Abstract: A system and a method of providing electromagnetic compatibility (EMC) protection. A removable component is inserted into an end product. The removable component includes a retractable EMC protection apparatus. In response to the insertion of the removable component a shape memory alloy on the EMC protection apparatus is heated to a temperature above the activation temperature of the shape memory alloy. The shape memory alloy then changes from a first shape to a second shape in response to the heating. In response to the change in the shape of the shape memory alloy an EMC protection component of the EMC protection apparatus is inserted into an enclosure opening of the removable component.

Abstract: A system for producing an object is disclosed including a build device having a build area and a material bonding component to receive portions of a material that are used to produce the object, at least one gripper within the build area to contact the object to provide support and to provide for at least one of a heat sink for the object, a cold sink for the object, and electrical dissipation path from the object, and a movement mechanism to move the build device relative to the object to position the build device at a position to further produce the object. Another system and methods are also disclosed.

Abstract: A conductive component structure of wire connection terminal is manufactured at lower cost and more securely assembled with the conductive wire. The conductive component includes a main body in the form of a plate body and a restriction body connected on the main body. The restriction body defines a mouth section and has an oblique wall connected with the mouth section. When the conductive wire is plugged into the case into contact with the conductive component, the restriction body guides the conductive wire and the rear end of the conductive wire is restricted and secured by the oblique wall. The conductive component improves the shortcomings of the conventional structure that the conductive wire is apt to deflect or swing due to external force to lead to unstable contact and insecurity and affect the electro-conductive efficiency.

Abstract: Embodiments provide methods, apparatuses, and systems for fixation of a fractured bone with a bone plate. In various embodiments, the systems and plates provide elastic suspension of the receiving holes relative to an osteosynthesis plate. This elastic suspension can promote load distribution between the screws that connect a bone segment to the plate, thereby reducing stress risers and load shielding effect. In addition, stress at the screw holes, and within the construct as a whole, is reduced by incorporation of these elastic elements in the plate. Additionally, in some embodiments where fracture healing by callus formation is desired, elastic suspension of the receiving holes relative to the osteosynthesis plate can enable small, controlled amounts of relative motion between bone fragments connected by the plate. This relative motion can promote fracture healing by callus formation.

Abstract: An implant for therapeutically separating bones of a joint has two endplates each having an opening through the endplate, and at least one ramped surface on a side opposite a bone engaging side. A frame is slideably connected to the endplates to enable the endplates to move relative to each other at an angle with respect to the longitudinal axis of the implant, in sliding connection with the frame. An actuator screw is rotatably connected to the frame. A carriage forms an open area aligned with the openings in the endplates. The openings in the endplates pass through the carriage to form an unimpeded passage from bone to bone of the joint. The carriage has ramps which mate with the ramped surfaces of the endplates, wherein when the carriage is moved by rotation of the actuator screw, the endplates move closer or farther apart.

Abstract: Embodiments provide methods, apparatuses, and systems for fixation of a fractured bone with a bone plate. In various embodiments, the systems and plates provide elastic suspension of the receiving holes relative to an osteosynthesis plate. This elastic suspension can promote load distribution between the screws that connect a bone segment to the plate, thereby reducing stress risers and load shielding effect. In addition, stress at the screw holes, and within the construct as a whole, is reduced by incorporation of these elastic elements in the plate. Additionally, in some embodiments where fracture healing by callus formation is desired, elastic suspension of the receiving holes relative to the osteosynthesis plate can enable small, controlled amounts of relative motion between bone fragments connected by the plate. This relative motion can promote fracture healing by callus formation.

Abstract: A receiving part for coupling a rod to a bone anchoring element includes a receiving part body including a rod receiving portion having a channel for receiving a rod, and a head receiving portion for accommodating a head of a bone anchoring element, the head receiving portion having an open end and being flexible for inserting and clamping of the head; and a locking ring around the head receiving portion, wherein in a pre-locking position, a spring portion on one of the locking ring or the receiving part body engages a corresponding portion on the other one of the locking ring or the receiving part body, and the locking ring exerts a first force onto the head receiving portion, and wherein in a locking position, the locking ring exerts a second force greater than the first force onto the head receiving portion to lock the head therein.

