Abstract: In order to prevent rotation of a piston of a hydraulic unit of a hydraulic vehicle braking system, a sleeve is provided having axially parallel cylindrical pins constituting rotation prevention elements on its inner circumference, the rear ends of which elements are pressed into axially parallel holes in an inwardly projecting flange of the sleeve, and the front ends of which are inserted into axially parallel blind holes in a diameter step in a mouth of the cylindrical hole in a hydraulic block of the hydraulic unit. A method for assembling the hydraulic unit thus configured is also described.

Abstract: A hydraulic cylinder is provided with a cylinder tube, a piston unit, and a piston rod. The piston unit has a piston body; packing mounted on the piston body; a holding member mounted on the piston body; and a magnet held by a magnet holding part of the holding member. The magnet holding part has a notch that is open on the outer circumferential surface of the holding member.

Abstract: A seal structure is provided which enables a reduction in the number of components and an improvement of the stability in sliding of the seal portion or the backup ring portion. A sealing structure seals two members which move relative to each other, in which a seal portion or a backup ring portion placed between the two members and a bearing portion similarly placed between the two members are formed into an integral structure. The seal portion or the backup ring portion is integrally provided to one end portion in the axial direction or both end portions in the axial direction of the bearing portion having a cylindrical shape. The seal structure is used as a piston seal or a rod seal in hydraulic and pneumatic devices in which a piston is inserted into a shell or a cylinder tube.

Abstract: A fluid pumping device includes a barrel body and a piston mechanism. The barrel body has a cavity. The piston mechanism includes a piston member, a first annular plug, and a second annular plug. The piston member movably extends into the cavity. The piston member has two annular grooves where the first and the second annular plugs are disposed respectively. Each of the first the second annular plugs has an annular base section and an annular protrusion section. The annular protrusion section has a first outer annular abutting face. The annular base section has an outer annular base face. The first outer annular abutting face abuts against the inner wall of the cavity.

Abstract: Systems, apparatus, and methods are directed toward manufacturing a diaphragm using three-dimensional printing techniques.

Abstract: A hydraulic fluid cylinder is equipped with a cylinder tube, a piston unit, and a piston rod. The piston unit has a piston body comprising a plurality of members and provided with a gasket-mounting groove. The piston body has a first piston member and a second piston member which are layered in the axial direction. The gasket-mounting groove is formed from a combination of at least two members. A thin section exhibiting depth in the axial direction is provided in the first piston member and/or the second piston member.

Abstract: A concrete pumping structure and a control method thereof are disclosed. The concrete pumping structure includes a first pumping cylinder structure and a second pumping cylinder structure. Each pumping cylinder structure includes a delivery cylinder (1), a water tank (3) and a driving oil cylinder (7). The delivery cylinder (1) has a concrete piston assembly (2) inside, and during the pumping process, a piston rod (6) of the driving oil cylinder (7) drives the concrete piston assembly (2) to reciprocate in the delivery cylinder (1), and the water tank (3) is positioned between the delivery cylinder (1) and the driving oil cylinder (7). The concrete pumping structure also includes a concrete return hydraulic system, which controls the two driving oil cylinders (7) and drives the two concrete piston assemblies (2) to return back to the water tank (3) during returning the concrete.

Abstract: In a fluid pressure apparatus, a packing includes an annular seal member made of an elastic material, and support rings made of a low-friction material, which are mounted on an outer circumference of the seal member. The seal member includes, on an outer circumference thereof, a sealing projection that contacts an inner surface of the slide hole. The support rings are disposed on both sides of the sealing projection, and protrude beyond the seal member in the axial direction. Outer circumferential surfaces of the support rings always contact the inner circumferential surface of the slide hole. When a transverse load does not act on a piston as a partitioning member, the inner circumferential surfaces of the support rings do not contact the outer circumference of the piston. When a transverse load acts on the piston, the inner circumferential surfaces of the support rings contact the outer circumference of the piston.

Abstract: Hydraulic machine, in particular hydraulic motor, comprising a casing, a differential piston (4) having a region of large cross section and a region of smaller cross section, which can slide with a reciprocating movement respectively in the casing and in a housing coaxial to, and of smaller diameter than, the casing, the piston separating two chambers of the casing and being provided at the location of its large cross section and its small cross section with sealing lips (48, 49) which are oriented in opposite directions and which face one another. The sealing lips (48, 49) are provided on detachable circular rings (50, 51), and the piston (4) is molded in one piece.

Abstract: A sealing arrangement which is designed for a cylinder-piston arrangement of a reciprocating piston vacuum pump for sealing a gap between a cylinder wall and a piston displaceable in the cylinder, includes at least one L-shaped annular seal having one of its leg secured on the piston for providing a static sealing, and its another free leg adjoining the cylinder wall for providing a dynamic sealing, and an annular guide member arranged on the piston between the piston and the cylinder on a side of the seal remote from a compression chamber of the pump.

Abstract: A piston or plunger is made by passing an annular sealing member blank around a piston body and by moving it towards a central outer cylindrical surface part of the piston body defined between first and second circular edges. The sealing member blank is deformed into tight engagement with the central outer cylindrical surface part and into grooves or depressions formed therein. In this manner, a tubular sealing member, which extends axially along the central outer surface part, and which has opposite first and second ends extending beyond the first and second circular edges, respectively, is formed. Thereby both of these opposite end portions of the tubular sealing member may function as sealing lips.

Abstract: A piston assembly including a piston having a work surface, a sidewall extending from the work surface, and ports in the sidewall. The piston assembly also includes a flexible lubricant-scraping ring clamped to the piston between the work surface and the ports, with the lubricant-scraping ring having an outer edge extending outwardly beyond the sidewall.

Abstract: A piston for a fluid power cylinder, which possesses two separate piston parts, which are detachably set together in a joint region axially with a sealing action. Each piston part has a rigid carrying element, which is molded on a holding portion, which in its radially outer region has a lip seal comprising sealing material with rubber-elastic properties and serving for sealing on a piston running face. The respective lip seal and the holding portion associated with same are constituted by components of an integral elastic body comprising a sealing material with rubber-elastic properties. Such elastic body is molded on the respectively associated carrying element. The two elastic bodies are in sealing contact with one another in the joint zone.

Abstract: A piston assembly that is movable back and forth parallel to its axis in a cylindrical housing, comprising a piston-like support part made of a hard material and a guide ring made of a polymer. The guide ring surrounds the support part along a portion of the axial length of the piston. The support part and the guide ring are joined to each other via frictional and/or form locking provided by mating between grooves on the support part and a corresponding number of radial projections on the guide ring. A set of axially spaced apart sealing lips, integrally molded with the guide ring, extends axially beyond the grooves to provide a seal with respect to the cylinder wall.

Abstract: A lightweight mud pump piston assembly for reciprocating inside of a cylinder. The piston has decreased weight because light weight materials are used to form the majority of the hub which is the heaviest part of the piston. The piston maintains its compressive strength because the critical stress portions of the hub are made with high strength material having higher tensile strength and density than the light weight material.

Abstract: An adjustable piston packing expander for use with conventional caulking gun piston assemblies is disclosed. The packing expander threads onto the piston rod and includes a frusto-conical expansion surface which contacts the inner surface of the packing wherein advanced threading of the packing expander onto the piston rod will adjustably expand the packing into sealing engagement with the gun barrel walls. A set screw locks the packing expander in adjustment relative to the packing. A lock washer keyed to the square piston rod and interlocked to a rear piston rod washer having locking pins extending into the packing and forming a part of the piston assembly interlocks the packing against motion relative to the piston rod.

Abstract: A side entry down-hole pump for oil wells which relies upon gravity rather than suction to receive incoming oil. A pump barrel is plugged at its bottom end and is anchored in the well. A pair of inlet slots in the side of the pump barrel admit oil to a pump chamber formed in the barrel between the inlet slots and the closed bottom end of the barrel. A pumping element is formed by a plunger assembly which includes a cup body carrying a pair of cup shaped seal rings. A pumping string reciprocates the pumping element up and down and provides a flow passage through which oil is pumped to the surface. During upstrokes, the seal rings move above the inlet slots so that oil flows by gravity through the slots and into the pump chamber. Downstrokes effect compression of oil in the pump chamber to pump it through the flow passage and through a check valve which prevents downflow of oil. A pair of discharge slots in the pump barrel relieve pressure created by oil trapped above the seal rings.

Abstract: A differential pressure-actuated valve with a piston slidable to open or to close an inlet port. The piston slides in a cylindrical wall, and separates a bias chamber and a flow chamber. The piston is fitted with two oppositely-directed lip seals, one of which seals against bias chamber pressure, and the other of which scrapes particulate matter off of the wall. Optionally, an elongated filter extends from the piston into an inlet pipe where it filters water which flows to the bias chamber. The filter may have a perforated mesh wall, or a solid wall with an open end.

Abstract: A piston sealing arrangement particularly for pistons used in railway brake cylinders, comprising a flexible piston seal and a multi-function ring in the form of a separate wear band. The wear band is allocated on the pressure side of the piston seal to minimize radial motion of the sealing ring if the piston rocks.In FIG. 1 is shown a pneumatic brake cylinder 10 in which is located a piston 11. Piston 11 has an external flange 14 which backs a piston seal 15. Located on the pressure side of the piston seal 15 is a wear band 16 which is located very close to the piston seal 15 on the pressure side. The rubber piston seal 15, has a sealing lip 18 in contact with the inner wall of the cylinder 10.The wear band is chamfered at 19 so that the portion 20 of the wear band closest to the sealing ring 15 is the part of the wear band that actually contacts the inner wall of the cylinder.

Abstract: A pump comprises a housing member bounding an elongated cylinder bore, a piston member received in the cylinder bore for reciprocation substantially longitudinally thereof, a drive for the piston member, and a sealing arrangement between the piston member and the housing member. The sealing arrangement includes at least one sealing element having a radial supporting section and at least one lip section sealingly contacting the housing member. The wall thickness of the supporting section exceeds that of the lip section. The sealing arrangement may further include another lip section pointing in the opposite direction counter to that of the one lip section, either provided integrally on the same sealing element or separately on a discrete second sealing element assembled with the initially mentioned sealing element to form the sealing arrangement.

Abstract: A casing gas pump is reciprocated by the pump jack of an oil well. Push rods slidable within rigid vertical cylinders are connected by a bridle bracket to bridle cables depended from the pump jack horsehead. Vertical reciprocation of the horsehead moves pump leathers connected to the push rods up and down within cylinder bores. The cylinders are vertical, non-pivoting and fluidly connected to a header. The header is connected to the annulus of the well and to a gas line. Check valves prevent back flow from the header into the annulus and from the gas line into the header. The pump leathers form reciprocating pistons that are formed and assembled to avoid pulling a vacuum on the annulus.

Abstract: A double-acting piston and cylinder assembly has a piston which in turn has an outer piston surface centered on an axis, a radially outwardly open piston groove and a pair of axially oppositely facing piston ends. The cylinder has an inner surface centered on the axis and spaced radially outside the outer piston surface. A tubularly annular element received in the piston groove has an outer surface centered on the axis and bearing radially outwardly on the cylinder so the piston is guided in the cylinder by the outer element surface.

Abstract: Driving device with a curved cylinder in which a spherical piston is guided and can be driven by a gaseous or liquid propellant, preferably for a pyrotechnical driving device for a back-tightening device of a safety belt system. The spherical piston, the diameter of which is smaller than the smallest inside width of the cylinder is connected on the driving side to a resilient sealing element which adapts itself in accordance with the changing cross-sectional shape of the curved cylinder.

Abstract: A mud pump piston assembly is provided which facilitates replacement and secure holding of piston parts which wear rapidly. A double acting piston includes a piston rod, a pair of hollow piston members on the rod, and a pair of wear rings located between the piston members. The wear rings fit over a flange on the rod and are slightly separated.

Abstract: A mud pump piston assembly is provided which facilitates replacement and secure holding of piston parts which wear rapidly. A hollow piston member which fits on the end of a piston rod to seal against the cylinder, is held in place by a thin pressure ring which is captured by a retainer ring lying in a groove around the piston rod. The piston member has a concave face and the thin pressure ring closely mates with the concave face to support it, while leaving most of the concave face of the piston member uncovered so it can be expanded by pressured mud to more completely seal against the cylinder. In one assembly, the retainer ring is formed with a circular cross section, and lies halfway within a groove of semicircular cross section while the pressure ring is formed of triangular shape and with one side of the triangle abutting the circular retainer ring at substantially the top of the groove.

Abstract: A pump piston construction for mud pumps and the like incorporating a resilient sealing member that establishes a pressure enhanced seal between the piston and pump cylinder. A bearing and anti-extrusion member composed of a relatively hard and flexible friction resistant plastic material is structurally interrelated with and may also be bonded to the sealing member. The anti-extrusion member is supported by an annular rigid flange of a piston hub about which both the sealing member and anti-extrusion member are received. The anti-extrusion member serves as a bearing to minimize wear of the piston and cylinder and is yielded radially outwardly responsive to fluid pressure transmitted through the resilient sealing member and functions to prevent extrusion of any of the resilient material of the sealing member into the space between the piston and cylinder.

Abstract: An annular seal having first and second annular end faces extending substantially perpendicular to the axis of symmetry of the seal, said annular end faces being connected to each other by two axially extending surfaces each having the same axis of symmetry as the seal, one of said axially extending surfaces defining at least in part the surface of a lobe having a summit region, and at least a first of said annular end faces being shaped to define an annular recess.

Abstract: The double-acting measuring piston of this invention is slidably positioned in a cylinder and is provided with oppositely disposed mirror image sealing members which encompass a supporting body and are retained in abutment therewith by spaced flanges. The sealing members have foil lip portions that form between them, the cylinder wall and the supporting body an annular pressure chamber. The mirror image sealing members have oppositely disposed surface areas that are subjected to chambers containing a medium pulsating at slight pressure differences.

Abstract: A mono-seal pump piston comprising a mono-seal assembly including a central seal-supporting hub having a plurality of annular support ribs and a pair of resilient seals oppositely disposed on either side of the supporting hub, the seals including an outer annular sealing lip for sealing engagement with an inner wall of a pump cylinder and an inner annular seaing lip for sealing engagement about the piston rod which passes therethrough. The pump piston is retained on the piston rod by a pair of mounting followers positioned on either side of the piston assembly and held thereon by a nut.

Abstract: In order to preclude the entrapment of low pressure fluid in the interior of U-form seal members in the peripheral grooves of a piston for a fluid power cylinder and in turn prevent the inward deflection of such seals, there are provided cuts or notches in the edges of the end portions of the piston member to effect the venting of the inside of the seal members. Preferably opposing flat chord-like cuts are made in the end portions of the piston down to a mid part of the peripheral groove such that the resulting flat sections can be used to fit into wrench or vise means for piston rod assembly purposes.