Abstract: The piston in the master cylinder of a hydraulic system of the kind that is used particularly in motor vehicles is made of a duroplastic polymer material.

Abstract: A device (10) for circulating sealing gas for mechanical dry seals (11) of a centrifugal compressor (13) at times when the machine is stationary and pressurized; the device comprises a sealed reciprocating compressor (12), which includes a piston (14) slidable in a cylinder (16), and the piston (14) is moved by a magnetic coupling to an external magnetic element (20) which moves along the said cylinder (16).

Abstract: A piston for a piston-cylinder arrangement, in particular a shock absorber piston exhibiting a piston body (6) provided with one peripheral web (12) protruding from the peripheral surface, disposed on said peripheral surface in both areas, each of which defining one end of the piston. Supporting connector elements (10), which extend longitudinally in the direction of the other end of the piston, are arranged successively at a distance from each other in a parallel manner contiguous to the peripheral web, whereby each two adjacent supporting connector elements (10) define a groove-shaped recess (11) and are provided with a collar-shaped seal (9) made of a thermoformable sealing material, which is formed on the piston body (6) in such a way that the peripheral webs (12) as well as the supporting connector elements (10) are incorporated into the material of the collar-shaped seal (9) over only a portion of their height.

Abstract: In a piston for a compressor, the piston comprises a stem by which the piston may be guided in the housing in an axially displaceable manner, and a force introducing section where an outer drive force can be introduced into the piston. The piston head, the piston skirt and the force introducing section are successively arranged in the direction of the piston axis. The piston head, the piston skirt and the force introducing section are produced as a single element of graphite or a synthetic material, and the piston skirt comprises a solid strut structure and a guide section, the cross-sectional area of the strut structure being smaller than the surface of the piston head. The piston consists of a non-organic, non-metallic material having an average thermal expansion of less than 7×106/° C. in the temperature range of 0° C. to 200° C.

Abstract: A fluid flow control damper assembly having a damper vane and a piston actuator is relatively easy to install when the outer surface of a duct is inaccessible. The piston actuator includes a powder metal piston, lacking an elastomeric (for example, rubber) seal, that is closely received within a glass cylinder. The glass cylinder has a fitting that closes one end of the cylinder and is connectable to a pneumatic control system. A drive rod is connected between the piston and the damper vane to move the damper vane between an open position and a closed position.

Abstract: A plunger for being inserted in a tubular barrel in an axially movable manner includes a plunger body having a distal end positioned within the barrel and a proximal end positioned outside of the barrel, and a seal member disposed on the distal end of the plunger body. The seal member has a base portion extending from the plunger body towards the distal end of the barrel, and a flange portion radially outwardly extending from the base portion and having a peripheral edge contacting an inner circumference of the barrel so as to define an accommodation space within the barrel.

Abstract: A hydraulic control device operates a sliding selector shaft, in particular a gearbox for motor vehicles, with a bore made in a wall of a gearbox housing for accommodating a plastic piston. The piston is actively connected to the sliding selector shaft and delimits a pressure chamber and, under hydraulic pressure, radially guides and axially displaces the sliding selector shaft. The piston has a body and a guide section consisting of plastic. The piston is guided directly at the bore, designed as a non-reinforced and unlined cylinder bore, in the wall of the gearbox housing, consisting of a light metal alloy. This creates control device, which is of a much simpler, and more compact design compared with prior art.

Abstract: A piston is used for a fluid machine. The fluid machine has a cylinder bore and a piston driving unit for driving the piston in a housing. The piston has a piston body made of resin, a coupler made of metal and a resin unit. The piston body is accommodated in the cylinder bore. The coupler is connected to the piston body. The coupler is operatively connected to the piston driving unit. The resin unit is connected to the coupler for preventing the coupler from contacting a contacting portion on the side of the housing. The piston body and the resin unit are made of the same resin.

Abstract: A composite part of a clutch for use in a motor vehicle has a plastic carrier and a film of oxidized aluminum or an aluminum alloy overlying and adhering to that part of the carrier which is in sliding contact with at least one other part of the clutch. Oxidizing of the film is the result of a chemical or electrochemical treatment.

