GB204792A - Improvements in and relating to electric switches - Google Patents

Abstract

204,792. British Thomson - Houston Co., Ltd., (General Electric Co.). July 11, 1922. Switch mechanism interlocking with lids; switches, quick-action.-A casing for enclosed switchgear comprises a detachable pivoted cover 6, a portion 7 of which forms a hinged lid, and interlocking arrangements whereby neither cover nor lid can be opened or closed unless the switch is open. The cover 6 is mounted on a bracket 11 which pivots on one side of the switch casing by means of hooks, one of which is locked by the overlapping edge of the end 2 of the casing. Detachably mounted in the casing is a combined switch and fuze cut-out, the switch portion lying beneath the main portion 6 of the cover, and the fuze portion lying beneath the lid 7. The switch comprises blades 31 pivoted at 29 and adapted to enter contact clips 30. The blades 31 are connected by an insulating bar 32 which carries two spring yokes 34 of which the ends 35, Fig. 4, break the shock of closing the circuit, and the ends 36 have elbows engaged by the switch-actuating rod 37. The rod 37 is engaged with lost motion by a shaft 39, Fig. 7, fixed to a crank 40 and a snap action is given by a dead centre thrust spring 42 arranged between a fixed bracket 25 and a member fixed to the rod 37. The locking arrangements for the lid comprise a member 22 fixed to it and having a tip 53 which rests on the top of a, flange 47 on the crank 40 when the switch is closed. When the switch is opened, the flange 47 moves clear of the tip 53 allowing the lid to be opened. The tip 53 then engages one end of the flange 47 and prevents the switch being closed. The cover is locked by a hasp 14 engaging a lug 18 and being padlocked, and to prevent the hasp being raised when the switch is closed a finger 54 on the crank 40 is adapted to overlie the portion 19. The switch may be locked " off " by inserting a padlock in a slot 55 in the path of a shoulder 56 on the crank 40.