Temperature control in liquid heating vessels

Abstract

A heater for a liquid heating vessel comprises a heater plate (2) for closing an opening in the base of the vessel and a heating element (10) formed on or mounted to the underside of the heater plate (2), the heater further comprising an automatically resettable thermally sensitive actuator (12) arranged to reduce or interrupt power to said heating element (10) at a first temperature and to re-establish power at a second lower temperature, wherein said second temperature is below the boiling point of the liquid and wherein the actuator (12) is arranged in direct thermal contact with the heating element (10). The actuator may comprise a button thermostat or a variable thermostat arrangement.

Description

technical field [0001] The present invention relates to temperature regulation of liquid in a liquid heating vessel, such as to maintain water at a temperature below boiling, suitable for brewing coffee. Background technique [0002] Liquid heating vessels with thermal insulation are well known in the art. Some units provide a first primary heater to initially heat the liquid, and a lower powered secondary heater to keep the liquid at or around the desired temperature. [0003] Alternatively, a single heating element may have a suitable thermostatic controller that cycles the element off and on to keep the liquid around the proper temperature. The latter arrangement is generally more cost-effective since it does not require the provision of additional components, but it does have some disadvantages. [0004] One problem associated with such devices is that thermostats used to sense water temperature tend to use snap-acting bimetal actuators or creep action bimetals with an...

Images