WO2018152579A1

WO2018152579A1 - A lock assembly with indicator mechanism

Info

Publication number: WO2018152579A1
Application number: PCT/AU2018/050148
Authority: WO
Inventors: Craig Stuart MURRAY; Malila Gabuardi Lopez; Jack Ou
Original assignee: Assa Abloy Australia Pty Ltd
Current assignee: Assa Abloy Australia Pty Ltd
Priority date: 2017-02-22
Filing date: 2018-02-22
Publication date: 2018-08-30
Anticipated expiration: 2019-08-22
Also published as: AU2018223218B2; NZ756441A; AU2018223218A1

Abstract

This invention relates to a lock assembly 1 including a bolt 5 which is movable relative to a housing 3 on operation of an inner actuator 6. A lock mechanism within the housing 3 when active renders the inner actuator 6 inoperable. An indicator mechanism including an indicator member 14 which is visible when the lock mechanism is in the active condition, and the indicator member 14 is movable to an obscured position without adjusting the condition of the lock mechanism.

Description

A LOCK ASSEMBLY WITH INDICATOR MECHANISM Technical Field

[0001 ] This invention relates to a lock assembly including a lock mechanism that is adjustable between an active condition and an inactive condition, and an indicator mechanism including an indicator member that is movable on adjustment of the lock mechanism. The lock assembly may take the form of a rim lock assembly having a housing which is suitable for mounting to a surface of a door or the like, and it will be convenient to hereinafter describe the invention with reference to this form of lock assembly. It should be appreciated however that the invention is suitable for other forms of lock assembly including a mortice lock assembly.

Background of Invention

[0002] A rim lock assembly will generally include a housing, a bolt movable relative to the housing and at least an inner turn knob or lever (hereinafter turn knob) that is rotatable to move the bolt from an extended positions towards a retracted position. A lock mechanism can be included to prevent rotation of the turn knob, in which condition the rim lock assembly is considered to be locked condition. The rim lock assembly may also include an indicator member to provide a visual indication of the condition of the rim lock assembly as locked or unlocked.

[0003] The indicator member may be as simple as a coloured plate that is visible through an opening in the housing. The indicator plate may be located on an element of the lock mechanism that is movable relative to the housing on adjustment of the lock mechanism. One element of the lock mechanism is a detent which is movable to a position in which it provides a physical impediment to the rotation of the turn knob. The applicant is aware of at least one rim lock assembly that has the indicator member located on the detent so as to be visible through the opening in the acting condition. Locating the indictor member on the detent, that is visible through an opening in the housing can render the detent vulnerable to tampering from outside the housing [0004] It would be preferable to provide a lock assembly that was less vulnerable to tampering.

[0005] A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

[0006] According to one aspect of this invention there is provided a lock assembly for use with a door, the lock assembly including a housing, a bolt movable relative to the housing between an extended position and a retracted position, an inner actuator that is operable to move the bolt from the extended position towards the retracted position, a lock mechanism that is adjustable between an active condition and an inactive condition which renders the inner actuator inoperable and operable respectively, an indicator mechanism including an indicator member that is movable relative to the housing between a visible position and an obscured position in which it is visible and obscured from outside the housing respectively, the indicator member being movable from the visible position to the obscured position as a result of adjustment of the lock mechanism from the active condition to the inactive condition, and movable independently of adjustment of the lock mechanism from the visible position towards the obscured position without adjusting the condition of the lock mechanism. Allowing the indicator member to be movable independently of the adjustment of the lock mechanism renders the lock mechanism less vulnerable to tampering by way of adjustment of the position of the indicator member. This type of tampering could occur for example with the prior locks having an opening in the housing with the indicator member located on the detent.

[0007] The indicator mechanism may include an indicator biasing means which urges on the visual indicator member. If a biasing means is included it is preferred that the indicator biasing means urges the visual indicator member towards the visible position, however this may vary. An advantage of this arrangement is that any tampering of the indicator member while in the visible position will be against the action of the biasing means. The indicator member may for example be configured to interact with the housing to be bistable so as to adopt either the visible position or obscured position.

[0008] It is preferred that the indicator mechanism include some form of intermediary element(s) acting between the lock mechanism and the indicator member so as to inhibit tampering of the lock mechanism by the indicator member. This may take any suitable form and one preferred form includes the indicator mechanism including a shuttle that is movable between a first position and a second position, and a shuttle biasing means that urges the shuttle towards the first position, wherein the shuttle interacts between the lock mechanism and the visual indicator member. It is further preferred that the interaction of the shuttle with the lock mechanism is such that the shuttle is movable from the first position towards the second position on adjustment of the lock mechanism from the inactive condition to the active condition. While it is preferred that the shuttle moves linearly between the first position and the second position, and the indicator member moves linearly between the visible position and the obscured position they may alternatively move between these positions along another non-linear path.

