Abstract

A mechanical turning device is provided, such as a wrench or screwdriver, for turning and tightening a fastener in a workpiece. In one form, the turning device contains a transducer, such as a strain gauge, operable to sense torque applied by the device to a fastener and to generate or modulate electrical signals to provide signals which are indicative of the torque applied. Computing and display means are provided for displaying the value of the torque generated in character form. In a particular form of the invention, a normally open switch is supported by the turning device and is closed when torque or force is first applied to a fastener by the turning device to connect a source of electrical energy, such as a battery, with the torque sensing and indicating devices. In another form, a synthetic speech generating circuit is provided together with computing means for operating such circuit to indicate by means of speech signals applied to a microphone supported by the device and by means of speech sounds generated by such microphone, the torque applied to the fastener. In yet another form, one or more transducers are supported by the torque turning device, which are operable to scan the fastener turned thereby and provide electrical signals indicative of the internal structure of the fastener for inspecting same when such electrical signals are applied to a visual display.