| 摘要 |
A ground working assembly has an inclined arm swingable up and down on a tool bar of an agricultural implement, the assembly being yieldably biased downwardly by a cushioning spring associated with a bracket which mounts the assembly on the tool bar. A tool-supporting shank depending from the arm at its lower, rear end is swingable rearwardly and upwardly relative to the arm, but held against tripping by linkage which is normally locked by the spring. During encounters by the ground-working tool with usual types of ground conditions tending to cause the tool to rise against the action of the spring, the assembly merely swings upwardly relative to the bracket. But tool damage is alleviated by unlocking of the linkage and tripping of the shank when more extreme conditions, such as large rocks, are encountered by the tool.
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