Abstract: A collar for a telescopic cylinder with a cap includes the terminal portion of the cap that presents the opening of the cap, such that the collar includes in the following order a first annular element with a contoured profile, which surrounds the terminal portion and is welded thereto, and a second annular element, which can move with respect to the terminal portion and to the first annular element. The collar further includes an O-ring, made of rubber, surrounding the terminal portion and a third annular element surrounding the terminal portion and welded thereto. The first annular element has, at its internal circumference, an annular guide with a curved internal circumferential surface, the internal circumferential surface having, at each point of its circumference, a vertical cross-section with a shape that is concave as it progresses toward the outside of the collar.

Abstract: A three-piece oil ring and a combination of the three-piece oil ring and a piston, those capable of realizing improved sealing property and reduction in lubrication oil consumption with avoiding generation of sticking even at low tension and thin width of the ring. The three-piece oil ring includes a spacer expander 10 and two side rails. The spacer expander has a radially inner end portion provided with seating tabs 13 protruding in an axial direction and having radially outer inclined surfaces for urging inner peripheral surfaces of the first and second side rails. The spacer expander has a radially outer end portion provided with side rail support portions 14 projecting in the axial direction for supporting axial end faces of the first and second side rails. A seating tab angle of the outer inclined surface relative to an axis is in a range of 10 to 20 degrees, and a ratio of 2X/Y is in a range of from 0.04 to 0.

Abstract: An oil-less/oil-free air brake compressor comprising a bore, a piston positioned for reciprocating in the bore, the piston having an annular recess and a rigid polymeric piston ring received within the annular recess, the piston ring having a predetermined non-circular profile in the free state.

Abstract: In a combined oil ring having a spacer expander to be installed between a pair of upper and lower side rails, a plurality of axially protruding inner peripheral protruding portions are formed on the inner peripheral side of the spacer expander along its peripheral direction. The inner peripheral protruding portions press the inner peripheral surface of the side rails. On the outer peripheral side of the spacer expander, a plurality of slits are formed, and a plurality of connecting portions are located in the peripheral direction isolated by the slits. On the plurality of connecting portions, axially protruding outer peripheral protruding portions are formed.

Abstract: An oil-free/oil-less air compressor with a piston positioned for reciprocating in a bore, the piston having a first piston ring assembly made from a rigid, high temperature polymer, and a second piston ring assembly comprising a first portion that engages the bore, the first portion made from a relatively soft, self-lubricating polymer, and a second portion that biases the first portion against the bore.

Abstract: A bore seal telescopic hoist is formed of a series of telescopically arranged tubular sections each having a circumferential reservoir. A circumferential wiper is lodged in the reservoir and is used to collect debris or dirt which may be present on the inner wall of an adjacent tubular section.

Abstract: The compressor contains at least one piston (5) guided in a dry-running manner which, together with a cylinder insert (33), bounds a ring gap which is open over the common longitudinal section in each case and permits a leakage flow of the compressed medium. The piston (5) is coupled via a piston rod (42) to a support part (38) which is displaceably guided in the direction of its longitudinal axis (6) and is connected to a drive device. The piston rod (42) cooperates with the piston (5) and the support part (38) via support surfaces (43) which are convex at the end faces and permit relative movements of the support part (38) with respect to the piston (5) which extend transversely to the longitudinal axis (6). Accordingly, a parallel guidance of the piston (5) in the cylinder insert (33) is achieved which is not influenced by oscillations of the driving parts.

Abstract: A four-piece oil seal is disclosed that includes a resilient expander spacer having an axial top edge, an axial bottom edge and an axial intermediate portion therebetween. The axial intermediate portion of the resilient expander spacer includes a plurality of intermittent radially outwardly extending tab pairs that define circumferential slots. A first rail contacts the axial top edge of the expander spacer. A second rail is disposed within the slots formed in the radially extending tabs. A third rail contacts the axial bottom edge of the expander spacer. Preferably, the radially extending tabs are in the form of intermittent U-shaped ridges and include spacer lugs located at a bridge portion therebetween. The ridges form center openings in the expander spacer while the spacer lugs maintain separation between adjacent rails.

Abstract: An actuator for a turbocharger includes a piston axially movable within a housing. The piston has a plurality of annular grooves thereon, and a plurality of O-rings are loosely restrained respectively in the annular grooves. Thus, the O-rings are axially movable within the grooves prior to moving with respect to the housing, so as to reduce the hysteresis which normally accompanies movement of the piston within the housing.

Abstract: An improved cylindrical working member and associated system comprising a simple cylindrical sleeve having an outer surface with two spaced grooves surrounding a cylindrical land. At the other end, a single groove is formed. A "SANDWICH" consisting of a simple O-ring, a single back-up ring, a low snap ring is installed in each groove. An additional low friction snap ring forms a limit stop front cap. A plurality of the cylindrical sleeves can be employed to form a telescoping cylinder system. An additional embodiment using a guide member consisting of a plurality of square tubes of sequentially increasing cross-section formed into a non-rotating telescoping guide member to attach one end to the telescoping system, and other end to a plug of the hollow central rod. A simple system is used for extending and retracting the telescoping cylinder.

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: A cylinder piston device comprises a cylinder and a piston rod. The piston rod is guided through one end of the cylinder inwards and outwards of the cylinder. A damping body is provided for damping the axial movement of the piston rod with respect to the cylinder. This damping body is deflectable in response to change of direction of the axial movement. A deflection of the damping body results in change of the frictional resistance.

