GB1265356A - - Google Patents

Abstract

1,265,356. Cam-operated switches. G. F. WHITELEY, and V. E. BOXALL. 21 Sept., 1970 [21 Oct., 1969], No. 51536/69. Heading HIN. A switch has a contact bridge 9 biased by a spring 16 against a pair of fixed contacts 7 and a device 19 is provided for moving bridge 9 to break contact, bridge 9 being maintained against one fixed contact 7 by a pocket 12 in which end 11 of bridge 9 is housed. As shown, device 19 is a cam having camming surfaces 22, 23, 24. On the opposite side of cam 19 are peaks 25a, 25b and troughs 26a, 26b, 26c which with detent leaf spring 27 locate the cam positions and also provide a snap-action when cam 19 is rotated from one position to the next. A plurality of switches may be ganged and actuated by a common spindle 21, Fig. 3 (not shown), operated by a key-operated lock. In a second embodiment, Fig. 4, contact bridge 9 is thinner, spring 16 is a flat strip hairpin-shaped spring and cam 19 has only one trough 34 and no detent. In all the other embodiments, bridge 9, spring 16 and fixed contacts 7 are the same as in Fig. 4, but the operating device is different. In Fig. 5 (not shown), cam 19 has three peaks and three troughs. In Fig. 6 (not shown), the cam is driven by a gear-wheel intended to be driven by opening a machine cover or door having 180 degrees of movement, the gears having a 2/1 ratio and the driving gear being fitted directly to the door hinge pin. In Fig. 7 (not shown), the gears are the same as in Fig. 6, but a driving quadrant or rack 39 is provided fitted either to the hinge pin or to the door and having a gear ratio of less than 4/1. In Figs. 8 and 8A (not shown), contact bridge 9 is operated by a rectilinearly moving pusher-cam 19a moved by a rectilinearly moving bar 40. This bar may be joined to a door, Fig. 8B (not shown), or joined to a reciprocating member, Fig. 9 (not shown). In Figs. 10 and 10A (not shown), the pushercam 19a is moved by a rectilinearly moving slide 45 manually operated by a handle 45a.