A system and method for controlling a shared memory bus in a computer of a multi-processor system prevents collisions on the shared bus and ensures that the bus is full at system start-up. Steady state operations are maintained without the need for a queuing mechanism in the system's memory controller and in view of the memory modules of the shared memory having different read access times, with the system and method being implemented in a system that includes a central unit and multiple uni-directional buses that are disposed between a shared memory and a plurality of processors, with the central unit controlling access to, and use of, the shared buses of the system.

In computer systems, it is common for one or more processors to access a memory, referred to as a "shared memory". Also, the shared memory may be a memory array that contains a number of memory modules. Access to the shared memory is generally over a shared memory bus. One such system is disclosed in copending application Ser. No. 07/546,547, entitled "HIGH SPEED BUS SYSTEM" filed on even date herewith.
Two separate uni-directional buses may connect a shared memory or memory array to a memory controller. One bus is for transmissions from the memory controller to the array and the second is for transmissions from the memory array to the memory controller.
The memory controller, in turn, may interface with a bus system that connects to memories of the system processors. This bus system may include a bidirectional bus or two uni-directional buses, with one for transmissions from the memory controller to the processor memories and the other for transmissions from the processor memories to the memory controller.
A characteristic of a system having a shared memory and number of processors is that one of the processors can issue a read command followed by an address, which when placed on the bus system is supplied not only to the memory controller but also to all of the other processors connected to the bus. This increases the system's processing speed by avoiding the need for the processor to separately notify each of the other processors.
After the memory controller receives the read command and address, it places this on the unidirectional bus between it and the memory array. The memory array responds by providing refill data on the other uni-directional bus between the memory controller and the memory array. The refill data is then placed on the bus system that supplies such data to all of the processors including, of course, the processor that requested it.
A consideration in the design of shared memory systems involving the request for, and receipt of, data from memory is memory latency, i.e., the period between the placing of a command on a bus and the returning of refill data from the memory on the bus. Without consideration of memory latency, this entire request and refill data scheme will not operate effectively since the system may not be able to handle the number of requests that are made resulting in collisions on the shared memory bus.
Most activities in any system, which include shared memory systems, require one or more cycles to complete. Typically, activities take more than one cycle and the required number of cycles vary depending on the dynamic conditions. Since this is the case, there is a strong possibility that simply placing commands and data on a common bus without controlling them may result in collisions on such a bus. Thus, such shared memory systems must have a means to prevent such collisions.
Another compounding factor is that in a single or multiprocessor system, there can be a plurality of successive read commands sent to memory. Each includes a command and an address. These read commands can be issued at a rate that exceeds the ability of the system to supply the refill data because of things such as memory latency.
Some shared memory systems include a number of state machines that are used to control placement of commands and addresses on the shared bus leading from the memory controller to the memory array. The number of state machines usually determine the number of commands and addresses a system is capable of handling at one time. Each of these separate commands and addresses that are being handled by a separate state machine, however, must be directed to different memory modules of the memory array.
If more than that number of commands and addresses are sent than can be handled by the state machines, they will be waiting for memory access at the memory controller. The memory controller, therefore, must have a queueing mechanism to handle them. Implementation of such a mechanism at the memory controller or dramatically increasing the number of state machines to expand system capabilities adds to system complexity and cost. Hence, it is desirable to accomplish memory accesses without the need to make these costly implementations.
Another consideration is a desire to efficiently use a shared bus. Normally unused or empty cycles occur between blocks of refill data on the shared bus. Preferably there should be no dead space or time on the bus. At a steady state operating condition, after each predetermined number of cycles of refill data are placed on the bus, a predetermined number of cycles of read commands and addresses should follow, immediately followed by another predetermined number of cycles of refill data. However, the elimination of dead space has to be done without causing collisions and without implementing a costly queuing mechanism.
Many systems also include a cache memory system which further complicates the collision problem. In such systems, each time a memory command and address are sent out, a check must be made to see if the requested information is contained in a cache memory of one of the system processors. If the data is found, that processor must be given access to the shared bus that links the processors, and links the processors to the memory controller. When this access is given, it will prevent other read commands from being sent out on that bus. Thus, systems must consider cache memory reads ("snoopy reads") in collision analysis.
A further complicating factor is that systems typically do not have just one type of memory in a memory array, but many types. These different memories have different read access times and, therefore, different memory latencies since read access time is part of memory latency. It follows that any method or scheme for memory bus control that depends upon a fixed timing schedule for placing commands and data on a shared bus will result in collisions on that bus. Hence there must be a method of memory bus control that considers the read access time in placing commands and addresses, and refill data on a shared memory bus.
There is a need for a memory bus control system that will overcome these problems.

Method of controlling a shared memory bus in a multiprocessor system for preventing bus collisions and for ensuring a full bus


A metal detector system includes two transmitter-receiver antenna pairs supported by respective side panels of a portal. The relative positions of an adjacent transmitter antenna and receiver antenna within an antenna pair may be adjusted to calibrate the antennas, such as by crossing adjacent antennas or by increasing the distance between adjacent antennas.

Pass-through metal detectors are used in the security access control field to screen people and objects passing through a portal at airports, courts, prisons, passenger ships, nuclear facilities, and other high-security areas, as well as to screen against employee theft, contamination and other purposes. Known metal detectors generally include one transmitter coil of one or more windings in an elongated symmetrical shape located in a panel on one side of the portal. The transmitter coil generally generates a pulsed magnetic field, which excites eddy currents in metal objects passing through the portal. Located in a panel on the opposite side of the portal is either one or a pair of receiver coils which are similar in size and shape to the transmitter coil. These receiver coils receive the magnetic field created by the eddy currents in the metal objects passing through the portal, as well as the magnetic field created by the transmitter coil.
A receiver antenna may include two identical receiver coils disposed in essentially the same plane and wound in opposite directions so that any signal that has equal amplitude through both coils, such as some forms of signal noise, are subtracted. This arrangement significantly reduces noise. The output of the receiver coils is connected to a resistor-capacitor circuit that creates a damped oscillating signal at the end of each transmitter pulse. A control circuit then processes this signal to amplify the eddy currents and to detect variations in the magnetic field caused by the moving metal. The circuit continuously compares the signal level to a threshold set by the operator, and triggers an alarm when the threshold is exceeded. The panels containing the coils may be connected at their tops with a crosspiece wide enough to permit passage.
Sheets of conductive metal (shields) are sometimes used on the outside of metal detectors to better prevent metal objects that are moving on the outside of the portal from being detected. The large eddy currents created in the metal shields can be much larger than the signal from the metal objects themselves, and can change the balance of the two coils, causing a very large output signal and saturation of the circuit.
Referring to FIG. 1, there is shown a schematic diagram of a metal detector of the prior art. Two receiver coils L1 and L2 are connected at their inner terminals to form a dual-coil receiver antenna. An outer terminal of receiver coil L1 is connected to an outer terminal of a resistor R1, a first terminal of a capacitor C1, and to a first input of a differential amplifier 1. Similarly, an outer terminal of receiver coil L2 is connected to an outer terminal of a resistor R2, a second terminal of capacitor C1, and to a second input of differential amplifier 1. The inner terminals of resistor R1 and resistor R2 are connected to each other, as well as to the inner terminals of receiver coil L1 and receiver coil L2. Together, the two receiver coils L1 and L2, resistors R1 and R2, capacitor C1 and differential amplifier 1 form a receiver 102.
An output of differential amplifier 1 is connected to an input of a control unit 2, an output of which is connected to an input of an amplifier 3. Finally, each of two outputs of amplifier 3 is connected to a respective terminal of a transmitter coil (transmitter antenna) L3. Together, the transmitter coil L3 and amplifier 3 form a transmitter 101.
The two receiver coils L1 and L2 are wound in opposite directions so that signals going through one coil are subtracted from signals going through the other coil. Because most electrical noise sources are a relatively long distance away, the noise through receiver coil L1 is approximately equal to the noise through receiver coil L2, i.e., the difference is approximately zero, and thus noise is reduced. This system of noise reduction operates without any active components and with signals of any amplitude.
The resistor-capacitor (RC) network including R1, R2, and C1 forms an oscillating circuit, which transmits a damped oscillating signal to differential amplifier 1. The oscillation starts when a pulse from the transmitter coil L3 ends. Amplifier 3 provides a pulse to transmitter coil L3 to form a magnetic field which creates eddy currents in a metal object (not shown) passing through a detection area 4. The control unit 2 performs various control functions, such as processing signals from the receiver, and controlling the transmitter timing.
Referring now to FIG. 2, there is shown a portion of the metal detector of the prior art of FIG. 1 disposed in a portal. The portal 201 includes a side panel 202 and a side panel 203, which are connected at the top by a crosspiece 204 wide enough to permit passage of a person. Side panel 202 contains the transmitter coil L3, while side panel 203 contains the two receiver coils L1 and L2.
A two-sided metal detector is known from U.S. Pat. No. 4,779,048, which describes a metal detector in which field coils and receiving coils are arranged on either side of a zone to be monitored. The field coil on one side and the field coil on the other side are alternately excited for radiating a magnetic field.
One problem with this system is that the indiscriminate placement of a transmitter antenna and a receiver antenna in a transmitter-receiver pair will cause the receiver to receive a much larger signal from the adjacent transmitter (i.e., the transmitter in the pair) than from the opposite transmitter, undesirably affecting the receiver's output. The indiscriminate placement may even create high output voltages caused by a field through one of the receiver coils being much larger than a field through the other receiver coil, so that the voltage difference between the coils is very large.
This system may attempt to overcome this high noise problem through the use of an analog switch (not shown). However, doing so chops the receiver signal and causes harmonics that affect the filtering of the signal. Moreover, when the receiver voltage is several volts, saturation and even damage to the system is possible. In order for damped oscillations to decrease to a safe level, a delay time would be too large to allow timely acquisition of the signal. High cost and resistance of the switch also cause problems with this technique. The system is very noisy, and may exhibit especially low detection in a zone approximately midway between the sides of the passage, resulting in a high false alarm rate.
It is an object of the present invention to provide a metal detector system and method of calibrating and operating a metal detector system which allows more information to be cleanly sensed and processed, among other advantages.