[0009] It is also preferred that the indicator biasing means applies a first force on the indicator member and the shuttle biasing means applies a second force on the shuttle, whereby the second force is in a direction opposite to the first force. It is further preferred that the second force is greater than the first force. This arrangement permits movement of the indicator member indirectly under the influence of the shuttle biasing means, without permitting movement of the shuttle under the influence of the indicator biasing means.

[0010] The indicator member may move in any direction between the visible position and the obscured position however in the preferred embodiment it moves in a direction that is parallel with a direction of movement of the bolt between the extended position and the retracted position.

[001 1 ] The housing preferably includes an aperture whereby the indicator member is visible through the aperture when in the visible position. The aperture may be located elsewhere, for example formed in the turn knob, so long as the indicator member can be visible when the user is adjusting the lock assembly. One of the advantages of having the aperture located on the housing, spaced from the turn knob, is that this location reduces the likelihood that the users hand will obscure the aperture.

[0012] The lock assembly may include any form of coded interface for adjusting the condition lock mechanism. The preferred form of interface includes a first key operated lock operable from an inner side of the housing for adjusting the condition of the lock mechanism between the active condition and the inactive condition. However alternatively the lock mechanism may interact with a key pad or an electronic key reader. The preferred embodiment of the key operated lock is a cylinder lock, including a casing and a barrel movable relative to the casing when a correctly coded key is inserted in a keyway of the barrel. It is still further preferred that the barrel is movable by rotating relative to the casing, however the barrel may alternatively move in an axial direction relative to the casing on insertion of the key.

[0013] The lock assembly preferably includes an outer actuator that is operable from an outer side of the housing to move the bolt from the extended position towards the retracted position. It is further preferred that the outer actuator is operable to adjust the condition of the lock mechanism between the active condition and the inactive condition. The outer actuator may take any suitable form, including a key pad or an electronic card reader, however it is preferred that the outer actuator is a second key operated lock. It is further preferred that the second key operated lock is a cylinder lock, including a casing and a barrel movable relative to the casing when a correctly coded key is inserted in a keyway of the barrel. The barrel is preferably movable by rotating relative to the casing, however alternatively the barrel may move axially relative to the casing.

[0014] The lock mechanism preferably includes at least one detent member that is movable relative to the inner actuator on adjustment of the lock mechanism between the active condition and the inactive condition. In the preferred embodiment the lock mechanism includes two detents however this may vary. It is preferred that the inner actuator is operable by rotation about an axis, and the detent, or each detent, is movable in a radial direction relative to the axis. It is preferred that the lock mechanism includes a drive member that interacts with the at least one detent and is movable relative to the housing on adjustment of the lock mechanism between the active condition and the inactive condition. Whilst the preferred embodiment of the lock assembly includes the drive member moving linearly to adjust the position of the detent(s), the drive member may move in some other manner. The drive member may, for example, relate to adjust the position of the detent(s).

[0015] The lock assembly is suitable for any form of bolt however the preferred embodiment includes a bolt biasing means for biasing the bolt towards the extended position, and more preferably the bolt includes a bevelled leading face, often referred to as a latch bolt. The preferred embodiment of the lock assembly is a rim lock assembly, however the invention may also apply to other forms of lock assembly.

[0016] A preferred embodiment of a lock assembly will be herein after described in greater detail by reference to the accompanying drawings. The detailed description and drawings are merely illustrative of how the invention might be put into effect so that the specific form and arrangement of the various features, as described and illustrated is not to be understood as limiting on the invention. Brief Description of Drawings

[0017] Figure 1 is a diagrammatic isometric view of a preferred embodiment of the lock assembly when installed according to this invention.

[0018] Figure 2 is an exploded isometric view of a preferred embodiment of the lock assembly according to the invention. [0019] Figure 3 is a rear elevation view of the lock assembly with at least the backing plate removed to reveal the bolt in an extended position.

[0020] Figure 4 is a rear elevation view of the lock assembly from Figure 3 with the bolt moved to retract a position on operation of the outer cam. [0021 ] Figure 5 is a rear elevation view of the lock assembly with the backing plate removed to reveal the bolt in an extended position.

