Patent US5312152A successfully refreshed from Google Patents.
US5312152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shape memory metal actuated separation device
Assignee: Lockheed Martin Corp
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Filing: 1991-10-23
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Granted: 1994-05-17
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Expires: 2011-10-23
Abstract
Abstract A shape memory alloy (SMA) actuator predeformed in tension actuates a separation device mechanism. A segmented nut, which engages a threaded bolt to be held and released, is held together by a nut retainer that is movable with respect to the nut and is affixed to the SMA element. The SMA element is heated by an electrical resistance heater to cause it to return to its undeformed state, thereby moving the retainer relative to the nut segments. When the retainer disengages from the segments, the segments are free to move outwardly thereby releasing the bolt or other item. Ones of the shape memory alloy actuator have a plurality of parallelly arranged SMA elements, every other one of which is predeformed in compression and intermediate ones of which are predeformed in tension. The elements are coupled end-to-end so that, when they are heated to cause them to return to their undeformed states, their respective elongations and shrinkages combine at the output to produce an actuation that is the cumulation in the same direction of the changes of all the elements. The plurality of elements may be in a side-by-side or concentric arrangement. Embodiments of the separation nut also include a plunger arrangement for urging the nut segments to move apart when released by the nut retainer and an ejector for pushing the released bolt or other item out of the separation device housing.
Inventors
- 👤 William H. Woebkenberg, Jr.
- 👤 Dominick A. DeAngelis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:54
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/64; B64G1/641; B64G1/645; B64G1/6457; F; F03; F03G; F03G7/00; F03G7/06; F03G7/061; F03G7/0614; F03G7/0615; F03G7/063; F03G7/0631
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
184 words
An apparatus for releasably grasping a workpiece having graspable features thereon comprising: a mounting; a segmented grasping device having grasping features thereon and having a plurality of segments thereof mounted in movable relationship for moving together for grasping the features of the workpiece and for moving apart for releasing the workpiece; engaging means movable between first and second positions in relation to said segmented grasping device for respectively engaging the segments of said grasping device together when in said first position and disengaging said segments when in said second position; a member having a predetermined deformation from an undeformed state, said member being affixed at one location thereon to said mounting and at another location thereon to said engaging means, said member being formed of a material that returns substantially to its undeformed state when heated to a predetermined temperature; and means for heating said member to said predetermined temperature for causing said member to return toward said undeformed state, said return toward said undeformed state tending to move said engaging means from one of said first and second positions to the other thereof.
Claim 2
Independent Claim
184 words
An apparatus for releasably grasping a workpiece having graspable features thereon comprising: a mounting; a segmented grasping device having grasping features thereon and having a plurality of segments thereof mounted in movable relationship for moving together for grasping the features of the workpiece and for moving apart for releasing the workpiece; engaging means movable between first and second positions in relation to said segmented grasping device for respectively engaging the segments of said grasping device together when in said first position and disengaging said segments when in said second position; a member having a predetermined deformation from an undeformed state, said member being affixed at one location thereon to said mounting and at another location thereon to said engaging means, said member being formed of a material that returns substantially to its undeformed state when heated to a predetermined temperature; and means for heating said member to said predetermined temperature for causing said member to return toward said undeformed state, said return toward said undeformed state tending to move said engaging means from one of said first and second positions to the other thereof.
Claim 3
Dependent Claim
24 words
The apparatus of claim 1 wherein said member includes a rod predeformed in tension, whereby said rod shrinks when heated to a predetermined temperature.
Claim 4
Dependent Claim
12 words
The apparatus of claim 1 wherein said member is nickel titanium alloy.
Claim 5
Dependent Claim
25 words
The apparatus of claim 1 wherein said means for heating includes an electrical resistance heater affixed in substantial conformity to a surface of said member.
Claim 6
Dependent Claim
24 words
The apparatus of claim 1 wherein said segmented grasping device is a segmented nut having as said grasping features threads on a cavity therethrough.
