Memory alloy-actuated apparatus
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 assembly, the SMA actuator assembly comprising:
one or more SMA filaments, the one or more SMA filaments being electrically coupled with respective ones of a plurality of terminals;
a driver element configured to move when power is applied to at least one of the one or more SMA filaments;
a pivot assembly, which in combination with the one or more SMA filaments, is configured to actuate the driver element; and
a housing assembly configured to house the one or more SMA filaments, the driver element, and the pivot assembly, the housing assembly comprising a body portion and end cap portions;
wherein the end cap portions are configured to be swapped on either end of the body portion, thereby enabling the configuration of the SMA actuator assembly from a pull-based configuration to a push-based configuration.
2. The SMA actuator assembly of claim 1 , further comprising a chassis, the plurality of terminals and the pivot assembly configured to be received within the chassis.
3. The SMA actuator assembly of claim 2 , further comprising a shaft, the shaft being configured to be received within the driver element.
4. The SMA actuator assembly of claim 3 , further comprising a compression spring, the compression spring configured to return the driver element into a non-actuated position when power is removed from the one or more SMA filaments.
5. The SMA actuator assembly of claim 4 , wherein the pivot assembly further comprises:
a trunnion configured to act as a pivot point for one or more pivot shuttles; and
wherein at least a portion of the one or more SMA filaments is configured to be coupled to the trunnion via the one or more pivot shuttles.
6. The SMA actuator assembly of claim 5 ; wherein the shaft is configured to freely move through an aperture located in the trunnion.
7. A shape memory alloy (SMA) actuator assembly, the SMA actuator assembly comprising:
one or more SMA filaments, the one or more SMA filaments being electrically coupled with respective ones of a plurality of terminals;
a pivot assembly, which in combination with the one or more SMA filaments, is configured to actuate a driver element, the driver element further comprising a filament routing channel, the filament routing channel used for the routing of a portion of the one or more SMA filaments;
a rod coupled with the driver element, the rod further configured to be received within an aperture located on the pivot assembly; and
a chassis configured to house the pivot assembly therein, the pivot assembly configured to rotate in either of two directions within the chassis.
8. The SMA actuator assembly of claim 7 , further comprising:
a compression spring; and
a spacer element;
wherein the compression spring is disposed between the spacer element and an end portion of the chassis and the compression spring is further disposed about the rod that is coupled with the driver element.
9. The SMA actuator assembly of claim 8 , wherein the compression spring is further configured to return the driver element into a non-actuated position when power is removed from the one or more SMA filaments.
10. The SMA actuator assembly of claim 7 , wherein the one or more SMA filaments comprises a loop filament, an upper filament, a lower filament and one or more jumper filaments.
11. The SMA actuator assembly of claim 10 , wherein the portion of the one or more SMA filaments routed in the filament routing channel comprises the loop filament.
12. The SMA actuator assembly of claim 10 , wherein ends associated with the one or more jumper elements are configured to be coupled to the pivot assembly.
13. The SMA actuator assembly of claim 10 , wherein the upper filament and the lower filament each comprise two ends, with one end of the respective upper or lower filament being coupled to the pivot assembly and with the other end of the respective upper or lower filament being coupled to a respective terminal of the plurality of terminals.
14. The SMA actuator assembly of claim 7 , further comprising a housing assembly configured to house the one or more SMA filaments, the driver element, the pivot assembly and the chassis.
15. The SMA actuator assembly of claim 14 , wherein the housing assembly comprises a body portion and end cap portions.
16. The SMA actuator assembly of claim 15 , wherein the end cap portions are configured to be swapped on either end of the body portion, thereby enabling the configuration of the SMA actuator assembly from a pull-based configuration to a push-based configuration.
17. A shape memory alloy (SMA) actuator assembly, the SMA actuator assembly comprising:
a plurality of SMA filaments, the SMA filaments being electrically coupled with respective ones of a plurality of terminals, the plurality of SMA filaments comprising a loop filament, an upper filament, a lower filament and one or more jumper filaments;
a pivot assembly, which in combination with the plurality of SMA filaments, is configured to actuate a driver element, the driver element further comprising a guide feature configured to facilitate lateral movement along a chassis, the driver element further comprising a routing channel configured to route at least one of the plurality of SMA filaments around a portion of the driver element; and
the chassis configured to house the pivot assembly therein, the pivot assembly configured to rotate within the chassis.
18. The SMA actuator assembly of claim 17 , wherein the at least one of the plurality of SMA filaments routed around the portion of the driver element comprises the loop filament.
19. The SMA actuator assembly of claim 18 , wherein ends associated with the one or more jumper elements are configured to be coupled to the pivot assembly.
20. The SMA actuator assembly of claim 19 , wherein the upper filament and the lower filament each comprise two ends, with one end of the respective upper or lower filament being coupled to the pivot assembly and with the other end of the respective upper or lower filament being coupled to a respective terminal of the plurality of terminals.