FIELD OF THE INVENTION This invention relates to a lock arrangement. More particularly, but not exclusively, this invention relates to a lock arrangement that could, when fitted to a barrier, be easily and securely operated either electronically, manually or remotely to lock such barrier in a closed position. BACKGROUND TO THE INVENTION

Lock arrangements are well known and widely used to secure a barrier in a closed position. Some of these lock arrangements are complicated in design with the result that the mechanics can fail or jam relatively easily, and/or they can be difficult to operate.

Further, at least some of these lock arrangements which are fail-secure are unable to be opened when a power outage occurs.

OBJECT OF THE INVENTION

It is accordingly an object of the present invention to provide a lock arrangement which overcomes, at least partially, the abovementioned problems and/or which will be a useful alternative to existing lock arrangements. SUMMARY OF THE INVENTION

In accordance with this invention, there is provided a lock arrangement for securing a barrier in a closed position, the lock arrangement comprising:

- a housing;

- a bolt displaceable relative to the housing between a forward position wherein the bolt is engageable with a socket in an adjacent body and a retracted position wherein the bolt is not engageable with the socket;

- first biasing means for biasing the bolt to its retracted position;

- a loading member for loading the first biasing means so to increase a biasing force exerted by it; and

- selector means engaging the first biasing means and being displaceable between a first position in which the first biasing means is prevented from displacing the bolt to its retracted position and a second position in which the first biasing means is permitted to displace the bolt to its retracted position.

The loading member may be displaceable between an operative position in which the first biasing means is loaded and an inoperative position in which the first biasing means is not loaded, wherein when the first biasing means is loaded it exerts a biasing force which is sufficient to displace the bolt to its retracted position.

There is provided for the lock arrangement to include a retracting member having a first end which is attached to the bolt so that it is displaceable with the bolt and an opposing second end. The retracting member may be an elongate retracting member. The first biasing means may comprise a first end which is connected to the loading member and an opposing second end which engages the selector means and is engageable with the second end of the retracting member so that under the influence of the biasing force exerted by the first biasing means on the retracting member, it is caused to displace to a position in which the bolt is retracted. The second end of the first biasing means may include a first block and a first protruding pin. The first biasing means may further comprise a first coil spring, a first rod and a first tube, wherein the first tube may be located within the first coil spring and teiescopicaliy movable over the first rod.

The selector means may include first guide means for engaging and guiding the second end of the first biasing means between a position in which the bolt is forward and the first biasing means is loaded and a position in which the bolt is retracted and the first biasing means is not loaded. The first guide means may comprise a first I- shaped guide slot.

There is further provided for the lock arrangement to include second biasing means for biasing the bolt to its forward position, the second biasing means comprising a first end which engages the selector means and an opposing second end which is connected to the bolt. The first end of the second biasing means may include a second block and a second protruding pin. The second biasing means may further comprise a second coil spring, a second rod and a second tube, wherein the second tube may be located within the second coil spring and teiescopicaliy movable over the second rod. The second biasing means may be loaded when the bolt is in its retracted position and not loaded when the bolt is in its forward position, wherein when the second biasing means is loaded it exerts a biasing force which is sufficient to displace the bolt to its forward position.

The selector means may include second guide means for engaging and guiding the first end of the second biasing means so to be displaceable with the bolt. The second guide means may comprise a second l-shaped guide slot.

There is further provided for the lock arrangement to include third biasing means for biasing the loading member to its inoperative position and the bolt to its forward position, the third biasing means comprising a first end which is retained in position by it resting against the housing and a second end which is connected to the loading member. The third biasing means may comprise a third coil spring, a third rod and a third tube, wherein the third tube may be located within the third coil spring and telescopically movable over the third rod.

The third biasing means may be loaded when the loading member is in its operative position and not loaded when the loading member is in its inoperative position, wherein when the third biasing means is loaded it exerts a biasing force which is sufficient to displace the loading member to its inoperative position and the bolt to its forward position. There is yet further provided for the lock arrangement to include retaining means for engaging and retaining the retracting member in a position wherein the bolt is in its forward position and prevented from being displaced to its retracted position. The retaining means may comprise a retaining pin which is displaceable between an engaged position wherein the retaining pin engages a retaining slot in the retracting member and a disengaged position wherein the retaining pin is withdrawn from the retaining slot and the bolt is permitted to be displaced to its retracted position. The lock arrangement may also include fourth biasing means for biasing the selector means to its first position. The fourth biasing means may comprise a fourth coil spring.

