Abstract: A refrigerant compressor has a reciprocating piston with a projection extending therefrom is disposed in a cylinder. The cylinder has an end wall with a discharge opening operably closeable by a discharge valve. The projection is disposed on an end face of the piston and extends into the opening of the discharge valve when the piston is in the region of its end position. Extending the projection into the discharge valve enables gas remaining in the region above the piston and in the region of the discharge opening to be displaced out of the discharge valve. The projection has an asymmetrical construction with a circumferential wall has a gradient changing along the circumference of the wall. The discharge valve seat and the flow channel in the region of the discharge valve are operably contoured to prevent turbulent flow from occurring when gas is discharged from the discharge valve.

Abstract: An advance mechanism for a pump comprises a fluid operable piston arranged to have pressurized fluid applied to a first end thereof to adjust the axial position of the piston. The arrangement further comprises means for applying fluid under pressure to a part of the piston remote from the first end thereof in order to apply a torque to the piston. In one embodiment, the means for applying comprises a passage extending within the piston, the passage communicating with the first end of the piston such that high pressure fluid is received by the passage.

Abstract: The invention relates to a piston, through which a fluid can flow, for a piston pump, which piston has a longitudinal bore into which a spring-loaded inlet valve body is inserted. In order to be able to bring a helical compression spring, which loads the inlet valve body, to bear against an annular shoulder in the longitudinal bore and to be able to check and if necessary improve its seating after installation, the invention proposes to produce the inlet valve body in two parts comprising the inlet valve disk and the inlet valve stem and to join these two parts to one another after the helical compression spring has been correctly inserted into the piston. The inlet valve disk can for example be joined to the inlet valve stem by ultrasonic welding, thermoplastic riveting or screwing.

Abstract: A swash plate compressor with single ended pistons improves piston stability by providing the ends of the pistons with open, conical rims, the outer surfaces of the which match, and thereby enlarge, the outer surface area of the pistons. The pistons therefore have increased sliding support within the cylinder bores, but without significant added mass. The pistons work in cooperation with matching conical protrusions on the discharge valve plate, which substantially fill the interior of the rims at piston full stroke. The piston compression ratio is therefore kept substantially the same.

Abstract: A door closing device comprises a piston (12) having at one end a seal (21) which seals the interface between the piston and a housing (10). The seal (21) also acts as a one-way valve and carries a pressure relief valve (37).

Abstract: This invention is directed to a new and novel envelope for housing a servo mechanism adapted to control a brake assembly used in conjunction with a vehicular transmission. The envelope is adapted to be demountably received within a receptacle provided in the transmission case. A pilot bore penetrates the transmission case and is located axially of the receptacle. The envelope incorporates a base portion, a cap portion and a coupler portion. A servo-apply pin extends outwardly through the coupler portion of the envelope to be reciprocatingly received within the pilot bore. A piston chamber is provided interiorly of the base and cap portions. An actuating piston is operatively received in the piston chamber, and means are included to effect communication of hydraulic pressure from a conduit within the transmission case, through the coupler portion of the envelope and the servo-apply pin into the piston chamber. Locking means are also provided selectively to secure the envelope to the transmission case.

Abstract: An actuator is driven in a first direction by equal working fluid pressures acting on different piston areas acting in opposite directions, and is driven in a second direction by applying equal pressures on both sides of one of the piston areas. Working fluid from an inlet port, acting in a working fluid chamber, pushes up a valve plate, closes ventilation holes and opens working fluid discharge holes, thereby permitting the working fluid to push the piston upward. Working fluid contained in the working fluid chamber is exhausted from working fluid discharge holes to the outside of the system through a working fluid discharge pipe. When the upward movement of piston reaches its limit, a valve plate is pushed by a spring, thereby causing simultaneous closing of the working fluid discharge holes and the opening of the ventilation holes. As a result of the opened ventilation holes, working fluid pressures in a lower working fluid chamber and an upper working fluid chamber become equal.

Abstract: A small hermetic refrigeration compressor of the single reciprocating piston-type has flat valve plate extending across the open end of the cylinder with a discharge port extending through the valve plate off the center line of the cylinder bore. The piston has a generally flat end face with a recess at least partially in alignment with the discharge port, to allow improved flow of gases to the discharge port with a decreased clearance volume. Further reduction of the clearance volume can be obtained by placing a projecting post on the end face of the piston in line with the discharge port to partially fill the discharge port at top dead center.

Abstract: A piston seal device of pneumatic cylinder which satisfies the required tightness of a seal as well as the required lubrication characteristics for a piston movement is disclosed. The piston seal device for maintining different pressures acting on each side of the piston of pneumatic cylinder comprises slide rings located on peripheries of both sides of piston, a seal ring located at the outer part of pressure room formed along the periphery of central part of the piston and operated by pneumatic pressure of the pressure room, and a solenoid valve which operates in selection modes to supply the pressurized air into the pressure room. Slide rings are located with a proper distance at the peripheries of both sides of a piston installed in a pneumatic cylinder and at the center of a piston an expansionable seal is applied.

