WO2009082778A1

WO2009082778A1 - Mortice lock with adjustable handing

Info

Publication number: WO2009082778A1
Application number: PCT/AU2008/001892
Authority: WO
Inventors: Donald John Newman
Original assignee: Assa Abloy Australia Pty Limited
Priority date: 2007-12-27
Filing date: 2008-12-23
Publication date: 2009-07-09
Also published as: AU2008344984B2; AU2008344984A1; NZ586019A

Abstract

This invention relates to a mortice lock assembly (1) including a housing (2) and a bolt (3), movable relative to the housing by a handle operated actuator (6). The actuator includes an inner and outer hub (7, 8) which may be locked by operation of a detent (12). A handing selector means (21) is operable from a front of the housing (2), for rendering either of the inner or outer hubs (7, 8) inoperable.

Description

MORTICE LOCK WITH ADJUSTABLE HANDING

This invention relates to a mortice lock assembly having a housing, a bolt moveable relative to the housing between an extended locked position and a retracted release position, by operation of an actuator operable from an inner or outer side. The actuator includes an inner and outer hub that are each independently operable to move the bolt. Locks of this kind are often used to secure doors and the like in a closed position. It will be convenient to hereinafter describe the invention with reference to door locks, however the invention may have other uses. A mortice lock assembly is designed for installation into a mortice cavity formed through an edge of a door, so that the bolt projects from the edge of the door when in the extended locked position. Door furniture is located on a front and rear face of the door and generally includes a turn knob or lever handle (hereinafter referred to as a handle) that interacts with the hubs to move the bolt. A detent means is often provided that is movable between an active position and an inactive position to render the hubs inoperable and operable respectively. The detent is generally controlled by a locking device such as a key operated cylinder lock, electro magnetic card reader or the like which interacts with a solenoid.

It is often preferable for the lock assembly to allow for locking of the inner hub only, or the outer hub only when the detent is in the active position. This provides the function of allowing the bolt to be retracted despite the locking device moving the detent to the active position. An example is a door to a hotel room may be set to prevent the outside handle from moving the bolt to the retracted position when the detent is in the active position, while allowing the inside handle to retract the bolt regardless of the detent. A mortice lock assembly may need to be installed in a left hinged door or a right hinged door. Rotating the mortice lock through the plane of the housing will result in an upside-down installation, which will adversely impact on the functionality of the cylinder lock. The preferred option is to pivot the lock assembly through its vertical axis, however when the lock assembly is pivoted the hub that was previously referred to as the inner hub is now the outer hub and the outer hub is now the inner hub. Rather than having mortice locks for installation in left hinged or right hinged door only it is preferable for the mortice lock to be adjustable for use in either. The adjustment is often referred to as adjusting the door's handing. The ability of selecting the handing reduces the amount of stock a locksmith or retailer needs to hold. It is generally preferable for the selection to be made when installing the lock assembly so the locksmith or carpenter (hereinafter carpenter) does not need to worry about what quantities of which handed locks are required. It is also generally preferable to minimise the time required by carpenter to make the selection and therefore the selection needs to be simple without requiring any substantial disassembly or reassembly of the lock. The detent is often located adjacent a rear wall of the lock assembly housing, and as such the housing may have an opening in or near the rear wall to allow access to the detent to make adjustment to the selection components without dismantling the lock housing. However if the lock assembly is installed in a door, and the handing needs to be changed, the lock assembly will have to be removed from the door to allow access to the opening.

The above discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of this invention.

It would be desirable to provide a mortice lock assembly that was relatively easy to adjust the selected handing. It is convenient in this specification to use terms such as inner and outer, for the purpose of describing an in use orientation of the mortice lock. The orientation of the lock can change, as explained in the previous paragraphs, and consequential changes in the interpretation of such terms need to be made for a proper understanding of the invention. In particular the term inner and outer have been used to describe the hubs, and for ease of explanation the inner hub is that hub shown on the near side of the mortice lock assembly of figure 1. Naturally if the mortice lock of figure 1 was pivoted the inner hub would be the distal hub.