[0022] Figure 6 is a rear elevation view of the lock assembly from Figure 5 with the bolt moved to a retracted position on operation of the inner cam. [0023] Figure 7 is a rear elevation view of the lock assembly with the backing plate and bolt removed to reveal the lock mechanism in an active condition.

[0024] Figure 8 is a rear elevation view of the lock assembly from Figure 7 with the lock mechanism having been adjusted by the outer cam to adopt an inactive condition.

[0025] Figure 9 is a rear elevation view of the lock assembly with a backing plate and bolt removed to reveal the locking mechanism in an active condition.

[0026] Figure 10 is a rear elevation view of the lock assembly from Figure 9 with the lock mechanism having been adjusted to an inactive condition on operation of a cylinder cam.

[0027] Figure 1 1 is a cross-sectional view through XI-XI of Figure 9.

[0028] Figure 12 is a cross-sectional view through XII-XII of Figure 1 1 .

[0029] Figure 13 is a cross-sectional view of Figure 1 1 with the indicator member being tampered with. Detailed Description

[0030] Figure 1 illustrates a lock assembly 1 according to a preferred embodiment of the invention when installed on a door 2. The lock assembly includes a housing 3 which is attached to an inner side of the door and positioned adjacent a free edge 4 of the door 2. The look assembly 1 includes a bolt 5 which projects to one side of the housing 3 when the bolt 5 is in an extended position as shown. The housing 3 is positioned relative to the edge 4 of the door 2 so that when the bolt 5 is in the extended position it is capable of interacting with a strike (not shown) which in use is fixed on a door jam (not shown) for retaining the door 2 in a closed position. The lock assembly 1 includes an inner actuator 6 and an outer actuator 7 each of which is operable in a manner that will be described later in the specification, for moving the bolt 5 from the extended position as shown towards a retracted position. The inner actuator 6 illustrated includes a turn knob 8 which is rotatable about an actuation axis X-X so as to retract the bolt 5. The turn knob 8 illustrated can be substituted by a lever handle (not shown) if preferred. In contrast the outer actuator 7 illustrated is in the form of a key operated cylinder lock 9 which includes a barrel 10 being rotatable relative to a casing 1 1 about the actuation X-X, on insertion of appropriately coded key 12.

[0031 ] Figure 1 also illustrates the housing 3 having an aperture 13 positioned proximate the bolt 5. Whilst the location of the aperture 13 may vary from that as illustrated, to be located for example on the turn knob 8, the function of the aperture is to provide a viewing window through which an indicator member 14 (see Figure 2) can be made visible. The manner in which the indicator member achieves this will be described in greater detail with reference to later illustrations. The lock assembly illustrated in Figure 1 may be described as a rim lock assembly.

[0032] Referring now to Figure 2, which illustrates a specific form of the outer actuator 7 including the cylinder lock casing 1 1 with a tumbler bible 15 orientated substantially vertically. A tail bar 16 is positioned to engage with a barrel 10 of the cylinder lock 1 1 . The length of a tail bar 16 may vary from that illustrated depending upon the thickness of the door 2 (See Figure 1 ) to which the lock assembly 1 is installed. When installed the tail bar 16 extends through a central aperture 17 formed in a backing plate 18 to engage with an outer cam 19 which is rotatable about the actuator axis X-X on rotation of the tail bar 16. It should be noted from Figure 2 that the outer cam 19 includes an axially extending projection 20 spaced radially from the centre of the outer cam 19. This projection is positioned to interact with the bolt 5, or more specifically the bolt frame 21 when moving the bolt 5 between the extended and retracted positions. The interaction of the outer actuator 7 with the bolt 5 is more clearly illustrated in greater detail with reference to Figures 3 and 4 which illustrate a rear view of the lock assembly 1 partially assembled, with the backing plate 18 and the majority of the outer cam 19 removed. Figure 3 illustrates the bolt 5 in the extended position relative to the housing 3, being urged towards this position by a bolt torsion spring 21 having a free end engaging behind a head 22 of the bolt 5. The bolt head 22 is connected to the bolt frame 21 and has an internally formed shoulder 23 positioned adjacent the projection 20. When comparing Figures 3 and 4 it is to be understood that the outer cam 19 has been rotated in an anti-clockwise direction to move the projection 20 through an arc which results in movement of the bolt 5 to the retracted position against the urging of the bolt torsion spring 24. The bolt 5 is considered to be in a retracted position when the bolt head 22 is within the housing 3.

