Patent ID: 9353734
Filing Date: 2016-05-31
CPC Classification: B23P,F03G,F16G,Y10T

Claim Text:
1. A method of connecting an end portion of a linear shape memory alloy (SMA) element to a mechanical device, the method comprising: connecting the SMA element to a moveable component of the mechanical device where the SMA element, when heated to a phase-changing temperature by passage of electric current along its length, repeatedly generates and applies a predetermined tensile force to the moveable component to displace the moveable component from an initial position and thereby operate the mechanical device, the moveable component incorporating a feature adapted and arranged to mechanically engage a complementary feature on an electrically-conductive unitary, load-transmitting connecter attached to the end portion of the SMA element, the method further comprising: providing the electrically-conductive unitary, load-transmitting connector, the connector having a length and the feature complementary to the engageable feature on the moveable component adjoining a retaining feature for joining the end portion of the elongated linear SMA element to the load-transmitting connector, the retaining feature comprising a deformable elongated metal casing with opposing openings, the casing having an inner wall defining a cavity with a length, the cavity being sized and adapted to receive the SMA element; inserting the end portion of the SMA element through one of the casing openings and into the cavity in a manner which does not prejudice the function of the complementary attachment feature, the length of the inserted end portion being at least equal to the length of the cavity, but less than the length of the connector, the length of the cavity being selected to enable a joint between the end portion of the SMA element and the retaining feature of the load-transmitting connector, the joint being adapted to prevent relative motion between the load-transmitting connector and the SMA element under application of the SMA-generated predetermined tensile force during repeated operation of the mechanism; crimping the metal casing by application of an inwardly-directed compressive force to collapse the casing inwardly to bring a portion of the casing inner wall surface into compressive engagement with a surface of the inserted end portion of the SMA element; inserting a filler into the casing to bond the casing to the SMA element end portion to further inhibit relative motion between the load-transmitting connector and the SMA element under application of the SMA-generated predetermined tensile force; and attaching the load-transmitting connector to the incorporated feature of the moveable component of the mechanical device.