Abstract: A downhole tool includes a body having a rounded or cylindrical surface, at least one relieved space in the rounded or cylindrical surface, and a protuberance within the relieved space. The downhole tool also has a generally cylindrical retaining ring that surrounds a portion of the body. One or more crimple detents are formed in the retaining ring, each crimple detent comprising a portion of the retaining ring that has been deformed radially inward into an underlying portion of the relieved space such that the deformed material of the retaining ring contacts and deforms an underlying portion of the protuberance in the relieved space, thereby joining the retaining ring to the body.

Abstract: The present disclosure provides a cylinder block for an internal combustion engine having a first cylinder, a first cylinder sleeve, a second cylinder, and a second cylinder sleeve. The first cylinder defines a first cylindrical wall while the second cylinder defines a second cylindrical wall. The first cylinder sleeve lines the first cylindrical wall while the second cylinder sleeve lines the second cylindrical wall. Each of the first and the second cylinder sleeves define a thrust sleeve region, an anti-thrust sleeve region opposite the thrust sleeve region, and a pair of Siamese regions. The outer wall of each of the first and second cylinder sleeves progressively widens toward the top sleeve surface of each of the first and second cylinder sleeves.

Abstract: The present disclosure provides for a force breaker assembly. The assembly includes a housing having a first channel, a body within the housing and including an engagement surface. A second channel is formed in the body. A spring is positioned adjacent the body. A snap ring is positioned within the housing and about the body. When a load is applied to the engagement surface that is below a preset limit, the ring remains engaged within the first and second channel, retaining the body in an extended position. When a load is applied to the engagement surface that is at or above the preset limit, the ring is expanded out of the second channel and into the first channel or is compressed out of the first channel and into the second channel, such that the body is forced into a depressed position.

Abstract: A suction cover assembly for a reciprocating pump includes a suction cover nut having a nut face and a thread configured to threadably connect the suction cover nut to a fluid cylinder of the reciprocating pump. The suction cover assembly includes a suction cover having a cover face. The suction cover is configured to be held by the fluid cylinder such that the cover face opposes the nut face of the suction cover nut. The suction cover includes first and second seals having a leakage trap defined therebetween. The leakage trap is configured to trap leakage pressure during operation of the reciprocating pump. The suction cover includes at least one leakage channel that is configured to channel the leakage pressure from the leakage trap to an interface between the cover face and the nut face.

Abstract: A method for processing an inner wall of a cylinder of an internal combustion engine includes providing a cylinder and processing an inner wall of the cylinder. The cylinder extends along a cylinder axis. The inner wall of the cylinder is processed in such a manner that at least one first structural region and one second structural region are formed along the cylinder axis. A geometry of the first structural region differs in design from a geometry of the second structural region.

Abstract: A rolling piston installed between a piston and a cylinder includes: a plurality of balls, wherein the balls are connected end to end to form the rolling piston ring, and a quantity of the balls is no less than three; or comprising: a plurality of columns, wherein the columns are connected end to end to form the rolling piston ring, and a quantity of the balls is no less than three; or comprising: balls and columns, wherein the balls and the columns are connected end to end to form the rolling piston ring, and a total quantity of the balls and the columns is no less than three; wherein both the balls and the columns are extendable, and/or a recess on the piston for installing the rolling piston ring is extendable and a slide on the cylinder for installing the rolling piston ring is extendable.

Abstract: The actuating device for a vehicle brake system comprises a force input member, which can be coupled to a brake pedal, and a brake master cylinder. The brake master cylinder has at least one force transmission member. The force transmission member is coupled to the force input member in an articulating fashion. The force transmission member is positioned to transmit a force, which has been exerted onto the force input member, to the brake master cylinder. The actuating device has at least one elastically deformable positioning element. The at least one positioning element produces a holding force with which the at least one positioning element holds the at least one force input member in an installation position relative to the brake master cylinder.

Abstract: An internal combustion engine with at least one cylinder having a cylinder barrel that forms a guide for a piston associated with the cylinder. The cylinder barrel is only partially formed by a cylinder wall of a crankcase or of a cylinder liner fastened to the crankcase. The cylinder barrel, in a central region as seen in the cylinder axial direction, is formed by the cylinder wall. The cylinder wall, in an upper region of the cylinder barrel adjoining the central region and/or in a lower region adjoining the central region, has an encompassing recess into which is inserted a one-piece or multi-piece annular sliding element, the radially inner wall of which forms a part of the cylinder barrel.

