| 摘要 |
<p>A roller (10) drives a workpiece (not shown, but to the right) along a fence. An electric motor (16) rotates the roller (10) through chains (18, 19) and a double sprocket (20) freely rotatable on a upright shaft (22). The roller (10) is rotatable in relation to an arm (26). The arm (26) is pivotable in relation to the shaft (22). A coil spring (30) around the shaft (22) is fastened at a lower end to a stop (32) and at an upper end of a collar (34), and urges the roller (10) towards the fence. The force of the spring (30) makes the roller (10) engage a wide workpiece strongly, and so increases its tractive effect.</p> |