[0033] The assembly and operation of the inner actuator 6 will now be explained with reference to Figure 2. The inner actuator 6 includes the turn knob 8 which is illustrated in the form of a turn knob assembly including a hand grip element 25, an outer bearing plate 26, and an inner bearing plate 27. The outer bearing plate 26 and the inner bearing plate 27 are positioned on opposed sides of the lock housing 3, and are secured in this position by four screws 28 which locate in appropriately spaced apertures 29, 30 formed in the inner bearing plate 27 and outer bearing plate 26 respectively. The finger grip element 25 is formed with screw flutes (not shown), internally thereof for engagement with the four screws 28 so as to retain the finger grip element 25 adjacent the outer bearing plate 26. The outer bearing plate 26 also includes a radially extending channel 31 to receive the finger grip element 25 therein, so as to facilitate transferring any rotational force applied by the user on the finger grip element 25 through the outer bearing plate 26 to rotate the inner bearing plate 27.

[0034] The inner actuator 6 also includes an inner cam plate 32 which is spaced from the inner bearing plate 27 in Figure 2 by a drive member 33. The function of the drive member 33 will be explained later in the specification. The inner cam plate 32 is attached to the inner bearing plate 27 by four screws 34 (only three of which are visible), so that rotation of the turn knob 25, 26, 27 results in rotation of the inner cam plate 32. It can be appreciated from Figure 2 that the inner cam plate 32 is formed with a radially spaced projection 35 which is positioned to interact with the shoulder 23 on the bolt frame 21. The purpose of this engagement is described in greater detail with reference to Figures 5 and 6.

[0035] Figure 5 illustrates the rear view of the lock assembly 1 , similar to Figure 3 with the outer cam plate 19 removed. The bolt 5 is shown in the extended position, urged towards that position by the bolt torsion spring 24. The turn knob 8, (see Figure 1 ), is in the horizontal position, whereby the projection 35 is spaced from the shoulder 23. When comparing Figures 5 and 6 it can be appreciated that rotation of the inner cam plate 32 causes the projection 35 to engage the shoulder 23 causing the bolt 5 to retract from the extended position illustrated in Figure 5 to the retracted position illustrated in Figure 6.

[0036] The lock assembly 1 according to the invention includes a lock mechanism, that when in an active condition the inner actuator is rendered inoperable for retracting the latch bolt 5 from the extended position. The preferred elements of and method for achieving this as illustrated in Figure 2 include the drive member 33 that is sandwiched between the inner cam plate 32 and inner bearing plate 27 in conjunction with an upper detent 36 and a lower detent 37. The drive member 33 includes an upper ramp surface 38 and a lower ramp surface 39 for driving an upper detent 36 and lower detent 37 in a radial direction respectively on movement of the drive member 33 in a direction substantially perpendicular to the actuator axis X-X. The drive member 33 is moved as a result of engagement and rotation by either the outer cam plate 19 or the inner cylinder cam 40. This engagement and movement is more clearly illustrated in Figures 7 to 1 1 .

[0037] Figure 7 illustrates a rear view of the lock assembly 1 with the backing plate 18, bolt 5, inner cam 32 and part of the outer cam 19 (see all in Figure 2) removed. The lock mechanism is shown in Figure 7 in an active condition. The internal configuration of the housing 3 is formed with an annular bearing wall 41 which intermittently surrounds the inner bearing plate 27 defining a space within which the inner bearing plate 27 can rotate when the lock mechanism is in the inactive condition. The annular bearing wall 41 is formed with an upper recess 42 and a lower recess 43 configured to accommodate a portion of the upper detent 36 and lower detent 37 respectively when the lock mechanism is in an active condition. This prevents retraction of the bolt 5 by rotation of the inner cam 32.

