Temperature responsive device

Claim 1

AN ELECTRICAL CIRCUIT RESPONSIVE TO VARIATIONS IN A VARIABLE CONDITION AND COMPENSATED FOR VARIATIONS IN AMBIENT TEMPERATURE, COMPRISING: (A) A BRIDGE CIRCUIT RESPONSIVE TO SAID VARIABLE CONDITION, SAID BRIDGE CIRCUIT INCLUDING: (1) A PAIR OF INPUT TERMINALS; (2) A PAIR OF OUTPUT TERMINALS; AND (3) ARMS INTERCONNECTING SAID INPUT AND OUTPUT TERMINALS, AT LEAST ONE ARM INCLUDING A VARIABLE RESISTANCE ELEMENT RESPONSIVE TO SAID CONDITION AND ALSO RESPONSIVE TO VARIATIONS IN AMBIENT TEMPERATURE; (B) A COMPENSATING RESISTANCE ELEMENT; (C) MEANS CONNECTING SAID ELEMENT IN SERIES WITH ONE OF SAID INPUT TERMINALS, SAID CONNECTING MEANS AND THE OTHER INPUT TERMINAL BEING ADAPTED FOR CONNECTION TO A SOURCE OF ELECTRICAL ENERGY; AND (D) MOUNTING MEANS FOR SAID RESISTANCE ELEMENT, INCLUDING: (1) AN INNER RING OF A MATERIAL HAVING A SUBSTANTIAL TEMPERATURE COEFFICIENT OF EXPANSION AND HAVING DIAMETRICALLY OPPOSED EXTERNAL PROTRUSIONS; (2) AN OUTER RING OF A MATERIAL HAVING A SUBSTANTIALLY LOWER TEMPERATURE COEFFICIENT OF EXPANSION ENGAGING SAID PROTRUSIONS SO AS TO STRESS BOTH SAID RINGS; AND (3) SAID INNER RING BEING ADAPTED TO CARRY SAID COMPENSATING RESISTANCE ELEMENT SO THAT SAID ELEMENT IS SUBJECTED TO STRAIN VARIATIONS CORRESPONDING TO VARIATIONS IN THE AMBIENT TEMPERATURE.