Icing prevention for windscreen wipers

摘要

The windscreen wipers can be lifted out of contact with the windscreen by a servo drive when a temperature sensor detects freezing conditions. This lifting action operates only when the vehicle is parked ie. with the engine/ignition switched off. When the vehicle is started the system drops the wipers blades back into contact with the windscreen. The system can be fitted to both the front and rear windscreens. The lift off action can be provided by cams linked to a servo motor. Alternately the lifting action can be provided by the end stop controls for the wiping action, with a servo drive to lift the stops and the wipers. The freezing point is determined by the setting on a Zener diode in the control circuit.