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WEB TENSION COMPENSATION

IP.com Disclosure Number: IPCOM000024890D
Original Publication Date: 1982-Aug-31
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 65K

Publishing Venue

Xerox Disclosure Journal

Abstract

In an electrophotographic printing machine, an original document is frequently automatically advanced to the platen for exposure thereat. ' After exposing the original document, the printing machine produces a copy thereof. Various techniques have been adapted for advancing succesive original documents to the platen of the printing machine. One type of document handling system employs an endless scroll with successive original documents secured thereon. As the web of the scroll advances, each original document is successively positioned on the platen for reproduction. It has been found that tension variations across the web can cause the documents to drift relative to the platen of the copy machine. The tension variations are caused by skewing of the scrolls, by the drive wheels being slightly misaligned relative to the web, or by uneven pressure on the drive pinch rolls, amongst others. In order to automatically reduce document drift, a teeter bar is positioned approximately midway between the drive roll and the scroll. The teeter bar comprises a thin rigid bar, teetering on a central hinge. The hinge is attached so that each end of the teeter bar is free to move up and down in response to web edge tension. This teetering action automatically minimizes lateral tension variations. Preferably, two teeter bars are employed one on each side of the drive.

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FEROX DISCLOSURE JOURNAL

WEB TENSION COMPENSATION
Proposed A. C. Martellock Classification

U.S. c1. 355/3
Int. C1. G03g 15/00

In an electrophotographic printing machine, an original document is frequently automatically advanced to the platen for exposure thereat. ' After exposing the original document, the printing machine produces a copy thereof. Various techniques have been adapted for advancing succesive original documents to the platen of the printing machine. One type of document handling system employs an endless scroll with successive original documents secured thereon. As the web of the scroll advances, each original document is successively positioned on the platen for reproduction. It has been found that tension variations across the web can cause the documents to drift relative to the platen of the copy machine. The tension variations are caused by skewing of the scrolls, by the drive wheels being slightly misaligned relative to the web, or by uneven pressure on the drive pinch rolls, amongst others. In order to automatically reduce document drift, a teeter bar is positioned approximately midway between the drive roll and the scroll. The teeter bar comprises a thin rigid bar, teetering on a central hinge. The hinge is attached so that each end of the teeter bar is free to move up and down in response to web edge tension. This teetering action automatically minimizes lateral tension variations. Preferably, two teeter bars are employed one on each side o...