| 摘要 |
The tool support normally holds the tool (32) at a min. height below the surface of the soil unless an obstacle is struck. A compression spring (28) encircles the tool mounting shaft (24) which is pivoted to the top of the tool. The upper mounting for the spring has a planar upper face which bears against a mounting plate (13), forming part of the tool lifting arm (10). The spring mounting provides a recoil force on the arm to lift the tool to the surface of the soil if an obstacle is encountered. The spring also damps the movement of the arm progressively as it reaches its position corresp. to max. tool height. |
