Abstract: A piston for a hydraulic piston machine in which a piston body receives a ball in a space defined at one end of thereof. A bearing dish supports the ball in the space with an O-ring engaging the recess to seal the bottom surface of the bearing dish. Preferably the bearing dish is formed with a steel support layer, a bronze layer cast onto the steel support layer, and a plastic layer supporting the ball.

Abstract: A planar body spring attaches the inboard shoe and lining assembly to the piston of a disc brake caliper. The spring also serves as a shield for the piston boot seal.

Abstract: A useful sealing device which serves to fluidtightly seal a clearance between a cylindrical member and a cylindrical bore into which said cylindrical member is to be fitted. The sealing device comprises an annular endless resilient seal ring made of a resilient sheet-like material and having an inner diameter smaller than an outer diameter of a seal fitting portion on the cylindrical member. One of the opposite surfaces of the resilient seal ring is tightly fitted around the fitting portion of the cylindrical member in a facing relation to each other, whereas the other surface of the same is faced to the sealing surface of the cylindrical bore and at least a part thereof is placed in resilient contact with the sealing surface.

Abstract: A double-acting piston and cylinder assembly has a piston which in turn has an outer piston surface centered on an axis, a radially outwardly open piston groove and a pair of axially oppositely facing piston ends. The cylinder has an inner surface centered on the axis and spaced radially outside the outer piston surface. A tubularly annular element received in the piston groove has an outer surface centered on the axis and bearing radially outwardly on the cylinder so the piston is guided in the cylinder by the outer element surface.

Abstract: An improvement for a variable volume device in the form of a rectilinear case having disposed therein a rectilinear outer piston structure and a rectilinear inner piston structure within the outer piston structure, the inner piston being carried for rotation on a crank shaft and in turn inducing a reciprocal movement of the outer piston structure in the case, the improvement comprising rollers positioned between the outer piston structure and the case, and the inner piston structure and outer piston structure to facilatate thrust and force accomodation therebetween, and sealing strip means positioned in sealing relationship between the outer piston structure and rectilinear case, and inner piston structure and outer piston structure, and particularly an embodiment in which the sealing strips means of the inner piston structure bear against the side portion of the outer piston structure sealing ring means and a bearing plate positioned to support the rollers, whereby the rectilinear innerrunning pistons may be

Abstract: A pump piston assembly for a single acting reciprocating pump used in slush pumps handling liquids and semi-liquids carrying abrasives and other solid matter for the circulation of drilling fluid or slush in oil well drilling operations. A cast iron (or forged steel) piston element, having a hub extension for the mounting of an annular piston seal, is provided with a through opening for mounting of the piston assembly on the end of a piston rod. The large diameter metal base of the piston element is provided with a multi-channeled, or grooved, peripheral surface and an annular beveled edge at the piston rear face for the optimal flow of fluid into the piston peripheral surface during back strokes of the piston assembly for optimal fluid lubrication of the piston element within the pump cylinder lining. An annular fluid reservoir groove is also provided in the metal base for optimized retention of fluid for the multi-channeled peripheral surface with some embodiments.

Abstract: A piston-shaped bottom closure for a hollow container has a closing member arranged so that when the closure is inserted into a container the closing member extends transversely of an inner wall of the container, a hollow guiding member extending from the closing member in an axial direction so that in the inserted condition of the closure the guiding member is guided by the inner wall of the container, at least one sealing lip provided on the guiding member and abutting against the inner wall of the container in the inserted condition of the closure, and a cover member arranged on the closing member at its side facing toward a storage chamber of the container and having a contour substantially corresponding to the contour of the closing member, wherein the cover is composed of a material having a different elasticity than the closing and guiding members and the sealing lip and is provided with an edge which extends towards the guiding member and overlaps an outer edge of the closing member so as to be arrest

Abstract: A double-acting pneumatic cylinder has a housing with a cylindrical chamber therein. A cylindrical piston is supported coaxially in the chamber for movement axially thereof and has a circumferential groove in the outer surface thereof. A pair of spaced, facing annular surfaces and a radially outwardly extending annular rib are provided in the groove, the rib being axially intermediate the annular surfaces. Two passageways in the housing communicate with the chamber on opposite sides of the piston for supplying compressed air to the chamber. A resilient O-ring encircles the piston within the groove and has annular bands of engagement with the chamber and the rib. The O-ring is transversely movable within the groove between two positions having annular bands of engagement with the respective annular surfaces in the groove in response to low air pressure selectively supplied to the chamber through the two passageways.

Abstract: An improved disc brake plastic piston is described which has a metallic cap or face which provides a means of attaching a brake shoe or a brake shoe assembly, or provides a dust boot groove, or, in a most preferred mode, the metallic cap component provides both a brake shoe retaining means and a dust boot groove.The piston is comprised of a cylindrical plastic body having an open end and a closed end. At least one ring bead can extend from the wall of the piston body contiguous to, or near, the open end. The bead or beads are suitably ejector beads utilized in the molding operation. A metallic cap extends over the end wall of the open end of the cylindrical body and is secured to the body by being snap fit or clamped over the ring bead. The cap is adapted to receive and hold a brake shoe clip, or provide a dust boot groove, and, in a most preferred embodiment, provides both a brake shoe retaining means and a dust boot groove.

Abstract: A permanent magnet on a piston for use with a magnetic force pickup for sensing the position of the piston is locked in place between two backup rings and is seated within the washer of the piston. The washer has two inwardly extending flanges placed on the two axial sides of the permanent magnet between it and the backup rings.

