| 摘要 |
The trailer has a deck assembly that includes a level main deck portion and a tail hinged to the main deck for vertical swinging movement between a level transport position, a downwardly and rearwardly inclined ground-loading position, and an upwardly and rearwardly inclined dock-loading position. Raising and lowering of the tail between such positions is carried out by fore-and-aft movement of the shiftable undercarriage of the trailer, such undercarriage being located under the tai l and generally behind the hinge when the trailer is in its roading position with the tail in its transport position. When the undercarriage is shifted forwardly beyond a los t motion segment of travel, the tail is allowed to progressively descend by gravity t o its ground- loading position. Returning the undercarriage to its roading position beneat h the tail causes the tail to be raised back to its transport position. If the tail is to be raised to dock height, the undercarriage is pulled forwardly until the forward termination of its lost motion segment of travel is reached, whereupon an air bag is actuated t o elevate a lifting strut member into an enabled position in contacting engagement with the underside of the tail. Thereafter, rearward movement of the undercarriage causes the lifting strut member to push thetail upwardly to the dock-loading height and to hold the tail at such position. To lower the tail back to its transport height, the undercarriage is shifted forwardly and the air bag is deflated, lowering the strut member bac k to its disabled position and allowing the tail to become once again fully supported by the undercarriage. When the undercarriage is thereafter returned to its rearmost roading position, the trailer is ready for travel. Only one hydraulic cylinder is required for carrying out the tail actuation, together with an air bag actuator when raising of the tail to dock height.
|