Claim 7
Dependent Claim
74 words
The apparatus of claim 1 where said segmented grasping device has at least first and second outer portions displaced axially from each other, said first portion having a larger radial dimension than that of said second portion, and said engaging means has a bore therethrough in which said segmented grasping device is axially movably mounted, the bore thereof having a radial dimension that is slightly larger than the radial dimension of said first portion.
Claim 8
Dependent Claim
146 words
The apparatus of claim 1 wherein said member comprises: at least three shape memory alloy elements arranged substantially parallelly, first and third ones of said elements each being deformed from its undeformed state in one of compression and tension and a second one thereof intermediate said first and third ones thereof begin deformed from tis undeformed state in the other one of compression and tension, each of said elements having a first end and a second end; the first end of the first of said elements being affixed to said mounting, and the second end of the third of said elements being coupled to said engaging means; the second one of said elements being coupled at its second end to the second end of the first one of said elements and at its first end to the first end oft he third one of said elements.
Claim 9
Dependent Claim
35 words
The apparatus of claim 7 wherein said elements each have a longitudinal axis lying between its first and second ends, and said elements are arranged with their respective longitudinal axes in substantially parallel spaced-apart relationships.
Claim 10
Dependent Claim
34 words
The apparatus of claim 7 wherein said elements each have a longitudinal axis lying between its first and second ends, and said elements are arranged substantially concentrically with their respective longitudinal axes substantially collinear.
Claim 11
Dependent Claim
215 words
Apparatus for releasably grasping a threaded workpiece comprising: a housing; a segmented nut having a plurality of segments with threads on first surfaces thereof for engaging the workpiece when said segments are together, said segmented nut having first and second outer portions displaced axially form each other, said first portion having a larger radial dimension than that of said second portion; a nut retainer having a bore therein with a radial dimension slightly larger than that of said first outer portion of said segmented nut, said nut retainer being movably axially in relation to said segmented nut for engaging the first outer portion thereof for maintaining the segments thereof together; an elongated member being affixed near one end thereof to said nut retainer and near the other end thereof to said housing, said member being formed of a shape memory alloy having the property of changing from a stressed dimensions to a substantially related dimension between its ends when heated to a predetermined temperature; and means for heating said shape memory alloy member to reach said predetermined temperature for causing said member to return toward said related dimension for moving said nut retainer axially for disengaging the first outer portion of said segmented nut, whereby the segments of said segmented nut are not maintained together.
Claim 12
Dependent Claim
215 words
Apparatus for releasably grasping a threaded workpiece comprising: a housing; a segmented nut having a plurality of segments with threads on first surfaces thereof for engaging the workpiece when said segments are together, said segmented nut having first and second outer portions displaced axially form each other, said first portion having a larger radial dimension than that of said second portion; a nut retainer having a bore therein with a radial dimension slightly larger than that of said first outer portion of said segmented nut, said nut retainer being movably axially in relation to said segmented nut for engaging the first outer portion thereof for maintaining the segments thereof together; an elongated member being affixed near one end thereof to said nut retainer and near the other end thereof to said housing, said member being formed of a shape memory alloy having the property of changing from a stressed dimensions to a substantially related dimension between its ends when heated to a predetermined temperature; and means for heating said shape memory alloy member to reach said predetermined temperature for causing said member to return toward said related dimension for moving said nut retainer axially for disengaging the first outer portion of said segmented nut, whereby the segments of said segmented nut are not maintained together.
Claim 13
Dependent Claim
96 words
The apparatus of claim 10 wherein said segmented nut has a bevel on one end of the segments thereof, said apparatus further comprising: a spreader having a bevel on an end thereof proximate the beveled ends of said segments, the bevels of said segments and the bevel of said spreader being at an angle for tending to separate the segments of said segmented nut; urging means for urging said spreader against the beveled ends of said segments for tending to separate said segments when said nut retainer disengages the first outer portion of said segmented nut.
Claim 14
Dependent Claim
37 words
The apparatus of claim 11 wherein the bevels of the segments of said segmented nut form a concave conical surface when the segments are together, and wherein the bevel of said spreader is a convex conical surface.
