Wiredrawing Machines, Straight-Line Type

Systems in which the wire takes the shortest path from one die round the block and straight into the next die. While the machine is being threaded up, the torque developed by each motor is adjusted until it is just sufficient to pull the wire through the die and in addition to provide a little extra pull through the wire itself to assist in turning the preceding capstan. This extra pull, known as “back pull,” ensures that the wire passes straight into each die, which is an important consideration, especially when drawing thick wires. The capstans are tilted in the direction of drawing to enable a substantial number of turns to be taken around each one and to permit the wire to run through the die to the bottom of the following capstan in a straight line.