| 摘要 |
<p>In electroerosion machines, the main wire-traction device is located in a lower head (4) arranged under the immediate area of the workpiece (5) and consists of a traction wheel (7), a first free wheel (81) and a second free wheel (82), each joined to a pivoting arm (131, 132), which arms are arranged 90 DEG apart with respect to the traction wheel (7), the first and second free wheels being pressed against the traction wheel under the effect of a first and a second spring (151, 152). Preferably the pressure on the second free wheel (82) is greater than on the first. A guide chute (16) is provided between the free wheels. <IMAGE></p> |
