GB463619A - Improvements in electric switches with compressed-gas blow-out - Google Patents

Abstract

463,619. Fluid -- blast switches. MARX, E. June 28, 1935, No. 18547. Convention date, June 29, 1934. [Class 38 (v)] A switch of the type in which the break-arc is extinguished by a gasblast and having oppositely-arranged apertured switch electrodes and main switch electrodes arranged behind the apertured electrodes, has' the latter serving mainly as electrical screens and the adjacent surfaces of each main and associated screen electrode so spaced and shaped that an area of low gas-velocity is set up in front of the main electrodes whilst the stream issuing from the aperture in the screen electrode is substantially deflected radially. The drawing shows, in the open position, a switch having two oppositely-arranged electrode systems of different construction, the screen electrodes 1, 2 surrounding the main electrodes 3, 4 and being provided with apertures 5, 6, the length b of which equals, or exceeds, the diameter d. The arrows show the blast directions, and the spaces 7, 8 show the regions of low velocity, which regions are enlarged by incurving the electrodes 3, 4 at 9, 10. The Specification gives an expression relating the electrodes separation a with the arc-chamber pressure and reverse break-down voltage. Each screen electrode may be made resilient adjacent the aperture, so that the latter may adjust itself to the gaspressure or to the pressure of a resilient contact engaging therewith. The main electrodes may serve as contact-making elements, the spacings then being those of the elements in the open position. The main and screen electrodes may be arranged so that one or other form main and auxiliary contact-making members, and the screen electrodes may be kept at a different potential from that of the main electrodes. Reference has been directed by the Comptroller to Specification 458,101.