AU2009202580A1 - A lock assembly - Google Patents

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: TNBT HOLDINGS PTY LTD Actual Inventors: DANIEL MASCIA AND BILL SIMS Address for Service: Chrysiliou Law Patent and Trade Mark Attorneys 114-115/Biztek, 20 Dale Street Brookvale NSW 2100 Invention Title: A Lock Assembly The following statement is a full description of this invention, including the best method of performing it known to me/us: \\serve\c\docs\patents\applicauons\18482.docpy 18482 2 A Lock Assembly Technical Field The present invention relates broadly to a lock assembly. More particularly, the invention relates to a lock assembly capable of converting between different s operating modes. Background Art Lock assemblies of known types are generally capable of operating in only one mode. For example, a cupboard lock may operate in "snap-lock", "key retained" or "key open and closed mode". At present, it is generally necessary to provide such 10 a lock in these separate versions, including a lock cylinder and housing. This is disadvantageous in that it requires a large inventory of hardware and components. To convert from one mode to another, it is generally necessary to replace the whole lock assembly in one mode with a lock assembly in the desired mode. The present invention aims to overcome or alleviate such problems encountered is with prior art lock assemblies. Summary of the Invention According to one aspect of the present invention there is provided a lock assembly including: a lock cylinder operable by a key and rotatable within a lock barrel, the lock barrel 20 being movable within a housing between at least first and second positions; a replaceable cam adapted to operatively engage the lock cylinder; and a replaceable member adapted to cooperate with the replaceable cam; 2 18482 3 wherein the replaceable member is configured and arranged such that rotational movement of the replaceable cam is selectively allowed when the lock barrel moves to the first or second position within the housing. The lock assembly of the invention may be suitable for a range of uses. For 5 example, the lock assembly may be used as a cupboard lock, a door such as a sliding patio door lock or a showcase lock. Examples of them are given in connection with the drawings, below, but the invention is not limited to these. The lock cylinder is preferably a known pin tumbler type which includes a key slot for operation by a key. Alternatively, the lock cylinder may be in a disk or any 10 other suitable form. It is preferred that the key slot is adapted to rotate in use between a substantially vertical position and a position at approximately 45* to the vertical. Optionally other angles may be chosen. The lock cylinder may take other forms, such as a disk lock, for example. The lock barrel may be fully or partially received within the housing in one of the 15 positions. Preferably, the lock bearing is fully received within the housing in one of the positions. The lock barrel is preferable movable longitudinally within the housing between the first position where the lock barrel is substantially encased to the second position where at least part of the lock barrel projects out of the housing. 20 Preferably the lock assembly includes a first biasing means adapted to urge the lock barrel to the position where at least part of the lock barrel projects out of the housing. More preferably the lock assembly includes a closure adapted to be detachably connected to the housing for entrapment of the lock barrel. The first biasing means may be adapted to engage the lock barrel at one end and the closure 25 at another end. 3 18482 4 Preferably the replaceable cam may be rotated between a first cam position and a second cam position. More preferably, the replaceable cam may be chosen from one of two versions: a first version wherein the cam is adapted to rotate in concert with the lock 5 cylinder; and a second version wherein the cam includes means such as a recess so configured as to enable rotation of the cam independently of the lock cylinder. The cam in the second version may be biased by a second biasing means which is connected at one end to the cam and at another end to the lock barrel. The cam may include means io such as a protuberance adapted to facilitate locking and unlocking of a latch or other element via the lock assembly. In a preferred embodiment, the cam is adapted to operatively engage the lock cylinder. In the first version, the cam may be configured such that rotation of the cam corresponds to that of the lock cylinder. In the second version the cam may be 15 configured such that rotation of the lock cylinder in one direction does not result in corresponding movement of the cam. The replaceable member may be chosen from one of two versions: a first version wherein the replaceable member provides a first means such as a hollow so as to allow rotational movement of the cam when the lock barrel moves 20 to at least one of the first or second positions; and a second version wherein the replaceable member provides the first and a second means such as two hollows so as to allow rotational movement of the cam when the lock barrel is in the first and second positions, respectively. The housing may include an internal wall having retaining means adapted to 25 removably engage the replaceable member. For example, the retaining means may include one or more shoulders adapted to hold the replaceable member. The 4 18482 5 retaining means may also include a further shoulder configured to engage the protuberance so as to prevent the lock barrel from escaping the housing. Preferably, the lock assembly is capable of converting between at least two out of three operating modes by way of replacement of the replaceable cam and/or the a replaceable member: a first operating mode wherein the cam and member are chosen such that insertion of the key into the lock cylinder is required to rotate