Patent ID: 7527483

Claim:
A pneumatic system of expansible chamber devices pneumatically connected in series, said system including: high-pressure (HP) and low pressure (LP) air chambers, each with and a piston movable therein; said pistons connected to a common rod for reciprocating movement in unison; an air direction control valve ( 50 ) disposed to receive input HP process air, said direction control valve operable alternately in first and second valve conditions; in said first condition ( FIG. 5 ), said direction control valve directing HP process air to said HP air chamber and simultaneously exhausting LP process air from said LP air chamber to thereby move said pistons in a first direction; in said second condition ( FIG. 6 ), said direction control valve directing LP process air from said HP air chamber to said LP air chamber to thereby reverse the movement of said pistons, and; a pilot valve ( 60 ) responsive to alternating strokes of said pistons to alternate said first and second conditions of said direction control valve, to thereby sequentially reverse the direction of movement of said pistons.