FIELD OF THE INVENTION

[0001] The present invention relates to a lock assembly, as well as to a method of operating a lock assembly.

[0002] The present invention has particular application to a lock assembly which is able to operate in different modes. In the case of the lock assembly being employed on a door, the modes of operation may include a latching mode (also known as a passage mode) in which the turning of a door-handle may move a locking bolt of the lock assembly between a first extended position and a retracted position, and a deadlock mode in which a key can be used to throw the bolt to a second, more extended position in order to securely lock the door and make forced entry more difficult. It will be convenient to describe the invention in this exemplary context. It will be appreciated by persons skilled in the art, however, that the invention is not limited to this particular context.

BACKGROUND OF THE INVENTION

[0003] Locks that are able to function in multiple modes are known. Indeed, the present applicant already markets lock assemblies that operate in a passage or latching mode, in a deadlock mode, and/or in a privacy mode. As noted above, in the passage mode, the turning of either door-handle withdraws the lock bolt from a first extended position to a retracted position to enable the door to be opened. In the deadlock mode, the key is used to throw the bolt to an extended position in order to securely lock the door and make forced entry more difficult. The privacy mode may be activated by a button or snib on an inner side of the door, and prevents retraction of the bolt by an outer door-handle only. Turning the inner door-handle disables the privacy mode function, permitting the door to be opened.

[0004] It has been found that conventional lock assemblies still suffer from reliability problems, especially in association with movement of the bolt as the lock assembly transitions or moves to and/or from the deadlock mode. For example, it would be desirable to provide a new lock assembly with improved control over movement of the bolt. It would also be desirable to provide a lock assembly which minimises or even avoids potential for the bolt 'skipping' during movement thereof upon turning the key into a deadlock mode. SUMMARY OF THE INVENTION

[0005] In view of the above, it is an object of the invention to provide a new lock assembly which may provide one or more of the above desirable outcomes.

[0006] According to a first aspect, the present invention provides a lock assembly comprising: a key barrel having an actuator provided in the form of a cam associated therewith configured to move in response to turning of a key in the key barrel; a bolt operatively associated with the cam and configured for movement between a retracted position, a first extended position, and a second, more extended position in response to movement of the cam; a motion transfer member for transferring movement of or from the cam to the bolt; and a catch mechanism for engaging and holding the motion transfer member to prevent further extension of the bolt when the bolt is in the first extended position. The cam is configured to release the catch mechanism for moving the bolt to the second, more extended position in response to turning of the key in the key barrel.

[0007] Typically, the bolt is configured for movement between the retracted position and the first extended position in a passage mode or latching mode. That is, the turning of the key or the turning of a door-handle may move the bolt from the first extended position to the retracted position to enable a door to be opened. The catch mechanism prevents further extension of the bolt beyond the first extended position, however. It is only upon the turning of the key in the key barrel that the motion transfer member is released from catch mechanism by the cam to move the bolt to the second, more extended position, which typically corresponds to the deadlock mode. The lock assembly of the invention thereby provides an arrangement in which the cam associated with the key barrel may act directly upon the motion transfer member, which, in turn, directly transfers movement to the bolt. In this way, an enhanced control over movement of the bolt can be achieved. For the purposes of this specification, the term "cam" as it is used herein may be understood as a reference to a projecting element, such as a lobe or a lug, associated with the key barrel which moves in response to turning of a key in the key barrel.

[0008] In a preferred embodiment, the lock assembly comprises a bolt drive member having a front end portion and a rear end portion. The bolt is provided at or connected to the front end portion of the bolt drive member for movement therewith between the retracted position, the first extended position, and the second, more extended position in response to movement of the cam. The bolt drive member is preferably a generally elongate member and may be configured as a linkage which is pivotally linked or pivotally connected at its front end portion to the bolt. The bolt is typically configured for generally linear movement between the retracted position, the first extended position, and the second, more extended position.

[0009] In a preferred embodiment, the motion transfer member is provided at or connected to the rear end portion of the bolt drive member and is configured to transfer movement of the cam to the bolt drive member. In this regard, the motion transfer member is preferably configured to move on a generally arcuate or curved path for transferring the movement of the cam to the bolt or the bolt drive member. The actuator cam associated with the key barrel is configured to rotate or turn about an axis of the key barrel in response to the turning of the key in the key barrel. Thus, the cam may be arranged to bear directly against part of the motion transfer member to move the motion transfer member along its generally arcuate or curved path and thereby to transfer the movement from the cam to the bolt or the bolt drive member. In this regard, the motion transfer member is preferably configured as a linkage that is pivotally linked or pivotally connected to the rear end portion of the bolt drive member.