the cam between the first (unlocked) and the second (locked) position (often referred to as "key open and close mode"); 10 a second operating mode wherein the cam and member are chosen such that the inserted key is retrievable only when the key slot is rotated to a selected position. Preferably the selected position is the vertical position (often referred to as "key retained mode"); and a third operating mode wherein the cam and member are chosen such that 15 the cam is able to rotate from the first (unlocked) to the second (locked) position without insertion of the key (often referred to as "snap lock mode"). Most preferably the lock assembly is capable of converting between the three operating modes. For convenience, the first and second positions above generally refer to unlocked 20 and locked positions, respectively. These references however are not intended to be restrictive. In one preferred embodiment, the lock assembly is adapted to be installed in an interface of an object and to be operable from one side only of the interface. The object may include a showcase, drawer or cupboard, in each of which case the 25 interface, such as a showcase, drawer or cupboard panel, acts as a barrier preventing access to the interior of the showcase, drawer or cupboard. As such, the 5 18482 6 lock assembly may be operable only from outside the showcase, drawer or cupboard. In another preferred embodiment, the object may include a door such as a sliding patio door. The lock barrel may include a movable elongate element adapted for 5 engaging and disengaging another object to achieve locking and unlocking. The movable elongate element may be configured to be held at a predetermined location by the lock barrel when the lock barrel moves to the position where it is substantially encased within the housing. The movable elongate element may include a third biasing means. Preferably the third biasing means is operatively 10 connected to the lock barrel and adapted to urge the movable elongate element from the predetermined location to another predetermined location. The movable elongate element may include a bolt. Especially in connection with the selected preferred embodiments referred to immediately above such as those (generally referred to as patio bolt locks) for 1s application on a patio sliding door, it is preferred that the lock barrel provides a mechanism whereby the lock barrel is capable of being operated from the other side of the interface. The mechanism may include a means for facilitating rotation of the replaceable cam independently of the lock cylinder. The means may include an extension stemming from the cam and engagable by a tool. 20 Brief Description of the Drawings In order to achieve a better understanding of the nature of the present invention, non-limiting preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded view of a first embodiment of a lock assembly of 25 the present invention; 6 18482 7 Figure 2 is a side view of most of the lock assembly of Figure 1 in assembled form, in locked configuration; Figure 3 is a side view corresponding to that of Figure 2 but in unlocked configuration with the lock barrel being partially projected out of the 5 housing; Figure 4 is an end view of an embodiment of a cam disposed in locked position relative to a cylinder of the lock assembly of Figure 1; Figure 5 is an end view of the cam of Figure 4 disposed in unlocked position; 10 Figure 6 is an exploded view from the back of some of the components of the first embodiment; Figure 7 is an exploded view corresponding to that of Figure 6 but from the front; Figure 8 is a perspective view from behind the housing of the first 1s embodiment; Figure 9a is a perspective view of an embodiment of a replaceable member of the lock assembly of Figure 1; Figure 9b is a perspective view of another embodiment of a replaceable member; 20 Figure 1 Oa is a perspective view corresponding to that of Figure 2 but partly broken away; Figure l0b is a perspective view corresponding to that of Figure 3, partly broken away; 7 18482 8 Figure 11 is an end view of another embodiment of a cam disposed in an unlocked position relative to the lock barrel; Figure 12 is an end view of the cam of Figure 11 in a locked position; Figure 13 is an exploded view from the back showing the first embodiment 5 in a different mode, with the cam of Figure 11; Figure 14 is an exploded view corresponding to that of Figure 13, but from the front; Figure 15 is an exploded view of the first embodiment in yet another mode with the replaceable member of Figure 9b; 10 Figure 16 is an exploded view of a second embodiment of the lock assembly of the present invention; Figure 17 is a side elevation of the second embodiment disposed in a projected position relative to the housing; Figure 18 is a side elevation corresponding to that of Figure 17 but with the 1s lock barrel disposed in an encased position; Figure 19 is an end view showing an embodiment of a cam assembled in the second embodiment; Figure 20 is an exploded view from the back of some of the components of the second embodiment with the cam of Figure 19; 20 Figure 21 is an exploded view corresponding to that of Figure 20 but from the front; Figure 22 is a perspective view showing the arrangement of an embodiment of a replaceable member and a housing of the second embodiment; 8 18482 9 Figure 23a is a perspective view of the replaceable member of Figure 22; Figure 23b is a perspective view of another embodiment of a replaceable member; Figure 24 is an exploded view showing the second embodiment with the 5 replaceable member of Figure 23b; Figure 25 is a perspective view corresponding to that of Figure 17 but partly broken away; Figure 26 is a perspective view corresponding to that of Figure 17 but partly broken away with the lock barrel disposed in an encased position; 10 Figure 27 is an end view of another embodiment of a cam; Figure 28 is an exploded view from the