Abstract: An apparatus for compressing a gas includes a preferably substantially vertically oriented cylinder body, having a longitudinally extending bore with a wall, and a preferably substantially vertically oriented piston adapted for reciprocating movement in the cylinder bore. The piston includes a piston head preferably having a substantially horizontally oriented top face and a seal groove extending around the periphery of the piston head and spaced from the piston head top face. At least one fluid passage extends in the piston head from the top face thereof to the seal groove. A seal member is positioned in the groove and has an outer face adapted to contact the cylinder inner wall. A layer of a lubricant is provided on the piston head top face. An inlet aperture is provided for allowing a gas to enter the cylinder above the piston head. A movement member is provided to urge the piston upwardly and compress the gas.

Abstract: A cylinder and piston assembly with an oil scraper ring having a radially washer seated in a radial piston groove, and a scraping skirt having a radially resilient truncated portion with the base edge engaging the cylinder wall in a scraping line located in or substantially close to the median plane of the washer so as to avoid bending moments on the washer tending to interfere with its free radial movement in the piston groove as required to maintain uniform scraping contact with the cylinder wall.

Abstract: A chuck actuator has a cylinder extending along an axis and having an axially extending stem whose outer surface is formed with a pair of central radially outwardly open and axially spaced intake ports, a piston axially displaceable in the cylinder and forming therein two compartments connected via respective passages connected to the intake ports, two axially spaced bearings on the stem, and a connector supported by the bearings on the stem. This connector normally is restrained against rotation relative to the axis and has an inner surface closely juxtaposed with and forming with the stem surface an interface. Respective radially inwardly open and axially spaced inner feed grooves open at the interface level with the respective intake ports. Two independent hydraulic fittings communicating with the inner feed grooves can pass pressurized liquid to the respective compartments.

Abstract: A piston for an internal combustion engine has the conventional skirt replaced by top and bottom bearing surfaces spaced apart by a substantial gap of constant width. The top bearing surfaces are connected to the piston crown through the ring band whereas the bottom surfaces are attached to piston bosses by struts. The gap allows the passage of lubricant to the cylinder to ensure adequate lubrication of the bearing surfaces.

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 charge forming apparatus or carburetor having a mixture passage and a throttle valve arranged therewithin. A fuel pressure control mechanism comprises a chamber from which controlled fuel is fed to the mixture passage. A flexible diaphragm defines one of the walls of the fuel chamber. A cam is formed at a throttle shaft which supports the throttle valve. An acceleration pump comprises a cylindrical chamber, a piston received in the cylindrical chamber, and a spring for contacting the piston with the cam on the throttle shaft.

Abstract: An air pump apparatus having a cylinder extending from a pump casing. The cylinder comprises a cylinder liner positioned within the walls of the cylinder and a piston is mounted for reciprocating movement within the cylinder liner. The pump chamber is formed between the front of the piston and the front portion of the cylinder wherein an annular gap is formed between the piston and the inner wall of the cylinder liner, wherein the piston has a plurality of annular grooves formed on the outer circumferential surface thereof, the annular gap and annular grooves forming a labyrinth path extending from the pump chamber.

Abstract: A piston for an engine or motor has a skirt which includes two portions which are urged towards an associated cylinder during the various strokes of the working cycle. Each portion is provided with a bearing surface or surfaces for sliding engagement with the associated cylinder during reciprocation. The piston is provided with formations which pass lubricant to and over the bearing surfaces.

Abstract: Double-headed pistons received within cylinder bores in the cylinder block are in engagement with the swash plate via shoes and balls. The pistons each have its intermediate bridge portion formed with at least one lubricating oil-guiding hole extending therethrough from a side surface of the same portion facing the inner peripheral surface of the cylinder bore to the opposite side surface facing the outer fringe of the swash plate. The bridge portion of each piston may also be formed with an axially extending lubricating oil-guiding groove joined at one end to the lubricating oil-guiding hole.