The lock arrangement may further include an actuator for displacing the selector means between its first and second positions. The actuator may be operated by means of at least one or more of electrically, mechanically, remotely. The actuator may comprise at least one or more of a solenoid, servo motor, magnet, key latch, and the like. The adjacent body may comprise a barrier frame, part of a wall, or the like. The barrier may comprise a door or a gate.

The loading member may comprise a link and a loading arm protruding therefrom, the loading arm having a tapered end portion. The selector means may be a selector plate.

These and other features of the invention are described in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described below, by way of non-limiting examples only and with reference to the accompanying drawings in which: figure 1 is a schematic perspective view of a lock arrangement fitted to a barrier in accordance with a first embodiment of the invention; figure 2 is a schematic perspective view of the lock arrangement of figure 1 engaging a socket in an adjacent body; figure 3 is a schematic plan view of the lock arrangement only shown in figure

1 , with part of its housing removed, wherein a bolt is in a forward position, a loading member in an inoperative position, and a selector means in a first position; figure 4 is a similar view to that shown in figure 3, wherein the bolt is in a partially retracted position and the loading member in a partially operative position; figure 5 is a schematic perspective view of the lock arrangement as shown in figure 4; figure 6 is a similar view to that shown in figure 3, wherein the bolt is in a forward position and the loading member in an operative position; figure 7 is a similar view to that shown in figure 6, wherein the selector means is in a second position; figure 8 is a similar view to that of figure 7, wherein the bolt in a retracted position; figure 9 is a similar view to that of figure 3, according to a second embodiment of the invention; figure 10 is a similar view to that of figure 3, according to a third embodiment of the invention; and figure 11 is a similar view to that of figure 3, according to a fourth embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the drawings, in which like numerals refer to like features, a lock arrangement according to a first embodiment of the invention is generally indicated by reference numeral 10A in figures 1 to 8, a lock arrangement according to a second embodiment of the invention is generally indicated by reference numeral 10B in figure 9, a lock arrangement according to a third embodiment of the invention is generally indicated by reference numeral 10C in figure 10, and a lock arrangement according to a fourth embodiment of the invention is generally indicated by reference numeral 10D in figure 11.

Referring firstly to figures 1 and 2, the lock arrangement 10A for securing a barrier 12, such as a swing door or gate, to an adjacent body 14, such as a barrier frame or part of a wall, comprises a housing 16 which is attached to the barrier 12 and a bolt 18 displaceable relative to the housing 16 between a forward position, wherein the bolt 18 is engageable with a socket 20 in the adjacent body 14, and a retracted position wherein the bolt 18 is not engageable with the socket 20 and retracted into the housing 16, in use. A first free end of the bolt 18 is tapered which facilitate displacement of the bolt 18 from its forward position to its retracted position, upon connection of the bolt 18 with the adjacent body 14, in use.

Turning now to figures 3 to 8, which show the lock arrangement 10A with part of the housing 16 removed to reveal its interior, the lock arrangement 10A also includes first biasing means 22 for biasing the bolt 18 to its retracted position. A loading member 24 is provided for activating and loading the first biasing means 22 whereby a biasing force exerted by it is increased. The loading member 24 is displaceable between an operative position in which the first biasing means 22 is fully loaded and an inoperative position in which the first biasing means 22 is not or partially loaded. When fully loaded, the first biasing means 22 exerts a biasing force which is sufficient to displace the bolt 18 to its retracted position. The loading member 24 comprises a link 26 and a loading arm 28 protruding from the link 26, the loading arm 28 having a tapered free end which facilitates displacement of the loading member 24 from its inoperative position to its operative position upon connection thereof with the adjacent body 14.

Selector means 30 in the form of a selector plate engages the first biasing means 22 and is displaceable between a first position in which the first biasing means 22 is prevented from displacing the bolt 18 to its retracted position, and a second position in which the first biasing means 22 is permitted to displace the bolt 18 to its retracted position.