back showing the second embodiment in a different mode, with the cam of Figure 27; Figure 29 is an exploded view corresponding to that of Figure 28 but from the front; 15 Figure 30 is an exploded view corresponding to that of Figure 16 with the replaceable member of Figure 23b; Figure 31 is a perspective view of a third embodiment of the present invention; Figure 32 is an end view showing an embodiment of a cam assembled in the 20 third embodiment; Figure 33 is a perspective view of a housing of the lock assembly of Figure 31; Figure 34 is a bracket of the lock assembly of Figure 31; 9 18482 10 Figure 35 is a cross sectional view of the housing of Figure 33 in engagement with the bracket of Figure 34; Figure 36 is a side elevation of the bracket of Figure 34 in engagement with a first embodiment of a bolt; 5 Figure 37 is a perspective view of an impediment of the third embodiment of the lock assembly; Figure 38 is a perspective view of the bolt of Figure 36; Figure 39 is a perspective view of a second embodiment of the bolt of Figure 38; 10 Figure 40 is a perspective view from the bottom corresponding to that of Figure 31 with the bolt of Figure 39; Figure 41 is the bottom view corresponding to that of Figure 31 with the bolt of Figure 39; and Figure 42 is the front view corresponding to that of Figure 31 with the bolt 15 of Figure 39. Detailed Description It will be appreciated that the lock assembly of the present invention may be installed in different objects for different purposes. The lock assembly includes a lock cylinder and a housing. By way of example, three types of housings will be 20 described below for application on a showcase, a drawer or cupboard, and a patio sliding door, respectively. In a general sense, the lock assembly of the present invention may be mounted in customised housings to be applied to different fixtures. Each of the three exemplified types of lock assembly is capable of operating in three different modes which will be discussed in turn below. 10 18482 11 Example 1 This example of a lock assembly of the present invention is most suitable for installation in a showcase. The lock assembly includes a replaceable cam and a replaceable member. Depending on the operating mode, both the replaceable s member and cam may be chosen from one of two versions. Mode 1 (Key Open and Closed Mode) As shown in Figure 1, there is a lock assembly generally referenced 1 including a lock cylinder 10, a lock barrel 12 and a housing 14. The lock cylinder 10 is operable by a key (not shown) and rotatable within the lock barrel 12. The lock 10 barrel 12 is movable within the housing 14 between two positions. For ease of reference, the positions are herein referred to as locked (first) and unlocked (second) positions. The lock assembly 1 also includes a replaceable cam 16A and a replaceable member 18A. The replaceable cam 16A is adapted to operatively engage the lock cylinder 10 whilst the replaceable member 18A is adapted to co 1s operate with the replaceable cam 16A. It should be noted that the lock cylinder 10 is a known pin tumbler type which includes a key slot 11 for operation by a key (not shown). The key slot 11 is adapted to rotate between a substantially vertical position and a position at approximately 450 to the vertical. It is anticipated that other angles may be chosen 20 to suit various designs of the lock assembly 1. Referring to Figures 2 and 3, the lock barrel 12 is shown as fully received within the housing 14 in Figure 2 and partially received within the housing 14 in Figure 3. The lock barrel 12 is moveable longitudinally within the housing 14 between the first (locked) position where the lock barrel 12 is substantially encased (as 25 illustrated in Figure 2) to the second (unlocked) position where part of the lock barrel 12 projects out of the housing 14 (as illustrated in Figure 3). The lock assembly 1 also includes a biasing means 20 adapted to urge the lock barrel 12 11 18482 12 from the encased (first) position to the projected (second) position. The biasing means 20 is relaxed when the lock barrel 12 is in the projected position and compressed when the lock barrel 12 is fidly encased by the housing 14. Referring back to Figure 1, the lock assembly 1 includes a closure 22 adapted to be s detachably connected to the housing for entrapment of the lock barrel. The biasing means 20 is adapted to engage the lock barrel 12 at one end and the closure 22 at the other end. The closure 22 takes the form of a plate with a step 24. The closure 22 has two apertures 26 and 28 to receive threaded bolts 30, respectively. The closure 22 has a circular recess 32 for accommodating and holding one end of the 10 biasing means 20, and small orifices 34 to receive two small screws 36 and 38. Referring to Figures 4 and 5, the cam 16A is shown in the first and second cam positions respectively. The cam 16A has a waist 40A and a means which in the present embodiment is in the form of a protuberance 42A. The protuberance 42A is moveable within an opening 44 provided in the lock barrel 12. 15 Referring now to Figures 6 and 7, it may be seen that the cam 16A has on one side a boss 46 which engages core 47 of hollow shaft 60. The other side of the cam 16A has a butterfly-shaped profile 50 (being a feature of a C530 cylinder) which is adapted to engage one end of the lock cylinder 10. The end of lock cylinder 10 has a corresponding profile 52 configured to co-operate with the butterfly-shaped 20 profile 50 of the replaceable cam 16A. The profile 52 includes an impediment 54 which is adapted to engage the cam 16A for effecting rotation thereof. The lock cylinder 10 also includes a T-shaped bible 56 complementarily shaped to a corresponding recess 58 provided within the lock barrel 12. 