage, a large cylinder sealed by a piston. # 15 Uncompressed Target Vapor piston.
[0029] FIG. 2 shows same view as FIG. 1 , with movable components in opposite positions. Annotated parts are the moving parts. Redundant annotations omitted for clarity.
[0030] FIG. 3 and FIG. 4 , Perspective views of same device.
[0031] FIG. 5 and FIG. 6 , Perspective views of same device, movable parts in opposite positions.
[0032] FIG. 7 shows magnified view of heat exchanger managing the vapor to liquid transitions. By controlling the Fluid Levels, the direction of heat flow, which fluid is liquefied and which gasified are also controlled.
# 1 Low Fluid Level for gas being liquefied. # 2 High Fluid Level for liquid being gasified # 3 Vapor (gas) counter flow heat exchange # 4 Liquid counter flow heat exchange # 5 Liquefaction/gasification counter flow region
[0038] FIG. 8 shows the basic block diagram of a continuous flow liquefy/gasify cycle. The diagram has Thermal Pressure Multiplier, Low Cost Counter Flow Heat Exchangers, and Fluid Pressure Ladder and Steam Generation cycle of Patents A, B, C, and D.
# 1 Shows Low Cost Counter Flow Heat Exchanger, linked with # 2 a 2 or more stage Fluid Pressure Ladder, to create a Thermal Pressure Multiplier. # 3 liquid Reservoir # 4 Boiler or Heat addition # 5 Turbine/generator # 6 Path for heat pump to make enclosable # 7 Path for excess heat if enclosability not required # 8 Fluid paths coupling heat exchangers and pressure ladder
DETAILED DESCRIPTION OF THE INVENTION
[0047] Both devices are based on a combination of counter flow heat exchangers (Patent A) and reservoirs of heat or cold. (Technically a cold reservoir is more accurately described as having less heat).
[0048] The fluids should be matched in thermal capacity. With the same type of material in both chambers, this simply means an equal mass of fluid. It would simplify the system to have a reservoir that remains in liquid state, if a material is available that is liquid over the required temperature range.
[0049] If liquid is to be cycled to gas and back to liquid, a hot fluid reservoir is required.
[0050] If a gas (vapor) is to be cycled to liquid and back to gas, a cold fluid reservoir is required.
[0051] In either case, optimal efficiency will be when the reservoir temperatures are just above or just below the boiling point.
[0052] The reservoir temperature is independent of the temperature of the fluid to have phase changed. It simply must have enough heat or cold capacity to supply or exhaust the heat of the incoming fluid, and change of state.
[0053] Ideally the incoming liquid or vapor will also be near the boiling point.
[0054] Each reservoir has a piston to facilitate movement of the fluid. The piston is coupled to a second empty storage chamber, in a manner that pressure in each storage chambers are in balanced opposition.
[0055] A similar reverse arrangement is made on the incoming fluid side.
[0056] Typical fluids may be 100 to 1000 times denser than their vapor at STP. To avoid extreme pressures, the gas storage chamber must be larger than the liquid. For example, if the density multiple of a liquid to its vapor is about 600, a gas chamber three times the size of the liquid chamber would yield a density of 200× density at STP.
[0057] Opposing pistons make fluid movement force independent of pressure. The vapor reservoirs must be larger in volume than the liquid reservoirs, but the area of the pistons must be the same, to equalize force. The reaction is begun by filling one side of counter flow heat exchanger with liquid and the other with vapor. Piston positions determine flow and direction of state exchange. If compression is required, a 5th, larger chamber of vapor will hold initial uncompressed target vapor. A simple valve switches connection of the target side of counter floe heat exchanger between the large uncompressed chamber and the small compressed target chamber.
[0058] Pressure in the system depends on temperature for all gases (vapors). Consider an application which first drops vapor temperature to 90 degrees, with a boiling point of 75. The cold liquid reservoir must be 60 degrees or colder to insure complete phase change.
[0059] Phase change is achieved via controlled flow on each side through the heat exchanger in opposite directions. The heat exchanger should be oriented vertically, liquid phases at bottom.
[0060] It is sufficient to insure complete phase change if the fluid being liquefied is not allowed to rise into the heat exchanger, but moved at a speed to keep liquid phase level at the bottom end of the heat exchanger, and to insure the liquid level of the other fluid being gasified, is maintained near the top of the heat exchanger. This insures heat flow from gas phase to liquid phase throughout the heat exchanger.
[0061] Completion of the level monitoring phase is done when target fluid is completely phase changed.
[0062] At this point, the expected benefit has occurred or will occur on the opposite phase change. Reverse phase change can begin immediately.
[0063] Reverse phase change requires flow directions from storage chambers of each fluid is reversed. The level monitoring control is the same, but liquid levels are reversed between target and reservoir sides.
[0064] At this point the benefit has been realized.
[0065] Benefits might include a) drastic reduction of a gas's (vapor's) volume without doing work of compression, separation of a mixed vapor into its components by boiling point, removal of contaminants from a liquid (e.g. distilled water).
[0066] The last step is to restore initial reservoir temperature, which will have moved toward the boiling point. Counter flow heat exchangers can approach 100% but not achieve it. To the extent heat was incompletely switched between the fluids, the heat reservoir temperature needs to be adjusted.
[0067] The hot reservoir can be adjusted by pumping heat from the liquid outflow into the hot reservoir. This is a very small adjustment relative to the energy of vaporization or condensation. Ideal setup will have intake and outtake as near boiling point as possible.
[0068] Adjusting the cold reservoir uses the same strategy, but instead pumps from the cold liquid reservoir into the hot fluid vapor outflow. Again, temperature differences will be small, so heat pump has a small amount of energy to move, compared to heat of Vaporization.
[0069] After operation of the heat pump, vapor based or thermoelectric device, the system is restored to its initial state and ready for the cycle to repeat.
[0070] A continuous flow system requires two sets of discrete devices operated on opposite phases, or the components of Patent A, Patent B, Patent C and Patent D connected as a Counter Flow Heat Exchanger coupled to a Fluid Pressure Ladder to make a Thermal Pressure Multiplier ( FIG. 8 ). Previous Patent disclosures did not describe creation of enclosable fluid envelope or fully enclosable, including heat flow.
[0071] To make a closed fluid system, fluid tight connection must be made between all components, such as Turbine and Heat Exchanger's intake, and Heat Exchanger's outtake and the reservoir, and the Reservoir must be enclosed as well. This is sufficient for enclosed fluid system, but also requires temperatures remain stable, within an operating range.
[0072] For a Vapor to Liquid to Vapor system, the necessary component to run fully encapsulated is to add a second Heat Pump connecting the reservoir to the pre-heated (by recycled heat) fluid. Since the middle of the temperature gap will include a phase change, this is actually a very small temperature rise. The Heat Pump does not need to be 100% efficient, as any added energy will end up in the pre-heated fluid, pre-heating it further.
[0073] For a Liquid to Vapor to Liquid system, the same can be done by pumping heat from a liquid outtake into a hot vapor reservoir. Again, heat pump inefficiency is also pumped to the hot Reservoirs, where the energy is desired. (So no energy is lost).
[0074] For a closed Vapor system, such as a steam generator, it may be more convenient to use ambient air to stabilize (cool) the reservoir temperature. This would reduce energy efficiency by the amount of heat lost, but would be a cheaper and much simpler system, requiring no heat pump.
[0075] Operation of continuous flow system requires only equal inflow and outflow, a rate allowing heat to be nearly completely transferred, and a series of heat exchangers sufficient to perform complete temperature exchange.
[0076] Operation of the discrete quantity device is by fluid level. The liquid fluid level is risen by lifting that dual piston until fluid is at the desired point in the vertically oriented counter flow heat exchanger. The fluid level on the gas side is similarly maintained at a physically lower point in the counter flower, by moving dual pistons down. In the case of liquefying a large volume, the pressure the gas is normally under keeps the counter flow heat exchanger filled with vapor exposed to temperatures which will cause condensation. It will take some time to condense enough fluid to reach the desired fluid level. As the vapor liquefies, the pressure drops to near zero, or volume drops to near zero under constant pressure.
[0077] Energy used by the system is 1) sufficient energy for movement of the mass of the fluids and friction and 2) sufficient to power a small heat pump to stabilize the Reservoir Temperature. Thermoelectric devices are ideal for the heat pump device. The much larger heat energy of vaporization (and energy given by condensation) are conserved and reused.
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Disclosed are two related devices which can convert gas to and from liquid, or liquid to and from gas, with no expenditure of energy for heat of vaporization or for condensation. One device is designed for discrete units of fluid, the other for continuous flow. Both devices can be made fully enclosable. Both devices can compress an uncompressed vapor an arbitrary amount without additional energy. Applications include chemical separation, vapor compression, water purification, heat engines and power generation.
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BACKGROUND
[0001] It is well known to use, for producing oxygen with low energy, a double air separation column which is applied, in particular, on the one hand, so as to minimize the delivery pressure of the air compressor, by reducing the head losses in the exchanger and reducing the temperature difference at the main vaporizer, and, on the other hand, to maximize the oxygen extraction efficiency, by reducing the temperature difference in the exchanger, by choosing a high number of theoretical distillation trays and by installing a sufficient number of sections of structured packings or trays.
[0002] Thus, low-pressure columns have four sections of structured packings or trays, including two sections between the bottom of the low-pressure column and an intake for rich liquid, this being an oxygen-enriched liquid taken from the bottom of the medium-pressure column. These two sections are necessary for providing high-performance distillation in the bottom of the low-pressure column. Thus also, the medium-pressure columns have four sections of structured packings or of trays, including two sections between the liquid air intake and the point of withdrawal of lean liquid.
[0003] The exchanger of an air separation unit is normally composed of an exchange body assembly or of several body subassemblies.
[0004] An exchange body assembly comprises an even number of exchange bodies, each of which is fed with the same fluids to be cooled and the same fluids to be warmed. The fluid feed is made via a common header line for each different fluid (different composition and/or pressure), as illustrated in FIGS. 1-3 of “ The Standards of the Brazed Aluminum Plate - Fin Heat Exchanger Manufacturers ' Association”, 2nd Edition, 2000.
[0005] Since the maximum number of bodies that can be fed via a single header line is 12 (i.e. 6 pairs of exchange bodies), it is often necessary for large-capacity units to use several exchange body subassemblies, each subassembly comprising an even number of exchange bodies and the bodies of each subassembly being fed via a common header line for each different fluid. Thus, an exchanger composed of two exchange body subassemblies will comprise a first delivery line sending air to be cooled to the first subassembly and a second delivery line sending air to be cooled to the second subassembly. Likewise, it will comprise a first header line recovering the cooled air from the first subassembly and a second header line recovering the cooled air from the second subassembly.
[0006] The purified and compressed air sent to the columns cools in an exchanger comprising a single body assembly which would normally have a volume of more than 200 m 3 , and therefore with a ratio of the total air volume sent to the exchanger to the volume of the exchanger that would be approximately 2,000 Nm 3 h/m 3 in the case of the example described below.
[0007] The refrigeration required for the distillation is frequently provided by an air stream sent to a blowing turbine that feeds the low-pressure column and/or an air stream sent to a Claude turbine. The ratio of the quantity of air sent to the exchanger to the volume sent to the blowing turbine would normally be between 5/1 and 15/1 in the case of the example described below.
[0008] In certain cases when energy is not expensive, or even free, it is profitable to reduce expenditure on equipment, while increasing energy requirements.
[0009] In a process for separating air by cryogenic distillation known from WO 03/033978 using an apparatus comprising a medium-pressure column and a low-pressure column that are thermally coupled, a quantity of compressed and purified air V is cooled in an exchange line down to a cryogenic temperature and is sent at least partly to the medium-pressure column, oxygen-enriched and nitrogen-enriched streams are sent from the medium-pressure column to the low-pressure column and nitrogen-enriched and oxygen-enriched streams are withdrawn from the low-pressure column, the medium-pressure column operating between 6 and 9 bar absolute and the ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger being between 3,000 and 6,000 Nm 3 /h/m 3 .
[0010] With a ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger of less than 6,000 Nm 3 /h/m 3 , and by considering an air separation unit having a volumetric flow rate of air of about 570,000 Nm 3 /h, the total volume of the exchanger is about 110 m 3 with an exchanger composed of at least 14 exchange bodies, the maximum volume of an exchange body being about 8 m 3 .
[0011] As regards questions about the uniform distribution of the streams between the various exchanger bodies, the prior art dictates two exchange body subassemblies, a first subassembly of which comprising 8 exchanger bodies grouped together in four pairs and a second subassembly of which comprising six exchanger bodies grouped together in three pairs. It is not conceivable to install a single assembly of 14 exchanger bodies (the distribution of the streams will not be uniform because of the long distances that exist in this case between the bodies, and the performance of the air separation unit will be affected).
[0012] With a ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger of about 7,000 Nm 3 /h/m 3 , and considering an air separation unit having a volumetric flow rate of air of about 570,000 Nm 3 /h, the total volume of the exchanger is about 80 m 3 with a single exchange body assembly that is composed of 10 exchanger bodies, the maximum volume of an exchange body being about 8 m 3 . In this case, the uniform distribution of the streams between the various exchanger bodies is achieved favorably with a single exchange body assembly, so that there is only a single common delivery or header line for each fluid fed into or coming from the 10 bodies.
[0013] Likewise, for an air separation unit having a volumetric flow rate of air of about 475,000 Nm 3 /h, owing to the low cost of the energy or to the amount of energy available, the investment cost will be minimized by installing an exchange line composed of a single assembly of exchanger bodies (8 bodies) and the volume of which will correspond to a ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger of about 7,400 Nm 3 /h/m 3 .
[0014] Moreover, increasing the ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger ought to result, according to the prior art, in an increase in the head losses in the exchanger for all the streams of the exchanger (waste nitrogen stream, air streams, oxygen stream, etc.), especially because of the increase in the flow rate due to the reduction in flow area.
[0015] However, for ratios of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger greater than 6,000 Nm 3 /h/m 3 , the head losses on the oxygen stream will not be increased but will be constant at a limiting value corresponding to a usually acceptable design with regard to an oxygen stream. To keep the oxygen stream rate constant while reducing the volume of the exchanger is generally possible only by keeping a constant flow area for each body of the exchanger, and therefore keeping the total number of passages of the exchanger with regard to the oxygen stream constant, which results in an increase in the number of oxygen passages in each body of the exchanger (since the number of bodies of the exchanger is reduced). Consequently, the head losses on the other streams will therefore increase more than what is obtained by the simple ratio of the number of bodies.
[0016] However, in particular in the case of liquid oxygen passages in which the liquid has to vaporize, a variable flow area, or an increase in the flow area, may be provided.
[0017] Typically, the head losses with regard to the oxygen stream will not exceed 400 mbar and the flow area with regard to the oxygen stream will not exceed 20 to 25 Nm 3 /h/cm 2 . The flow area corresponds either to the constant cross section or to the cross section at the point where the liquid vaporizes, for the case of a liquid stream.
[0018] The oxygen stream comprises at least 30 mol % oxygen, preferably at least 70 mol % oxygen, and even more preferably at least 90 mol % oxygen, and may be in gaseous or liquid form at the inlet of the exchanger.
SUMMARY
[0019] It is an object of the present invention to reduce the investment cost of an air separation installation and to increase its energy by reducing the size of the exchangers (and therefore increasing the head losses and the temperature differences in the exchanger, and increasing the temperature difference at the main vaporizer), by reducing the size of the distillation columns (by minimizing the number of theoretical trays and the number of sections of packings or trays).
[0020] The quantity of air V sent to the exchanger comprises all the air sent to the distillation unit and the possible streams of air that are expanded and then vented to atmosphere.
[0021] A section of structured packings is a section of structured packings between a fluid inlet and the adjacent inlet or outlet.
[0022] The structured packings are typically of the cross-corrugated type, but they may have other geometries. They may be perforated and/or partially staggered.
[0023] The subject of the present invention is a process for separating air by cryogenic distillation using an apparatus comprising a medium-pressure column and a low-pressure column that are thermally coupled, in which a quantity of compressed and purified air V is cooled in an exchanger down to a cryogenic temperature and is sent at least partly to the medium-pressure column, oxygen-enriched and nitrogen-enriched streams are sent from the medium-pressure column to the low-pressure column and nitrogen-enriched and oxygen-enriched streams are withdrawn from the low-pressure column, characterized in that the ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger is greater than 3,000 Nm 3 /h/m 3 and preferably between 3,000 and 10,000 Nm 3 /h/m 3 and in that the ratio of the oxygen stream leaving the exchanger to the total flow area of the passages of the exchanger that are reserved for this oxygen stream is less than 25 Nm 3 /h/cm 2 .
[0024] Preferably, the ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger is greater than 6,000 Nm 3 /h/m 3 and preferably between 6,500 and 10,000 Nm 3 /h/m 3 .
[0025] According to other optional aspects:
the ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger is between 6,500 and 10,000 Nm 3 /h/m 3 ; the ratio of the volumetric flow rate of air V entering the exchanger to the total volume of the exchanger is between 7,000 and 10,000 Nm 3 /h/m 3 ; the maximum temperature difference at the cold end of the exchanger is 10° C.; the maximum temperature difference at the warm end of the exchanger is 10° C.; the maximum temperature difference at the start of liquid oxygen vaporization in the exchanger is 3° C.; the maximum temperature difference at the end of liquid oxygen vaporization in the exchanger is 14° C.; an oxygen-enriched liquid is sent from the low-pressure column to a sump reboiler where it partially vaporizes by heat exchange with a nitrogen-enriched gas coming from the medium-pressure column, the reboiler having a ΔT of at least 2.5 K; a portion of the compressed and purified air is sent into a blowing turbine, having an inlet temperature of between −50 and −140° C., preferably between −100 and −130° C.; the ratio of the quantity of air V to the volume of air sent to the blowing turbine is less than 40 and preferably between 5 and 25; at least one liquid stream is withdrawn from a column, optionally pressurized and vaporized in the exchanger; the medium-pressure column operates at between 6.5 and 8.5 bar absolute; the head losses in the exchanger are greater than 200 mbar for a waste nitrogen stream coming from the low-pressure column; the head losses in the exchanger are greater than 250 mbar for the lower-pressure air stream; the ratio of the quantity of air V to the volume of air D is between 5/1 and 25/1;
i) a liquid-air expansion turbine is fed by all or part of a stream of liquid air output by the exchanger; and/or i) a refrigeration set or chilled water produced by a refrigeration set (which may be the same water circuit as that used for cooling the air at the inlet of the purification unit) cools the air output by an air supercharger and/or the air at the lowest pressure; and/or iii) an increased stream of air is sent to the blowing turbine in such a way that the ratio of the quantity of air V sent to the exchange line to the volume of air D sent to the blowing turbine is less than 10/1;
the purity of the oxygen is between 30 and 100 mol %, preferably between 95 and 100 mol %; the oxygen extraction efficiency is between 85 and 100%.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:
[0046] FIG. 1 illustrates a diagram of an installation for implementing the process according to the invention; and
[0047] FIG. 2 illustrates is an illustration of an exchanger used in the installation of FIG. 1 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0048] The subject of the invention is also an air separation installation for producing air gases using a process described above, comprising the medium-pressure column containing two or three sections of structured packings and/or the low-pressure column containing three sections of structured packings.
[0049] Optionally, the installation may include an argon column fed from the low-pressure column. A blowing turbine expands air and sends at least one portion thereof to the low-pressure column of a double column.
[0050] The invention will now be described with reference to the figures, of which FIG. 1 is a diagram of an installation for implementing the process according to the invention and FIG. 2 is an illustration of an exchanger used in the installation of FIG. 1 .
[0051] In FIG. 1 , a 475,000 Nm 3 /h stream of air 1 at 7 bar absolute, coming from a purification unit (not illustrated), is divided into three. A first stream 3 is supercharged in the supercharger 5 up to the pressure required to vaporize the liquid oxygen for example. The high-pressure air HP AIR 7 is sent to the exchanger 10 but does not reach the cold end, being cooled down to −160° C., expanded, liquefied and sent to the two columns 9 and 11 , namely the medium-pressure column and the low-pressure column, respectively, of an air separation double column.
[0052] A second, non-supercharged, stream MP AIR 13 is also sent to the exchanger 10 , through which it partly flows until reaching −140° C. before being sent to the bottom of the medium-pressure column 9 .
[0053] A third stream 15 of about 45,000 Nm 3 /h is sent to a supercharger 17 , partly cooled in the exchanger, and expanded in a blowing turbine 19 , with an inlet temperature of −130° C., before being sent to the low-pressure column 11 . The ratio of the volume of air sent through the blowing turbine 19 to the quantity of air sent to the exchanger is 10/1.
[0054] The head losses in the exchanger 10 are about 300 mbar in the case of the air stream 13 at the lowest pressure and about 250 mbar in the case of the waste nitrogen 35 .
[0055] The exchanger 10 has a volume of 60 m 3 , thus the ratio of the volumetric flow rate of air sent to the exchanger 10 (stream 1 or volume V) to the volume of this exchange line 10 (=number of bodies×total width×total stack×total length) is 7,900 Nm 3 /h/m 3 .
[0056] The double column is a conventional apparatus except as regards its dimensions and the number of theoretical trays of the columns, since the medium-pressure column contains 40 theoretical trays and the low-pressure column 45 of them, and as regards the temperature difference in the case of the reboiler 21 , which is greater than 2.5° C.
[0057] Conventionally, oxygen-enriched liquids (rich liquid RL) and nitrogen-enriched liquid (lean liquid LL) are sent from the medium-pressure column to the low-pressure column after subcooling in the exchanger SC and expansion in a valve.
[0058] The low-pressure column 11 contains three sections of structured packings, comprising a sump section I between the bottom of the column and the rich liquid intake (which is conjoint with the blown air intake), a section II between the rich liquid intake and the liquid air intake and a section III between the liquid air intake and the lean liquid intake.
[0059] The medium-pressure column 9 contains three structured packings, comprising a sump section I between the bottom of the column and the liquid air intake, a section II between the liquid air intake and the lean liquid outlet LL and a section III between the lean liquid outlet LL and the medium-pressure nitrogen outlet 31 . Of course, if there is no withdrawal of liquid nitrogen or gaseous nitrogen, the medium-pressure column contains only two sections, section III being omitted.
[0060] The sump reboiler 21 of the low-pressure column 11 is in fact incorporated with the medium-pressure column 9 and is warmed by a stream of medium-pressure nitrogen of this column 9 . A stream of liquid oxygen 23 coming from the bottom of the low-pressure column 11 is pumped in order to overcome the hydrostatic head and arrives in the reboiler 21 where it partially vaporizes, a gas stream 25 being sent back to the low-pressure column below the exchange means I and a liquid stream 27 being sent to the pump 29 , where it is pressurized up to its use pressure. The pumped stream 27 vaporizes in the exchanger 10 .
[0061] A stream of liquid nitrogen 31 is withdrawn as top product from the medium-pressure column 9 above section III, pumped and also vaporizes in the exchanger 10 .
[0062] The pressure of the liquid nitrogen and the pressure of the liquid oxygen may take any value, provided that the exchanger 10 is designed according to the maximum pressure of the air required for vaporization.
[0063] It will be understood that the invention also applies to the case in which a single stream of liquid vaporizes in the exchanger 10 , or no liquid withdrawn from a column vaporizes in the installation.
[0064] Instead of vaporizing against air, the stream or streams of liquid may vaporize against a stream of cycle nitrogen.
[0065] Alternatively, the liquid stream or streams may vaporize in a dedicated exchanger serving only to vaporize the liquid stream or streams against a stream of air or a stream of cycle nitrogen.
[0066] The process may also produce liquid oxygen and/or liquid nitrogen and/or liquid argon as final product(s).
[0067] Gaseous nitrogen 33 , 35 may be withdrawn from the medium-pressure column 9 and/or from the low-pressure column 11 .
[0068] The gaseous nitrogen 35 warms in the subcooler SC.
[0069] Alternatively or in addition, a stream of gaseous oxygen (not illustrated) may be withdrawn as final product from the low-pressure column 11 . Optionally, this stream may be pressurized in a compressor.
[0070] A stream of medium-pressure gaseous nitrogen MP NG 33 and a stream of low-pressure waste nitrogen 35 are warmed in the exchanger 10 .
[0071] The stream WN may serve to regenerate the air purification system in a known manner and/or may be sent to a gas turbine.
[0072] A process as described is used to produce 99.5 mol % pure oxygen HP OG with a yield of more than 95%. This oxygen serves typically in a gasifier supplied with a fuel such as natural gas.
[0073] In the installation, the low-pressure column 11 may be alongside the medium-pressure column 9 , as in the example, or else above the latter.
[0074] To produce a stream of liquid oxygen and/or liquid nitrogen and/or liquid argon and/or to reduce the pressure levels, especially the pressure of the HP AIR 7 , the refrigeration required may be provided by using:
[0075] i) a liquid-air expansion turbine fed completely or partly with the liquid air stream HP 7 output by the exchanger ( 10 ); and/or
[0076] ii) a refrigeration set or chilled water produced by a refrigeration set (which come from the same water circuit as that used for cooling the air at the inlet of the purification unit) in order to cool air output by the air supercharger 5 and/or the air output by the supercharger 17 and/or the MP 13 ; and/or
[0077] iii) by sending an increased stream of air to the blowing turbine 19 in such a way that the ratio of the quantity of air V sent to the exchanger to the volume of air D sent to the blowing turbine is less than 10/1.
[0078] These means for generating refrigeration may also be employed in the case in which no liquid is produced as final product.
[0079] The superchargers 5 , 17 and/or the main compressor (not illustrated) may be driven by an electric motor and/or by a hydraulic motor and/or by a steam turbine and/or by a gas turbine.
[0080] The turbine 19 may have a dedicated supercharger or a generator.
[0081] The installation may also include conventional components well known to those skilled in the art, such as a Claude turbine, a hydraulic. turbine, a medium-pressure or low-pressure nitrogen turbine, for refrigeration top-up by tippling, one or more argon production columns, a mixing column fed with air and oxygen from the low-pressure column, a column operating at an intermediate pressure, for example one fed with the rich liquid and/or with air, a double-reboiler or triple-reboiler low-pressure column, etc.
[0082] FIG. 2 shows an exchanger 10 suitable for being used in the process of FIG. 1 .
[0083] The exchanger 10 has a volume of 60 m 3 , thus the ratio of the volumetric flow rate of air sent to the exchanger 10 (stream 1 or stream V) to the volume of this exchange line 10 (=number of bodies×total width×total stack×total length) is 7,900 Nm 3 /h/m 3 .
[0084] Given that the maximum volume of a body is about 8 m 3 , the number of bodies 100 is 8, so as to have an even number of bodies, four bodies 100 of which are placed on each side of a central line.
[0085] The medium-pressure air 13 is sent to a delivery line 113 and then to 8 pipes 113 A, each of which feeds a body 100 . The cooled medium-pressure air is then sent to a header line (not illustrated) and then to the medium-pressure column. High-pressure air 15 is sent to a delivery line 115 and then to two pipes, each of which feeds four bodies 100 . High-pressure air 7 is sent to a delivery line 107 and then to two pipes, each of which feeds four bodies 100 .
[0086] Warmed waste nitrogen 35 is collected from the eight bodies 100 in a header line 135 .
[0087] Each body comprises passages fed via a pumped-liquid-oxygen delivery line having a diameter of at least 25 cm. The total flow area of all the passages reserved for the oxygen in the 8 bodies 100 is less than 25 Nm 3 /h/cm 2 , in the vicinity of 20 Nm 3 /h/cm 2 .
[0088] The gaseous oxygen produced by vaporization is sent to a header line 127 , the diameter of which is at least 25 cm, preferably about 30 cm.
[0089] Low-pressure nitrogen 33 is sent to the header line 133 .
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A process and an apparatus for separating air by cryogenic distillation. The apparatus has a medium pressure column thermally coupled to a low pressure column. Compressed and purified air is cooled to cryogenic temperature in an exchanger, and sent at least partly to the medium pressure column. Streams enriched in oxygen and nitrogen are sent from the medium pressure column to the low pressure column and, streams enriched in nitrogen and oxygen are removed from the low pressure.
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FIELD OF THE INVENTION
In general, the invention relates to devices and methods for non-invasive neurostimulation of a subject's brain. More specifically, the invention relates to devices and methods for non-invasive neurostimulation of a subject's brain to effect treatment of various maladies.
BACKGROUND OF THE INVENTION
Traumatic brain injury (TBI) is a leading cause of disability around the world. Each year in the United States, about two million people suffer a TBI, with many suffering long term symptoms. Long term symptoms can include impaired attention, impaired judgment, reduced processing speed, and defects in abstract reasoning, planning, problem-solving and multitasking.
A stroke is a loss of brain function due to a disturbance in the blood supply to the brain. Every year, about 800,000 people in the United States will have a stroke. Stroke is a leading cause of long-term disability in the United States, with nearly half of older stroke survivors experiencing moderate to severe disability. Long term effects can include seizures, incontinence, vision disturbance or loss of vision, dysphagia, pain, fatigue, loss of cognitive function, aphasia, loss of short-term and/or long-term memory, and depression.
Multiple sclerosis (MS) is a disease that causes damage to the nerve cells in the brain and spinal cord. Globally, there are about 2.5 million people who suffer from MS. Symptoms can vary greatly depending on the specific location of the damaged portion of the brain or spinal cord. Symptoms include hypoesthesia, difficulties with coordination and balance, dysarthria, dysphagia, nystagmus, bladder and bowel difficulties, cognitive impairment and major depression to name a few.
Alzheimer's disease (AD) is a neurodegenerative disorder affecting over 25 million people worldwide. Symptoms of AD include confusion, irritability, aggression, mood swings, trouble with language, and both short and long term memory loss. In developed countries, AD is one of the most costly diseases to society.
Parkinson's disease (PD) is a degenerative disorder of the central nervous system, affecting more than 7 million people globally. Symptoms of PD include tremor, bradykinesia, rigidity, postural instability, cognitive disturbances, and behavior and mood alterations.
One approach to treating the long term symptoms associated with TBI, stroke, MS, AD, and PD is neurorehabilitation. Neurorehabilitation involves processes designed to help patients recover from nervous system injuries. Traditionally, neurorehabilitation involves physical therapy (e.g., balance retraining), occupational therapy (e.g., safety training, cognitive retraining for memory), psychological therapy, speech and language therapy, and therapies focused on daily function and community re-integration.
Another approach to treating the long term symptoms associated with TBI, stroke, MS, AD, and PD is neurostimulation. Neurostimulation is a therapeutic activation of part of the nervous system. For example, activation of the nervous system can be achieved through electrical stimulation, magnetic stimulation, or mechanical stimulation. Typical approaches focused mainly on invasive techniques, such as deep brain stimulation (DBS), spinal cord stimulation (SCS), cochlear implants, visual prosthesis, and cardiac electrostimulation devices. Only recently have non-invasive approaches to neurostimulation become more mainstream.
Despite many advances in the areas of neurorehabilitation and neurostimulation, there exists an urgent need for treatments that employ a combined approach, including both neurorehabilitation and neurostimulation to improve the recovery of patients having TBI, stroke, multiple sclerosis, Alzheimer's, Parkinson's, depression, memory loss, compulsive behavior, or any other neurological impairment.
SUMMARY OF THE INVENTION
The invention, in various embodiments, features methods and devices for combining non-invasive neuromodulation with traditional neurorehabilitation therapies. Clinical studies have shown that methods combining neurostimulation with neurorehabilitation are effective in treating the long term neurological impairments due to a range of maladies such as TBI, stroke, MS, AD, and PD.
In one aspect, the invention features a mouthpiece for providing non-invasive neuromodulation to a patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having (i) a non-planar exterior top surface and (ii) internal structural members disposed within the housing, the internal structural members elastically responding to biting forces generated by the patient. The mouthpiece also includes a spacer attached to the top surface of the housing for limiting contact between a patient's upper teeth and the exterior top surface of the elongated housing. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. In some embodiments, the mouthpiece also includes ribs aligned parallel to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes ribs aligned perpendicular to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes ribs aligned parallel to a longitudinal axis of the elongated housing and ribs aligned perpendicular to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes an interpenetrating network of ribs, with at least some of the ribs aligned parallel to a longitudinal axis of the elongate housing and at least some of the ribs aligned perpendicular to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes pockets in a posterior portion of the elongated housing formed by the interpenetrating network of ribs. In some embodiments, the mouthpiece also includes integrated circuits located in the pockets. In some embodiments, the ribs have a rectangular cross section. In some embodiments, the ribs are comprised of arches. In some embodiments, the mouthpiece also includes one or more columns extending away from an interior surface of the elongated housing, the one or more columns configured to contact the mounted printed circuit board. In some embodiments, the structural elements can withstand a force of 700 Newtons without causing plastic deformation of the mouthpiece. In some embodiments, the mouthpiece also includes a rectangular sheet embedded on an interior surface of the elongated housing and located in a posterior region of the elongated housing, the rectangular sheet connecting the interpenetrating network of ribs. In some embodiments, the mouthpiece also includes a curvilinear sheet embedded on an interior surface of the elongated housing and located in a region connecting the anterior region and the posterior region of the elongated housing, the curvilinear sheet connecting the ribs aligned parallel to a longitudinal axis of the elongated housing.
In another aspect, the invention features a mouthpiece for providing non-invasive neuromodulation to a patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having (i) a non-planar exterior top surface and (ii) internal structural members disposed within the housing, the internal structural members elastically responding to biting forces generated by the patient. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. In some embodiments, the mouthpiece also includes ribs aligned parallel to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes ribs aligned perpendicular to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes ribs aligned parallel to a longitudinal axis of the elongated housing and ribs aligned perpendicular to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes an interpenetrating network of ribs, with at least some of the ribs aligned parallel to a longitudinal axis of the elongate housing and at least some of the ribs aligned perpendicular to a longitudinal axis of the elongated housing. In some embodiments, the mouthpiece also includes pockets in a posterior portion of the elongated housing formed by the interpenetrating network of ribs. In some embodiments, the mouthpiece also includes integrated circuits located in the pockets. In some embodiments, the ribs have a rectangular cross section. In some embodiments, the ribs are comprised of arches. In some embodiments, the mouthpiece also includes one or more columns extending away from an interior surface of the elongated housing, the one or more columns configured to contact the mounted printed circuit board. In some embodiments, the structural elements can withstand a force of 700 Newtons without causing plastic deformation of the mouthpiece.
In another aspect, the invention features a mouthpiece for providing non-invasive neuromodulation to a patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar interior top surface and internal fins located between the non-planar interior top surface and a bottom surface defined by a perimeter of the elongated housing, the internal fins forming a channel at the anterior region of the elongated housing. The mouthpiece also includes a spacer attached to the top surface of the housing for minimizing contact between a patient's upper teeth and the exterior top surface of the elongated housing. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes a cable having a first segment disposed within the housing and a second segment extending from the housing, the cable mounted in an s-shaped pattern along the channel formed by the internal fins, one end of the first segment of the cable connected to the printed circuit board. In some embodiments, the mouthpiece also includes a right angled grommet mounted to an anterior region of the elongated housing, the grommet surrounding the cable as it exits the channel formed by the internal fins, the grommet forcing the cable to make an approximately ninety degree turn as it exits the elongated housing. In some embodiments, the cable forms two consecutive s-shapes along the channel formed by the internal fins. In some embodiments, the mouthpiece also includes a grommet mounted to an anterior region of the elongated housing, the grommet surrounding the cable as it exits the channel formed by the internal fins. In some embodiments, the mouthpiece also includes a cylindrically symmetric elastomeric element, the elastomeric element surrounding a portion of the cable and having trench in a central portion thereof and surrounded by two regions having radii that decrease in relation to a distance from the trench. In some embodiments, the mouthpiece also includes an aperture located at an anterior region of the elongated housing, the aperture configured to form mechanical connection with the trench. In some embodiments, the mouthpiece also includes a cap, the cap having an elastomeric portion in contact with the printed circuit board and a rigid portion in contact with the elongated housing, the cap in cooperation with the elongated housing forming an aperture at an anterior region of the mouthpiece, the aperture configured to form mechanical connection with the trench. In some embodiments, the mouthpiece also includes a valley located in the interior surface of the elongated housing, the valley configured to receive the cable. In some embodiments, the mouthpiece also includes an elastomeric sleeve, the elastomeric sleeve in contact with the cable, and an anterior region of the elongated housing, the elastomeric sleeve providing resistance to bending and tensile strains in the cable.
In another aspect, the invention features a mouthpiece for providing non-invasive neuromodulation to a patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar interior top surface and a bottom surface defined by a perimeter of the elongated housing. The mouthpiece also includes a spacer attached to the top surface of the elongated housing for minimizing contact between a patient's upper teeth and the exterior top surface of the elongated housing. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes a first elastomeric ring located along an interior sidewall of the elongated housing, the first elastomeric ring forming a sealing surface with the printed circuit board. The mouthpiece also includes a plurality of mechanical protrusions extending from the interior sidewall of the elongated housing, the mechanical protrusions in contact with the printed circuit board. The mouthpiece also includes a cable having a first segment disposed within the housing and a second segment extending from the housing, one end of the first segment of the cable connected to the printed circuit board. In some embodiments, the mouthpiece also includes a valley located in the interior surface of the elongated housing, the valley configured to receive the cable. In some embodiments, the mouthpiece also includes internal fins extending from the interior top surface of the elongated housing, the internal fins forming a channel at an anterior region of the elongated housing. In some embodiments, the cable forms at least two consecutive s-shapes along the channel formed by the internal fins. In some embodiments, the mouthpiece also includes a second elastomeric ring attached to the first elastomeric ring, the second elastomeric ring surrounding a portion of the cable and forming a connection between an anterior portion of the elongated housing and the cable. In some embodiments, the mouthpiece also includes a second elastomeric ring attached to the first elastomeric ring, the second elastomeric ring surrounding a portion of the cable and forming a connection between an anterior portion of the elongated housing and the cable, the second elastomeric ring causing the cable to exit the mouthpiece at an angle of 90 degrees.
In another aspect, the invention features a mouthpiece for providing non-invasive neuromodulation to a patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar interior top surface and internal fins located between the non-planar interior top surface and a bottom surface defined by a perimeter of the elongated housing, the internal fins forming a channel at the anterior region of the elongated housing. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes a cable having a first segment disposed within the housing and a second segment extending from the housing, the cable mounted in an s-shaped pattern along the channel formed by the internal fins, one end of the first segment of the cable connected to the printed circuit board. In some embodiments, the mouthpiece also includes a right angled grommet mounted to an anterior region of the elongated housing, the grommet surrounding the cable as it exits the channel formed by the internal fins, the grommet forcing the cable to make an approximately ninety degree turn as it exits the elongated housing. In some embodiments, the cable forms two consecutive s-shapes along the channel formed by the internal fins. In some embodiments, the mouthpiece also includes a grommet mounted to an anterior region of the elongated housing, the grommet surrounding the cable as it exits the channel formed by the internal fins. In some embodiments, the mouthpiece also includes a cylindrically symmetric elastomeric element, the elastomeric element surrounding a portion of the cable and having trench in a central portion thereof and surrounded by two regions having radii that decrease in relation to a distance from the trench. In some embodiments, the mouthpiece also includes an aperture located at an anterior region of the elongated housing, the aperture configured to form mechanical connection with the trench. In some embodiments, the mouthpiece also includes a cap, the cap having an elastomeric portion in contact with the printed circuit board and a rigid portion in contact with the elongated housing, the cap in cooperation with the elongated housing forming an aperture at an anterior region of the mouthpiece, the aperture configured to form mechanical connection with the trench. In some embodiments, the mouthpiece also includes a valley located in the interior surface of the elongated housing, the valley configured to receive the cable. In some embodiments, the mouthpiece also includes an elastomeric sleeve, the elastomeric sleeve in contact with the cable, and an anterior region of the elongated housing, the elastomeric sleeve providing resistance to bending and tensile strains in the cable.
In another aspect, the invention features a mouthpiece for providing non-invasive neuromodulation to a patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface. The mouthpiece also includes a spacer attached to the top surface of the housing for minimizing contact between a patient's upper teeth and the exterior top surface of the elongated housing. The mouthpiece also includes a first printed circuit board mounted to a bottom portion of the elongated housing, the first printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes a rim extending from a bottom portion of the elongated housing, the rim surrounding a perimeter of the first printed circuit board and having a u-shaped cross section. The mouthpiece also includes a well shaped to accommodate an adhesive, the adhesive bonding the first printed circuit board to the elongate housing. In some embodiments, a portion of the rim rests below the first printed circuit board and prevents a patient's teeth from contacting the printed circuit board. In some embodiments, the first printed circuit board is non-planar and the plurality of electrodes are located on a non-planar surface of the first printed circuit board. In some embodiments, the first printed circuit board has a curved shape and the plurality of electrodes are located on a curved surface of the first printed circuit board. In some embodiments, the plurality of electrodes has a first density at an anterior region of the first printed circuit board and a second density at a posterior region of the first printed circuit board, wherein the first density is greater than the second density. In some embodiments, the mouthpiece also includes a second printed circuit board mounted above the first printed circuit board. In some embodiments, the rim is an integral part of the elongated housing. In some embodiments, the rim is dimensioned to define the glue well between the bottom portion of the elongated housing and the perimeter of the first printed circuit board. In some embodiments, the rim is concentric with the perimeter of the first printed circuit board. In some embodiments, the rim covers a bottom portion of the first printed circuit board along the perimeter thereof. In some embodiments, the rim covers a side portion of the first printed circuit board along the perimeter thereof. In some embodiments, the rim covers a bottom portion and a side portion of the first printed circuit board along the perimeter thereof.
In another aspect, the invention features a mouthpiece for providing non-invasive neuromodulation to a patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface. The mouthpiece also includes a spacer attached to the top surface of the housing for minimizing contact between a patient's upper teeth and the exterior top surface of the elongated housing. The mouthpiece also includes a first printed circuit board mounted to a bottom portion of the elongated housing, the first printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes a rim extending from a bottom portion of the elongated housing, the rim surrounding a perimeter of the first printed circuit board. The mouthpiece also includes a beveled well configured to accommodate an adhesive, the adhesive bonding at least two orthogonal surfaces of the first printed circuit board to the elongated housing. In some embodiments, a portion of the rim rests below the first printed circuit board and prevents a patient's teeth from contacting the first printed circuit board. In some embodiments, the first printed circuit board is non-planar and the plurality of electrodes are located on a non-planar surface of the first printed circuit board. In some embodiments, the first printed circuit board has a curved shape and the plurality of electrodes are located on a curved surface of the first printed circuit board. In some embodiments, the plurality of electrodes has a first density at an anterior region of the first printed circuit board and a second density at a posterior region of the first printed circuit board, wherein the first density is greater than the second density. In some embodiments, the mouthpiece also includes a second printed circuit board mounted above the first printed circuit board. In some embodiments, the rim is an integral part of the elongated housing. In some embodiments, the rim is dimensioned to define the glue well between the bottom portion of the elongated housing and the perimeter of the first printed circuit board. In some embodiments, the rim is concentric with the perimeter of the first printed circuit board. In some embodiments, the rim covers a bottom portion of the first printed circuit board along the perimeter thereof. In some embodiments, the rim covers a side portion of the first printed circuit board along the perimeter thereof. In some embodiments, the rim covers a bottom portion and a side portion of the first printed circuit board along the perimeter thereof.
In another aspect, the invention features a method of manufacturing a mouthpiece, the mouthpiece providing non-invasive neuromodulation to a patient. The method includes providing an elongated housing having internal fins located between a non-planar interior top surface and a bottom surface defined by a perimeter of the elongated housing, the internal fins forming a channel at the anterior region of the elongated housing. The method also includes attaching a spacer to the top surface of the elongated housing for minimizing contact between a patient's upper teeth and the exterior top surface of the elongated housing. The method also includes mounting a cable in an s-shaped pattern along the channel formed by the internal fins. The method also includes mounting a printed circuit board to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The method also includes connecting one end of the cable to the printed circuit board. In some embodiments, the method also includes forming a 90 degree bend in the cable at an exit of elongated housing. In some embodiments, the method also includes threading the cable through an elastomeric element located at the exit of the elongated housing. In some embodiments, the method also includes forming two consecutive s-shapes along the cable. In some embodiments, the method also includes mounting a cylindrically symmetric elastomeric element to the cable, the elastomeric element surrounding a portion of the cable and having a trench in a central portion thereof and surrounded by two regions having radii that decrease in relation to a distance from the trench. In some embodiments, the method also includes forming an aperture at an anterior region of the elongated housing, the aperture configured to form mechanical connection with the trench. In some embodiments, the method also includes providing a cap having an elastomeric portion and a rigid portion. In some embodiments, the method also includes contacting the elastomeric portion of the cap with the printed circuit board and contacting the rigid portion of the cap with the elongated housing. In some embodiments, the method also includes cooperatively forming an aperture with the cap and the elongated housing, the aperture forming a mechanical connection with the trench. In some embodiments, the method also includes forming a valley located in the interior surface of the elongated housing. In some embodiments, the method also includes receiving a cable in the valley. In some embodiments, the method also includes forming an elastomeric sleeve around the cable, the elastomeric sleeve in contact with an anterior region of the elongated housing, the elastomeric sleeve providing resistance to bending and tensile strains in the cable. In some embodiments, the method also includes applying an adhesive along the perimeter of the printed circuit board, the adhesive bonding at least two orthogonal surfaces of the first printed circuit board to the elongated housing.
In another aspect, the invention features a method of manufacturing a mouthpiece, the mouthpiece providing non-invasive neuromodulation to a patient. The method includes providing an elongated housing having a plurality of mechanical protrusions extending from an interior sidewall thereof and first elastomeric ring located along an interior sidewall of the elongated housing. The method also includes attaching a spacer to the top surface of the elongated housing for minimizing contact between a patient's upper teeth and a top surface of the elongated housing. The method also includes contacting a printed circuit board to the first elastomeric ring of the elongated housing to form a seal, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The method also includes providing a cable having a first segment disposed within the housing and a second segment extending from the housing. The method also includes connecting one end of the first segment of the cable connected to the printed circuit board. In some embodiments, the method also includes forming a 90 degree bend in the cable at an exit of elongated housing. In some embodiments, the method also includes threading the cable through an elastomeric element located at the exit of the elongated housing. In some embodiments, the method also includes forming two consecutive s-shapes along the cable. In some embodiments, the method also includes mounting a cylindrically symmetric elastomeric element to the cable, the elastomeric element surrounding a portion of the cable and having a trench in a central portion thereof and surrounded by two regions having radii that decrease in relation to a distance from the trench. In some embodiments, the method also includes forming an aperture at an anterior region of the elongated housing, the aperture configured to form mechanical connection with the trench. In some embodiments, the method also includes forming a valley located in the interior surface of the elongated housing. In some embodiments, the method also includes receiving a cable in the valley. In some embodiments, the method also includes forming an elastomeric sleeve around the cable, the elastomeric sleeve in contact with an anterior region of the elongated housing, the elastomeric sleeve providing resistance to bending and tensile strains in the cable.
In another aspect, the invention features a method of manufacturing a mouthpiece, the mouthpiece providing non-invasive neuromodulation to a patient. The method includes providing a printed circuit board, the printed circuit board having electronic circuitry and a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The method also includes forming an elongated housing directly onto the printed circuit board. The method also includes attaching a spacer to the top surface of the elongated housing for minimizing contact between a patient's upper teeth and a top surface of the elongated housing.
In some embodiments, the method also includes forming a strain relief mechanism integral with the elongated housing. In some embodiments, the method also includes providing a cable having a first segment disposed within the housing and a second segment extending from the housing. In some embodiments, the method also includes connecting one end of the first segment of the cable connected to the printed circuit board. In some embodiments, the method also includes encapsulating the electronic circuitry located on the printed circuit board.
As used herein, the terms “approximately,” “roughly,” and “substantially” mean±10%, and in some embodiments, ±5%. Reference throughout this specification to “one example,” “an example,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present technology. Thus, the occurrences of the phrases “in one example,” “in an example,” “one embodiment,” or “an embodiment” in various places throughout this specification are not necessarily all referring to the same example. Furthermore, the particular features, structures, routines, steps, or characteristics may be combined in any suitable manner in one or more examples of the technology. The headings provided herein are for convenience only and are not intended to limit or interpret the scope or meaning of the claimed technology.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of the invention described above, together with further advantages, may be better understood by referring to the following description taken in conjunction with the accompanying drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
FIG. 1 is a drawing of a patient engaged in a non-invasive neurostimulation therapy session according to an illustrative embodiment of the invention.
FIGS. 2A and 2B are diagrams showing a neurostimulation system according to an illustrative embodiment of the invention.
FIG. 2C is a diagram showing a neurostimulation system according to an illustrative embodiment of the invention.
FIG. 3A is a diagram showing a more detailed view of the neurostimulation system depicted in FIGS. 2A and 2B .
FIG. 3B is a diagram showing a more detailed view of the neurostimulation system depicted in FIG. 2C .
FIG. 3C is a diagram showing a more detailed view of an electrode array.
FIG. 3D is a graph showing an exemplary sequence of pulses for effecting neurostimulation of a patient.
FIG. 4A is a flow chart illustrating a method in accordance with one embodiment for operating a neurostimulation system.
FIG. 4B is a flow chart illustrating a method in accordance with one embodiment for operating a neurostimulation system.
FIG. 5A is a diagram showing an isometric view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 5B is a diagram showing a side view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 5C is a diagram showing a top view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 5D is a diagram showing a bottom view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIGS. 5E and 5F are diagrams showing a bottom view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 6A is a diagram showing an isometric view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 6B is a diagram showing a bottom view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 6C is a diagram showing a glue well in accordance with an illustrative embodiment of the invention.
FIG. 6D is a diagram showing a glue well in accordance with an illustrative embodiment of the invention.
FIG. 7A is a diagram showing an isometric view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 7B is a diagram showing a bottom view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 7C is a diagram showing a sectional view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIGS. 8A and 8B are diagrams showing an isometric view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 8C is a diagram showing a sectional view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 8D is a diagram showing a sectional view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIGS. 9A and 9B are diagrams showing an isometric view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 9C is a diagram showing a sectional view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIGS. 10A and 10B are diagrams showing an isometric view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 10C is a diagram showing a sectional view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIGS. 11A and 11B are diagrams showing an isometric view of a mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 11C is a diagram showing an isometric view of the mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 12 is a flow chart illustrating a method in accordance with one embodiment for manufacturing a mouthpiece.
FIGS. 13A-B are diagrams showing an overmolded mouthpiece in accordance with an illustrative embodiment of the invention.
FIG. 14 is a diagram showing an overmolded mouthpiece in accordance with an illustrative embodiment of the invention.
DETAILED DESCRIPTION
FIG. 1 shows a patient 101 undergoing non-invasive neuromodulation therapy (NINM) using a neurostimulation system 100 . During a therapy session, the neurostimulation system 100 non-invasively stimulates various nerves located within the patient's oral cavity, including at least one of the trigeminal and facial nerves. In combination with the NINM, the patient engages in an exercise or other activity specifically designed to assist in the neurorehabilitation of the patient. For example, the patient can perform a physical therapy routine (e.g., moving an affected limb, or walking on a treadmill) engage in a mental therapy (e.g., meditation or breathing exercises), or a cognitive exercise (e.g., computer assisted memory exercises) during the application of NINM. The combination of NINM with an appropriately chosen exercise or activity has been shown to be useful in treating a range of maladies including, for example, traumatic brain injury, stroke (TBI), multiple sclerosis (MS), balance, gait, vestibular disorders, visual deficiencies, tremor, headache, migraines, neuropathic pain, hearing loss, speech recognition, auditory problems, speech therapy, cerebral palsy, blood pressure, relaxation, and heart rate. For example, a useful non-invasive neuromodulation (NINM) therapy routine has been recently developed as described in U.S. Pat. No. 8,849,407, the entirety of which is incorporated herein by reference.
FIGS. 2A and 2B show a non-invasive neurostimulation system 100 . The non-invasive neurostimulation system 100 includes a controller 120 and a mouthpiece 140 . The controller 120 includes a receptacle 126 and pushbuttons 122 . The mouthpiece 140 includes an electrode array 142 and a cable 144 . The cable 144 connects to the receptacle 126 , providing an electrical connection between the mouthpiece 140 and the controller 120 . In some embodiments, the controller 120 includes a cable. In some embodiments, the mouthpiece 140 and the controller 120 are connected wirelessly (e.g., without the use of a cable). During operation, a patient activates the neurostimulation system 100 by actuating one of the pushbuttons 122 . In some embodiments, the neurostimulation system 100 periodically transmits electrical pulses to determine if the electrode array 142 is in contact with the patient's tongue and automatically activates based on the determination. After activation, the patient can start an NINM treatment session, stop the NINM treatment session, or pause the NINM treatment session by pressing one of the pushbuttons 122 . In some embodiments, the neurostimulation system 100 periodically transmits electrical pulses to determine if the electrode array 142 is in contact with the patient's tongue and automatically pauses the NINM treatment session based on the determination. During an NINM treatment session, the patient engages in an exercise or other activity designed to facilitate neurorehabilitation. For example, during an NINM treatment session, the patient can engage in a physical exercise, a mental exercise, or a cognitive exercise. In some embodiments, the controller 120 has pushbuttons on both arms. In some embodiments, a mobile device can be used in conjunction with the controller 120 and the mouthpiece 140 . The mobile device can include a software application that allows a user to activate the neurostimulation system 100 and start or stop an NINM treatment session by for example, pressing a button on the mobile device, or speaking a command into the mobile device. The mobile device can obtain patient information and treatment session information before, during, or after an NINM treatment session. In some embodiments, the controller 120 includes a secure cryptoprocessor that holds a secret key, to be described in more detail below in connection with FIGS. 9A and 9B . The secure cryptoprocessor is in communication with a microcontroller. The secure cryptoprocessor can be tamper proof. For example, if outer portions of the cryptoprocessor are removed in an attempt to access the secret key, the cryptoprocessor erases all memory, preventing unauthorized access of the secret key.
FIG. 2C shows a non-invasive neurostimulation system 100 . As shown, a mobile device 121 is in communication with a mouthpiece 140 . More specifically, the mobile device 121 includes a processor running a software application that facilitates communications with the mouthpiece 140 . The mobile device 121 can be, for example, a mobile phone, a portable digital assistant (PDA), or a laptop. The mobile device 121 can communicate with the mouthpiece 140 by a wireless or wired connection. During operation, a patient activates the neurostimulation system 100 via the mobile device 121 . After activation, the patient can start an NINM treatment session, stop the NINM treatment session, or pause the NINM treatment session by manipulating the mobile device 121 . During an NINM treatment session, the patient engages in an exercise or activity designed to provide neurorehabilitation. For example, during an NINM treatment session, the patient can engage in a physical exercise, a mental exercise, or a cognitive exercise.
FIG. 3A shows the internal circuitry housed within the controller 120 . The circuitry includes a microcontroller 360 , isolation circuitry 379 , a universal serial bus (USB) connection 380 , a battery management controller 382 , a battery 362 , a push-button interface 364 , a display 366 , a real time clock 368 , an accelerometer 370 , drive circuitry 372 , tongue sense circuitry 374 , audio feedback circuitry 376 , vibratory feedback circuitry 377 , and a non-volatile memory 378 . The drive circuitry 372 includes a multiplexor, and an array of resistors to control voltages delivered to the electrode array 142 . The microcontroller 360 is in electrical communication with each of the components shown in FIG. 3A . The isolation circuitry 379 provides electrical isolation between the USB connection 380 and all other components included in the controller 120 . Additionally, the circuitry shown in FIG. 3A is in communication with the mouthpiece 140 via the external cable 144 . During operation, the microcontroller 360 receives electrical power from battery 362 and can store and retrieve information from the non-volatile memory 378 . The battery can be charged via the USB connection 380 . The battery management circuitry controls the charging of the battery 362 . A patient can interact with the controller 120 via the push-button interface 122 that converts the patient's pressing of a button (e.g. an info button, a power button, an intensity-up button, an intensity-down button, and a start/stop button) into an electrical signal that is transmitted to the microcontroller 360 . For example, a therapy session can be started when the patient presses a start/stop button after powering on the controller 120 . During the therapy session, the drive circuitry 372 provides an electrical signal to the mouthpiece 140 via the cable 144 . The electrical signal is communicated to the patient's intraoral cavity via the electrode array 142 . The accelerometer 370 can be used to provide information about the patient's motion during the therapy session. Information provided by the accelerometer 370 can be stored in the non-volatile memory 378 at a coarse or detailed level. For example, a therapy session aggregate motion index can be stored based on the number of instances where acceleration rises above a predefined threshold, with or without low pass filtering. Alternatively, acceleration readings could be stored at a predefined sampling interval. The information provided by the accelerometer 370 can be used to determine if the patient is engaged in a physical activity. Based on the information received from the accelerometer 370 , the microcontroller 360 can determine an activity level of the patient during a therapy session. For example, if the patient engages in a physical activity for 30 minutes during a therapy session, the accelerometer 370 can periodically communicate (e.g. once every second) to the microcontroller 360 that the sensed motion is larger than a predetermined threshold (e.g. greater than 1 m/s 2 ). In some embodiments, the accelerometer data is stored in the non-volatile memory 378 during the therapy session and transmitted to the mobile device 121 after the therapy session has ended. After the therapy session has ended, the microcontroller 360 can record the amount of time during the therapy session in which the patient was active. In some embodiments, the recorded information can include other data about the therapy session (e.g., the date and time of the session start, the average intensity of electrical neurostimulation delivered to the patient during the session, the average activity level of the patient during the session, the total session time the mouthpiece has been in the patient's mouth, the total session pause time, the number of session shorting events, and/or the length of the session or the type of exercise or activity performed during the therapy session) and can be transmitted to a mobile device. A session shorting event can occur if the current transmitted from the drive circuitry to the electrode array 142 exceeds a predetermined threshold or if the charge transmitted from the drive circuitry to the electrode array exceeds a predetermined threshold over a predetermined time interval. After a session shorting event has occurred, the patient must manually press a pushbutton to resume the therapy session. The real time clock (RTC) 368 provides time and date information to the microcontroller 360 . In some embodiments, the controller 120 is authorized by a physician for a predetermined period of time (e.g., two weeks). The RTC 368 periodically communicates date and time information to the microcontroller 360 . In some embodiments, the RTC 368 is integrated with the microcontroller. In some embodiments, the RTC 368 is powered by the battery 362 , and upon failure of the battery 362 , the RTC 368 is powered by a backup battery. After the predetermined period of time has elapsed, the controller 120 can no longer initiate the delivery of electrical signals to the mouthpiece 140 and the patient must visit the physician to reauthorize use of the controller 120 . The display 366 displays information received by the microcontroller 360 to the patient. For example, the display 366 can display the time of day, therapy information, battery information, time remaining in a therapy session, error information, and the status of the controller 120 . The audio feedback circuitry 376 and vibratory feedback circuitry 377 can give feedback to a user when the device changes state. For example, when a therapy session begins, the audio feedback circuitry 376 and the vibratory feedback circuitry 377 can provide auditory and/or vibratory cues to the patient, notifying the patient that the therapy session has been initiated. Other possible state changes that may trigger audio and/or vibratory cues include pausing a therapy session, resuming a therapy session, the end of a timed session, canceling a timed session, or error messaging. In some embodiments, a clinician can turn off one or more of the auditory or vibratory cues to tailor the feedback to an individual patient's needs. The tongue sense circuitry 374 measures the current passing from the drive circuitry to the electrode array 142 . Upon sensing a current above a predetermined threshold, the tongue sense circuitry 374 presents a high digital signal to the microcontroller 360 , indicating that the tongue is in contact with the electrode array 142 . If the current is below the predetermined threshold, the tongue sense circuitry 374 presents a low digital signal to the microcontroller 360 , indicating that the tongue is not in contact or is in partial contact with the electrode array 142 . The indications received from the tongue sense circuitry 374 can be stored in the non-volatile memory 378 . In some embodiments, the display 366 can be an organic light emitting diode (OLED) display. In some embodiments, the display 366 can be a liquid crystal display (LCD). In some embodiments, a display 366 is not included with the controller 120 . In some embodiments, neither the controller 120 nor the mouthpiece 140 includes a cable, and the controller 120 communicates wirelessly with the mouthpiece 140 . In some embodiments, neither the controller 120 nor the mouthpiece 140 includes an accelerometer. In some embodiments, the drive circuitry 372 is located within the mouthpiece. In some embodiments, a portion of the drive circuitry 372 is located within the mouthpiece 140 and a portion of the drive circuitry 372 is located within the controller 120 . In some embodiments, neither the controller 120 nor the mouthpiece 140 includes tongue sense circuitry 374 . In some embodiments, the mouthpiece 140 includes a microcontroller and a multiplexer.
