GB937229A - Improvements in and relating to control electric switch devices chiefly for use in mines and the like - Google Patents

Abstract

937,229. Press-button retractive switches; switches held set and freed mechanically. J. DAVIS & SON (DERBY) Ltd., and W. B. DAVIS. June 9, 1961 [June 11, 1960; Dec. 30, 1960], Nos. 20623/60 and 44696/60. Class 38 (5). A switch assembly comprises a combination of latchable and non-latchable retractive switches which may be operated by respective press-buttons or alternatively by a pull-wire acting on a separate common actuator. The latchable switch is optionally latched and unlatched by rotation of its press-button when in the depressed condition, or unavoidably latched when operated by the pull-wire and then unlatched by a separate manual release. A split housing 10 (of which only one part is shown) carries two spring-loaded buttons 15 and 19 acting respectively on leaf spring actuator arms 14 and 18 of switches 12 and 13, the arm 18 simultaneously actuating two switches 13 mounted as shown. By means of a central rib 19a, the button 19 may be rotated after depression, whereupon a pin 30 (which normally moves in a recess 31) engages the housing 10 (as shown in Fig. 5) to prevent button 19 retracting until rotated back again. A pull-wire (not shown) is attached to spring-loaded rod 25 which it can move to the right causing two pins 27, 28 thereon to engage arms 14 and 18 respectively. On release of the pull wire, arm 14 and thus switch 11 restores, but the arm 18 is retained by a latch 35. To restore the switches 13 the button 19 must be depressed when it moves latch 35 aside and on release allows the arm 18 to rise with it. An indicator lamp 37 is provided as shown and is connected to one of the switches 13 to indicate the latched or unlatched condition of these switches.