| 摘要 |
<p>The rotating plate (2) has a number of shafts each fitted with two similar rollers (7, 8). The rollers locate in the spiral groove of the drum (3) fitted to the driving shaft (5). The groove cross section has two tracks, one at the bottom and one at the top of the groove, to align with the rollers. One of the rollers is offset in one direction and the other in the opposite direction so that one roller contacts the lower track on one side of the groove and the other roller contacts the upper track on the other side of the groove. At least two roller pairs are located in the spiral groove at a time. The separate rollers contact on the two sides of the groove provide a low wear grip. Depending on the position of the drum the spiral groove either has two roller pairs in the groove or has a ridge between two rollers pairs.</p> |
