Abstract: A piston with a slide shoe is described for a hydraulic piston engine, where the piston is designed with a ball socket, and where the slide shoe is provided with a corresponding ball head, whereby these are connected in a ball-and-socket joint, and where the ball head of the slide shoe is designed as a unit moulded into the ball socket in friction reducing material so that the ball head is captured in the ball socket. Hereby an improved fixation of the moulded-on all head on the slide shoe is achieved.

Abstract: A positive displacement inductive pump includes a housing having first and second ends, and a bore extending from the first end to the second end. A piston is positioned entirely within the bore and defines at least one substantially enclosed displacement chamber. The piston includes a metal rod, and a corrosion resistant lining that completely encapsulates the metal rod. First and second inductive coils are each wrapped around an outer circumference of the housing and are each alternatingly energizable to produce respective first and second induced magnetic fields causing metal piston to move to oppositely located first and second positions within the bore. At least one check valve assembly is attached to one of the first and second ends and is in communication with the at least one displacement chamber.

Abstract: A multiphase piston-type pumping system including a feed line (13) for the fluid to be pumped and a discharge line (19) for the pumped fluid, with at least one first variable-volume chamber (2) designed for pumping, the fluid, and with chamber being defined by a first cylinder head (3), a first cylinder (4), and a first piston (5), whereby piston (5) moves along the longitudinal axis of cylinder (4) in the cylinder (4). A first drive element (6) moves the piston (5) in the cylinder (4). The system also has a casing (23) surrounding at least the space swept by piston (5), with the space being opposite the first chamber (2) with respect to and with the piston (5), said easing (23) containing a gaseous fluid. The piston (5) has a recess (20) designed to receive a projection (10) integral with cylinder head (3), whereby these two elements produce a jet of fluid directed at a discharge port (15).

Abstract: A pump comprising a housing including first and second housing sections and a gasket between the first and second housing sections. The housing has a first pumping chamber, an inlet, an inlet passage in the housing leading from the inlet to the pumping chamber, an outlet and an outlet passage in the housing leading from the pumping chamber to the outlet. A pumping member is movable in the pumping chamber to pump fluid through the pump. Inlet and outlet check valves are provided in the inlet and outlet passages, respectively with each of the check valves including a movable valve element. The outlet check valve includes an outlet valve seat and a movable outlet valve element secured to the gasket at at least two spaced apart regions.

Abstract: A piston for a master cylinder comprises: a piston body made of resin which is inserted in a cylinder in such a manner that the piston body is in slide contact with the inner cylindrical surface of the cylinder, the piston body including a first cylindrical portion which has a first opening at one end and a bottom at the other end, a second cylindrical portion which has a second opening at one end and a bottom at the other end which is integral with the bottom of the first cylindrical portion, thus being integral with the first cylindrical portion; flanges formed on both end portions of the piston body; a first reinforcing member which is detachably inserted into the first opening; and a second reinforcing member which is detachably inserted into the second opening.

Abstract: A piston ring of Teflon (trademark of E.I du Pont de Nemours & Co, Ltd.), i.e., polytetrafluorethylene fiber, is mounted on a piston. The piston ring has an integral portion in the form of a series of axially spaced circumferential projections received in the respective circumferential spaced grooves of the piston. The piston is projected radially and outwardly to abut an axial end of a sleeve portion of the piston ring to limit axial movement of the piston ring.

Abstract: A swash-plate hydraulic pressure device for use as a hydraulic pump or motor includes a cylinder block having an annular array of cylinder holes defined therein around an axis. A plurality of plungers of a ceramic material are reciprocally movably disposed in the cylinder holes, respectively, the plungers having respective partly spherical tip ends. A swash plate of metal is disposed around the cylinder block for rotation with respect to the cylinder block, the swash plate having a annular groove of a partly spherical cross section defined therein and, the partly spherical tip ends of the plungers engaging in the groove. The tip ends of the plungers preferably have a pore area percentage of at most 7.8% and a maximum surface roughness of at most 1.6 s. The partly spherical tip end of each of the plungers has a radius R.sub.0 of curvature, each of the plungers has a diameter D, the groove has a radius R.sub.1 of curvature and a depth E. The ratios R.sub.0 /D, R.sub.0 /R.sub.1, and E/R.sub.

