Abstract: A packing case assembly includes a packing cup configured to be disposed along a piston rod of a reciprocating gas compressor system; and a packing ring set disposed in the packing cup, the packing ring set including multiple rings. The packing ring set is configured to be disposed circumferentially around a portion of the length of the piston rod. A backup packing ring of the packing ring set includes a first region including a polymer, and a second region including a metal.

Abstract: The ring mounting jig is a ring mounting jig for mounting a retaining ring made of metal having a first end portion, a second end portion having an outer diameter larger than that of the first end portion, and a first groove and a second groove provided in a circumferential direction of an outer peripheral surface of each of the first end portion and the second end portion, to the second groove on a shaft having the first end portion and the second end portion, without mounting a retaining ring made of metal having an inner diameter before expansion smaller than an outer diameter of the first end portion to the first groove from the first end portion. The ring mounting jig includes a ring expanding jig, a shaft fixing jig, a ring pushing jig, and a ring fitting jig.

Abstract: A wheel assembly may include an inner rim to be coupled to the hub of the vehicle, and an outer rim surrounding the inner rim. The wheel assembly may also include gas springs operatively coupled between the inner rim and the outer rim and permitting relative movement therebetween. The wheel assembly may also include a rigid inboard cover ring coupled to an inboard side of the outer rim and extending radially inward toward the inner rim. A flexible inboard seal may be coupled between the rigid inboard cover ring and the inner rim.

Abstract: A piston ring and a method of forming a piston ring. A masking agent is applied to a selective area on an exterior surface of a piston ring. The masking agent inhibits the subsequent application of additional coatings to the selective area on the exterior surface of the piston ring. In one form, the masking agent may inhibit the subsequent application of a nitride layer to the selective area on the exterior surface of the piston ring. A recess may be formed in an outer peripheral side of the piston ring, and a thermal spray coating may be formed within the recess in the outer peripheral side of the piston ring.

Abstract: An irrigation sprinkler canister seal comprising a flanged screw having a threaded rod and a circular flange extending perpendicular to the rod. The seal further includes a plug piece having a threaded bore adapted to receive the threaded rod, and further including a continuous frusto-conical surface extending around an elongate axis of the plug piece, the frusto-conical surface being configured to form a circumferentially continuous fluid seal against a cylindrical rim of a cylindrical bore.

Abstract: A piston assembly includes an annular body defining a groove, with a ring disposed within the groove. The piston assembly includes a centering device disposed within the groove between an inner face of the ring and a root of the groove. The centering device centers the ring concentrically within the groove when the ring is in an uncompressed condition, prior to installation into a bore of an engine block, to prevent the inner face of the ring from moving radially outward beyond an outer edge of the groove when the ring is in the uncompressed condition.

Abstract: A combined oil ring includes an oil ring having upper and lower rails formed integrally at an outer circumferential side of the oil ring to slide on a cylinder wall; a coil expander installed at an inner circumferential side of the oil ring to force the oil ring radially outwards; and a side rail installed at an upper side of the oil ring and having no torsion along an axial direction of the oil ring.

Abstract: A piston ring assembly includes a ring or rail defining a seal surface configured to seal against a piston bore surface of an engine. The seal surface defines a radially outer periphery. The oil control rail assembly further includes two positioning rings. A first one of the positioning rings is disposed axially above the oil control rail and a second one of the positioning rings is disposed axially below the oil control rail. Each of the positioning rings defines an outermost periphery of the positioning ring that is disposed radially inward with respect to the seal surface of the oil control rail. The outermost peripheries of the positioning rings thus generally do not contact a bore surface that is contacted by the seal surface of the oil control rail.

Abstract: A segmented piston ring assembly includes piston ring segments 2 having stepped ends 5, 6, at least one piston ring segment 2 including a radial step on a radially inner peripheral surface 9 over a part of the width of the piston ring segment 2, and a single-cut sealing ring 3, which bears radially against the inside of the peripheral surface 9 of the piston ring segments 2, the sealing ring 3 including an axial recess 10, 12 which cooperates with the radial step 4 of the piston ring segment 2 to prevent relative rotation therebetween.

Abstract: The invention relates to a piston for a piston-cylinder arrangement, particularly a shock absorber piston, which includes a piston body, that has a circumferential surface. A sealing collar has an outer circumferential surface, an inner circumferential surface, a first peripheral surface, and a first sealing lip, and extends around the circumferential surface of the piston body and covers at least part of the circumferential surface in the axial direction. The first peripheral surface connects the two circumferential surfaces to each other at a first end of the sealing collar. The first sealing lip is delimited by the first peripheral surface and the outer circumferential surface, and the first sealing lip is configured evenly in the circumferential direction.

