Patent GB-429997-A (GB)
Title: Improvements in or relating to electrode arrangements for controlling electric arcs
IPC: H01T11/00
Filed: 1933-10-10
Abstract: 429,997. Discharge apparatus. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and THOMPSON, W. G., c/o General Electric Co., Ltd., Wembley, Middlesex. Oct. 10, 1933, No. 27935. [Class 40 (v)] [See also Group XXXVII] An electrode arrangement for a converter or an alternating - current interrupter comprises an electrode with a relatively long but narrow working face, means for producing a magnetic flux having a component across the face, and means for producing streams of fluid adapted to flow on opposite sides of the working face and to assist in maintaining the arc rooted thereon. An arc converter is provided with a pair of electrode arrangements each of which comprises a ring-shaped main electrode 1, Fig. 1, located between auxiliary electrodes 3, 4; then are housed in chambers connected by the cylindrical portions 7. A pair of electrodes is provided to deal with each phase. A plate 10 bolted to the cylinder 6 carries cylinders 2, 5 which support respectively the electrodes 1, 3. A magnetizable member 11 shaped at one end to fit the electrode 3 passes through the plate 10, and is bolted to a spider 12 which supports rods 13 passing through the electrode 4 and secured to an annulus 14. The spider, rods and the annulus are formed of magnetic material, and together with the member 11 and the winding 15 form a magnetic field in the gap between the electrodes 3, 4 to produce a rotation of the arc. The winding 15 may be cooled by fluid circulated through a surrounding jacket or pipes or through the armature. The distance between the main electrodes may be adjustable and may be twice that between the auxiliary electrodes ; the electrodes may be rectangular in cross-section and may be cooled by a circulating liquid. An air pump 20, driven by a motor 21, supplies air to the converter through pipes 17, 18. Upon the occurrence of an arc between opposite auxiliary electrodes, the air, which flows through the member 11 and through the gaps between each main electrode and its auxiliary electrodes, blows the arc on to the main electrodes and maintains it thereon. The arc is extinguished at the end of the cycle. The air is expelled through outlets 22 and the velocity of the air stream may be adjusted at both the inlet and outlet pipes. In another form, the main arc faces are formed on the ring-shaped electrode 30, Fig. 3, and the cylindrical electrode 31 which is closed by an insulating disc 35. The arc is initiated between the electrodes 29, 31 and between the electrodes 30, 32, and the direction of the gas is as shown. The electrodes may be provided with magnetic inserts. In another form, an alternating- current interrupter comprises an insulating cylinder 37, Fig. 4, closed by plates 38, 39 each of which is integral with main and screen cylindrical electrodes 40, 41 respectively. The plate 39 is provided with a sleeve 43 which registers an inner screen electrode 42. A spring 44 presses downwardly the electrode 42, the travel of which is limited by suitable stops. An inner hollow screen electrode 49 is connected to the plate 38 and is adapted to be moved vertically by the operation of switch mechanism, preferably of the snapaction type ; it is provided with a flange 50 adapted to close, in its upper position, an aperture in the plate 38. To break the circuit, the member 49 which contacts with the member 42 is moved downwardly, and the arc formed therebetween is rotated by a magnetic field and is blown on to the main electrodes 40, and maintained thereon, by air which enters at the inlets 53, 54 and circulates as shown. The arc is extinguished at the end of the cycle.