25 A cap 48 is provided for removable connection to the lock barrel 12 thereby securing the cylinder 10 and the cam 16A in place. The cap 48 has an aperture 49 through which the shaft 60 passes. An extension 62 is attached to the shaft 60 by 12 18482 13 means of a threaded section 64. The shaft 60, which moves with the lock barrel 12, is adapted to facilitate actuation of, for example, a latch or the like for effecting locking and unlocking. Upon engagement of the cap 48 with housing 14, the cam 16A is sandwiched between the cylinder 10 and the cap 48. It is apparent from the s profiles 50 and 52 that the cam 16A is adapted to operatively engage the lock cylinder 10. As such, in this embodiment, rotation of the cam 16A corresponds to that of the lock cylinder 10. As best shown in Figure 8, the housing 14 includes an internal wall 76 having retaining means adapted to removably engage the replaceable member 18A. The 10 retaining means in the present embodiment take the form of shoulders 78 adapted to hold the replaceable member 18A in place. The retaining means also include shoulders (not visible) configured to engage the protuberance 42A so as to prevent the lock barrel 12 from escaping the housing 14. As best shown in Figure 1, the housing 14 may be detachably connected to the closure 22 for entrapment of the 1s lock barrel 12. Referring now to Figures 9a and b, as mentioned above, the replaceable member may be chosen from one of two versions 18A and 18B. (Replaceable member 18B will be discussed below under "Mode 2"). The replaceable member 18A includes two curved plates 68A and 70A with plate 68A overlapping plate 70A. The 20 replacement member 18A provides means in the form of two hollows 72A and 80 so as to allow rotational movement of the cam 16A when the lock barrel 12 is in the first and second positions, respectively. Referring back to Figure 3, the lock barrel 12 is disposed in the unlocked position with the bulk of its body projecting out of the housing 14 allowing the 25 protuberance 42 of the cam 16A to fall into the hollow 80 upon rotation of the cam 16A. As shown, the biasing means 20 is in a relaxed position. 13 18482 14 Referring to Figure 2, the lock barrel 12 is forced into a position where it is substantially encased within the housing 14 with the biasing means 20 in compression. The cam 16A is now moved to the rear of the plate 18A enabling the protuberance 42 to fall into the hollow 72A as the cam 16A rotates. As a result of 6 the rotation, the cam 16A is disposed at 45* to the vertical. As shown in Figures 10a & b, the protuberance 42 and the replacement member 18A are in engagement with one another both before and after displacement of the lock barrel 12. It should be appreciated that, in this operating mode, insertion of the key into the 10 lock cylinder 10 is required to rotate the cam 16A between the first (unlocked) and the second (locked) positions and vice versa, hence the description of this mode as being open and closed. Operation of the lock assembly I in this mode is now described. To lock, the key has to be inserted and turned 450 clockwise until it reaches the key stop. The lock 15 barrel 12 is then pushed from the projected (first) position to the encased (second) position with the key inserted. The key is turned 450 anticlockwise until it gets back into the vertical position and may then be retrieved. To unlock, the key has to be inserted and turned 45* clockwise. Once the key is turned, the lock barrel 12 will automatically project out of the housing 14. The key may be turned 450 20 anticlockwise back to the vertical position and then removed. As mentioned above, the lock barrel 12 of the present invention is capable of converting between three operating modes by way of replacement of the replaceable cam 16A and/or the replacement member 18A. To convert from Mode I to Mode 2, replacement of only one component namely the replacement member 25 18A, with replaceable member 18B is required. Mode 2 (Key Retained Mode) 14 18482 15 Referring back to Figures 9a and 9b, it can seen by comparison that the plate 68B (Figure 9b) is significantly longer than plate 68A (Figure 9a). The replaceable member 18B is configured such that it provides a means so as to allow rotational movement of the cam 16A when the lock barrel 12 moves to the first position. The s means in this embodiment is in the form of a hollow 72B. The plate 70 includes a cut-out 74B. It may be appreciated that since the plate 70B of replaceable member 18B does not possess a second hollow equivalent to hollow 80 of member 18A, the cam 16A will be restricted by the end portion 71 B of the plate 68B from rotating when the lock ia barrel 12 is in the projected position. In the present mode, locking involves pushing or sliding the lock barrel 12 from the projected to the encased position within the housing 14 with the key inserted and maintained at an angle of 45*. The key is then turned anticlockwise until it reaches a key stop. By this time, the key is back in the vertical position and may be 15 withdrawn. To unlock, the key has to be inserted and turned 45* clockwise. The lock barrel 23 will automatically project out of the housing 14. The key may then be removed. It is important to note that the inserted key is retrievable only when the key slot is rotated to a selected position. In the present case, the selected position is the 20 vertical position. Mode 3 (Snap Lock Mode) To convert from Mode 1 or 2 to Mode 3, the cam 16A will have to be replaced by cam 16B. Also, replaceable member 18B, which is adapted to cooperate with the cam 16B must be utilised in this mode. 25 Referring to Figures 11 and 12, the butterfly-shaped profile 50 of the second version of the cam 16B has a comparatively long waist 40B. The cam 16B includes 15 18482 16 a recess 82. The existence of the recess 82 means that the impediment 54 stemming from the lock cylinder 10 does not engage the butterfly-shaped profile 50 of the cam 16B as the lock cylinder 10 rotates between the predetermined positions. The recess 82 is so configured as to enable rotation of the cam 16B independently of s the