Abstract: A master brake cylinder arrangement for a hydraulic motor vehicle brake system, comprising a master brake cylinder housing with a cylindrical recess and at least one substantially annular groove which is oriented transversally to a longitudinal axis of the cylindrical recess and which is axially delimited by a protruding housing portion. The master brake cylinder arrangement also comprises at least one pressure piston which can be displaced axially in the cylindrical recess of the master brake cylinder housing and which is guided in a sealed manner by means of at least one seal element arranged in the groove. The housing portion has an edge portion which faces the seal element and an edge portion which faces away from the seal element when viewed in the axis-containing longitudinal section.

Abstract: Methods of honing a surface are disclosed. The method may include spraying a coating having an initial average bulk porosity onto an engine bore wall and honing the coating to create an intermediate honed surface. The method may then include cleaning the intermediate honed surface and honing the intermediate honed surface with a cutting force of, for example, 110-130 kgf after the cleaning step. This may create a honed surface having an average porosity greater than the initial average bulk porosity. The methods may create a honed surface having a porosity that is more porous than the initially sprayed coating. The increased porosity of the honed surface may allow for increased oil retention in, for example, engine bores.

Abstract: A cylinder for a V-twin engine includes a section of steel tubing cut to a length. The section of steel tubing includes a first portion having a first wall thickness and a second portion having a second wall thickness less than the first wall thickness. The second wall thickness is less than 0.050 inch. The section of steel tubing includes a first ribbing pattern on an outer surface, within the first portion, and a second ribbing pattern including multiple ribs formed on individual ribs of the first ribbing pattern. A cast body is provided on the first portion of the section of steel tubing so that the section of steel tubing is fixedly secured within the body to form a cylinder sleeve defining a cylinder bore. The second portion having the second wall thickness extends from an end of the body to be received within a bore of a crankcase.

Abstract: A method for machining a wall of a cylinder of an internal combustion engine, in which recesses in the wall are introduced by mechanical machining. The invention is characterized in that the wall is radiated with a medium under high pressure after the mechanical machining in order to introduce micro-recesses.

Abstract: The present invention provides a hypereutectic aluminum-silicon alloy die-cast member which contains 20.0% by mass to 30.0% by mass of silicon and also has a thickness of 2.5 mm or less, and a method for producing the same. Disclosed is a die-cast member made of a hypereutectic aluminum-silicon alloy containing 20.0% by mass to 30.0% by mass of silicon, wherein the die-cast member has a thickness of 2.5 mm or less and an average size of primary crystal Si is 0.04 mm to 0.20 mm.

Abstract: A linear compressor is provided. The linear compressor may include a shell including a suction inlet, a cylinder provided in the shell to define a compression space for a refrigerant, a piston reciprocated in an axial direction within the cylinder, a discharge valve provided at one side of the cylinder to selectively discharge the refrigerant compressed in the compression space, and at least one nozzle, through which at least a portion of the refrigerant discharged through the discharge valve may flow, the at least one nozzle being disposed in the cylinder. The at least one nozzle may include an inlet, through which the refrigerant may be introduced, and an outlet having a diameter less than a diameter of the inlet.

Abstract: A method for producing a cylinder liner surface for a cylinder crankcase of an internal combustion engine has the following method steps: (a) preliminary honing of the inner surface of a cylinder liner consisting of a cast iron material to form depressions in the surface; (b) application of a coating material containing zinc to the honed surface; (c) final honing of the coated surface in such a way that the coating material containing zinc remains only in the depressions formed by the preliminary honing.

Abstract: The current application discloses various embodiments where a portion of a fluid end pump body is made of a first material the other parts of the pump body are made of a second material where the first material is a material having better resistance to fatigue and the second material used is a material of less quality and cheaper than the first material.

Abstract: A multi-step autofrettage process for pre-treating a multi-cylinder reciprocating pump fluid end that has a central cylinder and at least two side cylinders is provided that includes autofrettaging the central cylinder; and autofrettaging the at least two side cylinders, wherein the autofrettaging of the central cylinder is performed independently of the autofettaging of the at least two side cylinders.

Abstract: A vacuum-operated brake booster includes a housing which consists of a bottom and a cover having an intermediate piston through which tubes, through which attachment screws are to pass, extend. The front end of the tube is threaded, and a peripheral groove is provided behind the thread, a flange being crimped in the groove behind the cover in the housing. The master cylinder is attached via the lugs thereof, which are fitted into the front end of the tube against the front surface of the cover and locked by the nut screwed onto the thread. The front end of the tube has a peripheral groove receiving the flange that consists of a ring and a sleeve, the lip of which penetrates into the groove by crimping. A gasket completes the seal.