FIG. 3B shows a more detailed view of FIG. 2C . The mouthpiece 140 includes a battery 362 , tongue sense circuitry 374 , an accelerometer 370 , a microcontroller 360 , drive circuitry 372 , a non-volatile memory 378 , a universal serial bus controller (USB) 380 , and battery management circuitry 382 . During operation, the microcontroller receives electrical power from battery 362 and can store and retrieve information from the non-volatile memory 378 . The battery can be charged via the USB connection 380 . The battery management circuitry 382 controls the charging of the battery 362 . A patient can interact with the mouthpiece 140 via the mobile device 121 . The mobile device 121 includes an application (e.g. software running on a processor) that allows the patient to control the mouthpiece 140 . For example, the application can include an info button, a power button an intensity-up button, an intensity-down button, and a start/stop button that are presented to the user visually via the mobile device 121 . When the patient presses a button presented by the application running on the mobile device 121 , a signal is transmitted to the microcontroller 360 housed within the mouthpiece 140 . For example, a therapy session can be started when the patient presses a start/stop button on the mobile device 121 . During the therapy session, the drive circuitry 372 provides an electrical signal to an electrode array 142 located on the mouthpiece 140 . The accelerometer 370 can be used to provide information about the patient's motion during the therapy session. The information provided by the accelerometer 370 can be used to determine if the patient is engaged in a physical activity. Based on the information received from the accelerometer 370 , the microcontroller 360 can determine an activity level of the patient during a therapy session. For example, if the patient engages in a physical activity for 30 minutes during a therapy session, the accelerometer 370 can periodically communicate (e.g. once every second) to the microcontroller 360 that the sensed motion is larger than a predetermined threshold (e.g. greater than 1 m/s 2 ). After the therapy session has ended, the microcontroller 360 can record the amount of time during the therapy session in which the patient was active. In some embodiments, the accelerometer 370 is located within the mobile device 121 and the mobile device 121 determines an activity level of a patient during the therapy session based on information received from the accelerometer 370 . The mobile device can then record the amount of time during the therapy session in which the patient was active. The mobile device 121 includes a real time clock (RTC) 368 that provides time and date information to the microcontroller 360 . In some embodiments, the mouthpiece 140 is authorized by a physician for a predetermined period of time (e.g., two weeks). After the predetermined period of time has elapsed, the mouthpiece 140 can no longer deliver electrical signals to the patient via the electrode array 142 and the patient must visit the physician to reauthorize use of the mouthpiece 140 . In some embodiments, the mouthpiece 140 includes pushbuttons (e.g., an on/off button) and a patient can manually operate the mouthpiece 140 via the pushbuttons. After a therapy session, the mouthpiece 140 can transmit information about the therapy session to a mobile device. In some embodiments, the mouthpiece 140 does not include a USB controller 380 and instead communicates only via wireless communications with the controller.
FIG. 3C shows a more detailed view of the electrode array 142 . The electrode array 142 can be separated into 9 groups of electrodes, labelled a-i, with each group having 16 electrodes, except group b which has 15 electrodes. Each electrode within the group corresponds to one of 16 electrical channels. During operation, the drive circuitry can deliver a sequence of electrical pulses to the electrode array 142 to provide neurostimulation of at least one of the patient's trigeminal or facial nerve. The electrical pulse amplitude delivered to each group of electrodes can be larger near a posterior portion of the tongue and smaller at an anterior portion of the tongue. For example, the pulse amplitude of electrical signals delivered to groups a-c can be 19 volts or 100% of a maximum value, the pulse amplitude of electrical signals delivered to groups d-f can be 14.25 volts or 75% of the maximum value, the pulse amplitude of electrical signals delivered to groups g-h can be 11.4 volts or 60% of the maximum value, and the pulse amplitude of electrical signals delivered to group i can be 9.025 volts or 47.5% of the maximum value. In some embodiments, the maximum voltage is in the range of 0 to 40 volts. The pulses delivered to the patient by the electrode array 142 can be random or repeating. The location of pulses can be varied across the electrode array 142 such that different electrodes are active at different times, and the duration and/or intensity of pulses may vary from electrode. For oral tissue stimulation, currents of 0.5-50 mA and voltages of 1-40 volts can be used. In some embodiments, transient currents can be larger than 50 mA. The stimulus waveform may have a variety of time-dependent forms, and for cutaneous electrical stimulation, pulse trains and bursts of pulses can be used. Where continuously supplied, pulses may be 1-500 microseconds long and repeat at rates from 1-1000 pulses/second. Where supplied in bursts, pulses may be grouped into bursts of 1-100 pulses/burst, with a burst rate of 1-100 bursts/second.
In some embodiments, pulsed waveforms are delivered to the electrode array 142 . FIG. 3D shows an exemplary sequence of pulses that can be delivered to the electrode array 142 by the drive circuitry 372 . A burst of three pulses, each spaced apart by 5 ms is delivered to each of the 16 channels. The pulses in neighboring channels are offset from one another by 312.5 μs. The burst of pulses repeats every 20 ms. The width of each pulse can be varied from 0.3-60 μs to control an intensity of neurostimulation (e.g., a pulse having a width of 0.3 μs will cause a smaller amount of neurostimulation than a pulse having a width of 60 μs).
FIG. 4A shows a method of operation 400 of a controller 120 as described in FIGS. 2A, 2B and 3A . A patient attaches a mouthpiece 140 to a controller 120 (step 404 ). The patient turns on the controller 120 (step 408 ) using, for example, a power button. The patient places the controller 120 around his/her neck (step 412 ) as shown in FIG. 1B . The patient places a mouthpiece 140 in his/her mouth (step 416 ). The patient initiates a therapy session by pressing a start/stop button (step 420 ). During the therapy session, the controller 120 delivers electrical signals to the mouthpiece 140 . The patient calibrates the intensity of the electrical signals (step 424 ). The patient raises the intensity of the electrical signals delivered to the mouthpiece by pressing an intensity-up button until the neurostimulation is above the patient's sensitivity level. The patient presses an intensity-down button until the neurostimulation is comfortable and non-painful. After the calibration step, the patient performs a prescribed exercise (step 428 ). The exercise can be cognitive, mental, or physical. In some embodiments, physical exercise includes the patient attempting to maintain a normal posture or gait, the patient moving his/her limbs, or the patient undergoing speech exercises. Cognitive exercises can include “brain training” exercises, typically computerized, that are designed to require the use of attention span, memory, or reading comprehension. Mental exercises can include visualization exercises, meditation, relaxation techniques, and progressive exposure to “triggers” for compulsive behaviors.
In some embodiments, the patient can rest for a period of time during the therapy session (e.g. the patient can rest for 2 minutes during a 30 minute therapy session). After a predetermined period of time (for example, thirty minutes) has elapsed, the therapy session ends (step 432 ) and the controller 120 stops delivering electrical signals to the mouthpiece 140 . In some embodiments, the intensity of electrical signals increases from zero to the last use level selected by the patient over a time duration in the range of 1-5 seconds after the patient starts a therapy session by pressing the start/stop button. In some embodiments, the intensity of electrical signals is set to a fraction of the last use level selected by the patient (e.g. ¾ of the last level selected) after the patient starts a therapy session by pressing the start/stop button. In some embodiments, the intensity of electrical signals increases from zero to a fraction of the last use level selected by the patient (e.g. ¾ of the last level selected) over a time duration in the range of 1-5 seconds after the patient starts a therapy session by pressing the start/stop button. In some embodiments, the intensity of electrical signals increases instantaneously from zero to the last use level selected by the patient after the patient starts a therapy session by pressing the start/stop button.
In some embodiments, the mouthpiece 140 is connected to the controller 120 after the controller 120 is turned on. In some embodiments, the mouthpiece 140 is connected to the controller 120 after the controller 120 is donned by the patient. In some embodiments, the patient calibrates the intensity of the electrical signals before initiating a therapy session. In some embodiments, a patient performs an initial calibration of the intensity of electrical signals in the presence of a clinician and does not calibrate the intensity of the electrical signals during subsequent treatments performed in the absence of a clinician.
FIG. 4B shows a method of operation 449 of the non-invasive neurostimulation system 100 described in FIGS. 2C and 3B . A patient activates a mobile device 121 (step 450 ). The patient places a mouthpiece 140 in his/her mouth (step 454 ). The patient initiates a therapy session by pressing a start/stop button within an application running on the mobile device 121 (step 458 ). During the therapy session, circuitry within the mouthpiece 140 delivers electrical signals to an electrode array 142 located on the mouthpiece 140 . The patient calibrates the intensity of the electrical signals (step 462 ). The patient first raises the intensity of the electrical signals delivered to the mouthpiece 140 by pressing an intensity-up button located within an application running on the mobile device 121 until the neurostimulation is above the patient's sensitivity level. The patient presses an intensity-down button running within an application on the mobile device 121 until the neurostimulation is comfortable and non-painful. After the calibration step, the patient performs a prescribed exercise (step 464 ). The exercise can be cognitive, mental, or physical. In some embodiments, the patient can rest for a period of time during the therapy session (e.g. the patient can rest for 5 minutes during a 30 minute therapy session). After a predetermined period of time (for example, thirty minutes) has elapsed, the therapy session ends (step 468 ) and the circuitry located within the mouthpiece 140 stops delivering electrical signals to the electrode array 142 . In some embodiments, the calibration of the intensity of the electrical signals takes place before the patient initiates a therapy session.
FIGS. 5A-5F show a mouthpiece 500 . The mouthpiece 500 includes a housing 504 , a spacer 508 , a transition region 520 , a posterior region 524 , an anterior region 528 , a printed circuit board 532 , internal circuitry 533 , an electrode array 542 , and a cable 544 . The housing 504 includes an outer shell 505 , longitudinal ribs 550 , transverse ribs 551 , columns 552 , valleys 553 , shoring 554 , pockets 555 , and a platform 558 . The mouthpiece 500 has three regions, a posterior region 524 , a transition region 520 , and an anterior region 528 . The transition region 520 smoothly connects the anterior region 528 with the posterior region 524 . The printed circuit board 532 attaches to the bottom side of the housing 504 . The internal circuitry 533 is mounted to the top side of the printed circuit board 532 and is covered by the housing 504 . The cable 544 is in communication with the internal circuitry 533 and the internal circuitry 533 is in communication with the electrode array 542 . The outer shell 505 of the housing 504 has an exemplary thickness in the range of 0.5 to 2 mm. The outer shell can be made of glass filled nylon, nylon, acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyether ether ketone (PEEK), alloy metal, or metal, having a compression strength in the range of 375 to 590 N. In some embodiments, the outer shell 505 has two different thicknesses. For example, the anterior region of the outer shell 505 can have a thickness in the range of 1.2 to 2 mm and the posterior region can have a thickness in the range of 0.5 to 1.2 mm. The thickness of the outer shell 505 can vary smoothly in the transition region such that there are no discontinuities or steps in the thickness of the outer shell 505 . In some embodiments, the thickness of the outer shell 505 in the anterior region is chosen to withstand biting by the patient. In some embodiments, the thickness of the outer shell 505 in the posterior region is selected to provide retention of the mouthpiece 500 , thereby preventing accidental ejection of the mouthpiece 500 . By itself, the outer shell 505 cannot withstand biting forces from the patient (e.g., the outer shell undergoes significant deflections and/or experiences plastic deformation). The longitudinal ribs 550 , transverse ribs 551 , columns 552 , shoring 554 , and platform 558 can provide structural support for the outer shell 505 to prevent damage due to biting by the patient. The longitudinal ribs 550 can extend longitudinally along the housing 504 . The longitudinal ribs 550 can be regularly spaced, creating valleys 553 therebetween as shown in FIG. 5E . Internal circuitry 533 can be located in the valleys 553 . In an exemplary embodiment, the longitudinal ribs 550 have a width in the range of 0.5 to 2 mm, and a height that varies from approximately 6 mm in the posterior region 524 to 1 mm in the anterior region 528 . In some embodiments, the longitudinal ribs are irregularly spaced, with the spacing between ribs being larger towards the perimeter of the outer shell 505 and smaller towards a central portion of the outer shell 505 . In some embodiments, the longitudinal ribs are separated by a distance in the range of 4 to 9.0 mm as measured from center to center. The transverse ribs 551 can be located in the posterior region 524 and traverse a width of the housing 504 . The transverse ribs can be spaced regularly, as shown in FIG. 5E . In an exemplary embodiment, the transverse ribs 551 have a width of in the range of 0.5 to 1.5 mm, and a height of in the range of 4 to 7 mm. In some embodiments, the transverse ribs 551 can intersect with the longitudinal ribs 550 , creating pockets 555 as shown in FIG. 5E . Internal circuitry 533 can be located in the pockets 555 . In some embodiments, the transverse ribs are irregularly spaced, with the spacing between ribs being larger towards the perimeter of the outer shell 505 and smaller towards a central portion of the outer shell 505 . The column 552 can have a rectangular cross section and be located in an anterior region 528 of the housing 504 . In some embodiments, one or more columns 552 are regularly spaced and traverse a width of the housing 504 . The columns 552 can provide resistance to compressive forces exerted on the mouthpiece 500 , thereby providing protection of the internal circuitry 533 . The columns 552 can have a thickness in the range of 0.5 to 2 mm. In some embodiments, the height of the columns 552 is greater than the thickness of the internal circuitry 533 , thereby providing a clearance between the internal circuitry 533 and the outer shell 505 . In some embodiments, the height of the columns 552 is at least 1 mm greater than the thickness of the internal circuitry 533 . In some embodiments, the platform 558 is directly connected to one or more longitudinal ribs and one or more transverse ribs, thereby providing increased capacity to withstand shear and compressive loads. The thickness of the platform 558 can be in the range of 1.5 to 3.5 mm. In some embodiments, the shoring 554 includes a layer of material with a thickness greater than the thickness of the outer shell 505 . The thickness of the shoring 554 can be in the range of 0.5 to 2 mm. In some embodiments, the thickness of the outer shell 505 is smaller in the region of the shoring 554 than in other regions to accommodate the spacer 508 . For example, the thickness of the outer shell can be 1.5 mm in the anterior and posterior regions and 0.5 mm in the region of the shoring 554 . During operation, a patient places a portion of the mouthpiece 500 in his/her mouth to engage in an NINM therapy session. The patient bites down on the mouthpiece 500 with his/her front teeth to secure a position of the mouthpiece. The patient's bottom teeth contact the printed circuit board 532 and the patient's tongue contacts the electrode array 542 . In some embodiments, the patient relaxes his/her mouth to secure a position of the mouthpiece. The internal circuitry delivers electrical neurostimulation signals to the patient's tongue via the electrode array 542 . In some embodiments, the spacer 508 can provide a soft and comfortable bite surface so that stress is not concentrated at small areas where the patient's teeth contact the mouthpiece 500 during biting. For example, the spacer 508 can be made from thermoplastic polyurethane (TPU), thermoplastic elastomer (TPE), or silicone. In some embodiments, the transverse ribs 551 are located in the anterior region and traverse a width of the housing 504 .
FIGS. 6A-6B show a more detailed view of the outer shell 505 . The outer shell includes a glue well 570 , internal fins 561 and 562 , and a central longitudinal axis 590 . The internal fins include at least one pair of entrance fins 561 . The entrance fins 561 can be symmetric about the longitudinal axis 590 and can guide the cable 544 along the longitudinal axis 590 without causing substantial bending thereof. A glue, adhesive, or epoxy can provide a rigid mechanical connection between the cable 544 and the entrance fins 561 . For example, the glue, adhesive, or epoxy can be a UV cured adhesive, or cyanoacrylate. The internal fins also in include an even number of guiding fins 562 . In some embodiments, the internal fins include an odd number of guiding fins 562 . For example, the internal fins can include three guiding fins. In some embodiments, the guiding fins 562 are not symmetric about the longitudinal axis 590 , with each guiding fin 562 causing an approximately 90 degree bend in the cable 544 , and each bend having a radius of curvature approximately equal to two diameters of the cable 544 . In some embodiment, each guiding fin 562 causes a bend in the cable 544 of greater than 90 degrees, but less than 180 degrees. The guiding fins 562 are in mechanical contact with the cable 544 and provide frictional resistance that compensates for any tensile strain applied to the cable, for example due to longitudinal forces applied along the cable 544 . In some embodiments, the guiding fins 562 provide frictional resistance of at least 100 Newtons. In some embodiments, the guiding fins provide frictional resistance greater than the weight of the mouthpiece. In some embodiments, the guiding fins provide frictional resistance greater than the forces required to disconnect the mouthpiece 140 from the controller 120 . In some embodiments, a rubber grommet 563 provides an elastic mechanical attachment between the outer shell 505 and the cable 544 with the outer shell 505 providing a resistance that counteracts any bending strain applied to the cable 544 (e.g., the patient may accidentally pull or tug on the cable while the mouthpiece 500 is secured within the patient's mouth). In some embodiments, the spacer 508 includes an elastomeric element that provides a mechanical connection between the cable 544 and the entrance fins 561 . The elastomeric element provides a frictional force that provides a frictional resistance that counteracts any bending stress applied to the cable 544 . In some embodiments, the cable 544 can exit the outer shell at a 90 degree angle and be attached to the outer shell by an epoxy, the epoxy providing mechanical resistance of up to 100 Newtons to accommodate bending strains induced by the patient. In some embodiments, the cable 544 is attached to the outer shell by an adhesive or glue. In some embodiments, the cable 544 can exit the outer shell at a 90 degree angle and be mechanically attached to the outer shell by a right-angled elastomeric element, the right-angled elastomeric element interlocking with the outer shell and providing mechanical resistance of up to 100 Newtons to accommodate both bending and tensile strains induced by the patient.
FIG. 6C shows a more detailed cross sectional view of the glue well 570 . The glue well 570 is located along an outer boundary of the outer shell 505 and accommodates an adhesive (e.g., a biomedical compatible epoxy or glue) that provides a mechanical connection between the printed circuit board 532 and the outer shell 505 . The glue well 570 includes a beveled lip 571 , and a discontinuously connected cross-section that includes a concave portion 572 and a vertical portion 573 that intersect to form a lowest point of the glue well 570 . In some embodiments, the shape of the glue well can be trapezoidal. In some embodiments, the shape of the glue well can be wedged. In some embodiments, the shape of the glue well can be triangular. In some embodiments, the shape of the glue well can be rectangular. In some embodiments, a portion of the glue well can overhang the printed circuit board 532 , thereby protecting portions of the printed circuit board from the teeth of the patient. In some embodiments, the adhesive is in contact with the outer shell 505 and the top of the printed circuit board 532 . In some embodiments, the adhesive is in contact with the outer shell 505 and the top and side portions of the printed circuit board 532 . In some embodiments, the glue well is shaped such that the adhesive is in contact with the outer shell 505 and the side portions of the printed circuit board 532 , but only has negligible contact with the top portion of the printed circuit board 532 (e.g., the glue well can have a width greater than a depth).
FIG. 6D shows an embodiment where the outer shell 505 includes two glue wells, 570 and 574 . A first glue well 570 and a second glue well 574 are located along an outer boundary of the outer shell 505 and accommodate an adhesive (e.g., a biomedical compatible epoxy) that provides a mechanical connection between the printed circuit board 532 and the outer shell 505 . The second glue well 574 is designed to accommodate a glue or adhesive that overflows from the first glue well 570 , thereby preventing glue or adhesive from overflowing onto the bottom side of the printed circuit board. A step 578 is positioned between the first and second glue well to define the height of the first glue well.
FIGS. 7A-7C show a mouthpiece 700 . The mouthpiece 700 includes an outer shell 705 having a central longitudinal axis 790 , a spacer 708 , a cable 744 , a sleeve 764 , exit fins 761 , a glue well 770 . The sleeve 764 is integrated with the cable 744 and mechanically couples the cable 744 with the outer shell 705 . The sleeve 764 includes two tapered outer portions 765 and a gap 766 separating the two tapered outer portions. The cable 744 can be pulled towards the outer shell 705 until the gap 766 is aligned with an outer boundary of the mouthpiece 700 . Once aligned with the outer shell 705 , the sleeve 764 provides a mechanical resistance of up to 100 Newtons to counteract both tensile and bending stresses applied to the cable 744 . The cable 744 may additionally be clamped between the printed circuit board 732 and the outer shell 705 as shown in FIG. 7C . The additional clamping can provide additional mechanical resistance to tensile stresses applied to the cable 744 .
FIGS. 8A-8D show a mouthpiece 800 . The mouthpiece 800 includes an outer shell 805 , a spacer 808 , a printed circuit board 832 , a cable 844 , a sleeve 864 , a glue well 870 , and a clamp 809 . A posterior portion of the cable 844 is connected to the printed circuit board 832 via solder, ribbon connector, or other mechanical connection. The sleeve 864 is integrated with the cable 844 and mechanically couples the cable 844 with the outer shell 805 and clamp 809 . The sleeve 864 is similar to the sleeve 764 , having two tapered outer portions and a gap. Instead of being pulled through the outer shell 805 as shown in FIG. 7 , the sleeve 864 is secured by a clamp 809 that connects to a bottom portion of the outer shell 805 . The clamp 809 mechanically secures the printed circuit board 832 to the outer shell 805 and in addition, secures the sleeve 864 to the outer shell 805 . In some embodiments, adhesive or glue is added to the glue well 870 to secure the printed circuit board 832 to the outer shell 805 . The sleeve 864 provides mechanical resistance (up to 100 Newtons) to bending stresses and tensile stresses in the cable 844 . The clamp 809 includes a rigid plastic portion 809 b and an elastomeric portion 809 a . The rigid plastic portion 809 b provides structural integrity, while the elastomeric portion 809 a provides a sealing mechanism. For example, the clamp 809 can be placed into contact with the outer shell 805 as shown in FIG. 8D . A narrow protrusion 810 extends from the rigid plastic portion 809 b of the clamp 809 , the narrow protrusion 810 interlocking with a recessed portion 806 of the outer shell 805 . The elastomeric portion 809 a contacts the outer shell 805 , the glue well 870 , and the printed circuit board 832 , forming an air tight seal. The air tight seal can protect portions of the printed circuit board 832 from moisture. In some embodiments, the clamp 809 is secured to the outer shell 805 by adding an adhesive or glue to the glue well 870 that contacts both the outer shell and the clamp.
FIGS. 9A-9C show a mouthpiece 900 . The mouthpiece 900 includes an outer shell 905 , a printed circuit board 932 , a cable 944 , a glue well 970 , a boot 945 . The outer shell 905 includes a valley 971 and a glue well 970 . The valley 971 guides the cable 944 within the outer shell 905 , and the glue well 970 accommodates an epoxy or other adhesive to provide a mechanical connection between the printed circuit board 932 , the outer shell 905 , and the cable 944 . The shape of the glue well 970 can be a wedge shape to advantageously provide an interface between the adhesive or epoxy and the printed circuit board 932 , the outer shell 905 , and the cable 944 . A protrusion 946 extends from the outer shell 905 and interlocks with a recessed portion 947 of the boot 945 . The interlocked boot 945 is in mechanical contact along an outer diameter of the cable 944 (e.g., the interlocked boot 945 can be in contact with the outer diameter of the cable 944 for a distance in the range of 0.5 to 10 mm). In some embodiments, the interlocked boot 945 can be overmolded, or glued onto the cable 944 . In some embodiments, the interlocked boot 945 is mechanically coupled to the cable 944 . The interlocked boot 945 can provide mechanical resistance to tugging or pulling (e.g., up to 100 Newtons) of the cable by the patient. In some embodiments, the interlocked boot can provide resistance to both bending strains and tensile strains. In some embodiments, the boot 945 can cover the glue well 970 . In some embodiments, the boot 945 can be extended to cover portions of the printed circuit board 932 that are not covered by an electrode array.
FIGS. 10A-10C show a mouthpiece 1000 . The mouthpiece 1000 includes an outer shell 1005 , a printed circuit board 1032 , a cable 1044 , a valley 1071 , a sealing ring 1081 , and clips 1080 . Epoxy and/or adhesives are not present in mouthpiece 1000 . The printed circuit board 1032 contacts the sealing ring 1081 and is held in place by clips 1080 . The clips 1080 can have vertical sidewall and a downward sloping overhang as shown in FIG. 10B . In some embodiments, the clips are spaced along an inner boundary of the outer shell 1005 . The cable 1044 is electrically connected to the printed circuit board 1032 . Additionally, the sealing ring 1081 forms an aperture at an anterior region of the outer shell 1005 , with the cable 1044 passing through the aperture. The valley 1071 guides the cable 1044 from the printed circuit board 1132 to the aperture. The aperture is in contact with the cable 1044 and provides resistance to tugging or pulling of the cable 1044 by the patient. In some embodiments, the aperture can provide resistance to both bending and tensile strains on the cable 1044 . In some embodiments, the sealing ring 1081 is composed of a low durometer elastomer such as TPE, TPU, or silicone. In some embodiments, the sealing ring can be replaced by a glue well or a layer of glue.
FIGS. 11A-11C show a mouthpiece 1100 . The mouthpiece 1100 includes an outer shell 1105 , a printed circuit board 1132 , a cable 1144 , and a fastener 1191 . The outer shell includes a glue well 1170 , a valley 1171 , and a port 1172 shaped to accommodate the fastener 1191 . The glue well 1170 can accommodate an epoxy or other adhesive that connects the outer shell 1105 to the printed circuit board 1132 . The cable 1144 is attached to the printed circuit board 1132 via solder, ribbon cable, or other mechanical connector. The cable rests in the valley 1171 before exiting at port 1172 . An O-ring surrounds the cable 1144 at the port 1172 . The fastener 1191 attaches to the outer shell 1105 at the position of the port 1172 . The fastener applies a force to the O-ring that holds the cable in place at the port. The O-ring together with the fastener 1172 protect the cable from pulling or tugging by the patient. In some embodiments, the O-ring and the fastener 1172 provide resistance to both bending and tensile strain. In some embodiments, an epoxy or adhesive surrounds the cable 1144 at the port 1172 .
FIG. 12 shows a method 1200 of manufacturing a mouthpiece such as the mouthpiece shown in FIG. 5 . Initially, a housing is provided (step 1204 ). A spacer is attached to the housing (step 1208 ). In some embodiments, the spacer is molded directly onto the housing. In some embodiments, the spacer attached to the housing via an adhesive or glue. The housing is attached to the printed circuit board (step 1212 ). In some embodiments, the housing is molded directly onto the printed circuit board. The molded housing can wrap around the edge of the printed circuit board and create a lip on the bottom side of the printed circuit board for better engagement. In some embodiments, features can be added to the printed circuit board (e.g., countersunk holes, beveled edge of the board, stepped edge of the board, tongue and groove edge of the board) such that when the molded housing is molded onto the board, the plastic hardens around the features to create better engagement. In some embodiments, the housing is attached to the printed circuit board via an adhesive and/or mechanical clips. In some embodiments, the housing is attached to the printed circuit board by a mechanical bond. In some embodiments, the housing is attached to the printed circuit board by a chemical bond. In some embodiments, the attached housing covers and encapsulates surface mounted electronics on the printed circuit board, while leaving the electrode array exposed such that the electrode array can be placed in contact with a patient's tongue for NINM therapy. A cable is provided (step 1216 ). The cable is connected to the printed circuit board (step 1220 ). In some embodiments, the cable is connected to the printed circuit board prior to the housing being molded onto the printed circuit board. The cable can be partially encapsulated by the housing after the molding process. In some embodiments, the housing is molded onto the printed circuit board in two steps. In a first step a first shot of plastic can be molded onto the board, where the mold temperatures and pressures are low enough that it is not hazardous to the electrical components on the board. The first shot can be used to pot the components, thereby protecting them. The first shot can be a softer material (TPE, TPU) or a rigid material with a lower mold pressure and/or temperature (Polyamide, Polyolefin). A second shot is molded over at least a portion of the first shot, where mold temperatures and pressures are higher than the first shot. This second shot may be of harder, more durable materials (e.g., nylon or glass filled nylon, ABS, PC, etc.). In some embodiments, the housing is molded onto, and completely surrounds the printed circuit board, such that only the electrode array is not covered by the housing. In this situation, the printed circuit board material would not come into contact with the patient, thereby protecting the patient in the case of harmful printed circuit board materials. In some embodiments, the electrode array is non-planar with the printed circuit board (e.g., the electrode array can protrude by a distance in the range of 0.1 to 1 mm from the printed circuit board). In some embodiments, the electrode array is an array of pins that protrude from the printed circuit board. The array of pins remains exposed after molding the housing onto the printed circuit board.
FIGS. 13A and 13B show a mouthpiece 1300 that has been manufactured by overmolding a housing 1304 directly onto a printed circuit board 1332 . The mouthpiece 1300 includes a spacer 1308 and a cable 1344 . In some embodiments, the printed circuit 1332 board includes features for mechanically engaging the molded housing 1304 (e.g., a beveled edge of the board, a stepped edge of the board, a notched edge of the board etc.). In some embodiments, the molded housing 1304 can wrap around the edge of the printed circuit board 1332 and create a lip on the bottom side of the printed circuit board to mechanically engage the printed circuit board 1332 . In some embodiments, the printed circuit board includes countersunk holes 1340 . The countersunk holes are filled with plastic as the housing 1304 is molded onto the printed circuit board. A rivet forms inside the countersunk hole 1340 , with the rivet being an integral portion of the housing 1304 . The tapered shape of the rivet provides a force that holds the printed circuit board 1332 in mechanical contact with the housing 1304 .
FIG. 14 shows a mouthpiece 1400 according to a two shot injection molding manufacturing method wherein a shot refers to the volume of material that is used to fill a mold cavity and compensate for material shrinkage. The mouthpiece 1400 includes a housing 1404 , a printed circuit board 1432 , a cable 1444 , and a frame 1450 . The frame 1450 is formed around the printed circuit board (one or both sides) 1432 during a first shot, which provides a seal between the printed circuit board and the external environment. The housing 1404 is formed around the printed circuit board 1432 and frame 1450 during a second shot, thereby encapsulating the components on the printed circuit board 1432 and chemically bonding to the frame 1450 . The first and second shots can be rigid, elastomeric, or a combination of both.
The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the inventive concepts. It will be understood that, although the terms first, second, third etc. are used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.
While the present inventive concepts have been particularly shown and described above with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art, that various changes in form and detail can be made without departing from the spirit and scope of the present inventive concepts described and defined by the following claims.
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A mouthpiece for providing non-invasive neuromodulation to a patient, the mouthpiece including an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface and internal structural members disposed within the housing, the internal structural members elastically responding to biting forces generated by the patient, a spacer attached to the top surface of the housing for limiting contact between a patient's upper teeth and the exterior top surface of the elongated housing, and a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue.
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This application is a continuation of application Ser. No. 08/171,628, filed Dec. 22, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The instant invention relates to a magneto-optical recording medium and an information recording method using the same, with which information is recorded by forming a bit of a reversed magnetic domain using a laser beam and an external magnetic field, and information is read out by utilizing a magneto-optical effect obtained upon radiating a polarized laser beam and, more particularly, to a magneto-optical recording medium and an information recording method using the same, which perform an over-write operation by a magnetic field modulation method.
2. Related Background Art
Conventionally, as a rewritable high-density recording method, a magneto-optical recording method has received a lot of attention. With this method, information is recorded by writing a magnetic domain in a magnetic thin film, and the recorded information is read out by utilizing a magneto-optical effect.
Since the magneto-optical recording method uses a magnetic member on a disk as a recording medium, it has features that the recording medium is exchangeable, and information is rewritable.
Such a conventional magneto-optical recording method requires three recording processes (to erase old data, to record new data, and to check whether or not new data is properly recorded). For this reason, in order to rewrite information, a disk must be rotated three times, and hence, the time required for rewriting information corresponds to three revolutions of the disk.
In recent years, over-write methods (an optical modulation method and a magnetic field modulation method) with which new data is directly recorded on old data without executing the erasing process of the three recording processes have been proposed and extensively examined. Of these methods, the optical modulation method performs recording by forming a bit using a modulated laser beam. However, in consideration of the Gaussian distribution of the laser beam intensity and the temperature distribution of a magneto-optical recording medium, the allowable range of laser power for forming a magnetic domain with a small diameter is very narrow with respect to a given beam size. Furthermore, when the magnetic domain interval (bit interval) is decreased to increase the density, a temperature rise of a medium caused by the laser beam which was radiated immediately before a current recording operation adversely affects the current recording. More specifically, when a random pattern is recorded, the optimal value of laser power undesirably changes depending on the pattern.
In contrast to this, since the magnetic field modulation method does not easily pose the above-mentioned problems caused by the temperature distribution although it requires a rather complicated apparatus arrangement, it has been considered promising for practical applications, and has been developed extensively.
When an over-write operation is performed by the conventional magnetic field modulation method, a high-frequency magnet must be generally used as an external magnetic field application means to reverse a magnetic field upward or downward in a direction perpendicular to the film surface in correspondence with a digital data signal "1" or "0".
In this case, when the reversing speed of the magnetic field is increased, the magnetic field that can be applied tends to decrease, and therefore the data transfer speed is limited. Also, since the magnetic field decreases, the magnetic head must be arranged sufficiently close to a medium, and the medium or the head may be damaged due to a contact between them.
SUMMARY OF THE INVENTION
The instant invention has been made in consideration of the above-mentioned problems, and has as its object to provide a magneto-optical recording medium and an information recording method using the same, which can realize a high data transfer speed as compared to the conventional method by improving the conventional magnetic field modulation method and the magneto-optical recording medium.
As a result of the extensive studies in consideration of the above-mentioned problems, we found that the data transfer speed in an over-write operation can be remarkably increased when recording is performed by turning on/off an external magnetic field in accordance with information while radiating a laser beam using a magneto-optical recording medium, which comprises a second magnetic layer (to be referred to as an initializing layer hereinafter) consisting of a magnetic layer, which is magnetized in advance in one direction, has a high Curie temperature, does not lose magnetization in a recording/erasing mode, and has a perpendicular magnetic anisotropy, and a first magnetic layer (to be referred to as a recording layer hereinafter) having a perpendicular magnetic anisotropy and exchange-coupled to the second magnetic layer, thus achieving the instant invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing an example of the structure of a magneto-optical recording medium according to the instant invention;
FIG. 2(a) and (b) are views illustrating magnetization states upon execution of recording based on an information recording method of the instant invention;
FIG. 3(a)-(c) are charts showing a recording signal and a corresponding change in polarity of an external magnetic field;
FIG. 4A is a graph showing a change in magnetic field of a conventional external magnetic field, and FIG. 4B is a graph showing a change in magnetic field of an external magnetic field of the instant invention;
FIG. 5A is a view showing, as an example of the magneto-optical recording medium of the instant invention, a structure obtained by adding an interfering layer and a protection layer to the basic structure shown in FIG. 1, FIG. 5B is a view showing a structure obtained by further adding a reproducing layer on the recording layer, and FIG. 5C is a view showing a structure obtained by further adding an intermediate layer between the recording layer and the initializing layer; and
FIG. 6 is a graph showing the linear velocity dependency of the C/N ratio of the magneto-optical recording medium of the instant invention, and the conventional magneto-optical recording medium.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A magneto-optical recording medium and an information recording method for recording onto the medium will be described in detail hereinafter with reference to the accompanying drawings.
Structure of Recording Medium
A magneto-optical recording medium used in the instant invention comprises at least two magnetic layers, i.e., an initializing layer and a recording layer, as shown in FIG. 1. To this structure, a reproducing layer having a large Kerr rotation angle, an intermediate layer for controlling interface magnetic wall energy, another magnetic layer for improving, e.g., magnetic field sensitivity, a dielectric layer or a metal layer for attaining an interference effect, protecting the magnetic layers, or improving thermal characteristics, and the like, may be further provided.
Materials of Magnetic Layer
The materials of the initializing layer preferably include rare earth-iron group amorphous alloys, e.g., TbCo, GdTbFeCo, TbFeCo, DyFeCo, GdTbCo, DyFeCo, TbDyFeCo, and the like.
The materials of the recording layer preferably include rare earth-iron group amorphous alloys, e.g., TbFeCo, DyFeCo, TbDyFeCo, and the like.
When a reproduction layer having a large Kerr rotation angle is formed on the light incident side of the recording layer, the materials of the reproduction layer preferably include rare earth-iron group amorphous alloys, e.g., GdCo, GdFeCo, TbFeCo, DyFeCo, GdTbFeCo, GdDyFeCo, TbDyFeCo, NdFeCo, NdGdFeCo, NdTbFeCo, NdDyFeCo, and the like, platinum group-iron group periodic structure films, e.g., Pt/Co, Pd/Co, and the like, or platinum group-iron group alloys, e.g., PtCo, PdCo, and the like.
When an intermediate layer for adjusting interface magnetic wall energy between the recording layer and the initializing layer is formed between these two layers, the materials of the intermediate layer preferably include rare earth-iron group alloys such as GdCo, GdFeCo, TbFeCo, DyFeCo, GdTbFeCo, GdDyFeCo, TbDyFeCo, and the like, or dielectrics such as SiN.
Note that elements such as Cr, Al, Ti, Pt, Nb, and the like may be added to magnetic layers such as the initializing layer, recording layer, intermediate layer, reproducing layer, and the like so as to improve an anti-corrosion resistance.
Characteristic Conditions of Each Layer in Medium
The initializing layer requires at least the following conditions. That is, the initializing layer must be magnetized in one direction by a large external magnetic field during or after the manufacture of a medium, and the direction of magnetization of the initializing layer must remain the same in recording, reproduction, and preservation modes later.
When a laser beam and an external magnetic field are applied to the recording layer, the direction of magnetization of the recording layer follows the same direction as that of the external magnetic field; when only the laser beam is applied, and no external magnetic field is applied, the direction of magnetization of the recording layer follows a stable direction with respect to the direction of magnetization of the initializing layer upon reception of an exchange interaction from the initializing layer. In a preservation state of the medium (at room temperature), even when a magnetic wall is generated between the recording layer and the initializing layer, at least the state of the recording layer must be stably maintained.
These conditions for the recording layer for achieving recording will be exemplified with reference to a case wherein the magnetic layers comprise rare earth-iron group alloys.
When the recording layer and the initializing layer are ferrimagnetic layers, if the dominant magnetization of both the recording and initializing layers is a rare earth element or an iron group element, the medium will be referred to as a P-type medium hereinafter; if the dominant magnetization of the recording layer is a rare earth element, and the dominant magnetization of the initializing layer is an iron group element, or vice versa, the medium will be referred to as an A-type medium hereinafter. [Magnetization States (arrows represent the sum total of sublattice magnetizations)]
1 When P-type structure is used: ##STR1##
2 When A-type Structure is used:
(the initial state a corresponds to, e.g., a "0" recording condition, and the initial state b corresponds to a "1" recording condition. Note that states 1 and 2 are unallowable states.) ##STR2##
Description of Symbols
Saturation magnetization of recording layer (first layer); Ms 1
Coercive force of recording layer (first layer); Hc 1
Saturation magnetization of initializing layer (second layer); Ms 2
Coercive force of initializing layer (second layer); Hc 2
Film thickness of recording layer (first layer); h 1
Curie temperature of recording layer (first layer); Tc 1
Film thickness of initializing layer (second layer); h 2
Curie temperature of initializing layer (second layer); Tc 2
External magnetic field; Hex
Interface magnetic wall energy between recording layer and initializing layer; σ w
1. Conditions for Curie temperature and coercive force
Since magnetization in the initializing layer must be stably present in all of normal-temperature, reproduction, and recording states, and the magnetization of the recording layer must disappear or the coercive force must decrease and the direction of magnetization of the recording layer must be reversed in the recording state, if the Curie temperatures of the recording and initializing layers are respectively represented by Tc 1 and Tc 2 , and their coercive forces are respectively represented by Hc 1 and Hc 2 , the following relations must be satisfied:
Tc.sub.1 <Tc.sub.2 (1)
Hc.sub.1 <Hc.sub.2 (2)
2. Type 1 recording condition (when external magnetic field Hex is applied)
(1) Initial state a → initial state b, initial state b → initial state b
A condition to cause the direction of magnetization of the recording layer to follow the direction of the external magnetic field upon radiation of a laser beam (light radiated in the recording state) is: ##EQU1##
A condition to cause the direction of magnetization of the recording layer not to follow the direction of the external magnetic field (initial state a→×initial state b) is: ##EQU2##
(2) Initial state a→×state 1 A condition to prevent the initial state a from becoming state 1 in both the laser radiated state and the laser non-radiated state is: ##EQU3##
(3) Initial state b→×state 1 A condition to prevent the initial state b from becoming state 1 in both the laser radiated state and the laser non-radiated state is: ##EQU4## 3. Type 2 Recording Condition (when no external magnetic field is applied)
(1) Initial state b→initial state a, initial state a →initial state a
A condition to align the direction of magnetization of the recording layer in a direction stable with respect to the direction of magnetization of the initializing layer in the laser radiated state is: ##EQU5##
A condition not to align the direction of magnetization of the recording layer in a direction stable with respect to the direction of magnetization of the initializing layer in the laser non-radiated state (initial state b→×initial state a) is: ##EQU6##
(2) Initial state b→×state 1 A condition to prevent the initial state b from becoming state 1 in both the laser radiated state and the laser non-radiated state is: ##EQU7##
Recording Method
When the type 1 recording (recording of one of two values) is performed on a medium which satisfies the above-mentioned conditions, a recording portion of the medium is heated by a laser beam, and an external magnetic field is applied. The polarity of the external magnetic field is a direction opposite to the direction of magnetization of the initializing layer for a P-type medium, and is the same direction as the direction of magnetization of the initializing layer for an A-type medium.
At this time, the direction of magnetization of the recording layer aligns in the direction of the external magnetic field, thus achieving the type 1 recording.
In this case, although an interface magnetic wall is generated between the initializing layer and the recording layer, the magnetization of the initializing layer does not influence the recording layer at room temperature, and hence, the recorded information is held.
When the type 2 recording (recording of the other one of two values different from that recorded by the type 1 recording) is performed, the external magnetic field is turned off, and only a laser beam is radiated. At this time, the direction of magnetization of the recording layer follows in a stable direction with respect to the magnetization of the initializing layer due to the exchange coupling force from the initializing layer, thus achieving the type 2 recording (see FIGS. 2(a) and (b).
Since the recording layer of a portion which is not irradiated with the laser beam has a sufficiently large coercive force, the direction of magnetization of the recording layer of this portion is not reversed upon reception of the exchange coupling force from the initializing layer. For this reason, new information can be over-written only on the portion irradiated with the laser beam.
The external magnetic field need not be focused to a size as small as the portion irradiated with the beam (spot region), and the region applied with the external magnetic field can be considerably larger than the spot region.
When the external magnetic field is turned on/off in correspondence with digital data "1" or "0" while radiating the laser beam, new information can be over-written on old information (see FIGS. 3(a)-(c).
Realization of High-speed Data Transfer
In this method, since the over-write recording is attained by turning on/off the external magnetic field, the magnetic field need not be reversed in the recording state, as shown in FIG. 3(c). Note that FIGS. 3(a)-(c) exemplify a case of pit position recording. Similarly, the instant invention can be applied to other recording methods such as pit edge recording. In contrast to this, in a conventional magnetic field modulation over-write recording method, recording is attained by reversing the direction of magnetization from "+" to "-" or vice versa as shown in FIG 3(b).
In this case, as shown in FIG. 4A, since a predetermined time (t sw ) is required for reversing a leakage magnetic field from a magnetic head, and a sufficient magnetic field cannot be applied within this time, an unstable magnetic domain is formed. When the ratio of t sw to a time (t bit ) required for forming one reversed magnetic domain increases, an accurate reproduced signal cannot be obtained, resulting in an error.
A high transfer speed can be achieved by increasing the rotational speed of the medium and the recording frequency without changing the size of one bit. In this case, however, since t sw remains the same, the above-mentioned problem becomes more serious if the transfer speed is increased.
In contrast to this, in the recording method of the instant invention, since the over-write recording is attained by turning on/off a magnetic field without reversing the direction of the magnetic field, t sw is shortened as compared to the conventional method, as shown in FIG. 4B. For this reason, even when the transfer speed is increased, a magnetic domain is accurately recorded, and a reproduced signal does not deteriorate.
More specifically, high-speed data transfer can be realized.
TEST EXAMPLES
The instant invention will be described in more detail hereinafter by way of its test examples. However, the instant invention is not limited to the following test examples if changes to be made fall within the scope of the invention.
TEST EXAMPLE 1
After a 1,000-Å thick SiN layer was formed on a polycarbonate (PC) substrate having pre-grooves (a diameter of 130 mm) using a magnetron sputtering apparatus so as to obtain anti-oxidation and interfering effects, an 800-Å thick TbFeCo layer serving as a recording layer and a 1,500-Å thick TbCo layer serving as an initializing layer were formed. Thereafter, in order to enhance the anti-oxidation and interfering effects, a 300-Å thick SiN layer was continuously formed without breaking the vacuum state, thus manufacturing a magneto-optical recording medium of the instant invention having the layer structure shown in FIG. 5A.
A bit was recorded on the magneto-optical recording medium to have a minimum mark length of 0.8 μm while increasing the recording frequency as the linear velocity was increased (e.g., recording at a frequency of 3.13 MHz at a linear velocity of, e.g., 5 m/s).
The recording power was set to be a value which maximized the C/N ratio. The laser wavelength was set to be 780 nm.
Solid curve 1 in FIG. 6 represents the C/N ratio measured after recording, and the linear velocity and recording frequency in the recording state. The C/N ratio did not deteriorate up to a linear velocity of 28.5 m/s and a recording frequency of 17.8 MHz (a C/N ratio of 45 dB or less).
Magneto-optical recording media of Test Examples 2 to 11 were manufactured by changing the film thicknesses, materials, and compositions of magnetic layers while the layer structure remained the same, and the same measurement was performed. Table 1 shows the film thicknesses, materials, and compositions of the magnetic layers of Test Examples 2 to 11. Table 4 shows the measurement results.
Test Example 12
After a 1,000-Å thick SiN layer was formed on a polycarbonate (PC) substrate having pre-grooves (a diameter of 130 mm) using a magnetron sputtering apparatus so as to obtain anti-oxidation and interfering effects, a 300-Å thick GbFeCo layer serving as a reproducing layer, a 300-Å thick TbFeCo layer serving as a recording layer, and a 400-Å thick TbCo layer serving as an initializing layer were formed. Thereafter, in order to enhance the anti-oxidation and interfering effects, a 300-Å thick SiN layer was continuously formed without breaking the vacuum state, thus manufacturing a magneto-optical recording medium of the instant invention having the layer structure shown in FIG. 5B.
A bit was recorded on the magneto-optical recording medium to have a minimum mark length of 0.8 μm while increasing the recording frequency as the linear velocity increased.
The recording power was set to be a value which maximized the C/N ratio. The laser wavelength was set to be 780 nm.
Alternate long and short dashed curve 2 in FIG. 6 represents the C/N ratio measured after recording, and the linear velocity and recording frequency in the recording state. The C/N ratio did not deteriorate up to a linear velocity of 31.2 m/s and a recording frequency of 19.5 MHz (a C/N ratio of 45 dB or less). Table 2 shows the compositions of this magneto-optical recording medium.
Test Example 13
After a 1,000-Å thick SiN layer was formed on a polycarbonate (PC) substrate having pre-grooves (a diameter of 130 mm) using a magnetron sputtering apparatus so as to obtain anti-oxidation and interfering effects, an 800-Å thick TbFeCo layer serving as a recording layer, a 50-Å thick GdFeCo layer serving as an intermediate layer for adjusting magnetic wall energy, and an 800-Å thick TbCo layer serving as an initializing layer were formed. Thereafter, in order to enhance the anti-oxidation and interfering effects, a 300-Å thick SiN layer was continuously formed without breaking the vacuum state, thus manufacturing a magneto-optical recording medium of the instant invention having the layer structure shown in FIG. 5C.
A bit was recorded on the magneto-optical recording medium to have a minimum mark length of 0.8 μm while increasing the recording frequency as the linear velocity increased.
The recording power was set to be a value which maximized the C/N ratio. The laser wavelength was set to be 780 nm.
Alternate long and short dashed curve 2 in FIG. 6 represents the C/N ratio measured after recording, and the linear velocity and recording frequency in the recording state. The C/N ratio did not deteriorate up to a linear velocity of 31.2 m/s and a recording frequency of 19.5 MHz (a C/N ratio of 55 dB or less).
A magneto-optical recording medium of Test Example 14 was manufactured by changing the film thicknesses, materials, and compositions of magnetic layers while the layer structure remained the same, and the same measurement was performed. Table 3 shows the film thicknesses, materials, and compositions of the magnetic layers of Test Example 14. Table 4 shows the measurement results.
Comparative Test Example 1
A magneto-optical recording medium having substantially the same structure as that of Test Example 1 was manufactured, except that an Al reflection layer was formed in place of the TbCo initializing layer.
A bit was recorded on the magneto-optical recording medium to have a minimum mark length of 0.8 μm while increasing the recording frequency as the linear velocity increased.
The recording power was set to be a value which maximized the C/N ratio. The laser wavelength was set to be 780 nm.
Broken curve 3 in Fig. 6 represents the C/N ratio measured after recording, and the linear velocity and recording frequency in the recording state. The C/N ratio deteriorated at a linear velocity of 19.8 m/s and a recording frequency of 12.4 MHz (a C/N ratio of 45 dB or less).
A magneto-optical recording medium of Comparative Test Example 2 was manufactured by changing the film thicknesses, materials, and compositions of magnetic layers while the layer structure remained the same, and the same measurement was performed. Table 1 shows the film thicknesses, materials, and compositions of the magnetic layers of Comparative Test Example 2. Table 4 shows the measurement results.
TABLE 1______________________________________ First Magnetic Layer Second Magnetic Layer Film Film Thick- Thick- Composition ness Composition ness (at %) (Å) (at %) (Å)______________________________________Test Tb.sub.21 Fe.sub.72 Co.sub.7 800 Tb.sub.30 Co.sub.70 1,500Example 1Test Tb.sub.21 Fe.sub.72 Co.sub.7 500 Tb.sub.30 Co.sub.70 1,500Example 2Test Tb.sub.21 Fe.sub.72 Co.sub.7 400 Tb.sub.30 Co.sub.70 1,500Example 3Test Tb.sub.21 Fe.sub.72 Co.sub.7 800 Tb.sub.30 Co.sub.70 1,000Example 4Test Tb.sub.21 Fe.sub.72 Co.sub.7 800 Tb.sub.30 Co.sub.70 800Example 5Test Tb.sub.21 Fe.sub.72 Co.sub.7 800 Tb.sub.30 Co.sub.70 400Example 6Test Dy.sub.20 Fe.sub.72 Co.sub.8 800 Tb.sub.30 Co.sub.70 1,000Example 7Test Tb.sub.21 Fe.sub.72 Co.sub.7 800 Gd.sub.15 Tb.sub.14 Co.sub.71 1,500Example 8Test Tb.sub.19 Fe.sub.74 Co.sub.7 800 Tb.sub.30 Co.sub.70 800Example 9Test Tb.sub.22 Fe.sub.71 Co.sub.7 300 Tb.sub.30 Co.sub.70 400Example 10Test Tb.sub.21 Fe.sub.64 Co.sub.15 600 Gd.sub.15 Tb.sub.14 Co.sub.71 600Example 11Comparative Tb.sub.21 Fe.sub.72 Co.sub.7 800 Al 500TestExample 1Comparative Tb.sub.23 Fe.sub.70 Co.sub.7 700 Al 400TestExample 2______________________________________
TABLE 2__________________________________________________________________________Reproducing Layer First Magnetic Layer Second Magnetic LayerComposition Film Composition Film Composition Film(at %) Thickness (at %) Thickness (at %) Thickness__________________________________________________________________________Test Gd.sub.20 Fe.sub.65 Co.sub.15 300 Tb.sub.21 Fe.sub.72 Co.sub.7 300 Tb.sub.30 Co.sub.70 400Example 12__________________________________________________________________________
TABLE 3__________________________________________________________________________First Magnetic Layer Intermediate Layer Second Magnetic LayerComposition Film Composition Film Composition Film(at %) Thickness (at %) Thickness (at %) Thickness__________________________________________________________________________Test Tb.sub.21 Fe.sub.72 Co.sub.7 800 Gd.sub.40 Fe.sub.40 Co.sub.20 50 Tb.sub.30 Co.sub.70 800Example 13Test Tb.sub.21 Fe.sub.72 Co.sub.7 500 Gd.sub.34 Fe.sub.42 Co.sub.24 40 Tb.sub.30 Co.sub.70 500Example 14__________________________________________________________________________
TABLE 4______________________________________Measurement Results Recording Linear Frequency Velocity (MHz) (m/s)______________________________________Test Example 1 17.8 28.5Test Example 2 16.0 25.6Test Example 3 14.0 22.4Test Example 4 17.2 27.5Test Example 5 17.0 27.2Test Example 6 16.5 26.4Test Example 7 17.3 27.7Test Example 8 16.4 26.2Test Example 9 15.9 25.4Test Example 10 16.2 25.9Test Example 11 15.8 25.3Test Example 12 19.8 31.7Test Example 13 19.0 30.4Test Example 14 18.1 29.0Comparative 12.4 19.8Test Example 1Comparative 11.0 17.6Test Example 2______________________________________ minimum bit length = 0.8 μm
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A magneto-optical recording medium and an information recording method using the medium in which over-write is performed by magnetic field modulation. The magneto-optical recording medium includes a second magnetic layer (initializing layer) consisting of a magnetic layer, which is magnetized in advance in one direction, has a high Curie temperature, does not lose magnetization in a recording/erasing mode, and has a perpendicular magnetic anisotropy, and a first magnetic layer (recording layer) having a perpendicular magnetic anisotropy and exchange-coupled to the second magnetic layer. The data transfer speed in an over-write operation is remarkably increased when recording is performed by turning on/off an external magnetic field in accordance with information while radiating a lazer beam using the magnetooptical recording medium.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a driving device for use in small office automation equipment or the like, and in particular to a driving pulley for a steel belt.
2. Related Background Art
For office automation equipment there is desired a compact and light pulley, in consideration of dimension of the equipment. For this reason there have been employed pulleys made of light metals. Also for driving such pulley there has been employed a steel belt for preventing elongation by fatigue, since a twisted wire belt or a rubber belt results in an elongation after prolonged use, thus deteriorating the precision of belt position.
The surface of such pulley should have a high hardness in order to increase the abrasion resistance. For this purpose, there is already proposed a pulley having a thin film of a hard metal on the belt driving surface, as disclosed in the Japanese Utility Model Laid-open No. 29148/1972.However such pulley tends to show a small friction resistance, in engagement with a mirror-finished steel belt, thus eventually resulting in slippage.
Also the Japanese Patent Publication No. 44684/l982 disclosed a process of mechanically finishing the surface of an aluminum pulley and depositing a suitable amount of an extremely hard material such as chromium oxide, alumina, tungsten or tungsten carbide on said surface by melt spraying, thereby obtaining a high hardness and a high friction on said surface.
However such forced spraying of chromium oxide, alumina etc. on the surface of pulley inevitably leads to an inexact external diameter of the pulley, and such uneven dimensional accuracy gives rise to defective frictional drive for the steel belt.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a pulley which is small in size, light in weight, has a high abrasion resistance at the surface and a high friction on the belt driving surface.
Another object of the present invention is to provide a pulley having a uniform eternal diameter and adapted for mass production.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a font view of a pulley embodying the present invention;
FIG. 2 is a schematic view showing a state of mixture of metal matrix and ceramic material;
FIG. 3 is a schematic view showing a state in which the ceramic material is exposed t the surface by dissolving the surface of the metal matrix;
FIG. 4 is a perspective view of the state of use in which a metal belt engages with a pulley;
FIG. 5 is a cross-sectional view of the second embodiment of the pulley of the present invention;
FIG. 6 is a perspective view thereof;
FIG. 7 is a schematic view of a cylindrical composite in extrusion molding;
FIG. 8A is a schematic view showing the cutting of said composite material into a predetermined dimension;
FIG. 8B is a schematic view showing the combination of said composite material with a bearing portion; and
FIG. 8C is a view of completed pulley.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In consideration of the foregoing, the present invention is to provide a pulley capable, even in combination with a mirror-finished steel belt with a low friction resistance, of generating a large friction resistance on the pulley surface by exposing hard materials of a high friction resistance by the etching of the surface thereby obtaining stable and reliable driving power.
This object can be achieved by forming a pulley with a mixture of a metal or resin matrix material and hard particles for example of ceramic material, and etching the surface of said pulley to partially expose said hard particles.
This invention will now be clarified in greater detail by the embodiments shown in the attached drawings. At first, as shown in FIG. 1, ceramic particles 2 are mixed in a metal matrix 3, for example aluminum metal. In this operation the aluminum 3 is formed as granules of suitable size, and the ceramic particles 2 of a particle size of 50 to 300 microns are mixed. The mixing ratio is about 30%. The above-mentioned range of particle size provides an almost constant result in the measurement of friction coefficient, and is therefore most preferable for use and for manufacture.
