Control apparatus for fuel burning apxliances

Claim 1

A TEMPERATURE RESPONSIVE DEVICE COMPRISING AN EXPANSIBLE POWER ELEMENT, A CAPILLARY TUBE OPERATIVELY CONNECTED AT ONE END THEREOF TO SAID POWER ELEMENT, SAID CAPILLARY TUBE HAVING A UNIFORM OUTER DIAMETER AND BEING FORMED AT THE OTHER END THEREOF WITH A BULB PORTION COMPRISING A COUNTERBORE, SAID BULB PORTION HAVING A WALL OF REDUCED THICKNESS RELATIVE TO THE WALL OF SAID CAPILLARY TUBE, SAID OTHER END BEING SEALED TO FORM A FLUID-TIGHT INTERIOR COMPRISING SAID CAPILLARY TUBE AND SAID POWER ELEMENT, A TUBULAR EXTENSION WELDED TO THE UNDER SIDE OF SAID POWER ELEMENT AND BEING IN COMMUNICATION WITH SAID FLUID-TIGHT INTERIOR, A CHARGE OF TEMPERATURE SENSITIVE EXPANSIBLE FLUID DISPOSED WITHIN SAID FLUID-TIGHT INTERIOR AND BEING RESPONSIVE TO TEMPERATURE CHANBES WITHIN SAID BULB PORTION TO CAUSE MOVEMENT OF SAID EXPANSIBLE POWER ELEMENT, AND A STEEL BALL WELDED TO FORM A SEAL OVER THE OPEN END OF SAID TUBULAR EXTENSION AND TO PROVIDE A MOTION TRANSMITTING MEANS FOR SAID POWER ELEMENT.