AU2011235991B2 - Fasteners and other assemblies - Google Patents

Abstract

The invention discloses several types of fastener, fastening systems, fastener assemblies and related areas. In particular, the invention discloses a releasable fastening system (150) which has a pin (152) with a locking cavity (163). The pin is intended for insertion in an aperture (154). A locking means (158, 160) engages the locking cavity (163) of the pin (152) when the pin (152) is received in the aperture (154). The system (150) also includes unlocking means (162) which includes material adapted to contract when activated. When a material contracts, engagement means (158) included in the locking means (158, 160), disengage the locking cavity (154). Figure 8A WO 200514047714 PCTAU2OO4OOI580 SUSIUE WE RL 6 OA

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: TELEZYGOLOGY INC Actual Inventors: RUDDUCK, Dickory & GOLDSPINK, Lachlan Richard & PARK, Joshua Robert & NG, Nicholas Anthony & BLATTMANN, Lee David & KELLIHER, Christopher Gerarh & FARREN-PRICE, Edward David James Address for Service: Chrysilion IP Patent and Trade Mark Attorneys 114-115/Biztek 20 Dale Street Brookvale, Sydney NSW 2100 invention Title: Fasteners And Other Assemblies The following statement is a full description of this invention, including the best method of performing it known to me/us: i:\dcs\pstents\applications\2 [48.docip Fasteners and Other Assemblies Technical Field This invention is concerned with fasteners and other assemblies. The invention in its various aspects has wide application, as will be apparent from the 5 description below. Background and Introduction The invention covers a wide range of fasteners, fastening systems, fastener assemblies and related areas. These represent improvements over prior art fasteners and fastener assemblies, etc. 10 In aspects of the invention discussed below, reference is made to material adapted to contract when activated. The material adapted to contract when activated is preferably shape memory alloy wire. Shape memory alloys are known and are usually made predominantly or wholly of titanium and nickel. They may also include other material, such as aluminium, zinc and 15 copper. A shape memory alloy is capable of adopting one shape below a predetermined transition temperature and changing to a second shape once its temperature exceeds the transition temperature. Conversely, when the shape memory alloy cools below the transition temperature, it is capable of adopting the first shape again. In connection with the various aspects of the present invention, the shape memory alloy contracts when 20 heated in situ. Shape memory alloy wire currently available, such as that sold under the trade mark Nitinol, is capable of contracting by about 3% when activated by heating. Activation of the material adapted to contract when activated is preferably achieved through electrical resistance heating, with a wire feed to the assembly. Activation of the shape memory alloy wire can be initiated from a central location, using the wiring 25 system of, for example, an air craft or automobile. It is also within the scope of this invention that the activation is initiated by remote means, such as a hand held tool operating through the use of any suitable form of energy, including microwave, electric magnetic, sonic, infra-red, radio frequency and so on. The scope of the invention in its various aspects is not necessarily limited to the use of o shape memory alloy. Other material may also be useful. Also, while activation may take place through heating, other means of activation may be suitable and are within the scope of this invention.

The fasteners and fastening systems of the invention may be particularly suitable for use in connection with automobiles and to some extent the description below may focus on this application. However, it is to be understood that the scope of the invention is not limited to this application. 5 There is a marked trend towards increasing electronic control in motor vehicles. Nowadays, many motor vehicles incorporate computer systems which use a Controller Area Network (CAN) in which modules communicate data to the computer via a bus, or a local interconnect network (LIN) which also enables communication of data via a bus. The present invention in some of its many aspects is intended to take advantage of the io trend towards increased electronic control in vehicles. The present invention provides several versions of fasteners which may be suitable for use in vehicles and which may provide significant advantages in relation to assembly of vehicles and service of vehicles. In particular, the fasteners of the present invention may be suitable for connection to a vehicle computer via a CAN or LIN. 5 Some fasteners and fastening systems of the invention can be designed to be activated only by authorised parties, such as those engaged in vehicle assembly or servicing. Others can be designed to be operated by vehicle owners. In appropriate forms, any of the fasteners and the fastening systems of the invention can have primary and secondary functions, the primary function being to attach components to the vehicle body and the secondary function being the control of component switching. It is possible that use of fastening systems according to the invention may reduce the number of sub-network wiring components required in a vehicle, through direct connection into the CAN bus, for example. In effect, each fastener may become its own multiplex module/communications gateway or node on the CAN bus. Disclosure of the Invention The invention provides a fastening system which can have widespread applications. One embodiment, referred to below as a ring clip fastener, was developed to suit multiple attachment points in retaining panels, such as in automotive use or for furniture. The fastener is not restricted to these applications. In another embodiment, the fastening system of the invention has been developed especially for rugged high-wear applications. This fastening system, which may be referred to as a stud fastener, is capable of being strong and carrying a high load, such as securing equipment to a vehicle. It is to be understood that the fastening system in this embodiment is not limited to these parameters, however. Stud fasteners can be useful in many other applications. They can be used, for example, to close doors, being attached to a door frame and adapted to receive a pin or stud on the door. In another embodiment, the fastening system of the invention can be used as an "inline" fastener, 5 Accordingly, this invention provides a releasable fastening system including a pin having a locking cavity; an aperture for receiving the pin; a locking means adapted to engage the locking cavity of the pin when the pin is received in the aperture; and 1o an unlocking means including material adapted to contract when activated, wherein the locking means comprises or includes engagement means adapted to disengage the locking cavity when the material contracts. The pin may be chosen from a large range of suitable shapes. As one example, the pin may be generally circular in cross-section, tapering in towards the base. The pin may be c a stud, peg, bolt or any other suitable element. The pin may be formed integrally with or attached to an element to be fastened. The attachment may be by adhesion, clipping or other suitable means. The material adapted to contract when activated is preferably attached to the engagement means to move it out of engagement with the locking cavity when activated and so o permit release of the pin. The material which contracts when activated is preferably the shape memory alloy wire described above. The locking cavity may take any suitable form but preferably is one or more indentations or a groove. If a groove, the groove may be adapted to receive the locking means in some or all of the groove. The aperture is preferably formed centrally in a body which may house the locking means and the unlocking means. The aperture is preferably of the same shape as the cross-sectional shape of the pin, for example, circular. The aperture may take any other suitable shape. If the pin is designed with a taper, it can be pushed into the aperture and be engaged without the need for any activation of the material. The taper on the pin can serve to

