A waveguide mounting board having an array of ridge type waveguides on a surface thereof is automatically centered with an optical fiber board having a corresponding array of optical fibers by seating elongated alignment rails on the waveguide mounting board within alignment V-grooves in the fiber board. The alignment rails each comprises a short length of an optical fiber mounted on a pair of parallel alignment ridges. The alignment ridges are generally similar to the ridge type waveguides and are formed simultaneously therewith using a common photomask.

This invention relates to optoelectronic devices, and particularly to components and techniques for automatically, and "purely mechanically," interconnecting arrays of optical fibers with waveguide arrays.
The problem addressed by the present invention, as well as various solutions therefor, are known, see, for example, E. J. Murphy, "Fiber Attachment for Guided Wave Devices", J. Lightwave Tech., Vol. 6, No. 6, 6/88, pp. 862-871, and W. Hunziker et al, "Self-Aligned Optical Flip-Chip OEIC Packaging Technologies", Proc. ECOC, 1993, pp. 84-91 and U.S. Pat. Nos. 4,639,074 and 4,725,114, both to E. J. Murphy, the subject matter of which is incorporated herein by reference. Briefly, in various optical-electronic systems, e.g., telecommunication systems, it is the practice to mount various optical components, e.g., lasers, optical waveguide switch matrices, etc., on a mounting board and to interconnect the various components by means of optical waveguides formed on a surface of the mounting board. The waveguides are connected to optical fibers for signal transmission. Efficient assembly of the systems requires that the ends of the optical fibers be precisely aligned with and abutted against the ends of the waveguides. The present invention is directed to the problem of automatically interconnecting arrays of optical fibers with arrays of waveguides mounted on waveguide mounting boards. Also, as discussed in the cited references, the interconnecting is preferably done "purely mechanically," i.e., without the need for actually operating the devices being assembled together for monitoring and maximizing coupling efficiencies as part of the assembly process.
In one known technology, an array of fibers is disposed in a corresponding array of parallel V-grooves on a substrate which includes two empty V-grooves in precise relationship with the fibers. An array of waveguides, corresponding to the fiber array, is disposed on a second substrate which includes alignment ridges in precise relationship with the waveguides. In the assembly process, the two substrates are disposed in overlapping relationship with the ridges being disposed within the empty V-grooves for aligning the two substrates in contacting relationship. The ridges comprise elongated blocks having rectangular top surfaces, and precise alignment is obtained by engagement of elongated edges of the ridge top surfaces with the side walls of the V-grooves. End-to-end abutting relationship between the waveguides and the fibers is obtained by sliding the fiber substrate along the ridges until the ends of the fibers abut against ends of the waveguides.
While the prior known technology is functional, two problems are present. One problem arises from the fact that, in order to obtain precise alignment of the ridges with the waveguides on the waveguide substrate, the ridges are made using photolithographic and etching techniques involving etching into the surface of the substrate. While precision is obtained, the problem is that only relatively small ridges are obtained which are relatively fragile. During assembly, alignment of the two substrates is provided by sliding contact of the ridge upper surface edges with the sides of the V-grooves, and rupture of the edges frequently occurs.
Another problem of the process is that the ridges are formed separately from the waveguides, and the final accuracy is a function of how accurately the ridges are registered with the waveguides. Some inaccuracy inevitably results and, in any event, the separate processing procedures add expense.

Optoelectronic device connecting techniques


A powdered cellulose, containing essentially 3-8% of ammonium sulfate forms a biologically active media which preferentially adsorbs hydrocarbons in the presence of water and supports the growth of naturally occurring hydrocarbon reducing bacterial forms resulting in rapid decomposition of the adsorbed hydrocarbons into water, carbon dioxide and other benign waste products.

This invention relates to the field of materials and processes for the absorption and removal of hydrocarbon contaminants from ground surfaces, water or the soil.
Hydrocarbons, especially oil, refined gasoline and the like, are intensely poisonous chemicals to most plant life, and, as a result, relatively low levels of hydrocarbon contamination are capable of sterilizing soil. Therefore, the extraction and removal of hydrocarbon contaminants and spills from the ground and from ground water in the soil has become a particularly important environmental objective.
Two basic products and processes exist for the alleviation of hydrocarbon or oil spills. The first are those products and processes which are used to absorb oil from ground spills. The most noted of these are the clay absorbents formed of various forms of calcined clay and/or zeolite mixtures sold as products under such trade names as "Speedi-Dri" and other similar names. Such products are also sold widely in the form of animal litters. All such products are generally characterized in that they are particulates with physical adsorption properties that are adapted to absorb and bind hydrocarbons in a disposable form. However, an absorbent becomes contaminated in turn by the hydrocarbon and, thus, still presents a major disposal problem.
A second technique in use is that of bacterial remediation of hydrocarbon spills. In these techniques, various specialized strains of bacteria have been developed which metabolize various hydrocarbons and gradually reduce them to carbon dioxide and water. Such remediation is the only process currently known which is capable of actually eliminating hydrocarbon contamination as opposed to merely absorbing it and removing it to a second location. However, such bacterial remediation requires that the bacteria and the hydrocarbon be brought into intimate contact under conditions in which the bacteria will act to metabolize the hydrocarbons. This requires extensive labor and effort to spread the bacteria on the soil and then to continually work and rework the contaminated area, turning and tilling the soil, until such time as the bacteria have been brought substantially into contact with all of the contaminated hydrocarbon particles. Further, this leaves a problem in that the bacteria may themselves be an undesirable or toxic contaminant in the soil, since the bacteria have been specially bred for the purposes of metabolizing and reducing hydrocarbons. Such bacteria may otherwise be an undesirable species for future use of the soil as a growing or plant support medium.

Process and material for bioremediation of hydrocarbon contaminated soils


A method and apparatus for low voltage start circuit is provided. The start circuit (140) includes a first voltage converter (203) having a first booster circuit (210) and a first voltage multiplier (220) for converting a DC battery voltage to a converted DC voltage. The converted DC voltage is connected to an input of a second booster circuit (230) of a second voltage converter (205). The second voltage converter (205) includes the second booster circuit (230) and a second voltage multiplier (240). An output of the second voltage multiplier (240) is fed back to the input of the second booster circuit (230) for boosting the converted DC voltage to a predetermined threshold value. A voltage detector (136) compares the converted DC voltage to the predetermined threshold value. A controller (141) disables the start circuit (140) and enables a main DC-DC conversion circuit of the pager (100) when the converted DC voltage reaches the predetermined threshold value.

Portable receivers such as selective call receivers, pagers, personal messaging units (PMUs), and the like generally utilize a single cell battery for operation having a voltage in the range of 1.1 to 1.5 volts. In the design of selective call or paging receivers, it is desirable to prolong the operating time between battery charges or replacement. The physical size of paging receivers has reduced over the years. The size and electrical capacity of their batteries have also been reduced, potentially causing a reduction in the paging receiver's operating time. To compensate for the reduced battery capacity, circuitry has been developed to reduce the power drain of the paging products. Special battery saving techniques have been developed such that the only portions of the paging receiver are switched ON for brief intervals determined by the selective call coding protocol.
These devices can contain components which require more operating voltage than is available from a 1.4 V single cell battery. Accordingly, such devices require DC to DC conversion to provide the operating voltage needed for these components, such as a CMOS microprocessor, controller or LCD panel. DC to DC converters are used to boost the battery voltage to a converted voltage high enough to operate these components.
Inductive DC to DC converters have been used in the industry to boost battery voltage. One such converter is illustrated in U.S. Pat. No. 5,028,861 to Pace, assigned to the assignee of the present invention, generally described below. The DC to DC converter regulates the maximum current through an inductor. It operates within a paging receiver and boosts a voltage from a 1.4 V DC single cell battery to substantially 3.1 V DC in order to operate the circuits which require more voltage than provided by the single cell battery. The disadvantages of using inductive DC to DC converters versus capacitive DC to DC converters is that inductors are less efficient, larger, and cost more than capacitors. Inductors are also less reliable, since they are more susceptible to shock and vibration.
Other technologies, such as CMOS, have been investigated to increase the conversion efficiency. Current CMOS capacitive voltage doublers (DC-DC converters) use capacitors and alternate precharge and dump phases to generate double the battery voltage. For battery voltage VBB, the doubler increases this voltage to 2 VBB. A voltage regulator can then be used to lower this voltage to the required level for operating the various components. However, these systems require higher battery voltage during start up under heavy load current operation. Accordingly, a major problem with CMOS circuitry is establishing a voltage high enough to start the operation.
This high voltage requirement has forced the use of bipolar start (switching) circuits since their low turn on voltage can provide direct operation from a single cell battery. An example of a low power start circuit using bipolar technology is described in U.S. Pat. No. 4,961,006 to Pace et al., (the '006 patent), assigned to the assignee of the present application, generally described below.
The inductively loaded switching transistor of the '006 patent used in a DC to DC converter includes an inductive load and a coil switching transistor (NPN transistor) has a first emitter coupled to a first source of a supply voltage and a second emitter coupled to ground via a resistor. The collector of the transistor is coupled via an inductive load to a second source of supply voltage for conducting current flowing therethrough when the switching transistor is on. A drive circuit is provided which is coupled to the switching transistor for supplying a drive current thereto, and feedback is provided for adjusting the amount of base drive supplied to the switching transistor from the drive circuit.
A problem with these bipolar devices is that they require base drive currents to operate. Accordingly, the efficiency of the DC to DC conversion is degraded in high load current operation and is severely degraded in low load current operation.
Thus, there is a need in the art for boosting low battery voltage to a level sufficient to operate a device without requiring base drive currents to operate.

