Thermo Web Systems, Inc.

Steven J Coleman

Ronald F Goodnow

David A Leeman

William K Giguere

David J Dziadzio

A method and system of measuring deflected doctor blade angle and loading force of an arrangement including a doctor apparatus operating in connection with a rotating cylinder, the apparatus having a doctor blade and a support member which pivots about at least one pivot point in response to an externally applied force for applying the doctor blade to a contact point on the cylinder. The arrangement corresponds to a kinematic model of linkages including a first link defined between the at least one pivot point and the contact point, a second link defined between the contact point and the center of the cylinder, and a third link defined between the center of the cylinder and the at least one pivot point. The method includes measuring the angle between a selected pair of the links; determining the remaining angles between the links as a function of the measured angle; determining an undeflected blade angle which corresponds to an angle between the doctor blade and a tangent line through the contact point on the cylinder, the undeflected blade angle being a function of the determined angle between the first and second links; measuring the externally applied force; ascertaining the blade load as a function of moment balances of the measured angle and the measured externally applied force; and ascertaining the deflected blade angle as a function of the undeflected blade angle and the blade load.

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Marlborough, MA, United States of America

Steven J Coleman