Sheet-wise hole punching after folding in booklet maker

#1. Field of the Invention

#The present invention generally relates to finishing printed sheets of paper and, more particularly, to hole-punching folded sheets of printed paper.

#2. Background Information

#Other objects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments, when read in conjunction with the accompanying drawings wherein like elements have been represented by like reference numerals and wherein:

#FIG. 1 illustrates a process flow in accordance with an embodiment of the present invention;

#FIG. 2 is a perspective view of a hole punching apparatus in accordance with an embodiment of the present invention;

#FIG. 1 illustrates a process flow according to an embodiment of the present invention. The process flow 100 breaks the paradigm for traditional, non-sheetwise booklet-making and begins with the feeding and alignment 101 of a printed sheet. The operations of trimming 103, scoring 105, folding 107, and hole-creation 109 (e.g., by punching or drilling) are performed on each sheet individually. Operation 109 shows the creation of two holes near the folded edge of a sheet, but of course the number of holes created is not limited by this example. Although trimming to length is shown in the diagram, trimming to width can also be done. In either event, the trimmed portions are ejected for disposal 113. In operation 111, the folded and punched sheets are assembled by stacking and are bound (e.g., by stapling) into a booklet form.

#To produce booklets having perfect sheet-to-sheet hole alignment in a sheet-wise process, the step of hole-punching 109 must take into account information relating to each individual folded sheet. In other words, the distance between each punched hole and the folded edge of a sheet is a very important consideration in sheet-wise booklet processing. For example, if holes were punched in the same locations on folded sheets on a sheet-by-sheet basis, at the same distances from each folded edge, the resultant booklet would have holes out-of-alignment from one sheet to another. Such a booklet may not be easily inserted into a ring binder.

#Therefore, to achieve sheet-to-sheet hole alignment in an assembled booklet, the distances between the folded edges and hole locations of each folded booklet must be different. This is necessitated by the effect of outer booklet sheets wrapped over inner booklet sheets. That is, hole locations for a folded booklet sheet depend upon the sheet's position within a completed booklet and upon the accumulated thickness of other booklet sheets positioned between the sides of the folded booklet sheet. As a result, for example, the distance between the folded edge and hole locations of the outermost folded sheet (e.g., the booklet cover) must be greater than the distances between the folded edges and hole locations of all of the folded sheets stacked within the outermost folded sheet. The innermost folded sheet will necessarily have the least distance relative to the other sheets between its folded edge and hole locations.