Incandescent lamp having seal-anchored filament mount, and method of making such lamp
AssigneeWestinghouse Electric Corp.
InventorsJack Martin, Elam Pitkjaan
Life of this patent
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Abstract
The envelope of a compact halogen-cycle incandescent lamp is made from hard glass and the uncoiled legs of the tungsten filament are used as filament connector-support members by fastening them directly to flattened ends of a pair of single lead wires and embedding the resulting electrical junctures in the hermetic seal of fused glass which is formed on the end of the envelope. The lead wires originally comprise the legs of a hairpin-shaped wire member which permits the filament-mount to be made and handled as a separate subassembly. The U-bent part of the hairpin-shaped wire member is severed and removed after the mount has been sealed into the envelope to provide the required pair of separate lead wires.
Claims11
In an electric incandescent lamp that has a glass envelope which is terminated at one end by an hermetic seal of fused glass, the improvement comprising the combination of;
- a refractory wire filament having a coiled body and a pair of uncoiled leg portions the ends whereof are substantially disposed in side-by-side relationship, and
- a pair of lead-in wires that have flattened end portions which are fastened to the ends of the filament leg portions by a welded juncture or a brazed junction and thus form electrical junctures that are devoid of separate interconnecting conductor members,
- the uncoiled leg portions of said filament being of such length that at least a part of each of the electrical junctures is embedded in the fused-glass seal so that said leg portions are securely anchored in the seal and thus serve as electrical-connector members and the sole mechanical-support means for the coiled body of the filament,
- the lead-in wires being of such length that the free ends thereof protrude from the sealed end of the envelope.
In the manufacture of an incandescent lamp that has a glass envelope which is adapted to be closed at one end by an hermetic seal that is formed by fusing and collapsing an end portion of the envelope, the method of first fabricating a filament-mount assembly for the lamp that can be handled as a separate component and then subsequently sealing said assembly into the envelope, which method comprises;
- bending a piece of lead-in wire material into a hairpin-shaped member,
- flattening the free ends of said lead-in wire member,
- forming a filament having a coiled body and laterally-extending uncoiled leg portions and fastening the ends of said leg portions to the flattened ends of the lead-in wire member to provide electrical junctures that hold the lead-in wire member and filament in operative relationship and thus produce a filament-mount assembly,
- inserting the filament-mount assembly into the envelope and positioning said assembly in a manner such that the electrical junctures are so located relative to the end portion of the envelope that they are at least partly embedded within the hermetic seal of fused glass when the said end portion of the envelope is fused and collapsed onto and joined to the assembly during the sealing-in operation, and then
- severing the U-bent portion of the hairpin-shaped lead-in wire member to provide the required pair of separate lead-in wires for the lamp.
Dependencies are inferred from the claim text.