GB406133A - Improvements in and relating to the control of electrically operated mechanism - Google Patents

Abstract

406,133. Control of motors. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A.- (Assignees of Allgemeine Elektricitõts-Ges.; 2, Friedrich Karl-Ufer, Berlin.) March 2, 1933, No. 6418. Convention date, March 2, 1932. [Class 38 (iii).] Travelling between predetermined limits.-A motor UVW operating, for example, a chuck, is disconnected from its supply when it is stalled for a predetermined period after unobstructedly reaching its limit of movement in one or other of its operating directions, by one of two thermally operated overload devices 12, 23, according to its direction of rotation. Closure of one of two press-buttons 1, 2, causes the corresponding forward or reverse contactor 11, 22, to close, and the operation of the appropriate overload device 12, or 23, at the limits of travel, de-energizes the closed contactor, by opening contacts 15 or 25. A third thermally operated overload device 3, operative independently of the direction of rotation, and adjusted to the motor current limit, is provided. The torque exerted by the motor when stalled may be adjusted by resistances 16, 17, shown connected for one direction of rotation only, and the periods before which the overload devices 12, 23, become effective may be independently adjusted. Each of two supply conductors to the motor may contain an overload device such as 12, 23, the two devices acting in common on the contacts 15, 25.