GB155554A - Improvements relating to electron-discharge devices - Google Patents

Abstract

155,554. Lilienfeld, J. E. Dec. 12, 1919, [Convention date]. Vacuum tubes; R÷ntgen-ray tubes.-The electron stream of a high vacuum tube for use as a detector, relay, oscillation-generator, or R÷ntgen ray tube, is produced by a discharge across a small gap between two electrodes. One or both electrodes are preferably formed with a pointed end or sharp edge, and the gap is of the order of 3 mm. Adjustment of the length of the gap may be effected bv means of one or two heating-coils mounted inside the hollow copper or iron supports for the electrodes, or by means of a press acting on an elastic glass or metal part. In the R÷ntgenray tube shown in Fig. 3, the electrode C is mounted on a spring-controlled iron core J, theposition of which can be adjusted by means of a solenoid M. The electrodes, of tungsten, tantalum, or platinum, may be arranged symmetrically or otherwise, and may be of disk, annular, hemispherical, or paraboloidal shape, or may be arranged as co-axial cylinders or cones, or one electrode as a cone and the other as a disk. An incandescent filament may be used for expelling gases from the electrodes during exhaustion. In the arrangement shown in Fig. 4, the electrode C is spaced by quartz rings Q from a hollow electrode B having a focussing extension J, and mounted on a spring F and wire loops S. The discharge between the electrodes B, C is started by a transformer Z, and the discharge to another electrode D maintained bv means of another transformer R, or a single transformer may be used, the electrode C being connected with a point on a high resistance in the secondary circuit. In the arrangement shown in Fig. 5 for producing high-frequency oscillations, two anodes A<1>, A<2> are mounted symmetrically with respect to the pointed cathode K. The anode A<1> is connected with the positive terminal of a dynamo D through an inductance L and condenser C in parallel, and the other anode A<2> is connected therewith through an inductance L<1> and condenser C<1> in parallel, an inductance L<3> coupled with the inductance L, and a switch S. Closure of the switch S causes oscillations to be set up in the circuits LC, L<1>C<1>, which are tuned to the same frequency, and coupled to an aerial. In another arrangement, Fig. 6, for producing oscillations, an electron discharge is produced between a sharpedged or pointed cathode K and a closely adjacent electrode H. An anode A is connnected with a dynamo D<2> through a condenser C in parallel with an inductance L coupled with an inductance L<1> between a grid G and the electrode H. Specifications 14892/13 and 15788/14 are referred to.