Patent GB-167231-A (GB)
Title: Improvements in or relating to electric switches and locking devices therefor
IPC: H01H89/02
Filed: 1920-04-27
Abstract: 167,231. Winning, R. K. April 27, 1920. Switches, locking and unlocking; bases, boxes, and cases; switches, quick-action. - Switches for the control of lighting and ignition circuits of motor - vehicles &c. comprise two concentric switch elements and means for locking one against all movements and the other only against its complete movement. The switch elements are contained within a cupshaped casing 16, a dial plate 18 being secured to the front plate 15<1> of the casing. The centre portion of the casing is provided with an opening 19 to receive the inner end of the cup-like extension 20. Within the extension 20 is housed a locking-barrel 26, which is maintained in position by abutment of a flange thereon against the shoulder 22 of the extension 20. Metallic tumbler plates 32 are placed within a longitudinal slot 25 of the barrel 26, the tumbler plates being pierced by rectangular slots 32 at varying distanoes from their ends to permit the passage of a removable key 30, which is shaped to pass along an irregularlyshaped keyhole 27. Around the casing extension 20 is mounted a switch lever 36 controlling the outer switch element, the inner element being controlled by the key-operated lock cylinder 26. Two longitudinal slots 21 are formed in the casing extension 20, and when the key is removed the tumbler plates 33 project through these slots into segmental slots 34 formed in the bore of the handle 36, Fig. 10, thereby preventing its motion in a counter-clockwise direction but permitting limited motion in the opposite direction. When the key 30 has been inserted in the slot 39, the configuration of the sides 31 of the key and the disposition of the rectangular perforation 32 of the tumbler plates are such that the ends of the tumbler plates are flush with the periphery of the lock barrel, thereby permitting in either direction the limited rotation of the locking-barrel and switch lever and their corresponding switch elements. The switch elements comprise floating contact-carrying rings spring- pressed against a rear terminal-carrying plate 17. The outer element controlling the lighting circuits has an annular insulating-ring 47 carrying a contact ring 51 with rounded contact projections 51<1>. The handle 36 controlling this element is connected to the guide-ring by screws 47 passing through holes in the guide-ring into segmental projections 39 of the switch lever 36, slots 40 being formed in the dial plate 18 and casing front 15' to guide and limit the rotation of the handle and guide-ring. Motion is transmitted from the guide-ring 42 to the switching-ring 47 by means of guide-fingers 45 working loosely in recesses of the latter, coiled springs 49 being interposed between the two members. The inner switch element comprises a floating switching- ring 66 bearing a contact ring 72 with rounded projections 72', two pins 67 on the locking-barrel 26 transmitting its rotation to the switching-ring 66. A central coiled spring 69 is interposed between recesses in the locking-barrel and the switching-ring, pressing the latter towards the fixed contact-plate 17. The terminal plate 17 carries terminals connected to the various circuits, these terminals being formed with rounded depressions to enable the projecting switching- ring contacts to be snapped into engagement with the fixed terminals, rounded depressions 56 being formed in the plate 17 corresponding to off positions of the switch elements. The terminal plate 17 is secured to the casing 16 by bayonet pin-andslot connections 78, 79, the disposition of the pins and slots and the guide fingers and recesses being unsymmetrical to prevent incorrect assembly of the switch parts.