US3750067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferrofluidic solenoid
Assignee: National Aeronautics and Space Administration
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Filing: 1972-03-16
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Granted: 1973-07-31
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Expires: 1992-03-16
Abstract
Abstract An electromechanical actuator for producing mechanical force and/or motion in response to electrical signals applied thereto, is disclosed. The actuator includes a ferromagnetic fluid and a coil which are contained within an elastomeric capsule. Energization of the coil by application of current to a pair of coil electrodes extending through the walls of the elastomeric capsule produces distortion of the capsule, i.e., radial expansion and axial contraction. This distortion is caused by the redistribution of the ferromagnetic fluid within the capsule under the influence of the magnetic field produced by the energized coil. Variation of the current input will produce corresponding variations in the degree of capsule distortion.
Inventors
- 👤 J Fletcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:27
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/50; A61F2/68; A61F2/70; A61F2/72; F; F16; F16K; F16K31/00; F16K31/02; H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/20; A61F2/02; A61F2/08; A61F2002/0894
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
129 words
An electromechanical actuator for producing mechanical movemeNt in response to the application of electric current, the actuator comprising: a flexible closed shell capable of omnidirectional deformation having an interior cavity formed by the wall thereof; an electrical coil maintained unattached in said cavity so that the entire shell is relatively movable to said electrical coil; means for energizing said electrical coil including a pair of terminals extending through said wall of said shell and connected to said electrical coil; a magnetizable fluid completely surrounding said suspended coil and fully occupying said cavity to exert a hydrostatic pressure on said shell, said shell being deformed when a magnetic pressure is created in said magnetizable fluid within said shell by the application of current through said terminals to energize said coil.
Claim 2
Dependent Claim
129 words
An electromechanical actuator for producing mechanical movemeNt in response to the application of electric current, the actuator comprising: a flexible closed shell capable of omnidirectional deformation having an interior cavity formed by the wall thereof; an electrical coil maintained unattached in said cavity so that the entire shell is relatively movable to said electrical coil; means for energizing said electrical coil including a pair of terminals extending through said wall of said shell and connected to said electrical coil; a magnetizable fluid completely surrounding said suspended coil and fully occupying said cavity to exert a hydrostatic pressure on said shell, said shell being deformed when a magnetic pressure is created in said magnetizable fluid within said shell by the application of current through said terminals to energize said coil.
Claim 3
Dependent Claim
59 words
The electromechanical actuator defined by claim 1, said shell comprising an elastomeric material forming a continuous closed wall and an oblong configuration when subject to only said hydrostatic pressure, said fluid comprising a ferromagnetic fluid responsive to a magnetic field created by energization of said coil, said shell assuming a substantially spherical shape when subject to said magnetic pressure.
Claim 4
Dependent Claim
114 words
A ferrofluidic solenoid comprising: a flexible capsule having a hollow interior area formed by the wall thereof; a coil having an open bore positioned in said hollow interior area so that the entire wall is movable relative to said coil; means connected to said coil for permitting the application of electrical current to said coil; a magnetizable fluid contained within said capsule and fully immersing said coil, said open bore containing only said magnetizable fluid, said flexible capsule producing an output force by being deformed by said magnetizable fluid when the fluid pressure of said magnetizable fluid within said shell is varied by the application of current through said terminals to energize said coil.
Claim 5
Dependent Claim
114 words
A ferrofluidic solenoid comprising: a flexible capsule having a hollow interior area formed by the wall thereof; a coil having an open bore positioned in said hollow interior area so that the entire wall is movable relative to said coil; means connected to said coil for permitting the application of electrical current to said coil; a magnetizable fluid contained within said capsule and fully immersing said coil, said open bore containing only said magnetizable fluid, said flexible capsule producing an output force by being deformed by said magnetizable fluid when the fluid pressure of said magnetizable fluid within said shell is varied by the application of current through said terminals to energize said coil.
Claim 6
Dependent Claim
12 words
The actuator defined by claim 1, said shell comprising an elastomeric material.
Claim 7
Dependent Claim
12 words
The actuator defined by claim 1, said fluid comprising a ferromagnetic fluid.
Claim 8
Dependent Claim
21 words
The actuator defined by claim 1, said fluid comprising a colloidal, non-flocculating suspension of high permeability particles in an inert liquid.
Claim 9
Dependent Claim
34 words
The actuator defined by claim 1 further including output members connected at opposing points along the exterior of said shell for transmitting mechanical forces developed by deformation of said shell to articles connected thereto.
Claim 10
Dependent Claim
50 words
The actuator defined by claim 7, said shell comprising an elastomeric material and having an oblong spherical configuration, said coil having the longitudinal axis thereof superimposed with the longitudinal axis of said shell, said output members connected to said shell at opposing points on said shell intersecting said longitudinal axis.
Claim 11
Dependent Claim
12 words
The actuator defined by claim 8, said fluid comprising a ferromagnetic fluid.
Claim 12
Dependent Claim
41 words
The ferrofluidic solenoid defined by claim 3, said capsule comprising an elastomeric shell having a continuous closed wall and an oblong configuration, said fluid comprising a ferromagnetic fluid responsive to introduction to a magnetic field created by energization of said coil.
Claim 13
Dependent Claim
47 words
The ferrofluidic solenoid defined by claim 10, said coil having the longitudinal axis thereof superposed with the longitudinal axis of said capsule, said solenoid further including connecting arms secured to the exterior surface of said capsule at opposing points thereon intersecting said longitudinal axis of said capsule.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |