| 摘要 |
1,104,674. Contacts; heavy current switches. LA TELEMECANIQUE ELECTRIQUE. 21 June, 1965 [22 June, 1964; 13 May, 1965], No. 26165/65. Heading H1N. The contact members 3 of a heavy current switch are divided in two by slots 6 and the contact surfaces 7 are so formed that current entering the contact by a base portion 1 can reach an arc root X only by an inwardly curving path such as M so as to create a magnetic force tending to move the arc root inwardly towards the slot and upwardly towards the tips of horns 12. Each contact is a channel-shaped member 3, slotted at 6 and cut away at 11, made of copper or a copper-chromium alloy, and having a silver contact element 7 brazed to it, the edges 8, 9, 10 of element 7 being bevelled. In a modification (Figs. 3, 4, not shown) the moving contact consists of two separately biased portions (29a, 29b) mounted together, to form the slot and cut away portions between them, upon a carrier (30). An arc extinguishing chamber composed of metal plates is mounted upon the switch terminals (21, 22). In another modification (Figs. 5-7, not shown), the triangular cut-away portion 11 is replaced by a circular hole (55). |
