Inventors:
Robert L. Douglas - Janesville WI
William P. Jezo - Janesville WI
Assignee:
Giddings & Lewis, Inc. - Fond du Lac WI
International Classification:
H02P 700
Abstract:
An electric torquing device comprises a d-c. motor for producing an output torque that varies in proportion to variations in the armature current, a power source for supplying d-c. current to the armature to produce an output torque, and regulating means for maintaining the d-c. current at a relatively low level during the run-on stage of a torquing operation. Sensing means responsive to a preselected parameter of the torquing operation, such as the velocity of the motor output, produces a control signal when the tightening stage of the torquing operation begins. Control means responsive to the control signal from the sensing means adjusts the regulation of the d-c. current to maintain the current supply to the armature at a relatively high level during the tightening stage of the torquing operation.