In practice, as shown in FIG. 2, ceramic particles 2 of predetermined particle size are collected by passing a suitable filter, and are mixed in the metal matrix 3. The metal matrix 3 is preferably composed of a low-melting metal such as aluminum, but other metals such magnesium, zinc or copper may also be employed in consideration of the ease of manufacture.
The ceramic particles 2 are mixed, with a mixing ratio of about 30%, into the metal matrix 3, and the mixture is then fused by heating in a high-frequency electric furnace. By such heating, the metal matrix 3 is fused and turns to liquid in a stage mixed with said ceramic particles 2.
Then the liquid metal matrix 3 is poured in a metal mold and cooled. The size of the pulley is determined by said metal mold.
Said pulley 1 has smooth surface obtained by casting in the mold, and the metal matrix 3 of said surface is etched with a chemical agent to obtain a friction resistance on said surface.
For example, aluminum metal 3 in the present embodiment is dissolved, while partially exposing the ceramic particles 2 on the surface, by immersion in aqueous solution of sodium hydroxide.
Thus the exposed amount of the ceramic particles 2 is determined by the mixed amount thereof, and the members providing the friction resistance are formed in this manner.
FIG. 4 shows a state in which a metal belt 5 is wound around the pulley 1 thus formed. The mirror-finished surface of the metal belt 5 and the surface of the pulley 1, maintained in contact during rotation, do not cause mutual slippage but can achieve stable driving due to the friction resistance of the surface 4 of the pulley.
The surface 4 of the pulley 1 is made coarse by the presence of the ceramic particles 2 and generates a friction resistance in contact with the surface of the belt 5 by means of the irregular coarse surface, thus obtaining stable driving capability.
Since the pulley 1 is formed by molding with molten metal, the exposed ceramic particles 2 have a uniform exposed height over the entire surface, and said exposed height is small, so that the metal belt 5 is not damaged by said particles.
Consequently there can be constantly obtained stable driving performance.
Though the foregoing explanation has been limited to aluminum metal, similar results can be obtained with other soft metals or resin materials. Also the ceramic material may be replaced by similar hard materials, and the present invention can therefore be modified in various manners within the scope and spirit of the appended claims.
In the following there will be explained a second embodiment of the present invention.
As shown in a cross-sectional view in FIG. 5 and a perspective view in FIG. 6, a pulley 11 of the second embodiment is composed of a cylindrical composite member 12 of a predetermined width L composed of a light metal or a resinous material incorporating powdered hard material 14 in a similar manner as in the foregoing embodiment, and a bearing portion 13 consisting of a core member inserted in a penetrating hole 15 of said cylindrical composite member 12.
More specifically, said cylindrical composite member 12 is obtained by fusing light metal or resin chips in which the powdered hard material 14 such as alumina or tungsten carbide is mixed, and extruding the fused material in a long form as shown in FIG. 7 from an extrusion molding machine.
Such integral molding of a long cylindrical member allows to obtain pulleys with uniform internal and external diameters in mass production.
Among the above-mentioned powdered hard materials, either one can be selected, according to the molding conditions to be employed.
The bearing portion 13 is molded with a resin material, by means of a mold of a width corresponding to that of the pulley 1, in such a manner that the external diameter becomes equal to the internal diameter of said cylindrical composite member 12 and that a penetrating hole 16 is formed in the center.
The hole 16 at the center of said bearing portion 13 serves for accepting a shaft when the completed pulley 11 is rotated.
For mutually combining the molded parts 12 and 13, the composite member 12 is cut to pieces of a predetermined width L as shown in FIG. 8A.
The cutting may be achieved with a diamond cutter since the mixed powdered hard material 14 has a high hardness.
Then, as shown in FIG. 8B, the bearing portion 13 is pressed into the penetrating hole 15 of the composite member 2 which is already cut as explained above. The width of said bearing portion 3 is selected equal to or slightly smaller than the width L of the composite member 2.
Through these steps an independent pulley 11 as shown in FIG. 8C can be obtained.
Also in this embodiment powdered hard particles are exposed to increase the friction resistance, by etching the matrix material on the surface of the pulley with a chemical agent or the like, as already explained in the first embodiment.
As explained in the foregoing, the pulley of the present embodiment can be mass produced inexpensively with uniform performance, as it is composed of a composite member and a bearing portion, both of which can be obtained by mass production by means of molding operation.
Also the presence of powdered material mixed in the composite member constituting the pulley provides a high hardness and ensures a high abrasion resistance, thereby significantly extending the service life of the pulley.
On the other hand, the resin core member inserted into the pulley allows to reduce the weight thereof and to economize the matrix material and the powdered hard material.
Furthermore, in contact with a metal belt, there is generated a friction resistance between the pulley and said belt, and said resistance prevents the slippage and always ensures stable driving performance. This fact is important in the use of the office automation equipment an in the protection of the belt.
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A pulley composed of a composite material in which hard particles are dispersed in a matrix material, in which a part of the hard particles is exposed to the outside by removal of the matrix material at the pulley surface.
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BACKGROUND OF THE INVENTION
The invention relates to a method for continuously cleaning a heat exchanger during operation as well as to an apparatus to be used with such a method.
More specifically, the invention relates to a method for continuously cleaning a heat exchanger of a type called the closed loop type, which is provided with a series of heat exchanging pipes, with one medium--for instance the cooling medium--passing through the pipes and the other medium--for instance the medium to be cooled--being carried along the pipes. Heat exchangers of this type are used on a large scale in many branches of industry, for instance in the petroleum and coal industries for cooling the products obtained from hydrocrackers and gasifiers. A cooling medium often used is water or air. When air is used, the cooling medium is usually passed through the heat exchanging pipes while the air is blown along the pipes at a high velocity. In a heat exchanger in which water is used as the cooling medium the water is usually carried through the pipes while the medium to be cooled flows along the pipes.
The invention relates to a method and apparatus for continuously cleaning a heat exchanger used for cooling a gaseous medium which is polluted by solid particles. Such a gaseous medium to be cooled may be for instance product gas obtained from the partial combustion of liquid or solid hydrocarbons. Such product gases usually contain fairly large quantities of small to very small solid particles, such as soot and fly ash. Particularly when the solid particles are somewhat sticky there is a risk of these particles adhering to the walls of the heat exchanging pipes when, along with the gas to be cooled, they are carried through a heat exchanger. However, such a particle buildup on the pipe walls will soon lead to a decrease in the rate of heat transfer between gas to be cooled and cooling medium. When the heat transfer efficiency of the heat exchanger has fallen to a certain level, the heat exchanging pipes have to be cleaned in order to restore their efficiency.
In practice, a vast variety of methods and devices are used for cleaning the surfaces of heat exchanging pipes. A well known cleaning method comprises passing solid particles, for instance grains of sand and tiny steel balls, along or through the heat exchanging pipes. During their passage these solid particles strike against the pipe walls and thus remove deposits from the pipe walls. The solid cleaning particles can be introduced into the heat exchanger during operation, which obviates the need for shutting down the heat exchanger for a turn-out.
If in case of severely polluted gases a heat exchanger is to maintain a constant maximum heat transfer efficiency, the pipe walls must preferably be cleaned continuously. According to the known method the continuous cleaning of the pipe walls can be performed by moving a stream of solid particles together with the gases in continuous circulation through the heat exchanger. In case of a heat exchanger used for cooling gas which is polluted by solid particles, the solid cleaning particles are preferably passed through the heat exchanger together with the gas stream forcing the solid cleaning particles along. When the gas containing the cleaning particles has left the heat exchanger, it is passed through a separator in order to remove the cleaning particles together with the entrained solid impurities from the gas stream. The separated cleaning particles may subsequently be recirculated to the heat exchanger to perform another cleaning cycle. In the abovementioned known method of continuously cleaning heat exchangers the solid particles are circulated by means of mechanical pumping. Particularly the use of rigid cleaning particles, such as sand grains, leads to a great deal of wear in the circulating pump due to the scouring effect of the solid particles.
According to another known method for continuously cleaning vertical pipe walls of a heat exchanger, solid cleaning particles are provided inside or outside the heat exchanging pipes in such a manner that, during operation, a fluidized bed is created by an upward flow of the heat absorbing or the heat emitting medium. This method has the advantage over the aforementioned method that the particles remain in the heat exchanger permanently and that therefore the medium carried along those particles need not be subjected to further treatment for separating the medium from the cleaning particles. However, the latter method does have a number of disadvantages, for instance the possibility of the fluidized bed of cleaning particles becoming choked by impurities, instability of the bed in case of fluctuations of the medium passing through the bed during operation, as well as the limited possibility of working at reduced throughput rates, since a certain minimum velocity of the medium is required to prevent the fluidized bed from collapsing.
It is an object of the invention to provide an improved method of continuously cleaning a heat exchanger, which does not require the use of mechanical pumping devices that can easily be damaged, and by which the solid particles themselves are continuously cleaned, so that the cleaning particles in the heat exchanger will produce an optimum effect which will also be maintained with none of the drawbacks adhering to the last-named clearing method.
It is another object of the invention to provide an apparatus to be used with such an improved cleaning method.
SUMMARY OF THE INVENTION
According to the present invention the method for the continuous cleaning, during operation, of a heat exchanger with heat exchanging pipes used for treating a gas which is polluted by solid particles, comprises feeding solid cleaning particles into a polluted gas which is to be cooled, allowing the gas containing the cleaning particles to pass through the heat exchanger, separating the cleaning particles from the treated gas, collecting the separated cleaning particles in a virtually vertically disposed, oblong collector, passing a gas stream through the collector in an upward direction in order to create a fluidized bed of cleaning particles in a manner causing said bed to both remove impurities from the cleaning particles and build up a thrust for moving the cleaning particles towards the heat exchanger in order to allow the cleaning particles to be recirculated into the heat exchanger.
According to the invention the apparatus to be used in the aforementioned method for continuously cleaning a heat exchanger with heat exchanging pipes during operation comprises a virtually vertically disposed cyclone with a tangential inlet for gas and cleaning particles, which inlet communicates with an outlet of the heat exchanger, a gas outlet in the upper part of the cyclone and an outlet for cleaning particles in the lower part of the cyclone, a virtually vertically disposed, oblong collector with an inlet which connects to the cleaning particles outlet of the cyclone and an outlet which communicates with an inlet of the heat exchanger, means for feeding a gas into the lower part of the collector and an open tubular element for the discharge of gas from the collector to the gas outlet of the cyclone, which element is fitted virtually coaxially to the inlet of the collector and the cleaning particles outlet of the cyclone.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a diagram of a system for continuously cleaning a heat exchanger according to the invention.
FIG. 2 shows a longitudinal section of an apparatus for use in this cleaning system.
DESCRIPTION OF THE INVENTION
In the afore-described method and apparatus according to the invention for continuously cleaning a heat exchanger with heat exchanging pipes, it is with two objectives that gas is supplied to the cleaning particles after they have been separated from the gas that has passed through the heat exchanger, viz. the removal of impurities entrained with the cleaning particles and the creation of a pressure gradient by building up a fluidized bed in a manner which allows the cleaning particles to be formed from the lower part of the bed to the entrance of the heat exchanger without mechanical pumping means being needed for this transport. The proposed method and apparatus enable heat exchangers to be kept in operation over a long period and with maximum efficiency.
FIG. 1 gives a schematic representation of what is called a closed circulation system for the use and cleaning of heat exchangers. This system comprises a heat exchanger 1, which is used for instance for cooling product gases polluted by fine solid particles, such as fly ash or soot. Heat exchanger 1 is provided with a number of bundles of heat exchanging pipes 2 through which during operation for instance water, with or without steam, flows. The heat exchanger is provided with a gas inlet 3 and a gas outlet 4 which are connected with a circulation system--referred to as number 5--for solid cleaning particles which are passed through the heat exchanger together with the gas to be cooled.
The cleaning particles may be of a regular or an irregular shape and by preference they are hard. Suitable cleaning particles are, for instance, sand grains. While these particles pass through the heat exchanger together with the polluted gas to be cooled, they regularly collide with or scrape along the pipe walls. Thus, impurities which have been deposited on the walls are removed and carried along with the gas stream through the heat exchanger.
The cooled gas, together with the cleaning particles and the impurities contained therein, is subsequently fed through pipe 6, tangentially into a cyclone 7, where the cleaning particles are separated from the gas stream. Subsequently the gas stream is passed through a next cyclone not shown here in order to separate fine particles, such as fly ash, which have been left behind.
The separated cleaning particles are collected in a vessel 8, where they are brought into the fluidized state in a manner controlled to achieve a pressure build-up along the length of the vessel which is sufficiently large that the particles can be forced via the bottom of the vessel to mixing vessel 9 through a pipe 10. Moreover, in vessel 8 remaining impurities are removed from the cleaning particles, which will hereinafter be further discussed, with the aid of FIG. 2.
In mixing vessel 9 a monitored quantity of cleaning particles is continuously fed into a polluted gas stream to be cooled as the stream enters the mixing vessel through pipe 11. Then the gas and the cleaning particles are passed through pipe 12 to inlet 3 of the heat exchanger. Fresh cleaning particles can be fed to the gas to be cooled in mixing vessel 9, through pipe 13.
Cyclone separator 7 and vessel 8, which constitute the most important parts of the system for circulating the cleaning particles, will now be further discussed with the aid of FIG. 2.
Cyclone separator 7, which during operation is positioned virtually vertically, comprises a cylindrical part 20 and a conical lower part 21, the open bottom of which constitutes the opening of the outlet 22 for cleaning particles. A tangential gas inlet 23 is fitted into the side wall of the cylindrical part 20. The cyclone is further provided with an open gas outlet pipe 24, the bottom end of which is situated below gas inlet 23. This gas outlet pipe 24 is fitted virtually coaxially with the cylindrical part 20.
In the lower part of cyclone 7 an open tubular element 25 is supported (on brackets not shown). The outer and inner walls of element 25 are virtually concentric with the cyclone wall and gas outlet 24. The opening through element 25 narrows slightly to the top and its walls are so shaped that the top 26 of element 25 forms a sharp edge. This sharp edge serves to enhance the stability of the cyclone, since the vortex of gas flowing to the outlet, which is created during operation, can adhere as it were to this edge.
The outer surface of the lower part of element 25 runs virtually concentrically with the inner surface of the conical part 21, so that an annular passage 27 is formed for the discharge of cleaning particles separated in the upper part of the cyclone. Immediately below the discharge opening 22 and virtually concentrically therewith, is arranged vessel 8, which in the drawn example is virtually tubular, with an open top end 28 and an open bottom end 29. Near the bottom end the wall of the vessel 8 is provided with a number of openings 30 for the admission of fluidization gas. Solid particles can be removed from the circulation system by way of a discharge pipe 31 which is fitted in the wall of the vessel. The bottom of the vessel 8 communicates with mixing vessel 9 via pipe 10, the lower part of vessel 8 being conical in order to create a smooth through-flow of cleaning particles into pipe 10, free from the risk of blocking-up.
During operation of heat exchanger 1 the cleaning particles, separated from the gas, leave cyclone 7 via the annular area 27 between the cyclone wall and element 25. Upon arriving in vessel 8 the particles are brought into the fluidized state by the injection of gas into vessel 8 through gas inlet openings 30. The rate of the gas injection is controllable to provide a hydrostatic pressure within the column of particles and compensate for the loss of pressure in heat exchanger 1 and cyclone 7 and to raise the overall pressure to such a level that, upon opening of a valve (not shown) situated in pipe 10, the cleaning particles are forced toward mixing vessel 9 and from there flow into heat exchanger 1 together with gas to be cooled.
The minimum length of the pressure recovery vessel 8 is determined by the pressure to be maintained in vessel 8 with the aid of a fluidized bed. A bed depth of 8 m of fluidized sand having for instance a density of 1000 kg/m 3 can lead to a pressure build-up of 0.8 bar. The gas injection into vessel 8 is primarily intended for pressure recovery and has an additional function to perform, i.e., that of cleaner. Solid impurities which have been carried along with the cleaning particles from cyclone 7, will be loosened by the upward flowing gas and carried off therewith. The gas enters the cyclone via the cleaning particles outlet 22 and then flows through the conduit in element 25 to the cyclone outlet 24 where, together with the gas separated in the cyclone, it will leave the cyclone. The cleaning particles which leave the cyclone through the annular passage 27 seal this passage off to the entering gas. A backpressure within the cyclone 7 and thus within the heat exchanger 1 is maintained by the next cyclone or other device (not shown) connected to the outlet of cyclone 7.
It is noted here that for the creation of the fluidized bed in vessel 8, for instance part of the gas separated in cyclone 7 can be used.
During the process of gas cooling the cleaning particles themselves will become somewhat polluted, for instance by sticky impurities from the gas adhering to them. It is therefore advisable to draw off part of the cleaning particles continuously or intermittently while simultaneously adding fresh cleaning particles. It is noted that, if required, further pressure can be added within the closed circulation system by injecting gas into pipe 10 which is situated between the pressure recovery vessel 8 and the mixing vessel. The quantity of cleaning particles needed may be controlled, for instance, by measuring the temperature prevailing in the gas reaching the end of the heat exchanger and adding cleaning particles as needed to maintain the desired extent of cooling. The thrust in pipe 10 can be used to adjust the supply of cleaning particles to the heat exchanger.
FIG. 1 represents a circulation system in which the gas, together with the cleaning particles, is carried through the heat exchanger in an upward direction. However, it is also posdible to arrange the circulation system in such a manner that the gas is forced to flow through the heat exchanger in a downward direction. In the system shown the mixing vessel 9 may, for instance, be constituted by what is called a "lift pot", in which the gas to be cooled is introduced at a lower level than the cleaning particles, so that said particles are carried along by the upward gas stream to the heat exchanger. In the above-mentioned alternative system the mixing vessel 9 is constituted for instance by a collector having a gas outlet in the bottom.
Finally, it is remarked that the cleaning procedure may be started up using, for instance sand as the cleaning particles, which sand may in the course of the procedure gradually be replaced by larger impurities from the gas stream which are separated from the gas stream together with the sand.
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The walls of a heat exchanger for cooling a particle-contaminated gas are continuously cleaned by adding cleaning particles to the gas, separating the cleaning particles, and collecting the separated cleaning particles into a fluidized bed providing sufficient hydrostatic pressure to displace cleaning particles into the heat exchanger.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 11/206,602, now U.S. Pat. No. 7,494,435, filed Aug. 18, 2005.
TECHNICAL FIELD
The present invention relates to electrically variable transmissions with selective operation both in power-split variable speed ratio ranges and in fixed speed ratios, and having three planetary gear sets, two motor/generators and five torque transfer devices.
BACKGROUND OF THE INVENTION
Internal combustion engines, particularly those of the reciprocating piston type, currently propel most vehicles. Such engines are relatively efficient, compact, lightweight, and inexpensive mechanisms by which to convert highly concentrated energy in the form of fuel into useful mechanical power. A novel transmission system, which can be used with internal combustion engines and which can reduce fuel consumption and the emissions of pollutants, may be of great benefit to the public.
The wide variation in the demands that vehicles typically place on internal combustion engines increases fuel consumption and emissions beyond the ideal case for such engines. Typically, a vehicle is propelled by such an engine, which is started from a cold state by a small electric motor and relatively small electric storage batteries, then quickly placed under the loads from propulsion and accessory equipment. Such an engine is also operated through a wide range of speeds and a wide range of loads and typically at an average of approximately a fifth of its maximum power output.
A vehicle transmission typically delivers mechanical power from an engine to the remainder of a drive system, such as fixed final drive gearing, axles and wheels. A typical mechanical transmission allows some freedom in engine operation, usually through alternate selection of five or six different drive ratios, a neutral selection that allows the engine to operate accessories with the vehicle stationary, and clutches or a torque converter for smooth transitions between driving ratios and to start the vehicle from rest with the engine turning. Transmission gear selection typically allows power from the engine to be delivered to the rest of the drive system with a ratio of torque multiplication and speed reduction, with a ratio of torque reduction and speed multiplication known as overdrive, or with a reverse ratio.
An electric generator can transform mechanical power from the engine into electrical power, and an electric motor can transform that electric power back into mechanical power at different torques and speeds for the remainder of the vehicle drive system. This arrangement allows a continuous variation in the ratio of torque and speed between engine and the remainder of the drive system, within the limits of the electric machinery. An electric storage battery used as a source of power for propulsion may be added to this arrangement, forming a series hybrid electric drive system.
The series hybrid system allows the engine to operate with some independence from the torque, speed and power required to propel a vehicle, so the engine may be controlled for improved emissions and efficiency. This system allows the electric machine attached to the engine to act as a motor to start the engine. This system also allows the electric machine attached to the remainder of the drive train to act as a generator, recovering energy from slowing the vehicle into the battery by regenerative braking. A series electric drive suffers from the weight and cost of sufficient electric machinery to transform all of the engine power from mechanical to electrical in the generator and from electrical to mechanical in the drive motor, and from the useful energy lost in these conversions.
A power-split transmission can use what is commonly understood to be “differential gearing” to achieve a continuously variable torque and speed ratio between input and output. An electrically variable transmission can use differential gearing to send a fraction of its transmitted power through a pair of electric motor/generators. The remainder of its power flows through another, parallel path that is all mechanical and direct, of fixed ratio, or alternatively selectable.
One form of differential gearing, as is well known to those skilled in this art, may constitute a planetary gear set. Planetary gearing is usually the preferred embodiment employed in differentially geared inventions, with the advantages of compactness and different torque and speed ratios among all members of the planetary gear set. However, it is possible to construct this invention without planetary gears, as by using bevel gears or other gears in an arrangement where the rotational speed of at least one element of a gear set is always a weighted average of speeds of two other elements.
A hybrid electric vehicle transmission system also includes one or more electric energy storage devices. The typical device is a chemical electric storage battery, but capacitive or mechanical devices, such as an electrically driven flywheel, may also be included. Electric energy storage allows the mechanical output power from the transmission system to the vehicle to vary from the mechanical input power from the engine to the transmission system. The battery or other device also allows for engine starting with the transmission system and for regenerative vehicle braking.
An electrically variable transmission in a vehicle can simply transmit mechanical power from an engine input to a final drive output. To do so, the electric power produced by one motor/generator balances the electrical losses and the electric power consumed by the other motor/generator. By using the above-referenced electrical storage battery, the electric power generated by one motor/generator can be greater than or less than the electric power consumed by the other. Electric power from the battery can sometimes allow both motor/generators to act as motors, especially to assist the engine with vehicle acceleration. Both motors can sometimes act as generators to recharge the battery, especially in regenerative vehicle braking.
A successful substitute for the series hybrid transmission is the two-range, input-split and compound-split electrically variable transmission now produced for transit buses, as disclosed in U.S. Pat. No. 5,931,757, issued Aug. 3, 1999, to Michael Roland Schmidt, commonly assigned with the present application, and hereby incorporated by reference in its entirety. Such a transmission utilizes an input means to receive power from the vehicle engine and a power output means to deliver power to drive the vehicle. First and second motor/generators are connected to an energy storage device, such as a battery, so that the energy storage device can accept power from, and supply power to, the first and second motor/generators. A control unit regulates power flow among the energy storage device and the motor/generators as well as between the first and second motor/generators.
Operation in first or second variable-speed-ratio modes of operation may be selectively achieved by using clutches in the nature of first and second torque transfer devices. In the first mode, an input-power-split speed ratio range is formed by the application of the first clutch, and the output speed of the transmission is proportional to the speed of one motor/generator. In the second mode, a compound-power-split speed ratio range is formed by the application of the second clutch, and the output speed of the transmission is not proportional to the speeds of either of the motor/generators, but is an algebraic linear combination of the speeds of the two motor/generators. Operation at a fixed transmission speed ratio may be selectively achieved by the application of both of the clutches. Operation of the transmission in a neutral mode may be selectively achieved by releasing both clutches, decoupling the engine and both electric motor/generators from the transmission output. The transmission incorporates at least one mechanical point in its first mode of operation and at least two mechanical points in its second mode of operation.
U.S. Pat. No. 6,527,658, issued Mar. 4, 2003 to Holmes et al, commonly assigned with the present application, and hereby incorporated by reference in its entirety, discloses an electrically variable transmission utilizing two planetary gear sets, two motor/generators and two clutches to provide input split, compound split, neutral and reverse modes of operation. Both planetary gear sets may be simple, or one may be individually compounded. An electrical control member regulates power flow among an energy storage device and the two motor/generators. This transmission provides two ranges or modes of electrically variable transmission (EVT) operation, selectively providing an input-power-split speed ratio range and a compound-power-split speed ratio range. One fixed speed ratio can also be selectively achieved.
SUMMARY OF THE INVENTION
The present invention provides a family of electrically variable transmissions offering several advantages over conventional automatic transmissions for use in hybrid vehicles, including improved vehicle acceleration performance, improved fuel economy via regenerative braking and electric-only idling and launch, and an attractive marketing feature. An object of the invention is to provide the best possible energy efficiency and emissions for a given engine. In addition, optimal performance, capacity, package size, and ratio coverage for the transmission are sought.
The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including first, second and third differential gear sets, a battery, two electric machines serving interchangeably as motors or generators, and five selectable torque-transfer devices. Preferably, the differential gear sets are planetary gear sets, but other gear arrangements may be implemented, such as bevel gears or differential gearing to an offset axis.
In this description, the first, second or third planetary gear sets may be counted first to second in any order (i.e., left to right; right to left; middle, left, right; etc.).
Each of the three planetary gear sets has three members. The first, second or third member of each planetary gear set can be any one of a sun gear, ring gear or carrier, or alternatively a pinion.
Each carrier can be either a single-pinion carrier (simple) or a double-pinion carrier (compound).
The input shaft is continuously connected with at least one member of the planetary gear sets. The output shaft is continuously connected with another member of the planetary gear sets.
A first fixed interconnection continuously connects the first member of the first planetary gear set with the first member of the second planetary gear set.
A second fixed interconnection continuously connects a second member of the second planetary gear set with the first member of the third planetary gear set or with the second member of the first planetary gear set.
A first torque transfer device, such as a clutch, selectively connects a member of the first or second planetary gear set with a member of the third planetary gear set.
A second torque transfer device, such as a clutch, selectively connects a member of the first, second or third planetary gear set with another member of the third planetary gear set, this pair of members being different from the ones connected by the first torque transfer device.
A third torque transfer device, such as a brake, selectively connects a member of the first, second or third planetary gear set with a stationary member (ground/transmission case).
A fourth torque transmitting device, such as a clutch, selectively connects a member of the second planetary gear set with a member of the third planetary gear set. Alternatively, a fourth torque transmitting device, such as a brake, is connected in parallel with one of the motor/generators for selectively preventing rotation of the motor/generator.
A fifth torque transfer device, such as a brake, is connected in parallel with one of the motor/generators for selectively preventing rotation thereof.
The first motor/generator is mounted to the transmission case (or ground) and is continuously connected to a member of the first or second planetary gear set.
The second motor/generator is mounted to the transmission case and is continuously connected to a member of the first, second or third planetary gear set, this member being different from the one continuously connected to the first motor/generator. Alternatively, a dog-clutch is introduced between the second motor/generator and the planetary gear sets. This allows the motor/generator to be selectively connected to one of two members on the first or second planetary gearset. However, the same function could be achieved by a pair of conventional torque-transmitting mechanisms.
The five selectable torque transfer devices are engaged in combinations of two or three to yield an EVT with a continuously variable range of speeds (including reverse) and up to five mechanically fixed forward speed ratios. A “fixed speed ratio” is an operating condition in which the mechanical power input to the transmission is transmitted mechanically to the output, and no power flow (i.e. almost zero) is present in the motor/generators. An electrically variable transmission that may selectively achieve several fixed speed ratios for operation near full engine power can be smaller and lighter for a given maximum capacity. Fixed ratio operation may also result in lower fuel consumption when operating under conditions where engine speed can approach its optimum without using the motor/generators. A variety of fixed speed ratios and variable ratio spreads can be realized by suitably selecting the tooth ratios of the planetary gear sets.
Each embodiment of the electrically variable transmission family disclosed has an architecture in which neither the transmission input nor output is directly connected to a motor/generator. This allows for a reduction in the size and cost of the electric motor/generators required to achieve the desired vehicle performance.
The torque transfer devices and the first and second motor/generators are operable to provide five operating modes in the electrically variable transmission, including battery reverse mode, EVT reverse mode, reverse and forward launch modes, continuously variable transmission range mode, and fixed ratio mode.
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 a is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
FIG. 1 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 1 a;
FIG. 2 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 2 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 2 a;
FIG. 3 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 3 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 3 a;
FIG. 4 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 4 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 4 a;
FIG. 5 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 5 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 5 a;
FIG. 6 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 6 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 6 a;
FIG. 7 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 7 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 7 a;
FIG. 8 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 8 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 8 a;
FIG. 9 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention;
FIG. 9 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 9 a;
FIG. 10 a is a schematic representation of a powertrain having an electrically variable transmission incorporating another family member of the present invention; and
FIG. 10 b is an operating mode table and fixed ratio mode table depicting some of the operating characteristics of the powertrain shown in FIG. 10 a.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 a , a powertrain 10 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 14 . Transmission 14 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 14 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a diesel engine which is readily adapted to provide its available power output typically delivered at a constant number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 14 .
An output member 19 of the transmission 14 is connected to a final drive 16 .
The transmission 14 utilizes three differential gear sets, preferably in the nature of planetary gear sets 20 , 30 and 40 . The planetary gear set 20 employs an outer gear member 24 , typically designated as the ring gear. The ring gear member 24 circumscribes an inner gear member 22 , typically designated as the sun gear. A carrier member 26 rotatably supports a plurality of planet gears 27 such that each planet gear 27 meshingly engages both the outer, ring gear member 24 and the inner, sun gear member 22 of the first planetary gear set 20 .
The planetary gear set 30 also has an outer gear member 34 , often also designated as the ring gear that circumscribes an inner gear member 32 , also often designated as the sun gear member. A plurality of planet gears 37 are also rotatably mounted in a carrier member 36 such that each planet gear member 37 simultaneously, and meshingly, engages both the outer, ring gear member 34 and the inner, sun gear member 32 of the planetary gear set 30 .
The planetary gear set 40 also has an outer gear member 44 , often also designated as the ring gear that circumscribes an inner gear member 42 , also often designated as the sun gear member. A plurality of planet gears 47 are also rotatably mounted in a carrier member 46 such that each planet gear member 47 simultaneously, and meshingly, engages both the outer, ring gear member 44 and the inner, sun gear member 42 of the planetary gear set 40 .
The transmission input member 17 is connected with the carrier member 36 of the planetary gear set 30 . The output drive member 19 of the transmission 14 is secured to the carrier member 46 of the planetary gear set 40 .
The first preferred embodiment 10 also incorporates first and second motor/generators 80 and 82 , respectively. The stator of the first motor/generator 80 is secured to the transmission housing 60 . The rotor of the first motor/generator 80 is secured to the sun gear member 22 of the planetary gear set 20 .
The stator of the second motor/generator 82 is also secured to the transmission housing 60 . The rotor of the second motor/generator 82 is secured to the sun gear member 32 of the planetary gear set 30 .
A first fixed interconnection 70 continuously connects the ring gear member 24 of the planetary gear set 20 with the carrier member 36 of the planetary gear set 30 . A second fixed interconnection 72 continuously connects the ring gear member 34 of the planetary gear set 30 with the sun gear member 42 of the planetary gear set 40 .
A first torque transfer device, such as a clutch 50 , selectively connects the carrier member 26 of the planetary gear set 20 to the ring gear member 44 of the planetary gear set 40 . A second torque transfer device, such as clutch 52 , selectively connects the carrier member 26 of the planetary gear set 20 with the carrier member 46 of the planetary gear set 40 . A third torque transfer device, such as brake 54 , selectively connects the carrier member 26 of the planetary gear set 20 with the transmission housing 60 . That is, the carrier member 26 is selectively secured against rotation by an operative connection to the non-rotatable housing 60 . A fourth torque transfer device, such as the brake 55 , is connected in parallel with the motor/generator 80 for selectively braking rotation thereof. A fifth torque transfer device, such as the brake 57 , is connected in parallel with the motor/generator 82 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque transfer devices 50 , 52 , 54 , 55 and 57 are employed to assist in the selection of the operational modes of the hybrid transmission 14 , as will be hereinafter more fully explained.
Returning now to the description of the power sources, it should be apparent from the foregoing description, and with particular reference to FIG. 1 a , that the transmission 14 selectively receives power from the engine 12 . The hybrid transmission also receives power from an electric power source 86 , which is operably connected to a controller 88 . The electric power source 86 may be one or more batteries. Other electric power sources, such as fuel cells, that have the ability to provide, or store, and dispense electric power may be used in place of batteries without altering the concepts of the present invention.
General Operating Considerations
One of the primary control devices is a well known drive range selector (not shown) that directs an electronic control unit (the ECU 88 ) to configure the transmission for either the park, reverse, neutral, or forward drive range. The second and third primary control devices constitute an accelerator pedal (not shown) and a brake pedal (also not shown). The information obtained by the ECU from these three primary control sources is designated as the “operator demand.” The ECU also obtains information from a plurality of sensors (input as well as output) as to the status of: the torque transfer devices (either applied or released); the engine output torque; the unified battery, or batteries, capacity level; and, the temperatures of selected vehicular components. The ECU determines what is required and then manipulates the selectively operated components of, or associated with, the transmission appropriately to respond to the operator demand.
The invention may use simple or compound planetary gear sets. In a simple planetary gear set a single set of planet gears are normally supported for rotation on a carrier that is itself rotatable.
In a simple planetary gear set, when the sun gear is held stationary and power is applied to the ring gear of a simple planetary gear set, the planet gears rotate in response to the power applied to the ring gear and thus “walk” circumferentially about the fixed sun gear to effect rotation of the carrier in the same direction as the direction in which the ring gear is being rotated.
When any two members of a simple planetary gear set rotate in the same direction and at the same speed, the third member is forced to turn at the same speed, and in the same direction. For example, when the sun gear and the ring gear rotate in the same direction, and at the same speed, the planet gears do not rotate about their own axes but rather act as wedges to lock the entire unit together to effect what is known as direct drive. That is, the carrier rotates with the sun and ring gears.
However, when the two gear members rotate in the same direction, but at different speeds, the direction in which the third gear member rotates may often be determined simply by visual analysis, but in many situations the direction will not be obvious and can only be accurately determined by knowing the number of teeth present on all the gear members of the planetary gear set.
Whenever the carrier is restrained from spinning freely, and power is applied to either the sun gear or the ring gear, the planet gear members act as idlers. In that way the driven member is rotated in the opposite direction as the drive member. Thus, in many transmission arrangements when the reverse drive range is selected, a torque transfer device serving as a brake is actuated frictionally to engage the carrier and thereby restrain it against rotation so that power applied to the sun gear will turn the ring gear in the opposite direction. Thus, if the ring gear is operatively connected to the drive wheels of a vehicle, such an arrangement is capable of reversing the rotational direction of the drive wheels, and thereby reversing the direction of the vehicle itself.
In a simple set of planetary gears, if any two rotational speeds of the sun gear, the planet carrier, and the ring gear are known, then the speed of the third member can be determined using a simple rule. The rotational speed of the carrier is always proportional to the speeds of the sun and the ring, weighted by their respective numbers of teeth. For example, a ring gear may have twice as many teeth as the sun gear in the same set. The speed of the carrier is then the sum of two-thirds the speed of the ring gear and one-third the speed of the sun gear. If one of these three members rotates in an opposite direction, the arithmetic sign is negative for the speed of that member in mathematical calculations.
The torque on the sun gear, the carrier, and the ring gear can also be simply related to one another if this is done without consideration of the masses of the gears, the acceleration of the gears, or friction within the gear set, all of which have a relatively minor influence in a well designed transmission. The torque applied to the sun gear of a simple planetary gear set must balance the torque applied to the ring gear, in proportion to the number of teeth on each of these gears. For example, the torque applied to a ring gear with twice as many teeth as the sun gear in that set must be twice that applied to the sun gear, and must be applied in the same direction. The torque applied to the carrier must be equal in magnitude and opposite in direction to the sum of the torque on the sun gear and the torque on the ring gear.
In a compound planetary gear set, the utilization of inner and outer sets of planet gears effects an exchange in the roles of the ring gear and the planet carrier in comparison to a simple planetary gear set. For instance, if the sun gear is held stationary, the planet carrier will rotate in the same direction as the ring gear, but the planet carrier with inner and outer sets of planet gears will travel faster than the ring gear, rather than slower.
In a compound planetary gear set having meshing inner and outer sets of planet gears the speed of the ring gear is proportional to the speeds of the sun gear and the planet carrier, weighted by the number of teeth on the sun gear and the number of teeth filled by the planet gears, respectively. For example, the difference between the ring and the sun filled by the planet gears might be as many teeth as are on the sun gear in the same set. In that situation the speed of the ring gear would be the sum of two-thirds the speed of the carrier and one third the speed of the sun. If the sun gear or the planet carrier rotates in an opposite direction, the arithmetic sign is negative for that speed in mathematical calculations.
If the sun gear were to be held stationary, then a carrier with inner and outer sets of planet gears will turn in the same direction as the rotating ring gear of that set. On the other hand, if the sun gear were to be held stationary and the carrier were to be driven, then planet gears in the inner set that engage the sun gear roll, or “walk,” along the sun gear, turning in the same direction that the carrier is rotating. Pinion gears in the outer set that mesh with pinion gears in the inner set will turn in the opposite direction, thus forcing a meshing ring gear in the opposite direction, but only with respect to the planet gears with which the ring gear is meshingly engaged. The planet gears in the outer set are being carried along in the direction of the carrier. The effect of the rotation of the pinion gears in the outer set on their own axis and the greater effect of the orbital motion of the planet gears in the outer set due to the motion of the carrier are combined, so the ring rotates in the same direction as the carrier, but not as fast as the carrier.
If the carrier in such a compound planetary gear set were to be held stationary and the sun gear were to be rotated, then the ring gear will rotate with less speed and in the same direction as the sun gear. If the ring gear of a simple planetary gear set is held stationary and the sun gear is rotated, then the carrier supporting a single set of planet gears will rotate with less speed and in the same direction as the sun gear. Thus, one can readily observe the exchange in roles between the carrier and the ring gear that is caused by the use of inner and outer sets of planet gears which mesh with one another, in comparison with the usage of a single set of planet gears in a simple planetary gear set.
The normal action of an electrically variable transmission is to transmit mechanical power from the input to the output. As part of this transmission action, one of its two motor/generators acts as a generator of electrical power. The other motor/generator acts as a motor and uses that electrical power. As the speed of the output increases from zero to a high speed, the two motor/generators 80 , 82 gradually exchange roles as generator and motor, and may do so more than once. These exchanges take place around mechanical points, where essentially all of the power from input to output is transmitted mechanically and no substantial power is transmitted electrically.
In a hybrid electrically variable transmission system, the battery 86 may also supply power to the transmission or the transmission may supply power to the battery. If the battery is supplying substantial electric power to the transmission, such as for vehicle acceleration, then both motor/generators may act as motors. If the transmission is supplying electric power to the battery, such as for regenerative braking, both motor/generators may act as generators. Very near the mechanical points of operation, both motor/generators may also act as generators with small electrical power outputs, because of the electrical losses in the system.
Contrary to the normal action of the transmission, the transmission may actually be used to transmit mechanical power from the output to the input. This may be done in a vehicle to supplement the vehicle brakes and to enhance or to supplement regenerative braking of the vehicle, especially on long downward grades. If the power flow through the transmission is reversed in this way, the roles of the motor/generators will then be reversed from those in normal action.
Specific Operating Considerations
Each of the embodiments described herein has at least sixteen functional requirements (corresponding with the 16 or more rows of each operating mode table shown in the Figures) which may be grouped into five operating modes. These five operating modes are described below and may be best understood by referring to the respective operating mode table accompanying each transmission stick diagram, such as the operating mode tables of FIG. 1 b , 2 b , 3 b , etc.
The first operating mode is the “battery reverse mode” which corresponds with the first row (Batt Rev) of each operating mode table, such as that of FIG. 1 b . In this mode, the engine is off and the transmission element connected to the engine is not controlled by engine torque, though there may be some residual torque due to the rotational inertia of the engine. The EVT is driven by one of the motor/generators using energy from the battery, causing the vehicle to move in reverse. Depending on the kinematic configuration, the other/motor/generator may or may not rotate in this mode, and may or may not transmit torque. If it does rotate, it is used to generate energy which is stored in the battery. In the embodiment of FIG. 1 b , in the battery reverse mode, the clutch 50 and brake 54 are engaged, the motor 80 has a torque of 1.00 units, the generator 82 has a torque of 0.49 units, and a torque ratio of −5.79 is achieved, corresponding to an engine input torque of 1 unit, by way of example. In each operating mode table an (M) next to a torque value in the motor/generator columns 80 and 82 indicates that the motor/generator is acting as a motor, and the absence of an (M) indicates that the motor/generator is acting as generator.
The second operating mode is the “EVT reverse mode” (or mechanical reverse mode) which corresponds with the second row (EVT Rev) of each operating mode table, such as that of FIG. 1 b . In this mode, the EVT is driven by the engine and by one of the motor/generators. The other motor/generator operates in generator mode and transfers 100% of the generated energy back to the driving motor. The net effect is to drive the vehicle in reverse. Referring to FIG. 1 b , for example, in the EVT reverse mode, the clutch 50 and brake 54 are engaged, the generator 80 has a torque of 1.96 units, the motor 82 has a torque of 0.70 units, and an output torque of −8.33 is achieved, corresponding to an engine torque of 1 unit.
The third operating mode includes the “reverse and forward launch modes” (also referred to as “torque converter reverse and forward modes”) corresponding with the third and fourth rows (TC Rev and TC For) of each operating mode table, such as that of FIG. 1 b . In this mode, the EVT is driven by the engine and one of the motor/generators. A selectable fraction of the energy generated in the generator unit is stored in the battery, with the remaining energy being transferred to the motor. In FIG. 1 , this fraction is approximately 99%. The ratio of transmission output speed to engine speed (transmission speed ratio) is approximately +/−0.001 (the positive sign indicates that the vehicle is creeping forward and negative sign indicates that the vehicle is creeping backwards). Referring to FIG. 1 b , in the reverse and forward launch modes, the clutch 50 and brake 54 are engaged. In the TC Reverse mode, the motor/generator 80 acts as a generator with 1.73 units of torque, the motor/generator 82 acts as a motor with 0.59 units of torque, and a torque ratio of −7.00 is achieved. In the TC Forward mode, the motor/generator 80 acts as a motor with −0.29 units of torque, the motor/generator 82 acts as a generator with −0.39 units of torque, and a torque ratio of 4.69 is achieved.
The fourth operating mode is a “continuously variable transmission range mode” which includes the Range 1 . 1 , Range 1 . 2 , Range 1 . 3 , Range 1 . 4 , Range 2 . 1 , Range 2 . 2 , Range 2 . 3 and Range 2 . 4 operating points corresponding with rows 5 - 12 of each operating point table, such as that of FIG. 1 b . In this mode, the EVT is driven by the engine as well as one of the motor/generators operating as a motor. The other motor/generator operates as a generator and transfers 100% of the generated energy back to the motor. The operating points represented by Range 1 . 1 , 1 . 2 . . . , etc. are discrete points in the continuum of forward speed ratios provided by the EVT. For example in FIG. 1 b , a range of torque ratios from 4.69 to 1.86 is achieved with the clutch 50 and brake 54 engaged, and a range of ratios 1.36 to 0.54 is achieved with the clutches 50 and 52 engaged.
The fifth operating mode includes the “fixed ratio” modes (F 1 , F 2 , F 3 and F 4 ) corresponding with rows 13 - 16 of each operating mode table (i.e. operating mode table), such as that of FIG. 1 b . In this mode the transmission operates like a conventional automatic transmission, with three torque transfer devices engaged to create a discrete transmission ratio. The clutching table accompanying each figure shows only 4 fixed-ratio forward speeds but additional fixed ratios may be available. Referring to FIG. 1 b , in fixed ratio F 1 the clutch 50 and brakes 54 , 57 are engaged to achieve a fixed torque ratio of 3.00. Accordingly, each “X” in the column of motor/generators 80 , 82 in FIG. 1 b indicates that the respective brake 55 or 57 is engaged and the motor/generators 80 or 82 is not rotating. In fixed ratio F 2 , the clutch 52 and brakes 55 , 57 are engaged to achieve a fixed ratio of 1.52. In fixed ratio F 3 , the clutch 50 and brakes 55 , 57 are engaged to achieve a fixed ratio of 1.21. In fixed ratio F 4 , the clutches 50 , 52 and brake 57 are engaged to achieve a fixed ratio of 0.75.
The transmission 14 is capable of operating in so-called single or dual modes. In single mode, the engaged torque transfer device remains the same for the entire continuum of forward speed ratios (represented by the discrete points: Ranges 1 . 1 , 1 . 2 , 1 . 3 and 1 . 4 ). In dual mode, the engaged torque transfer device is switched at some intermediate speed ratio (e.g., Range 2 . 1 in FIG. 1 ). Depending on the mechanical configuration, this change in torque transfer device engagement has advantages in reducing element speeds in the transmission.
In some designs, it is possible to synchronize clutch element slip speeds such that shifts are achievable with minimal torque disturbance (so-called “cold” shifts). For example, the transmissions of FIGS. 5 a and 6 a have cold shifts between ranges 1 . 4 and 2 . 1 . This also serves as an enabler for superior control during double transition shifts (two oncoming clutches and two off-going clutches).
As set forth above, the engagement schedule for the torque transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 1 b . FIG. 1 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 1 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 20 ; the N R2 /N S2 value is the tooth ratio of the planetary gear set 30 and the N R3 /N S3 value is the tooth ratio of the planetary gear set 40 . Also, the chart of FIG. 1 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 1.97, and the ratio spread is 4.00.
Description of a Second Exemplary Embodiment
With reference to FIG. 2 a , a powertrain 110 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission, designated generally by the numeral 114 . Transmission 114 is designed to receive at least a portion of its driving power from the engine 12 .
In the embodiment depicted the engine 12 may also be a fossil fuel engine, such as a diesel engine which is readily adapted to provide its available power output typically delivered at a constant number of revolutions per minute (RPM). As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 114 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 114 . An output member 19 of the transmission 114 is connected to a final drive 16 .
The transmission 114 utilizes three differential gear sets, preferably in the nature of planetary gear sets 120 , 130 and 140 . The planetary gear set 120 employs an outer gear member 124 , typically designated as the ring gear. The ring gear member 124 circumscribes an inner gear member 122 , typically designated as the sun gear. A carrier member 126 rotatably supports a plurality of planet gears 127 such that each planet gear 127 meshingly engages both the outer, ring gear member 124 and the inner, sun gear member 122 of the first planetary gear set 120 .
The planetary gear set 130 also has an outer gear member 134 , often also designated as the ring gear, that circumscribes an inner gear member 132 , also often designated as the sun gear. A plurality of planet gears 137 are also rotatably mounted in a carrier member 136 such that each planet gear member 137 simultaneously, and meshingly, engages both the outer, ring gear member 134 and the inner, sun gear member 132 of the planetary gear set 130 .
The planetary gear set 140 has an outer gear member 144 , often designated as the ring gear, that circumscribes an inner gear member 142 , often designated as the sun gear. A plurality of planet gears 147 are rotatably mounted in a carrier member 146 such that each planet gear member 147 simultaneously, and meshingly, engages both the outer, ring gear member 144 and the inner, sun gear member 142 of the planetary gear set 140 .
The transmission input member 17 is connected with the carrier member 136 of the planetary gear set 130 , and the transmission output member 19 is connected with the carrier member 146 of the planetary gear set 140 .
The transmission 114 also incorporates first and second motor/generators 180 and 182 , respectively. The stator of the first motor/generator 180 is secured to the transmission housing 160 . The rotor of the first motor/generator 180 is secured to the sun gear member 122 of the planetary gear set 120 .
The stator of the second motor/generator 182 is also secured to the transmission housing 160 . The rotor of the second motor/generator 182 is secured to the sun gear member 132 of the planetary gear set 130 .
A first fixed interconnection 170 continuously connects the ring gear member 124 of the planetary gear set 120 with the carrier member 136 of the planetary gear set 130 . A second fixed interconnection 172 continuously connects the ring gear member 134 of the planetary gear set 130 with the sun gear member 142 of the planetary gear set 140 .
A first torque transfer device, such as a clutch 150 , selectively connects the carrier member 126 of the planetary gear set 120 to the ring gear member 144 of the planetary gear set 140 . A second torque transfer device, such as clutch 152 , selectively connects the sun gear member 142 with the ring gear member 144 of the planetary gear set 140 . A third torque transfer device, such as brake 154 , selectively connects the carrier member 126 of the planetary gear set 120 with the transmission housing 160 . That is, the carrier member 126 is selectively secured against rotation by an operative connection to the non-rotatable housing 160 . A fourth torque transfer device, such as the brake 155 , is connected in parallel with the motor/generator 180 for selectively braking rotation thereof. A fifth torque transfer device, such as the brake 157 , is connected in parallel with the motor/generator 182 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque transfer devices 150 , 152 , 154 , 155 and 157 are employed to assist in the selection of the operational modes of the hybrid transmission 114 .
Returning now to the description of the power sources, it should be apparent from the foregoing description, and with particular reference to FIG. 2 a , that the transmission 114 selectively receives power from the engine 12 . The hybrid transmission also exchanges power with an electric power source 186 , which is operably connected to a controller 188 . The electric power source 186 may be one or more batteries. Other electric power sources, such as fuel cells, that have the ability to provide, or store, and dispense electric power may be used in place of batteries without altering the concepts of the present invention.
As described previously, each embodiment has sixteen functional requirements (corresponding with the 16 rows of each operating mode table shown in the Figures) which may be grouped into five operating modes. The first operating mode is the “battery reverse mode” which corresponds with the first row (Batt Rev) of the operating mode table of FIG. 2 b . In this mode, the engine is off and the transmission element connected to the engine is effectively allowed to freewheel, subject to engine inertia torque. The EVT is driven by one of the motor/generators using energy from the battery, causing the vehicle to move in reverse. The other motor/generator may or may not rotate in this mode. As shown in FIG. 2 b , in this mode the clutch 150 and brake 154 are engaged, the motor 180 has a torque of 1.00 units, the generator 182 has a torque of 0.49 units and an output torque of −5.79 is achieved, by way of example.
The second operating mode is the “EVT reverse mode” (or mechanical reverse mode) which corresponds with the second row (EVT Rev) of the operating mode table of FIG. 2 b . In this mode, the EVT is driven by the engine and by one of the motor/generators. The other motor/generator operates in generator mode and transfers 100% of the generated energy back to the driving motor. The net effect is to drive the vehicle in reverse. In this mode, the clutch 150 and brake 154 are engaged, the generator 180 has a torque of 1.96 units, the motor 182 has a torque of 0.70 units, and an output torque of −8.33 is achieved, corresponding to an input torque of 1 unit.
The third operating mode includes the “reverse and forward launch modes” corresponding with the third and fourth rows (TC Rev and TC For) of each operating mode table, such as that of FIG. 2 b . In this mode, the EVT is driven by the engine and one of the motor/generators. A selectable fraction of the energy generated in the generator unit is stored in the battery, with the remaining energy being transferred to the motor. In this mode the clutch 150 and the brake 154 are engaged. In the TC Reverse mode, the motor/generator 80 acts as a generator with 1.73 units of torque, the motor/generator 82 acts as a motor with 0.59 units of torque, and a torque ratio of −7.00 is achieved. In the TC Forward mode, the motor/generator 80 acts as a motor with −0.29 units of torque, the motor/generator 82 acts as a generator with −0.39 units of torque, and a torque ratio of 4.69 is achieved. For these torque ratios, approximately 99% of the generator energy is stored in the battery.
The fourth operating mode includes the “Range 1 . 1 , Range 1 . 2 , Range 1 . 3 , Range 1 . 4 , Range 2 . 1 , Range 2 . 2 , Range 2 . 3 and Range 2 . 4 ” modes corresponding with rows 5 - 12 of the operating mode table of FIG. 2 b . In this mode, the EVT is driven by the engine as well as one of the motor/generators operating as a motor. The other motor/generator operates as a generator and transfers 100% of the generated energy back to the motor. The operating points represented by Range 1 . 1 , 1 . 2 . . . , etc. are discrete points in the continuum of forward speed ratios provided by the EVT. For example in FIG. 2 b , a range of ratios from 4.69 to 1.86 is achieved with the clutch 150 and the brake 154 engaged, and a range of ratios from 1.36 to 0.54 is achieved with the clutches 150 and 152 engaged.
The fifth operating mode includes the fixed “ratio” modes (F 1 , F 2 , F 3 and F 4 ) corresponding with rows 13 - 16 of the operating mode table of FIG. 2 b . In this mode the transmission operates like a conventional automatic transmission, with three torque transfer devices engaged to create a discrete transmission ratio. In fixed ratio F 1 the clutch 150 and brakes 154 and 157 are engaged to achieve a fixed ratio of 3.00. In fixed ratio F 2 , the clutches 150 , 152 and brake 155 are engaged to achieve a fixed ratio of 1.52. In fixed ratio F 3 , the clutch 150 and brakes 155 , 157 are engaged to achieve a fixed ratio of 1.21. In fixed ratio F 4 , the clutch 152 and brakes 154 , 157 are engaged to achieve a fixed ratio of 0.75.
As set forth above, the engagement schedule for the torque transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 2 b . FIG. 2 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 2 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 120 ; the N R2 /N S2 value is the tooth ratio of the planetary gear set 130 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 140 . Also, the chart of FIG. 2 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratio is 1.97, and the ratio spread is 4.00.
Description of a Third Exemplary Embodiment
With reference to FIG. 3 a , a powertrain 210 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission, designated generally by the numeral 214 . The transmission 214 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 214 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission 214 .
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member is operatively connected to a planetary gear set in the transmission 214 . An output member 19 of the transmission 214 is connected to a final drive 16 .
The transmission 214 utilizes three differential gear sets, preferably in the nature of planetary gear sets 220 , 230 and 240 . The planetary gear set 220 employs an outer gear member 224 , typically designated as the ring gear. The ring gear member 224 circumscribes an inner gear member 222 , typically designated as the sun gear. A carrier member 226 rotatably supports a plurality of planet gears 227 such that each planet gear 227 meshingly engages both the outer, ring gear member 224 and the inner, sun gear member 222 of the first planetary gear set 220 .
The planetary gear set 230 also has an outer ring gear member 234 that circumscribes an inner sun gear member 232 . A plurality of planet gears 237 are also rotatably mounted in a carrier member 236 such that each planet gear member 237 meshingly engages both the sun gear member 232 and the ring gear member 234 of the planetary gear set 230 .
The planetary gear set 240 employs an outer gear member 244 , typically designated as the ring gear. The ring gear member 244 circumscribes an inner gear member 242 , typically designated as the sun gear. A carrier member 246 rotatably supports a plurality of planet gears 247 such that each planet gear 247 meshingly engages both the outer, ring gear member 244 and the inner, sun gear member 242 of the planetary gear set 240 .
The transmission input member 17 is connected with the ring gear member 224 , and the transmission output member 19 is connected to the carrier member 246 .
The transmission 214 also incorporates first and second motor/generators 280 and 282 , respectively. The stator of the first motor/generator 280 is secured to the transmission housing 260 . The rotor of the first motor/generator 280 is secured to the sun gear member 222 of the planetary gear set 220 .
The stator of the second motor/generator 282 is also secured to the transmission housing 260 . The rotor of the second motor/generator 282 is secured to the carrier member 236 of the planetary gear set 230 .
A first fixed interconnection 270 continuously connects the sun gear member 222 of the planetary gear set 220 with the sun gear member 232 of the planetary gear set 230 . A second fixed interconnection 272 continuously connects the ring gear member 234 of the planetary gear set 230 with the sun gear member 242 of the planetary gear set 240 .
A first torque-transfer device, such as clutch 250 , selectively connects the ring gear member 224 of the planetary gear set 220 with the ring gear member 244 of the planetary gear set 240 . A second torque-transfer device, such as clutch 252 , selectively connects the carrier member 226 of the planetary gear set 220 with the ring gear member 244 of the planetary gear set 240 . A third torque-transfer device, such as a brake 254 , selectively connects the carrier member 226 with the transmission housing 260 . A fourth torque transfer device, such as the brake 255 , is connected in parallel with the motor/generator 280 for selectively braking rotation thereof. A fifth torque transfer device, such as the brake 257 , is connected in parallel with the motor/generator 282 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque-transfer devices 250 , 252 , 254 , 255 and 257 are employed to assist in the selection of the operational modes of the hybrid transmission 214 .
The hybrid transmission 214 receives power from the engine 12 , and also from electric power source 286 , which is operably connected to a controller 288 .
The operating mode table of FIG. 3 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 214 . These modes include the “battery reverse mode” (Batt Rev), “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “range 1 . 1 , 1 . 2 , 1 . 3 . . . modes” and “fixed ratio modes” (F 1 , F 2 , F 3 and F 4 ) as described previously.
As set forth above the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 3 b . FIG. 3 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 3 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 220 ; the N R2 /N S2 value is the tooth ratio of the planetary gear set 230 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 240 . Also, the chart of FIG. 3 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between the first and second fixed forward torque ratios is 2.02, the ratio spread is 3.37.
Description of a Fourth Exemplary Embodiment
With reference to FIG. 4 a , a powertrain 310 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission, designated generally by the numeral 314 . The transmission 314 is designed to receive at least a portion of its driving power from the engine 12 .
As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 314 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 314 . An output member 19 of the transmission 314 is connected to a final drive 16 .
The transmission 314 utilizes three planetary gear sets 320 , 330 and 340 . The planetary gear set 320 employs an outer ring gear member 324 which circumscribes an inner sun gear member 322 . A carrier member 326 rotatably supports a plurality of planet gears 327 such that each planet gear 327 meshingly engages both the outer ring gear member 324 and the inner sun gear member 322 of the first planetary gear set 320 .
The planetary gear set 330 also has an outer ring gear member 334 that circumscribes an inner sun gear member 332 . A plurality of planet gears 337 are also rotatably mounted in a carrier member 336 such that each planet gear member 337 simultaneously, and meshingly engages both the outer, ring gear member 334 and the inner, sun gear member 332 of the planetary gear set 330 .
The planetary gear set 340 employs an outer ring gear member 344 which circumscribes an inner sun gear member 342 . A carrier member 346 rotatably supports a plurality of planet gears 347 such that each planet gear 347 meshingly engages both the outer ring gear member 344 and the inner sun gear member 342 of the planetary gear set 340 .
The transmission input member 17 is connected with the ring gear member 324 of the planetary gear set 320 , and the transmission output member 19 is connected with the carrier member 346 of the planetary gear set 340 .
The transmission 314 also incorporates first and second motor/generators 380 and 382 , respectively. The stator of the first motor/generator 380 is secured to the transmission housing 360 . The rotor of the first motor/generator 380 is secured to the sun gear member 322 of the planetary gear set 320 . The stator of the second motor/generator 382 is also secured to the transmission housing 360 . The rotor of the second motor/generator 382 is secured to the carrier member 326 of the planetary gear set 320 .
