Abstract: Pistons are disclosed herein. An apparatus includes an actuator defining a first chamber; and a piston disposed in the first chamber, the piston including a second chamber and a seal groove in which a seal is disposed, the second chamber to receive fluid from the first chamber to enable a force imparted by the fluid within the second chamber to urge the seal into sealing engagement with a surface defining the first chamber.

Abstract: Pistons are disclosed herein. An apparatus includes an actuator defining a first chamber; and a piston disposed in the first chamber, the piston including a second chamber and a seal groove in which a seal is disposed, the second chamber to receive fluid from the first chamber to enable a force imparted by the fluid within the second chamber to urge the seal into sealing engagement with a surface defining the first chamber.

Abstract: A gas-powered actuator is provided. The actuator includes a housing and a piston movably positioned within the housing. A cavity is formed in the piston. The housing includes an opening formed therein. The opening is structured to permit insertion of a piston rod into the opening, then into the piston cavity.

Abstract: A piston for an air pump has a connecting rod and a sealing valve. The connecting rod has a seat. The seat has a groove and a retaining surface. The groove is defined in an outer surface of the seat. The retaining surface is adjacent to the groove. The sealing valve movably engages the seat of the connecting rod and has an engaging ring and a sealing part. The engaging ring has an inwall which extends into the groove and has an engaging surface facing the retaining surface. The sealing part is connected with the inwall of the engaging ring and sealingly covers the through hole. The sealing valve is not prone to deformation and warpage during the operation of the piston to prevent any operating noise problem.

Abstract: A piston pump includes a pump mechanism configured to compress fluid sucked from an inlet port by increasing or decreasing a volume of a pump chamber which faces a front end of a piston by reciprocating the piston housed in a housing, a feed mechanism including a feed ring mounted to an annular groove provided at an outer periphery of the piston and following a motion of the piston, a feed chamber formed between the feed ring and the housing, and a valve portion. The piston pump includes a pressure wall provided at the piston and configured to contact the feed ring to axially move the feed ring, and a restriction portion provided at the feed ring and configured to engage with an outer periphery of the piston at a position approximate to the pressure wall for restricting a radial displacement of the feed ring on the piston.

Abstract: A pump piston assembly for use with a high-pressure pump includes a first section extending axially from a first end, a second section positioned adjacent to the first section and extending axially towards a second end, and an attenuation feature disposed within the piston bore such that the attenuation feature is part of the second end. By integrating the attenuation feature directly into the pump piston, pressure spikes, such as pressure peaks and valleys of an oscillatory pressure wave originating from the reciprocating motion of the piston, may be compensated directly in a supply pressure chamber. By providing a variety of attenuation features, such as a ball/spring assembly, an elastomer insert, an elastomer insert/internal piston assembly, and an elastomer insert/spring/ball assembly, attenuation for applications with a variety of frequencies and pressures can be utilized.

Abstract: A vibration damper piston includes a piston body with a bore from which first and second apertures respectively provide paths to first and second chambers of the vibration damper. A valve spool in the bore defines a pilot chamber and controls fluid flow between the first and second apertures. First and second springs bias the valve spool in opposing directions. A control orifice provides a continuous fluid path between the first chamber and the pilot chamber, and a variable orifice provides another fluid path between the second chamber and the pilot chamber. An actuator is operably connected to adjust the variable orifice in response to a control signal.

Abstract: The present invention provides an air compressor, characterized in that the piston head has a concave portion having a plurality of through holes therein and a reed piece having a smaller area than that of said concave portion is disposed in said concave portion, said reed piece having an opening in its center to allow a seizing member, respectively, which is seized on a top center of said piston head, for freely moving through said opening, and said seizing member having a confining portion to confine said reed piece within a predetermined space for moving so that said reed piece moves toward or away from said plurality of through holes by means of reciprocally moving said piston rod to improve the air compression efficiency while said air compressor is operating.

Abstract: A regulating unit for accomplishing a linear movement includes a cylindrical frame part (1) having a cylinder part (11) and cylinder head (12), which define a piston space (131, 132), and a piston unit (2) to be moved by a pressurized medium in the piston space. The height of a first space (131), in which a piston part (22) is moveable, is bigger than the height of a piston part, the cross section area is bigger than a cross section area of a piston rod. A cross section area of a second space (132) is smaller that the cross section area of the piston part. Pressurized medium may be fed into a cavity space (15), which is between the facing surfaces of the piston part and the piston space, for moving the piston unit towards the cylinder head (12) or vice versa.

