Piston-cylinder assembly and drive transmitting means

A piston-cylinder assembly comprising, a cylinder body having a bore formed therein, means defining an annular recess within said body, said annular recess having opposite ends, one of said ends being open and in communication with said bore, the other of said ends of the recess being permanently closed, an inlet means in communication with said bore, an outlet means in communication with said bore, a piston mounted for reciprocation within said bore, said piston including an annular skirt defining a space therewithin, said skirt being adapted to fit within said annular recess, said skirt reciprocating within said recess during reciprocation of said piston within said bore and compressing air within said annular recess as the skirt moves toward the closed end of said annular recess to provide an annular body of compressed air forming an annular seal of compressed air within said annular recess between said skirt and said closed end of the recess.