A first fixed interconnection continuously connects the sun gear member 322 of the planetary gear set 320 with the sun gear member 332 of the planetary gear set 330 . A second fixed interconnection continuously connects the ring gear member 334 of the planetary gear set 330 with the ring gear member 344 of the planetary gear set 340 .
A first torque-transfer device, such as the clutch 350 , selectively connects the ring gear member 324 of the planetary gear set 320 with the sun gear member 342 of the planetary gear set 340 . A second torque-transfer device, such as the clutch 352 , selectively connects the carrier member 336 with the sun gear member 342 . A third torque-transfer device, such as brake 354 , selectively connects the carrier member 336 with the transmission housing 360 . A fourth torque transfer device, such as the brake 355 , is connected in parallel with the motor/generator 380 for selectively braking rotation thereof. A fifth torque transfer device, such as the brake 357 , is connected in parallel with the motor/generator 382 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque-transfer devices 350 , 352 , 354 , 355 and 357 are employed to assist in the selection of the operational modes of the transmission 314 .
The hybrid transmission 314 receives power from the engine 12 , and also exchanges power with an electric power source 386 , which is operably connected to a controller 388 .
The operating mode table of FIG. 4 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 314 . These modes include the “battery reverse mode” (Batt Rev), the “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “continuously variable transmission range modes” (Range 1 . 1 , 1 . 2 , 1 . 3 . . . and “fixed ratio modes” (F 1 , F 2 , F 3 and F 4 ) as described previously.
As set forth above, the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 4 b . FIG. 4 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 4 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 320 ; the N R2 /N S2 value is the tooth ratio of the planetary gear set 330 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 340 . Also, the chart of FIG. 4 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 2.17, and the ratio spread is 4.34.
Description of a Fifth Exemplary Embodiment
With reference to FIG. 5 a , a powertrain 410 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission, designated generally by the numeral 414 . The transmission 414 is designed to receive at least a portion of its driving power from the engine 12 .
As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 414 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 414 . An output member 19 of the transmission 414 is connected to a final drive 16 .
The transmission 414 utilizes three planetary gear sets 420 , 430 and 440 . The planetary gear set 420 employs an outer ring gear member 424 which circumscribes an inner sun gear member 422 . A carrier member 426 rotatably supports a plurality of planet gears 427 such that each planet gear 427 meshingly engages both the outer ring gear member 424 and the inner sun gear member 422 of the first planetary gear set 420 .
The planetary gear set 430 also has an outer ring gear member 434 that circumscribes an inner sun gear member 432 . A plurality of planet gears 437 are also rotatably mounted in a carrier member 436 such that each planet gear member 437 simultaneously, and meshingly engages both the outer, ring gear member 434 and the inner, sun gear member 432 of the planetary gear set 430 .
The planetary gear set 440 employs an outer ring gear member 444 which circumscribes an inner sun gear member 442 . A carrier member 446 rotatably supports a plurality of planet gears 447 such that each planet gear 447 meshingly engages both the outer ring gear member 444 and the inner sun gear member 442 of the planetary gear set 440 .
The transmission input member 17 is continuously connected with the carrier member 426 , and the transmission output member 19 is continuously connected with the ring gear member 444 .
The transmission 414 also incorporates first and second motor/generators 480 and 482 , respectively. The stator of the first motor/generator 480 is secured to the transmission housing 460 . The rotor of the first motor/generator 480 is secured to the ring gear member 424 .
The stator of the second motor/generator 482 is also secured to the transmission housing 460 . The rotor of the second motor/generator 482 is secured to the sun gear member 422 .
A first fixed interconnection 470 continuously connects the carrier member 426 with the ring gear member 434 . A second fixed interconnection 472 continuously connects the carrier member 436 with the carrier member 446 .
A first torque-transfer device, such as a clutch 450 , selectively connects the ring gear member 424 with the sun gear member 442 . A second torque-transfer device, such as clutch 452 , selectively connects the carrier member 446 with the ring gear member 444 . A third torque-transfer device, such as brake 454 , selectively connects the sun gear member 432 with the transmission housing 460 . A fourth torque transfer device, such as the brake 455 , is connected in parallel with the motor/generator 480 for selectively braking rotation thereof. A fifth torque transfer device, such as the brake 457 , is connected in parallel with the motor/generator 482 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque-transfer devices 450 , 452 , 454 , 455 and 457 are employed to assist in the selection of the operational modes of the transmission 414 .
The hybrid transmission 414 receives power from the engine 12 and also from an electric power source 486 , which is operably connected to a controller 488 .
The operating mode table of FIG. 5 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 414 . These modes include the “battery reverse mode” (Batt Rev), the “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “continuously variable transmission range modes” (Range 1 . 1 , 1 . 2 , 1 . 3 . . . and “fixed ratio modes” (F 1 , F 2 , F 3 and F 4 ) as described previously.
As set forth above, the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 5 b . FIG. 5 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 5 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 420 ; the N R2 /N S2 value is the tooth ratio of the planetary gear set 430 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 440 . Also, the chart of FIG. 5 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 1.90, and the ratio spread is 4.64.
Description of a Sixth Exemplary Embodiment
With reference to FIG. 6 a , a powertrain 510 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission, designated generally by the numeral 514 . The transmission 514 is designed to receive at least a portion of its driving power from the engine 12 .
As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 514 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 514 . An output member 19 of the transmission 514 is connected to a final drive 16 .
The transmission 514 utilizes three planetary gear sets 520 , 530 and 540 . The planetary gear set 520 employs an outer ring gear member 524 which circumscribes an inner sun gear member 522 . A carrier member 526 rotatably supports a plurality of planet gears 527 such that each planet gear 527 meshingly engages both the outer ring gear member 524 and the inner sun gear member 522 of the first planetary gear set 520 .
The planetary gear set 530 also has an outer ring gear member 534 that circumscribes an inner sun gear member 532 . A plurality of planet gears 537 are also rotatably mounted in a carrier member 536 such that each planet gear member 537 simultaneously, and meshingly engages both the outer, ring gear member 534 and the inner, sun gear member 532 of the planetary gear set 530 .
The planetary gear set 540 employs an outer ring gear member 544 which circumscribes an inner sun gear member 542 . A carrier member 546 rotatably supports a plurality of planet gears 547 such that each planet gear 547 meshingly engages both the outer ring gear member 544 and the inner sun gear member 542 of the planetary gear set 540 .
The transmission input member 17 is continuously connected with the carrier member 526 , and the transmission output member 19 is continuously connected with the carrier member 546 .
The transmission 514 also incorporates first and second motor/generators 580 and 582 , respectively. The stator of the first motor/generator 580 is secured to the transmission housing 560 . The rotor of the first motor/generator 580 is secured to the ring gear member 524 .
The stator of the second motor/generator 582 is also secured to the transmission housing 560 . The rotor of the second motor/generator 582 is secured to the ring gear member 534 .
A first fixed interconnection 570 continuously connects the sun gear members 522 and 532 . A second fixed interconnection 572 continuously connects the carrier member 536 with the ring gear member 544 .
A first torque-transfer device, such as a clutch 550 , selectively connects the sun gear member 532 with the sun gear member 542 . A second torque-transfer device, such as a clutch 552 , selectively connects the carrier member 526 with the sun gear member 542 . A third torque-transfer device, such as a brake 554 , selectively connects the sun gear member 522 with the transmission housing 560 . A fourth torque transfer device, such as the brake 555 , is connected in parallel with the motor/generator 580 for selectively braking rotation thereof. A fifth torque transfer device, such as the brake 557 , is connected in parallel with the motor/generator 582 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque-transfer devices 550 , 552 , 554 , 555 and 557 are employed to assist in the selection of the operational modes of the hybrid transmission 514 .
The hybrid transmission 514 receives power from the engine 12 , and also exchanges power with an electric power source 586 , which is operably connected to a controller 588 .
The operating mode table of FIG. 6 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 514 . These modes include the “battery reverse mode” (Batt Rev), the “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “continuously variable transmission range modes” (Range 1 . 1 , 1 . 2 , 1 . 3 . . . and “fixed ratio modes” (F 1 , F 2 , F 3 and F 4 ) as described previously.
As set forth above, the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 6 b . FIG. 6 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 6 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 520 ; the N R2 /N S2 value is the tooth ratio of the planetary gear set 530 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 540 . Also, the chart of FIG. 4 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 1.47, and the ratio spread is 3.68.
Description of a Seventh Exemplary Embodiment
With reference to FIG. 7 a , a powertrain 610 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission, designated generally by the numeral 614 . The transmission 614 is designed to receive at least a portion of its driving power from the engine 12 .
As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 614 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 614 . An output member 19 of the transmission 614 is connected to a final drive 16 .
The transmission 614 utilizes three planetary gear sets 620 , 630 and 640 . The planetary gear set 620 employs an outer ring gear member 624 which circumscribes an inner sun gear member 622 . A plurality of planet gears 627 , 628 are rotatably mounted in a carrier member 626 such that each planet gear member 627 meshingly engages the sun gear member 622 , each planet gear 628 engages the outer, ring gear member 624 and the respective planet gears 627 .
The planetary gear set 630 also has an outer ring gear member 634 that circumscribes an inner sun gear member 632 . A plurality of planet gears 637 are rotatably mounted in a carrier member 636 such that each planet gear member 637 simultaneously, and meshingly engages both the outer, ring gear member 634 and the inner, sun gear member 632 of the planetary gear set 630 .
The planetary gear set 640 employs an outer ring gear member 644 which circumscribes an inner sun gear member 642 . A carrier member 646 rotatably supports a plurality of planet gears 647 such that each planet gear 647 meshingly engages both the outer ring gear member 644 and the inner sun gear member 642 of the planetary gear set 640 .
The transmission input member 17 is connected with the carrier member 636 of the planetary gear set 630 , and the transmission output member 19 is connected with the carrier member 646 of the planetary gear set 640 .
The transmission 614 also incorporates first and second motor/generators 680 and 682 , respectively. The stator of the first motor/generator 680 is secured to the transmission housing 660 . The rotor of the first motor/generator 680 is secured to the sun gear member 622 of the planetary gear set 620 . The stator of the second motor/generator 682 is also secured to the transmission housing 660 . The rotor of the second motor/generator 682 is secured to the sun gear member 632 of the planetary gear set 630 .
A first fixed interconnection 670 continuously connects the carrier members 626 and 636 . A second fixed interconnection 672 continuously connects the ring gear member 634 with the sun gear member 642 .
A first torque-transfer device, such as the clutch 650 , selectively connects the ring gear member 624 with the ring gear member 644 . A second torque-transfer device, such as the clutch 652 , selectively connects the ring gear member 624 with the carrier member 646 . A third torque-transfer device, such as brake 654 , selectively connects the ring gear member 624 with the transmission housing 660 . A fourth torque transfer device, such as the brake 655 , is connected in parallel with the motor/generator 680 for selectively braking rotation thereof. A fifth torque transfer device, such as the brake 657 , is connected in parallel with the motor/generator 682 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque-transfer devices 650 , 652 , 654 , 655 and 657 are employed to assist in the selection of the operational modes of the transmission 614 .
The hybrid transmission 614 receives power from the engine 12 , and also exchanges power with an electric power source 686 , which is operably connected to a controller 688 .
The operating mode table of FIG. 7 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 614 . These modes include the “battery reverse mode” (Batt Rev), the “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “continuously variable transmission range modes” (Range 1 . 1 , 1 . 2 , 1 . 3 . . . and “fixed ratio modes” (F 1 , F 2 , F 3 and F 4 ) as described previously.
As set forth above, the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 7 b . FIG. 7 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 7 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 620 , the N R2 /N S2 value is the tooth ratio of the planetary gear set 630 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 640 . Also, the chart of FIG. 7 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 1.97, and the ratio spread is 4.00.
Description of an Eighth Exemplary Embodiment
With reference to FIG. 8 a , a powertrain 710 is shown, including an engine 12 connected to the improved electrically variable transmission (EVT), designated generally by the numeral 714 . Transmission 714 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 714 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a diesel engine which is readily adapted to provide its available power output typically delivered at a constant number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connectable to planetary gear members in the transmission 714 . An output member 19 of the transmission 714 is connected to a final drive 16 .
The transmission 714 utilizes three differential gear sets, preferably in the nature of planetary gear sets 720 , 730 and 740 . The planetary gear set 720 employs an outer gear member 724 , typically designated as the ring gear. The ring gear 724 circumscribes an inner gear member 722 , typically designated as the sun gear. A carrier member 726 rotatably supports a plurality of planet gears 727 such that each planet gear 727 meshingly engages both the inner, sun gear member 722 , and the ring gear member 724 .
The planetary gear set 730 also has an outer gear member 734 , often also designated as the ring gear, that circumscribes an inner gear member 732 , also often designated as the sun gear. A carrier member 736 rotatably supports a plurality of planet gears 737 such that each planet gear 737 meshingly engages both the inner, sun gear member 732 , and the ring gear member 734 .
The planetary gear set 740 employs an outer gear member 744 , typically designated as the ring gear. The ring gear 744 circumscribes an inner gear member 742 , typically designated as the sun gear. A carrier member 746 rotatably supports a plurality of planet gears 747 such that each planet gear 747 meshingly engages both the inner, sun gear member 742 , and the ring gear member 744 .
The input member 17 is secured to the carrier member 726 of the planetary gear set 720 . The output member 19 is continuously connected with the carrier member 746 of the planetary gear set 740 .
This embodiment 710 also incorporates first and second motor/generators 780 and 782 , respectively. The stator of the first motor/generator 780 is secured to the transmission housing 760 . The rotor of the first motor/generator 780 is connected to the ring gear member 724 .
The stator of the second motor/generator 782 is also secured to the transmission housing 760 . The rotor of the second motor/generator 782 is selectively alternately connectable to the ring gear member 734 or sun gear member 732 via a torque-transmitting mechanism 792 , such as a dog clutch. The dog clutch 792 is controlled to alternate between positions “A” and “B” as will be understood by those skilled in the art. The rotor of the second motor/generator 782 is connected to the dog clutch 792 . Alternatively, a conventional torque transmitting device(s), such as a two way clutch or a pair of clutches could be used in place of the dog clutch.
A first fixed interconnection 770 continuously connects the sun gear members 722 and 732 . A second fixed interconnection 772 continuously connects the carrier member 736 and the ring gear member 744 .
A first torque transfer device, such as clutch 750 , selectively connects the sun gear member 732 with the sun gear member 742 . A second torque transfer device, such as clutch 752 , selectively connects the carrier member 726 with the sun gear member 742 . A third torque transmitting device, such as brake 754 , selectively connects the ring gear member 744 with the transmission housing 760 . A fourth torque transfer device, such as brake 755 , selectively brakes the rotor of the motor/generator 780 . A fifth torque transfer device, such as brake 757 , selectively brakes the rotor of the motor/generator 782 . The first, second, third, fourth and fifth torque transfer devices 750 , 752 , 754 , 755 and 757 and dog clutch 792 are employed to assist in the selection of the operational modes of the hybrid transmission 714 .
The hybrid transmission 714 receives power from the engine 12 , and also exchanges power with an electric power source 786 , which is operably connected to a controller 788 .
The operating mode table of FIG. 8 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 714 . These modes include the “battery reverse mode” (Batt Rev), the “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “continuously variable transmission range modes” (Range 1 . 1 , 1 . 2 , 1 . 3 . . . and “fixed ratio modes” (F 1 , F 2 , F 3 and F 4 ) as described previously.
As set forth above, the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 8 b . FIG. 8 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 8 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 720 , the N R2 /N S2 value is the tooth ratio of the planetary gear set 730 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 740 . Also, the chart of FIG. 8 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 3.25, and the ratio spread is 6.06.
Description of a Ninth Exemplary Embodiment
With reference to FIG. 9 a , a powertrain 810 is show, including an engine 12 connected to the improved electrically variable transmission (EVT), designated generally by the numeral 814 . Transmission 814 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 814 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a diesel engine which is readily adapted to provide its available power output typically delivered at a constant number of revolutions per minute (RPM).
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connectable to planetary gear members in the transmission 814 . An output member 19 of the transmission 814 is connected to a final drive 16 .
The transmission 814 utilizes three differential gear sets, preferably in the nature of planetary gear set 820 , 830 and 840 . The planetary gear set 820 employs an outer gear member 824 , typically designated as the ring gear. The ring gear member 824 circumscribes an inner gear member 822 , typically designated as the sun gear. A carrier member 826 rotatably supports a plurality of planet gears 827 such that each planet gear 827 meshingly engages both the inner, sun gear member 822 , and the ring gear member 824 .
The planetary gear set 830 also has an outer gear member 834 , often also designated as the ring gear, that circumscribes an inner gear member 832 , also often designated as the sun gear. A carrier member 836 rotatably supports a plurality of planet gears 837 such that each planet gear 837 meshingly engages both the inner, sun gear member 832 , and the ring gear member 834 .
The planetary gear set 840 employs an outer gear member 844 , typically designated as the ring gear. The ring gear 844 circumscribes an inner gear member 842 , typically designated as the sun gear. A carrier member 846 rotatably supports a plurality of planet gears 847 such that each planet gear 847 meshingly engages both the inner, sun gear member 842 , and the ring gear member 844 .
The input member 17 is secured to the ring gear member 824 of the planetary gear set 820 . The output member 19 is continuously connected with the carrier member 846 of the planetary gear set 840 .
This embodiment 810 also incorporates first and second motor/generators 880 and 882 , respectively. The stator of the first motor/generator 880 is secured to the transmission housing 860 . The rotor of the first motor/generator 880 is connected to the ring gear member 834 .
The stator of the second motor/generator 882 is also secured to the transmission housing 860 . The rotor of the second motor/generator 882 is connected to the sun gear member 842 .
A first fixed interconnection 870 continuously connects the sun gear member 822 and the ring gear member 834 . A second fixed interconnection 872 continuously connects the carrier member 826 and the carrier member 836 .
A first torque transfer device, such as clutch 850 , selectively connects the carrier member 836 with the sun gear member 842 . A second torque transfer device, such as clutch 852 , selectively connects the carrier member 836 with the carrier member 846 . A third torque transmitting device, such as clutch 854 , selectively connects the sun gear member 832 with the sun gear member 842 . A fourth torque transmitting device, such as brake 855 , selectively connects the ring gear member 844 with the transmission housing 860 . A fifth torque transfer device, such as brake 857 selectively brakes the rotor of the motor/generator 880 . The first, second, third, fourth and fifth torque transfer devices 850 , 852 , 854 , 855 and 857 are employed to assist in the selection of the operational modes of the hybrid transmission 814 .
The hybrid transmission 814 receives power from the engine 12 , and also exchanges power with an electric power source 886 , which is operably connected to a controller 888 .
The operating mode table of FIG. 9 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 814 . These modes include the “battery reverse mode” (Batt Rev), the “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “continuously variable transmission range modes” (Range 1 . 1 , 1 . 2 , 1 . 3 . . . and “fixed ratio modes” (F 1 , F 2 , F 3 , F 4 and F 5 ) as described previously.
As set forth above, the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 9 b . FIG. 9 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 9 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 820 , the N R2 /N S2 value is the tooth ratio of the planetary gear set 830 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 840 . Also, the chart of FIG. 9 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 1.50, and the ratio spread is 8.06.
Description of a Tenth Exemplary Embodiment
With reference to FIG. 10 a , a powertrain 910 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission, designated generally by the numeral 914 . The transmission 914 is designed to receive at least a portion of its driving power from the engine 12 .
As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 914 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 914 . An output member 19 of the transmission 914 is connected to a final drive 16 .
The transmission 914 utilizes three planetary gear sets 920 , 930 and 940 . The planetary gear set 920 employs an outer ring gear member 924 which circumscribes an inner sun gear member 922 . A plurality of planet gears 927 are rotatably mounted in a carrier member 926 such that each planet gear member 927 simultaneously and meshingly engages both the sun gear member 922 and the ring gear member 924 .
The planetary gear set 930 has an inner sun gear member 932 , a carrier member 936 and a plurality of pinion gears 937 , 938 . The pinion gears 937 meshingly engage both the sun gear member 932 and the pinion gears 938 . The pinion gears 938 are integral with the pinion gears 927 (i.e., the are formed by long pinion gears).
The planetary gear set 940 employs an outer ring gear member 944 which circumscribes an inner sun gear member 942 . A carrier member 946 rotatably supports a plurality of planet gears 947 such that each planet gear 947 meshingly engages both the outer ring gear member 944 and the inner sun gear member 942 of the planetary gear set 940 .
The transmission input member 17 is connected with the ring gear member 924 , and the transmission output member 19 is connected with the carrier member 946 .
The transmission 914 also incorporates first and second motor/generators 980 and 982 , respectively. The stator of the first motor/generator 980 is secured to the transmission housing 960 . The rotor of the first motor/generator 980 is secured to the sun gear member 922 of the planetary gear set 920 . The stator of the second motor/generator 982 is also secured to the transmission housing 960 . The rotor of the second motor/generator 982 is secured to the sun gear member 942 of the planetary gear set 940 .
The carrier member 926 is continuously connected with (i.e., integral with) the carrier member 936 . This integral connection is referred to herein as the first interconnecting member 970 . The integral connection of the pinion gears 927 and 938 is referred to herein as the second interconnecting member 972 .
A first torque-transfer device, such as the clutch 950 , selectively connects the carrier member 936 with the sun gear member 942 . A second torque-transfer device, such as the clutch 952 , selectively connects the carrier member 936 with the carrier member 946 . A third torque-transfer device, such as clutch 954 , selectively connects the sun gear member 932 with the sun gear member 942 . A fourth torque transmitting device, such as brake 955 , selectively connects the ring gear member 944 with the transmission housing 960 . A fifth torque transfer device, such as the brake 957 , is connected in parallel with the motor/generator 980 for selectively braking rotation thereof. The first, second, third, fourth and fifth torque-transfer devices 950 , 952 , 954 , 955 and 957 are employed to assist in the selection of the operational modes of the transmission 914 .
The hybrid transmission 914 receives power from the engine 12 , and also exchanges power with an electric power source 986 , which is operably connected to a controller 988 .
The operating mode table of FIG. 10 b illustrates the clutching engagements, motor/generator conditions and output/input ratios for the five operating modes of the transmission 914 . These modes include the “battery reverse mode” (Batt Rev), the “EVT reverse mode” (EVT Rev), “reverse and forward launch modes” (TC Rev and TC For), “continuously variable transmission range modes” (Range 1 . 1 , 1 . 2 , 1 . 3 . . . and “fixed ratio modes” (F 1 , F 2 , F 3 , F 4 and F 5 ) as described previously.
As set forth above, the engagement schedule for the torque-transfer devices is shown in the operating mode table and fixed ratio mode table of FIG. 10 b . FIG. 10 b also provides an example of torque ratios that are available utilizing the ring gear/sun gear tooth ratios given by way of example in FIG. 10 b . The N R1 /N S1 value is the tooth ratio of the planetary gear set 920 , the N R2 /N S2 value is the tooth ratio of the planetary gear set 930 , and the N R3 /N S3 value is the tooth ratio of the planetary gear set 940 . Also, the chart of FIG. 10 b describes the ratio steps that are attained utilizing the sample of tooth ratios given. For example, the step ratio between first and second fixed forward torque ratios is 1.50, and the ratio spread is 8.06.
In the claims, the language “continuously connected” or “continuously connecting” refers to a direct connection or a proportionally geared connection, such as gearing to an offset axis. Also, the “stationary member” or “ground” may include the transmission housing (case) or any other non-rotating component or components. Also, when a torque transmitting mechanism is said to connect something to a member of a gear set, it may also be connected to an interconnecting member which connects it with that member.
While various preferred embodiments of the present invention are disclosed, it is to be understood that the concepts of the present invention are susceptible to numerous changes apparent to one skilled in the art. Therefore, the scope of the present invention is not to be limited to the details shown and described but is intended to include all variations and modifications which come within the scope of the appended claims.
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The electrically variable transmission family provides low-content, low-cost electrically variable transmission mechanisms including first, second and third differential gear sets, a battery, two electric machines serving interchangeably as motors or generators, and five selectable torque-transfer devices. The selectable torque transfer devices are engaged in combinations of two or three to yield an EVT with a continuously variable range of speeds (including reverse) and four or five mechanically fixed forward speed ratios. The torque transfer devices and the first and second motor/generators are operable to provide five operating modes in the electrically variable transmission, including battery reverse mode, EVT reverse mode, reverse and forward launch modes, continuously variable transmission range mode, and fixed ratio mode.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 12/137,732, filed Jun. 12, 2008, which claims the benefit of priority from U.S. Provisional Application No. 60/943,397, filed Jun. 12, 2007, the disclosures of which are hereby incorporated in its entirety by reference thereto.
TECHNICAL FIELD
Embodiments of the present invention relate to syringe assemblies having a passive locking mechanism which restricts distal movement of the plunger rod after injection to prevent reuse, syringe assemblies wherein the stopper and plunger rod operate using relative motion to passively disable the syringe, syringe assemblies including a removeably connected stopper and plunger rod to prevent disassembly of the syringe prior to use and syringe assemblies including visual indication or markings to indicate use of the syringe or a disabled syringe.
BACKGROUND
Reuse of hypodermic syringe products without sterilization or sufficient sterilization is believed to perpetuate drug abuse and facilitate the transfer of contagious diseases. The reuse of syringes by intravenous drug users further exacerbates the transfer of contagious diseases because they comprise a high-risk group with respect to certain viruses such as the AIDS virus and hepatitis. A high risk of contamination also exists in countries with shortages of medical personnel and supplies.
A syringe which can be rendered inoperable after use presents a viable solution to these issues. Various syringes have been proposed and are commercially available that can be disabled by the user by taking active steps to disable the syringe. Single-use syringes that do not require the user to actively disable the syringe are also thought to offer a solution. It would be desirable to provide syringes that are automatically or passively disabled from reuse and can be manufactured in a cost-effective manner by, for example, utilizing fewer parts. Further, markings or other indicators which visually indicate whether a syringe has been used or is disabled would also be desirable.
SUMMARY
A passive disabling system for a syringe assembly that activates after completion of an injection cycle is provided. A syringe assembly incorporates a stopper and plunger rod attached in a manner to prevent users from disassembling the syringe prior to completion of the injection cycle. In one or more embodiments of the invention, a user can fill, inject and/or reconstitute medication.
In this disclosure, a convention is followed wherein the distal end of the device is the end closest to a patient and the proximal end of the device is the end away from the patient and closest to a practitioner.
A syringe assembly is provided which includes a barrel, an elongate plunger rod and stopper having respective structures and assembly which allow the user to passively lock the plunger rod within the barrel to prevent reuse of the syringe assembly. The barrel includes a distal end, an open proximal end, a cylindrical sidewall with an interior surface, which defines a chamber in which fluid may be held, and a distal wall. An opening in the distal wall permits fluid to flow from the chamber through the opening. In one embodiment, the barrel includes a marker or indicator which indicates whether the syringe has been disabled or the plunger has been locked within the barrel.
In one or more embodiments, the interior surface of the sidewall of the barrel has a continuous diameter or first inner diameter. As used throughout this application, the term “diameter” is a measurement of the longest distance between the walls of the barrel having any cross-sectional shape. However, it will be appreciated that conventional syringes are typically cylindrical with a circular cross-sectional shape. In accordance with some embodiments of the present invention, the barrel includes a rib, locking rib or other such impediment suitable for restricting the proximal movement of the plunger rod, adjacent to its proximal end. In one embodiment, the rib has a second inner diameter, wherein the second diameter is less than the first diameter. One or more embodiments of the present invention include an increased diameter region located proximally from the rib having a third inner diameter, wherein the third diameter is greater than the first diameter and second diameter. A diameter transition region or a ramp having an axial length located between the rib and the increased diameter region may be included. The diameter transition region or ramp can have a varying inner diameter, which increases in the proximal direction.
Embodiments of the present invention also include an extended plunger rod which has a proximal end, a distal end, and a main body between the proximal and distal end. A thumb press may also be disposed at the proximal end of the plunger rod. In some embodiments, the plunger rod slides or otherwise moves proximally and distally within the chamber of the barrel.
The distal end of the plunger can include a stopper-engaging portion having a distal and proximal end. Alternative embodiments further include an optional disc disposed at the distal end of the plunger rod between the main body and the stopper engaging portion of the plunger rod and/or between the main body and the flexible protrusion (described below). The stopper-engaging portion provides a means for the stopper and plunger rod to move proximally and distally within the barrel. In one or more embodiments, the stopper-engaging portion allows the stopper and plunger rod to move proximally and distally relative to each other. In a specific embodiment, the distal end of the stopper-engaging portion may include a rim, retainer, retaining ring or alternate means suitable for restraining the stopper. The stopper-engaging portion according to one or more embodiments may also include a visual indicator or a visual display that indicates use of the syringe or whether the syringe is disabled.
The plunger rod can further include means for locking the plunger rod in the barrel to prevent reuse of the syringe assembly when the syringe is fully injected or “bottomed.” As used herein, the term “bottomed” shall refer to the position of the syringe assembly wherein the stopper, while attached to the plunger rod, is in contact with the distal wall of the barrel and the plunger rod can no longer move in the distal direction. As used herein, the term “activation force” shall mean the force required to bottom the syringe or the force required to move the plunger rod in the distal direction such that the stopper is in contact with the distal wall of the barrel and can no longer move in the distal direction. For example, application of the activation force to the thumb press in the distal direction “activates” or causes the means for locking the plunger rod to move distally past the rib of the barrel. The means for locking the plunger rod can have an outer diameter greater than the inner diameter of the barrel at the rib or the second inner diameter. One or more embodiments of the present invention utilize a protrusion, or annular protrusion that extends radially from the plunger rod as a means for locking the plunger rod. In some embodiments, the protrusion is located between the thumb press and the main body and is an example of a means for locking the plunger rod in the barrel. According to an embodiment of the invention, the protrusion is integrally molded to the plunger rod. The protrusion according to one or more embodiments may be rigid or flexible. Embodiments utilizing a flexible protrusion may further include a support adjacent to the flexible protrusion.
In one configuration, the protrusion has an outer diameter greater than the second inner diameter or the diameter of the barrel located at the rib. Once the protrusion distally moves through the diameter transition region, past the rib and into the barrel, it becomes locked by the rib and the plunger rod is prevented from moving in the proximal direction. The protrusion of one embodiment is tapered or otherwise shaped in such a manner such that it may move in the distal direction past the rib more easily. In embodiments utilizing a flexible protrusion, the protrusion may facilitate distal movement of the plunger rod by flexing in the proximal direction as a force is applied to the plunger rod in the distal direction. In one embodiment, the flexible protrusion also flexes as the plunger rod is moved in the distal direction past the rib. The diameter transition region or ramp of the barrel may further facilitate distal movement of the plunger rod. In such embodiments, the ability for the flexible protrusion to flex and the plunger rod to move in the proximal direction may be limited after the flexible protrusion has moved distally past the rib.
The plunger rod can further comprise at least one frangible portion or other means for separating a portion of the plunger rod from the body. In this configuration, when a user attempts to reuse the syringe assembly or otherwise pull the plunger in the proximal direction out of the barrel, after the plunger rod has been locked, the plunger rod breaks at the frangible portion, leaving a portion of the plunger rod locked within the barrel. In a specific embodiment, the frangible portion is located between the protrusion and the thumb press. It will be appreciated that the frangible portion can be located in various locations near the proximal end of the plunger rod. In one embodiment, the frangible portion comprises a narrowed frangible connection or a frangible bridge having a dimension that is at least about 50% less than the overall dimension of the plunger rod. More particularly, the dimension can be either the diameter or the width of the plunge rod. In a more specific embodiment, the frangible portion includes a plurality of frangible connections or bridges, which may further include two or more point connections. The plurality of frangible connections or bridges are adapted to withstand application of a force on the plunger rod in the distal direction and to break upon application of a force in the proximal direction after the flexible protrusion has advanced distally past the rib or the syringe has been bottomed.
In a specific embodiment, the term “deactivation force” includes the force required to separate a portion of the plunger rod from the body and the term “withdrawal force” includes the force needed to move the plunger rod in the proximal direction after the syringe has been bottomed or the plunger rod has been locked in the barrel by the rib. In a more specific embodiment, the withdrawal force is greater than the deactivation force and the activation force.
The stopper has a proximal end and a distal end and the stopper is attached the stopper-engaging portion of the plunger rod. In some embodiments, the stopper moves distally and proximally within the barrel. In one or more embodiments, the stopper also moves distally and proximally along a pre-selected axial distance relative to the stopper-engaging portion of the plunger rod, thereby allowing the protrusion to move distally past the rib into the locked position when the syringe assembly is bottomed.
The stopper may further comprise a stopper body or stopper boss at the proximal end of the stopper. A peripheral lip may be included at the proximal end of the stopper body. A frangible link may be provided to connect the stopper to the plunger rod, which may connect the stopper and the peripheral lip. Alternative means for separating the stopper from the plunger rod or to destroy the stopper may also be provided.
In one embodiment, when a user aspirates or fills the syringe assembly, the stopper begins to move in the proximal direction in tandem with the plunger rod, while maintaining the pre-selected axial distance. An optional visual indicator or display disposed on the stopper-engaging portion of the plunger rod is visible when the user fills the syringe assembly. In one or more embodiments of the present invention, when a user injects the contents of the syringe assembly, the attachment of the stopper and the stopper-engaging portion allow the plunger rod to move distally for a length of the pre-selected axial distance, while the stopper remains stationary. After the plunger rod travels distally for the length of the pre-selected axial distance, the stopper begins to move distally with the plunger rod. During such distal movement, where a visual indicator or display is utilized, the visual indicator or display disposed on the stopper-engaging portion of the plunger rod is no longer visible. Where a visual marker is utilized, the visual marker disposed on the barrel continues to be visible, even after the plunger rod is locked. As will be more fully described herein, the marker provides an alternative means of indicating the syringe has been disabled.
According to one embodiment of the present invention, the total length of the plunger rod is decreased by pre-selected axial distance when the stopper and plunger rod move together in the distal direction during injection of the contents of the syringe assembly. As such, the stopper and stopper-engaging portion of the syringe assembly are attached in a manner such that when a user has fully completed the injection cycle, the protrusion of the plunger rod advances past the rib of the barrel. In some embodiments, once the protrusion advances past the rib of the barrel, it locks the plunger rod within the barrel and prevents the user from reusing the syringe assembly or otherwise pulling the plunger rod out of the barrel. Once the plunger rod is locked within the barrel, the optional visual indicator or display on the stopper-engaging portion of the plunger rod is no longer visible, indicating the syringe has been disabled.
According to an alternative embodiment, the stopper and the plunger rod are connected in a fixed relationship such that when the distal end of the stopper is contact with the distal wall of the barrel, the flexible protrusion is permitted to advance distally past the rib in the barrel. In embodiments utilizing a stopper and plunger rod having a fixed relationship, the pre-selected axial distance is zero and application of a continuous force in the proximal direction during aspiration or filling causes the stopper and plunger rod move together. In the initial position as supplied or packaged, the stopper is not in contact with the distal wall of the barrel and, instead, there is a gap between the distal end of the barrel and the distal wall of the barrel. In such embodiments, the user may fill the barrel of the syringe to accommodate the initial gap between the stopper and the distal wall of the barrel. The user may thereafter expel the air present in the barrel from the presence of the gap before injecting the contents of the syringe. During injection and application of a force in the distal direction to the plunger rod, the fixed stopper and plunger rod move together until the stopper reaches the distal end of the barrel and the protrusion is permitted to advance distally within past the rib of the barrel.
The syringe assembly may include one or more frangible portions of the plunger rod, which break when a user attempts to move the plunger rod in a proximal direction after the protrusion has advanced past the rib of the barrel. Other suitable means may be utilized for separating a portion of the plunger rod from the main body when the user applies sufficient proximal force to the plunger rod or otherwise attempts to reuse the syringe assembly after it is bottomed.
In accordance with one embodiment of the invention, the stopper and the stopper-engaging portion are attached in such a manner such that when a user attempts to disassemble the syringe assembly prior to aspiration, injection or bottoming, the stopper-engaging portion disengages from the stopper, leaving the stopper inside the barrel and allowing the separated plunger rod to be removed. In some embodiments, inner diameter of the barrel at the rib, or the second inner diameter, is less than the outer diameter of the stopper, and thereby prevents the stopper from moving proximally past the rib and causes the stopper-engaging portion to detach from the stopper, leaving the stopper inside the barrel. An optional frangible link of the stopper breaks when a user attempts to disassemble the syringe assembly by applying a continuous force in the proximal direction to the plunger rod prior to aspiration, injection or bottoming.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a perspective view of a syringe assembly according to an embodiment of the invention shown;
FIG. 2 illustrates a disassembled perspective view of a syringe assembly according to an embodiment of the invention;
FIG. 3 shows a cross-sectional view of the barrel shown in FIG. 2 taken along line 3 - 3 ;
FIG. 4 is an enlarged view of a portion of the barrel shown in FIG. 3 ;
FIG. 5 is a cross-sectional view of the stopper shown in FIG. 2 taken along line 5 - 5 ;
FIG. 6 is a cross-sectional view of the plunger rod shown in FIG. 2 taken along line 6 - 6 ;
FIG. 7 is a cross-sectional view taken along line 7 - 7 of FIG. 1 ;
FIG. 8 is an illustration of FIG. 7 showing the plunger rod being moved in the proximal direction;
FIG. 9 is an illustration of FIG. 8 showing the plunger rod being moved in the distal direction;
FIG. 10 is an illustration of FIG. 9 showing the plunger rod in a locked position in the syringe barrel;
FIG. 11 is an enlarged view of a proximal portion of the assembly shown in FIG. 10 ;
FIG. 12 illustrates a perspective view of an embodiment of a syringe assembly having a visual marker disposed on the barrel;
FIG. 13 illustrates a disassembled perspective view of an embodiment of a syringe assembly with visual indicators or markers disposed on the barrel and the stopper-engaging portion of the plunger rod;
FIG. 14 is a cross-sectional view taken along line 14 - 14 of FIG. 12 ;
FIG. 15 is an illustration of FIG. 14 showing the plunger rod in a locked position in the syringe barrel;
FIG. 16 is an enlarged view of a proximal portion of the assembly shown in FIG. 15 ;
FIG. 17 is an illustration of FIG. 10 showing a proximal portion of the plunger rod being broken from the syringe assembly after the plunger rod has been locked in the syringe barrel;
FIG. 18 is an illustration of FIG. 7 showing the plunger rod being moved in the proximal direction and the stopper disengaging from the plunger rod;
FIG. 19 a disassembled perspective view of a syringe assembly according to another embodiment of the invention;
FIG. 20 is a perspective view of the plunger rod shown in FIG. 19 ;
FIG. 21 is a side elevational view of the stopper shown in FIG. 19 ;
FIG. 22 is a cross-sectional view taken along line 22 - 22 of the syringe assembly shown in FIG. 19 ;
FIG. 23 is an illustration of FIG. 22 showing the plunger rod being moved in the proximal direction;
FIG. 24 is an illustration of FIG. 23 showing the plunger rod being moved in the distal direction;
FIG. 25 is an illustration of FIG. 24 showing the plunger rod in a locked position in the syringe barrel;
FIG. 26 is an illustration of FIG. 25 showing a proximal portion of the plunger rod being broken from the syringe assembly after the plunger rod has been locked in the barrel;
FIG. 27 is an illustration of FIG. 22 showing the plunger rod being moved in the proximal direction and the stopper disengaging from the plunger rod;
FIG. 28 shows a disassembled perspective view of a syringe assembly according to another embodiment of the invention;
FIG. 29 shows a cross-sectional view of the barrel shown in FIG. 28 taken along line 29 - 29 ;
FIG. 30 is an enlarged view of a portion of the barrel shown in FIG. 29 ;
FIG. 31 is a cross-sectional view of the stopper shown in FIG. 28 taken along line 31 - 31 ;
FIG. 32 illustrates a perspective view of the plunger rod shown in FIG. 28 ;
FIG. 33 is a cross sectional view of the plunger rod shown in FIG. 28 taken along lines 33 - 33 ;
FIG. 34 is a cross-sectional view taken along line 34 - 34 of the syringe assembly shown in FIG. 28 ;
FIG. 35 is an illustration of FIG. 34 showing the plunger rod being moved in the proximal direction;
FIG. 36 is an illustration of FIG. 35 showing the plunger rod being moved in the distal direction;
FIG. 37 is an illustration of FIG. 36 showing the plunger rod in a locked position in the syringe barrel;
FIG. 38 is an enlarged view of a proximal portion of the assembly shown in FIG. 37 ;
FIG. 39 is an illustration of FIG. 37 showing a proximal portion of the plunger rod being broken from the syringe assembly after the plunger rod has been locked in the barrel; and
FIG. 40 is an illustration of FIG. 34 showing the plunger rod being moved in the proximal direction and the stopper disengaging from the plunger rod.
DETAILED DESCRIPTION
Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.
One aspect of the present invention provides for a syringe assembly including a barrel, plunger rod and stopper having individual features and construction which allow the user to passively lock the plunger rod within the barrel to prevent reuse of the syringe assembly.
FIG. 1 shows a syringe assembly 100 according to one or more embodiments. As shown in FIG. 2 , the syringe assembly includes a barrel 120 , a plunger rod 140 and a stopper 160 , arranged such that the proximal end 169 of stopper is attached to the distal end 141 of the plunger rod. The connected stopper 160 and plunger rod 140 are inserted into the proximal end 129 of the barrel 120 .
As best shown in the FIG. 3 , the barrel 120 has a cylindrical sidewall 110 with an interior surface 126 that defines a chamber 128 . In one embodiment, the chamber 128 holds the contents of the syringe assembly which may include medication in powdered or fluid form. The barrel 120 is shown as having an open proximal end 129 , a distal end 121 , and a distal wall 122 . The distal wall 122 has an opening 111 in fluid communication with the chamber 128 .
The sidewall 110 of the barrel 120 defines a chamber having a continuous inner diameter along the longitudinal axis of the syringe. Alternatively, the barrel can include a sidewall has an inner diameter, which decreases linearly from the proximal end to the distal end. It is to be understood that the configuration shown is merely exemplary, and the components can be different in shape and size than shown. For example, the barrel can have an exterior prism shape, while retaining a cylindrical interior shape. Alternatively, both the exterior and interior surfaces of the barrel can have non-circular cross-sectional shapes.
The syringe barrel 120 is shown as having a peripheral flange 124 attached at the proximal end 129 of the barrel 120 . The barrel 120 further includes a needle cannula 150 , having a lumen 153 attached to the opening 111 in the distal wall 122 of the barrel 120 . As is known in the art, attachment means 152 is provided for attaching the needle cannula 150 to the distal wall 122 . The assembly 100 may also include a protective cap over the needle cannula (not shown).
As shown more clearly in FIG. 4 , the barrel 120 further includes a rib 123 adjacent its proximal end 129 . The inner diameter of the barrel at the location of the rib 123 is smaller than the inner diameter of the barrel 120 at other locations along the length of the barrel. One or more optional tabs or detents can be used to create a region of the barrel having a diameter smaller than the inner diameter of the barrel 120 . In a specific embodiment, the rib can include a ring formed along entire circumference of the interior surface 126 or a portion of the interior surface 126 of the inner diameter of the barrel 120 (not shown). The barrel 120 also includes a diameter transition region 127 adjacent to the rib 123 at the proximal end 129 (as shown in FIG. 3 ) of the barrel 120 . The inner diameter of the barrel at the diameter transition region 127 increases from the distal end 121 to the proximal end 129 (as shown in FIG. 3 ) of the barrel 120 . In the embodiment shown, the barrel includes an increased diameter region 125 adjacent to the diameter transition region at the proximal end 129 (as shown in FIG. 3 ) of the barrel. The inner diameter of the barrel 120 at the increased diameter region 125 is greater than the inner diameter of the barrel of the entire diameter transition region 127 .
The barrel may be made of plastic, glass or other suitable material. The barrel further includes optional dosage measurement indicia (not shown).
Referring now to FIG. 5 , the stopper 160 has a distal end 161 , a proximal end 169 , a stopper body 164 and a peripheral edge 162 which forms a seal with the interior surface 126 of the barrel. In one or more embodiments, the peripheral edge 162 of the stopper 160 has a larger diameter than the diameter of the interior surface of the rib 123 . The stopper 160 shown in FIG. 5 includes an optional elongate tip 166 on its distal end 161 to facilitate reduction of the residual fluid and expulsion of fluid from the syringe barrel.
The stopper 160 is shown as further having a tapered portion 165 adjacent to the stopper body 164 at its proximal end 169 . A neck 163 is adjacent to the tapered portion 165 at the proximal end 169 of the stopper 160 . The stopper body 164 is shown as also including an interior recess 168 , which allows the stopper-engaging portion 146 of the plunger rod 140 to connect to the stopper 160 . A peripheral rim 147 may be provided to help retain the stopper 160 on the plunger rod 140 . As with the rib of the barrel, detents or tabs can be used to retain the stopper 160 on the plunger rod 140 .
The stopper is typically made of plastic or other easily disposable and/or recyclable material. It may be desirable to incorporate natural or synthetic rubber in the stopper or use a natural or synthetic rubber seal with the stopper. It will be understood that the stopper may incorporate multiple seals.
Referring now to FIG. 6 , the syringe assembly includes a plunger rod 140 having a proximal end 149 , a distal end 141 , and a main body 148 extending between the proximal end 149 and distal end 141 . The plunger rod 140 further includes a thumb press 142 at the proximal end 149 of the plunger rod 140 . In the embodiment shown, the thumb press 142 further includes a textured surface, writeable surface and/or label.
Still referring to FIG. 6 , the plunger rod 140 further includes a protrusion 144 shown as an annular protrusion 144 between the thumb press 142 and the main body 148 . The outer diameter of the plunger rod at the protrusion 144 is greater than the inner diameter of the barrel 120 at the rib 123 . In some embodiments of the invention, the protrusion 144 includes a tapered portion 145 that facilitates distal movement of the protrusion past the rib 123 and into the barrel 120 , as will become apparent in the subsequent discussion of operation of the syringe. In at least one embodiment, the syringe assembly is configured to allow the protrusion 144 to advance distally past the rib 123 , to lock the plunger rod in the barrel when the user bottoms out the plunger rod in the barrel (as more clearly shown in FIGS. 10-11 ). In certain embodiments, the plunger rod 140 further includes at least one frangible connection or point 143 for separating at least a portion of the plunger rod from the main body when a user applies sufficient proximal force to the plunger rod after it has been locked. In the embodiment shown, the frangible point 143 is located between the protrusion 144 and the thumb press 142 . It will be understood that the frangible connection or point 143 shown is exemplary, and other suitable means for permanently damaging the plunger rod or otherwise separating at least a portion of the plunger rod from the main body may be provided.
In the embodiment shown, the stopper 160 is permitted to move distally and proximally within the barrel when connected to the stopper-engaging portion 146 of the plunger rod 140 . As will be understood better with the description of operation of the syringe assembly and with reference to FIG. 7 , the stopper is capable of moving distally and proximally a pre-selected axial distance 132 relative to the stopper-engaging portion.
In alternative embodiments, the stopper is fixed with respect to the plunger rod. In such embodiments, the axial distance may now be zero. It will be appreciated that in such embodiments, the syringe will be in an initial position, as supplied, where there is a gap between the stopper and the distal wall of the barrel. As the user fills the syringe, the stopper and the plunger rod move together in a proximal direction. As the user expels the contents of the syringe, the stopper and the plunger rod move together in the distal direction, the flexible protrusion is permitted to move past the locking rib.
The plunger rod may be made of plastic or other suitable material. The protrusion may also be comprised of plastic or a harder material suitable for locking the plunger rod within the barrel.
In FIG. 7 , the barrel 120 holds the stopper 160 and plunger rod 140 in the chamber, wherein the stopper is bottomed, “parked” or is in contact with the distal wall 122 of the barrel 120 . The peripheral edge of the stopper 162 forms a seal with the interior surface 126 of the barrel 120 . In one embodiment, the stopper 160 is connected to the stopper-engaging portion 146 of the plunger rod 140 . The stopper-engaging portion 146 is removeably held in the recess 168 of the stopper body 164 by the neck 163 .
In FIG. 7 , a gap between stopper 160 and the distal end of the main body 148 defines a pre-selected axial distance 132 prior to the injection cycle. In at least one embodiment, the protrusion 144 remains on the proximal side of the rib 123 because the length of the plunger rod 140 and stopper combined, along with the pre-selected axial distance 132 , is greater than the length of the barrel 120 from the distal wall 122 to the proximal end of the barrel 120 . The distance between the protrusion 144 and the peripheral edge 162 of the stopper body 164 defines a first distance, D 1 .
FIG. 8 illustrates the syringe assembly in use and specifically shows an aspiration or filling step, according to one or more embodiments of the present invention. When the user applies a force to the plunger rod 140 in the proximal direction shown by the arrow in FIG. 8 , the plunger rod 140 and the stopper 160 move together in the proximal direction, while the stopper-engaging portion 146 is connected to the stopper 160 by the rim 147 . In one or more embodiments, the gap defining the pre-selected axial distance 132 is maintained while the stopper 160 and plunger rod 140 move together in the proximal direction along the interior surface of the syringe barrel. The user terminates the application of proximal force on the plunger rod 140 once the desired amount of medicament is drawn into the syringe. During the aspiration step, the plunger rod and the stopper body move in the proximal direction together to draw medication into the syringe, while maintaining the first distance D 1 .
FIG. 9 also shows the syringe assembly in use and specifically demonstrates application of distal force to the plunger rod during injection. In one embodiment, when the user applies a force in the distal direction to the plunger rod 140 as indicated by the arrow, the plunger rod 140 moves in a distal direction for the length of the gap defining the pre-selected axial distance 132 in FIG. 7 , while the stopper 160 remains stationary. The stopper 160 remains stationary because the frictional force created by the peripheral edge 162 of the stopper on the interior surface 126 of the barrel is greater than the frictional force created by the stopper-engaging portion 146 entering the recess 168 of the stopper 160 . Consistent with at least one embodiment, once the stopper-engaging portion has distally moved the length of the pre-selected axial distance 132 and is in contact with the proximal end of the recess 169 , the stopper 160 and the plunger rod 140 begin to move in tandem in the distal direction. Further, the force applied by the user is greater than the friction between the peripheral edge 162 of the stopper 160 and the interior surface 126 of the barrel, and therefore the stopper 160 is forced to move in the distal direction with the plunger rod 140 . In one embodiment, the user may inject a limited amount of the fluid aspirated or exert a limited force on the plunger rod in the distal direction to flush or expel some of the aspirated fluid, without locking the plunger rod, provided that the syringe assembly is not bottomed. However, as will be described further with respect to FIG. 10 , a user may bottom the stopper against the distal wall of the syringe barrel, locking the plunger rod in the barrel.
When expelling the contents of the syringe, the plunger rod moves in a distal direction the length of the pre-selected axial distance 132 shown in FIG. 7 while the stopper body remains stationary, consequently closing the gap defining the pre-selected axial distance 132 . After the contents of the syringe have been fully expelled, the distance between the protrusion 144 and the peripheral edge 162 defines a second distance, D 2 , wherein D 2 is the difference between the first distance, D 1 , and the gap defining a pre-selected axial distance 132 .
FIG. 10 illustrates an embodiment of the syringe assembly after the plunger rod has been locked inside the barrel. In one or more embodiments, the entry of the stopper-engaging portion into the recess 168 of the stopper 160 (as also shown in FIG. 9 ) closes the gap defining the pre-selected axial distance 132 , allowing the protrusion 144 to advance past the locking rib 123 (as more clearly shown in FIG. 11 ). The protrusion 144 has an outer diameter greater than the inner diameter of the barrel at the rib 123 . Accordingly, in one or more embodiments, the rib 123 locks the protrusion 144 inside the barrel 120 , and prevents proximal movement of the plunger rod 140 .
FIG. 12 shows a syringe assembly 100 in which the barrel 120 includes a visual marker 300 . The marker is aligned with the rib 123 , as more clearly shown in FIG. 16 . The marker can be integrally formed on the sidewall of the barrel or can be added to the exterior surface of the sidewall. The marker can be printed in ink, adhesively applied, a textured surface or a separate piece that is fixed around the syringe barrel. The marker can form a ring around the circumference of the side wall or be in the form of tabs disposed at regular intervals around the circumference of the side wall. In a specific embodiment, the marker is a colored stripe. In a more specific embodiment, the marker can include text in the form of one or more letters and/or numbers, geometric shapes, symbols or combinations thereof to inform users the syringe is disabled.
FIG. 13 shows a plunger rod 140 having a visual indicator or display 310 disposed on the stopper-engaging portion 146 . As with the visual marker 300 , the visual indicator 310 can be integrally formed with the stopper-engaging portion of the plunger rod or be added to the exterior surface thereof. The indicator or display can be printed in ink, adhesively applied, a textured surface or a separate piece that is fixed to the stopper engaging portion. In one or more embodiments, the indicator or display can comprise a pattern, a solid portion and or can cover the entire surface of the stopper-engaging portion. In a specific embodiment, the indicator is a colored stripe disposed along the length of the stopper-engaging portion 146 between the distal end 141 and the main body 148 of the plunger rod. In a more specific embodiment, the indicator is a colored stripe disposed along the circumference of the stopper-engaging portion 146 of the plunger rod. In an even more specific embodiment, the marker can include text in the form of one or more letters and/or numbers, geometric shapes, symbols or combinations thereof.
As more clearly shown in FIG. 14 a gap between stopper 160 and the distal end of the main body 148 defines a pre-selected axial distance 132 prior to the injection cycle. The visual indicator 310 is visible when the gap is present. The visual marker 300 is disposed on the exterior surface of the barrel 120 and aligned with the rib 123 . As described with reference to FIG. 8 , when the user applies a force to the plunger rod 140 in the proximal direction shown by the arrow in FIG. 8 , the plunger rod 140 and the stopper 160 move together in the proximal direction, while the stopper-engaging portion 146 is connected to the stopper 160 by the rim 147 . In one or more embodiments, the gap defining the pre-selected axial distance 132 is maintained while the stopper 160 and plunger rod 140 move together in the proximal direction along the interior surface of the syringe barrel. Accordingly, the visual indicator 310 continues to be visible.
As described with reference to FIG. 9 , when expelling the contents of the syringe, the plunger rod moves in a distal direction the length of the pre-selected axial distance 132 shown in FIGS. 7 and 14 while the stopper body remains stationary, consequently closing the gap defining the pre-selected axial distance 132 . The movement of the stopper-engaging portion, in the distal direction relative to the stopper allows the stopper-engaging portion 146 of the plunger rod to move into the recess 168 of the stopper (as shown in FIG. 9 ). As can be more clearly seen in FIG. 15 , this relative movement allows the stopper body 164 to cover the stopper-engaging portion and block visibility of the visual indicator 310 .
As more clearly shown in FIGS. 15 and 16 , the visual marker 300 disposed on the barrel 120 and aligned with the rib 123 also shows advancement of the protrusion 144 past the rib 123 . In addition, the entry of the stopper-engaging portion into the recess 168 of the stopper 160 (as also shown in FIG. 9 ) also closes the gap defining the pre-selected axial distance 132 , allowing the protrusion 144 to advance past the rib 123 (as more clearly shown in FIGS. 11 and 16 ). The location of the protrusion relative to the visual marker indicates whether the plunger rod has been locked within the barrel and the syringe assembly has been disabled. Before the plunger rod is locked, the protrusion 144 is proximally adjacent to the visual marker 300 . Once the plunger rod is locked, the protrusion 144 is distally adjacent to the visual marker 300 .
It will be appreciated that each of the visual marker 300 and the visual indicator 310 can be used alone or in combination.
FIG. 17 shows the assembly after the plunger rod 140 has been locked in the barrel 120 . An attempt to reuse the syringe assembly by applying a force to the plunger rod 140 in the proximal direction causes a portion of the plunger rod 140 to separate at the frangible connection or point 143 . The frangible connection or point 143 is designed so that the force holding exerted on the protrusion by the locking rib 123 while proximal force is being applied to the plunger rod 140 is greater than the force needed to break the plunger rod at the frangible point 143 and, therefore, the frangible point breaks or separates before the user is able to overcome the force exerted on the protrusion by the rib.
FIG. 18 shows the syringe assembly in a configuration in which the stopper 160 has separated from the stopper-engaging portion 146 . According to one or more embodiments of the invention, the stopper 160 and stopper-engaging portion 146 disengage to prevent a user from disassembling the parts of the syringe assembly prior to use. As otherwise described in reference to FIG. 5 , the peripheral edge 162 of the stopper 160 has a diameter greater than the diameter of the interior surface of the rib 123 . Consistent with at least one embodiment of the invention, when a user applies a force to the plunger rod 140 in the proximal direction, the rib 123 locks the peripheral edge 162 of the stopper 160 , and the rim 147 of the stopper-engaging portion 146 disconnects from the neck 163 of the stopper. The rib 123 exerts a greater force on the peripheral edge of the stopper than the force or friction exerted by the rim of the stopper-engaging portion of the plunger rod and neck portion of the stopper while proximal force is applied to the plunger rod.
FIG. 19 shows an example of a syringe assembly 200 according to another embodiment of the present invention. In the embodiment shown in FIG. 19 , the assembly includes a barrel 220 , a plunger rod 240 and a stopper 260 , arranged so that the proximal end of stopper 269 is attached to the distal end of the plunger rod 241 . The stopper 260 then plunger rod 240 is inserted into the proximal end of the barrel 229 . A flange 224 is attached at the proximal end 229 of the barrel 220 . The barrel 220 further includes a needle cannula 250 having a lumen 253 , attached to the opening in the distal wall 222 at the distal end 221 of the barrel 220 . One or more embodiments also include an attachment hub 252 for attaching the needle cannula 250 to the distal wall 222 . The assembly may also include a protective cap over the needle cannula (not shown).
Similar to the barrel illustrated previously in FIGS. 3 and 4 , and as shown in FIG. 22 , the barrel further include a rib 223 , locking rib or other means for locking the plunger rod within the barrel, having an interior surface with a smaller diameter than the diameter of the interior surface of the barrel.
Referring now to FIG. 20 , a perspective view of a plunger rod 240 is shown as having a main body 248 , a distal end 241 and a proximal end 249 . The plunger rod 240 further includes a thumb press 242 at its proximal end and a stopper-engaging portion 246 at its distal end. Plunger rod 240 also includes a protrusion in the form of an annular protrusion 244 between the thumb press 242 and the main body 248 . The protrusion 244 may include a tapered portion 245 to facilitate distal movement of the protrusion 244 past the rib 223 into the barrel 220 . In some embodiments, the protrusion 244 has an outer diameter greater than the inner diameter of the barrel at the rib 223 . In at least one embodiment, the configuration of the syringe assembly allows for the protrusion 244 to advance distally past the rib 223 , to lock the plunger rod 240 in the barrel 220 , when the user bottoms the syringe assembly (as more clearly shown in FIGS. 25-26 and discussed further below).