Abstract: A fluid pressure cylinder apparatus comprises a cylinder tube integrally connected between a head cover and a rod cover; a piston internally installed in the cylinder tube, for making displacement in accordance with an action of a pressure fluid supplied into the cylinder tube; and a piston rod connected to the piston; wherein a pair of first dust-removing members are installed on an outer circumferential surface of the piston with a piston packing intervening therebetween; and a second dust-removing member and a third dust-removing member are installed to an inner circumferential surface of a support section of the rod cover for the piston rod with a rod packing intervening therebetween.

Abstract: A method for sealing a working zone in a cylinder of a thermal cycle engine. The method includes providing a seal ring within a ring groove of the piston, and, additionally, applying a backing force on the seal ring by means of a backing ring having a width that varies with circumferential displacement from a fiducial circumferential position on the backing ring. The backing force is provided by means of a backing ring that has a non-circular shape in an uncompressed condition.

Abstract: A master brake cylinder for use in a braking system of a vehicle, which contains pistons, having seals molded thereon. Overmolding the elastomer directly onto the pistons forms the seals. Also disclosed are improved master brake cylinder pistons having seals for automotive and other vehicles, and master brake cylinders which comprise brake fluid resistant, synthetic elastomer seals molded directly onto the piston of the master brake cylinder.

Abstract: A method of forming a floating piston includes fabricating a piston cup, wherein the piston cup includes a top, a sidewall void of any seal-gripping irregularities, and an open end, and forming an elastomer seal over the sidewall of the piston cup. A floating piston includes a piston cup having a top, a sidewall extending about the periphery of the top and an open end, wherein the sidewall is void of any seal-gripping irregularities; and an elastomer seal formed about the sidewall of the piston cup.

Abstract: A piston (1) with a piston ring (10) for a hydraulic or pneumatic unit fitted with a damping device and is mounted on a piston rod, dividing a cylinder (9) into two working areas and consisting of at least two parts (2, 9) that are adjacent to a surface (4) extending perpendicularly to the axis of symmetry (5). The piston ring (10) has an axial extension (14) that is several times greater than the thickness (15) of the wall of the ring and is disposed in an outer circumferential groove (6) that extends over both parts (2, 3). The invention provides a piston that prevents rumbles and is easy to produce, requiring only a few components.

Abstract: The invention relates to a piston for a cylinder, in particular a brake piston for a brake cylinder, made of a plastic. Such a piston is improved so that the piston is not damaged by wear, and furthermore can be manufactured inexpensively within the prescribed tolerances. Furthermore contact of the hydraulic fluid with the plastic of the piston is prevented. This is achieved by the piston being provided with a container, made out of metal, which at least partially covers the outer surface of the piston and is adapted to be brought into contact with the cylinder wall.

Abstract: A hydraulic piston for a disc brake assembly includes a metallic cylinder with a bottom at one end and a hollow resin cylinder with an opening at each end. The hollow resin cylinder is disposed in an inner surface of the metallic cylinder and closes the opening at one end of the hollow resin cylinder. The hollow resin cylinder further includes a main part disposed in the inner surface of the metallic cylinder and a flange portion having an outer diameter which is wider than the outer diameter of the main part of the hollow resin cylinder. The flange portion is formed on the main part at the other end of the hollow resin cylinder, integrally or with a separate member. An annular groove is defined between the flange portion and an open end of the metallic cylinder.

Abstract: The invention relates to a piston for a hydraulic control device for a clutch, especially the clutch of an automobile, having a tubular metal sleeve with an internal transversal wall which is integral with the tubular body of the sleeve. A hydraulic chamber is defined towards the front of the sleeve where the piston is mounted so as to slide axially.