[0038] Figure 7 also illustrates a central projection 44 of the outer cam plate 19 (see also Figure 2), having a pair of opposed bores, with each bore accommodating a leg 79 of a lock release 80 (See Figure 2). The lock release member 80 forms part of lock release mechanism that is considered to be in a selected condition when the release member 80 is located with its legs 79 in the opposed bores of the outer cam plate 19. Rotation of the outer cam plate 19 causes either one of the legs 79 to engage a block 81 (see also Figure 1 1 ) on a rear surface of the drive member 33 to adjust the condition of the lock mechanism. For example, rotation of the outer cam plate 19 in an anticlockwise direction from the position shown in Figure 7 will cause the lower leg 79 to engage the block 81 as illustrated in Figure 8. That rotation causes the drive member 33 to move to the left. This movement of the drive member 33 results in retraction of the lower detent 37 as a knob 45 (see Figure 7) on the lower detent 37 slides along the lower ramp surface 39, whilst the upper detent 36 slides along the upper ramp surface 38 to move free of the upper recess 36. With the upper detent 37 and lower detent 37 in these positions the inner turn knob 8 (see Figure 1 ) is free to rotate to retract the bolt 5, and the lock mechanism is considered to be in the inactive condition. It ought to be appreciated that rotation of the outer cam plate 19 in a clockwise direction from the position illustrated in Figure 8, can result in the drive member 33 moving back to the right hand position as illustrated in Figure 7. Accordingly this allows the outer actuator 7 to operate to adjust the condition of the lock mechanism from an unlocked condition to a locked condition.

[0039] Referring now to Figure 9 which again illustrates the lock mechanism in the active condition similar to the arrangement illustrated in Figure 7, however illustrating the cylinder cam 40, rather than the outer cam 19 interacting with the drive member 33. The upper detent 36 and lower detent 37 are located in the upper recess 42 and lower recess 43 respectively resulting from the location of the drive member 33 relative to inner bearing plate 27. Figure 9 illustrates the surface formation 46 on the inner cam designed to interact with opposed abutments 47, 48 of the drive member 33, to adjust its position relative to the inner bearing plate 27. In contrast Figure 10 illustrates the cylinder cam 40 being rotated, by rotation of a barrel 49 (see Figure 1 ) of the inner cylinder lock 50, by an appropriately coded key 51 . This adjusts the position of the upper detent 36 and lower detent 37 relative to the upper recess 42 and lower recess 43 respectively. Once the upper detent 36 and lower detent 37 are in the position illustrated in Figure 10, the lock mechanism is considered to be in an inactive condition, whereby the inner actuator 6 (See Figure 1 ) is free to rotate to retract the bolt 5.

[0040] Referring now again to Figure 2 which illustrates the rectangular shaped aperture 13 in the housing 3 through which the indicator member 14 is visible when the lock mechanism is in an active condition. When the lock assembly 1 is assembled, the aperture 13 is occupied by a transparent window 52. The indicator member 14 forms part of an indicator mechanism which also includes a shuttle 53. The indicator member 14 and shuttle 53 are each biased in opposite directions by an indicator biasing spring 54 and a shuttle spring 55 respectively. Figure 1 1 illustrates the lock assembly in cross section with the lock mechanism in the active condition. When the lock mechanism is in this active condition, the indicator member 14 is positioned over the aperture 13 so as to be visible therethrough. The indicator member 14 is urged towards this position by an indicator biasing spring 54. Figure 1 1 also illustrates the drive member 33 including a nose portion 56 abutting the shuttle 53. The shuttle 33 is retained in a right-hand position compressing the shuttle spring 55.

[0041 ] In contrast Figure 12 illustrates the lock mechanism in the inactive condition. It can be seen in Figure 12 that the indicator member 14 has been moved laterally relative to the aperture 13 so as to no longer be visible therethrough. This is achieved by the shuttle 53 being biased towards a left- hand position by the shuttle biasing means 55, once the drive member 33 has been moved from the position illustrated in Figure 1 1 to the position as illustrated in Figure 12. The shuttle biasing spring 55 is capable of applying a force to the shuttle 53, and indirectly to the indicator member 14 which is greater than the force applied by the indicator biasing spring 54 to the indicator member 14. [0042] Figures 1 1 and 12 also illustrate a ball detent acting between the drive member 33 and the inner bearing plate 27. The force produced by the ball detent 57 is greater than the force acting on the shuttle 53 from the shuttle spring 55 so as to prevent movement of the drive member 33 under the influence of the shuttle spring 55.

[0043] Referring now to Figure 13, which illustrates the lock assembly 1 in cross-section with the lock mechanism in an active condition. The drive member 33 is in the right-hand position moving the shuttle 53 to compress the shuttle spring 55. The indicator member 14 however is being tampered with by, for example, a screw driver 58 or the like. However it can be appreciated from Figure 13 that movement of the indicator member 14 in this manner does not result in adjustment of the lock mechanism from the active condition. Instead the indicator member 14 separates from the shuttle 53 without adjusting the position of the drive member 33. [0044] It ought to be appreciated from the foregoing that configuring the indicator member 14 to move independently of adjustment of the lock mechanism from the visible position to the obscured position reduces the vulnerability of the lock mechanism to circumvention by tampering.

