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US 6,782,818 B2Granted
Method for adjustment of a belt tension in a rotary press machine
AssigneeKoenig & Bauer Aktiengesellschaft
InventorsErhard Herbert Glöckner, Dieter Koch
Life of this patent
Estimating the term…
Abstract
The tension of a web in a rotary printing machine is monitored and adjusted. The web runs through at least one printing group in the rotary printing machine. Any change in the stretch of the web during the production run is determined by noting any difference between first and second speeds of the web. The change in stretch is compensated for by a change in the tension of the web before the first printing group.
Claims17
A method for controlling a web tension in a rotary printing press including:
- providing at least one printing unit in the rotary printing press;
- passing a web to be printed through said at least one printing unit;
- measuring first and second speeds of web travel at two different locations in the rotary printing press;
- determining a speed difference between said first and second speeds;
- providing a reference value for said speed difference between said first and second speeds;
- comparing said determined speed difference with said reference value for said speed difference;
- sensing an amount of a change in said determined speed difference between said first and second speeds;
- using said amount of said change in said determined speed difference between said first and second speeds for ascertaining an amount of a change in longitudinal stretch in said web after said at least one printing unit;
- changing a tension in said web before said at least one printing unit in response to said amount of said change in longitudinal stretch in said web after said at least one printing unit;
- and
- using said change in tension in said web before said at least one printing unit for controlling said longitudinal stretch in said web after said at least one printing unit.
8 more elements
A method for controlling a web tension in a rotary printing press comprising:
- providing at least one printing unit in the rotary printing press;
- passing a web to be printed through said at least one printing unit;
- measuring a first speed of web travel as a circumferential speed in said at least one printing unit;
- providing a web draw roller after, in a web transport direction, said at least one printing unit;
- measuring a second speed of web travel as a circumferential speed in said web draw roller;
- determining a speed difference between said first and second speeds;
- recording said speed difference between said first and second speeds as a reference value;
- using said speed difference between said first and second speeds for ascertaining a change in a longitudinal stretch in said web after said at least one printing unit;
- determining an actual speed difference between said first and second speeds of web travel during operation of the rotary printing press;
- providing a web infeed unit;
- comparing said actual speed difference with said reference value and determining a deviation;
- forming an interference variable using said deviation in said actual value. from said reference value;
- using said interference variable for controlling said infeed unit;
- and
- using said infeed unit for tensioning said web before said at least one printing unit in response to said change in said speed difference until said reference value for said speed difference is reached.
12 more elements
Dependencies are inferred from the claim text.