| 摘要 |
PURPOSE:To perform simple and accurate steerage without entailing any misoperation by performing a changeover to an up position of a working device by operation of a lift lever and to a negative phase mode at the specified timing with a selector switch. CONSTITUTION:In a lift lever 2 for lifting a working device to a car body 1, there is provided with a selector switch 5 which is selected to a four-wheel steering negative phase mode interlockingly steering a front wheel 3 and a rear wheel 4 to a negative steering mode by operating the working device to the up position with this lift lever 2. When turning takes place at ridge edges and furrow ends, the lift lever 2 is lift-operated in a working posture, whereby the working device is made to go up once, making it into a non- working posture, while the selector switch 5 is changed over to the negative phase mode by the lift-operation of this lift lever 2. Accordingly, when turning steering operation is performed by a steering, steerage of both the front wheel 3 and the rear wheel 4 is steered so as to be reversed to each other, so that turning travel is performed at an acute angle. |
