Micro-coupling active release mechanism
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsWilliam Mike Crane, Paul Michael Oppenheimer, Marcello Romano, James Hansen Newman
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Abstract
A micro-coupling active release mechanism including a shape memory alloy (SMA) cylindrical ring that is fit into a bushing or other mating attachment creating an interference joint held in place by frictional forces. The interference joint can be released upon actuation in which the SMA cylindrical ring is heated causing it to shrink in size, relieving the frictional forces of the interference joint thereby releasing the SMA cylindrical ring from the bushing or other mating attachment.
Claims20
An active release mechanism comprising:
- a bushing connectable to a first component, the bushing having a recess for receiving a shape memory alloy (SMA) cylindrical ring;
- and
- a shape memory alloy (SMA) cylindrical ring connectable to a second component, wherein the SMA cylindrical ring is fit into the recess of the bushing to form an interference joint that is releasable when the SMA cylindrical ring is heated to a transformation temperature that causes it to reduce in size.
A method for releasably coupling a first component to a second component, the method comprising:
- fitting a shape memory alloy (SMA) cylindrical ring into a bushing to create an interference joint;
- passing a bolt shaft of retaining bolt through an interior diameter of the SMA cylindrical ring, a portion of the bolt shaft extending out and from the SMA cylindrical ring, a bolt head of the retaining bolt catching on the SMA cylindrical ring and not passing through the SMA cylindrical ring;
- attaching the bushing to the first component;
- and
- attaching the SMA cylindrical ring to the second component using the portion of the bolt shaft extending out and from the SMA cylindrical ring;
- wherein heating the SMA cylindrical ring at or above a transformation temperature causes the SMA cylindrical ring to transform from a larger martensitic phase diameter to a smaller austenitic phase diameter and to release the interference joint allowing the first component to separate from the second component.
An active release mechanism comprising:
- a first component, the first component having a first hole for receiving a first end portion of a shape memory alloy (SMA) cylindrical ring;
- a second component, the second component having a second hole for receiving a second end portion of the shape memory alloy (SMA) cylindrical ring;
- and
- a shape memory alloy (SMA) cylindrical ring connectable to the first component at a first end portion and to the second component at a second end portion,
- wherein the first end portion of the SMA cylindrical ring is press-fit into the first hole to form a first interference joint and press-fit into the second hole to form a second interference joint,
- and further wherein the first interference joint and the second interference joint are releasable when the SMA cylindrical ring is heated to a transformation temperature that causes it to reduce in size.
Dependencies are inferred from the claim text.