[0010] In a preferred embodiment, the bolt drive member forms an intermediate link between the motion transfer member, which moves on a generally arcuate or curved path, and the bolt, which moves on a generally linear path. As such, the front end portion of the bolt drive member may follow a substantially linear path of movement with the bolt, whereas the rear end portion of the bolt drive member may follow a substantially arcuate or curved path of movement with the motion transfer member.

[0011] In a preferred embodiment, the catch mechanism comprises: a catch member configured to engage and hold a part of the motion transfer member when the bolt is in the first extended position, and a follower connected to or associated with the catch member and presenting a follower surface designed for contact with or engagement by the cam. The cam is adapted or configured to contact or engage the follower surface to move the follower and thereby release the catch member from its engagement with the motion transfer member for moving the bolt to the second, more extended position in response to movement of the cam by the key. In this regard, the follower is preferably resiliently biased towards the cam (for example, by spring means) such that the cam contacts or engages the follower surface to move the follower and release the catch member against the resilient bias. [0012] In a preferred embodiment, the catch member and the follower are substantially rigidly connected and are arranged to pivot between an engaged position, in which the catch member engages and holds the motion transfer member, and a disengaged position, in which the catch member is released from its engagement with the motion transfer member.

[0013] In a preferred embodiment, the catch mechanism, especially the catch member, includes an angled or sloping surface configured to be contacted or engaged by a respective part of the motion transfer member as the bolt is moved from the second extended position back to the first extended position by the cam in response to turning of the key in the key barrel. In this way, the motion transfer member may contact or engage the angled or sloping surface of the catch member to displace or pivot it out of the way as the bolt is retracted from the second, more extended position back to the first extended position. That is, this feature of the lock assembly is designed to move the catch mechanism to prevent it from interfering with retraction of the bolt from the second, more extended position to the first extended position as the lock assembly transitions from the deadlock mode back to the passage mode or latching mode.

[0014] According to a second aspect, the present invention provides a method of operating a lock assembly, the lock assembly comprising: a key barrel configured to move a cam associated therewith in response to turning of a key in the key barrel; a bolt operatively associated with the cam for movement between a retracted position, a first extended position, and a second extended position in response to movement of the cam; and a motion transfer member for transferring movement of the cam to the bolt. The method comprises steps of: engaging and holding the motion transfer member against further extension of the bolt via a catch mechanism when the bolt is in the first extended position; and releasing the catch mechanism to move the bolt to the second extended position by moving the cam in response to turning of the key in the key barrel.

[0015] In a preferred embodiment, the step of engaging and holding the motion transfer member against further extension of the bolt comprises: engaging and holding a part of the motion transfer via a catch member.

[0016] In a preferred embodiment, the step of releasing the catch mechanism includes: contacting or engaging a follower surface of the catch mechanism with the cam to move and thereby to release the catch mechanism from engagement with the motion transfer member for moving the bolt to the second, more extended position in response to turning the key. [0017] In a preferred embodiment, the step of releasing the catch mechanism comprises: pivoting the catch member from an engaged position, in which it engages and holds the motion transfer member, to a disengaged position, in which it is released from the motion transfer member. The pivoting preferably occurs against a resilient bias, such as a spring bias.

[0018] In a preferred embodiment, the lock assembly comprises: a bolt drive member having a front end portion and a rear end portion, with the bolt being provided at or connected to the front end portion of the bolt drive member for movement therewith between the retracted position, the first extended position, and the second extended position in response to movement of the cam. The motion transfer member is provided at or connected to the rear end portion of the bolt drive member and is configured for transferring movement of the cam to the bolt drive member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For a more complete understanding of the invention and the advantages thereof, exemplary embodiments of the invention are explained in more detail in the following detailed description with reference to the accompanying drawing figures, in which like reference signs designate like parts and in which:

[0020] Fig. 1 is a perspective view of a lock assembly according to a preferred embodiment of the invention;

[0021] Fig. 2 is an exploded view of the lock assembly shown in Fig. 1 ;

[0022] Fig. 3 is a front view of the lock assembly in Fig. 1 shown inside the lock body housing in the latching mode or passage mode with the bolt in the first extended position;

[0023] Fig. 4 is a front view of the lock assembly in Fig. 1 shown inside the lock body housing in the latching mode or passage mode with the bolt in the retracted position as operated by a door-handle;

[0024] Fig. 5 is a front view of the lock assembly in Fig. 1 shown inside the lock body housing in the latching mode or passage mode with the bolt in the retracted position as operated by the key; [0025] Fig. 6 is a front view of the lock assembly in Fig. 1 shown inside the lock body housing as the bolt is moved under operation by the key from the first extended position to the second, more extended position into the deadlock mode; and

[0026] Fig. 7 is a front view of the lock assembly in Fig. 1 shown inside the lock body housing with the bolt in the second, more extended position in the deadlock mode.

[0027] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate particular embodiments of the invention and together with the description serve to explain the principles of the invention. Other embodiments of the invention and many of the attendant advantages of the invention will be readily appreciated as they become better understood with reference to the following detailed description.

[0028] It will be appreciated that common and/or well understood elements that may be useful or necessary in a commercially feasible embodiment are not necessarily depicted in order to facilitate a more abstracted view of the embodiments. The elements of the drawings are not necessarily illustrated to scale relative to each other. It will also be understood that certain actions and/or steps in an embodiment of a method may be described or depicted in a particular order of occurrences while those skilled in the art will understand that such specificity with respect to sequence is not actually required.

DETAILED DESCRIPTION OF EMBODIMENTS

[0029] With reference firstly to Figs. 1 and 2 of the drawings, a preferred embodiment of a lock assembly 1 is shown. The lock assembly 1 includes a lock body 2 having a housing 3 that substantially encloses various components of the locking mechanism and is configured to be mounted within a cavity formed in a door (not shown). The housing 3 comprises a two-part casing 4 and a sleeve or tube 5 which extends from the casing 4 to an end plate 6 that is configured to be fastened with a fascia plate 7 via screws 8 within a recess at an edge of the door. Although the door and respective door-handles are not illustrated, it will be noted that the lock assembly 1 includes a drive shaft 9 via which torque from turning of either of the door-handles is transmitted to the lock assembly 1 for operating the lock assembly 1 in a passage mode or latching mode, as will be discussed in more detail later. [0030] The lock assembly 1 includes a key barrel 10 which is operable from both sides of the door by a key K inserted into the key barrel 10. In particular, by turning the key K in the key barrel 10, an actuator lug or cam 11, operatively associated with the key barrel 10 and located within the lock body 2 turns with the key. The lock assembly 1 further includes a bolt 12 which is configured for latching and/or locking engagement in a complementary recess (not shown) provided in a door frame or door jamb for alignment with the bolt when the door is closed. The bolt 12 is configured for movement between a retracted position, a first extended position as shown in Fig. 1, and a second, more extended position in response to movement of the cam 11. In this way, the lock assembly 1 is designed to operate in at least two modes; i.e. a passage or latching mode, and a deadlock mode. In the passage mode or latching mode, the turning of the key K or the turning of either of the door-handles operates to withdraw or retract the bolt 12 from the first extended position (Fig. 1) for latching engagement in the recess (not shown) of a door frame, to a retracted position such that the bolt 12 disengages the recess to enable the door to be opened. In the deadlock mode, the key is used to move the bolt 12 from the first extended position to a second, more extended position so the bolt 12 projects into further engagement with the recess to securely lock the door and thereby make forced entry more difficult.

[0031] With reference now also to Figs. 3 to 5 of the drawings, details of this embodiment of the lock assembly 1 and its operation will become more apparent. Fig. 3 illustrates the lock assembly 1 in the passage mode or latching mode with the bolt 12 in the first extended (latching) position. As noted above, in this particular mode of operation, the bolt 12 can be moved or withdrawn to the retracted position (i.e. as shown in Fig. 4 and Fig. 5) by turning either of the door-handles or by turning the key .

[0032] The movement of the bolt 12 by operating either of the door-handles will be described first with reference to Fig. 3 and Fig. 4. The lock assembly 1 comprises an elongate bolt drive member 13 which forms part of a bolt retractor mechanism for moving the bolt 12 from the first extended position (i.e. where it latches in the recess of the door frame) back towards the lock body 2 to the retracted position for disengagement from that recess. The bolt 12 is received and accommodated within the sleeve or tube 5 of the housing 3 for generally linear movement in or along an axial direction of the sleeve or tube 5. The consistency and alignment of this linear movement of the bolt 12 within the sleeve or tube 5 is assured not only by the geometry of the sleeve or tube itself, but by a registration pin 14 which is configured to be received in a complementary bore (not shown) in the bolt 12. The bolt 12 is pivotally connected to a front end portion of the bolt drive member 13 via a hook-like element 15 which engages and holds a pin 16 of the bolt 12. As noted above, torque is transmitted from either of the door-handles (not shown) to the lock assembly 1 via the drive shaft 9. Integrally formed with, or rigidly connected to, the drive shaft 9 is a retractor member 17 which rotates or pivots with the drive shaft 9 as either one of the door-handles is turned. The retractor member 17 extends radially away from an axis of the drive shaft 9 and terminates in a curved nose 18 which abuts and engages an inclined surface 19 formed on an upper edge region of the bolt drive member 13. From the position shown in Fig. 3, when one of the door-handles is turned, the drive shaft 9 is also turned or rotated in a clockwise direction. This forces the curved nose 18 into and along the angled or inclined surface 19 on the upper edge region of the bolt drive member 13 which, in turn, drives the bolt drive member 13 towards the left-hand side of the drawing and, thus, draws the bolt 12 (connected via hook-like element 15 to the front end portion of the bolt drive member 13) into the retracted position shown in Fig. 4. The movement of the bolt 12 to the retracted position occurs against a resilient bias provided by a spring member 20 accommodated on the registration pin 14. Thus, when the door-handle is released, the bolt 12 is biased to return to the first extended position shown in Fig. 3 by this spring member 20. This also assists the retractor member 17 and the drive shaft 9, and therefore also the door-handle, to turn or pivot back to their respective original positions.

[0033] The movement of the bolt 12 by turning the key K will now be described with reference to Fig. 3 and Fig. 5. As noted above, by turning the key K in key barrel 10, the cam 11 which is operatively associated with the key barrel 10 and located within the lock body 2 turns with the key . The lock assembly 1 further includes a motion transfer member 21 which is configured and arranged for transferring the movement of the cam 1 1 to the bolt 12. In this regard, the rear end portion of the bolt drive member 13 is formed with a hook-like element 22 which engages and holds a pin 23 extending between two arms 24 of the motion transfer member 21. In this way, the bolt drive member 13 is pivotally linked or connected at its rear end portion with the motion transfer member 21 . The motion transfer member 21 is configured to move along a curved path which is approximately centred on the turning axis of the key barrel 10 and generally corresponds to a path traversed by the cam 11. Thus, referring to Fig. 3, as the key K is turned in the key barrel 10 anticlockwise through an angle of about 130°, the cam 1 1 rotates or turns about the key barrel axis from the vertically downward (6 o'clock) position and comes to bear against an end part of one of the arms 24 of the motion transfer member 21 adjacent the pin 23. Further turning the key K in the anticlockwise direction through a total angle of about 180° rotates or turns the cam 1 1 about the key barrel axis towards the vertically upward (12 o'clock) position and drives or pushes the motion transfer member 21 along its curved path, thereby transferring the movement from the cam 11 to the bolt drive member 13 (via its link to the pin 23 of the motion transfer member 21) and to the bolt 12. In this way, turning of the key K in the key barrel 10 can move or withdraw the bolt 12 to the retracted position, as shown in Fig. 5. Again, the movement of the bolt 12 to the retracted position occurs against the bias of the spring member 20 held on the registration pin 14. Accordingly, when the key K is released, the bolt 12 is biased to return to the first extended position shown in Fig. 3 by this spring member 20. This also causes the key K to turn or pivot back to its original position in the key barrel 10.

[0034] Referring now also to Figs. 6 and 7 of the drawings, further details of this embodiment of the lock assembly 1 and its operation will become more apparent. Despite the resilient bias acting on the bolt 12 via the spring member 20, the bolt 12 is held in the first extended position shown in Fig. 3 by a catch mechanism 25. In particular, the catch mechanism 25 is configured for engaging and holding the motion transfer member 21 to prevent further extension of the bolt 12 when the bolt is in the first extended position. In order to move or switch the lock assembly 1 into the deadlock mode, therefore, the cam 11 is configured to release the catch mechanism 25 to move the bolt 12 to the second, more extended position in response to turning of the key K in the key barrel 10.

