Abstract: A piston assembly is provided for a human-powered vehicle. The piston assembly includes a main body and a primary seal. The main body is configured to be movable from a rest position to an actuated position along an actuation direction in a cylinder bore. The primary seal includes a primary seal body arranged on the main body. The primary seal body is made of a resin material. The main body includes a first part and a second part. The first part is at least partly arranged upstream of the primary seal with respect to the actuation direction. The second part is coupled to the first part to be at least partly arranged downstream of the primary seal with respect to the actuation direction. The at least one of the first part and the second part includes a support portion supporting the primary seal.

Abstract: The bearing component comprises a contact surface inside a periphery, which surrounds a centre, and a coupling feature arranged inside the periphery for rotatably engaging a component of a piston rod perpendicular to the contact surface. The coupling feature includes at least one flexible feature extending from the periphery towards the centre, and the flexible feature is arranged to be deflected towards the periphery by a force exerted on the flexible feature in a direction towards the contact surface and deflected towards the centre by a force exerted on the flexible feature in the opposite direction. The flexible feature may have a sloping surface facilitating assembly and preventing disassembly in combination with a further component of the piston rod. The component of the piston rod may be a lead screw, and the piston rod may be used in a drug delivery device.

Abstract: A damper includes a piston provided with a rod, and a housing storing the piston, and generates a braking force by an operation of the piston. The piston includes a seal member relative to an inner wall of the housing; and a slider contacting the inner wall of the housing with a predetermined frictional force. When the braking force is generated, the slider presses against the seal member, and a portion contacting the inner wall of the housing in the seal member deforms toward an outside of the housing. At an inner side of the portion contacting the inner wall of the housing in the seal member, a deformation control portion is provided, which suppresses the seal member from deforming toward an inside of the housing.

Abstract: The present disclosure provides for a syringe that is designed to enable a plunger to be locked or secured in position thereby freeing a user's hand from the plunger for other tasks. The syringe may be coupled to a needle or hypodermic needle or other apparatus such as an intravenous line/port or catheter. The syringe takes advantage of a tapered barrel and a positive stop to prevent movement of the piston along the inner surface of the barrel when no force is being actively applied to the plunger. This prevents unwanted suction or spillage of the contents contained therein.

Abstract: A vehicular hydraulic braking pump includes a sleeve having an inner bore defining an inner bore surface and a piston having a stop collar and a ramped seal face. The stop collar, ramped seal face, and the inner bore cooperating to define a seal pocket which traps a high pressure seal therein. The ramped seal face provides contact of the high pressure seal to the sleeve inner bore that is proportional to fluid pressure acting on the high pressure seal.

Abstract: The invention relates to a pneumatic brake cylinder including a piston for transferring the pneumatic pressure to a brake, a pressure chamber defined by the piston and part of the inner wall of the brake cylinder, and a sealing ring sealing a gap between the piston and the inner wall of the brake cylinder. According to the invention, the sealing ring is vulcanised onto the piston.

Abstract: A sealing member for a piston slidably disposed within the cylinder bore of a hydraulic system includes a seal body having an outer sealing surface arranged to contact the cylinder bore and a glide ring at least partially disposed within the outer sealing surface of the seal body. The glide ring includes an outer surface and the outer sealing surface of the seal body includes at least one seal lip projecting beyond the outer surface of the glide ring.

Abstract: In one aspect, a brake pump assembly with a hydraulic block and a pumping element including a polymer piston that is received in a piston bore. A circumference of the polymer piston defines a high-pressure seal slideably engaging adjacent structure. The polymer piston may include a peripheral sealing lip projecting primarily longitudinally from the polymer piston for sealing engagement with the piston bore. In another aspect, a brake pump assembly with a hydraulic block, a straight bore polymer piston, a peripheral sealing lip projecting from a proximal portion of the polymer piston, and a elastomeric seal mounted to a distal portion of the polymer piston, where the peripheral sealing lip selectively acts to depressurize fluid accumulating between the peripheral sealing lip and elastomeric seal.

Abstract: The invention relates to a method for producing essentially rotationally symmetrical, undercut contours on workpieces (13) that can for example be produced by forging or casting, said workpieces having at least one sub-section (14) to be machined with an essentially symmetrical initial contour. The workpiece (13) is braced by the end that is not to be machined in a recess (11) and when in said recess (11) the sub-section (14) of the workpiece that is to be machined is placed against a tool (12). The tool (12) rotates with a constant or variable speed in relation to the sub-section (14) of the workpiece (13) that is to be machined. An undercut contour is thus produced on the sub-section (14) of the workpiece (13) by machining under the axial pressure.

