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US 4,045,654 AGranted
Electric hotplate with thermostat
AssigneeA/S Ardal og Sunndal Verk
InventorSvein Eide
Life of this patent
Estimating the term…
Abstract
An electric hotplate with a thermostat includes a heating plate which is joined to the surrounding cold zones by means of a bridge of relatively thin sheet metal. The actuating device for a thermostatic switch is operated by the vertical movement of the heating plate. This movement arises as a consequence of the horizontal expansions and contractions of the heating plate due to changes in temperature, such movements being converted, by means of the bridge, which acts as a hinge, to vertical movements.
Claims9
A thermostatically controlled electric hotplate comprising:
- a horizontally aligned heating plate formed of thermally expandable material;
- an unheated zone surrounding said heating plate;
- electric heating element means, positioned beneath said heating plate, for, upon energization of said electric heating element means, heating said heating plate to cause horizontal expansion thereof, said heating plate being capable of horizontal contraction upon deenergization of said electric heating element means;
- bridge means, formed of flexible sheet material connecting said heating plate with said unheated zone, for transforming said horizontal expansion into upward vertical movement of said heating plate relative to said unheated zone and for transforming said horizontal contraction into downward vertical movement of said heating plate relative to said unheated zone;
- a switch electrically coupled to said electric heating element means, said switch having a closed position causing energization of said electric heating element means and an open position causing deenergization of said electric heating element means;
- and
- actuating member means, mechanically coupled to said heating plate and to said switch, for transmitting upward vertical movement of said heating plate to said switch to move said switch to said open position thereof and for transmitting downward vertical movement of said heating plate to said switch to move said switch to said closed position thereof.
4 more elements
Dependencies are inferred from the claim text.