| 摘要 |
<p>A forage harvester (11), pulled via its tongue (16) by a tractor, has dividers (19,21) between which a crop row (18) is received, and each divider (19,21) has a row sensing unit (41, 43). The crop row (18) passes between a pair of biased arms (47, 48) of the unit. An arm (47, 48) is deflected when the machine is misaligned with the row (18), the arm (47, 48) having an upright pivot shaft (79) which turns with it. The shaft (79) carries an actuator plate (95) which closes a switch (145) to trigger a guidance control circuit (45) to steer the harvester by way of a piston and cylinder (33) moving the tongue (16) to return the harvester to alignment with the crop row (18). The row sensing unit (41, 43) includes a unit support (51) and the arm (47, 48) is mounted on this support (51) which is adapted to be bolted or clamped to the divider (19, 21). The bias for the arm (47,48) is provided by a torsion spring (101) received over the pivot shaft (79) with one end of the spring (101) connected to the arm (47, 48) and the other end adjustably connected to the unit support (51) so that the bias can be varied.</p> |
