Assembly Plant Torque Control Using a Transducer and Computer

An assembly line torque control system has been developed which makes use of the inherent repeatability of air-powered wrenches. This system utilizes a small, portable, torque transducer to initially set the power tool and to periodically inspect its performance. On applications to be controlled, a clutch-controlled, or air-stall air shut-off, power tool is connected to a process control computer which signals the production line worker when his job is completed and produces a permanent record of the assembly. In-plant tests of power tool shut-off characteristics and theoretical background of this system are discussed.