Abstract: A preload reducing fastener adapted to be fastened into a system in which includes a release system. The fastener may have an integral collar which is adapted to change shape, as in the case of a shape memory alloy. The application of heat to fastener may deform the collar such that the fastener may move axially in the load direction, thus reducing the preload previously held by the fastener. A preload reducing device including a preload reducing fastener may include an outer case adapted to center and capture a preload reducing fastener. The case may center the fastener in a desired location in a preloaded system, and may also capture the fastener after release of the system.

Abstract: Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion therebetween. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

Abstract: The invention pertains to a method and apparatus for delivering an article formed of a shape memory alloy to a surgical implantation site. The apparatus may include a body having a passage for receiving the proximal portion of the shape memory article, the passage being shaped to substantially prevent the shape memory article from deforming in accordance with its shape memory properties when the proximal portion of the shape memory article is positioned in the passage. An exemplary involves placing the distal portions of legs of a staple in at least one passage in a constraining device that substantially constrains the legs from deforming; and placing the proximal portions of the legs of the staple in at least one passage in an apparatus that, independently of the constraining device, substantially prevents the legs from deforming.

Abstract: An assembly comprises first and second components provided with holes receiving a retaining element in the form of a pin, in order to retain the components together. The pin is made from a shape memory effect material, and is inserted into the holes in a straight configuration, following which a change in temperature causes a retaining portion of the pin to deform into a second configuration, in which withdrawal of the pin is prevented.

Abstract: A lock ring (6), which comprises a core part (61) and a twisted wire part (62) around it. The lock ring (6) comprises shape memory alloy or bimetal, whereby the lock ring is arranged to deform as the temperature changes to a predetermined value.

Abstract: A fastener (10) is adapted to releasably fix a first element (12) and a second element (14). The fastener (10) includes a channel (22) having a plurality of spaced lockers (28). The lockers (28) are movable into the channel (22). The fastener (10) also has a locking tongue (30), having a plurality of spaced blockers (32). The tongue (30) is movable within the channel (22) between a locked position in which the blockers (32) prevent movement of the lockers (28) into the channel (22) and an unlocked position in which the lockers (28) are not prevented from moving into the channel (22).

Abstract: A fastening body structure having a screw member which uses a module screw having a countersunk head and a washer made of a shape memory alloy. With this structure, the washer does not expand even if subjected to large fastening force and the washer can be easily removed when the screw fastening is released. The fastening body structure fastens and fixes a desired part to the installation section by using the screw member having the module screw and the washer. The module screw has a male screw used as a pair with a female screw thread section formed in the installation section. The washer has an inner diameter corresponding to the module screw. An irregular surface section is formed on a slope surface at the lower part of the head of the module screw or on the surface of the washer that makes contact with the screw.

Abstract: The disclosure provides bearing sleeves or bushings made of memory shape material, and processes for installing such bearing sleeves or bushings. In one process, inner and outer surfaces of a bearing sleeve, made of a memory shape material, may be compressed at least one first temperature. A bearing may be inserted in a cavity of the bearing sleeve, and the bearing sleeve may be disposed adjacent to a surface of a structure, while the bearing sleeve is at the at least one first temperature. The inner and outer surfaces of the bearing sleeve may be expanded, at least one second temperature, to abut against the bearing and the surface of the structure.

Abstract: The invention provides a fastener (10) which has an actuating means (12), a bias means (14) and a flexible core (16). The flexible core (16) has an means for engaging (18) which may be integral with but is preferable separate from the flexible core (16) The actuating means (12) includes a material adapted to contract when activated, such as shape memory alloy. Upon contraction of this material, the means for engaging (18) is movable between an engagement position and a disengagement position. The bias means (14) biases the flexible core (16) to the engagement position.

Abstract: A fastener (10) is adapted to releasably fix a first element (12) and a second element (14). The fastener (10) includes a channel (22) having a plurality of spaced lockers (28). The lockers (28) are movable into the channel (22). The fastener (10) also has a locking tongue (30), having a plurality of spaced blockers (32). The tongue (30) is movable within the channel (22) between a locked position in which the blockers (32) prevent movement of the lockers (28) into the channel (22) and an unlocked position in which the lockers (28) are not prevented from moving into the channel (22).

