Patent Publication Number: US-4149103-A

Title: Incandescent lamp having embedded support means

Description:
THE INVENTION 
     This application is a continuation-in-part of Ser. No. 702,659 filed July 7, 1976. 
    
    
     This invention concerns press-sealed single-ended incandescent lamps. An example of such a lamp is shown in U.S. Pat. No. 3,829,729 the disclosure of which is incorporated herein by reference. This invention is particularly concerned with the situation where such a lamp is coaxially mounted in a curved reflector. In such a case support rods extend through the reflector and the lamp is supported on the rods. 
    
    
     FIG. 1 shows a lamp in which a single support wire extends from each side of the press. 
     FIG. 2 shows a lamp in which two support wires extend from each side of the press. 
     FIG. 3 shows a lamp in which a sheet metal support extends from each side of the press. 
    
    
     The same element in each figure in the drawing is identified by the same number. Each lamp comprises a tubular glass envelope 1 containing a coiled tungsten filament 2 mounted on lead-in wires 3 which are sealed in, and extend through, press seal 4. If desired, the external portion of each lead-in wire 3 could be curved back on itself, the end secured in press seal 4, to form loop 5. 
     When the support means for the lamp is a single support wire 7 extending from each side of press seal 4, as shown in FIG. 1, and when the lamp is horizontally mounted in a reflector after support wires 7 have been welded to support rods 8, there can be an undesirable torsional force on each support wire 7. 
     In this invention such torsional forces are substantially eliminated by providing a support means which can be fastened to support rod 8 at more than one point running lengthwise with the lamp. In FIG. 2 each support means comprises two support wires 6 spaced apart from each other, embedded in press seal 4 and extending from the same longitudinal edge of press seal 4. If desired, the two support wires 6 can be a single U shaped wire or more than two support wires 6 can be used on each side. Support rods 8 are welded or brazed to support wires 6 as shown in FIG. 2. 
     In the embodiment shown in FIG. 3, each support means comprises a flat sheet metal support 9, for example, 10 mil thick kovar alloy, embedded in press seal 4 and extending from the longitudinal edge of press seal 4. Support rod 8 is welded to sheet metal support 9 at two or more points along the length of rod 8.