Abstract: A piston for axial piston machines in the form of a hollow body with an axial cavity therein into which an insert is inserted and is secured axially by means of a collar in the wall of the hollow body surrounding the insert overlapping its outer end face is designed so that while ensuring simple and economical manufacture, stable support of the filler piece and a stability of the shaft of the piston is obtained. This is achieved by providing the collar by pressing the wall of the hollow body, which is longer than its final length, into a plurality of oppositely disposed recesses or into an annular recess in the insert and by cutting the piston formed in this way to length in the general region of the recesses or the annular recess.

Abstract: A piston for an axial piston machine, comprising a hollow body having an axial cavity into which a filler piece of a material of lower specific gravity than the material of the piston is inserted which at least partially fills said cavity, said filler piece being secured axially in the cavity by a shoulder projecting radially inwards from the hollow body, is to be designed so that with simple construction a stable axial securing of the filler piece is ensured. This is achieved in that the filler piece has a recess arranged between its ends on its outer surface into which the section of the hollow body overlapping the recess is pressed in a form fitting and force locking manner.

Abstract: A pressure fluid reservoir having at least an approximately vertically disposed cylinder with a displaceably guided divider piston therein. The piston divides a pressure fluid reservoir chamber of the cylinder, located below the piston from a gas chamber located above the piston. The divider piston has a hollow chamber, which is covered with respect to the gas chamber by a cap having an opening. The cap has a fluid seal for lubricating piston sealing rings. A riser pipe that begins at an opening in the cap extends as far as a bottom of the hollow chamber that contains fluid. In an expansion of a gas cushion located in the gas chamber in the riser pipe and in the hollow chamber, fluid is pumped through the riser pipe to the fluid seal, to regenerate it the fluid seal. The pressure fluid reservoir is particularly well suited to vehicle brake systems, where long functional reliability of a piston seal is crucial.

Abstract: In a piston for piston machines comprising a hollow body, open at least at its free end, having an axial cavity in which there is a filler piece at least partly filling the latter and consisting of a material of lower specific gravity than the material of the piston, said filler piece being secured in the cavity and being held axially in the cavity by a locking element arranged at the free end of the hollow body and a spring arranged between the locking element and the filler piece, the filler piece is inserted axially and the axial securing and locking is effected solely by the spring, which is pretensioned by the locking element to such an extent that it acts against the filler piece with a spring force greater than the maximum inertial forces of the filler piece acting against the spring to be expected when in operation.

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 piston for a gas-operated linear actuator wherein a double-acting piston moves axially within a cylinder in response to gas pressure applied intermittently to chambers on either side of the piston. The piston has reservoirs in the form of holes in each of its faces and a pair of spaced-apart circumferential grooves, one communicating with the holes in one piston face and the other with the holes in the other piston face, the two sets of grooves and holes being kept out of communcation with one another. Gas under pressure introduced into one chamber forces the piston to move toward the opposite chamber, and a portion of the gas passes into the holes and out through the adjacent groove, providing a stream of gas between piston and cylinder walls, producing a gas-bearing effect.

Abstract: A piston assembly for high-pressure, high-temperture, internal combustion engines, the piston assembly having a piston unit with a piston head and a piston skirt which interconnect to form a substantially sperical internal socket, the assembly also having a wrist pin unit with a substantially spherical ball engageable in the socket of the piston unit, the ball being connected to a connecting rod through the wristpin for limited articulation of the connecting rod and free rotation of the piston unit on the ball of the wrist pin unit, the piston assembly also having a recessed combustion chamber with cooling features.

Abstract: A yarn false twisting apparatus is disclosed which comprises a pair of rotating circular discs having cooperating friction surfaces for engaging a running yarn at a twisting zone. A pressure applying member is positioned to apply a biasing force to the rear surface of one of the discs locally at the twisting zone, and the pressure applying member comprises a receptacle slideably mounting a piston which extends from the end of the receptacle to engage the disc. The receptacle is eccentrically mounted to permit selective positioning of the biasing force with respect to the yarn path of travel. The discs are mounted on pivotal rocking arms whereby the ratio of yarn twist to yarn speed may be adjusted, and an eccentrically mounted pin provides closely controlled adjustability for the arms and thus the twist ratio.

Abstract: A composite piston for ejecting a plastic mass from a receptacle includes a piston head and a pressure component which in combination form a chamber. The piston head and pressure component are displaceable within the receptacle from an insertion position into a locked position. When being moved into the locked position, a part of the plastic mass flows through an opening in the piston head into the chamber. After the locked position is established, the opening in the piston head is closed by an extension on the pressure component.

Abstract: An air weapon air compression system of the type in which air is compressed in a cylinder and expelled through a discharge port, to propel a projectile along the barrel and fire it out of the weapon, by the rapid movement of a piston within the cylinder. Such a system incorporating grooves in one or both of opposed portions of the cylinder and piston, for the transfer of air towards the discharge port during the final compression stage, to enhance the performance of the weapon.

