Patent GB-129700-A (GB)
Title: Improvements in Spark-gap Apparatus for use in Wireless Telegraphy.
Inventor: MARINO ALGERI
IPC: H01T9/00
Filed: 1917-11-29
Abstract: 129,700. Marino, A. Nov. 29, 1917. Spark-gap apparatus.-In a multiple spark-gap apparatus of the kind in which perforated plates provided with ridged electrodes are spaced apart by insulating-sheets, the mounting of the plates is effected by bolts situated outside the area occupied by the electrodes, which may be annular or rectilinear. The plates carrying the electrodes may be rotated, and, if a direct-current source is employed, the adjacent electrodes are of different shape and material. Means are provided for varying the number of gaps in the circuit. The electrodes are of silver or silvered copper, and the gaps may be placed in series, parallel, or seriesparallel. In the arrangement shown in Figs. 2 and 3, electrodes having curved surfaces 5, 5<1>, 5<11>, 5<111> are mounted upon rectangular plates 4 having central bosses 3 and boss extensions 8, 8<1>. The bosses 3, 8, 8<1> are insulated and separated by mica strips 2, 2<1> the thickness of which determines the distance between two adjacent electrodes. The portions of the plates 4 enclosed by the electrodes are provided with ventilating-holes 4<1>. The plates 4 are keyed to a rotating shaft 1; while the number of gaps in circuit is varied by means of bars 12 connected to slip-rings 10 and provided with set-screws 12<1> adapted to engage the electrodes. In the modification shown in Fig. 5, the central portions 3 of the plates 4 are provided with extensions having electrodes 5, 5<1> and ventilating- holes 4<1>. The central portions 3 may be provided with four or more extensions provided with electrodes. In the modification shown in Fig. 6, the plates 3 are provided with rectilinear electrodes having curved surfaces 5, 5<1> and with extensions 8 through which mounting-bolts 9 pass. The extensions 8 are provided with edges 12" which engage contacts connected to the generator. In a further modification, the rectilinear electrodes shown in Fig. 6 are replaced by two annular electrodes. In the modification shown in Fig. 9, the electrodes shown in Fig. 6 are rotatably mounted upon a spindle 1<1> by means of plates 13, and the connexions are varied by means of bars 12 and set-screws 12<1>. In the modification shown in Figs. 10 and 11, each central portion 3 is provided with extensions 4, 4<1> having annular electrodes 5, 5<1> and insulated extensions 8, 8<1>. The extensions of adjacent central portions 3 are placed at rightangles to each other. In a further modification, each central portion 3 is provided with a single electrode extension arranged at right-angles to adjacent pairs. Conducting-bars 12 and set-screws 12<1> are provided to vary the connexions of the apparatus. In the modification shown in Figs. 12 and 13, four piles of plates 3 are mounted between insulated spoke-plates 13<1> secured to a hub 14 upon a rotating shaft. The plates 3 are provided with rectilinear or annular electrodes. Each pile of plates is provided with two conducting- rings 10 so that the piles may be connected in series, in parallel, or in series-parallel. When direct current generators are used in conjunction with the spark-gap apparatus, the section of one electrode 5 is preferably triangular and the other electrode 5<1> rectangular, as shown in Fig. 15, while they are preferably made of different material. The use of insulating-material between the extensions 8 and bolts 9 may be avoided by forming the holes in the extensions 8 in the manner shown in Fig. 16, and by placing an insulating-sleeve 18 around the bolt 9. In a modification, the truncated portion 17<1> of the holes in the extensions 8 may be replaced by a cylindrical hole of larger diameter than the sleeve 18,