Metal detector system having multiple, adjustable transmitter and receiver antennas


A induction exhaust system, for an internal combustion engine, capable of the multi step processes of 1) scavenging the chamber of exhaust gases and free radicals, 2) breaking the scavenge vacuum wave behind each energetic exhaust pulse, releasing said free radicals and the overscavenged air fuel vacuumed from the intake manifold during valve overlap, and 3) induction of such free radicals, unburned fuel, and fresh matter including atmospheric air. Such multi step process 1) relatively improves the fuel efficiency of such engines by reducing the wasted potential energy normally expelled by exhaust systems; unburned fuel, sound pressure energy, waste heat energy, energy rich free radicals formed by incomplete combustion, and energy rich catalytic converter products rich in potential energy that can be further combusted via induction, 2) increases catalytic converter efficiency by forcing unburned air fuel and free radicals to make multiple passes through such converter, thereby increasing residency time, 3) reduces emissions of undesirable compounds and free radicals via induction, 4) improves relative effective octane rating of fuel used by creating a unique composition of matter that acts to refract and reflect sonic detonation shock waves, disrupting and disbursing them, reducing detonation, thereby improving combustion efficiency, and 5) allows a new means to direct combustion process products and/or remove undesirable products, and/or introduce desirable matter into a combustion chamber, allowing further alteration of such unique composition of matter layered on top of such engine's prime mover combustion surface, and 6)including an adaptive means to dynamically optimize its function.

1. Technical Field
This invention relates generally to exhaust systems for internal combustion engines.
2. Description of Related Art
In the early days of exhaust development, when flat head engines were common, scavenge resonant exhaust systems helped to remove residual exhaust gases from the combustion chamber & helped to initiate intake flow into the combustion chamber. Scavenge has evolved into expanding tube extractors, anti-reversion mufflers and structures to prevent loss of scavenge vacuum at low rpms. During this time, cylinder head design has evolved from flat heads to overhead designs incorporating three, four, five and even eight valve per cylinder designs. Combining state of the art scavenge technology with state of the art head designs creates "overscavenge;" a situation where raw, unburned air fuel is swept through the combustion chamber during valve overlap, and out of the tail pipe. Horsepower is lost due to reduced dynamic cylinder pressure. Fuel economy is lost due to the quantity of fuel and free radicals left unburned. Emissions increase as unburned matter is vacuumed out of the engine into the atmosphere. Catalytic converters were added in 1975 to incinerate such unburned products; restricting flow while emitting cyanide (CN—) compounds.


A molded plastic package for an integrated-circuit die includes a lead frame having a central die-attach paddle. One side of the die-attach paddle has an integrated-circuit die fixed thereto. A heat sink member is resiliently fixed to the other side of the die-attach paddle using a layer of viscous thermal grease between the heat sink member and the other side of the die-attach paddle. One or more holes are formed in the lead frame and are engaged by corresponding studs on the heat sink. The stud has a shoulder portion which engages the lead frame to prevent the stud from further passing through the hole in the lead frame.

1. Field of the Invention
This invention relates to packaging techniques for integrated circuits and, more particularly, to molded plastic packages in which a heat sink is included.
2. Prior Art
A heat sink is attached directly to a die-attach paddle of a lead frame using one of a number of conventional attachment techniques, including welding, soldering, brazing, and adhesive-bonding.
An example of an integrated-circuit package which uses a heat sink is shown in a U.S. Pat. No. 3,930,114, invented by R. Hodge and granted Dec. 30, 1975. The Hodge patent shows an integrated-circuit chip fixedly secured to the upper surface of a die-attachment pad. An elongated copper heat sink is brazed to the under side of the die-attachment pad. The Hodge patent provides a pair of L-shaped flexible fingers which forces the heat sink against the lower surface of a mold so that the lower, exposed surface of the heat sink is pressed against the surface of the mold and no molten plastic can penetrate onto the normally exposed surface of the heat sink. This eliminates the need to grind away hardened encapsulent material to expose the surface of the copper heat sink.
Using conventional attachment techniques to rigidly attach a heat sink to a lead frame for an integrated circuit may raise several problems, particularly if dissimilar materials are used. One of these problems is the dissimilarity in the temperature coefficients of expansion (TCE) for the different materials used in the lead frame, the heat sink, and sometimes the attachment material. These differences in the temperature coefficients of expansion are important because of the possible reliability problems caused when stresses are built up in a package assembly at various temperature due to the differences in the TCE's. Restrictions on selection of material to avoid dissimilarities in TCE's may preclude using the best materials possible for particular functions. For example, copper or a copper alloy is a good material for a lead frame and aluminum or an aluminum alloy is a good material for a heat sink. The TCE's (in units of 10.sup.-7 /degree Centigrade) for various materials are: copper: 170; Cu/W alloy: 70; Cu/Mo: 72; and aluminum: 230.
Another problem is the extra cost incurred in using special tooling and special materials for a package with a heat sink, as compared to the standard cost incurred in using a standard package without heat sinks. For example, a package mold designed for use with an aluminum alloy leadframe cannot be used with copper lead frames. High tensile strength copper is typically more expensive than A142 aluminum alloy or aluminum.
Another cost item is that heat sinks must be prefabricated and attached to the lead frame at the lead frame manufacturing site. This increases the need for additional inventories of lead frames with heat sinks and lead frames without heat sinks at an assembly sites to accommodate needs for both types of lead frames. This also requires that additional raw materials be stocked at a lead frame manufacturing sites.
Various types of drop-in or floating heatsink designs have addressed the problems associated with the inventory problems and problems associated with dissimilarities in the temperature coefficients of expansion (TCE) for the different materials. These drop-in heatsinks sometimes fail to provide positive thermal coupling between a lead frame and a heatsink. Too large of a gap between the drop-in heatsink and the lead frame allows molding compound to fill the space between the lead frame and the heatsink. Because the molding compound is a thermal insulator, the thermal efficiency of the package can be affected. Too small of a gap between the drop-in heatsink and the lead frame can create a trapped air space. The trapped air space is also a thermal insulator and can be a source of unreliability because moisture tends to gather in the trapped air pocket. An additional concern with a drop-in or floating heatsink design is called pad tilting. Molding compound injected into a mold cavity at a high velocity can differentially fill the gap between the heatsink and the lead frame. This creates pad tilt which creates a reliability problem for plastic quad packages with high pin counts.
The need has arisen for an economical integrated-circuit packaging technique which provides a standardized lead frame which can be mechanically isolated from an optionally used heat sink.

Apparatus and method for thermally coupling a heat sink to a lead frame


Pressure hardware for a seal block assembly used to form a modular, annular seal around a conduit passing through a wall, the assembly including elastomer seal blocks joined in an annulus around the conduit, the seal blocks having pressure bolt apertures parallel to the conduit; the seal blocks are axially compressed and radially expanded to form the seal. The assembly includes pressure hardware in sets each including a bolt, a matching nut, and a first molded resin pressure plate that has a recess large enough for the bolt head to seat in freely rotatable relation in it, with peripheral access for a wrench around the bolt head; a washer is rotatably positioned in the bottom of the recess, which is deep enough so that the bolt head does not project substantially out of the recess. The first pressure plate has a bolt-receiving aperture large enough to admit the bolt rod but small enough to block the bolt head. A second molded resin pressure plate has a socket complementary to the nut, so that the nut seats it in non-rotatable relation; the second pressure plate also has a bolt-receiving aperture to admit the distal end of the bolt rod into engagement with the nut.

A modular seal assembly that has become a standard device for positive, hydrostatic sealing of the annular space between a pipe or other conduit and a passage or casing through which the conduit extends, usually traversing a wall, is described in Barton U.S. Pat. No. 3,528,668 issued Sept. 15, 1970. Variations of that modular seal construction are disclosed in Barton U.S. Pat. No. 3,649,034 issued Mar. 14, 1972 and in Gignac U.S. Pat. No. 3,703,297 issued Nov. 21, 1972. These annular seals are each made up of a plurality of individual elastomer seal blocks faced with two sets of pressure plates. Bolts that interconnect the pressure plates may also join the blocks in a ring structure surrounding the conduit where it passes through a wall. The bolts are utilized to pull the pressure plates toward each other, once the annular seal structure is in place, compressing the elastomer seal blocks in a direction parallel to of the conduit and expanding the seal blocks radially outwardly in the space between the conduit and the wall passage or other passage. In this way a highly versatile and economical seal structure is formed with a single set of components that may be used for many different conduit sizes. Many years of rugged on-the-job use have demonstrated that this modular, annular conduit-to-wall-opening seal is far superior to most other seal structures.
Despite their proven versatility and value, the modular, annular seals of the aforementioned Barton and Gignac patents, particularly U.S. Pat. No. 3,528,668, have demonstrated some technical difficulties. In large sizes, particularly, the weight of the overall assembly is substantial and may make it difficult for workmen to install, especially due to the use of relatively large and heavy metal components in the pressure hardware that joins and expands/contracts the elastomer seal blocks. The pressure hardware, particularly metal components, have usually entailed non-standard members, so that costs tend to be higher than desirable. At the same time, the exposed metal, in some environments, may be susceptible to undesirable corrosion, particularly galvanic corrosion. The strength of the seal may be less than desirable in some instances. And perhaps the most important problem encountered with these seals pertains to consistency of the required expansion/contraction during installation. It has been difficult if not impossible to specify the tightening of the pressure hardware required to attain the desired positive sealing effect without over-stressing that hardware or some other component of the seal assembly.

