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:
Aug. 01, 2000
Filed:
Mar. 05, 1997
Douglas E Ivers, Cary, NC (US);
J David Carlson, Cary, NC (US);
Mark R Jolly, Holly Springs, NC (US);
Michael J Chrzan, Apex, NC (US);
Donald R Prindle, North East, PA (US);
Kenneth A St Clair, Cary, NC (US);
Lord Corporation, Cary, NC (US);
Abstract
A controllable valve assembly (18) applicable in Magnetorheological (MR) fluid devices (20), such as MR mounts and MR dampers. The valve assembly (18) includes a valve body (32) having a magnetic circuit (40) contained therein which carries magnetic flux .PHI., a controllable passageway (42) within the magnetic circuit (40), a MR (magnetically controlled) fluid (44) including soft-magnetic particles in a liquid carrier contained in the controllable passageway (42), a magnetic flux generator, such as a wound wire coil (46), generating magnetic flux .PHI. which is directed through the MR fluid (44) in the controllable passageway (42) thereby generating 'rheology' changes causing restriction in flow of MR fluid (44) therethrough. In one aspect, a one-way check valve (34) is operative with a passive passageway (36) which is arranged in parallel relationship to the controllable passageway (42) provides 'asymmetric' damping across the controllable valve (18) creating higher pressure differentials in a first direction and a lower in a second direction without 'rapidly switching' the current to the coil (46). In another aspect, 'asymmetric' damping is provided by a 'changeable gap' formed by a moveable wall portion of the controllable passageway (42). In a third aspect, a first controllable passageway provides controllable flow in a first direction and a second controllable passageway provides controllable flow in a second direction, thereby provide 'asymmetry.' In a fourth aspect, 'asymmetry' is provides by a 'variable magnetic short' which changes magnetic circuit reluctance dependent on flow direction.