Lampe électrique à courant continu à atmosphère de gaz noble avec cathode incandescente

398,829. Discharge lamps. LEDERER, A., Hermesvilla, Vienna. Feb. 19, 1932, No. 5061. Convention date, Feb. 20, 1931. [Class 39 (i).] Direct-current electric gaseous discharge lamps of the kind described in Specifications 364,088 and 371,372, wherein one or more heated, electron - emissive electrodes in an atmosphere-of a rare gas or gases produce an intense core light or aureole adjacent to and all around the hot electrode or electrodes, and a feebler lighting outer zone or shell, the anode is formed of rods or wire so as to have a small total surface area and surrounds the electron-emissive electrode or its imaginary extension so as to provide a substantially uniform, or at least symmetrical, electric field around the electron-emissive electrode. In one form the anode 10, Fig. 1, consists of a wire arranged as a helix with its axis substantially coincident with the axis of the tubular hot cathode 2, a wire 17 serving as a support for the wire helix. The hot cathode 2 consists of a nickel tube with a thermionic active coating and a heating filament 3 passing through the interior, the lower end of the filament being connected to a leading in wire 4 and the upper end connected through the anode to the other leading-in wire 5. The tube 2 is closed at its ends by stoppers 6, 7 of refractory insulating material which have a central aperture for the passage of the wire 3. A clamp 8 supports the tube 2 on the supporting wire 4, and an oblique wire 9 secured to the latter forms a strut for supporting the lower stopper 6. An insulator may be interposed between the tube 2 and the heating filament. In a modification the anode forms a cage consisting of parallel wires or rods arranged parallel to the axis of the hot electrode, with their ends connected by annular conductors. Two rods only arranged in the same plane and equidistant from the hot electrode may, in some instances, produce the symmetrical field. In a further modification, the anode 14, Fig. 3, consists of an annular wire arranged within the neck of the bulb to encircle the mount 15.