of such copying apparatus and a description of its operation are found for example in u s pat no 3 990 695 in use original material to be copied is supplied to the copier for reproduction of a selected number of copies which are transported to the sorter by transport rollers or other known transport means t incorporated in the copier the sorter of the present invention is operable to receive in a non sort mode a number of copies of a single sheet or in a sort mode to receive and collate sets of copies of plural originals supplied to the copier in succession in the illustrated sorter provision is made for collating twenty sets of copies but it will be understood that the principals of the invention may be employed in sorters capable of collating more or less than twenty sets the sorting machine may be positioned to receive sheets from the copier in various ways such as on a slide or by hinge means adapted to permit separation between the copier and sorter in the event of a sheet misfeed or by suitable support brackets frame structure for the sorting machine includes a box like structure having opposed sides 10 a top support 11 and a base 12 auxilary sheet transport means 13 are provided to receive sheets from the copier including driven rolls 14 on a shaft 15 which extends horizontally between the sides 10 and knurled pinch rolls 16 on a shaft 17 which extends between the side walls a drive motor 18 has an output shaft 19 frictionally engaging a resilient drive disc 20 mounted on a transport drive shaft 21 supported on top of the frame structure a belt 22 is driven by shaft 21 and drives the transport shaft 15 the.