Timing unit for use in domestic equipment - has bimetallic disc heated to open and close contacts and operate lever to increment disc with ratchet to open contacts

摘要

A timing device for use in household equipment has an electrical heating element (4) on an aluminium oxide substrate (5). On the other side is a heated contact finger (6) that heats a bimetallic disc (7) when a set temperature is reached the contacts open and when the temperature falls the contacts close. The opening and closing cycle is used to operate a lever (18) coupled to a pawl (22) that increments a toothed wheel. After a specific rotation and time interval the main contacts (34) are opened. ADVANTAGE - Simple, reliable timing device.