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form a ramp pushing the locking means apart until it snaps into the locking cavity, such as a groove. In this configuration, the fastening system is engaged. To disengage the fastening system, it is necessary to activate the material so that it contracts and pulls the locking means out of engagement with the groove. For example, if the locking means is a a clip, one or more loops of shape memory alloy wire may encircle the clip, with one end of a loop being fastened to one arm of the clip and one end of another loop being attached to the other arm of the clip. The locking means includes or consists of engagement means which is adapted to disengage the locking cavity when the material contracts. In one embodiment, the 10 engagement means is a clip. In a different embodiment, the engagement means is one or a plurality of elements, such as teeth. The invention is not limited to these embodiments. When the engagement means includes or consists of a clip, the clip may take any suitable form but preferably is a collar, a bias spring or a type of circlip, in each case with arms which can be pulled apart out of engagement with the locking cavity. The clip may 15 generally follow the shape of the groove (eg, circular), but may take another suitable shape, such as "U" shape. The locking means may consist of the clip, as described above, or it may include other elements, such as a clip chassis. A clip chassis may be convenient to carry the clip and to facilitate, operation of the unlocking means. For example, the clip may be mounted in 20 or on the clip chassis and the unlocking means, such as one or more loops of shape memory alloy wire, may be connected to the clip chassis. In this example, when the shape memory alloy contracts, it causes the clip chassis to open, forcing apart the arms of the clip so that the clip moves out of engagement with the grooves. The clip chassis may be hinged to enable it to open during this procedure. 26 In another embodiment, the clip chassis may be used alone, the clip chassis including bias means such as a spring to urge it to the engaged position. In all embodiments, the clip is preferably biased towards the engagement configuration. This can enable the pin to be engaged passively - without activation of the material - if the pin is shaped to push the clip open on entry into the aperture as described above. The 3o bias of the clip may also assist the material which contracts when activated, such as the shape memory alloy wire, to return to the relaxed or elongated shape when it cools or is otherwise no longer activated. When the engagement means includes or consists of one or a plurality of elements such as teeth, each of these is preferably designed to fit into the locking cavity, in this embodiment being a groove in the pin. Preferably, there is a plurality of such elements, being teeth. In this embodiment, the teeth are preferably surrounded by a rotatable body, such as a shuttle. The shuttle is rotatable to an engagement position, where the teeth engage the , groove, and to a disengagement position, where the teeth disengage from the groove. In a particularly preferred embodiment, the shuttle has one or more apertures or spaces into which the engagement means may be received in the unlocking position. When the engagement means, such as teeth, are not in these apertures or spaces, the shuttle is designed to push the engagement means into the locking cavity and hence to the locking 10 position. In another embodiment, the shuttle may include or be associated with means adapted to engage the engagement means and draw them out of engagement with the locking cavity, when the shuttle is rotated to the unlocking position. The shuttle may be rotated by the locking means which includes material adapted to 16 contract when activated, Preferably, this material is shape memory alloy wire, as discussed above. It is further preferred that the shape memory alloy wire is wound around the shuttle which is rotatable within a body for the fastening system. In this embodiment, the shape memory alloy wire is attached at one end to the shuttle and at the other to a non-rotatable part of the fastener. When the shape memory alloy wire is o caused to contract by the application of suitable energy to reach the necessary temperature, the shuttle can rotate from the locking position to the unlocking position. A second shape memory alloy wire may be similarly connected to the shuttle in order to rotate it from the unlocking position to the locking position. It is particularly preferred that a retractable cap is included in the releaseable 5 fastening system of the invention, to present a smooth appearance when the pin is not inserted in the cavity. An example of this is described in connection with the drawings, below. If the retractable cap is included, it can be pushed further into the cavity by the pin when the pin is inserted in the cavity, the retractable cap being spring biased towards the cavity opening. This embodiment can have a clean flat o visual finish when not in use. It is also preferred that the retractable cap, when used, also has first engagement means, similar to the pin, In this way, the retractable cap can work the same way as the pin in the releaseable fastening system of the invention in so far as the cap is locked or released by the locking means. If this embodiment is utilised, it may be necessary to include means enabling the cap to be withdrawn from the cavity and/or to provide some indication that the cap has been released. As a variation of the fastening system of the invention, the pin and a core in the cavity may contain conductors for power and data connections for the releaseable 5 fastening system or conduits for other material, e.g., liquid, gas. This may accommodate, for example, a GPS system connected to the power source of, for example, a motor cycle. As set out above, the fastening system of the invention can be constructed so as to be rugged for high load and high usage applications. It can be dust and water resistant if 10 it includes the retractable cap or a sprung cover. It can be designed so that the pin can be inserted in the cavity and engaged without any need for activation of the contractible material. However, it is intended that the contractible material must be activated before disengagement can take place. It is preferred that the fastening system of the invention requires positive disengagement 15 of the locking means before the pin may be inserted in the cavity. Disclosed above are embodiments of the invention. These embodiments have been referred to as ring clip fasteners and stud fasteners. The invention can also provide a third type of fastener known as an "inline" fastener. This type of fastener can be useful for locks, latches, closures and the like. The fastener can be made of sufficiently slim 20 profile to be able to be concealed within elements having at least one narrow dimension, for example having a thickness of between 15 and 20 mm. When the fastening system of the invention is used as an inline fastener, it is preferred that the locking cavity is one or more indentations engagable by the engagement means. For use as an inline fastener, it is preferred that the fastening system is contained within a 25 box which may be inserted into a panel. The engagement means is preferably a pair of latch arms. Preferably, the locking means also include a slidable shuttle inl which the latch arms are generally received. In a preferred embodiment, the locking means has pair of arms adapted to embrace the latch arms in the locking position and to hold the latch arms in locking contact with a latch, bar, projection or the like. In this embodiment, 30 drawing of the shuttle away from the latch arms is designed to allow the latch arms to release contact with the latch, bar, projection or the like, The engagement means further preferably includes a pawl to facilitate rapid resetting of the fastening system after activation of the material. In this embodiment, the fastening system of the invention can eliminate unnecessary delay between sequential unlocking and locking actions. It is also an option that this facility can be cancelled if rapid locking followed by unlocking is not desirable. Preferably, the fastening system of the invention includes means for indicating the locked or unlocked states of the fastening system. By way of a non limiting example, this can be 6 effected by microswitches in contact with the shuttle or an extension thereof. Information as to the locked or unlocked status of the fastening system can be conveyed to an indicator light or similar indicium locating in a convenient position. The engagement means is preferably biased towards the locking position, preferably by a coiled spring, positioned in the fastening system of the invention so that the spring urges io the locking means, such as the shuttle, toward the locking position.- When the material is activated, this may cause compression of the spring, which accordingly can return the locking means towards the locking position once the material is no longer activated. It is preferred that the fastening system of the invention includes additional biasing means, such as a spring attached to the pawl and a spring for ejecting the latch, bar or 15 projection. Shape memory alloy wire currently available, such as that sold under the trade mark Nitinol, is capable of contracting by about 3 percent when activated by heating. Consequently, in order to provide sufficient "travel" in drawing the engagement means from the locking position to the unlocking position, the drawing means may include 20 Nitinol wire in a single, relatively long or double line and a fastening system having this configuration may be referred to as an "inline" fastening system. This configuration enables the fastening system to have a slim profile, for the purpose of fitting into panels and similar elements, as referred to above. In other applications, particularly where a slim profile is not a priority, or in those 25 circumstances where a greater amount of "travel" is desirable, the Nitinol wire may be provided over a non-linear path. This may have the effect of permitting the fastening system of the invention to be provided in a more compact configuration compared to the inline fastening system referred to above. In addition, if, for example, the length of Nitinol wire in a non-linear path was around 200nun, the amount of contraction of 30 Nitinol in its presently available form would be about 6mm. In a non-linear path, the Nitinol wire preferably loops over one or more spindles or rollers. Activation of the material adapted to contract when activated is preferably achieved through electrical resistance heating, with a wire feed to the fastening system. The fastening system of the invention may include many other options. One such option 35 is the sensing of change in temperature, for example to indicate a dangerously high temperature, so that an appropriate alarm can be initiated, the fastening system of the invention being wired into, for example, the aircraft electrical system. Other sensing functions may be incorporated in the fastening system of the invention. The fastening system of the invention may include multiple material such as shape 5 memory alloy wire. This can provide redundancy, so that if activation of one shape memory alloy wire fails to operate the system, the other or another of the wires can be activated, The fastening system of the invention may be constructed in modular form. For instance, the engagement means may form one module, with the material being located in a 10 separate module. This allows interchangeability so as to permit different types of engagement means to be exchanged in the fastening system of the invention, or to substitute, for example, a single shape memory alloy wire with a multi-strand wire. The fastening system of the invention is preferably enclosed in a housing which can be bonded or fitted into the panel, door or the like. This arrangement can assist in 15 electromagnetic protection, can facilitate exchange of one fastening system with another and can enable better adjustment of the fastening system within its surroundings. This can be particularly important if the fastening system of the invention includes facility for manual release as mentioned herein. It can also permit the status (locked or unlocked) indicator to be visible from the same aperture which can be used for manual release. 20 In present aircraft design, most fasteners are designed to be hidden behind doors, panels, etc. It is common to include a manual release for a hidden fastener, whereby a tool can be inserted through a small aperture visible from the cabin side of the door, panel or the like. It will be appreciated that this invention can provide a fastening system which can be manually released if desired z, Preferably, the fastening system of the invention includes one or more sensors which can detect whether the pin is present in the system, regardless of whether the fastening system is in the locked or unlocked state. It is also preferred that the fastening system of the invention includes lock status sensors, which can report whether the fastening system is in the locked or unlocked state. Such sensors may act as a reed switch, for example, so 30 that when they make contact a report is generated that the fastening system is in the locked or unlocked state, depending on the construction of the fastening system. The lock status sensors may also work by enabling completion of an electrical circuit. Other configurations and means of sensing may also be applicable. The fastening system of the invention may also include a temperature sensor for sensing 35 the temperature of the shape memory alloy wire in the preferred embodiments. This can adjust the amount of energy applied to the shape memory alloy wire, depending on sensed temperature, to take into account varying conditions. For example, if the temperature is relatively low, a larger amount of power may need to be delivered to the shape memory alloy wire to heat it to the desired temperature. Conversely, if the 5 temperature is high, the amount of power to be delivered to the shape memory alloy wire in order to cause it to contract may be far less. A temperature sensor can enable feedback and cause adjustment of power delivery in this regard. In an especially preferred embodiment, the fastening system includes a microprocessor which can carry out one or several roles, The microprocessor can control the energy 1o delivery to the shape memory alloy wire, preferably by a temperature-dependent algorithm. The microprocessor can control temperature of the shape memory alloy wire, It can sense the state of the fastening system and whether it is engaged or not. The microprocessor can detect Whether the pin is present in the fastening system. The microprocessor may report this, along with secondary sensed information, to a network 16 of which the fastening system forms a part. Preferably, the microprocessor carries out all these roles. The fastening system of the invention also preferably includes bias means, such as a spring, biasing the fastening system towards the locked state. The fastening system of the invention also preferably includes an ejector spring, to assist ejection of the pin or 20 stud when the engagement means is no longer engaged with the locking cavity. This fastening system is capable of being produced at a low cost, with minimum parts and in a very small size. It is suited to high volume mass production and may be designed so as to require only low power consumption, if thin shape memory alloy wires are used. 25 In one version, the fastening system may take the form of a ring grip or clip fastener, and may be particularly suitable for fixing interior panels or door trims, for example, in automobiles, The fastening function of the fastening system of the invention may be regarded as a primary function. The fastening system may have a secondary function, according to 30 which the fastening system controls simple component switching. One example of this is the control of a window motor in a car door. In this context, the releaseable fastening system can be used to connect one element, such as the interior lining of a car door, to a second element, such as the car door itself. Alternately or additionally, the releaseable fastening system is used to act as a switch in connection with the operation of, for 3s example, a window motor, a door lock assembly, headlights and so on. The releasable fastening system may carry out both functions.