The plunger rod 240 shown further includes at least one frangible point 243 . In the embodiment shown, the frangible point 243 of the plunger rod 240 is located between the protrusion 244 and the thumb press 242 , but the frangible point could be in another location. A stopper-engaging portion 246 is included on the distal end 241 of the plunger rod 240 . As shown, the stopper-engaging portion 246 also includes a plunger recess and a retainer 247 . At least one embodiment of the invention includes a press-fit attachment or other suitable means for retaining the end of the stopper.
Referring now to FIG. 21 , which shows an embodiment of the stopper 260 having a distal end 261 and a proximal end 269 . According to at least one embodiment, the stopper 260 includes a peripheral edge 262 which forms a seal with the interior wall of the barrel 220 and has a diameter greater than the diameter of the interior surface of the barrel at the location of the rib 223 (as more clearly shown in FIGS. 22-24 ). As shown, an elongate tip 266 is provided at the distal end 261 of the stopper 260 to help expel the entire contents of the syringe. The stopper 220 can further include a stopper body 264 having a peripheral lip 263 at its proximal end 269 , according to at least one embodiment of the invention. Further, the stopper 260 can include a stopper frangible connection 265 connecting the stopper body 264 to the stopper 260 .
In this configuration, the stopper 260 and plunger rod 240 occupy the chamber of the barrel 220 and the stopper is bottomed against the distal wall of the barrel. Further, the peripheral edge 262 of the stopper 260 forms a seal with the interior surface of the barrel 220 . The stopper 260 is connected to the stopper-engaging portion 246 of the plunger rod 240 . As shown, the retainer 247 of the stopper-engaging portion 246 retains the peripheral lip 263 of the stopper 260 .
Embodiments of the syringe assembly of FIGS. 19-27 can also include a visual marker 300 , visual indicator 310 or both, as described with reference to FIGS. 13-16 . In a specific embodiment, the barrel 220 of one or more embodiments can also include a visual marker aligned with the locking rib 223 . In a more specific embodiment, the syringe assembly can include a visual indicator disposed on the stopper body 264 .
According to one or more embodiments, there is a gap between the stopper 260 and the distal end of the main body 248 defining a pre-selected axial distance 232 . In one or more embodiments, the distance between the protrusion 244 and the peripheral edge 262 of the stopper 260 defines a first distance, D 1 .
FIG. 23 illustrates the syringe assembly in use and specifically shows movement of the plunger rod during an aspiration or filling step according to one or more embodiments of the present invention. When the user applies a force to the plunger rod in the proximal direction, the plunger rod 240 and the stopper 260 move together in the proximal direction as indicated by the arrow, while the stopper-engaging portion 246 is connected to the stopper 260 by the rim 263 . In this configuration, the gap defining the pre-selected axial distance 232 is maintained while the stopper 260 and plunger rod 240 move together in the proximal direction. The user applies proximal force to the plunger rod until a predetermined or desired amount of medicament is aspirated or drawn into the syringe. During the aspiration step, the plunger rod and the stopper body move in the proximal direction together to draw medication into the syringe, while maintaining the first distance D 1 .
FIG. 24 also shows the syringe assembly when distal force is applied to the plunger rod during an injection step according to at least one embodiment of the present invention. Application of a force in the distal direction closing the gap and moving the pre-selected axial distance 232 shown in FIG. 22 , while the stopper 260 remains stationary. Consistent with at least one embodiment, once the stopper-engaging portion 246 has distally moved the pre-selected axial distance 232 and is in contact with stopper frangible connection 265 , the stopper 260 and the plunger rod 240 begin to move in tandem in the distal direction.
When expelling the contents of the syringe, the plunger rod moves in a distal direction the length of the pre-selected axial distance 232 while the stopper body remains stationary. During and after the contents of the syringe have begun to be or have been fully expelled, the distance between the protrusion 244 and the peripheral edge 262 defines a second distance, D 2 , wherein D 2 is the difference between the first distance, D 1 , and the gap defining a pre-selected axial distance 232 .
In one embodiment, the user may inject a limited amount of the fluid aspirated or exert a limited force on the plunger rod in the distal direction to flush or expel some of the aspirated fluid, without locking the plunger rod, provided that the syringe assembly is not bottomed. However, as will be described further below, a user will typically expel substantially all of the contents of the syringe by bottoming the stopper on the distal wall of the barrel.
Referring now to FIG. 25 , which illustrates the syringe assembly after the plunger rod 240 has been locked inside the barrel 220 , the distal movement of the stopper-engaging portion 246 to the stopper frangible connection 265 of the stopper 260 (as also shown in FIG. 24 ) closes the gap defining the pre-selected axial distance and allows the protrusion 244 to advance past the rib 223 , thereby locking the plunger rod 240 inside the barrel 220 , preventing re-use of the syringe assembly
Referring now to FIG. 26 , the syringe assembly is shown in a configuration in which a user attempts to reuse the syringe assembly after the plunger rod 240 is locked inside the barrel 220 by applying a force to the plunger rod 240 in the proximal direction. Application of sufficient proximal force to the plunger rod causing a portion of the plunger rod 240 to separate at the frangible connection or point 243 , as the holding force of the protrusion 244 and the rib exceeds the breaking force of the frangible point or connection.
FIG. 27 shows the syringe assembly in a configuration after which proximal force has been applied to the plunger rod and the stopper has moved to the proximal end of the barrel. As shown in FIG. 27 , the stopper 260 has separated from the stopper-engaging portion 246 of the plunger rod. The stopper frangible connection 265 breaks to prevent a user from disassembling the parts of the syringe assembly. As otherwise described herein, the peripheral edge of the stopper 262 has an outer diameter greater than the inner diameter of the interior surface of the barrel at the location of the rib 223 . Consistent with at least one embodiment of the invention, when a user applies a force to the plunger rod 240 in the proximal direction, the rib 223 of the barrel 220 locks the peripheral edge 262 of the stopper 260 , and the stopper frangible connection 265 breaks, separating the stopper body 264 from the stopper 260 . Without being limited by theory, it is believed that the force required to break the stopper frangible connection is less than the force exerted on the peripheral edge of the stopper.
FIG. 28 shows an example of a syringe assembly 400 according to another embodiment of the present invention. In the embodiment shown in FIG. 28 , the assembly includes a barrel 420 , a plunger rod 440 and a stopper 460 , arranged so that the proximal end of stopper 469 is attached to the distal end of the plunger rod 441 . The stopper 460 then plunger rod 440 is inserted into the proximal end of the barrel 429 . The barrel includes a flange 424 attached at the proximal end 429 of the barrel 420 and a needle cannula 450 having a lumen 453 attached to the opening in the distal wall 422 at the distal end 421 of the barrel 420 . One or more embodiments also include an attachment hub 452 for attaching the needle cannula 450 to the distal wall 442 .
The barrel as shown more clearly in FIG. 29 further includes a cylindrical sidewall 410 with an inside surface 426 defining a chamber 428 . As more clearly shown in FIG. 30 , the barrel further includes a rib 423 , locking rib or other means for locking the plunger rod within the barrel, having an interior surface with a smaller diameter than the diameter of the interior surface of the barrel. The distal end of the rib 423 further includes a distal portion 412 facing the distal end of the barrel 421 . It will be understood that the rib 423 and the distal portion of the rib 412 can have different shapes and configurations. A ramp 427 is disposed proximally adjacent to the rib 423 having an increasing diameter from the rib to the open proximal end. An increased diameter region 425 is disposed proximally adjacent to the ramp 427 . The increased diameter region 425 may have the same or larger diameter than the inside surface of the barrel 426 .
Referring now to FIG. 31 , which shows an embodiment of the stopper 460 having a distal end 461 and a proximal end 469 . According to at least one embodiment, the stopper 460 includes a sealing edge 462 which forms a seal with the inside surface of the barrel 426 and has a diameter greater than the diameter of the inside surface of the barrel at the location of the rib 423 (as more clearly shown in FIGS. 29 and 30 ). The stopper 460 can further include a stopper body 464 defining an interior recess 468 and a neck 463 disposed at its proximal end 469 , according to at least one embodiment of the invention. According to one or more embodiments, the stopper may be formed from an elastomeric or plastic material. The stopper may also be formed from other known materials in the art.
Referring now to FIG. 32 , a perspective view of a plunger rod 440 is shown as having a main body 448 , a distal end 441 and a proximal end 449 . The plunger rod 440 further includes a thumb press 442 at its proximal end and a stopper-engaging portion 446 at its distal end. Plunger rod 440 also includes a flexible protrusion 444 between the thumb press 442 and the main body 448 and a support 445 proximally adjacent to the flexible protrusion, which provides additional stability to the plunger use and syringe 400 during use. In some embodiments, the flexible protrusion 444 has an outer diameter greater than the inner diameter of the barrel at the rib 423 . In at least one embodiment, the configuration of the syringe assembly allows for the flexible protrusion 444 to advance distally past the rib 423 , to lock the plunger rod 440 in the barrel 420 , when the user bottoms the syringe assembly (as more clearly shown in FIGS. 37-38 and discussed further below). The plunger rod may further include an optional pair of discs 430 , 431 disposed on the distal end and proximal end of the main body 448 . The discs 430 , 431 provide additional stability and may have alternate shapes, depending on the shape of the barrel.
As shown in FIG. 33 , the plunger rod 440 further includes a plurality of frangible connections or bridges 443 adjacent to the support 445 . In the embodiment shown, the plurality of frangible connections 443 of the plunger rod 440 is located between the support 445 and the thumb press 442 , but the frangible connections could be in another location.
The distal end of the plunger rod 441 further includes a stopper-engaging portion 446 . As shown, the stopper-engaging portion 446 also includes a retaining ring 447 for retaining the neck 463 of the stopper 460 . At least one embodiment of the invention includes a press-fit attachment or other suitable means for retaining the end of the stopper.
When assembled, the stopper 460 is connected to the stopper-engaging portion 446 of the plunger rod 440 . In the embodiment shown in FIG. 34 , the stopper 460 and plunger rod 440 may occupy the chamber of the barrel 420 with the distal end 461 of the stopper face positioned against the distal wall of the barrel 422 . Further, the sealing edge 462 of the stopper 460 forms a seal with the interior surface of the barrel 420 . As shown, the retaining ring 447 of the stopper-engaging portion 446 retains the stopper 460 . As will be more fully described with reference to FIG. 40 , the connection between the retaining ring 447 and stopper-engaging portion 446 may be frangible.
Embodiments of the syringe assembly 400 may also include visual markers as described with reference to FIGS. 13-16 . In a specific embodiment, the barrel 420 of one or more embodiments can also include a visual marker aligned with the locking rib 423 . In a more specific embodiment, the syringe assembly can include a visual indicator disposed on the stopper body 464 .
Referring now to FIGS. 34-35 , a defined space between the stopper 460 and the distal end of the main body 448 defining a pre-selected axial distance 432 . In one or more embodiments, the distance between the flexible protrusion 444 and the sealing edge 462 of the stopper 460 defines a first distance, D 1 .
The aspiration or filling step, the injection step and the locking step is shown in FIGS. 35-38 . As with the embodiments of FIGS. 7-11 , 14 - 16 and 22 - 24 , when the user applies a force to the plunger rod in the proximal direction, the plunger rod 440 and the stopper 460 , joined by the neck 463 and retaining ring 447 , move together in the proximal direction as indicated by the arrow. As shown in FIG. 35 , the space defining the pre-selected axial distance 432 and the first distance D 1 is maintained as the stopper 460 and plunger rod 440 move together in the proximal direction. FIG. 36 shows the syringe assembly 400 when distal force is applied to the plunger rod 440 during an injection step. This force causes the plunger rod 440 to move the pre-selected axial distance 432 shown in FIG. 34 while the stopper 460 remains stationary. This closes the space between the plunger rod 440 and stopper 460 as the plunger rod 440 moves into the interior recess 468 . Application of a continuous force in the distal direction to the plunger rod causes the stopper 460 and the plunger rod 440 to move in tandem in the distal direction.
During and after the contents of the syringe have begun to be or have been fully expelled, the distance between the flexible protrusion 444 and the sealing edge 462 defines a second distance, D 2 , wherein D 2 is the difference between the first distance, D 1 , and the space defining a pre-selected axial distance 432 .
As described otherwise herein, the user of the syringe assembly 400 may inject a limited amount of the fluid aspirated or exert a limited force on the plunger rod in the distal direction to flush or expel some of the aspirated fluid, without locking the plunger rod, provided that the syringe assembly is not bottomed.
Referring now to FIGS. 37-38 , which illustrate the syringe assembly after the plunger rod 440 has been locked inside the barrel 420 , the distal movement of the stopper-engaging portion 446 relative to the stopper 460 closes the gap defining the pre-selected axial distance and allows the flexible protrusion 444 to advance past the rib 423 , thereby locking the plunger rod 440 inside the barrel 420 , preventing re-use of the syringe assembly.
According to one or more embodiments, the flexible protrusion 444 permits the plunger rod to bottom during normal use of the syringe assembly. Specifically, the flexible protrusion 444 flexes as it moves past the narrowed diameter of the rib 423 of the barrel. In one or more embodiments, as the protrusion 444 moves distally past the rib 423 , a slight increase in force may be applied to the plunger rod. According to the embodiment shown, this slight increase in force applied to the plunger rod is not perceptible to a user during normal use of the syringe. Further, the ramp 427 of the barrel facilitates movement of the flexible protrusion 444 past the rib 423 . After the flexible protrusion 444 has advanced distally past the rib 423 , the distal portion of the rib 412 restricts movement of the flexible protrusion 444 in the proximal direction. It is believed that the activation force, as defined herein, is less than the force required to withdraw the plunger rod.
Referring now to FIG. 39 , the syringe assembly 400 is shown in a configuration in which a user attempts to reuse the syringe assembly after the plunger rod 440 is locked inside the barrel 420 by applying a withdrawal force, as defined herein, to the plunger rod 440 in the proximal direction. Application of sufficient proximal force to the plunger rod causing a portion of the plunger rod 440 to separate at the plurality of frangible connections 443 , as the withdrawal force exceeds the deactivation force needed to separate a portion of the plunger rod from the body or break the plurality of frangible connections or bridges.
FIG. 40 shows the syringe assembly 400 in a configuration after which proximal force has been applied to the plunger rod and the stopper has moved to the proximal end of the barrel. As otherwise described herein, the sealing edge of the stopper 462 has an outer diameter greater than the inner diameter of the interior surface of the barrel at the location of the rib 423 and therefore, application of a force in the force in the proximal direction causes the stopper 460 to separated from the stopper-engaging portion 446 of the plunger rod
According to one or more embodiments, the syringe barrel may include identifying information on the syringe assembly. Such information can include, but is not limited to one or more of identifying information regarding the contents of the syringe assembly or information regarding the intended recipient.
Reference throughout this specification to “one embodiment,” “certain embodiments,” “one or more embodiments” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention include modifications and variations that are within the scope of the appended claims and their equivalents.
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Syringe assemblies having a passive disabling system to prevent reuse are provided. According to one or more embodiments, the syringe assembly comprises a barrel, plunger rod and stopper wherein the plunger rod further comprises a flexible protrusion that locks the plunger rod within the barrel. Certain embodiments further include a frangible portion on the plunger rod that breaks when reuse is attempted. One or more embodiments include a plunger rod and stopper attachment that prevents disassembly of the syringe assembly prior to use. Syringe assemblies of one or more embodiments also include visual indicators or markers indicating whether a syringe assembly is used or the plunger rod is locked within the barrel.
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TECHNICAL FIELD
[0001] The present invention relates to a device for setting image acquisition conditions, such as a charged particle beam device, typified by a scanning electron microscope, and a computer program. In particular, the present invention relates to a device and a computer program that set device conditions of a device of forming an image by integrating signals.
BACKGROUND ART
[0002] Recently, semiconductor processes have become further finer. Fine patterns are measured and inspected using a microscope. Images of processed patterns are taken by the microscope and displayed on a display, and inspection and measurement (which hereinafter may be simply referred to as “inspection”) are performed using an image processing technique.
[0003] In the case of inspecting processed circuit patterns in the middle of semiconductor processes, inspection of all the patterns on a semiconductor chip is ineffective. Accordingly, areas where a malfunction tends to occur in the process or occurred in the past are specified, and inspection is performed.
[0004] At this time, it is significantly difficult to find the specified areas to be subjected to the inspection using a microscope having a high resolution. A method that is referred to as template matching disclosed in Patent Literature 1 is used.
[0005] The template matching is a method of specifying a desired target pattern in a search region on a sample. On each position in the search region, a degree of matching with a pattern image, which is referred to as a template, is determined, and a position indicating the highest degree of matching with the template in the search region is identified, thereby specifying the position. The operation is performed by a computer. More specifically, a plurality of gradation values representing the unevenness of a pattern in the microscope image are compared with a template diagram in a certain region. If the degree of matching is high, it is determined that matching is achieved. Preliminary registration of position information and the template allows automatic measurement.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: JP-A-2002-328015
SUMMARY OF INVENTION
Technical Problem
[0007] A charged particle beam device, such as scanning electron microscope (SEM), is a device that forms an image on the basis of detection of charged particles (electrons or ions) emitted from a sample, and synchronizes a beam scanning signal and scanning of a display device with each other to thereby form a two-dimensional image. In this case, an image having a high S/N ratio is formed by integrating a plurality of image signals (frames). The number of frames is proportional to the number of scanning by a scanning deflector. As the number of frames increases, the amount of signals supplied to form an image increases. Accordingly, a large number of frames to be integrated enables an image having a high S/N ratio to be formed.
[0008] In a scanning electron microscope or the like that automatically measures and inspects a sample of a semiconductor device or the like, image acquisition conditions including the number of frames are required to be preset. Conditions of image signals provided for template matching are also required to be preset. A large number of integrations enables an image having a high S/N ratio to be formed as described above. However, unnecessary times of beam scanning increases processing time accordingly. This also causes a possibility that contaminates a sample, shrinks a pattern, or increases charging or the like. Accordingly, in order to maintain a high S/N ratio while suppressing processing time and the like, the optimum number of frames is required to be selected. However, Patent Literature 1 does not describe selection of an optimal number of frames for pattern matching.
[0009] Hereinafter, a device for setting image acquisition conditions and a computer program that have an object to set image acquisition conditions maintaining a high S/N ratio while suppressing processing time and the like will be described.
Solution to Problem
[0010] As an aspect to achieve the object, a device for setting image acquisition conditions and a computer program causing a computer to execute the processes are hereinafter proposed that include: an image integration unit that integrates a plurality of image signals and forms an image; and a pattern matching unit that performs pattern matching on the image integrated by the image integration unit using a preliminarily registered template, wherein the image integration unit changes the number of integrations on each of a plurality of preliminarily acquired integrated images, and forms a plurality of images with the different numbers of integrations, the pattern matching unit performs pattern matching on the plurality of images with the different numbers of integrations, and acquires a score representing a degree of matching between the template and a position specified by the template, and the device further comprises a selection unit that selects the number of integrations where variation in the scores is within a prescribed allowable range, the number of integrations where all the plurality of integrated images represent a score of at least a prescribed value, the number of integrations where variation in dimensions of a pattern specified by the pattern matching is within a prescribed allowable range, or the number of integrations where an average of dimensions of the pattern is within a prescribed range.
Advantageous Effects of Invention
[0011] The configuration can select the appropriate number of integrations for image acquisition using integrated images having already been acquired. Accordingly, appropriate image acquisition conditions can be set in accordance with process variation or the like.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a schematic configuration diagram of a scanning electron microscope.
[0013] FIG. 2 is a diagram showing examples of images acquired by the scanning electron microscope.
[0014] FIG. 3 is a schematic configuration diagram of the scanning electron microscope and a device for setting image acquisition conditions.
[0015] FIG. 4 is a diagram illustrating the device for setting image acquisition conditions in detail.
[0016] FIG. 5 is a diagram illustrating an example of an image formed on the basis of integrations of plural pieces of image data.
[0017] FIG. 6 is a diagram illustrating an example of forming images with different number of integrations on the basis of a plurality of integrated images.
[0018] FIG. 7 is a diagram showing a graph of scores in the case where a plurality of images according to different numbers of integrations are formed on the basis of a plurality of evaluation target images, and template matching is performed on the images.
[0019] FIG. 8 is a diagram showing an example of a table representing an average and variation of scores of the numbers of integrations.
[0020] FIG. 9 is a flowchart illustrating a step of determining the optimal number of integrations on the basis of the scores of pattern matching.
[0021] FIG. 10 is a flowchart illustrating a step of determining the optimal number of integrations on the basis of the scores of pattern matching.
[0022] FIG. 11 is a graph showing a relationship between the numbers of integrations and measured lengths.
[0023] FIG. 12 is an average and variation of measured lengths according to the numbers of integrations.
[0024] FIG. 13 is a flowchart illustrating a step of determining the optimal number of integrations on the basis of measurement result.
[0025] FIG. 14 is a flowchart illustrating a step of determining the optimal number of integrations on the basis of measurement result.
[0026] FIG. 15 is a diagram illustrating a step of determining an acceptance of a template.
[0027] FIG. 16 is a flowchart illustrating a step of setting the optimal acceptance on the basis of the score of pattern matching.
[0028] FIG. 17 is a flowchart illustrating a step of setting the optimal acceptance on the basis of the score of pattern matching.
[0029] FIG. 18 is a flowchart illustrating a step of setting the appropriate number of integrations on the basis of pattern matching.
DESCRIPTION OF EMBODIMENTS
[0030] Microscopes include a type of emitting light and a type of emitting electron beams. The types are different in resolution. However, in some cases, both types can adopt the same image processing.
[0031] This is because, although an optical microscope with a high resolution causes a CCD sensor or the like to detect light reflected by a sample and an electron microscope having a higher resolution detects electrons generated on the sample, both types perform digital signal processing for imaging.
[0032] Image acquisition conditions (presence and absence of focus, the number of integrations, magnification, etc.) of an electron microscope and the like automatically measuring and inspecting a sample are to be preliminarily registered. However, a semiconductor manufacturing process includes process variation. Accordingly, conditions at the time of registration are sometimes incapable of appropriately extracting a pattern to cause a matching error.
[0033] In order to solve the problem, the number of integrations (the number of frames), which is one of the image acquisition conditions, may be set larger to sharpen the pattern. Unnecessary increase in the number of integrations unfortunately reduces the throughput. Furthermore, there is a possibility of increasing adverse effects of contamination, shrinkage, and charging.
[0034] Accordingly, measures to appropriately set the number of integrations according to process variation and the like are preferable to realize achievement of a matching success rate and reduction in processing time and the like. However, there are no clear indicator for appropriate setting, and is a possibility of erroneous setting. Accordingly, it is difficult to reset the number of integrations. Furthermore, erroneous setting may affect measurement results and the like, which is a cause of giving up resetting.
[0035] In many cases, an unnecessary number of integrations, which is one of image acquisition conditions requiring preliminary setting in the template matching method, are set. This setting is largely affected by contamination, shrinkage, charging and the like, while throughput is reduced. In order to solve the problem, it is preferred to correct the number of integrations to an appropriate number. The correction requires verification using a device and a sample. This verification prevents the device from being used for inspection, which is the original object, and results in reducing the operating ratio of the device. That is, once operation on a mass production line has started, it is significantly difficult to change the image acquisition conditions.
[0036] Hereinafter, a device for setting image acquisition conditions and a computer program that can find setting conditions of the device without using a device or a sample will be described in further detail.
[0037] In order to set device conditions without using a device or a sample, a method is proposed that sets conditions using images acquired by automatic measurement or automatic inspection. A critical dimension SEM (CD-SEM) is a device for continuously measuring many samples formed through the same manufacturing process. That is, as the measurement process progresses, image information is accumulated. The accumulation of the image information and use thereof for determination for setting image acquisition conditions negate the need to operate the device only for setting the device conditions.
[0038] The previously acquired images include variation in pattern size, brightness at pattern edges, and pattern noise due to process variation. Use of data of the image group can verify variation in the case of changing the image acquisition conditions without using a device or a sample. In the device of this embodiment, which will be described below, the image acquisition conditions are changed using the data of the image group including process variation.
[0039] Use of the image group including process variation acquired by automatic measurement negates the need to use the device or a sample again for verifying change of image acquisition conditions, thereby allowing changing off-line. Furthermore, mass production can be developed in a short time period. Accordingly, even a user who cannot have tried correction concerning matching error can easily perform change.
Embodiment 1
[0040] FIG. 1 is a schematic configuration diagram of a CD-SEM. A primary electron beam 104 drawn from a negative pole 101 by a voltage V 1 applied to a first positive pole 102 is accelerated by a voltage Vacc applied to a second positive pole 103 and travels toward a lens system on a succeeding stage. The primary electron beam 104 is converged as a minute spot on a sample 107 by a converging lens 105 and an objective lens 106 controlled by a lens control power source 114 , and two-dimensionally scans the sample 107 by means of two stages of deflection coils 108 .
[0041] Scanning signals for the deflection coils 108 are controlled by a deflection controller 109 in conformity with an observation magnification. A secondary electron 110 emitted from the sample by the primary electron beam 104 scanning the sample 107 is detected by a secondary electron detector 111 . Information on the secondary electron detected by the secondary electron detector 111 is amplified by an amplifier 112 and displayed on a display of a computer 113 .
[0042] The process of manufacturing a semiconductor device processes a silicon wafer to manufacture a semiconductor device. The wafer is adopted as the sample 107 . A circuit pattern in the middle of manufacturing is displayed on a screen of the display of the computer 113 , which allows an operator to observe a manufacturing failure of the circuit pattern and an adhering foreign body. Some CD-SEMs have a function of automatically measuring the width of a circuit pattern using secondary electron information. The process using the image information and the template matching identifying a desired pattern from the image are performed in an operation unit in the computer 113 . Images used for template matching and an automatic measurement file for automatic measurement are registered in a storage in the computer 113 . The automatic measurement is performed on the basis of the registered information. The acquired image is registered in a data accumulation unit in the computer 113 .
[0043] FIG. 2 schematically shows images acquired by automatic measurement by a CD-SEM. In the case of adopting FIG. 2 (a) as a standard, (b) has a large pattern size and (c) has a small pattern size. There is what has a large noise as with (d). These images include an image having a strong pattern edge as with (e) and an image having a weak pattern edge as with (f). The differences between images (a) to (f) occur owing to effects of process variation or differences in layer, even in the case of automatic measurement with the identical image acquisition conditions. The differences of images (d) to (f) also appear owing to differences in the number of integrations, which is one of the image acquisition conditions. The larger the number of integrations, the stronger the pattern edge is and the lower the noise is. The smaller the number of integrations, the weaker the pattern edge is and the higher the noise is. The differences of images (a) to (f) affect scores acquired by matching with the template.
[0044] In particular, in the case of an image with high noise and a weak pattern edge, the pattern is not successfully detected, which tends to cause a matching error. The score will now be described. For instance, the score represents a degree of matching with the template from 0 to 1000. Complete matching is represented as 1000. The lower the degree of matching, the lower the score becomes. In the CD-SEM, in order to prevent erroneous detection, an acceptance is set as a reference value for determining presence or absence of a target pattern. The acceptance is a threshold set automatically or by a user. If the score is at least the acceptance, it is determined that the pattern is successfully detected. Instead, if the score is equal to or less than the acceptance, it is determined that matching error occurs.
[0045] FIG. 3 is a schematic configuration diagram of the CD-SEM and image acquisition conditions optimization function/device. An image acquired by a CD-SEM 301 is accumulated in a data accumulation unit 302 residing in the computer 113 in FIG. 1 . As necessary, the image is transmitted to an image acquisition conditions optimization function/device 303 . The image acquisition conditions optimization function/device 303 optimizes the image acquisition conditions. A result calculated here is transmitted to a storage 304 residing in the computer 113 in FIG. 1 , and registered again as new setting content of automatic measurement. A CD-SEM 305 performs automatic measurement with the new setting content.
[0046] The image acquisition conditions optimization function/device 303 in FIG. 3 will now be described in detail with reference to FIG. 4 . First, image data accumulated in a data accumulation unit 401 is transmitted to an image acquisition conditions optimization function/device 409 . A conversion unit 402 of the number of integrations converts the data into a plurality of images with the number of integrations. The converted images are transmitted to a pattern matching unit 403 at any time, which matches each image with the number of integration with the template to thereby acquire the score.
[0047] The acquired score is temporarily accumulated in a matching result (score) accumulation unit 404 . Meanwhile, in the case where the optimization target is a length measurement image, there is a possibility where the measured length varies owing to contamination or variation in shrinkage according to the number of integrations. Accordingly, it is required to verify that the measured length is within a control value, in addition to the acceptance. Thus, while the image converted by the conversion unit 402 of the number of integrations is transmitted to the pattern matching unit 403 , the image is transmitted to a length measurement unit 405 in parallel. Length measurement with each image with the number of integrations acquires the measured length. The measurement result is accumulated in a length measurement result accumulation unit 406 .
[0048] Accordingly, verification of the results accumulated in the matching result accumulation unit 404 and the length measurement result accumulation unit 406 allows a simulation of the case of changing the number of integrations, which is one of the image acquisition conditions. A score average, variation in the scores (3σ), a length measurement average, and a length measurement reproducibility (3σ) are calculated from the accumulated information. A filter unit 407 automatically determines the optimal number of integrations from the calculated result, thereby determining optimum conditions.
[0049] The conversion unit 402 of the number of integrations in FIG. 4 will now be described in detail with reference to FIG. 5 . Image data in the data accumulation unit 401 includes gradation values of respective pixels per scan. For instance, in the case of the image with the number of integrations N (N frames), N times of scans are repeatedly performed as shown in FIG. 5 , and one image is generated from the data. Thus, N pieces of data exist. Use of the N pieces of data can generate images with 2 frames, 4 frames, 6 frames to N frames at the maximum as shown in FIG. 6 . The number of generated frames can be automatically or arbitrarily set.
[0050] The pattern matching unit 403 in FIG. 4 will now be described in detail with reference to FIG. 7 . After the images with the respective numbers of integrations are transmitted from the conversion unit 402 of the number of integrations to the pattern matching unit 403 , matching with the template registered in the automatic length measurement file in the storage of the computer 113 in FIG. 1 is performed on each image. As exemplified in FIGS. 5 and 6 , a plurality of images with the numbers of integrations can be generated from one image. Accordingly, a plurality of scores per image can be acquired as shown in FIG. 7 . Likewise, acquisition of scores of images 2 to X allows the score average and the variation in the scores (3σ) of each number of integrations to be calculated. Here, it is provided that the calculated result is shown in FIG. 8 .
[0051] Meanwhile, the filter unit 407 in FIG. 4 determines the optimal number of integrations on the basis of the acceptance registered in the automatic measurement file and an arbitrarily set allowable value of the variation in the scores. That is, the filter unit 407 functions as a selection unit that selects a candidate of the number of integrations or the final number of integrations.
[0052] Here, FIG. 9 exemplifies a matching result determination flowchart. In a matching result accumulation unit 701 , the score average and the variation in the scores (3σ) with each number of integrations are calculated as described above. The information is transmitted to a filter unit 702 , and, first, it is determined whether the variation in the scores (3σ) is within the allowable range or not. Here, it is provided that, if a value where 3σ is within R is the allowable value, a plurality of applicable conditions exist. Next, it is determined whether the score average is higher than the acceptance set in the automatic length measurement file by at least a certain amount U or not.
[0053] This is because errors may frequently occur if the difference from the acceptance is not at least the certain amount. If a plurality of applicable conditions exist at this stage, a condition with the smallest number of integrations is determined as the optimum condition. Here, FIG. 10 shows a determination example in the case of FIG. 8 . For instance, provided that the acceptance Q set in the automatic length measurement file is 300, the allowable value R of the variation in the scores (3σ) is 100, and the certain amount U is 100, it is determined that 8 frames or more is optimal.
[0054] Next, the length measurement unit 405 in FIG. 4 will be described in detail with reference to FIGS. 11 and 12 . After the images with the respective numbers of integrations are transmitted from the conversion unit 402 of the number of integrations to the length measurement unit 405 , length measurement with the same condition as the length measurement method registered in the automatic length measurement file is performed on each image. As described above, plural images with the numbers of integrations can be generated from one image. Accordingly, a plurality of measured lengths can be acquired on the basis of one image as in FIG. 11 . Likewise, acquisition of measured lengths with the respective numbers of integrations on images 2 to X allows the length measurement average and the length measurement reproducibility (3σ) to be calculated. Here, it is provided that the calculated result is shown in FIG. 12 .
[0055] Meanwhile, the filter unit 407 determines the optimal number of integrations on the basis of the length measurement managing value set in the automatic measurement file and the automatically or arbitrarily set length measurement variation (3σ). Here, FIG. 13 shows a measurement length result determination flowchart. In a length measurement result accumulation unit 901 , the length measurement average and the length measurement reproducibility (3σ) with each number of integrations are calculated, as described above. The information is transmitted to a filter unit 902 , and, first, it is determined whether the length measurement reproducibility (3σ) is within the allowable range or not. Here, it is provided that, if a value where the allowable value is 3σ is within M, a plurality of applicable conditions exist. Next, it is verified whether the length measurement average falls within the length measurement managing value set in the automatic length measurement file. This is because, change in the number of integrations prevents the measured length from being significantly changed. If a plurality of applicable conditions exist at this stage, a condition with the smallest number of integrations is determined as the optimum condition.
[0056] Here, a determination example in the case of FIG. 12 is shown in FIG. 14 . For instance, provided that the set length measurement managing value (N±P) is within 51.5 nm±1 nm and the length measurement reproducibility M is within 3 nm, 16 frames or more is determined optimal. Even if the pattern matching result is determined such that 8 frames is optimal, determination of the measurement result has precedence in the case of the length measurement image.
[0057] FIG. 18 is a flowchart illustrating a process of determining image acquisition conditions. After processing is started, image data is read from a storing medium accumulating the images (step 1201 ). Image data for forming one image includes plural pieces of data of images to be integrated. Accordingly, a plurality of images including the different numbers of integrations are formed using these pieces of image data (step 1202 ). For instance, a plurality of images including the different numbers of integrations, for instance, one, two, three, . . . , N are formed. In the case where a operation device preliminarily forming the images with the different numbers of integrations, and a storing medium accumulating the differently integrated images are provided, step 1202 is not required.
[0058] Next, template matching is performed on the integrated image, thereby acquiring the score (step 1203 ). The template matching process is performed on each image with the different number of integrations, thereby acquiring a plurality of scores (degree of matching between the template and the position specified by the template) on one evaluation target image (step 1204 ). Next, the process of acquiring a plurality of scores is performed even on a different evaluation target image, thereby acquiring a plurality of scores on the evaluation target images (step 1205 ). The scores acquired as described above are compared with the preset acceptance (step 1206 ). The number of integrations having a score of at least the acceptance on every evaluation target image is selected (step 1207 ). The acceptance is a threshold for determining whether matching succeeds or not. Accordingly, it can be considered that the number of integrations where all the scores exceed the acceptance is the image acquisition condition where success of matching is compensated on a plurality of images acquired from the different samples (different samples acquired under the same manufacturing conditions). Thus, selection of the number of integrations from there among at least allows the matching success rate to be maintained high.
[0059] Next, the minimum one is selected from among the selected numbers of integrations (step 1208 ). The selection of the minimum one from among the numbers of integrations where the high matching success rate is compensated can minimize beam irradiation on the sample while maintaining the matching success rate in a high state.
[0060] Finally, the selected number of integrations is stored in a recipe as the image acquisition conditions (step 1209 ). The above steps allow appropriate image acquisition conditions to be set without reducing the operating ratio of the device.
Embodiment 2
[0061] On the automatic length measurement file in the CD-SEM, it is determined whether template matching succeeds or not according to the acceptance, as described above. In the case where the matching success rate is set to have priority, the acceptance may sometimes become higher than necessary. Automatic determination of the acceptance will be described in detail with reference to FIG. 15 . First, an image 1001 to be registered as a template is acquired. Next, a target pattern 1002 to be a target of image recognition in the acquired image is registered. At the same time of registering the target pattern, image recognition 1003 is performed with the target pattern in the acquired image. A first candidate score S1 with the highest score and a second candidate score S2 with the second highest score are extracted. The acceptance is calculated from S1 and S2. The acceptance is the average between S1 and S2. In the case where S1 is 800 and S2 is 300, the acceptance is 550.
[0062] Here, the acceptance is a value that can be set to an arbitrary value. The value can be rewritten in the case where it is determined that the value automatically determined on registration of the template is high. Thus, a method is proposed that automatically determines whether the automatically determined acceptance is optimal or not and, if the value is determined inappropriate, automatically or arbitrarily rewrites the value to an appropriate value. It should be noted that, setting the acceptance too low causes a possibility of erroneously recognizing a pattern different from the target pattern as the target pattern. In order to prevent erroneous recognition, a minimum value Qmin with an acceptance that can be preset is determined.
[0063] Even without difference between the acceptance and the score average, errors frequently occur. Accordingly, the acceptance is required to be set such that at least a certain difference is secured. FIG. 16 exemplifies an acceptance optimization flowchart in consideration therewith. If the acceptance is high, the variation in the scores (3σ) is small. Accordingly, even with a high score average, the verification of score average 1103 unfortunately processes the condition as an inapplicable condition. Here, it is verificated whether the score average of the inapplicable conditions is at least a minimum acceptance Qmin and the certain amount U of difference is secured or not. If the condition is met, reduction in acceptance allows adoption of the condition where the number of integrations is further reduced.
[0064] It is provided that the optimal acceptance value is a value acquired by subtracting the certain amount U from the score average of the inapplicable condition. However, it can be automatically or arbitrarily selected whether to adopt a condition with a reduced acceptance or not. That is, the optimum condition is selected from between two cases, or the case where the acceptance is not optimized and the case where the acceptance is optimized (a plurality of conditions if, on optimization, a plurality of applicable conditions exist). In the case of setting optimization to be automatic, it can be preset whether to select acceptance-optimized one or not.
[0065] Here, FIG. 17 shows an example of simulation based on the result in FIG. 8 . In the case where the acceptance Q registered in the automatic length measurement file is 550, the allowable value R of the variation in the scores (3σ) is 100, the certain amount U is 100, and the minimum acceptance Qmin is 300, it is determined that the number of integrations is required to be at least 16 unless the acceptance is optimized. In the case where the optimization of the acceptance is valid, the number of integrations can be reduced to 8 frames.
REFERENCE SIGNS LIST
[0000]
101 negative pole
102 first positive pole
103 second positive pole
104 primary electron beam
105 converging lens
106 objective lens
107 sample
108 deflection coils
109 deflection controller
110 secondary electron
111 secondary electron detector
112 amplifier
113 computer
114 lens control power source
301 , 305 CD-SEM
302 , 401 data accumulation unit
303 , 409 image acquisition conditions optimization function/device
304 storage
402 conversion unit of the number of integrations
403 pattern matching unit
404 matching result (score) accumulation unit
405 length measurement unit
406 , 901 , 903 length measurement result accumulation unit
407 , 702 , 704 , 902 , 904 , 1102 , 1105 filter unit
701 , 703 , 1101 , 1104 matching result accumulation unit
1001 template registration image
1002 target pattern registration
1103 verification of score average
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The present invention relates to a device ( 303 ) for setting image acquisition conditions for charged particle beam devices or the like. An image integration unit ( 402 ) forms a plurality of images with a number of different integrations (number of integrations 2, 4 . . . N) from one image (number of integrations N) acquired in advance. A pattern matching unit ( 403 ) matches the patterns of each of the plurality of images having a number of different integrations with template images registered in advance and then finds a score that shows the degree of matching between images. A selection unit ( 407 ) selects a number of integrations such that any variation in the scores is contained within a prescribed allowable range. The selected number of integrations is stored in a recipe of the device. Thus, it is possible to determine the number of integrations in the recipes without having to operate the device, and to set image acquisition conditions so as to allow a minimization of the processing time while maintaining a sufficient S/N ratio.
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BACKGROUND OF THE INVENTION
The present invention relates to a pneumatic air intake throttle valve control device for a diesel engine for pneumatically controlling an intake throttle valve therein operated at engine idle speed.
Recently, diesel engine vehicles, particularly passenger cars, have become more popular due to their economic advantages. However, vibration and noise produced by diesel engines have been problematic. Particularly, the engine idle speed torque fluctuations, that is, angular velocity fluctuation during a single engine cycle, have been remarkably high in comparison with gasoline engines. This is one factor causing the large amounts of noise and vibration.
In view of the above noted defects, an object of the present invention is to provide an intake air throttle valve control device in which at idle speed or for no-load operation of the engine the air intake is controlled while at the same time the amount of throttle opening is controlled in accordance with exhaust pressure, engine water temperature, intake pressure and the like.
SUMMARY OF THE INVENTION
In accordance with this and other objects of the invention, there is provided an intake air throttle valve control system for a diesel engine having an intake manifold and an exhaust manifold including an intake passage connected to the intake manifold with the intake passage being partitioned by divider into first and second parallel intake passages. A throttle valve is disposed in a first intake passage which provides a throttling effect depending upon the angular position thereof. A negative pressure control valve is disposed in the second passage for maintaining a negative pressure downstream of the first and second passages at a predetermined substantially constant value when the engine is operating at idle speed. The system preferably further includes a source of negative pressure, a first pressure responsive actuator coupled to the throttle valve with the first actuator having an atmospheric pressure chamber, a negative pressure chamber and a diaphragm separating the atmospheric pressure chamber from the negative pressure chamber and a spring biasing the diaphragm towards the negative pressure chamber. An engine temperature sensing valve having inlet and outlet ports is operatively positioned to operate in response to the temperature of the engine. The outlet port of the water temperature sensing valve is in fluid communication with the negative pressure chamber of the actuator. A vacuum cut-off valve having inlet and outlet ports with the outlet port of the vacuum cut-off valve in fluid communication with the inlet port of the engine temperature sensing valve vents the inlet port thereof to the atmosphere in response to a predetermined engine operational parameter. A second pressure responsive actuator operates the control valve. The second actuator has an atmospheric pressure chamber and a negative pressure chamber separated by a diaphragm with spring means biasing the diaphragm towards the atmospheric pressure chamber. The negative pressure chamber of the second actuator communicates with a portion of the intake passage downstream of the first and second intake passages.
Yet further, the vacuum cut-off valve has a negative pressure chamber, an atmospheric pressure chamber and a pressure chamber which is in fluid communication with the exhaust manifold. A diaphragm dividing the atmospheric pressure chamber from the pressure chamber which is in fluid communication with the exhaust manifold is coupled to a rod which moves a valve body disposed in the negative pressure chamber. A partitioning plate divides the atmospheric pressure chamber from the negative pressure chamber. A spring biases the diaphragm away from the partitioning plate. The valve body operates to open and block a connecting tube to the negative pressure source. The vacuum cut-off valve may operate in response to the pressure in an oil line of the engine. The vacuum cut-off valve, in a preferred embodiment, includes a three-way electromagnetic valve having an inlet port, an outlet port and atmospheric venting port along with means for operating the three-way electromagnetic valve in response to the predetermined engine parameter. The means for operating the three-way electromagnetic valve may include an electrical switch connected to be operated in response to the pressure in an oil line of the engine. The operating means may also be an electrical generator which operatively coupled to the engine with the electrical generator producing an output voltage which varies in response to the speed of rotation of the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram, partially as a cross-sectional view, of an intake air throttle valve control system constructed in accordance with a first embodiment of the invention;
FIG. 2 is a diagram showing an alternative embodiment of a vacuum cut-off valve utilized in the system shown in FIG. 1; and
FIG. 3 is a diagram showing a further alternative embodiment of the vacuum cut-off valve of the system shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A diesel engine system constructed according to the present invention will now be described with reference to FIG. 1. Reference numeral 1 designates an intake passage of a diesel engine which includes an intake air throttling portion 5 which is divided into first and second passages 3 and 4 by a partitioning wall 2. In the first passage 3, an intake air throttle valve 6 is rotatably supported by a peripheral wall of the passage by a shaft 7. An arm 8 is coupled to one end of the shaft 7 for rotating the throttle valve 6. The construction and operation of the valve and shaft are well known in the art.
Reference numeral 9 denotes a negative pressure responsive actuator which is separated into a negative pressure chamber 11 and an atmospheric pressure chamber 12 which is vented to the atmosphere through a suitable hole (not shown). The negative pressure chamber 11 communicates with a vacuum pump 14 through a suitable tube 13 and includes therein a return spring 15 which presses upon a diaphragm 10. One end of a rod 16 extends into the atmospheric pressure chamber 12 and is coupled to the diaphragm 10 while the other end of the rod 16 extends outwardly and is connected directly or through a suitable linkage to the arm 8.
A vacuum cut-off valve 17 is coupled in series with actuator 9 through the tube 13. The vacuum cut-off valve is divided into a pressure chamber 20, an atmospheric pressure chamber 21 and a negative chamber 22 by a partitioning plate 18 and a diaphragm 19, respectively. The pressure pressure chamber 20 communicates with an exhaust passage 24 of the engine through a tube 23 so as to detect the exhaust pressure in the exhaust passage 24. A valve body 25 is coupled via a valve stem 25a to the diaphragm 19 so that when a predetermined exhaust pressure acts on the diaphragm 19 the valve body 25 is operated to close an opening 13a in series with the tube 13 against a return spring 26.
A water temperature detecting valve 27 is disposed between the vacuum cut-off valve 17 and the actuator 9. A water temperature detecting element 28 is mounted on a cylinder body B and disposed in a water jacket W of the engine. The water temperature detecting valve 27 is operated to open or close an inner passage (not shown) therethrough in response to the water temperature detecting element.
An intake air negative pressure control valve 29 operatively mounted in the second passage 4 is rotatably supported by a shaft 30 by a wall of the intake air throttle portion 5. An arm 31 is coupled to the other end of the shaft 30 to operate the control valve 29.
An actuator 32 has a negative pressure chamber 34 and an atmospheric pressure chamber 35 separated by a diaphragm 33. The negative pressure chamber 34 communicates through a tube 36 with a portion 1a of the air intake passage 1 downstream of the intake air throttle portion 5 so as to detect the intake negative pressure at the portion 1a. A spring 37 is disposed in the negative pressure chamber 34 to bias the diaphragm 33 leftward in FIG. 1, that is, in the direction to close the control valve 29. The atmospheric pressure chamber 35 is vented to the atmosphere through a suitable hole (not shown). One end of a rod 38 extends into the atmospheric pressure chamber 35 and is connected to the diaphragm 33 while the other end of the rod 38 is connected to the above described arm 31 directly or through a suitable linkage.
The operation of the thus constructed system according to the present invention will now be described. When the engine is operating at idle speed at a normal temperature, the exhaust pressure in the exhaust passage 24 is low and the water temperature detecting valve is opened so that the diaphragm 10 and the rod 16 are positioned to the left acting against the return spring 15 by action of the vacuum pump. As a result, the intake air throttle valve 6 is rotated clockwise to thereby throttle the intake air flow. Accordingly, the flow rate of intake air is decreased so that the rate of rotation and vibromotive acceleration of the engine are reduced advantageously.
However, if the throttling effect of the intake air throttle valve 6 is further increased and as a result the intake air negative pressure in the portion 1a downstream of the intake air throttle portion 5 excessively increased, an increased negative pressure is also applied to the negative pressure chamber 34 of the actuator 32 in proportion to the magnitude of the intake air negative pressure in the portion 1a. Therefore, the diaphragm 33 and the rod 38 are moved to the right against the force of the return spring 37 so that the control valve 29 is rotated clockwise by the arm 31 to thereby increase its opening angle. As a result, excessive increases in the negative pressure in the downstream portion 1a are prevented.
When the engine temperature is sufficiently low, just after starting the engine and when the engine is running at idle speed, although the vacuum cut-off valve 17 is open, the inner passage of the water temperature detecting valve 27 is closed until the detecting element 28 reaches a predetermined temperature. Accordingly, the actuator 9 is then inoperative and the intake air throttle valve 6 is maintained in the fully open state to thereby avoid degrading the engine start performance.
Moreover, irrespective of the temperature, when the engine is running at speeds other than idle speed, the exhaust pressure in the exhaust passage 24 is increased and a high pressure is applied to the pressure chamber 20 so that the diaphragm 19 and the valve body 25 are moved against the return spring 26 upwardly to thereby close the opening 13a. As a result, the actuator 9 is rendered inoperative to hence return the intake air throttle valve 6 to the open position and to remove any throttling effect in the intake air throttle portion 5.
Therefore, according to the present invention, at normal engine speeds except idle speed, no engine performance degradation such as output power reduction is caused by the presence of the valves 6 and 29. As vibration is reduced at the idle speed of the engine as mentioned above, chassis vibration and a gear shift lever vibration are effectively reduced with the use of the invention.
FIG. 2 shows another embodiment of the present invention is which a three-way electromagnetic valve 40 is employed instead of the cut-off valve 17 shown in FIG. 1. The three-way electromagnet valve 40 is provided with a negative pressure inlet port 42, a negative pressure outlet port 44 and a vent hole 46 to the atmosphere and is so constructed that the outlet port 44 can be selectively communicated with the inlet port 42 or the vent hole 46. A pressure detecting switch 48 such as a hydraulic pressure detecting switch for detecting the hydraulic pressure in the engine oil lines is employed to operate the electromagnetic valve 40. In FIG. 2, the detecting switch 48 is constructed so that when the hydraulic pressure is low, for example, at engine idle speed, the contact points of the switch are open while when the engine speed is increased with an accompanying hydraulic pressure increase above a predetermined value, the contact points are closed to thereby operate the above described electromagnetic valve 40 by causing electric current from a battery 50 to flow through a circuit 52. The other elements of the system of FIG. 2 are the same as in the embodiment of FIG. 1.
In operation, the hydraulic pressure in the engine oil lines is low at engine idle speed. Accordingly, it will be understood that substantially the same effect as in the embodiment of FIG. 1 is obtained in the system partially shown in FIG. 2. That is, a negative pressure produced at the vacuum pump 14 is supplied through the inlet and outlet ports 42 and 44 at the engine idle speed to the negative pressure chamber 11 of the actuator 9 while when the engine speed is increased and the hydraulic pressure increased above the predetermined value, communication between the negative pressure inlet and outlet ports 42 and 44 is blocked and the outlet port is shunted to the atmosphere through the vent hole 46 by the action of the electromagnetic valve 40 to thereby render the actuator inoperative and to remove the throttling effect in the first passage 3.
FIG. 3 shows a still another embodiment of a control system according to the present invention in which an engine generator and associated components are utilized for controlling the system. A three-way electromagnetic valve 40 having an inlet port 42, an outlet port 44 and a vent hole 46 of the type shown in FIG. 2 is also utilized in the system of FIG. 3. A relay 62 is connected in a circuit 68 which controls the electromagnetic valve 40. A contact point 64 of the relay 62 is closed when a coil 66 connected to an E terminal of a generator 60 driven by the engine is energized through a circuit 70. A battery 72 is connected to the generator 60 at B and E terminals as shown, respectively.
In operation, since at engine idle speed, the output voltage from the generator 60 is low, the relay coil 66 is inoperative so that the relay contact 64 remains in the open state. In this case, communication between the inlet and outlet ports 42 and 44 is maintained so that the negative pressure produced by the vacuum pump 14 is introduced into the negative pressure chamber 11 of the actuator 9 to thereby produce a throttling effect in the first passage 3 in the same manner described above. On the other hand, when the engine speed is increased above the engine idle speed, the output voltage from the generator 60 is increased thereby energizing the relay coil 66 and closing the contact point 64. Accordingly, communication between the inlet and outlet ports 42 and 44 is blocked and the outlet port vented to the atmosphere through the vent hole 46 to thereby render the actuator 9 inoperative.
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An intake air throttle valve control system for a diesel engine which greatly reduces vibration, noise and rough engine running at idling speeds. An intake passage connected in series with the intake manifold of the engine is divided into first and second parallel intake passages. A throttle valve is disposed in a first intake passage to provide a throttling effect therein in response to predetermined engine conditions such as engine temperature, oil line pressure and/or exhaust manifold pressure. A negative pressure control valve is disposed in the second passage to maintain a negative pressure downstream of first and second passages at a fixed value to prevent the pressure from being overly reduced by the throttle valve.
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BACKGROUND OF THE INVENTION
U.S. application Ser. No. 07/599,751, filed Oct. 19, 1990 by me under the title FLUORINE-FREE PHOSPHATE GLASSES, now U.S. Pat. No. 5021,366, is directed to the preparation of chemically durable, weather resistant, essentially fluorine-free glass compositions with annealing points within the range of about 300°-340° C., thereby enabling them to be molded into lenses at temperatures of about 360°-400° C., and with refractive indices of about 1.605 and linear coefficients of thermal expansion (25°-300° C.) between 145-170×10 -7 /°C. Those glasses were designed to replace the alkali metal fluoroaluminophosphate glasses disclosed in U.S. Pat. No. 4,362,819 (Olszewski et al.) marketed by Corning Incorporated, Corning, New York for pressing optically finished lenses as described in U.S. Pat. No. 4,481,023 (Marechal et al.) As was explained in that application, fluorine in the glasses attacked the surfaces of the molds during pressing of the lenses, and volatilization thereof during melting of the glass batch gave rise to environmental hazards. The glasses of U.S. Ser. No. 07/599,751 consisted essentially, expressed in terms of mole percent on the oxide basis, of:
______________________________________Li.sub.2 O 5-10 P.sub.2 O.sub.5 30-36Na.sub.2 O 5-15 Al.sub.2 O.sub.3 0-5K.sub.2 O 0-6 CeO.sub.2 0-2Li.sub.2 O + Na.sub.2 O + K.sub.2 O 15-25 SnO 0-20ZnO 10-33 PbO 0-20CaO 0-20 Sb.sub.2 O.sub.3 0-12SrO 0-20 Bi.sub.2 O.sub.3 0-6BaO 0-20 SnO + PbO + Sb.sub.2 O.sub.3 + 0-20 Bi.sub.2 O.sub.3______________________________________
The primary objective of the instant invention was to devise fluorine-free glass compositions demonstrating chemical and physical properties similar to those exhibited by the glasses of U.S. Ser. No. 07/599,751, but wherein refractive indices ranging from at least 1.65 to values in excess of 1.8 can be achieved. In like manner to the definition set out in U.S. Ser. No. 07/599,751, the expression essentially fluorine-free indicates that no material containing substantial concentrations of fluorine is intentionally included in the glass.
SUMMARY OF THE INVENTION
That objective can be attained in glasses having base compositions within the R 2 O-P 2 O 5 system, wherein R 2 O consists of at least one metal oxide selected from the group consisting of Li 2 O, Na 2 O, K 2 O, Ag 2 O, and Tl 2 O. The compositions can desirably also contain at least one metal oxide selected from the group consisting of Bi 2 O 3 , PbO, and Sb 2 O 3 . At least one member of the group Ag 2 O, Bi 2 O 3 , PbO, Sb 2 O 3 , and Tl 2 O must be present to assure attainment of the required high refractive index, viz., at least 1.65, coupled with the desired low annealing point, viz., 300°-340° C., and linear coefficient of thermal expansion, viz., 135-180×10 -7 /°C. over the temperature range 25°-300° C. Hence, more specifically, the inventive glasses consist essentially, expressed in terms of mole percent on the oxide basis, of:
______________________________________P.sub.2 O.sub.5 24-36 SrO 0-20ZnO 0-45 BaO 0-20Li.sub.2 O 0-15 CaO + SrO + BaO 0-25Na.sub.2 O 0-20 Sb.sub.2 O.sub.3 0-61K.sub.2 O 0-10 Bi.sub.2 O.sub.3 0-10Ag.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-61Tl.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 7-76 Ag.sub.2 O + Tl.sub.2 OLi.sub.2 O + Na.sub.2 O + K.sub.2 O + 15-30 SnO 0-5Ag.sub.2 O + Tl.sub.2 OPbO 0-20 Al.sub.2 O.sub.3 0-5CuO 0-5 B.sub.2 O.sub.3 0-10CaO 0-20 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-10CeO.sub.2 0-2______________________________________
with the provisos that:
(a) in the absence of Sb 2 O 3 and/or Bi 2 O 3 , the total Ag 2 O+Tl 2 O will range 11-25;
(b) in the absence of Ag 2 O and/or Tl 2 O, the total Sb 2 O 3 +Bi 2 O 3 will range 7-61;
(c) when present in the absence of Bi 2 O 3 and/or Ag 2 O and/or Tl 2 O, Sb 2 O 3 will range 10-61 and, when present in the absence of Sb 2 O 3 and/or Ag 2 O and/or Tl 2 O, Bi 2 O 3 will range 7-10;
(d) when present in the absence of Bi 2 O 3 , Sb 2 O 3 , and Tl 2 O, Ag 2 O will range 13-25; and
(e) when present in the absence of Ag 2 O, Bi 2 O 3 , and Sb 2 O 3 , Tl 2 O will range 11-25.
As will be appreciated, the required combination of chemical and physical properties demands that the above-outlined composition intervals be strictly observed, with special attention being directed to the levels of Ag 2 O, Bi 2 O 3 , Sb 2 O 3 , and Tl 2 O. Thus, their inclusion raises the refractive index of the base glass as desired, but also impacts upon other properties of the glass for which compensation must be made. To illustrate:
Ag 2 O and Tl 2 O behave in like manner to the alkali metal oxides in softening the glass, i.e., lowering the annealing point thereof. At the same time, however, they adversely affect the chemical durability and weatherability of the glasses.
The inclusion of alkaline earth metal oxides acts to raise the refractive index of the glass somewhat without increasing the dispersion therein and raising the annealing point thereof, while also improving the chemical durability thereof. Nevertheless, when the total concentration of alkaline earth metal oxides exceeds 25%, the glasses become quite susceptible to devitrification.
Whereas the addition of PbO to a glass composition is well-recognized in the art as raising the refractive index thereof, its inclusion increases the dispersion therein. Moreover, the linear coefficient of thermal expansion is raised significantly through the addition of PbO to the inventive base compositions which must be offset through the addition of Sb 2 O 3 and/or SnO and/or Al 2 O 3 and/or B 2 O 3 and/or alkaline earth metal oxides. Consequently, whereas PbO can be tolerated in the inventive glasses, it will desirably be maintained at a relatively low level.
As was alluded to immediately above, Al 2 O 3 , B 2 O 3 , and SnO act to enhance the chemical durability of the inventive glasses. The concentrations thereof must be held at low concentrations, however, to avoid elevating the annealing point of the glass outside of the desired range.
