Single step shape memory alloy expansion
AssigneeW. L. Gore & Associates, Inc.
InventorsJoel M. Greene, Christopher C. Lasley
Life of this patent
Estimating the term…
Abstract
Exposing nitinol to a shape setting temperature while the nitinol is in an unstrained or minimally strained condition. The nitinol is then substantially deformed in shape while at elevated temperature. After deformation, the nitinol remains at the elevated temperature for a time to shape set the material. The nitinol is then returned to approximately room temperature 20° C. by means of water quenching or air cooling for example.
Claims15
A method of forming a shape memory alloy tube, comprising:
- deforming a shape memory alloy (SMA) tube from a first (smaller) diameter to a second (larger) diameter in a single step while at a single temperature within a shape setting temperature range from 300° C. to 650° C., wherein the second (larger) diameter is at least twice as large as the first (smaller) diameter.
A method of forming a shape memory alloy tube, comprising:
- deforming a shape memory alloy (SMA) tube from a first (smaller) diameter to a second (larger) diameter in a single step while at a single temperature within a shape setting temperature range, wherein the second (larger) diameter is at least twice as large as the first (smaller) diameter, and the ratio of the second (larger) diameter to the first (smaller) diameter is greater than 4:1.
A device for deforming a shape memory alloy article, comprising:
- a. a slotted tubular mandrel comprising;
- i. a longitudinal axis and a first outer perimeter;
- ii. a tube having a length, a through lumen and a wall;
- iii. the lumen defining a first inner perimeter;
- iv. the tube having at least two slots through the wall;
- v. the slots being oriented essentially parallel to the tube longitudinal axis;
- vi. the slots extending partially along the tube length;
- vii. the tube having a first portion with a constant first perimeter;
- viii. the tube having a tapered portion;
- ix. the tapered portion having a varying perimeter transitioning from the tube first perimeter to a larger second perimeter, wherein the second perimeter is at least twice as large as the first perimeter;
- and
- b. a translating device comprising;
- i. a pull rod sized to extend and slide through the slotted elongate tube through lumen;
- ii. an expander die coupled to the pull rod, wherein the expander die is configured to concentrically surround and advance over an outer surface of the slotted tubular mandrel and comprises at least two fins sized to extend and slide through said slots through the wall of the slotted elongated tube;
- c. a shape memory alloy article surrounding at least a portion of said slotted tubular mandrel.
Dependencies are inferred from the claim text.