Abstract: An oil-control ring for an internal combustion engine, to be mounted between the sidewalls of a respective groove of a piston has two ring segments and an annular expander disposed between the two ring segments and presenting a support body defining a seating plane for each ring segment. The ring has at least one expander portion axially projecting from the support body of the expander, beyond at least one of the seating planes of a ring segment, and at least one superficial irregularity provided in at least one of the ring segments and which is dimensioned to be contained in the thickness of the respective ring segment and to interfere with at least one expander portion, in order to rotatively lock the ring segment in relation to the expander.

Abstract: A seal assembly, for an additive pump having a reciprocating piston, is provided. The seal assembly includes a seal carrier having first and second components each having a bore therein to receive the piston. Each component has an end face arranged to abut one another when arranged axially on the piston, and a face seal is interposed between the end faces to inhibit egress of fluid between the end faces. A pair of circumferential seals at axially spaced locations are provided along the seal carrier and operable to engage the piston during reciprocating thereof, and a drain port intersecting one of the bores intermediate the seals is provided to permit egress of fluid from between the seals.

Abstract: This method to allow the use of low VOC (volatile organic compounds) solvents in blanket cleaning operations and the resultant product that is produced by this method involves the retrofitting of currently existing seals on printing press so that operators can use low VOC solvents in place of high VOC solvents. High VOC solvents are harmful to the atmosphere and humans alike. As VOC are lighter than the surrounding air, humans are subjected to inhalation of these harmful vapors which cause respiratory and other health ailments. The VOC continue to rise, mixing with nitrogen oxides, until they reach the troposphere forming thick layers of ozone or smog. The current movement of municipalities to limit the use of high VOC solvents have lead printers and others to use low VOC solvents which are inherently less evaporative than high VOC solvents. This lack of evaporation causes problems with having to handle greater volumes of waste to handle and dispose properly.

Abstract: A method of manufacturing an oil ring is disclosed. The oil ring includes an annular oil ring body having a pair of rail portions at its axially upper and lower portions and butt ends, and a coil expander assembled in the inner periphery of the oil ring body. A number of oil ring bodies and annular spacers having a smaller diameter than the oil ring bodies are stacked, and then aligned and retained using a jig such that an outer periphery of the oil ring bodies becomes a circle. The aligned oil ring bodies are rotated and a flat region that is substantially level with respect to the outer peripheral sliding surface of the plurality of oil ring bodies is formed. Curved regions extending on both sides of that flat region are formed using a buff or an elastic grindstone.

Abstract: In a piston pump, the improvement of providing a locating disc on the piston extending radially outwardly from the piston to engage a chamber wall of the piston chamber and with the locating disc having an opening axially therethrough permitting fluid flow both in an inward direction and an outward direction.

Abstract: A seal structure channels drainage of machining fluid from the periphery of an opening for a lower arm of a wire-cut electric discharge machine. The seal structure restricts flowage to the outside of machining fluid through the opening (slot) in a side of a machining tank and has a first seal and a second seal (a seal plate) affixed to the first seal so as to cover the opening. An unevenly shaped part including ridges and grooves extending in the long direction of the first seal is formed on the first seal, and passages are provided that communicate with the groove and the outside to channel the machining fluid drainage path. The first seal may be composed of a plurality of members. A suction device sucks up machining fluid draining from the passages.

Abstract: A piston ring for use at temperatures above 350° F. at pressures greater than or equal to about 2000 psi, comprising a gap having a gap width about 1.4 to about 2.0 times greater than a thickness of the piston ring; a height about 4.5 to about 6.4 times larger than the thickness, and a leading edge characterized by an arc having a radius of curvature of less than or equal to about 4 times the height. The piston ring may be formed of a material comprising cobalt, chromium, tungsten, and carbon. A gas compressor and method of sealing a piston using the above piston ring is also provided for.

Abstract: An improved seal/bearing arrangement employs an O-ring type seal which has segmented fingers. The seal ring has a recess which is sized to mate with a corresponding projecting lug of a bore use, for example, in brake actuator mechanisms. The seal ring can be made from synthetics such as polyamides and polyethylenes. The fingers are so arranged that locking of the seal rings in the bore occurs with insertion of a sliding, oscillating and/or rotating shaft or the like through the rings.

