PURPOSE: To simplify an automatic outer package assembly line, and to curtail the cost of equipment by providing a center frame drop preventing pin being movable up and down, and an assembly guide of the same shape as the inside diameter of the center frame, on an assembly pallet of the automatic outer package assembly line.

CONSTITUTION: To an assembly pallet 1, center frame drop preventing pins 3a, 3b are fixed frictional force of 0 rings 4a, 4b. Also, in the pallet 1, a projection of the same shape as the inside diameter of a center frame is provided as an assembly guide of the center frame, on which movement use guide pins 2a, 2b are installed. The center frame 5 is positioned by fitting of the assembly guide of the pallet 1 and the inside diameter shape of the center frame. Subsequently, in a state that a movement 6 has been held down from the upper part, the center frame 5 and the center frame drop preventing pins 3a, 3b are pushed up simultaneously. Thereafter, in the automatic outer package assembly line, other outer package arts are integrated onto this assembly pallet and the outer package assembly is ended. In such a way, a sub-assembly process of the center frame and the movement can be eliminated, and the assembly line is simplified.