GB649822A - Improvements in push-pull electric selector switches - Google Patents

Abstract

649,822. Press-button retractive switches; switches held set and freed mechanically. ARROW ELECTRIC SWITCHES, Ltd. Feb. 20, 1948, No. 5040. Convention date, Feb. 5, 1945. [Class 38(v)] A switch operating shaft is rotatable to select a desired set of contacts only after the operating shaft has been moved axially to open power-line circuits and without selecting other undesired control circuits. The power circuits are controlled by movable contacts 34, 46, cooperating, respectively, with fixed contacts 32a, 48. Contact bar 34 is mounted on a sleeve 36, slidable on the shaft 20, and is urged against a flange on the sleeve by a spring 38, the contacts 32a, 34, normally being open, as shown, a spring 44 compressed between sleeve 36 and the contact bar 46, which is also slidable on shaft 20, normally closing contacts 46, 48. If the shaft 20 is pushed to the right, the bar 46 is moved by a shoulder 20a on the shaft so as to open contacts 46, 48, the contacts 32a. 34, remaining open. If, however, the shaft is pulled to the left, a sleeve 40 thereon moves contacts 34 into engagement with contacts 32a, so that both power circuits are closed. In either case, the spring 44 restores the contacts to normal when the shaft is released. The control contacts are arranged in bases B, any number of which may be used. Each base contains two spring: contacts 54c, Fig. 13, normally urged into engagement with fixed contacts 52 by springs 50a, the contacts 54c being fixed at 54d to a terminal bar 56. The contacts 54c are operated by face cams which are prevented from axial movement on shaft 20 by flanges 66 which engage in recesses formed between adjacent bases B. The cams are mounted on a square sleeve 21 on the shaft 20, the sleeve 21 only being rotatable by the shaft when the latter has been moved to the right. Fig. 2. This coupling is made by a key 96, Fig. 15, fixed to shaft 20, and having wings 96w which move into slots 95 in a member 84 fixed on the end of sleeve 21. The member 84 carries a number of spring-pressed balls 80 which co-operate with depressions in a fixed plate 88 to provide a locating device for the switch. The wings 96w have one or more extensions 96x which, in the normal and pulled positions of the shaft, engage between projections 102 on a fixed member 100 so as to prevent operation of contacts 54c except in the pushed position of the shaft, the amount of rotation of the shaft being limited by an adjustable stop 112 and a fixed stop 104. A handle (not shown) on the shaft may have an arrow or other indicator thereon.