According to this invention there is provided a mortice lock assembly having a housing, a bolt moveable between an extended locked position whereby it extends out a front face of the housing and a retracted release position whereby it is retracted within the housing, an actuator means including an inner and outer hub each for interaction with a handle, the inner and outer hubs being operable from inner and outer sides of the lock assembly respectively to move the bolt from at least the extended locked position to the retracted release position, a detent means being movable between an active position and an inactive position whereby the inner and outer hubs are operable when the detent is in the inactive position, a handing selector means adjustable from the front face of the housing controlling interaction between the detent in the active position and each of the inner hub and outer hub, the handing selector being operable in at least two modes when the detent is in the active position including an inner mode whereby the inner hub only is operable, or an outer mode whereby the outer hub only is operable.

The handing selector means may also be operable in a combined mode whereby neither hub is operable when the detent is in the active position.

The mortice lock assembly preferably also includes a face plate releasebly attachable to the front face of the housing and having an aperture to accommodate the movement of the bolt there through, wherein the face plate obstructs the adjustment of the handing selector means when attached to the housing. It is preferred that each of the inner hub and the outer hub rotate about an axis that is substantially transverse to a plane within which the bolt moves. It is further preferred that the latch bolt and the assembly includes a biasing means for urging the latch bolt towards the extended locked position. It is further preferred that the bolt moves rectilinearly, however the bolt may rotate between the extended locked position and the retracted release position.

The handing selector means preferably includes a stop member that is associated with the detent to so as to move therewith between the active position and the inactive position. It is preferred that the stop member is pivotable relative to the detent when adjusting between modes of operation of the handing selector means. It is further preferred that the stop member is pivotable only when the detent is in the inactive position. The handing selector means preferably includes a geared arrangement for pivoting the stop means. The geared arrangement preferably includes a rack and pinion, whereby the stop member includes a pinion portion for engagement by at least one rack to pivot the stop member. It is further preferred that the geared arrangement includes two racks each being moveable relative to the pinion to adjust the mode of operation of the handing selector means. It is further preferred that each rack is movable in a direction substantially perpendicular to the front face of the housing. The stop member preferably includes an abutment portion that, when the detent is in the active position, interacts with at least one of the inner hub or outer hub to render said hub inoperable. It is preferred that the abutment portion interacts with said hub by engaging said hub. It is preferred that the abutment portion includes at least one surface that interacts with said at least one of the inner hub or outer hub. It is most preferred that the abutment portion includes three surfaces, where each surface interacts with either the inner hub, the outer hub or both hubs respectively. It is preferred that the surface that interacts with both hubs is substantially perpendicular to each of the surfaces that interact with the inner hub or outer hub only.

It is further preferred that the stop member is configured with pivot limiting means to limit pivoting of the stop member relative to the housing when the detent is in the active position. The pivot limiting means preferably includes at least one lug formed on the stop member for locating in a groove that is fixed relative to the housing. It is preferred that the housing includes a sub frame including at least the groove.

It is further preferred that the mortice lock assembly include positive position means so as to positively position the stop member relative to the detent when adjusting the mode of operation of the selector means. It is preferred that the positive position means includes an element that engages with at least one feature of the stop member to positively position the stop member. It is further preferred that the element is an arm that locates in one of two grooves, each groove being aligned substantially perpendicular to the other, formed in an upper surface of the stop member when the stop member is positively positioned relative to the detent.

