Abstract: A portable apparatus and method for collecting and testing ground water samples including a container (12) defining a chamber (14) in which a control atmosphere is established. A valve means (22) is included which is capable of bypassing water away from the chamber (14) and continuously admitting water samples to the chamber (14). A preferred method of collecting a ground water sample includes the steps of establishing a controlled atmosphere in the chamber (14), directing the flow of water into the chamber (14), collecting the water sample inside the chamber (14), and testing the sample inside the chamber (14) to prevent contamination from the air on the exterior of the chamber (14).

Abstract: An apparatus, suitable for monitoring the efficiency of a containment system, has an elongate platform for spanning a duct. A carriage is slidably mounted on the platform. First and second drive shaft are arranged for driving the platform across the duct and the carriage along the platform. An intermediate drive shaft is arranged for driving the first drive shafts. A drive means is arranged outside the duct, connected to the intermediate shaft and a fluid seal is provided around the intermediate shaft. The second drive shaft can either be driven from the intermediate drive shaft, or from a separate drive unit.

Abstract: A feed-through apparatus for use in rotating a shaft which typically forms part of a system. The apparatus includes a feed-through shaft which is to be rotated and structure for rotatably mounting the shaft on a panel or wall. A cap rotatably coupled to the mount has a driver coupled with it, the driver including a stub shaft having bearings at one end thereof received within a groove of an end face of the driven shaft. The driver includes a cylindrical member mounted by a bearing in the inner periphery of the cap, such inner periphery being provided with a beveled surface so that the cylindrical member and the stub shaft wobble when the cap is rotated. When the bearings on the outer end of the stub wobble, they move along a circular path surrounding the central axis of the driven shaft, causing the driven shaft to rotate in the direction of movement of the bearings on the driver.

Abstract: A tiltable horse-head shaped transmission part at the end of a rocking beam of a cornish type pump drive, is pivotably supported at one end portion of the rocking beam. The rocking beam is pivotably supported on a stationary stand. The horse-head transmission part is mounted in bearing blocks which are shiftable in longitudinal direction of the rocking beam and at the same time are tiltable about an axis which extends parallel to the longitudinal direction of the rocking beam. In this manner an accurate adjustment of the horse-head transmission part relative to a polished rod in the bore hole is made possible so that the polished rod can be accurately guided in corresponding stuffing boxes. The horse-head shaped transmission part is provided with two force application points serving for introducing tilting movement in a backward direction toward a stand and in a forward direction away from the bore hole. The force application points are equipped with fastening means for the attachment of a pulling rope.

Abstract: A variable displacement wobble plate compressor is disclosed having vibration isolation mounting cups supporting the opposite ends of a guide rod that operates through a multiple axis joint to prevent rotation while permitting angulation of the wobble plate.

Abstract: A transmission for a self-propelled working vehicle (100) including an engine (2), and a load source (5, 21) adapted to be driven with drive power from the engine (2), in which the transmission (6) is interposed between the engine (2) and the load source (5, 21) and adapted to transmit the drive power to the load source (5, 21) while shifting same into one of at least two speed modes.The transmission comprises at least two input gear members (37, 38) to which the drive power of the engine (2) is transmitted, at least two output gear members (48, 49) each respectively meshed with one of the input gear members (37, 38), a changeover mechanism (52, 11, 48a, 49a, 10) for selectively bringing any one of the output gear members (48, 49) into operative connection to the load source (5, 21), and a friction type power transmitting mechanism (9) interposed between the engine (2) and the input gear members (37, 38).

Abstract: A fluid-powered helical actuator including a cylindrical body; a rotatable output member supported for rotation relative to the body and connectable to an external device; first and second independently rotatable sleeves reciprocally mounted within the body; a piston reciprocally mounted within the body for application of fluid pressure to one or the other opposing sides thereof to produce axial movement, the piston operatively engages at least one or the other of the sleeves to axially move the sleeves in response to axial movement of the piston; and torque-transmitting elements for transmitting torque between the first sleeve and the body, between the first sleeve and the output member, between the second sleeve and the output member, and between the second sleeve and the body.