Abstract: The description relates to an actuator for use at high and low temperatures, with a cylinder block (8), a piston (14) movable therein and a piston rod (22) secured to the piston. A first and a second flange cover (46, 48) and a sleeve (40) in the cylinder block (8) in which the piston (14) can move to and fro are made of ceramic. The piston rod (22) is secured to the piston (14), also of ceramic, by a head bearing (24) movable transversely to the longitudinal axis of the piston. The seal between the piston (14) and the sleeve (40) is provided solely by a close fit, without the need for additional sealing components. The low thermal expansion of the ceramic components used also means that the tolerances change little even at great temperature fluctuations. The radial head bearing (24) prevents the piston (14) from jamming during forces transverse to the longitudinal axis of the piston possibly arising at the piston rod (22).

Abstract: A piston for a swash plate type compressor having a swash plate, including an engaging portion which engages the swash plate through a pair of shoes such that the shoes are held in contact with opposite surfaces of the swash plate at a radially outer portion of said swash plate, and a hollow cylindrical head portion having an end section which is located on the side remote from the engaging portion, wherein the engaging portion is formed of a material which is different from that of the end section of the hollow cylindrical head portion.

Abstract: An actuator having a piston member slideable within a cylinder, the piston member defining with the cylinder a first chamber and a second chamber, the effective cross-sectional of the piston member exposed to the fluid pressure within the first chamber being greater than that exposed to the fluid pressure within the second chamber. The actuator further has first and second ports through which fluid can be supplied to the first and second chambers, respectively, and a third port located intermediate the first and second ports. The piston member and the third port are cooperable to throttle the rate at which fluid is able to escape from the first and second chambers through the third port, in use.

Abstract: A metallic cap for a plastic disc brake piston is provided with openings in a cylindrical side wall thereof and the plastic is caused to flow into the openings during molding of the piston to create an extension of the plastic material which locks the cap onto the piston. The cap has an end wall and at least one side wall and preferably has inner and outer side walls. The openings are generally in the form of holes or slots. At least one opening is required and at least two openings are preferred. The cap is integrally molded to the piston by placing the cap in the mold, adding resin material and causing molding of the resin material by heating and/or compression.

Abstract: The invention relates to a piston-cylinder arrangement, especially a shock absorber piston, comprising a piston body fitted with at least two peripheral webs on its peripheral surface, said webs limiting a groove and also including a collar-shaped sealing element made of thermoformable plastic material that overlaps the webs. Said piston also comprises axial passage channels in the piston body that are closed by throttle valves opening on one side and at least one radial hole connecting at least one passage channel to the groove formed between two webs.

Abstract: An actuating piston (10) of a hydraulically and mechanically actuable, spot-type disk brake for motor vehicles, which is disposed in a sealing and displaceable manner in a cylinder bore of the disk brake is provided with an axial-force-transmitting conical surface (18) cooperating with a corresponding conical surface of a mechanical actuating device of the disk brake. To make the actuating piston (10) lighter in weight but nevertheless to withstand greater stress, the part of the actuating piston (10) comprising the axial-force-transmitting conical surface (18) consists of steel and the part of the actuating piston (10) cooperating with the cylinder bore of the disk brake is made of light metal or of plastics material, said components of the actuating piston being constructed as a single-piece composite component.

Abstract: The invention relates to a piston for a piston-cylinder arrangement, especially a shock absorber piston, comprising a piston body (6) that is fitted with at least one peripheral web (10) on its peripheral surface, wherein a collar-shaped sealing element (9) made of thermoformable plastic material is also formed on the peripheral surface of the piston body (6) in such a way that the web (10) is only formed in part of the height of the material of the collar-shaped sealing element (9).

Abstract: This invention relates to an improved structure for a piston assembly adapted for use in a wheel cylinder of a drum brake assembly, the drum brake assembly having a pair of brake shoes which are adapted to be urged into frictional engagement with a brake drum. The piston assembly includes a piston body formed from a first material, and a piston cover formed from a second material and integrally molded in situ with the piston body. The piston cover includes an end wall defining an abutment surface which is adapted to engage an upper end of the brake shoe during brake actuation. The piston cover further includes a plurality of circumferentially spaced projections extending from the end wall of the piston cover into the piston body and integrally molded and embedded within the piston body. Each of the projections of the piston cover defines first and second side edges which are in contact with the piston body to thereby assist in securing the piston cover to the piston body.

