EP4692493A1

EP4692493A1 - Lock assembly

Info

Publication number: EP4692493A1
Application number: EP25192875.0A
Authority: EP
Inventors: Bruce Mccarthy
Original assignee: Assa Abloy Ltd
Current assignee: Assa Abloy Ltd
Priority date: 2024-08-09
Filing date: 2025-07-30
Publication date: 2026-02-11
Also published as: GB202411819D0; GB2643318A

Abstract

A lock assembly (26) comprises a lock housing (60) having a rear surface (64) for mounting to a face of a door (2) and a faceplate surface (46) for facing towards a keep of a door frame; a bolt (65) extendable and retractable relative to the faceplate surface (46); and a handle (62) rotatable from a first position to a second position. The handle (62) is coupled to the bolt (65) such that rotation of the handle (62) from the first position to the second position retracts the bolt (65). The lock assembly (26) further comprises a lock cylinder (52) arranged to selectively prevent rotation of the handle (62) from the first position; and a fastener hole (72a, 72b) extending through the housing and intersecting the rear surface. The fastener hole (72a, 72b) is located in a position in which it is blocked when the handle (62) is in the first position, and exposed to allow the insertion or removal of a fastener therethrough when the handle (62) is in the second position.

Description

Field of the Invention

The present invention concerns lock assemblies. More particularly, but not exclusively, the invention concerns a lock assembly, a method of fitting a lock assembly to a door, and a door.

Background of the Invention

A night latch assembly or just "night latch" is a type of door lock which in use has a cylinder assembly on one face of a door, and a lock case assembly on an opposite face of the door. Generally, the lock case assembly is positioned on the face of the door which faces into a building or room, and the cylinder assembly is positioned on the face of the door which faces out from the building or room. The cylinder assembly usually has a key-operated lock cylinder. The lock case assembly usually has a bolt which extends from a faceplate surface of the lock case assembly and is receivable in a keep mounted to the frame of the door, and a handle that can be rotated by hand so as to retract the bolt.
Generally, the lock cylinder has a tail bar which is received in an aperture in the lock case assembly and couples the lock cylinder to the handle such that the bolt can be retracted by rotating either one. Thus, a person can pass through the door in one direction (for instance leaving the room or building) simply by rotating the handle, but to pass in the opposite direction (for instance entering the room or building) they must operate the lock cylinder using the key.
While the ability to leave a room or building simply by rotating the handle of a night latch is often beneficial, in some cases it is counterproductive. In particular, if an intruder breaks into a building through a window or the like, they are then able to exit the building through the door simply by rotating the handle of the night latch. This can allow them to leave the building with goods that may be too large to fit through the window by which the intruder entered. Instead or as well, it can allow the intruder to open the door for accomplices and/or to make a second trip into the building to steal additional goods.
To combat this problem, some night latches have a function in which they can be locked with a key from the inside as well, meaning that an intruder inside the building is nonetheless prevented from exiting through the door. However, in some cases an intruder within the building can easily remove the lock case assembly from the inside merely by removing the screws holding the lock case assembly to the door. With the lock case assembly removed, the door can again be opened without a key being used.
Some designs of night latch address this problem by using a mounting plate by which the lock case assembly is attached to the door. The mounting plate is screwed onto the door first, then the lock case assembly is attached to the mounting plate. The mounting plate has projections which are received within the lock case assembly, and screws are passed through the faceplate surface of the lock case assembly to connect it to the mounting plate. With the screws running through the faceplate surface, which faces the keep when the door is locked, access to those screws is prevented when the door is closed. Thus, an intruder cannot remove the lock case assembly without first opening the door (which is not possible when the door is locked, of course).
Night latches using mounting plates are usually fitted to a door as follows. A relatively large hole (normally 32mm in diameter) is drilled through the door near its edge, through both faces. The cylinder assembly and mounting plate are presented to opposite faces of the door, held in their required positions on the door, with the tail bar extending from the cylinder assembly through an aperture in the mounting plate. The mounting plate and cylinder assembly are then attached together using screws which run through the hole. Tightening the screws clasps the door between the cylinder assembly and mounting plate, holding those components in position.
With the cylinder assembly and mounting plate in position, the lock case assembly is presented to the side of the door, over the top of the mounting plate. The tail bar of the cylinder assembly is aligned with a corresponding aperture in a rear face of the lock case assembly, and then the lock case assembly is placed on top of the mounting plate. Projections extending forward from a front face of the mounting plate are received in corresponding recesses in the rear face. The function of the night latch can then be tested to ensure that all the components are in the right location and orientation.
If the cylinder assembly, mounting plate and lock case assembly are all correctly positioned, the lock case assembly is removed from the mounting plate and the mounting plate is screwed to the door. The lock case assembly is then replaced and screwed to the mounting plate.
Although use of a mounting plate does combat the problem of the lock case assembly being removed by an intruder, the process of attaching the lock case assembly to the door can be quite time consuming. For example, fitting the night latch to a door can be very fiddly in terms of positioning each component and ensuring it does not move from that position. Firstly, to attach the cylinder assembly and mounting plate to one another requires them to be positioned on opposite sides of the door with respective screw holes (which are hidden from view) aligned, then held there while a screw is inserted through those holes and then driven home with a screwdriver. This requires significant dexterity on the part of the fitter, and/or takes multiple attempts. Secondly, with those components attached together the screws must be tightened so that the door is clasped between them and they cannot move. This can be problematic, particularly when tightening the first screw where the torsion applied to the screw can be transmitted to the cylinder assembly and cause it to rotate out of position.
Also, while securing the cylinder assembly and mounting plate, the mounting plate must be located in a position at which the lock case assembly, when attached thereto, will positioned correctly (i.e. spaced the correct distance from the edge of the door, at the right height up the door, with the bolt running horizontally). Whilst this is simple in theory, in practice it often requires a degree of trial and error with the lock case assembly being placed onto the mounting plate, checked, removed so that the mounting plate position can be loosened and adjusted, replaced for re-checking, and so on. Each time the mounting plate is re-positioned there is a chance of the cylinder assembly moving out of position, and each time the lock case assembly is placed onto or taken off the mounting plate there is a risk of the mounting plate or cylinder assembly being knocked out of position.
Compounding the above problems is the fact that the tail bar is normally loosely attached to the cylinder assembly. This allows the position of the tail bar to vary slightly so as to soak up tolerance stacks which could otherwise prevent it from being aligned with the lock case assembly and rotating freely. However, it also means that it is sometimes necessary to jiggle the tail bar to align it with the aperture in the lock case assembly as the lock case assembly is being placed onto the mounting plate. Jiggling the tail bar either requires a tool to be inserted into the gap between the lock case assembly and the mounting plate, or requires the cylinder assembly to be loosened so that the entire cylinder assembly can be jiggled. In either case, there is a risk of a component moving out of position.
Still further, with the lock case assembly having the bolt, which bears the force of any attempt to force the door open without unlocking it, the lock case assembly should be robustly attached to the door. The mounting plate, by which the lock case assembly is attached to the door, therefore needs to be relatively strong. It must therefore be relatively thick (and thus use a lot of material) and/or made of high strength material (which tends to be expensive). The tooling costs associated with making such a mounting plate can also be higher.
Similar problems also exist in respect of different types of lock assemblies, for instance those with a structure and function similar to just the lock case assembly of a night latch.
The present invention seeks to mitigate or obviate at least one of the above disadvantages, and/or to provide an improved or alternative lock assembly, method of fitting a lock assembly to a door, or door.