Method and apparatus for low voltage CMOS start circuit


An implantable electrode paddle is adapted to receive an electrical signal from a medical device and generate an electrical field to stimulate selected body tissue. The paddle includes a housing including walls that define an interior space and a plurality of windows formed through at least a first one of the walls for transmitting the electrical field to the body tissue, an electrode array including a plurality of electrode groups, each electrode group including at least two electrodes individually secured in a respective window and spaced between about 0.1 mm and about 10 mm apart, and a plurality of wires, each of the wires being coupled to a respective electrode and routed within the interior space to receive the electrical signal. A lead assembly and an implantable medical device can include the paddle.

Dorsal columns are long myelinated fibers oriented along the spinal cord axis and centrally located around the lumbar spine between the dorsal roots. Researchers have found that fibers enter the dorsal horn, and are arranged in approximately v-shaped layers. Fibers that enter at a higher vertebral level form a v-shaped layer covering the layers that originated at lower levels. The nerve fiber organization is less structured below the dorsal column surface, where the fibers are two or more vertebral levels away from their point of entry. M. C. Smith et al., Topographical Anatomy of the Posterior Columns of the Spinal Cord in Man, 107 Brain 671 (1984). FIG. 1 is a cross sectional view of different vertebra through the spinal cord with symbols illustrating the spinal nerve pathways through the dorsal column.
Chronic pain originating in the lower back is quite common. Spinal cord stimulation is an accepted therapy for chronic pain. However, physicians have found that it can be difficult to properly position the spinal cord stimulation lead to achieve good pain relief for lower back pain. As illustrated in FIG. 1, nerve fibers associated with lower back pain (S4 to L5), are only close to the dorsal column surface for a short distance and are consequently difficult to locate. Physicians who consider properly treating lower back pain with SCS must develop an effective SCS technique and must learn to manipulate a stimulating lead with unusual skill and patience. Such a technique often involves implanting a stimulating device and carefully positioning at least one stimulating lead into a patient's spinal area. Even if the technique is performed properly, the leads may need to be repositioned over time. Repositioning the stimulating leads is typically an invasive surgical procedure that carries risks and requires great patience, care, and skill.
Accordingly, it is desirable to provide a system and method that physicians can readily adopt for stimulating the spinal cord, particularly areas of the spinal cord that have low surface concentrations of readily manipulated nerves such as those in the dorsal columns. In addition, it is desirable to provide a system and method for non-invasively relocating an electrical field after the system is implanted. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

Field steerable electrical stimulation paddle, lead system, and medical device incorporating the same


A power converter with output voltage level indicating device is disclosed. The power converter includes a casing, an interior of which is disposed with a control circuit. The control circuit includes a feedback circuit and a DC-to-DC conversion circuit. The feedback circuit is coupled to the DC-to-DC conversion circuit and connected to a level-selecting terminal by at least one resistor to provide a feedback signal to the DC-to-DC conversion circuit which in turn changes the voltage level of the DC output. An output socket is formed at the casing, which is connected with the control circuit. The output socket includes two primary, power terminals and at least one secondary, level-selecting terminals. A level-selecting terminal device is connected to the output socket via an extension cable for getting the DC voltage and supplying the DC voltage to an appliance via an output terminal. A display device is provided at the casing for showing the output voltage level to the output terminal of the level-selecting terminal device.

1. Field of the Invention
The present invention relates generally to a power converter, and in particular to a power converter comprising an output voltage level indicating device for indication and easy reading of output level of voltage.
2. Description of the Prior Art
Portable electronic appliances, such as mobile phone and notebook computer, play an important role in the modern world in doing business and society activities. Such portable appliances are often powered by built-in power sources, which must be constantly recharged in order to maintain operability of the portable appliances. Also, external powering is also available for most of the portable appliances, such as wall outlet, automobile electrical system including cigarette lighter socket and electrical socket regularly available in airplanes. Often the external powering must be converted by for example a conversion circuit made in the form of an adaptor before it can be supplied to the portable appliances.
However, the portable appliances are often operated with different working voltages and for such a reason, the general consumers that own and use two or more different portable appliance must regularly bring two or more adaptors corresponding to those portable appliances. This complicates the use of the portable appliances and is very troublesome to the consumers. U.S. Pat. No. 6,628,535, issued to the present inventor, teaches a power converter that provides selectable output voltage levels to different appliances or loads. The power converter of the '535 patent comprises an output to which a terminal connector is selectively coupled. The terminal connector comprises a circuit comprised of resistors that generates a feedback signal to a control circuit of the power converter, inducing a corresponding voltage level at the output of the conversion device.
Such a conventional power converter works well in supplying voltage of different levels to electronic appliances that operates with different working voltages. It, however, is still unclear to a user what voltage level is being output by the power converter when the device is powering an electronic appliance. This may cause problem to the user.
Thus, the present invention is aimed to provide a power converter that overcomes the drawback of the conventional devices.

Power converter with output voltage level indicating device


A differential assembly including a rotatable casing, first and second axially moveable side gears disposed within the casing, at least one pinion gear disposed within the casing and intermeshed with the side gears, a cone clutch operatively coupled to the first side gear, the cone clutch being frictionally coupled to the casing in response to being exposed to a magnetic field, and a disc clutch having at least one clutch disc operatively coupled to the second side gear in response to axial movement of the second side gear.