Pressure hardware for a modular inter-wall elastomer seal


An optoelectronic integrated circuit includes an N.sup.+ type cladding layer, an N type cladding layer, an active layer smaller in band gap than the N type cladding layer and a P type waveguide greater in band gap than the active layer sequentially formed on a semi-insulating substrate, a P type cladding layer partially formed on the surface of the P type waveguide, a laser composed of these N.sup.+ type and N type cladding layers, active layer, waveguide and P type cladding layer, and an N type emitted layer wider in band gap than the P type waveguide formed partially on the surface of the P type waveguide, thereby composing a heterojunction bipolar transistor using the N type cladding layer as the collector and the P type waveguide as the base.

This invention relates to an optoelectronic integrated circuit (OEIC) having a semiconductor laser, light emitting diodes and other light emitting devices, and heterojunction bipolar transistors (HBTs) and other electronic devices for driving these light emitting devices integrated on a same substrate.
The optoelectronic integrated circuit having a semiconductor laser, light emitting diodes and other light emitting devices, and heterojunction bipolar transistors and other electronic devices for driving these light emitting devices integrated on a same substrate is expected to be high in performance, high in reliability and low in price as the light source to be used in long distance optical fiber communication using local area network (LAN) and silica glass fiber, and high speed data communication by optical fibers between computers. Various methods have been proposed for the OEIC. For example, as disclosed in Applied Physics Letters, pp. 191-193, vol. 45 (published 1984), a conventional device integrating a buried heterostructure (BH) laser and a heterojunction bipolar transistor is known. The method of fabrication and structure of this prior art are described below. As shown in FIG. 4A, in order to form a double heterojunction (DH) on an N type InP substrate 301, an N type InP cladding layer 302 (carrier density 5.times.10.sup.17 cm.sup.-3, thickness 5 .mu.m), an InGaAsP active layer 303 (band gap wavelength .lambda.g=1.3 .mu.m, thickness 0.15 .mu.m), and a P type InP cladding layer 304 (carrier density 5.times.10.sup.17 cm.sup.-3, thickness 2.5 .mu.m), and a P type InGaAsP contact layer 305 (band gap wavelength .lambda.g=1.3 .mu., thickness 0.5 .mu.m) are sequentially formed by liquid phase epitaxy (LPE) technique. A silicon dioxide film (SiO.sub.2 film) 306 formed in a thickness of 50 nm by a thermal chemical vapor deposition (CVD) method is formed in stripe in a width of, for example, 7 .mu.m, and using this silicon dioxide film 306 as the mask, a dove-tail shaped mesa 307 is formed as shown in FIG. 4B with the bromine diluted to 2 wt. % by methanol. Afterwards, by the liquid phase epitaxial method, the dove-tail shaped mesa 307 is sequentially (buried up) with a P type InP separation layer 311 (carrier density 1.times.10.sup.17 cm.sup.-3, thickness 1 .mu.m), an N type InP collector layer 312 (carrier density 1.times.10.sup.17 cm.sup.-3, thickness 2 .mu.m), a P type InGaAsP base layer 313 (band gap wavelength .lambda.g=1.1 .mu.m, carrier density 1.times.10.sup.17 cm.sup.-3, thickness 0.3 .mu.m), and an N type InP emitter layer 314 (carrier density 5.times.10.sup.17 cm.sup.-3, thickness 0.7 .mu.m), an N type InGaAsP emitter contact layer 315 (band gap wavelength .lambda.g=1.3 .mu.m, carrier density 1.times.10.sup.17 cm.sup.-3, thickness 0.5 .mu.m) (FIG. 4C).
In the next step, a 200 nm thick silicon nitride film (Si.sub.3 N.sub.4 film) is deposited by plasma-assisted CVD method on the surface of laser part 316 and emitter contact layer 315 in the heterojunction bipolar transistor part 317, and using it as the mask, the emitter contact layer 315 is selectively etched by a mixed solution of H.sub.2 SO.sub.4 :H.sub.2 O.sub.2 :H.sub.2 O=1:1:5. Next, using a newly deposited 300 nm thick silicon nitride film 318 as the mask, the emitter layer 314 and base layer 313 are selectively etched by a mixed solution of HCl:H.sub.3 PO.sub.4 =1:2 and a mixed solution of H.sub.2 SO.sub.4 :H.sub.2 O.sub.2 :H.sub.2 O=1:1:5 respectively, and a mesa of the laser part 316 and the transistor part 317 is formed, so that the shape as shown in FIG. 4D is obtained.
Furthermore, using the newly deposited 300 nm thick silicon nitride film 319 and 200 nm thick silicon dioxide film 320 as the mask by opening holes in these two films, a P type impurity Zn is diffused for 1 hour at 500.degree. C. until reaching a P type InP separation layer 311 in a fused silica ampule using ZnP.sub.2 as diffusion source, and a isolation region 321 for electric isolation between heterojunction bipolar transistors is formed. Further opening holes in the graft base of the two films 319, 320, a P type impurity Zn is diffused for 10 minutes at 500.degree. C. until reaching or passing through the base layer 313 in a fused silica ampule using ZnP.sub.2 as diffusion source, thereby forming a graft base region 322 as shown in FIG. 4E.
After completely removing the two films 319, 320, a 400 nm thick silicon dioxide film 323 is deposited, and 10/15/300 nm thick Au/Sn/Au is evaporated, and an emitter electrode 324 and a collector electrode 325 are formed by the lift-off method. Furthermore, evaporating 10/10/300 nm thick Au/Zn/Au, an anode electrode 326, a base electrode 327, and a electrode 328 of isolation region are formed by the lift-off method as shown in FIG. 4F.
Then, in order to electrically separate the laser part 316 and heterojunction bipolar transistor part 317, an opening is made in the silicon dioxide film 323, and the collector layer 312 and separation layer 311 are etched by using a mixed solution of HCl:H.sub.3 PO.sub.4 =1:2, and a separation groove is formed, and an polyimide film 329 is buried in the separation groove as shown in FIG. 4G.
Evaporating 100/1000 nm thick Ti/Au, an interconnection 330 between devices is formed by the lift-off method. When the back side of the N type InP substrate 301 is polished to a thickness of 100 .mu.m and a cathode electrode 331 is formed by evaporating 10/15/300 nm thick Au/Sn/Au, an optoelectronic integrated circuit having BH laser and heterojunction bipolar teansistor integrated together is obtained as shown in FIG. 4H.
FIG. 5 shows the equivalent circuit of the conventional optoelectronic integrated circuit of FIG. 4. In this optoelectronic integrated circuit, three heterojunction bipolar transistors are integrated, and they compose a differential switch for driving the BH laser, and since the heterojunction bipolar transistors are provided adjacent to the BH laser, the wiring parasitic capacity between devices is small, and high speed operation is possible. In addition, since the heterojunction bipolar transistors are formed in the buried layer, the epitaxial growth is required only twice, and the fabrication is easy.
In said conventional optoelectronic integrated circuit, when an attempt is made to raise the operating speed over 1 GHz, since the P type InP buried layer is forming a PN junction nearly over the entire surface of the (heterojunction bipolar transistor) collector layer and an N type InP cladding layer of the BH laser, the junction capacity is large, and when an attempt is made to lower the resistance of the collector layer, the carrier density of the collector layer cannot be raised over 2.times.10.sup.17 cm.sup.-8 in order to set the breakdown voltage over 10 V due to the relationship of the breakdown voltage between the collector layer and separation layer, and the collector resistance is high, and since the carrier density of collector layer is 1.times.10.sup.17 cm.sup.-3, the contact resistance of the collector is as high as 30 .OMEGA., which was an obstacle to increasing the operation speed.
In the prior art, moverover, each layer of a heterojunction bipolar transistor is formed by a second liquid phase epitaxial growth, but since the reverse mesa shape has been already formed at this time, and the surface is not flat, the film thickness of each layer is uneven within the plane. Therefore, the thickness of base layer differs with the heterojunction bipolar transistor device, and the current gain varies with the device. The nonuniformity particularly matters for more sophisticated optoelectronic integrated circuits.
Still more, when an attempt is made to raise the speed of heterojunction bipolar transistor, it is necessary to raise the carrier density of the base, lower the base resistance, lower the carrier density of the collector contacting the base, and reduce the collector capacity, but when an attempt is made to raise the carrier density of the base, the base impurity (for example, Zn) diffuses again into the collector side at the time of the second liquid phase epitaxial growth, and a band gap to block the diffusion of the few carriers not present in the base is formed in a wide layer to lower the current gain.
In the prior art, yet, thermal diffusion is conducted for a long period of time in order to separate the devices electrically, and by this heat treatment, thermal damage was induced to lower the yield of the circuit.

Matsushita Electric Industrial Co., Ltd.


The present invention provides a controlled release composition showing release of an active ingredient (proton pump inhibitor) controlled in two or more steps at different release rates, which contains 1) a release-controlled part A capable of controlling release of the active ingredient to occur at a predetermined rate, 2) a release-controlled part B capable of controlling release of the active ingredient to occur at a predetermined rate lower than the release rate of the release-controlled part A, and where necessary, 3) a release-controlled part C capable of controlling release of the active ingredient to occur at a predetermined rate faster than the release rate of the release-controlled part B, wherein the release of the active ingredient from the release-controlled part B precedes the release of the active ingredient from the release-controlled part A (when release-controlled part C is contained, the release of the active ingredient from the release-controlled part C precedes the release of the active ingredient from the release-controlled part B).

