Abstract: A rotary/linear fluid actuator includes a cylinder closed at one end by a rotary actuator and at its other end by a forward housing. A piston is disposed in the cylinder. A hollow piston rod, the forward end of which is closed, extends out of the cylinder through the forward housing. A splined shaft extends into the open end of the piston rod and is coupled to the rotary actuator. The splined shaft includes an axial bore therethrough for delivering pressurized fluid to the piston rod cavity to cause extension of the piston. The piston, cylinder and forward housing define a cavity which is pressurized to cause retraction of the piston. According to the invention, the size of the piston surface can be selected independent of the size of the piston rod cavity actuation surface so that extension and retraction forces, and thereby fluid requirements are independent of one another.

Abstract: A pipe joint for mating with a standard S.A.E. port includes at its outermost portion standard S.A.E. threads, an innermost threaded portion for receiving a nut, an annular groove between the innermost and outermost threaded portions for receiving a back-up washer adjacent the nut, and an "O"-ring between the washer and outermost threaded portion.