System and method for measuring untensioned product length of a web during production
AssigneeGoss International Americas, Inc.
InventorsDouglas Joseph Dawley, Daniel Matthew Perdue, Drew Edwin Kiefaber
Life of this patent
Estimating the term…
Abstract
A system and method is provided for determining an untensioned product length of a web moving through a printing press under tension. A controller determines a tensioned repeat length of the web in a span of the printing press while the web is moving through the printing press under tension; determines an elastic strain of the web in the span of the printing press while the web is moving through the printing press under tension; and calculates an untensioned product length of the web in the span of the printing press while the web is moving through the printing press under tension as a function of the tensioned repeat length and the elastic strain.
Claims20
A method for determining an untensioned product length of a web moving through a printing press under tension, comprising, using a controller:
- determining a tensioned repeat length of the web in a span of the printing press while the web is moving through the printing press under tension;
- determining an elastic strain of the web in the span of the printing press while the web is moving through the printing press under tension;
- calculating an untensioned product length of the web in the span of the printing press while the web is moving through the printing press under tension as a function of the tensioned repeat length and the elastic strain;
- and
- controlling the printing press using the untensioned product length.
A web fed printing press for printing on a continuous web and cutting the web into printed products having an untensioned product length, the press comprising:
- a printing unit including a plate cylinder, a blanket cylinder, and an impression cylinder, the plate cylinder having a reference repeat length;
- a plurality of rollers located downstream of the printing unit, the web moving under tension through the printing unit and the plurality of rollers as it moves through the press,
- a controller configured and arranged to generate an untensioned product length of the web as it moves through a printing press under tension, the controller determining a tensioned repeat length of the web in a span located between an adjacent pair of the plurality of rollers, while the web is moving through the printing press under tension, determining an elastic strain of the web in the span of the printing press while the web is moving through the printing press under tension, and calculating an untensioned product length of the web in the span of the printing press while the web is moving through the printing press under tension as a function of the tensioned repeat length and the elastic strain.
A system for determining an untensioned product length of a web moving through a printing press under tension, comprising:
- a first tensioning roller, the moving web contacting the first tensioning roller;
- a first roller located downstream of the first tensioning roller, the first roller driving the web, a first span of the web extending between the first tensioning roller and the first roller;
- a first motor driving the first roller;
- a second tensioning roller located downstream of the first roller, the moving web contacting the second tensioning roller;
- a second roller located downstream of the second tensioning roller, the second roller driving the web, a second span of the web extending between the second tensioning roller and the second roller;
- a second motor driving the second roller;
- and
- a controller, the controller detecting a tension T1 in the first span with the first tensioning roller, the controller detecting a tension T2 in the second span with the second tensioning roller, the controller calculating an untensioned product length as a function of T1, T2, drive setpoints for the first and second motors, a web thickness of the web (h), and a reference repeat length (COREF).
Dependencies are inferred from the claim text.