Abstract: A hydraulic pumping device for use in a hydraulic machine having a piston and slider shoe unit made of a combination of plastic and metal material to operate with virtually lubricant free fluid.

Abstract: The invention relates to a high accuracy flowmeter for testing and calibrating flowmeters and the like, and more particularly to a positive displacement flowmeter which may include a cylinder (12), a piston (10) within the cylinder (12) which makes a clearance seal with the inside of the cylinder, an encoder (40) associated with the piston, and a control valve (V) for controlling the supply of a fluid flow (A1) to be measured. More generally, the flowmeter includes a channel for receiving a fluid flow so as to move the piston (10) within its enclosure (12); and a device (36, 38, 40) for detecting movement of the piston and generating electrical signals representative of the fluid flow to be measured. The movement of the piston is detected as a function of a known volume of the enclosure traversed by the piston, and a measured variable elapsed time over which the piston traverses the volume. Preferably, the flowmeter system includes a damping device (FIGS. 6A-6D) which may be mechanical, pneumatic, or fluidic.

Abstract: A ceramic-metal composite structure which minimizes tensile ceramic loads and accommodates differences in thermal expansion characteristics between a metal member and a ceramic member without reliance on precise feature control for either member. The composite includes a mechanical retainer which allows a loose fitting relationship between the metal and ceramic members. The ceramic member is secured within a receiving bore in the metal member by the retainer in a manner which eliminates the need for precise machining of the ceramic and metal members. The metal member may be configured to accept either an internal or an external mechanical retainer element. The composite ceramic-metal structure of the present invention finds particular utility in forming a durable wear-resistant interface in internal combustion engine actuator or actuating components, such as compression brake master pistons.

Abstract: Piston assemblies for use in fluid translating devices normally are made of hardened metal alloy materials which require very smooth surface and are always subject to varying degrees of thermal expansion when being operated at high operating temperatures. In the subject arrangement, a piston assembly is provided and is constructed of most, if not all, ceramic components. The piston assembly includes a ceramic piston having a spherical head portion at one end thereof which rests in a spherical cavity of a ceramic slipper and held therein by a cylindrical ring. The cylindrical ring can be of a one-piece or a two-piece design which is in contact with the spherical head portion and bonded to the ceramic slipper, thus, retaining the spherical head portion. The cylindrical ring could also be made of a metallic material. The metallic ring is bonded to the ceramic slipper and subsequently swaged to hold the spherical head portion within the spherical cavity.

Abstract: In a piston with an encompassing seal, which is seated slidably in a cylindrical receiving bore of a structural part such as a housing block and which can be acted upon by pressure on at least one end, the piston is intended to have a shoulder for receiving the seal. This shoulder divides a cylindrical running face of the piston of a segment having a jacket face, and a groove is formed into the jacket face for receiving a ring that secures the seal in the axial direction and also acts as a stripper ring protecting the sealing ring.

Abstract: An accumulator piston is formed as a two-piece plastic molding for simplifying its construction and for cost reduction and weight reduction purposes. The piston has a radially stepped construction in which each step includes a radial flange carrying an annular elastomeric sealing element. The sealing elements have deformable, resilient lips which slidably engage the side surfaces of a stepped cylinder in which the piston reciprocates. One of the elastomeric sealing elements is molded to an annular insert member that is seated in an annular recess formed in one end of the main piston body. The two-piece piston construction facilitates installation and removal of mold cavity members relative to the respective elastomeric sealing elements such that the mold cavity members can be of simplified economical construction.

Abstract: A compressible seal member is provided with peripherally distributed and axially spaced lubricant retaining grooves, or with radially extending lubricant channels in communication with a central lubricant reservoir. The sealing member has land portions and groove portions on the outer periphery, with the lubricant grooves or channels located along the groove portions. The seal member is installed within a pharmaceutical container with the tool having a working end received within a central aperture formed in the seal member so that the insertion forced is applied near the bottom end of the seal member to prevent compression during installation. When the pharmaceutical is expelled from the container, a plunger pushes on the accessible end of the seal member to compress the seal member axially and force the lubricant out of the grooves or channels and into contact with the inner wall surfaces of the container.

