| 摘要 |
405,931. Vacuum switches. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Rankin, W. K.; 267, Highland Avenue, and Hayward, C. De W.; 59, East Plumstead Avenue, both in Lansdowne, Pennsylvania, U.S.A.) Oct. 12, 1933, No. 28225. Convention date, Oct. 12, 1932. [Class 38 (v).] Contacts.-A vacuum switch comprises a highlyevacuated glass or other insulating envelope 1 in which is sealed a metal bellows 5 carrying a bronze or other movable contact 4 and an operating member 7 for tilting 4 into selective engagement with either of two fixed contacts 2, 3. The latter are mounted on the ends 11 of conductors 8, 9 (Fig. 6) by means of the jaws 17 which are pressed tightly together about the ends 11, a disc 12 of lava or other insulating material being then applied and the conductors spread apart as shown in Fig. 1. In manufacture, a tapered glass collar 16 is placed within the top 5<a> of the bellows 5 over which it extends to form a bead, and is sealed to 5<a> by fusing, Fig. 3. The tube 15 is then slipped over 5a and heat and pressure applied to fuse and squeeze in the glass. Contact 4 and member 7 are then simultaneously butt welded to 5, after which the fixed contact assembly is located in position in the upper end of the tube 15, together with a glass exhaust tube. The end of 15 is then pinch or press-sealed to 8, 9 and the exhaust tube, and the glass is annealed and condensable vapours baked out. A vacuum pump is then applied to the exhaust tube and the latter is finally sealed off after exhaustion. Such a switch may be used for control of signal lights or for the reversal of a small motor by the split-field method. |
