Abstract: A piston for a high temperature internal combustion engine is provided. The piston includes an upper wall, base wall, outer rib, and inner rib defining a cooling chamber therebetween, and a plurality of ring grooves formed in the outer rib. Only the second ring groove is formed with the keystone cross-section, and all of the other ring grooves are formed with the conventional rectangular cross-section. Thus, the piston can be formed with low manufacturing costs and can also provide exceptional performance when used in high temperature combustion engines, wherein the temperature at the first ring groove is greater than 280° C., and thus prevents carbon from depositing or burns off any carbon deposits, but the temperature at the second ring groove is between 200° C. and 280° C., in which case carbon deposits can form and cause the piston ring to stick.

Abstract: The present disclosure generally relates to sealing a bonnet in a valve system. Using novel combinations of seals and gaskets, the present systems can prevent fugitive emissions in a high pressure piping system. For example, in certain embodiments, the present systems combine spring energized seals, O-rings, and PTFE spacers in a bonnet to create a gas-tight seal in a fluid transportation system.

Abstract: The present invention relates to a fluidic cylinder. This fluidic cylinder is configured in such a manner that a piston unit is received in an axially displaceable manner within a cylinder tube formed in a rectangular cross-sectional shape. The piston unit has: a base body having the front end of a piston rod staked thereto; a wear ring having the base body received therein and having a magnet incorporated therein; and piston packing adjacent to the wear ring. The piston unit is integrally held at one end of the piston rod. The wear ring and the piston packing are formed in a rectangular cross-sectional shape corresponding to the rectangular cross-sectional shape of the cylinder tube and are provided rotatable relative to the piston rod.

Abstract: Seal with a body that has bilateral symmetry. The body comprises of a first sealing lip on a right side of the body and a second sealing lip on the right side of the body that is positioned radially below and axially inward with respect to the first sealing lip. The body further comprises of a third sealing lip on a left side of the body and a fourth sealing lip on the left side of the body positioned radially below and axially inward with respect to the third sealing lip. In the installed position, the first sealing lip is flexed away from the second sealing lip and the third sealing lip is flexed away from the fourth sealing lip.

Abstract: A dust preventing seal may include a body and first and second dust lips. The body may be installed at a locking portion between an arm and a bucket of a construction machine. The body may have an annular shape. The first and second dust lips may be protruded from an outer surface of the body to the outside.

Abstract: The pressure of compressed air supplied to an object to be filled with air is controlled at a specified pressure or less without using a relief valve. Given that a cylinder volume (stroke volume) during a piston moves from the lower dead point to the top dead point is V1, a cylinder volume (compression volume) when the piston reaches the top dead point is V2, the atmospheric pressure is P0, and the specified pressure is PP, the compression volume V2 in the compressor system satisfies the following expression (1). The diameter D of the air intake hole of an air intake valve provided on the piston is 3 to 15 mm. 0.8×{V1×P0/(PP?P0)}=<V2<1.

Abstract: A seal element for sealing a conduit is described. The seal element comprises a frusto conical portion and a first lip extending from an external edge of the frusto conical portion, the lip being adapted to be pivoted into engagement with a conduit surface. In a described embodiment, two seal elements are provided on a plug for sealing a conduit, the seal elements facing in opposite directions to seal from above and below.

Abstract: A seal for a cross member unit for universal joints has a carrier ring to be inserted into a bearing cup of the cross member unit. The carrier ring has an L-shaped cross section with a cylindrical portion coaxial to a longitudinal axis and a flange portion extending form the cylindrical portion inwardly. An elastomeric sealing lip element is connected to the carrier ring. The sealing lip element has first engagement elements form fittingly engaging into first engagement apertures. The first engagement apertures extend through the flange portion of the carrier ring. The sealing lip element further has second engagement elements form fittingly engaging into second engagement apertures. The second engagement apertures extend through the cylindrical portion of the carrier ring.

Abstract: A circumferential wall of a circumferential groove near a bottom section of a cylinder main body has an outer wall section extending from a bottom section of the circumferential groove in a radial direction of the cylinder main body, a stepped surface section extending from the outer wall section in a bottom direction of the cylinder main body, and an inner wall section having a flat surface section parallel to the radial direction of the cylinder main body and formed further inside in the radial direction of the cylinder main body than the stepped surface section. The inner wall section is formed at a position at which the center lip section first abuts the inner wall section prior to the outer wall section when the seal member moves toward the bottom section of the cylinder main body.

