Abstract: There is disclosed a pneumatic driving device having a cylindrical housing in which a piston element is axially displaceable. The piston element has at its ends a front piston and a rear piston which are connected to each other by a connecting pipe. A switch element is mounted in the housing between the pistons and defines a variable front chamber with the front piston and a variable rear chamber with the rear piston. Two inlet openings acted on by pressure are formed in the housing and can be connected with the front and rear chambers respectively. The switch element, in a first position, frees the inlet opening to the rear chamber so that the rear piston travels axially outward and the front piston axially inward and, in a second position, frees the inlet opening to the front chamber so that the front piston moves axially outward and the rear piston axially inward. The inwardly moving pistons reverse the switch element between the two positions.

Abstract: An air-operated expansible chamber motor comprising a cylinder having first and second end heads, a piston reciprocable in the cylinder, a spool valve for controlling the supply to and exhaust of air from opposite ends of the cylinder, a relay valve mounted in one of the end heads for controlling the spool valve, a pilot valve in each end head having a stem engageable by the piston for controlling the relay valve via pressurization and exhaust of a pilot line, and a bleed for feedback of pressure air to the pilot line.

Abstract: A reciprocating piston fluid powered motor having fluid inlet and outlet, wherein reciprocation is controlled by a reciprocable valve spool carrying a manifold communicating with said fluid inlet and outlet and cooperating with a valve slide shiftable on said valve spool to control reciprocation of said valve spool.

Abstract: An air driven diaphragm pump having an actuator valve for converting a source of compressed air into a reciprocating drive. The actuator valve includes a valve piston for alternately directing air to one side or the other of the pumps, a control rod fixed to the reciprocating elements of the pump and means for shifting the valve piston responsive to the position of the control rod. An axially spaced bifurcated inlet is employed to provide additional energy to the shifting of the valve piston. The valve piston also is arranged to cover vent ports as a mechanism for closing off all compressed air under stalled conditions of the pump.

Abstract: A high pressure pump comprising a valve body having a first housing secured at one of its ends to one end of the valve body and having a body member secured to the other end thereof. A second housing is secured to the body member with a piston rod movably extending through the body member and the first and second housings. A first piston secured to the piston rod and movably positioned in the first housing defines first and second chambers. A second piston secured to the piston rod and movably positioned in the second housing defines third and fourth chambers. Check valve means are in communication with the third and fourth chambers and sources of fluid to be pumped. The valve body has a pilot valve therein. The pilot valve means is connected to the piston rod so that the pilot valve means will be moved from a first position to a second position when the piston rod moves from a first position to a second position and vice versa. The valve body also has a main valve therein.