| 摘要 |
The agricultural machine has a supporting part, on which an implement, such as a seed drill, movable up and down vertically is mounted via parallelogram linkages arranged at a mutual transverse spacing. A prestressing device which prestresses the implement downwards acts on the parallelogram linkages in interaction with at least one spring. The springs are arranged essentially perpendicularly to the longitudinal direction of the links. To adjust the spring prestress force, there is a connecting device having a crossmember which is displaceable on the top edge of the upper links of the parallelogram linkages from the front rearwards, and vice versa. The upper ends of the springs are anchored to this crossmember, so that all the springs can be adjusted at one time. A simple locking device allows an easy release of the lock and an adjustment and easy secure locking of the set position of the crossmember on the upper links. For this, there is a locking element anchored pivotally to the supporting part, extending rearwards, having catch recesses and displaceable in a longitudinal pocket in the middle of the crossmember. The pocket has an upper transverse member which can be engaged into one of the recesses, the arrangement being such that, in the engagement position, the element anchored to the supporting part rests firmly on the bottom of the pocket. A relative pivoting movement between the locking parts causes the lock to be released, an adjustment to be made and locking in the new position to be obtained again. |
