Abstract: The present invention relates in particular, but not limited to, a wind turbine hydraulic brake calliper. The brake calliper comprising a cylinder bore, a piston having a piston head and a piston skirt. The piston being received in the cylinder bore in an orientation where the piston head faces towards the brake pad. The calliper comprising a fluid connection connected to or connectable to a source of hydraulic fluid for leading hydraulic fluid into the void of the cylinder bore below the piston head (1b), so as to move the piston. The piston is formed at least partly and preferably solely from a polymeric material or from polymeric materials.

Abstract: A lubricant pump includes a housing in which at least one pair of intermeshing gear wheels is arranged for conveying lubricant. One gear wheel is rotatably supported on a drive shaft and the other gear wheel is rotatably supported on an axially shiftable displacement unit for adjusting a variable flow volume. Axially displaceable in a housing receptacle is a control piston for hydraulically adjusting the position of the displacement unit. The control piston is configured as composite structural part and has a central longitudinal shaft and cylinder rings which include control edges for clearing or closing control channels feeding into the receptacle. The cylinder rings are made from a material which reduces friction and/or wear with respect to the receptacle, and the central longitudinal shaft has at least one section made from a material having a coefficient of thermal expansion at least substantially corresponding to the one of the receptacle.

Abstract: A linear actuator such as a hydraulic cylinder has linear position sensing apparatus. At least one magnet is provided in a recess in outer surface of the piston for generating a magnetic field that passes through the wall of the cylinder housing. A magnetic sensor arrangement determines the axial position of the piston relative to the housing and comprises at least a pair of magnetic sensor elements arranged at spaced apart locations along the external surface of the wall for sensing the strength of the magnetic field passing through the wall of the housing. The recess in the piston is axially positioned between the first and second end surfaces of the piston and the at least one magnet is disposed between axially spaced north and south pole pieces.

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: A metering receptacle has an elongate hollow body which at one end has a closable exit opening, and which at the other end is closable by way of a plastic plunger stopper. The plunger stopper is at the same time longitudinally displaceable in the hollow body by way of a plunger rod. The metering receptacle is configured such that the plunger stopper is formed of two parts, with a sealing stopper part of plastic which is rigidly positionable in the elongate hollow body and has a centric bore for the passage of the plunger rod, and with a longitudinally displaceable plunger part of lubricious plastic which is connected to the plunger rod.

Abstract: The present invention relates to a hydraulic piston and a process for its surface treatment in order to improve above all the wear resistance and corrosion resistance at the surface of the piston. As a favorable manufacturing process for the surface treatment of an above-mentioned hydraulic piston, a multistage process is disclosed which arranges a nitrocarburization with a subsequent oxidation and a following mechanical solidification of the oxidized surface for the piston. As a result, several superposed layers—layer of oxide, connecting layer, diffusion layer—develop at the piston surface which exhibit the desired qualities.

Abstract: A molded piston includes a base plate, having a plurality of holes, and a polymeric material molded around the base plate and extending through the holes so as to form a mechanical bond between the base plate and the polymeric material. The molded piston preferably includes integral seals in its outer circumferential surface and integral standoffs on its end surfaces. In some preferred embodiments, the molded piston also includes a magnet which creates a magnetic field in the area of the piston.

Abstract: An accumulator piston is formed as a two-piece plastic molding for simplifying its construction and for cost reduction and weight reduction purposes. The piston has a radially stepped construction in which each step includes a radial flange carrying an annular elastomeric sealing element. The sealing elements have deformable, resilient lips which slidably engage the side surfaces of a stepped cylinder in which the piston reciprocates. One of the elastomeric sealing elements is molded to an annular insert member that is seated in an annular recess formed in one end of the main piston body. The two-piece piston construction facilitates installation and removal of mold cavity members relative to the respective elastomeric sealing elements such that the mold cavity members can be of simplified economical construction.

Abstract: This invention relates to a flexible diaphragm assembly for use in a flush valve having a hollow body, an inlet, an outlet, a valve seat formed in the body between the inlet and outlet, and an operating handle assembly. The diaphragm assembly includes a diaphragm adapted to be peripherally attached to the flush valve body and a barrel integral with the diaphragm. The barrel has a seat member on its exterior positioned for sealing engagement with the body valve seat. There is an annular valve seat on the interior of the barrel and a relief valve is positioned within the barrel and has a seat portion positioned to close upon the barrel valve seat. The relief valve has an annular flexible lip in contact with the interior of the barrel and spaced from the relief valve seat portion. The relief valve further has a stem extending outwardly from the barrel and positioned for contact by the flush valve handle assembly.

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 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 pneumatic pressure actuator including a cylinder assemblage having a pair of metallic cylinder heads and a fiberglass cylinder casing held together by a plurality of tie bolts and nuts. A piston and piston rod reciprocally movable within the cylinder assemblage and including a greased nylon cushion ring and polyurethane wiper ring for reducing frictional wear between the relatively movable surfaces.

Abstract: A piston seal device for a reciprocating compressor, having a piston slidably mounted in a cylinder bore and having a circumferential groove, and a resilient piston ring fitted in the circumferential groove of the piston and sealingly engageable with the cylinder bore. The circumferential groove includes a centrally recessed bottom wall for causing the piston ring to be resiliently and arcuately deformed to have a pair of opposite outer corner edges sealingly engageable with the cylinder bore. The piston sealing device thus provides a great sealing force both at the discharge stage and the intake stage, thereby improving the efficiency and lubrication of the compressor.

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: A one-piece, self-lubricating, thermoplastic sealing member suitable for a single action piston pump, the sealing member comprising a tubular shaped body, a peripheral portion of which is radially cut into two flanges of preselected length and thickness. One of the flanges has a shorter radial length and a thinner width than the other flange. The flanges are substantially in registry with one another and are bent, preferably in the vicinity of their respective bases, in the same direction to a preselected angle below 20.degree. relative to a transverse axis of the sealing member. When the sealing member is disposed in an annular space between the piston and the cylinder, the double 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 two sealing engagements therebetween in seriatim, and the oppositely disposed peripheral portion of the sealing member is secured in the piston, or alternately, in the cylinder.

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 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 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: 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: 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: A piston for use in pneumatically operated piston-cylinder apparatus has a disc-shaped steel core for connection with a piston rod, a sealing ring of resilient material surrounding the core and having an integral sealing lip extending from each axial end an incomplete guide ring fitted around the sealing ring. The guide ring is formed of a graphite-filled plastics material and embraces a circumferential surface of the sealing ring to be axially fixed but radially resilient relative to the piston core.

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 piston for use in pneumatic cylinders includes a tubular support with flange-like parts, a reinforcement ring received in the support and having a groove on its outside circumference, a guide ring rigidly mounted in the groove, and angular packing washers pre-vulcanized onto the reinforcement rings on both sides of the guide ring.

Abstract: A dispenser for precisely metering viscous fluids from a cartridge. The dispenser includes a cartridge body and a plunger having a piston head at its extremity. The plunger is unitarily configured from a plastic material, including seal rings in the piston head. Each piston head including two such seal rings axially spaced from one another and configured to include sharp peripheral edges permitting resilient wedging contact within the bore of the cartridge.

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.