| 摘要 |
<p>1,157,180. Glass-metal seals. D. J. BELKNAP. 21 June, 1967 [8 July, 1966], No 28690/67. Heading C1M. [Also in Division H1]. An incandescent lamp, Fig. 2, comprises a tubular envelope 10 having a main section 14 made of soft or hard glass or ceramic material and a pair of conductive end sections 16, 18, e.g. of Pt, Fe-Ni alloy, Ni or Al, sealed to the main section and of sufficient diameter for the filament 12 e.g. of W to be inserted therethrough, the extremities 20, 22 of the filament being gripped by cold-weld vacuumtight pinch-offs formed in the end sections. Various methods are described for improving the electrical contact between the end sections and the filament, including providing larger diameter leads for the filament, forming indentations in the end sections between the pinchoffs and the regions at which they are sealed to the main section to grip the filament extremities, and providing an additional metal collar over each end section in the region of the pinch-off. In one method of producing the lamps a series of coiled filaments connected by straight sections of wire is constructed and envelopes, either separate or with successive main sections joined to common intermediate conductive sections, are threaded over the string of filaments, pinch-offs then being formed at one end of each envelope. The envelope-filament assemblies can then be evacuated or gas filled and completely sealed. An automatic machine for making the lamp is shown in Figure 17, and comprises a mounting block 46 consisting of metal plates 48, 52 separated by a rubber layer 50 and formed with a plurality of receptacles 60 for envelopes 10. A filament 12 is inserted into each envelope from above, if necessary with the aid of a thin-walled guide tube inserted from below, the nipple 66 of a vacuum manifold is applied to the lower end of the envelope, and pressure is applied between the plate 48, 52 to compress the rubber layer 50 thus forming a vacuum-tight seal. The upper end section is then indented and pinched-off by jaws 70 while the envelope is being flushed with argon or nitrogen and if necessary baked, and the envelope is evacuated or gas filled through the lower end section. The filament may be flashed before finally pinching-off the lower end section. The block 46 can be moved along in steps to several work stations at which the various operations are performed on the lamps.</p> |
