Abstract: A piston assembly may include a piston rod and a piston disposed on the piston rod. The piston may include a frame end cap defining a through-bore for receiving the piston rod, and the frame end cap may form a first end of the piston. The piston may include an outer end cap defining a through-bore for receiving the piston rod, and the outer end cap may form a second end of the piston. The piston may also include a center support defining a through-bore for receiving the piston rod. The center support may be disposed between the frame end cap and the outer end cap, and an outer surface of the piston rod and an inner circumferential surface of the center support may define a radial gap.

Abstract: The invention relates to a reciprocating piston composed of ceramic material for a reciprocating-piston engine with crank drive, wherein the reciprocating piston is rigidly screwed to a piston rod by a screw, wherein between the reciprocating piston and the piston rod there is braced at least one disc composed of metallic material, wherein the screw is composed of a metallic material, wherein the coefficient of thermal expansion ?piston of the material of the reciprocating piston is lower than the coefficient of thermal expansion ?screw of the material of the screw, and the disc is an expansion compensation disc, wherein the coefficient of thermal expansion ?Disc 1;2 of the material of the expansion compensation disc is greater than the coefficient of thermal expansion ?screw of the material of the screw, and to a reciprocating-piston engine having a reciprocating piston of said type, and to a cylinder of a reciprocating-piston engine having a cylinder of said type.

Abstract: A device and a piston for segregating articles is being disclosed. The device encompasses a segregating element comprising at least one cylinder with a cylinder housing and a piston installed in the cylinder that has at least one valve. A medium can be fed into and discharged from the cylinder via at least one line. The at least one valve interacts with the at least one line so as to create a hard sealing, and a housing sealing element interacts with a piston sealing element so as to create a hard sealing. The piston can used in a device for segregating liquid containers.

Abstract: A piston device for internal combustion engines includes a first compression ring and a second compression ring in an outer circumference of a piston, wherein the second compression ring includes a notch extending from the inner circumference to the outer circumference on a lower surface of at least one of a pair of ends of the ring, and a gap between the ring ends at the notch on the second compression ring is larger than a gap between the ring ends of the first compression ring, and a gap between the ring ends at the section other than the notch on the second compression ring is the same or smaller than the gap between the ring ends of the first compression ring, and the second compression ring contains an outer circumferential surface comprised of a tapered surface decreasing the ring radial thickness towards the upper side, and an axial parallel surface formed below the tapered surface.

Abstract: A fluid cylinder for high temperature applications is disclosed. The fluid cylinder includes an extensible member that moves between a retracted position and an extended position by forcing a fluid, such as a pneumatic fluid or a hydraulic fluid, into the cylinder. In order to seal the extensible member against an internal surface of the cylindrical housing, the extensible member includes a sealing member defining a plurality of grooves. A corresponding plurality of metallic sealing rings are placed in each of the grooves. The sealing rings include a gap that allow for thermal expansion. The sealing rings are positioned in the grooves so that the gaps on the rings are in a staggered arrangement in the axial direction. Further, a metal alloy coating may be applied to at least certain parts of the fluid cylinder. Through the above configuration, the fluid cylinder can be made without any polymeric sealing rings, composite bearings, or lubricants that may degrade during high temperature applications.

Abstract: A piston and ring assembly operative within a cylindrical bore wall to retain fluid to one side of the assembly, comprising a piston having at least one annular stepped groove in the side wall of the piston, the groove being stepped into uppermost and lowermost spaces with the uppermost space having the greatest depth; at least two split compression rings in the groove, effective to each substantially annularly engage the bore wall, the rings having mating surfaces superimposed one upon another and having their split ends out of superimposed alignment, and a solid lubricant that coats essentially all of the groove and constitutes the non-mating surfaces of the superimposed rings. Pressure of the retained fluid forces the rings together to act in unison and seal jointly against both the step and a side of the groove opposite the retained fluid.

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: A plunger for forcing molten aluminum or brass out of a casting cylinder of a diecasting machine includes a cap which is screwed via an internal thread onto an external thread of a supporting body and is made of a material, in particular a copper alloy, which has a greater coefficient of thermal expansion than the material of the cylinder, in particular steel, and the material of the supporting body, in particular steel. An inner cover face of the cap bears against a front face of the supporting body and, with its internal thread, is screwed thermally onto the external thread of the supporting body, and in addition, is preferably shrunk on thermally.

Abstract: A dynamic seal for effecting the sealing of a piston which is axially movable in a cylinder bore comprising a primary sealing element formed of a non-elastomeric sealing material having a hub portion secured to the piston element and an outwardly flaring skirt portion sealingly engagable with the cylinder bore. A secondary sealing element formed of a resilient metal has its central body portions secured to the piston element and defines a frustro-conical lip portion snugly engaging the exterior of the skirt portion of the primary seal element. Fluid pressure applied to the primary seal element causes it to expand the secondary seal element into a metal-to-metal sealing engagement with the bore of the cylinder.

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: A well packer for use in a well bore having initially retracted packing seal and slip means which are actuated by hydraulic pistons, the improvement in various seals which allow the packer to be used in high temperature environments. The pistons are ring shaped with cup-shaped sealing surfaces extending towards a hydraulic supply port for sealing by hydraulic fluid. Spacers are provided between the pistons for preventing damage to the piston seals. First and second abutments are provided adjacent one end of the seal packer with a metal seal ring between the abutments and coacting wedge surfaces are provided on the metal seal and each of the abutments for sealing against both abutments and wedging the seal inward for sealing. Metal static seals are provided in the packer which are compressed by threads for providing high temperature seals.

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 method of expanding the shot tip in a die cast machine to maintain a sealing fit between the cold chamber and shot tip includes positioning a separate tool with an annular projecting beveled rim in the cold chamber and between the chamber and the movable die half and advancing the shot plunger to cause the beveled rim to project into and expand the periphery of the working end of the shot tip to provide a sealing fit. The expanding tool is used periodically in the casting cycle when required to maintain the desired fit of the shot tip with the cold chamber to prevent entry of metal in the space between the shot tip and the chamber which can cause galling and binding of the plunger in the chamber.

Abstract: The present invention concerns a piston for high pressure hydraulic machines. Said piston comprises a cylindrical body having at the periphery thereof a resiliently deformable cylindrical flange which, in use, forms a tight seal with the cylinder, the flange being integral with the piston body and forming, by means of its inner surface, a recess in the end face of the piston which is subjected to high pressure.

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.