| 摘要 |
A drill has a pivotally mounted coulter bar (3) which carries a coulter in the form of a narrow blade (6) to cut a slit in the ground. An elongate member (10) is pivotally connected to the coulter bar (3) and a member (16) is axially slidable on the elongate member. A hydraulic arrangement (23) is provided which, by means of levers and a rota table shaft drives the member 16 downwardly thus causing two springs (14, 15) located between the slidable member and the coulter bar around the elongate member (10) to be compressed thus driving the coulter (6) into the ground. One spring (14) is relatively long and of low strength, and the other spring (15) is relatively short but of higher strength. When the drill is operated the coulter forms a swirl of tilth behind it as it is drawn through the ground. Seeds dropped into this swirl of tilth come to rest entirely surrounded by tilth and are thus under optimum conditions for successful germination. <IMAGE> |