An oral preparation is a dosage form most frequently used among pharmaceutical products. Many oral preparations capable of maintaining drug efficacy with the administration of once or twice a day have been developed in recent years to improve QOL. While synthesis of compounds showing kinetics of sustained drug efficacy with the administration of once or twice a day has been tried in the synthetic stage of the compound itself, the kinetics are quite often modified by designing a long acting preparation with ingenuity in formulation.
As the dissolution property of a long acting preparation, which is suitable for prolonged blood concentration of a drug, zero-order release has been reported. This is based on an idea that, when absorbability of a drug from the gastrointestinal tract does not show changes depending on the absorption sites, prolonged drug concentration in plasma can be achieved by releasing the drug at a constant rate over the whole area in the gastrointestinal tract (small intestine, large intestine) after taking a preparation. However, the inside of the gastrointestinal tract is not the same, and pH, amount of digestive juice, mechanical force on the preparation, effective surface area and the like vary depending on the sites. Thus, a preparation that shows zero-order dissolution in an in vitro dissolution test does not necessarily show similar dissolution property and absorbability in the gastrointestinal tract. Depending on the kind of the drug to be an active ingredient, the blood concentration cannot be maintained within an effective therapeutic range for a long period of time. Therefore, a development design of a long acting preparation, which is based on a different release-control strategy suitable for drug property and environment in the gastrointestinal tract, has been desired (e.g., WO 99/51209, JP-B-6-11699, JP-A-9-143073, Eur. J. Pharm. Sci., 1: 195-201 (1994)).
Controlled release preparations containing, as an active ingredient, a compound having a proton pump inhibitory activity such as omeprazole and the like are generally described in some literatures (US 2002-0051814, JP-A-2002-532425). However, there is no report yet on the release-control strategy that should be employed to achieve desired sustained drug efficacy.
It is an object of the present invention to provide a long acting preparation, wherein the release of the active ingredient (e.g., proton pump inhibitor) is controlled in multisteps, and the active ingredient is released in the gastrointestinal tract over a long period of time.


A microsuspension system and method for its preparation is disclosed. The microsuspension contain lipospheres, which are solid, water-insoluble microparticles that have a layer of a phospholipid embedded on their surface. The core of the liposphere is a solid substance to be delivered, or a substance to be delivered that is dispersed in an inert solid vehicle, such as a wax.

This invention is in the area of controlled delivery systems for substances, including pharmaceuticals.
Many dispersion systems are currently in use as, or being explored for use as, carriers of substances, particularly biologically active compounds. These systems are designed to protect the substance from the environment during delivery and to provide a controlled release of the substance to a targeted area. In some cases, the goal is to target specific sites in the body using the dispersion. In other cases, the goal is to prepare a drug carrier system that acts as a reservoir at the site of injection. Dispersed systems for delivery are also important in the non-pharmaceutical area, for example, for use in the controlled release of substances such as insecticides, fungicides, herbicides and pheromones.
Dispersion systems used for pharmaceutical and cosmetic formulations can be categorized as either suspensions or emulsions. Suspensions are defined as solid particles ranging in size from a few nanometers up to hundreds of microns, dispersed in an aqueous or nonaqueous medium using suspending agents. Solid particles include microspheres, microcapsules, and nanospheres.
Emulsions can be defined as dispersions of one liquid in another, stabilized by an interfacial film of emulsifiers such as surfactants and lipids. Despite their long history, emulsions are used less often today than many other dosage forms due to the inherent instability. Emulsion formulations include water in oil and oil in water emulsions, multiple water/oil/water emulsions, microemulsions, microdroplets, and liposomes.
Microdroplets are unilamellar phospholipid vesicles that consist of a spherical lipid layer with an oil phase inside, as defined in Haynes U.S. Pat. No(s). 4,622,219 and 4,725,442. These phospholipid coated microdroplets of hydrophobic liquid drugs, or drugs dissolved in an organic solvent, can be used as a means to deliver a water insoluble general anesthetic to a local region of the body.
Liposomes are phospholipid vesicles prepared by mixing water-insoluble polar lipids with excess water or an aqueous solution. The unfavorable entropy caused by mixing the insoluble lipid in the water produces a highly ordered assembly of concentric closed membranes of phospholipid with entrapped aqueous solution. The membrane consists of a bimolecular sheet of lipid molecules that have their hydrophobic centers aligned in the middle of the membrane, and hydrophilic ends on the outside of the membrane, interfacing with the aqueous solution, and on the inside, interfacing with entrapped aqueous solution. A unilamellar liposome has a single membrane encapsulating a solution. A multilamellar liposome has a series of membranes, each of which is separated from the neighboring membrane by water. Unilamellar liposomes have a minimum size of about 25 nanometers in diameter, while multilamellar liposomes can range up to several micrometers. The rigidity and permeability of phospholipid bilayers can be adjusted by including other water-insoluble components such as sterols and amphiphiles with the phospholipid.
As noted above, while emulsion based delivery systems are useful for certain applications, the delivering vesicles are subject to physical rupture because of the delicate nature of the liquid/membrane/liquid structure. Emulsion based delivery systems also have relatively short release times. Further, it is difficult to isolate emulsion based vesicles from the aqueous media used for storage for subsequent reconstitution.
The solid phase vesicles in suspension based delivery systems are more stable than the liquid vesicles in emulsion based delivery systems. However, in suspension based systems the concentration of the suspension and the interaction between the vesicles and the liquid carrier is limited because of the repulsive interaction between the solid and the carrier.
It is therefore an object of the present invention to provide a controlled delivery system for substances that is stable for an extended time.
It is another object of the present invention to provide a controlled delivery device that has a relatively long release time.
It is still another object of this invention to provide a suspension delivery vesicle that can be isolated for storage and then resuspended when desired.

Lipsopheres for controlled delivery of substances


In one embodiment, a method includes receiving flight path data regarding the presence of an unmanned aerial vehicle (UAV) at a location at a future time, detecting the presence of the UAV at the location at the future time, determining radio identity data of the UAV using a radio mode of identification, determining optical identity data of the UAV using an optical mode of identification, and certifying the UAV based on a comparison of the radio identity data and the optical identity data to the flight path data.

The ongoing development, maintenance, and expansion of air traffic control systems involve an increasing number of unmanned aerial vehicles, autonomous aerial vehicles, and drones (collectively referred to as UAVs). To that end, it is important to insure that such UAVs are positively identified and immune from hacking and spoofing.
Lacking sufficient safeguards, someone seeking to steal commercial goods could equip an UAV with false identification marking or signals, pick up a load of cargo belonging to someone else, and deliver the load to any location in range, effectively stealing the load. Surveillance UAVs could be misused by a person either by falsely commanding another person's UAV to go to an unintended location or by commanding their own UAV to go to an unauthorized location. People who object to UAV operations could jam or falsify UAV command streams, causing them to crash. People could hijack UAVs, swap their payloads with dangerous materials, and pilot the UAV to any location in the guise of being a something innocuous, such as a pizza delivery. Accordingly, systems and methods are desired to minimize these and other threats.
In accordance with common practice various features shown in the drawings may not be drawn to scale, as the dimensions of various features may be arbitrarily expanded or reduced for clarity. Moreover, the drawings may not depict all of the aspects and/or variants of a given system, method or apparatus admitted by the specification. Finally, like reference numerals are used to denote like features throughout the figures.


The present invention relates to novel polyketides, host cells that produce the novel compounds, and methods fort their use. The compounds of the present invention are cyclic polyketides (also referred to as a xe2x80x9cmacrolidesxe2x80x9d or xe2x80x9cmacrolactonesxe2x80x9d) that include