Abstract: The invention relates to a stabilising device (120) for an assembly which includes two shape memory alloy wires (104, 106) adapted to operate in conjunction. The stabilising device (120) includes a rocker plate (108) for attachment to each of the shape memory alloy wires; the rocker plate (108) is adapted to pivot when one shape memory alloy wire (104 or 106) is subjected to a stress greater than that to which the other shape memory alloy wire (106 or 104) is subjected, in order to reduce the stress on the first-mentioned shape memory alloy wire. The invention further relates to a fastener (60) including a stud (54) having a locking cavity (56), an aperture (58) adapted to receive the stud (54), a locking means (teeth) (62) adapted to engage the locking cavity (56), a shuttle (66) rotatable by a rotating means including material adapted to contract when activated and a plug (87) slidable within the shuttle (66) to close off the aperture (58) when not occupied by the stud (54).

Abstract: A Bolted Flanged Connection (BFC) includes “negative creep” bolts with cores manufactured from Shape Memory Alloy (SMA) and “negative creep” gasket manufactured from the same SMA. The gasket is shape-memorized to the “swelling”, and bolt cores are shape-memorized to the compression. Temperature interval of reverse martensitic phase transformation of SMA is close to operational temperature interval of the assembly. The constrained shape recovery of the gasket and bolt cores is combined with inverse flexion flange design that constitutes original type of BFC with feature to inhibit flange rotation and creep of bolts and gasket under conditions of a variety of operational temperatures and internal pressures.

Abstract: A fastener (10) is adapted to releasably fix a first element (12) and a second element (14). The fastener (10) includes a channel (22) having a plurality of spaced 5 lockers (28). The lockers (28) are movable into the channel (22). The fastener (10) also has a locking tongue (30), having a plurality of spaced blockers (32). The tongue (30) is movable within the channel (22) between a locked position in which the blockers (32) prevent movement of the lockers (28) into the channel (22) and an unlocked position in which the lockers (28) are not prevented from moving into o the channel (22).

Abstract: A fastener system and method of inserting it, that includes a screw or bolt having two interleaved helical threads, which brackets or forms a groove for a helicoil. The helicoil expands and torques by various means to maintain hold and purchase between the screw coil combination and the substrate into which the screw and helicoil are inserted even when the substrate recedes a significant distance from the screw and helicoil combination. The fastener system includes means for latching the tilt of the coil so as to minimize the constraining forces and optimize the motion of the helicoil, that results in the screw or bolt being pushed into the substrate. The fastener may be actuated after it has been partly or completely turned into the substrate.

Abstract: A fastening device, which will facilitate the assembly of associated parts or manufactured articles, and electromagnetic energy absorptive component for absorbing electromagnetic waves and converting wave energy to heat; an expansive component, which expands upon exposure to heat emanating from the target material; matrix material, which will become adhesively active and effect the adherence of the associated parts upon exposure to heat emanating from the target material, and a stiffening component.

Abstract: A bolt made from shape memory alloy that exists in a first state and is capable of changing to a second state when heated and remains in that second state even when cooled is used to self torque itself and clamp a first fixture to a second fixture. Preferred methods for using the self-torquing bolt are disclosed.

Abstract: A fastening device, which will facilitate the assembly of associated parts or manufactured articles, and electromagnetically absorptive component for absorbing electromagnetic waves and converting wave energy to heat; an expansive component, which expands upon exposure to heat emanating from the target material; matrix material, which will become adhesively active and effect the adherence of the associated parts upon exposure to heat emanating from the target material, and a stiffening component.

Abstract: In one embodiment, a spinal fixation assembly includes an elongated member, such as a spinal rod, configured for placement adjacent the spine and a bone engaging fastener, such as a bone screw having a lower portion configured for engaging a vertebra and a head that is at least partially spherical. The assembly further includes a receiver member defining a bore therethrough from a top end to a bottom end, a recess for receiving the head of the bone screwing fastener therein, and a lower opening at said bottom end of the receiver member through which the bone screw extends. The recess is configured to at permit pivoting of the bone screw within the receiver member until the head is fixed within the recess. The receiver member also includes a channel communicating with the bore and having an upper opening at the top end of the receiver member for insertion of the spinal rod into the channel.

