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. 09, 1983
Filed:
Oct. 30, 1981
Fujitsu Fanuc Limited, Tokyo, JP;
Abstract
A spindle orientation control system having a speed control circuit and a position control circuit for rotating the spindle of a machine tool at a commanded speed and for stopping the spindle at a designated position with a high accuracy, the speed control circuit decelerating the spindle drive motor on the basis of a spindle stopping command. When a predetermined speed has been attained, a counter contained in the position control circuit is triggered by a one-revolution pulse generated whenever the spindle makes one full revolution, whereby the counter begins to count up position pulses which are generated whenever the spindle rotates by a predetermined angle. After a preset predetermined number of pulses have been counted, operation shifts from the speed control mode to a position control mode, and said counter is preset to a number of pulses corresponding to the angle from the present position of the spindle to the desired stopping position. Said pulse number is counted down by the position pulses and, at the same time, a voltage having a level which is proportional to the content of the counter is applied to the spindle drive motor, thereby reducing its rotational speed. When the content of the counter reaches a value of zero, the spindle is stopped at the predetermined position. Adjusting the value preset in the counter makes it possible to correct a spindle stopping position error that results from a difference in the position of the leading or trailing edge of the one revolution pulse, said difference arising because the position of the leading or trailing edge of the one-revolution pulse varies depending upon the direction of spindle rotation.