US4879056A
Expired / Lapsed
US
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Electric field dependent fluids
Assignee: BOARD OF REGENTS ACTING FOR AND ON BEHALF OF UNIVERSITY OF MICHIGAN ANN ARBOR MICHIGAN A CORP OF MI
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Filing: 1987-10-21
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Granted: 1989-11-07
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Expires: 2007-10-21
Abstract
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-lbsx10-3/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.
Inventors
- 👤 Frank E. Filisko
- 👤 William F. Armstrong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:35
CPC Classifications
H; H01; H01G; H01G9/00; C; C10; C10M; C10M171/00; C10M171/001; C10M125/00; C10M125/26; C10M2201/00; C10M2201/10; C10M2201/102; C10M2201/103; C10N; C10N2040/00; C10N2040/14; C10N2040/16; C10N2040/17; C10N2040/175; C10N2040/18; C10N2040/185
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
86 words
A method of inducing a change in 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; (b) dispersing in said nonconductive liquid phase a particulate phase substantially free of adsorbed water, thus producing an electrorheological fluid; and (c) subjecting said electrorheological fluid prepared in step (b) to an electric potential in excess of about one kilovolt at a current density of less than about 1/3 microamp per square inch.
Claim 2
Independent Claim
86 words
A method of inducing a change in 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; (b) dispersing in said nonconductive liquid phase a particulate phase substantially free of adsorbed water, thus producing an electrorheological fluid; and (c) subjecting said electrorheological fluid prepared in step (b) to an electric potential in excess of about one kilovolt at a current density of less than about 1/3 microamp per square inch.
Claim 3
Dependent Claim
29 words
A method of claim 1 wherein the rate of increase of the dynamic transmission of torque per unit voltage, dM/dV, is in excess of about 0.034 ft-lbs×10 -3 /kV.
Claim 4
Dependent Claim
40 words
A method of claim 1 wherein the ratio of the 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, is at least about 2.
Claim 5
Dependent Claim
25 words
A method of claim 1 wherein the increase in dynamic transmission of torque is reversed by the further step of decreasing the electric field potential.
Claim 6
Dependent Claim
13 words
A method of claim 1 wherein said particulate phase is an inorganic zeolite.
Claim 7
Dependent Claim
61 words
A method of claim 1 wherein said particulate phase is a crystalline zeolite characterized by the formula: M.sub.(x/n) [(AlO.sub.2).sub.x (SiO.sub.2)·wH.sub.2 O where M is a metal cation or mixture of metal cations of average valence charge n, x and y are integers and the ratio of y to x is from about 1 to about 5, and w is a variable.
Claim 8
Dependent Claim
54 words
A method of claim 6 wherein said crystalline zeolite is present from about 500 grams per liter of liquid to about 900 grams per liter of liquid and the rate of increase in dynamic transmission of torque per unit voltage, dM/dV, is from about 0.034 ft-lbs×10 -3 /kV to about 8.4 ft-lbs×10 -3 /kV.
Claim 9
Dependent Claim
31 words
A method of claim 1 wherein said increase in dynamic transmission of torque is achieved at temperatures from about 40° C. to about 120° C. without releasing significant amounts of water.
Claim 10
Independent Claim
89 words
A method of inducing a change in 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; (b) dispersing in said non-conductive liquid phase an organic polymeric polyelectrolyte particulate phase substantially free of adsorbed water, thus producing an electrorheological fluid; and (c) subjecting said electrorheological fluid prepared in step (b) to an electric potential in excess of about one kilovolt at a current density of less than about 1/3 microamp per square inch.
Claim 11
Independent Claim
89 words
A method of inducing a change in 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; (b) dispersing in said non-conductive liquid phase an organic polymeric polyelectrolyte particulate phase substantially free of adsorbed water, thus producing an electrorheological fluid; and (c) subjecting said electrorheological fluid prepared in step (b) to an electric potential in excess of about one kilovolt at a current density of less than about 1/3 microamp per square inch.
Claim 12
Independent Claim
103 words
A method of inducing a change in 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; (b) dispersing in said nonconductive liquid phase a particulate phase substantially free of adsorbed water selected from the group consisting of polymeric cation exchange resin, polymeric anion exchange resin, and resinous polyelectrolyte, thus producing an electrorheological fluid; and (c) subjecting said electrorheological fluid prepared in step (b) to an electric potential in excess of about one kilovolt at a current density of less than about 1/3 microamp per square inch.
Claim 13
Independent Claim
103 words
A method of inducing a change in 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; (b) dispersing in said nonconductive liquid phase a particulate phase substantially free of adsorbed water selected from the group consisting of polymeric cation exchange resin, polymeric anion exchange resin, and resinous polyelectrolyte, thus producing an electrorheological fluid; and (c) subjecting said electrorheological fluid prepared in step (b) to an electric potential in excess of about one kilovolt at a current density of less than about 1/3 microamp per square inch.
Claim 14
Dependent Claim
49 words
A method of claim 8 wherein said particulate phase is present from about 500 grams per liter of liquid to about 900 grams per liter of liquid and the rate of increase in dynamic transmission of torque per unit voltage, dM/dV, is up to about 1.2 ft-lbs×10 -3 /kV.
Claim 15
Dependent Claim
17 words
A method of claim 6 wherein said electrorheological fluid contains less than 5% by weight zeolite water.
Claim 16
Dependent Claim
25 words
An electric field dependent fluid comprising: (a) a nonconductive liquid phase; and (b) a dispersed particulate organic polymeric polyelectrolyte phase, substantially free of adsorbed water.
Claim 17
Dependent Claim
25 words
An electric field dependent fluid comprising: (a) a nonconductive liquid phase; and (b) a dispersed particulate organic polymeric polyelectrolyte phase, substantially free of adsorbed water.
Claim 18
Dependent Claim
23 words
An electric field dependent fluid of claim 13 selected from the group consisting of cation exchange resin, anion exchange resin, and resinous polyelectrolyte.
Claim 19
Dependent Claim
34 words
An electric field dependent fluid of claim 13 wherein said fluid exhibits significant viscosity dependence upon an imposed electric field at temperatures in excess of 100 ° C. without releasing significant amounts of water.
Claim 20
Independent Claim
105 words
A method of preparing a field dependent fluid adapted to be operative at a temperature range of from at least about 40 ° C. to at least about 100 ° C. without the release of water, comprising the steps of: (a) selecting a nonconductive liquid of said field dependent fluid; (b) selecting an organic polymeric polyelectrolyte as the particulate phase of said field dependent fluid; and (c) subjecting said nonconductive liquid and said organic polymeric polyelectrolyte to a temperature in excess of the temperature to which the field dependent fluid will be subjected to during use for a sufficient time to degas and remote water.
Claim 21
Independent Claim
105 words
A method of preparing a field dependent fluid adapted to be operative at a temperature range of from at least about 40 ° C. to at least about 100 ° C. without the release of water, comprising the steps of: (a) selecting a nonconductive liquid of said field dependent fluid; (b) selecting an organic polymeric polyelectrolyte as the particulate phase of said field dependent fluid; and (c) subjecting said nonconductive liquid and said organic polymeric polyelectrolyte to a temperature in excess of the temperature to which the field dependent fluid will be subjected to during use for a sufficient time to degas and remote water.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-06 | 1993-05-08 | 1993-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-06 | 1997-05-08 | 1997-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-06 | 2001-05-08 | 2001-11-07 | $7700.00 | Window Closed / Lapsed |