GB1113381A - Improvements in wire drawing drums for wire drawing machines - Google Patents

Abstract

1,113,381. Drawing drum. FASTENER ENGINEERS Inc. 22 Aug., 1966 [17 March, 1966], No. 37553/66. Heading B3P. A wire drawing drum 11 for a wire drawing machine comprises a wire engaging surface 50 and a flange 51 at one end of this surface to engage the wire as it is wound on to the drum to force the turns of the wire axially along the drum to where it is wound off the drum, the engaging surface 50 being in two portions, a cylindrical outlet portion 50<SP>1</SP> and an inlet portion which defines a shallow concave depression. The wire is pulled through a die (13), Fig. 2 (not shown), housed in a draw-box (22) with a lubrication compartment (23). After passing through the die the wire winds on to one end of the coil and winds off the other end as the drum rotates so that the number of turns in the coil remains constant. On leaving the drum the wire passes over an idler roller (37), Fig. 1 (not shown), biased away from the drum 11 by springs (37) or other suitable means, e.g. pneumatic. In the embodiment illustrated in Fig. 3, the inlet portion merges smoothly in a continuous curve with the inclined face 51<SP>1</SP> of the flange 51 and with the outlet portion 50<SP>1</SP>. In a further embodiment, Fig. 4 (not shown), a similar drawing drum has a wire engaging surface (150) with an outlet portion (150<SP>1</SP>), an inlet portion (150<SP>11</SP>) and a flange (151) at the inlet end. The inlet portion merges in a smooth curve with the face (151<SP>1</SP>) of the flange (151) and flares outwards with a uniform conical surface and merges smoothly with the outlet portion. In operation the drawing drum is driven slightly faster than the speed at which the wire is advanced to a subsequent machine, e.g. for further drawing, cutting, straightening &c., and a slack loop (L) is taken up by the idler roll (35). As the amount of slack increases the tension in the wire leaving the drum decreases and the drum slips relative to the coils thereon with a consequential reduction in the amount of wire fed from the drum and hence the slack is reduced. The recessed type of drum of the embodiments enables drawing of larger diameter wire and also wires of high tensile strength, for a given drum size and any set number of turns of wire on the drum than could be drawn using a conventional cylindrical drum.