The invention provides a lock assembly ( 10 ) which has a support base ( 80 ) and a bolt ( 14 ) movable between an unlocked position, in which the bolt ( 14 ) is substantially within the support base in ( 80 ) and a locked position in which the bolt ( 14 ) extends from the support base ( 80 ). The lock assembly ( 10 ) also includes locking means ( 32 ) to block movement of the bolt ( 14 ) in the locked position and actuating means ( 46 ) for moving the blocking means ( 32 ) to release the bolt ( 14 ) from the locked position. The actuating means ( 46 ) can comprise electromechanical means, an electro restrictive polymer, piezoelectric material or a material adapted to contract when activated, such as shape memory alloy wire ( 36 ).

CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from earlier filed U.S. provisional applications: 61/033,936 filed on Mar. 5, 2008 and 61/051,047 filed on May 7, 2008. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to a lock assembly. More particularly, the invention relates to a lock assembly with electronic locking features. 
         [0004]    2. Description of Related Art 
         [0005]    Electronic lock assemblies are commonly useful in door applications and the like. The door can be locked and unlocked by input of an entry code or by other authorisation, such as a biometric identification or even a key. 
         [0006]    It is desirable to have an easy and relatively simple assembly for an electronic lock assembly, in particular, having an electronically activated blocking means. 
         [0007]    It is therefore an object of the present invention, at least in one aspect, to provide an electronic lock assembly with an electronically activated blocking means which is easy to assemble and cost efficient. 
         [0008]    This and other objects of the invention will be apparent from the following description. At the very least, the invention provides an alternate arrangement to presently known electronic lock assemblies. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    According to the present invention, there is provided a lock assembly including a support base, a bolt moveable between an unlocked position in which the bolt is substantially Within the support base and a locked position in which the bolt extends from the support base, blocking means to block movement of the bolt in the locked position and actuating means for moving the blocking means to release the bolt from the locked position, the actuating means comprising electromechanical means, an electro restrictive polymer, piezoelectric material or a material adapted to contract when activated. 
         [0010]    The lock assembly of the invention may have a single bolt or may include, as well as the bolt, a tongue or latch. When the lock assembly of the invention includes a tongue or latch as well as the bolt, the lock assembly can be mounted on a door or the like to provide a passage function when the bolt is in the unlocked position. Such a latch or tongue may be operated by a handle rotatable in relation to the support base, in known manner. When the lock assembly of the invention does not include such a separate tongue or latch, it is preferred that the bolt can be operated by a handle rotatable in relation to the support base, when the bolt is not blocked in the unlocked position by the blocking means. The bolt may also function as a latch in the unlocked position. In either case, optionally, the handle may be biased to a predetermined position by suitable means such as a compression spring. 
         [0011]    It is preferred that the bolt is biased to the locked position by a spring or other suitable biasing means. 
         [0012]    The bolt may take any suitable form. The bolt may be a dead bolt or a live bolt. Preferably, the dead bolt form is used when the lock assembly includes a latch or tongue and the live bolt form is used when there is no separate latch or tongue. 
         [0013]    In one preferred embodiment, the bolt includes one or more cavities to cooperate with the blocking means. In a different preferred embodiment, the bolt is of conventional design, with the blocking means operating differently. 
         [0014]    The support base may take any suitable form. Preferably, the support base includes at least one backing plate to support some or all of the components of the lock assembly of the invention, as well as a second plate, preferably at right angles to the backing plate. The second plate in this embodiment has an aperture through which the bolt extends in the locked position. Where the lock assembly of the invention includes a tongue or latch, the second plate preferably has a second aperture through which the tongue or latch can extend. 
         [0015]    The blocking means is adapted to hold the bolt in the locked position. In one embodiment, the bolt includes a cavity and the blocking means is adapted to at least partially enter the cavity so as to prevent the bolt moving to the unlocked position. In another embodiment, the blocking means takes the form of a catch which, when the bolt is in the locked position, blocks a lever which would otherwise retract the bolt from the locked position. Other configurations are possible. It is preferred that the blocking means is biased towards the position where it holds the bolt in the locked position. 
         [0016]    The actuating means for moving the blocking means to release the bolt from the locked position includes electromechanical means, an electro restrictive polymer, piezoelectric material, or material adapted to contract when activated. One skilled the art will recognise that there are many options available for material within the actuating means. The electromechanical means can comprise an electric motor or solenoid for example. However, for purposes of describing this invention, it will be discussed in terms of the material adapted to contract when activated. Preferably, this material adapted to contract when activated is a 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 copper. A shape memory alloy is capable of adopting one shape below a predetermined transition temperature (Martensitic) and changing to a second shape once its temperature exceeds the transition temperature (Austenitic). Conversely, when the shape memory alloy cools below the transition temperature, it is capable of adopting the first shape again. In connection with the preferred embodiments of the present invention, the shape memory alloy contracts when heated in situ. Shape memory alloy wire currently available, such as that sold under the name Nitinol, is capable of contracting when activated by heating. For longevity, it is preferred that the contraction is limited to about 3%. 