Abstract: The invention relates to an oil scraper ring groove ring arrangement for pistons of internal combustion engines. The inventive arrangement comprises a disk that is provided with parallel flanks and a bearing surface having an asymmetrical crowned form with a vertex line extended over the periphery of the disc, with the disk being arranged in a ring groove of the piston with a ring groove side opposing the piston head and a ring groove side facing the piston head. The aim of the invention is to achieve an improved oil scraping action compared to that of prior art, while reducing the friction and the abrasion in such a way that it is radially outwardly inclined to the outer diameter of the piston, the bearing surface of the disk being embodied in such a way that it corresponds to an almost worn end contour in the started engine state, and, when the oil scraper ring is mounted in the piston, the vertex line of the bearing surface is oriented in the direction of the ring groove side opposing the piston head.

Abstract: It is a main object of the present invention to provide an oil ring which is capable of reducing sliding friction even in a high speed revolution region of a piston, and capable of reducing the consumption of oil.

Abstract: The present invention pertains to a wiping and/or sealing element for sealing a piston (11) guided movably in a housing (10) with a seal held in a groove (21, 30). The present invention pertains, furthermore, to a process for sealing a movable piston (11) by means of a seal inserted into a groove (21, 30) and a clamping and/or support element with a piston (21), which is guided in a housing (10) such that it can be withdrawn and extended, wherein the piston (11) is sealed by means of a seal arranged in a groove (21). To achieve sealing of the piston (11) with a high sealing force for high liquid pressures at low friction, the wiping and/or sealing element according to the present invention as well as the clamping and/or support element according to the present invention are wherein the seal is a quad ring (22) with a square cross section.

Abstract: Joining connections are presented for joining the functional parts of hydraulic or pneumatic operating devices the joining connections including a first part exhibiting an external wall section and a second part exhibiting an internal wall section, which are joined together with mutually overlapping wall sections having depressions that form a cavity, in the connected state that is filled with a fluid casting compound of plastic that connects the two parts together by means of a positive form fit after hardening to prevent relative displacements between the two functional parts and to seal the separating gap clearance between the wall sections of the two functional parts.

Abstract: A combined steel oil control ring is provided which has steel side rails and a steel spacer expander. The spacer expander includes ear portions for contacting the side rails. The ear portions are substantially equally spaced with respect to each other along the internal circumferential portion of the spacer expander. The ear portions have radially external circumferential surfaces adapted to press the side rails radially outwardly by using the resilient force caused by the spacer expander. The spacer expander has up-and-down contours formed circumferentially along the radially external circumferential surface, for preventing the side rails from circumferentially rotating relatively to the spacer expander. The up-and-down contours each include at least two axially extending groove regions and at least three axially extending flat regions. The groove regions and flat regions are dimensioned to extend the life span of the contours and the dies.

Abstract: A ring assembly, including a first oil scraper ring, a center oil scraper ring and a gas seal ring, adapted for disposition in a single groove of a packing cup which can be stationarily mounted over and around a reciprocally movable piston rod of a gas compressor. The function of the assembly is to both scrape lubricating oil from the piston rod for return to one side of the cup and to provide a seal against gas leakage from an opposite side of the cup, both along the piston rod under the seal ring and between the seal ring and opposing sides of the center ring and groove to prevent mixing of gas with the oil and escape of gas from the compressor. The center ring features a tapered outer peripheral surface portion. An annular side loading element, which can be a garter spring, is mounted in compression around the center ring so as to bear against the tapered surface portion and against an adjacent side of the first ring.

Abstract: The present invention provides a piston ring comprising a piston ring main body and an expander ring arranged on an inner peripheral surface thereof, the expander ring comprising two oil expander rings, one of which is housed in a space in a spiral of the other. The expander ring is formed so that the pressing force in the diameter expanding direction is larger in a high temperature state than in a low temperature state. The expander comprises two different kinds of expander members. One of these expander members has the same functions as those of a conventional expander, and the other is a member in which there occurs a change in tension in the diametral direction with temperature. As a result, the pressing force of the master expander member having the same effects as those of the conventional expander is made variable.

Abstract: A seal for hydraulically sealing a piston rod that travels axially into and out of a housing, preferably in a hydraulic dashpot. The seal comprises a preferably resilient-plastic sealing component (5). The sealing component is provided with one or more sharp ridges (10, 11, & 12) that rest against the piston rod, is tensioned across an elastomeric component (8), and is radially and axially secured along with the latter in a seal holder (2). The sealing component has an axial cylindrical wall (6) and a radial annular flange (7). The wall rests snug against the piston rod. The elastomeric component is annular and is provided with an inner surface (9) that tapers in toward the center of the housing and that the wall rests against. The outer surface of the elastomeric component is accommodated subject to radial tension in a setback (13) in the seal holder.

