GB601843A - Improvements in thermostatically controlled electric water heaters - Google Patents

Abstract

6 0 1,8 4 3. Electric water heaters. McDOWELL, O. A. Oct. 5, 1945, No. 25953. [Class 39(iii)] [Also in Group XIII] An electric water heater comprises a thermostat n, o, within a riser tube f enclosed in a down cast pipe i which is surrounded by and heat-conductively connected to electric heater elements sand t at at least two levels, the whole assembly, which is removable, being disposed within a water tank a having an outlet tube v. Water to be heated enters the tank a, which is enclosed in an outer casing b, by a tubular spigot d in the base of the tank, and flows into the inner pipe f, through a slot f<1> into the outer pipe i, and from there via a slot il into the tank. The thermostat consists of a brass sleeve n, depending from a cover plate j, secured at its lower end to an inner rod o of iron-nickel which carries at its upper end a cross bar r carrying adjustable tappets r<1>, r<2>, which cooperate respectively with switches s<1>, t<1>. The cold incoming water cools the sleeve n, which contracts, so raising the tappets r<1>, r2, and allows first switch t<1>, then subsequently switch s<1> to close, the arrangement of the tappets being such that the circuit to heater t is closed before, and opened after, that of heater s. A corrugated copper sheet u facilitates the transfer of heat from the elements to the outer tube i. Tube f is closed at its upper end, and tube i at its upper and lower, except for a vent l<2> to prevent back-siphoning should the connection to the tube d become broken.