         [0017]    Activation of shape memory alloy (SMA) such as Nitinol is preferably achieved through electrical resistance heating. 
         [0018]    The actuating means may be powered in any suitable way, including by hard wiring and by battery. The actuating means may be activated in any suitable way. Non-limiting examples are pressing a button, entering a code on a keypad or using a key. The actuating means may be activated remotely. Preferably, in this embodiment, the actuating means is activated by radio frequency devices. 
         [0019]    The lock assembly of the invention preferably includes retaining means for retaining the bolt in the unlocked position. For example, in the embodiment where the bolt has at least s one cavity, the retaining means may be adopted to at least partially enter that cavity once the bolt has been moved to the unlocked position and thus retain the bolt in that position. In a second embodiment, where the bolt does not include such a cavity, the retaining means may be designed to hold back the blocking means (against its bias to the blocking position, if the bias is present). In either case, it is preferred that the retaining means can be actuated to lock the blocking means or the bolt, such that the bolt is either in the unlocked postion or free to move between the locked and unlocked positions, by actuating means including material adapted to contract when activated, as described above. 
         [0020]    The lock assembly of the invention may include a relief spring adapted to allow the handle (if present) to rotate when the bolt is in the locked position, even though in this situation the handle will not move the bolt to the unlocked position. 
         [0021]    In an especially preferred embodiment, the assembly of the invention includes manual release means for enabling movement of the bolt from the locked position. 
         [0022]    In one embodiment, the manual release means moves the blocking means away from the position where it blocks movement of the bolt in the locked position. The blocking means may be spring loaded towards the position where it blocks movement of the bolt in the locked position. The manual release means may enable the blocking means to be retracted against the bias of the spring, so that the bolt is no longer blocked from retracting from the locked position. 
         [0023]    The manual release means, if included in the lock assembly of the invention, may be operable from either side of the lock assembly or from both sides. For example, the manual release means may be operable from inside a room or passageway closed by a door having an embodiment of the lock assembly. Where the lock assembly is operable by a key pad, the key pad may include a facility for manual release. 
         [0024]    The manual release means may be activated manually, or by remote activation, or electronically. In the last-mentioned situation, the manual release means is more of an override than a true manual release. Remote activation may take place by a suitable signal to a receiver in the manual release means. For example, the manual release may respond to a radio signal, ultrasound, use of a magnetic or electromagnetic field. Other remote activation methods are within the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The invention will now be described in connection with the following non-limiting embodiments in the accompanying drawings, in which: 
           [0026]      FIG. 1  is a plan view of a first embodiment of the lock assembly of the present invention; 
           [0027]      FIG. 2  is a perspective view showing internal components of the lock assembly of  FIG. 1 ; 
           [0028]      FIG. 3  is a plan view showing blocking means used in the lock assembly; 
           [0029]      FIGS. 4(   a ), ( b ) and ( c ) are plan views showing internal components of the lock assembly of  FIG. 2  in various positions; 
           [0030]      FIG. 5  is a plan view of the lock assembly of  FIG. 4(   b ) but with manual release activated; 
           [0031]      FIG. 6  is is a plan view of a second embodiment of the lock assembly of the present invention; 
           [0032]      FIGS. 7(   a ), ( b ) and ( c ) are plan views showing internal components of the lock assembly of  FIG. 6  in various positions; 
           [0033]      FIG. 8(   a ) is a view of a third embodiment, similar in many respects to the first embodiment in  FIGS. 1 to 5 , in perspective, partially exploded view, from one side; 
           [0034]      FIG. 8(   b ) shows the embodiment of  FIG. 8(   a ) from the other side; 
           [0035]      FIG. 9  is a perspective view showing internal components of the lock assembly of  FIGS. 8(   a ) and  8 ( b ); 
           [0036]      FIG. 10  is a perspective view showing internal components of the blocking cartridge for the embodiment in  FIGS. 8 and 9 ; 
           [0037]      FIG. 11  shows a detail from part of the view of  FIG. 8(   b ), at a slightly different angle, and showing a detail of manual release; and 
           [0038]      FIG. 12  shows a component of the  FIG. 11  view, being a manual release cam mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]    It will be readily appreciated that the views in the various Figures are not all drawn to the same scale. 
