Abstract: In order to protect a cup-seal non-return valve (1) against permanent deformation, it is suggested to provide radial supporting walls (15) between the cylindrical inner wall (10)* (*translator's note: the correct reference numeral is `14`) and the sealing lip (13). Preferably, three supporting walls (15), roughly 1 mm thick, are provided because both the natural stability and the valve function are safeguarded this way.

Abstract: A piston and seal assembly that has a rigid core with an elastomeric seal bonded thereto. The core has an annular outer cylindrical edge, a forwardly facing surface and a rearwardly facing surface. The elastomeric member is bonded to the core so as to encase the annular cylindrical edge. The elastomeric member extends outboard of the rearwardly facing surface of the core to provide a sealing lip. An annular concave surface merges with an annular convex surface located axially rearwardly of the rearward facing surface on the core. A radially outwardly directed surface on the lip portion merges tangentially with the convex surface.

Abstract: A door closing device comprises a piston (12) having at one end a seal (21) which seals the interface between the piston and a housing (10). The seal (21) also acts as a one-way valve and carries a pressure relief valve (37).

Abstract: A piston for use in a hydraulic cylinder which is subject to sudden and extremely high shock load pressures and high temperature operating conditions is provided with a plurality of interlocking axially-spaced circumferential grooves. A relatively thin, flat washer of heat-formable fluoropolymer is snapped over a retaining ring integral with the piston and the piston is then moved axially through a heated hot-forming cylinder, causing the washer to conform to the cylindrical shape of the piston. At least one circumferential groove has a side wall which is undercut relative to its cylindrical surface to provide a locking angle. Preheating the washer prior to hot-forming the band and forming a sloping ramp in opposition to the undercut side wall result in improved flow of the fluoropolymer toward the undercut side wall. An additional advantage of the preheating is the formation of an improved band skirt with an improved, sharply-defined sealing edge.

Abstract: An apparatus for recovering a compressible refrigeration fluid from a refrigeration system and delivering the recovered fluid to a receiver includes a discriminator tank for discriminating between influent liquid phase fluid and gas phase fluid. Liquid phase fluid is directed to the receiver. Gas phase fluid is condensed and directed to the receiver. The apparatus further includes a safety tank for preventing overfilling of the receiver and a lightweight compressor particularly adapted to refrigerant recovery. The lightweight compressor includes self lubricating bidirectional seals and renders the recovery apparatus easily transportable to allow convenient field servicing of refrigeration systems.

Abstract: A reciprocating vacuum pump has a disc shaped piston (22, 122) having a peripheral elastomeric seal (52, 152) with oppositely directed, radially outwardly extending skirt portions (54,56); the piston is driven axially by a rod (34, 134) reciprocal in a lubricated bearing (42, 142) and a lubrication flowpath (50,48; 150,148) is defined between the bearing (42, 142) and the side of the piston (22, 122) opposite thereto.

Abstract: An impact damping element is provided including an annular bumper portion and a seal portion surrounding the bumper portion for engaging an inner wall of a cylinder in sealing contact. The impact damping element is adapted to absorb the impact between a piston and the end of a cylinder wall. In one embodiment of the invention, a primary and a secondary bumper are provided wherein the primary bumper has a greater height than the secondary bumper such that the primary bumper absorbs an initial impact between the piston and the cylinder wall and the secondary bumper absorbs the remaining force to prevent direct contact between the piston and the cylinder wall.

Abstract: A piston for use in a hydraulic cylinder which is subject to sudden and extremely high shock load pressures and high temperature operating conditions is provided with a plurality of interlocking axially-spaced circumferential grooves. A band of a heat-formable fluoropolymer is snapped over a retaining ring integral with the piston and the piston is then moved axially through a heated hot-forming cylinder, causing the washer to conform to the cylindrical shape of the piston. At least one circumferential has a side wall which is undercut relative to its cylindrical surface to provide a locking angle. A method of washer preheating prior to hot-forming the band results in better flow of the fluoropolymer toward the undercut side wall. The method of preheating also produces a band skirt with a relatively sharply-defined sealing edge.

Abstract: An angulating piston assembly for a vehicle air conditioning system compressor comprises a composite piston including a metal rod having a ball at a proximal end and a plastic head at a distal end. A piston ring subassembly is operatively received about the periphery of the plastic piston head. The subassembly is characterized by a rigid support collar molded into the piston head and a piston ring of low friction material stretched and snugly received over the collar. An integral molded lip on the piston head and an outwardly projecting skirt on the support collar maintain the piston ring in position. An inwardly projecting flange is provided on the support collar and molded into the plastic piston head to provide a lock to prevent relative axial movement between the support collar and the piston head.