Abstract: A transmission ratio selector actuator has a transmission ratio selector assembly including a selector shaft and a toothed gear segment secured thereto. The selector shaft is adapted to drive a conventional transmission detent sector plate or "rooster comb". The toothed segment meshes with a gear member which is formed integrally with or otherwise secured to a Geneva drive sector. A drive pin for the Geneva drive sector is secured to a worm wheel which is driven by a worm shaft integrally formed with or otherwise secured to an electric motor. A plurality of electrical control switches are actuated by the Geneva drive sector to control the operation of the motor and thereby provide for proper positioning of the selector shaft. The worm wheel has integral therewith a cam surface which is actuated upon by brake shoes to ensure stoppage of the drive pin during disengagement from the Geneva drive sector upon deactuation of the drive motor.

Abstract: A synthetic resin rack guide in a rack-and-pinion type steering gear is provided with a projection formed on an outer peripheral surface at an end portion which is in contact with a rack bar. The projection is designed in such a manner that a diameter thereof after shrinkage due to annealing is equal to or slightly larger than an inner diameter of a guide hole for receiving the rack guide. With this arrangement, an abnormal noise created between rack teeth and a pinion may be prevented.

Abstract: The present invention comprises a balancing gear assembly employed to statically balance a camera or like equipment mounted upon angular positioning equipment. Remote angular positioning equipment for a camera or other similar devices permits remote angular positioning along the perpendicular axes of rotation of the equipment. The driving force to the camera along each of the two axes is supplied through a separate driving gear. The present invention balancing gear apparatus is disposed between each of the drive gears and the power source for rotating the drive gear. The power source is coupled to a worm gear through a universal joint which permits 360.degree. rotation of the shaft upon which the worm gear is mounted. The worm gear is appropriately journaled within a yoke which is moveable in the plane of the drive gear. The yoke supporting the rotatable worm gear can be positioned to engage the worm gear and the drive gear during operation.

Abstract: A gear-teeth protector for a change-speed gearing unit in which a pair of upper and lower change-speed gears of high meshing rate are arranged adjacent to an upright wall in a housing for the gearing unit. The gear-teeth protector comprises a U-shaped shroud member secured at its outer peripheral flanges to one face of the upright wall so as to prevent metallic alien particles being trapped between the change-speed gears, the shroud member forming a pair of side walls enclosing the teeth on the upper change-speed gear and extending adjacent to the upper teeth on the lower change-speed gear to enclose the meshing engagement portion between the two change-speed gears.

Abstract: A remotely operated hand gear train for the orientation of an end effector has an external housing mounted onto a robot arm and defines a first axis A.sub.1. A first housing is rotatably mounted within the external housing for movement about the first axis A.sub.1 and defines therein a second axis A.sub.2 which is substantially perpendicular to the first axis A.sub.1. A second housing is rotatably mounted in the first housing for rotation about the second axis A.sub.2 and defines therein an axis A.sub.3 which is normal to axis A.sub.2 and radially spaced from axis A.sub.1. A third housing is rotatably mounted in the second housing for rotation about axis A.sub.3 and has a gear rack circumferentially disposed about the end thereof.

Abstract: A new type of robotic device is disclosed, using several cable trussed compression members in concert. The cable trussed compression members are deformed along the length of their central compression mast, by the lengthening and shortening in concert of all of the cables of each cable trussed compression member, through the use of motors. Weights traveling on tracks, or fluid filled hoses, are used in addition to the deformation of the cable trussed compression members, to change the location of the center of gravity of the entire assembly, thereby enhancing the balancing and stability of the robotic device. Additional known mechanical and electrical devices may be used in conjunction with the several cable trussed compression members.

Abstract: A bowden cable wherein an intermediate section of the tubular casing is replaced with or an end portion of the casing is constituted by a hollow insert containing a motor for a blocking element which is movable relative to the insert and, when moved to an operative position, prevents an abutment on and hence the wire of the bowden cable from moving axially. The bowden cable is then inoperative, i.e., the wire cannot transmit motion to a lever or to another movable component which holds the hood, the trunk or another mobile part of a motor vehicle in a predetermined (e.g., closed) position.

Abstract: A speed sensing differential axle mechanism provides a plurality of teeth formed in a small diameter end portion of a differential case. In a preferred form, the teeth are integral to the case, spaced uniformly about the small diameter end portion thereof, and are disposed for relative rotation with respect to a stationary electronic pickup element secured rigidly in an associated external carrier. In the preferred embodiment, the pickup element is totally enclosed within the carrier, whereby it is protected from external environments, as well as from splash and spray oil circulating within the differential assembly. For the latter purpose, an internal baffle is utilized to protect the internal pickup element from the oil.