Abstract: A two-stage seal, such as a ring seal for use in a pressurized process fluid line, has a dynamic sealing member and a static sealing member. The dynamic sealing member is arranged to continuously sealingly engage against a seal surface that slides along the dynamic sealing member. The static sealing member is arranged to sealingly engage against the seal surface in response to an increased process fluid pressure within the process fluid line to increase static seal pressure against the seal surface. The static sealing member is also arranged to release from the seal surface to minimize friction with the seal surface when the process fluid pressure drops and/or in response to movement of the seal surface. The two-stage seal may be used in arrangements requiring both dynamic sealing and static sealing, such as in some process control valves. A process control valve having the two-stage seal is disclosed.

Abstract: A pin clamp has a housing with a bore. A piston is coupled to a shaft, where the piston is in sliding engagement with the bore. The housing has first and second ports on opposing sides of the piston. A clamping arm coupled to the shaft extends and retracts with respect to the locating pin. A check valve is in the housing, where the check valve selectively maintains a pneumatic pressure on one of the first and second axial sides of the piston when pneumatic pressure is removed from the respective first or second axial side of the piston. One or more passages are further defined within the housing, defining a pneumatic circuit coupling the first port, second port, check valve, and a volume associated the bore. The check valve can be a pilot-operated check valve that is configured to be selectively energized by an application of pneumatic pressure.

Abstract: A linear actuator has a housing with a bore extending therethrough. A first portion of the bore extends into the housing from a first end, and a second portion of the bore extends into the housing from a second end of the housing. The second portion of the bore has a rectangular geometry with substantially rounded corners when viewed from the second end. A shaft is in sliding engagement with the first portion of the housing. A piston member is coupled to the shaft and has a rectangular geometry with substantially rounded corners. The piston member is in sliding engagement with a first interior surface of the second portion of the bore via one or more o-rings. An anti-rotation apparatus is associated with one or more of the piston member and the shaft, wherein the anti-rotation member generally prevents a rotation of the shaft with respect to the housing.

Abstract: A pin clamp is provided, comprising a housing having a bore extending therethrough, therein defining an axis. A shaft in sliding engagement with at least a first portion of the bore comprises an axial hole. A piston coupled to the shaft is in sliding engagement with a second portion of the bore. A clevis has a clevis base and two clevis prongs extending along the axis. The clevis base an axial hole and first and second radial clevis holes, wherein the first and second radial clevis holes are opposed to one another by 90-degrees. The axial hole accepts the shaft, and the clevis base is coupled to the shaft in one of four 90-degree-opposed positions by a screw passing through one of the first and second radial clevis holes and the axial hole. Each clevis prong has a radial prong hole. A locating pin has a mounting portion configured to be coupled to the housing in one of the four 90-degree-opposed positions.

Abstract: A landing collar having a housing, a first sleeve configured to receive a lead wiper plug, and a latching mechanism configured to couple the first sleeve to an inner wall of the housing. The latching mechanism including a c-ring coupled to the housing and a landing insert disposed within the c-ring.

Abstract: Disclosed is a sealing member for a master cylinder. The sealing member for a master cylinder, which is formed in a ring shape and is installed between an inner surface of a cylinder body and an outer surface of a piston, includes an inner wing part configured to contact the outer surface of the piston, an outer wing part configured to contact the inner surface of the cylinder body, and a sealing rear wall part configured to connect the inner wing part and the outer wing part. The sealing rear wall part is provided with an oil passage to connect an oil entrance formed at the inner wing part and an oil entrance formed at the outer wing part, and the oil passage includes a retardation passage which is longer than a shortest straight-line distance which directly connects the oil entrances.

Abstract: A spring (1) with fluid (2) including a containment body (3) having an inner chamber (4) in which the fluid (2) is inserted, a compression unit (8) slidably mounted on the containment body (3) and a sealing gasket (11) for the fluid (2) interposed between the containment body (3) and the compression unit (8) for preventing escape of the fluid (2) from the inner chamber (4); the spring (1) includes at least one closed loop (13) surrounding the compression unit (8), connected to the containment body (3) and in contact with the sealing gasket (11) so as to limit the deformation of the latter.