Abstract: A lip ring is attached to a piston so as to be rotatable relative to the piston in a circumferential direction, and a seal portion is provided between a ring attachment groove of the piston and an attachment portion of the lip ring. During a suction stroke, the lip ring can be rotated in a circumferential direction of the piston, thus distributing wear around the entire periphery of a lip portion of the lip ring. During a compression stroke, leakage of air from a compression chamber can be prevented by means of the seal portion provided between the ring attachment groove and the lip ring.

Abstract: A piston for an air pump is disclosed. The piston has a piston rod having a connecting axle hole for positioning a bearing, which is protected with a bearing protection cap. The bearing is firmly secured within the axle hole.

Abstract: A plunger for being inserted in a tubular barrel in an axially movable manner includes a plunger body having a distal end positioned within the barrel and a proximal end positioned outside of the barrel, and a seal member disposed on the distal end of the plunger body. The seal member has a base portion extending from the plunger body towards the distal end of the barrel, and a flange portion radially outwardly extending from the base portion and having a peripheral edge contacting an inner circumference of the barrel so as to define an accommodation space within the barrel.

Abstract: A sealing structure is provided with a seal member for sealing a double fitting portion where an annular member is fit in the internal surface of an outer member at its outer circumferential surface and is also fit on the outer circumferential surface of an inner member at its internal surface. In the sealing structure, the seal member is attached to an end surface of the annular member with an annular groove on its back surface being fit on an annular projection axially protruding from an end surface of the annular member at a radially mid position. At its forward end surface, the seal member is provided with annular outer and inner lips which are axially protruded for respective contacts with the internal surface of the outer member and the outer circumferential surface of the inner member, and is further provided an annular separation zone between the annular outer and inner lips.

Abstract: A method of forming a floating piston includes fabricating a piston cup, wherein the piston cup includes a top, a sidewall void of any seal-gripping irregularities, and an open end, and forming an elastomer seal over the sidewall of the piston cup. A floating piston includes a piston cup having a top, a sidewall extending about the periphery of the top and an open end, wherein the sidewall is void of any seal-gripping irregularities; and an elastomer seal formed about the sidewall of the piston cup.

Abstract: A pressure fluid-delivery device comprising a cylinder (1), a piston (2) and a reservoir (61) for a fluid. A V-seal (10) is mounted in an annulus between the cylinder (1) and the piston (2). An axial movement of the piston (2) forwards relative to the cylinder (1) results in a delivery of a pressure fluid from the cylinder space (40). A first leg (12), in a similar fashion to a check valve, hereby springingly attempts to seal an outlet opening (43) of a channel (30) which communicates with the reservoir (61). When the piston is moved backwards, this leg (12) can open the outlet opening (43), admitting fluid into the cylinder space (40). The seal (10) rests on a forwardly facing, radially outwardly extending surface (6) of the piston (2). The seal's (10) first leg (12) projects slantingly radially inwards and is arranged to come into abutment against an axially extending portion (3) of the piston.

Abstract: The present invention is directed to a wobble piston and seal assembly for an oil free compressor. An upwardly directed curvature is provided on a piston surface which supports the seal. The curvature is located adjacent the perimeter of the surface to impart a slight dish shape to the surface. Preferably, the curvature has the same radius as the bend radius of the seal when the piston head is inserted into a cylinder. When the seal is initially clamped to the support surface, the seal is formed to take on the curvature of the support surface. Consequently, the seal is preformed into a shallow cup shape prior to final forming when the piston and seal assembly are inserted into a cylinder.

Abstract: An improved wobble piston and seal assembly for an oil free air compressor. The piston has a seal support surface which is provided with an upwardly directed curve adjacent its perimeter. A flat annular seal is secured to the piston to be supported by the support surface. The curve imparts a limited bend to the seal adjacent the perimeter of the piston. The piston and seal are then inserted into a cylinder which increases the bend to substantially 90°. The region of the bend in the seal adjacent the top of the piston is supported by the curved top to reduce flexing during operation at high air pressures. By preventing a reduction in the bend radius at high air pressures, stress in the seal at the bend is reduced, permitting use of a harder more durable seal material.

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

Abstract: A novel reciprocating pump for cryogenic fluids. The pump has a cylinder sleeve, head, intake valve, discharge valve, and a reciprocating piston including a mechanical spring energized seal having a generally U-shaped jacket and a helical spring in the bight of the U.

