PURPOSE: To provide the title unit so designed that a locking device is provided between the traveling lever and reaping lever of a reaping machine such as a mower to establish such a constitution as to be able to automatically locking or unlocking the reaping level through the operation of the travelling lever, thereby simplifying the operation and reducing the labor.

CONSTITUTION: A locking device 4 is provided between a travelling lever 2 to make an 'on-off' operation for travelling transmission equipped on an operating handle 1 and a reaping lever 3 to make an 'on-off' operation for reaping transmission. Said locking device 4 operates as follows: the 'on' position for the reaping transmission through the reaping lever 3 is locked by the 'on' operation for the travelling transmission through the travelling lever 2 and, at the same time, the reaping lever 3 is returned to the 'off' position through the 'off' operation of this travelling lever 2.