Abstract: An annular sealing device for a shaft and housing that can maintain sealing properties under fluid pressure load when creep occurs in a cut portion due to thermal expansion and the perimeter is shortened. The sealing device includes a seal ring unit configured to fit within an annular groove in the shaft, and has, on the side thereof where the outer periphery is located, a sliding surface on which the seal ring unit slides on the housing; and a lip portion on the inner periphery of the seal ring. The lip portion of tip is disposed on the side of the annular groove where a groove bottom thereof is located, in such a way that the tip thereof is deformable in a direction in which the tip increases the distance between the seal ring unit and the groove bottom of the annular groove when under pressure.

Abstract: An annular seal member configured to seal a gap between a shaft hole and a shaft inserted into the shaft hole, the annular seal member comprises: an annular base part; an annular lip, which includes a lip edge that is configured to be contact with one of a hole face of a shaft hole and an outer periphery of a shaft, the one of which is a seal mating face; a first convex part, a second convex part and a passage recess, which is provided at a face of the base part facing the seal mating face; a concave part, which is formed at a position between the second convex part and the base end portion of the annular lip, and which has a circumferential size larger than a recess width of the passage recess.

Abstract: Master cylinder for a hydraulic braking circuit, particularly for a motor vehicle, comprising an annular seal (1) placed in a housing (6) of the body comprising an internal dynamic sealing lip (14) surrounding the piston, fitting into an annular groove (20) of the piston when this piston is in a rear rest position, an outer static sealing lip (10) pressing against a wall of the housing, and an additional static sealing lip (16) which presses against a wall of the housing of this seal and with the outer lip defines a small closed volume (V) of liquid.

Abstract: A bonded piston seal, which comprises a metal ring, and a rubbery elastomer seal as vulcanization-bonded thereto expect the sliding site along which a mating seal member slides, where the rubbery elastomer seal is partially bonded to the metal ring through an adhesive layer, wherein the adhesive layers comprises (a) an underlayer adhesive layer comprising a phenol resin and an epoxy resin, and (b) an overlayer adhesive layer comprising a phenol resin, a halogenated polymer, and a metal oxide. Not only the distinguished initial adhesiveness, but also the distinguished water-resistance can be obtained by providing (a) the underlayer adhesive layer of the afore-mentioned components and (b) the overlayer adhesive layer of the afore-mentioned components.

Abstract: A device to enhance sealing is provided. The device includes a body and a pressure cup. The pressure cup includes a channel, a first pressure channel, and a second pressure channel. The channel is formed in a surface of the body to surround a first portion of the surface. The channel is configured to hold an o-ring. The first pressure channel extends through the body and opens into the first portion of the surface. The second pressure channel extends through the body and opens into the channel. Pneumatic pressure within the second pressure channel is controlled to hold the o-ring in the channel when a second pressure within the first pressure channel changes.

Abstract: A seal is disclosed, for sealing a seal surface (5) between two machine parts (6, 7) which move relative to each other, wherein a seal body of the seal (1) comprises a retainer piece (10), arranged towards the groove base in a groove (8) in one of the machine parts (7), a sealing part (11), arranged in the groove (8) facing the sealing surface and a resilient connector part (12) between the sealing part (11) and the retaining part (10). The seal (1) has a recess (21) between the retainer part (10) and the connector part (12) and a further recess (20) between the connector part (12) and the sealing part (11). The seal (1) has spacer elements (25), said spacer elements (25) extending into at least one of the recesses (20, 21), preferably at least into the recesses (20) between the sealing part (11) and the connector part (12).

Abstract: The piston seal member is formed of a crosslinked rubber composition, the rubber composition including 100 parts by weight of an ethylene-propylene rubber, 20 to 60 parts by weight of a first carbon black, 50 to 100 parts by weight of a second carbon black, and 5 to 20 parts by weight of carbon nanofiber having an average diameter of 0.5 to 500 nm, the total amount of the first carbon black and the second carbon black being 70 to 160 parts by weight. The first carbon black has an average particle diameter of 35 to 100 nm and a DBP absorption of 50 to 200 ml/100 g. The second carbon black has an average particle diameter that is greater than the average particle diameter of the first carbon black and ranges from 60 to 500 nm and a DBP absorption of 5 to 50 ml/100 g.

