Patent ID: 6035259
Filing Date: 2000-03-07
Classification: B65H

Abstract:
An apparatus for measuring camber in a web material, the web material having a first and second edge, comprising:a rotatable roller conveying the web material, said roller having a first and second end;a first and second edge detector detecting a position of said first and second edges, respectively, relative to a reference position as the web is conveyed by said roller;a first tension measuring apparatus disposed at said first end of said roller, said first tension measuring apparatus determining the tension applied to said roller at said first end as the web material is conveyed across said roller, a first electrical signal being provided which corresponds to the applied tension;a second tension measuring apparatus disposed at said second end of said roller, said second tension measuring apparatus determining the tension applied to said roller at said second end as the web material is conveyed across said roller, a second electrical signal being provided which corresponds to the applied tension; anda computer for collecting said first and second electrical signals and manipulating said first and second electrical signals to provide the camber measurement according to the equation Camber=Differential Tension/C wherein: ##EQU30## C is a constant for a particular set of web material parameters, D is a distance between said first and second load cells,F.sub.LC1, F.sub.LC2 are a first and second load cell force corresponding to said first and second electrical signals, respectively,W is a lateral width of the web material, andZ is a distance that the web material is offset from a midpoint between said first and second load cells.