The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 03, 1978
Filed:
Oct. 10, 1975
Francis G Bardwell, Elmhurst, IL (US);
Edmund C Dudek, St. Charles, IL (US);
Thor Power Tool Company, Aurora, IL (US);
Abstract
This disclosure deals with a control circuit for a tool including a motor for turning a rotatable power output shaft of the tool. A torque measuring device is coupled to the shaft and generates a signal which is a function of the torque output. The control circuit responds to the torque output and to a reference signal representing a preselected torque, and automatically turns off the motor when the torque output reaches the preselected torque. Further, the control circuit may cyclically turn the tool on and off at very short time intervals as the preselected torque value is being approached, in order to reduce the reaction torque felt by an operator of the tool. In addition, the lengths of the on times in successive cycles may be gradually decreased as the torque output level increases, with the result that the average reaction torque remains substantially constant even though the peak torque output increases.