Abstract: The present invention provides a seal assembly for sealing between two relatively slideable members of non-circular cross-section. A plurality of adjacent seal members may be staggered and grouped within a groove so that all leakage surfaces between the two relatively slideable members are sealed. Multiple seal members or seal member groups may be used to reduce leakage caused by incomplete contact of the seal members with leakage surfaces. An actuator system may comprise various embodiments of the present invention to enable the actuation of one member in relation to another.

Abstract: A two-stroke internal combustion engine having a seal assembly disposed between a piston and a running surface. The seal both lubricates and prevents exhaust of combustion gases. A first element, which ensures gas tightness, is received in a countersunk portion of the running surface. A second element, which ensures oil tightness, is partially embedded into the first element. A biasing element presses the second element against the first element so that the second and third elements are at least partially held within the first element.

Abstract: A compact simplified compressor apparatus is provided with a rotating shaft rotationally driven by a motor, a compact compressor activated by the rotating shaft, an air feeding means for feeding a high-pressure air from the compact compressor to a tire, and a power source plug supplying an electricity to the motor. The compact compressor is provided with a rod attached to the rotating shaft via a crank, a piston having a peripheral groove in an outer peripheral surface and integrally formed with the rod, a cylinder having a cylinder chamber receiving the piston so as to freely reciprocate, and a ring seal sealing between the piston and an inner peripheral surface of the cylinder chamber. The ring seal is provided with a base portion having a base surface seating on a groove wall surface in the rod side of the peripheral groove, and inner and outer lip portions, each extending from the base portion toward radially inside and outside so as to be opened toward the opposite rod side.

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: A hydraulic accumulator includes a piston (3) capable of moving in an accumulator housing (1) in its axial direction and separating a gas side (5) from a liquid side (7) of the accumulator housing (1). Guide elements (9, 17) designed to co-operate with the accumulator housing wall (1), as well as at least one sealing element (15), are arranged at the periphery of the piston. The sealing element is arranged offset in the axial direction relative to the guide elements (9, 17), and is located between the guide elements. In the piston (3), a pressure compensating channel (19) forms, at the piston periphery, a liquid flow path between the liquid side (7) and a space (2) located between the guide element (17) nearest to the liquid side (7) and the sealing element immediately next in the axial direction. A device (25) reducing the cross-section of the passage of the pressure compensating channel (19) is located in it.

Abstract: The annular sealing cup with axis ?, a so-called replenishment cup, which is intended to be positioned between a hydraulic cylinder and piston and which has a <<U>> axial section and has application to braking circuits comprises: a static branch (10) defining a static sealing annular lip, a dynamic branch (12) defining a dynamic sealing annular lip, and a core (14) connecting the static (10) and dynamic (12) branches and defining a annular bead (15) opposite the lips. According to the invention, the cup is characterized in that the connecting surface (24) between the static branch (10) and the core (14), located opposite the bead (15), has a concave shape corresponding to a local reduction in the thicknesses of the static branch (10) and of the core (14) at the connecting region between the static lip and the core (14), so as to define a rotation area (21).

Abstract: A sealing material for sealing liquid composed of a seal main body of resin, having a U-shaped cross section and a concave groove opening to an axis direction, and an O-ring of rubber fit to the concave groove of the seal main body used for medical appliances and paint appliances. The seal main body is provided with an end lip portion on a side along the axis direction and a main lip portion on a middle position of the axis direction on a sliding face side, and, in a pressure-receiving state in which pressure works on the side along the axis direction and the O-ring is compressed, a dimension of the axis direction from a base end face of the seal main body on other side along the axis to a cross-section central point of the O-ring and another dimension of the axis direction from the base end face to an end portion of the main lip portion are set to be approximately equal.

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 secondary seal gasket is formed of a graphite material for higher temperature applications. The gasket is formed by multiple wraps of a graphite ribbon and then is shaped in a mold to provide a U-shaped cross-sectional configuration having a self-energizing spring disposed therein. The gasket is formed from an L-shaped ribbon wrap having additional ribbon overwraps thereon to define a gasket ring which is then molded in a die press to form the U-shape. The L-shaped ribbon wrap thereby extends axially and then radially outwardly to define an end wall of the gasket to impede migration of fluid between the axial ribbon wraps.

