GB609568A - Improvements relating to vehicle direction indicators - Google Patents

Abstract

609,568. Road-traffic signals on vehicles. LUCAS, Ltd., J., and TAYLOR, H. C. March 16, 1946, No. 8218. [Class 118 (ii)] A vehicle directionindicator of the pivotedarm type operated by an electro-magnet has an additional winding or a resistance brought into action by a contact device operable automatically when the indicator arm is moved into its service position, and one or each of the contacts of said contact device is carried by a thermallydeformable bi-metal strip. When the operating winding e of the operating magnet is energized, the core d is pulled down and a spring- loaded catch h mounted on a core extension-piece i engages a pin g on the indicator arm a. The continued descent of the core d therefore turns the arm a about its pivot f into the raised or service position, in which position a finger n on the base of the core d opens contacts k, mounted on spring members m, one or each of which is a bi-metal strip. Should the contacts k fail to open when the arm a is in the raised position, then the continued heavy operating current heats the bi-metal strip and should the arm a remain raised beyond a normal period, the bi-metal strip flexes and opens the contacts k to remove a short circuit from an additional winding j, or a resistance, in series with the operating winding e. Alternatively the additional winding j may be of much higher resistance than, and in parallel with, the operating winding e the contacts k then being arranged to break the circuit of the latter. In another embodiment (Figs. 3 and 4, not shown) the contacts k are mounted near the upper end of the core d and are opened by a shoulder of the core extensionpiece i. The bi-metal strip may be heated by passing the operating current through a surrounding coil instead of through the strip itself.