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:
Nov. 07, 1989
Filed:
Oct. 21, 1987
Frank E Filisko, Ann Arbor, MI (US);
William F Armstrong, Ann Arbor, MI (US);
Board of Regents Acting for and on Behalf of University of Michigan, Ann Arbor, MI (US);
Abstract
An improved method of inducing a change in the dynamic torque transmission of an electrorheological fluid in response to an electric field at low current comprising the steps of: (a) selecting a nonconductive liquid phase (e.g. high dielectric hydrocarbon oil); (b) dispersing in the nonconductive liquid phase a particulate phase substantially free of adsorbed water (e.g. zeolite); and (c) subjecting the resulting electrorheological fluid to an electric potential in excess of about one kilovolt at a current density of less than about one-third microamp per square inch. Such a method achieves a rate of increase of dynamic transmission of torque per unit voltage, dM/dV, in excess of about 0.034 ft-lbs.times.10.sup.-3 /kV and a ratio of dynamic transmission of torque at an electric field strength of at least 2.4 kV to the dynamic transmission of torque at zero field strength, M/Mo, of at least about 2.