Abstract: Two members which initially have a very loose, complementary dovetail relationship to one another are firmly secured together by causing the material of a ductile locking member to flow into the space which initially exists between the complementary dovetail shapes. This technique is especially suitable for joining materials which are otherwise difficult to unite. For example, this technique can be used to secure an insert of tungsten carbide or ceramic in a main member of steel. Wear or bearing inserts of hard material can be secured in this way to the hydraulic pistons (especially the master pistons) used in compression release engine brakes.

Abstract: Portable lift structure for moving a support platform between a comparatively dry position above the surrounding deck of a liquid spa tank to a wetting position in the spa tank including two longitudinally extending structural members pivotally connected at corresponding top ends thereof to be moved between a portable and operating positions, one structural member serving as a mast to be removably mounted in the spa tank deck and the other as a platform mount, to be pivoted from above the surrounding spa tank deck to a position above the spa tank and lowered by a hydraulic cylinder and piston to a wetting position.

Abstract: An angulating piston assembly for a vehicle air conditioning system compressor comprises a composite piston including a metal rod having a ball at a proximal end and a plastic head at a distal end. A piston ring subassembly is operatively received about the periphery of the plastic piston head. The subassembly is characterized by a rigid support collar molded into the piston head and a piston ring of low friction material stretched and snugly received over the collar. An integral molded lip on the piston head and an outwardly projecting skirt on the support collar maintain the piston ring in position. An inwardly projecting flange is provided on the support collar and molded into the plastic piston head to provide a lock to prevent relative axial movement between the support collar and the piston head.

Abstract: A cylinder and sleeve combination, such as those found in fluid control devices, having closely positioned moving elements that leach one or more substances upon sustained contact with the subject, reactive fluid. One embodiment comprises a metering pump which utilizes small clearances that were heretofore unacceptably tight for the applications disclosed. The materials used to form at least one of the moving elements allow a substance to leach out of the moving elements as a result of a chemical reaction with the fluid, and the leached substance undergoes a separate reaction with the fluid which causes it to coagulate. The various embodiments of the present invention avoid binding of the moving elements by providing at least one scraping edge which continuously scrapes away the coagulum forming between these elements. The scraping edge is advantageously configured so as not to interfere with the operative movement of these elements.

Abstract: A ceramic-metal composite structure which minimizes tensile ceramic loads and accommodates differences in thermal expansion characteristics between a metal member and a ceramic member without reliance on precise feature control for either member. The composite includes a mechanical retainer which allows a loose fitting relationship between the metal and ceramic members. The ceramic member is secured within a receiving bore in the metal member by the retainer in a manner which eliminates the need for precise machining of the ceramic and metal members. The metal member may be configured to accept either an internal or an external mechanical retainer element. The composite ceramic-metal structure of the present invention finds particular utility in forming a durable wear-resistant interface in internal combustion engine actuator or actuating components, such as compression brake master pistons.

Abstract: A clutch master assembly made of plastic material for an automotive vehicle. The assembly a plastic cylinder housing (1) and a piston (2) and a plastic bushing (3). The plastic bushing is arranged to allow it to be screwed in by means of a thread portion (4) which is located in the housing. By the screwing-in of the bushing a grooved disc (5) and a grooved cup (6) are secured in the assembly. The grooved cup is furnished with knobs (21, 22, 23) which exert a force in axial direction on the arrangement consisting of the grooved cup (6) and the grooved disc (5). The piston-side enlarged end of the piston rod (31, 104) is secured within the piston (2, 103) by a back injection.

Abstract: A one-piece piston assembly including a hollow frusto-conical piston is secured to a crankshaft ring via a hollow joint or waist member. Preferably the joint or waist member is frusto-conically shaped as well.

Abstract: A method of manufacturing a piston for transferring an output force to another member in response to pressurized fluid being communicated to a bore in a housing. The piston has a cylinder body made of a plurality of triaxial braided layers of carbon fibers which are placed on a mandrel with spacers located between the layers to form an annular projection of a first end and a taper of a second end. The carbon fibers are impregnated with a thermoset resin and cured to define a unitary solid structure. A cone and collar is attached to the second end to form a unitary piston. The piston is inserted in the bore and moved by the pressurized fluid to provide the output force for the other member.