The present invention relates to limited slip differentials, and more particularly to limited slip differentials having an electromagnetically actuated clutch.
Differentials are well known in the prior art and allow each of a pair of output shafts or axles operatively coupled to a rotating input shaft to rotate at different speeds, thereby allowing the wheel associated with each output shaft to maintain traction with the road while the vehicle is turning. Such a device essentially distributes the torque provided by the input shaft between the output shafts.
The completely open differential, i.e., a differential without clutches or springs which restrict relative rotation between the axles and the rotating differential casing, is not well suited to slippery conditions in which one driven wheel experiences a much lower coefficient of friction than the other driven wheel: for instance, when one wheel of a vehicle is located on a patch of ice and the other wheel is on dry pavement. Under such conditions, the wheel experiencing the lower coefficient of friction loses traction and a small amount of torque to that wheel will cause a xe2x80x9cspin outxe2x80x9d of that wheel. Since the maximum amount of torque which can be developed on the wheel with traction is equal to torque on the wheel without traction, i.e. the slipping wheel, the engine is unable to develop any torque and the wheel with traction is unable to rotate. A number of methods have been developed to limit wheel slippage under such conditions.
Prior means for limiting slippage between the axles and the differential casing use a frictional clutch mechanism, either clutch plates or a frustoconical engagement structure, operatively located between the rotating case and the axles. Certain embodiments of such prior means provide a clutch element attached to each of the side gears, and which frictionally engages a mating clutch element attached to the rotating casing or, if the clutch is of the conical variety, a complementary interior surface of the casing itself. Such embodiments may also include a bias mechanism, usually a spring, to apply an initial preload between the clutch and the differential casing. By using a frictional clutch with an initial preload, a minimum amount of torque can always be applied to a wheel having traction, e.g., a wheel located on dry pavement. The initial torque generates gear separating forces between the first pinion gears and the side gears intermeshed therewith. The gear separating forces urge the two side gears outward, away from each other, causing the clutch to lightly engage and develop additional torque at the driven wheels. Examples of such limited slip differentials which comprise cone clutches are disclosed in U.S. Pat. No. 4,612,825 (Engle), U.S. Pat. No. 5,226,861 (Engle) and U.S. Pat. No. 5,556,344 (Fox), each of which is assigned to Auburn Gear, Inc., the disclosures of which are all expressly incorporated herein by reference.
Certain prior art limited slip differentials provide, between the first of the two side gears and its associated clutch element, interacting camming portions having ramp surfaces or ball/ramp arrangements. In response to an initiating force, this clutch element is moved towards and into contact with the surface against which it frictionally engages, which may be a mating clutch element attached to the casing, or an interior surface of the casing itself, as the case may be, thereby axially separating the clutch element and its adjacent first side gear, the interacting camming portions slidably engaging, the rotational speed of the clutch element beginning to match that of the differential casing due to the frictional engagement. Relative rotational movement between the ramp surfaces induces further axial separation of the clutch element and the first side gear. Because the clutch element is already in abutting contact with the surface against which it frictionally engages, the first side gear is forced axially away from the clutch element by the camming portions.
Certain embodiments of such limited slip differentials utilize an electromagnet having an electrical coil to effect the initiating force and actuate the clutch, as disclosed in U.S. Pat. No. 5,989,147 (Forrest et al.), U.S. Pat. No. 6,019,694 (Forrest et al.), and U.S. Pat. No. 6,165,095 (Till et al.), each of which is assigned to Auburn Gear, Inc., the disclosures of which are all expressly incorporated herein by reference. Each of these references discloses that the differential casing, in which the clutches are disposed, rotates within the housing and is rotatably supported by a pair of bearings. An electromagnet, which actuates a primary cone clutch element, is mounted in fixed relationship to the axle housing and is rotatably supported by the differential casing. Alternatively, as disclosed in pending U.S. patent application Ser. No. 09/484,967, filed Jan. 18, 2000, which is assigned to Auburn Gear, Inc., the disclosure of which is expressly incorporated herein by reference, the electromagnet may be fixedly supported by the axle housing. In either case, activation of the electromagnet draws a primary cone clutch element into frictional engagement with the rotating differential housing.
The camming portions, described above, act between the primary cone clutch element and the first side gear to axially separate them, forcing the first side gear into abutment with a transfer block located intermediate the first and second side gears. Responsive to this force, the transfer block is moved into abutment with the second side gear, which is rotatably fixed to a secondary cone clutch element, which frictionally engages a mating interior surface of the rotating differential casing. The frictional engagement of the secondary cone clutch element and the differential casing effects further clutched engagement between the axles and the differential casing, enhancing the locking capability of the limited slip differential. Notably, the load carrying capability of the secondary cone clutch mechanism is usually significantly greater than that of the primary cone clutch mechanism, owing to a greater axial engagement force exerted thereon. Examples of prior limited slip differentials are described in more detail below, with reference to FIGS. 1 and 2.
FIG. 1 depicts an embodiment of prior axle assembly 10 having electrically or electromagnetically actuated limited slip differential assembly 12. Axle assembly 10 may be a conventional axle assembly or comprise part of a transaxle assembly. Therefore, it is to be understood that the term xe2x80x9caxle assemblyxe2x80x9d encompasses both conventional (rear wheel drive) axle assemblies as well as transaxle assemblies. Differential assembly 12 comprises electromagnet 14, ferrous rotatable casing 16 constructed of joined first and second casing parts 16a and 16b, respectively, and providing inner cavity 18, which is defined by the interior surface of the circumferential wall portion of first casing part 16a and end wall portions 20, 22 of first and second casing parts 16a, 16b, respectively. Casing part 16a may be a machined iron or steel casting; casing part 16b may also be such a casting, or a ferrous, sintered powdered metal part. Disposed within cavity 18 are side gears 24, 26 and pinion gears 28, 30. The teeth of the side gears and pinion gears are intermeshed, as shown. Pinion gears 28, 30 are rotatably disposed upon cylindrical steel cross pin 32, which extends along axis 34. The ends of cross pin 32 are received in holes 36, 38 diametrically located in the circumferential wall of casing part 16a.
Axles 40, 42 are received through hubs 44, 46, respectively formed in casing end wall portions 20, 22, along common axis of rotation 48, which intersects and is perpendicular to axis 34. Axles 40, 42 are respectively provided with splined portions 50, 52, which are received in splines 54, 56 of side gears 24, 26, thereby rotatably fixing the side gears to the axles. The axles are provided with circumferential grooves 58, 60 in which are disposed C-rings 62, 64, which prevent the axles from being removed axially from their associated side gears. The terminal ends of the axles 98 and 100 may abut against the cylindrical surface of cross pin 32, thereby restricting the axles"" movement toward each other along axis 48.
Primary clutch element 66 is attached to side gear 24 and rotates therewith. Clutch element 66 is ferrous and of the cone clutch variety and has frustoconical surface 68 which is adjacent to, and clutchedly interfaces with, complementary surface 70 provided on the interior of casing part 16a. Secondary clutch element 72 is also of the cone clutch variety and has frustoconical surface 74 which is adjacent to, and clutchedly interfaces with, complementary surface 76 also provided on the interior of casing part 16a. Cone clutches 66 and 72 may be of the type described in U.S. Pat. No. 6,076,644 (Forrest et al.) or U.S. Pat. No. 6,261,202, each of which is assigned to Auburn Gear, Inc., the disclosures of which are both expressly incorporated herein by reference, or may also be of any other suitable structure.
Disposed between primary cone clutch element 66 and side gear 24 is annular cam plate 78, which abuts thrust washer 82 adjacent end wall portion 22. Ball and ramp arrangement 84, 86, 88 is comprised of a first plurality of paired spiral slots 84, 86 located in cam plate 78 and primary cone clutch element 66, respectively. Slots 84, 86 define a helically ramping path followed by ball 88, which may be steel, disposed in each slot pair and a first ramp angle. With electromagnet 14 de-energized, balls 88 are seated in the deepest portion of slots 84, 86 by Belleville spring 90. The actuation sequence is created by the momentary difference in rotational speed between cone clutch element 66 and cam plate 78 as frustoconical surfaces 68 and 70 seat against each other. A more detailed discussion of ball/ramp camming arrangements is disclosed in U.S. Pat. No. 5,989,147.
In operation, a variable coil current on electromagnet 14 induces a variable amount of magnetic clamping force between casing part 16a and primary cone clutch element 66, which induces a variable amount of torque to be exerted by casing part 16a on clutch element 66. As electromagnet 14 is activated, axial separation of primary cone clutch element 66 and cam plate 78 is induced as cone clutch element 66 is magnetically pulled to the left against the force of Belleville spring 90 into clutched engagement with casing part 16a through frustoconical surfaces 68 and 70. In response to the initial flow of magnetic flux, cone clutch element 66 is pulled by the magnetic field to the left and surfaces 68 and 70 abut, and enter frictional engagement. As cone clutch element 66 and cam plate 78 separate axially, balls 88 are caused to rotate along the ramping helical paths of slots 84, 86 due to the relative rotation between clutch element 66 and cam plate 78. Cam plate 78 is urged against thrust washer 82 by the force of Belleville spring 90 and gear separation forces between pinion gears 28, 30 and side gear 24. As balls 88 rotate further along the helical ramp paths, frustoconical surfaces 68, 70 are forced into tighter frictional engagement and cam plate 78, still abutting thrust washer 82, reaches the end of its rotational travel relative to cone clutch member 66.
First side gear 24 moves towards the right, forcing secondary cone clutch element 72 into abutment with casing part 16a via transfer block 92 and second side gear 26 in the manner described above. Transfer block 92, which may be steel, is disposed about cross pin 32 and adapted to move laterally relative thereto along axis 48 to transfer movement of first side gear 24 to second side gear 26, thereby engaging secondary clutch element 72. As shown, transfer block 92 is attached directly to cross pin 32, and supports the cross pin in position within the differential casing as described in U.S. Pat. No. 6,254,505, assigned to Auburn Gear, Inc., the disclosure of which is expressly incorporated herein by reference. Alternatively, the transfer block may be loosely fitted about the cross pin, the cross pin being directly attached to the differential housing by a bolt extending through one end of the cross pin, as shown, for example, in U.S. Pat. No. 5,226,861. The shear loads associated with torque transmission are exerted on cross pin 32 near its opposite ends, particularly between the circumferential wall of casing part 16a and the adjacent pinion gears 28, 30.
Transfer block 92 includes opposite bearing sides 94, 96 which respectively abut first and second side gears 24, 26, and allows terminal ends 98, 100 of axles 40, 42, respectively, to abut the cylindrical side surface of cross pin 32. Transfer block 92 moves laterally relative to cross pin 32, along axis 48, such that rightward movement of side gear 24, described above, is transferred to side gear 26. Thus, during actuation of electromagnet 14, first side gear 24 is urged rightward, as viewed in FIG. 1, into abutting contact with transfer block 92. Transfer block 92 moves rightward, into abutting contact with second side gear 26; and second side gear 26 moves rightward, urging surface 74 of secondary clutch element 72 into frictional engagement with surface 76 of casing part 16a, thereby providing additional torque transfer capacity to the differential than would otherwise be provided with single cone clutch element 66.
Provided on the exterior surface of casing part 16a, near electromagnet 14, is flange 102, to which ring gear 104 is attached. The teeth 136 of ring gear 104 are in meshed engagement with the teeth of pinion gear 106 which is rotatably driven by an engine (not shown), thus rotating differential casing 16 within axle housing 108. As casing 16 rotates, the sides of holes 36, 38 bear against the portions of the cylindrical surface of cross pin 32 in the holes. The rotation of cross pin 32 about axis 48 causes pinion gears 28, 30 to revolve about axis 48. The revolution of the pinion gears about axis 48 causes at least one of side gears 24, 26 to rotate about axis 48, thus causing at least one of axles 40, 42 to rotate about axis 48. Engagement of the clutches as described above arrests relative rotation between the side gears and the differential casing.
Differential casing 16 is rotatably supported within axle housing 108 by means of identical first and second bearings 110, 112. Because of the proximity of ring gear flange 102 to the end of casing 16 nearest first bearing 110, in operation, that bearing is more heavily loaded than is second bearing 112.
Electromagnet 14 is rotatably supported on second differential casing portion 16b by third bearing 114. Electromagnet 14 is rotatably fixed relative to axle housing 108 and disposed in close proximity to casing 16, which rotates relative thereto. The voltage applied to electromagnet 14 to energize same and actuate primary clutch element 66 may be controlled by a control system (not shown) which is in communication with sensors (not shown) which indicate, for example, excessive relative rotation between axles 40, 42, and thus the need for traction control. Housing 108 includes hole 116 fitted with rubber grommet 118 through which extend leads 120. Through leads 120 the control system provides voltage to electromagnet 14. As electromagnet 14 is energized, a magnetic initiating force is applied to primary cone clutch element 66 by a toroidal electromagnetic flux path (not shown) which is established about the annular electromagnet coil 126; the flux path flows through ferrous casing portions 16a and 16b and through clutch element 66. Clutch element 66 is thus magnetically drawn into engagement with casing 16 during operation of electromagnet 14. Because it is made of a magnetic material (e.g., steel) and has a solid structure, primary cone clutch element 66 is better suited for conducting the magnetic flux path therethrough than would be a clutch comprising a series of interleaved discs, which may have gaps therebetween and which would likely be formed of materials which would not so readily transmit the magnetic flux. Further, casing part 16b may include annular nonmagnetic portion 122 to help direct the toroidal magnetic flux path through primary cone clutch element 66, as described in U.S. Pat. No. 6,019,694 (Forrest et al.), assigned to Auburn Gear, Inc., the disclosure of which is expressly incorporated herein by reference.
FIG. 2 depicts a second embodiment of a prior axle assembly which is identical in structure and operation to the above-described axle assembly 10 except as follows: Axle assembly 10xe2x80x2 comprises electromagnet 14xe2x80x2 which is fixed to the axle housing, rather than being rotatably supported by a bearing 114 disposed about casing part 16b. Bearing 110xe2x80x2 is disposed in cup 124 which extends inwardly of the axle housing to engage and support electromagnet 14xe2x80x2 in the manner described in pending U.S. patent application Ser. No. 09/484,967, filed Jan. 18, 2000. Notably, bearing 110xe2x80x2 is somewhat smaller than bearing 110 (and identical bearing 112) and, as noted above, would be more heavily loaded during operation than larger bearing 112 due to the proximity of the ring gear.
Although cone clutches of the type disclosed above are better suited than disc-type clutches as primary clutch elements in electromagnetically-actuated limited slip differentials, for the reasons set forth above, their load carrying capability is limited, for a give axial engagement force, by the angle of the included angle formed by the cone clutch engagement surfaces. Typically, these angles range from 9xc2x0 to 12.5xc2x0. The smaller this angle, the greater the torque capacity of the cone clutch. The smaller this angle, however, the harsher the clutch engagement, and the smaller the tendency for the clutch to release. Clutches having multiple interleaved discs, or xe2x80x9cclutch packs,xe2x80x9d are well known in the art and generally have greater torque capacity than a cone clutch of approximately equal package size. Moreover, the required tolerances associated with manufacturing cone clutches tend to be somewhat smaller than with disc clutches.
Further still, compared to the axial movement needed to engage disc clutches, a greater distance is needed when using cone clutches because a portion of the movement is absorbed by the casing as it is being radially stretched. Therefore, relatively more movement between the pinion and side gears is needed to accommodate proper movement of the cone clutch, and optimal gear mesh clearances therebetween, which are on the order of xc2x10.010 inch, may be compromised. An electromagnetically-actuated limited slip differential assembly which provides the respective benefits of cone clutches and clutch packs is highly desirable.
A further issue associated with electromagnetically-actuated limited slip differentials is that the electromagnet tends to magnetize ferrous components within the axle housing, particularly those in close proximity to the electromagnet. This can be of particular concern where relatively moving, interengaging components such as bearings or gears of the differential or axle assembly become magnetized and attract metal shavings or other ferrous debris, or where the shavings and debris are themselves magnetized and become attached to these interengaging components. The collection of such contamination on these components can substantially accelerate their wear and lead to premature failure.
One known approach to addressing this issue is to provide a magnetic drain plug in the axle housing, which may attract and retain some of the debris. However, the debris may be equally attracted to other magnetized components within the axle housing, rather than to only the drain plug. Another approach to addressing this issue is described in
U.S. Pat. No. 6,165,095, which discloses an apparatus and method for demagnetizing the components initially magnetized by the electromagnet. While effective, this means for demagnetization involves providing additional controls for directing current through the electromagnet(s). It is desirable to provide a simple and effective means for reducing the likelihood or severity of magnetization of at least some of the relatively moving, interengaging components within the axle housing.
Further, one way to reduce the cost and improve the reliability of an axle assembly is to reduce the number of components parts, or at least the number of complex, high precision parts. For example, reducing the number of ball or roller bearings may reduce the cost of material, the cost of assembly labor, and the number of moving parts, thereby improving durability and reliability. Reduction in the number of parts, however, may compromise the ability of the remaining parts to perform satisfactorily. For example, reducing the number of bearings may increase the load to be borne by the remaining bearings, which may adversely affect the durability of those remaining bearings. The reduction of costs without compromising performance is an ongoing and important goal in virtually every commercial endeavor, and means for accomplishing that goal are therefore highly desirable.
The present invention provides a differential assembly including a rotatable casing, first and second axially moveable side gears disposed within the casing, at least one pinion gear disposed within the casing and intermeshed with the side gears, a cone clutch operatively coupled to the first side gear, the cone clutch being frictionally coupled to the casing in response to being exposed to a magnetic field, and at least one clutch disc operatively coupled to the second side gear in response to axial movement of the second side gear.
The present invention also provides a differential assembly including a rotatable casing having opposite ends, a differential gear mechanism and a magnetically-activated clutch disposed within the casing, relative rotation of at least a portion of the gear mechanism being selectively frictionally engaged with the casing by the clutch, an electromagnet being disposed proximal to one of the casing ends, and a ring gear attached to the casing at a location proximal to the other of the casing ends.
The present invention also provides a differential assembly including a rotatable casing, a differential gear mechanism and a magnetically-activated clutch disposed within the casing, relative rotation of at least a portion of the gear mechanism being selectively frictionally engaged with the casing by the clutch, an electromagnet disposed proximal to the casing, the casing and the electromagnet having relative rotation therebetween, and a self lubricating bearing disposed between the electromagnet and the casing, the electromagnet being supported relative to the casing by the bearing.

