The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 1999
Filed:
Jul. 15, 1997
Dino J Rossetti, Chapel Hill, NC (US);
Stephen F Hildebrand, Erie, PA (US);
John J Quinn, Raleigh, NC (US);
Mark A Norris, Raleigh, NC (US);
Lane R Miller, Fuquay-Varina, NC (US);
Lord Corporation, Cary, NC (US);
Abstract
A vibration control apparatus (20) and method for a calender (18) for controlling vibration between two or more rolls (ex. 22, 24) which controls vibration induced thickness variations in a medium (27) exiting from the nip. The apparatus (20) includes a frame (19), a first and second rolls (22, 24) mounted relative to the frame (19), and a force generator (32), such as an electromechanical active actuator, servo-hydraulic actuator, controllable semi-active damper, Active Vibration Absorber (AVA), or Adaptive Tuned Vibration Absorber (ATVA), provides cancelling forces to control vibration between the first and second roll (22, 24) thereby, controlling such vibration induced thickness variations in the medium (27). Preferably, the apparatus (20) includes at least one sensor (ex. 42, 42', 42', 42'') for providing a signal representative of a vibration condition of at least one of the first or second roll (22, 24), and preferably both, and a digital controller (50) for processing the signal representative of said vibration condition preferably according to a feed-forward-type control and providing a control signal to a force generator (32). Vertical and/or lateral vibration of the rolls (22, 24) may controlled simultaneously. Likewise, fundamental vibrational frequencies and their harmonics may be controlled individually, or in combination.