Abstract: A piston head assembly for reciprocating in a cylinder is disclosed, the cylinder having an inside surface and the inside surface having an inside diameter, comprising: a piston head including a central portion and a flange, the flange having a diameter that is no more than 0.010 inches less than the inside diameter and an annular seal removably mounted on the flange, the seal including a lip and a heel, the lip having an uncompressed diameter that is at least 0.20 inches larger than the inside diameter and the heel being free of a separate retaining means. The seal can also be manufactured so as to be free of any annular depression in its outer surface.

Abstract: A piston having a body member made from plastic material adapted for mounting to a piston rod for axial movement with the piston rod in a hydraulic cylinder under high working pressure conditions is disclosed. The plastic piston body member has a first axial end portion, an opposite second axial end portion, an outer circumferential surface portion adapted to be located in intimate relation with a cylinder wall of the hydraulic cylinder when the piston is positioned for axial movement therein, and an inner peripheral surface portion defining a centrally located axially extending aperture through the body member adapted for cooperatively receiving a mounting portion of the piston rod, one of the axial end portions being positioned to abut an adjacent shoulder of the piston rod when the mounting portion of the piston rod is located in a fully received position in the aperture.

Abstract: A piston assembly comprising a piston sleeve having an interior wall, a piston carried in the piston sleeve, a cup seal carried by the piston which engages the interior wall of the piston sleeve, and a valve plate matingly adapted to receive the piston sleeve. A firm thermal-insulating barrier is disposed between the valve plate and the piston sleeve for reducing the heat flow from the valve plate to the piston sleeve.

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

Abstract: An external slave cylinder particularly suited for use in a hydraulic clutch release system for a motor vehicle. The cylinder includes a cylindrical body defining a bore, a piston slidably mounted in the bore, a seal positioned between the piston and the bore, a pushrod engaging the rear end of the piston and extending out of the bore, and a preload spring. The spring comprises a conical coil spring positioned exteriorly of the bore, bearing at the reduced diameter rear end thereof against the rear end of the pushrod, and bearing at the large diameter front end thereof against the rear end of the body in surrounding relation to the pushrod. The seal has a cup-shaped configuration and fits over a nose portion provided on the front end of the piston. The seal includes a peripheral lip portion sealingly engaging the bore and a base portion closing the area within the peripheral lip portion and seated against the front end of the piston.

Abstract: A slave cylinder of the annular cylinder type is proposed, whereof the annular piston (45) able to slide axially between an outer cylinder wall (29) and an inner cylinder wall (33) is sealed by a grooved sealing ring (53) with respect to the pressure chamber (37). In order to be able to evacuate by means of a suction pump a hydraulic actuating system for a motor vehicle friction clutch, constructed using a slave cylinder of this type, before filling with hydraulic fluid, means are provided on the annular cylinder or in addition to the sealing lips (57) on the grooved sealing ring, which increase the sealing action of the sealing lips (57) when applying a vacuum to the hydraulic pressure chamber (37). The said means may be conical surfaces (61, 63) on the cylinder walls or a conical ring engaging in an annular groove (59) of the sealing ring (53). Additional sealing beads having a cross-sectional contour in the shape of a circular sector may be formed if necessary on the grooved sealing ring.

Abstract: Piston sealing and dampening device in a pressurized-fluid cylinder, where a piston (3) has a central recess (3a) facing towards a cylinder end cap (1a) and disposed such that when the piston is in the vicinity of its end position, said recess accommodates a sleeve portion (5) provided with an internal pressurized-fluid connection (6) and projecting from the cylinder end cap. An integrated sealing ring (10) seals against the outside of the sleeve portion (5) with an inner sealing ring lip (10e) and against the inside of the cylinder tube (2) with an outer sealing ring lip (10c).

Abstract: A piston for a door closer comprises metal cups on opposite ends of a stem. A plastics ring is a snap-fit in one of the cups and protrudes from that cup to seal against the wall of a cylinder. A groove in the side wall of the cup for receiving a rib on the ring is formed by pressing a substantially flat blank before the blank is formed into the cup.

Abstract: An annular elastomeric seal, a piston utilizing the seal, and a fluid cylinder assembly utilizing the seal. The seal includes an axially forward portion defining a circumferentially inner and a circumferentially outer deflectable lip seal and an axially rearward portion defining a circumferentially inner and a circumferentially outer arcuate heel seal. When positioned in an annular groove in a piston and with the piston slidably received in the bore of a cylinder, the annular seal provides fluid pressure sealing at the deflectable lip seals, provides secondary fluid pressure sealing at the arcuate heel seals, provides air sealing at the arcuate heel seals, and functions at the arcuate heel seals to preclude the entry of contaminants into the sealing interfaces. The seal is especially effective when employed in a hydraulic pressure cylinder of the center feed type since it allows the usage of a single annular seal positioned in a singular annular groove in the piston.

