Oil burner control system

Claim 1

IN AN OIL BURNER CONTROL SYSTEM COMPRISING AN OIL BURNER IGNITER, ROOM THERMOSTAT SWITCH, AND A BURNER SUPPLY UNIT WHICH INCLUDES AN OIL CHAMBER MEANS, AN OUTLET PORT FOR THE CHAMBER MEANS ADAPTED TO COMMUNICATE WITH THE BURNER, A VERTICALLY MOVABLE METERING STEM ARRANGED WITHIN THE CHAMBER MEANS TO MOVE UPWARDLY FROM A FIRST POSITION FULLY CLOSING THE OUTLET PORT TO A SECOND PARTIALLY OPEN LOW FIRE POSITION AND THEN TO A THIRD FULLY OPEN HIGH FIRE POSITION, SPRING MEANS TENDING TO MOVE THE METERING STEM UPWARDLY FROM ITS FULLY CLOSED POSITION TOWARD ITS FULLY OPEN POSITION, A SOLENOID-ARMATURE ASSEMBLY EFFECTIVE WHEN THE SOLENOID IS ENERGIZED TO PERMIT THE STEM TO MOVE UNDER THE INFLUENCE OF THE SPRING MEANS, A THERMOSTATIC STRIP HAVING A PORTION THEREOF ARRANGED TO LIMIT UPWARD MOVEMENT OF THE STEM TO THE LOW FIRE POSITION WHEN THE SOLENOID IS ENERGIZED, AND AN ELECTRIC HEATER ARRANGED TO THERMALLY WARP THE THERMOSTATIC STRIP FOR THEREBY ALLOWING THE SPRING MEANS TO RAISE THE STEM FROM ITS LOW FIRE POSITION TO ITS FULLY OPEN HIGH FIRE POSITION: THE IMPROVEMENT COMPRISING A UNITARY CONTROL CASING STRUCTURE POSITIONED ATOP THE CHAMBER MEANS AND DEFINING A FLOOR; SAID SOLENOID ARMATURE ASSEMBLY, THERMOSTATIC STRIP, AND ELECTRIC HEATER BEING LOCATED IN SAID CONTROL CASING STRUCTURE WITH THE UPPER END PORTION OF THE METERING STEM EXTENDING INTO SAID STRUCTURE; A SINGLE STEP-DOWN TRANSFORMER LOCATED WITHIN THE CONTROL CASING STRUCTURE; AN ENERGIZING CIRCUIT FOR THE SOLENOID AND ELECTRIC HEATER CONNECTED TO THE SECONDARY OF THE TRANSFORMER, SAID CIRCUIT INCLUDING SAID THERMOSTAT SWITCH TO CONSTITUTE A CONTROL FOR THE SOLENOID AND HEATER; THE ARMATURE COMPRISING A PLUNGER LOCATED ON THE SOLENOID AXIS DIRECTLY ABOVE THE METERING STEM WITH ITS LOWER FACE ARRANGED TO ENGAGE THE STEM UPPER END; A CONTROL CIRCUIT FOR THE IGNITER INCLUDING A SOURCE OF LINE VOLTAGE AND A SNAP SWITCH MECHANISM LOCATED IN THE CONTROL CASING STRUCTURE AND HAVING A HINGED OPERATOR ARM EXTENDING INTO ENGAGEMENT WITH THE PLUNGER LOWER FACE; SAID THERMOSTATIC STRIP BEING LOCATED SUBSTANTIALLY DIRECTLY ABOVE THE HEATER AND PARALLEL THERETO, A HEAT SHIELD INTERPOSED BETWEEN THE HEATER AND THERMOSTATIC STRIP, AND A MOUNT FOR THE THERMOSTATIC STRIP COMPRISING A BIMETAL ARM EXTENDING UPWARDLY FROM THE AFOREMENTIONED FLOOR AT ONE END OF THE STRIP; SAID BIMETAL ARM BEING POSITIONED SO THAT AMBIENT TEMPERATURE DECREASE TENDS TO CAUSE IT TO EXERT AN UPWARDLY ACTING FORCE ON SAID PORTION OF THE THERMOSTATIC STRIP SUCH THAT LOW AMBIENT TEMPERATURES ARE INEFFECTIVE TO PREVENT THE HEATER FROM WARPING THE STRIP UPWARDLY.