Patent ID: 7775295

Claim:
A control system for use in conjunction with a primary power system, the primary power system operable to power a hand-held tool, and the control system operable to control the amount of power to the tool, the control system comprising: an air delivery assembly including a first supply line of pressurized air in fluid communication with the primary power system; a control assembly including— an exhaust line from the primary power system and to the control assembly, a spool valve having a spool containment body, a spool housed within the body and operable to move freely along at least a portion of a length of the body, and a compression spring housed within the body, wherein a location of the spool within the body determines formation of a control chamber, a load chamber, and a reference chamber within the body, said spool valve being in fluid communication with the first supply line and the exhaust line, and a control line in fluid communication with the spool valve and the hand-held tool, wherein the first supply line is fed to the control chamber of the spool valve, and the exhaust line is fed to the load chamber of the spool valve; and a second supply line of pressurized air in fluid communication with the primary power system and the hand-held tool.