Abstract: A cylinder having a radially movable or pivoting rod slidably received in a floating gland disposed in a cavity or recess in an end cap of the cylinder. Preferably, seals are provided between the rod, gland and recess. Hence, the rod and gland can move radially while a fluid tight seal is maintained between the atmosphere and the interior of the cylinder to retain pressurized fluid therein. Preferably, to facilitate radial movement of the rod and hence the gland in the recess, the forces on opposed faces of the gland are equalized by an appropriate arrangement of seals to define equal surface areas on the opposed faces both of which communicate with the interior of the cylinder.

Abstract: The radial gear driven piston pump (10) comprises a stationary pintle or pin (40) having a rotatable rotor (30) mounted thereon. The rotor (30) and pintle (40) are disposed within a pumping bore (18) that is eccentrically aligned relative to bore extensions (28) receiving the pintle (40). The rotor (30) is driven by an offset motor (12) which engages a periphery of the rotor (30). The pintle (40) has therein two pairs of longitudinal passages comprising supply (46, 53) and discharge (47, 54) channels which communicate with respective intake (41, 43) and exhaust (42, 44) ports within the pump housing (16). The rotor (30) has sets of axially offset pistons (90, 100) received within piston cavities (93, 93'). Each set of piston (90, 100) comprises a metal piston cap (95) having a central opening (90) which receives a longitudinal extension (97) of a piston sealing ring (98).

Abstract: A piston having a cup seal retainer assembly wherein the cup seal is secured between an underside of a circumferential flange of the piston and a retainer ring that is secured to the underside of the piston.

Abstract: A piston and piston support rod assembly in which the piston is formed as a sheet metal stamping. A central sleeve is attached to the end wall of the stamped piston by a swaging operation performed on an annular section of the end wall. An undercut area of the sleeve defines a mandrel surface that effectively grips the end wall material deformed by the coining operation. A principal advantage of the new structure is a relatively low manufacturing cost.

Abstract: A wobble piston apparatus incorporates a cup-type seal seated on a land formed about the head of the piston, and secured by an annular ring. The head of the piston and the ring have chamfered edges which facilitate an engagement of the ring with the piston head, on assembly, and the chamfered edge of the ring further cooperates with the piston to define a void which accommodates therein an extruded expansion of an innermost, peripheral edge of the seal.

Abstract: A dispenser for dispensing metered amounts of a viscous material includes a rigid tube which defines a compartment for the material, a discharge passage at one end of the tube, a push button activated and reciprocatingly movable rod which moves back and forth between two positions in the tube, and a sealing plunger which moves step-wise on the rod, from the push button end to the discharge end. Each activation of the push button expels a metered amount of the viscous material. The plunger is formed of a short inner tube section which makes sealing contact with the rod, an outer tube section which is in sealing contact with the interior surface of the tube and a radially extending, ring-shaped, rib which connects the two sealing tubes to one another. In a preferred embodiment, the radial cross-section of the plunger exhibits and H-shape. A metallic gripper is secured to the plunger and has a free end which is inclined toward the rod.

Abstract: A low pressure metering pump having a hollow piston reciprocated in a cylindrical guide by a solenoid coil. A pair of check valves provide for unidirectional fluid flow through the cylindrical guide in response to the reciprocation of the piston. A seal attached to the piston prohibits a fluid backflow between the external surface of the piston and the internal surface of the cylindrical guide. A bumper seal at the output end of the piston prevents fluid flow through the cylindrical guide when the solenoid coil is de-energized. A control circuit periodically energizes the solenoid coil at a frequency determined by a variable resistance responsive to predetermined operational parameters. In a preferred embodiment, the metering pump is a fuel control element for a heater and the variable resistance is a thermistor or similar type of temperature sensitive resistance, which controls the rate at which fuel is delivered to the heater.

Abstract: An improved ringless piston construction having particular use in a closed fluid system. The piston includes a metal core, which is attached to a piston rod, and a resilient outer member is secured to the core and is formed from a material, such as nitrile rubber. The outer member includes an outer peripheral surface and at least one of the axial ends of the outer surface is provided with a tapered lip. The resilient outer member also includes an inner flange that is spaced radially inward of the base of the lip, and the lip and flange, in combination, define an annular recess having outwardly diverging walls. When subjected to fluid pressure, the lip will be deformed outwardly into sealing engagement with the inner wall of the cylinder, while the flange acts to deflect the fluid toward the lip to increase the sealing pressure.