Abstract: A pair of circumferential sliders are positioned symmetrically on opposite sides of a piston, an inner surface of each circumferential slider being connected to a respective bevel rack gear. The rack gears are driven by bevel pinion gears that are attached to opposite ends of a wrist pin connecting the piston to a connecting rod. A pair of passages extend from the top of the piston to a pair of opposite, symmetrically positioned windows that are enlarged and reduced as a crankshaft connected to the lower portion of the connecting rod rotates in order to apply combustion or compression gas pressure in a cylinder to opposed varying areas of the cylinder wall so as to offset the varying lateral component of force applied by the connecting rod to the piston.

Abstract: A piston machine, particularly a hydraulically-actuated piston machine, comprises at least one cylinder having an axis, a piston axially slidable in the cylinder and having a piston bottom with an inner surface, a piston rod turnably connected with the piston and having a piston rod shaft, a turning member mounted on the piston rod and having a side which is opposite to the piston rod shaft and has a convex circular surface, a pressing member having a shell surface which is in sliding contact with the circular surface of the turning member, the pressing member having a side which is opposite to the turning member and is provided with a convex circular surface abutting against the inner surface of the piston bottom, the circular surface of the pressing member and one of the circular surfaces of the turning member and the shell surface of the pressing member having central axes with central axes projections along their common orthogonals forming an angle of approximately 90.degree..

Abstract: An internal combustion engine is illustrated having an engine block, a cylinder located in the engine block, and a cylinder head defining an end wall of the cylinder. A piston is housed in the cylinder and defines with the cylinder and the cylinder head a combustion space adapted to receive a mixture of fuel and air therein. The piston is reciprocably movable toward the cylinder head to compress a fuel mixture in the cylinder and movable away from the cylinder head, the piston engaging one side of the cylinder as the piston moves toward the cylinder and engaging an opposite side of the cylinder as the piston moves away from the cylinder head. The piston includes an annular groove, and the piston ring is housed in the annular groove, the piston ring including opposite ends being spaced apart and forming a gap.

Abstract: A sliding piston joint of a hydrostatic piston machine has a piston having a recess or cavity and a sliding shoe having a head portion receivable into the recess or cavity of the piston so as to support the latter. The sliding shoe has a base portion having a surface which faces away from the piston and faces toward a hydrostatic pressure zone generated during operation of the machine. The head portion of the sliding shoe and the piston have surfaces which are in sliding contact with one another. A throughgoing passage extends through the sliding shoe so that a portion of working fluid flows from the hydrodynamic pressure zone to the contacting surfaces of the sliding shoe and the piston to thereby relieve the latter.

Abstract: A piston for a hydrostatic piston machine, especially an axial-piston pump or motor in which the piston is formed with a ball head riding in a slide shoe which is supported by a fluid-pressure cushion against a countersurface, e.g. a swashplate. The piston is formed with a central passage which communicates with a bore in the ball head, this bore being provided with a throttle to prevent the fluid medium from being forced at an excessive rate into the fluid-pressure cushion and thereby lift the shoe from the countersurface. According to the invention, the end of the piston remote from the ball head is provided with a gap filter of large area and narrow gap width to prevent large particles from entering and blocking the passage and the throttle.

Abstract: A hollow piston for a hydrostatic piston machine and especially for a swash-plate-type axial-piston pump or motor, comprises a hollow outer cylinder member which is formed at one end with a ball head and at the other end with a cover. Extending centrally through this hollow piston is a central post having its opposite ends secured to or engaging the opposite ends of the outer piston member and formed with a central bore communicating between a passage in the cover and a passage in the ball head. At least one of these ends of the central post is juxtaposed with a respective end of the piston and the juxtaposed ends are formed with a conical surface and an edge engaging this surface to seal the post to the outer member.

Abstract: Fluid passages machined in the annular brake piston and in the outboard brake ring of a wet disc brake system allows the circulation of cooling and lubricating fluid. An annular disc brake will deliver cooling fluid to the circumferential periphery of the brake disc operating cavity where the fluid relief passages machined in the annular brake piston and in the outboard brake ring will allow the passage of this fluid out of the brake disc operation cavity thus preventing the stagnation of cooling fluid in the brake disc operating cavity.

Abstract: An anti-pollution piston construction is disclosed containing at least one storage chamber having inlet orifices contained in the periphery of the cylindrical side wall of the piston adjacent the imperforate piston end wall, said storage chamber being adapted to receive unburnt hydrocarbons during the compression stroke of the engine. During the expansion stroke following ignition, the unburnt hydrocarbons are returned to the cylinder chamber for mixing with the combustion gases to reduce the oxides of nitrogen having an excess concentration relative to an equilibrium value which is a function of the temperature, pressure and composition parameters of the combustion gases. The unburnt hydrocarbons in the storage chamber are returned in a manner that displaces unburnt hydrocarbons from the relatively cold wall of the cylinder which further aids the reduction of the oxides of nitrogen.

Abstract: The bearing surface of each piston is provided with hydrostatic pressure medium during operation to maintain the axis of the piston perpendicular to the guide surface. The pressure medium is supplied through throttle passages which terminate in feed openings at the corners or at uniformly distributed points remote from the piston axis. Cooperating guide ledges are also provided on each foot and on the guide member to prevent the piston bearing surfaces from falling away from their respective guide surfaces of the guide member.

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.