GB658442A - Improvements in and relating to the manufacture of bars provided with "corkscrew" ends - Google Patents

Abstract

658,442. Coiling. OUTIMINES. May 5, 1949, No. 12046. Convention date, May 8,1948. [Classes 83 (ii) and 83 (iv)] Treating bars.-In a method of making bars with corkscrew ends that facilitate series connection, a bar, preferably of steel, is fed along a feed channel until it reaches an abutment 13, is gripped between two sets of jaws 6, 7 and 12, 12a and cut off to the required length by shears 4, 5, whereupon the feed channel is retracted, each end of the bar is then wound helically on a mandrel, the mandrels are retracted and the jaws and shears opened so that the bar drops on to ejecting ramps 8, 11. The feed channel comprises grooved rollers 9 supported by side-plates 10 and the bar is fed into the machine over additional rollers 2. Each mandrel has a tapered shank 30 by which it is mounted in the end of a shaft 19 keyed within a sleeve 22 formed with a pinion 26 engaging a rack 27. The rear end of the shaft has a screw-thread co-operating with a fixed nut 21 so that rotation of the sleeve by the rack 27 rotates the mandrel and at the same time feeds it forward, the pitch of the screw being the same as that of a helical groove 31 formed in the mandrel. As the bar is fed into the machine it passes along part of the groove 31 and beneath a bending roll 46 mounted on a lateral extension 43 of a shaft 33 coaxial with the shaft 19 and also adapted to be rotated and moved longitudinally by rack-andscrew means. In operation, after the bar has been clamped and sheared, the mandrels are rotated and at the same time fed forwardly, the ends 32 entering bores 48 in the shafts 33, which are then rotated and retracted by the racks 42 so that the rolls 47 move helically along the mandrels and wind the ends of the bar round the mandrel into the grooves 31. The various parts of the machine are operated hydraulically under the control of valves operated electrically so as to render the machine fully automatic.