Apparatus and method for controlling tension in a web
OwnerMichael E. McAleaveyinventor
Life of this patent
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Abstract
An apparatus for controlling tension in a web includes devices such as unwinding and calendar or wind-up rollers for supporting opposite ends of the web. A pressure region is formed between the opposite ends of the web adjacent a first side of the web. The pressure region is at a lower pressure than ambient pressure, such that the web is urged in a direction of the pressure region. The web supported at its opposite ends by the supporting devices is placed in tension in an amount corresponding to the pressure of the pressure region.
Claims16
An apparatus for controlling tension in a web supported at opposite ends of the web, the apparatus comprising;
- means, between the opposite ends of the web, for forming a pressure region adjacent a first side of the web, the pressure region being at a lower pressure than ambient pressure, such that at least a portion of the web is urged in a direction of the pressure region;
- the web supported at its opposite ends being placed in tension in an amount corresponding to the pressure of the pressure region;
- means for adjusting a pressure of the pressure region;
- sensor means for determining a position of the portion of the web and for generating a signal corresponding to the position of the portion of the web;
- and
- a control apparatus, the control apparatus receiving the signal from the sensor means and generating a signal, received by the pressure adjusting means, in response to the signal from the sensor means, the pressure adjusting means adjusting the pressure of the pressure region in response to the signal from the control apparatus.
A method for controlling tension in a web supported at opposite ends, the method comprising the steps of:
- forming a pressure region adjacent a first side of the web between the opposite ends of the web, the pressure region being at a lower pressure than ambient pressure, such that at least a portion of the web is urged in a direction of the pressure region, the web supported at its opposite ends being placed in tension in an amount corresponding to the pressure of the pressure region;
- detecting, with a sensor means, a position of the portion of the web adjacent the pressure region and generating a signal corresponding to the position of the portion of the web;
- adjusting a pressure of the pressure region in response to the signal corresponding to the position of the portion of the web.
Dependencies are inferred from the claim text.