Improvements in contact arrangements applicable to electrical follow-up switches

摘要

556,288. Follow-up control systems. PRECISION DEVELOPMENT CO., Ltd., and OLAH, G. April 29, 1942, No. 5728. [Class 40 (i)] [Also in Group XXXVII] Two pairs at least of co-operating contacts such as contacts for controlling a reversible motor are actuated by the relative movement of two contact members, an intermediate member or members located in the path of the switching movement of the contact members, carrying at least one each of every pair of co-operating contacts controlled, and being able to float between the limits provided by the relative displacement of the two contact members when contacts are broken. In one example, Fig. 3, an input shaft moves a central member A bearing contacts co-acting with one or other of spaced contacts C1, D2 on an intermediate member CD, which when driven in one direction or the other by movement of A causes other spaced contacts D1, C2 to co-act with the sides of contact member BX on a driven member B shown as co-axial, with A and CD. Thus if member A moves clockwise contacts A1 and C1 are made and by driving the intermediate member CD contacts D1 and B1 are made establishing a circuit to drive a servomotor operating on the output member B in the same direction. When the driven member overtakes the input member A the circuit is broken and the slow-up operation continues in known manner in one or other directions according to the direction and extent of the input movement. In the example, Fig. 4, the member P is a frame holding the planet wheels of a differential gear the two sun wheels of which are connected with the input and output. The movement in one direction of the input shaft will cause movement of contact member AX into contact with one or other of contacts C1, D2 or a pivoted intermediate member CD which is thereby rocked to cause consequential contact movements between member BX and contacts D1 and C2 to operate a servomotor actuating the output shaft to an extent to cause disengagement.