Automatic gas burner with variable flame port area

Claim 1

IN A FUEL GAS HEATER, AN ELONGATE GAS MANIFOLD, A GAS INLET FOR THE MANIFOLD, SAID MANIFOLD PROVIDED WITH SIDE OPENING APERTURE MEANS ARRANGED LONGITUDINALLY ALONG THE MANIFOLD FROM THE INLET AND THROUGH WHICH GAS MAY ESCAPE FROM THE MANIFOLD, A PLURALITY OF BURNERS WITH EACH COMMUNICATING IN GAS-RECEIVING RELATION WITH A PORTION OF THE LENGTH OF SAID APERTURE MEANS ALONG THE MANIFOLD, A RECIPROCABLE PISTON VALVE ELEMENT SLIDABLY SUPPORTED IN THE MANIFOLD AND YIELDINGLY BIASED TOWARD THE INLET AND RESPONSIVE TO AN INCREASE IN GAS PRESSURE WITHIN THE MANIFOLD TO SHIFT AWAY FROM THE INLET AND INCREASE THE EFFECTIVE LENGTH OF SAID APERTURE MEANS EXPOSED TO THE GAS TO MAINTAIN A CONSTANT GAS PRESSURE IN THE MANIFOLD AND RESPONSIVE TO A DECREASE IN THE GAS PRESSURE TO SHIFT TOWARD THE INLET AND REDUCE THE EFFECTIVE LENGTH OF SAID APERTURE MEANS EXPOSED TO THE GAS WHEREBY THE NUMBER OF OPERATIVE BURNERS IS A FUNCTION OF THE RATE AT WHICH GAS ENTERS THE MANIFOLD THROUGH SAID INLET, AND VALVE MEANS CONNECTED IN GAS DISCHARGE COMMUNICATION WITH SAID INLET TO REGULATE THE RATE AT WHICH GAS ENTERS THE MANIFOLD.