OFFSET COLLATOR

In an apparatus for and method of collating sheets, sheets are conveyed to a stacking platform 154 in alternate offset fashion by grippers 84 and 86 (not shown). After the first group of sheets has been stacked, the platform is raised above a reciprocable arm 250 which is then swung into a position to support a non-overlapped portion of the bottom sheet and the platform lowered. The grippers then convey the second group of sheets to the platform 154 where they are inserted below correspondingly offset sheets of the first group, the arm 250 being reciprocated between sheets to allow a previously stacked sheet supported thereon to drop. Thus the non-overlapped portions of adjacent sheets are supported sequentially and the second group of sheets collated with the first group. The method is repeated until all the sheets comprising a set have been inserted into all the sets. The stack of offset sets is then ready for removal from the apparatus by an operator.