GB582893A - Improvements in switching arrangements for electric vehicles - Google Patents

Abstract

582,893. Retractive switches. TATTERSALL, T. W. Feb. 7, 1944, No. 2257. [Class 38 (v)] A two-speed switch intended for light electric vehicles in which a bar 1 carrying insulated contact discs 3, 14, slides through a hole in framework 13 on which are mounted two fixed contacts 7, 8. A circuit through motor 18, battery 17 and resistance 16 is closed when the driver operates a lever (not shown) which, through a bowden wire 2 moves bar 1 against spring 6 and carries contact 3 to bridge contacts 7, 8. Further movement carries contact 14 against spring 15 to touch contact 3 and thereby short circuit resistance 16. Spring 12 takes up extra movement of the bar. In Fig. 3, 8', 8" are each one of a pair of contacts mounted on an insulating base 13<1>. The pairs are bridged by moving contacts 3' and 14<1> when insulating block 19 moves against spring 12 on bar 1 being pulled. Contact 3' bridges its pair of fixed contacts first and completes a circuit including a resistance, and then contact 14<1> bridges its pair and short-circuits the resistance, compression of spring 24 allowing the further movement needed. A combined twospeed and reversing switch is described in which two further fixed and one further moving contacts are provided, block 19 can rotate through 90‹ relative to block 13, contacts 3<1>, 14' bridge fixed contacts simultaneously and one of them is then connected by the extra moving contact to one of the extra fixed contacts to short-circuit the resistance; Figs. 5, 6 (not shown).