US4700541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shape memory alloy actuator
Assignee: Nokia Bell Labs
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Filing: 1986-10-16
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Granted: 1987-10-20
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Expires: 2006-10-16
Abstract
Abstract An electrically controlled shape memory alloy actuator capable of being miniaturized for use in robotics and other fields. The actuator is made of a shape memory alloy wire which is torsioned end along its longitudinal axis and with its ends constrained against movement. A lever or other suitable element is attached to the wire at a desired point other than at a wire end. A plurality of electrical connections spaced along the wire define a plurality of different sections of the wire. The wire and attached control element is made to rotate by selectively applying voltages to the different sections of the wire to heat the individual sections.
Inventors
- 👤 Kaigham J. Gabriel
- 👤 William S. N. Trimmer
- 👤 James A. Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:11
CPC Classifications
B; B25; B25J; B25J9/00; B25J9/10; B25J9/1085; F; F03; F03G; F03G7/00; F03G7/06; F03G7/061; F03G7/0614; F03G7/06143; F03G7/063; F03G7/0633; F03G7/064; F03G7/0641; F03G7/066; H; H01; H01H; H01H61/00; H01H61/01; H01H61/0107; H01H2061/0122
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
70 words
An actuator comprising: a wire made of a shape memory alloy, the wire being torsioned about its longitudinal axis and the ends of the wire being fixed to a support structure; a control member attached to the wire at a prescribed point; and a plurality of electrical connections to different longitudinal sections of the wire to which voltages may be selectively applied, thereby to rotate the wire and control element.
Claim 2
Dependent Claim
70 words
An actuator comprising: a wire made of a shape memory alloy, the wire being torsioned about its longitudinal axis and the ends of the wire being fixed to a support structure; a control member attached to the wire at a prescribed point; and a plurality of electrical connections to different longitudinal sections of the wire to which voltages may be selectively applied, thereby to rotate the wire and control element.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 further comprising means for indicating the rotated position of the control member.
Claim 4
Dependent Claim
25 words
The apparatus of claim 2 wherein the position indicating means comprises: optical reflecting means located on the control member for reflecting a beam of light.
Claim 5
Dependent Claim
49 words
The actuator of claim 1 comprising: a first electrical connection; a second electrical connection; a third electrical connection located between the first and second connections; the three connections defining first and second sections of the wire; and the control member being attached to the wire at approximately its midpoint.
Claim 6
Dependent Claim
20 words
The actuator of claim 1 further comprising heat insulators located between the ends of the wire and the support structure.
Claim 7
Dependent Claim
16 words
The apparatus of claim 1 wherein the wire is made of a tin and nickel alloy.
Claim 8
Dependent Claim
12 words
The apparatus of claim 1 wherein the control member is a lever.
Claim 9
Dependent Claim
15 words
The apparatus of claim 1 wherein the control member is a hollow air directing tube.
Claim 10
Dependent Claim
63 words
A mechanical actuating system comprising: a wire made of a shape memory alloy, the wire being torsioned about its longitudinal axis and the ends of the wire being constrained against movement; a control member attached to the wire at a prescribed point; and means for selectively applying control voltages to different longitudinal sections of the wire to rotate the wire and control element.
Claim 11
Dependent Claim
63 words
A mechanical actuating system comprising: a wire made of a shape memory alloy, the wire being torsioned about its longitudinal axis and the ends of the wire being constrained against movement; a control member attached to the wire at a prescribed point; and means for selectively applying control voltages to different longitudinal sections of the wire to rotate the wire and control element.
Claim 12
Dependent Claim
21 words
The system of claim 9 further comprising: sensing means for generating electrical signals indicating the rotated position of the control element.
Claim 13
Dependent Claim
19 words
The system of claim 10 further comprising: control means responsive to the position signals for generating the control voltages.
Claim 14
Dependent Claim
23 words
The system of claim 11 wherein the sensing means comprises: optical reflecting means on the control element for reflecting a beam of light.
Claim 15
Dependent Claim
17 words
The system of claim 12 wherein the sensing means further comprises: optical beam detecting and transducing means.
Claim 16
Dependent Claim
37 words
The system of claim 10 wherein the control means comprises: a software controlled computer responsive to the electrical position signals from the sensing means for selectively applying control voltages to the different wire sections of the actuator.
Claim 17
Dependent Claim
66 words
The system of claim 9 wherein the control member is a hollow tube, and wherein the system further comprises: a source of a stream of air positioned such that the air stream enters the hollow interior of the control member; an air driven turbine positioned such that its operation is controlled by the air stream emerging from the control element as the control element is rotated.
Claim 18
Dependent Claim
34 words
The system of claim 15 further comprising: means for detecting the angular velocity of the turbine; and means for controlling the position of the control member in response to the angular velocity detecting means.
Claim 19
Dependent Claim
47 words
The system of claim 16 wherein the angular velocity detecting means comprises: means located on the turbine for generating a rotating beam of light in synchronism with rotation of the turbine; and means responsive to the rotating beam of light for generating the actuator position control signals.
Claim 20
Dependent Claim
61 words
The system of claim 9 wherein the means for selectively applying voltages to the wire sections further comprises: means for applying a voltage to a first wire section to rotate the control element in a first direction from a rest position; and means for applying a voltage to a second wire section to return the control element to its rest position.
References Cited (Backward Citations)
US4010455A
Cited
US4553393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |