Abstract: A shock for a vehicle includes a tube elongated along an axis. A piston is disposed in the tube and is moveable relative to the tube along the axis. A rod is connected to the piston. A floating piston is spaced from the piston along the axis and is moveable relative to the tube along the axis. The tube defines a working chamber between the piston and the floating piston. The tube defines a gas chamber. The floating piston separates the gas chamber from the working chamber. The floating piston has a housing slideably engaged with the tube and a membrane fluidly separating the working chamber from the gas chamber. The membrane is flexible relative to the housing.

Abstract: A piston for a fluid-actuated working cylinder, with a piston base unit which is coaxial to a piston longitudinal axis, consisting of a rigid core body which has radial outer peripheral surface and of an annular filling body which is seated in an annular receiving groove. The receiving groove is coaxial to the piston longitudinal axis and in the region of the radial outer peripheral surface is designed with a radially outwardly facing groove opening in the core body. The piston further includes a ring element which consists of plastic. The ring element radially outwardly coaxially encompasses the piston base unit at least in the region of the filling body, being radially supported with a radial inner peripheral surface on the piston base unit, projecting radially beyond the radial outer peripheral surface of the core body and comprising an axially orientated axial support surface radially outside the piston base unit on its two axial face sides.

Abstract: Cement slurry injected or delivered into a wellbore during cementing operations can be positively placed with a positive placement tool. The tool can be located along to a casing string and have a mandrel with a tubular centralizer sleeve rotatably fit thereabout, the centralizer sleeve having one or more radial guides extending longitudinally thereon. Reciprocal stroking of the casing string causes a helical drive arrangement, acting between the mandrel and the centralizer sleeve, to drive the centralizer sleeve longitudinally along a length of the mandrel while concurrently rotating the centralizer sleeve thereabout. The rotational movement of the centralizer sleeve provides positive impetus to force the injected cement slurry fully about the casing string.

Abstract: The invention relates to a piston having a first face, a second face opposite to the first face, a third face connecting said first and second faces together and presenting a groove, and a sealing gasket housed in said groove. The piston includes a duct constituted by a first segment situated inside the piston and connecting said first face to said groove, by a second segment situated inside the piston and connecting said second face to said groove, and by an intermediate segment connecting together said first and second segments and crossing said groove, the walls of said intermediate segment being formed by the walls of said groove and by said sealing gasket in such a manner that said intermediate segment forms a leaktight tube that opens out solely via the first segment and via the second segment, said intermediate segment presenting at least one obstacle suitable for impeding the flow of fluid that flows along said intermediate segment.

Abstract: A pump including a pressure compensated piston is disclosed. In some embodiments, the pump includes a piston with an annular body and an annular sealing element disposed radially outward of the annular body. The annular body has a radially-facing outer surface adjacent an inner surface of the sealing element and an axially-facing surface with an inlet port. A flowpath extends between the inlet port and the radially-facing outer surface of the annular body.

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 multipart cooled piston for a combustion engine has a piston upper part of steel comprising a combustion bowl and a ring wall with ring belt, and a piston lower part comprising a piston skirt, pin bosses for receiving the piston pin connecting the piston to the connecting rod, and pin boss supports connected to the piston skirt. An inexpensive manufacture and high form stability are achieved in that a cooling channel formed in the piston upper part has holes towards the piston crown spread over its circumference, with the piston material present between such holes forming supporting ribs that each form sections of an all-round ring rib radially to the longitudinal piston axis (K), The piston lower part has an annular and all-round carrier rib with a connection surface connected to the pin boss supports.

Abstract: The invention relates to a piston-cylinder arrangement, especially a shock absorber piston, comprising a piston body fitted with at least two peripheral webs on its peripheral surface, said webs limiting a groove and also including a collar-shaped sealing element made of thermoformable plastic material that overlaps the webs. Said piston also comprises axial passage channels in the piston body that are closed by throttle valves opening on one side and at least one radial hole connecting at least one passage channel to the groove formed between two webs.

