the cylinder 81 is projected to pivot each lid 79 and open the lower end of the associated shuttle retainers 77 by means of the connecting lever 82 as shown in fig1 this causes the retained shuttle 31 which holds a full bobbin to fall onto the associated shuttle carrier 30 the operation of the sewing machine will now be described with reference to fig7 12 as shown in fig1 and 7 when the sewing machine performs the sewing operation the shuttle holders 29 supporting shuttles 31 are located at the sewing position on the movable platform 27 of the sewing device 21 the front end 29a of each shuttle holder 29 is engaged with the associated fixed stoppers 36 and the rear end 29b of each holder 29 is engaged with the associated movable stoppers 39 thus each shuttle holder 29 is fixed at its predetermined position on the movable platform 27 in this state each needle 26 is reciprocated vertically to pierce the fabric web 25 simultaneously the lever 33 is reciprocally pivoted by the drive shaft 32 between the positions shown by the solid lines and the dashed lines in fig1 and 2 this moves the shuttle holders 29 which is supported on the movable platform 27 back and forth in a direction perpendicular to the axes of the needles 26 the cooperative motion of the needle 26 and the associated shuttle 31 forms stitching patterns on the fabric web 25 with the upper thread supplied to the needle 26 and the lower thread from the bobbin held in the shuttle 31 when the bobbins become empty or nearly empty the shuttles.