GB1478837A - Fuse-switches - Google Patents

Abstract

1478837 Mechanical switches IMI SANTON Ltd 19 April 1974 [22 March 1973] 17232/74 Heading H1N A fuse-switch has a base 11, a readily demountable fuse carrier 10 and operating mechanism comprising a cam 34 which actuates cam follower 22 to move carrier 10 and thus open and close the switch. The fuse switch has fixed contacts 27a held by base member 11 and movable contacts 15 held by movable member 10 which is moved to make and break contact by cam follower 22 connected to movable member 10 and engaging a cam surface 37, 38 on pivotal cam 34 mounted in base 11 and operable to switch open and closed positions. Each contact 15 comprises an insulating portion 16 between conductive portions 17. Cam 34 is rotated by spindle 31 engaging an element 32 having a projection 33 which engages, with lost motion, the ends of recess 35 in cam 34. In the position of the cam shown, the switch contacts are open. Rotation of cam 34 anti-clockwise does not close the contacts 15, 27a but closes test circuit contacts (not shown). Further rotation anticlockwise frees cam follower 22 from slot 38 so that member 10 can be lifted clear of member 11 and the fuse 19 changed. Rotation of cam 34 clockwise from the position shown in Fig. 1 causes follower 22 to be pulled downwards by slot 37 pulling down bracket 21, guided in recess 25, on member 10 to close the contacts. Cam 34 may comprise a plate having the grooves on both sides and brackets 21 with followers 22 engaging both sides of the plate, Fig. 3 (not shown). An indexing mechanism comprising a square cam (40), Fig. 2 (not shown) between spring loaded pressure members (41), is provided on the rear of member 11, square cam (40) being on spindle 31. Spindle 31 may be operated by a handle (31b), Fig. 3, or a number of switches may be mounted in axial alignment with common spindles (44, 47), Fig. 9 (not shown), spindles (44, 47) being operated by a spindle (43) through bevel gearing (48).