| 摘要 |
<p>There is provided a position control drive system (30) having first (16) and second (18) drive units linked (20) together and travelling on parallel running rails (12, 14). A passive unit (38) riding on a third parallel running rail (32) is pivotally linked (42) to one of the drive units (16, 18). The pivoting link (42) allows movement of the drive units (16, 18) longitudinally (59) along the rails (12, 14), but prevents movement in other directions. The pivot (42) compensates for positional differences between the electronic positional control of the drive units (16, 18) and the mechanical linkage (20) preventing inefficiency in the electronic system, stresses in the mechanical system and, in severe cases, binding of the drive units (16, 18) to the rails (12, 14).</p> |
