Flame safeguard systems and devices

Claim 1

A FURNACE HAVING A FIRE BOX INCLUDING A REFRACTORY BURNER SUPPORTING WALL HAVING A NUMBER OF THROAT APERTURES THEREIN EXTENDING FROM THE EXTERIOR OF SAID FURNACE TO AN INNER END WITHIN THE SAID FIRE BOX, A MAIN BURNER DISPOSED ADJACENT THE OPPOSITE OUTER END OF EACH OF SAID THROAT APERTURES TO PROJECT AIR AND FUEL TOWARD SAID FIRE BOX THROUGH SAID THROAT APERTURE FOR COMBUSTION IN AN AREA WITHIN SAID THROAT APERTURE ADJACENT THE INNER END THEREOF AND SPACED A SUBSTANTIAL DISTANCE FROM SAID MAIN BURNER, A PILOT BURNER ADJACENT ONE SIDE OF EACH OF SAID THROAT APERTURES ADAPTED TO PRODUCE A PILOT FLAME IN SAID COMBUSTION AREA, A PASSAGE IN SAID WALL ADJACENT EACH OF SAID THROAT APERTURES EXTENDING FROM THE EXTERIOR OF SAID WALL AND OPENING INTO SAID THROAT APERTURE AT A SIDE THEREOF OPPOSITE SAID PILOT BURNER, SAID OPENING OF SAID PASSAGE INTO SAID THROAT APERTURE BEING NEARER THE INNER END OF SAID THROAT APERTURE THAN SAID PILOT BURNER, THE AXIS OF SAID PASSAGE ADJACENT ITS OPENING INTO SAID THROAT APERTURE BEING SUBSTANTIALLY ALIGNED WITH SAID PILOT BURNER, AN ELONGATED LIGHT-CONDUCTING MEMBER HAVING ONE END WITHIN SAID PASSAGE AND SPACED INWARDLY FROM THE OPENING A DISTANCE SUFFICIENT TO RESTRICT THE ANGLE OF VIEW OF SAID LIGHT-CONDUCTING MEMBER TO SUBSTANTIALLY ONLY THE COMBUSTION AREA WITHIN SAID THROAT APERTURE, THE OTHER END OF SAID LIGHT-CONDUCTING MEMBER BEING COUPLED TO A LIGHT RESPONSIVE CELL.