Abstract: A rotary actuator device having an annular piston rod, the device comprising at least one piston held provided with sealing means and co-operating with an annular piston rod mounted so as to be capable of moving in an annular chamber, together with means for selectively applying a fluid under pressure in said annular chamber, wherein the piston head co-operates with the piston rod via a hinge having one degree of freedom in rotation and one degree of freedom in translation, said hinge comprising a piece in the form of a knife whose edge co-operates with a V-groove in a female portion of triangular profile, the knife edge and the V-groove being parallel to the axis of rotation of the piston rod. This disposition enables the forces exerted on the sealing means to be brought back into balance, thereby increasing sealing even under high pressures.

Abstract: An improved wobble piston for an air compressor. The piston has a head integrally connected to a connecting rod. The connecting rod has a free end for connection to a rotating eccentric. The piston head has an internal chamber. Openings are formed through the piston head into the chamber on opposite sides of the connecting rod in a plane perpendicular to the eccentric axis. The location of the chamber openings establishes a flow of cooling air through the chamber as the piston is reciprocated in a cylinder.

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 portable fluid pumping device includes a piston-cylinder drive in which the piston head is formed with a central section of smaller diameter than the cylinder, and a peripheral flexible section slidably engageable with the side wall of the piston, to thereby produce a slidable seal which obviates the need of a rolling diaphragm. The device further includes a noise-muffling construction, a relief valve presettable for presetting the degree of suction, and a detachable collection container having a cut-off valve for disconnecting the container when it is full with liquid.

Abstract: A dispenser for flowable materials, such as toothpaste, includes a hollow barrel in the form of a tube open at its lower end and closed at its upper end with the flowable material being inserted in the tube. A plunger which is also in the form of a hollow tube having a closed upper end, is telescopically arranged in the barrel. A seal is effected by a hinged peripheral rim on the outer surface of the piston near its upper end. The flow of the material forces the peripheral rim to pivot into sealing contact with the inner surface of the barrel.

Abstract: A low-resistance, liquid-tight seal for use in a valve having a nozzle that telescopes into an axial fluid passage in a valve body. The nozzle has a peripheral portion of reduced diameter near one end thereof for supporting a flat annular seal. The inner edge of the annular seal grips the nozzle while the outer portion of the seal undergoes a flip-flop action against the inner wall of the valve body as the nozzle moves in an out of the valve body. A closure can be provided for the nozzle which is opened by movement of the nozzle into the valve body and closed by the return motion of the nozzle.An improved valve and bottle-filling machine is provided for containers with low-crush resistance. The annular flip-flop seal provides a low resistance to movement when a container is used to push the nozzle into the valve body opening the fluid passage for filling the container.

Abstract: An apparatus includes a tilt piston having a piston head. The piston head is reciprocally disposed within a cylindrical bore formed in a housing, the bore being oriented along an axis. A seal is mounted circumferentially about the piston head. The seal has an outer diameter that exceeds an inner diameter of the cylindrical bore. The seal extends radially in a first direction having an axial component. A support is mounted circumferentially of the piston head adjacent the seal. The support has an outer diameter less than the outer diameter of the seal. The seal is a continuous annular ring which may be of a circular or rectangular cross section. The seal and the support may be formed as a unitary member or may be two distinct elements. The support contacts the bore during a portion of travel of the piston within the bore.

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: 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 sealing device particularly suitable for sealing pistons of working cylinders and for sealing two machine components which can slide against one another is disclosed. A conventional sealing element consisting of low-friction, but not very elastic material, such as PTFE plastic material, and resting on an elastic support, is used. The cross-section of the sealing element in a direction of the sliding motion is U-shaped and encircles the support. The dimensions of the support and the sealing element are determined such that the support exerts prestress forces on the sealing element which try to bend the rim areas of the sealing element outward against the sliding surface for the sealing element. Consequently, an additional force component, directed toward the sliding surface, results for the pressure force which is exerted on the sealing element by the support and functions as a sealing force.

Abstract: In a piston-cylinder assembly for hydraulic brake systems of automotive vehicles, the piston is at least partially composed of ceramics. A hydraulic seal is interposed between the piston and the cylinder. To simplify the assembly while allowing comparatively great tolerances, the seal is fitted at the end of the piston that is adapted to be mounted close to a pressure chamber within the system. The seal is provided with radially-extending projections which cause the piston to spring back by a roll-back effect.

