초록 ▼

Actuators that employs a shape memory alloy component as the driving element include linear and rotational devices. An Intrinsic Return Means (IRM) may be imparted to the SMA actuator, thereby reducing the use of a spring return mechanism. The rotational actuator may include a cylindrical bobbin wit

Actuators that employs a shape memory alloy component as the driving element include linear and rotational devices. An Intrinsic Return Means (IRM) may be imparted to the SMA actuator, thereby reducing the use of a spring return mechanism. The rotational actuator may include a cylindrical bobbin with a helical groove to receive an SMA wire. A number of turns may be placed in a small length of bobbin to amplify the rotational excursion. In another rotational actuator, a plurality of narrow, coaxial rings are provided, the rings being nested in close concentric fit or stacked in side-by-side fashion. Each ring is provided with a groove extending thereabout to receive an SMA wire and contraction of the wire causes each ring to rotate with respect to the adjacent ring. In an embodiment for linear actuation, the invention provides a bar-like component having SMA wires joined between bars. The invention includes a lost motion coupling to join two counter-acting SMA stroke amplification devices, whether linear or rotational.

대표청구항 ▼

1. An actuator assembly, including:a plurality of sub-modules disposed in closely spaced array and adapted to undergo reciprocal translation in a first direction;a plurality of shape memory components, each extending longitudinally generally in said first direction and connected between two adjacent

