| 摘要 |
<p>An expandable and retractable ramp assembly for conveying moving objects onto a cargo carrying surface of a cargo transporting apparatus comprising: a) a pair of opposed, parallel scissors assemblies, with each scissors assembly including a plurality of scissors link members pivotally attached to other scissors link members of the same scissors assembly. A plurality of tread support assemblies, extend between and are pivotally attached to one of the scissors link members of each opposed scissors assembly. Each tread support assembly is constructed of a plurality of support members pivotally attached to the scissors link members of each opposed scissors assembly. Each tread support assembly supports at least one tread plate. In an embodiment, each slidable mounting bracket includes a compressible cushion member that prevents the ramp from reaching a flat or over-center position when in the expanded position. In a further embodiment, certain of the scissors link members are no longer than others, providing an upwardly extending arcuate bend in the mid-portion of the ramp assembly to prevent vehicles with low-frame constructions from contacting the junction between the ramp and a truck tailgate, or other structure to which the ramp is attached, when the vehicle is moving up or down the ramp.</p> |