Abstract: A cylinder block (1) for a compressor has a central opening (3) for accommodating a drive shaft of a drive unit and defines a central axis of the cylinder block (1) with a plurality of cylinder bores (2) arranged around the central opening and each of the cylinder bores (2) adapted for accommodating a piston (14).The cylinder block (1) also has at least one stop (10) on a drive side of the cylinder block (1) with the stop (10) arranged within a triangular area which is delimited by the central opening (3) and the two adjacent cylinder bores (2).

Abstract: In one or more embodiments, a method of forming a coated cylinder bore includes honing a cylinder bore to produce a honed cylinder bore, masking partially the honed cylinder bore to form a partially masked cylinder bore, and contacting the partially marked cylinder bore with an electrolytic bath to form the coated cylinder bore. The method may further include applying a pulsed direct current at a voltage of 400 to 500 volts to the electrolytic bath. The contacting step may be carried out via one or more of plasma electric oxidation, plasma electrolytic deposition and micro arc oxidation.

Abstract: A cylinder assembly is provided. The cylinder assembly includes a cylinder body, a rod member, and a cylinder position sensor assembly. The cylinder body may have a bearing sleeve to support the rod member. The cylinder position sensor assembly may include a cylinder position sensor for sensing the position of the rod member. The cylinder position sensor assembly may be mounted inside a hole in the bearing sleeve.

Abstract: A fluid actuator includes a housing having a fluid chamber providing a first friction surface. An actuating member is arranged in the fluid chamber and has a second friction surface slideably engaging the first friction surface. The actuating member is configured to slide within the chamber between first and second positions. An insert is constructed from a first thermoplastic material and provides one of the first and second friction surfaces. A body structurally supports the insert and provides one of the housing or actuating member. The body is constructed from a second thermoplastic material molded about the insert and including short reinforcing fibers.

Abstract: A lid member has an external shape inscribing a quadrilateral formed by two sets of two facing sides, and has: a pair of first cut-out sections configured by cutting out, in the same size, a pair of diagonal corners from among the two sets of diagonal corners of the quadrilateral; and a pair of second cut-out sections configured by cutting out the other diagonal corners in the same size. The outer shape of the lid member is formed in a point-symmetric shape relative to the center of an opening in a peripheral wall section. The first cut-out sections have a larger surface area than the second cut-out sections, and one out of the pair of first cut-out sections is configured so as to be arranged in the vehicle progression direction and at the bottom in the vertical direction, when a base body is mounted to a vehicle.

Abstract: A cylinder seat of an air compressor of a tire repair machine, comprising a seat board, a cylinder, and a motor seat is provided; the seat board includes a first surface and a second surface that is opposite to the first surface; the cylinder is integrated with the seat board and is disposed on the first surface of the seat board; an opening configured to accommodate a plunger is defined in one end of the cylinder, and a one-way valve device is mounted on another opposite end of the cylinder; and the motor seat is integrated with the seat board and is disposed on the second surface of the seat board. Thus, the overall structure of the cylinder seat is simple, and the manufacturing cost can be decreased.

Abstract: Disclosed is grey cast iron having an excellent durability and comprising carbon (C) in an amount of about 2.6 to 3.2 wt %, copper (Cu) in an amount of about 0.7 to 0.9 wt %, phosphorus (P) in an amount of about 0.4 to 0.7 wt %, molybdenum (Mo) in an amount of about 0.2 to 0.4 wt %, tin (Sn) in an amount of about 0.02 to 0.08 wt %, and a balance of iron (Fe) and trace amounts of unavoidable impurities, and a method for production thereof. The present invention improves tensile strength, fatigue strength, and the like and further reduces friction coefficient of the grey cast iron as compared with a conventional material. The grey cast iron has an excellent durability and provides a cost reduction of about 10% or more as compared with a conventional material.

Abstract: A pair of penetrating holes are formed along a longitudinal direction in the interior of a cylinder body that constitutes a fluid pressure cylinder. One end of the pair of penetrating holes is sealed by a pair of caps formed in plate-like shapes. The caps, for example, are formed by press molding a plate body made up from a metal material such as aluminum or the like. Outer edge portions of the caps include bent portions, which are inclined at a predetermined angle in a radial outward direction. In addition, the caps are installed by means of the bent portions biting into inner circumferential surfaces of the penetrating holes.

