GB814743A - Improvements in windscreen wiper actuator mechanisms - Google Patents

Abstract

814,743. Toothed gears. GENERAL MOTORS Ltd. Nov. 12, 1956 [Nov: 24, 1955], No. 33726/55. Class 80 (1). [Also in Group XXIII] An electrically operated windscreen wiper mechanism comprises a manually operated switch and a second switch comprising a movable contact embodied in a gear-wheel for rotating the wiper actuating shaft and a fixed contact engaging the movable contact but which is electrically disconnected therefrom in a predetermined position of the shaft. As shown, a wormwheel 5, made of a synthetic plastic material, e.g. nylon, driven by a worm 4 on a motor spindle has a metal disc 9 flush with its surface, the disc having a 90 degrees sector removed. A resilient contact 15, attached to an insulating cover 10 by a pin passing therethrough and connected to a second resilient contact 17, engages the disc 9. The resilient contact 17 engages a fixed contact 19 and is engaged by a manually operated lever 22 adjustable into three positions, one in which it is disengaged from the contact 17, one in which it engages the contact 17, and one in which it engages the contact 17 but disengages the contact from the fixed contact 19. In the first position the motor is switched off, in the second position the motor is rotated at slow speed, and in the third at high speed. On moving the lever 22 to the " off " position the motor circuit is completed through the switch 9, 15 until the 90 degrees gap in the disc 9 comes in contact with the fixed contact when the motor is stopped. The gap is so arranged in relation to the position of the wiper arm that the latter is in the " parked " position when the motor is switched off.