Abstract: A coat layer formed on the outer perimeter side surface of a piston comprises a fluorocarbon resin and a binder as main components, and further contains 0.05-12% by volume of a wear resistance additive with a Mohs hardness of 2.0-5.0. This provides a piston compressor piston having a coat layer with excellent wear resistance.

Abstract: A hydraulic device is disclosed for operating a sliding selecter shaft, in particular a gearbox for motor vehicles, with a bore made in a wall of a gearbox housing for accommodating a plastic piston, which is actively connected to the sliding selecter shaft and which delimits a pressure chamber and, under hydraulic pressure, radially guides and axially displaces the sliding selector shaft. The piston has a body and a guide section consisting of plastic, via which the piston is guided directly at the bore, designed as a non-reinforced and unlined cylinder bore, in the wall of the gearbox housing, consisting of a light metal alloy. This creates control device, which is of a much simpler, and more compact design compared with prior art.

Abstract: Pistons, which are reciprocated by a swash plate of a compressor, have two separate parts joined together. Each piston has a body and a coupler. The coupler is connected to the swash plate. The body is made of thermosetting resin. The body is molded to the coupler. Accordingly, the piston body to be firmly connected to the coupler.

Abstract: The invention relates to a piston pump with a piston (10) that is guided so that it can move axially in a pump bore (12) of a pump housing (14). In order to simplify the manufacture of the piston (10), the invention proposes providing the piston (10) with a support ring (64), which is connected to a guide ring (66). By connecting the support ring (64) and guide ring (66), the structural length of the piston pump (10) can be shortened.

Abstract: A master brake cylinder for use in a braking system of a vehicle, which contains pistons, having seals molded thereon. Overmolding the elastomer directly onto the pistons forms the seals. Also disclosed are improved master brake cylinder pistons having seals for automotive and other vehicles, and master brake cylinders which comprise brake fluid resistant, synthetic elastomer seals molded directly onto the piston of the master brake cylinder.

Abstract: A piston or plunger and a method for making the same A piston or plunger comprises a piston body and a sealing member. The piston body is preferably made from metal by moulding, such as casting or pressure moulding and sintering. The sealing member is made from a thermoplast, such as polytetrafluoroethylene (PTFE). The piston body has an outer or an inner peripheral surface part in which axially extending depressions or grooves are formed during moulding of the piston body. The axially extending grooves may be open at one or at opposite ends. An annular sealing member blank is applied to the peripheral surface part and is deformed and forced into tight engagement with the peripheral surface part and into the grooves or depressions formed therein. The sealing member formed is also exposed to a heat treatment. The piston or plunger having the sealing member applied to an outer peripheral surface part may, for example, be used in shock absorbers.

Abstract: A hydraulic piston for a disc brake assembly includes a metallic cylinder with a bottom at one end and a hollow resin cylinder with an opening at each end. The hollow resin cylinder is disposed in an inner surface of the metallic cylinder and closes the opening at one end of the hollow resin cylinder. The hollow resin cylinder further includes a main part disposed in the inner surface of the metallic cylinder and a flange portion having an outer diameter which is wider than the outer diameter of the main part of the hollow resin cylinder. The flange portion is formed on the main part at the other end of the hollow resin cylinder, integrally or with a separate member. An annular groove is defined between the flange portion and an open end of the metallic cylinder.

Abstract: The compressor contains at least one piston (5) guided in a dry-running manner which, together with a cylinder insert (33), bounds a ring gap which is open over the common longitudinal section in each case and permits a leakage flow of the compressed medium. The piston (5) is coupled via a piston rod (42) to a support part (38) which is displaceably guided in the direction of its longitudinal axis (6) and is connected to a drive device. The piston rod (42) cooperates with the piston (5) and the support part (38) via support surfaces (43) which are convex at the end faces and permit relative movements of the support part (38) with respect to the piston (5) which extend transversely to the longitudinal axis (6). Accordingly, a parallel guidance of the piston (5) in the cylinder insert (33) is achieved which is not influenced by oscillations of the driving parts.

