Thermostatic control for fireplace damper

Claim 1

IN A FIREPLACE HAVING A FLUE OPENING AND A DAMPER PLATE MOUNTED IN THE FIREPLACE FOR MOVEMENT BETWEEN POSITIONS CLOSING AND OPENING THE FLUE OPENING; (A) SAID DAMPER PLATE BEING PROVIDED WITH A VENT THERETHROUGH, (B) AN AUXILIARY DAMPER PLATE, (C) MEANS MOUNTING SAID AUXILIARY DAMPER PLATE FOR PIVOTAL MOVEMENT BETWEEN POSITIONS CLOSING AND OPENING THE VENT IN SAID DAMPER PLATE, (D) SAID AUXILIARY DAMPER PLATE HAVING OPPOSITELY OFFSET SIDE EDGE PORTIONS ENGAGEABLE WITH CORRESPONDING MARGINAL PORTIONS OF SAID DAMPER PLATE BOUNDING THE SIDES OF THE VENT THERETHROUGH IN OVERLYING AND UNDERLYING RELATION RESPECTIVELY WHEN SAID AUXILIARY DAMPER PLATE IS DISPOSED IN THE POSITION CLOSING THE VENT IN SAID DAMPER PLATE, (E) THERMOSTATIC CONTROL MEANS OPERABLY ASSOCIATED WITH SAID AUXILIARY DAMPER PLATE FOR REGULATING THE PIVOTAL MOVEMENT OF SAID AUXILIARY DAMPER PLATE IN RESPONSE TO CHANGES OF TEMPERATURE IN THE FIREPLACE, (F) SAID AUXILIARY DAMPER PLATE BEING IN A POSITION OPENING THE VENT IN SAID DAMPER PLATE WHEN THE TEMPERATURE IN THE FIREPLACE EXCEEDS A PREDETERMINED MAGNITUDE, AND (G) SAID DAMPER PLATE BEING MOVABLE TO A POSITION CLOSING THE FLUE OPENING WHEN A FIRE IN THE FIREPLACE HAS BEEN EXTINGUISHED AND SAID AUXILIARY DAMPER PLATE BEING OPERABLE TO MAINTAIN THE VENT OPEN FOR EXHAUSTING THE PRODUCTS OF COMBUSTION FROM SMOLDERING PORTIONS OF THE FIRE THROUGH THE VENT IN THE DAMPER PLATE AND THE FLUE OPENING UNTIL THE TEMPERATURE IN THE FIREPLACE DROPS TO THE PREDETERMINED MAGNITUDE.