Patent ID: 8092191

Claim:
A control system for a reciprocating device, the control system comprising: (a) a switching valve having a fluid supply inlet, an exhaust outlet, a first drive line, and a second drive line, wherein the valve may alternate between a first position wherein the fluid supply inlet is connected to the first drive line and a second position wherein the fluid supply inlet is connected to the second drive line; (b) means for alternating the valve from the first position to the second position; (c) a reciprocating device that is operable to move in a first direction due to fluid pressure in the first drive line and a second, opposed, direction due to fluid pressure in the second drive line; (d) an exhaust circuit providing fluid communication between the first drive line, the second drive line and the exhaust outlet, wherein said exhaust circuit comprises a first flow restrictor disposed between the first drive line and the exhaust outlet, and a second flow restrictor disposed between the second drive line and the exhaust outlet.