Abstract: The invention concerns a device comprising a shift cylinder with a cylinder body (17) bearing a first sleeve (54) for guiding a second sleeve (42) enclosing an axially mobile piston (21) with an intervening piston seal between the second sleeve (42) and the piston (21) and a secondary seal (59) between the body (17) and the second sleeve (42) penetrating into the hydraulic chamber. The invention is applicable to motor vehicles.

Abstract: A fuel feed pump in which the number of steps for machining a piston portion is reduced to realize a reduction in cost. A fuel feed pump 1A for delivering fuel fed from a low-pressure pump to an injector at a high pressure, comprises a pump chamber 13 communicated with a fuel introduction passage 14 and a delivery passage 15, a plunger 3A being reciprocatingly driven upon abutting a cam 5 that is driven by the output of an engine, and a sleeve 7 for guiding the lateral surface of said plunger in the axial direction, wherein said plunger is formed of ceramic as a single structure, has a sliding portion 31 at one end surface thereof to abut said cam, and forms said pump chamber at the other end thereof.

Abstract: A filled hydraulic piston assembly includes a piston body having first and second ends and a compartment in the piston body extending inwardly from the second end toward the first end. The piston is filled with an insert element which is inserted into the compartment of the piston and then held therein by pushing an annular lip on the second end of the body inwardly and against the adjacent end of the insert element. The insert element is comprised of a material that is less dense than the material of the body but has a higher bulk modulus than hydraulic oil. Oil channels can be formed in a variety of shapes on or around the insert so that oil may flow through the filled piston. The piston insert element can be formed from a variety of materials, such as plastic, magnesium, aluminum or other nonferrous metals. The body is generally comprised of steel.

Abstract: An internal combustion engine component assembly including piston, wrist pin, and cylinder sleeve, all constructed of a matching carbon-carbon composite is disclosed. The piston is a two-piece assembly divided in crown and skirt, each fabricated individually to optimize the most desirable properties in the respective cylinder areas in which they operate. The crown is fabricated by placing the fiber and binder into a compression mold and pyrolizing(heating) the resulting preform at a high temperature in the range of 1500 to 2000 degrees C. to achieve high temperature strength, and high thermal conductivity that continue after machining to the finished crown part. The skirt, a separate piece, on the other hand is fabricated differently to seek higher lubricity and better wear resistance along the cylinder wall with lower thermal conductivity to minimize heat loss.

Abstract: A composite molded plastic brake piston which comprises a phenolic resin body that is co-molded to a skin which comprises a phenolic sheet molding compound. The skin adheres to at least one surface of the article. The phenolic resins of the two compounds are cross-linked into a molded product which resists separation by mechanical, chemical or thermal methods.

Abstract: A piston pump for a slip-controlled motor vehicle brake system, with a piston which, by means of a piston restoring spring, is pressed with an end face that constitutes a strike face against a circumference of a cam. The cam is driven to rotate, wherein the cam is used to drive the piston in a reciprocating stroke motion. In order to be able to inexpensively manufacture the piston as an injection molded part made of plastic, the piston is provided with a cam strike piece made of wear resistant material on the strike face which is in contact with the cam.

Abstract: Disclosed is a piston having a cylindrical body made from a thermosetting molding compound. The body has a central well and a molded-on metal cap having sides that extend downward over the exterior of the body and into the well. There is insulation under and in contact with the metal cap.

Abstract: A hydraulic piston machine is disclosed, having a piston arranged to move back and forth in a cylinder body. In such a machine it is desirable to be able to achieve a longer service life, even when the hydraulic medium is not suitable for lubricating the bearing faces. For that purpose, at least on its outer face sliding on the cylinder body, the piston has a layer of a friction-reducing plastics material, wherein at the end of the piston there is provided a bearing face of an articulated joint by means of which a slide shoe is connected, articulated to the piston, the layer being continued onto the bearing face.