Sb 2 O 3 is more preferred than Bi 2 O 3 for raising the refractive-index. It is less subject to reducing conditions and is much more soluble in the base glass than Bi 2 O 3 . Ag 2 O and Tl 2 O exert an extreme effect upon the refractive index of the glass. That is, the refractive index commonly increases by about 0.008 per mole percent addition of Tl 2 O and by about 0.0065 per mole percent addition of Ag 2 O. Tl 2 O demonstrates a further advantage over Ag 2 O in that the glasses are characterized by better weatherability.
When desired, CeO 2 may be included to render the glasses resistant to such radiations as x-radiations.
Whereas it is not mathematically possible to convert composition intervals expressed in terms of mole percent to exact composition ranges described in terms of weight percent, the following values represent approximations of the compositions of the inventive glasses defined in terms of weight percent:
______________________________________P.sub.2 O.sub.5 11.1-47.2 SrO 0-11.1ZnO 0-34.2 BaO 0-25.9Li.sub.2 O 0-4.5 CaO + SrO + BaO 0-29.7Na.sub.2 O 0-12.2 Sb.sub.2 O.sub.3 0-82.0K.sub.2 O 0-9.2 Bi.sub.2 O.sub.3 0-39.6Ag.sub.2 O 0-46.5 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-83.4Tl.sub.2 O 0-61.4 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 17.5-88.8 Ag.sub.2 O + Tl.sub.2 OLi.sub.2 O + Na.sub.2 O + 1.9-64.4 SnO 0-7.3K.sub.2 O + Ag.sub.2 O +Tl.sub.2 OPbO 0-34.3 Al.sub.2 O.sub.3 0-5.1CaO 0-12.2 B.sub.2 O.sub.3 0-7.0CuO 0-4.0 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-8.4CeO.sub.2 0-4.0______________________________________
with the provisos that:
(a) in the absence of Sb 2 O 3 and/or Bi 2 O 3 , the total Ag 2 O+Tl 2 O will range 17.7-64.4;
(b) in the absence of Ag 2 O and/or Tl 2 O, the total Sb 2 O 3+Bi 2 O 3 will range 17.5-83.4;
(c) when present in the absence of Bi 2 O 3 and/or Ag 2 O and/or Tl 2 O, Sb 2 O 3 will range 17.5-82.0 and, when present in the absence of Sb 2 O 3 and/or Ag 2 O and/or Tl 2 O, Bi 2 O 3 will range 18.7-39.6;
(d) when present in the absence of Bi 2 O 3 , Sb 2 O 3 , and Tl 2 O, Ag 2 O will range 17.7-46.5; and
(e) when present in the absence of Ag 2 O, Bi 2 O 3 , and Sb 2 O 3 , Tl 2 will range 24.8-61.4.
In essence, the instant inventive glasses are founded in the utilization of at least one of the group Ag 2 O, Bi 2 O 3 , Sb 2 O 3 , and Tl 2 O to raise the refractive index of the glasses disclosed in U.S. Ser. No. 07/599,751, but wherein the concentrations of the other components of the latter glasses have been altered to produce products exhibiting the desired ranges of chemical and physical properties.
PRIOR ART
In addition to U.S. Ser. No. 07/599,751, the following patent is also believed to have relevance to the instant inventive glasses:
U.S. Pat. No. 3,853,568 (Chvatal) discloses three groups of Ag 2 O-containing glass compositions, one of which comprised, in weight percent, 20-70% Ag 2 O and 30-80% of two oxides selected from the group of As 2 O 3 , B 2 O 3 , Bi 2 O 3 , GeO 2 , P 2 O 5 , Sb 2 O 3 , and TeO 2 . The patent referred to the following two ranges of components within that group which are pertinent to the present inventive glasses:
______________________________________Sb.sub.2 O.sub.3 10-45 Ag.sub.2 O 20-60 P.sub.2 O.sub.5 30-50Bi.sub.2 O.sub.3 10-45 Ag.sub.2 O 20-60 P.sub.2 O.sub.5 30-45______________________________________
Whereas partial overlap may be possible between those ranges and those of the inventive glasses, no mention is made in the patent to pressing lenses and the chemical and physical properties required in glasses destined for that application, and none of the working examples supplied in the patent had a composition coming within the ranges of the inventive glasses.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Table I records a group of glass compositions melted on a laboratory scale and reported in terms of mole percent on the oxide basis illustrating the parameters of the present inventive glasses. Table IA lists the same group of compositions expressed in terms of parts by weight on the oxide basis. Inasmuch as the sum of the individual components recited in Table IA totals or very closely approximates 100, for all practical purposes the tabulated values may be deemed to reflect weight percent. The actual batch ingredients can comprise any materials, either oxides or other compounds, which, when melted in combination with the other constituents, will be converted into the desired oxide in the proper proportions. For example, zinc orthophosphate may be employed as a source of ZnO and P 2 O 5 , and Li 2 CO 3 and AgNO 3 may comprise the sources of Li 2 O and Ag 2 O, respectively.
The batch ingredients were compounded, tumble mixed together to aid in obtaining a homogeneous melt, and then charged into platinum crucibles. After placing lids thereon, the crucibles were moved into a furnace operating at about 900°-1200° C. and the batches melted for about three hours. Thereafter, the melts were poured into steel molds to produce glass slabs having dimensions of about 6"×4"×0.5" which were transferred immediately to an annealer operating at about 300°-325° C.
(Whereas the above description reflects melting on a laboratory scale only, it must be appreciated that large scale melts thereof can be conducted in commercial melting units. Thus, it is only necessary that the batch materials be melted at a temperature and for a time sufficient to secure a homogeneous melt.)
TABLE I______________________________________(Mole Percent)______________________________________ 1 2 3 4 5 6 7 8______________________________________Li.sub.2 O 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.6Na.sub.2 O 8.0 8.0 8.0 8.0 8.0 8.0 8.0 7.5K.sub.2 O 5.0 5.0 5.0 5.0 -- -- -- --ZnO 13.5 11.0 10.0 21.0 18.5 13.5 11.0 9.4CaO 10.0 10.0 10.0 7.5 10.0 10.0 10.0 9.4BaO 5.0 5.0 3.5 7.5 5.0 5.0 5.0 3.3SnO 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.9Sb.sub.2 O.sub.3 15.0 17.5 20.0 -- 10.0 15.0 17.5 18.7Bi.sub.2 O.sub.3 -- -- -- 8.0 -- -- -- --Tl.sub.2 O -- -- -- -- 5.0 5.0 5.0 11.0Al.sub.2 O.sub.3 0.5 0.5 0.5 -- 0.5 0.5 0.5 0.5P.sub.2 O.sub.5 35.0 35.0 35.0 35.0 35.0 35.0 35.0 32.7______________________________________ 9 10 11 12 13 14 15 16______________________________________Li.sub.2 O 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.1Na.sub.2 O 8.0 8.0 8.0 8.0 8.0 8.0 8.0 7.0K.sub.2 O 5.0 5.0 5.0 5.0 5.0 5.0 5.0 4.4ZnO 10.0 10.0 10.0 18.5 8.5 -- -- 2.5CaO 6.8 1.8 3.5 -- -- -- -- --BaO 6.7 1.7 -- -- -- -- -- --SnO 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0PbO -- -- -- -- -- -- -- 20.0Sb.sub.2 O.sub.3 20.0 30.0 30.0 25.0 35.0 43.5 46.0 21.8Al.sub.2 O.sub.3 0.5 0.5 0.5 0.5 0.5 0.5 0.5 2.2P.sub.2 O.sub.5 35.0 35.0 35.0 35.0 35.0 35.0 32.5 35.0______________________________________ 17 18 19 20 21 22 23 24______________________________________Li.sub.2 O 7.0 -- -- -- -- -- -- --Na.sub.2 O 8.0 -- -- -- -- -- -- --K.sub.2 O 5.0 -- -- -- -- -- -- --ZnO 2.5 45.0 30.0 15.0 44.0 29.0 15.0 13.5SnO 1.0 -- -- -- 1.0 1.0 -- 1.0PbO 17.5 -- -- -- -- -- -- --Sb.sub.2 O.sub.3 23.0 -- 15.0 30.0 -- 15.0 30.0 30.0Al.sub.2 O.sub.3 2.2 2.0 -- -- 2.0 2.0 -- 0.5Ag.sub.2 O -- 20.0 20.0 20.0 -- -- -- --Tl.sub.2 O -- -- -- -- 20.0 20.0 20.0 20.0P.sub.2 O.sub.5 33.8 33.0 35.0 35.0 33.0 33.0 35.0 35.0______________________________________ 25 26 27 28 29 30 31 32______________________________________Li.sub.2 O -- 7.0 6.7 7.0 5.3 7.0 7.0 7.0Na.sub.2 O -- 8.0 7.6 8.0 6.0 8.0 8.0 8.0K.sub.2 O -- 5.0 4.8 5.0 3.7 5.0 -- --ZnO -- -- 9.5 -- -- 23.5 24.5 24.5CaO -- 7.5 9.5 -- -- 10.0 11.3 11.3BaO -- 7.5 3.3 -- -- 5.0 3.7 3.7SnO 1.0 1.0 1.0 -- -- -- 1.0 --Sb.sub.2 O.sub.3 43.5 28.5 19.1 55.0 53.0 -- 4.1 4.1Bi.sub.2 O.sub.3 -- -- -- -- -- 6.0 -- --Al.sub.2 O.sub.3 -- 0.5 0.5 -- -- 0.5 0.4 0.4Ag.sub.2 O -- -- -- -- -- -- -- 5.0Tl.sub.2 O 20.0 -- -- -- -- -- 5.0 --P.sub.2 O.sub.5 35.0 35.0 33.3 25.0 30.0 35.0 35.0 35.0CuO -- -- -- -- 2.0 -- -- --B.sub.2 O.sub.3 -- -- 5.0 -- -- -- -- --______________________________________
TABLE IA______________________________________(Parts By Weight)______________________________________ 1 2 3 4 5 6 7 8______________________________________Li.sub.2 O 1.6 1.5 1.5 1.6 1.5 1.4 1.4 1.1Na.sub.2 O 3.8 3.6 3.5 3.7 3.6 8.0 8.0 2.7K.sub.2 O 3.6 3.4 3.3 3.5 -- -- -- --ZnO 8.4 6.5 5.8 12.8 10.9 7.4 5.8 4.4CaO 4.3 4.1 4.0 3.2 4.1 3.8 3.7 3.0BaO 5.8 5.6 3.8 8.6 5.6 5.2 5.0 2.9SnO 1.2 1.1 1.1 1.1 1.1 1.0 1.0 0.8Sb.sub.2 O.sub.3 33.2 37.3 41.3 -- 21.2 29.5 33.3 31.3Bi.sub.2 O.sub.3 -- -- -- 28.0 -- -- -- --Tl.sub.2 O -- -- -- -- 15.4 14.3 13.8 26.8Al.sub.2 O.sub.3 0.4 0.4 0.4 -- 0.4 0.3 0.3 0.3P.sub.2 O.sub.5 41.0 36.3 35.2 37.3 36.1 33.5 32.4 26.6______________________________________ 9 10 11 12 13 14 15 16______________________________________Li.sub.2 O 1.5 1.3 1.3 1.4 1.2 1.1 1.1 1.1Na.sub.2 O 3.4 3.0 3.1 3.3 2.9 2.6 2.6 2.5K.sub.2 O 3.3 2.9 2.9 3.1 2.7 2.5 2.4 2.4ZnO 5.6 5.0 5.0 9.9 4.0 -- -- 1.2CaO 2.6 0.6 1.2 -- -- -- -- --BaO 7.2 1.7 -- -- -- -- -- --SnO 1.0 0.9 0.9 1.0 0.9 0.8 0.8 0.9Sb.sub.2 O.sub.3 40.4 53.7 54.2 48.1 59.1 66.5 69.0 36.5Al.sub.2 O.sub.3 0.4 0.3 0.3 0.3 0.3 0.3 0.3 1.3P.sub.2 O.sub.5 34.4 30.5 30.8 32.8 28.8 26.1 23.7 28.5______________________________________ 17 18 19 20 21 22 23 24______________________________________Li.sub.2 O 1.2 -- -- -- -- -- -- --Na.sub.2 O 2.9 -- -- -- -- -- -- --K.sub.2 O 2.7 -- -- -- -- -- -- --ZnO 1.2 27.8 14.9 6.2 20.9 11.6 5.2 4.7Ag.sub.2 O -- 35.2 28.2 23.7 -- -- -- --PbO 22.7 -- -- -- -- -- -- --SnO 0.8 -- -- -- 0.9 0.7 -- 0.6Sb.sub.2 O.sub.3 39.0 -- 26.6 44.6 -- 27.6 37.3 37.2Tl.sub.2 O -- -- -- -- 49.6 41.9 36.2 36.1Al.sub.2 O.sub.3 1.3 1.6 -- -- 1.2 1.0 -- 0.2P.sub.2 O.sub.5 27.9 33.5 30.2 25.4 27.4 23.1 21.2 21.1______________________________________ 25 26 27 28 29 30 31 32______________________________________Li.sub.2 O -- 1.3 1.5 1.0 0.8 1.7 1.7 1.8Na.sub.2 O -- 3.1 3.4 2.4 1.8 4.1 4.0 4.4K.sub.2 O -- 2.9 3.3 2.3 1.7 3.9 -- --ZnO -- -- 5.6 -- -- 15.6 16.1 18.3CaO -- 2.6 3.9 -- -- 4.6 5.1 5.6BaO -- 7.1 3.7 -- -- 6.3 4.6 5.1SnO 0.6 0.9 1.0 -- -- -- 1.2 --Sb.sub.2 O.sub.3 48.1 51.1 40.3 77.0 74.3 -- 9.7 10.5Bi.sub.2 O.sub.3 -- -- -- -- -- 22.9 -- --Tl.sub.2 O 32.2 -- -- -- -- -- 17.1 --Al.sub.2 O.sub.3 0.2 0.3 0.4 -- -- 0.4 0.3 0.4P.sub.2 O.sub.5 18.8 30.6 34.4 17.1 20.5 40.6 40.1 43.8CuO -- -- -- -- 0.8 -- -- --B.sub.2 O.sub.3 -- -- 2.4 -- -- -- -- --Ag.sub.2 O -- -- -- -- -- -- -- 10.2______________________________________
Table II records the softening point (S.P.) and the annealing point (A.P.) in °C., the linear coefficient of thermal expansion (Exp) over the temperature interval 25°-300° C. expressed in terms of ×10 7- /°C, the refractive index (n D ), and the dispersion (ν) determined in accordance with measuring techniques conventional in the glass art. Table II also reports the weight loss (W.L.) expressed in terms of percent demonstrated by the glasses after an immersion for six hours in a bath of boiling deionized water, and a qualitative analysis of the weatherability (Weath) of the glasses based upon the visual appearance thereof after an exposure in a humidity cabinet for 500 hours at 60° C. and 98% relative humidity. A weight loss greater than 0.33% is considered to represent unsatisfactory chemical durability, with losses less than 0.1% being greatly preferred. Legends for the weatherability character exhibited include: nc =no change in appearance; xl =extremely light frosted appearances; vl =very light frosted appearance; lt =light frosted appearance; and hf =heavy frosted appearance. The most preferred glasses will display no frosting or haze. Where haze can be observed only when the glass is viewed at a small angle (exemplified by xl and vl), however, the glasses will be satisfactory for use in most applications. (When subjected to the above-described weatherability test, the current commercial glass produced under U.S. Pat. No. 4,362,819, supra, exhibits a very light frosted appearance.)
TABLE II__________________________________________________________________________1 2 3 4 5 6 7 8__________________________________________________________________________S.P. 438 445 437 .sup.˜ 440 426 -- -- --A.P. 333 336 333 .sup.˜ 335 .sup.˜ 325 -- -- --Exp. 153 149 152 .sup.˜ 153 -- -- -- --n.sub.D 1.682 1.696 1.710 .sup.˜ 1.670 1.686 1.72 .sup.˜ 1.73 1.77ν 40 35 -- .sup.˜ 40 -- -- -- --W.L. 0.02 0.02 0.04 0.01 0.01 0.00 -- --Weathnc nc nc -- nc nc nc nc__________________________________________________________________________9 10 11 12 13 14 15 16__________________________________________________________________________S.P. 433 414 415 409 407 396 396 .sup.˜ 410A.P. .sup.˜ 330 .sup.˜ 315 .sup.˜ 315 .sup.˜ 310 .sup.˜ 310 .sup.˜ 300 .sup.˜ 300 .sup.˜ 310Exp. -- 169 162 160 160 164 180 --n.sub.D1.71 1.75 1.755 1.72 1.77 1.83 >1.80 .sup.˜ 1.77W.L. 0.04 0.26 0.22 0.19 0.21 0.24 0.27 0.01Weathnc nc nc vl nc nc nc xl__________________________________________________________________________17 18 19 20 21 22 23 24__________________________________________________________________________S.P. .sup.˜ 400 372 -- -- 416 419 -- --A.P. .sup.˜ 300 .sup.˜ 280 -- -- .sup.˜ 315 .sup.˜ 320 0 0n.sub.D1.76 1.681 1.760 >1.80 1.696 1.783 >1.80 >1.80W.L. 0.01 0.04 0.05 -- 0.02 0.01 -- --Weathxl -- -- -- -- -- nc nc__________________________________________________________________________25 26 27 28 29 30 31 32__________________________________________________________________________S.P. -- .sup.˜ 445 .sup.˜ 450 .sup.˜ 382 .sup.˜ 400 435 420 .sup.˜ 405A.P. -- 336 .sup.˜ 345 -- -- 325 .sup.˜ 320 307Exp. -- 160 139 -- -- 149 -- 150n.sub.D>1.80 .sup.˜ 1.79 .sup.˜ 1.71 1.86 >1.8 1.644 1.643 1.638ν -- -- -- -- -- 43 -- --W.L. -- -- 0.02 -- -- 0.00 -- 0.01Weathnc nc nc vl -- hf nc lt__________________________________________________________________________
As can be observed from the above Tables, Examples 30-32 illustrate glasses having compositions somewhat outside of the ranges yielding glasses demonstrating the desired chemical and physical properties. That is, because of the lack of control of the amounts and the interrelationships existing between the individual components, one or more of the properties listed in Table II will not be satisfactory.
Based upon an overall appraisal of the chemical and physical properties demonstrated by the inventive glasses in conjunction with their melting and forming characteristics, the preferred glasses consist essentially, expressed in terms of mole percent on the oxide basis, of
______________________________________P.sub.2 O.sub.5 25-35 SrO 0-20ZnO 0-35 BaO 0-20Li.sub.2 O 0-10 CaO + SrO + BaO 0-20Na.sub.2 O 0-15 Sb.sub.2 O.sub.3 0-61K.sub.2 O 0-6 Bi.sub.2 O.sub.3 0-10Ag.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-61Tl.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 7-76 Ag.sub.2 O + Tl.sub.2 OLi.sub.2 ONa.sub.2 O + K.sub.2 O + 15-25 SnO 0-2Ag.sub.2 O + Tl.sub.2 OPbO 0-20 Al.sub.2 O.sub.3 0-3CuO 0-3 B.sub.2 O.sub.3 0-3CaO 0-20 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-5CeO.sub.2 0-2______________________________________
The most preferred composition for a glass having a refractive index ˜1.7 is Example 3 and for a glass having a refractive index ˜1. 8 is Example 14.
Although the inventive glasses were designed particularly for being press molded into optically finished lenses, their chemical and physical properties recommend their utility in preparing glass-plastic alloys of the type described in U.S. application Ser. No. 07/403,655, filed Sep. 11, 1989, under the title GLASS/GLASS-CERAMIC-PLASTIC ALLOY ARTICLES by W. A. Bahn et al. now U.S. Pat. No. 5043,369.
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This invention is drawn to fluorine-free glasses having refractive indices of at least 1.65 which generally consist, in mole percent, of:
______________________________________
P 2 O 5 24-36ZnO 0-45Li 2 O 0-15Na 2 O 0-20K 2 O 0-10Ag 2 O 0-25Tl 2 O 0-25Li 2 O + Na 2 O + K 2 O + Ag 2 O + Tl 2 O 15-30PbO 0-20CaO 0-20CuO 0-5CeO 2 0-2SrO 0-20BaO 0-20CaO + SrO + BaO 0-25Sb 2 O 3 0-61Bi 2 O 3 0-10Sb 2 O 3 + Bi 2 O 3 0-61Sb 2 O 3 + Bi 2 O 3 + Ag 2 O + Tl 2 O 7-76SnO 0-5Al 2 O 3 0-5B 2 O 3 0-10Al 2 O 3 + B 2 O 3 0-10______________________________________
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method and apparatus of supplying fuel in an electronic control fuel injection engine for controlling the supply of fuel from a fuel injection valve to an intake system by operating the fuel injection valve according to electric signals and more particularly to a method and apparatus of supplying fuel for controlling the rotational frequency of an engine when fuel cut-off is completed and then fuel supply is resumed.
2. Description of the Prior Arts
In an electronic control fuel injection engine, it is well known to cut off fuel in the deceleration of a vehicle for improving efficiency of fuel consumption and restraining amount of purge of noxious components. When rotational speed of the engine is lowered to a predetermined value or less, fuel needs to be cut off completely and then supplied again for avoiding the stoppage of the engine rotation (engine stop). However, when the fuel supply is resumed, the output torque of the engine is abruptly increased, unbalance between the output torque of the engine and torque of driving wheels gives impact to the vehicle. In prior method and apparatus of supplying fuel to electronic control fuel injection engines, the rotational speed of the engine at the resumption of fuel supply could not be set to a small value to avoid the impact to the vehicle at the resumption of fuel supply after the completion of fuel cut-off so that the improvement of efficiency of fuel consumption during the deceleration and the restraint of purge of noxious components could not be sufficiently achieved. Also, a fuel supplying method has been proposed in which the rotational speed of the engine at the resumption of fuel supply is changed over from a large value to small one to increase a period of fuel cut-off when the transmission at the deceleration is changed over from the high speed stage to the low speed one. However, in this method, the impact at the resumption of fuel supply can not sufficiently restrained.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and apparatus of supplying fuel to an electronic control fuel injection engine, which can avoid impact at the resumption of fuel supply while increasing a period of fuel cut-off at the deceleration to thereby improve efficiency of fuel consumption and reduce the purge of noxious components.
To achieve this object, in the method of supplying fuel to the electronic control fuel injection engine according to the present invention, when a brake device is operated or the vehicle speed is higher than a predetermined value, the rotational speed of the engine at the resumption of fuel supply after the completion of fuel cut-off in the deceleration is set to a value smaller than that set otherwise.
Also, the fuel supplying apparatus for the electronic control fuel injection engine according to the present invention comprises a first detecting means for detecting the operation of the brake device, a second detecting means for detecting vehicle speed, a comparator means for allowing a fuel injection valve to be operated when the rotational speed of the engine is compared with a reference value and found lower than the reference value and a control means for receiving detecting signals from the first and second detecting means and thereby, when the brake device is operated or the vehicle speed is higher than a predetermined value, reducing the reference value of the comparator means smaller than that set otherwise.
When the vehicle speed is large, difference between the output torque of the engine at the resumption of fuel supply after the competion of fuel cut-off and the torque of the driving wheel is small so that the impact at the resumption of fuel supply can be restrained. Thus, according to the present invention, the rotational speed of the engine at the resumption of fuel supply in the large vehicle speed is set to a small value so that the impact at the resumption of fuel supply can be restrained while the period of fuel cut-off can be increased.
Since negative acceleration applied to the vehicle during the operation of the brake device is large, a feeling of the impact on a driver and other passengers at the resumption of fuel supply is small. Thus, according to the present invention, the rotational speed of the engine at the resumption of fuel supply during the operation of the brake device is set to a small value so that the period of fuel cut-off can be increased without giving any uncomfortable feeling of impact to passengers.
Whether or not the brake device is operated can be detected by whether or not the brake pedal is operated. Whether or not the brake pedal is operated is detected at intervals of time and preferably the rotational speed of the engine at the resumption of fuel supply is set to a small value when the brake pedal is continuously operated. The driver may operate the brake pedal intermittently. In such a case, the fuel supply is resumed when the brake device is not operated so that the feeling of impact may be enlarged. By setting the rotational speed of the engine at the resumption of fuel supply to the small value only when the brake pedal is continuously operated, the resumption of fuel supply can be avoided when the driver releases the brake pedal.
In the fuel supply apparatus according to the present invention, the fuel is preferably cut off by blocking the generation of fuel injection pulse sent to the fuel injection valve. The first detecting means may be a switch for detecting the operational amount of the brake pedal.
Hereinafter will be described embodiments of the present invention with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of the whole electronic control fuel injection engine according to the present invention;
FIG. 2 is a block diagram of the electronic control shown in FIG. 1;
FIG. 3 is a flow chart of an example of a program carrying out the method according to the present invention;
FIG. 4 is a schematic illustration of the whole another electronic control fuel injection engine according to the present invention;
FIG. 5 is a block diagram of the electronic control shown in FIG. 4;
FIG. 6 is a timing chart of the electronic control shown in FIG. 4; and
FIG. 7 is a detailed circuit diagram of a fuel cut-off circuit shown in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic illustration of the whole electronic control fuel injection engine according to the present invention. Air sucked from an air cleaner 1 is sent to a combustion chamber 8 in a main body 7 of an engine through an intake path 12 comprising an air flow meter 2, throttle valve 3, surge tank 4, intake port 5 and intake valve 6. The throttle valve 3 is interlocked with an accelerator pedal 13 in a cab. The combustion chamber 8 is defined by a cylinder head 9, cylinder block 10 and piston 11, and exhaust gas produced by the combustion of mixture is purged to the atmosphere through an exhaust valve 15, exhaust port 16, exhaust branch pipe 17 and exhaust pipe 18. A bypass path 21 connects the upstream of the throttle valve 3 to the surge tank 4, and a bypass flow controlling valve 22 controls the sectional area of flow in the bypass path 21 to maintain the rotational speed of the engine constant in the idling. To restrain the generation of nitrogen oxide, an exhaust gas recirculation (EGR) path 23 for conducting the exhaust gas to the intake system connects the exhaust branch pipe 17 with the surging tank 4, and an exhaust gas recirculation (EGR) controlling valve 24 of on-off valve type opens and closes the EGR path 23 in response to electric pulses. An intake temperature sensor 28 is provided in the air flow meter 2 to detect the intake temperature, and a throttle position sensor 29 detects the opening of the throttle valve 3. A water temperature sensor 30 is mounted on the cylinder block 10 to detect cooling water temperature, i.e. engine temperature, an air fuel ratio sensor 31 well known for a oxygen concentration sensor is mounted on the aggregate portion of the exhaust branch pipes 17 to detect the oxygen concentration in the aggregate portion, and a crank angle sensor 32 detects the crank angle of crank-shaft (not shown) in the engine body 7 through the rotation of a shaft 34 of a distributor 33 coupled with the crank-shaft. A vehicle speed sensor 35 detects the rotational speed of an output shaft of an automatic transmission or manual one 36, and a limit switch 38 detects the operation of a brake pedal 39. When the brake pedal 39 is depressed, the limit switch 39 is changed over from OFF to ON. The outputs of these elements 2,28,29, 30,31,32,35 and 38 and voltage of an accumulator 37 are sent to an electronic control 40. Fuel injection valves 41 are provided respectively near the respective intake ports 5 corresponding to the respective cylinders, and a pump 42 sends fuel to the fuel injection valves 41 from a fuel tank 43 through a fuel path 44. The electronic control 40 calculates the amount of fuel injection on the basis of input signals from the respective sensors to send electric pulses having pulse width corresponding to the calculated amount of fuel injection to the fuel injection valve 41. The electronic control 40 also controls the bypass flow controlling valve 22, EGR controlling valve 24, a solenoid 45 in a circuit for controlling the oil pressure in the automatic transmission or manual transmission 36 and an ignition system 46. The secondary side of a ignition coil in the ignition system 46 is connected to the distributor 33.
FIG. 2 is a block diagram of the interior of the electronic control. CPU(Central Processing Unit) 56, ROM(Read-Only Memory) 57, RAM(Randon Access Memory) 58, 59, A/D(Analog/digital) converter 60 with multiplexer and input/output interface 61 are connected to each other through a bus 62. RAM 59 is connected to an auxiliary power source so that it is supplied with a predetermined power to maintain the memory even when the ignition switch is opened and the engine is stopped. The analog signals of the air flow meter 2, intake temperature sensor 28, water temperature sensor 30 and air fuel ratio sensor 31 are sent to the A/D converter 60. The outputs of the throttle position sensor 29, crank angle sensor 32, vehicle speed sensor 35 and limit switch 38 are sent to the input/output interface 61, and the input signal of the input/output interface 61 is sent to the bypass flow controlling valve 22, EGR controlling valve 24, fuel injection valve 41, solenoid 45 and ignition system 46.
FIG. 3 is a flow chart of an example of a program according to the present invention. In step 65 is judged according to the input signal from the throttle position sensor 29 whether or not the throttle valve 3 has the idling opening, and the program proceeds to step 66 if it is judged yes and to step 83 if no. In step 66 is judged according to the input signal from the vehicle speed sensor 35 whether or not the vehicle speed is lower than a predetermined value A, and the program proceeds to step 67 if it is judged yes and to step 73 if no. In step 67 is judged according to the input signal from the limit switch 38 whether or not the vehicle is being braked, and the program proceeds to step 68 if it is judged yes and to step 69 if no. In step 68, flag F1 is set to "1", provided binary logic is defined as "1", "0". The flag F1="1" means the vehicle is now being braked. In step 69, flag F1 is set to "0". The flag F1="0" means the vehicle is not now braked. In step 70 is judged whether or not flag F2 is "1" and the program proceeds to step 78 if it is judged yes and to step 79 if no. As will be understood from step 82 which will be described, the flag F2 is a flug for judging whether or not the limit switch 38 is turned on when this program was previously carried out. The flag F2="1" means that the limit switch 38 at the previous time was turned on and the vehicle was being braked. The reason why step 70 is provided is that the driver may depress or release the brake pedal 39 without operating continuously the brake pedal so that the fuel supply may be resumed when the vehicle is not braked and in this case the selection of small value of rotational speed set in the resumption of the fuel supply by the performance of step 78, which will be described, should be avoided. In step 73, similarly to step 67, is judged whether or not the limit switch 38 is turned on and the program proceeds to step 74 if it is judged yes and to step 75 if no. In step 74, flag F1 is set to "1" and, in step 75, flag F1 is set to "0". In step 78, the rotational speed P of the engine at which the fuel cut-off is completed is set to a predetermined value P1. In step 79, the rotational speed P of the engine at which the fuel cut-off is completed is set to P2 (provided P2>P1.) Namely, when the vehicle speed is larger than a predetermined value A or the brake switch is turned on, P is set to smaller value P1 and when the vehicle speed is smaller than the predetermined value A and the brake switch is turned off, P is set to larger value P2. In step 80 is judged whether or not the rotational speed N of the engine is larger than P and the program proceeds to step 81 if it is judged yes and to step 83 if no. In step 81, fuel is cut off. In step 82, value of flag F1 is substituted for flag F2. Value of flage F2 is utilized in step 70 for carrying out the program at the next time. In step 83, the fuel cut-off is stopped and fuel is supplied.
FIG. 4 shows a further embodiment of the electronic control fuel injection engine according to the present invention. Air flow sucked into an intake path 89 through an air cleaner 88 is controlled by a throttle valve 90 interlocked with an accelerator pedal in a cab and conducted the combustion chanber of an engine body 92 through an intake branch pipe 91. An exhaust system is provided with a catalyst converter 95 receiving an exhaust branch pipe 93, exhaust pipe 94 and ternary catalyst sequentially from the upstream side. Current supplied to the ignition plug in the combustion chamber is controlled by an ignition coil 96 and distributor 97. A vehicle speed sensor 99 detects the vehicle speed, an air flow meter 100 detects intake air flow, an intake temperature sensor 101 detects intake temperature, a water temperature sensor 102 mounted on the cylinder block detects cooling water temperature, an air fuel ratio sensor 103 mounted on the exhaust branch pipe 93 detects oxygen concentration in exhaust gas, a throttle sensor 104 detects the opening of the throttle valve 90 and a limit switch 105 detects the operation of a brake pedal 108 in the cab. When the brake pedal 108 is depressed, the limit switch 105 is turned from OFF to ON. Primary current signal of the ignition coil 96, outputs of the air flow meter 100, intake temperature sensor 101, water temperature sensor 102, air fuel ratio sensor 103, throttle sensor 104 and limit switch 105 are sent to an electronic control 106. A fuel injection valve 107 is provided in each branch portion of the intake branch pipe 91 to be opened and closed in response to electric pulses from the electronic control 106.
FIG. 5 is a block diagram of the interior of the electronic control 106 and FIG. 6 is a wave-form diagram of voltage in each portion shown in FIG. 5. Primary current signal from the ignition coil 96 is sent to a frequency dividing circuit 109 which produces pulses having same pulse width as that of cycle of the primary current signal from the ignition coil 96. Namely, the output of the frequency dividing circuit 109 from rise time t1 to the next rise time t2 of the primary current signal from the ignition coil 96 is maintained at "1". The output of a fuel cut-off circuit 110 is sent to the frequency dividing circuit 109 and the output of the circuit 109 is maintained at "0" during period of fuel cut-off. A basic injection pulse generating circuit 111 comprises a capacitor 112 which is charged by pulses from the frequency dividing circuit 109 from time t1 to time t2 and discharged from time t2 on by discharge current related to the output voltage of the air flow meter 100. Period of time τa from time t1 to time t2 is in inverse proportion to rotational speed N of the engine and terminal voltage of the capacitor 112 in the time t2 is in proportion to 1/N. The terminal voltage of the capacitor 112 becomes zero at time t3 and the output of the basic injection pulse generating circuit 111 is maintained at "1" between time t2 and time t3. The discharge current of the capacitor 112 is reduced as intake air flow Q is increased so that the period of time τb from time t2 to time t3 increase as intake air flow Q increases. As a result, τb can be proportional to Q/N. The output of the basic injection pulse generating circuit 111 is sent to an injection pulse correcting circuit 113 which comprises a capacitor 114. This capacitor 114 is charged from time t2 to time t3. The charge current to the capacitor 114 varies in relation to the inputs from the intake temperature sensor 101, digital correcting section 115, etc. so that the terminal voltage of a capacitor 115 at time t3 varies in relation to these input signals. The capacitor 114 is discharged from time t3 on by the discharge current related to the input signal from the water temperature sensor 102, and the terminal voltage of the capacitor 114 at time t4 becomes zero. A period of time τc from time t3 to time t4 varies in relation to cooling water temperature and, in time t4, pulses with a predetermined pulses width τv are generated. The pulse width τv is equal to ineffective injection time of the fuel injection valve 107. Pulses with pulse width equal to the period of time from time t2 to time t5 are generated as the output of the injection pulse correcting circuit 113. The fuel injection valve 107 is on one end connected to an accumulator 117 through a resistance 116 and on the other end to an amplifier 118. The amplifier 118, while receiving pulses from the injection pulse correcting circuit 113, conducts electricity so that the fuel injection valve 107 is energized to inject fuel to the intake system at this time. In a digital circuit 115, a timer 121, interruction control 122, input interface 123, CPU(Central Processing Unit) 124, RAM(Random Access Memory) 125, ROM(Read-Only Memory) 126, A/D(Analog/Digital) converter 127 and D/A(Digital/Analog) converter 128 are interconnected through a bus 129. The output of the basic injection pulse generating circuit 111 is sent to the interruption control 122, the output pulses of the air fuel ratio sensor 103 and throttle sensor 104 sent to the input interface 123, the analog output of the air flow meter 100 sent to the A/D converter 127. The output of the D/A converter 128 is sent to the injection pulse correcting circuit 113.
FIG. 7 shows details of the fuel cutting-off circuit 110 shown in FIG. 5. The primary current signal from the ignition coil 96 is sent to a F/V(Frequency/Voltage) converter 133, and on the output terminal of the F/V converter 133 is generated voltage proportional to the rotational speed N of the engine. The output of the F/V converter 133 is sent to an inverted input terminal of an operational amplifier 135 through a resistance 134. Braking signal 136 and vehicle speed signal 137 are sent to "or" circuit 138. When the brake pedal 108 is operated to turn on the limit switch 105, the braking signal becomes "1", and when the vehicle speed is larger than predetermined value A, the vehicle speed signal becomes "1". The output of "or" circuit 138 is sent to an analog switch 139. A resistance 140, variable resistance 141 and resistance 142 are interconnected in series between the accumulator 117 and earth. The analog switch 139 is connected in parallel to the resistance 142. The tap terminal of the variable resistance 141 is connected to non-inverted input terminal of the operational amplifier 135, and a diode 146 and resistance 147 are connected between the output terminal and non-inverted input terminal of the operational amplifier 135. The output of the operational amplifier 135 and idle signal 148 are sent to an "or" circuit 149. The idle signal becomes zero when the throttle valve 90 is in the opening of idling. The output of the "or" circuit 149 is sent to an "and" circuit 150. Since the output of the frequency dividing circuit 109 is sent to the basic injection pulse generating circuit 111 through the "and" circuit 150. The signal sent from the frequency dividing circuit 109 to the basic injection pulse generating circuit 111 becomes zero, resulting in the stoppage of fuel injection when the output of the "or" circuit 149 is "0".
When the vehicle speed is larger than predetermined value A or the brake pedal 108 is operated, the output of "or" circuit 138 is "1" and the analog switch 139 is closed. Hence, the non-inverted input terminal of the operational amplifier 135 is set to low voltage V1. Also, when the vehicle speed is smaller than the predetermined value A and the brake pedal 108 is released, the output of the "or" circuit 138 becomes "0" and the analog switch 139 is opened. Thus, the non-inverted input terminal of the operational amplifier 135 is set to high voltage V2(V2>V1). The voltages V1,V2 correspond respectively to the vehicle speeds P1,P2 in steps 78,79 shown in FIG. 3. Thus, when the rotational speed of the engine is larger than the predetermined value P1 or P2 in the deceleration, the output of the operational amplifier 135 is "0", and since the throttle valve 90 is maintained in the opening of idling, the idle signal 148 becomes "0" so that the output of the "or" circuit is maintained at "0" and the pulse of the frequency dividing circuit 109 is prevented from being sent to the basic injection pulse generating circuit 111 so as to cut off fuel.
When the vehicle speed is larger than the predetermined value A or the brake device is operated and the rotational speed of the engine is lower than the predetermined value P1, and also when the vehicle speed is lower than the predetermined value A and the brake device is not operated with the rotational speed of the engine being lower than the predetermined value P2, the output of the operational amplifier 135 becomes "1" and thereby the output of the "or" circuit 149 becomes "1" so that the output pulse of the frequency dividing circuit 109 is sent to the basic fuel injection pulse circuit 111 to stop the fuel cut-off and resume the fuel supply.
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Fuel is cut off in the deceleration of a vehicle to improve efficiency of fuel consumption. Rotational speed of an engine in the resumption of fuel supply in the completion of the fuel cut-off is set to a value smaller than that otherwise set when a brake device is operated or the vehicle speed is higher than a predetermined value. While the torque of the engine varies abruptly to produce impact when the fuel cut-off is completed, passengers have a slight feeling of impact while the vehicle is being braked and travelling with high speed. Thus, while the feeling of impact is reduced, a period of fuel cut-off is increased to improve further the efficiency of fuel consumption and others.
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[0001] This application claims the benefit of provisional U.S. application Ser. No. 60/297,262 filed Jun. 12, 2001, under 35 U.S.C. 119(e)(1).
BACKGROUND OF THE INVENTION
[0002] Tire manufacturers exercise the greatest care in constructing modem tires for a variety of vehicles. As the traveling speeds and distances traveled increase with more people on the roadways traveling at higher velocities and even greater distances than some years ago, tire manufacturers are assiduously working towards greater improvement in tire performance.
[0003] With the increased popularity of all terrain vehicles and the demands that owners make regarding performance of such vehicles, the need has arisen for greater safety and predictability with respect to tire characteristics.
[0004] As tire manufacturers strive to perfect their tires, they recognize the difficulty in achieving a tire with zero probability of error. Nevertheless, researchers and engineers work towards the development of an “intelligent tire” that will minimize the risk of a catastrophic failure.
[0005] Thus, efforts have taken the form of developing a tire that will enable the driver to recognize an impending tire failure from having fill information about the operating condition of the tire far enough in advance so that the vehicle can be brought to a standstill safely in a time span short of an accident.
[0006] As described in European Patent Application 849 597, a tire comprising at least one magnetized area can be used to provide information regarding the rotary speed of the tire when mounted on a vehicle. In addition, the tire may also provide information regarding the forces and/or torques acting on the tire, in particular, the circumferential torque, lateral force and radial force. We call this type of tire either an Intelligent® Tire or SWT® (Side Wall Torsion system) tire.
[0007] Usually, a magnetic field sensor(s) is mounted on the chassis of the vehicle. As the Intelligent® Tire rotates past the magnetic sensor(s) at a constant angular velocity, a magnetic field pattern or signature develops that is characteristic of the tire's materials, construction and deformation state. In particular, magnetic field amplitude signatures and phase signatures (difference in the alignment of two annular magnetic bands, one near the bead of the tire and the other near the tread) are found to be useful. For example, if the angular velocity of the tire changes, such as through a braking or acceleration maneuver, the magnetic field signature also changes, thus allowing for the measurement of circumferential torque acting on the tire using suitable algorithms. Furthermore, as described in U.S. patent application 09/307,605, when any deformation of the Intelligent® Tire occurs, such as through the application of a lateral force resulting from a cornering maneuver, there is an accompanying change in the magnetic field signature allowing for the measurement of the acting force using suitable algorithms. The information can be interfaced to vehicle control systems to improve, for example, antilock braking systems (ABS), traction control systems (TCS), rollover prevention systems (ROP) and electronic stability program (ESP) performance.
[0008] In the past, such monitoring activities generally used a passive integrated circuit embedded within the body of the tire and activated by a radio frequency transmission which energizes the circuit by inductive magnetic coupling. Passive devices which rely on inductive magnetic coupling or capacitive coupling generally have the disadvantage of requiring lengthy coil windings, thus requiring major modifications in the tire construction and assembly process. Another serious disadvantage with such passive devices is that an interrogator must be positioned in very close proximity to the tire, usually within a few inches of the tire, in order to allow communication between the tire and the device. Because of the proximity requirements, continuous monitoring is impractical since it would require that an interrogator be mounted at each wheel of the vehicle. Manual acquisition of data from the passive devices embedded in each of the tires of a parked vehicle is also cumbersome and time consuming because of the proximity requirements.
[0009] Another disadvantage with known tire monitoring and identification devices is that communication transmissions are achieved using conventional radio frequencies which generally require a relatively large antenna which must be mounted externally or secured to the tire in such a manner which requires relatively major modifications in the tire construction or assembly process.
[0010] Prior approaches to monitoring tire conditions and identification with various communication techniques have met with limited success. In one approach disclosed in U.S. Pat. No. 5,960,844, a method for monitoring tires included an activatable memory device permanently mounted within at least one tire of a vehicle on the inner surface. The device contained stored data pertaining to the tire, and in which the memory device was activated by means of a monitoring device mounted on the tire rim within the pressurized cavity formed within the tire.
[0011] In a different approach shown in U.S. Pat. No. 5,573,610, a method for monitoring various conditions of pneumatic tires and to tires containing a monitoring device involved monitoring tires which used an active, self-powered, programmable electronic device which was generally installed in or on the interior portion of a pneumatic tire or on a tire rim. The device could be used for monitoring, storing and telemetering information such as temperature, pressure, tire mileage and/or other operating conditions of a pneumatic tire along with tire identification information.
[0012] In yet another approach, U.S. Pat. No. 5,562,787, a method of monitoring tires was provided in which an activatable monitoring device was mounted within at least one tire of a vehicle, on the interior surface thereof, or on the tire rim. The device was activated by means of an interrogator signal having a frequency in the microwave range. In response to the signal, the monitoring device measured and transmitted information relating to one or more conditions such as the internal pressure and temperature of the tire, the number of rotations of the tire, and tire identification information. The monitoring device was secured within the tire in such a manner and location as to minimize stress, strain, cyclic fatigue, impact and vibration.
[0013] In still yet another approach, U.S. Pat. No. 5,573,611, the invention depicted was a method of monitoring tires which used an active, self-powered programmable electronic device which was installed in or on the interior surface of a pneumatic tire or on a tire rim. The device was activated by externally transmitted radio frequency waves and in response, the device compared or transmitted information and provided a warning in the event a preselected limit was exceeded. An interrogator was used to communicate with and retrieve digitally coded information from the electronic monitoring device.
[0014] In U.S. Pat. No. 5,838,229, a system for indicating low tire pressure in vehicles was depicted. Each vehicle wheel had a transmitter with a unique code. A central receiver in the vehicle was taught, at manufacture, to recognize the codes for the respective transmitters for the vehicle, and also a common transmitter code, in the event one of the transmitters needed to be replaced. During vehicle operation and maintenance, when the tires were rotated, the system could be recalibrated to relearn the locations of the transmitters.
[0015] In another application, U.S. Pat. No. 5,731,754, the invention included a transponder and sensor apparatus with on-board power supply mounted in or on a vehicle tire. A pressure sensor, a temperature sensor and a tire rotation sensor were mounted in a housing along with the transponder the power supply and an antenna. Upon receipt of an interrogation signal from a remote interrogator, the transponder activated the sensors to sense tire pressure and temperature and then backscatter-modulate the radio frequency signal from the interrogator with the tire condition parameter data from the sensors to return the backscatter modulated signal to the interrogator.
[0016] In yet another application, U.S. Pat. No. 5,977,870, a method for monitoring various engineering conditions of a pneumatic tire such as temperature, pressure, tire rotation and other operating conditions of the tire was depicted. A tire tag was mounted on the interior of the tire within the pressurizable cavity and contained the stored data and sensors for detecting certain conditions within the cavity. A separate transponder was mounted on the tire rim. The tire tag contained a battery, an antenna and stored data pertaining to the tire. The transponder used electronic circuitry for collecting data from the tire tag. The tire tag was actuated by transmitted radio frequency waves from the transponder, which data was transmitted by the transponder to the remote location by an antenna which extended from the transponder through the rim to a location externally of the tire.
[0017] In spite of the teachings of the above-mentioned patents, there is still a significant need for a tire monitoring system for sensing, transmitting, and interpreting the operating condition of the vehicular tire in advance of an impending failure. This information could be used to bring the vehicle to a standstill safely in a time span short of an accident.
SUMMARY OF THE INVENTION
[0018] Recently it has been found that the amplitude and phase signatures may be used as a sensitive measure of the operating condition (state) of the tire. For example, tread, sidewall and bead splices that are overlapped too far or separated too much can be identified from the characterization of the magnetic signatures as is done routinely during the manufacture of the Intelligent® Tire. The present invention relates to a method for monitoring the operating condition or “state” of a vehicular tire. The method includes employing magnetized areas in the vehicle tire, and magnetic field sensors on the vehicle chassis at predetermined locations. As the tire is rotated at a constant angular velocity, a magnetic field pattern (signature), characteristic of the tire's materials, construction and deformation conditions, is established. The amplitude and phase (difference in the alignment of two annular magnetic bands, one near the bead of the tire and the other near the tread) signatures of the magnetic field pattern reflect the tire's tread, sidewall and bead conditions. A change in the signature of one tire, without a corresponding change in the signatures of the remaining vehicle tires, would indicate a problem with that particular tire that could be attributed to low inflation, the onset of tread separation, a problem with the bead or perhaps an incipient sidewall failure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will be further understood with reference to the drawings, wherein:
[0020] [0020]FIG. 1 is a plot of signature characteristics corresponding to splice construction of a tire;
[0021] [0021]FIG. 2 depicts the change in amplitude signature showing tire tread separation;
[0022] [0022]FIG. 3 depicts amplitude signature change during imminent failure of a vehicle tire; and
[0023] [0023]FIG. 4 is a plot showing the signature change as a function of tire air pressure changes.
DETAILED DESCRIPTION OF THE INVENTION
[0024] In one embodiment of the invention it is intended to make the SWT tire “more intelligent” and address some of the issues relating to failure of tires. The SWT data is used for more than just a measure of the lateral force, circumferential torque and, possibly the normal load acting on the tire. The SWT phase and amplitude “signatures” can be used as a sensitive measure of the “state” of the tire. For example, tread, sidewall and bead splices that are overlapped too far or separated too much readily show up during magnetization characterizations routinely run on SWT tires which include at least one magnetized area (not shown) in the tire. Anything that affects the geometry or stiffness (compliance) of the SWT tire is reflected in its magnetic signatures. In particular, a change in the signature of one tire, without a corresponding change in the signatures of the other three, would probably indicate a problem with that tire possibly due to low inflation, the onset of tread separation, a problem with the bead or perhaps an incipient sidewall failure. In field tests (FIGS. 1 - 4 ), tread separation failures were introduced by building tires with a small amount of polyethylene between the belt and tread and then running them on a pulley wheel (not shown) while monitoring, through the use of magnetic field sensors (Not shown), the SWT signatures. This enabled detection of incipient tread separations. Tread separations can occur without the loss of inflation pressure, so that traditional tire pressure monitoring systems may be of no use in detecting these tire failures while SWT would offer an unparalleled safety advantage.
[0025] Algorithms (not shown) are required similar to the existing prior art digital data systems but, instead of looking at changes in the radius of the tire and relating these changes to inflation pressure, changes in the SWT signatures would be related to inflation pressure. Monitoring the signatures of all four tires would probably be required. For example, an AKRON “C” machine could be used to obtain the required data relating inflation pressures to SWT signature changes. Some work has already been done during FMEA studies of the effect of inflation pressure variations on SWT stiffness (compliance).
[0026] SWT technology could be used to measure normal load variations and thus use the data for anti roll over control and enhance suspension control systems. Tests have been performed using two sets of SWT magnetic field sensors (not shown). The first set was placed at the usual 180 degree position (using zero degrees to mark the tire footprint). The second set was placed at 225 degrees from the tire footprint. A bilinear fit algorithm (not shown) allowed not only prediction of lateral forces and circumferential torques better than with just the usual 180 degree pair of sensors, but also gave an excellent prediction of normal load variations. A second pair of sensors at the 270 or 90 degree positions enabled measuring normal loads. Easily mountable sensors on a vehicle at these positions is problematic. The 225 degree position is possible.
[0027] For example, as shown in FIG. 1, at a location where a sidewall splice is overlapped too far or separated too much, the amplitude of the magnetic field at that location is either increased or decreased, correspondingly. Locations where tread splices are overlapped too far or separated too much may also be reflected in the magnetic field signature. Apparently, the non-unifornity detected at the tread splice affects the uniformity of the adjacent magnetic material in the sidewall of the tire. Anything that affects the geometry or the stiffness (compliance) of the Intelligent® Tire is reflected in its magnetic signatures.
[0028] Monitoring of the signatures is particularly useful in predicting the onset of imminent tire failure, for example due to a tread separation at high speed. FIG. 2 depicts a modified step-speed endurance test. FIG. 2 shows data taken at 120 mph and 150 mph in 30 second frames. Top two rows show magnetic field data taken with magnetic field sensors (not shown) mounted at 90 and 180 degrees from the tire contact patch. The bottom two rows show the normal load, kiN, and speed, revolutions per second (corresponding to 120 and 150 mph), respectively. Magnetic field sensors (not shown) were mounted on a high speed dynamometer at 90 and 180 degrees from the tire footprint to monitor the magnetic field of an Intelligent® Tire. Two sensors were mounted at each position, one at the “in” position, i.e., close to the bead of the tire and one at the “out” position, close to the tread of the tire. Thus, both phase and amplitude signatures were measured at each position. In addition to the magnetic field data, vertical load in kiN and tire speed in revolutions per second were collected at a sampling rate of 75,000 samples per second. Thirty seconds of data were collected and stored in the computer in five sequential files. After five files were collected, the sequence repeats starting with file one. Thus. a continuous record of events traced back 150 seconds prior to tire failure was available. (A slight interruption occurred after every 30 seconds that depended on the time taken to write the file to hard disk and resume data collection).
[0029] [0029]FIG. 3 shows expansion of Amplitude data (see FIG. 1) at the 90 degree, inner sensor position. Each frame shows a single tire revolution, thus a signal amplitude signature, starting at the times indicated on the Horizontal axes in seconds. Tire failure due to tread separation occurred at approximately 14 seconds. A marked change in the signature from the base line (shown in frame one) can be clearly seen at the 2.86 second mark (frame two) and grows with each successive frame, apparently corresponding to the growth of the tread separation.
[0030] [0030]FIG. 4 depicts the changes in magnetic field patterns that represent the tire signatures regarding tire inflation pressures. In everyday use, the signature from one tire would be compared to the signatures of the remaining vehicle tires, and any marked changes from an established base line would indicate that a tire failure was imminent.
[0031] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification and following claims.
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A method for monitoring an operating condition of a vehicular tire. The method includes providing magnetized areas in the tire and magnetic field sensors on the chassis of the vehicle. Rotation of the tire produces magnetic field pattern signatures which characterize the tire's materials, construction and deformation conditions. Changes in magnetic field pattern signatures from a baseline are indicative of impending abnormalities in tire integrity that can be recognized in advance to forestall vehicle accidents attributed to tire faults.
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FIELD OF THE INVENTION
The present invention relates to improvements in kraft cooking processes. More particularly, the present invention relates to improvements in batch processes for kraft pulp production in which fouling of heat transfer surfaces is reduced.
BACKGROUND OF THE INVENTION
In the kraft cooking process, cellulosic material, most conveniently in the form of chips, is treated at elevated temperatures, typically from about 160° C. to 180° C., with alkaline cooking liquor containing sodium hydroxide and sodium sulfide. The fresh inorganic liquor is referred to as white liquor, and the spent liquor containing the dissolved wood material is referred to as black liquor.
Since the emergence of such kraft cooking processes, and to the present date, one of the most important objectives has been the attempt to reduce the energy consumption of the cooking process. Processes have therefore been developed for the purpose of, among other aspects, energy saving. In continuous processes, this may take place by heating the chip material with secondary steam which is obtained from flashing the hot black liquor. In batch cooking processes, the most useful technique is to recover the hot black liquor at the end of the cooking stage, and to reuse its energy 1) as a direct heating medium to be pumped into the digester during a subsequent batch, and 2) to heat up white liquor by means of heat exchangers. Good examples of these developments are batch processes described in, e.g. Fagerlund, U.S. Pat. No. 4,578,149 and Östman, U.S. Pat. No. 4,764,251. The displaced liquors of over 10° C. are stored in one or more pressurized accumulators which further contain a continuous heat recovery system (see, e.g. U.S. Pat. No. 5,643,410). As a result, the energy efficiency of batch cooking has increased.
Another important objective has been to improve the properties and quality of the pulp produced by these processes. In the liquor displacement batch method, avoiding digester discharge by means of hard hot blow techniques has made this possible. Gentle digester discharge is typically accomplished by cooling the digester prior to discharge, relieving the overpressure in the digester and then pumping the cooked material from the digester (see, e.g., U.S. Pat. No. 4,814,042). Further development of liquor-displacement kraft batch cooking has also involved the combination of energy efficiency and efficient usage of residual and fresh cooking chemicals to facilitate delignification and high pulp strength (see, e.g., U.S. Pat. No. 5,183,535 and U.S. Pat. No. 5,643,410). This can be accomplished by arranging the displacement at the end of the cook to first recover the “mother” black liquor, which is hot and rich in residual sulfur, into one accumulator, and then to recover the portion of black liquor contaminated by wash filtrate and lower in solids and temperature in another accumulator. The accumulated black liquors are then reused in reverse order to both impregnate and react with the next batch of wood chips prior to finalization of the cook with white liquor. Thus, it has become possible to start a kraft cook with a high charge of sulfur and a low charge of alkali and carry out important sulfur-lignin reactions in the early phase, especially in the hot black liquor treatment, facilitating subsequent delignification with fresh cooking liquor.
The above-mentioned development of the batch cooking technology has thus been characterized by improvements in terms of energy savings and properties of the delignified cellulosic material such as strength and uniformity.
Also important in the cooking process is that the process have a good fit to surrounding processes as e.g. spent liquor evaporation and pulp washing. Through black liquor evaporation, incineration, melting of the smelt into a water solution and causticizing the resulting liquor, white liquor is regenerated from the chemicals contained in the black liquor. This is the basis for recovery of alkaline spent liquors.
Traditionally, both in the case of batch cooking processes and continuously operated cooking processes, the black liquor led to evaporation originates from the main cooking stage at elevated temperature. In the search for improved energy efficiency and improved properties of the delignified cellulosic material, cooking methods have been developed in which the black liquor fed to the evaporation plant is recycled black liquor originating from the early stages of the cooking sequence. Such processes have been disclosed in e.g., U.S. Pat. No. 5,643,410.
It has been observed that the properties of the black liquor originating from the early stages of the cook differ from those of black liquor from a traditional cook. Recycled black liquor originating from the early stages of the cooking sequence may complicate the evaporation of black liquor. A particular problem is fouling of the surfaces of heat exchangers in the evaporation plant, leading to a decrease in heat transfer. Fouling may be so extensive that the heat transfer surfaces must be repeatedly cleaned, which requires special procedures, calls for an evaporation plant shutdown, and may even limit production. The evaporator fouling problems with black liquors that originates from the early stages of cooking are typically related to calcium.
In the early stage of alkaline cooking, calcium-containing material dissolves into the black liquor from the lignocellulosic material. In a traditional cook, the cook proceeds by heating, the temperature increases and no essential liquor exchange occurs. Then, a major part of the dissolved calcium-containing material in the cooking liquor is broken down, calcium carbonate is formed, and as a result a major part of the calcium is resorbed onto the lignocellulosic material in the digester. Typically, following such a cooking process, evaporation of the black liquor can be carried out without problems caused by precipitation of calcium on the heat transfer surfaces, as the black liquor fed to evaporation originates from the cooking stage at elevated temperatures.
The evaporation problems with black liquors originating from the early stages of cooking typically relate to such calcium-containing material being dissolved in the early stages of a cook. The dissolved calcium-containing material has not been degraded, and the amount of calcium bound to the dissolved material in the black liquor is high. In subsequent evaporation processes, the solids content of the black liquor rises and the evaporation temperature typically increases. Thus, the dissolved material is degraded further as evaporation proceeds and the solids content and temperature both rise. The calcium bound to the dissolved material in the black liquor is thereby set free. The liberated calcium reacts with the carbonate in the black liquor, forming calcium carbonate. A significant amount of crystallization occurs on the evaporation plant's heat transfer surfaces, whereby the plant's water evaporation capacity is severely limited. Crystallization may be so extensive that the heat transfer surfaces must be repeatedly cleaned.
It has been shown that a liquor's potential for calcium carbonate precipitation is dependent on the temperature history of the liquor. Fredrick and Grace (Southern Pulp and Paper Manufacturer 42 (1979) 8:16–23) have proposed that the amount of dissolved calcium is increased because in the black liquor the calcium forms a complex with the lignin. This complex is unstable at higher temperatures. At higher temperatures, the complex breaks down, and if calcium ions are released close to a hot surface, the calcium ion reacts with carbonate ions present in the liquor, and the precipitate is formed on the surface.
