Heavy duty windscreen wipers with self parking control - has bistable parking switch to prevent hang up between switch settings

摘要

The windscreen wiper motor is linked to the control switch by a single wire, with an earth return. The wiper is fitted with a parking switch for self parking. In large windscreen wiper systems the parking switch can finish in an intermediate setting, if there is too much drag on the blades. This effectively disconnects the motor from the supply, no matter what the switch setting. The parking switch is designed as a bistable mechanical switch which cannot stop in an intermediate setting. A simple alternative uses a conventional microswitch operated by the wiper cam.