PURPOSE: To promptly drop a strip cut piece, by constituting a telescopic cylinder rotatively operating a guide flapper so as to increase a tilt angle of the guide flapper.

CONSTITUTION: In a conveying line of a strip A, the strip A is rolled into a winding device through feed rollers 10, rotary flying shear 1, guide flapper 4, guide 11 and guide roller 12. Then overpassing of the following strip is smoothly performed at separate cutting or scrap and sample cutting while a cut piece is not dropped to a gap at gathering of the cut piece by the scrap and sample cutting further a downward tilt angle of the flapper 4 can be increased, an the cut piece can be quickly dropped to surely perform its gathering and promptly sort the cut piece.