Optionally, the fastening system of the invention has a manual override so that the fastening system can be released in case of a power failure or if it is required to test the fastening system before power has been connected, for example The fastening system of the invention in various embodiments may include the manual 5 override, Some examples are shown in the drawings, In the case of the ring grip embodiment, a manual override may involve a slot through which a suitable tool can be passed to prise apart the engagement means, such as a cirelip. In the case of the stud fastener embodiment, the manual override may enable the shuttle, if present, to be rotated to the unlocking position. 1o Accordingly, the invention also provides a manual override for a stud fastener of the invention or for any other suitable fastener having a shuttle movable between a locking position and a unlocking position, the override including: a manual actuator adapted to cause the shuttle to move from the locking position to the unlocking position; and 15 means for drawing the manual actuator so that the shuttle moves to the unlocking position. Preferably, the means for drawing the manual actuator so that the shuttle moves to the unlocking position comprises or includes a rod connected to the manual actuator. For example, the rod may include a protrusion pivotally connected to the manual actuator, 2o When the rod is pulled in a chosen direction, the manual actuator may be caused to move through its connection via the protrusion on the rod to a position where the shuttle moves to the unlocking position. Preferably, the manual actuator is connected mechanically to the shuttle for this purpose. For security, it is preferred that the drawing means is biased away from the unlocking 26 position. For example, when the drawing means includes a rod, the rod may need to be pulled against a spring. To further protect against accidental or inadvertent release, the drawing means may include means for engagement with retaining means. The purpose of this is to ensure that the drawing means must deliberately be disengaged from the retaining means before the manual override can be operated. Both of these safety 3o mechanisms can help to ensure that accidental manual release does not occur though vibration, for example. The drawing means may take any other suitable form, including that of a Bowden cable. There may be several fasteners which need to be released through manual override. Consequently, the manual override of the invention can be adapted to manually release I A more than one fastener at the same time. Preferably, this is achieved by linking the manual actuator for the first fastening system with a manual actuator for the second fastening system and, optionally, with third and subsequent fasteners. The linkage preferably takes place using a connecting rod. 5 efDeritionofthe Drawings The invention will now be described in connection with certain non-limiting examples thereof in the accompanying drawings in Figures 5 to 55. The remaining Figures do not illustrate the invention now claimed herein, and may be disregarded. Referring to Figures 5 to 55: 10 Figure 5 is a side elevation of a first embodiment of the fastening system of the invention; Figure 6 is the fastening system of Figure 5 in plan view, in the engaged state; Figure 7 is the fastening system of Figures 5 and 6 in the disengaged state; Figure 8A is an exploded view of a second embodiment of the invention; 15 Figure 8B is an exploded view of a variation of the second embodiment shown in Figure 8A; Figure 8C shows a sub-assembly of Figure 8B; Figure 8D shows part of the assembly of Figure 8B in the engaged position; Figure 8E is a sectional view taken along the lines A-A of Figure 8D; 20 Figure 8F is a similar view to Figure 8D but showing the disengaged position; Figure 8G is a sectional view taken along the lines A-A of Figure 8F; Figure 9 is an enlarged detail of the embodiment of Figure 8A; Figure 10 is a top plan view of a third embodiment of the fastening system of the invention; 25 Figure 11 is a side sectional view of the fastening assembly of Figure 10, in the locked state; Figure 12 is a top plan view of the fastening system of Figures 10 and 11, but in the unlocked state; Figure 13 is a cross-sectional view of the ring clip fastener of Figure 12 in the unlocked state and is useful for comparison with Figure 11; Figure 14 is a further embodiment of the fastening system of the invention, being a stud fastener, before entry of the pin into the aperture; 5 Figure 15 shows the fastening system of Figure 14 in the locked position; Figure 16 shows the fastening system of Figures 14 and 15 in the unlocked position; Figure 17 is an exploded view of a further embodiment of the invention, showing a second embodiment of stud fastener; Figure 18 is a top view of a variation of the embodiment in Figure 17; 10 Figure 19 is a cross-sectional view of the embodiment of Figure 18, taken along the lines A-A of Figure 18; Figure 20 is a top view of a third embodiment of stud fastener; Figure 21 is a cross-sectional view of the embodiment of Figure 20 taken along the lines A-A of Figure 20; 15 Figure 22 is a top plan view of a further embodiment of the fastening system of the invention being a type of stud fastener; Figure 23 is a cross-sectional view of the fastener of Figure 22 in the locked state; Figure 24 is the same cross-sectional view as that of Figure 23, but showing engagement of a pin; 20 Figure 25 is a cross-sectional view of the fastening system of Figure 22 in the unlocked state and is useful for comparison with Figure 24; Figure 26 is a perspective view of a further embodiment of the fastening system of the invention being a stud fastener; Figure 27 is a bottom end view of the embodiment of Figure 26 with the rear cap 25 removed; Figure 28 shows the embodiment of Figure 26 with the pin removed, in the locked state; Figure 29 shows the embodiment of Figure 26 with the pin removed, in the unlocked state; Figure 30 is a bottom end view of the embodiment of Figure 26, in the locked position; Figure 31 is a sectional view of the fastening assembly of Figure 30, taken along the lines 17-17 in Figure 30; Figure 32 is a bottom end view of the embodiment of Figure 26, in the unlocked position; c Figure 33 is a sectional view of the fastener of Figure 30, taken along the lines 19-19 in Figure 32, in the unlocked position; Figure 34 is a plan view of a manual override for the fastening system of the invention; Figure 35 is sectional side view of the override of Figure 34, taken along the lines 20-20; Figure 36 shows the manual override of Figure 34 in the unlocked position; 10 Figure 37 is a side sectional view taken along the lines 23-23 of Figure 36; Figure 38 is a perspective view of linked fastening systems according to the invention; Figure 39 is an enlargement of one of the fastening systems of Figure 38; Figure 40 is yet a further enlargement of the fastening system of Figure 39 with cover removed; 1s Figure 41 is a side sectional view of a further embodiment of the fastening system of the invention, being a type of in-line fastener, showing the fastening system in the locked position and also illustrating an embodiment of a strain reduction assembly; Figure 42 is a top sectional view of the embodiment of Figure 41; Figure 43 is an enlarged view of the left hand end of the embodiment in Figure 41; 20 Figure 44 shows the embodiment of Figure 43 as soon as the unlocking position has been attained; Figure 45 shows the embodiment of Figure 44 during cooling of the drawing means; Figure 46 shows the embodiment of Figure 45, fully reset in the open position, ready to move to the locking position and if required to unlock again immediately; 6 Figure 47 shows an example of how the fastening systems of the invention may be integrated into a typical vehicle CAN network, in relation to a vehicle door; Figure 48 is a diagrammatic illustration of at least part of the system in Figure 47; Figure 49 shows how the network concept exemplified in Figure 47 and 48 may be extended throughout many vehicle components; Figure 50 is similar to Figure 48 but gives an example of the extension of the function of fastener system of the invention; , Figure 51 exemplifies architecture of a fastening system of the invention in a motor vehicle; Figure 52 is a cross-sectional view of an embodiment of fastening system, in the unlocking position; Figure 53 is an end view of the latch which is included in Figure 52; 1o Figure 54 is a cross-sectional view of the embodiment of Figure 52 in the locking position; and Figure 55 is an end view of the embodiment in Figure 54, taken along the lines 4-4 in Figure 54. Best Modes of Carrying out the Invention in its Various Aspects s Reference is made to the embodiment of the invention in Figures 5 to 7. In this embodiment, fastening system 50 includes pin 48 adapted to be received in aperture 52. Locking means 54 in the form of a circlip 54 are adapted to lock into groove 56 in pin 48. Aperture 52 is formed in plastic fastener body 58 which includes ridge 60. Travelling o around ridge 60 is shape memory alloy wire 40. Insulated plastic caps 62 connect crimped ends (not shown) of wire 40 to circlip 54 and power leads 64. Figure 6 shows fastening system 50 in the locked state. In this state, pin 48 may be pushed into aperture 52. Taper 66 on pin 48 serves to push circlip 54 apart, until it rides into groove 56, where it remains locked. Thus, there is no need to activate wire 40 in order to insert pin 48 in aperture 52. Figure 7 shows fastening system 50 in the unlocked position. In this Figure, wire 40 has been heated through power fed from leads 64 to wire 40, to the extent that wire 40 contracts. Through its connection at caps 62 with circlip 54, wire 40 in the contracted state, and restrained by ridge 60, draws circlip 54 apart, freeing circlip 54 from groove 56 and permitting the unfastening of pin 48.