Abstract: A vacuum pump includes two pairs of piston and cylinder assemblies mounted on opposite sides of a crankshaft in a common plane with the gas inlets for the first and second cylinders of a first pair of piston and cylinder assemblies being connected to the device to be evacuated and the gas outlets thereof being connected to a common outlet having a spring biased one-way valve controlling the outlet and to a passage connected to the inlet of a third cylinder in said second pair of piston and cylinder assemblies. The gas outlet of the third cylinder is connected to the inlet of the fourth cylinder and the gas outlet of the fourth cylinder is connected to the common outlet through spring biased one-way valves.

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: Apparatus and method of improving the performance of a pump for pumping fireproofing material and the like viscous materials is disclosed wherein the pump is the type which includes a compression chamber (44) having an inlet (48) and an outlet (50). A piston cylinder (19) is disposed in fluid communication with the compression chamber and, a piston assembly (A, D, G) is carried in the piston cylinder driven in reciprocating suction and compression strokes. The piston assembly includes an extended piston (B,E) carried on a push rod (18) having a piston face (42, 61) terminating adjacent an inlet ball limit pin (52), having a reduced pin length of 5/16 inch, at the end of the compression stroke.

Abstract: A swabbing apparatus has a plurality of swab cups molded on a single core, with at least two swab cups having a different fluid load carrying capacity, so that the swabbing apparatus will have a relatively broad fluid load carrying capacity. Each swab cup has one or more lips with the fluid load carrying capacity of a swab cup being determined primarily by lip thickness.

Abstract: A cylinder and piston assembly with an oil scraper ring having a radially washer seated in a radial piston groove, and a scraping skirt having a radially resilient truncated portion with the base edge engaging the cylinder wall in a scraping line located in or substantially close to the median plane of the washer so as to avoid bending moments on the washer tending to interfere with its free radial movement in the piston groove as required to maintain uniform scraping contact with the cylinder wall.

Abstract: Disclosed is a single acting mud pump piston assembly adapted for use in a mud pump mechanism including a piston and having an end portion with a shoulder reciprocatingly mounted in a cylinder. The assembly includes a circular flange mounted on the end portion in abuttment with the shoulder. A hub is removably mounted on the end portion in abuttment with the flange. A piston cap is mounted about the hub in abuttment with the flange. The assembly is held together by a washer and a nut engaging the end portion.

Abstract: A seal and retainer assembly for an air compressor piston includes a cup-shaped seal with its marginal edge extending at an angle relative to the cylinder wall, the seal having a notch extending circumferentially at the base of its marginal edge defining a hinge which allows pivoting of the marginal edge relative to the main body portion of the seal which is clamped to the piston. A head plate includes an air intake port for communicating the compression chamber with an air inlet and a discharge port for communicating the compression chamber with a compressed air discharge outlet, each of the ports having a flexible spring closure member cooperating with an inclined valve seat to allow the ports to be open whenever the compressor is shut off.

Abstract: A lightweight and portable volumetric spirometer for measuring the volume of and rate of flow of air inhaled by human lungs. The device includes a movable piston within a first transparent cylindrical chamber provided with calibrated markings along its surface for measuring the volume of air withdrawn from the chamber. The first chamber communicates with a breathing tube assembly through which the user inhales. The breathing tube assembly is uniquely adapted so that the inhaled air flow is divided into two fixed portions, one portion of which comes from the chamber, the other portion of which comes from a second chamber communicating with the outside atmosphere. As air is inhaled, the piston rises to a height that can be related to the total volume inhaled. Preferably, there is a counterweight in the second chamber which also rises during inhalation to counterbalance the resistance to movement of the piston and which gives an indication of the rate of inhalation.

Abstract: In a radial piston machine, there is provided an outer stator and an inner rotor rotatable on a control pintle provided with supply and discharge channels. The rotor contains at least one radial bore in which is slidable a spherical piston comprising an outer ball and an inner cylindrical sleeve. The radially inward end of the sleeve, which end is adapted to be acted upon by the outlet pressure of the machine, includes a sealing lip which, during operation, in particular at higher pressures, expands circumferentially and, under certain circumstances, moves in sealing abutment with the inner wall of the radial bore.

