Electric lamp manufacture

Claim 1

IN THE MANUFACTURE OF A TIPLESS DOUBLE-ENDED INCANDESCENT LAMP, THE STEPS WHICH COMPRISE ARRANGING IN END PORTION OF AN EXHAUST TUBE OF VITREOUS MATERIAL DIRECTLY WITHIN A FIRST END PORTION OF AN ELONGATED TUBULAR ENVELOPE OF VITREOUS MATERIAL, HEATING AND SOFTENING THE SAID FIRST END PORTION OF SAID ENVELOPE AND PRELIMINARILY COLLAPSING IT UPON AND FUSING AROUND THE SAID END PORTION OF THE EXHAUST TUBE WHILE MAINTAINING THE OPENING THROUGH SAID EXHAUST TUBE TO THE INTERIOR OF THE ENVELOPE, THREADING INTO THE ENVELOPE A FILAMENT ASSEMBLY COMPRISING A COILED FILAMENT HAVING FIRST AND SECOND LEAD-IN CONDUCTORS ATTACHED TO RESPECTIVE ENDS THEREOF AND MAINTAINING THE RESULTING ASSEMBLY WITH THE SAID FIRST CONDUCTOR EXTENDING INTO AND THROUGH SAID EXHAUST TUBE AND HELD THEREIN AGAINST LONGITUDINAL MOVEMENT AND THE SAID SECOND CONDUCTOR EXTENDING ALONG AND OUTWARDLY THROUGH THE SECOND END OF SAID ENVELOPE WITH THE FILAMENT STRETCHED TAUT BETWEEN SAID CONDUCTORS, SEALING THE SAID SECOND END OF THE ENVELOPE WITH A PORTION OF THE SECOND CONDUCTOR SEALED THEREIN, EVACUATING THROUGH AID EXHAUST TUBE WHILE A DESIRED ATMOSPHERE THROUGH SAID EXHAUST TUBE WHILE HEATING SAID FILAMENT BY PASSAGE OF ELECTRIC CURRENT THERETHROUGH DURING AT LEAST PART OF THE OPERATIONS OF EVACUATING AND FILLING THE ENVELOPE, HEATING AND SEALING CLOSED THE PRELIMINARILY COLLAPSED FIRST END PORTION OF SAID ENVELOPE WITH A PORTION OF THE FIRST CONDUCTOR SEALED THEREIN, AND REMOVING THE PORTION OF SAID EXHAUST TUBE EXTENDING FROM THE SEALED FIRST END OF SAID ENVELOPE.