| 摘要 |
<p>The lorry has two guidance columns (6a, 6b) formed by a lower frame (2), for a plate (7) vertically moved relative to the frame. A set of adjustment units includes a staged battery of compression springs (10a, 10b) i.e. gas springs, that are linked with each other in series between the frame of a rolling base and the plate so as to make an upper position of the plate to correspond with maximum extension of the springs, where a lower position of the plate is close to the frame. A bolt (17) is designed to maintain the plate in the lower position.</p> |