Abstract: A ceramic-metal friction welded member includes a ceramic member formed with an annular notch in an outer circumference of its surface and a metal member joined onto the annular notch of the ceramic member by friction welding. A ceramic cast-in bonded piston includes a crown made of a ceramic material having an annular notch formed in an outer circumference of its surface, a metal annular member joined onto the annular notch of the crown by friction welding, and a piston main body made of an aluminum alloy surrounding the crown by cast-in bonding. A ceramic cast-in bonded piston includes a crown made of a ceramic material, a piston main body made of an aluminum alloy surrounding the crown by cast-in bonding, and an annular member made of a metal different from aluminum and joined by friction welding to an outer circumference of a surface of the crown in contact with the piston main body.

Abstract: A method of manufacturing a plunger for a downhole reciprocating oil well pump for use in sandy environments including the step of machining a metal plunger to the required base configuration with an external cylindrical pump surface having a diameter of about 0.025 inches less than the design diameter, grit blasting the plunger cylindrical pump surface to achieve a textured surface thereon, heating the plunger, flame spraying a thin layer of ceramic composite on the plunger cylindrical pump surface, repeating the flame spraying steps sequentially until the diameter of the cylindrical pump surface having the ceramic composite thereon is about 0.015 to 0.020 inches above the design diameter, cooling the plunger and grinding the ceramic covered plunger pump surface to the design diameter.

Abstract: The caliper disc brake comprises at least one hydraulic working chamber (20) intended for spacing apart from one another a piston (16) bearing on one brake shoe (12) and a caliper (18) bearing on the other brake shoe (14). The inner walls of the working chamber (20) are covered with a layer (22, 24) of a thermally insulated material.

Abstract: A clutch master assembly made of plastic material for an automotive vehicle. The assembly a plastic cylinder housing (1) and a piston (2) and a plastic bushing (3). The plastic bushing is arranged to allow it to be screwed in by means of a thread portion (4) which is located in the housing. By the screwing-in of the bushing a grooved disc (5) and a grooved cup (6) are secured in the assembly. The grooved cup is furnished with knobs (21, 22, 23) which exert a force in axial direction on the arrangement consisting of the grooved cup (6) and the grooved disc (5). The piston-side enlarged end of the piston rod (31, 104) is secured within the piston (2, 103) by a back injection.

Abstract: The present invention relates to an oilless reciprocating compressor and expansion apparatus each comprising a piston body to which a piston ring made of a self-lubricating material is fitted and a metal cylinder, and in the first invention and the second invention a self-lubricating material can be formed on the piston itself or on the circumferential surface side thereof without influencing adversely the durability of the piston itself by the compression heat at the piston top, and in the third invention a ring groove formed into the shape of the letter C whose ends are spaced a little is provided in the piston circumferential surface at least whose surface side is made of a self-lubricating material, and said ring groove is positioned on the side thrust line orthogonal to the piston pin, so that the compression efficiency is improved.

Abstract: A method of manufacturing a piston for transferring an output force to a member in responsive to pressurized fluid being communicated to a bore in a housing. The piston has a cylinder body made of a plurality of triaxial braided layers of carbon fibers which are placed on a mandrel with spacers located between the layers to form an annular projection of a first end and a taper of a second end. The carbon fibers are inpregnated with a thermoset resin and cured to define a unitary solid structure. Thereafter a cone and collar, throughwhich an output force is suppled to member, is attached to the second en dand the unitary structure inserted in the bore.

Abstract: In the pump piston for axial piston pumps which comprises a ceramic piston and a drive member of metallic material the ceramic piston has an end face of which from 20 to 80% is in the form of a joint surface for a soldered connection to the drive member.

Abstract: A piston stem insert to be received within a hollow receptacle that is molded at the interior of a carpule based piston, so that a piston stem may be easily attached to and detached from the piston by way of the insert. In a first embodiment of the invention, a set of flexible, anti-displacement wings extend radially from the insert to releasable and frictionally engage the inside walls of a carpule, so as to prevent an inadvertent and premature displacement of the piston through the carpule. In a second embodiment, a set of anti-rotation wings extend radially from the piston stem insert to be received within respective cavities of the receptacle that are shaped so that the wings may be rotated in a single (e.g. clockwise) direction but blocked from rotation in an opposite direction.

