GB321503A - Improvements in electric heaters - Google Patents

Abstract

321,503. Collins, G. H., and Collins, H. F. Sept. 18, 1928. Wire resistances mounted on flat, curved, or grooved surfaces.-A firebar for an electric heater having pin or blade contacts at its ends adapted to be pushed into fixed sockets on the frame has these contacts so arranged as to permit slight variations in the length of the bar. which is built up from sections strung on a metal strip and each formed with a projection at one end and a recess at the other, so that the length of the bar may be adjusted by reversing one or more of the sections. Each end block 3 carries a blade contact 4 having oppositely bent lugs 5 at one end which are secured to the black 3 by screws 8. The blade is preferably tapered as shown. The sockets engaged by the blades 4 each consist of a pair of spring jaws 9 housed within an insulating block 10 having a longitudinal slot to receive the jaws and a transverse slot 12, into which the blade 4 may be inserted so as to engage between spring jaws. The spring jaws 9 are formed from a strip of spring metal bent at the centre into a loop 14 from which the jaws 9 extend in parallelism, and normally in contact. At their upper edge the jaws are bent apart so as to provide a flared mouth for receiving the blade 4. One of the jaws has a projection 16 carrying a terminal screw 19 and nut (not shown) the edges of the projection 16 being bent over to prevent rotation of the nut. Each insulating block 1 is provided at one end with one or more projections and at the other end with corresponding recesses, the blocks either being arranged so that the projections engage the recesses of the adjacent blocks, or one or more blocks being reversed so that the projection abut against one another, giving a longer bar. The projection and recesses may be curved to permit the bar to be curved. Each block 1 has a T-shaped aperture through which passes a metal strip 2 of flat or channel section. Alternatively the blocks 1 may be formed on the back with undercut slots of T or dovetail section. The openings through the sections may be curved to allow a curved fire-bar to be produced. The supporting bar 2 is bent at one end into a loop 31 which receives the transverse end 32 of a U- shaped guard 37, the other ends 34 of which are riveted to a metal plate 35, which is bolted to the end of the supporting bar 2.