Filament shield for sealed headlamp and mounting method therefor

Abstract

The two legs of a headlamp filament are welded to a headlamp filament shield to form a subassembly intermediate in the manufacturing process. The rigid nature of the filament/shield subassembly thereupon allows handling during assembly without displacing the filament from its precise location with respect to the shield as required by modern automotive headlamps. The filament/shield subassembly is welded to support pins in its final location in the lamp. A portion of the filament shield, orginally providing an electrical short circuit across the filament is trimmed away after welding to the support pins to make the lamp operational.

What is claimed is: 
     
       1. A method of assembling the filament and metallic filament shield in a automotive type headlamp comprising: a. preassembling said filament and filament shield into a rigid subassembly, said filament being welded at each of its two mounting legs to said filament shield whereby an electrical short circuit is formed through said metallic filament shield between the ends of said filament; then   b. welding said subassembly to support pins in a reflector of said headlamp, said support pins also being adapted to providing electrical connection to said filament; and then   c. cutting away the connecting metal between i. a portion of said filament shield to which one of said support pins and one end of said filament are welded and   ii. the remainder of said filament shield, whereby the electrical short circuit of said filament previously existing through the body of said filament shield is removed.     
     
     
       2. An automotive headlamp comprising: a. reflector;   b. first and second support pins sealably piercing said reflector;   c. a metallic filament shield;   d. a lateral projection from said filament shield;   e. a lamp filament initially welded at its first end to said filament shield and welded at its second end to said lateral projection from said filament shield;   f. a mounting flange on said filament shield adapted to engagement with said first support pin;   g. means for weldably bonding said mounting flange to said first support pin;   h. said lateral projection on said filament shield being adapted to engagement with said second support pin;   i. means for weldably bonding said lateral projection to said second support pin; and   j. a narrow region on said lateral projection adapted to being cut away to sever the mechanical and electrical connection between the portion of said projection containing the connection with said second end of said filament and said second support pin and the remainder of said filament shield, whereby the electrical short circuit previously provided between the ends of said filament through said filament shield is removed.   
     
     
       3. In an automotive headlamp of the type containing a helical filament and a filament shield, the filament and shield assembly comprising: a. a flat flange containing a generally rectangular depression;   b. a mounting flange containing a longitudinal concavity adapted to assembly to a mounting pin;   c. a depression in said flat flange adapted to providing clearance for one leg of a lamp filament;   d. a bump in said flat flange adapted to welding attachment of a second leg of a lamp filament; and   e. a lamp filament fitted with said depression having one of its filament legs passing through said depression to a welded attachment to a mounting pin, said second filament leg being welded to said bump.   
     
     
       4. A headlamp filament and shield assembly comprising: a. a flat flange containing a generally rectangular depression;   b. a mounting flange containing a longitudinal concavity at one edge of said flat flange;   e. a lateral projection at the edge of said flat flange remote from said mounting flange;   d. a depression in said flat flange adjacent to said lateral projection;   e. a bump in the same side of said flat flange as said lateral projection; and   f. a lamp filament suspended within said depression having one of its filament legs welded to said bump and the other of its filament legs passing through said depression and being welded to said lateral projection.   
     
     
       5. A lamp filament shield comprising: a flat flange containing a generally rectangular depression;   b. a mounting flange containing a longitudinal concavity at one edge of said flat flange;   c. a lateral projection at the edge of said flat flange remote from said mounting flange;   d. a depression in said flat flange adjacent to said lateral projection; and   e. a bump in the same side of said flat flange as said lateral projection.   
     
     
       6. An automotive headlamp made by the method in claim 1.