The lock arrangement 10 also includes an elongate retracting member 32 or casing having a first end 34 which is attached to the bolt 18 so to be displaceable with the bolt 18, and an opposing second end 36.

The first biasing means 22 has a first end 38 which is connected to the link 26 and an opposing second end 40 which engages the selector means 30. The first biasing means 22 further comprises a first coil compression spring 42, a first rod 44 and a first tube 46, wherein the first tube 46 is located within the first coil spring 42 and telescopically movable over the first rod 44. The first biasing means 22 also includes at its second end 40 a first block 48 and a first pin 50 protruding laterally from the first block 48. Second biasing means 52 is provided for biasing the bolt 18 to its forward position. The second biasing means 52 is fully loaded when the bolt 18 is in its retracted position and not or partially loaded when the bolt 18 is in its forward position. When fully loaded, the second biasing means 52 exerts a biasing force which is sufficient to displace the bolt 18 to its forward position.

The second biasing means 52 comprises a first end 54 which is connected to the selector means 30, and an opposite second end 56 which is connected to the bolt 18. The second biasing means 52 further comprises a second coil compression spring 58, a second rod 60 and a second tube 62, wherein the second tube 62 is located within the second coil spring 58 and telescopically movable over the second rod 60. The second biasing means 52 also includes at its first end 54 a second block 64 and a second pin 66 protruding laterally from the second block 64. The selector means 30 includes first and second guide means 68 and 70 in the form of two l-shaped guide slots. The first guide means 68 engages and guides the first pin 50 between a position in which the bolt 18 is forward (shown in figures 3, 6 and 7) and the first biasing means 22 is loaded, and a position in which the bolt 18 is retracted and the first biasing means 22 is not loaded (shown in figure 8). Similarly, the second guide means 70 engages and guides the second pin 66 so that the second biasing means 52 is displaceable with the bolt 18 (see figures 6 to 8).

Referring particularly to figure 3, the lock arrangement 0A further includes third biasing means 72, portions of which are shown in hidden detail, for biasing the loading member 24 to its inoperative position and the bolt 18 to its forward position. The third biasing means 72 is fully loaded when the loading member 24 is in its operative position and not or partially loaded when the loading member 24 is in its inoperative position. When fully loaded, the third biasing means 72 exerts a biasing force which is sufficient to displace the loading member 24 to its inoperative position and the bolt 18 to its forward position. The first, second and third biasing means 22, 52 and 72 are located adjacent and extend in directions which are substantially parallel to each other.

The third biasing means 72 comprises a third coil compression spring 74, a third rod 76 and a third tube 78, wherein the third tube 78 is located within the third coil spring 74 and telescopically movable over the third rod 76. The third biasing means 72 further includes a first end 80 and an opposing second end 82 which is connected to the link 26. The first end 80 is retained in position by it resting against the housing 16 by it including a collar 84 which is attached to the third rod 76 which presses against an inside of the housing 16.

Even though the second biasing means 52 is sandwiched between the first and third biasing means 22 and 72, it is important to note that the second end 56 of the second biasing means 52 is free to move independent of the link 26, as it is connected to the bolt 8, and not the link 26. The link 26 has an opening (not shown) through which the second biasing means 52 extends between the bolt 18 and the selector means 30.

Referring now particularly to figure 5, retaining means in the form of a retaining pin 86 and a retaining slot 88 in the retracting member 32 is provided for retaining the retracting member 32 in a position wherein the bolt 18 is in its forward position and is prevented from being displaced to its retracted position. The retaining pin 86 is displaceable between an engaged position wherein it engages the retaining slot 88 to retain the retracting member 32 in position, and a disengaged position wherein it is withdrawn from the retaining slot 88 and the bolt 18 is permitted to be displaced to its retracted position.

A cam formation 90 is associated and movable with the retaining pin 86 and causes the retaining pin 86 to retract from the retaining slot 88 when it connects with a lifting pin 92 which is associated and movable with the loading member 24. Therefore, with the lock arrangement 10A in a position as illustrated in figures 4 and 5, retraction of the bolt 18 causes the lifting pin 92 to engage the cam formation 90, causing the retaining pin 86 to lift and retract from the retaining slot 88, thus permitting the bolt 18 to retract fully before it engages the socket 20.

