Switch and electric switch, based on the principle of the spark negligible

摘要

432,250. Mercury and other conducting-liquid switches. HARTMANN, J. F. G. P., 10, Kastelsvej, Copenhagen. Dec. 21, 1934, No. 36753. Convention date, Dec. 22, 1933. [Class 38 (v)] In electric liquid jet commutators or interrupters such as are described in Specifications 102,977, 166,654, 227,720, 227,721, 243,958, 251,189, 292,790, 295,817, [all in Class 38 (v)], 395,748, and 398,455 in which the arc produced during operation takes place between points substantially on the conductive liquid and in which one or more jets of a conductive liquid, preferably mercury are utilized, the liquid being moved in a circuit comprising an electrode chamber, and a pump outside said chamber, the said liquid being separated from the external atmosphere area a substantial part of the circuit by the walls of the circuit and an inactive gas being present in the electrode chamber, all parts of the circuit are closed and sealed from the exterior and all spaces of the circuit which are riot occupied by the liquid are filled with inactive gas. As shown in Fig. 1, the mercury jet is projected from a pipe 30 projecting through the cover of the electrode chamber 10 which is filled with inert gas the mercury being afterwards moved around a circuit consisting of pipes 16, 17, 23, 24 and 29 by means of a motor-driven centrifugal pump 22. This circuit is closed and sealed from the exterior and the free space therein is filled with inactive gas which is led in from a pipe 43, cock 41 and pipe 40 into the electrode chamber 10 and a pipe 33 into the portion below pipe 24. The chamber 10 has a liquid seal 13, 14 between the cases and the body and a sealed relief valve 15. The pump is sealed by arranging a long narrow annular space between the driving shaft 20 and a cylindrical portion 21 of the casing so that a volume having little free surface and not participating in the circulation produced by the pump is separated from the main part of the mercury in the casing 21. Alternatively the complete motor and pump unit may be mounted in a sealed casing. After passing through the pipe 21 the mercury emerges in a continuous stream from an aperture 25, strikes the base 26 and emerges from side apertures 27. The falling mercury is received in a container 28 surrounding the lower end of the tubular member 24 the bottom of this container being perforated so that the mercury falls therethrough as a shower of drops and is received in the container 29. This provides an electric interruption in the mercury circuit. A similar device 37 deals with overflow from the chamber 29. The whole circuit being thus free from oxygen, sparking is suppressed and oxidation of the mercury is obviated. When the gas filling takes place the cock 41 is moved to the position shown at II so that air in the circuit can escape through pipe 42.