Abstract: A Nitinol element is threaded by first heating it to a temperature of about 800° C., and then applying a threading tool, such as a tap or die, to form the threads. Nitinol has a unique property of increasing yield strength as cold work is applied, but this property ceases to exist above a temperature of about 800° C. The strength of the material at this temperature, however, is sufficient to resist the torque applied by a threading die being screwed onto a Nitinol blank even though it is low enough to permit the Nitinol to flow when the cutting threads of the threading die are forced into the material. At this temperature, the Nitinol is not actually cut by the cutting threads of the tap, die or other threading tool, but instead, the material flows around the cutting threads to form threads in the Nitinol.

Abstract: Conductive devices and tools to provide electrical conduction with a generally planar conductor which is covered with an insulation substance such as paint, rust or dust, by scraping a portion of the conductor and removing the insulation substance. A conductive device includes a conductive metal serration means and a tool utilizes such a serration device. Such a serration device can be a bolt device, nut device or washer device, or washer-incorporated threaded device. A connector device is also disclosed to provide electrical conduction between a conductor and a conductor plate covered with an insulation substance.

Abstract: Conductive devices and tools to provide electrical conduction with a generally planar conductor which is covered with an insulation substance such as paint, rust or dust, by scraping a portion of the conductor and removing the insulation substance. A conductive device includes a conductive metal serration means and a tool utilizes such a serration device. Such a serration device can be a bolt device, nut device or washer device, or washer-incorporated threaded device. A connector device is also disclosed to provide electrical conduction between a conductor and a conductor plate covered with an insulation substance.

Abstract: The invention is a tamper-evident fastener comprising a fastener-thermomshrinkable sleeve assembly and method of using the assembly. The device includes a thermoshrinkable sleeve that fits over a fastener having a shaft and head. Upon placing the fastener and sleeve in a position of use and heating the thermoshrinkable sleeve, the sleeve shrinks to substantially conform to the configuration of the fastener head it surrounds and provides a protective sheath that must be dislodged or removed to alter the position of the fastener. The sleeve may additionally function as a washer between the fastener and the object receiving the fastener. One example of use of this device is as a motor oil drain plug.

Abstract: Conductive devices and tools to provide electrical conduction with a generally planar conductor which is covered with an insulation substance such as paint, rust or dust, by scraping a portion of the conductor and removing the insulation substance. A conductive device includes a conductive metal serration means and a tool utilizes such a serration device. Such a serration device can be a bolt device, nut device or washer device, or washer-incorporated threaded device. A connector device is also disclosed to provide electrical conduction between a conductor and a conductor plate covered with an insulation substance.

Abstract: In one embodiment, a spinal fixation assembly includes an elongated member, such as a spinal rod, configured for placement adjacent the spine and a bone engaging fastener, such as a bone screw having a lower portion configured for engaging a vertebra and a head that is at least partially spherical. The assembly further includes a receiver member defining a bore therethrough from a top end to a bottom end, a recess for receiving the head of the bone screwing fastener therein, and a lower opening at said bottom end of the receiver member through which the bone screw extends. The recess is configured to at permit pivoting of the bone screw within the receiver member until the head is fixed within the recess. The receiver member also includes a channel communicating with the bore and having an upper opening at the top end of the receiver member for insertion of the spinal rod into the channel.

Abstract: A fastener system includes a screw or bolt which can be attached in a helicoil. The helicoil expands and torques by various means to maintain hold and purchase between the screw coil combination and the substrate into which the screw and helicoil are inserted even when the substrate recedes a significant distance from the screw and helicoil combination.

Abstract: The device includes an inverted first cup shaped member having a center portion with an aperture therethrough and further having a side wall. A second cup shaped member includes a center portion with and aperture therethrough and a side wall in slidable engagement with the inner wall of the side wall of the first cup forming a compartment therebetween. An is mounted within the compartment which is made of a shape memory alloy having first and second sides at least partially engaged with the center portions of the first and second cups, respectively; and also having an aperture therethrough aligned with the apertures in the center portions of the first and second cups. At least one heating element is mounted about the insert and a flexible compound encapsulates the at least one heating element. The insert can be made from the memory alloy where a deformation undergone in the martensitic state is definitively cancelled out during the passage to the austenitic state.

Abstract: A fastening device, which will facilitate the assembly of associated parts or manufactured articles, features a conductive target material for absorbing electromagnetic waves and converting wave energy to heat; an assembly element, contiguous with the target material, which expands upon exposure to heat emanating from the target material; and a solid adhesive material, contiguous with the conductive target material, which will become adhesively active and effect the adherence of the associated parts upon exposure to heat emanating from the target material.