Abstract: A seal assembly which acts as a piston in a vehicle power steering unit. The seal includes a casing and an elastomeric seal body and is affixed to a movable rack at two attachment points. One point is the tail portion of an axial flange swaged into a groove in the rack, and a second part of the same axial flange has a groove for retaining a locking ring in a second groove in the rack. The rack moves within a housing having a first bore, a counterbore, and an enlarged bore. The seal comprises two oppositely facing lips and a lip body bonded to a radial flange of the seal assembly and engaging the enlarged bore which divides the space into two pressurizable fluid receiving cavities. An auxiliary seal is seated in the counterbore and seals the first bore. The seal assembly has a nose portion which engages the auxiliary seal to fully seat it in the counterbore. The nose portion, in one case, is a separate axially extending plastic piece that seats in a groove in the seal body.

Abstract: In order to increase in concentration of HC in an exhaust gas due to an axial gap between a ring groove and a piston ring, when an internal combustion engine is at a lower temperature, particularly, during the starting or the low-speed operation of the internal combustion engine in which the moving speed of a piston is lower, a restricting ring having a radially outward tension is inserted in a wedge shape into between axially opposed surfaces of a ring groove and a piston ring so that in a lower-speed operational range of a piston, the axial movement of the piston ring within the ring groove is restricted by the wedging action of the restricting ring, and in a higher-speed operational range of the piston, the wedging action of the restricting ring is removed by a floating force of the piston ring generated with the descending movement of the piston.

Abstract: A seal for preventing leakage of fluid from an opening (42) formed in a side wall (41) of a work tank (40) of a wire electric discharge machine comprises a slide plate (1) movable with respect to the work tank for closing the opening, and a rail member (22) attached to the work tank for guiding movements of the slide plate. The slide plate gas a waterproof thin flexible strip (13) and a number of rigid blocks (11, 12) attached to the flexible strip and arranged in a row so as to engage with each other at the edges. The rigid block gas a convex edge (111) and a concave edge (112) complementary to the convex edge. A method of forming the seal is also disclosed.

Abstract: A piston-rod scraping ring (7) of elastic material accommodated in an inward opening groove (9) in a dashpot cap (2) and especially intended to scrape water and dirt off a piston rod (1). The object is to allow the ring to be easily inserted into the groove and secured there until the overall dashpot is assembled. The groove is accordingly higher at its outer circumference and its inner circumference (12) is deformed, compressing the rim (8) in place.

Abstract: The present seal system is in two parts. First is that of an elastomer energizer, which may be in the shape of a square ring, o-ring, or an other custom design for energizing the seal system. Second is that of a seal element having a particular geometry and composition. The geometric layout of the seal element ensures firm contact between the seal and groove bottom, independently of the seal pressure and radial position of the moving part, and concentrates contact forces against the moving part by means of a seal apex. In the installed state, the seal is forced into contact with the groove bottom by having an outer diameter matching or exceeding that of the groove bottom, and a radial height exceeding that of the housing groove. Further, the influence of the compression ring or energizer is balanced out by positioning the seal apex near the axial position of the center of the energizer.

Abstract: A seal arrangement having a bore within which a component is to be received, in use, the seal arrangement comprising a seal member formed from a resilient material, the seal member having an inner periphery and an outer periphery and being provided with a fracture to define two ends of the seal member. When in a relaxed condition, the inner periphery of the seal member has a smaller diameter than the diameter of the component such that, when the component is received through the bore of the seal arrangement, the two ends of the seal member are caused to part, the resilience of the seal member causing the inner periphery of the seal member to form a substantially fluid tight seal with the component. The seal arrangement further comprises a support member upon which the seal member is mounted, the support member being of generally annular form and having inner and outer peripheries, wherein the inner periphery of the support member is of generally circular form except for a region of irregularity.