Frederick and Grace have proposed that calcium precipitation can be decreased or avoided by heating the black liquor between evaporation stages to temperatures of between about 150° C. to 160° C. and times of from about 10 to 20 minutes. However, the above mentioned method has not been extensively in use because it raises investment and operating costs.
Magnusson, Sjölander and Liden have suggested, that the existence of dissolved calcium in kraft black liquors can be explained by the high amounts of dissolved carbon present (Tappi 1998 International Chemical Recovery Conference Proceedings, Tampa, Fla., USA, 1–4 Jun. 1998, Vol. 1, p. 379–383). The introduction of dissolved forms of calcium into the black liquor will lead to an increased degree of supersaturation. Since this form of calcium is thermodynamically unstable with respect to calcium carbonate formation, heating of such liquors will, at some elevated temperatures, cause rapid precipitation. These authors have shown that calcium carbonate precipitation occurs in the temperature range of from about 110° C. to 145° C., and they have also suggested that potential danger of scaling problems in evaporation plants could be avoided by heat treatment that triggers calcium carbonate precipitation during a process stage where it does not lead to harmful scaling.
Others have proposed direct heating of black liquors fed to the evaporator at a temperature of from about 110° C. to 145° C. and times of from about 1 to 20 minutes (patent application FI 980387). However, this method also increases the investment costs.
SUMMARY OF THE INVENTION
In accordance with the present invention, these and other objects have now been realized by the discovery of a method for producing chemical pulp from lignocellulose-containing material by means of alkaline cooking, comprising the steps of (a) charging the lignocellulose-containing material to a digester; (b) initially treating the lignocellulose-containing material with an impregnation liquor to produce an impregnated lignocellulose-containing material; (c) treating the impregnated lignocellulose-containing material with hot liquor so as to produce a heated lignocellulose-containing material, and displacing calcium-containing spent liquor from the digester during the treatment; (d) heating and cooking the heated lignocellulose-containing material at predetermined cooking temperatures and pressures so as to produce cooked lignocellulose-containing material and cooking liquor; and (e) displacing the cooking liquor from the digester using at least a portion of the displaced calcium-containing spent liquor. Preferably, the method includes collecting the displaced calcium-containing spent liquor from the digester in a first portion having a first calcium content and at least one second portion having a second calcium content, the at least one second portion having a lower calcium content, on a dry solids basis, than the first portion. In a preferred embodiment, the method includes combining the at least one second portion of the calcium-containing spent liquor with a portion of the displaced cooking liquor to produce a combined liquor, and supplying the combined liquor to a subsequent batch of the lignocellulose-containing material to supply heat thereto.
In accordance with one embodiment of the method of the present invention, the method includes displacing the cooking liquor from the digester using the first portion of the displaced calcium-containing spent liquor. Preferably, the displacing of the cooking liquor from the digester using the first portion of the displaced calcium-containing spent liquor comprises the first portion of liquor introduced into the digester for displacing the cooking liquor therefrom.
In accordance with another embodiment of the method of the present invention, the method includes displacing the cooking liquor from the digester using the at least one second portion of the calcium-containing spent liquor.
In accordance with another embodiment of the method of the present invention, the method includes monitoring the calcium content, on a dry solids basis, of the calcium-containing spent liquor during its displacement.
In accordance with another embodiment of the method of the present invention, the method includes monitoring the temperature of the calcium-containing spent liquor during its displacement.
In accordance with the present invention, these and other objects has now been accomplished by the discovery of a new method for preparing pulp. More particularly, the present invention relates to processes for preparing pulp in which cellulosic material is treated in one or several impregnation and pretreatment stages before delignifying the heated cellulosic material with fresh alkaline cooking liquor at elevated temperatures. The present invention specifically relates to the liquor exchange in a cooking process that produces high quality pulp, is energy efficient and generates spent liquor, which liquor can be processed in the evaporation plant without forming scaling of low solubility.
For the purpose of this specification, “calcium-containing spent liquor” refers to a process liquor containing calcium bound to dissolved organic material. The calcium content is calculated on the basis of calcium in the dry solids content of the liquor.
In accordance with the present invention, a process is provided for the preparation of pulp from lignin-containing cellulosic material using alkaline cooking, which process comprises the stages of a) charging lignocellulose-containing material to a digester, b) treating the lignocellulose-containing material initially with an impregnation liquor, and subsequently with hotter liquors, and displacing calcium-containing spent liquor from the digester, c) heating and cooking the lignocellulose-containing material at cooking temperatures and pressures to produce cooked lignocellulose-containing material and cooking liquor, and d) displacing the cooking liquor using at least part of the calcium-containing spent liquor, whereby the calcium-containing spent liquor is heated by the digester contents.
Preferably, stage b) includes the sequential introduction of impregnation liquor, hot black liquor and preheated white liquor in proper ratios. The last part of the final displacement stage in d) is preferably carried out using wash filtrate from the downstream process.
In accordance with one embodiment of the process of the present invention, the temperature of the impregnation liquor is between about 20° C. and 100° C., the temperatures of the hotter liquors are between about 120° C. and 180° C. and the temperature of displaced calcium-containing spent liquors are between about 20° C. and 160° C.
In accordance with one embodiment of the process of the present invention, the method includes monitoring the calcium content of spent liquor being displaced, in order to determine the proper cut points for isolating displaced calcium-containing spent liquor which may cause calcium precipitation at higher temperatures and/or dry solid contents.
In accordance with another embodiment of the process of the present invention, the method includes monitoring the temperature of spent liquor being displaced, in order to determine the proper cut points for isolating displaced calcium-containing spent liquor.
In accordance with another embodiment of the process of the present invention, the temperature of displaced calcium-containing spent liquor is between about 20° C. and 100° C.
In accordance with another embodiment of the present invention, a process using alkaline cooking is provided for the preparation of pulp from lignin-containing cellulosic material, which process comprises a) charging lignocellulose-containing material to a digester; b) treating the lignocellulose-containing material initially with an impregnation liquor and subsequently with hotter liquors, displacing from the digester during the subsequent treatments a first portion of calcium-containing spent liquor, and at least a second portion of calcium-containing spent liquor at lower calcium content compared to the first portion of calcium-containing spent liquor, c) heating and cooking the lignocellulose-containing material to produce cooked lignocellulose-containing material and cooking liquor, d) displacing the cooking liquor initially with the first portion of calcium-containing spent liquor, whereby the calcium-containing spent liquor is heated by the digester contents, and subsequently with wash filtrate so as to displace spent liquor and cool the digester content; and e) discharging the digester.
In accordance with another embodiment of the present invention, several portions of calcium-containing spent liquor containing different amounts of calcium are used for displacement of cooking liquor, sequentially or in combination with wash filtrate.
In accordance with the present invention, a process using alkaline cooking is provided for the preparation of pulp from lignin-containing cellulosic material, the process comprising the steps of a) charging lignocellulose-containing material to a digester; b) treating the lignocellulose-containing material initially with an impregnation liquor and subsequently with hotter liquors, thereby displacing from the digester a first portion of calcium-containing spent liquor and a second portion of calcium-containing spent liquor having a lower calcium content compared to the first portion of calcium-containing spent liquor; c) heating and cooking the lignocellulose-containing material to produce cooked lignocellulose-containing material and cooking liquor; d) displacing the cooking liquor initially with a portion of the calcium-containing spent liquor, whereby the calcium-containing spent liquor is heated by the digester contents, and subsequently with wash filtrate so as to displace a first portion of cooking liquor, the first portion of cooking liquor having a temperature and dry solids content substantially corresponding to the temperature and dry solids content of the cooking liquor at the end of the cook; and to displace a second portion of cooking liquor, the second portion of cooking liquor having a temperature and dry solids content substantially lower than the temperature and dry solids content of the cooking liquor at the end of the cook; maintaining the first and second portion of cooking liquor separate from each other; combining the second portion of calcium-containing liquor and the second portion of cooking liquor; utilizing the first portion of cooking liquor for pretreating and heating the lignocellulosic material of a subsequent batch; and using the combined second portion of calcium-containing liquor and second portion of cooking liquor for supplying heat to a subsequent batch of lignocellulose-containing material.
In a preferred embodiment of the present invention, the method includes transferring the combined second portion of calcium-containing liquor and second portion of cooking liquor, after supplying heat to the subsequent batch of lignocellulose-containing material, to a liquor tank at atmospheric pressure. Preferably, the method includes separating and removing soap contained in the combined portions of liquor.
In a preferred embodiment of this method of the present invention, the method includes transferring the combined second portion of calcium-containing liquor and second portion of cooking liquor, after supplying heat to a subsequent batch of lignocellulose-containing material, to an evaporation plant for recovery of cooking chemicals.
In accordance with one embodiment of this method of the present invention, the method includes utilizing wash filtrate and a combined second portion of calcium-containing liquor and second portion of cooking liquor and for impregnating the lignocellulose-containing material in an impregnation step.
In a preferred embodiment, the wash filtrate comprises a filtrate from a subsequent wash plant for kraft pulp.
In accordance with another embodiment of this method of the present invention, the method includes utilizing the combined second portion of calcium-containing liquor and second portion of cooking liquor for preheating fresh alkaline cooking liquor supplied to the digester.
As calcium-containing spent liquor is fed into the digester following the cooking stage, when the cooking liquor at cooking temperature is displaced, the calcium-containing material extracted in the early stages of the process decomposes when the calcium-containing liquor enters the hot digester. Thus, the calcium bound to dissolved material is set free in the digester because of the high temperature. The liberated calcium reacts with carbonate ion, and calcium carbonate is formed in the digester where no scaling can be formed on heat transfer surfaces. Thus, the formed calcium carbonate is retained in the pulp and is not extensively carried to the evaporating plant.
In general, the present invention provides a method for overcoming a drawback in prior art low energy kraft batch cooking processes. In the process according to the present invention, kraft pulp is prepared and spent liquor is generated which, when fed to an evaporation plant, can be processed without forming scaling of low solubility. An essential advantage is that the method does not require any essential investments and has no impact on sequence times and production capacity.
BRIEF DESCRIPTION OF THE FIGURE
The present invention may be more fully appreciated with reference to the following detailed description which, in turn, refers to the FIGURE, which is a schematic representation of a liquor displacement kraft batch process according to the present invention.
DETAILED DESCRIPTION
FIG. 1 shows a block diagram of a liquor-displacement kraft batch process according to the present invention. The FIGURE defines the required tanks, streams and the cooking sequence. Charging the digester with wood chips and evacuating the digester starts the kraft cook. The chips can be packed with steam or be pre-steamed, before the digester is filled essentially with impregnation liquor A from the impregnation liquor tank 5 , soaking and heating the chips. Wood chip charging and impregnation liquor charging preferably overlap. An overflow, A 1 , to black liquor tank, point AB, is carried out in order to remove air and diluted first front of liquor. Preferably, the volume of A 1 is kept low. After closing the flow, the digester is pressurized and impregnation is completed. During impregnation, a relatively low temperature is preferred, since a higher impregnation temperature will consume residual alkali too fast, resulting in higher rejects and non-uniform cooking. Preferably, the temperature of this impregnation step is below about 100° C. In practice, temperatures of from about 20° C. to 100° C. can be utilized.
In the next stage, the wood chips are further treated with hotter liquors before actual cooking. The temperatures of the hotter liquors are between about 120° C. to 180° C. In FIG. 1 , a method is described where hot black liquor B is pumped in from hot black liquor tank 1 . Black liquor from tank 1 is at constant temperature, dry solids content and residual alkali, which makes it easy to maintain conformity from cook to cook. This is extremely important because the hot black liquor has a major chemical effect on the wood, and controls the selectivity and cooking kinetics in the main cooking phase with white liquor. The cooler and partly diluted impregnation liquor A 2 , displaced by hot black liquor, is essentially conducted to black liquor tank 4 , point AB. In the spent liquor portions A 1 and A 2 , the dissolved material typically has the highest content of calcium. The cooking sequence is continued by pumping in hot white liquor, point C, from the hot white liquor tank 3 and a smaller amount of hot black liquor, B, 1) simultaneously with the hot white liquor, in order to dilute the very high alkali concentration of fresh white liquor and 2) after white liquor charge, in order to flush lines into the digester. The liquor D 2 , displaced by hot liquor, preferably above about the atmospheric boiling point, is conducted to hot black liquor tank 2 .
According to the prior art as disclosed in e.g. U.S. Pat. No. 5,643,410, the displaced liquors A 1 and A 2 are essentially conducted to the evaporation plant. This procedure will, however, transfer the calcium-containing dissolved material, which has not yet been degraded in the cooking process, to the evaporation plant. In the subsequent evaporation process, during which the solids content and temperature typically increase, the calcium bound to the dissolved material in the black liquor is set free. As a consequence, calcium carbonate scaling occurs on heat transfer surfaces of evaporation units, whereby the plant's evaporation capacity is severely impaired.
According to the present invention, tank 4 is used for storing the spent cooking liquor portions containing released calcium-containing material from the early impregnation and pretreatment stages of the cooking sequence, which liquors tend to form calcium precipitates at higher temperatures and dry solid contents. Preferably, the portion at the highest concentration of calcium is stored in tank 4 . Most preferably, tank 4 is an atmospheric tank. The exact volume to be recovered to tank 4 is most suitably controlled by monitoring the calcium content, dry solids concentration and temperature of the displaced liquor exiting from the digester. After detecting a clear drop in calcium content bound to the dissolved material, the displaced liquor is switched to enter black liquor tank 2 . The switch preferably occurs before the atmospheric boiling point of the displaced liquor is exceeded.
Further division of the calcium-containing displaced liquor is also possible, depending on available tank capacity. Preferably, the fractions are then used for final displacement in the same order, as described below.
After the filling procedure described above, the digester temperature is close to the final cooking temperature. The final cooking temperature can be between about 140° C. to 180° C., depending on the wood raw material. The final heating-up is carried out using direct or indirect steam heating and digester re-circulation. During cooking, additional fresh cooking liquor, C, from tank 3 can be added to even out the alkali profile. Spent liquor, B 2 , is then removed from the digester to tank 1 or tank 2 .
After the desired cooking time, when delignification has proceeded to the desired degree of reaction, the now spent cooking liquor is ready to be displaced with cool liquor, which serves to stop the cooking reactions and to cool and wash the digester content. According to the present invention, the cooking liquor is at least partly displaced with a liquor portion E from the black liquor tank 4 . Preferably, portion E is initially introduced followed by washing filtrate, point F, from the wash filtrate tank 6 . In this manner, the calcium-containing liquors generated in the early stages of the process, i.e. portion E from tank 4 , which contains the highest amount of calcium bound to dissolved material, and is most liable to cause scaling precipitates in evaporation according to prior art methods, is introduced in the digester as the digester contents are at a high initial temperature. Consequently, the dissolved material decomposes and calcium carbonate is formed mainly within the bulk of the liquor, and remains in the liquor as calcium carbonate crystals, or is absorbed into the pulp. In this manner, the spent liquor conducted to the evaporation plant from the cooking process is essentially free of problematic calcium bound to dissolved material.
If further subdivision of the calcium-containing liquors displaced from the digester has taken place, the fractions may be used in the same order for the final displacement, the latter fractions of successively lower calcium content experiencing successively lower temperatures.
No prior art technology using the impregnation and pretreatment procedures described above is able to produce spent liquor for the evaporation plant without calcium carbonate-related problems. The black liquor tank 4 now has a new role in the cooking process. It first collects the most problematic calcium-containing spent liquors and then transfers these liquors to the terminal displacement of the hot cooking liquor, preferably to the initial stages of the terminal displacement.
The present invention will not essentially affect the washing efficiency of the terminal displacement, since the portion E contains chip water and some diluted spent liquor. Thus, the dissolved solids content of portion E is in the same order as that of the washing filtrate F. The cooling efficiency of the terminal displacement will be improved since the portion E has a low temperature, preferably about 20° C. to 100° C.
In the terminal displacement step, the first portion B 1 of exiting hot black liquor corresponds to the total of the volumes B required in the filling stages. Preferably, the terminal displacement is carried out to produce a displaced portion of spent cooking liquor having a temperature and dry solids content substantially corresponding to the predetermined temperature and dry solids content of the cooking liquor. The second portion D 1 of displaced spent cooking liquor, which is diluted by the displacement filtrate but is still above its atmospheric boiling point, is conducted to the hot black liquor tank 2 . After completed final displacement, the digester contents are discharged for further processing of the pulp. The above cooking sequence may then be repeated.
The equipment for the cooking process includes the tank farm, where fresh liquors and spent liquors are stored and heat is recovered. The impregnation liquor tank is provided with wash liquor from the washing plant. The hot black liquor tank 2 provides spent black liquor to the evaporation plant through fiber separation, and also partly provides cooled impregnation black liquor to the impregnation liquor tank, transferring heat to white liquor and water by means of heat exchange. The spent liquor transferred to the evaporation plant, according to the present invention, thus originates from conditions at higher temperatures compared to prior art technology, such as that described in U.S. Pat. No. 5,643,410. According to the present invention, tank 2 also has a function of decomposing calcium-containing dissolved material, as tank 2 provides residence times of from about 10 to 60 minutes and temperatures from about 100° C. to 135° C. The temperature of tank 2 depends, among other factors, on the arrangement of terminal displacement, temperature of charged lignocellulosic material, and the switching point from collecting to tank 4 to tank 2 in the pretreatment step. An additional advantage of the present invention compared to prior art such as the process of U.S. Pat. No. 5,643,410, is that the temperature of the spent liquor conducted to the evaporation plant can be controlled. This is especially important when outside temperatures are low, e.g. during winter when temperatures in the lignocellulosic material charged to the cooking system is below the freezing point of water. In prior art processes, the temperature of the evaporation liquor has dropped in winter conditions, causing control difficulties and increased heating requirements in the evaporation plant. Another advantage of the present invention is that the fiber separation of the spent liquor conducted to the evaporation plant can occur at higher temperatures, facilitating soap solubility and reducing carryover of soap to the separated fiber fraction. The soap is preferably conducted with the spent liquor to the evaporation plant, where soap can be further removed.
Tanks 4 , 5 and 6 are furnished with soap separation equipment according to prior art soap separation technology. Practical experience on mill-scale has proven that soap removal in these locations of the black liquor transfer sequence is of major importance, especially when processing soap-containing softwood raw materials. It is of great importance to use only low-in-soap black liquor for impregnation or other digester filling purposes.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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Methods for producing chemical pulp from lignocellulose-containing material in processes for kraft pulp production are disclosed including charging the lignocellulose-containing material to a digester, initially treating the lignocellulose-containing material with an impregnation liquor, and then treating the impregnated lignocellulose-containing material with hot liquor and displacing calcium-containing spent liquor from the digester during that treatment, heating and cooking the heated lignocellulose-containing material to produce cooked lignocellulose-containing material and cooking liquor and displacing the cooking liquor from the digester using at least a portion of the displaced calcium-containing spent liquor.
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BACKGROUND
[0001] Viscous hydrocarbon recovery is a segment of the overall hydrocarbon recovery industry that is increasingly important from the standpoint of global hydrocarbon reserves and associated product cost. In view hereof, there is increasing pressure to develop new technologies capable of producing viscous reserves economically and efficiently. Steam Assisted Gravity Drainage (SAGD) is one technology that is being used and explored with good results in some wellbore systems. Other wellbore systems however where there is a significant horizontal or near horizontal length of the wellbore system present profile challenges both for heat distribution and for production. In some cases, similar issues arise even in vertical systems.
[0002] Both inflow and outflow profiles (e.g. production and stimulation) are desired to be as uniform as possible relative to the particular borehole. This should enhance efficiency as well as avoid early water breakthrough. Breakthrough is clearly inefficient as hydrocarbon material is likely to be left in situ rather than being produced. Profiles are important in all well types but it will be understood that the more viscous the target material the greater the difficulty in maintaining a uniform profile.
[0003] Another issue in conjunction with SAGD systems is that the heat of steam injected to facilitate hydrocarbon recovery is sufficient to damage downhole components due to thermal expansion of the components. This can increase expenses to operators and reduce recovery of target fluids. Since viscous hydrocarbon reserves are likely to become only more important as other resources become depleted, configurations and methods that improve recovery of viscous hydrocarbons from earth formations will continue to be well received by the art.
SUMMARY
[0004] A SAGD system including at least one borehole having a tubular therein; and at least one baffle disposed on the tubular, the baffle extending radially outwardly of the tubular into proximity with a formation.
[0005] A downhole configuration for a SAGD system including a tubular; and one or more baffles on the tubular, the one or more baffles configured to be extendible in a radial direction from the tubular to reduce annular flow along the tubular when installed in a borehole.
[0006] A borehole system including a borehole; and one or more metal-to-formation baffles extending radially to proximity with a formation interface.
[0007] A borehole system including a tubular configured to be disposed within an open hole borehole, the tubular being intended to be exposed to a heated fluid; and one or more tubular-to-formation baffles spaced along the tubular and extending into proximity with the formation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Referring now to the drawings wherein like elements are numbered alike in the several figures:
[0009] FIG. 1 is a schematic view of a wellbore system in a viscous hydrocarbon reservoir;
[0010] FIG. 2 is a chart illustrating a change in fluid profile over a length of the borehole with and without permeability control.
DETAILED DESCRIPTION
[0011] Referring to FIG. 1 , the reader will recognize a schematic illustration of a portion of a SAGD wellbore system 10 configured with a pair of boreholes 12 and 14 . Generally, borehole 12 is the steam injection borehole and borehole 14 is the hydrocarbon recovery borehole but the disclosure should not be understood as limiting the possibilities to such. The discussion herein however will address the boreholes as illustrated. Steam injected in borehole 12 heats the surrounding formation 16 thereby reducing the viscosity of the stored hydrocarbons and facilitating gravity drainage of those hydrocarbons. Horizontal or other highly deviated well structures like those depicted tend to have greater fluid movement into and to of the formation at a heel 18 of the borehole than at a toe 20 of the borehole due simply to fluid dynamics. An issue associated with this property is that the toe 20 will suffer reduced steam application from that desired while heel 18 will experience more steam application than that desired, for example. The change in the rate of fluid movement is relatively linear (declining flow) when querying the system at intervals with increasing distance from the heel 18 toward the toe 20 . The same is true for production fluid movement whereby the heel 28 of the production borehole 14 will pass more of the target hydrocarbon fluid than the toe 30 of the production borehole 14 . This is due primarily to permeability versus pressure drop along the length of the borehole 12 or 14 . The system 10 as illustrated alleviates this issue as well as others noted above.
[0012] According to the teaching herein, one or more of the boreholes (represented by just two boreholes 12 and 14 for simplicity in illustration) is configured with one or more permeability control devices 32 that are each configured differently with respect to permeability or pressure drop in flow direction in or out of the tubular. The devices 32 nearest the heel 18 or 28 will have the least permeability while permeability will increase in each device 32 sequentially toward the toe 20 and 30 . The permeability of the device 32 closest to toe 20 or 30 will be the greatest. This will tend to balance outflow of injected fluid and inflow of production fluid over the length of the borehole 12 and 14 because the natural pressure drop of the system is opposite that created by the configuration of permeability devices as described. Permeability and/or pressure drop devices 32 useable in this configuration include inflow control devices such as product family number H48688 commercially available from Baker Oil Tools, Houston Tex., beaded matrix flow control configurations such as those disclosed in U.S. Ser. Nos. 61/052,919, 11/875,584 and 12/144,730, 12/144,406 and 12/171,707 the disclosures of which are incorporated herein by reference, or other similar devices. Adjustment of pressure drop across individual permeability devices is possible in accordance with the teaching hereof such that the desired permeability over the length of the borehole 12 or 14 as described herein is achievable. Referring to FIG. 2 , a chart of the flow of fluid over the length of borehole 12 is shown without permeability control and with permeability control. The representation is stark with regard to the profile improvement with permeability control.
[0013] In order to determine the appropriate amount of permeability for particular sections of the borehole 12 or 14 , one needs to determine the pressure in the formation over the length of the horizontal borehole. Formation pressure can be determined/measured in a number of known ways. Pressure at the heel of the borehole and pressure at the toe should also be determined/measured. This can be determined in known ways. Once both formation pressure and pressures at locations within the borehole have been ascertained, the change in pressure (ΔP) across the completion can be determined for each location where pressure within the completion has been or is tested. Mathematically this is expressed as ΔP location=P formation−P location where the locations may be the heel, the toe or any other point of interest.
[0014] A flow profile whether into or out of the completion is dictated by the ΔP at each location and the pressure inside the completion is dictated by the head of pressure associated with the column of fluid extending to the surface. The longer the column, the higher the pressure. It follows, then, that greater resistance to inflow will occur at the toe of the borehole than at the heel of the completion. In accordance with the teaching hereof permeability control is distributed such that pressure drop at a toe of the borehole is in the range of about 25% to less than 1% whereas pressure drop at the heel of the borehole is about 30% or more. In one embodiment the pressure drop at the heel is less than 45% and at the toe less than about 25%. Permeability control devices distributed between the heel and the toe will in some embodiments have individual pressure drop values between the percentage pressure drop at the toe and the percentage pressure drop at the heel. Moreover, in some embodiments the distribution of pressure drops among the permeability devices is linear while in other embodiments the distribution may follow a curve or may be discontinuous to promote inflow of fluid from areas of the formation having larger volumes of desirable liberatable fluid and reduced inflow of fluid from areas of the formation having smaller volumes of desirable liberatable fluid.
[0015] Referring back to FIG. 1 , a tubing string 40 and 50 are illustrated in boreholes 12 and 14 respectively. Open hole anchors 42 , such as Baker Oil Tools WBAnchor™ may be employed in the borehole to anchor the tubing 40 . This is helpful in that the tubing 40 experiences a significant change in thermal load and hence a significant amount of thermal expansion during well operations. Unchecked, the thermal expansion can cause damage to other downhole structures or to the tubing string 40 itself thereby affecting efficiency and production of the well system. In order to overcome this problem, one or more open hole anchors 42 are used to ensure that the tubing string 40 is restrained from excessive movement. Because the total length of mobile tubing string is reduced by the interposition of open hole anchor(s) 42 , excess extension cannot occur. In one embodiment, three open hole anchors 42 , as illustrated, are employed and are spaced by about 90 to 120 ft from one another but could in some particular applications be positioned more closely and even every 30 feet (at each pipe joint). The spacing interval is also applicable to longer runs with each open hole anchor being spaced about 90-120 ft from the next. Moreover, the exact spacing amount between anchors is not limited to that noted in this illustrated embodiment but rather can be any distance that will have the desired effect of reducing thermal expansion related wellbore damage. In addition the spacing can be even or uneven as desired. The determination of distance between anchors must take into account. The anchor length, pattern, or the number of anchor points per foot in order to adjust the anchoring effect to optimize performance based on formation type and formation strength tubular dimensions and material.
[0016] Finally in one embodiment, the tubing string 40 , 50 or both is configured with one or more baffles 60 . Baffles 60 are effective in both deterring loss of steam to formation cracks such as that illustrated in FIG. 1 as numeral 62 and in causing produced fluid to migrate through the intended permeability device 32 . More specifically, and taking the functions one at a time, the injector borehole, such as 12 , is provided with one or more baffles 60 . The baffles may be of any material having the ability to withstand the temperature at which the particular steam is injected into the formation. In one embodiment, a metal deformable seal such as one commercially known as a z-seal and available from Baker Oil Tools, Houston Tex., may be employed. And while metal deformable seals are normally intended to create a high pressure high temperature seal against a metal casing within which the seal is deployed, for the purposes taught in this disclosure, it is not necessary for the metal deformable seal to create an actual seal. That stated however, there is also no prohibition to the creation of a seal but rather then focus is upon the ability of the configuration to direct steam flow with relatively minimal leakage. In the event that an actual seal is created with the open hole formation, the intent to minimize leakage will of course be met. In the event that a seal is not created but substantially all of the steam applied to a particular region of the wellbore is delivered to that portion of the formation then the baffle will have done its job and achieved this portion of the intent of this disclosure. With respect to production, the baffles are also of use in that the drawdown of individual portions of the well can be balanced better with the baffles so that fluids from a particular area are delivered to the borehole in that area and fluids from other areas do not migrate in the annulus to the same section of the borehole but rather will enter at their respective locations. This ensures that profile control is maintained and also that where breakthrough does occur, a particular section of the borehole can be bridged and the rest will still produce target fluid as opposed to breakthrough fluid since annular flow will be inhibited by the baffles. In one embodiment baffles are placed about 100 ft or 3 liner joints apart but as noted with respect to the open hole anchors, this distance is not fixed but may be varied to fit the particular needs of the well at issue. The distance between baffles may be even or may be uneven and in some cases the baffles will be distributed as dictated by formation condition such that for example cracks in the formation will be taken into account so that a baffle will be positioned on each side of the crack when considered along the length of the tubular.
[0017] 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 is to be understood that the present invention has been described by way of illustration and not limitation.
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A SAGD system including at least one borehole having a tubular therein; and at least one baffle disposed on the tubular, the baffle extending radially outwardly of the tubular into proximity with a formation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relate to a method for treating a cloth, and more particularly to at reatment method in which, for example in a dyeing process, a cloth to be treated is dipped in a solution, e.g., dye or resin solution, and is wet and impregnated with a substance such as dye, resin, chemical or the like contained in the solution, and then heating the substance electrically so that it is physically or chemically fixed to the cloth.
2. Background of the Prior Art
Dyeing processes heretofore known are generally classified into different methods. The first method is continuous dyeing in which, after a cloth to be treat is impregnated with a dye, the whole cloth is uniformly squeezed so that a certain amount of the dye may be fixed to the cloth, then the dye is further fixed to the cloth by heating the cloth by vapor heating, hot air heating, etc. The second method is barch dyeing in which a batch the cloths each cut into a certain length are dyed.
Further, from the viewpoint of apparatus or system to be used, the conventional dyeing processes are also classified into following three method. The first method is jigger dyeing in which a cloth spread out is wound round a cylinder to be dyed by repeating normal rotation and reverse rotation of the cylinder. The second method is wince dyeing in which each cloth of a plurality of cloths is formed into a shape of string by being squeezed in a longitudinal direction, the string-like cloth is placed on a rotary wheel and ends of each cloth are sewn to those of other strings eventually forming a looped, and the loop cloths are subjected to dyeing. The third method is circular dyeing in which a cloth of about 500 m (50 m × 10 rolls) in length is formed into a shape of a string, which is then circulated in a cylinder together with a dye solution. The fourth method, i.e., jet dyeing, has been increasingly employed in recent years.
The foregoing known dyeing methods, rsepectively, have their own advantages and disadvantages. That is, the continuous dyeing is certainly suited for mass treatment, but there is a difficulty in adjustment of deep color dyeing, and thus the method is not suited for dying small amount of cloth or short cloth. To the contrary, the batch dyeing is certainly suited for dyeing a cloth of small dimensions or length, but neds a relatively long treating time of two hours or so, and thus the method is not suited for treatment of continuous dyeing.
In jigger dyeing, there is a problem that the two end portions of cloth to be treated are deeply colored with dye, and that it takes a long time before completing the treatment because rotation of the cylinder should be repeated in even numbers.
In wince dyeing, there is a problem of requiring a large amount of dye and that it takes a long time before completing the treatments. Moreover, it is required a troublesome work such as taking out the treated cloths one by one in this method.
In circular dyeing, there is a problem requiring troublesome work such as spreading out the treated cloth after completing the dyeing process.
As a further problem common to all of the foregoing conventional treatment methods, a considerable amount of water is essential the treatment mechanism is large-scaled.
SUMMARY OF THE INVENTION
The present invention was made to solve the above problems and has an object of providing a cloth treatment method by which continuous treatment of a cloth in a spread state can be carried out with a simple mechanism, by which even a cloth of small dimensions or length can be easily dyed, and by which deep color adjustment can be easily carried out.
In order to achieve the foregoing object, in the cloth treatment method in accordance with the rpesent invention a cloth to be treated is dipped in a treating solution and wet thereby to be impregnated with a treating substance, the treating substance being fixed to the cloth by the steps of dipping the cloth to be treated in the treating solution, squeezing the cloth, disposing th cloth wet and impregnated with the treating solution between two electrode rolls (or rolelrs) opposed in parallel to each other, and applying a voltge to the two electrode rolls to pass a current between the two electrode rolls through teh treating solution with which the cloth is impregnated, whereby heat being generated due to electric resitance of the treating solution affixes the treatment substance to the fabric.
In the cloth treatment method described above, when applying a voltage to the two electrode rolls, a part of the electric energy passing throug hthe treating solution with which the cloth to be treated is impregnated is converted to a heat energy by generation of heat due to electric resistance of the treating solution, whereby the temperature of both treating solution and cloth is increased, the treating substance contained in the treating solution being thus physically and chemically fixed to the cloth. The treated cloth can be continouously treated and conveyed outside by the rotation of each electrode roll. Because the cloth in a spread state is wound over and between the two electrode rolls, there is no troublesome work such as spreading the cloth after completing the treatment, which results in sparing of treating time. Because electric energy is used as a heating energy and electric current is directly applied to the treating solution, a very simplified mechanism is sufficient for conveniently increasing temperature of the cloth as compared with the conventional system wherein vapor or hot air is used as a heating source. Becase the electric current passes almost evenly through the cloth, there is no problem of unwanted deep coloring, and the temperature requird for the treatment can be easily obtained by adjusting the voltage applied. Pieces of cloth of different lengths and dimensions cna also be easily treated by changing the number of electrode rolls used, i.e., by adding more rolls if needed. Furthermore, the cloth treatment method is also adaptable for mass treatment.
Other objects and advantages of the invention will become apparent in the course of the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view illustrating an example of a treatment apparatus used for practicing the cloth treatmet method in accordance with the present invention; and
FIG. 2 is a perspective view to explain the basic arrangement of elements for practicing the preferred cloth treatment method.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention is now described hereinafter with reference to the accompanying drawings.
Describing first the basic technological arrangement of the invention referring to FIG. 2, the anode side electrode roll 10 and the cathode side electrode roll 12, both comprising an electrical conductor, are opposedly disposed with a certian distance therebetween. An anode and cathode of the DC power supply 14 are respectively connected t othe electrode rolls 10, 12. The cloth 16 to be treated is dipped in the treating solution, and is then squeezed in such a manner between rollers 24 and 26 as to be uniformly impregnated with the treating solution. The wet cloth 16 is then disposed over and between each of at least two electrode rolls 10a, 12a. In applying a DC voltage from the DC power suppy 14 to the at least two electrode rolls10a, 12a, because cloth 16 imprengated with the treating solution is in electrical contact with the two electrode rolls 10, 12, a DC current passes from the anode of the DC power supply 14 to the cathode thereof by way of the anode side electrode roll 10a through the treating solution impregnated into the cloth 16 and from the cathode side electrode roll 12. At this time, the temperature of the impregnated cloth 16 is raised by heat generation in the treating solution because of the electric resistance of the solution. Thus the temperature can be easily raised, e.g., to 90° C. to 100° C. necessary for dyeing, just by controlling the applied voltage from the DC power supply 14.
FIG. 1 is a schematic view of one exmaple of the apparatus used for embodying the cloth treating method of the invention. In the drawing, the cloth 16 to be treated is dipped in the treating solution 22 in the treating solution tank 20 through the guide roll 18, then squeezed by a pair of squeezing rolls 24, 26 in such a manner as to be impregnated uniformly with the treating chamber 28. A plurality of anode side electrode rolls 10a to 10n are horizontally disposed in an treating chamber 28 at the upper portion, with a certain distance between one and the other, in such a mnner as to be opposed respectively to each portion located between one and the other of a plurality of cathode side electrode rolls 12a to 12n. The cloth 16 guided into the treating chamber 28 is alternately wound round the anode side electrode rolls 10a to 10n and the cathode side electrode rolls 12a to 12n, and conveyed in the direction of the arrow by rotational drive of a torque motor (not illustrted) to be finally sent outside the treating chamber 28.
The anode side electrode rolls 10a to 10n and the cathode side electrode rolls 12a to 12n are respectively connected to the anode and cathode of the DC power supply so that a DC voltage corresponding to treatment speed may be applied to the anode side electrode rolls 10a to 10n and the cathode side electrode rolls 12a to 12n, the anode side electrode rolls 10 a to 10n being rotationally driven to convey the cloth 16.
The treating solution 22 with which the cloth 16 is impregnated experiences electrical resistance heating as described. Referring to FIG. 2, the temperature of the cloth 16 is raised and, accordingly, the treating substance such as dye or resin contained in the treating solution 22 is fixed to the cloth 16.
As electricity is used the heating source of the cloth 16 in this embodiment, no vapor is needed, this being different from the conventional treatment. But is may also be desirable to provdie auxiliary heating with a certain amount of vapor to accelerate the dyeing process.
As the cloth 16 is wound round evh of the electrode rolls 10a to 10n and 12a to 12n in its spread state, there is not need for troublesome work such as spreading the cloth 16 after the treatment. Varieite sof cloths 16 can be continouosly treated because the number of electrode rolls 10a to 10n and 12a to 12n that are engaged by the cloth may be variably changed according to the condition of the cloth 16.
The inventor has actually carried out several experiments to verify that cloths treated by the method of the invention have their performance suitable for conditions of normal use, and results of these experiments are described hereinafte.r
(1) Dyueing with Direct Dyes
A bleached cotton cloth of 130 g/m 2 in weight was in a dyeing solution of 10 g/l Kasyarus Spura Browm GTL (trade name produced by Nippon Kayaku Co., Ltd., then was squeexed once at a squeezing percentage of 85%. The wet cotton cloth was laid over and between two electrode rollers 10, 12 illustrated in FIG. 2, and a load of 100 g was applied to both ends of the cloth. Applying B 130 V for 20 seconds form a DC power supply 14 while keeping the cloth in a loaded state, the temperature of the cloth was raised to 90° C., when a dyeing reaction took place. Thus a cloth of required color was obtained after washing with water and drying.
(2) Dyeing with Cationic Dye
A 100% acylic desized cloth of 180 g/m 2 in weight was dipped once in a mixed treating solution of 10 g/l Kayacryl Yellow 3RL-ED (trade name, produced by Nippon Kayaku Co., Ltd.), 1 g/l Kayacryl Red GRL-Ed (same as above), 0.5 g/l Kayacry Blue GRL-ED (same as above) and 3 ml/l Naganol (trade name of an organic acid produced by Sanpo Chemical Industry Co., Ltd.), then was squeezed once at a squeezing percentage of 75%. The wet cloth was laid over and between two electrode rollers 10, 12 as illustrated in FIG. 2, and a load of 100 g was applied to both ends of the cloth. Applying B 120 V for 20 seconds from the DC power supply 14 while keeping the cloth in a loaded state, the temperature of the cloth was raised to 95° C., when a dyeing reaction took place. Thus a cloth of required color was obtained.
(3) Polyester Reducing (Finishing)
A polyester desized cloth of 120 g/m 2 in weight was dipped once in a mixed treating solution of 250 g/l caustic soda and 3 ml/l penetrant, then was once squeezed at a squeezing percentage of 85%. The wet cloth was laid over and between the two electrode rollers 10, 12 as illustrated in FIG. 2, and a load of 100 g was applied to both ends of the cloth. Applying 120 V for 25 seconds from the DC power supply 14 while keeping the cloth in loaded state, the temperature of the cloth was raised to 95° C. After turning off electricity, the cloth was subjected to washing with water, neutralization by dipping in 2 ml/l acetic acid for 30 seconds washing with water for 1 minute, dehydration squeezing at the squeezing percentage of 75% with mangle, and drying at 120° C. for 3 minutes in order. Thus a cloth of 20% in loss was obtained.
(4) Resin Treatment
A yellow-colored cotton cloth of 150 g/m 2 in weight was dipped once in a mixed treating solution of thermo-setting resin of 10% Sumitex resin NS-19 (trade name), produced by Sumitomo Chemical Industries Co., Ltd, 3% Accelerator X-80 (same as above). 0.1% Accelerator X-100B (same as above) and 0.5% Silicon Softner N85 (trade name), produced by Matsumoto Yushi Co., Ltd, then was once squeezed at a squeezing percentage of 80%. The wet cloth was laid over and between two electrode rollers 10, 12 as illustrated in FIG. 2, and a load of 100 g was applied to both ends of the cloth. Applying 120 V for 20 seconds from the DC power supply 14 while keeping the cloth in loaded state, the temperature of the cloth was raised to 90° C. After drying the cloth at 120° C. for 2 minutes, the cloth was subjected to heat treatment by heating at 140° C. for 3 minutes. Thus, a treated cloth of low surface resin and good elastic return was obtained.
Having described specific examples of our cloth treatment method, it is believed obvious that modification and variation of the invention is possible in light of the above teachings.
In this disclosure, there are shown and described only the preferred embodiments of th einvention, but, as aforementioned, it is to be understood that the invention is capable of use in various other combination and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
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A cloth treatment method includes the steps of dipping a cloth in a solution of a treating substance to wet the cloth therewith, squeezing the cloth to uniformly impregnate it with the substance, disposing the cloth impregnated with the treating solution between two electrode rolls parallel to each other, and applying a voltage to the two electrode rolls to pass an electric current between therebetween through the treating solution with which the cloth is impregnated, whereby heat generated due to electric resistance of the treating solution promotes fixation of the treatment substance to the fabric.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of 11/244,231 filed Oct. 6, 2005 now U.S. Pat. No. 7,304,172 which claims benefit of 60/616,630 filed Oct. 8, 2004.
The invention was made at least in part with U.S. Government support under National Science Foundation Contract No. DMR-0079992. The U.S. Government has certain rights in the invention.
TECHNICAL FIELD
The invention is directed at high selectivity cobalt containing catalysts for producing poly(alkylene carbonates) from alkylene oxide and carbon dioxide, to a process for producing polycarbonates using the catalysts and to polycarbonates produced thereby.
BACKGROUND OF THE INVENTION
The generalized mechanism of CO 2 /epoxide copolymerization involves two steps, namely epoxide ring opening by a metal carbonate followed by CO 2 insertion into a metal alkoxide. When aliphatic epoxides such as propylene oxide are used, a common side-product is the cyclic carbonate. The most active catalysts, namely [Zn(BDI)OAc] and [Cr(salph)Cl]/DMAP, reported to date, produce 10-30% of unwanted cyclic propylene carbonate (CPC) by-product, under optimized conditions.
SUMMARY OF THE INVENTION
It has been discovered herein that catalysts of sufficient activity for commercial production and which have selectivity of greater than 90:1 poly(propylene carbonate) (PPC) to CPC, often greater than 99:1 PPC to CPC, are enantiomerically pure cobalt catalysts, e.g., (salen)Co III (X)complexes and the like.
In a first embodiment herein, there are provided cobalt containing compounds useful as catalysts for CO 2 /C 2 -C 10 alkylene oxide copolymerization with little or no cyclic alkylene carbonate by-product. These compounds have the structural formula:
where R 1 is a hydrocarbon bridge which may be substituted with C 1 -C 20 alkyl, C 1 -C 20 alkoxy, halogen (e.g., Cl, Br, I), nitro, cyano or amine; where R 2 , R 3 and R 4 can be the same or different and are selected from the group consisting of H, C 1 -C 20 alkyl, C 6 -C 20 aryl, and C 1 -C 20 fluorocarbon and where R 2 and R 3 or R 3 and R 4 can form a ring which can be substituted with H, C 1 -C 20 alkyl, C 6 -C 20 aryl, C 1 -C 20 alkyl C 6 -C 20 aryl substituted with C 1 -C 20 alkyl, C 1 -C 20 alkoxy, phenoxy, C 1 -C 20 carboxylate, C 1 -C 20 acyl, amino, C 1 -C 20 fluoroalkyl, cyano, nitro or halogen (e.g., Cl, Br, I) or a solid support and where X is any nucleophile which can ring open an epoxide.
The term “solid support” as used herein refers to a soluble or insoluble polymeric structure, such as crosslinked polystyrene, or an inorganic structure, e.g., of silica or alumina.
The cases of X being nitro-substituted phenoxide are excluded when R 1 is 1,2-cyclohexanediyl to avoid disclosure in Lu, X-B, et al, Angew. Chem. Int. Ed 43, 3574-3577 (2004).
For the structure where X is Br, R 1 is ethyl and R 3 and R 4 form a phenyl ring, the case is excluded where the substituents on the phenyl ring on carbons which are not also part of another ring, are all H, because this compound has been found to be inactive in producing poly(propylene carbonate).
For the structure where X is Br, R 1 is 1,2-cyclohexanediyl and R 3 and R 4 form a phenyl ring, the case is excluded where substituents on carbon on the phenyl ring which is not also part of another ring and is closest to O is not H, because this compound has been found to be inactive in producing poly(propylene carbonate).
In another embodiment, denoted the second embodiment, there is provided a catalyst system for use in catalyzing the copolymerization of C 2 -C 10 alkylene oxide, and carbon dioxide to produce poly(C 2 -C 10 alkylene carbonate), e.g., poly(propylene carbonate), with less than 10% cyclic alkylene carbonate, e.g., cyclic propylene carbonate, by-product, comprising compound of the first embodiment as catalyst and a salt cocatalyst which is bulky and non-coordinating where the cation is any bulky cation, e.g., a phosphorus and/or nitrogen based cation, e.g., [R 4 N] + , [R 4 P] + , [R 3 P═N═PR 3 ] + or [P[NR 3 ] 3 ] 3+ where R is C 1 -C 20 alkyl or C 6 -C 20 aryl or a solid support, where the unsupported cation or the ionic portion of a supported cation has a molecular weight ranging, for example, from 750 g/mol to 2000 g/mol, and the anion is a nucleophile which can ring open an epoxide, and the R groups can be the same or different.
In another embodiment, denoted the third embodiment, there is provided a method for preparing poly(C 2 -C 10 alkylene carbonate)s, e.g., poly(propylene carbonate), by copolymerization of C 2 -C 10 alkylene oxide, e.g., propylene oxide, and carbon dioxide with less than 10% cyclic C 2 -C 10 alkylene carbonate, e.g. cyclic propylene carbonate, by-product, comprising the step of reacting C 2 -C 10 alkylene oxide and carbon dioxide at a CO 2 pressure ranging from 1 to 1,000 psi, a reaction temperature of 0 to 150° C. and a reaction time of 0.1 to 50 hours, in the presence of a catalyst which is compound of the first embodiment at alkylene oxide to catalyst ratio on a cobalt basis ranging from 200:1 to 100,000:1
In another embodiment, denoted the fourth embodiment, there is provided a method for preparing poly(C 2 -C 10 alkylene carbonate), e.g., poly(propylene carbonate), with less than 10% cyclic alkylene carbonate, e.g., cyclic propylene carbonate by-product, comprising the step of reacting C 2 -C 10 alkylene oxide, e.g., propylene oxide, and CO 2 at a CO 2 pressure ranging from 1 psi to 300 psi, a reaction temperature of 0 to 100° C., and a reaction time of 0.1 to 50 hours, e.g., 0.5 to 4 hours, in the presence of the catalyst system of the second embodiment, where the ratio of alkylene oxide to cocatalyst to catalyst ranges from 500-100,000:0.5-1.5:0.5-1.5
In another embodiment, denoted the fifth embodiment, there is provided poly(propylene carbonate) of M n ranging from 500 to 1,000,000 g/mol and polydispersity index (PDI) ranging from 1.05 to 5.0, e.g., 1.05 to 1.30, with greater than 90% head-to-tail linkages. In one case, the polymer has random stereochemistry. In another case, more than 90% of adjacent stereocenters have the same relative stereochemistry (isotactic).
In another embodiment, denoted the sixth embodiment, there is provided poly(propylene carbonate) of M n ranging from 500 to 1,000,000 g/mol and PDI ranging from 1.05 to 5.0, e.g., 1.05 to 1.30, where greater than 90% of the stereocenters are of the same stereochemistry.
The molecular weight of the polycarbonate can be increased within the stated range by longer polymerization times. The molecular weight of the polycarbonate can be decreased within the range by the addition of chain transfer agents in the form of carboxylic acids (e.g. pentafluorobenzoic acid), alcohols (e.g. methanol), dicarboxylic acids, diols, poly acids, polyols, and their deprotonated forms (e.g., sodium pentafluorobenzoate) and other additives known to promote chain transfer. The polymerization can also be conducted in solvent.
M n and PDI here are determined by gel permeation chromatography in tetrahydrofuran at 40° C., calibrated with polystyrene standards.
DETAILED DESCRIPTION
In an example of the first embodiment
in the structure (I) is selected from the group consisting of:
where R 5 and R 6 can be the same or different and are H, C 1 -C 20 alkyl, C 6 -C 20 aryl, halogen (e.g., F, Cl, Br, I), nitro, cyano, C 1 -C 20 alkoxy or amine.
X in the formula (I) can be selected, for example, from the group consisting of C 1 -C 20 alkyl, halogen (e.g., Cl, Br, I), C 1 -C 20 amido, cyano, azide, C 1 -C 20 alkyl carboxylate, C 6 -C 20 aryl carboxylate, C 1 -C 20 alkoxide and phenoxide.
In one case, the compounds have the structure:
where R is selected from the group consisting of Br, H and t Bu.
In an overlapping case, the compounds have the structure
where X is Br, Cl, I, OAc, OBzCF 3 (p-trifluoromethylbenzoate) or OBzF 5 where OBzF 5 is 2,3,4,5,6-pentafluorobenzoate. The compound of structure (VIII) where X is OBzF 5 is novel.
In still another case, the compounds have the structure
where R 11 is t Bu and R 10 is selected from the group consisting of H, Br and OMe; R 11 is Me and R 10 is H; or R 11 is CPh(CH 3 ) 2 and R 10 is CPh(CH 3 ) 2 . The compounds are novel.
In still another case, the compound has the structure
This compound is novel.
In yet another case, the compounds have the structure
where R 7 is Me, R 8 is H and R 9 is H; or where R 7 is Me, R 8 is Me and R 9 is H; or where R 7 is Ph, R 8 is H and R 9 is Ph.
The cobalt carboxylate compounds are made by adding oxygen and the appropriate carboxylic acid to the (salen)Co(II) complex. The cobalt halide compounds are made by reacting (salen)Co(III) tosylate complex with the appropriate sodium halide.
The term “salen” means any tetradentate ligand derived from a diamine and 2 equivalents of salicylaldeyde.
We turn now to the second embodiment.
Preferably the cocatalyst is a salt where the cation is
and the anion is selected from the group consisting of Cl − and OBzF 5 − where OBzF 5 is 2,3,4,5,6-pentafluorobenzoate. [PPN][OBzF 5 ] is novel.
Catalyst systems used in reactions set forth in working examples are: catalyst system where the catalyst has the structural Formula (VIII) where X is OBzF 5 and the cocatalyst is [PPN]Cl; catalyst system where the catalyst has the structural Formula (VIII) where X is Cl and the cocatalyst is [PPN][OBzF 5 ]; catalyst system where the catalyst has the structural formula (VIII) where X is Cl and the cocatalyst is [PPN]Cl; and catalyst system where the cocatalyst is NBu 4 Cl and the catalyst has the structural formula (VIII) where X is OBzF 5 .
The [PPN] carboxylate complexes can be prepared by reacting [PPN]X with the appropriate sodium carboxylate.
We turn now to the third embodiment herein.
Preferably the CO 2 pressure ranges from 10 to 850 psi, the reaction temperature ranges from 20 to 25° C., the reaction time ranges from 0.5 to 4 hours, the catalyst has the structure (VIII) where X is Br, Cl or OBzF 5 and the alkylene oxide to catalyst ratio on a cobalt basis ranges from 400:1 to 600:1.
The alkylene oxide used herein can be, for example, rac-propylene oxide, or enantiomercially enriched-propylene oxide, e.g., S-propylene oxide or R-propylene oxide. Other epoxides such as butene oxide or cyclohexene oxide can also be employed.
We turn now to the fourth embodiment herein.
In a preferred case, the catalyst has the structural formula (VIII) where X is Cl and the cocatalyst is [PPN][OBzF 5 ].
In the experiments carried out, the propylene oxide was rac-propylene oxide.
We turn now to the fifth embodiment herein.
The polymers of the fifth embodiment can be made by the method of the fourth embodiment and working examples are set forth hereinafter.
We turn now to the sixth embodiment herein. The polymers of the sixth embodiment can be made by the methods of the third and fourth embodiments and working examples are set forth in Qin, Z., et al, Angew. Chem. Ind. Ed. 42, 5484-5487 (2003) and in working examples hereinafter.
The polymers of the fifth and sixth embodiments can be produced as crystalline polymers. Crystalline polymers have the advantage that they are mechanically strong and resist thermal deformation.
The poly(propylene carbonates) produced herein can be converted to polyurethanes by reaction with polyacid, polyol or water to make a poly(propylene carbonate) with two or more OR groups which in turn would be reacted with a diisocyanate to prepare polyurethane.
The invention is illustrated in Qin, Z., et al., Angew. Chem. Int. Ed. 42, 5484-5487 (2003) and in working examples below.
Working Example I
Synthesis of (VII) Where R is Br [(R,R)-(salen-8)CoOAc]
First (R,R)-N,N′-bis(5-bromo-3-tert-butyl-salicylidene)-1,2-cyclohexanediamine, [(R,R)-(salen-8)H 2 ], was synthesized as follows:
Under an atmosphere of nitrogen, to an aqueous solution of (R,R)-1,2-diaminocyclohexane L-tartrate (1.321 g, 5.0 mmol) and K 2 CO 3 (1.382 g, 10.0 mmol) in water (10 mL) was added ethanol (50 mL). The mixture was heated to 80° C., and to it was dropwise added 5-bromo-3-tert-butyl-2-hydroxybenzaldehyde, prepared by a modification of the methods described in Cavazzini, M., et al., Eur. J. Org. Chem. (2001), 4639-4649 and Lam, F., et al., J. Org. Chem. 61, 8414-8418 (1996) (2.571 g, 10.0 mmol) in THF (10 mL), resulting a yellow solution. After the mixture was stirred for 2 h and cooled down to room temperature, water (150 mL) was added to precipitate yellow crude title compound. The precipitate was redissolved in diethyl ether (100 mL) and washed with brine (100 mL), water (100 mL), and dried over anhydrous Na 2 SO 4 , and then concentrated. A yellow crystalline product was obtained after recrystallization from ethanol. Yield: 2.60 g, 88%. 1 H NMR (CDCl 3 , 500 MHz) δ 13.80 (s, 2H), 8.18 (s, 2H), 7.31 (d, 4 J=2.0 Hz, 2H), 7.09 (d, 4 J=2.0 Hz, 2H), 3.33 (br, 2H), 2.00 (br, 2H), 1.90 (br, 2H), 1.75 (M, 2H), 1.47 (m, 2H), 1.38 (s, 18H), 13 C NMR (CDCl 3 , 125 MHz) δ 24.40, 39.31, 159.57, 164.68, LRMS (EI) Cald. 592, found 592.
(R,R)-N,N′-bis(5-bromo-3-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (ID), [(R,R)-(salen-8)Co], was prepared as follows:
To a solution of the ligand [(R,R)-(salen-8)H 2 ] (1.777 g, 3.0 mmol) in toluene (10 mL) under nitrogen was added a solution of Co(OAc) 2 (0.708 g, 4 mmol) in MeOH (10 mL) via a cannula, affording a dark red precipitate. The mixture was stirred at 80° C. for 2 h. After the reaction mixture was cooled down to room temperature and concentrated in vacuo, the residue was dissolved in CH 2 Cl 2 (50 mL) and passed through a celite pad to remove the excess Co(OAc)2. Removing solvent of the filtrate afforded a dark red powder. Yield: 1.85 g, 95%. The molecular structure of this complex was determined by single crystal X-ray diffraction.
(R,R)-N,N′-bis(5-bromo-3-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) acetate, [(R,R)-(salen-8)CoOAc] was prepared as follows:
To a solution of the [(R,R)-(salen-8)Co] (1.750 g, 2.70 mmol) in toluene (15 mL) and CH 2 Cl 2 (50 mL) was added acetic acid (1.62 g, 27.0 mmol). The solution quickly changed from red to brown. After 2 h, all solvents and excess acetic acid were removed and the residue was dried to constant weight under vacuum, quantitatively affording a brown powder. 1 H NMR (CD 2 Cl 2 , 400 MHz) δ 7.52 (s, 1H), 7.43 (br, 2H), 7.34 (d, 4 J=2.4 Hz, 1H), 7.32 (d, 4 J=2.4 Hz, 1H), 7.14 (s, 1H), 4.16 (m, 1H), 3.22 (M, 1H), 2.81 (M, 1H), 2.74 (M, 1H), 2.00 (M, 2H), 1.96 (br, 1H), 1.89 (br, 2H), 1.73 (M, 1H), 1.53 (s, 3H), 1.48 (s, 9H), 1.24 (s, 9H).
Working Example II
Synthesis of (VII) Where R is H, [(R,R)-(salen-7)CoOAc]
(R,R)-N,N′-Bis(3-tert-butyl-salicylidene)-1,2-cyclohexanediamine, [(R,R)-(salen-7)H 2 ] was prepared as described in Pospisil, P. J., et al., Chem. Eur. J. 2, 974-980 (1996).
(R,R)-N,N′-bis(3-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt, [(R,R)-(salen-7)Co] was prepared from [(R,R)-(salen-7)H 2 ] by a similar procedure to that used for [(salen-8)Co] in working Example I. The yield was 98%.
(R,R)-N,N′-bis(3-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) acetate, [(R,R)-(salen-7)CoOAc] was prepared in similar fashion to [(R,R)-(salen-8)CoOAc] except only toluene was used as solvent. A dark brown powder was obtained quantitatively. 1 H NMR (CD 2 Cl 2 , 400 MHz) δ 7.60 (s, 1H), 7.42 (s, 1H), 7.28 (s, 2H), 7.20 (s, 2H), 6.62 (s, 1H), 6.43 (s, 1H), 4.39 (s, 1H), 3.38 (s, 1H), 2.84 (br, 2H), 1.77-2.20 (br M, 6H), 1.56 (br, 12H), 1.38 (s, 9H).
Working Example III
Synthesis of (VII) Where R is t Bu and (VIII) Where X is OAc. [(R,R)-(salen-1)CoOAc]
(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) acetate, [(R,R)-(salen-1)CoOAc] is synthesized as described in Schaus, S. E., et al., J. Am. Chem. 124, 1307-1315 (2002) and Tokunaga, M., Science 277, 936-938 (1997). The material here was purchased from Strem.