Alternatively it is preferred that the handing selector means includes a stop means having an inner portion and an outer portion, the inner portion and outer portion being movable with the detent to interact with the inner and outer hubs respectively when the detent is in the active position, when the handing selector means is operable in an inner mode the inner portion is restrained from moving with the detent means to the active position, and when the handing selector means is operable in an outer mode the outer portion is restrained from moving with the detent means to the active position. It is further preferred that the handing selector means includes biasing means for urging the inner and outer portion independently towards an engagement position whereby the inner and outer portions engage the detent so as to be capable of moving therewith towards the active position. It is further preferred that the handing selector means includes a switch located at the front face of the housing which is moved in the direction of the front face of the housing to adjust the mode of operation of the handing selector. It is still further preferred that the handing selector means includes a pair of rods that interact with the switch and the inner and outer portions of the stop means, so that sliding movement of the switch causes pivoting of the inner or outer portion. It is still further preferred that the switch includes a pair of ramps, one for each rod, so that moving the switch in the direction of the face of the housing causes either rod to move perpendicular to the face. It is still further preferred that the inner portion and the outer portion both include a lug that locate in a recess formed in the detent when they adopt the engagement position. It will be convenient to hereinafter describe the invention in greater detail by reference to the accompanying drawings showing two example embodiments of the invention. The particularity of the drawings and the related detailed description is not to be understood as superseding the generality of the broad definition of the invention as provided by the claims. Figure 1 is a front isometric view of a mortice lock assembly according to a preferred embodiment of the invention.

Figure 2 illustrates the actuator, handing selector means and detent from the mortice lock of figure 1.

Figure 3 illustrates the detent and handing selector means operating in an outer mode.

Figure 4 illustrates the detent and handing selector means operating in an inner mode.

Figure 5 illustrates a rack interacting with a pinion portion of the stop member with the detent in the active position. Figure 6 illustrates an inverted plan view of the interaction of the racks and pinion portion of the stop member with the handing selector means operating in outer mode. Figure 7 illustrates an inverted plan view of the interaction of the racks and pinion portion of the stop member with the handing selector means operating in a combined mode.

Figure 8 illustrates an inverted plan view of the interaction of the racks and pinion portion of the stop member with the handing selector means operating in an inner mode.

Figure 9 illustrates an element that engages the rack for adjusting the mode of operation of the handing selector means.

Figure 10 illustrates the stop member. Figure 1 1 illustrates a sub frame element of the housing.

Figure 12 illustrates an exploded view of an alternate embodiment of the handing selector means interacting with the detent and actuator from Figure 1.

Figure 13 illustrates an assembled view of the actuator, handing selector means and detent from Figure 12. Figure 14 illustrates a side elevation view of the assembly from Figure 13 with the detent in the inactive position and the inner and outer portion of the stop means engaging the detent.

Figure 15 illustrates a side elevation view of the assembly from Figure 13 with the detent in the active position and the inner and outer portion engaging the detent. Figure 16 illustrates a side elevation view of the assembly from Figure 13 with the detent in the inactive position and the handing selector adopting the inner mode of operation.

Figure 17 illustrates a side elevation view of the assembly from Figure 13 with the detent in the active position and the handing selector adopting the inner mode of operation.

The mortice lock assembly 1 shown in Figure 1 is normally located in a mortice cavity formed in a side edge of a swinging door (not shown). The mortice lock assemblyl includes a housing 2 and a bolt 3 mounted on the housing so as to be movable relative thereto. Figure 1 shows the bolt 3 in the extended position whereby in use it engages a strike element (not shown) associated with a door jam. The bolt 3 illustrated in Figure 1 is a latch bolt and is movable rectilinearly relative to the housing 2 between an extended position shown and a retracted position where the bolt is located within the housing. The invention however is not limited to lock assemblies including a rectilinearly movable latch bolt 3, and is also applicable to a mortice lock assembly 1 including, for example a swing bolt.

