Stitchers

A method of binding sets of sheets wherein a piece of wire is fed from a supply of wire, a movable cutter is positioned along said wire, and said wire is cut from said supply of wire and formed and driven through each set to bind the sheets together, the improvement comprising the step of determining automatically the length of wire to be cut in dependence on the thickness of each set of sheets during the binding operation for that set, the step of feeding the length of wire accordingly during said determining, said feeding being of a distance dependent upon the thickness of the set and the step of positioning a wire cutter in dependence upon the thickness of the set.

A wire stitcher apparatus having a cutter for cutting a length of wire from a supply thereof and a stitcher head for forming and driving the length of cut wire in the form of a staple for binding a set of sheets, the improvement including means for moving the cutter and means for advancing the wire to the stitching head, said means for moving the cutter arranged to position the same a distance in accordance with the thickness of a set, and said means for advancing the wire arranged to advance the same a length in accordance with the thickness of a set, said cutter having a rest position and said means for advancing the wire being adapted to advance the same past the rest position of the cutter by a predetermined distance approximately equal to the crown length of the staple plus twice clinch length plus a minimum set thickness plus the set thickness and with the cutter adapted to be retracted from its rest position by a distance equal to the set thickness minus the minimum set thickness.

A wire stitcher apparatus having a cutter for cutting a length of wire from a supply thereof and a stitcher head for forming and driving the length of cut wire in the form of a staple for binding a set of sheets, the improvement including means for moving the cutter and means for advancing the wire to the stitching head, said means for moving the cutter arranged to position the same a distance in accordance with the thickness of a set, and said means for advancing the wire arranged to advance the same a length in accordance with the thickness of a set, said cutter having a rest position and said means for advancing the wire being adapted to advance the same past the rest position of the cutter by a predetermined distance approximately equal to the crown length of the staple plus twice clinch length plus the set thickness and with the cutter adapted to be retracted from its rest position by a distance equal to the set thickness.