lock cylinder 10. The cam 16B is biased by a biasing means such as a torsion spring 84 (Figure 10). The torsion spring 84 has two ends 86 and 88 (shown in Figure 13). One end 86 of the torsion spring 84 is connected to a depression 90 of the closure 22 of the lock barrel 12 whilst the other end 88 is connected to the cam 16B. In contrast to Mode 1, the cam 16B is configured such that rotation of the io lock cylinder 10 between predetermined positions in a selected direction, namely in this embodiment the anticlockwise direction, does not result in corresponding movement of the cam 16B. Turning now to Figures 13 and 14, the configuration and arrangement of most of the components of the lock assembly 1 in this mode remain substantially the same 15 as those shown in Figures 6 and 7 with the exception that the torsion spring 84 is included to facilitate rotation of the cam 16B. As shown in Figure 15, the cam 16B is inserted in place of cam 16A. As a consequence, the cam 16B in the present mode is able to rotate from the unlocked (first) to the locked (second) position without insertion of the key. 20 Operation of the lock assembly I in this mode will now be described. To effect locking, the lock barrel 12 is pushed into the housing 14 until-the cam 16B is set free to rotate. The cam 16A is restricted by the replaceable member 18A to rotate as the lock barrel 12 moves from the projected (second) position to the encased (first) position. Once the lock barrel 12 reaches the encased (first) position, the cam 25 16B is urged to rotate by the torsional spring 84 resulting in falling of the protuberance 42 into the hollow 72B (Figure 9b). A "click" sound would be heard as this happens. To unlock, the key is inserted and turned 45* clockwise until the biasing means 20 urges the lock barrel 12 to project out of the housing 14. During 16 18482 17 the projection, the key remains at 45* to the vertical. Once the lock barrel 12 is in the projected position, the key may be turned 450 anticlockwise back to the vertical position where it may be withdrawn. Example 2 s As shown in Figures 16 to 25, there is shown a second embodiment of a lock assembly 2 of the present invention applicable to a cupboard or drawer or the like. For ease of reference, like "componentry" of the lock assembly 2 as compared to the lock assembly 1 have been designated with an additional "0". For example, the lock cylinder of the lock barrel is 100. The lock assemblies 1 and 2 are 10 substantially similar in construction and configuration except for the design of the housing and replacement member. Mode 1 (Key Open and Closed Mode) The lock assembly 2 includes a replacement cam and a replacement member, each of which may be chosen from one of two versions. 15 Referring first to Figure 16, there is a lock assembly generally referenced 2 including a lock cylinder 100, a lock barrel 120 and a housing 140. Once again, the lock barrel 120 is moveable within the housing 140 between first and second positions. The lock assembly 2 includes a replaceable cam 160A and a replaceable member 180A. The replaceable cam 160A is adapted to operatively engage the 20 lock cylinder 100 whilst the replacement member 180A is adapted to cooperate with the replaceable cam 160A. The key slot 110 is provided within the lock cylinder 100 being rotatable between a substantially vertical position and a position at approximately 45 degrees to the vertical. A circular rose 92 is provided to mount on the housing 140. 25 Referring to Figures 17 and 18, the lock barrel 120 is partially and fully received within the housing 140, respectively. The lock barrel 120 is moveable 17 18482 18 longitudinally within the housing 140 between a first position where the lock barrel 120 is substantially encased to a second position where part of the lock barrel 120 projects out of the housing 140. The lock barrel 120 also includes a biasing means 200 adapted to urge the lock barrel 120 to the position where part of the lock barrel s 120 projects out of the housing 140. Referring back to Figure 16, the biasing means 200 is adapted to engage the lock barrel 120 at one end and a closure 220 at another end. The closure 220 is in the form of a substantially flat plate adapted to be connected to the housing 140 for entrapment of the lock barrel 120. The features of the closure 220 are substantially similar to those of the closure 22 in 10 example 1 and hence will not be discussed in detail. It should be noted that the housing 140 in the present example has upper and lower flanges 94 and 96 which correspond to the upper and lower portions of the plate 220. Turning now to Figure 19, the cam 160A is shown in the first cam position. The cam 160A has a waist 400A and a protuberance 420A. The protuberance 420A is 15 moveable within an opening 440 provided in the lock barrel 120. Referring to Figures 20 and 21, the cam 160A on one side has a cavity 98. Similar to the cam 16A in Example 1, the other side of the cam 160A has a butterfly shaped profile 500 which engages one end of the lock cylinder 100. The end of lock cylinder 100 has a corresponding profile 520 including two impediments 540 20 adapted to engage the cam 160A. A cap 480 is provided for connection to the lock barrel 120 thereby securing the cylinder 100 and the cam 160A in place. In contrast to the cap 48 in Example 1, the cap 480 includes a shaft 600 and an opening 440. The cam 160A is adapted to operatively engage the lock cylinder 100. As a result, rotation of the cam 160A 25 corresponds to that of the lock cylinder 100. As best shown in Figure 22, the housing 140 includes an internal wall 760 having retaining means adapted to removably engage the replaceable member 180A. The 18 18482 19 retaining means in the present embodiment take the form of shoulder 780 adapted to hold the replaceable member 180A in place. As best shown in Figure 16, the housing 140 may be detatchably connected to the closure 220 for entrapment of the barrel 120. 