Electromagnetically-actuated limited slip differential


One embodiment of the present invention provides a system that performs a query-based convergecast scheduling in a convergecast network, which includes a base-station and a plurality of nodes. During operation, the system receives a convergecast tree for the convergecast network. Each node in the convergecast tree is associated with a hop-count to the base-station through a specific branch and each node can generate zero or more packets to transmit. Next, the system initializes a query from the base-station, wherein the query is successively propagated to the nodes through the branches. In response to the query, the system computes distributed-timing-information indicating a packet transmission schedule for the nodes. The system next aggregates the distributed-timing-information associated with the nodes toward the base-station through the branches. The system then forwards the aggregated distributed-timing-information to the plurality of nodes. Finally, each node constructs an optimized-convergecast-schedule for the convergecast tree based on the aggregated distributed-timing-information.

1. Field of the Invention
The present invention relates to wireless sensor networks. More specifically, the present invention relates to a method and an apparatus for performing a query-based convergecast scheduling to achieve an optimal convergecast time in a wireless sensor network.
2. Related Art
Many applications of sensor networks involve periodically collecting all the data generated by sensor nodes at the base-station. In these applications, all the data packets generated in the network have to be transmitted to a base-station for record-keeping or for intensive computational-analysis. Examples of such applications include acquiring periodic global snapshots of the network state, monitoring the residual energy of nodes, and localizing a sniper in urban environment. Consequently, this many-to-one communication pattern, referred to as a "convergecast," is highly important in sensor networks.

This patent is subject to a terminal disclaimer.

Method and apparatus for performing a query-based convergecast scheduling in a wireless sensor network


A testing device is disclosed. The testing device includes: a testing platform; an electromagnetic relay platform arranged opposite to the testing platform; and a plurality of probe assemblies disposed between the electromagnetic relay platform and the testing platform. Each of the probe assemblies includes an electromagnetic base and a probe mounted in a side of the electromagnetic base away from the electromagnetic relay platform. Each of the electromagnetic bases is attracted together with the electromagnetic relay platform under an electromagnetic attraction force when the electromagnetic relay platform is energized. The above testing device may be used for testing a variety of circuit boards, and has a relatively wide application.

Field of the Invention
The present disclosure relates to a field of circuit board testing technology, and specifically relates to a testing device.
Description of the Related Art
Currently, in general, testing points are previously provided in a printed circuit board assembly (PCBA) when manufacturing the assembly. In conventional testing devices for testing the PCBA, each testing device has probes distributed corresponding to the testing points of the PCBA to be tested, and the functionality of the PCBA is tested by means of connecting the probes with the testing points. Thus, each testing device can only be used for testing one type of PCBA.
Currently, a wide variety of PCBA products are used. Since each type of the PCBA products requires a corresponding testing device, the existing PCBA products have a significantly high design cost. In addition, once a project involving circuit board testing is completed, many testing devices will be left unused, even discarded, resulting in a significant waste in cost.

