Patent GB-201594-A (GB)
Title: Improvements in or relating to electric switches for use in motor road vehicles
IPC: H01H89/02
Filed: 1922-04-01
Abstract: 201,594. Block, N. A., and Coward, J. W. April 1, 1922. Switches, locking and unlocking; bases, boxes, and cases; switchboards.-In a switch for use in motor vehicles adapted to control selectively the lighting and one or more of the ignition, starting, charging or other circuits, an insulatng block is fixed to the switch casing and carries detachably a second insulating block on which are secured fixed contacts, two independent switch members moving over the switch contacts. The block C is secured by screws C<1> to the hinged front A of a casing A<2>, a lock A<6> on the front plate locking it to a tongue A<3> projecting from the fixed casing A<2> which may accommodate an induction coil A<8>. The second block D carries segmental contact rings D<1> and is detachably secured on the block C leads being led from rear terminal plates to the contacts D<1> by plug and socket members D<3>, D<4> passing through holes C<7> in the block C, and a working fuze T and spare T<1> may be mounted in suitable positions on the block D. The outer movable switch member consists of an insulating disc F with two pairs of interconnected contacts F<1>, F<2> .and F<3>, F<4> the connection between the latter pair including a fuze F<5>. The disc F is operated by an annular milled head G<2> connected thereto by arms G<1> working in segmental slots A<9> of the front plate A<5>. Rotation of the member G<2> causes the contacts F<1> - - F<4> to wipe over the outer set of segmental contact rings. The inner switch member consists of an insulating block H bearing contact brushes H<1>, H<2>, H<3> which wipe over the inner set of fixed contact segments. The block H is secured to the barrel of a Yale lock J, being rotated by means of a removable key J<4>. The member H is provided with a spring pressed ball H<9> which engages recesses J' in a fixed plate J<3> in different switch positions. The outer member F has a flange E in which are a number of sets of holes E<2> engaged by spring plungers C<8> in the block C in various switching positions. The positions of the outer member are indicated by pointers G<3>, G<4> attached to the head which moves over graduations A<10> indicating the circuits controlled. The position of the inner member being indicated by the key co-operating with graduations A<11>. The insertion of the key J<4> depresses a central plunger K against a spring K<2> causing its conical exterior K<4> to press apart the centres of two overlapping U-shaped spring locking members K<5> mounted in grooves of the plate C, their outer ends passing through pivoted supports K<6> and projecting into the holes E<2> in such a manner that the outer switch member F is locked in position except when the key J<4> is in position. The key J<4> can only be removed when the inner switch member is in the " off " position, and in the " off " position it is pressed further home bringing its straight portion J<6> within the lock J the locking bars A<5> are pressed to draw their outer ends within the flanga E<1> of the drum E so enabling the front AS and all the switch parts carried thereby to be withdrawn for inspection or repair. An ammeter B and voltmeter B<1> are mounted in the front plate A<5>.