Method of and apparatus for simultaneously flame-cutting and hardening toothed objects

Claim 1

IN THE METHOD OF FLAME CUTTING TOOTHED OBJECTS SUCH AS GEARS FROM HARDENABLE METAL BLANKS, THE CHARACTERIZING STEPS OF: WHILE TEETH ARE BEING CUT IN THE BLANK BY A CUTTING TORCH AND INDEPENDENTLY OF SAID TORCH, LOCALLY HEATING NARROW ZONES OF THE BLANK ARCOSS WHICH THE FLAME OF THE CUTTING TORCH IS TO PASS IN CUTTING THE FLANKS OF THE TEETH, IMMEDIATELY PRIOR TO FLAME CUTTING THE FLANKS OF TEETH, TO RAISE THE TEMPERATURE OF THE METAL AT SAID ZONES TO A VALUE LESS THAN THE MELTING POINT OF THE METAL, SO THAT THE PREHEATED METAL ALONG THE FLANKS OF THE TEETH BEING CUT BY THE FLAME ATTAINS ITS CRITICAL HARDENING TEMPERATURE TO A GREATER DEPTH THAN THE METAL ALONG THE ROOTS OF THE TEETH AND OUSTIDE OF SAID ZONE; AND QUENCHING THE FLAME CUT FLANKS OF HE TEETH AT A ZONE REMOTE FROM THAT AT WHICH LOCALIZED PREHEATING IS TAKEN PLACE.