Abstract: A vented pressurized gas-powered actuator includes a housing having a central longitudinal axis and an inner surface. At least one vent groove extends from the inner surface in a direction away from the axis. The at least one groove has a first end spaced apart from a first plane extending perpendicular to the axis, and a second end spaced apart from a second plane extending perpendicular to the axis. The groove second end is closer to the second plane than to the first plane.

Abstract: A vented pressurized gas-powered actuator includes a housing having a central longitudinal axis and an inner surface. The inner surface has a constant radius between first and second planes extending perpendicular to the axis. At least one vent groove extends from the inner surface in a direction away from the axis. The at least one groove has a first end intersecting the first plane.

Abstract: A cutting tool. The cutting tool includes a cylindrical body and one or more axial rows of cutting elements, which project outwardly from and are situated radially to the circumference of the cylindrical body. Each cutting element of each row includes one or more pocket cutting elements and one or more groove cutting elements. Each pocket cutting element includes a cutting surface. Each groove cutting element includes a cutting surface having groove cutting teeth.

Abstract: Remanufacturing a variable displacement swash plate-type hydraulic device includes receiving a body of a used hydraulic device defining first and second actuator guide bores, at least one of which is out of specifications for guiding a swash plate linear actuator. The method further includes removing material forming the first and second guide bores, and interference fitting first and second sleeves into the body in place of the removed material. Additional material is removed from the first and second sleeves to form new first and second actuator guide bores, each satisfying specifications for guiding a swash plate linear actuator.

Abstract: A fluid end of a high-pressure pump having a power end bore, a discharge bore, a suction bore, an access bore, and a cross-bore intersection formed in portions of the fluid end is provided. A transitional open area opens into the cross-bore intersection from the power end bore; a transitional open area opens into the cross-bore intersection from the access bore; a transitional open area opens into the cross-bore intersection from the suction bore; and a transitional open area opens into the cross-bore intersection from the discharge bore. A spherical geometry is created in the cross-bore intersection. A spherical surface forms an outer boundary of the cross-bore intersection.

Abstract: There is provided a cylinder device having optimal arrangement of fine textures and optimal surface roughness capable of reducing wear of a cylinder bore side and a piston ring by processing fine textures in an optimal selection region of the cylinder bore side to improve lubrication characteristics between the piston ring and the cylinder bore side while reducing engine oil consumption by processing surface roughness of the cylinder bore side to an optimal status.

Abstract: Disclosed is a device that includes a natural-gas compression system having a natural-gas powered combustion engine, a compression cylinder configured to receive natural gas and output compressed natural gas, a piston disposed in the compression cylinder and configured to translate through the compression cylinder in response to mechanical power received from the natural-gas powered combustion engine, and a variable-volume head mounted to the compression cylinder and configured to vary a compressed volume of the compression cylinder. In some instances, the variable-volume head includes a head body, an adjustment screw rotatably coupled to the head body, a plug moveable in threaded engagement with the adjustment screw, and an anti-rotation device coupled to the plug, the head body, or both. The anti-rotation device may be configured to impede the plug from rotating relative to the head body as the adjustment screw rotates.

Abstract: Disclosed embodiments include hydraulic cylinder assemblies and piston assemblies for use in hydraulic cylinder assemblies. A rod is attached to a piston. The rod has first portion, a second portion with a cross-sectional area that is less than a cross-sectional area of the first portion, and a third portion positioned between the first and second portions. The third portion has a cross-sectional area that transitions between the cross-sectional area of the first portion and the cross-sectional area of the second portion. A collar is sized to fit over the rod with an internal feature that engages the third portion of the rod. A fastener holds the piston against the collar and provides a clamp force on the piston.

Abstract: A cylinder has an insulating gas boundary layer (IGBL) across the cylinder wall inner surface, the IGBL formed by injection of an insulator fluid into the combustion chamber of the cylinder. In one implementation, a pressure differential is engineered between the top region of the cylinder and the bottom region of the cylinder. In yet another implementation, the insulator injection pressure is temporally modified in synchronicity with the piston cycle and/or in accordance with other temporal factors to provide appropriate IGBL coverage.