[0035] To this end, the catch mechanism 25 of the lock assembly 1 comprises a catch member 26 having a projecting element or lug 27 configured to engage and hold a complementary element or shoulder 28 of the motion transfer member 21 when the bolt 12 is in the first extended position. The catch member 26 further includes a follower 29 rigidly connected therewith which presents a follower surface 30 designed for contact or engagement by the cam 1 1. The catch member 26 is pivotally mounted within the casing 4 on a pivot pin 31 and is arranged to pivot between an engaged position (shown in Fig. 3), in which the catch member 26 engages and holds the motion transfer member 21 via the projecting lug 27 and the complementary shoulder 28, and a disengaged position (shown in Fig. 6), in which the catch member 26 is released from its engagement with the motion transfer member 21. In this regard, the pivoting of the catch member 26 is resiliently biased towards the cam 11 by a spring member 32 such that the cam 11 contacts or engages the follower surface 31 to move the follower 29 and release the catch member 26 against the spring bias. [0036] Thus, referring to Fig. 3, as the key K is turned in the key barrel 10 clockwise through an angle of about 90°, the cam 1 1 rotates or turns about the key barrel axis from the vertically downward (6 o'clock) position towards an end part of the arms 24 of the motion transfer member 21 remote from the pin 23. Referring to Fig. 6, however, before the cam 11 makes contact with the motion transfer member 21, the cam 11 is adapted or configured to contact or engage along the follower surface 30 to pivot the catch member 26 on the pin 31 away from the motion transfer member 21 and thereby release the projecting lug 27 of the catch member 26 from engagement with the complementary shoulder 28 on the motion transfer member. In this way, further turning the key K in the clockwise direction through a total angle of about 180° rotates or turns the cam 1 1 about the barrel axis towards the vertically upward (12 o'clock) position, so that it drives or pushes the motion transfer member 21 along its curved path, thereby transferring the movement of the cam 11 to the bolt drive member 13 (via its link to the pin 23 of the motion transfer member 21) and to the bolt 12. Thus, turning the key K in the key barrel 10 in this manner moves the bolt 12 to the second, more extended position, as shown in Fig. 7 for the deadlock mode of the lock assembly 1. After release of the catch mechanism 25, the movement of the bolt 12 to the second, more extended (deadlock) position is also assisted by the bias acting on the bolt 12 via the spring member 20.

[0037] When it is desired to return the lock bolt 12 from the second, more extended position of the deadlock mode shown in Fig. 7 back to the first extended position of the passage mode or latching mode shown in Fig. 3, it is again necessary to employ the key K. In particular, the key K is turned in the key barrel 10 anticlockwise through an angle of about 70° so that the cam 11 turns about the key barrel axis from the vertically downward (6 o'clock) position and comes to bear against the end part of the arms 24 of the motion transfer member 21 adjacent the pin 23. Further turning the key in the anticlockwise direction through a total angle of about 140° rotates or turns the cam 11 about the key barrel axis towards the vertically upward (12 o'clock) position and pushes the motion transfer member 21 along its curved path to move the bolt 12 back to the first extended position. To prevent the catch mechanism 25 from interfering with this retraction of the bolt 12 from the second, more extended position back to the first extended position as the lock assembly 1 transitions from the deadlock mode back to the passage mode or latching mode, the catch member 26, and specifically the projecting element or lug 27, includes an angled or sloping surface 33 which is configured to be contacted or engaged by a respective part of the motion transfer member 21 (e.g. the complementary shoulder 28) as the bolt 12 is moved from the second extended position back to the first extended position by the cam 11. In this way, the motion transfer member 21 contacts or engages the angled or sloping surface 33 in order to pivot or displace the catch member 26 out of the way as the bolt 12 is retracted from the second, more extended position back to the first extended position.

[0038] Although specific embodiments of the invention are illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternative and/or equivalent implementations exist. It should be appreciated that the exemplary embodiment or exemplary embodiments are examples only and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

[0039] It will also be appreciated that in this document the terms "comprise", "comprising", "include", "including", "contain", "containing", "have", "having", and any variations thereof, are intended to be understood in an inclusive (i.e. non-exclusive) sense, such that the process, method, device, apparatus or system described herein is not limited to those features or parts or elements or steps recited but may include other elements, features, parts or steps not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms "a" and "an" used herein are intended to be understood as meaning one or more unless explicitly stated otherwise. Moreover, the terms "first", "second", "third", etc. are used merely as labels, and are not intended to impose numerical requirements on or to establish a certain ranking of importance of their objects.

LIST OF REFERENCE SIGNS

1 lock assembly 18 nose

2 lock body 19 inclined surface

3 housing 20 spring

4 two part casing 21 motion transfer member

5 sleeve or tube 22 hook-like element

6 end plate 23 pin

7 fascia plate 24 arm

8 screw 25 catch mechanism

9 drive shaft 26 catch member

10 key barrel 27 projecting element or lug

11 cam 28 complementary element or shoulder

12 bolt 29 follower

13 bolt drive member 30 follower surface

14 registration pin 31 pin

15 hook-like element 32 spring

16 pin 33 angled or sloping surface

17 retractor member K key