Abstract: A piston sealing ring assembly (70) for sealing the piston/cylinder interface of a double-acting gas compressor including a first and second cut piston sealing ring (54,72) each bounded by first and second planar surfaces (6,8), the first piston sealing ring (54) having an overlapped cut with generally circumferentially extending inner and outer overlapping portions (56,58) which contact each other to form a continuous seal extending from the first surface (6) to the second surface (8) of the first piston sealing ring (52) and separating an inner ring gap (62) from an outer ring gap (64). The periphery of the outer ring gap (64) of the first piston sealing ring (54) at the first surface (6) is sealed by the second surface (8) of the second piston sealing ring (72). The second piston sealing ring (72) is similarly disposed in relation to the first piston sealing ring (54) so its outer ring gap (64) is sealed at the second surface (8) by the first surface (6) of the first piston sealing ring (54).

Abstract: A piston and split piston ring assembly having a piston ring locator to prevent substantial rotation of the piston ring in a ring groove. A notch is provided in a wall of the ring groove and an abutment pocket is formed by the ends of the split piston ring. The piston ring locator is a flattened wire clip within the groove between the piston ring and the wall of the groove. A segment of the clip is displaced into the notch and another segment is displaced into the pocket.

Abstract: The present invention relates to an oil sealing ring, especially that used in piston of internal combustion engine or compressor. This oil sealing ring comprises a base ring (2) with a split. An elastic ring (3) is provided in the inner circumference surface of the base ring. A radially outward annular flange (18) is provided in the outer circumference surface of the base ring. An axially upward annular projecting part (19) is provided in the area beyond the outer circumference surface of the projecting part (19). The splits of said disc ring (1) and said base ring (2) are respectively staggered from each other. This oil sealing ring can effectively prevent the leakage of the oil and the gas.

Abstract: An improved seal for a rotary valve for high temperature and high pressure fluids. A removable seal member adapted for disposition between a valve body and a valve member rotatably disposed in the valve body is provided. In one aspect of the invention, the seal member is adapted so that pressure exerted by the valve is sufficient to induce cold flow in the seal member. In another aspect of the invention, the seal member includes a pair of longitudinally disposed slots.

Abstract: A Y-block fluid section plunger pump housing has a cylinder bore which is transversely elongated at its intersection with suction and discharge bores to provide stress relief and a reduction in housing weight. An integral suction valve retainer arm further reduces stress near the bore intersection. Tapered cartridge packing assemblies facilitate use of a one-piece plunger in Y-block housings and also allow packing in such housings to be changed without removing the plunger.

Abstract: The invention relates to a sealing ring for sealing a piston rod of a piston compressor. The sealing ring comprises three segments, wherein the segments have portions extending in the circumferential direction of the sealing ring, which form an overlapping joint. The overlapping joint brings about an excellent sealing effect in the axial direction.

Abstract: In an annular groove carried by one of a pair of reciprocally movable members, a pin extending into the annular groove and a sidewall of the other one of the pair of reciprocally movable members, a seal assembly comprising a ring carried by an annular body mounted in the annular groove for sealing the reciprocally movable members for minimizing fluid leakage between the members, wherein the pin extends into and through a notch carried by the annular body and an end gap of the ring for retarding rotation of and between the annular body and the ring.

Abstract: A piston and compression ring combination with a piston having a generally cylindrical configuration for mounting in a cylinder of an internal combustion engine, an annular groove adjacent the top of the piston; and a piston ring having an upper inwardly directed flange adapted to rest on top of the piston, the ring having a lower inwardly retaining foot adapted for fitting into the ring groove in the piston. Such combination for the purpose of diminishing ring crevice volume, improving performance and reducing engine emissions.

Abstract: A seal configuration for both reciprocating pistons and for rotating valves of internal combustion engines. A first embodiment, applicable to reciprocating pistons, provides minimum crevice volume (MCV). The MCV seal assembly according to the present invention, which replaces, at least, a conventional top piston ring and its annular groove, includes an annular groove in the piston, a wavy spring at the bottom of the annular groove and an MCV seal received in the annular groove and biased outwardly by the wavy spring, wherein the MCV seal assembly is configured and oriented so as to minimize the crevice volume above the MCV seal, wherein the spring biasing ensures an excellent sealing of the MCV seal to the cylinder wall.

Abstract: Sealing arrangement for a piston rod with a circular cross-section, comprising a one-piece sealing ring with a parting joint and compensation clearance as well as a cover ring surrounding the sealing ring in the peripheral direction, with the sealing ring having a section which extends in the peripheral direction of the sealing ring at at one end and forms an overlapping ring joint together with the other end of the sealing ring, and with the sealing ring having a radial wall thickness decreasing towards the parting joint. This arrangement has an excellent sealing action in a direction axial to the arrangement.

