GB550151A - Improvements in liquid-immersed electric circuit breakers - Google Patents

Abstract

550,151. Oil-blast switches. ELECTRIC CONSTRUCTION CO., Ltd., and BOYD, J. M. Aug. 23, 1941, No. 10770. [Class 38 (v)] An arc-chamber for a liquid-immersed switch comprises a series of insulating plates B ... H clamped between end plates A, J which, with the plates C, E, G, define the end walls of cells 16 ... 19, the side walls of which are defined by aligned openings in each of the sets of plates B, D, F, H. The openings may be elliptic, or circular and eccentric to the contactaxis, but are preferably Pear-shaped as shown in Fig. 2 for the openings b in the upper set of three plates B. The openings of plates D, F, H forming the cells 17 ... 19 are angularly displaced from one another and from b, Fig. 2. The subsequent plates are each formed, below, and aligned with, the small ends of the pear-shaped openings, with apertures leading to the open space below the structure, the so-formed passage from cell 16 being shown on the left of Fig. 1. When the contact 11 is being lowered to open the circuit, there is always sufficient pressure in any cell to prevent arc-gases from the cell below from rising into it through the contact aperture. The arrangement of the contacts may however be transposed, and the assembly may also be mounted horizontally. The Specification refers to an assembly having more than four cells, and to a plunger 12 arranged in the hollow contact 11 as in Specification 504,832. The Provisional Specification refers to an arrangement in which the pear-shaped cells are successively displaced angularly from one another by 90 degrees.