Memory alloy-actuated apparatus and methods for making and using the same
View Patent ↗Improved actuator apparatus and methodologies for manufacturing and using the same. In one exemplary embodiment, the actuator apparatus includes an SMA filament that: (1) minimizes size and increases stroke length via a serpentine-like routing of the SMA filament within the device itself; (2) reduces power consumption as a result of a relatively flat stroke force as a function of stroke displacement operating profile; (3) enables the actuator assembly to remain in a fully actuated state, at a consistent stroke force, for longer periods of time; and (4) is also fully reversible so as to be capable of use in both push-based and pull-based actuator applications. Methods of operation and manufacturing associated with the aforementioned actuator apparatus are also disclosed.
1. A shape memory alloy (SMA) actuator apparatus, comprising:
an actuator housing having a plurality of terminals coupled to the actuator housing;
an SMA filament coupled to respective ones of the plurality of terminals; and
a driver element configured to move when power is applied to the SMA filament, the driver element comprising an SMA protection apparatus, the SMA protection apparatus comprising:
a primary shaft having a primary spring disposed thereon; and
a secondary shaft having a secondary spring disposed thereon;
wherein when the primary shaft is inoperable, the SMA filament is configured to compress the secondary spring along the secondary shaft, thereby enabling the movement of the driver element.
2. The SMA actuator apparatus of claim 1 , wherein the SMA filament comprises a serpentine routing.
3. The SMA actuator apparatus of claim 2 , wherein the driver element comprises a plurality of routing channels, the SMA filament being disposed within the plurality of routing channels.
4. The SMA actuator apparatus of claim 1 , wherein the secondary shaft and the secondary spring are configured to prevent the SMA filament from breaking when the driver element becomes stuck.
5. The SMA actuator apparatus of claim 4 , wherein the driver element further comprises an actuator element disposed within a driver element cavity, the actuator element coupled to the secondary shaft.
6. The SMA actuator apparatus of claim 5 , wherein the secondary spring is configured to compress during instances when the driver element becomes stuck.
7. The SMA actuator apparatus of claim 6 , wherein the secondary spring is disposed between a first stop element and a second stop element.
8. The SMA actuator apparatus of claim 7 , wherein the actuator element is coupled directly to an item to be actuated and the primary spring is configured to compress when the SMA filament is actuated.
9. The SMA actuator apparatus of claim 8 , wherein a spring constant of the see-end secondary spring is higher than a spring constant of the primary spring.
10. The SMA actuator apparatus of claim 9 , wherein the actuator housing comprises one or more housing mounts, the one or more housing mounts being configured to couple the SMA actuator apparatus to an ice dispenser apparatus.
11. The SMA actuator apparatus of claim 10 , wherein the driver element is further configured to couple to an actuating element located on the ice dispenser apparatus.
12. The SMA actuator apparatus of claim 11 , wherein the actuating element located on the ice dispenser apparatus further comprises an offset actuator element.
13. A shape memory alloy (SMA) actuator apparatus, comprising:
an SMA filament; and
a driver element configured to move when power is applied to the SMA filament, the driver element comprising an SMA protection apparatus;
wherein the SMA protection apparatus comprises a primary compression spring disposed around a primary shaft linearly disposed with respect to a secondary compression spring, the SMA protection apparatus being configured to prevent the SMA filament from breakage during actuation and operation of the SMA actuator apparatus by compression of the secondary compression spring when the primary shaft becomes stuck.
14. The SMA actuator apparatus of claim 13 , wherein the actuation and operation of the SMA actuator apparatus is utilized in a climate in which liquid water will freeze.
15. The SMA actuator apparatus of claim 14 , wherein the driver element is coupled directly to an item to be actuated and the primary compression spring is configured to compress when the SMA filament is actuated.
16. The SMA actuator apparatus of claim 13 , wherein a spring constant of the secondary compression spring is higher than a spring constant of the primary compression spring.
17. The SMA actuator apparatus of claim 13 , wherein the secondary compression spring is disposed around a secondary shaft.
18. The SMA actuator apparatus of claim 13 , wherein the driver element comprises a cavity, the cavity comprising an actuator element configured to receive an item to be actuated.
19. The SMA actuator apparatus of claim 18 , wherein the actuator element is further configured to move within the cavity.
20. The SMA actuator apparatus of claim 19 , wherein the compression of the secondary compression spring is configured to cause the movement within the cavity.