1. An actuator assembly, including:a plurality of sub-modules disposed in closely spaced array and adapted to undergo reciprocal translation in a first direction;a plurality of shape memory components, each extending longitudinally generally in said first direction and connected between two adjacent sub-modules;means for heating said shape memory components beyond the memory transition temperature to contract said shape memory components and urge said sub-modules to translate in said first direction, each sub-module undergoing a stroke displacement with respect to the adjacent sub-module;said shape memory components exhibiting reversible shape memory effect; and,structural means for confining said shape memory components and restricting said shape memory components to movement only longitudinally in said first direction. 2. An actuator assembly, including:a plurality of sub-modules disposed in closely spaced array and adapted to undergo reciprocal motion;a plurality of shape memory components, each extending longitudinally generally in said first direction and connected between two adjacent sub-modules;means for heating said shape memory components beyond the memory transition temperature to contract said shape memory components and urge said sub-modules to move from a rest position, each sub-module undergoing a stroke displacement with respect to the adjacent sub-module;intrinsic return means for restoring said sub-modules to said rest position, including said shape memory components being configured to exhibit reversible shape memory effect; and structural means for confining and constraining said shape memory components to reversible movement only along the longitudinal extent of said shape memory components. 3. An actuator assembly, including:an annular member adapted for rotation about an axis;a shape memory component extending longitudinally about said annular member;means for heating said shape memory component beyond the memory transition temperature to contract said shape memory component, said shape memory component exerting a tangential force on said annular member to rotate said annular member in a first direction from a rest position;means for returning said annular member to said rest position;said means for returning said annular member to said rest position including intrinsic return means. 4. The actuator assembly of claim 3, wherein said means for returning said annular member to said rest position includes intrinsic return means. 5. The actuator assembly of claim 3, wherein said intrinsic return means includes said shape memory component configured to exhibit reversible shape memory effect; and structural means for confining said shape memory component and restricting said shape memory component to movement only annularly and reversibly about said annular member. 6. The actuator assembly of claim 3, wherein said shape memory component expands upon cooling to substantially the original length thereof before contraction, and said annular member counter-rotates in a second direction substantially to its rest position before said rotation in said first direction. 7. The actuator assembly of claim 3, wherein said means for returning said annular member to said rest position includes spring means. 8. The actuator assembly of claim 3, wherein said means for returning said annular member to said rest position includes a second actuator assembly configured to counter-rotate with respect to said annular member, and coupling means for operatively connecting said second actuator to said annular member. 9. The actuator assembly of claim 8, wherein said coupling means includes lost motion coupling means. 10. The actuator assembly of claim 9, wherein said lost motion coupling means includes a coupling ring interposed between said annular member and said second actuator assembly. 11. The actuator assembly of claim 2,wherein said plurality of sub-modules includes a plurality of rings disposed in axially aligned, closely adj acent fashion;each shape memory component extending annularly and connected between each two adjacent rings;said shape memory components connected to contract and urge said plurality of rings to translate in a first rotational direction, each ring undergoing a stroke displacement with respect to the adjacent ring; and,means for rotating said plurality of rings in a second rotational direction counter to said first direction. 12. The actuator assembly of claim 11, wherein said means for rotating said plurality in said second rotational direction includes intrinsic return means. 13. The actuator assembly of claim 12, wherein said intrinsic return means includes said shape memory component configured to exhibit reversible shape memory effect; and structural means for confining said shape memory component and restricting said shape memory component to movement only annularly and reversibly about said plurality of rings. 14. The actuator assembly of claim 11, wherein said shape memory component expands upon cooling to substantially the original length thereof before contraction to counter-rotate said plurality of rings in said second direction substantially completely prior to said rotation in said first direction. 15. The actuator assembly of claim 11, wherein said means for rotating said plurality of rings in said second direction includes spring means. 16. The actuator assembly of claim 11, wherein said means for rotating said plurality of rings in said second direction includes a second actuator assembly configured to counter-rotate with respect to said plurality of rings, and coupling means for operatively connecting said second actuator to said plurality of rings. 17. The actuator assembly of claim 16, wherein said coupling means includes lost motion coupling means. 18. The actuator assembly of claim 17, wherein said lost motion coupling means includes a coupling ring interposed between said annular member and said second actuator assembly. 19. The actuator assembly of claim 11, further including a plurality of annular grooves, each disposed in one of said plurality of rings, each groove configured to receive and retain a portion of said shape memory component. 20. The actuator assembly of claim 19, wherein said plurality of rings are disposed in stacked, axially adjacent fashion. 21. The actuator assembly of claim 20, wherein each of said rings includes first and second annular end surfaces, each first annular end surface in confronting relationship to a second annular end surface of an adjacent ring. 22. The actuator assembly of claim 21, wherein each of said grooves is disposed in a respective first annular end surface of a respective one of said rings. 23. The actuator assembly of claim 22, wherein each of said grooves and the confronting second annular end surface of the adjacent ring define a channel to constrain said shape memory component to movement solely along the extent of said channel. 24. The actuator assembly of claim 23, further including crimp means for securing said shape memory component to each of said rings. 25. The actuator assembly of claim 24, wherein said crimp means includes a crimp receptacle formed in each ring and intersecting said groove in each ring. 26. The actuator assembly of claim 25, wherein said crimp receptacle includes a crimp hole extending through each ring. 27. The actuator assembly of claim 25, wherein said crimp means includes a plurality of crimp lugs secured on said shape memory component, each crimp lug disposed to be received and secured in a respective one of said crimp receptacles in one of said rings. 28. The actuator assembly of claim 19, wherein said plurality of rings are disposed in concentric, coaxial fashion. 29. The actuator assembly of claim 28, wherein each of said rings includes inner and outer concentric surfaces, each inner surface in confronting relationship to an outer surface of an inwardly adjacent ring. 30. The actuator assembly of claim 29, wherein each of s aid grooves is disposed in a respective outer surface of a respective one of said rings. 31. The actuator assembly of claim 30, wherein each of said grooves and the confronting inner surface of the outwardly adjacent ring define a channel to constrain said shape memory component to movement solely along the extent of said channel. 32. The actuator assembly of claim 31, further including crimp means for securing said shape memory component to each of said rings. 33. The actuator assembly of claim 32, wherein said crimp means includes a crimp receptacle formed in each ring. 34. The actuator assembly of claim 33, wherein said crimp receptacle includes a crimp hole extending through each ring. 35. The actuator assembly of claim 33, wherein said crimp means includes a plurality of crimp lugs secured on said shape memory component, each crimp lug disposed to be received and secured in a respective one of said crimp receptacles in one of said rings. 36. The actuator assembly of claim 35, further including a passageway extending in each ring from said groove through said crimp receptacle to said inner surface of each ring, said passageway dimensioned to receive said shape memory component therethrough. 37. The actuator assembly of claim 2, wherein said sub-modules include a plurality of longitudinally extending struts in stacked relationship;at least one groove extending longitudinally in each strut;said shape memory components including a plurality of SMA wire components, each wire component received in a groove of one of said struts, said wires being confined and constrained to move reversibly and longitudinally in said grooves.