Air bearing support assembly for paper slitting apparatus

In an apparatus for slitting a horizontal running paper web, said apparatus including a thin annular rotary cutting blade positioned with its axis of rotation on one side of the web and having a smooth peripheral cutting edge defined by opposite blade faces, said cutting edge extending through the path of the web to slit the web in the direction of web travel, and a supporting surface on the other side of the web for supporting the web at the point of slitting and including a slot in the supporting surface for receiving the blade cutting edge, the improvement in said apparatus comprising:

• a flat plate positioned to provide a flat supporting surface upstream and downstream of the point of slitting and including lateral surface portions having opposed edges defining the slot;
• aperture means in the supporting surface adjacent said opposed edges operatively connected to a source of compressed air to supply a flow of air therethrough sufficient to support a portion of the running web along the length of the slot spaced slightly from the supporting surface for preventing the entry of paper fibers into the slot and abrasive contact between components of the paper and the slot edges to prevent wear of said slot edges and to maintain tolerance between said slot edges and said blade.