Claim 15
Dependent Claim
54 words
The apparatus of claim 11 wherein said urging means comprises: a spring compressed in a direction axial with respect to said segmented nut, one end of said spring bearing on said housing, and a plunger movable axially and having a first end bearing on said spring and a second end bearing on said spreader.
Claim 16
Dependent Claim
27 words
The apparatus of claim 13 wherein said elongated member has a bore therein and said spring and said plunger are located in the bore of said member.
Claim 17
Dependent Claim
56 words
The apparatus of claim 14 further including ejecting means bearing on said workpiece when the threads of said segmented nut engage said workpiece for urging the workpiece axially out of said segmented nut, and wherein each of said spring and said plunger have an axial passage therethrough and said ejecting means is located in the passage.
Claim 18
Dependent Claim
67 words
The apparatus of claim 15 wherein said ejecting means includes an ejector rod movable axially with respect to said segmented nut, a second spring compressed in a direction axial with respect to said segmented nut, a first end of said second spring bearing on said housing and a second end thereof bearing on an end of said ejector rod distal the end thereof for urging the workpiece.
Claim 19
Dependent Claim
33 words
The apparatus of claim 10 further including ejecting means bearing on said workpiece when the threads of said segmented nut engage said workpiece for urging the workpiece axially out of said segmented nut.
Claim 20
Dependent Claim
230 words
The apparatus of claim 10 wherein said elongated member comprises: a plurality of prestressed elements defining first and second ends, each of said prestressed elements being formed of said shape memory alloy, said plurality of elements including at least one first element which, in a direction parallel to a first axis lying between said first and second ends of said first element, has a stressed dimension which is one of greater than and less than its relaxed dimension, and at least second and third elements, each of which, in directions parallel to second and third axes lying respectively between said first and second ends of said second and third elements, respectively, have stressed dimensions which are the other one of greater than and less than their relaxed dimensions; mechanical coupling means coupled to said first, second and third elements, for, with said first, second and third axes mutually parallel, rigidly connecting (a) said first end of said second element to said housing, (b) said second end of said second element to said first end of said first element, and (c) said second end of said first element to said first end of said third element; and wherein said means for heating is thermally coupled to said first, second ad third elements for causing them to reach said predetermined temperature at a time when said moving said nut retainer is desired.
Claim 21
Dependent Claim
42 words
An apparatus according to claim 18 wherein said first, second and third elements are elongated in the direction of said first, second and third axes, respectively, and wherein said elements are located side-by-side with said first, second and third axes mutually parallel.
Claim 22
Dependent Claim
94 words
An apparatus according to claim 18, wherein: said second element is elongated in the direction of said second axis and has an outer dimension; said first element is elongated in the direction of said first axis, with an outer dimension, and with a bore having an inner dimension greater than the outer dimension of said second element; said third element is elongated in the direction of said third axis, with a bore having an inner dimension greater than the outer dimension of said first element; and said first, second and third axes are coaxial.
References Cited (Backward Citations)
US2994933A
Cited
US3075348A
Cited
US3450372A
Cited
US4044358A
Cited
US3513429A
Cited
US3622941A
Cited
US4314682A
Cited
US3753792A
Cited
US4198081A
Cited
US3953253A
Cited
US4019925A
Cited
US4022519A
Cited
US4010455A
Cited
US3999790A
Cited
US4031704A
Cited
US4149911A
Cited
US4233731A
Cited
US4501058A
Cited
US4412872A
Cited
US4450616A
Cited
US4405387A
Cited
US4559512A
Cited
US4554027A
Cited
US4531988A
Cited
US4553393A
Cited
US4712969A
Cited
US4586335A
Cited
US4619568A
Cited
US4497241A
Cited
US4617448A
Cited
US4740253A
Cited
US4753465A
Cited
US4700541A
Cited
US4900078A
Cited
JPS6440246A
Cited
US4836496A
Cited
JPH01144105A
Cited
JPH01216787A
Cited
US4798051A
Cited
US4899543A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-16 | 1997-11-15 | 1998-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-16 | 2001-11-15 | 2002-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-16 | 2005-11-15 | 2006-05-17 | $7700.00 | Window Closed / Lapsed |