Abstract: A piston sealing arrangement particularly for pistons used in railway brake cylinders, comprising a flexible piston seal and a multi-function ring in the form of a separate wear band. The wear band is allocated on the pressure side of the piston seal to minimize radial motion of the sealing ring if the piston rocks.In FIG. 1 is shown a pneumatic brake cylinder 10 in which is located a piston 11. Piston 11 has an external flange 14 which backs a piston seal 15. Located on the pressure side of the piston seal 15 is a wear band 16 which is located very close to the piston seal 15 on the pressure side. The rubber piston seal 15, has a sealing lip 18 in contact with the inner wall of the cylinder 10.The wear band is chamfered at 19 so that the portion 20 of the wear band closest to the sealing ring 15 is the part of the wear band that actually contacts the inner wall of the cylinder.

Abstract: A pump comprises a housing member bounding an elongated cylinder bore, a piston member received in the cylinder bore for reciprocation substantially longitudinally thereof, a drive for the piston member, and a sealing arrangement between the piston member and the housing member. The sealing arrangement includes at least one sealing element having a radial supporting section and at least one lip section sealingly contacting the housing member. The wall thickness of the supporting section exceeds that of the lip section. The sealing arrangement may further include another lip section pointing in the opposite direction counter to that of the one lip section, either provided integrally on the same sealing element or separately on a discrete second sealing element assembled with the initially mentioned sealing element to form the sealing arrangement.

Abstract: Gas and oil well swabs, particularly a dynamic seal for maintaining gas-tight contact between the moving swab and the well casing. The seal includes a reinforcing tube and a flexible annulus having an upper throat portion complementally engaging the exterior of the reinforcing tube and a lower bell-shaped skirt portion, engageable with the well casing. The lower bell-shaped skirt portion of the seal defines an expansion chamber for the well gas, which lifts the swab.

Abstract: New assembly of cylinder, lightweight piston and piston rings for engines and compressors comprising in a cylinder a reduced weight piston provided with a new simpler piston rings set of a high efficiency producing a very small tension against the cylinder and lighter than the piston rings set known heretofore and wherein each of the purposes ascribed to the individual piston rings of the set is entirely attained by each piston ring of this assembly.

Abstract: A reversible valve for reversible refrigeration cycle. The valve means used therein is a hollow cylindrical body longitudinally extending within the valve body. It has a pair of inclined annular walls projecting from around the hollow cylindrical body to define an annular chamber therearound in cooperation with the valve body such that the annular chamber communicates the suction tube selectively with either one of said pair of tubes.

Abstract: A cylinder device including a piston working in a cylinder and partitioning the interior of the cylinder into an oil space and an air space, and a seal in the form of a molded packing ring such as a U-packing or U-cup packing mounted on the piston to seal the oil space from the air space. An additional lip is formed on the seal in addition to a conventional annular lip and is spaced from the conventional lip in the direction toward the air space and is angled toward the air space.

Abstract: A pneumatic reciprocating mechanism comprising a working member (11) reciprocably powered in a housing (10) and forming together with a vibration absorbing reaction support member (12) and an elastic seal element (47) a working chamber (49) which is supplied with pressure via an air feed valve (54,55). The latter is positively coupled to the working member (11) and controls the air flow through openings (54) in the reaction support member (12) in response to the relative positions of the working member (11) and the reaction support member (12).The elastic seal element (47) is associated with the working member (11) and has an annular valve collar (48) which is arranged to establish sealing contact with a diverging peripheral wall (52) of the reaction support member (12) by radial expansion due to the air pressure in the working member (49).

Abstract: A packer nose assembly for pumping downhole equipment of the free type into and out of a tubing string located within a borehole. The assembly includes a mandrel having a lower end portion attachable to the downhole equipment and an upper end portion terminating in the form of a fishing neck. One or more packers are slidably received in a telescoping manner upon the mandrel and fixed in spaced-apart relationship respective to one another by spaced sleeves which are likewise slidably received upon the mandrel. Each packer is cylindrical in form and includes a resilient cup member which is affixed to the mandrel by a mount member. A marginal end of the cup is in the form of a lip which circumferentially extends about the mandrel and is biased into sealed engagement with the tubing wall. A marginal end of the mount member is in the form of a skirt which protects the cup member from damage.

Abstract: A mud pump piston assembly is provided which facilitates replacement and secure holding of piston parts which wear rapidly. A hollow piston member which fits on the end of a piston rod to seal against the cylinder, is held in place by a thin pressure ring which is captured by a retainer ring lying in a groove around the piston rod. The piston member has a concave face and the thin pressure ring closely mates with the concave face to support it, while leaving most of the concave face of the piston member uncovered so it can be expanded by pressured mud to more completely seal against the cylinder. In one assembly, the retainer ring is formed with a circular cross section, and lies halfway within a groove of semicircular cross section while the pressure ring is formed of triangular shape and with one side of the triangle abutting the circular retainer ring at substantially the top of the groove.

