Patent GB-409099-A (GB)
Title: Improvements in electric circuit-breakers
IPC: H01H33/985
Filed: 1933-01-23
Abstract: 409,099. High-tension switches; arcrupturing in switches. ALLMANNA SVENSKA ELEKTRISKA AKTIEBOLAGET, Vasteras, Sweden. Jan. 23, 1933, No. 2166. Convention date, June 22, 1932. [A Specification was laid open to inspection under Sect. 91 of the Acts, July 24, 1933.] Addition to 408,077. [Class 38 (v).] The invention described in the parent Specification is modified by arranging that the arc causes a flow of fluid from the chamber which, in the closed position of the breaker, contains the contact points of the contacts, the flow being thus in the same direction as that of the opening movement of the movable contact. In Fig. 1 the fixed contact 1 is mounted on a member 10 which is pressed downwards by a spring 12 and is slidable within a member 7 carrying a cylinder 8 and plate 9. The movable contact 2 engages the fixed contact 1 by passing through 9 and a plate 15 separating chamber 5 from chamber 6 and having the aperture 16 for the movable contact 2. When an arc is struck between the contacts, the pressure set up thereby on the fluid acts through an aperture 17 on the upper face of 10 and also through aperture 16 on the lower face of 15 and of flange 11, and as the latter area is larger, the parts 1, 10, 11, 15 move upwards, so contracting the space 5 and expelling fluid therefrom by way of 17 and 16 and across the arc. In a modification, Fig. 2 (not shown), the part 10 is fixed and parts 7, 8, 9 move downwards, and in another form, Fig. 3 (not shown), the cylinders are arranged one outside the other. A combination of these last arrangements is shown in Fig. 4, in which the parts 9, 8, 24 move downwards, whereas the contact 1 and the parts 7, 15, 10 are fixed. Here the pressure acts on the upper face of 9 and on the lower face of flange 26 of the part 24, so that, as 26 is smaller, it and the associated parts move downwards and drive fluid through the holes 17, 16, thereby extinguishing the arc. Fig. 5 shows a construction suitable for use with water as the extinguishing fluid. An outer container 30 houses an inner cylinder 33 secured by webs to a cylinder 35 co-operating with a further cylinder 38 which is fixed by rods 37 to the base 31 of container 30. The fixed contact 1 is resilientlv mounted on a post 40 on the base 31 and co-operates with a movable contact 2 having an aperture 44 whereby chambers 5, 6 are placed in communication with one another. The normal waterlevel is shown by the arrow. When 1, 2 separate, the pressure set up in 5 is transmitted by the hole 44 to chamber 6 and acts on the lower face of the top 34 of cylinder 33. The pressures on the faces 36 of cylinder 35 balance, so that 33 moves upwards, together with 35, and the chamber 5 is contracted whereby a stream of fluid is forced through the aperture 16. Modifications of this form comprise (1) a solid movable contact and hollow fixed contact communicating with chamber 6 between bases 36, 31 ; (2) as in (1) but using segments and garter springs for the fixed contact ; and (3) the use of spaced, superposed baffles to provide an additional cross-blast issuing from cylinder 38 by way of an outlet remote from the outlet 16. Two arrangements such as shown in Fig. 5 may be mounted on insulators and their movable contacts connected by a bridgemember, Fig. 10 (not shown).