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US 8,281,585 B2Granted
Controlling heat transfer in active material actuators using external elements
AssigneeGM Global Technology Operations LLC
InventorsXiujie Gao, Alan L. Browne, Nancy L. Johnson, Nilesh D. Mankame, Guillermo A. Herrera, Geoffrey P. McKnight, Patrick B. Usoro, Nicholas William Pinto, Richard J. Skurkis, Paul W. Alexander
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Abstract
An actuator includes a thermally activated active material member, and an external element configured to selectively engage the member and presenting a predetermined rate of thermal conductivity configured to transfer heat energy to and/or from the member, so as to reduce the actuation period or rate of cooling after actuation, when engaged.
Claims17
A thermally activated active material actuator comprising:
- an active material member operable to undergo a reversible change in fundamental property when exposed to or occluded from a thermal activation signal, so as to be activated over an actuation period, and deactivated respectively, and presenting an ambient rate of cooling after being activated;
- and
- an external element presenting a predetermined thermal conductivity, and configured to selectively engage the member, so as to reduce the period and/or accelerate the rate,
- wherein the shape memory alloy member presents a first cross-sectional area when deactivated and a second cross-sectional area greater than the first when activated, the external element is an exterior sheath defining an interior space presenting a third cross-sectional area greater than the first, and less than or equal to the second, and the SMA member is disposed within the space.
1 more element
Dependencies are inferred from the claim text.