This invention relates to sheet handling and, more particularly, to collators of the type which accept sheets from a printer, processing machine, feeder, copier, or by hand, one sheet at a time or as signatures, in multiples of the desired book or other document, and sort the sheets into one or more copies of the document or groups in individual bins or receiver trays ready for binding or other handling. The invention is illustrated and described herein with reference to acceptance of sheets from a copier of the type in which fresh sheets are supplied individually from a sheet holding cassette to a sheet input located adjacent one end of the copier with the sheets discharged from the copier at a sheet output also located adjacent the same end of the copier with the information bearing surface of the sheet oriented in a predetermined direction (e.g. face up).
Collators of the type to which this invention pertains typically are comprised of an infeed which accepts incoming sheets and a distributor which delivers sheets of paper from the infeed to an upright receiver which includes a vertical column of spaced shelves which form sheet receiver bins for reception and storage of the collated sheets delivered in proper order by the distributor. In one type of collator (hereinafter referred to as a "front entry" collator), the receiver bins are arranged to be fed from the front by the distributor and manually emptied from the rear or side when the collation process is complete. In this instance, the various sheets to be collated are fed in appropriate order by the copier, one sheet at a time, into the distributor and are conveyed by a suitable sheet conveyor along a vertical conveyor run adjacent the front side of the receiver in proximity to the respective inlets to the receiver bins. During the course of downward or upward movement on the vertical conveyor run, the sheets are deflected by a suitable sheet deflector mechanism onto the respective shelves of the receiver or into respective receiver bins by an indexing deflector assembly or individual deflector fingers, as the case may be. In this type of collator, sheets are accepted by the infeed adjacent the front side of the receiver. As a consequence, sheets which are delivered from the copier with a predetermined surface face up, for example, will be distributed into the receiver bins with the same predetermined surface also face up. The terms "front" and "rear" as used herein refer to opposite sides of the receiver, sheets being accepted adjacent the front side. These terms are not intended as constituting limitations to a particular direction of sheet movement or receiver orientation.
In another type of collator (hereinafter referred to as a "rear entry" collator to distinguish it from the aforementioned front entry collator), essentially the same distributor and sheet receiver are utilized, except that the receiver bins are arranged to be fed from the rear. Sheets are accepted by the infeed adjacent the front side of the receiver, are conveyed from the infeed over or under the receiver, and then along a vertical conveyor run adjacent the rear side of the receiver for distribution into respective receiver bins in the customary manner. In this instance, however, the sheets are assembled within the receiver bins inverted or upside down in relation to the surface orientation thereof when accepted by the infeed. In other words, in the rear entry type of collator, sheets which are delivered from the copier with a predetermined surface thereof face up will be assembled within the receiver bins with that surface face down.