Rotary web chopper

A shear cutter for a running web comprising:

• a pair of axially co-parallel counter rotating shafts power driven in synchronism one with the other;
• said web being trained over said first shaft, said shafts having interacting blades for cutting said web, the first shaft of said pair being provided over a major expanse of its periphery with a multiplicity of web retaining vacuum ports and at least one peripheral inwardly extending recess within which is mounted a first of said blades, said first blade being a radially disposed straight edge blade having a cutting edge located near the outside perimeter of said first shaft;
• control means operating in a predetermined time sequence relative to the rotation of said shafts repetitively imposing preselected time durations for vacuum web retention;
• means mounted within said recess and responsive to said control means for effecting, in seriatim, vacuum retention of the leading edge of said web during and after severance thereof, followed by means relieving said vacuum retention proximal to said leading edge following each said cut, thereby to release said leading edge;
• and
• means stripping said leading edge at a preselected delivery point for severed sheets of said web.