HEFEI XINSHENG OPTOELECTRONICS TECHNOLOGY CO., LTD.


The outboard motor of the present invention comprises a pedestal that is attached to a transom of a boat, a motor support platform that is attached to the outboard motor, and a steering mechanism that is attached to both the pedestal and the motor support platform. It comprises a hydraulic tilting mechanism that is attached to the motor support platform and to the outboard motor. The outboard motor is rotatable about a tilt axis relative to both the pedestal and the motor support platform. A hydraulic pump is connected in fluid communication with the hydraulic tilting mechanism to provide pressurized fluid to cause the outboard motor to rotate about its tilting axis. An electric motor is connected in torque transmitting relation with the hydraulic pump. Both the electric motor and the hydraulic pump are disposed within the steering mechanism.

1. Field of the Invention
The present invention is generally related to outboard motors and, more particularly, to specific mounting configurations of an outboard motor to a transom of a boat, including the arrangement of a motor and hydraulic pump relative to the steering components of the outboard motor and further including a secure means for fastening the outboard motor to the transom of a boat.
2. Description of the Prior Art
Many different types of outboard motors are well known to those skilled in the art. Numerous techniques have been developed for mounting an outboard motor to a transom of a boat, including many different types of steering and tilting arrangements.
U.S. Pat. No. 3,911,853, which issued to Strang on Oct. 14, 1975, describes a low profile outboard motor with an in-line engine. The outboard motor comprises a propulsion unit that is adapted to be attached to the transom of a boat for vertical swinging movement relative to the transom about a horizontal tilt axis and for steering movement relative to the transom about a steering axis extending transversely of the tilt axis. The propulsion unit comprises a lower unit including an exhaust gas discharge outlet normally located under water, a power head assembly rigidly fixed to the top of the lower unit and including an engine with a plurality of vertical in-line cylinders each including an exhaust port, together with an exhaust gas discharge system including an inverted "U" shaped passageway comprising an upper junction portion located above the at rest water level when the outboard motor is boat mounted, a first leg extending downwardly from the junction portion and communicating with at least one of the exhaust ports, and a second leg extending downwardly from the junction portion and separately from the first leg and communicating with the lower unit underwater exhaust gas discharge outlet. Also included in the outboard motor is an upwardly open water guard which extends upwardly from above the lower unit, in watertight encircling relation to the engine, to above the at rest water level.
U.S. Pat. No. 4,354,847, which issued to Blanchard on Oct. 19, 1982, describes a high tilt pivot mounting arrangement for an outboard motor. The marine propulsion device comprises a transom bracket adapted to be fixed to a boat transom, a swivel including a vertical leg having upper and lower ends, and a pair of arms extending upwardly in laterally spaced relation from the upper end of the swivel bracket vertical leg and including respective upper ends, a first pivot connecting the upper ends of the arms and the transom bracket for vertical swinging of the swivel bracket relative to the transom bracket about a first axis which is horizontal when the transom bracket is boat mounted, a propulsion unit including a power head and lower unit fixedly connected to the power head and including, at the lower end thereof, a propeller, and a second pivot connecting the propulsion unit and the swivel bracket vertical leg for movement of the propulsion unit in common with the swivel bracket about the first axis and for steering movement of the propulsion unit relative to the swivel bracket about an axis which extend transversely to the first axis.
U.S. Pat. No. 4,355,986, which issued to Stevens on Oct. 26, 1982, describes an outboard motor with elevated horizontal pivot axis. The outboard comprises a transom bracket adapted to be fixed to a boat transom and having a generally flat mounting surface for engagement with the back of the transom, a swivel bracket, a pivot on the swivel bracket and on the transom bracket rearwardly of the mounting surface for pivotally connecting the swivel bracket and the transom bracket for tilting movement between a normal operating position and a raised tilt position and about a tilt axis which is generally horizontal when the transom bracket is fixed to the boat transom, a propulsion unit including a power head and a lower unit rigidly secured to the power head, and a pivot connected to the propulsion unit and located below the power head and connected to the swivel bracket for pivotally connecting the propulsion unit and the swivel bracket for steering movement about an axis transverse to the tilt axis and such that the propulsion unit remains rearwardly of the plane of the transom bracket mounting surface throughout movement of the swivel bracket from the normal operating position to the tilt position.
U.S. Pat. No. 4,363,629 which issued to Hall et al on Dec. 14, 1982, describes a hydraulic system for outboard motors with sequentially operating tilt and trim means. The marine propulsion device comprises a transom bracket adapted to be connected to a boat transom, a first pivot connecting a stem bracket to the transom bracket for pivotal movement of the stem bracket relative to the transom bracket about a first pivot axis which is horizontal when the transom bracket is boat mounted, a second pivot connecting a swivel bracket to the stem bracket below the first pivot for pivotal movement of the swivel bracket with the stem bracket and relative to the stem bracket about a second pivot axis parallel to the first pivot axis, a king pin pivotally connecting a propulsion unit including a rotatably mounted propeller to the swivel bracket for steering movement of the propulsion unit relative to the swivel bracket about a generally vertical axis and for common pivotal movement with the swivel bracket in a vertical plane about the first and second horizontal axes, a trim cylinder piston assembly pivotally connected to the stem bracket and to the swivel bracket, a tilt cylinder-piston assembly pivotally connected to the transom bracket and to the stem bracket, and a fluid conduit system communicating between a source of pressure fluid and each of the tilt cylinder-piston assembly and the trim cylinder-piston assembly and including apparatus operable, during reverse operation of the propulsion unit, for causing initial full extension to the trim cylinder-piston assembly, followed by extension of the tilt cylinder-piston assembly, and for causing initial full contraction of the tilt cylinder-piston assembly, followed by subsequent contraction of the trim cylinder piston assembly.
U.S. Pat. No. 4,384,856, which issued to Hall et al on May 24, 1983, describes a lateral support arrangement for outboard motors with separate tilt and trim axes. The outboard motor comprises a transom bracket adapted to be connected to a boat transom, a propulsion unit which is mounted to the transom bracket for pivotal steering movement of the propulsion unit in a horizontal plane and for pivotal movement of the propulsion unit in the vertical plane between a lowermost running position and a full tilt position, which propulsion unit mounting includes a first pivot connecting an intermediate bracket to the transom bracket for pivotal movement of the intermediate bracket relative to the transom bracket about a first pivot axis which is horizontal when the transom bracket is boat mounted, whereby to enable movement of the propulsion unit through a tilt range, a second pivot connecting a swivel bracket to the intermediate bracket for pivotal movement of the swivel bracket with the intermediate bracket and relative to the intermediate bracket about a second pivot axis parallel to the first pivot axis, whereby to enable movement of the propulsion unit through a trim range, and a king pin pivotally connecting the propulsion unit to the swivel bracket for steering movement of the propulsion unit relative to the swivel bracket about a generally vertical axis and for common pivotal movement of the swivel bracket in a vertical plane above the first and second horizontal axes, hydraulic cylinders for sequentially displacing the propulsion unit from the lowermost position through the trim range and then through the tilt range to the full tilt position, and a support on the transom bracket for providing side support to the intermediate bracket.
U.S. Pat. No. 4,395,238, which issued to Payne on Jul. 26, 1983, describes an outboard motor mounting means which affords upward tilting without travel of the motor forward of the boat transom. The marine propulsion device comprises a bracket adapted to be fixed to the transom of a boat and including a generally planar mounting surface engaged with the boat transom when the boat is boat mounted, which bracket also includes a lower part having a lower bearing with a steering axis which extends generally vertical when the bracket is boat mounted, a member including a lower portion extending in the lower bearing and a pair of laterally spaced arms connected to the lower portion and respectively including upper horizontal bearings having a common axis located in spaced relation above the lower bearing, a steering arm fixed to the member for steerably rotating the member within the lower bearing about the generally vertical axis, a propulsion unit including a power head and a lower unit extending fixedly downward from the power head and including a rotatably mounted propeller, and trunnions on the power head adjacent the top thereof and received in the upper horizontal bearings for pivotally connecting the propulsion unit to the member for movement about the horizontal axis between a running position with the propeller submerged in water and with the propulsion unit located wholly aft of the bracket mounting surface and an elevated position with the propeller substantially out of the water and with the propulsion unit located wholly aft of the bracket mounting surface.
U.S. Pat. No. 4,406,634, which issued to Blanchard on Sep. 27, 1983, describes an outboard motor with steering arm located aft of the transom and below the tilt axis. The outboard motor comprises a transom bracket adapted to be fixed to the transom of a boat, a propulsion unit supporting a thrust producing element, and a bracket assembly connecting the propulsion unit to the transom bracket so as to provide for pivotal steering movement of the propulsion unit relative to the transom bracket and for tilting of the propulsion unit relative to the transom bracket about a tilt axis located rearwardly of the transom, which bracket assembly connecting the propulsion unit to the transom bracket includes a steering arm connected to the propulsion unit and extending forwardly therefrom below the tilt axis and having a forward end terminating rearwardly of the transom.
U.S. Pat. No. 4,449,945, which issued to Ferguson on May 22, 1984, describes an outboard motor mounting arrangement. The marine propulsion installation comprises a marine propulsion device including a transom bracket having a mounting portion fixed to the rear of the boat transom below the upper edge thereof, and a pair of laterally spaced arms extending upwardly from the mounting portion and including respective upper ends located rearwardly of the boat transom and above the upper edge thereof, a swivel bracket comprising a mounting portion and a pair of laterally spaced arms extending upwardly from the swivel bracket mounting portion and including respective upper ends, a tilt pin connecting the upper ends of the transom bracket and swivel bracket arms to provide the pivotal movement of the swivel bracket relative to the transom bracket about a tilt axis which is horizontally located rearwardly of the transom and above the upper edge thereof, a propulsion unit including an internal combustion engine and a propeller mounted for rotation and driven by the engine, and a king pin connecting the propulsion unit to the swivel bracket mounting portion for pivotal steering movement of the propulsion unit relative to the swivel bracket about a second axis transverse to the tilt axis and for common movement of the propulsion unit with the swivel bracket about the tilt axis and without travel of the propulsion unit over the transom upper edge or into engagement with the transom.
U.S. Pat. No. 4,545,770, which issued to Ferguson on Oct. 8, 1985, describes an outboard motor mounting arrangement. The marine propulsion installation comprises a marine propulsion device including a transom bracket having a mounting portion fixed to the rear of the boat transom below the upper edge thereof, and a pair of laterally spaced arms extending upwardly from the mounting portion and including respective upper ends located rearwardly of the boat transom and above the upper edge thereof, a swivel bracket comprising a mounting portion and a pair of laterally spaced arms extending upwardly from the swivel bracket mounting portion and including respective upper ends, a tilt pin connecting the upper ends of the transom bracket and swivel bracket arms to provide the pivotal movement of the swivel bracket relative to the transom bracket about a tilt axis which is horizontally located rearwardly of the transom and above the upper edge thereof, a propulsion unit including an internal combustion engine and a propeller mounted for rotation and driven by the engine, and a king pin connecting the propulsion unit to the swivel bracket mounting portion for pivotal steering movement of the propulsion unit relative to the swivel bracket about a second axis transverse to the tilt axis and for common movement of the propulsion unit within the swivel bracket about the tilt axis and without travel of the propulsion unit over the transom upper edge or into engagement with the transom.
U.S. Pat. No. 5,154,651, which issued to Binversie et al on Oct. 13, 1992, describes a marine propulsion device tilt tube. An outboard motor comprises a transom bracket which is adapted to be mounted on the transom of a boat and which includes first and second generally horizontally spaced apart portions, a tilt tube which extends through the transom bracket portions and along a generally horizontal tilt axis and which includes a first end portion extending outwardly of the first transom portion and a second end portion extending outwardly of the second transom bracket portion, a swivel bracket mounted on the tilt tube for pivotal movement relative to the transom bracket above the tilt axis, a propulsion unit mounted on the swivel bracket for common movement therewith about the tilt axis and for pivotal movement relative thereto about a generally vertical steering axis, the propulsion unit including a propeller shaft adapted to support a propeller, and a steering arm adapted to be mounted to a remote steering system, and structure on both of the tilt tube end portions for permitting the remote steering system to be alternatively connected to the first end portion or to the second end portion.
Known outboard motor mounting arrangements exhibit several disadvantages. First, most known outboard motor mounting arrangements cause the steering axis to be tilted when the outboard motor is trimmed or tilted. In other words, the steering axis moves with the outboard motor relative to the transom when the outboard motor is trimmed or tilted. In addition, known mounting configurations for outboard motors typically leave hydraulic pumps and electric motors exposed within their structure and also require valuable space for mounting the hydraulic pump and its related electric motor. In addition, most outboard motors are attached to a transom of the boat in a way that results in disadvantageous force vectors and torques being imposed on the components of the outboard motor and mounting structure. It would therefore be beneficial if an outboard motor mounting structure arrangement could be provided which does not require the steering axis to be tilted when the outboard motor is trimmed or tilted. It would be further beneficial if a means could be provided which allowed the hydraulic pump and associated electric motor to be housed within components of the steering and tilting system to avoid the necessity of using valuable space for these components. In addition, it would be beneficial if a simple, but secure, fastening system could be providing for mounting the outboard motor to the transom of a boat.

