BOILING LIQUID SWITCH FOR ELECTRICAL APPLIANCES Russian patent published in 1995 - IPC

FIELD: domestic electrical appliances. SUBSTANCE: switch has vapor-trapping screen with gas vent 2 mounted in liquid being heated, device for turning off heater 3 in case vapor is held under screen 1, rod 4 loosely mounted in gas vent 2 and joined with float 5 moving vertically in respect to screen and possessing permanent positive buoyancy or that provided by raising vapor. In case of water level variation or liquid boiling, rod 4 is set in vertical displacement from float 5 and as soon as it comes in contact with edges of gas vent 2, the latter is cleaned of scale together with rod 4. In particular case, to ensure reliable turn-off of heater at slow boiling, rod 4 may be made for partial or full closure of gas vent 2 in its top position and is joined with float 5 placed above screen 1. EFFECT: improved reliability in operation. 2 cl, 1 dwg