Abstract: A reciprocating pump for a cryogenic fluid includes a pump cylinder made of a material with low thermal expansivity, a piston displaceable in the pump cylinder, and self-lubricating piston rings made of polytetrafluorethylene held on the circumferential surface of the piston. The rings have a larger thermal expansivity than the pump cylinder. The arrangement allows optimum matching of piston rings and pump cylinder at cryogenic fluid pumping temperatures. The piston has a core made of a material with relatively large thermal expansivity which is surrounded by a spacer sleeve made of a material with a low coefficient of thermal expansion. The core protrudes on both sides from the spacer sleeve and has expanding regions increasing conically towards its free ends. The piston rings surround the core in the expanding regions and are supported against the end faces of spacer sleeve. The conical expanding regions bias the rings toward the cylinder at low temperatures to insure effective sealing.

Abstract: A hydraulic jack includes a body (1) with front (2) and rear (3) covers and a rod (4) moving relative to said body (1) and having at least one projection made therein and mounting an additional member (7) and at least two grooves which form the respective projection (8) and of which each accomodates piston semi-rings (6) installed therein by pairs, the rod (4) portion having the projections (8) and the grooves forming a piston unit (5).

Abstract: A dynamic seal for effecting the sealing of a piston which is axially movable in a cylinder bore comprising a primary sealing element formed of a non-elastomeric sealing material having a hub portion secured to the piston element and an outwardly flaring skirt portion sealingly engagable with the cylinder bore. A secondary sealing element formed of a resilient metal has its central body portions secured to the piston element and defines a frustro-conical lip portion snugly engaging the exterior of the skirt portion of the primary seal element. Fluid pressure applied to the primary seal element causes it to expand the secondary seal element into a metal-to-metal sealing engagement with the bore of the cylinder.

Abstract: A fluid cylinder assembly comprising a cylinder housing including a closed end portion and a piston assembly including an end piece member having at least one projection extending therefrom for abutting the closed end portion of the cylinder housing so as to prevent the piston assembly from completely engaging the closed end portion, a washer member having a projection extending therefrom and a cup member. The washer includes bulges on both sides thereof circumferentially spaced from the projection such that the bulges are disposed against the surfaces of the end piece member and cup member when the projection of the washer is inserted within the projection of the end piece member so as to allow fusing of the bulges with the end piece member and the cup member.

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: Each of the pistons has a metallic, ceramic or high glass nylon plastic core insert with glass-filled nylon plastic molded around it to form the finished piston. The finished piston is ready to use as it comes from the mold. The core insert is designed to maintain a substantially uniform plastic wall thickness and provide support lands behind the high pressure lands of the piston. The core insert also incorporates undercuts or grooves to prevent the core from being pushed out of the piston assembly. The grooves also allow the plastic to bond to the core. The core insert transmits the direct axial force of the push rod, and the plastic outer case supports the seals.

Abstract: A packer nose assembly for pumping downhole equipment of the free type into and out of boreholes. The assembly includes a mandrel having a lower end portion attachable to the downhole equipment and an upper end portion terminating in the form of a fishing neck. One or more packers are slidably received in a telescoping manner upon the mandrel and anchored into position by spaced sleeves which are likewise slidably received upon the mandrel. The packer is cylindrical in form and includes a plurality of spaced fins formed about the exterior thereof with each fin being circumferentially disposed about and radiating from the body portion. The fins taper in thickness in an outward direction from the body portion.

Abstract: A solenoid operated metering pump for displacement of exact amounts of fluid pumped by reciprocation of pumping piston incorporating integral check valve has an elongated valve housing with solenoid operator serving as pump actuating means attached to one housing end while the other housing end is adaptable to serve as the fluid pumping means including an appropriate housing bore passing therethrough and adaptable to receive a differential diameter piston assembly slidably movable therein to reciprocate when solenoid operator becomes electrically cycled inducing fluid flow through appropriate pump chamber created therein between piston and housing bore portion provided with fluid supply port having a detachable check valve with a simple floater for a directional flow control therethrough, means of piston actuation from a first position checking flow and discharge of the fluid delivered to the pump chamber to a second position discharging exact fluid quantity per each stroke of pump reciprocation, and means of

Abstract: An actuator, and a system employing the same, which will continue to operate after deformation of a portion thereof which deformation would normally restrict movement between the piston and cylinder of the actuator. The piston or gland of the actuator is constructed so as to include segmented flanges which will fracture responsive to forces applied to them upon engagement of the deformation. Slots defining the segments are filled with a rubber-like material which is bonded to the piston or gland thus providing a solid structure to enable appropriate sealing while not interfering with the fracturability of the segments.

Abstract: An improved oil damped piston for use in internal combustion engines, pumps, compressors, or the like. The piston includes a generally cylindrical piston body having a crown and a depending skirt. A pair of spaced bands of polytetrafluoroethylene are carried by the skirt and each has a surface radially outwardly of the skirt. Each of the band surfaces includes a configuration defining a pumping surface for directing lubricant on a cylinder wall into the space between the band. The oil in the space damps side to side movement of the piston within its cylinder.

Abstract: A hydraulic cylinder assembly for farm machinery or the like including a tubular elongate cylinder with a smooth inner cylindrical wall and a fluid inlet at a first end with a hollow piston rod slidable therein having an annular piston secured at a first end and slidable within the cylinder wall with the piston carrying axially spaced wear rings and plastic annular sealing rings therebetween and a T-shaped backup ring therebetween, a guide and seal retainer within the cylinder at the second end thereof for the second end of the piston rod held in place by a retainer nut threaded onto the cylinder and carrying a wiper ring in a groove and holding a seal between the guide ring and retainer nut.