GB428054A - A lock-switch for the electrical circuits of automobiles - Google Patents

Abstract

428,054. Mechanical switches without quick action. HARRIS, F., Harris' Garage, High Street, Barrow-on-Soar, Loughborough. Oct. 26, 1933, Nos. 29727/33 and 9151/34. [Class 38 (v)] A key-operated lock-switch for controlling the electrical circuits of motor vehicles, comprises a cylindrical casing 10 having its ends closed by insulating walls 12, 13. Rotatable in the upper end wall 13 is a lock barrel 14 formed with a square extension 17 terminating in a round spindle 18 having a bearing in the end wall 12 in which are fixed contacts 24, 25, 26, 28 and 29 having binding posts 22. A movable contact arm 20 is fixed at its centre to an insulating bush 23 which fits on the squared spindle 17 surrounding which is a spring 21 for biassing the arm 20 against the fixed contacts. The lock barrel is provided with tumblers 19 which, in the off position with the key 15 removed, engage in a recess 30, Fig. 4, in the central opening of member 13. The contact arm 20 bridges contacts 28, 29, to earth the ignition and by turning a knurled knob 16 the barrel 14 can be turned so as to cause the contacts 24, 25 to be bridged to connect the battery 37 to the side and tail lights 40, 41. The tumblers 19 now rest against a projection 31 and the switch cannot be rotated farther unless the key 15 is inserted to cause the tumblers to be withdrawn and projected oppositely into a wide recess 32. The switch can now be turned so that the arm 20 lies over the gap between contacts 25, 26 and this connects in circuit, in addition to the side and tail lights, the head lights 39 and the ignition coil and any other electrical devices through a switch box 42 and also the starter 38 through a switch 43. If the switch is rotated farther, the arm 20 bridges only contacts 24, 26 and the side and tail lights are switched off. If the key is withdrawn in the last two positions, the tumblers engage in the recess 35, but due to a sloping edge to stop 31 the switch can be rotated back to the first positions without the key, but not in the other direction. Thus on parking the car, the side and tail lights may be illuminated without using the key, but the ignition and starter are locked against unauthorized use. A modified circuit is shown in which the side and tail lights have no earth return. Reference has been directed by the Comptroller to Specification 407,967.