| 摘要 |
The invention relates to an arrangement for vertically raising and lowering a unit, e.g. a plate, a monitor or the like, suspended at the top, comprising an upper attachment (2) and a lower attachment (3), said lower attachment beig able to be fixed on a desired ce from the attachment fixed at the top. The arrangement comprising furthermore several groups of interconnected rodlike elements (50) provided with apertures for pivot means, whereof two outer apertures (at 6) are spaced a predetermined distance from each other and at least one intermediate aperture (at 51) is symmetrically disposed between said outer apertures, said groups of rodlike elements forming one of at least three interconnected lazy tongs linkages, whose crossing elements are pivotally connected with each other at each crossing point, said at least three lazy tongs linkages being interconnected by means of a connector (5) pivotally secured at each of opposite outer joints, so that said at least three united lazy tongs linkages form together a retractable (4), and said member being connected at either end with said attachments (2, 3) by means of a device assuming the lateral movements occuring when the unit is retracted or extended, said device comprising shafts (21) provided at the ends of the retractable member at each outer joint, said shafts each being slidably mounted in a bore (20) in members secured to the lower and to the upper attachment, respectively. <IMAGE> |
