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:
Mar. 08, 2011
Filed:
Sep. 28, 2007
Alan L. Browne, Grosse Pointe, MI (US);
John C. Ulicny, Oxford, MI (US);
Chandra S. Namuduri, Troy, MI (US);
Nancy L. Johnson, Northville, MI (US);
Norman M. Wereley, Potomac, MD (US);
Young Tai Choi, Laurel, MD (US);
Wei HU, Rockville, MD (US);
Min Mao, College Park, MD (US);
Alan L. Browne, Grosse Pointe, MI (US);
John C. Ulicny, Oxford, MI (US);
Chandra S. Namuduri, Troy, MI (US);
Nancy L. Johnson, Northville, MI (US);
Norman M. Wereley, Potomac, MD (US);
Young Tai Choi, Laurel, MD (US);
Wei Hu, Rockville, MD (US);
Min Mao, College Park, MD (US);
GM Global Technology Operations LLC, Detroit, MI (US);
Abstract
An energy absorbing device is provided that includes a damper assembly having inner and outer concentric tubes and a piston movable within the inner tube. The damper assembly is configured to form bi-fold valve-type cavities to operatively connect an inner chamber of the inner tube with an outer chamber formed between the inner and outer tubes. A magnetorheological fluid fills the chambers and the bi-fold valve-type cavities. The magnetorheological fluid preferably contains coated magnetic particles at about 10 to 60 percent by volume. Electrical coils adjacent the bi-fold valves are selectively energizable to such that the energy absorbing device provides a tunable damping force, preferably over the entire range of velocities of the piston, especially in automotive applications.