         [0040]    Turning to the Figures generally and to  FIG. 1  in particular, there is shown lock assembly  10  having handle  50  rotatably mounted in support base  80  (not shown in  FIG. 1 , but see  FIG. 2 ). Handle  50  is adapted to rotate to release latch  16  to open a door. Blocking cartridge  12  is shown projecting from panel  15 . 
         [0041]    In  FIG. 2 , locking assembly  10  is shown with blocking cartridge  12 , bolt  14 , levers  18 ,  22 , springs  20 ,  24  and latch  16 . Lever  18  is connected to handle  50  (not shown). Blocking cartridge  12  is shown having retaining means  30  received by cavity  29  of bolt  14 , preventing bolt  14  from moving from the unlocked position illustrated to the locked position in which bolt  14  would extend from the support base. The support base in this embodiment comprises backing plate  17  and side plate  19 , at a right angle to backing plate  17 . 
         [0042]    Blocking cartridge  12  shown in  FIGS. 3 to 5  has blocking means  32  and retaining means  30  connected to actuating means  46  and  42 , respectively, by shape memory alloy (SMA) wires  36  and  34 , respectively. Blocking means  32  and retaining means  30  are biased towards the position shown by retaining means  30  in  FIG. 3 , by torsion springs  33  and  31 , respectively. When actuating means  42  is activated, SMA wire  34  contracts and pulls down retaining means  30  against the bias of spring  31 . When actuating means  46  is activated, SMA wire  36  contracts and pulls down blocking means  32  against the bias of spring  33 . 
         [0043]      FIG. 4(   b ) shows lock assembly  10  in the locked position, with bolt  14  extending from support base  80  and blocked against withdrawal by blocking means  32 . Retaining means  30  is being held down by the bottom part of bolt  14 . Latch  16  is in the closed position. Levers  18 ,  22  form a levering mechanism. When actuating means  46  is activated, SMA wire  36  contracts and pulls blocking means  32  out of cavity  29  to free bolt  14 . Within a pre-determined time, when handle  50  (not shown) is turned, lever  18  pivots and in turn rotates lever  22  to move bolt  14  from the locked position to the unlocked position, as shown in  FIG. 4(   c ). Retaining means  30  is pushed up by torsion spring  31  and received by cavity  29  when bolt  14  is in the unlocked position. Handle  50  also causes latch  16  to be retracted within support base  80  to allow the door to open. 
         [0044]    If handle  50  is not turned within the pre-determined time, SMA wire  36  will cool and extend and blocking means  32  will be pushed up again by torsion spring  33 , holding bolt  14  in the locked position. 
         [0045]    Alternatively, actuating means  46  may continue to be activated, which would keep SMA wire  36  in the contracted form, and there would be no time limit for turning handle  50 . 
         [0046]    As shown in  FIG. 4(   a ), when handle  50  is released and pushed back to the original position by spring  20 , latch  16  returns to the closed position. Bolt  14  remains in the unlocked position, being blocked by retaining means  30 . 
         [0047]    To change to the locked position, actuating means  42  is activated. SMA wire  34  contracts and pulls down retaining means  30 . Bolt  14  is now freed and pushed by torsion spring  28  to the locked position. This in turn causes lever  22 , which has end  23  inserted in cavity  25 , to pivot, assisted by the influence of spring  24 , to the position shown in  FIG. 4(   b ). While in the locked position, if handle  50  is turned with excessive force, lever  22  vill not pivot but will be pushed forward, compressing spring  24 . This allows handle  50  to rotate, but the door remains locked. 
         [0048]    Lock assembly  12  can be manually unlocked in case of failure of blocking cartridge  12 . A small screwdriver can be inserted into manual release hole  70  of blocking cartridge  12  (shown in  FIG. 3 ) through hole  60  of lock assembly  12  (shown in  FIG. 1 ) and pulled down to move entire blocking cartridge  12  down, causing blocking means  32  to move out of cavity  29 , as shown in  FIG. 5 . Bolt  14  is now free to move. When handle  50  is turned, bolt  14  moves to the unlocked position in the usual manner described above. 
         [0049]    Now turning to the second embodiment of the invention shown in  FIGS. 6 and 7 , lock assembly  110  has retaining means  124 , blocking means  122 , and lever means  118  biased to a pre-determined position by torsion spring  120 , on support base  180 . A handle (not shorten) is adapted to rotate lever means  118  to release latch bolt  116  to open a door, unless lever means  118  is blocked by blocking means  122 , as shown in  FIG. 6 . 
         [0050]    In  FIG. 7(   a ), locking assembly  110  is in an unlocked position with the handle (not shown) having been turned. This has caused lever means  118  to rotate until it reaches stop  121 . Torsion spring  120  is thus compressed. Blocking means  122  is retained by pawl  139  of retaining means  124 . Retaining means  124  is biased to this retained position by a torsion spring (not shown). 
