| 摘要 |
<p>A unit for raising and lowering an agricultural implement, which unit is connected to a tractor. The unit includes an attachment device (6) for attaching the implement to the tractor, a raising and lowering device (2, 5) for raising and lowering the implement, and a control and regulation device including a linkage and regulation device including a linkage system and an operating lever (27) disposed between the attachment device (6) and the raising and lowering device (2, 5). The unit further includes a flexure bar (7) and is controlled by two control levers (36 and 38) which act on the operating lever (27) to determine the furrow depth and maximum force acceptable by the bar (7). The principal characteristic of the present invention lies in the fact that it includes a leverage mechanism (61 or 83) which is operable to act on the operating lever (27) for causing the operation of the raising and lowering device (2, 5) and the implement independently of the position of the control levers (36, 38) and independently of the deflection of the flexure bar (7). The leverage mechanism can cause complete raising of the implement and is operable to lower the implement back to the initial position set for the implement by the control levers.</p> |