Abstract: A molded piston includes a base plate, having a plurality of holes, and a polymeric material molded around the base plate and extending through the holes so as to form a mechanical bond between the base plate and the polymeric material. The molded piston preferably includes integral seals in its outer circumferential surface and integral standoffs on its end surfaces. In some preferred embodiments, the molded piston also includes a magnet which creates a magnetic field in the area of the piston.

Abstract: Disclosed is a piston for a water pump, e.g., a pressure washer pump. The piston includes a piston body and a piston head and in the improvement, the piston body is solid, homogeneous ceramic. That is, the piston body has a generally cylindrical surface and the body is circumscribed by the surface and is homogeneous ceramic. A method for making a piston for a water pump includes the steps of providing a piston body made of a ceramic material, and making a piston head of steel and having a pocket formed therein. The head is heated, the pocket and the body are engaged in overlapping relationship and the head is allowed to cool and "shrink-fit" to the piston body. The piston head is formed to have a relief groove circumscribing the pocket for reducing compression forces resulting from such cooling.

Abstract: A versatile apparatus (2) for controlling the transmission of rotational forces between first and second rotatable members preferably takes the form of a clutch that can be activated by axially shifting an internal actuation member (140) through the introduction of either liquid or gaseous mediums. The clutch includes first and second transmission members (177, 281) which are rotatably mounted within a housing (5) and adapted to be attached to the first and second rotatable members respectively. A coupling assembly (226), preferably including first and second sets of axially spaced interface elements (252-254 and 274, 275), is interposed between the transmission members (177, 284) within the housing and axial movement of the actuation member (140) causes the interface elements (252-254 and 274, 275) to be frictionally engaged.

Abstract: In order to reduce the weight and manufacturing cost of a piston for a hydraulic actuating cylinder, the piston, the piston rod and the external reinforcement cap are combined to form a unitary integral part. The unitary part is advantageously a single extrusion product. The piston is shaped so as to be able both to slide along the length of the inner cylinder wall, and to tilt upon deflection or lateral displacement of the piston rod in the bore of the cylinder, while still maintaining its hydraulic seal.

Abstract: A piston for use in a disc brake assembly includes: a hollow plastic body defining an axis and including an open end and a closed end, the body defining an inner surface and an outer surface extending axially between the open end and the closed end; and a first steel cover integrally molded about portions of the outer surface and the closed end of the body, the first cover including an outer side wall and an end wall, the outer side wall of the first cover extending axially inwardly toward the open end along a portion of the outer surface of the body, and the end wall of the first cover extending radially inwardly along a portion of the closed end of the body.

Abstract: A corrosion resistant cermet comprises a ceramic component (e.g., WC) and a binder alloy comprised of a major component (e.g., one or more of iron, nickel, cobalt, their mixtures, and their alloys) and at least one additive component (e.g., one or more of ruthenium, rhodium, palladium, osmium, iridium, and platinum).Plungers for hyper compressors used in the corrosive environments generated during the manufacture of low density polyethylene (LDPE) or ethylene copolymers are an example of the use of the corrosion resistant cermet.

Abstract: A pressure-applying arrangement in a hydraulic axial piston machine is disclosed, having a pressure plate (7) and a piston (9) that is axially displaceable in a cylinder body (3), is biased by a spring (10) and acts against the pressure plate (7). It should also be possible to use such a pressure-applying arrangement when the axial piston machine is operated with a hydraulic fluid that has no or only very little lubricating property, for example, water. For that purpose, the piston (9) is formed from a high-strength thermoplastics material.

Abstract: A piston with a slide shoe for a hydraulic piston engine, where the slide shoe comprises a ball socket, and where the piston is arranged with a corresponding ball head, whereby these are joined in a ball-and-socket joint, and where at least partially the ball head is constituted of a spherical surface of a friction reducing material moulded onto and retained in relation the piston. As a consequence of the subsequent shrinking of the moulded-on, friction reducing material, a possibility is obtained of good fixation of the ball head on the piston, while at the same time a gap can be created between the ball socket and the ball 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.