Abstract: A piston is disclosed that includes a longitudinal passage disposed between outlets on the opposing faces of the piston, and a radial passage extending from a node with the longitudinal passage to an outlet on the annular wall between opposing piston seals. Check valves are disposed in the longitudinal passage between the node and each of the piston faces, such that each of the check valves enables fluid flow from its inlet to the outlet on the annular wall, and block fluid flow from the outlet on the annular wall to the inlet. In the event of pistons in a fluid system becoming out of phase with each other, fluid may be admitted through the inlet of the longitudinal passage and the respective check valve and out a side wall outlet, thereby bypassing the piston to exit via the respective end port, until another, out-of-phase piston or pistons in the system also reach full extension or retraction, automatically returning all pistons in the system to be in phase with each other.

Abstract: A piston assembly of an air pump is provided herein. The piston of the piston assembly has a through exhaust channel along the direction of the piston's back-and-forth movement. The exhaust channel is made up of two aligned exhaust holes, and a space is preserved at where the two exhaust holes interface. A flexible valve piece is provided inside the space, which will flip upward and downward to block the exhaust holes when the piston moves downward and upward, respectively. When the air pump is turned off and the piston stops moving, the exhaust valve piece would be automatically restored to its un-bended state by its own flexibility, allowing the compressed air inside the cylinder to escape through the exhaust holes and around the exhaust valve piece inside the space.

Abstract: A hydraulic cylinder comprising a cylinder, a piston which is adjustable in the cylinder, and at least one pressure connection which is disposed in the vicinity of an end position of the piston and through which a pressure fluid can be introduced into the cylinder, is characterized in that the piston is provided with a valve element which can cooperate with the pressure connection, in order to cover the pressure connection when the piston approaches its end position, and in order to uncover the pressure connection when pressure fluid is introduced into the cylinder.

Abstract: A hydraulic actuator comprises piston that divides the interior into a piston chamber and a rod chamber and a valve disc assembly to regulate flow of hydraulic fluid between the piston chamber and the rod chamber through a passage in the piston. The disc valve assembly includes a washer, a valve pack that includes at least one flexible disc valve, and a spacer arrangement spacing the valve pack apart from the washer. During operation, the valve pack flexes to open and close the passage. The spacer arrangement includes a first support point supporting the valve pack relative to the washer and at least one second support point spaced apart from the flexible portion of the disc valve pack. In the open position, the valve pack engages the second support point to reduce stress build-up at the first support point, thereby reducing work fatigue of the valve disc and extending the useful life of the hydraulic actuator.

Abstract: A high pressure press for treatment of substances such as food includes a floating piston in a pressure chamber, with seals. The floating piston has drainage system for collecting any pressure fluid that leaks past a seal of the floating piston. The drainage system includes a pressure reducer arranged inside the floating piston. The drainage system also includes an elastometic pad which is so arranged as to supply an underpressure to a space where pressure fluid leaking past a seal may collect. Collected pressure fluid is returned to the pressure chamber later in the cycle.

Abstract: A pump comprises a housing having a fluid inlet and a fluid outlet. A piston is mounted for reciprocating motion in first and second directions within the housing. The housing has first and second cavities on first and second sides of the piston, respectively. The first and second cavities are fluidly coupled to the fluid inlet and fluid outlet, so that fluid is pumped to the fluid outlet when the piston moves in either of the first and second directions. A bleed valve is coupled between the first and second cavities. The bleed valve has first and second closed states and an open state. The bleed valve changes from the first closed state through the open state to the second closed state when the piston moves in the first direction. The bleed valve changes from the second closed state through the open state to the first closed state when the piston moves in the second direction.

Abstract: A bypass valve is disclosed which relieves pressure on the end cap and rod guide of a cylinder as the piston approaches them. The bypass valve has a cylindrical body with end caps on each end, the end caps serving as stop members. The bypass valve is provided with longitudinal grooves along the cylinder body, along which working fluid can pass through a bore in the piston in which the bypass valve is inserted. Inner smaller diameter counterbores and outer larger diameter counterbores are provided coaxially with the bore on the opposing faces of the piston. The end caps of the bypass valve are received in the counterbores when the piston is urged along the cylinder. When the piston approaches either the rod guide or the end cap, the bypass valve is urged away from its seated position when an end cap of the bypass valve touches the approached rod guide or end cap of the cylinder.