Abstract: Improvements in a downhole submerged pump assembly having a plunger formed of a cast or machined cylindrical member includes seal ring grooves capable of receiving flat metallic seal rings formed of a plurality of segments which are interlocked in a manner wherein the segments can expand during the upstroke of the pump movement and retract during the downstroke.

Abstract: A shock-absorbing piston, a blank for the piston and a method for producing the piston include two parts being constructed radially symmetrically, but formed with outer and inner parts differing from each other. This offers great variability in the shaping of the functionally essential elements of the shock-absorbing piston.

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: An oil well subsurface pump comprising a housing for reciprocal disposition with a working barrel and having one end thereof adapted to be secured to the lowermost end of a sucker rod, or the like, and the opposite end thereof in open communication with the fluid reservoir in a well bore, a ball check valve carried by the housing and disposed within a ball chamber having a stop at one end for limiting the movement of the ball member in one direction and the opposite end open to the well fluid, resilient sealing assemblies interposed between the outer periphery of the housing and the inner periphery of the working barrel and slidable with respect to the barrel during a pumping operation, longitudinally disposed passageways provided in the housing and extending from the ball chamber to a position beyond the upper limit of the sealing assemblies to provide communication through the housing to the annulus between the housing and the working barrel for passage of the well fluid from the fluid reservoir to the annu

Abstract: A diaphragm type vacuum actuator movably providing in a case a rod having piston plates, the piston plates being connected to an inner peripheral surface of the case by means of two diaphragms so as to divide a case inside into a first chamber and a second chamber and form an intermediate chamber in between the both diaphragms, and the rod being made movable by subjecting one of said first and second chambers to vacuum and by opening the other thereof to atmospheric pressure; characterized by that air passages are formed in the piston plates, one ends of the air passages are interconnected to the intermediate chamber, and the other ends thereof are interconnected to chambers under atmospheric pressure.

Abstract: A linear motion damper is disclosed which comprises a hollow sleeve member, a rod reciprocating within the sleeve member, and a piston adapted to engage a fluid filled cylinder to provide resistance to linear motion by the exertion of lateral fluid pressure between the rod and the sleeve. The damper of the present invention exhibits greater efficiency and durability in operation, and is adaptable for a wide variety of applications.

Abstract: A dynamic metal-to-metal seal for use in a double acting piston and cylinder for use in high pressures and temperatures. First and second metal cup seals engage the piston and face in opposite directions for sealing against the cylinder wall whereby the higher pressure in the cylinder acting against the first or second seal will move the piston. In order to prevent high differential pressures across the seals when the piston is actuated, means are provided for transmitting fluid pressure from the lower pressure in the cylinder to the cylinder between the cup seal. The piston includes first and second oppositely directed seats with first and second metal seals telescopically movable on the piston adjacent one of the seats and each metal seal includes a sealing surface adapted to mate with one of the seats. Each metal seal also includes an outwardly directed cup seal extending away from their seats and sealingly engaging the cylinder.

Abstract: An oil well subsurface pump comprising a housing for reciprocal disposition within a working barrel and having one end thereof adapted to be secured to the lowermost end of a sucker rod, or the like, and the opposite end thereof in open communication with the fluid reservoir in a well bore, a ball check valve carried by the housing and disposed within a ball chamber having one end closed for limiting the movement of the ball member in one direction and the opposite end open to the well fluid, resilient sealing assembly interposed between the outer periphery of the housing and the inner periphery of the working barrel and slidable with respect to the barrel during a pumping operation, longitudinally disposed passageways provided in the housing and extending from the ball chamber to a position beyond the upper limit of the sealing assembly to provide communication through the housing to the annulus between the housing and the working barrel for passage of the well fluid from the fluid reservoir to the annulus f

Abstract: Worm to rack piston seal for power steering gear having a resilient cylindrical body with internal thread construction conforming to the profile and lead of the worm for a rack piston nut. During powered right and left turns, the seal is pressure loaded radially for improved fluid sealing and relaxed during low pressure conditions when there is no steering input for improved returnability of the rack piston nut to its centered position.

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.