Abstract: A piston for a brake caliper of a disc brake constructed as a pot which is open at one end, having a longitudinal axis, a wall, and a piston head. The piston is supported in a cylinder of the brake caliper such that it can be moved along the longitudinal direction, and it can be placed against a brake pad in the region of the piston head by an axial contact surface. When the piston is subjected to pressure by a hydraulic fluid, the piston moves in the cylinder and presses the brake pad against a brake disc. A projection having a conical surface is provided on an inner surface of the piston head. A recess is provided, which is substantially at the same distance from the longitudinal axis as the projection on the inner surface of the piston head, on an outer surface of the piston head.

Abstract: A piston (1) and cylinder (2) assembly that can reduce efficiency losses due to the gas in a linear compressor with aerostatic bearings. The space between the piston (1) and cylinder (2) in the piston-cylinder assembly was designed to decrease radial clearance (12) in the upper portion of the piston (1) when the piston approaches the headpiece (3), i.e., when the density of the gas not being used in the refrigeration process is the highest. The piston (1) and cylinder (2) assembly must exhibit such a geometric ratio that radial clearance (12) changes in inverse proportion to the density of the gas in the radial clearance (12).

Abstract: In general, a piston-type pump includes a wash flow path that allows a wash liquid such as water to pass through to provide washing and cleaning as the pump operates. The pump may be used in precision liquid dispensing systems and particularly with liquid solutions that have a tendency to precipitate solid particulate. By washing a portion of the pump piston, the liquid solution being dispensed and any solid particulates may be carried away and removed from the pump.

Abstract: In some two-stroke engines, a stationary ring is disposed in a groove in the cylinder liner. However, it is a challenge to install such a stationary ring while maintaining a narrow gap to minimize gas flow through the gap. A ring system for an internal combustion engine is disclosed that includes an L-shaped, split ring with a reentrant angle and a nested, split ring with a convex quadrilateral cross section nested with the L-shaped ring proximate the reentrant angle. The two rings are affixed so that the two gaps of the split rings cannot align. Or, in other embodiments, the two are allowed to rotate relative to each other over a predetermined angle.

Abstract: The present invention refers to a compressor block (21), which has at least one passage opening of driving member (22), at least one frontal of support (24a) and at least one portion (26), so that at least one first and one second means of structural connection between the portion (26) and the frontal extensions of support (24a) are defined by at least one structural wall (28a) and at least one wall structure (28b). The structural walls (28a, 28b) define the main perimeter of the compressor block (21) and are provided with at least one section of physical association between each other.

Abstract: An air compressor assembly includes a cylinder housing, an outlet receptacle disposed on the cylinder housing, and a partition having an air passage formed between the cylinder housing and the outlet receptacle, a piston slidably received in the cylinder housing and having a piston rod extended from a piston head for moving relative to the cylinder housing to generate a pressurized air, the piston head includes an upper surface, and includes a cavity formed in the piston head and defined by a bottom surface and an inner peripheral surface and opened upwardly through the upper surface of the piston head and faced and directed toward the partition of the cylinder housing for partially receiving the pressurized air.

Abstract: A fluid pressure cylinder includes a cylinder tube, a piston and a solid piston rod. The piston rod includes a head-side passage defined by a head-side shaft hole extending in an axial direction, a head-side outer hole open on a part projecting from the cylinder tube and a head-side inner hole open to a head-side chamber and allowing communication between a head-side chamber and a fluid pressure source, and a bottom-side passage allowing communication between a bottom-side chamber and the fluid pressure source. The head-side shaft hole includes an opening end and a tip formed inside the piston rod. The opening end of the head-side shaft hole is sealed by a sealing member.

Abstract: In order to provide a master cylinder, in particular for a clutch system, an actuating system or a braking system of a vehicle, which enables secure sealing of the cylinder chamber relative to the outside, as well as a reliable flow of hydraulic medium into the cylinder chamber, it is proposed that the piston comprises a first section which has a cylindrical lateral surface and a second section which has at least one region which is set back radially inwardly with respect to the cylindrical lateral surface of the first section, wherein at least one set-back region extends to an end of the piston and wherein the first and second sections are arranged on the piston in such a way that in an actuating position of the piston, the main sealing element in the first section of the piston abuts in sealing manner thereagainst and in the pressure equalisation position of the piston, in the second section of the piston between the piston and the main sealing element, at least one gap is formed, through which hydraulic me

Abstract: A cylinder-piston unit, with at least one cylinder accommodating an injection solution and having an outlet opening, and with at least one piston. The cylinder, or a component mounted upstream of the cylinder, has an end face from which, during correct emptying of the cylinder-piston unit, a short cannula protrudes, which has an outlet opening at its free end. The outlet opening has a surface with a border which has a point near the bottom or an edge near the bottom. The point near the bottom or the edge near the bottom lies 0.15-0.3 mm away from the end face or the front-most point or edge thereof. A cylinder-piston unit is developed which is intended for a disposable injector and which is suitable for virtually painless penetration of the human skin, among other reasons for the administration of highly viscous injection solutions.