Abstract: An improved wobble-type piston and rod assembly wherein the assembly includes a conical or infundibularly shaped piston that is capable of withstanding non-axial stress and strain forces induced by reciprocation of the crank shaft ring. An apex of the infundibularly shaped piston is attached to the ring. The piston can be attached to the crank shaft ring by means of a plurality of axial ribs, the ribs flaring outwardly from the apex of the piston to the ring. Alternatively, the piston can be attached to the ring by means of a flattened beam with two ribs/fins that flare outwardly within the plane of the beam. The piston rod assembly is formed as a unitary body.

Abstract: The actuator comprises a clutch pedal lever (12) which is pivotally connected to a support (17). The pedal is integral with a cylinder (18) having a piston (20) therein which is connected to a hollow pushrod (28). The pushrod is also pivotally connected to the mounting (17). Pivoting movement of the pedal (12) causes the cylinder (18) to move relative to the piston so that fluid within the cylinder will operate a slave cylinder (44). The clutch and pushrod have spaced axes of pivoting (13a, 14a) and the piston (20) is shaped to permit a degree of tilting to take place between the piston and the cylinder. The system also includes a reservoir which can communicate with the cylinder when the piston occupies a particular position in the cylinder.

Abstract: The Assembly comprises a piston body having a longitudinal axis to which are added, in interlayered fashion, separate, piston-ring lands and spacers. In one embodiment, a pair of rider rings are coupled to the piston body, in spaced apart locations, to guide the piston assembly in reciprocation, and to space the piston-ring lands away from the surface of an enclosing cylinder. The lands have a diameter which is slightly less than that of the rider rings. The lands are formed of ceramic to offer, thereby, a substantially wear-resistant surface to the piston rings which are set between pairs of the lands, and about the spacers. The body is centrally bored and tapped, and the lands and spacers are centrally apertured; a headed bolt has the shank thereof in penetration of the lands, spacers and rider rings, and threadedly engaged with the tapped bore, to secure the assembly together.

Abstract: For a hydraulic actuation arrangement of a motor vehicle friction clutch a hydraulic cylinder is proposed of which the cylinder, displaceably receiving a piston (7), consists of a synthetic plastics material moulding (3) and a tube piece (5) of metal arranged in the moulding (3) and guiding the piston (7). The tube piece (5) is cut off from a semi-finished tube and guided with axial play, but with resilient initial stress, in the moulding (3). Seals (27, 49) arranged at the ends of the tube part (5) seal the tube part (5) off from the moulding (3).

Abstract: Improved techniques are provided for manufacturing a toroidal arc segment piston for use in a fluid pressure responsive rotary actuator, and for forming an actuator housing defining an arcuate chamber for receiving a rotary actuator piston. A moldable polymeric material is positioned within an arcuate master chamber in a piston-forming fixture, and a metal piston core is rotatably mounted to the fixture. The piston core is rotated to displace the polymeric material and form a sheath about the piston core. After curing, the piston core and sheath are rotated out of the arcuate master chamber, and are installed in a rotary actuator housing. A master piston may similarly be used to form a polymeric lining which defines the chamber for receiving the piston in the actuator housing.

Abstract: In order to produce a high-pressure cleaning apparatus with a wobble plate piston pump which is of less expensive and more wear-resistant design, it is proposed that the piston be made of ceramic and carry a metallic contact element in the region where it contacts the wobble plate.

Abstract: A composite piston for an automotive air conditioning compressor is provided having an aluminum shank or piston rod, a reinforced plastic piston head and a steel ball for engaging a socket plate or the like. The shank has a distal end that has a slight reverse taper and a knurled surface for providing attachment to the plastic head that is molded thereon. The proximal end of the shank has a barrel to which the steel ball is press fitted. The shank is provided with a first collar adjacent the knurled distal end of the shank and a second collar adjacent to and intermediate the first collar and the proximal end of the shank. The first collar provides a seal for the mold cavity into which plastic is injected to form the piston head over the knurled surface of the shank. The second collar provides a support for the press fit operation of the steel ball onto the distal end of the shank.

Abstract: A piston having a cup seal retainer assembly wherein the cup seal is secured between an underside of a circumferential flange of the piston and a retainer ring that is secured to the underside of the piston.

