초록 ▼

A servo cylinder having a piston of the kind having spaced sections which move into an enlarged diameter low pressure bore portion of the cylinder is provided with a gasket assembly for each piston section in the form of an elastic sealing gasket having a resiliently flexible radial flange extending

A servo cylinder having a piston of the kind having spaced sections which move into an enlarged diameter low pressure bore portion of the cylinder is provided with a gasket assembly for each piston section in the form of an elastic sealing gasket having a resiliently flexible radial flange extending from an integral collar and supported by a rigid ring having a certain circumferential clearance from the collar to permit radial movement for misalignment compensation. The gasket may be formed in the cross-sectional shape of an L or of a T. Where an L-shape is used, a single support ring is provided and where a T-shape is used a support ring on each side of the radially extending flange which forms the leg of the T oriented 90°would be used. The ring or rings are protective of the radial flange in either direction of movement of the respective piston.

대표청구항 ▼

In a double-acting hydraulic servo cylinder of the kind having continuously cylindrical high pressure chambers for travel of a piston under pressure force and wherein said chambers extend to an intermediate continuously cylindrical low pressure chamber of said cylinder; including a piston in each ch

In a double-acting hydraulic servo cylinder of the kind having continuously cylindrical high pressure chambers for travel of a piston under pressure force and wherein said chambers extend to an intermediate continuously cylindrical low pressure chamber of said cylinder; including a piston in each chamber disposed for travel therein and connected to a common output with each piston carrying a sealing gasket assembly movable sufficiently past the transition between respective high pressure chambers and the low pressure chamber to effect a pressure relief flow from said high pressure chambers to said low pressure chamber toward the end of a pressure stroke of said piston; the improvement wherein: each sealing gasket assembly comprises a seal of flexible and resilient material having a collar mounted in a groove on said piston and having an integral radial flange extending therefrom to resiliently and sealingly engage said cylinder in said high pressure chambers and wherein said flange is of a diameter to preclude sealing in said low pressure chamber when moving thereinto so as to permit relief flow from said high pressure to said low pressure chamber for preventing excess pressure force being exerted on said piston; said sealing gasket assembly including support ring means on said piston encompassing said collar with predetermined radial clearance, extending beyond the piston exterior in supporting engagement with said flange and a wall of said groove, spaced from said cylinder with radial clearance, and radially displaceable to compensate for piston and cylinder misalignment.