METHOD AND APPARATUS FOR MANUFACTURING BOOK BLOCK FROM PRINTING SHEETS STITCHED WITH THREAD AT FOLD SIDE

PROBLEM TO BE SOLVED: To utilize operating cycles during transferring printing sheets to a supply unit, thread stitching the sheets in a stitching unit and thread stitching machine to improve reliability and quality by moving the supply unit toward the stitching unit before the sheets arrive at a stitching position. SOLUTION: Printing sheets 2 are lowered over a supply conveyor 1, and continuously fed by a tensile unit 3 for circulating the sheets 2 by fixing a carrier to a conveying direction F. A supply unit 5 stepwisely connected to the conveyor 1 in the direction F conveys the sheets 2 to a stitching position by an accelerator formed of an annular conveyer 7 adjacent to the sheets 2. The stitching position corresponds to a stitching unit 9 arranged at a side of the unit 5 according to the stitching position of the sheets. The unit 8 stitches with thread by two thread-stitching needles 9, 10. Before the sheets 2 arrives at finally stitching position, the unit 5 starts moving toward the stitching position of the front side of the sheets 2 stitched with thread to a book block 11.