Whilst Figure 1 shows a mortice lock assembly 1 for a 60mm backset, the invention also applies to mortice lock assemblies of other backset lengths. A draw bar 4 is positioned and interacts with the rear of the bolt 3 and is engaged by an armed member 5 of an actuator 6. The actuator 6 also includes an inner and outer hub 7, 8 which in Figure 1 are rotated clockwise so as to move the armed member 5 to retract the latch bolt 3. A biasing arrangement 9 acts on a protrusion 10 extending from both the inner and outer hub 7, 8 to urge the inner and outer hub 7, 8, and in turn the armed member 5, to adopt the position shown in Figure 1. A handle (not shown) may be attached by way of a spindle (not shown) to each of the inner and outer hubs, whereby the spindle can locate in a square recess 1 1 formed at the rotational axis of each of the inner and outer hubs 7, 8.

A detent means 12 is provided for interaction with either or both the inner and outer hub 7, 8. The detent means 12 illustrated includes a substantially elongated member 13 located adjacent a rear wall of the housing 2 having a platform 14 at its lower end for supporting a stop member 15. An upper end of the elongate member 13 interacts with a cam assembly 16 including an inner and outer cam 17, 18, a slide member 19 and a fulcrum 20. The inner and outer cam 17, 18 are normally rotated by operation of, for example, a cylinder lock (not shown) or a turn knob (not shown) so that rotation in the anti-clockwise direction will move the slide member 19 in a downwards direction. This will in turn cause the fulcrum 20 to pivot raising the elongate member 13 causing an interaction between the stop member 15 and both the inner and outer hub 7, 8. The invention is not limited to the cam assembly as illustrated and described, and may be suitable for use with other forms of cam assembly.

Figure 1 shows the detent means 12 in the inactive position whereby both the inner and outer hubs 7, 8are rotatable. When the elongate member 13 is moved up the platform 14 raises the stop member 15 so that it can interact with both hubs 7, 8, as shown in Figure 2. The form of interaction illustrated in Figure 2 is direct engagement by the inner and outer hub 7, 8 of the stop member 15. Other forms of interaction including indirect engagement are clearly possible. The interaction of the inner hub and outer hub 7, 8 with the stop member 15 presents a barrier to the hub members 7, 8 being rotatable in the clockwise direction. Accordingly when the detent 12 is in the active position as shown in Figure 2 the hub members 7, 8 are incapable of retracting the latch bolt 3.

Where it is desirable for the detent 12 to be capable of controlling operation of only one of the inner or outer hubs 7, 8, the stop means 15 is rotatable relative to the platform 14 so that only one of the hubs 7, 8 can interact with the stop member 15. The stop member 15 preferably forms part of handing selector means 21 which is operable in a variety of modes. The handing selector means 21 illustrated in Figure 2 is operating in a combined mode where neither hub 7, 8 is operable when the detent 12 is in the active position. Figure 3 is an illustration with the actuator 6 removed showing the handing selector means 21 operable in an outer mode whereby the outer hub 8 only is operable when the detent 12 is in the active position. Both the inner and outer hubs 7, 8 are operable when the detent is in the inactive position however when the detent 12 is in the active position the inner hub interacts with the stop member.

In contrast Figure 4 illustrates the handing selector means 21 operating in an inner mode whereby when the detent 12 is in the active position the inner hub only 7 is operable. When the detent 12 is in the inactive position both the inner and outer hubs 7, 8 are operable however when the detent 12 is in the active position the outer hub 8 interacts with the stop member 15.

Referring still to Figures 3 or 4 which illustrate the stop member 15 including an abutment portion 22 that interacts with the inner hub 7, or outer hub 8, or both hubs 7, 8 when the detent is in the active position. The abutment portion 22 may take any form however the Figures 3 and 4 illustrate the abutment portion 22 including three surfaces 22a, 22b, 22c that interact with the inner and outer hubs 7, 8. The surface 22b that interacts with both the inner and outer hub 7, 8 when the handing selector means 21 is operating in the combined mode is interrupted by a ridge 34. The ridge 34 has a function that will be explained later in the specification. Whilst the illustrations show that the surfaces 22a 22c that interact with either the inner or outer hub 7, 8 are perpendicular to the surface 22b that interacts with both hubs 7, 8, this orientation may vary. The handing selector means 21 also includes a positive positioning means 24 including an element 25 that engages with at least one feature of the stop member 15 to positively position the stop member 15 relative to the hubs 7, 8. The preferred form of positive position means is illustrated in Figures 3 and 4 whereby the element 25 is located in one of two grooves 26a, 26b formed in an upper surface of the stop member 15. The figures 3 to 5 show the element located in the groove 26b. Each groove 26a, 26b is aligned substantially perpendicular to the other and the element 25 is made to flex when not located in a groove 26a, 26b.

