| 摘要 |
The invention relates to a process for obtaining electric contact plates for switches of low and medium power. According to the invention, the process consists in the thermal diffusion of the zinc oxide or cadmium oxide between two rolled metal strips, a thin silver rolled strip (2) and a thicker copper rolled strip (4), the two strips (2 and 4) being slowly unwound from some drums (1 and 3), and the oxide being spread on the entire surface of the copper strip (4) by means of an electrodynamically vibrated leveling system. After overlapping the two metallic strips (2 and 4) over the oxide layer, an infrared laser (13) is moved, on the X-Y coordinates, and emits a photon impulse towards the silver strip (2), at pre-set computer-controlled intervals, to generate a local melting, forming a local metal bath of melted silver which includes oxide particles and small quantities of copper, and, after the melted metal bath solidification, resulting in a sandwich-type welded structure from which, by a multiple punching, some coarse cylindrical contact plates (18) result in a first stage and, by compacting them and after cylindrical calibration, finished electric contact plates (19) are finally obtained. |
