ES343576A1 - Improvements in or relating to electrical capacitors - Google Patents

Abstract

A pressure-release valve for a capacitor particularly an electrolytic capacitor comprises an aperture in the capacitor housing covered by a sealing element controlled by a spring return element. As shown in Fig. 1, spring 1 fixed in slots 2 urges hemispherical resilient sealing member 3 against aperture 4. Spring 1 may be plate shaped (Fig. 2, not shown) or star-shaped (Fig. 3, not shown) and may be perforated (Fig. 4, not shown). It may be fixed at one end only with the sealing member at the opposite end (Fig. 7, not shown) and in this case it may be curved (Fig. 8, not shown). In Fig. 9, the sealing element is a layer 3 of e.g. rubber on the spring 1 which may be a plate of resin-bonded paper. The sealing element bears on a raised part 13 surrounding aperture 4, the spring is fixed by turned-over edge 2 and baffles 11 prevent escape of electrolyte or impregnating fluid. Aperture 8 allows escape of the gases. The sealing element may alternatively be a surface layer or a disc of synthetic material which layer has been treated with a softener. In a modified arrangement (Fig. 10, not shown) the sealing member is a portion upstanding from the e.g. aluminium spring member and urged against a resilient sealing plate.