Outboard motor with a hydraulic pump and an electric motor located within a steering mechanism


An evaporable foam pattern for casting a metal air induction manifold for an internal combustion engine. The pattern is formed from an evaporable foam material, such as polystyrene, and in the assembled condition the pattern is in the form of an elongated body member having a generally rectangular cross section. One end of the body member is enclosed by an end wall while the opposite end of the body member is open. One of the side walls of the body member is provided with a plurality of generally parallel slots which are elongated in a lateral direction with respect to the longitudinal axis of the body member. The pattern is composed of a pair of longitudinal pattern sections each being generally U-shaped in cross section and having abutting edges disposed on a parting line. An adhesive joins the abutting edges. The parting line between the pattern section splits the opening in the end of the body member and all of the slots are formed in one pattern section.

Evaporable foam casting procedures have been used in casting metal engine blocks for internal combustion and other engine components. In a typical evaporable foam casting process, a pattern, which is identical in configuration to the metal part to be cast, is formed of an evaporable foam material, such as polystyrene. In the casting procedure, the pattern is placed in a mold and a flowable material, such as sand, is introduced into the mold around the pattern and also fills the cavities within the pattern.
A molten metal, such as an aluminum alloy, is introduced to the pattern via a sprue and the heat of the molten metal will vaporize the pattern with the vapor entering the interstices of the sand while the molten metal will fill the void created by vaporizaton of the pattern to provide a cast metal part which is identical in configuration to the foam pattern.
Evaporable foam casting has advantages over conventional sand casting procedures in that it is less costly, and more dimensionally accurate parts can be obtained. Moreover, certain complex configurations may be castable using evaporable foam techniques, while such parts cannot be cast using sand casting techniques.

Evaporable foam pattern for casting an air induction manifold


A mold clamping apparatus for injection molding machines includes a stationary plate 2 for supporting a stationary mold Cc; a moving plate 6 for supporting a moving mold Cm; a plurality of parallel tie bars 3a, 3b, 3c, and 3d of which end portions are secured to the stationary plate 2; a plurality of different cylinders 4a-4d . . . which accommodate piston sections 5a, 5b, 5c, and 5d set at the middle of each tie bar, and arranged movably along the tie bars and integrally with the movable plate; and a hydraulic circuit 7 capable of selective feeding of pressurized oil to the oil chambers of the cylinders. The piston sections of different cylinders are formed in different diameters and all portions of all tie bars are formed in the same diameter.

1. Field of the Invention
The present invention relates to a mold clamping apparatus for injection molding machines, in which a tie bar for movably supporting a movable plate is provided with a clamping cylinder.
2. Description of the Relevant Art
A mold clamping apparatus for injection molding machines is known which has: a stationary plate; a plurality of parallel tie bars of which one end portion is secured to the stationary plate; a plurality of different cylinders accommodating a piston section set at the middle of each tie bar respectively, and are movable along the tie bars; a movable plate integrated with each cylinder; and a hydraulic circuit for selectively feeding pressurized oil to the oil chamber of each cylinder; whereby various mold opening/closing speeds or various mold opening/closing forces can be selected.
For example, the official gazette of Japanese patent publication No. 53-6668 discloses a mold clamping apparatus having a cylinder in which the diameter of the one side of the tie bar differs from the diameter of the other side of the tie bar, wherein a piston section set at the middle of the tie bar serves as a boundary between the two sides, so that the pressure area of each piston section differs.
The official gazette of Japanese utility model publication No. 62-22348 discloses a mold clamping apparatus in which the diameter of a tie bar and that of a piston section set at the middle of the tie bar are made different from each other in different cylinders, so that the pressure area of each piston section differs. For this mold clamping apparatus, two of four cylinders are made as rapid traverse cylinders for performing high-speed movement, and the other two cylinders are made as clamping cylinders for performing high-power clamping, and are made to operate independently. Therefore, the diameter of each tie bar is set so as to be suitable for the particular cylinder function.
However, the existing mold clamping apparatus requires various types of tie bars because each pressure area is set by varying the diameter of each tie bar. Therefore, increased man-hours for machining of tie bars and assembling them with piston sections and the like leads to greatly increased manufacturing cost.
Moreover, because tie bars with different diameters may become mixed, problems may arise with the balance, uniformity, and stability of the clamping force throughout the whole mold clamping control. For example, tie bars with small diameter are easily distorted, and may degrade the quality of products and the accuracy of control.

Method of opening and closing molds of injection molding machines


Generally, the present invention relates to industrial cleaning solvents for removing coatings and adhesives and methods for using these solvents. More specifically, the invention relates to solvents for industrial cleaning and for removing/dissolving urethane, varnish, and epoxy coatings and adhesives.

