Shape memory alloy actuation apparatus
AssigneeCambridge Mechatronics Limited
InventorsStephen Matthew Bunting, Andrew Benjamin Simpson Brown, Marc-Sebastian Scholz, James Howarth
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Abstract
Broadly speaking, the present techniques provide specific arrangements of shape memory alloy (SMA) actuator wires in SMA actuation apparatuses. In one arrangement, a single straight shape memory alloy actuator wire may be used, which may be inclined at an acute angle greater than 0 degrees with respect to a plane normal to the movement direction. In another arrangement, two straight lengths of shape memory alloy actuator wire may be used, where the SMA wires may be inclined at an acute angle greater than 0 degrees with respect to a plane normal to the movement direction.
Claims21
A shape memory alloy actuation apparatus comprising:
- a support structure;
- a movable element supported on the support structure by a suspension system arranged to guide movement of the movable element along a movement direction with respect to the support structure, wherein the suspension system comprises a bearing arrangement configured to constrain movement of the movable element with respect to the support structure in degrees of freedom other than along the movement direction;
- two straight lengths of shape memory alloy actuator wire each connected by a crimp portion to the movable element and connected by a crimp portion to the support structure for driving movement of the movable element relative to the support structure, the two straight lengths of shape memory alloy actuator wire being inclined at an acute angle greater than 0 degrees with respect to a plane normal to the movement direction;
- and
- wherein the two straight lengths of shape memory alloy actuator wire have an angle therebetween in the range from 70 to 110 degrees as viewed along the movement direction.
Dependencies are inferred from the claim text.