Abstract: A linear hydraulic actuator of small size having limited clearance between the inside of the cylindrical housing and the outside of the piston rod is provided with a deformable or frangible piston of an engineered plastic material which is sufficiently strong to survive normal operation of the actuator but which will break or deform if the cylinder is punched through or "petalled" causing inward projections tending to block movement of the piston. Another embodiment discloses a plastic end gland which is frangible, or deformable in the event of an impact deforming the rod such that it would not pass through the end gland except for such deformation. Because of the relative weakness of the plastic material, the width of the land on the piston acting against the inside of the cylinder is maximized by placing the dynamic seals at or near its outside circumferential edges.

Abstract: The invention relates to the dry run-high pressure stage of a multistage piston compressor with a piston designed as a tappet (2) guided in the high pressure cylinder (1) and sealed against the compression space of the cylinder (1) by means of self-lubricating sealing elements (3) forming an annular gap together with the working surface, whereby the latter is formed by a material suitable for dry run. According to the invention, the sealing elements having a height conforming at least to their diameter are embodied in the form of at least two cylindrical sealing elements (3), which are loosely placed one on top of the other in the cylinder (1) on the free end of the tappet (2), provided with working surface guides at least in part areas, and have chamfers (6) on the face side.

Abstract: An enclosed adjustable servo-actuator is provided. This servo-actuator includes an elongated hollow cylinder; a first closed end member; a second closed end member; a through passageway is provided in each closed end member; an enclosed housing attached exterior of the hollow cylinder at or near the center of the cylinder, said housing adapted to comunicate with the interior of the hollow cylinder; an elongated piston assembly is slidably carries interior of said hollow cylinder; A torque arm is arrayed to engage said piston assembly by means of a closed-end transverse groove provided in said piston assembly; an output shaft is journaled in said enclosed housing, said output shaft engages said torque arm for converting the linear displacement of the piston to an arcuate rotation of said output shaft; and an adjustment means is provided to selectively limit the arcuate rotation of the output shaft.

Abstract: A plastic piston of master cylinder has a first member having a small diameter portion and a second member having a large bore portion. Excess welding resin is prevented from being leaked into a seal ring mounting groove formed on a part of the outer peripheral surface of the small diameter portion by provision of welding portions in the form of a space defined between an outer peripheral surface of the small diameter portion of the first member and the large bore portion of the second member, and a gap defined between a tip end of the small diameter portion of the first member and the bottom of the large bore portion, the space and gap being provided respectively for preventing the excess welding resin from being leaked into the seal ring mounting groove. The plastic piston has no parting lines along the seal ring mounting groove which results in achieving a superior seal effect.

Abstract: In a combination of sliding members which are suitable for use in the compressor for an automotive air conditioner, one of the members consists of an aluminum alloy which contains silicone particles consisting solely of eutectic silicon; and the other sliding member consists of a fluoride resin which contains carbon fibers and a calcium compound. The surface of the aluminum alloy can be finished to a desired smoothness as it does not contain any excessively hard substance. Also, since a calcium compound which is intermediate between carbon fibers and teflon resin in hardness is distributed in the teflon resin, the tendency of the carbon fibers to attack the aluminum alloy is reduced, and the aluminum alloy can achieve a sufficient wear resistance even though it does not contain any primary crystal silicon particles having a high hardness. Furthermore, the calcium compound serves as a lubricant, and reduces friction between the two sliding members.

Abstract: A piston has a first endwall, a second endwall and a tubular ceramic sidewall extending between and forming a closed cylinder with the endwalls. The piston does not include a piston ring. The first endwall is substantially flexible and is releasably interconnected with the second endwall by means of connection with an extended portion of an associated piston rod mounted in a hub of the second endwall. As a result, the first endwall is urged into a concave configuration. The ceramic piston sidewall is mounted for reciprocation within a ceramic cylindrical wall. An anti-rotation device is provided to limit rotation of the endwalls relative to the sidewall, and another anti-rotation device is provided to limit rotation of the hub relative to the piston rod.