Polyketides are a diverse class of compounds that are the source of many biologically active molecules such as tetracycline, erythromycin, epothilone, narbomycin, picromycin, rapamycin, spinocyn, and tylosin. Other important examples include naturally occurring immunosuppressants FK-506 (also known as tacrolimus) and FK-520 (also known as ascomycin).
Differing by a single substituent (R1) at C-21, FK-506 has an allyl group whereas FK-520 has an ethyl group at this position. Of the two, FK-506 has been particularly well studied and is used currently as an immunosuppressive drug.
FK-506 and FK-520 exert their biologic effects through the initial formation of an intermediate complex with proteins known as FKBPs (FK-506 binding proteins) such as FKBP-12 and FKBP-52. These proteins are a class of cytosolic proteins that form complexes with molecules such as FK-506, FK-520, and rapamycin that in turn serve as ligands for other cellular targets involved in signal transduction. Binding of FK-506, FK-520, and rapamycin to FKBP occurs through the structurally similar segments of the polyketide molecules, known as the xe2x80x9cFKBP-binding domainxe2x80x9d (as generally but not precisely indicated by the stippled regions in the structures below).
The FK-506-FKBP complex then binds calcineurin, while the rapamycin-FKBP complex binds to a protein known as RAFT-1. Binding of the FKBP-polyketide complex to these second proteins occurs through the dissimilar regions of the drugs known as the xe2x80x9ceffectorxe2x80x9d domains.
The three component FKBP-polyketide-effector complex is required for signal transduction and subsequent immunosuppressive activity of FK-506, FK-520, and rapamycin. Modifications in the effector domains of FK-506, FK-520, and rapamycin that destroy binding to the effector proteins (calcineurin or RAFT) but leave FKBP binding unaffected lead to loss of immunosuppressive activity. Further, such analogs antagonize the immunosuppressive effects of the parent polyketides, because they compete for FKBP. Such non-immunosuppressive analogs also show reduced toxicity (see Dumont et al., 1992, Journal of Experimental Medicine 176, 751-760), indicating that much of the toxicity of these drugs is through a mechanism not mediated by FKBP binding.
In addition to immunosuppressive activity, FK-520, FK-506, and rapamycin have neurotrophic activity. In the central nervous system and in peripheral nerves, the corresponding target proteins are referred to as neuroproteins. The neuro-FKBP is markedly enriched in the central nervous system and in peripheral nerves. Molecules that bind to the neuro-FKBP, such as FK-506 and FK-520, have the remarkable effect of stimulating nerve growth. In vitro, they act as neurotrophins. More particularly, they promote neurite outgrowth in NGF-treated PC12 cells and in sensory neuronal cultures, and they promote regrowth of damaged facial and sciatic nerves, and repair lesioned serotonin and dopamine neurons in the brain in intact animals. See Gold et al., June 1999, J. Pharm. Exp. Ther. 289(3): 1202-1210; Lyons et al., 1994, Proc. National Academy of Science 91: 3191-3195; Gold et al., 1995, Journal of Neuroscience 15: 7509-7516; Steiner et al., 1997, Proc. National Academy of Science 94: 2019-2024; and U.S. Pat. Nos. 5,968,921 and 6,210,974. Further, the restored central and peripheral neurons appear to be functional.
Compared to protein neurotrophic molecules (e.g., BNDF, NGF, etc.), the small-molecule neurotrophins such as FK-506, FK-520, and rapamycin have different, and often advantageous, properties. First, whereas protein neurotrophins are difficult to deliver to their intended site of action and may require intra-cranial injection, the small-molecule neurotrophins display excellent bioavailability; they are active when administered subcutaneously and orally. Second, whereas protein neurotrophins show quite specific effects, the small-molecule neurotrophins show rather broad effects. Finally, whereas protein neurotrophins often show effects on normal sensory nerves, the small-molecule neurotrophins do not induce aberrant sprouting of normal neuronal processes and seem to affect damaged nerves specifically. Neuro-FKBP ligands have therapeutic utility in a variety of disorders involving nerve degeneration (e.g. multiple sclerosis, Parkinson""s disease, Alzheimer""s disease, stroke, traumatic spinal cord and brain injury, peripheral neuropathies).
The metabolism and pharmacokinetics of FK-506 have been extensively studied, and FK-520 is believed to be similar in these respects. Absorption of FK-506 is rapid, variable, and incomplete from the gastrointestinal tract (Harrison""s Principles of Internal Medicine, 14th edition, 1998, McGraw Hill, 14, 20, 21, 64-67). The mean bioavailability of the oral dosage form is 27% (range 5 to 65%). The volume of distribution (VolD) based on plasma is 5 to 65 L per kg of body weight (L/kg), and is much higher than the VolD based on whole blood concentrations, the difference reflecting the binding of FK-506 to red blood cells. Whole blood concentrations may be 12 to 67 times the plasma concentrations. Protein binding is high (75 to 99%), primarily to albumin and alpha1-acid glycoprotein. The half-life for distribution is 0.9 hour; elimination is biphasic and variable: terminal-11.3 hours (range, 3.5 to 40.5 hours). The time to peak concentration is 0.5 to 4 hours after oral administration.
FK-506 is metabolized primarily by cytochrome P450 3A enzymes in the liver and small intestine. The drug is extensively metabolized with less than 1% excreted unchanged in urine. Because hepatic dysfunction decreases clearance of FK-506, doses have to be reduced substantially in primary graft non-function, especially in children. In addition, the bioactivity of FK-506 is affected by drugs that modulate the activity of P450 3A enzymes. Drugs that induce the cytochrome P450 3A enzymes reduce FK-506 levels, while drugs that inhibit these P450s increase FK-506 levels. For example, FK-506 bioavailability doubles with co-administration of ketoconazole, a drug that inhibits P450 3A. See, Vincent et al., 1992, Arch. Biochem. Biophys. 294: 454-460; Iwasaki et al., 1993, Drug Metabolism and Disposition 21: 971-977; Shiraga et al., 1994, Biochem. Pharmacol. 47: 727-735; and Iwasaki et al., 1995, Drug Metabolism and Disposition 23: 28-34.
FIG. 1 shows the eight isolated metabolic products formed from incubation of FK-506 with liver microscomes. As can be seen, four metabolites of FK-506 involve demethylation of the methoxy groups on carbons 13, 15, and 31, and hydroxylation of carbon 12. The 13-demethylated (hydroxy) compounds undergo cyclizations of the 13-hydroxy at carbon 10 to give M-I, M-VI and M-VII, and the 12-hydroxy metabolite at carbon 10 to give M-I. Another four metabolites formed by oxidation of the four metabolites mentioned above were isolated by liver microsomes from dexamethasone treated rats. Three of these are metabolites doubly demethylated at the methoxy groups on carbons 15 and 31 (M-V), 13 and 31 (M-VI), and 13 and 15 (M-VII). The fourth, M-VIII, was the metabolite produced after demethylation of the carbon 31-methoxy group, followed by formation of a fused ring system by further oxidation. Among the eight metabolites, M-II has immunosuppressive activity comparable to that of FK-506, whereas the other metabolites exhibit weak or negligible activities. Importantly, the major metabolite of human, dog, and rat liver microsomes (representing approximately about 90% of the metabolic products after a 10 minute incubation) is the 13-demethylated and cyclized FK-506 (M-I).
A disadvantage of using FK-506 and FK-520 as drugs is dosing unpredictability. Due to the significant variability in metabolism among patients, an appropriate dosing regimen is difficult to ascertain for an individual patient. Another disadvantage of FK-506 and FK-520 is their dual pharmacological effects as immunosuppressants and as neurotrophic agents. In general, compounds having a single specificity are desired. For example, a FK-506 like compound having only neurotrophic activity without immunosuppressive activity or vice versa may be used to treat the intended symptom without the side effects of the other bioactivity.
As a result, derivatives that improve upon the properties of FK-506 and FK-520 are needed and desired. However, because FK-506 and FK-520 are complex structures that are generally not amenable to either de novo chemical synthesis or facile derivation, this need remains unfulfilled.
The present invention relates to novel polyketides, host cells that produce the novel compounds, and methods fort their use. The compounds of the present invention are cyclic polyketides (also referred to as a xe2x80x9cmacrolidesxe2x80x9d or xe2x80x9cmacrolactonesxe2x80x9d) that include
as part of their structure and bind to a FK binding protein wherein R4 and R5 are each selected from the group consisting of hydrogen, methyl, ethyl, and methoxy, provided that at least one of R4 and R5 is hydrogen, methyl, or ethyl. As will be explained in greater detail below, the compounds of the present invention have properties such as favorable P450 enzyme activity profiles that are desirable for use of these compounds as drugs.


An extending portion of a vibration transmitting unit. is capable of transmitting ultrasonic vibration from a proximal side to a distal side, and in the extending portion, a second component provided on the distal side with respect to a first component. A third component provided between the first component and the second component in the extending portion has a third cross-sectional area that is larger than a first cross-sectional area of the first component and is smaller than a second cross-sectional area of the second component, and one of vibration anti-nodes is positioned at third component by the extending portion vibrating at a frequency in a predetermined frequency range.

1. Field of the Invention
The present invention relates to a vibration transmitting unit that enables ultrasonic vibration to be transmitted, and an ultrasonic treatment instrument including the vibration transmitting unit.
2. Description of the Related Art
European Patent No. 2074955 specification discloses an ultrasonic treatment instrument including a vibration transmitting unit which is designed so as to vibrate at a standard resonance frequency by an ultrasonic vibration transmitted from a proximal side to a distal side. This vibration transmitting unit is provided with a plurality of cross-sectional reduction portions at which a cross-sectional area perpendicular to a longitudinal axis decreases towards the distal side. In a state where the vibration transmitting unit vibrates at the standard resonance frequency, all of the vibration anti-nodes are positioned away from each of the cross-sectional reduction portions in a direction parallel to the longitudinal axis. Therefore, stress caused by vibration acts on each of the plurality of cross-sectional reduction portions, thereby increasing the amplitude of the vibration. Furthermore, in the vibration transmitting unit, a cross-sectional increasing portion, at which a cross-sectional area perpendicular to the longitudinal axis increases towards the distal side, is provided between two cross-sectional reduction portions in a direction parallel to the longitudinal axis in a state where the vibration transmitting unit vibrates at the standard resonance frequency, one of the vibration anti-nodes is positioned at the cross-sectional increasing portion. Since a vibration anti-node in which stress caused by vibration becomes zero is positioned, the amplitude of the vibration does not decrease even at the cross-sectional increasing portion at which the cross-sectional area increases.

Vibration transmitting unit and ultrasonic treatment instrument


The present application relates to a freezer and a hinge for the same. The hinge comprises a base, in which a left side of the base is provided with a first flange portion, a right side of the base is provided with a second flange portion opposite to the first flange portion, and the first flange portion and the second flange portion is provided with sliding grooves opposite to each other; a connecting seat; a first pivot shaft; a second pivot shaft parallel to the first pivot shaft, in which both ends of the second pivot shaft may slide in the corresponding sliding grooves respectively; a guide rod; a supporting seat; a positioning part; a spring sheath fitted over the guide rod and movable between the positioning part and the supporting seat; and a spring fitted over the spring sheath.

A hinge of a freezer industry is mostly made of metal materials, and performs transmission of a force by compression of a spring, which achieves an effect of opening and closing of a door body, but the mechanical movement results in certain friction noise between metals, mainly concentrated in positions such as the spring, a guide rod and a rotary shaft, etc. The spring of the hinge in the related art is easily deformed under a pressure when the door is opened, abrasion easily occurs between the guide rod of the hinge and a bearing shell or between the bearing shell and the rotary shaft, and it is found that the spring is easily damaged through a long-term experiment. Furthermore, the amount of extension and contraction of the spring of the hinge is constant and unadjustable; for example, an excessively great or small elastic force will result in inconvenience for use.


A device for positioning a processing tool: a processing tool for processing the to-be-processed workpiece's surface while pressing the surface to be processed; a movement mechanism able to displace processing tool's distal end in a first direction orthogonal to the surface to be processed and/or a second direction parallel with the surface to be processed; a force sensor able to detect a force in the first and second direction applied to the processing tool's distal end pressed onto the surface to be processed; and a control device for executing a correction step for controlling the movement mechanism so the surface to be processed is pressed while the distal end's position of the processing tool is aligned with a processing reference position on the surface to be processed, and correcting the processing tool's position so that the force in the second direction is within a specific value or less.

