Claims
- 1. A linear actuator, including:
at least one sub-module adapted to undergo reciprocal translation in a first direction; at least one shape memory component, extending generally in said first direction; means for heating said at least one shape memory component beyond the memory transition temperature to contract said shape memory component and urge said at least one sub-module to translate in said first direction and undergoing a stroke displacement.
- 2. The linear actuator of claim 1, wherein said means for heating includes an electrical circuit connected to said at least one shape memory components for ohmic heating thereof.
- 3. The linear actuator of claim 1, further including return spring means for resiliently opposing said stroke displacement.
- 4. The linear actuator of claim 3, wherein said return spring means generates a return force versus displacement characteristic that is optimized to relax and extend said at least one shape memory component with minimum residual strain.
- 5. The linear actuator of claim 4, wherein said return spring means comprises a rolamite spring assembly.
- 6. The linear actuator of claim 3, further including a fixed anchor point, and said return spring means is connected between said at least one sub-module and said fixed anchor point.
- 7. The linear actuator of claim 1, further including a housing having interior features impinging on said at least one sub-module to support said sub-module in reciprocally translating fashion.
- 8. The linear actuator of claim 1, further including means for cooling said at least one shape memory component.
- 9. The linear actuator of claim 1, wherein said means for cooling includes a heat-conducting fluid surrounding said at least one shape memory component.
- 10. The linear actuator of claim 3, wherein said return spring means generates a return force versus displacement characteristic that is substantially linear through a portion of the excursion of said return spring means.
- 11. The linear actuator of claim 3, wherein said spring means comprises a deflectable beam spring.
- 12. The linear actuator of claim 3, wherein said spring means comprises a bar adapted for reciprocal translation, said bar including a cam surface, and cam follower means impinging on said cam surface to exert a restoring force that is a function of the slope of said cam surface.
REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of application Ser. No. 09/566,446, filed May 8, 2000, now U.S. Pat. No. 6,326,707, issued Dec. 4, 2001, for which priority is claimed.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09566446 |
May 2000 |
US |
Child |
10056233 |
Dec 2001 |
US |