摘要 |
The screw (4) is in drive contact with the sleigh (3) and extends along at least one side of the sleigh through a passage (10) in a screw support (7) movable backwards and forwards along the rail (2) to form stop surfaces for the screw. A sliding part (9) mounted in the screw support cooperates with the screw thread, causing the support to move between two end position as the screw is rotated. The sliding part also makes the support slide onto the screw in the support end position until the rotation direction of the screw is changed. |