Generally, the present invention relates to industrial cleaning solvents for removing coatings and adhesives and methods for using these solvents. More specifically, the invention relates to solvents for industrial cleaning and for removing/dissolving urethane, varnish, and epoxy coatings and adhesives.
Urethane materials are commonly used as adhesives, coatings, foam fillers, foam structures, and foam cushions. From an application perspective there is no meaningful-distinction between the terms "urethane" and "polyurethane." These materials are sometimes formulated as single part compositions and sometimes formulated as multi-part compositions that are mixed prior to application. Sometimes the urethanes are heated ("hot melted") for applications, sometimes special curing agents such as moisture are used. Urethanes are often applied as coatings to components and are often fabricated as molded mechanical components.
Urethanes are capable of forming strong bonds with other materials such as wood, glass, masonry, and metal. As a consequence urethanes are often used as coatings and adhesives.
Varnish materials were traditionally comprised of a drying oil, a resin, and a solvent. Today, varnishes include a range of natural and synthetic resins including unpigmented and lightly pigmented acrylic, polyurethane, and epoxy. Varnishes can create hard, lustrous, semi-transparent coatings that enhance and protect substrates. Varnishes are often applied to wood products such as furniture, floors, and musical instruments so that the natural aesthetics of the wood are visible yet protected. Varnishes are also widely used in the electrical component industry for sealing and insulating parts such as electric motor windings where they are used as an adhesive sealer. Varnishes are capable of forming strong bonds with other materials such as wood, glass, masonry, and metal. As a consequence, varnishes are often used as coatings and adhesives.
Epoxy materials are commonly used as adhesives, coatings, and as matrix components in the manufacture of composite materials. These materials are copolymers formed from a resin and activator combination creating cross linked arrays of polymer chains. Epoxies are often applied as coatings to components. They are also often used as the bonding matrix in composite materials which are made from other materials with desirable properties such as strength or conductivity. Epoxies are capable of forming strong bonds with other materials such as wood, glass, masonry, and metal. As a consequence, epoxies are often used as coatings and adhesives.
Frequently it is desirable to detach a urethane, varnish, or epoxy from a component, or to separate two components that have been bonded together by a urethane, varnish, or epoxy adhesive. Often it is desirable to detach a coating system comprised of layers of these materials superimposed upon and bonded to each other from a substrate. For many years, dichloromethane (DCM) was the "gold standard" solvent for debonding. However, this solvent has been identified as a hazardous air pollutant, a poison, and a suspected carcinogen. Hence, its use has been eliminated by much of industry and it is highly regulated by government environmental, health, and safety agencies. Halogenated materials like DCM are also unsatisfactory for certain applications in that free halogens which are released by the halogenated hydrocarbons will attack metals such as copper, nickel, and iron. The presence of halogenated stripper residues, which are entrapped on the substrate, can cause latent attack and reliability problems. While a number of replacement solvents have been identified, very few approach the effectiveness of DCM. Also, many of the replacement solvents are flammable, corrosive, highly reactive, or have other characteristics that constitute hazardous wastes under the Resource Conservation and Recovery Act (RCRA) at 42 U.S.C. 6921-6939e. Other replacement materials have various shortcomings such as a pungent odor, the potential for diversion to illicit drug manufacturing, or ineffectiveness in attacking urethanes, varnishes, and epoxies; particularly in thin bond lines.
N-methyl-pyrrolidone (NMP) has been used as a replacement solvent in some applications. The relative strength of N-methyl-pyrrolidone compared to more conventional solvents like DCM is weak. NMP is regulated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) section 313 and suspected to be a reproductive toxicant. Certain states like California have recognized NMP as a chemical of concern and as a result, some industries have moved away from using this as a solvent. Very few chemicals closely related to NMP (cyclic amides) are liquids at room temperature. Those that are, are less desirable solvents because they are higher in cost and display weaker solvency than NMP. Other solvents that have been used to replace conventional solvents (i.e., benzyl alcohol, dibasic ester, and propylene glycol n-butyl ether) are only modestly effective at removing paints and adhesives. What is needed, therefore, are more effective and practical solvents that can be used in debonding urethane, varnish, and epoxy coatings and adhesives from components.
Solvents designed to remove coatings and adhesives generally consist of up to four types of components: primary solvents, cosolvents, activators, and extenders. Primary solvents are those chosen for their ability to substantially attack the coatings of interest. Cosolvents are chosen to increase the versatility of the solvent with regard to the types of the materials it attacks. Activators are chosen for their catalytic effects; their ability to accelerate penetration of the coating and enable faster, more complete breakdown of the film's molecular bonds. Extenders are chosen to enhance some other desirable characteristic like flash point, drying time, or cost and may also contribute to the overall effectiveness of the solvent.
One such desirable characteristic is lower volatile organic compound (VOC) content. Solvents with lower VOC content have become more desirable as regulations governing VOC emissions have increased. VOC-exempt materials, such as dimethyl carbonate, tertiary butyl acetate, and water, are useful cosolvents and extenders to lower the VOC content of a solvent. The state of California is a leader in regulations that define VOC content limits with regulations that define VOC limits by product type and application. Like California, some states are excluding Low Vapor Pressure (LVP) solvents from the VOC content calculation: The California Air Resource Board (CARB) defines LVPs as solvents that boil above 216° C. or have vapor pressures below 0.1 mm Hg at 20° C.
CARB regulations contain rules that cover solvent VOC limits based on percent by weight, grams/liter, and partial vapor pressure. Increasingly restrictive regulations are creating urgent needs for effective solvents that are safer to use and have lower VOC content. For this reason it is desired to utilize VOC-exempt or LVP cosolvents and extenders when practical.
In addition to these four possible main components of a solvent for removing paint and adhesive, other materials may be used as additives to enhance the solvent's physical characteristics such as thickening agents to increase viscosity, emulsifiers to improve solubility of the solvent's various components, and materials that form floating, evaporative caps, a device particularly useful for reducing evaporation when the solvent is to be used in a heated tank application.


A data recovery apparatus for minimizing errors due to clock skew and a data recovery apparatus therefor are provided. The data recovery apparatus comprises a phase locked loop (PLL), an oversampler, a level transition detector, a transition accumulator, a state selector, and a data selector. The PLL generates a plurality of phase clock signals having different delay times, which signals are synchronized with an input clock signal. The oversampler 110 M (>1) times oversamples data serially input from the outside in response to the plurality of phase clock signals and outputs the oversampled result as a plurality of bit data items. The level transition detector receives the plurality of bit data output from the oversampler, detects the point of time at which the level transitions between adjacent bits and outputs the detection result as first through Mth transition signals. The transition accumulator accumulates the number of generations of the first through Mth transition signals output from the level transition detector and outputs a signal whose generation frequency is high as first through Mth transition accumulation signals. The state selector generates a state signal for selecting bit data items of corresponding positions among the plurality oversampling data items in response to the first through Mth transition accumulation signal. The data selector receives the oversampled plurality of bit data, selects bit data items of the sampling positions corresponding to the state signal, and outputs the selected bit data items in parallel. It is possible to minimize errors due to clock skew, which can be generated during the reproduction of data.

1. Technical Field
The present invention relates generally to a data transmission system and, more particularly, to a data recovery circuit and method for minimizing errors due to clock skew.
2. Description of Related Art
In general, in a data transmission system for transmitting predetermined data, the use of parallel transmission channels is a popular method for digitally interfacing systems. However, problems may occur with this method of using the parallel transmission channels if the number of data transmission channels increases. Consequently, a serial transmission method is gradually replacing the parallel transmission method.
With the serial transmission method, the number of channels used for transmitting data is less than the number of channels used for transmitting data using the parallel transmission method. However, in most cases, when data is transmitted using serial transmission channels, a high speed serial signal must be converted to a parallel data format at a receiving end. When serial data is converted to the parallel data format, it may be difficult to recover data due to clock skew at the receiving end.
Using conventional technology, in order to solve such a problem, a bit section of a received signal is sampled many times and a data level is determined by detecting the generation frequency of the sampled result. With this method of determining data by detecting the generation frequency of data, however, errors may occur in a portion at which the level of data is converted due to the accumulation of clock skew. For example, in a level transition section, in which the level of data is transited from a logic "high" level to a logic "low" level or from the logic "low" level to a logic "high" level, there is every possibility that the data determined by the generation frequency thereof is not real data but erroneous data.

Data recovery apparatus and method for minimizing errors due to clock skew


N-substituted .omega.-aminoalkanoyl-.omega.-aminoalkanoic acids and their pharmacologically-acceptable salts (with a base) are useful, e.g., in pharmaceutical-composition form for the treatment or prophylaxis of diseases which are based on inadequate performance of the pancreas, the bile and/or the liver. The compounds are prepared, e.g., by reacting an N-(mono- or di-substituted) .omega.-amino-alkanoic acid with an N-(unsubstituted or monosubstituted) .omega.-aminoalkanoic acid.

N-acyl-.omega.-anilinoalkanoic acids produce a choleretic effect (U.S. Pat. No. 3,780,095), as well as other effects (U.S. Pat. No. 4,034,111). Trialkoxybenzoylpeptides (ZA 73 05 128 and DT-OS 2 338 172) are suitable for the prophylaxis and treatment of cardiac diseases. A new class of .omega.-aminoalkanoyl-.omega.-aminoalkanoic acids, which is neither mentioned in the cited published Patent Applications nor rendered obvious by them, has now been synthesized. These new compounds possess interesting and particularly advantageous pharmacological properties.

