GB748277A - Equipment for use in the installation of electrical wiring in buildings - Google Patents

Abstract

748,277. Junction boxes. HARTLEY ELECTROMOTIVES, Ltd. Feb. 18, 1954 [Feb. 11, 1953; Feb. 23, 1953], Nos. 3917/53 and 5064/53. Class 38 (1). A junction box comprising a body 1, Fig. 1, and a lid 4 clamped onto a gasket 6 has nipples 13 in one or more side walls through which are led leads 12 surrounded by flexible sheaths 14 which engage over the nipples. The leads and sheaths are assembled to the box prior to installation in a building, the sheaths being sealed at their outer ends and inflated with air introduced through a valve 17 in the box lid, so that concrete may be cast round the sheaths and box, the air being released when the concrete has set. Fig. 3 shows a modification wherein the sides 24 of the box through which the leads are introduced are detachable, being retained in assembled relation with the box by lugs 22 on the fixed sides 20. Inwardly directed flanges 26 on the sides 24 engage flanges 23 on the box base and flanges 29 on the lid 27 with the interposition of gaskets. The sheaths 31 in this case comprise helically wound strips and are a push fit in grommets 30 in apertures 25 in sides 24, being sufficiently rigid to withstand the application of moist concrete without collapse. Fig. 5 shows a further embodiment wherein the sides of the box through which sheaths 49 similar to those in Fig. 3 are introduced, are formed by rubber blocks 45 having mating rebates, some or all of the blocks being centrally apertured to receive the sheaths. The upper and lower sides of the blocks are grooved at 47 to receive flanges on the base of the box and the cover.