Heating and temperature control device for a bath-liquid

Claim 1

A bath-liquid heating and temperature control device, comprising a thermally conductive metal panel including means adapting one side of said panel for direct thermal response to a body of liquid, and a thermostat enclosure carried by the other side of said panel such that said panel forms part of at least one wall of the inner space otherwise defined by said enclosure, said enclosure having at least one vent to ambient air, whereby the air temperature of space within said enclosure is a composite reflection of both ambient-air temperature and the temperature of liquid to which said panel is thermally exposed, an electrical-heater element within said space, a power-input connection to said enclosure, thermostatic-switch means within said space and set to effectively disconnect said power-input connection from said heater element upon achievement of a predetermined upper limit of heating of said space above ambient temperature, the setting of said thermostatic-switch means being also such as to connect said heater element to said power-input connection for a detected temperature of said space below a lower limit above ambient temperature, and power-output connection means including a liquid-immersion electrical heater for immersion in the body of bath-liquid and so connected to said thermostatic-switch means that output power is deliverable via said power-output connection means coincidentally with connection of said heater element to said power-input connection, whereby said liquid-immersion heater may be effectively on-off regulated by said thermostatic-switch means in accordance with its composite response to the temperature of ambient air and of bath liquid.