Control unit null for job department of paddy field job

摘要

PURPOSE:To grade a field in good levelness and evenness by disposing a switching means for switching a driving mechanism into a non-free state or free state, the driving mechanism being used for lifting or lowering a working device based on a traveling mechanism. CONSTITUTION:When a driving mechanism C1 is switched by a switching means into a non-free state, a working device 3 is supported with the driving mechanism C1 so that a float may grade a field at a low ground pressure. When the driving mechanism C1 is switched into a free state, the dead weight lowering of the working device 3 is enabled to increase the ground pressure of the ground float.