| 摘要 |
<p>A loading platform for building-construction use has an extendable deck-carrying frame 2 which is mounted within a static-frame 5 and which for extension and retraction from the static-frame 5 runs on preferably flanged rollers 19 mounted beneath it on the outboard end 20 of the static-frame 5. The platform-deck 1 is carried between two I-section beams 3 of the moving-frame 2, each of which runs on a respective pair of the flanged rollers 19 with the edges of its bottom flange 13 between the roller-flanges 21 for lateral guidance. The beams 3 nest respectively in I-section beams 6 either side of the static-frame 5 and at the inboard end 16 carry a web-engaging roller 22 for added lateral guidance, and two rollers 17 located one above the other for engagement with the flanges 14,15 of the static-frame beams 6. One or other of the latter rollers 17 makes effective flange-engagement according to the extended-retracted condition of the moving-frame 2. Rollers 24,25 on the static-frame 5 support the moving-frame 2 when it is retracted off the flanged rollers 19 for servicing. In a modification the flanged rollers 19 are replaced by plain rollers (27 Fig 9) and web-engaging rollers (28) are added for lateral guidance.</p> |