Fourth biasing means 94 in the form of a fourth coil compression spring is provided for biasing the selector means 30 to its first position, in a direction perpendicular to the orientation of the first, second and third biasing means 22, 52 and 72. A first actuator 96, in the form of an electrically operated solenoid is mounted onto the housing 16 for regulating displacement of the selector means 30 from its first to its second positions. The first actuator 96 includes a linearly movable actuating pin 98 which is interconnected to the selector means 30 via a u-shaped lifting arm 100, and an actuating compression spring 102 positioned around the actuating pin 98 for biasing the lifting arm 100 to a position in which the selector means 30 is in its second position. The first actuator 96 holds the selector means 30 in its first position against a biasing force of the actuating spring 102. It should be appreciated that this arrangement ensures that the lock arrangement 10A is in a fail-safe mode, in which the bolt 18 is able to retract, should a power failure occurs. The biasing force exerted by the actuating spring 102 is greater than that exerted by the fourth biasing means 94. It should be further appreciated that the first actuator 96 could be operated in any way, for example, by means of wirelessly, keypad, password, biometrics, and the like. It is envisaged that the first actuator 96 could also comprise a servo motor, magnet, or the like.

A second actuator 96, in the form of a mechanically operated lock having a pivotally movable key latch 106 is also mounted onto the housing 16 for regulating displacement of the selector means 30 from its first to its second positions. The key latch 106 engages an aperture (not shown) in the lifting arm 100 for displacing the lifting arm 100.

In use, the lock arrangement 0A is mounted to the barrier 12 by using suitable fasteners such as, for example, bolts 108 so that the tapered portions of the bolt 18 and loading member 24 extend from the housing 12, as shown in figure 1 , when the lock arrangement 10A is not in operation.

The operation of the lock arrangement 10A will now be further described with reference to figures 3 to 8, which show a step-by-step approximation of the various stages of the lock arrangement 10A and the positions of its components, in use, and how these components interact with each other. In these figures part of the housing 16 is not shown and the barrier 12 and adjacent body 14 are also not shown.

Referring firstly to figure 3, the lock arrangement 10A is in a position similar to that shown in figure 1 , wherein the lock arrangement 10A does not in operation and does not engage the adjacent body 14. The bolt 18 and loading member 24 protrude from the housing 16 and are in their respective forward and inoperative positions. The first, second and third biasing means 22, 52 and 72 are not or only partially loaded. The retaining pin 86 (see figure 5) is seated in the retaining slot 88 (see figure 5).

As the lock arrangement 10A moves towards the adjacent body 14 and engages it, as illustrated in figure 4, the tapered portions of the bolt 18 and loading member 24 cause the bolt 18 and loading member 24 to retract towards their respective retracted and operative positions which load the first, second and third biasing means 22, 52 and 72. Movement of the loading member 24 causes the lifting pin 92 to push against the cam formation 90, causing it to lift and retract the retaining pin 86 from the retaining slot 88. The retracting member 32 is now freely dispiaceable with the bolt 18. When the lock arrangement 10A fully engages the adjacent body 14, as shown in figure 2, the bolt 18 aligns with the socket 20 and is allowed to move to its forward position under the influence of the biasing force exerted by the second biasing means 52, causing the second biasing means 52 to extend and only be partially loaded. The positions of the various components with the lock arrangement 10A in this position are shown in figure 6. The socket 20 is dimensioned to only accommodate the bolt 18, and as a result the loading member 24, which is positioned adjacent the bolt 18, is not permitted to return to its inoperative position. Its actual position is indicated in broken lines. The loading member 24 presses against the adjacent body 14 to keep it in its operative position, wherein the first and third biasing means 22 and 72 are loaded. With the bolt 18 in its forward position, the retaining pin 86 is again seated in the retaining slot 88, thus preventing movement of the bolt 18 to its retracted position. In this position, the lock arrangement 10A secures the barrier 12 in a closed position. When the barrier 12 is to be opened, an authorised user activates either the first or second actuator 96 or 104, causing the selector means 30 to lift from its first position to its second position, as shown in figure 7. In lifting the selector means 30, the retaining pin 86 is retracted from the retaining slot 88. The first biasing means 22 is configured such that under the influence of the biasing force exerted by it, the bolt 18 is caused to displace to its retracted position. This is achieved by the second end 40 of the first biasing means 22 and the first end 54 of the second biasing means 52 now being free to move to their left as a result of the aforementioned displacement of the selector means 30. The second end 40 of the first biasing means engages the second end 36 of the retracting member 32 and under the influence of its biasing force, causes the retracting member 32 to displace to a position in which the bolt 18 is retracted, as illustrated in figure 8. Since the loading member 24 presses against the adjacent body 14, the link 26 is prevented from moving in a direction towards the bolt 18. The barrier 12 is now free to be opened. In this position, only the third biasing means 72 is loaded, but is prevented from moving the link 26 as the loading member 24 still presses against the adjacent body 14.

