Abstract: A piston is disclosed that includes a longitudinal passage disposed between outlets on the opposing faces of the piston, and a radial passage extending from a node with the longitudinal passage to an outlet on the annular wall between opposing piston seals. Check valves are disposed in the longitudinal passage between the node and each of the piston faces, such that each of the check valves enables fluid flow from its inlet to the outlet on the annular wall, and block fluid flow from the outlet on the annular wall to the inlet. In the event of pistons in a fluid system becoming out of phase with each other, fluid may be admitted through the inlet of the longitudinal passage and the respective check valve and out a side wall outlet, thereby bypassing the piston to exit via the respective end port, until another, out-of-phase piston or pistons in the system also reach full extension or retraction, automatically returning all pistons in the system to be in phase with each other.

Abstract: A continuously lockable adjustment device for immobilizing elements which are movable relative to each other includes a stepped cylinder having a first cylinder step and a second cylinder step, the second cylinder step having a larger cross-sectional area than the first cylinder step, a stepped piston having a first piston step guided in the first cylinder step and a second piston step guided in the second cylinder step, and a piston rod connected to the piston opposite the first piston step and extending sealed off out an end of the cylinder. The cylinder has a first working space and a second working space separated by the piston and filled with a working fluid in which the piston can be displaced axially, thereby displacing working fluid from one working space to the other working space.

Abstract: For a pivot motor with frame-like sealing elements which are situated in grooves of its vanes, the invention proposes a design in which the frame has an encircling channel which faces its interior and in which an inner sealing insert engages by means of its periphery.

Abstract: The present invention relates to a filled piston assembly for a hydraulic pump or motor. The filled hydraulic piston assembly includes a blank piston body having first and second ends and a cavity or compartment in the piston body extending inwardly from one of the ends. The piston is filled with a lightweight solid insert element which is placed into the compartment of the piston. The material of the blank piston body is then cold formed around the insert element to encapsulate the element. The piston body is then further cold rolled to receive a spherical ball in one end. It is then cut to length, machine finished, and a longitudinal center bore is drilled therein.

Abstract: A ported piston for increasing the cylinder displacement of internal combustion engines which includes, in a first embodiment, an inertia-activated wafer provided in a cavity located in the piston, with one or more ports connecting the bottom of the cavity to the engine cylinder and typically provided with a check valve and one or more ports connecting the upper section of the divided cavity to the underside of the piston. In a second embodiment the cavity is annular in shape and receives a wafer ring and in a third embodiment the annular cavity and wafer ring, as well as the port or ports, are provided in an insert that seats in an opening provided in the top of the piston. The wafer and wafer ring move up and down by inertia in the cavity and cavity ring opening, respectively, to effectively increase the cylinder displacement and efficiency of the engine.

Abstract: A piston seal device of pneumatic cylinder which satisfies the required tightness of a seal as well as the required lubrication characteristics for a piston movement is disclosed. The piston seal device for maintining different pressures acting on each side of the piston of pneumatic cylinder comprises slide rings located on peripheries of both sides of piston, a seal ring located at the outer part of pressure room formed along the periphery of central part of the piston and operated by pneumatic pressure of the pressure room, and a solenoid valve which operates in selection modes to supply the pressurized air into the pressure room. Slide rings are located with a proper distance at the peripheries of both sides of a piston installed in a pneumatic cylinder and at the center of a piston an expansionable seal is applied.

Abstract: An improved piston-and-cylinder arrangement has a pressure-balanced piston head mounted on an actuator rod. The piston head is mounted for axial movement with the rod, and for radial movement relative thereto. Three annular ring-type seals are provided between facing cylindrical surfaces of the piston head and rod. The frictional impediment to radial movement of the piston head relative to the rod is minimized, and the improved device exhibits a reduction in the average maximum longitudinal frictional force per stroke.

Abstract: A fluid actuated, valveless sanding tool is disclosed which comprises a housing containing a cylinder, a double-ended piston mounted for reciprocal movement within the cylinder, a mounting plate to which an abrasive tool can be attached, and a double rack and pinion connecting means reciprocally driving the mounting plate. A fluid supply system delivers pressurized fluid to a central portion of the bore and a vent system permits venting of the ends of the cylinder. The piston has two end seals and three internal, main seals which maintain a fluid tight relationship with the inner cylinder wall. Two internal passages in the piston are in communication with the annular areas between the three main seals and the respective ends of the piston.

Abstract: In order to preclude the entrapment of low pressure fluid in the interior of U-form seal members in the peripheral grooves of a piston for a fluid power cylinder and in turn prevent the inward deflection of such seals, there are provided cuts or notches in the edges of the end portions of the piston member to effect the venting of the inside of the seal members. Preferably opposing flat chord-like cuts are made in the end portions of the piston down to a mid part of the peripheral groove such that the resulting flat sections can be used to fit into wrench or vise means for piston rod assembly purposes.