When the detent 12 is in an inactive position the stop means 15 may be pivoted. The handing selector means 21 includes a geared arrangement for facilitating pivoting of the stop means 15. The preferred form of geared arrangement is illustrated in Figure 5 and includes a rack and pinion type arrangement whereby the stop member 15 includes a pinion portion 27 for engagement by at least one rack 28. The preferred embodiment illustrated in Figures 6, 7 and 8 show a pair of racks 28a, 28b operating on opposing sides of the pinion 27. It can be appreciated by comparing Figures 6, 7 and 8 that the racks 28a, 28b are movable in a direction substantially perpendicular to the axis of rotation of the stop member 15. It can also be appreciate when comparing Figures 1 and 2 that the racks 28 can slide vertically relative to the stop member 15 when the detent 12 moves between the active and inactive positions. The racks 28 can be moved by any suitable means however in the preferred embodiment illustrated in Figure 1 a face plate 30 that is releasably attachable to a front face of the housing 2, can be removed to expose an opening that provides access to each rack 28. It is preferred to provide a probe 31 having one or more arms 32, 33 of fixed length (see Figure 9) that may enter the housing 2 and engage with one or more of the racks 28a 28b to accurately move the rack 28 relative to the pinion portion 27 to cause rotation of the stop member 15 to enable the handing selector 21 to operate in the preferred mode.

A preferred form of stop member 15 is illustrated in figure 10 including the abutment portion 22 and the pinion portion 27. The abutment portion 22 illustrated includes a plurality of ridges 34a, 34b and 34c which are preferably an extension of teeth of the pinion portion 27. The ridges 34 are provided to interact with one or more grooves 35 that are formed in the housing sub frame elements 36, one of which is illustrated in figure 1 1 and can also be seen in figure 1. It ought to be appreciated that figure 1 has a side wall of the housing and an equivalent sub frame element 36 removed to reveal the features of the mortice lock. The ridge 34 locate within the groove 35 when the detent is in the active position and provides a pivot limiting means for resisting the stop member 15 from being pivoted. The situation may arise where an unauthorised person may try to rotate an actuator by forcing a handle when the detent 12 is in the active position and the pivot limiting means reduces the likelihood of the stop member 15 pivoting under such an unauthorised action. The form of pivot limiting means may vary from that shown and for example the location of the groove 35 and the ridge 34 may be swapped.

Figure 12 illustrates an alternate form of handing selector means and detent to that illustrated in Figures 1 to 5. In summary like features from previous illustrations are allocated the same reference numerals so that Figure 12 illustrates a pair of sub- framing elements 36a and 36b, a detent 12, and an actuator 6. The actuator 6 includes an inner hub 7 and an outer hub 8 which when rotated rotate the armed member 5. A biasing arrangement 9 which acts on the inner and outer hub 7, 8 in the same manner as described with reference to the embodiment illustrated in Figure 1.

This embodiment of the handing selector means includes a switch plate 40 which is positioned at the front face of the housing 2 (not shown). The plate can be located behind the face plate 30 (not shown) so as to reduce the likelihood of unauthorised manipulation. The switch interacts with a pair of rods 40a and 40b in a manner that will be described later with reference to Figures 14 to 17.

