Automatic lock de-icing esp. for vehicle - using key or pressure on lock to close contact to supply resistance heater built into lock casing

摘要

The electrically heated lock or key switch has an electric resistance heating element (1) either outside the outer casing (5) of the lock or between the outer casing (5) and the rotating inner part (4). The heating element (1) is surrounded by a heat resistant insulating material (2). The electric heating element is connected to the electricity supply by a contact which is operated either by pressure on the lock or by rotation of the key. In both cases the physical displacement of the lock brings the mobile part of the assembly into contact with the stationary part to close the electrical contact and initiate heating. A spring action opens the contact when the pressure is released.