6 Referring now to Figures 23a and 23b, the replaceable member may be chosen from one of two versions 180a and 180b. (Replaceable member 180B will be discussed below under Mode 2.) The replaceable member 180A provides two means in the form of two hollows 720A and 800 so as to allow rotational movement of the cam 160A when the lock barrel 120 is in the first and second 10 positions, respectively. The replaceable member 180A has a stud 51A which is adapted to engage a corresponding recess (not shown) provided in the internal wall 760 of the housing 140. Referring back to Figure 17, the lock barrel 120 is disposed in the projected position with the bulk of its body projecting out of the housing 140A allowing the 15 protuberance 420A of the cam 160A to be snugly received within the hollow 800 upon rotation of the cam 180A. As shown, the biasing means 200 is in the relaxed position. Referring to Figure 18, the lock barrel 120 is forced into the position where it is substantially encased within the housing 140 with the biasing means 200 in 20 compression. The cam 160A is now moved to a position where the protuberance 420A may fall into the hollow 720B as the cam 160A rotates. It should be appreciated that lock assembly 2 operates in substantially the same way as lock assembly I and hence its operation will not be discussed in detail. Once again, the lock barrel 120 is capable of converting between three operating 25 modes by way of replacement of the replaceable cam 160A and/or the replaceable member 180A. To convert from mode 1 to mode 2, replacement of only one 19 18482 20 component, namely the replaceable member 180A, with replaceable member 180B is required. Mode 2 (Key Retained Mode) Referring to Figures 23a and 23b, it can be seen by comparison that the replaceable 5 cam 180B only provides one hollow 720B. As such, rotational movement of the cam 180B is allowable only when the lock barrel moves to the encased position. In other words, the cam 160B is restricted to rotate when the lock barrel 120 is in the projected (second) position. Referring to Figure 24, it may be seen that the lock assembly 2 in this mode ia involves insertion of the lock barrel 120 into the housing 140 with the replaceable member 180B on the side. A stud SIB on engagement with the corresponding recess (not shown) on the wall 760 of the housing 140 secures the replaceable member 180B in place. Upon engagement of the closure 220 with the housing 140 by means of the screws 300, the shaft 600 extending from the cap 480 protrudes is through the aperture 490. Turning now to Figures 25 and 26, it may be seen that the biasing means 200 is in relaxed and compressed states when the barrel 120 is in the projected and encased positions, respectively. It should be appreciated that the operation of the lock assembly 120 in this mode is 20 substantially the same as that of the corresponding mode of the lock assembly 2 and hence will not be discussed in detail, Mode 3 (Snap Lock Mode) To convert from Mode 1 or 2 to Mode 3, the cam 160A will have to be replaced by cam 160B. Also, replaceable member 180B which is adapted to co-operate with the 25 cam 160B must be utilised in this mode. 20 18482 21 Referring to Figure 27, the configuration of the cam 160B is substantially the same as the cam 16B in Example 1 with the exception that the protuberance 420B is provided in a different position. Turning now to Figures 28 and 29, the configuration and arrangement of most of 5 the components of the lock assembly 2 in this mode remain substantially the same as those shown in Figures 20 and 21 with the exception that the torsion spring 840 is included to facilitate rotation of the cam 160B. As shown in Figure 30, the cam 160B is used in place of cam 160A. The cam 160B in this mode is able to rotate from the unlocked (first) to the locked (second) position by assistance of the 10 torsion spring 840 without insertion of a key. It should be appreciated that the operation of the lock assembly 2 in this mode is substantially the same as that of the corresponding mode of the lock assembly 1 and hence will not be discussed in detail. Example 3 15 As shown in Figure 31, there is a further embodiment of a lock assembly 3 of the present invention applicable to a door such as a patio sliding door. Once again, for ease of reference, like "componentry" of the lock assembly 3 as compared to the lock assemblies 1 and 2 have been designated with two additional "0"s. For example, the lock cylinder of the lock assembly 3 is 1000. 20 The design of the lock barrel 1200 of the lock assembly 3 remains substantially similar to those described in Examples 1 and 2. It should be noted that the lock assembly 3 is also capable of converting between three operating modes by way of replacement of a replaceable cam 1600A or B and/or a replaceable member 1800A or B. 25 Referring now to Figure 32, the rear facing side of the cam 1600A or B is shown having a profile 52 with a knob 55. The knob 55 is adapted to be engageable by a 21 18482 22 suitable tool for effecting rotation of the cam 1600A or B. Operation of the cam 1600A or B from the rear facing side will be discussed below. As shown in Figure 31, the lock barrel 1200 is designed to lock or release a moveable elongate element in the form of a bolt 53 adapted for engaging and 5 disengaging another object (not shown) to effect locking and unlocking. Referring to Figure 33, to accommodate the bolt 53, the design of the housing 1400 is shown having a bracket 57 with a slanting surface 59 (Figure 30). The bracket 57 is configured to engage a corresponding closure 2200 which is shown in Figure 34. The closure 2200 includes two side panels 61 and 63, each having an aperture 65 10 and 67 through which the bolt 53 passes. Connected to each of the panels 61 and 63 is a resilient S-shaped spring clip 69, 71. The housing 2200 also includes an opening 73 and four holes 75. The housing 2200 may be affixed to a patio sliding door (not shown) provided with a vent which corresponds to the opening 73 so as to allow access to the knob 55 from the patio when the sliding door is closed. 