| 摘要 |
<p>An agricultural drill incorporating foam bout markers (11) each comprising a tubular arm pivotally mounted at each side of the drill to be raised and lowered in use, and foam generating apparatus (13 to 17) that selectively supplies foam to each marker arm (11) so that it flows through the tubular body of the arm to a foam dispension head (23) carried at its outer end. An individual hydraulic actuator (12) operates each arm (11). A hydraulic control valve (50) allows one or the other actuator (12) to be operated to raise the corresponding marker arm (11). Operation of rams (8) to raise the coulters (4) causes both actuators (12) to operate automatically to raise the marker arms (11). Lowering of each marker arm (11) is used to trigger the supply of foam to it.</p> |