Working Example IV
Copolymerizations
Copolymerizations of propylene oxide (PO) and CO 2 were carried out as follows using [(R,R)-(salen-8)CoOAc], the product of Working Example I, [(R,R)-(salen-7)CoOAc], the product of Working Example II, [(R,R)-(salen-1)CoOAc], the product of Working Example III, [Zn(BDI)OAc] prepared as described in Allen, S. D., et al., J. Am. Chem. Soc. 124, 14284-14285 (2002), Reference [14], and [Cr(salph)Cl] prepared as described in Darensbourg, D. J., et al., J. Am. Chem. Soc. 125, 7586-7591 (2003), Reference [16]:
General PO/CO 2 copolymerization Procedure: A glass tube equipped with a stir bar was charged with catalyst, and then was inserted into a pre-dried 100 mL Parr autoclave. After the assembled autoclave was evacuated under vacuum and refilled with nitrogen for three times, PO was added through a valve using a syringe. The autoclave was brought to appropriate temperature, and then pressurized to the appropriate pressure with CO 2 . After the allotted reaction time, the unreacted PO was recovered using vacuum transfer and analyzed by a chiral GC. A small amount of the residue was removed for 1 H NMR analysis. The crude polymer was dissolved in CH 2 Cl 2 (10-20 mL), and then a small amount of MeOH was added. The polymer was precipitated from diethyl ether, collected by filtration and dried in vacuo to constant weight.
Conditions and results are set forth in Table 1 below.
TABLE 1
Carbonate
Pressure
Temp
Time
TOF [b]
Selectivity
Linkages
M n [d]
PDI
Entry [a]
Catalyst
Epoxide
[PO]:[Cat]
(psi)
(° C.)
(h)
(h −1 )
(% PPC) [c]
(%) [c]
(g/mol)
(M w /M n )
1
[(R,R)-(salen-
rac-PO
500
800
25
3
81
>99
95
15 300
1.22
8)CoOAc]
2
[(R,R)-(salen-
rac-PO
500
600
25
3
19
>99
94
3100
2.60
8)CoOAc]
3
[(R,R)-(salen-
rac-PO
500
800
40
3
17
>99
90
5600
1.21
8)CoOAc]
4
[(R,R)-(salen-
rac-PO
500
800
30
3
69
>99
94
12 200
1.26
8)CoOAc]
5
[(R,R)-(salen-
rac-PO
500
800
20
3
42
>99
95
8000
1.44
8)CoOAc]
6
[(R,R)-(salen-
rac-PO
500
800
15
3
31
>99
95
7600
1.51
8)CoOAc]
7
[(R,R)-(salen-
rac-PO
200
800
25
3
51
>99
95
8200
1.25
8)CoOAc]
8
[(R,R)-salen-
rac-PO
2000
800
25
8
38
>99
95
21 700
1.41
8)CoOAc]
9
[(R,R)-(salen-
rac-PO
200
800
25
3
51
>99
96
6600
1.21
7)CoOAc]
10
[(R,R)-(salen-
rac-PO
500
800
25
3
66
>99
96
9000
1.31
7)CoOAc]
11
[(R,R)-(salen-
rac-PO
200
800
25
3
42
>99
99
5700
1.28
1)CoOAc]
12
[(R,R)-(salen-
rac-PO
500
800
25
3
59
>99
99
8100
1.57
1)CoOAc]
13
[(R,R)-(salen-
(S)-PO
500
800
25
3
71
>99
99
6900
1.58
1)CoOAc]
14 [e]
[Zn(BDI)OAc]
rac-PO
2000
300
25
2
184
87
99
35 900
1.11
15 [f]
[Cr(salph)Cl]
rac-PO
1500
490
75
4
160
71
98
16 700
1.38
All of the polymerizations were carried out in 3.5 mL of neat propylene oxide (PO).
[b] Turnover frequency of PO to PPC.
[c] Determined by using 1 H NMR spectroscopy.
[d] Determined by gel permeation chromatography in tetrahydrofuran at 40° C., calibrated with polystyrene standards.
[e] Reference [14].
[f] Reference [16].
As indicated by the percent selectivity (% PPC) for entries 1-13 of Table 1, cyclic propylene carbonate was not formed. [(R,R)-(salen-1)CoOAc] was found to be highly regioselective with 80% head to tail linkages. In contrast, the catalysts [(R,R)-(salen-8)CoOAc], [(R,R)-(salen-7)CoOAc] and [Zn (BDI) OAc] gave typical regioselectivities of 70, 75 and 60%, respectively.
Polymerization of (S)-propylene oxide with enantiomerically pure [(R,R)-(salen-1)CoOAc], entry 13 in Table 1, yielded isotactic (S) polymer with head-to-tail content of 93%.
Working Example V
Synthesis of (VIII) Where X is I[[(R,R)-(salen-1)CoI]
(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt [(R,R)-(salen-1)Co] was purchased from Aldrich and recrystallized from methylene chloride and methanol.
(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) iodide, [(R,R)-(salen-1)CoI] is synthesized as described in Nielsen, L. P. C.; Stevenson, C. P.; Blackmond, D. G.; Jacobsen, E. N. J. Am. Chem. Soc. 2004, 126, 1360-1362 with the substitution of NaI for NaCl. 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.32 (s, 18H) 1.63 (m, 2H), 1.76 (s, 18H), 1.91 (m, 2H), 2.02 (m, 2H), 3.10 (m, 2H), 3.66 (m, 2H), 7.45 (d, 4 J=2.5 Hz, 2H), 7.50 (d, 4 J=2.5 Hz, 2H), 7.83 (s, 2H). 13 C NMR (DMSO-d 6 , 1.25 MHz): δ 24.23, 29.54, 30.36, 31.49, 33.47, 35.71, 69.22, 118.59, 128.63, 129.16, 135.82, 141.74, 161.95, 164.49. Anal. Calcd for C 36 H 52 N 2 O 2 COI: C, 59.18; H, 7.17; N, 3.83. Found: C, 59.14; H, 7.05; N, 3.75.
Working Example VI
Synthesis of (VIII) Where X is Br [(R,R)-(salen-1)CoBr]
(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt [(R,R)-(salen-1)Co] was purchased from Aldrich and recrystallized from methylene chloride and methanol.
(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) bromide, [(R,R)-(salen-1)CoBr] is synthesized as described in Nielsen, L. P. C.; Stevenson, C. P.; Blackmond, D. G.; Jacobsen, E. N. J. Am. Chem. Soc. 2004, 126, 1360-1362 with the substitution of NaBr for NaCl. 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.30 (s, 18H), 1.58 (m, 2H), 1.74 (s, 18H), 1.92 (m, 2H), 2.00 (m, 2H), 3.06 (m, 2H), 3.59 (m, 2H), 7.44 (d, 4 J=3.0 Hz, 2H), 7.47 (d, 4 J=3.0 Hz, 2H), 7.83 (s, 2H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 24.32, 29.57, 30.43, 31.55, 33.58, 35.82, 69.32, 118.61, 128.78, 129.28, 135.87, 141.84, 162.11, 164.66. Anal. Calcd for C 36 H 52 N 2 O 2 CoBr: C, 63.25; H, 7.67; N, 4.10. Found: C, 63.05; H, 7.69; N, 4.06.
Working Example VII
Synthesis of (VIII) Where X is Cl[(R,R)-(salen-1)CoCl]
(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) chloride, [(R,R)-(salen-1)CoCl] was prepared as previously described described in Nielsen, L. P. C.; Stevenson, C. P.; Blackmond, D. G.; Jacobsen, E. N. J. Am. Chem. Soc. 2004, 126, 1360-1362. Additional characterization: 13 C NMR (DMSO-d 6 , 125 MHz): 624.34, 29.51, 30.40, 31.56, 33.51, 35.78, 69.27, 118.58, 128.78, 129.28, 135.86, 141.84, 162.08, 164.68.
Working Example VIII
Synthesis of (VIII) where X is OBzF 5 [(R,R)-(salen-1)CoOBzF 5 ]
(R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt [(R,R)-(salen-1)Co] was purchased from Aldrich and recrystallized from methylene chloride and methanol.
[(R,R)-(salen-1)Co] (1.2 g, 2.0 mmol) and pentafluorobenzoic acid (0.42 g, 2.0 mmol) were added to a 50 mL round-bottomed flask charged with a Teflon stir bar. Toluene (20 mL) was added to the reaction mixture, and it was stirred open to air at 22° C. for 12 h. The solvent was removed by rotary evaporation at 22° C., and the solid was suspended in 200 mL of pentane and filtered. The dark green crude material was dried in vacuo and collected in quantitative yield. 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.30 (s, 18H), 1.59 (m, 2H), 1.74 (s, 18H), 1.90 (m, 2H), 2.00 (m, 2H), 3.07 (m, 2H), 3.60 (m, 2H), 7.44 (d, 4 J=2.5 Hz, 2H), 7.47 (d, 4 J=3.0 Hz, 2H), 7.81 (s, 2H). 13 C NMR (DMSO-d 6 , 125 MHz): 824.39, 29.61, 30.13, 30.42, 31.55, 33.57, 35.83, 69.38, 118.59, 128.78, 129.29, 135.86, 141.83, 162.21, 164.66. Carbons on the phenyl group of pentafluorobenzoate were not assigned in the 13 C NMR spectrum owing to complex carbon fluorine splitting patterns. 19 F NMR (470 MHz, DMSO-d 6 ): δ-163.32 (m), −162.50 (m), −144.48 (m). Anal. Calcd for C 43 H 52 O 4 N 2 F 5 Co.H 2 O: C, 62.01; H, 6.54; N, 3.36. Found: C, 62.25; H, 6.38; N, 3.42.
Working Example IX
Synthesis of (IX) Where R 11 is t Bu and R 10 is H [(R,R)-(salen-7)CoBr]
(R,R)-N,N′-bis(3-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt [(R,R)-(salen-7)Co] is synthesized as described in Sun, W.; Xia, C.-G.; Zhao, P.-Q. J Mol Catal A: Chem 2002, 184, 51.
(R,R)-N,N′-bis(3-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) bromide [(R,R)-(salen-7)CoBr] was prepared as follows: [(R,R)-(Salen-7)Co] (470 mg, 0.96 mmol) and p-toluenesulfonic acid monohydrate (190 mg, 1.0 mmol) were added to a 50 mL round-bottomed flask with a Teflon stir bar, and 10 mL of methylene chloride was added. The mixture was stirred open to air for 1 h at 22° C., and the methylene chloride was removed in vacuo. The solid was suspended in pentane and filtered to afford the intermediate [(R,R)-(salen-7)CoOTs] (OTs=tosylate). This solid was dissolved in 25 mL of methylene chloride and added to a 100 mL separatory funnel. The organic layer was rinsed with saturated aqueous NaBr (3×25 mL). The organic layer was dried over Na 2 SO 4 , filtered and dried in vacuo. The crude material was suspended in pentane and filtered to afford the solid [(R,R)-(salen-7)CoBr] (210 mg, 38%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.59 (m, 2H), 1.73 (s, 18H), 1.90 (m, 2H), 2.01 (m, 2H), 3.06 (m, 2H), 3.60 (m, 2H), 6.59 (t, 3 J=7.0 Hz, 2H), 7.38 (d, 3 J=7.0 Hz, 2H), 7.49 (d, 3 J=7.0 Hz, 2H), 7.87 (s, 2H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 24.18, 29.49, 30.31, 35.62, 69.33, 114.47, 119.19, 131.17, 133.83, 142.49, 164.19, 164.37.
Working Example X
Synthesis of (IX) Where R 11 is t Bu and R 10 is Br [(R,R)-(salen-8)CoBr]
The procedure for the synthesis of [(R,R)-(salen-7)CoBr] was applied to the synthesis of (R,R)-N,N′-bis(5-bromo-3-tert-butylsalicylidene)-1,2-diaminocyclohexane cobalt (III) bromide (R,R)-(salen-8)CoBr; however, [(R,R)-(salen-8)Co] (synthesis described above) (360 mg, 0.56 mmol) and p-toluenesulfonic acid monohydrate (110 mg, 0.60 mmol) were stirred for 12 h in methylene chloride (10 mL). Following the salt metathesis with NaBr, the product (R,R)-(salen-8)CoBr was obtained (180 mg, 44%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.59 (m, 2H), 1.71 (s, 18H), 1.88 (m, 2H), 2.00 (m, 2H), 3.04 (m, 2H), 3.61 (m, 2H), 7.37 (d, 4 J=2.5 Hz, 2H), 7.80 (d, 4 J=2.5 Hz, 2H), 7.96 (s, 2H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 24.06, 29.51, 29.85, 35.78, 69.55, 104.97, 120.73, 133.45, 135.04, 145.16, 163.19, 164.22.
Working Example XI
Synthesis of (IX) Where R 11 is Me and R 10 is H [(R,R)-(salen-10)CoBr]
(R,R)-N,N′-Bis(3-methylsalicylidene)-1,2-diaminocyclohexane cobalt [(R,R)-(salen-10)Co] is synthesized as described in Szlyk, E.; Surdykowski, A.; Barwiolek, M.; Larsen, E. Polyhedron 2002, 21, 2711.
The procedure for the synthesis of [(R,R)-(salen-7)CoBr] was applied to the synthesis of (R,R)-N,N′-bis(3-methylsalicylidene)-1,2-diaminocyclohexane cobalt (III) bromide [(R,R)-(salen-10)CoBr], however; [(R,R)-(salen-10)Co] (210 mg, 0.52 mmol) and p-toluenesulfonic acid monohydrate (100 mg, 0.53 mmol) were stirred for 2 h in methylene chloride (20 mL). An excess of methylene chloride (200 mL) was used in the salt metathesis with NaBr in order to dissolve all of the [(R,R)-(salen-10)CoOTs] intermediate. Following this reaction, the product [(R,R)-(salen-10)CoBr] was obtained (170 mg, 67%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.57 (m, 2H), 1.86 (m, 2H), 1.99 (m, 2H), 2.64 (s, 6H), 3.05 (m, 2H), 3.63 (m, 2H), 6.58 (t, 3 J=7.0 Hz, 2H), 7.31 (d, 3 J=7.0 Hz, 2H), 7.48 (d, 3 J=7.0 Hz, 2H), 8.02 (s, 2H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 17.12, 24.17, 29.45, 69.60, 114.57, 117.89, 130.68, 132.86, 134.36, 163.32, 164.13.
Working Example XII
Synthesis of (IX) Where R 11 is CPh (CH 3 ), and R 10 is CPh (CH 3 ) 2 [(R,R)-(salen-11)CoBr]
3,5-Bis(α,α′-dimethylbenzyl)-2-hydroxybenzaldehyde was synthesized as described in A. E. Cherian, E. B. Lobkovsky and G. W. Coates, Macromolecules, 2005, 38, 6259-6268.
Synthesis of (R,R)-N,N′-bis(3,5-bis(α,α′-dimethylbenzyl)salicylidene)-1,2-diaminocyclohexane, [(R,R)-(salen-11)H 2 ]: (R,R)-1,2-Diaminocyclohexane-L-tartrate (0.74 g, 2.8 mmol) and K 2 CO 3 (0.77 g, 5.6 mmol) were stirred in H 2 O (8 mL) until all was dissolved. To it was added a solution of 3,5-bis(α,α′-dimethylbenzyl)-2-hydroxybenzaldehyde (2.0 g, 5.6 mmol) in ethyl alcohol (35 mL) and the mixture was refluxed for 3 h. The reaction mixture was then cooled to 22° C., filtered, and washed thoroughly with H 2 O and then with cold ethyl alcohol. The crude yellow solid was dried and collected (1.8 g, 81%). 1 H NMR (CDCl 3 , 500 MHz): δ 1.29 (m, 2H), 1.52 (m, 2H), 1.59 (s, 6H), 1.67 (s, 12H), 1.68 (s, 6H), 1.73 (m, 4H), 3.11 (m, 2H), 6.94 (d, 4 J=2.5 Hz, 2H), 7.16 (tt, 3 J=7.0 Hz, 4 J=1.5 Hz, 2H), 7.16-7.29 (m, 20H), 8.08 (s, 2H), 13.21 (broad s, 2H). 13 C NMR (CDCl 3 , 125 MHz): δ 24.31, 28.71, 30.38, 30.95, 31.04, 33.22, 42.25, 42.44, 72.25, 118.01, 125.11, 125.68, 125.70, 126.78, 127.74, 127.92, 128.11, 129.27, 135.82, 139.46, 150.64, 150.76, 157.77, 165.38. HRMS (ESI) m/z calcd (C 56 H 62 N 2 O 2 +H + ) 795.4890, found 795.4900.
Synthesis of (R,R)-N,N′-bis(3,5-bis(α,α′-dimethylbenzyl)salicylidene)-1,2-diaminocyclohexane cobalt, [(R,R)-(salen-11)Co]: [(R,R)-(salen-11)H 2 ] (0.69 g, 0.87 mmol) and cobalt acetate tetrahydrate (0.26 g, 1.0 mmol) were added to a Schlenk flask charged with a Teflon stir bar under N 2 . A 1:1 mixture of toluene and methanol (30 mL); (degassed for 20 min by sparging with dry N 2 ) was added and stirred at 22° C. for 2 h. The resultant red precipitate was filtered in air and washed with distilled water (50 mL) and methanol (50 mL) and collected as a crude solid (0.59 g, 80%). IR (KBr, cm −1 ): 766, 809, 1034, 1105, 1246, 1325, 1340, 1362, 1459, 1528, 1605, 2872, 2937, 2968, 3026, 3061, 3453. HRMS (ESD m/z calcd (C 56 H 60 CoN 2 O 2 ) 851.3987, found 851.3972.
Synthesis of (R,R)-N,N′-bis(3,5-bis(α,α′-dimethylbenzyl)salicylidene)-1,2-diaminocyclohexane cobalt (III) bromide, [(R,R)-(salen-11)CoBr]: [(R,R)-(salen-11)Co] (0.50 g, 0.59 mmol) and p-toluenesulfonic acid monohydrate (0.11 g, 0.59 mmol) were added to a 50 mL round bottomed flask charged with a Teflon stir bar. Methylene chloride (10 mL) was added to the reaction mixture and stirred for 2 h open to air at 22° C. The solvent was removed by rotary evaporation at 22° C., and the crude solid was washed with pentane (100 mL) and filtered. The crude material was dissolved in methylene chloride (25 mL) and added to a 125 mL separatory funnel. The organic layer was rinsed with saturated aqueous NaBr (3×25 mL). The organic layer was dried over Na 2 SO 4 and evaporated under reduced pressure. The solid was washed with pentane (100 mL) and filtered to afford [(R,R)-(salen-11)CoBr] (0.16 g, 29%).
Working Example XIII
Synthesis of (X)-[(salen-6)CoBr]
N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminophenylene cobalt, [(salen-6)Co] is synthesized as described in H. Shimakoshi, H. Takemoto, I. Aritome and Y. Hisaeda, Tetrahedron Lett., 2002, 43, 4809-4812.
Employing the same reaction conditions as for [(R,R)-(salen-11)CoBr], [(salen-6)Co] (1.0 g, 1.7 mmol) and p-toluenesulfonic acid monohydrate (0.32 g, 1.7 mmol) were used to produce N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminophenylene cobalt (III) bromide, [(salen-6)CoBr] (0.35 g, 30%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.35 (s, 18H), 1.78 (s, 18H), 7.55 (d, 4 J=2.5 Hz, 2H), 7.56 (td, 3 J=6.5 Hz, 4 J=3.5 Hz, 2H), 7.66 (d, 4 J=2.5 Hz, 2H), 8.63 (dd, 3 J=6.5 Hz, 4 J=3.5 Hz, 2H), 8.95 (s, 2H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 30.34, 31.34, 33.79, 36.01, 117.40, 117.45, 128.14, 129.97, 131.00, 136.59, 142.07, 144.72, 161.60, 165.59. HRMS (EI) m/z calcd (C 36 H 46 BrCoN 2 O 2 −Br) 597.2891, found 597.2878.
Working Example XIV
Synthesis of (XI) Where R 7 is Me R 8 is H and R 9 is H [(R)-(salen-2)CoBr]
(R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminopropane [(R)-(salen-2)H 2 ] was synthesized as described in D. J. Darensbourg, R. M. Mackiewicz, J. L. Rodgers, C. C. Fang, D. R. Billodeaux and J. H. Reibenspies, Inorg. Chem., 2004, 43, 6024-6034.
(R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminopropane cobalt [(R)-(salen-2)Co] was synthesized as follows: Employing the same reaction conditions as for [(R,R)-(salen-11)Co], [(R)-(salen-2)H 2 ] (2.8 g, 5.5 mmol) and cobalt acetate tetrahydrate (1.7 g, 6.8 mmol) in a 1:1 mixture of degassed toluene and methanol (150 mL) were used to afford a crude red solid (2.9 g, 95%). IR (KBr, cm −1 ): 787, 837, 874, 1179, 1204, 1255, 1320, 1361, 1385, 1466, 1528, 1596, 2871, 2909, 2956. HRMS (ESI) m/z calcd (C 33 H 48 CoN 2 O 2 ) 563.3048, found 563.3046.
(R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminopropane cobalt (III) bromide [(R)-(salen-2)CoBr] was synthesized as follows: [(R)-(salen-2)Co] (1.0 g, 1.8 mmol) and p-toluenesulfonic acid monohydrate (0.34 g, 1.8 mmol) were added to a 50 mL round-bottomed flask charged with a Teflon stir bar. Methylene chloride (30 mL) was added to the reaction mixture and stirred for 2 h open to air at 22° C. The solvent was removed by rotary evaporation at 22° C., and the crude dark green solid was dissolved in pentane (50 mL) and filtered. The solvent was removed by rotary evaporation, and the material was dissolved in methylene chloride (50 mL) and added to a 250 mL separatory funnel. The organic layer was shaken vigorously with saturated aqueous NaBr (3×50 mL). The organic layer was dried over Na 2 SO 4 and evaporated under reduced pressure. The solid was suspended in pentane and filtered to afford a crude black solid (0.50 g, 43%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.30 (s, 18H), 1.61 (d, 3 J=6.5 Hz, 3H), 1.73 (s, 18H), 3.86 (m, 1H), 4.21 (m, 1H), 4.32 (m, 1H), 7.33 (d, 4 J=2.0 Hz, 1H), 7.40 (d, 4 J=2.0 Hz, 1H), 7.44 (s, 1H), 7.45 (s, 1H), 7.93 (s, 1H), 8.09 (s, 1H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 18.45, 30.34, 30.38, 31.51, 31.54, 33.39, 33.43, 35.71, 35.73, 62.99, 64.57, 118.57, 118.88, 128.15, 128.67, 128.74, 128.82, 135.84, 136.01, 141.73, 142.01, 161.67, 161.94, 167.03, 168.55. HRMS (EI) m/z calcd. (C 33 H 48 BrCoN 2 O 2 −Br) 563.3048, found 563.3037.
Working Example XV
Synthesis of (XI) Where R 7 , R 8 and R 9 are H [(salen-3)CoBr]
N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminoethane cobalt [(salen-3)Co] was synthesized as described in B. Rhodes, S. Rowling, P. Tidswell, S. Woodward and S. M. Brown, J Mol Catal A: Chem, 1997, 116, 375-384.
Synthesis of N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminoethane cobalt (III) bromide [(salen-3)CoBr]: Employing the same reaction conditions as for [(R,R)-(salen-2)CoBr], [(salen-3)Co] (0.30 g, 0.55 mmol) and p-toluenesulfonic acid monohydrate (0.10 g, 0.55 mmol) were used. Following the salt metathesis with NaBr, the crude product [(salen-5)CoBr] was obtained (86 mg, 25%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.30 (s, 18H), 1.73 (s, 18H), 4.14 (s, 4H), 7.31 (d, 4 J=3.0 Hz, 2H), 7.45 (d, 4 J=3.0 Hz, 2H), 8.12 (s, 2H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 30.36, 31.52, 33.43, 35.77, 58.24, 118.51, 128.27, 128.74, 135.93, 142.05, 162.13, 168.65. HRMS (EI) m/z calcd (C 32 H 46 BrCoN 2 O 2 −Br) 549.2891, found 549.2885.
Working Example XVI
Synthesis of (XI) Where R 7 is Me, R 8 is Me and R 9 is H [(salen-4)CoBr]
Synthesis of N,N′-bis(3,5-di-tert-butylsalicylidene)-2-methyl-1,2-diaminopropane [(salen-4)H 2 ]: To a solution of 3,5-di-tert-butyl-2-hydroxybenzaldehyde (3.0 g, 13 mmol) in ethyl alcohol (60 mL) was added 2-methyl-1,2-propanediamine (0.67 mL, 6.4 mmol) and the mixture was refluxed for 3 h. The reaction was cooled to 22° C., and the solvent was removed in vacuo. The crude yellow solid was recrystalized from ethyl alcohol at −20° C. affording yellow needles (3.1 g, 93%). 1 H NMR (CDCl 3 , 500 MHz): δ 1.28 (s, 9H), 1.29 (s, 9H), 1.43 (s, 24H), 3.71 (s, 2H), 7.07 (d, 4 J=4.5 Hz, 1H), 7.09 (d, 4 J=4.5 Hz, 1H), 7.35 (d, 4 J=4.5 Hz, 1H), 7.36 (d, 4 J=4.5 Hz, 1H), 8.35 (s, 1H), 8.39 (s, 1H) 13.67 (s, 1H), 14.21 (s, 1H). 13 C NMR (CDCl 3 , 125 MHz): δ 25.73, 29.60, 29.63, 31.63, 31.66, 34.26, 35.17, 35.19, 60.14, 70.71, 117.99, 118.08, 126.22, 126.35, 126.90, 127.18, 136.78, 136.80, 139.98, 140.12, 158.32, 158.52, 162.88, 167.78. HRMS (ESI) m/z calcd (C 34 H 52 N 2 O 2 +H + ) 521.4107, found 521.4110.
Synthesis of N,N′-bis(3,5-di-tert-butylsalicylidene)-2-methyl-1,2-diaminopropane cobalt [(Salen-4)Co]: [(Salen-4)H 2 ] (2.3 g, 4.4 mmol) and cobalt acetate tetrahydrate (1.3 g, 5.2 mmol) were added to a Schlenk flask charged with a Teflon stir bar under N 2 . A 1:1 mixture of toluene and methanol (100 mL); (degassed for 20 min by sparging with dry N 2 ) was added and stirred at 22° C. for 2 h. The resultant red precipitate was filtered in air and washed with distilled water (50 mL) and methanol (50 mL) and collected as a crude solid (2.3 g, 90% yield). IR (KBr, cm −1 ): 786, 842, 871, 1178, 1255, 1318, 1363, 1390, 1464, 1528, 1595, 2870, 2909, 2959. HRMS (ESI) m/z calcd (C 34 H 50 CoN 2 O 2 ) 577.3204, found 577.3226.
Synthesis of N,N′-bis(3,5-di-tert-butylsalicylidene)-2-methyl-1,2-diaminopropane cobalt (III) bromide [(salen-4)CoBr]: [(salen-4)Co] (0.30 g, 0.52 mmol) and p-toluenesulfonic acid monohydrate (99 mg, 0.52 mmol) were added to a 50 mL round-bottomed flask charged with a Teflon stir bar. Methylene chloride (30 mL) was added to the reaction mixture and stirred for 2 h open to air at 22° C. The solvent was removed by rotary evaporation at 22° C., and the crude dark green solid was dissolved in pentane (50 mL) and filtered. The solvent was removed by rotary evaporation, and the material was dissolved in methylene chloride (50 mL) and added to a 250 mL separatory funnel. The organic layer was shaken vigorously with saturated aqueous NaBr (3×50 mL). The organic layer was dried over Na 2 SO 4 and evaporated under reduced pressure. The solid was suspended in pentane and filtered to afford a crude black solid (92 mg, 27%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.30 (s, 9H), 1.32 (s, 9H), 1.63 (s, 6H), 1.73 (s, 9H), 1.74 (s, 9H), 4.02 (s, 2H), 7.36 (d, 4 J=2.5 Hz, 1H), 7.45 (d, 4 J=2.5 Hz, 1H), 7.475 (s, 1H), 7.482 (s, 1H), 7.88 (s, 1H), 8.03 (s, 1H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 27.10, 30.35, 31.28, 31.32, 31.55, 31.61, 33.43, 33.50, 35.72, 35.77, 66.98, 70.93, 118.36, 119.57, 128.05, 128.75, 128.98, 129.35, 135.85, 136.41, 141.42, 142.12, 161.11, 161.96, 166.31, 168.37. HRMS (EI) m/z calcd (C 34 H 50 BrCoN 2 O 2 −Br) 577.3204, found 577.3199.
Working Example XVII
Synthesis of (XI) Where R 7 is Ph, R 8 is H and R 9 is Ph, [(R,R)-(salen-5)CoBr]
The synthesis of (R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethyienediamino cobalt (II) [(R,R)-(salen-5)Co] is described in T. Fukuda and T. Katsuki, Tetrahedron, 1997, 53, 7201-7208.
Synthesis of (R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethylenediamino cobalt (III) bromide [(R,R)-(salen-5)CoBr]: [(R,R)-(salen-5)Co] (0.25 g, 0.36 mmol) and p-toluenesulfonic acid monohydrate (68 mg, 0.36 mmol) were added to a 50 mL round bottomed flask charged with a Teflon stir bar. Methylene chloride (10 mL) was added to the reaction mixture and stirred for 2 h open to air at 22° C. The solvent was removed by rotary evaporation at 22° C., and the crude solid was washed with pentane (100 mL) and filtered. The crude material was dissolved in methylene chloride (25 mL) and added to a 125 mL separatory funnel. The organic layer was rinsed with saturated aqueous NaBr (3×25 mL). The organic layer was dried over Na 2 SO 4 and evaporated under reduced pressure. The solid was washed with pentane (100 mL) and filtered to afford (R,R)-(salen-5)CoBr (0.12 g, 43%). 1 H NMR (DMSO-d 6 , 500 MHz): δ 1.22 (s, 18H), 1.76 (s, 18H), 5.62 (s, 2H), 6.97 (s, 2H), 7.23 (s, 2H), 7.41-7.48 (m, 12H). 13 C NMR (DMSO-d 6 , 125 MHz): δ 30.37, 31.35, 33.31, 35.73, 76.61, 117.64, 128.48, 129.18, 129.90, 134.93, 136.07, 142.02, 162.31, 166.50. HRMS (EI) m/z calcd. (C 44 H 54 BrCoN 2 O 2 −Br) 701.3517 found 701.3502.
Working Example XVII
Application of [PPN]Cl, [PPh 4 ]Cl, [PPh 4 Br], [NBu 4 Cl]
Bis(triphenylphosphine)iminium chloride ([PPN]Cl), tetraphenylphosphonium chloride [PPh 4 Cl], tetraphenylphosphonium chloride [PPh 4 Cl] were purchased from commercial sources and recrystallized from dry methylene chloride and diethyl ether under nitrogen before use. Tetrabutylamonium chloride [NBu 4 ]Cl was purchased from commercial sources and used as received. The synthesis of bis(triphenylphosphine)iminium tetraphenyl borate [PPN][BPh 4 ] is described in Reibenspies, J. H. Z. Kristallogr. 1994, 209, 620-621. Prakash, H.; Sisler, H. H. Inorg. Chem. 1968, 7, 2200-2203.
Working Example XIX
Synthesis of [PPN][OBzF 5 ]
Synthesis of bis(triphenylphosphine)iminium pentafluorobenzoate ([PPN][OBzF 5 ]): NaOH (0.19 g, 4.7 mmol) and pentafluorobenzoic acid (1.0 g, 4.7 mmol) were added to a 50 mL round-bottomed flask charged with a Teflon stir bar. Distilled H 2 O (20 mL) was added to the reaction mixture, and it was stirred until all was dissolved. The solution was added to a 250 mL separatory funnel along with [PPN]Cl (0.40 g, 0.70 mmol) and methylene chloride (40 mL), and the mixture was shaken vigorously for 10 min. The organic layer was collected and dried by rotary evaporation to yield crude [PPN][OBzF 5 ] in quantitative yield. Precipitation from dry methylene chloride and diethyl ether under N 2 at −20° C. afforded a white powder (0.35 g, 67%). 1 H NMR (CDCl 3 , 500 MHz): δ 7.39-7.46 (m, 24H), 7.60-7.63 (m, 6H). 13 C NMR (CDCl 3 , 125 MHz): δ 116.93, 126.91 (dd, 1 J P-C =108.0 Hz, 3 J P-C =1.5 Hz), 129.55 (m), 132.02 (m), 133.88, 137.07 (d of m, 1 J F-C =255.5 Hz), 139.92 (d of m, 1 J F-C =250.3 Hz), 143.24 (d of m, 1 J F-C =247.3 Hz), 161.21. 19 F NMR (470 MHz, CDCl 3 ): δ−164.64 (m), −159.92 (broad s), −142.52 (m). Anal. Calcd for C 43 H 30 F 5 NO 2 P 2 : C, 68.89; H, 4.03; N, 1.87. Found: C, 69.07; H, 3.95; N, 1.83.
Working Example XX
Copolymers Made Using [(R,R)-(salen-1)CoI] and [(R,R)-(salen-1)CoOAc]
Copolymerizations were carried out with conditions and results set forth in Table 2 below:
TABLE 2
Theoretical
Reaction
Time
Yield b
TOF c
M n d
M n e
Head-to-Tail
Entry
Complex
Conditions
(h)
(%)
(h −1 )
(kg/mol)
(kg/mol)
M w /M n e
Linkages f (%)
1
[(R,R)-(salen-1)CoI]
air-free
5
43
43
21.9
19.6
1.15
79
2
(R,R)-(salen-1)CoI
ambient
5
37
37
18.9
9.5
1.33
81
3
(R,R)-(salen-
air-free
2
30
74
15.1
15.5
1.16
83
1)CoOAc
4
(R,R)-(salen-
ambient
2
25
62
12.7
10.4
1.31
83
1)CoOAc
a Polymerizations run in neat rac-propylene oxide (PO) with [PO]/[Co] = 500:1 at 22° C. with 800 psi of CO 2 . Selectivity for poly(propylene carbonate) (PPC) over propylene carbonate was >99% in all cases. All product PPC contains ≧96% carbonate linkages as determined by 1 H NMR spectroscopy.
b Based on isolated polymer yield.
c Turnover frequency (TOF) = mol PO · mol Co −1 · h −1 .
d Theoretical number average molecular weight (M n ) = TOF · h · 102 g/mol.
e Determined by gel permeation chromatography calibrated with polystyrene standards in THF.
f Determined by 13 C NMR spectroscopy.
As shown in Table 2, the runs in an inert atmosphere (entries 1 and 3) gave higher M n and lower PDI than the same reactions carried out in air (entries 2 and 4).
Working Example XXI
Copolymerizations Using [(R,R)-(salen-1)CoI], [(R,R)-(salen-1)CoBr], [(R,R)-(salen-1)CoCl], [(R,R)-(salen-1)CoOAc] and [(R,R)-(salen-1)CoOBzF 5 ]
Copolymerizations were carried out with conditions and results set forth in Table 3 below:
TABLE 3
Yield b
TOF c
M n d
Head-to-Tail
Entry
Complex
(%)
(h −1 )
(kg/mol)
M w /M n d
Linkages e (%)
1
[(R,R)-(salen-1)CoOAc]
30
75
15.5
1.16
83
2
[(R,R)-(salen-1)CoBzF 5 ]
32
80
14.1
1.22
82
3
[(R,R)-(salen-1)CoCl]
26
65
13.4
1.19
82
4
[(R,R)-(salen-1)CoBr]
36
90
21.0
1.14
82
5
[(R,R)-(salen-1)CoI]
13
32
10.4
1.17
85
6
[(R,R)-(salen-1)CoI] + [(R,R)-
28
70
16.2
1.24
81
(salen-1)CoBr] (50:1)
a Polymerizations run in neat rac-propylene oxide (PO) with [PO]/[Co] = 500:1 at 22° C. with 800 psi of CO 2 for 2 h. Selectivity for poly(propylene carbonate) (PPC) over propylene carbonate was >99% in all cases. All product PPC contains ≧92% carbonate linkages as determined by 1 H NMR spectroscopy.
b Based on isolated polymer yield.
c Turnover frequency (TOF) = mol PO · mol Co −1 · h −1 .
d Determined by gel permeation chromatography calibrated with polystyrene standards in THF.
e Determined by 13 C NMR spectroscopy. [OBzF 5 ] = pentafluorobenzoate.
As shown in Table 3, all the initiating groups tested, gave high molecular weight polycarbonate with narrow molecular weight distributions. Complex [(R,R)-(salen-1)CoI] provided the lowest TOF whereas complex [(R,R)-(salen-1)CoBr] provided the highest TOF.
Working Example XXII
Using [(R,R)-(salen-1)CoBr] and Varying Reaction Conditions
Copolymerizations were carried out with conditions and results set forth in Table 4 below:
TABLE 4
carbonate
time
yield
TOF b
selectivity c
linkages c
M n d
head to tail e
entry
(h)
(%)
(h −1 )
(% PPC)
(%)
(kg/mol)
PDI
(%)
1
1
20%
99
>99:1
98%
12.6
1.07
82%
2
2
36%
89
>99:1
97%
21.0
1.14
82%
3
3
38%
62
>99:1
97%
20.2
1.15
81%
4 f
8
19%
47
>99:1
97%
16.6
1.18
81%
5 g
10
12%
6
>99:1
91%
7.2
1.15
85%
6 h
2
49%
121
>99:1
20.1
1.21
Reaction conditions: 800 psi CO 2 , 22° C., 1 mL of neat rac-PO, [PO]/[Co] = 500.
b Turnover frequency = (mol PO/(mol Zn•h)).
c Determined by 1 H NMR spectroscopy.
d Determined by gel permeation chromatography in tetrahydrofuran at 40° C. relative to polystyrene standards.
e Determined by 13 C NMR spectroscopy.
f [PO]/[Co] = 2000.
g 0° C.
h S-PO was used instead of rac-PO.
As shown in Table 4, increasing the time of polymerization increases molecular weight while slightly decreasing activities (entries 1-3) while more dilute reaction conditions decrease the catalyst activity (entry 4) as does lowering the reaction temperature to 0° C. (entry 5). As indicated by comparison of entries 2 and 6, the activity is enhanced if enantiomerically pure S—PO is used instead of racemic PO.
Working Example XXIII
Effect of Change of Catalyst Backbone on Copolymerizations
Copolymerizations were carried out with conditions and results set forth in Table 5 below:
TABLE 5
Yield
TOF
Carbonate
M n
Head-to-Tail
Entry
Catalyst
(%) b
(h −1 ) c
Linkages (%) d
(kg/mol) e
M w /M n e
Linkages (%) f
1
[(R,R)-(salen-1)CoBr]
38
63
97
20.2
1.15
81
2
[(R)-(salen-2)CoBr]
32
53
97
13.9
1.18
82
3 g
[(salen-3)CoBr]
0
0
NA
NA
NA
NA
4
[(salen-4)CoBr]
38
63
>99
21.1
1.16
85
5
[(R,R)-(salen-5)CoBr]
12
20
99
10.1
1.14
76
6
[(salen-6)CoBr]
14
23
89
11.3
1.29
79
7
[(R,R)-(salen-7)CoBr]
33
55
96
15.2
1.13
76
8
[(R,R)-(salen-8)CoBr]
43
72
94
35.8
1.15
70
9 g
[(R,R)-(salen-9)CoBr]
0
0
NA
NA
NA
NA
10
[(R,R)-(salen-
8
13
69
4.5
1.12
80
10)CoBr]
11
[(R,R)-(salen-
11
18
>99
9.1
1.13
89
11)CoBr]
a Copolymerizations were run in neat rac-propylene oxide (PO) with [PO]:[Co] = 500:1 at 22° C. with 800 psi of CO 2 for 3 h. Selectivity for poly(propylene carbonate) (PPC) over propylene carbonate was >99:1 for entries 1-10, and 97:3 for entry 11.
b Based on isolated PPC yield.
c Turnover frequency for PPC (mol PO · (mol Co) −1 · h −1 ).
d Determined by 1 H NMR spectroscopy.
e Determined by GPC.
f Determined by 13 C NMR spectroscopy.
g Entries 1 and 4 produced the best results.
Working Example XXIV
Effect of Different Relative Levels of PPNCl Co-catalyst on Copolymerization Results
Copolymerizations were carried out with variations and results as set forth in Tables 6 and 7 below:
TABLE 6
Yield b
TOF c
Selectivity d
M n e
Head-to-Tail
Entry
Complex
(%)
(h −1 )
(% PPC)
(kg/mol)
M w /M n e
Linkages f (%)
1
[(R,R)-(salen-1)CoOAc]
11
110
86
7.9
1.15
93
2
[(R,R)-(salen-
52
520
>99
43.0
1.10
93
1)CoOBzF 5 ]
3
[(R,R)-(salen-1)CoCl]
43
430
>99
35.4
1.09
95
4
[(R,R)-(salen-1)CoBr]
46
460
89
33.2
1.09
95
a Polymerizations run in neat rac-propylene oxide (PO) with [PO]:[[PPN]Cl]:[Co] = 2000:1:1 at 22° C. with 200 psi of CO 2 for 2 h. All product poly(propylene carbonate) (PPC) contains ≧98% carbonate linkages as determined by 1 H NMR spectroscopy.
b Based on isolated polymer yield.
c Turnover frequency = mol PO · mol Co −1 · h −1 .
d Selectivity for PPC over propylene carbonate.
e Determined by gel permeation chromatography calibrated with polystyrene standards in THF.
f Determined by 13 C NMR spectroscopy. [PPN] = bis (triphenylphosphine)iminium. [OBzF 5 ] = pentafluorobenzoate.
TABLE 7
PO:[PPN]Cl:[(R,R)-
(salen-
Time
Yield b
TOF c
Selectivity d
M n e
Head-to-Tail
Entry
1)CoOBzF 5 ]
(h)
(%)
(h −1 )
(% PPC)
(kg/mol)
M w /M n e
Linkages f (%)
1
2000:1:1
1
31
640
99
26.8
1.13
94
2
2000:1:1
2
52
520
>99
43.0
1.10
93
3
2000:1:1
6
59
200
56
41.4
1.36
93
4
2000:2:1
2
53
530
97
33.9
1.08
93
5
2000:0.5:1
2
36
360
>99
46.3
1.07
94
a Polymerizations run in neat rac-propylene oxide (PO) at 22° C. with 200 psi of CO 2 . All product poly(propylene carbonate) (PPC) contains ≧98% carbonate linkages as determined by 1 H NMR spectroscopy.
b Based on isolated polymer yield.
c Turnover frequency = mol PO · mol Co −1 · h −1 .
d Selectivity for PPC over propylene carbonate.
e Determined by gel permeation chromatography calibrated with polystyrene standards in THF.
f Determined by 13 C NMR spectroscopy. [PPN] = bis(triphenylphosphine)iminium. [OBzF 5 ] =
Working Example XXV
Effect of Cocatalyst
Copolymerizations were carried out with variations in catalyst and co-catalyst with results as set forth in Table 8 below:
TABLE 8
Time
Yield
Selectivity
M n
M w /
Head-to-Tail
Entry a
Cocatalyst
(h)
(%) b
TOF(h −1 ) c
PPC:PC d
(kg/mol)
M n
Linkages (%)
1
None
24
trace
NA
NA
NA
NA
NA
2
[PPN][BPh 4 ]
24
trace
NA
NA
NA
NA
NA
3
[PPN]Cl
0.5
30
600
99:1
9.8
1.18
94
4
[PPN][OBzF 5 ]
0.5
36
720
>99:1
15.9
1.16
94
5
[PPh 4 ]Br
0.5
24
480
96:4
6
[PPh 4 ]Cl
0.5
25
550
97:3
8.6
1.19
94
7
[n-Bu 4 N]Cl
2
29
150
>99:1
6.6
1.15
93
8
N(CH 2 CH 3 ) 3
2
38
190
>99:1
18.5
1.17
9
N((CH 2 ) 7 CH 3 ) 3
2
35
175
>99:1
18.1
1.14
93
a Polymerizations run with catalyst [(R,R)-(salen-1)CoOBzF 5 ] in neat rac-PO with [PO]:[Co]:[cocatalyst]= 1000:1:1 at 22° C. with 100 psi of CO 2 .
b based on isolated PPC yield.
c TOF for PPC.
d Selectivity for PPC over PC.
e [PO]:[Co]:[cocatalyst] = 2000:1:1.
f [PO]:[Co]:[cocatalyst] = 500:1:1.
Working Example XXVI
Copolymerization at 10 psi of CO 2
The [(R,R)-(salen-1)CoOBzF 5 /[PPN]Cl catalyzed PO/CO 2 copolymerization carried out at 10 psi resulted in a TOF of 160 h −1 , affording 32% yield of PPC.
Working Example XXVII
Use of R 1 substituted ethylene oxides in the copolymerization using [(R,R)-(salen-1)CoOBzF 5 ]/[PPN]Cl
TABLE 9 Carbonate Time Yield b TOF d Linkages e M n f Head-to-Tail Entry R 1 (h) (%) Polymer:Cyclic c (h −1 ) (%) (kg/mol) M w /M n f Linkages g (%) 1 CH 2 OCH 3 6 56 85:15 93 4.7 1.42 2 CH 2 OPh 8 40 92:8 50 13.1 1.19 3 CH 2 OSi t Bu(CH 3 ) 2 50 90 81:19 2 45.4 1.15 87 4 h CH═CH 2 48 58 91:9 24 >99 44.8 1.15 52 5 i CH 2 CH 3 2 39 95:5 194 98 24.1 1.15 >99 6 CH 2 CH 2 CH 2 CH 3 6 58 74:26 97 94 20.7 1.22 7 H 2 80 99:1 400 80 32.1 1.18 NA a All reactions were performed in neat rac-epoxide with catalyst [(R,R)-(salen-1)CoOBzF 5 ] and cocatalyst [PPN]Cl with [epoxide]:[Co]:[[PPN]Cl] = 1000:1:1 at 22° C. with 100 psi of CO 2 unless otherwise noted. b Based on total polymer + cyclic carbonate.
Variations
The foregoing description of the invention has been presented describing certain operable and preferred embodiments. It is not intended that the invention should be so limited since variations and modifications thereof will be obvious to the skilled in the art, all of which are within the spirit and scope of the invention.
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Poly(propylene carbonates) are prepared from propylene oxide and CO 2 with less than 10% cyclic propylene carbonate by product using cobalt based catalysts of structure
preferably in combination with salt cocatalyst, very preferably cocatalyst where the cation is PPN + and the anion is Cl − or OBzF 5 − . Novel products include poly(propylene carbonates) having a stereoregularity greater than 90% and/or a regioregularity of greater than 90%.
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BACKGROUND OF THE INVENTION
The present invention relates to an inkjet printing head, and more particularly to an inkjet printing head for ejecting the ink by means of piezoelectric devices.
Among non-impact printing methods, the inkjet printing method does not create a noise when printing, prints on normal sheets of paper, and does not require a special setting of the ink, and is therefore considered a method for simple printing accomplished by a simply structured apparatus. Therefore, in the recent years the inkjet printing method has been on the way to its most active development. In the case of this method, a printing head having an ejecting hole is provided for ejecting dyed liquid, to thereby propel droplets thereof. Here, an inlet hole for receiving the liquid is utilized.
Of such inkjet printing heads, the drop-on-demand type printing head for ejecting the ink only upon the signal input, has certain variations. Among these, a Kyser type printing head disclosed in U.S. Pat. No. 3,946,398, is one in that the ink channel is connected to the nozzle, and the piezoelectric device being combined with a bimetal is arranged on one side of the channel, so that the piezoelectric device deforms only when supplied with a voltage. Therefore, liquid ink is even more pressurized in the channel, to ultimately eject the ink through the nozzle. However, such a printing head shows a disadvantage in that the nozzle cannot be fabricated for high-integration due to the size of the piezoelectric device and thus the manufacturing cost rises.
Being different from the Kyser type printing head, the Fischbeck type printing head disclosed in U.S. Pat. No. 4,584,590 is one that utilizes a principle of shear deformation of the piezoelectric device in the electrical field. Here, the piezoelectric device constituting a wall of the channel deforms toward the channel, so that the ink within the channel is forced to be ejected through the nozzle. Such a printing head exhibits a disadvantage in that the nozzle cannot be used for high-integration due to its structural cause.
Another type of printing head, using a shear deformation, is the Bartky type disclosed in U.S. Pat. No. 4,879,568. In this type, the piezoelectric device is arranged parallel to the electrical field for its shear deformation, so that the printing density of the nozzle can be enhanced. However, such a printing head also provides a disadvantage in that the contact portion is easily disrupted due to the tension stress occurring on the contact portion by a deformation (mainly related to the piezoelectric constant) other than shear deformation generated since the manufacture the piezoelectric devices. Moreover, the above printing head has another disadvantage in that the contact portion is easily disrupted by a tension stress thereon, even if the piezoelectric device is combined with an electrode for mass production.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an inkjet printing head capable of being manufactured with ease and capable of a multi-nozzle formation for high-printing density.
It is another object of the present invention to provide an inkjet printing head which utilizes tensile and compressive deformations as well as the shear deformation so as to minimize the tension stress on the contact portion between the piezoelectric device and the supporting plate, and which therefore can be used for increasing the lifetime of the printing head.
To accomplish the above object, the present invention provides an inkjet printing head comprising upper and lower plates having a predetermined interval therebetween; a nozzle arranged on a wall connecting the upper plate with the lower plate for ejecting ink droplets; a channel connected to the nozzle for transmitting the pressure wave towards the nozzle so as to eject the ink droplets; at least one piezoelectric device installed on the channel, having shear, tensile and compressive modes, and attached to the upper and lower plates by its upper and lower parts; and a piezoelectric actuator having a composite mode of the shear, tensile and compressive modes and having an electrode for supplying an electrical field for the piezoelectric device.
BRIEF DESCRIPTION OF THE DRAWINGS
The above object and other advantages of the present invention will become more apparent by describing in detail a preferred embodiment of the present invention with reference to the attached drawings in which:
FIG. 1 is a schematic side view of an inkjet printing head according to the present invention;
FIG. 2 is a sectional view along line 2--2 of FIG. 1;
FIG. 3 illustrates operation of the printing head according to the present invention;
FIGS. 4 and 5 are a sectional view of the printing head according to another embodiment of the present invention and a sectional view illustrating the operation thereof, respectively;
FIGS. 6 and 7 are a sectional view of the printing head according to still another embodiment of the present invention and a sectional view illustrating the operation thereof, respectively;
FIGS. 8 and 9 are a sectional view of the printing head according to yet another embodiment of the present invention and a sectional view illustrating the operation thereof, respectively;
FIGS. 10 and 11 are a sectional view of the printing head according to still a further embodiment of the present invention and a sectional view illustrating the operation thereof, respectively;
FIGS. 12 and 13 are a sectional view of the printing head according to yet another embodiment of the present invention and a sectional view illustrating the operation thereof, respectively; and
FIGS. 14 and 15 are a sectional view of the printing head according to yet a further embodiment of the present invention and a sectional view illustrating the operation thereof, respectively.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, an upper plate 3 and a lower plate 2 having a predetermined interval therebetween is interposed by a fixed wall 12 and an actuator 103, thereby a channel is formed between the upper and lower plates. The actuator is comprised of two plates, i.e., upper and lower piezoelectric devices 16 and 13, which are arranged longitudinally end to end. A second electrode 18 is interposed between two piezoelectric devices, and a lower piezoelectric device 13 is furnished with third and fourth electrodes 14 and 15 on its sides. A first electrode 17 is formed beneath upper plate 3, and the first electrode corresponds to the second electrode. Here, the upper and lower piezoelectric devices are polarized longitudinally, while their polarization directions are indicated by reference numerals 19 and 20 (FIG. 3).
Referring to FIG. 1, one side of the channel is connected with ink supplying means 6 for supplying ink for the channel with a predetermined pressure, and the other side thereof is furnished with a nozzle plate 4 having a nozzle for ejecting the ink. Here, reference numeral 8 indicates a meniscus caused by a surface tension of ink, and reference numeral 11 denotes an ink droplet attached to the paper.
The operation of the printing head according to the present invention is described in reference to FIG. 3. When only third and fourth electrodes 14 and 15 are supplied with voltage V 1 without the application of voltage V 2 between the first and second electrodes 17 and 18, an electrical field is formed perpendicular to the polarization direction 19 of lower piezoelectric device 13. Therefore, lower piezoelectric device 13 deforms in the direction of the electrical field by means of the shear deformation thereof and, at this moment, a tensile stress is generated at contact portions 101 and 102.
To help remove the tensile stress, another electrical field is formed parallel to the polarization direction 19 by applying voltage V 2 between the upper and lower electrodes, first and second electrodes 17 and 18, of upper piezoelectric device 16 elongated parallel to its length. Therefore, the tensile stress at the contact portions 101 and 102 due to the deformation of lower piezoelectric device 13 is eradicated. Thus, the life of the overall head can be extended by means of the compensating operation of the upper piezoelectric device.
FIGS. 4 through 13 are schematic views of the printing head according to other embodiments of the present invention and views thereof while in operation. Here, the structure of the printing head is same as that of FIGS. 1 and 2 except for the piezoelectric actuator and the electrode.
In accordance with an embodiment of the present invention shown in FIGS. 4 and 5, the second and third electrodes which are separately formed as shown in FIG. 2, are combined with each other so as to form a fifth electrode 22. Here, a piezoelectric actuator 104 comprises the upper and lower piezoelectric devices 16 and 13 having the polarization directions 25 and 26 (FIG. 5) along their lengths, respectively. A horizontal part 18' of fifth electrode 22 is interposed between piezoelectric devices 16 and 13, and a first electrode 17 is formed beneath upper plate 3. A fourth electrode 15 is formed on one side of lower piezoelectric device 13, which opposes to the vertical portion of fifth electrode 22.
FIG. 5 is a view showing the actuator in operation, which is constructed as shown in FIG. 4. When a voltage V 3 is applied between the fourth and fifth electrodes and a voltage V 4 is applied between the first and fifth electrodes, the operation of the actuator is same as in the aforementioned embodiment shown in FIGS. 1 through 3. That is, when voltage V 4 is not applied between first and fifth electrodes 17 and 22, but voltage V 3 is applied between fourth and fifth electrodes 15 and 22, an electrical field is formed vertical to the polarization direction 26 of lower piezoelectric device 13; and thereby a shear deformation deforms lower piezoelectric device 13 in the direction of electrical field as shown in FIG. 5.
At this time, a tensile stress is produced at contact portions 101 and 102. To help remove the tensile stress, a voltage V 2 is simultaneously applied between the upper and lower electrodes, first and fifth electrodes 17 and 22, of tipper piezoelectric device 16, and thereby an electrical field is formed in parallel to the polarization direction 25. Accordingly, the upper piezoelectric device is elongated lengthwise, so that the tensile stress at contact portions 101 and 102 due to the deformation of lower piezoelectric device 13 is canceled.
FIG. 6 illustrates the printing head according to the third embodiment of the present invention, which is more simply constructed by making the piezoelectric actuator using one piezoelectric device. The piezoelectric actuator is comprised of a piezoelectric device 27 which is polarized along the polarization direction 30 parallel to its length, and two electrodes 28 and 29 which are of different lengths and attached to either side of the piezoelectric device so as to oppose each other. The actuator is interposed between the upper and lower plates 3 and 2, as in the other embodiments.
FIG. 7 shows the actuator of FIG. 6 in operation. Due to voltage V 5 , piezoelectric device 27 deforms in a shear mode along the direction of the electrical field which is caused by voltage V 5 . Due to voltage V 6 , an electrical field is formed between long electrode 29 and upper electrode 17, so that a part of piezoelectric device 27 is elongated lengthwise and, thereby, the tensile stress on a contact portion between the upper and lower plates is reduced.
FIG. 8 illustrates a fourth embodiment of the printing head according to the present invention. Here, piezoelectric actuator 106 is comprised of an tipper piezoelectric device 31 which is latitudinally polarized in the direction of polarization direction 38 and combined with a pair of upper electrodes 32 and 33 on either side thereof, and a lower piezoelectric device 34 which is longitudinally polarized in the polarization direction 39 and combined with a pair of lower electrodes 35 and 36 on either side thereof, while the upper and lower piezoelectric devices 31 and 34 are attached lengthwise end to end.
FIG. 9 illustrates an operation of the printing head according to the fourth embodiment of the present invention shown in FIG. 8. Here, the deformations in the longitudinal direction of the piezoelectric devices due to voltages V 7 and V 8 reduce the stresses on contact portions 101 and 102.
FIG. 10 shows a fifth embodiment of the printing head according to the present invention, wherein actuator 107 is constructed such that the upper and lower electrodes in the above embodiment is combined on one side. The actuator is comprised of all upper piezoelectric device 40 which is latitudinally polarized in the direction 45 and a lower piezoelectric device 43 which is longitudinally polarized in the direction 46 and is positioned between the upper and lower plates 3 and 2, while the upper and lower piezoelectric devices are combined with each other end to end. The actuator is equipped with a common electrode 41 on one side thereof, and with electrodes 42 and 44 corresponding to upper and lower piezoelectric devices 40 and 43 on the upper and lower parts of the other side thereof.
FIG. 11 illustrates an operation of the piezoelectric actuator according to the fifth embodiment of the printing head of the present invention, while the operational principle thereof is same as the fourth embodiment.
FIG. 12 illustrates a sixth embodiment of the present invention, showing a piezoelectric actuator 108 having a similar structure as the third embodiment of FIGS. 6 and 7. The piezoelectric actuator 108 is comprised of a piezoelectric device 47 which is polarized in any direction, and a pair of electrodes 48 and 49 of different lengths attached to either side of the piezoelectric device.
FIG. 13 illustrates an operation of the aforementioned piezoelectric actuator. The actuator deforms in a shear mode at its lower part due to the electrical field which is formed in a latitudinal direction 50 affected by voltage V 11 , and deforms lengthwise at the upper part due to the electrical field which is formed longitudinally by voltage V 12 . Therefore, the stresses at the contact portions between the piezoelectric devices and the upper and lower plates can be reduced to a minimum level.
So far, only those embodiments wherein just one wall of channel 7 is made of a piezoelectric actuator have been described. However, two or more channel walls can be made of a piezoelectric actuator.
All embodiment thus constructed is illustrated in FIG. 14. Piezoelectric actuator 109 has the same structure as piezoelectric actuator 103 shown in FIG. 2, except that two actuators 103 are arranged in parallel so as to constitute a channel.
FIG. 15 illustrates an operation of the actuator shown in FIG. 14, in which the operating principle is same as in FIG. 3.
As described above, the printing head of the present invention comprises an actuator having the combination of a shear mode, a tension mode and a compression mode. Accordingly, the breakage of the contact portion between the piezoelectric devices and the upper and lower plates can be prevented by the stress concentration occurring on the contact plane, and, as a result, the life of the head can be extended further.
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Inkjet printing head utilizing a shear mode and, simultaneously, tension and compression modes for effectively preventing damage to the contact interface of the piezoelectric device, includes at least one piezoelectric device installed on a pressure channel, having shear, tension and compression modes and combined with the upper and lower plates of the channel, the piezoelectric device having electrodes supplying an electrical field thereof.
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