Abstract: To command notably the unclamping and the separation of two components, on a spacecraft, such as a satellite or a probe, a single actuation pushing device (10) is driven by a form memory device (36) positioned in a casing (12), between a wall (18) of the latter and a boss (24). It is linked to a heater (38). A system to prevent mistakes (20, 26, 32), sensitive to a displacement of the component (24) caused by an elongation of the device (36), prevents assembly of the pushing device (10) when it has already been actuated.

Abstract: A plate-like washer of generally annular shape and a method of using the washer for pre-tensioning. The washer is adapted to be placed between a fastening element, used to attach two pieces to form a coupling, and a piece to be fastened. The washer is manufactured from a shape-memory metal whose upper transformation temperature is higher than the highest use and assembly temperature of the coupling. The thickness of the washer is adapted in view of the length and pre-tensioning need of the fastening element, as well as the expansion of the washer at the upper transformation temperature. The washer is actively heated to its upper transformation temperature and undergoes a phase transformation which expands the washer and pre-tensions the coupling to the desired degree.

Abstract: A pre-tensioning device is used with a fastening element for fastening pieces together, the fastening element having a tightening element movable longitudinally along a first region thereof, which fastening element is to be subjected to a pre-tensioning expansion. The device comprises a locking piece fixedly attachable to the first region of the fastening element and extending over the tightening element; the tightening element being movable with respect to a piece to be fastened independently of the locking piece; and an annular sleeve made of a shape memory metal and positioned between the locking piece and the piece which is to be fastened to another piece, whereby when the annular sleeve is heated it undergoes an expansion due to a phase transformation and forces the locking piece upwards such that the fastening element is stretched and the tightening element can be tightened against the piece to be fastened.

Abstract: Screw or nut braking rings and mountings established with the rings include a nut having an upper portion hollowed from a circular throat. Slits divide the upper portion into blocks by cutting the throat. A shape-memory alloy ring is housed in the throat so as to retighten the blocks on the threaded portion of the mounting and thus tighten it. The ring exhibits a change between the tightening state and a mounting state where it is free in the throat and can be easily mounted.

Abstract: A fastener useful for attaching components of an eyeglass frame together. The fastener includes a pin having a smooth or fluted shank and a retainer having a hole for receiving the shank, the hole being sized to provide an interference fit with the shank. The retainer is made from a titanium nickel shape memory alloy in an optimized elastic condition. The optimized elastic condition is provided by work hardening a tube or wire of Ni--Ti and cutting the retainer out of the tube/wire. The retainer accommodates wear in moving parts held together by the retainer and pin assembly.

Abstract: A heat operated release mechanism. The release mechanism is controllable to allow a heat exchanger to be firmly held in place over a heat producing element and effortlessly withdrawn when so desired. A spring is disposed above a heat producing element forming a variable-volume cavity between the spring and the heat producing element. The spring applies pressure to a heat exchanger inserted into the cavity. A memory metal plate is disposed between the spring and the heat exchanger. The memory metal plate has a selectable first shape at a low temperature for allowing the spring to apply pressure to the heat exchanger and a selectable second shape at elevated temperatures for displacing the spring to increase the volume of the cavity. Finally, a controllable heater is disposed between the spring and the memory metal plate for applying heat to the memory metal to select the second shape thereby increasing the volume of the cavity to facilitate insertion and withdrawal of the heat exchanger.

Abstract: A system for internal fixation of bone includes a fixation plate having a number of bores therethrough, a corresponding number of screws each having an enlarged head portion and an elongated shaft portion defining bone engaging threads thereabout and a non-threaded portion between the head and threaded portions, and a corresponding number of screw anti-backout members each having a bore therethrough. The screw anti-backout members are positioned within the bores of the fixation plate and are initially sized to slidingly receive an elongated shaft therethrough. The screws are advanced through the plate bores and screw anti-backout members so that the fixation plate is secured to the underlying bone with the bores of the screw anti-backout members surrounding a non-threaded portion of the shafts. The system is thereafter heated sufficiently to shrink the bores of the screw anti-backout members, thereby trapping the non-threaded portions of the screw shafts between the fixation plate and the threaded portions.