Abstract: A filled piston (10) has a tube (19) extending axially through the core (13) of filler material. The tube (19) provides the passage (23) through which hydraulic fluid passes to lubricate the bearing surfaces of components associated with the piston (10). This eliminates the problem of the hydraulic fluid eroding the filler material and thus the need for visual inspection of the passage through the piston.

Abstract: A hydrostatic piston machine has a housing, a rotor, a plurality of pistons rotatable with the rotor, and a displacing element operative for effecting reciprocation of the pistons and having a surface which is in sliding contact with the latter. Means is provided for reducing friction between the surface of the displacing element and the pistons during the sliding contact. This means includes a recess formed in the surface of the displacing element and communicating with a space which is under pressure so that a cushion of pressure fluid develops between the surface and the piston. The space under pressure may be constituted by a low pressure zone of the machine or by the low pressure and a high pressure zone of the machine.

Abstract: New assembly of cylinder, lightweight piston and piston rings for engines and compressors comprising in a cylinder a reduced weight piston provided with a new simpler piston rings set of a high efficiency producing a very small tension against the cylinder and lighter than the piston rings set known heretofore and wherein each of the purposes ascribed to the individual piston rings of the set is entirely attained by each piston ring of this assembly.

Abstract: A reduced impact piston assembly including a cylindrical body with a cavity formed therein and having a cross-bore formed therethrough which intersects the cavity. The cross-bore receives a piston pin which has an exposed intermediate portion aligned with the cavity for attachment of a connecting rod thereto. A wide groove is formed about the outer circumference of the cylindrical body which has its center aligned with the center of the cross-bore. Positioned within this groove are a pair of C-shaped inserts, the legs of which abut the ends of the piston pin to prevent axial movement of the pin within the cylindrical body. The C-shaped inserts cooperate with the pin to form a closed loop having a circumferential length which is larger than the circumferential length of the cylinder body. In addition, a portion of each of the C-shaped inserts is in constant contact with a cylinder wall.

Abstract: A piston ring and piston assembly designed for operation with the piston skirt fully flooded with oil and with the piston rings operating as fully hydrodynamic sliders is disclosed. Geometries of rings and piston skirt are arranged to conform elastically to the real out-of-round deformations of cylinder walls in such a fashion as to maximize the advantages of full film lubrication physics. The rings are loaded in circumferential compression and are flexible. This elastic configuration makes the rings conform instantaneously to cylinder wall out-of-round to a scale of microinches. This conformability is required to maintain oil control (zero oil pumping to the top of the cylinder wall) with fully hydrodynamic conditions between the rings and the cylinder wall. The piston has a piston skirt which is flexible enough to conform to cylinder wall out-of-round and maximize squeeze film effects. The piston skirt is arranged to superimpose squeeze film and pivoted pad slider physics.

Abstract: A piston ring and cylinder assembly designed for fully hydrodynamic operation with oil control is disclosed. The rings are loaded in circumferential compression and are flexible. They conform instantaneously to cylinder wall distortions and oil film forces. The elastic properties of the ring, combined with the ring crown geometry maintain oil control (zero oil pumping to the top of the cylinder wall) with fully hydrodynamic conditions between ring and cylinder wall. The cylinder wall is finished to a very smooth surface and may be provided with a number of axial grooves near the top dead center position of the top ring so that oil is positively blown down from the top of the cylinder for oil control.

Abstract: The invention relates to an oil pump for hand rail chain saw machines in which a pump plunger has an annular groove at its end remote from the drive and which is connected via a duct to the pump oil pressure channel, so that the sucking in of secondary air, high wear and an undefined lubrication are avoided.

Abstract: The present invention relates to an assembly, for use in a pressurized fluid mechanism equipped with pistons bearing against a reaction plate by way of slipper blocks, which assembly consists in such a piston and the associated slipper block coupled to one end of said piston by means of a "ball and socket" type assembly, the male element of the assembly being constituted by that part of the slipper block facing the face supporting the said slipper block on the reaction plate. A bolt comprising a screw and nut, joins the slipper block to the piston, the supporting surfaces of the nut and of the screw head on the corresponding parts of the slipper head and of the piston being of the "ball and socket" type.The invention finds an application in the production of high power hydraulic motors.

