| US 11,788,517 B2 | ||
| Bistable shape memory alloy inertial actuator | ||
| Marco Citro, Varese (IT); Stefano Alacqua, Como (IT); Salvatore Coco, Cesano Maderno (IT); and Giorgio Vergani, Monza (IT) | ||
| Assigned to SAES GETTERS S.P.A., Milian (IT) | ||
| Appl. No. 17/797,509 | ||
| Filed by SAES GETTERS S.P.A., Lainate MI (IT) | ||
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PCT Filed Mar. 24, 2021, PCT No. PCT/EP2021/057648 § 371(c)(1), (2) Date Aug. 4, 2022, PCT Pub. No. WO2021/197980, PCT Pub. Date Oct. 7, 2021. |
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| Claims priority of application No. 102020000006634 (IT), filed on Mar. 30, 2020. | ||
| Prior Publication US 2023/0054660 A1, Feb. 23, 2023 | ||
| Int. Cl. F03G 7/06 (2006.01); H01H 61/01 (2006.01) | ||
| CPC F03G 7/06143 (2021.08) [F03G 7/0616 (2021.08); F03G 7/0635 (2021.08); F03G 7/0636 (2021.08); F03G 7/064 (2021.08); H01H 61/0107 (2013.01)] | 15 Claims |
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1. A bistable shape memory alloy inertial actuator comprising a body connected to one or more shape memory alloy wires actuatable through a current pulse generated by an electrical circuit, said one or more shape memory alloy wires having a diameter comprised between 0.025 and 0.5 mm and being in operational contact with an inertial element movable between a first stable position and a second stable position and vice versa under the concurrent actuation of the one or more shape memory alloy wires,
wherein said actuator is subjected to a locking force with an elastic constant K, expressed in g/mm, wherein the actuator has a parameter P defined as the inverse of said elastic constant multiplied by the ratio between the mass M of said inertial element, expressed in grams, and the total cross-sectional area A, expressed in mm2, of the shape memory alloy wires in operational contact with the inertial element, said parameter P=(⅟K)*(M/A) being comprised between 15 and 750 mm-1, and wherein said electrical circuit is configured to generate a current pulse with a duration comprised between 0.1 and 50 ms. |