         [0051]    To latch the door, the handle (not shown) is released to allow lever means  118  to be biased by torsion spring  120  to return to the pre-determined position, extending latch bolt  116  from side plate  119 , as shown in  FIG. 7(   b ). In this position, blocking means  122  continues to be retained by pawl  139  of retaining means  124  and locking assembly  110  can be used in passage mode. 
         [0052]    To lock the door, SMA wire  136  is activated and contracts, pulling retaining means  124  to release blocking means  122 . Blocking means  122  is pushed up by a torsion spring (not shown) to engage with lever means  118 , preventing lever means  118  from moving, as shown in  FIG. 7(   c ). Now the handle cannot be turned, retaining latch bolt  116  in the locked position. 
         [0053]    To unlock the door, SMA wire  134  is activated, pivoting blocking means  122  away from lever means  118 . While blocking means  122  is being pulled down, blocking means  122  travels past pawl  139  of retaining means  124  until blocking means  122  is locked/retained by pawl  139 , as shown in  FIG. 7(   a ). Now the handle can be turned to open the door, in the manner referred to above. 
         [0054]    Turning now to the third embodiment of the invention in  FIGS. 8 to 12 , this is in many respects similar to the first embodiment in  FIGS. 1 to 5 . To indicate similar parts, the same labels will be used as those used in reference to  FIGS. 1 to 5 , with the addition of the letter “a”. 
         [0055]    As can be seen from  FIGS. 8(   a ) and  8 ( b ), lock assembly  10   a  has handle  50   a  rotatably mounted in support base  80   a.  Handle  50   a  can be rotated from either side of lock assembly  10   a  to release latch  16   a  to open a door (not shown) on which lock assembly  10   a  is mounted. 
         [0056]      FIG. 8(   a ) shows lock assembly  10   a  from the outside of the door, while  FIG. 8(   b ) shows lock assembly  10   a  from the inside of the door. Push buttons  150  are shown in  FIG. 8(   a ). Push buttons  150  are used to enter an allocated entry code to trigger unlocking of bolt  14   a,  using a very similar mechanism to that described in connection with  FIGS. 1 to 5 . Push buttons  150  are mounted in panel  15   a.    
         [0057]    Blocking cartridge  12   a  is shown projecting below lock assembly  10   a.  It will be appreciated that blocking cartridge  12   a  will normally be installed within the door (not shown). 
         [0058]      FIG. 9  shows the mechanism of lock assembly  10   a  with part only of blocking cartridge  12   a  visible. 
         [0059]    As with the first embodiment, the support base comprises backing plate  17   a  and side plate  19   a.  Levers  18   a  and  22   a  are similar to levers  18  and  22  in the first embodiment, although not identical. Spring  20  of the first embodiment is replaced by spring  152  in  FIG. 9 . 
         [0060]    Bolt  14   a  includes cavity  29   a  for receiving (in this illustration) locking means  32   a . Retaining means  30   a  can be discerned, maintained in the retracted position by the base of bolt  14   a.    
         [0061]    The manual release mechanism in the third embodiment will now be described. 
         [0062]    As may be seen in  FIG. 8(   b ), face plate  154  is connected to blocking cartridge  12   a  through manual release cam  156 . Manual release cam is shown on its own in  FIG. 12 . Blocking cartridge  12   a  has an oval aperture  158  ( FIG. 9)  for securing cam  156 . 
         [0063]    As the detailed view in  FIG. 11  shows, cam  156  has projection  160  which mates with a ledge around aperture  158  in a normal situation. If it is desired to activate the manual release, grooved thumb plate  162  on cam  156 , which is set into the base of face plate  154 , is rotated to turn cam  156  so that projection  160  no longer contacts the ledge of aperture  158 . Blocking cartridge  12   a  is spring loaded away from bolt  14   a.  Consequently, when the ledge of aperture  158  is no longer constrained by projection  160  of cam  156 , blocking cartridge  12   a  moves away from bolt  14   a  to the limit permitted by the shape of aperture  158 , until cam  156  reaches the upper limit of aperture  158 . 
         [0064]    This movement away from bolt  14   a  is sufficient to allow locking means  32   a  to clear cavity  29   a,  freeing bolt  14   a.    
         [0065]    If desired, lock assembly  10   a  may be set up so that manual release can be achieved through use of buttons  150 . 
         [0066]    In relation to  FIG. 10 , this is similar in layout to the view in  FIG. 3 , except that aperture  158  is included for the purposes of the manual release mechanism. 
         [0067]    It will be appreciated by one skilled in the art that various changes may be made to the embodiments of the invention without departing from the spirit and scope of the invention. 
         [0068]    Throughout the specification and claims the word “comprise” and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word “comprise” and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.