| 摘要 |
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) bolted to it. The crop row (18) passes between a pair of 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). The arm (47, 48) 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). When crop of field conditions render the use of the sensing unit inappropriate, the pair of arms (47, 48) can be swung into lockout positions below the dividers (19, 21) where they are entirely confined within the periphery (in plan view) of the dividers so that the units need not be dismounted. |
