GB595513A - Improvements in or relating to electrical ducts or conduits for use in building construction - Google Patents

Abstract

595,513. Conduits. STORY, J. G., and CLARK, J. S. July 4, 1945, No. 17093. [Class 36] A metal conduit for electric conductors carrying different kinds of currents consists of a trough base and a cover, both magnetisable and conducting, the trough having two or more channels with separating webs forming with the cover alternative paths for currents induced by the conductors. One form suitable for a dado, Figs. 1, 3, with two equal channels 3, 4 consists of a base 1 and cover 2 both of plated mild-steel sheet, the base 1 having a web 8 slotted at 11 to give access to elongated non- magnetic nuts 16 and the cover 2 and junction plate 19 being secured by non-magnetic screws 17. The edges of the base 1 and cover 2 are strengthened by turned flanges 5,1.4. The channels 3, 4 are for telephone and radio loudspeaker leads, and the perforations 11 produce a high reluctance magnetic path between the channels. The leads are retained within the channels by spring straps 20 spot-welded at 21 to the web 8 and engaging the flanges 5 at their free ends. In another form suitable for a skirting-board, Fig. 6, two equal channels 26, 27 and a larger channel 25 are provided, the channel 25 being for power and lighting leads. The base 23 and cover 24 have turned flanges 28, 41 and the webs 34, 35 between the channels retain nuts 47. The spring straps 52, 57 have flanged or crimped ends engaging either the flanges 29 or metal strips 56 secured by spotwelding to the webs, similar strips 46 serving to retain the nuts 47. The third form, Fig. 15, suitable for use in strips comprises a cover 62 and base 61, the latter consisting of a base plate 63 to which are spot-welded plated mild-steel sheet members 69, 70 to form two equal channels 66,'68 and a larger central channel 67. The side walls 70 have shoulders 71 and lips 72 to engage clamp-plates in the grooves 73 between the channels and also within the channels. The former are carried by bolts retained on the cover 62 and the latter 91, 94 carry strip springs 93, 96 which engage the leads to hold them in place. In order to provide clearance for bulkhead bolts &c., the plate 63 may have its flanges 64 turned rearwardly as at 64a, Fig. 18.