Method of crosscutting a moving web
AssigneeMAN Roland Druckmaschinen AG
InventorsRobert Kersch, Wolfgang Zeller
Life of this patent
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Abstract
A method of cross-cutting a moving web uses a cutting knife operably mounted on a knife cylinder having a circumferential distance LZ where LZ is smaller than a cut length, LA. The knife cylinder for revolving in a first and a second opposite direction is powered by a drive motor in either direction. The method includes revolving the knife cylinder in a first direction, cutting the web with the cutting knife, and completing a first cut. The knife cylinder is then reversed to retard progress in the first direction and then accelerated to the speed of the moving web until starting the second cut.
Claims7
A method of cross-cutting a web along a series of cutting lines in a web-fed rotary printing press to produce a series of sheets, each sheet having a cut length, said method comprising:
- providing a knife cylinder in a web fed rotary printing press, the knife cylinder having an axis of rotation, a cutting knife, and a circumference which is less than the cut length of a sheet;
- moving the web through the press at an approximately constant web speed;
- rotating the knife cylinder in a first direction with a circumferential speed that corresponds to the web speed while the web is being cross-cut by the cutting knife;
- reversing the direction of rotation of the knife cylinder after completing a cross-cut;
- bringing the knife cylinder to a stop following the reversing;
- and
- accelerating the knife cylinder in the first direction until the knife cylinder is again rotating with a circumferential speed which corresponds to the web speed, prior to making another cross-cut.
Dependencies are inferred from the claim text.