15 Turning now to Figure 35, the housing 1400 has two arms 109, each with a hump 77 which is adapted to engage with the spring clip 69 or 71 upon engagement of the bracket 57 with the housing 1400. The housing 1400 has a passageway 79 along which the lock barrel 1200 is adapted to move. The passageway 79 is in communication with the opening 73 enabling exposure of the knob on the rear 20 facing side of the cam 1600A or 1600B. As such, when the sliding door is closed, the cam 1600A or 1600B and hence the lock assembly 3 may be operated from the patio. Although not shown in Figure 35, it should be appreciated that a biasing means such as a spring is provided for urging the lock barrel 1200 from an encased (first) 25 position to a projected (second) position. Furthermore, the housing 1400 includes two cavities 81 and 83 which are adapted to store the replaceable members 1800A and 1800B respectively. This arrangement provides a neat way of storing the 22 18482 23 replaceable members 1800A and 1800B and minimises the risk of the replaceable members 1800A and 1800B being lost when not in use. Turning now to Figure 36, it may be seen that the bolt 53 having passed through apertures 65 and 67 is held in place by retainers 85 and 87 which are releasably 5 attached to the housing 1400. Turning to Figure 37, each retainer 85 or 87 includes a rod 89 extending from an element 91. An extension 93 being biased by a hidden spring (not visible) is telescopically connected to the underside of the element 91. The upper edge 95 of the element is adapted to engage an indent 97 (see Figure 36) provided at two 10 selected locations of the bolt 53 thereby preventing the bolt 53 from slipping out of the bracket 57 under gravity when the lock barrel 1200 is in the projected position. The rod 89 protrudes through and stands proud of the housing 1400 allowing a user to press thereon in order to release the bolt 53. Referring to Figure 38, it may be observed that the bolt 53 includes two depressed 15 regions 101 and 103 adapted to be engaged by part of the lock barrel 1200 when it is in the encased position. The bolt 53 is configured to be held at a predetermined location by the lock barrel 1200 when the lock barrel 1200 moves to the position where it is substantially encased within the housing 1400. Once engaged by the lock barrel 1200 at region 101 or 103, the bolt 53 is held either in a locked position 20 where the end portion of the bolt 53 stands proud of the upper edge of the door engaging another member of the lock assembly 3 which is typically fixed to the door frame, or in an unlocked position where the end portion of the bolt 53 is positioned lower than the upper edge of the door. Turning now to Figure 39, another version of the bolt 53A is shown with depressed 25 indents lOlA and 103A and a lug 99 which is adapted to be biased by a biasing means such as a spring 105. This spring loading mechanism is adapted to enable unlocking (ie. releasing) of the bolt 53A from outside the patio. 23 18482 24 Referring now to Figure 40, it may be appreciated that the bolt 53A may be pushed towards the housing 1400 and locked in place once the lock barrel 1200 is pushed into the encased position (ie. the rear end of the barrel 1200 engaging one of the depressed regions 101 or 103). In this circumstance, the spring 105 is brought into s a compressed state with the lug 99 abutting the external surface 107 of the panel 61. Once the lock barrel 1200 is released into the projected position, the bolt 53 will be urged away from the housing 1400 to a position where the edge 95 of the retainer 85 engages the indent 97 thereby preventing the bolt 53A from dropping out of the bracket 57. 1o Turning now to Figure 41, it may be seen that the user is provided with access from the patio to the cam 1600B. By means of the knob 55, the bolt 53A may be released into the unlocked position. Referring to Figure 42, in order to manually shift or fully retrieve the bolt 53A (or 53B) the user may press on the end of the rod 89A (or 89B). This releases the bolt 15 53A or B to move up and down relative to the bracket 57. As mentioned above, the lock assembly 3 of the present invention is adapted to be installed in the interface of an object. It should be noted that only when the bolt 53A with the spring loading mechanism is applied, the lock assembly 3 is operable from both sides of the interface. In contrast, in Examples I and 2, the object 20 includes a showcase, drawer or cupboard, in which cases the interface acts as a barrier preventing access to the interior of the showcase, drawer or cupboard. As such, the lock assemblies 1 and 2 may be operable only from the outside of the showcase, drawer or cupboard. Now that several preferred embodiments of the present invention have been 25 described in some detail, it will be apparent to those skilled in the art that the lock assemblies have at least the following advantages: 24 18482 25 1. the lock assemblies 1, 2 and 3 require a small inventory of hardware components; 2. the lock assemblies 1, 2 and 3 can be easily and effectively manipulated to convert from one mode to another with a minimum degree of skill and s dexterity. Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. For example, the housing may take other forms adopted for installation of the lock assembly in other objects. The replaceable cams and members need not be limited 10 to the shapes and forms described above. For instance, the cam shown in Figures 6 and 7 may take other shapes and configurations to suit various types of end profiles. All such variations and modifications are to be considered within the scope and spirit of the present invention the nature of which is to be determined from the foregoing description. 25

