| 摘要 |
<p>A driven member (18) has flat parallel top and bottom surfaces over at least a portion of its length. A motor actuated drive roller (16) is mounted between two parallel, spaced side plates (11, 12) between which the driven member (18) reciprocates and bears against the driven member (18). Back-up rollers (26) engage the drive roller (16) to prevent the drive roller (16) from backing away from the driven member (18). A spring-mounted pressure roller (28) bears against the side of the driven member (18) directly opposite the drive roller (16). As the motor turns the drive roller (16), the latter frictionally engages the driven member (18) and causes the latter to move linearly without the backlash characteristic of rack and pinion mechanisms.</p> |
