| 摘要 |
<p>The height adjustable platform (1) for a viewing screen for data processing is supported on an upper frame (2) connected by a scissor linkage (4) to a fixed lower frame (6). The scissor linkage consists of two crossed arms each side, the top of one arm of each side pair being connected by a hinge pin to the top frame, and the top of the other arm sliding in a slot in the same frame member. The bottom connections are similar. The connections at the slots are formed by spindles, the full width of the frames, each spindle carrying a toothed wheel at its end, which rotate against toothed racks along the frames. The lower spindle is pulled inwards by springs (23) connected at the other end to a tension adjusting block (24) anchored to that end of the frame. An adjusting handle (27) is attached to the upper frame.</p> |