Claims (19)

1. A lock assembly including: a lock cylinder operable by a key and rotatable within a lock barrel, the lock barrel being movable within a housing between at least first and second 5 positions; a replaceable cam adapted to operatively engage the lock cylinder; and a replaceable member adapted to cooperate with the replaceable cam; wherein the replaceable member is configured and arranged such that rotational movement of the replaceable cam is selectively allowed when the 10 lock barrel moves to the first or second position within the housing.

2. The lock assembly of claim 1, wherein the lock cylinder is a pin tumbler type which includes a key slot for operation by a key, the key slot being adapted to rotate in use between a substantially vertical position and a position at approximately 450 to the vertical. 15 3. The lock assembly of either claim 1 or 2, wherein the lock barrel is movable longitudinally within the housing between the first position where the lock barrel is substantially encased to the second position where at least part of the lock barrel projects out of the housing.

4. The lock assembly of claim 3, which includes a first biasing means adapted 20 to urge the lock barrel to the second position.

5. The lock assembly of any one of the preceding claims, wherein the lock assembly includes a closure adapted to be detachably connected to the housing for entrapment of the lock barrel.

6. The lock assembly of claim 5 when dependent on claim 4, wherein the first 25 biasing means in use engages the lock barrel at one end and the closure at another end. 26 18482 27

7. The lock assembly of any one of the preceding claims, wherein the replaceable cam is rotatable between a first cam position and a second cam position.

8. The lock assembly of any one of the preceding claims, wherein the s replaceable cam is chosen from one of two versions: a first version wherein the cam is adapted to rotate in concert with the lock cylinder; and a second version wherein the cam includes a first means so configured as to enable rotation of the cam independently of the lock cylinder. 10 9. The lock assembly of claim 8, wherein the first means includes a recess.

10. The lock assembly of either of claim 8 or 9, wherein the cam in the second version is biased by a second biasing means which is connected at one end to the cam and at another end to the lock barrel.

11. The lock assembly of any one of claims 8 to 10, wherein the cam includes a 15 second means adapted to facilitate locking and unlocking of a latch or other element via the lock assembly.

12. The lock assembly of claim 11, wherein the second means includes a protuberance.

13. The lock assembly of any one of 8, 9, 10 and 12, wherein in the second 20 version, the cam is configured such that rotation of the lock cylinder in one direction does not result in corresponding movement of the cam.

14. The lock assembly of any one of the preceding claims, wherein the replaceable member is chosen from one of two versions: a first version wherein the replaceable member provides a first means so as 25 to allow rotational movement of the cam when the lock barrel moves to at least one of the first and second positions; and 27 1 482 28 a second version wherein the replaceable member provides the first and a second means so as to allow rotational movement of the cam when the lock barrel is in the first and second positions, respectively.

15. The lock assembly of claim 15, wherein the first means in the first version is s a hollow and the first and second means in the second version are two hollows.

16. The lock assembly of any one of the preceding claims, wherein the housing includes an internal wall having retaining means adapted to removably engage the replaceable member. 10 17. The lock assembly of claim 16, wherein the retaining means includes a shoulder adapted to hold the replaceable member.

18. The lock assembly of claim 17, wherein the retaining means includes a further shoulder configured to engage the protuberance so as to prevent the lock barrel from escaping the housing. 1s 19. The lock assembly of claim 18, wherein the lock assembly is capable of converting between at least two operating modes by way of replacement of the replaceable cam and/or the replaceable member, the two operating modes chosen from: a first operating mode wherein the cam and member are chosen such that 20 insertion of the key into the lock cylinder is required to rotate the cam between the first (unlocked) and the second (locked) position; a second operating mode wherein the cam and member are chosen such that the inserted key is retrievable only when the key slot is rotated to a selected position; and 25 a third operating mode wherein the cam and member are chosen such that the cam is able to rotate from the first (unlocked) to the second (locked) position without insertion of the key. 28 18482 30 elongate element from the predetermined location to another predetermined location.

30. The lock assembly of any one of claims 26 to 29, wherein the movable elongate element includes a bolt. s 31. The lock assembly of any one of claims 25 to 30, wherein the lock barrel provides a mechanism whereby the lock barrel is capable of being operated from the other side of the interface.

32. The lock assembly of claim 31, wherein the mechanism includes a means for facilitating rotation of the replaceable cam independently of the lock 10 cylinder.

33. The lock assembly of claim 32, wherein the means includes an extension stemming from the cam and engagable by a tool.

34. A lock assembly substantially as described herein with reference to any one of the accompanying drawings. 30 18482 29 20. The lock assembly of claim 19, which is capable of converting between first, second and third operating modes. 21. The lock assembly of any one of the preceding claims, which is adapted to be installed in an interface of an object and to be operable from one side 5 only of the interface. 22. The lock assembly of claim 21, wherein the object includes a showcase, drawer or cupboard, in each of which case the interface is adapted to act as a barrier preventing access to the interior of the showcase, drawer or cupboard. 10 23. The lock assembly of claim 22, wherein the interface includes a showcase, drawer or cupboard panel. 24. The lock assembly of either claim 22 or 23, which is operable only from outside the showcase, drawer or cupboard. 25. The lock assembly of claim 21, wherein the object includes a door. 15 26. The lock assembly of claim 25, wherein the lock barrel includes a movable elongate element adapted for engaging and disengaging another object to achieve locking and unlocking. 27. The lock assembly of claim 26, wherein the movable elongate element is configured to be held at a predetermined location by the lock barrel when 20 the lock barrel moves to the position where it is substantially encased within the housing. 28. The lock assembly of claim 27, wherein the movable elongate element includes a third biasing means. 29. The lock assembly of claim 28, wherein the third biasing means is 25 operatively connected to the lock barrel and adapted to urge the movable 29