Abstract: An apparatus for measuring the length of a sheet moving at a constant speed in one direction comprises front and rear edge detectors for detecting front and rear edges of the sheet to output front and rear edge signals, respectively, and an angle detector for detecting the angle at which the sheet moving in that one direction is inclined relative to that one direction to output an angle signal representative of the angle of inclination. An arithmetic circuit operates to calculate an apparent length of the sheet in the direction based on the front and rear edge signals and to correct that apparent length of the sheet with the angle signal so as to determine the actual length of the sheet.

Abstract: A method of stacking metal sheet materials which is characterized by interposing between each adjacent metal sheet material an interleaf comprising paper with plastic coated on only one side.

Abstract: A corrugated fibreboard shipping box for packing a stack of sheet material stacked into a flat rectangular shape having a certain thickness is made of a single box blank. The box blank is comprised of a rectangular bottom section, a pair of rectangular side sections connected to the opposite sides of the bottom section, a pair of top half sections connected to the sides of the side sections, and flaps connected to the opposite ends of the bottom section, side section and top half sections. The flaps are provided with parallel folding lines at which the flaps are folded inside to form folded end portions. The folded end portions close the open ends of the box. The corrugated fibreboard shipping box packs and protect the stack of sheet materials without pads.