GB431224A - Improvements in or relating to electric motor control apparatus - Google Patents

Abstract

431,224. Actuating controllers. WESTINGHOUSE ELECTRIC & MANUFACTURING CO., East Pittsburg, U.S.A.- (Assignees of Riley, L. G. ; 905, Milton Street, Pittsburg, U.S.A.) April 20, 1934, No. 11950. Convention date, April 22, 1933. [Class 38 (iii)] With auxiliary switches; disposition of resistances.-A controller comprises resistance elements, displacable contact members therefor each mounted on a stationary part of the apparatus and arranged about a common centre, and a common contact displacing member rotatable about the common centre and carrying a resiliently mounted roller adapted to press against the contact members to actuate them in sequence to a circuit operating position. Contacts 10 mounted on leaf springs 13 are arranged around the inside of a circular bus-bar 15, and are pressed into contact with the bar to shunt sections of resistance 17 in sequence by means of a roller 26 carried in a ball-bearing 34 on a cross-member 29. The member 29 is pivoted at one end in a fork on one arm 31 of a bifurcated member 27, the other end of the member 29 sliding in a fork on the other arm of the member 27 and being acted on by a spring 33 which forces the roller 26 against the top of rigid plates 40 attached to the back of the leaf springs 13. The member 27 is mounted on a shaft 35 driven through worm gearing 42 by an electric or pneumatic motor 28, the speed of which may be controlled. The contact bar 15, and the leaf springs 13 are mounted on opposite sides of an insulating ring 11 carried on a panel 12, and the resistance elements 17 are supported by L-shaped arms 18 secured to an insulating ring 19 mounted on a metal plate 21 by means of insulated extension bolts 22. Connection between the resistance elements 17 and the contacts 10 is made by means of clamps 30 and studs 25. The contacts 10 are formed with rounded surfaces and rub vertically and horizontally on the contact bar 15 when contact is made. Spring-biassed plungers 46, acted on by cams 47 may be arranged to close selected contacts 10 independently of the roller 26, and limit switches for the motor 28 may be similarly operated. A hinged cover 54 with felt washers 55 is provided.