| 摘要 |
A display rack includes an upright support, a sliding block moved along a longitudinal sliding groove at the upright support, two clamping blocks coupled to the sliding block by a screw rod, and a holder frame fixedly fastened to the screw rod and turned between the operative position for holding a board where the clamping blocks are clamped on the sliding block to fix the sliding block to the upright support at the desired elevation and the non-operative position where the sliding block is released from the clamping blocks and allowed to be moved along the longitudinal sliding groove to the desired elevation, wherein a pulley is suspended inside the upright support and aimed at a transverse through hole within the longitudinal sliding groove at the upright support, a spring member is fixedly mounted inside the upright support at the bottom, and a steel cable is inserted through the transverse through hole on the upright support and passed through the pulley and connected between the spring member and the sliding block to prevent the sliding block from falling down suddenly when the sliding block is release from the clamping blocks.
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