GB351335A - - Google Patents

Abstract

351,335. Arc-rupturing in switches. ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Bush House, Aldwych, London.-(Assignees of Baker, B. P. ; R.F.D. No. 1, Monroeville, Turtle Creek, and Dickinson, R. C. ; 750, Princeton Boulevard, Wilkinsburg, both in Pennsylvania, U.S.A.) Sept. 10, 1930, No. 27074. Convention date, Sept. 11, 1929. [Class 38 (v).] Magnetic blow-outs. - In switches of the deionization type, the arc formed on interrupting the circuit is formed in two seriesrelated sections of which one is established across a stack of spaced deionizing plates disposed in shunt with a field coil for producing a magnetic field to propel the other arc section into the deionizing structure. The stack of plates is preferably disposed in the centre of the deionizing structure. When the contact 3 moves away from the fixed contact 2, the arc formed impinges on an extension 12 of venting plates 5, such as described in Specification 332,851, [Class 38 (v), Electric switches &c.], and is divided thereby into two series-connected sections 13, 14. The section 13 is transferred to a deion structure 6, across which is connected at 9, 11 a blow-out winding 8, which thereupon is energized and drives the other section of the arc, which has assumed the position 15, into the main deion structure 4. The arc is arranged to rotate about a recurrent path in the structure 4, as described in Specifications 288,326 and 289,778, [both in Class 38 (v), Electric switches &c.]. The plates 5 may be of magnetic material and may, in a modification, Fig. 3 (not shown), carry a movable contact for engaging the contact 3 whereby the main arc is not built up until a strong blow-out field has been set up. The coil 8 in the form shown in Fig. 4 is connected by leads 26,27 to U-shaped plates 21,22 between which is an extended part 19 of the structure 4. When the contacts 17, 18 move away from one another, the arc is divided into sections by the members 21, 22, the current in which and magnetic members 24, 25 sets up a field acting on the arc. When the arc section 31 establishes the field due to coil 8, the arc is driven into the structure 4, assisted by interaction between the arc and the parallel currentcarrying conductors 26, 27, and caused to rotate by means of the radial field produced by coils 33. Tinfoil sheets may be placed round the covering of the structure to even out the potential gradient therein.