In general, in a case where positioning of a processing tool with high accuracy is required, and processing (e.g., drilling a hole) in which a processing reaction (reactive) force is generated is performed, the position of the tip end of the processing tool is deviated due to the processing reaction force, so that accuracy of a processing position is reduced and a processing target (hereinafter will be referred to as a workpiece) is damaged. To avoid this, the processing tool attached on the tip end of a positioning device is pressed against the workpiece with a force (hereinafter will also be referred to as a pressing force) that is equal to or larger than the processing reaction force, prior to the processing. At this time, flexure of the positioning device occurs due to a counteracting force of the pressing force, and thereby the position of the tip end of the processing tool is deviated. This position deviation (position gap) negatively affects accuracy of the processing position.
Conventionally, to compensate the flexure of the positioning device, there is a method in which a flexure amount of the positioning device is calculated from a force applied to a positioning controller, by use of a stiffness value of the positioning device (see, e.g., Patent Literature 1).
In an exemplary prior art, a force sensor is attached on the tip end of an arm of a robot, a force applied to a member held by the robot and a flexure of the member occurring due to the force are detected by use of the force sensor, and the position of the member held by the robot is compensated (e.g., see Patent Literature 2). Also, there is a method in which a feeding device mounted on the tip end of an arm together with a machining tool is secured to a support base on which a workpiece is placed, during processing performed by a drilling robot (e.g., see Patent Literature 3).

Positioning device and positioning method of processing tool


The invention is directed to a connector for optically coupling one or more fibers to a like number of fibers. The individual fibers are supported upon members having resilient supports to permit the fibers on one member to be positioned onto the support of the other member and provide support during the complete coupling operation. Various clamps and strain reliefs are provided to minimize the effects of forces upon the cable or individual fibers. The cable may take a flat, circular or other configuration and the fibers may be of glass or plastic and may be coated with reflective sheaths or the like.

1. Field of the Invention
The invention is directed to connectors for coupling together one or more individual fibers to a like number of fibers to provide an extended signal transmission line.
2. Description of the Prior Art
Until recently, signals were transmitted through optical wave guides made up of a plurality of fibers in bundles, each fiber receiving the same signal and thus providing redundant paths so that the possibility of total signal loss was very low. This use of multiple fiber bundles minimized alignment problems and allowed for low accuracy connections without a loss of information transmitted. The bundle was, unfortunately, rather large and inflexible and most optical wave guides were necessarily relatively short and straight.
Recently, techniques have been developed whereby high strength, low loss glass and plastic fibers are now possible. Also, due to the great band width, which is possible, as many as 50,000 conversations can now be transmitted on a single fiber. The biggest remaining problem is a connector for coupling individual fibers of two cables with low loss characteristics. The cables can take the form of flat cables wherein layers of material are bonded over and around individual fibers, somewhat in the manner of forming conventional round conductor flat cable. Also, the cables can take circular configurations using a support core or support strands interleaved with optical fibers. The cable can carry as few as one fiber or as many as ten or more fibers. Other configurations of cables can be used in whatever form is desirable.
Some of the devices being used as connectors resemble those devices used to join metallic conductors and are crimped, compressed or clamped to the individual fibers. The brittleness and size of the glass fibers, particularly, make such techniques unsuitable to this new medium.


A flat plastic key suitable for replacing a corresponding metal key having a key alignment groove disposed in a side of the key is configured to actuate a rotary cylinder lock having a rectangular lock entrance slot. The plastic key includes a head, a shank and a bit. The shortened key alignment groove extends along the side of the key creating a decreased key thickness adjacent to the groove. The shortened groove terminates in the key shank at a groove termination point to define a groove length less than the corresponding groove length of the metal key to thereby increase the volume and strength of the plastic key shank relative to the volume and strength of an exact plastic duplicate of the metal key shank to increase the strength of the plastic key and its capacity to transfer the input torque to the sidewalls of the lock entrance slot.

1. Field of the Invention
The present invention relates to molded plastic keys, whether individual keys, or plastic card/key combinations on the order of the disclosure in my U.S. Pat. No. 4,677,835 dated Jul. 7, 1987, and is more particularly concerned with reinforcing such keys against breaking at their shanks due to extraordinary twisting stress applied through the handles of the keys.
2. Description of Related Art
Conventional metal keys for operating tumbler locks such as in automobiles, building doors, apparatus controls, and the like, have heretofore been generally constructed throughout the shank and bit portions, and generally the handles, or head portion of a uniform thickness common with the bit thickness. Molded plastic keys have also heretofore been constructed of substantially uniform thickness throughout their length similar to comparable metal keys.
The key bit must be fairly snuggly fitted in the key slot in the cylinder plug. Looseness of the bit in the key slot might defeat proper engagement of the lock tumblers in the key notches. On the other hand, especially in the USA, to avoid difficulty in quick insertion of the key bit into the slot, the general practice has been to provide enlarged entrance dimensions. This results in the key shank often having little if any torque support when subjected to the considerable twisting stress which may occur if for any reason there is resistance to turning of the key in the lock. Such resistance may be variously caused such as by faulty cutting of the key notches, binding due to corrosion or icing, and the like. The general tendency of the user, where there is any such resistance to turning of the key in the lock, is to apply additional torque or twisting force to the key through its handle. Metal keys will generally withstand such extraordinary twisting stress.
In normal U.S. automobile ignition or trunk lock, only about three to eight inch pounds of torque (IPT) are necessary to open the lock; non U.S. automobiles typically require higher torques. A normal uniform thickness molded plastic key will withstand up to eight to nine IPT. If greater torque is applied there is danger of breaking the plastic key shank. An average women can apply up to seven to ten IPT and an average man can apply up to ten to fourteen IPT. Therefore, there has been some key shank breakage experienced in respect to molded plastic keys having a substantially common thickness throughout their lengths.
Molded plastic keys have been disclosed in U.S. patent of Donald F. Almblad U.S. Pat. No. 4,637,236, and in U.S. Pat. No. 4,677,835 of the present applicant. In both of those patents the keys are shown as of a common thickness throughout their lengths.
By way of a typical disclosure of a metal key and tumbler lock, U.S. Pat. No. 4,656,851 is referred to.

Flat plastic key with shortened key alignment groove


A homokinetic universal joint assembly including an outer and an inner joint member with roller bodies engaged for torque transmission therebetween includes a guide member which is located centrally of the assembly within the inner joint member and which supports the roller bodies in the bisecting plane of the assembly. A control sleeve defines a mounting groove extending through the joint center and the guide member is supported within the mounting groove for movement in a direction radially of the joint assembly. The control sleeve is provided with spherical surfaces located equivalent distances on opposite sides of the joint center which are engaged to guide the control sleeve within the inner and outer joint members.

The present invention relates generally to the structure of a homokinetic universal joint and more particularly to a joint wherein an inner joint member and an outer joint member are engaged for torque transmission therebetween by roller bodies which comprise essentially spherical balls. The roller bodies are engaged within grooves formed on the inner wall of the outer joint member and recesses formed on the inner joint member, with a corresponding number of grooves and recesses being provided.
Furthermore, the invention relates to an assembly wherein there is provided at the center of the joint a guide member supported in the inner joint member for mounting the roller bodies in the bisecting plane of the assembly.
Joint assemblies known in the prior art, for example U.S. Pat. No. 1,847,677, have been found to be uneconomical to manufacture and rather expensive to produce because of cumbersome design characteristics. In such prior art devices, the outer member consists of two parts and a separation must be provided inasmuch as the spherical inner joint member must be enclosed. However, since grooves for retaining the torque transmitting balls extend concentrically to the center of the joint, the separation which must be provided extends through the grooves for the balls. This results in the requirement that the ball grooves of both parts of the joint must be manufactured with very exacting standards in order to ensure a precise shape for the grooves. Moreover, because of the fact that the inner joint member is guided in a hollow space of the outer guide member, a joint of this type will involve large friction surfaces. Additionally, it can only be constructed as a fixed joint. The use of the guide element of such a joint is also uneconomical. For this purpose, the inner joint member must have continuous grooves into which the individual guide elements are placed in order to be subsequently centered by means of a spring element. The grooves receiving the guide elements in the joint member have a very complicated shape and therefore they must be manufactured under very difficult conditions.
Moreover, joints are known, for example from U.S. Pat. No. 2,462,700, which do consist of two joint halves and which are provided with a central control lever. However, guidance of the roller bodies in the bisecting plane of the joint is very difficult and can only be effected by means of additional guide members. Also, in this joint, the first joint member is encircled by the second joint member so that, again, only a fixed joint can be provided. Moreover, in the design of the joint members, only roller bodies which are capable of being supported by pins may be used.
In view of the foregoing, the present invention is directed toward provision of a homokinetic universal joint having a design which is relatively simple and wherein a control member may be provided having long, symmetrical staggered portions for reducing friction losses in a manner whereby the structural length of the joint does not become larger.


A receptacle exchange for a pick or put receptacle and method for exchanging a pick or put receptacle includes a process location at which an operator processes a receptacle by picking articles from or putting articles to a receptacle. A lift moves a receptacle from a supply location to the process location. An extractor retrieves a receptacle from the process location to an extracted location. A first drive elevates the lift between the supply location and process location and moves the extractor between the process location and extracted location. A second drive moves an inclination of the extractor. A control controls the first and second drives.

The present invention is directed to a receptacle exchange for a pick or put receptacle and a method for exchanging a pick or put receptacle with a process location at which an operator processes a receptacle by picking articles from or putting articles to a receptacle. While the invention is illustrated for use with a one-to-many pick station, it may also find use with a one-to-one pick/put station. While the invention is illustrated for use with a goods-to-person station, it may also find application, such as with a goods-to-robot station, or the like.

