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.
Claims12
A method of cross-cutting a moving web (1) with a cutting knife (3) operably mounted on a knife cylinder (2), wherein the knife cylinder has a circumferential distance LZ, LZ being smaller than a cut length LA, the knife cylinder (2) for revolving in a first and a second opposite direction powered by a drive motor (5) in either direction;
- the method comprising the steps of:
- revolving the knife cylinder (2) in a first direction;
- cutting the web (1) with the cutting knife (3);
- completing a first cut;
- reversing the knife cylinder (2) to retard progress in the first direction;
- and
- accelerating the knife cylinder (2) to the speed of the moving web (1) until starting a second cut with the cutting knife (3).
A method of cross-cutting a moving web (1) with a first cutting knife (3) and a second cutting knife operably mounted on a knife cylinder (2), wherein the first and second cutting knives are separated by a circumferential distance LZ, LZ being smaller than a cut length LA, the knife cylinder (2) for revolving in a first and a second opposite direction powered by a drive motor (5) in either direction;
- the method comprising the steps of:
- revolving the knife cylinder (2) in a first direction;
- cutting the web (1) with the first cutting knife (3);
- completing a first cut;
- reversing the knife cylinder (2) to retard progress in the first direction;
- and
- accelerating the knife cylinder (2) to the speed of the moving web (1) until starting a second cut with the second cutting knife.
A method of crosscutting a moving web (1) in a web-fed rotary press, having a knife cylinder (2) with at least one cutting knife (3) that rotates about an axis parallel to the cutting line, comprising the steps of:
- moving the web (1) with an approximately constant speed;
- rotating the knife cylinder (2) during a first cut at a circumferential speed that corresponds approximately to the web speed;
- rotating the knife cylinder (2) otherwise at a changing circumferential speed, the circumference of the knife cylinder (2) being different than the cut length (LA).
Dependencies are inferred from the claim text.