PURPOSE: To enable a passenger to get in and out of a rear seat without any driver's operation by halving a drive shaft for the rear seat door opened and closed only by the driver's operation and providing a clutch engaged and disengaged from the drive shaft by the operation of the driver in a cab.

CONSTITUTION: A rotary shaft 1 is divided into a drive section 1a and driven section 1b both of which are connected disengageably to a clutch 5 while a clutch operating lever 2 is provided near a cab seat A. A ratchet wheel 51a of the clutch 5 is urged normally by a tension spring 52 to disengage the clutch 5. Also, to the ratchet wheel 51 is attached a wire 62 through which the ratchet wheel 51 is urged by the operation of the clutch operating lever 2 to be connected to the clutch 5. Thus, a passenger can normally get in and out of a rear seat freely and a driver can open and close a rear door by operating the clutch only when needed. Thus, the passenger can get out of the rear seat in an accident.