It should be appreciated that it is only necessary to activate the actuators 98 or 104 for a limited time only to affect displacement of the selector means 30, and when the actuators 98 or 104 are deactivated, the biasing force of the fourth biasing means 94 urges the selector means 30 to its first position. The selector means 30 is, however, prevented from returning to its first position as a result of the shape of the l-shaped guide slots 68 and 70. As the barrier 12 is opened and the lock arrangement 10A displaces from the adjacent body 14, both the bolt 18 and the loading member 24 return to their respective forward and inoperative positions under the influence of the biasing force of the third biasing means 72 imparted onto the link 26. The lock arrangement 10A will then return to its configuration shown in figure 3, wherein the selector means 30 returns to its first position.

According to a second embodiment of the invention, shown in figure 9, the lock arrangement 10B is similar to the lock arrangement 10A discussed above, save for the selector means 30 being wider and having roller slots 110 for receiving rollers 112 which are secured to the housing 16. The rollers 112 reduce friction that might arise between the internal components of the lock arrangement 10B, especially between the selector means 30 and the retracting member 32.

According to a third embodiment of the invention, shown in figure 10, the lock arrangement 10C is similar to the lock arrangement 0A discussed above, save for the first actuator 96 turned upside-down. This shows and arrangement wherein the lock arrangement 10C operates in a fail-secure mode, wherein the actuating spring 102 biases the selector means 30 to its first position when a power outage occurs. It should be appreciated that the second actuator 104 (not shown) could also be included in this arrangement of the lock arrangement 10C.

According to a fourth embodiment of the invention, shown in figure 11 , the lock arrangement 10D is similar to the lock arrangement 10A discussed above, save for the omission of the first actuator 96, thus making the lock arrangement 10D only manually operatable. The lifting arm 92 is also shortened to be l-shaped.

It is envisaged that any hand operated extension or device (not shown) could be attached to a paddle 114 which extends from a lower end of the selector means 30. Such hand operated device could be used for displacing the selector means 30 between its first and second positions from an inside of the barrier 12.

It is further envisaged that the lock arrangements 10A to 10D disclosed herein are robust, easy and safe to operate, and will not fail or jam easily. The inclusion of the retaining pin 86 and slot 88 ensures that the bolt 18 is not retractable when the lock arrangements 10A to 10D are in a locked position, unless the selector means 30 is caused to be displaced, as explained above. This is especially useful for when the lock arrangements 10A to 10D are used on vehicles and centrifugal forces urge the bolt 18 to its retracted position. Furthermore, at least some of the embodiments of the lock arrangements 10A to 10 could be installed where a fail-safe mode of operation is required, and at least some of the embodiments of the lock arrangements 10A to 10 could be installed where a fail-secure mode of operation is required.

It will be appreciated by those skilled in the art that this invention is not limited to the precise details as described herein and that many variations are possible without departing from the scope of the invention. For example, in the embodiment illustrated above the lock arrangements 10A to 10D are mounted onto as side of the barrier 12, however, it is envisaged that the lock arrangements 10A to 10D could also be adapted so to be seatable in a recess in the barrier 12.

It will further be appreciated that the foregoing examples have been provided merely for the purposes of explanation and is in no way to be construed as limiting of the present invention. While the present invention has been described with reference to exemplary embodiments only, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. The present invention is also not intended to be limited to the particulars disclosed herein. Rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the invention.