Abstract: A set of piston rod packing rings for use in each of the packing cups of a gas compressor is disclosed. The packing ring set includes segmented first and second rings constructed of a material such as plastic, nylon, Teflon or bronze. The segments of the first ring have a plurality of opposing ends, each of which plurality preferably forms a radial cut butt joint. The segments of the second ring also have a plurality of opposing ends, each of which plurality preferably forms a butt/tangent joint. The second ring is disposed next to and on a low pressure side of the first ring as measured during a compressor piston rod compression stroke. The packing ring set also includes a third uncut ring constructed of a compressible, non-metallic material and a fourth uncut, anti-extrusion ring constructed of a relatively less compressible material than the third ring such as cast iron, bronze or hard plastic.

Abstract: The present invention provides a piston ring structural body composed of an outer ring continuously formed of a resinous material, an inner ring continuously formed of a resinous material and a ring tensile force applying member for pressing the outer ring radially outwards via the inner ring. The piston ring structural body has a construction wherein the outer ring continuously formed of polyimide is pressed outwards in the radial direction of the piston by a coil expander via the inner ring continuously formed of PTFE. A sliding face of the outer ring, which slides on a cylinder wall, is divided into upper and lower sliding faces, whose respective upper edge portions are provided with chamfers. A contact portion of the inner ring that contacts the coil expander is provided with an upper inclined face extending inwards and upwards and a lower inclined face extending inwards and downwards. The angles of inclination of the upper and lower inclined faces range from 30° to 60°.

Abstract: The present invention provides a sealing structure employing a piston ring structural body of a type wherein an outer ring continuously formed of a resinous material is pressed radially outwards by a metal coil expander via a metal inner ring provided with an abutment. The piston ring structural body has a construction wherein the outer ring continuously formed of polyimide is pressed radially outwards by the coil expander via the steel inner ring provided with the abutment. A sliding face of the outer ring, which slides on a cylinder wall, is divided by a groove into upper and lower sliding faces, whose respective upper edge portions are provided with chamfers.

Abstract: A seal comprises a support member having an outer periphery of substantially circular form, and a resilient seal member mounted upon the support member, the seal member, when occupying a relaxed condition, having an outer periphery of generally circular form and a diameter greater than that of the support member, the seal member and support member being eccentric to one another when the seal member occupies the relaxed condition, the seal member being compressible towards a compressed condition in which the seal member and the support member are of substantially equal diameter and are substantially coaxial.

Abstract: A seal for acceptance in an annular gland in a piston comprises an annular primary sealing element, an annular secondary sealing element disposed radially inwardly of the primary sealing element, and a pair of axially spaced back up rings disposed in axially spaced relation on opposite sides of the primary sealing element and having radially inner portions, respectively, engaged with the primary sealing element so as to lock the backup rings in the gland of the piston.

Abstract: A packing seal is provided which is intended in particular for reciprocating piston engines and which can be placed into a circumferential groove of a piston of such a reciprocating piston engine. The packing seal includes a first segment ring (1), which has at least two sealing segments (3) and locking segments (4) arranged between them in alternating order. These locking segments (4) and sealing segments (3) taper wedge-shaped in opposite directions radially inward and outward, respectively. In addition, the packing seal includes at least one additional or second segment ring (20) which also has at least two sealing segments (23) and locking segments (24) arranged between them in alternating order. The sealing segments (23) and locking segments (24) both taper radially inward in this case. The locking segments (24) extend over a larger arc area than the sealing segments (23).

Abstract: A sealing arrangement for establishing a seal between two machine elements, such as a rod or piston undergoing axial motion within a housing. A rod or piston seal is arranged in a groove of the second machine element, which typically is the housing of the rod or piston. The groove is open in the direction of the first machine element, and contains a seal ring and a prestress ring made of elastomeric material. The seal ring has an essentially T-shaped cross-section and touches the surface of the first machine element which is to be sealed with the sealing surface of its radial ridge, forming a seal. The prestress ring is arranged between the base of the groove and the axial ridge of the seal ring, under elastic prestress. The transition from the faces of the radial ridge to the sealing surface is rounded.

Abstract: A seal for acceptance in an annular gland in a piston comprises an annular primary sealing element, an annular secondary sealing element disposed radially inwardly of the primary sealing element, and a pair of axially spaced back up rings disposed in axially spaced relation on opposite sides of the primary sealing element and having radially inner portions, respectively, engaged with the primary sealing element so as to lock the backup rings in the gland of the piston.