Abstract: A piston for a piston-cylinder unit comprises a piston body having passages which connect two spaces in a cylinder on opposing sides of the piston. The passages are covered by at least one valve disk which is centered relative to a center of the piston by a centering sleeve. A spring element is arranged between the piston body and the centering sleeve. This spring element, when mounted, spaces the centering element from the piston body and accordingly displaces the useful range of the centering element until the piston is assembled in its entirety and every structural component part of the piston occupies its intended position.

Abstract: A forming die set has one or more independently operated hydraulic punch assemblies mounted directly in one of the die shoes to enable a programmed piercing pattern to be carried out at the time the workpiece is formed. Each punch assembly includes a compact self contained actuator, punch holder, stripper plate and punch retainer, with supply and return connections both made at one end of a cylinder housing with a return flow path through a tube extending through the piston. A purging system using a check valve in the supply line establishes an incremental flow back to the reservoir eliminate air bubbles. An accumulator having a charge volume detector is used to operate the punch assembly actuator.

Abstract: An accumulator for use in a hydraulic control circuit comprises a check valve for allowing a suction of air into a working fluid pressure chamber from the atmosphere. The check valve includes a valve cylinder integrally formed with a member for defining the working fluid pressure chamber. The check valve includes a check ball movable within a bore of the cylinder, and a ball stopper having an outer peripheral surface formed with mesh-like grooves press fitted into the bore to retain the ball within the bore.

Abstract: A reduce waiting time drilling jar 1 includes a mandrel 2, a housing 3 telescopingly positioned about the mandrel 2, and first and second pistons 89, 111 positioned axially between the mandrel 2 and the housing 3. The pistons 89, 111 are spaced longitudinally apart, forming a substantially sealed chamber 88 therebetween. The first piston 89 has a first and second substantially parallel flow passage 94, 200 formed therein and extending longitudinally therethrough to provide first and second flow characteristics. A valve 204 is hydraulically connected to the second flow passage 200. The valve 204 is translatable between first and second operating positions, wherein fluid flows relatively freely through the second flow passage 200 in the first operating position, but is restricted in the second operating position.

Abstract: An actuation member (B) supported by a housing (A) is actuated for clamping upwardly by means of a spring force and actuated downwardly for unclamping by means of an actuation means (D). A piston (11) is inserted into a cylinder (10) fixedly secured to the upper portion of the housing (A), and a liquid sealing chamber (12) is formed below the piston (11). The piston (11) is fixedly secured to the actuation member (B). When the actuation member (B) is held in the clamped condition, a liquid sealing valve (15) is closed so as to seal an oil (L) within the liquid sealing chamber (12). Whereby, in case that a pulling down force larger than the clamping spring force is imposed to the actuation member (B), a pressure generated within the liquid sealing chamber (12) serves to prevent the piston (11) from lowering, against the pulling down force.

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 rotary actuator defining a first arcuate chamber and a second chamber, the housing having an inwardly projecting, peripherally extending rib which defines an aperture in open communication with the arcuate chamber, a peripherally extending groove being formed in the rib in surrounding relationship to the aperture, the groove having first and second peripherally extending spaced side surfaces, an arcuate shaped piston being disposed in the housing for reciprocable movement in the arcuate chamber, a shaft rotatably journaled in the housing and connected to the piston and being rotatable in response to movement of the piston, a floating seal disposed in the groove for effecting sealing between the piston and the housing, the seal being in sealing engagement with the first and second side surfaces forming the groove, a fluid pressure inlet to introduce fluid pressure into at least one of the arcuate chamber or the second chamber to provide a pressurized chamber and effect movement of the piston in a first direc

Abstract: An actuator (10) tolerant of ballistic damage thereto includes a piston (25) longitudinally reciprocable within a cylinder (15) and connected to a rod (30), the piston comprising a plurality of longitudinally stiff, circumferentially spaced ribs (35) joined by a bulkhead (40) which transfers hydraulic loading to the ribs and readily ruptures in response to impact with an obstruction (45) in the cylinder wall due to for example, ballistic damage to the actuator. The bulkhead carries a sealing ring (60) for sealing leakage around the piston and may be formed integrally with the ribs or separately therefrom and attached thereto as an end cap to the piston. Analogous structure may be employed in a gland (20) for the actuator to accommodate ballistic damage to the rod.