The handing selector means also includes a stop means having an inner portion 41 a and an outer portion 41 b which pivot about a shaft 42 extending from sub- frame element 36b. A biasing means 43, which in the embodiment illustrated is in the form of a leaf spring interacts with the inner and outer portions 41 a and 41 b of the stop means to urge those portions towards an engagement position whereby they engage the detent 12. More specifically, both the inner portion 41 a and outer portion 41 b include a lug 44a and 44b which locate within a recess 45 of the detent 12 when in the engagement position. This position can be more clearly seen in Figure 13.

Referring now to Figure 14 which illustrates a side elevation of the features of the lock assembly from Figure 13. More specifically the detent is illustrated in an inactive position with the inner and outer portion 41 a, 41 b of the stop means in an engagement position with the detent 12. In contrast, Figure 15 illustrates the detent 12 in the active position which causes the inner portion 41 a and outer portion 41 b to rotate anti-clockwise and interact with the respective inner hub 7 and outer hub 8. It will be appreciated that in this position the inner hub 7 and outer hub 8 are restrained from rotation by engagement with the inner portion 41 a and outer portion 41 b.

Figure 16 illustrates the handing selector operating in an inner mode. In order to achieve this mode, the switch 40 has been moved in the direction of the arrow X so as to cause the rod 40a to slide along the ramp and force the inner portion 41 a to rotate. This rotation is against the biasing force of the leaf spring 43 so as to move the inner portion away from the engagement position. It will be appreciated that having regard to Figure 17 that when the detent is moved to the active position, the inner portion is not rotated anti-clockwise and therefore it does not interact with the inner hub 7. This permits the inner hub 7 to rotate and thereby retract the latch bolt 3 regardless of the condition of the detent 12.

It will be appreciated that being able to adjust the handing of the mortice lock without having to remove the mortice lock from the mortice cavity can provide a time saving to the carpenter installing the lock. The way the stop member interacts with the sub frame when the detent is in the active position provides a further advantage.

Various alterations, modifications and or additions may be made to the embodiment described without departing from the spirit and scope of the invention as defined in the claims.

Claims

THE CLAIMS DEFINING THE INVENTION:

1. A mortice lock assembly having a housing, a bolt moveable between an extended locked position whereby it extends out a front face of the housing and a retracted release position whereby it is retracted within the housing, an actuator means including an inner and outer hub each for interaction with a handle, the inner and outer hubs being operable from inner and outer sides of the lock assembly respectively to move the bolt from at least the extended locked position to the retracted release position, a detent means being movable between an active position and an inactive position whereby the inner and outer hubs are operable when the detent is in the inactive position, a handing selector means adjustable from the front face of the housing controlling interaction between the detent in the active position and each of the inner hub and outer hub, the handing selector being operable in at least two modes when the detent is in the active position including an inner mode whereby the inner hub only is operable, or an outer mode whereby the outer hub only is operable.

2. A mortice lock assembly according to claim 1 wherein the handing selector means is operable in a combined mode whereby neither hub is operable when the detent is in the active position.

3. A mortice lock assembly according to claim 1 including a face plate releasebly attachable to the front face of the housing and having an aperture to accommodate the movement of the bolt there through, wherein the face plate obstructs the adjustment of the handing selector means when attached to the housing.

4. A mortice lock assembly according to anyone of the preceding claims wherein each of the inner hub and the outer hub rotate about an axis that is substantially transverse to a plane within which the bolt moves.

5. A mortice lock assembly according to anyone of the preceding claims wherein the bolt is a latch bolt and the assembly includes a biasing means for urging the latch bolt towards the extended locked position.

6. A mortice lock assembly according to anyone of the preceding claims wherein the bolt moves rectilinearly.

7. A mortice lock assembly according to any one of claims 1 to 6 wherein the bolt rotates between the extended locked position and the retracted release position.

8. A mortice lock assembly according to any one of the preceding claims wherein the handing selector means includes a stop member that is associated with the detent so as to move therewith between the active position and the inactive position.

9. A mortice lock assembly according to claim 8 wherein the stop member is pivotable relative to the detent when adjusting between modes of operation of the handing selector means.

