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:
Aug. 31, 1982
Filed:
Dec. 14, 1979
Fujitsu Fanuc Limited, , JP;
Abstract
A control system for rigidly stopping the spindle of a machine tool at a prescribed angular position when a tool is to be changed, without the use of a mechanical brake. Provided for this purpose is an orientation control circuit adapted to produce an output signal of zero potential when the spindle is at a prescribed stopping position, and an output signal of a potential proportional to the amount of angular deviation when the spindle is displaced from the prescribed stopping position. To stop the spindle at a prescribed stopping position, the output signal from the orientation control circuit is delivered in place of a speed command signal to a speed control loop of the type which limits to zero the difference between the speed command signal and a speed feedback signal. When the spindle is at rest, the feedback function of the speed control loop holds the rotary shaft of the spindle motor rigidly at the stopping position as if a mechanical brake were applied thereto.