Pick or put station with controllable receptacle exchange


A computerized method for filtering a digital audio file to generate an output audio file that induces optimal health and cognitive ability in a listener of a playback of the output audio file is described herein. The method includes the steps of identifying a plurality of target frequencies that span within an octave, identifying a plurality of mid-point frequencies that are situated at mid-points between any two adjacent target frequencies, applying a peaking filter to the digital audio file centered around the plurality of mid-point frequencies to produce highest frequency attenuation at the plurality of mid-point frequencies, and generating the output audio file.

Pythagoras is credited for defining a mathematical equation back in 570-495 BC which gives the understanding that frequency specific vibration is not limited to an eight-note octave. Up to the 12th and 13th centuries, musicians were allowed to find and use frequencies which individually targeted vibrational connections with the human body. But in the 13th and 14th centuries, the Roman Catholic Church started to mandate which frequencies could and could not be used in music composition.
Around 1888, the great opera composer, Giuseppe Verdi, mandated that all symphony orchestras would tune Concert A to 432 Hz. It was late believed (evidence not proven) that scientists went to Adolph Hitler in and around 1937, telling him that if orchestras would tune to 440 Hz instead of 432 Hz, that the listening audience would be more susceptible to subliminal directions. This was in turn given to Joseph Gerble, the propaganda manager of the 3rd Reicht to implement into ever city's orchestra under control of the Reicht.
After WWII, the International Standards Organization (ISO) mandated that concert A for all music be at 440 Hz and has not been changed and rarely questioned. It has only been since Hans Jenny (1904-1972) https://en.wikipedia.org/wiki/Cymatics defined a new term CYMATICS which filmed studies have taken place to understand how energy moves through matter. Modulating frequencies is seen through the simple design of laying a stereo speaker on its back, placing a flat metal plate on top of the speaker, pouring fine sand on top and then turning on an amplifier and frequency generator. As the frequency is modulated up or down, it is only on specific frequencies do we find that the sand forms specific geometric patterns. As the frequencies continue to modulate, the sand dissolves from the patter, back into a blob and then into another geometric pattern. These patterns show frequencies which energy moves through matter. Over the past 8-10 years, we now have new scientific studies of epigenetics https://en.wikipedia.org/wiki/Epigenetics and from here is the application of understanding signal transduction https://en.wikipedia.org/wiki/Signal_transduction

System and method for auditing and filtering digital audio files


A building puzzle block includes an elongated body portion in the form of a rectangular parallelepipedon. Spheres are attached to the body portion along edges thereof and at spaced distances. An equal number of receiving sockets are formed at spaced distances. An equal number of receiving sockets are formed at spaced distances on the edges of the body portion for interconnecting the blocks with other similar blocks.

Numerous designs have been used for toy and structural building blocks. Examples of the toy building blocks are disclosed in the patents to N. I. Paulson, U.S. Pat. Nos. 2,262,199, 3,405,479 and 3,481,068; G. Morin, U.S. Pat. No. 3,420,527; Yoshihiro Kishi, U.S. Pat. No. 3,570,170; Takashi Matsubayashi, et al., U.S. Pat. No. 3,605,322; C. O. Perry, U.S. Pat. No. 3,611,620; J. Pippet, U.S. Pat. No. 3,716,939; W. Schnabel, U.S. Pat. No. 3,717,946; J. B. De Vos, U.S. Pat. No. 3,822,499; G. Vogel, U.S. Pat. No. 3,862,512; J. A. Gale, U.S. Pat. No. 4,129,960 and Y. Chatani, et al., U.S. Pat. No. 4,306,373. An example of structural interconnecting blocks is shown in the patent to G. L. Hernandez, U.S. Pat. No. 4,060,952.
In each of the disclosures of these patents, building blocks are provided having structure for permitting the interconnection of the individual blocks. In each of these cases, the interconnection is by way of protrusions from one or more faces of the blocks which protrusions are received in apertures also provided in the blocks. The protrusions and receiving apertures are generally sized for a snug or interference fit to effect an interlocking force upon engagement of one block to another. By way of example only, in the patent to Y. Chatani, et al., U.S. Pat. No. 4,306,373, a frictional interconnecting toy block is provided having a male cylindrical coupler extending from selected sidewalls of a cube for engagement within a female receiving aperture. The male cylindrical couplers are sized to provide an interlocking fit upon engagement of the male coupler into the female coupler. In this arrangement, as is generally the case, upon interconnection of one block with another, the male coupler is completely received within the female coupler and is not viewable after interconnection.
Similar interconnecting blocks have been used as game pieces for use in playing games or solving puzzles defined by use of such blocks. Examples of such structures are shown in the patents to M. J. J. Sugden, U.S. Pat. No. 3,481,603; D. Wolf, U.S. Pat. No. 3,672,681; and to D. G. Henderson, U.S. Pat. No. 4,239,233.
In these patents, interconnecting blocks have either male or female coupling structures formed on one or more faces of the blocks for engagement with corresponding female or male coupling structures, respectively. In the patent to D. Wolf, cubes are formed with holes in the faces thereof and assembly of the cubes is achieved by using a tubular coupling member for insertion into the apertures of a pair of the playing pieces. In these structures, the coupling protrusions are also hidden from view upon assembly. Thus, these elements of the building blocks are not used as a part of the overall finished design and likewise are not intended for use as part of the puzzle or game associated with the assembly of the component blocks.


A compound semiconductor pellet has a zincblende crystal structure and is formed of a III-V compound semiconductor, such as GaAs. The major surface of the pellet and side surfaces thereof are both {100} planes. To obtain this type of pellet, [010] and [001] directions are selected as dicing directions. In the case of a crystal having a zincblende crystal structure, a direction which forms 45.degree. with reference to a cleavage plane of the crystal is selected as a dicing direction.

1. Field of the Invention
The present invention relates to a compound semiconductor pellet, and also to a method for dicing a compound semiconductor wafer.
2. Description of the Related Art
A compound semiconductor wafer formed of a single crystal is diced along a cleavage plane since along this plane the single crystal easily splits. For example, a GaAs single crystal, one of III-V compound semiconductor, has a cleavage plane expressed as {011}, so that it is diced along the {011} plane in the direction of [011].
In the present specification, the crystal plane and the crystal orientation are expressed on the basis of the Miller indices. In the case where a cubic crystal has identical planes, such as (100), (100), (010), (010), (001) and (001), these identical planes will be generically represented by a notation using braces, such as {100}. The direction in which a crystal axis extends (i.e., a crystal orientation) will be denoted by a notation using the symbols "<" and ">", and equivalent crystal orientations, such as <001>and <001>will be generically represented by a notation using brackets, such as [001].
FIG. 1 is a plan view of a GaAs wafer. This GaAs wafer is a well-known type wherein the major surface on which elements are to be formed is a (100) plane.
A is shown in FIG. 1, the cleavage plane of the GaAs wafer 100 (which is a single crystal) is a {011}. plane, so that the GaAs wafer 100 is diced in the [011]direction, as is indicated by arrow A. Reference numeral 104 in FIG. 1 denotes dicing lines.
The wafer 100 has an orientation flat 102. This orientation flat 102 allows easy recognition of the posture of the wafer 100 in the semiconductor device-manufacturing process, or allows easy recognition of the cleavage plane of the wafer 100. The orientation flat 102 is formed by cutting the wafer 100 along the cleavage plane, i.e., in the [011] direction, such that a [011] plane is exposed.
FIG. 2 is a schematic perspective view of a GaAs pellet obtained by the dicing method mentioned above.
As is shown in FIG. 2, the major surface 106 of the GaAs pellet 108 is a (100) plane, and semiconductor elements 105 are formed on the major surface. The side surfaces 110 of the GaAs pellet 108 are exposed cleavage planes (011), (011), (01 1) and (011), respectively. That is, all side faces 110 of the GaAs pellet 104 are {011} planes if a (100) plane is selected as the major surface of the pellet 104.
The reason for selecting the cleavage plane as a dicing plane is that the semiconductor wafer easily cracks along the cleavage plane if only the groove is formed in the wafer by use of a blade or the like. It should be noted, however, that if the groove is formed in the [011] direction, a large kerf width will be produced at the time of dicing.
FIG. 3 is an enlarged view of the portion circled in FIG. 1 and illustrates details of a dicing line 104 and its neighboring regions.
As is shown in FIG. 3, the kerf width 112 will be large if the groove is formed in the [011] direction. In addition, a coarse surface will be produced at the time of dicing the wafer, as indicated by 114 in FIG. 3. If the surface is greatly roughened, not only the reliability of a semiconductor element formed inside the pellet 106 but also the outward appearance of the pellet 106 is adversely affected. In some cases, the pellet 106 itself may be cut at the time of dicing, resulting in damage to the element formed inside the pellet 106.
In the case of a III-V compound semiconductor single crystal, the atoms join in two ways: covalent bonding which occurs through electron clouds expanding in four directions; and ionic bonding which is based on Coulomb force. The reason that the Coulomb force is generated is that the III-group atoms and the V-group atoms differ in electronegativity. More specifically, the III-group atoms tend to emit three electrons and become a cation having a valence of +3, while the V-group atoms tend to receive three electrons and become an anion having a valence of -3.
The atoms of a single silicon or germanium crystal join by the covalent bonding alone. In contrast, the atoms of the III-V compound semiconductor single crystal join by both the covalent bonding and ionic bonding, as mentioned above. In connection with the III-V compound semiconductor single crystal, it should be also noted that the force of the ionic bonding is greater than that of the covalent bonding, so that the direction of the interatomic bonding force is determined mainly by the direction of the ionic bonding.
As may be understood from the above, the III-V compound semiconductor single crystal differs from the single silicon or germanium crystal, in light of the easiness of cleavage, the direction of cleavage, etc. The differences will be described in more detail below.
In the base of the III-V compound semiconductor single crystal, a {111} planes is totally occupied with either III-group atoms or V-group atoms. In addition, since the III-group atoms of one {111} plane and the V-group atoms of another 111 plane are very close to each other, the Coulomb force acting between the two {111} planes is so intense as to provide the strongest possible bonding. Unlike the {111} planes, the {011} planes are occupied with III-group atoms and V-group atoms. Since the {011} planes are electrically neutral and the Coulomb force weak, they are used as cleavage planes.
Let it be assumed that the groove is formed in the III-V compound semiconductor single crystal by moving a blade along a {011} plane (i.e., a cleavage plane) in the [011] direction. In this case, the movement of the blade may be affected by a {111} plane (i.e., a plane which provides the strongest possible bonding) since the {111} plane is 45.degree. slanted with reference to the depth direction of the crystal. That is, the blade may slide along the {111} plane when the groove is formed.
In practice, the {111} planes are hard to expose in a satisfactory manner. As is indicated in FIG. 3, there may be a certain kerf width 112, and the exposed surfaces may be coarse.
As long as the groove formed by use of the blade is not deep, the above problems can be solved to a certain extent, even if the blade is slid in the [011] direction. If the groove is formed by use of a diamond scriber, the above problems can be almost solved.
However, if the groove formed by the blade is shallow or if it is formed by use of a diamond scriber, the thickness of that portion of the crystal which should be divided by cracking will increase. As a result, the following problems occur:
(1) It is likely that crack-dust will be produced in large quantities at the time of cracking the GaAs wafer. If crack-dust is produced, it is hard to remove, since the GaAs wafer is a semi-insulating material and is electrified due to the static electricity generated at the time of cracking. If such crackdust is left on the pellet, wire bonding cannot be satisfactorily performed with respect to the pellet. In addition, the reliability of the semiconductor device incorporating the pellet may be adversely affected.
(2) The direction of the dicing line has to be accurately the same as the direction of cleavage. If not, the pellets obtained by dicing the GaAs wafer cannot be easily separated from one another. This means that the wafer has to be set accurately at the right position in the photolithography step of the manufacture of a semiconductor element. If the wafer is not accurately set, the mass production of pellets is adversely affected.
(3) To crack the GaAs wafer, a great load is required, so that the GaAs wafer may be mechanically damaged. If the GaAs wafer is mechanically damaged, a pellet is stressed, resulting in deterioration in the reliability of the pellet.

