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:
Apr. 08, 2008
Filed:
May. 18, 2004
Randy C. Foster, Strafford, MO (US);
Richard J. Meckstroth, Vonore, TN (US);
Randy C. Foster, Strafford, MO (US);
Richard J. Meckstroth, Vonore, TN (US);
Dayco Products, LLC, Miamisburg, OH (US);
Abstract
A tensioner for a power transmitting belt is provided having a base, an arm pivotably attached to the base, a pulley rotatably attached to the arm and a spring operatively connected to the arm and the base for urging the arm in direction to tension the belt. A hydraulic strut is pivotably attached to the base and the arm to restrict the movement of the arm through asymmetric fluid damping. The hydraulic strut includes a hydraulic cylinder filled with magnetorheological fluid, a piston rod axially mounted through the cylinder and a piston mounted on the piston rod to divide the cylinder into first and second fluid chambers. The strut further includes a fluid flow path between the first and second fluid chambers, a check valve in the fluid flow path to provide asymmetric fluid flow and a coil that is operable to generate a magnetic field across the fluid flow path when energized. When the coil is energized fluid flow between the first and second fluid chambers is halted such that the arm of the tensioner locks up.