Abstract: A telescoping housing for a single acting fluid actuator includes an outer actuator housing section and an inner actuator housing section mounted to reciprocate axially relative to the outer housing section while being surrounded thereby. The housing sections cooperate to form a chamber, and the housing is extended axially by supplying an actuator fluid under pressure to the chamber. A positive pressure is maintained in the chamber to avoid infiltration of outside contaminants into the chamber. Retraction is accomplished by reducing the fluid pressure sufficiently to allow the housing to retract under the influence of gravity, spring force, or other external force. The telescoping housing design eliminates the need for a reciprocating piston and piston rod.

Abstract: A fluid actuator includes a cylindrical housing with a flared open end and an opposite end having a diameter less than the flared end. A rod cap is insertable into the housing at the open end, and moveable through the housing to the opposite end where it is contained by an annular rim welded to the housing. A piston and piston rod assembly is inserted into the housing through the open end. A blind end cap, also insertable into the housing at the open end, is releasably secured near the open end to substantially close the housing. The piston is reciprocable in the housing between the rod cap and the blind end cap. The housing incorporates a conical ramp portion between the flared end and the smaller diameter end of the housing, to provide a gradual transition between the larger and smaller diameters. The ramp tends to center the components as they are inserted, and gradually and evenly compresses elastomeric seals of the components during their insertion, to better preserve the integrity of the seals.