Referring now to Figure 8A, releasable fastening system 150 includes a pin 152 adapted to be received in an aperture 154 of main body 156. Clip spring 158, together with clip chassis 160 and shape memory alloy wire 162, comprise the locking means for pin 152. Pin 152 has a wide groove 163 around its circumference. Groove 163 is adapted to 5 receive clip chassis 160 which can embrace groove 163. Clip chassis 160 carries clip 158 and acts as a type of circlip. Shape memory wire 162 is engaged with clip chassis 160 in the manner shown in Figure 9. When shape memory alloy wire 162 is activated, it shrinks and pulls apart clip chassis 160. 10 To lock pin 152 into main body 156, pin 152 may be pushed by hand, by pressure on cap 164, into aperture 154. Clip chassis 160 and clip spring 158 open sufficiently to allow pin 152 to be received, so that clip chassis 160 engages groove 163 on pin 152. To unlock pin 152 from main body 156, as already described, wire 162 is heated sufficiently for it to contract. Because of the manner of attachment of wire 162 to clip 15 chassis 160 (refer Figure 9) through engagement in channels 166 and 170, contraction of wire 162 pulls apart clip chassis 160 sufficiently for pin 152 to be withdrawn from clip chassis 160. Clip chassis 160 is hinged at 168. Fastening system 150 includes controller panel 172 which receives instructions for unlocking and which generates the heat necessary for contraction of wire 162. Rear 20 cover 174 completes the housing of fastening system 150. Clip spring 158 biases clip chassis 160 towards the locked position and in this embodiment assists wire 162 to return to the locked position when it relaxes. In a variation of fastening system 150, clip chassis 160 may be eliminated. In this case, clip spring 158 is adapted to be engaged by shape memory alloy wire 162 and to be 25 pulled apart by contraction of the wire when it is desired to unlock the fastening system. Reference is now made to the embodiment shown in Figures 8B to 8G. Where parts are similar to those in Figures 8A and 9, the same numbers will be used, with the addition of the letter "a". As shown in Figure 8B, releasable fastening system 150a includes a pin 152a adapted to 3o be received in an aperture 154a of main body 156a. Spring 158a, together with clip chassis 160a and shape memory alloy wires 162a comprise the locking means for pin 152a.