Abstract: A piston for internal combustion engines, especially for high-performance internal combustion engines. The piston has several ring grooves for piston rings, and an oil control groove which is provided below the top ring groove, is separated therefrom, and opens only towards the cylinder bore. The land between the topmost ring groove and the oil control groove, seen in cross section, is designed as a support having constant bending stress and has a finite height at its outer surface. The inner confine of the oil control groove has a finite radius or rounded-off section to avoid an increased stress concentration factor.

Abstract: A two-piece piston assembly comprises an upper portion or a ring carrier part that may be made of malleable iron, cast iron, or a similar iron, and a lower portion or cross-head part, referred to as a skirt, that may be made of aluminum or an alloy thereof. The assembly is configured to increase the contact of cooling liquid with the underside of the crown and eliminate problems accompanying undue heating in this area of the piston. The cocktail-shaker action of the two-piece piston assembly is employed to enhance the cooling effect. A separate cup-like device is secured around the outside of the lower end of the crown member of the piston and is thus positioned between the upper and lower portions of the piston to retain the oil and effectively deliver it to the underside of the crown.

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: An engine piston and ring assembly providing improved oil control and where applicable sealing of scavenging air. In a preferred embodiment applicable to two-cycle port scavenged diesel engines and similar applications, the piston is provided with dual oil ring grooves near its open end, which is free from drain openings through the wall in the vicinity of the ring grooves to the oil cooled hollow interior of the piston. Drainage of lubricating oil scraped from the cylinder walls by the rings is provided instead by scalloped recesses in the lower wall surface extending from the open end of the piston to the nearest ring groove. The arrangement reduces leakage of scavenging air from the inlet ports to the engine crankcase as well as the occasional flooding of the piston rings with the cooling oil from the piston interior.

Abstract: A reciprocating piston used in particular in heat engines and other industrial machines comprises at least one decompression chamber delimited between the bottom of an annular groove and the inner face of the first ring housed in this groove. A split ring of small cross section is movable in this decompression chamber. Additionally the upper bead of the piston presents on its periphery projecting parts and recessed parts, the projecting parts having an initial deameter, before running-in, such that the diametrical clearance when cold, between the periphery of the bead and the bore of the cylinder in which the piston is housed, is substantially equal to half the corresponding usual clearance between conventional upper bead and cylinder.

Abstract: This invention effects a significant reduction in leakage along a piston reciprocating in a cylinder and having a high fluid pressure differential existing between one end of the piston and the other. A large number of closely spaced, annular grooves are provided on the periphery of the piston and the clearance between the non-grooved piston diameter and the interior wall of the cylinder is maintained at a value significantly larger than that commonly employed between a smooth cylindrical shaft and a cylindrical interior sealing surface. The employment of such unexpectedly large clearance not only provides reduced fluid leakage for lighter density fluids when the equipment is relatively new, but the leakage becomes substantially less than that encountered in a smooth surface bearing construction as the piston and cylinder surfaces wear and increase the clearance.

Abstract: A connecting rod assembly for a two-stroke cycle reciprocating piston internal combustion engine has the piston pin axis slightly skewed from the crank-shaft axis to provide favorable conditions for lubricating the piston pin.

Abstract: The cylinder has an open-ended longitudinal bore. A removable plug closes one end of the bore. A power piston is slidably mounted in the bore. A pressure inlet port admits pressure fluid into the bore between the plug and the piston for shifting the piston in the bore. A rod is slidably and preferably sealingly mounted in the opposite end of the bore. The rod shifts in response to an external force and to the force exerted by the power piston. The power piston is easily removed from the bore by removing the plug from the cylinder.