N-(Substituted amino)alkanoyl-aminoalkanoic acids and salts, their use and their compositions

BYK Gulden Lomberg Chemische Fabrik GmbH


A method, system, and computer-usable medium are disclosed for controlling unauthorized access to encrypted application program code. Predetermined program code is encrypted with a first key. The hash value of an application verification certificate associated with a second key is calculated by performing a one-way hash function. Binding operations are then performed with the first key and the calculated hash value to generate a third key, which is a binding key. The binding key is encrypted with a fourth key to generate an encrypted binding key, which is then embedded in the application. The application is digitally signed with a fifth key to generate an encrypted and signed program code image. To decrypt the encrypted program code, the application verification key certificate is verified and in turn is used to verify the authenticity of the encrypted and signed program code image. The encrypted binding key is then decrypted with a sixth key to extract the binding key. The hash value of the application verification certificate associated with the second key is then calculated and used with the extracted binding key to extract the first key. The extracted first key is then used to decrypt the encrypted application code.

1. Field of the Invention
Embodiments of the disclosure relate in general to the field of computers and similar technologies, and in particular to software utilized in this field. Still more particularly, it relates to controlling unauthorized access to encrypted application program code.
2. Description of the Related Art
The use of cryptographic encryption and digital signatures to control user access to sensitive applications has become increasingly common in recent years. These applications may contain application secrets such as passwords and encryption keys, either in the application code itself or in associated data. As an example, a content protection key is typically embedded within a content protection application. To avoid unauthorized access to the content protection key by a malicious user, application programmers generally encrypt the content protection key before embedding it into the application image. As a further safeguard, decryption of the content protection key is intended to be limited to authorized users or trusted applications.
However, many approaches to encryption, and key management such as those found in the ISO/IEC JTC SC27, NIST FIPS Pub 196, and ANSI X9 series of security standards only address low-level implementation guidelines, such as how to securely select the size of a modulus. As such, they fail to provide guidance for higher-level design issues, such as how to securely combine encryption and authentication. As a result, naïve combinations of encryption and authentication often provide opportunities for attacks including forgery and the stealing of secrets. Even security protocols that address high-level design issues, such as Pretty Good Privacy (PGP) and S/MIME, fail to address sophisticated attacks such as an encrypted section replacement attack.
In such an attack, a malicious user copies encrypted application program code and its associated encrypted application encryption/decryption key from an encrypted application into a new application. Then, the malicious user signs the new application with their private signature key to generate a new digital signature. A digital certificate authenticating the malicious user's public signature verification key is then combined with the new digital signature, the copied encrypted section, and the copied encrypted application decryption/decryption key to generate a signed/encrypted application for the malicious user. An attempt is then made to decrypt the encrypted section. Since the digital certificate verifies that the malicious user's public signature verification key is authentic, the encrypted section is decrypted as if the malicious user was an authorized user. In view of the foregoing, there is a need for improved protection against an encrypted section replacement attack.

Method to protect secrets against encrypted section attack

International Business Machines Corporation


A selection system and method to receive an indication of a security format from a network and to select one of a plurality of security format conversions based on the received indication is described. The indication may be an indication of a wireless security format such as WTLS used by a wireless access device or a wired security format such as SSL used by a wired access device and the security format conversion selected based on the indication may be to another secured format or a plain data format. The indication may include an indication of a port and an indication of a security feature that is supported by the access device.

1. Field of the Invention
The invention relates generally to extending the capabilities of network security. More particularly, the invention relates to a system and method for selecting and performing different security format conversions in a data center based on security format information received from a network.
2. Background Information
Cell phones are often used to exchange sensitive personal and financial information over unsecure public networks. Accessing information from a financial account over the Internet is one example. Security solutions that encrypt data at the cell phone and transmit the encrypted data over the public networks have been devised to reduce the likelihood of an unintended recipient discovering the sensitive data. The goal is to provide end-to-end security between the cell phone user and a recipient. However this goal has been limited by a Wireless Application Protocol (WAP) gap wherein conversion from one security standard to another is performed within an untrusted intermediate WAP gateway that links the wireless access network to another public carrier network and renders the sensitive data unencrypted and vulnerable to attack even if only for a brief period of time.
FIG. 1 shows a system 100 that allows a cell phone 110 to exchange secure data with a server 170 subject to the limitations of a WAP gap 150. The cell phone 110 sends a Wireless Transport Layer Security (WTLS) encrypted request using either Wireless Datagram Protocol (WDP) or User Datagram Protocol (UDP) as a transport protocol to a wireless network 120. The request may include an access identification and password to access a financial account. The wireless network 120 receives the request and sends the request to a WAP gateway 130.
The WAP gateway 130 receives the request and includes a converter 140 to perform a first conversion 142 from either WDP or UDP to Transmission Control Protocol (TCP) and from WTLS to Secure Sockets Layer (SSL). During the conversion between WTLS and SSL, the secure data passes through an unsecured and vulnerable state that is susceptible to attack. Typically, the WAP gateway is owned and operated by a third party mobile operator. Leaving the sensitive data unencrypted in the hands of an unknown and untrusted third party is not a good practice. After the conversions the WAP gateway 130 sends the converted request to the Internet 160.
The Internet 160 receives the converted request and sends the converted request to the server 170. The server 170 receives the request in TCP and SSL format, converts from SSL format to a plain data format, and may run applicaton scripts such as CGI scripts 180 to access content 190 and generate an SSL encrypted response comprising the content 190. The server 170 uses TCP to transport the response in SSL format to the Internet 160. The Internet 160 receives the response and sends the response to the WAP gateway 130. The WAP gateway 130 performs a second conversion 144 from TCP to WDP and from SSL to WTLS. The WAP gateway 130 sends the converted response to the wireless network 120, which sends the response in WTLS encrypted format to the cell phone 110.
FIG. 2 further illustrates the vulnerability of data in a WAP gateway 200 having a WAP gap 250. The WAP gateway 200 receives WTLS encrypted data, which is conceptually represented by a WTLS security envelope 210. The WAP gateway 200 decrypts the WTLS data, which is conceptually represented by the open WTLS security envelope 220. Once decrypted, the data resides in the memory of the WAP gateway 200, at least for a brief period of time, as unsecure data that is in plain view 230. This vulnerability is known as the WAP gap 250. The WAP gateway 200 then encrypts the data in SSL format, as represented by the insertion of the data 230 into the open SSL security envelope 240 and subsequent sealing of the envelope 260. The SSL encrypted data, which is conceptually represented by the SSL security envelope 260 is provided to the Internet. As indicated by the bi-directional arrows, the WAP gap 250 may also be encountered when conversion is performed in the reverse direction from SSL to WTLS. Accordingly, as a result of the WAP gap 250 the data resides in a vulnerable, unsecured state that is under the untrusted control of the WAP gateway 200 and may be subjected to a man-in-the-middle attack.
FIG. 3 shows a prior art system 300 to avoid the WAP gap. A cell phone 310 exchanges WTLS data with a WAP gateway 320. The WAP gateway 320 sends the WTLS secure data to a trusted WTLS/SSL conversion system 330. The conversion system 330 resides at the same physical location as the WAP gateway 320 and is partially controlled by a party that controls the server 340. The WTLS/SSL conversion system 330 converts between WTLS and SSL by passing the data through an unsecured plain data state. Accordingly, this solution does not provide an end-to-end solution in which data is always in encrypted format. Also, although conversion in the WTLS/SSL conversion system 330 may be comparatively more trusted than conversion in the WAP gateway 320, the conversion system 330 resides at the physical location of the WAP gateway 320 and therefore the party of the server 340 does not have entirely trusted control of the conversion system 330. An additional disadvantage is the increased latency introduced by sending WTLS data to the WTLS/SSL conversion system 330 and awaiting responsive SSL data from the system 330. The WAP gateway receives the converted data in SSL encrypted format and provides the SSL encrypted data to the server 340 which runs CGI scripts to access data and format a response. The need to perform both a conversion from WTLS to SSL and then from SSL to plain data is yet another disadvantage of the system 300.

Selecting a security format conversion for wired and wireless devices


This structure is provided with a first composite material 11, a second composite material 12 joined to the first composite material 11 by a film adhesive 21 provided between the first composite material 11 and the second composite material 12, and a corner fillet part 13 provided on a corner part 15 formed by the first composite material 11 and the second composite material 12. The shape of the corner fillet part 13 is a design shape P designed in advance, and the corner fillet part 13 is formed by curing the film adhesive 21 after arranging the film adhesive 21 on the corner part 15 so as to fit into the design shape P.

In the related art, a hat type reinforcing member made of a composite material is known as a composite structure having a corner part (for example, refer to PTL 1). The hat type reinforcing member made of a composite material includes a hat section made of a composite material, a plurality of reinforcing plies made of a composite material joined to the hat section made of a composite material, and a noodle-like corner filler. The noodle-like corner filler is arranged in a substantially triangular noodle-like corner filler region formed by the plurality of reinforcing plies made of a composite material.

Composite structure and method for molding composite structure