Abstract: A wobble piston usable in a cylinder comprising one or both of the confronting surfaces of wobble piston head or valve plate being convexly curved in the plane of the wobble motion and being straight in a plane that is transverse to the plane of the wobble motion.

Abstract: Intake or exhaust reed valves of a compressor or vacuum pump have T-shaped flappers which are received in similarly T-shaped pockets so as to be substantially flush with the valve plate. A dirt trap groove is formed in each pocket adjacent to the hinge line of the flapper, a corner relief groove surrounds lands which support the flappers in their associated pockets above the groove, and the extending-part of each pocket widens in the direction away from the cross-part of the pocket. The mating T-shapes of a flapper in a pocket restrain the flapper in the pocket without interfering with the opening and closing motion of the flapper.

Abstract: A valve plate assembly includes a flapper valve and restraint in recessed intake and outlet ports of a valve plate. The recessed ports have guides located therein corresponding to notched sections of the flapper valve and the restraint such that a foolproof method of assembly can be achieved. In addition, a screw clearance in the top of the piston is not required since the recessed portion allows for the screw to be at or below the surface of the valve plate.