Abstract: A locking assembly is formed of a first article (40), a second article (44), and a locking fastener (46) positioned between the two articles and made of a shape memory alloy material. The locking fastener (46) is dimensioned to have a first shape below the transformation temperature wherein the first article (40) and the second article (44) are not locked together, and a second shape above the transformation temperature wherein the first article (40) and the second article (44) are locked together by the locking fastener (46). In one form, the first article (40) has a cylindrical bore (42) therein, the second article (44) is a cylinder that fits within the bore (42), and the locking fastener (46) is a helical coil or an annular ring having a radial slot therethrough, placed between the cylinder and the wall of the bore.

Abstract: A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures.A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy.

Abstract: A fastener useful for attaching components of an eyeglass frame together. The fastener includes a pin having a smooth or fluted shank and a belleville washer having a hole for receiving the shank, the hole being sized to provide an interference fit with the washer. The washer is made from a titanium nickel shape memory alloy in an optimized elastic condition. The optimized elastic condition is provided by work hardening a sheet of Ni-Ti and cutting or stamping the washer out of the sheet. The washer is also plastically deformed into a conical shape.

Abstract: An anchor pin, for anchoring one component upon another, such as an electrical connector upon a printed circuit board, by way of a passage defined by a mounting hole in one of the components that is substantially aligned with an opening in the other component. The anchor pin having a first form with a volume larger than the volume defined by the passage while being receivable within the passage and a second form in response to an external energy input, whereby the anchor pin within the passage becomes fluid deforming to substantially fill the passage, automatically accommodating any misalignment, and overflowing therefrom to form opposing heads. The mounting pin hardens in this form to anchor the components together.

Abstract: A lock fastener includes a tubular collar having a plurality of protuberances extending radially inwardly from an inner surface thereof and adapted for cooperating with a bolt to retain the collar thereon. A lock ring surrounds an outer surface of the collar and has an initial inner diameter. The lock ring is formed of shape memory metal alloy effective for shrinking the lock ring to a final inner diameter less than the initial inner diameter upon change in temperature thereof to in turn shrink the collar for clamping the protuberances in locking contact with the bolt.

Abstract: A retainer member (2) suitable for retaining a gap filler (1) placed in gaps (20) between adjacent tile members (21, 22). One edge of the retainer member (2) may be attached to the gap filler (1) and another edge may be provided with a plurality of tab members (4, 5, 6, 7, 8, 9) which in an intermediate position do not interfere with placement or removal of the gap filler (1) between tile members (21, 22). The retainer member may be fabricated from a shape memory alloy which when heated to a specified memory temperature will thermally activate the tab members (4, 5, 6, 7, 8, 9) to predetermined memory positions engaging the tile members (21, 22) to retain the gap filler (1) in the gap (20).

Abstract: A retaining mechanism for an externally threaded part or element which can release without exerting a shock load to the structure which it assembles. The retaining mechanism has a spring biased shiftable ring which retains three threaded nut segments by peripheral surface contact on aligned external cylindrical surfaces of the segmented nut. The retained threaded nut segments maintain threaded engagement with a threaded part to form an assembly. The threaded segments are distanced from the assembled structure by a column of Titanium-Nickel shape memory alloy (SMA) material that has been pre-worked to an increased length at a temperature below its transition temperature from face-centered to body-centered structure so that the column will shrink in length upon the application of heat. A heating element is incorporated within or about the SMA column.

Abstract: A releasable fastening apparatus includes a connecting member and a housing, the housing supporting a gripping mechanism adapted to engage the connecting member. A triggering member is movable within the housing between a first position in which it constrains the gripping mechanism in locked engagement with the connecting member, and a second position in which the gripping mechanism is disengaged from the connecting member. A shaped memory alloy actuator is employed for translating the triggering member from its first to its second position, the actuator being operable to expand longitudinally when transitioned from a martensitic to an austenitic state.

Abstract: This invention provides a temperature responsive self-locking fastener which includes a threaded shank and a threaded mating element both having approximately equal coefficients of thermal expansion and a temperature responsive locking member having a coefficient of thermal expansion different than that of the threaded shank and the mating element. The locking member expands relative to the threaded shank and the mating element at the operating temperature to prevent disengagement of the locking fastener. At the installation temperature, the locking fastener can be easily installed or removed even after one or more cycles between the operating and the installation temperature.