Abstract: A fluid flow regulating valve for controlling the flow of a corrosive fluid, the valve including an axially unrestrained movement of the piston in accordance with the fluid flow varies the effective size of a flow control orifice to regulate the fluid flow.

Abstract: A reciprocating pump piston includes a piston rod which is adapted to be disposed within a cylinder. A piston hub is secured to the piston rod and is adapted to be reciprocated thereby within the cylinder. The hub includes a flange portion having a cylindrical outer periphery of slightly smaller diameter than the inner diameter of the cylinder and a generally cylindrical body portion having a diameter smaller than the flange portion. An annular piston seal ring is disposed about the hub body portion. The seal ring includes an inner leg disposed in mating relation with the body portion and an outer leg defining an annular sealing lip which yields radially inward upon insertion of the hub into an associated pump cylinder. Yielding of the outer leg is to a predetermined extent sufficient to block dislodgement of the inner leg from mounted association with the hub body portion.

Abstract: A one-piece, self-lubricating, thermoplastic sealing member suitable for a double action piston pump, the sealing member comprising a tubular shaped body, a peripheral portion of which is radially cut into two flanges of substantially equal length and thickness. The flanges are substantially in registry with one another and are bent, preferably in the vicinity of their respective bases, in opposite directions to a preselected angle below about 20.degree. relative to a transverse axis of the sealing member and are symmetrically disposed about such axis back to back in a double cup-like shape. When the sealing member is disposed in an annular space between the piston and the cylinder, the double cup flange portions of the sealing member are in contact with the annular surface of the cylinder or alternately, with a fixed or moveable shaft, providing sealing engagements therebetween, and the oppositely disposed peripheral portion of the sealing member is secured in the piston, or alternately, in the cylinder.

Abstract: A rotary power element for tensioning devices of safety mechanisms for protecting the occupants of vehicles by the use of safety belts has a rotatable drive mechanism, a compress-gas generator, and a tubular element between the drive mechanism and the compressed-gas generator. Also, the element includes at least one preformed acceleration member arranged in the tubular element. This member is capable of being driven forward against the drive mechanism under the action of compressed gas produced by said compressed-gas generator to accelerate the drive mechanism.

Abstract: A pneumatic brake cylinder device employs a pair of different sized fluid motors, the pressure chambers of which serve as air storage reservoirs. The cylinder of the larger fluid motor is formed by the main casting and contains a larger piston, while the cylinder of the smaller fluid motor is mounted to the main casting in coaxial relationship with the larger cylinder and contains a smaller piston having an elongated hollow body that is connected at its open end to one side of the larger piston to form a pressure chamber therebetween. The smaller piston fits within the smaller cylinder in spaced-apart relationship therewith to form a pressure chamber delimited by a seal fixed on the main casting for engagement with the piston periphery at any point along its longitudinal axis. The larger piston cooperates with the larger cylinder to form pressure chambers on opposite sides thereof.

Abstract: The invention pertains to the sealing of pistons for pressurizing, pumping and displacing aggressive liquids and organic solvents. The design includes the sealing head proper and its attachment to the piston. Owing to its shape and material it is made of, the sealing head ensures a variable sealing thrust proportional to the pressure acting on the piston, thus enhancing the useful life of the seal.

Abstract: Device for supplying fuel to the atomizer of a combustion engine comprises at least a pump to be connected with the atomizer having a piston-bounded pump chamber and an electromagnet for reciprocating said piston.Said device is improved, particularly with regard to the seal of the pump piston, the control and the adjustment of the pumped quantity of fuel, the life-time and the cooling of the device, the compactness and simplicity of construction and/or simplification of maintenance.

Abstract: A wheel cylinder piston made of powdered metal is provided with a through hole and a steel or powdered metal insert of hard metal received in and fills the hole. The hardened insert acts directly against a tang of the brake shoe, eliminating the need for reaction pins. The piston of the assembly is made in a die set having a through rod to define the hole, the piston green preform being sintered and sized before or after the insert is in place.

Abstract: A master brake cylinder comprises a spring biased piston reciprocally mounted in a bore defined in a housing thereof. A cup seal, disposed in the bore to abut the piston, comprises a flexible annular flange portion having a plurality of circumferentially disposed grooves formed thereon to induce rotation of the cup seal upon the return stroke of the piston, subsequent to a braking operation. The cup seal is composed of a cured elastomeric material having a cup-shaped reinforcing fabric encapsulated therein.