Pin 152a has a wide grove 163a around its circumference. Grove 163a is adapted to receive clip chassis 160a which can embrace grove 163a. Spring 158a snaps into grove 116 of clip chassis 160a and biases it towards the engagement position Shape memory wire 162a has two separate loops, 118 and 120. These are engaged with 5 clip chassis 160a in the manner shown in Figure 8C. It will be appreciated in comparing Figure 8C with Figure 9, that shape memory alloy wires 118 and 120 will be under less strain than wire 162 in Figure 9, when activated to contract. To lock pin 152a into main body 156a, pin 152a may be pushed by hand, by pressure on cap 164a, into aperture 154a. Clip chassis 160a, although bias to the closed position by 10 spring 158a, will open sufficiently to allow pin 152a to be received, so that clip chassis 160a engages grove 163a on pin 152a. To unlock pin 152a from main body 156a, as already described, both wires 118 and 120 of wires 162a are heated sufficiently for them to contract. Each of wires 118 and 120 is attached to clip chassis 160a as shown in Figure 8C. Consequently, contraction of wires 15 118 and 120 pulls apart clip chassis 160a sufficiently for pin 152a to be withdrawn from clip chassis 160a. Clip chassis 160a is hinged at 168a. Means for a manual override of fastening system 150a are shown in Figures 8B. and 8E, Cap 164a includes slot 122. A suitable tool may be inserted in slot 122 in cap 164a and through corresponding slot 123 in main body 156a. The tool can then penetrate between 20 the arms of clip chassis 160a to force them apart sufficiently to release pin 152a. In this embodiment, the manual override can be operated not only from the cap side of fastening system 150a, but also from rear cover 174a. As shown in Figure 8E, slot 124, corresponding to slot 122 on cap 164a in plate 126 is accessible from rear cover 174 and the same tool may be used to manually release pin 152a, in a similar way to that 25 described for slot 122. In Figures 10 to 13, ring clip fastener 94 is particularly suitable for securing components to a panel, such as an instrumentation panel. Fastener 94 is shown in the locked state in Figures 10 and 11 as engaging fastener peg 98 and in Figures 12 and 13 after release of fastener peg 98, 30 Fastener peg 98 includes groove 104. When peg 98 is pushed into fastener 94, arms 106 of bias spring 108 are pushed apart by ramp 110 on peg 98. Arms 106 snap fit into groove 104 to lock peg 98 in fastener 94. Thus an instrumentation panel can be mounted in a panel housing by simple manual pressure, for example.

Included in fastener 94 is engagement sensor 112 which senses contact with base 114 of peg 98. Engagement sensor 112 confitns engagement of peg 98 in fastener 94 and can communicate that information to a computer (not shown). As can be seen from Figure 10, fastener 94 includes a shape memory alloy (SMA) wire s 416 which is connected to terminals 418 which bear on arms 106 of bias spring 108. When appropriate energy is applied to SMA wire 416 - for example, electrical energy and SMA wire 416 is heated to the necessary temperature, SMA wire 416 contracts as shown in Figure 12. Contraction of SMA wire 416 causes terminals 418 to move apart. Because terminals 418 bear on arms 106, those arms 106 are forced apart. Arms 106 10 move out of groove 104, permitting release of peg 98. Engagement sensor 112 can report on the release of peg 98. Included in fastener 94 are sensors 420 which sense the locked status of fastener 94. When fastener 94 is in the unlocked state as shown in Figure 14, it will be seen that arms 106 contact sensors 120 and thus can complete a circuit or act as a reed switch so that 16 sensors 120 can report on the locked or unlocked status of fastener 94. Referring now to Figures 14 to 16, these show an embodiment of a stud fastening system in the second aspect of the invention. In this embodiment, releaseable fastening system 70 includes pin 68 adapted to be received in aperture 72. Pin 68 has a locking cavity in the form of indentation 74 around the circumference of pin 68. Associated with aperture 20 72 in fastener body 76 are locking means in the form of arms 78 having protrusions 80 designed to fit within indentation 74 in pin 68. Once pin 68 is pushed into aperture 72, protrusions 80 on arms 78 snap into indentation 74. Stop 82 prevents disengagement by blocking outward movement of protrusions 80 on arms 78. Activation of shape memory alloy wire 40 contracts wire 40 and draws stop 25 82 from its blocking position against arms 78. Arms 78 may be biased to spring outwardly as shown in Figure 16, facilitating withdrawal of pin 68 from aperture 72. Spring 84 is biased to urge stop 82 to the locked position shown in Figures 14 and 15. In the illustrations in Figures 14 to 16, both pin 68 and fastener body 76 include conductor pins 86. These are optional. They may be used to provide power and data 30 connections for the fastening system 70. Another optional feature is shown in Figures 14 to 16, in the form of retractable cap 88, This is used to provide a flat visual appearance on outer surface 90 of frame 10. In the embodiment shown, it is necessary to activate wire 40 in order to draw stop 82 from its blocking position against arms 78. Once that has occurred, pin 68 can push cap 88 s against the bias provided by spring 92, from the position shown in Figure 14 to that in Figure 15. In this position, shape memory alloy wire has relaxed to lock pin 68 into position. Figure 16 shows the unlocked position before withdrawal of pin 68 from aperture 72. Referring now to Figures 17, 18 and 19, the stud fastening system 180 in this 5 embodiment is particularly suitable for heavy duty use. In this embodiment, pin 182 having groove 184 and cap 186 is adapted to be received in aperture 188 of main body 190. Received in main body 190 is shuttle 192. Shuttle 192 is adapted to rotate within main body 190 when a shape memory alloy wire (not shown) wound in grooves 194 contracts. Activation of the shape memory alloy wire causes shuttle 192 to rotate in a 10 direction which allows unlocking of fastening system 180. Shuttle 192 includes projections 196 which axe designed to engage feet 198 of teeth 200. Projections 196 may be inclined as shown in Figure 17 or may be set an angle of approximately 45 degrees as shown in Figure 19. Washer 202 rests at the base of feet 198 when fastening system 180 is assembled. Small 16 coil springs (not shown) are mounted in apertures 204 and bear against washer 202 to apply pressure against teeth 200. Apertures 204 are formed in centre plug 206. Aperture 208 is designed to receive a further bias spring (not shown), which assists in returning that the shape memory alloy wire (not shown) to its relaxed configuration, when no longer activated. 20 Electronics module 210 is shown in this embodiment as being hard wired through cable 212 and controls unlocking of fastening system 180. End cap 214 completes the assembly. In the variation shown in Figures 20 and 21, main body 190 is shown with a screw thread 216 on which is received a nut 218. The purpose of nut 218 is to allow an element, such 25 as a panel (not shown), to be received in gap 220, End cap 214 has a central aperture (not shown) through which it is possible to insert an appropriate tool to rotate shuttle 192 manually in the event that there is some malfunction of the fastening system. It will be noted from Figure 21 that washer 202 has been omitted and that teeth 200 are 30 of a slightly different configuration to those in Figure 19. Reference is now made to Figures 22 to 25. These illustrate a stud fastener which can be substituted for the ring clip fastener of Figures 10 to 13, The stud fastener of Figures 22 to 25 can be regarded as more robust and can carry a higher load compared to the ring fastener of the previous Figures 10 to 13.