Abstract: A planetary gearing arrangement for automotive transmissions wherein a fourth simple planetary gear set and a fourth brake are added to a gearing arrangement containing three simple planetary gear sets, three brakes and two clutches. In the fourth planetary gear set, the sun gear is connected to the input shaft, the carrier is connected to the fourth brake, and the ring gear is connected to the carrier and to the ring gear of two of the planetary gear sets described in the above-mentioned patent. The gearing arrangement of this invention achieves nine forward speed ranges and one reverse speed range with only single transition shifts and also has the capability for small, evenly spaced ratio steps including a first forward ratio low enough to permit use of the gearing arrangement without a torque converter.

Abstract: An engine starter device for a motor cycle including an engine, a primary transmission having a neutral gear position, and a secondary transmission having a reverse gear position. The engine starter device starts the engine only when the primary transmission is in the neutral gear position and the secondary transmission is not in the reverse gear position.

Abstract: In a system for controlling a drive unit, particularly a boat drive unit, which comprises an internal combustion engine and a reversible gearing, with an operating member for adjusting the power and the direction of rotation, the operating member (1) feeds electric signals corresponding to the power and the direction of turning to a control device (5) which contains a microcomputer (6). Actuators (11, 12) for the power of the internal combustion engine and the switching of the reversible gearing respectively are connected to the control device (5). The control device (5) is developed in such a manner that switching of the reversible gearing is only possible when the speed of rotation of the internal combustion engine lies below a predetermined value.

Abstract: Method and apparatus for controlling a continuously variable transmission operatively connecting an engine and drive wheels of a vehicle, wherein a speed ratio of the transmission is controlled such that an actual engine speed coincides with a target engine speed.

Abstract: A saw chain sharpener for sharpening the left hand and right hand cutting teeth and the rakers of a saw chain while the chain is mounted in situ on a saw bar. The apparatus includes a base, a saw bar clamp mounted on the base for clamping a saw bar in a substantially vertical position. A grinding assembly including an electric motor and a grinding wheel is mounted respectively on first or second grinding assembly mounting posts. The mounting posts are secured on opposite sides of the saw bar clamp. The apparatus also includes an indexing device mounted on the bar clamp and which is spaced from the grinding surface of the grinding wheel when the grinding wheel is pivoted into the grinding position for selective supporting engagement with the rear edges of the saw chain cutting links. The saw chain can therefore move forwardly but not rearwardly when the indexing tooth is in position. The indexing device is adjustable to determine the lengths to which the cutting teeth are to be ground.

Abstract: Tools, and particularly rock bit cutter cones, having "hard" cermet cutter inserts enveloped in an intermediate layer or coating of a suitable high melting metal, and embedded in a cast steel matrix, are disclosed. The cermet inserts, which usually comprise tungsten carbide in a cobalt phase (WC-Co), are coated with a layer of a metal or metal alloy, preferably nickel, which does not substantially melt during the subsequent step of casting the steel matrix of the tool. An additional layer of copper is advantageously employed on the cermet insert beneath the layer of the high melting metal, such as nickel. The coated inserts are held in appropriate position in a suitable mold, and the steel matrix of the tool is poured from molten metal. The coatings on the cermet inserts prevent thermal shock to the inserts, prevent deterioration of the cermet due to diffusion of carbon into the adjacent steel, and metallurgically bond the inserts to the embedding steel matrix.

Abstract: A microcentrifuge tube opener adapted to open a microcentrifuge tube comprising a container with an opening, and a lid for the container, the lid having a lip projection extending past the outer perimeter of the opening and an inner portion shaped to sealing fit inside the opening. The opener comprises a base, having a recess shaped to accept the lip projection, comprising a lower projection below and adjacent the recess; and an upper projection above and adjacent the recess. Both the lower projection and the upper projection are positioned to touch the lid, but the base cannot touch the inner portion of the lid when the lid is removed from the cup and the lip is positioned in the recess. The lid can be moved from the cup by positioning the lip in the recess and causing the lower projection to apply pressure to the lip away from the cup and, at the same time, causing the upper projection to apply pressure to the tube at a position distant from the lip, in a direction towards the cup.

