| 摘要 |
<p>The positions of print wheels (42) are controlled by the positions of axially displaceable racks (52) which in turn are controlled by a helical nut (62) and pinion (58) system which is driven by motor. In order to compensate for the angle between the helical thread of the drive gear (62) and the teeth of the driven rack (52), the drive gear (62) and the rack (52) engage the pinion (58) at diametrically opposed positions and the axis of rotation of the pinion (58) is skewed relative to the teeth of the rack (52) by half the angle and the teeth themselves are also skewed relative to the axis of the pinion (58) by half the angle. This has the effect that the teeth of the pinion (58) are parallel at one side to the helical thread and are also parallel at the opposite side to the teeth of the rack (52). The drive system may be used in a postage meter for adjusting the print value wheels. <IMAGE></p> |