Peg 98 of Figure 10 is substituted by peg 98a shown in Figures 24 and 25. Fastening system 230 of Figures 22 to 25 has a plurality of teeth 222 adapted to engage groove 104a in peg 98a. Teeth 222 are biased towards the locked position by tension spring 424, Tension spring 424 also serves to keep teeth 222 in position. Peg 98a can be 5 pushed into aperture 102. Ramp 1 10a on peg 98a will push against teeth 222 and against the tension of spring 424. As peg 98a is pushed into aperture 102, teeth 222 will spring back into groove 104a to lock peg 98a into fastening system 230. Fastening system 230 includes engagement sensor 112. When contacted by base 114a of peg 98a, engagement sensor 112 can report connection of peg 98a in fastening system 10 230 and hence connection of elements to be fastened, such as an instrumentation panel in a panel housing. Fastening system 230 includes shape memory alloy wires 426. These are wound around shuttle 428 which is rotatable within body 432 of fastening system 230. Shape memory alloy wires 426 are fastened at each end to a non-rotatable part of fastening system 230 15 (not illustrated). When shape memory alloy wires 426 are caused to contract by the application of suitable energy to reach the necessary temperature, shuttle 428 rotates to the position shown in Figure 25. Shuttle 428 includes camming surface 434. As can be seen by Figure 25, camming surface 434 ramps down on tail 436 of tooth 222, pushing tail 436 against the bias provided by tension spring 424 and drawing each tooth 222 out 20 of engagement with groove 104a, Thus peg 98a is freed from fastening system 230. Tension spring 424 may also bias shape memory alloy wires 426 to their relaxed configuration. Included in fastening system 230 are lock status sensors 438 and 440. When these are separated as shown in Figures 23 and 24, the sensors report that fastening system 230 is 25 in the locked state. When the sensors make contact, as shown in Figure 25, the sensors report that fastening system 230 is in the unlocked state, Sensors 438 and 440 may act as a reed switch, for example, or their contact may enable completion of an electrical .circuit, to signal the unlocked state. Other configurations and means of sensing may of course be applicable, 3o Reference is now made to the embodiment of the second aspect of the invention in Figures 26 to 33. Fastening system 260 includes stud 254 having a locking cavity being circumferential groove 256 (refer Figures 31 and 33). Fastening system 260 includes aperture 258 into which stud 254 can be received by a push-fit. Fastening system 260 includes eight teeth 262, each having a tongue 264 which can 35 engage groove 256. in Shuttle 266 is mounted for rotation within body 268 between two positions, The first position is that shown in Figure 28 where locking protrusions 270 maintains teeth 262 in the locking position into aperture 258 (and groove 256 of stud 254 when stud 254 is in aperture 258). The second position is that shown in Figure 29, in which shuttle 266 has 5 rotated sufficiently so that teeth 262 are located in spaces 272 between locking protrusions 270. In this configuration, teeth 262 are no longer maintained in the locked position in aperture 258 (and groove 256 in stud 258 when present). Shuttle 266 is rotated from one position to the other through shape memory alloy wires 274 and 276, one being used to rotate shuttle 266 to the locking position and the other to 10 rotate it to the unlocking position, As shown in Figure 26, fastening system 260 includes rear cap 278. Power is supplied via electrical wires 280. In Figure 27, in which rear cap 278 has been removed, shape memory alloy wire 274 can be seen. Also shown is shuttle position sensor 282. This senses whether shuttle 266 is 5 in the locking or unlocking position and can report to an external source (not shown). Figure 27 also shows wire temperature sensor 284. This senses the temperature of shape memory alloy wire 274 and 276 and can enable the calculation of the amount of power to be delivered to raise wire 274 or 276 to the desired temperature at which it contracts. Temperature sensor 84 can prevent overheating of wires 274 and 276 and can also o minimise the amount of electrical energy required to be delivered to wires 274 and 276. As best shown in Figures 31 and 33, fastening system 260 includes in this embodiment sliding plug 286. In the locked position (Figure 31), sliding plug 286 is in contact with stud detector switch 288, because stud 254 has pushed sliding plug 286 down into contact with stud detector switch 288. This enables fastening system 260 to report on z5 whether stud 254 is engaged. Also shown in Figures 31 and 33 are bias spring 290 and ejector spring 292. Bias spring 290 biases fastening system 260 to the locking position. Ejector spring 292 facilitates ejection of stud 254 when teeth 262 are no longer engaged in groove 256, as shown in Figure 33. o Shape memory alloy wires 274 and 276 are attached via crimps 294 and 295 as shown in Figures 31 and 33. Shuttle detector switch 297 detects whether shuttle 266 is in the locked or unlocked position.