Abstract: A car door opening tool for opening a car door of the type having a locking bar located within that functions to open the car door in response to the application of an unlatching force thereto. A shaft of sufficient length to access the locking bar through the car door's window slot from a position outside of the car door is provided with coupling device at its gripping end for both engaging the locking bar and for gripping it in response to a force-couple applied to the handle end of the shaft. By inserting the gripping end of the shaft through the window slot to engage the locking bar and then applying a force-couple to the handle end while simultaneously impressing the unlatching force to the shaft, the car door is caused to open.

Abstract: This invention relates to a hammer which includes a handle which is made from a flexible material and carries, in combination, rod and strip shaped reinforcing elements which extend over the effective length of the handle. The or each strip shaped reinforcing element is normal to the strike direction of the hammer head. The reinforcing elements are held apart by spacers located along the length of the element.

Abstract: A worm screw has two threaded portions of opposite hand cut on a single shaft, using a lathe. Several passes of the cutting tool are used to form each of these threaded portions, and in order to provide a compact and robust worm screw of this type the two threaded portions are separated by a groove having a depth shallower than that of the threads being cut and having a width at least equal to 15% of the greater axial pitch of the threaded portions.

Abstract: A numerically controlled turning machine comprises a main spindle (H.sub.s) and at least two cross slides (K.sub.1,K.sub.2) each provided with a saddle (W.sub.1 and W.sub.2, respectively). Another saddle (W.sub.3) is provided at the main spindle end. The cross slide (K.sub.1) is provided in addition with a driven tail spindle (G.sub.s). The control of the machine is subdivided into a first control system which includes X-axis and Z-axis controls as well as C-axis control with positional adjustment and a second control system which does not have any C-axis control but does include X-axis and Z-axis controls.

Abstract: A method of machining a workpiece, which is rotatable about a first axis, by a tool pivotable about a second axis parallel to the first axis and drivable about a third axis perpendicular to the second axis. To allow the circumference of the workpiece to be machined off-center without the necessity of moving the first or the second axis transversely to the plane defined by these two axes, the workpiece and the tool are rotated or pivoted about the first or second axis, respectively, at the same time, in the same direction and at the same angular velocity and, simultaneously the second axis is displaced transversely to the first axis at such a velocity that the equation X.sup.2 =Y.sup.2 +A.sup.2 always applies, wherein X is the distance of the second axis from the first axis, Y is the distance of the first axis from the plane defined by the second and third axes and A is the distance of the second axis from the vertical projection of the first axis onto this plane.

Abstract: The invention describes a method and a device for processing by chip-cutting of workpieces. It is preferentially applied for the cross-cutting and chamfering of extruded plastics material tubes. A chip-raising or cutting tool may be fed forward radially with respect to a rotational displacement of the workpiece in the direction of a center of relative rotation. An undulant approach motion is superimposed over the feed motion of the tool. The undulant approach motions of two directly consecutive revolutions are displaced in phase. As a result chip cuttings of uniform and predetermined length are produced with consequent facility in removal and avoidance of interference with the cutting operation.

Abstract: The instant invention is particularly directed to a method and apparatus for automated handling of panels comprising a plurality of interconnected substrates in order to control and separate the circuit boards in a continuous processing line. One embodiment incorporates two shearing stations and a rotary transfer device therebetween in order to transfer a panel portion from the first station to the second station while controlling and rotating the panel for subsequent feed to the second station such that the panel portion is cut on a line of the substrate which is perpendicular to the original line of cut of the substrate. Throughout the handling of the panels and panel portions, sensing, gripping, and indexed feeding of the panels and panel portions are under the control of a programmable computer.

Abstract: In order to further develop a disc cutter machine, in particular for cutting sugar beet, which is provided with a machine frame, a disc cutter having passages for the cut material, and blade receivers arranged in the region of the passages, in such manner that with the same disc cutter diameter a higher cutting output can be achieved, the blade receivers (18) are mounted on the flat upper surface (16) of the disc cutter (12) and the disc cutter is formed in the region of the blade receivers of radially extending and uniformly spaced inclined ribs (14).

Abstract: Apparatus for cutting foam or the like products into predetermined patterns under electronic computer control and employing an apparatus that includes a frame, a table disposed in the frame and for receiving the product that is to be cut, and a carriage carrying at least one hot wire and preferably four hot wires. The carriage is disposed over the table and is suitably supported from the frame. There is provided associated with the carriage, both a first drive means for controllably driving the carriage in a first x direction and second means for controllably driving the carriage in a second Y direction. Control means are provided for controlling the first and second drive means to control product cutting along a predetermined path which in the disclosed embodiment is a diagonal path to provide final foam pieces cut in a pyramidal array configuration.

