| 摘要 |
417,553. Leading-in wires for electric incandescent lamps &c. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Zabel, W. P. ; 2060, Hanover Road, Cleveland Heights, Ohio, U.S.A.) Jan. 5, 1934, No. 454. Convention date, Jan. 5, 1933. [Class 39 (ii).] In an electric incandescent lamp or similar device having a bulb with a filament sealed therein, with an inner leading-in wire in the bulb connected at one end to the filament, this latter end is in a soft annealed condition passive to oxidation. The leading-in wire assembly comprises the inner leading-in wire 16, Fig. 1, of nickel or an alloy thereof, such as manganese nickel, which is connected to one end of a short wire 19 of a metal having the same coefficient of expansion as the stem-press 17 into which it is adapted to be sealed, the other end of the wire 19 being connected to an outer leading-in wire 20 of copper. The end of the wire 16 that is to be connected to the filament 12 may be annealed by heating it by the passage of an electric current therethrough in an atmosphere of a non-oxidizing gas or in a vacuum, or by radiated or conducted heat from a muffle or electric tube furnace. In one method the leading-in wire assembly, comprising a nickel or nickel-alloy inner wire 16, press wire 19, and copper outer wire 20 are placed in a horizontal tube 24 with the free end of the wire 16 projecting about an inch beyond the end of the tube. A gas, preferably hydrogen, is passed through the tube 24 and ignited at the end thereof, so that the flame surrounds a portion of the exposed end of the wire. An additional hydrogen flame may be directed on the exposed end by a burner 26 located below it. The end of the wire is thus heated to a temperature above 700‹ C., approximately 1100‹ C. in the case of a nickel wire, the purification and annealing being effected in one or two minutes. After the heating is effected a sleeve 27 surrounding the tube 24 is slid forward beyond the end of the wire 16, after which the flames are extinguished but the flow of hydrogen through the tubes 24, 27 is continued in order to cool the hot end of the wire without oxidation. In the case of heavy leading-in wires the whole of the wire assembly may be annealed in an ordinary hydrogen annealing furnace at about 750-800‹ C. before the end of the inner wire is brought to the softannealed oxidation-resisting condition. |