Figure 30 shows rear cap 278 with manual release 296. This can be operated, for example by hand, to manually rotate shuttle 266 from the locking to the unlocking position, as shown in Figure 32. Referring now. to Figures 34 to 37, these show a fastening system 260a similar to 5 fastening system 260 in conjunction with a manual override. Another suitable fastening system could be substituted for fastening system 260a. Manual override 400 has manual actuator 298 and drawing means being rod 402. Manual actuator 400 is joined to fastening system 260a and to rod 402 via protrusion 704 which engages manual actuator 298 through slot 706. io Rod 402 is attached to knob 708 which has engagement ledge 710. Engagement ledge 710 is shown in Figure 34 in engagement with catch 712. Spring 714 biases towards the locking position. In order to operate manual override 400, knob 708 must be rotated by hand until ledge 710 is no longer in engagement with catch 712. Knob 708 is then drawn upwardly 15 (Figure 34) against the bias of spring 714, to rotate manual actuator 298 upwardly, through engagement of protrusion 704 in slot 706, Thus shuttle 266 is -rotated from the locking position shown in Figure 35 to the unlocking position shown in Figure 37, manual actuator 298 being in the position shown in Figure 36. At this stage, stud 254 is ejected as shown in Figure 37 because of ejector spring 292. 20 Also shown in Figure 37 is actuator linkage 716. This links rod 402 with a second fastening system 260b, travelling through conduit 718, as shown in Figure 38. As shown by the detail in Figures 39 and 40, when knob 708 is rotated free of catch 712 and drawn upwardly against the bias of spring 714, actuator linkage 716 ensures that both fastening system 260a and 260b are manually released, 25 As can be seen in more detail in Figures 39 and 40, in this embodiment fastening system 260a is situated under cover 720 and partly within mechanism casing 722, mounted on bracket 724. Figures 41 to 46 show an embodiment of an in-line fastener, according to the second aspect of the invention. 3o As shown in Figures 41 to 46, fastening system 510 is contained within fastener mounting box 512 attached to an external power source through conduit 514. Fastening system 510, contained within box 512, is inserted into a panel (not shown) and secured in position by screws 516 attaching face plate 518 to flange 520 of fastener case 522, contained within box 512. Electrical connection via conduit 514 is continued into fastener case 522 by means of cable connector 526. Spring clip 528 is inserted beneath flange 520. Fastening system 510 is intended to engage projection 524 (as shown in Figures 41 to 43), projection 524 protruding from a panel or door (not shown). In fastening system 5 510, the engaging means includes latch arms 530, shuttle. 532 and pawl 534. Spring 536 biases shuttle 532 towards the locking position shown in Figure 41. Spring 540 urges ejector plug 542 towards the unlocked position. Shuttle 532 includes Teflon pad 544 to facilitate sliding of shuttle 532 within fastener case 522. Fastening system 510 also includes shape memory alloy wire 546 which loops over pin 10 548 on pawl 534. Activation of wire 546 is controlled though printed circuit board sub assembly 550. Spring 538 is for urging shape memory alloy wire 546 to the locked position shown in Figure 41. Sensor switches 552 contact extension 554 of shuttle 532 in order to provide an indication of the locked or unlocked status of fastening system 510. As shown in Figure 16 43, only one sensor switch 552 is in contact with extension 554 and assembly 510 can therefore indicate that the system is in the locked position, When both sensor switches 552 make contact with extension 554 as shown, for example, in Figure 46, the indication is that assembly 510 is in the unlocked state. As shown in Figures 41 and 42, assembly 510 also includes spring 560 to relieve strain 20 on shape memory alloy wire 546 should it be unable to draw pawl 534 away from the locking position. Referring now to Figure 43, this shows fastening system 510 in the locked position. In this position, projection 556 on pawl 534 bears against pin 558 and ramp 562 engages shoulder 564 of shuttle 532. 25 Ends 566 of shuttle 532 bear against ends 568 of latch arms 530, ensuring engagement of ends 568 with recess 570 in projection 524 (see Figure 44), When sufficient electrical energy is applied through the electrical connection via cable connector 526, wire 546 contracts, drawing pawl 534 away from the locking position, as shown in Figure 44, In this position, ramp 562 of pawl 534 has pushed against shoulder so 564 until projection 556 has encountered travel limit pin 572, which has pivoted ramp 562 away from full contact with shoulder 564, as shown in Figure 44. At this stage, wire 546 is still contracted. The withdrawal of shuttle 532 has moved ends 566 of shuttle 532 out of contact with ends 568 of latch arms 530. Latch arms 530 pivot around pivot points 574 and move out of engagement with recess 570 of projection 524. Ejector spring 540 pushing against ejector plug 542 has caused partial ejection of projection 524 from fastening system 510. It will be appreciated that if travel limit pin 572 is removed, pawl 534 will pivot so that there is no contact with shoulder 564 at all. Shuttle 532 will then be free to move towards 5 the locking position under the influence of spring 536, Projection 524 can then be engaged with fastening system 510. However, unlocking will not be possible until wire 546 has cooled sufficiently. In the next stage shown in Figure 45, projection 524 has been ejected completely from fastening system 510. Wire 546 has elongated to some extent while cooling and so pawl 10 534 has been able to move out of contact with pin 572. In the configuration shown in Figure 46, wire 546 has completed elongation through cooling, pawl 534 has moved sufficiently away from pin 572 so that projection 556 has contacted pin 558, causing pawl 534 to pivot so that ramp 562 is in position to engage shoulder 564. 15 If projection 524 is pushed into fastening system 510 at this point, ejector plug 542 will be compressed against spring 540, ends 568 of latch arms 530 will snap into place into recess 570, ends 566 of shuttle 532 will be able to move into position against ends 568 of latch arms 530, spring 536 will move shuttle 532 to the left in Figure 46 and ramp 562 will engage shoulder 564 of shuttle 532, ready for unlocking if wire 546 is activated. zo Aperture 576 though projection 524 is available for use as a light pipe - for example, for indication of locked or unlocked state. In addition, a suitable tool can be inserted though aperture 576, through an aperture (not shown) in ejector plug 542 and though gap 578 (see Figure 43) between latch arms 530. The tool can then exert pressure on shuttle 532 to manually move shuttle 532 towards the unlocked position, whereupon the contact 25 between ends 566 and ends 568 will be removed, allowing ejection of projection 524 out of fastening system 510. Reference was made above to the fastening system of the invention including sensors for temperature, for example, In Figure 41 these are shown at 580. Sensing is not limited to temperature sensing. As will be apparent to one skilled in the art, the fastening system of 3o the invention can sense or control various other functions, such as lights, heaters, fans and so on, Thus the fastening system 510 of the invention may have multiple functions and may be involved in control of lighting, for example, control of lights within a compartment, the door of which is fastened by fastening system 510. Figure 47 is an example of integration of the fastening systems of the invention in a 5 typical vehicle CAN network, specifically showing a car door. This illustration is largely self-explanatory. Some of the fasteners of the invention are referred to in Figure 47 as part of the "Intelligent Fastener network". These perform the primary functions of the fastener of the invention, namely to attach components within the vehicle. Other fasteners referred to in Figure 47 as "Fastener nodes" are performing a secondary 5 function, namely control of the relevant component, such as the window motor, the rear vision mirror, etc.. Connection to the CAN bus is also shown. It is to be appreciated that the component layout and wiring harness in Figure 47 is merely an example and not limiting on the scope of the invention. Figure 48 is a diagrammatic illustration of part of the system in Figure 47, Some of the io fasteners of the invention, referred to as "TZ Intelligent Fasteners" are carrying out the primary function discussed above and some are carrying out the secondary function, The primary and secondary functions referred to can be expanded to control or fasten several other vehicle components, such as those shown in Figure 49. This Figure is self explanatory. 15 Figure 50 shows how the fasteners of the invention may be arranged to reduce the number of sub-network wiring components through direct connection into the CAN bus. Figure 50 should be compared with Figure 48 in this regard, In effect, each fastener of the invention may be able to act as its own multiplex module/communications gateway or node on the CAN bus. This network structure may also enable the fasteners of the 20 invention to extend their function into control of components switching. With reference to Figure 51, this illustrates an example of the architecture of a fastening system of the invention in a motor vehicle, At the bottom of the chain is a fastener of the invention, which fastens a component to the vehicle. This fastener (the "Intelligent Fastener") is connected to the vehicle computer via the CAN bus. The vehicle computer 25 transmits data and/or instructions between the Intelligent Fastener and an "Intelligent Tool" such as a personal digital assistant (hand-held computer). The master control resides at the top level of the hierarchy, providing Intelligent Fastener identity and security information to the Intelligent Tool and logging diagnostic and historical fastener function information. 3o As before, the Intelligent Fastener may have a primary function of attaching a component to the vehicle and a secondary function of control of switching. Reference is now made to Figures 52 to 55, which illustrate an embodiment of the invention. In Figures 52 to 55, fastening system 610 has engagement means 612 movable between the locking position shown in Figure 54 and the unlocking position shown in Figure 52. Engagement means 612 includes a pair ofjaws 614 pivotable at pivot point 616. Block 618 includes cavity 620 defined by arms 622, base 624 and stop 626. 5 When engagement means 612 is in the locking position as illustrated in Figure 54, pivot point 616 lies as close to base 624 as possible and stop 626 does not prevent the closing of jaws 614, as illustrated. In contrast, when engagement means 612 is in the unlocking position shown in Figure 52, pivot point 616 is spaced from base 624 and stop 626 forces apartjaws 614, as illustrated. 10 Block 618 is urged towards engagement means 612, in the locking position, by coil spring 628 which is positioned between block 618 and tube 630. Block 618 includes projection 632 containing aperture 634 to which is attached smart memory alloy wire 642. Smart memory alloy wire 642 is connected electrically to printed circuit board 638 which in turn is hard wired via wires 640 to an energy source 15 (not shown). Electrical wire 636 completes the circuit for smart memory alloy wire 642. Fastening system 610 is intended to be inserted into the edge of a panel through a round hole or bore in the panel, with wires 640 projecting from the rear of the panel. Jaws 614 engage latch 644 on external element 646, in order to secure the panel (not shown) to the external element 646, 20 To attach the panel to the external element 646, smart memory alloy wire 642 is energised by the external energy source via wires 640 to cause smart memory alloy wire 642 to heat and contract to the position shown in Figure 52. In this position, block 618 has been drawn back so that stop 626 forces jaws 614 apart. The panel is positioned so that jaws 614 are poised around latch 644. At this stage, power to smart memory alloy 25 wire 642 is cut off and smart memory alloy wire 642 cools and elongates to the configuration shown in Figure 54. Coil spring 628 pushes block 618 to the left (towards latch 644). Stop 626 is no longer bearing against the base of jaws 614 and accordingly jaws 614 close as shown in Figures 54 and 55, engaging latch 644. In this way, the panel is fastened to the external element 646. 30 To remove the panel, smart memory alloy wire 642 is again energised so that it heats and contracts and fastening system 610 assumes the position shown in Figure 52, releasing jaws 614 from latch 644.

