Revolving head for straightening wire 10 to 20 I.W.G. on c.i. stand

The old method of straightening considerable lengths of wire was by drawing it between inclined pins fixed in a slab, the pins being so set that they bent the wire slightly in opposite directions during its passage. Adjustable rollers superseded the fixed pins and improved action was obtained by using two sets of rollers in series, the second set acting in a plane at right angles to the first. A revolving head, carrying adjustable dies, between which the wire passed, was introduced about 1 870, and this perfected the action by operating equally all round the wire; further improvement was effected, as in this example, by the use of hardened and polished steel rollers, instead of dies, thus reducing the friction on the wire and the power required to drive the head.

The head consists of an open hollow spindle running in ball bearings and provided with a pulley at one end. It contains five rollers, fitted in slots cut through cylindrical pieces that pass transversely through holes in the spindle; these pieces are adjusted radially by set screws bearing on their ends. The wire is drawn through the head by a suitable gripping device. This example straightens wire from 0.036 in to 0.128 in diameter; it is driven at about 1,500 rpm, and requires about 1 hp.