Abstract: A lubricant injector having a body containing a reciprocal piston for dispensing lubricant from the body, a pin extending from the piston through an opening in the body, and a sealing assembly in the opening surrounding the pin for sealing against leakage of lubricant from the body along the pin. The sealing assembly includes a low-pressure sealing member for sealing at low pressures, and a high-pressure sealing member for sealing at higher pressures. The injector includes a measuring chamber, venting of the injector involving transmission of lubricant from its inlet to the measuring chamber.

Abstract: A relief valve is provided with an elastic body seal sealed into an annular gap between a ball receiver and a valve hole, and is slidably in contact with an inner periphery of the valve hole such that the elastic body seal is not compressed in an axial direction of the ball receiver.

Abstract: The invention relates to a combustion gas seal for injectors and to a seal structure disposed therewith, for preventing leakage of combustion gas in a state in which an injector is mounted to an engine head. And, the number of parts is reduced, vibration and noise are reduced, and sealing performance is improved. A tapered surface, in which an clearance between the tapered surface and an inner peripheral surface of a mounting hole of the engine head narrows from an engine bore side towards an atmospheric side, is disposed at a groove bottom of an attachment groove of the injector, and an abutment portion that abuts against the tapered surface is disposed at the combustion gas seal for injectors.

Abstract: Seal sections, which support first and second piston rods, are provided on inner circumferential surfaces of first and second cover members of a cylinder mechanism. A lubricant is supplied via supply passages and oil supply ports to first oil-retaining members, which are installed in installation grooves provided in the seal sections. The lubricant, which has characteristics different from those of an operation oil used for driving a piston of the cylinder mechanism, is retained by the first oil-retaining members. Further, the lubricant is supplied to clearances formed between the first and second cover members and the first and second piston rods, thereby forming an oil film.

Abstract: The annular sealing cup with axis &Dgr;, a so-called replenishment cup, which is intended to be positioned between a hydraulic cylinder and piston and which has a <<U>> axial section comprises

Abstract: The present invention discloses a sealing insert, in particular for a piston in a hydraulic brake system, comprising a central valve arranged in a cavity, a supporting body and a rubber-elastic sealing body that is adhesively connected to said supporting body. The supporting body exhibits through holes which are penetrated by the sealing body for fixing purposes.

Abstract: A wiper having an integrated seal, comprising at least one dynamically stressed, first sealing lip arranged in the direction of a space to be sealed, and at least one wiping lip disposed on the side facing away from the space to be sealed. The wiper having an integrated seal also includes quasi-statically stressed second, third and fourth sealing lips which are each configured to be placed against at least one counter-surface of a mounting space of the wiper with integrated seal. The second sealing lip is fluid-conductive. The third and fourth sealing lips are each configured as a pressure relief valve, and sealing lips are arranged in series.

Abstract: A metal-to-metal seal assembly provides a dynamic seal between a piston and a cylinder. A first seal engages the inner diameter of the piston, while a second seal engages an outer diameter of the piston. The piston is disposed between an inner mandrel and an outer tubular member that form an annular space therebetween. The seal uses a hollow seal ring is provided having a “C”-shaped cross section and containing a coiled spring. The seals form an interference fit against the mandrel and tubular member.

Abstract: In a fuel injector having a plunger-and-barrel pumping assembly, a sealing member is mounted within an annulus of a plunger to prevent the dilution of pressurized fuel within the barrel of the tool. The sealing member includes a hollowed cavity which traps upward moving pressurized fuel and forces an extension or wiper of the sealing member upward and outward into sealing engagement with the inner surface or bore of the barrel.

Abstract: A pressure regulator uses a pliable seal to segregate a pressure confinement volume from the remaining cylinder volume. The pliable seal has a cross section comprising a pair of apexes that are disposed into grooves incorporated into the piston and the cylinder internal wall. The radii of the pliable seal establish a rolling contact to ensure pressure seal in the presence of seal deformation. The seal promotes linear regulator response and minimizes hysteresis causes by frictional forces of prior art piston rings.