Compound semiconductor pellet, and method for dicing compound semiconductor wafer


In a vertically storing dock leveler having a platform which is stored in an upright position, a control circuit which enables retention of the platform in position in response to power failure, and which compensates for possible operator error or inattentiveness during power failure. A normally closed main solenoid valve can be opened only by pressing a lower switch to lower the platform. During normal operation, the valve will remain open to enable the platform to float, but when the platform is to be raised, or electrical power is removed, the valve is closed. As a result, after the platform is raised, the pressure in the main lift cylinder is maintained, and the platform stays at its upright position. Also, during an electrical power interruption, the deck is prevented from falling.

This invention relates to an electric and hydraulic control circuit for a vertically storing dock leveler, offering, among other features, enhanced control over a platform of the leveler in emergency situations.
There are horizontally storing and vertically storing dock levelers. Horizontally storing dock levelers are stored so that their platforms are raised into position for operation, and vertically storing dock levelers are stored so that their platforms are lowered into position for operation. A conventional horizontally storing dock leveler usually is installed in a pit in a bay of a loading dock. The platform version is raised into position using an hydraulic pump which pumps fluid, usually oil, through various control valves to and from hydraulic cylinders. Once the deck is raised to a sufficient height, and the lip is extended, the deck is allowed to fall by gravity so that it may float up and down with the truck or other vehicle being loaded.
Some horizontally storing models have employed an hydraulic circuit including a normally open (N/O) main solenoid valve, and an electrically operated "emergency stop" valve to hold the deck in a partially raised position. An example of the electrical and hydraulic control circuits for this conventional approach are shown in FIGS. 1 and 2.
In FIG. 2, a pump manifold 1 contains a shuttle valve 25, a pump 30, and a motor 35. When the motor 35 is energized, and the pump 30 is started, fluid is caused to flow from a reservoir 7 through the pump 30. The shuttle valve 25 thus is moved to the left, so that fluid flows through the conduit indicated by arrow 25a, out of a primary port 3 of the pump manifold 1.
Fluid flowing out of the primary port 3 enters a lip cylinder 160 at its retract (rod) end, and also passes through solenoid valve 20 to a main lift cylinder 110. Fluid flowing into both places causes the main lift cylinder 110 to extend, and fluid to flow out of the extend (piston) end of the lip cylinder 160 and into a secondary port 5. A sequence valve 15 is set so that fluid entering the secondary port 5 passes through the valve 15 and into the reservoir 7. As a result, the lip of the leveler retracts as the platform extends.
When the main lift cylinder is fully extended, pressure builds at the primary port 3. As a result, the sequence valve 15 is switched over (in FIG. 2, it is moved to the right against pressure exerted by a spring 16), so that flow may be reversed through the secondary port 5. As a result, the lip cylinder 160 extends, causing the lip of the leveler to extend. Thus, the lip extends after the platform extends.
In the course of operation, when an emergency stop switch 10 (FIG. 1) is pressed, the main solenoid valve 20, which is a spool valve, is energized. The valve 20 normally is open, and permits fluid flow in either of two directions when open. However, energization of the valve 20 causes it to close, prohibiting fluid flow in either direction. As a result, the platform cannot be lowered.
With a normally open valve system, it also happens that when the platform is lowered from a raised position, it cannot be stopped unless the pump 30 is started or the emergency stop switch 10 is depressed. Both of these actions require electrical power. Thus, if there is a power failure, the platform will fall because there is nothing to stop it. The fall is controlled by the rate of fluid flow through the left-hand portion of the shuttle valve.
Vertically storing dock levelers, such as the one shown in FIGS. 3A and 3B, special consideration because when they are stored, people can walk all around them. Thus, it is important that the platform 40 not fall for any reason while it is stored, or while it is being lowered. A system such as that described above for horizontally storing dock levelers, then, would be inappropriate for vertically storing levelers, because in the event of loss of electrical power, the platform naturally would lower in an out of control manner, causing a potential danger to those in its path. Even having an electrically operated emergency stop control, for a system with a normally open valve, would not solve this problem because the platform still could fall in the event of electrical failure. Further, the platform could not be raised (i.e. stored) in the event of power failure.
One type of vertically storing dock leveler control circuit uses a normally closed (N/C) main solenoid valve which requires electrical power in order to open. The operation of such a valve, then, would be the opposite of that for a normally open valve. Examples of the electrical and hydraulic circuits for such a system are shown in FIGS. 4 and 5.
In FIG. 5, a pump manifold 150 includes a shuttle valve 152, a primary port 153, a sequence valve 154, a secondary port 155, a reservoir 157, a pump 162, and a motor 164. A main difference between this hydraulic circuit and that of FIG. 2 is that, when the main solenoid valve 100 is in its normally closed position, fluid cannot flow into or out of the main lift cylinder 110, so that the platform remains locked.
In operation, first a lock/unlock switch 130 (FIG. 4) is turned to the unlock position, energizing the solenoid valve 100, and permitting fluid flow through the valve. This fluid flow allows the platform 40 to float at a speed determined by the rate of fluid flow. In normal operation, this switch 130 remains in the unlock position, to permit the platform to float up and down with the truck which is being loaded or unloaded.
To raise the platform, a raise button 120 is pushed, which causes the platform 40 to rise. When the platform is raised, the raise button is released, and the lock/unlock switch 130 is turned to the lock position, deenergizing the solenoid and closing the valve 100 to keep the platform 40 raised. This type of valve requires two types of action, then, to raise and stop the deck. First, the lock/unlock switch 130 must be turned to the unlock position to open the valve (this is done at the start of operation), and second, the raise button 120 must be pressed to start the motor 35 (after operation is complete, and the platform 40 is to be stored). Similarly, to stop the deck, first the raise button must be released, and second, the lock/unlock switch 130 must be turned to the lock position (closed) as soon as the raise switch 120 is released. If the lock/unlock switch 130 is not in the lock position, the deck will fall again.
An additional deficiency of this type of control valve is that, if the lock/unlock switch 130 inadvertently is left in the unlocked position when there is a power failure, the valve will open as soon as power is restored, allowing the platform 40 to fall, because fluid will be able to flow out of the main lift cylinder 110, resulting in a potentially dangerous situation.

Control circuit for vertically storing dock leveler


A method for handling content requests received in a CDN using an intermediate server may include maintaining a virtual file server that provides virtualized access to content in multiple POPs throughout the CDN, receiving a content request sent to the CDN, making a local request to the virtual file server for the content, where the specialized virtual file server may determine that the content is stored in a second POP that is remotely located from the first POP, and the specialized virtual file server may retrieve the content from the second POP and provide the content to the intermediate server as though it were stored locally in the first POP. The method may also include receiving the content from the specialized virtual file server, where the specialized virtual file server makes the requested content appear to be a locally-stored file to an operating system of the intermediate server.

This disclosure relates in general to a content delivery network (CDN) and, but not by way of limitation, to intermediate caching and processing to more efficiently utilize the CDN.
A CDN is a large distributed system of servers deployed in multiple data centers in the Internet. The goal of a CDN is to serve content to end-users with high availability and high performance. Besides better performance and availability, CDNs also offload the traffic served directly from the content provider's origin infrastructure. CDNs can include geographically distributed points of presence (POPs) to locate edge servers close to end users. CDNs are capable of delivering content in high demand with higher levels of quality of service (QoS). Content can be requested by universal resource locator (URL) from a CDN. Various techniques are used to route a URL request to a nearby POP, for example, in order to efficiently retrieve content.
Customers are using CDNs and cloud services in more creative ways. Applications, storage, and other services are being provided remotely. New forms and formats for content delivery are constantly being provided that can possibly provide greater access to content, faster transfer rates, and less burden on origin servers.

This patent is subject to a terminal disclaimer.

Intermediate content processing for content delivery networks