This invention relates to apparatus and method for indexing sheets and, more particularly, to the indexing of multi-page reports where separator sheets protrude outwardly between adjacent copies of the stacked reports.
It is known to index zig-zag folded forms as, for example, seen in U.S. Pat. No. 5,065,992. There, the trailing panel of one set and the leading panel of an adjacent set were of different lengths so that the longer of the two would protrude to serve as a visual separator. The zig-zag forms were less preferable than individual sheets because they required special binders and also if separated into individual sheets subsequently required a bursting step which very often left ragged edges where the perforation bonds had occurred.
It is also known to indicate the presence of a flawed sheet by having the same protrude as seen in U.S. Pat. No. 3,375,744. Still further, it is known to index or tab sheets via a guillotine cutter so as to provide different lengths as stack separators. In such a case, the sheet advance is intermittent which is speed limiting. Also the stationary knife operation creates problems in subsequent sheet handling.
According to the instant invention, sheets are provided in set or report form, i.e., a predetermined number of sheets or pages per set or report and which are separated by longer and shorter sheets than those in the set or report. This is all done continuously by means of cyclically varying the speed relationship between the web and the rotary cutter associated with the printer which sets down the report information.