Abstract: A fluid-operated friction engaged torque transmitting device, such as a clutch or brake, has a piston member. The piston has a rigid material, such as metal or plastic body member which is encased in an elastomeric cover. The elastomeric cover is a molded structure which is bonded to the rigid body. The elastomeric cover has integrally formed therewith, during molding, a pair of annular lip seals, a valve structure and a spring portion. A reaction plate or ring is molded or bonded to the spring portion.

Abstract: An actuator (10) tolerant of ballistic damage thereto includes a piston (25) longitudinally reciprocable within a cylinder (15) and connected to a rod (30), the piston comprising a plurality of longitudinally stiff, circumferentially spaced ribs (35) joined by a bulkhead (40) which transfers hydraulic loading to the ribs and readily ruptures in response to impact with an obstruction (45) in the cylinder wall due to for example, ballistic damage to the actuator. The bulkhead carries a sealing ring (60) for sealing leakage around the piston and may be formed integrally with the ribs or separately therefrom and attached thereto as an end cap to the piston. Analogous structure may be employed in a gland (20) for the actuator to accommodate ballistic damage to the rod.

Abstract: A hydropneumatic suspension unit includes a large diameter flanged road arm spindle which is bolted to the vehicle hull; a road arm has one end rotatably mounted on the road arm spindle and another end mounting a road wheel; a barrier fluid sealed piston is reciprocated relative to a road arm bore to seal an in-arm mechanically operated pneumatic spring which has a gas volume trapped by the barrier fluid sealed piston to support the sprung mass of the vehicle; the sealed piston is defined by a pair of spaced seals and an oil chamber which has an oil charge therein pressurized by preload spring on the piston to displace the oil barrier to both lubricate and preload the pair of spaced seals as the piston is dynamically operated to vary gas compression and produce a resultant pressure on the piston to counteract vertical forces on the road wheel.

Abstract: A fluidic bearing seal assembly comprised of a plurality of floating back ring seals positioned in a plurality of annular grooves in a piston with at least one free-floating sealing wedge fitted to the outer peripheral edge of each backing ring for sliding along the cylinder wall. The piston has an inlet port and one way check valve means in the head thereof through which the working fluid is compressed during the compression stroke into a plurality of passageways that route the working fluid under pressure against said plurality of floating backing ring seals and into a pressure reservoir directly in contact with the cylinder wall and between adjacent backing ring seals to press the backing ring seals and seal wedges against the cylinder wall during the compression stroke and release the pressure from the ring seals and wedges during the return stroke of the piston.

Abstract: A gas bearing supported piston assembly (2) for an internal combustion engine including a piston body (14, 14') and a segmented piston ring (3) arranged to expand to compensate for wear. A piston supporting gas layer (27) is formed between the cylinder walls (8) and the exterior surface of each piston ring segment (32) by means of a plurality of restricted flow passages (40) formed in each segment (32) and extending between the inner and outer surfaces of the segment (32). In one embodiment, gas under pressure is supplied to the ring segments (32) through a single annular cavity (36) formed in piston body (14). In another embodiment, gas under pressure is supplied to the ring segments (32) through a plurality of corresponding holes (70) in piston body (14').

Abstract: An internal combustion engine having a piston assembly such that gaseous flow into a cylinder is through the piston assembly and wherein all gaseous flow in a cylinder is in a single direction. The piston assembly includes inner and outer piston members which are relatively movable so as to form a gaseous passage therethrough in certain conditions. The engine also features a special valve mounting arrangement and a special crankshaft construction.

Abstract: An internal combustion engine is provided with pistons having openings connecting the space behind one of the piston rings with the crankcase during certain portions of the operating cycle of the engine. This is accomplished by the use of a differential pressure control valve that vents the unburned hydrocarbons trapped behind the compression ring to the crankcase during periods when the pressure in the combustion chamber is at the lower values during the internal combustion engine operating cycle. These unburned hydrocarbons are, therefore, directed into the crankcase of the engine rather than being permitted to leak back into the combustion chamber and to be discharged into the atmosphere during the exhaust stroke of the engine.

Abstract: The sealing device comprises two interengaged members forming a clearance space in which is imprisoned a deformable seal for ensuring pressure-tightness between the members and the internal surface of the press chamber. The member which is in contact with the liquid medium under hydrostatic pressure comprises means for establishing pressure equilibrium within the press chamber and within the clearance space immediately after deformation of the seal.