| 摘要 |
467,720. Discharge apparatus. SHEVLIN, J. T. (Siemens & Halske Akt.-Ges.) Nov. 9, 1936, No. 30514. [Class 39 (i)] [Also in Group XXXVI] A ceramic envelope is provided with small openings for the leads and one or more larger openings for the electrodes, and the openings are sealed up by soldering. The ceramic parts may be metallized by applying a metal, e.g. iron, powder and heating in vacuo to sinter the layer to the base at a temperature of from 126‹ to 127‹ C. The soldering is effected by using silver solder in a hydrogen furnace, or the two steps may be performed in a single furnace. Diffusion resistances may be employed to keep a mercury vapour filling from the joint and the metal surface may be carbon-coated to prevent solder adhering where vapour may be present. The ceramic materials known under the Registered Trade Mark " Calit " or the names " calan " and " ultra-calan " may be used. In one form, Fig. 1, a ceramic envelope 1 has apertures 2, 3 for the anode leads, 4 for the pumping tube and 5 for the receptacle 6 of the mercury cathode 13. The caps 6, 7, 8, 9 are soldered over the openings, the anodes 11 being introduced at 5. Mercury is inserted through the tube 9 and after pumping this tube is sealed by hard solder 14. In a modification, a thermionic cathode and the anodes are introduced through a side-hole subsequently closed, and the cathode is mounted on leads passing through apertures similar to 2 and 3. The apertures may be closed by soldering-on metallized ceramic caps. The anodes may be replaced by a single anode plate closing the large aperture, or three such anodes, together with a cathode mounted on smaller plates, may be employed, Fig. 4 (not shown). The supply leads may be connected to bayonet pins on the envelope. The anode plates may be convex to the interior and metal screen members or coatings may protect the ceramic wall ; a cooling jacket may then be slipped over the device. In another modification, the anodes are corrugated or provided with cooling fins. As shown in Fig. 9, a control-grid 15 may be arranged between the cathode 2 and the anodes 7,8.
|