Abstract: An apparatus for cutting a foam block into a predetermined shape and comprising a frame having a table supported therein at a lower position of the frame. The table is driven in a horizontal plane at a controlled speed and there is provided at least one cutting hot wire. This hot wire is supported from the frame at a position over the table. A drive system is employed for driving the hot wire support means in a vertical direction at a controlled speed.

Abstract: A keyboard operated musical instrument is disclosed in which the musical tones are generated by reading out data values stored in a waveshape memory. The number of stored data points is reduced by storing the data values in segments corresponding to one-half of the number of data points for a period of a waveshape. By using synthesized data having a symmetry about the midpoint the second half of the waveshape is recovered by a forward and backward memory address read of each waveshape segment. After reading each segment a predetermined number of cycles, an abrupt jump is made to the next segment of waveshape data points.

Abstract: A plurality of rhythm designation data are supplied from a CPU, and latched in corresponding individual latches which are responsive to channel data from a decoder. The latched data are supplied to an address ROM in response to corresponding channel timing signals, wherein start and end address data for a rhythm waveform data ROM are read out from the address ROM. If the rhythm designation data latched in one of the individual latches is the same as in another one of the latches, the same rhythm is sounded concurrently and without sound interruption.

Abstract: An electronic musical instrument includes a memory in which digital samples of an aperiodic waveform are stored. Digital samples stored in a first portion of the memory represent a rapidly rising portion of the waveform and those stored in a second portion of the memory represent a rapidly declining portion of the waveform whose amplitude and spectral energy distributions are equalized. The first memory portion is addressed in forward scan and subsequently the second memory portion is addressed recyclically in forward and rearward scans to generate an output waveform having a first part corresponding to the rising waveform section and a second part corresponding to a series of the recyclically addressed versions of the equalized waveform section. After delivery of the first part of the output waveform, a monotonically declining envelope is impressed upon the amplitudes and the spectral energy distributions of the second part.

Abstract: A mouthpiece (1) for a musical wind instrument comprises an inlet (5), an outlet (6), a hollow chamber (7) for collecting liquid from inlet air, and an enclosed windway (2), in which is disposed in the mouthpiece and leads to the outlet (6), wherein the inlet (5) and the windway (2) are interconnected via the hollow chamber (7). In use, the player's breath passes through the hollow chamber (7), allowing liquid to collect in the chamber, and then through the windway (2) out of the mouthpiece. The moisture-reduced air prevents sound disturbance and can be used for a considerable time before cleaning out becomes necessary. Also, the flow can be constricted which reduces the likelihood of overblowing by inexperienced players.

Abstract: An existing military system for clearing a path through an enemy mine field (by use of an explosively-charged line) is equipped with a safety mechanism for preventing premature detonation of explosive charges. The safety mechanism includes means responsive to weight changes, incident to withdrawal of an explosively-charged line from a storage container. The weight-responsive mechanism permits electrical detonation of the explosive charges only when the container is emptied of the explosive charges.

Abstract: A transition region for a missile launch chamber providing a smooth transition from a generally square cross-section chamber in which a missile is stored and launched to a round exit opening of the chamber which connects with an exhaust manifold or plenum. The transition section is provided with a pair of pivoted doors for closing off the bottom of the missile chamber to prevent the flow of recirculation gases from the plenum into the chamber when a missile in another chamber coupled to the same plenum system is being fired. The portion of the missile exhaust chamber between the square cross-section and the circular exit opening serves to direct the exhaust gases of a missile being fired into a smooth round exhaust plume which functions as a "gas plug", preventing the recirculation of the exhaust gases back into the chamber of the missile being fired.

Abstract: This invention relates to an arrangement for rapidly stopping an automatic weapon having an external drive where the breech block is driven by parallel shafts. This arrangement provides for the rapid stopping of the shafts and thus the weapon by providing the shafts with coaxially mounted pockets at their ends in which a pair of claws may be engaged to stop the rotation of the shafts.