Abstract: A hydrostatic transmission having a pump and a motor of the radial piston type with each cylinder slipper bearing rotatably supported by a hybrid or combination hydrostatic and hydrodynamic bearing on an internal bearing. The hydrostatic bearing component has a restricted port connecting hydrostatic pressure fluid from the cylinder to supply a distribution recess in the slipper bearing surface for hydrostatic pressure feed of the fluid film providing hydrostatic balancing pressure gradient between the slipper and internal bearing to balance a high percentage of the hydrostatic pressure load and to meet flow requirements for low speed operation.

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: An improved piston structure for Diesel and like reciprocating piston engines is provided having a top and foot, a sealing section on said piston connecting said top and foot, a guide section articulatedly connected to said sealing section through trunnion means on a connecting rod, said guide section having a sliding shell in the form of a collar at its periphery surrounding a wrist pin in the region of its bearing points, and at least one rib for each bearing side in the form of a chord connected to said shell in the region of the bearing point.

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: A flexible boot surrounds a piston rod and is sealed at one end to the free end portion of the piston rod and at its other end to the rod end of the associated cylinder. The head end of the cylinder is connected to a source of gas under pressure and the interior of the boot communicates freely with the interior of the cylinder at the rod end thereof. A check valve is provided for relieving the pressure in the boot when it reaches a predetermined value.

Abstract: A piston for internal combustion engines, preferably made from aluminum alloy, has machined, oil-dragging grooves formed on the periphery of the piston skirt and concave transitions with a sawtoothlike profile with an obtuse profile angle. The piston skirt is provided with an electrodeposited hard iron layer having a thickness of 1-30 .mu.m and contains 0.5-6% metal-oxy compounds incorporated therein.

Abstract: A piston such as is used in internal combustion engines, steam engines, gas engines, air engines, pumps, compressors and the like from which the usual piston rings are absent the sealing of the piston being affected by means of right and left hand intersecting helical channels formed on a portion of the surface of the piston wall.It is preferred that the helical channels terminate at each end in a circumferential groove. The sealing is effected by means of oil trapped by the channels between the piston wall and a cylinder in which the piston operates.

Abstract: A piston for a hydrostatic machine comprises a cam follower ball in a seating in a piston body. An aperture through the piston body provides access for working fluid to reach the seating to give lubrication and hydrostatic support. A low friction insert of synthetic plastics material in the seating provides a bearing surface for the ball. The insert is retained in the piston body by a lip which prevents or inhibits extrusion of the plastics material under working load pressure.

Abstract: A piston and slipper arrangement for a hydraulic pump or motor includes a tortuous fluid flow passage through the piston to a fluid pressure recess in the thrust face of the slipper at the opposite end of the piston. The fluid passage is formed by a plurality of spaced, cylindrical pockets interconnected by restricted flow channels which tangentially join the pockets.

Abstract: An improvement in liquid pumps having a piston with a packing surface which reciprocates in contact with a cylinder, comprising means for increasing the life of the packing by transmitting thereto a small portion of the liquid being pumped, for absorption thereby to cool and lubricate the frictional interface. The structure includes a groove in the piston head and an annular member of flexible material having inherent lubricity which continuously engages the cylinder, but is smaller in cross-section than the groove so that at each reversal of the piston a tortuous passage is briefly opened past the member through the groove.

Abstract: A piston shoe for fluid pressure pump motors of the piston type is substantially disc-shaped and includes a concave portion provided upon one end face thereof for seating the convex portion of a piston rod associated with the piston and cylinder assemblies of the pump motor, while the other end face thereof is substantially flat for contacting the sliding surface of a swash plate. A holder or retainer is also provided in association with the shoe for retaining the piston rod within the concave seat, such retainer being secured to the shoe by biasing means, or alternatively by being pressed or crimped thereon.

Abstract: New assembly of cylinder, lightweight piston and piston rings for engines and compressors comprising in a cylinder a reduced weight piston provided with a new simpler piston rings set of a high efficiency producing a very small tension against the cylinder and lighter than the piston rings set known heretofore and wherein each of the purposes ascribed to the individual piston rings of the set is entirely attained by each piston ring of this assembly.