Abstract: A packing is provided with a multilayered construction and a cup-like shape. The packing is configured to be carried in a packing holder for reciprocating motion within a pump cylinder. Some of the layers in the packing terminate on the convex face of the cup shape at radially spaced locations therearound. Thus, a peripheral portion of a number of the layers behind the cup lip are exposed to be engaged by the cylinder wall at a continuous contact area therearound. The hardness of the layer located outermost on the convex face is the greatest, and the hardness of each succeeding adjacent layer is lesser than the one immediately preceeding when progressing toward the cup lip along the convex face. Extrusion of the packing between the packing holder and the cylinder wall and subsequent severe localized wear is resisted by the greater hardness layers.

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

Abstract: A pump piston construction for mud pumps and the like incorporating a resilient sealing member that establishes a pressure enhanced seal between the piston and pump cylinder. A bearing and anti-extrusion member composed of a relatively hard and flexible friction resistant plastic material is structurally interrelated with and may also be bonded to the sealing member. The anti-extrusion member is supported by an annular rigid flange of a piston hub about which both the sealing member and anti-extrusion member are received. The anti-extrusion member serves as a bearing to minimize wear of the piston and cylinder and is yielded radially outwardly responsive to fluid pressure transmitted through the resilient sealing member and functions to prevent extrusion of any of the resilient material of the sealing member into the space between the piston and cylinder.

Abstract: In a pump having a cylinder liner, there is a piston therein, a seal around the piston and rear wearband around the piston body to align the piston within the liner. An elastomeric seal ring is in sealing and sliding contact with the liner. A gap filler, with minimal axial creep and controlled radial creep, abuts the rear surface of the seal and maintains continuous contact with the liner thereby continuously closing the extrusion gap between the gap filler and the liner as the liner wears. The wearband has a plurality of angled grooves longitudinally traversing it. Abrasive particles are directed within and through the grooves in the wearband while a source of liquid is communicated into the piston body, through water channels in the gap filler and through the flowpaths in the wearband to create a vortex action which washes the liner wall. The wearband insures no metal to metal contact between the piston and liner and provides a constant piston gap between the metal piston and liner.

Abstract: A cylinder device has a main body having therein a cylinder having an inner closed end and an outer open end, a piston slidably fitted in the cylinder and having a small diameter portion on the inner end thereof, a liquid pressure chamber defined between the piston and the inner end of the cylinder, a cup seal fitted around the small diameter portion of the piston with a lip portion thereof directed toward the liquid pressure chamber and sealingly engaged with the cylinder, an annular retainer disposed in the liquid pressure chamber, a spring acting between the piston and the annular retainer to urge the retainer against the inner end of the cylinder, the configuration of the annular retainer being such that when the piston is at the innermost position in the cylinder the annular retainer engages the lip portion of the cup seal to prevent the lip portion from radially inward deflection.

Abstract: A follower assembly for a lubrication gun that effectively seals in either the gun cylinder after bulk-loading of the lubricant, or a smaller diameter lubrication cartridge positioned alternatively in the gun cylinder. The primary element of the follower assembly is a one-piece elastomeric follower body slidably received on a follower rod in the gun cylinder. This elastomeric follower body has a heavy central portion with a thin forwardly extending outer wall that seals against different diameter bores. The forward end of this thin outer wall has a heavy inwardly directed flange portion that stabilizes the thin wall. A plurality of forwardly projecting posts on the heavy central portion of the follower body engage this flange to pull the thin wall when the follower assembly moves forwardly.

Abstract: A piston for an aerosol container, particularly adapted for insertion through the top of the container; the piston includes an annular, cylindrical collar near its top end and a conical outwardly flaring flange atop the cylindrical collar, with the flange flaring wider toward the top of the container, whereby the flange scrapes the container interior as it moves up; the cylindrical collar is more flexible than the conical flange to ease insertion of the piston and for more effective piston sealing despite the piston cocking in the container; an anti-cocking ring are provided on the piston.

Abstract: A piston comprising a core molded from a rigid thermoplastic material and a seal element molded on the core from a flexible thermoplastic material to form a unitary assembly.

Abstract: New assembly of cylinder, lightweight piston and piston rings for engines and compressors comprising in a cylinder a reduced weight piston provided with a new simpler piston rings set of a high efficiency producing a very small tension against the cylinder and lighter than the piston rings set known heretofore and wherein each of the purposes ascribed to the individual piston rings of the set is entirely attained by each piston ring of this assembly.