Abstract: A hermetic compressor includes a closed vessel for storing lubricating oil, an electric-driving element, and a compressing element driven by the electric-driving element. The compressing element includes a cylinder block forming a compression chamber, a piton that reciprocates inside the compression chamber, and an oiling device for supplying the lubricating oil to an outer circumference of the piston. A first oil groove is concavely formed on the outer circumference of the piston, and a second oil groove is concavely formed on a side opposite to the compression chamber relative to the first oil groove. The second oil groove has a spatial volume same or greater than that of the first oil groove. An expanded clearance portion is provided such that a clearance between the piston and the cylindrical hole portion broadens from a top dead point to a bottom dead point.

Abstract: According to one embodiment, there is provide a piston pump, including: a cylinder having a bottomed cylindrical shape; a piston slidable within the cylinder, the cylinder and the piston defining a pressure chamber therebetween; a suction valve unit disposed in a suction passage of the pressure chamber; and a discharge valve unit disposed in a discharge passage of the pressure chamber, wherein the piston includes a cylindrical piston portion and a large diameter piston portion provided to cover one end of the cylindrical piston portion, and wherein the large diameter piston portion includes a working fluid guide groove extending thereinside along the axial direction of the piston.

Abstract: A hydraulic cylinder comprising: a cylinder body which has an open end with an opening and an edge extending therearound, which cylinder body also has an inner surface; a piston rod; a close-off member which has an insert part, which insert part protrudes in a fitting manner into the open end of the cylinder body, which insert part has an outer circumferential face, wherein the close-off member also has a flange opposing the edge of the cylinder body; coupling means which are operable between the inner surface of the cylinder body and the outer circumferential face of the insert part for securing, in at least one axial direction, the close-off member in the cylinder body, and a clamping ring which is clamped between the flange and the edge at the open end of the cylinder body. The clamping ring is made of a resilient, compressible material, in particular is made of an elastomer. The clamping ring is clamped, when compressed in the axial direction, between the flange and the edge at the open end.

Abstract: A rocking cylinder assembly comprising a cylinder, rotatable about a rocking axis between first and second end positions, having a cylinder bore terminating at a cylinder bearing surface and a cylinder aperture, and a bearing component having a component bore terminating at a component bearing surface and a component aperture. The ratio of the area of the second one of the apertures to the square of the maximum extent of the second one of the apertures in a direction perpendicular to the rocking axis and perpendicular to a second axis for fluid flow is greater than the ratio of the area of the first one of the apertures to the square of the maximum extent of the first one of the apertures in a direction perpendicular to the rocking axis and perpendicular to a first axis for fluid flow.

Abstract: The present invention relates to a four-way reversing valve for refrigerating cycle system, in particular to an end cover for fitting with a valve body of a main valve of a four-way reversing valve, a four-way reversing valve using the same and an assembling method thereof. The end cover has a larger diameter section and a smaller diameter section sequentially provided in an axial direction, wherein an outer periphery of the larger diameter section of the end cover is adapted to be tightly connected with the valve body, and an end portion of the smaller diameter section of the end cover is adapted to be fitted with a piston of the main valve, so as to define an operating position of the piston, characterized in that the larger diameter section of the end cover has a frustum shape with a larger outer end and smaller inner end, or an end portion of the larger diameter section of the end cover has radially projected flange for abutting against and fitting with an end surface of the valve body.

Abstract: A piston is provided displaceably in the interior of a cylinder tube that constitutes a fluid pressure cylinder, and a piston cover made from an elastic material is disposed so as to cover one end surface of the piston. The piston cover comprises a main body portion confronting a head cover of the cylinder tube, a guide portion covering an outer circumferential surface of the piston and disposed in sliding contact with an inner circumferential surface of a cylinder hole, and a hook portion folded toward an inner circumferential side with respect to the guide portion. Upon displacement of the piston toward the head cover, shocks are absorbed by abutment of the main body portion against the head cover. When the piston is displaced along the cylinder tube, the guide portion serves to guide the piston in the axial direction by sliding contact with the cylinder hole.