Abstract: A fluid operable engine has a cylinder in which a piston slides up and down. The cylinder has a cylindrical wall and two end walls. The piston divides the cylinder into two chambers. The piston is hollow, has a cylindrical wall and two end walls, with a rigid tube extending from and through one end wall of the piston through an adjacent end wall of the cylinder so that the interior of the piston communicates with the exterior through the tube. The cylinder has an aperture in each end wall or in its cylindrical wall close to the end walls and the piston has an opening in each of its end walls. A closure member is provided for alternately closing the openings or the apertures as the piston reaches each end wall. The engine is operated either in a positive or negative manner, with fluid being charged into or sucked from the piston or the cylinder. The openings may be closed from within or without and the apertures may be closed from inside or outside. The closure member may be mechanically or fluid operable.

Abstract: A fluid actuated cylinder assembly including a piston and piston rod and having a cylinder head capable of shifting in any direction throughout 360.degree. along a plane perpendicular to the long axis of the cylinder. The piston and piston rod are rockable throughout 360.degree., the piston maintaining a fluid tight seal with the cylinder at all times. The cylinder, piston rod and shiftable head are preferably made of acetal resin or equivalent thermoplastic material. The piston comprises a sleeve made of acetal resin or equivalent thermoplastic material mounted on the piston rod and having an integral enlarged flange portion with a peripheral surface carrying a seal maintaining a sealing engagement with the cylinder. Alternatively, the piston comprises a spherical rubber member mounted on the piston rod and making the seal with the cylinder. The cylinder assembly can be pneumatically or hydraulically actuated and may be of the single-acting or double-acting type.

Abstract: An improved disc brake plastic piston is described which has a metallic cap or face which provides a means of attaching a brake shoe or a brake shoe assembly, or provides a dust boot groove, or, in a most preferred mode, the metallic cap component provides both a brake shoe retaining means and a dust boot groove. The piston is comprised of a cylindrical plastic body having an open end and a closed end. At least one ring bead can extend from the wall of the piston body contiguous to, or near, the open end. A metallic cap extends over the end wall of the open end of the cylindrical body and is secured to the body by being snap fit or clamped over the ring bead. Alternative means for anchoring the metallic cap are provided, such as by crimping the interior lip of the metallic cap or by providing threads on the internal or external walls of the piston adjacent to the open end of the piston, and corresponding or matching threads on the metallic cap.

Abstract: Plastic molded articles having low friction and excellent wear resistance are produced by treating the surface of the plastic article with an aqueous solution of an inorganic fluoride such as hydrogen fluoride. Plastic articles which can be made in accordance with the invention include plastic brake pistons, bearings, motors and drives, commutators, slip ring alternators for DC drive motors, thrust washers, spacers and reactors, clutch plates, electrical switching equipment with sliding parts, gears, pulleys for belt drives, such as cog belt pulleys, V-belt pulleys and poly V-belt pulleys, gas meter discs, and the like. In addition to the treatment step, the plastic articles are neutralized, washed and dried.

Abstract: A fluid operable engine has a cylinder in which a piston slides up and down. The cylinder has a cylinder wall and two end walls. The piston divides the cylinder into two chambers. The piston is hollow, has a cylindrical wall and two end walls, with a rigid tube extending from and through one end wall of the piston through an adjacent end wall of the cylinder so that the interior of the piston communicates with the exterior through the tube. The cylinder has an aperture in each end wall or in its cylindrical wall close to the end walls and the piston has an opening in each of its end walls. A closure member is provided for alternately closing the openings or the apertures as the piston reaches each end wall. The engine is operated either in a positive or negative manner, with fluid being charged into or sucked from the piston or the cylinder. The openings may be closed from within or without and the apertures may be closed from inside or outside. The closure member may be mechanically or fluid operable.

Abstract: An apparatus for providing a gas phase film lubrication between a reciprocal piston and a cylinder of an uncooled oilless internal combustion engine; the piston is effective to drive a rotary crankshaft in response to an expanding gas charge. The apparatus comprises: (a) means connecting the crankshaft to said piston for transferring reciprocal thrust into rotary thrust, such means aligning the piston concentrically within the cylinder wall to limit the imposition of side loads on said piston (i.e., less than 80 psi); (b) interfacing walls on the piston and cylinder (i) sized to provide a predetermined annular gap therebetween at ambient conditions that has a radial dimension in the range of 0.001.+-.0.