GB692626A - Improvements in or relating to dolly-operated electric switches - Google Patents

Abstract

692,626. Tumbler switches. ASHLEY ACCESSORIES, Ltd. July 27, 1951 [July 29, 1950], No. 18984/50. Class 38(v) The movable contact of a switch is slidable rectilinearly against spring bias by movement in one direction of a dolly having a cam part carrying a roller cooperating with the contact, the dolly having an overcentre action so that when it is moved back over the centre the spring means will return the movable contact with a snap-action. In a double-pole form, two contact bars 24, 25 co-operating with fixed contacts 12-15 are pressed apart by springs 29, 30 and are slidable in slots 18, 21, being urged to the closed position by springs 19. Each bar has an upstanding insulation portion 32 co-operating with rollers 33 on a dolly 16 so that clock wise rotation of the dolly over the deadcentre position to the Fig. 3 position pushes the bars to the left to open the switch. Bars 24, 25 bear continuously against contacts 12, 14 and are cranked at 27 and carry insulating members 31a which are moved opposite contacts 13, 15 in the open position. The fixed contacts may be in the form of resilient jaws in which case springs 29, 30 are omitted, or butt contacts may be used with or without a partial sliding movement obtained by a wedge-shaped movable contact co-operating with a wedge-shaped recess in the fixed contacts. A single-pole switch having resilient jaw contacts is also described, Figs. 5-7 (not shown).