[0045] Various alteration and/or additions may be introduced into the lock assembly as hereinbefore described without departing from the spirit or amber of the invention.

Claims

1 . A lock assembly for use with a door, the lock assembly including a housing, a bolt movable relative to the housing between an extended position and a retracted position, an inner actuator that is operable to move the bolt from the extended position towards the retracted position, a lock mechanism that is adjustable between an active condition and an inactive condition which renders the inner actuator inoperable and operable respectively, an indicator mechanism including an indicator member that is movable relative to the housing between a visible position and an obscured position in which it is visible and obscured from outside the housing respectively, the indicator member being movable from the visible position to the obscured position as a result of adjustment of the lock mechanism from the active condition to the inactive condition, and movable independently of adjustment of the lock mechanism from the visible position towards the obscured position without adjusting the condition of the lock mechanism.

2. A lock assembly according to claim 1 wherein the indicator mechanism includes an indicator biasing means which urges on the visual indicator member.

3. A lock assembly according to claim 2 wherein the indicator biasing means urges the visual indicator member towards the visible position.

4. A lock assembly according to claim 2 or 3 wherein the indicator mechanism includes a shuttle that is movable between a first position and a second position, and a shuttle biasing means that urges the shuttle towards the first position, wherein the shuttle interacts between the lock mechanism and the visual indicator member.

5. A lock assembly according to claim 4 wherein the interaction of the shuttle with the lock mechanism is such that the shuttle is movable from the first position towards the second position on adjustment of the lock mechanism from the inactive condition to the active condition.

6. A lock assembly according to claim 4 or 5 wherein the shuttle moves linearly between the first position and the second position.

7. A lock assembly according to any one of claims 4 to 6 wherein the indicator biasing means applies a first force on the biasing member and the shuttle biasing means applies a second force on the shuttle, whereby the second force is in a direction opposite to the first force.

8. A lock assembly according to claim 7 wherein the second force is greater than the first force.

9. A lock assembly according to any one of the preceding claims wherein the indicator member moves linearly between the visible position and the obscured position.

10. A lock assembly according to any one of the preceding claims wherein the indicator member moves in a direction between the visible position and the obscured position that is parallel with a direction of movement of the bolt between the extended position and the retracted position.

1 1 . A lock assembly according to any one of the preceding claims wherein the housing includes an aperture whereby the indicator member is visible through the aperture when in the visible position.

12. A lock assembly according to any one of the preceding claims including a first key operated lock operable from an inner side of the housing for adjusting the condition of the lock mechanism between the active condition and the inactive condition.

13. A lock assembly according to claim 12 wherein the key operated lock is a cylinder lock, including a casing and a barrel movable relative to the casing when a correctly coded key is inserted in a keyway of the barrel.

14. A lock assembly according to claim 13 wherein the barrel is movable by rotating relative to the casing.

15. A lock assembly according to any one of the preceding claims including an outer actuator that is operable from an outer side of the housing to move the bolt from the extended position towards the retracted position.

16. A lock assembly according to claim 15 wherein the outer actuator is operable to adjust the condition of the lock mechanism between the active condition and the inactive condition.

17. A lock assembly according to claim 15 or 16 wherein the outer actuator is a second key operated lock.

18. A lock assembly according to claim 17 wherein the second key operated lock is a cylinder lock, including a casing and a barrel movable relative to the casing when a correctly coded key is inserted in a keyway of the barrel.

19. A lock assembly according to claim 18 wherein the barrel is movable by rotating relative to the casing.

20. A lock assembly according to any one of the preceding claims wherein the lock mechanism includes at least one detent member that is movable relative to the inner actuator on adjustment of the lock mechanism between the active condition and the inactive condition.

21 . A lock assembly according to claim 20 wherein the inner actuator is operable by rotation about an axis, and the detent is movable in a radial direction relative to the axis.

22. A lock assembly according to claim 20 or 21 wherein the lock mechanism includes a drive member that interacts with the at least one detent and is movable relative to the housing on adjustment of the lock mechanism between the active condition and the inactive condition.

23. A lock assembly according to any one of the preceding claims including a bolt biasing means for biasing the bolt towards the extended position.

24. A lock assembly according to claim 23 wherein the bolt includes a bevelled leading face.

25. A lock assembly according to any one of the preceding claims wherein the lock assembly is a rim lock assembly.