Water heater for making drinks - has bimetal spring expanding to release spring lid that breaks electric supply

摘要

A tea or coffee making vessel has an immersion heater inside a suitably sized container and a thermostat that switches off the electricity supply when a given water temperature is reached. The container (4) has a hinged lid (8), and a helical spring (22) inside the handle tends to open the lid. The lid is held closed by a circular spring (104) consisting of a bimetal strip located in a slot around the underside of the lid. When a given temperature is reached the circular spring expands and releases the lid, which the springs open. As the lid opens, a contact fixed to it breaks with a contact near the lip of the container and interrupts the electricity supply.