Abstract: A combined oil ring is comprised of an oil ring and an expander. The cross section of the oil ring is a generally I-shape, and the outer circumferential surfaces of outer rail portions form sliding surfaces to make contact with the cylinder wall surface. The cross section of an expander installation groove formed on the inner circumferential surface of the oil ring is formed in a rectangular shape, and an expander formed of axially corrugated ring-shaped plate material is mounted in the expander installation groove. The expander is formed by forming a rectangular cross sectional plate material in a corrugated shape in the direction of plate thickness and further forming in a ring shape. The expander installation groove of the oil ring is not limited to a rectangular shaped cross section.

Abstract: The present invention aims at reducing the amount of oil consumption in a piston using a piston ring continuously formed of resin without being provided with an abutment. A stepped portion is formed on a third land, which is located below a second ring having a construction wherein an outer ring continuously formed of polyimide without being provided with an abutment is pressed against a cylinder wall by a coil expander via an inner ring continuously formed of PTFE without being provided with an abutment. Oil spill ports are provided so as to allow communication between the stepped portion and an inner wall of the piston.

Abstract: A piston rod seal includes a sealing disk provided with a reinforcement element, a guide mechanism, and a support piece which are adapted to be placed consecutively in a metal pipe or similar object functioning as a housing, and which are adapted to surround a piston rod when installed. To create a seal having relatively few components and a relatively small axial dimension, the reinforcement element is connected to the sealing disk and is constructed to function as a guide element for guiding the axial movement of the piston rod.

Abstract: The invention provides a submersible pumping system which includes a motor containing self-centering rotor bearing assemblies. Each rotor bearing assembly in accordance with the present invention includes a sleeve, a journal, and at least two seals. The journal is preferably disposed about the sleeve which is keyed to the power transmission shaft of the motor. The journal has a peripheral surface which is configured to have at least two circumferential support regions which are spaced apart from one another. Each of these circumferential support regions supports a corresponding seal. Each seal includes an interface member and an activating member. When in place in a rotor section of a submersible pump motor, the seals frictionally engage the inner surface of the stator and exert a centering force against the journal and thus against the bearing sleeve and the power transmission shaft.

Abstract: A continuous compression ring and a continuous oil control ring for a piston reciprocally operable in a combustion cylinder of an IC engine, the continuous compression ring being cooperatively receivable in a groove extending around the piston and having a generally G-shaped cross-sectional shape including a circumferentially extending lip positioned to be located radially outwardly of a cylindrical outer surface extending around the piston, the lip adapted for forming a substantially sealed condition around the piston in cooperation with an oil film on the combustion cylinder wall, the continuous oil control ring being cooperatively receivable in another groove extending around the piston and having a generally n-shaped cross-sectional shape including a circumferentially extending leg portion adapted to be positioned radially outwardly of the outer surface of the piston around the piston for scraping the oil film on the combustion cylinder wall during the reciprocal operation of the piston in the combustion

Abstract: A gas valve has a solenoid actuator which is energized to open the valve an de-energized to permit spring closure of the valve. A seal element is secured on the armature of the solenoid armature. The seal element has a skirt portion which sealingly engages an armature sleeve to inhibit exhaust gas vapors from entering the chamber housing the solenoid coil and electronic sensing elements. The solenoid actuator has a pole piece defining one end of the chamber. A plurality of vent slots formed in the pole piece provide communication to atmosphere for the chamber to permit removal of any inadvertent intrusion by moisture or vapor.

Abstract: An elastomer ring seal for pressurized fluids that is particularly suited for preventing unidirectional fluid flow between outer and inner cylindrical surfaces of two or more mating members, which resists permanent deformation, and is highly leak resistant.The ring seal has an annular body with a central longitudinal axis and an irregular polygonal profile in right cross section comprising a solid base portion at its back axial end, concentric outer and inner asymmetrical independent arm members axially extending from said base portion to its front axial end. The arm members are set apart from each other by a deep annular depression which forms opposing radial walls of said arm members.The outer arm, configured to resist compression strain, includes; an outermost radial sealing portion near midpoint along the arm length; and includes a supporting narrow section toward the base portion, forming a thin flexible conical band around the ring seal outer side.