Abstract: A modular armor includes a matrix of interfitted elements which forms a self-supporting layer. Each element has a first rectangular parallelepiped leaf having a length substantially twice the width. The element further includes a second rectangular parallelepiped leaf having the same width and length as the first leaf and which is suitably attached as by integral formation with the first leaf to form a cruciform. The elements in the matrix are suitably held together to form the modular armor. In one embodiment, the leaves of one element are provided with pockets in which ceramic blocks are located. Additional leaves can also be provided with each element to further strengthen the element and to hold the matrix together. Each of the elements can be joined to one another to hold the elements together, or a frame could be provided for the elements.

Abstract: A remotely-operated lock mechanism for the main gun of a military vehicle. n arm structure is swingable between a prone (inactive) position and an upright position disposed to bear the weight of the main gun. A clamp device is swingably attached to the arm structure for movement between a position overlying the gun barrel and another position displaced laterally from the gun barrel. A single power mechanism is remotely actuable to operate both the arm structure and the clamp device.

Abstract: A load self-leveling system for a vehicle utilizing hydraulic cylinders to operate a telescopic lifting boom and a material handling carriage. The system includes a pair of fluid flow dividers interposed between the source of hydraulic fluid under pressure and the hydraulic cylinders operating the boom and carriage. The flow dividers are structured to direct a greater flow of hydraulic fluid to the boom cylinder and a lesser flow to the carriage cylinder, the precise numeric proportions of flow division being engineered to best suit a particular vehicle, combined with the specific componentry of that vehicle. In addition to the flow dividers, the system includes reversible flow piloted check valves, override control including override relief valves to allow independent adjustments, and matched cylinder area ratios. A compact assembly housing various of the components comprising the system is disclosed.

Abstract: A swash plate compressor is disclosed having integral plastic ball and shoe parts with opposing working surfaces of equal area providing the drive between the opposite sides of the swash plate and the inner ends of double-ended pistons that straddle the plate.

Abstract: A swash plate type compressor is provided with a compressor shoe having a sliding contact surface for making sliding contact with a swash plate. The sliding contact surface is formed with a central hole. A crest portion is formed between the hole and the outer periphery of the shoe, and smooth surface portions connect the crest portion with the hole and the outer periphery, the crest portion being located substantially at or inwardly of a radially middle point of the sliding contact surface between the hole and the outer periphery.

Abstract: A rotary actuator of the rack and pinion type having a two-piece rack and piston assembly. This rack and piston assembly comprises a rack insert and a one-piece piston member, which includes a piston at each end, a connecting strut extending from one piston to the other and means for retaining the rack insert in such manner that the rack is free to float in any direction except longitudinally but is constrained from longitudinal movement.

Abstract: In a radial piston engine, in order to reduce the friction forces appearing at the pistons, a guide part is provided which engages a hollow piston through a guide section and which includes a bearing section at its outer end, by means of which the guide part is pivotably mounted in the cylinder cover.

Abstract: A vacuum brake booster assembly comprising front and rear housing shells connected to form a single piece their output peripheral edges and mounted within the passenger compartment of a vehicle, a piston body axially movable in the housing shells, a diaphragm member hermetically secured at its inner peripheral edge to the piston body and clamped at its outer peripheral edge by the outer peripheral edges of the housing shells to subdivide the interior of the housing shells into a vacuum chamber and a variable pressure chamber, and a pressure control valve cooperable with the piston body for selectively communicating the variable pressure chamber to the vacuum chamber or the atmospheric air in response to movements of the piston body, wherein at least the rear housing shell is formed as a double or multi layer wall for the variable pressure chamber to dampen air suction noises caused by expansion and vibration of the air flowing through the valve into the variable pressure chamber from the passenger compartment

Abstract: A light alloy piston for internal combustion engines has a skirt which is closed at its lower end and at locations disposed adjacent to the bosses on both sides of the horizontal plane through the piston pin is set back so as to form respective recesses. In order to avoid a retention of oil in the recesses those end portions of the skirt which adjoin the recesses are inwardly offset from the outside peripheral surface of the piston.

Abstract: A lightweight piston 12 composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials, such as aluminum, reduces piston weight and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall 10 clearance is so small as to eliminate the necessity of piston rings. Use of the carbon-carbon piston has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

Abstract: A metal and plastic two-stage composite piston including an annular metal cup, a hollow plastic annular core bonded about the periphery of the cup, a plastic high pressure piston bonded to the interior of the cup, and a plastic low pressure piston bonded about the periphery of the core at the base of the high pressure piston in a fashion such that substantially all of the pressure loads on the pistons are carried directly by the cup and the core of the composite piston.