10. A mortice lock assembly according to claim 8 or 9 wherein the stop member is pivotable only when the detent is in the inactive position.

1 1. A mortice lock assembly according to any one of claims 8 to 10 wherein the stop member includes an abutment portion that, when the detent is in the active position, interacts with at least one of the inner hub or outer hub to render said hub inoperable.

12. A mortice lock assembly according to claim 1 1 wherein the abutment portion interacts with said hub by engaging said hub.

13. A mortice lock assembly according to claim 1 1 or 12 wherein the abutment portion includes at least one surface that interacts with said at least one of the inner hub or outer hub.

14. A mortice lock assembly according to any one of claims 8 to 13 wherein the handing selector means includes a geared arrangement for pivoting the stop means.

15. A mortice lock assembly according to claim 14 wherein the geared arrangement includes a rack and pinion, whereby the stop member includes a pinion portion for engagement by at least one rack to pivot the stop member.

16. A mortice lock assembly according to claim 15 wherein the geared arrangement includes two racks each being moveable relative to the pinion to adjust the mode of operation of the handing selector means.

17. A mortice lock assembly according to claim 16 wherein each rack is movable in a direction substantially perpendicular to the front face of the housing.

18. A mortice lock assembly according to claim 17 wherein the abutment portion includes three surfaces, where each surface interacts with either the inner hub, the outer hub or both hubs respectively.

19. A mortice lock assembly according to claim 18 wherein the surface that interacts with both hubs is substantially perpendicular to each of the surfaces that interact with the inner hub or outer hub only.

20. A mortice lock assembly according to any one of claims 8 to 19 wherein the stop member is configured with pivot limiting means to limit pivoting of the stop member relative to the housing when the detent is in the active position.

21. A mortice lock assembly according to claim 20 wherein the pivot limiting means includes at least one ridge formed on the stop member for locating in a groove that is fixed relative to the housing.

22. A mortice lock assembly according to claim 22 wherein the housing includes a sub frame including at least the groove.

23. A mortice lock assembly according to any one of claims 8 to 23 including positive position means so as to positively position the stop member relative to the detent when adjusting the mode of operation of the selector means.

24. A mortice lock assembly according to claim 24 wherein the positive position means includes an element that engages with at least one feature of the stop member to positively position the stop member.

25. A mortice lock assembly according to claim 25 wherein the element is an arm that locates in one of two grooves, each groove being aligned substantially perpendicular to the other, formed in an upper surface of the stop member when the stop member is positively positioned relative to the detent.

26. A mortice lock assembly according to any one of claims 1 to 7 wherein the handing selector means includes a stop means having an inner portion and an outer portion, the inner portion and outer portion being movable with the detent to interact with the inner and outer hubs respectively when the detent is in the active position, when the handing selector means is operable in an inner mode the inner portion is restrained from moving with the detent means to the active position, and when the handing selector means is operable in an outer mode the outer portion is restrained from moving with the detent means to the active position.

27. A mortice lock assembly according to claim 26 including biasing means for urging the inner and outer portion independently towards an engagement position whereby the inner and outer portions engage the detent so as to be capable of moving therewith towards the active position.

28. A mortice lock assembly according to any one of claims 26 or 27 wherein the handing selector means includes a switch located at the front face of the housing which is moved in the direction of the front face of the housing to adjust the mode of operation of the handing selector.

29. A mortice lock assembly according to claim 28 wherein the handing selector means includes a pair of rods that interact with the switch and the inner and outer portions of the stop means, so that sliding movement of the switch causes pivoting of the inner or outer portion.

30. A mortice lock assembly according to claim 29 wherein the switch includes a pair of ramps, one for each rod, so that moving the switch in the direction of the face of the housing causes either rod to move perpendicular to the face.

31. A mortice lock assembly according to any one of claims 26 to 30 wherein the inner portion and the outer portion both include a lug that locate in a recess formed in the detent when they adopt the engagement position.