Feeder-folder unit

A feeder-folder unit for use in folding paper sheet stock and delivering it to a signature gathering machine comprises a main frame with a hopper assembly carried by the main frame for receiving and storing a supply of sheets of paper stock. A sheet extractor and transfer drum assembly is located adjacent the hopper for extracting individual sheets of paper stock from the hopper means and conveying the extracted sheets along a path to a scoring and folding unit located adjacent the path. The hopper assembly includes a pair of spaced support surfaces for supporting the sheets of stock and intermittently actuated drive chains are provided for driving the sheets along the support surfaces toward the sheet extractor and transfer drum assembly. Each of the support surfaces is adjustable independently of the other and the drive chains to selectively vary the presentation of the sheets to said sheet exterior and transfer drum assembly to thereby permit precise positioning of the sheets relative to the scoring and folding unit.