Variable width envelope feeder

Abstract

A sheet feeding apparatus for feeding vertically disposed sheet material from a horizontally extending stack comprising a platform adapted to support a stack of sheet material, a vertically extending frame disposed at one end of the platform, and first and second rollers vertically supported in spaced relation by the frame. Endless webs extend around and are driven by the first and second rollers, wherein the webs include a plurality of perforations therein and have one run facing the platform. The one run has a portion which provides an effective contact surface to engage the first article in the stack of sheet material to transport the article from the stack of sheet material as the endless webs are driven. A carriage adjustably located between the first and second rollers supports third and fourth rollers, and the endless webs pass between the third and fourth rollers to continue movement in a different plane. Adjustment of the carriage establishes the effective contact surface of the webs to prevent corners of the sheet material from becoming caught by the perforations in the web. A vacuum force is applied to the face of the webs through the perforations and to enhance adhesion of the first article in the stack to the webs. Once removed from the stack, the sheet material is engaged by a nip roller and advanced to a work station.