As will be apparent to one skilled in the art, the design of engagement means 612 can be varied considerably from that shown in Figures 52 to 55, as can latch 644. Engagement means 612 and block 618 may be provided as a module, replaceable by a different module with a different engagement mechanism. 5 Fastening system 610 as illustrated in Figures 52 to 55 is a type of "inline" fastener. Industrial Applicability It will be apparent to one skilled in the art that the invention in its various aspects has wide industrial applicability, providing fasteners, fastening systems and other aspects for a plurality of industries. 10

Claims (20)

1. A releasable fastening system including: a pin having a locking cavity; an aperture for receiving the pin; a locking means adapted to engage the locking cavity of the pin when the pin is received in the aperture; and an unlocking means including material adapted to contract when activated, wherein the looking means comprises or includes engagement means adapted to disengage the looking cavity when the material contracts.

2. The fastening system of claim 1 wherein the pin is a stud, peg or bolt, ending in a tapered base.

3. The fastening system of claim I or 2, wherein the locking cavity is a groove around the perimeter of the pin and the engagement means is adapted to engage at least some of the groove.

4. The fastening system of claim I or 2, wherein the locking cavity is or one or more indentations in the pin.

5. The fastening system of any one of claims 1 to 4, wherein the engagement means is one or more locking elements.

6. The fastening system of any one of claims 1 to 5, wherein the engagement means is one or more locking elements, being a collar, a bias spring, a circlip or a clip chassis. 27

7. The fastening system of any one of claims 1 to 6, wherein the locking means includes a clip chassis together with a bias spring or a circlip.

8. The fastening system of any one of claims 1 to 7 wherein the unlocking means is connected to the engagement means.

9. The fastening system of claim 7, wherein the unlocking means is connected to the clip chassis.

10. The fastening system of claim 1, wherein the engagement means is a single locking element, being a tooth.

11. The fastening system of claim 1, wherein the engagement means is plurality of locking elements, each being a tooth.

12. The fastening system of claim 10 or 11, wherein the or each tooth is surrounded by a rotatable shuttle.

13. The fastening system of claim 12, wherein the material adapted to contract when activated is wound around the shuttle.

14. The releasable fastening system of any one of claims 1, 2 or 4 wherein the locking means includes a slideable shuttle.

15. The fastening system of any one of claims 1 to 14, wherein the material adapted to contract when activated is shape memory alloy wire.

16. The fastening system of any one of claims 1 to 15 which includes a micro-processor

17. The fastening system of claim 16, wherein the microprocessor is adapted to: 28 control energy delivery to the material adapted to contract when activated; and/or sense whether the engagement means is engaged or disengaged; and/or control temperature of the material adapted to contract when activated.

18. The fastening system of any one of claims 1 to 17, which includes means to disengage the engagement means without activation of the material adapted to contract when activated.

19. The fastening system of claim 14, which includes a manual override having a manual actuator adapted to cause the shuttle to move from a locking position to an unlocking position and having means for drawing the manual actuator so that the shuttle moves to the unlocking position.

20. A fastening system substantially as herein described with reference to any one of Figures 5 to 55 of the accompanying drawings. 2,.