Abstract: In a cylinder piston device, a piston unit is fixed to a piston rod member within a cavity defined by a cylinder member. The piston unit is provided with a piston ring supporting face, which is directed substantially in a radially outward direction towards the inner circumferential surface of the cylinder member. A piston ring member with a radially inner circumferential face and a radially outer circumferential face is supported by its radially inner circumferential face on said piston ring supporting face and engages by its radially outer circumferential face the inner circumferential surface of the cylinder member. The piston ring member is provided with at least one radially inward directed projection extending in the radially inward direction beyond the radially inner circumferential face, the projection axially engaging a securing face of the piston unit, and the securing face extending radially inward of the piston ring supporting face.

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: A piston for a metering device with a glass cylinder which comprises a cylindrical core of glass, ceramic or metal and a casing of poly(tetrafluoroethylene) reinforced with 10 to 60 weight percent glass fibers.

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 piston for a pneumatic cylinder having a guide and sealing annular member extending around the circumference of the piston, and a resilient bearing member biassing the guide and sealing member in a direction for sealing engagement with the internal surface of the cylinder. The guide and sealing member has a plurality of axially consecutive, radially projecting sections for surface contact with the internal surface of the cylinder, each pair of adjacent sections defining a cavity therebetween. The material of the guide and sealing member between adjacent radially projecting sections of the guide and sealing member define a hinge-like connection therebetween.

Abstract: A piston for use as a TFL locomotive or well swab having a seal unit forming a fluid seal between the piston and the inner wall of a flow conductor or tubing string. The seal unit comprising at least one annular fin or lip extending radially from the piston. The annular fin or lip having an exterior portion formed from elastomeric material which is deformable to seal with the flow conductor and an interior portion formed from elastomeric material molded on wire mesh. The interior portion providing increased wear resistance and strength for the annular lip. In one version, the piston carries several individual seal units each having an annular lip.

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: A two-axis positioning servoactuator includes a support, a movable member arranged adjacent the support for independent pivotal movement relative thereto about each of two perpendicular intersecting axes, a pair of differential piston and cylinder actuators operatively interposed between the support and movable member for effecting such angular movement about each of the axes, an electrohydraulic servovalve for each of the actuators and operatively associated therewith to control the same, and means providing a position feedback signal to the corresponding servovalve for effecting controlled movement of the member about each of the axes.

Abstract: The piston of a hydraulic cylinder is provided with a corrugated running surface composed of angularly disposed ribs and valleys therebetween, the ribs bearing against the relatively smooth bore of the tubular casing in which the piston reciprocates. Whereas the ribs on the piston provide a corrugated running surface bearing against the bore, the cylinder head, in which the piston rod is journaled, is formed with a similarly corrugated running surface.

Abstract: A piston for pressure fluid cylinders which comprises, fixed on the piston rod, a disc member and a sleeve-like body of elastic material associated with said disc member. The sleeve-like body has an outwardly projecting annular lip, limited by an annular substantially frontal slit. The annular lip engages the cylinder liner, thereby providing the sealing action.

Abstract: A piston pump comprising a cylindrical sleeve member, a tetrafluoroethylene plunger head contained within the sleeve member, at least one O-ring contained within a circular recess concentric with and extending axially from the lower transverse face of and into the plunger head, and a piston rod having one end concentric with and rigidly mounted to this lower transverse face. Also, a pressure cap having a cylindrical uppermost portion dimensioned to fit into the circular recess of the plunger head, is adjustably mounted upon the piston rod, for axially compressing the O-ring(s), causing the O-ring(s) to exert a radial force against and effect a seal of a portion of the circular side walls of the plunger head against the opposing interior wall of the sleeve.

Abstract: A piston-cylinder assembly having a circumferential groove around the piston near the end of the piston facing the cylinder chamber, a cuff around the piston at a location more remote from said chamber from the groove, a guide ring mounted in the groove for slideably abutting the cylinder wall, the guide ring having a convex inner configuration and a generally cylindrical outer configuration.

Abstract: An internal combustion engine crosshead piston assembly having an outer skirt elastomerically mounted on an inner skirt to reduce piston-slap-caused noise.

Abstract: A laser formed hole is used as a "weep" hole in a hydraulic jack to limit the power stroke of the ram thereby permitting the use of a urethane packing on the ram instead of the usual leather packing.

Abstract: A piston for a compressor having at both ends a step-down portion which defines an annular cavity when the piston is mounted in the cylinder, the said cavity being very thin while its length is dependent on the weight and the length of the piston. A rider ring is located at the center of the piston and piston rings are inserted between the rider ring and the step-down portion.

Abstract: An impact drive tool has a cylinder within which a percussive piston is mounted for actuating a ram to drive a nail into a workpiece. Valve means are provided for introducing compressed air to one side of the piston to cause the impact stroke, and an air storage chamber is provided for returning the piston to its rest position. A truncated cone shaped first buffer element of a cellular polyurethane is affixed to the bottom of the percussive piston. A second buffer element of a harder material, such as a cross-linked polyurethane is mounted in the bottom of the cylinder. The second buffer element has a recess facing the first buffer element and shaped to receive the first element. The buffer elements are positioned so that, at the end of an impact stroke, the first buffer element is initially deformed, followed by the striking of a bottom portion of the piston on the second buffer element to absorb the impact energy.