To shorten a length of an end part, to reduce the loss of a conveyor and to simplify a structure of a driving part by cutting an arbitrary position (for example, the middle) of a timing screw, and mounting a gear or a pulley to a bottom.

A cut is formed on an arbitrary position of the timing screw 1. Any part of the timing screw 1 can be used as a cutting position. The cut is formed on the middle of the timing screw. A gear 2 is mounted on the cut. The gear 2 is engaged with a driving gear 4 through an intermediate gear 3. The driving gear 4 is directly connected to a motor 5. A belt can be also used for the gear as a driving method. A pulley is mounted on the timing screw 1 for the gear 2. A driving pulley is mounted on the motor 5, and a belt is hung between the pulley and the driving pulley. Whereby an end part of the timing screws can be shortened, and a structure of the driving part can be simplified.