Digital torque-responsive pneumatic tool

A portable, pneumatic torque tool automatically controls torque applied by it to a workpiece. In a portable hand-held housing, including a trigger control, a pneumatic motor provides an output shaft output shaft to a workpiece with which is associated a torque sensor within the housing for systematically measuring the amount of torque being applied by the shaft. A control module carried by the housing includes a keypad for providing a torque control input by which the operator selects a predetermined torque value. A torque control circuit interconnected with the torque control input and torque sensors operates to compare the torque being applied by the output shaft with the predetermined torque value. An air control within the housing includes a solenoid operating in response to the control module to prevent air from being supplied to the motor when the torque supplied by the shaft reaches the predetermined torque value, so the tool applies to the workpiece torque at substantially no more than the predetermined level.