| 摘要 |
<p>1,187,736. Making electron-guns. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 21 Oct., 1968 [24 Oct., 1967], No. 49868/68. Headings B3A and B3V. [Also in Division D4] A method of making an assembly comprising a plurality of elements of sheet material arranged parallel to and behind each other and provided with apertures in coaxial alignment, which method includes securing the components in their correct relative positions before providing the apertures and then forming the apertures by spark erosion in a flowing liquid. Electrodes 1, 2, 3 of an electron-gun are arranged on a jig (not shown) and welded to supporting rods 4 which are sealed in glass rods 5. After removing the jig, the assembly is placed on a centring jig 6 and the electrodes connected to one terminal of a spark generator power supply 11. An electrode 7 is moved forwardly to make progressively larger holes in the electrodes and during this process the assembly is in a flowing liquid, e.g. deionized water, to remove metal particles released by the sparks. With deionized water, to avoid electrolytic pickling of the apertures, a pulse generator may be used or the polarity of the spark voltage may be inverted. The apertures may be of any shape and if desired the largest aperture may be formed in the intermediate electrode.</p> |
