| 摘要 |
A load carrier for supporting, raising or lowering a load includes a frame member, a telescoping mast, and a support frame. The frame member is adapted for being movably supported by a rail. The telescoping mast is supported by the frame member, with the support frame supported by the telescoping mast. The telescoping mast includes at least one fixed mast section and at least one movable mast section, with the support frame being coupled to the movable mast section. The movable mast section is supported for movement between a plurality of extended positions in which the support frame is lowered and raised with respect to the frame member and the fixed mast section with the movable mast section being guided by the fixed mast section when the movable mast section is moved to its extended position. The driver selectively moves the movable mast section to its extended position and includes at least one cord for raising and lowering the movable mast section. The cord is arranged by whereby the cord bends in a single direction to eliminate back bending in the cord thereby increasing the longevity of the cord. In preferred form, the telescoping mast includes a second movable mast section, which is synchronized with the first movable mast section whereby the first and second movable mast sections move in substantially the same direction at about the same speed. The first and second mast sections, for example may be supported for movement in the first movable mast section by a plurality of guide rods and guide pulleys which cooperate to guide the first and second movable mast sections in a manner to minimize play between the first movable mast section, the second movable mast section, and the fixed mast section, thus permitting the movable mast sections to be moved at a greater speed.
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