Summary of the Invention

According to a first aspect of the present invention there is provided a lock assembly comprising:

a lock housing having a rear surface for mounting to a face of a door, and a faceplate surface for facing towards a keep of a door frame;
a bolt extendable and retractable relative to the faceplate surface;
a handle rotatable from a first position to a second position, the handle being coupled to the bolt such that rotation of the handle from the first position to the second position retracts the bolt;
a lock cylinder arranged to selectively prevent rotation of the handle from the first position; and
a fastener hole extending through the housing and intersecting the rear surface,
wherein the fastener hole is located in a position in which it is blocked when the handle is in the first position, and exposed to allow the insertion or removal of a fastener therethrough when the handle is in the second position.

With the fastener hole being blocked when the handle is in the first position, which is the position it occupies when locked, a person is not able to access a fastener running through the fastener hole. Accordingly, it is not possible to remove the fastener, so as to remove the lock, without first moving the handle from the first position (which requires unlocking the lock cylinder). In short, therefore, it is not possible to remove the lock assembly from a door without first unlocking it.
The presence of fastener hole which is selectively blocked and unblocked in this way may allow attachment of the lock assembly to the door to be quicker than in arrangements in which the lock assembly is attached to the door via a mounting plate, and/or may allow the lock assembly to be lighter and/or more compact than such an arrangement.
The rear surface may be a generally planar surface, or may for example be a concave surface an edge of which is configured for mounting to the face of the door.
The fastener hole may be considered to be blocked if a driver bit of conventional design is unable to reach the fastener hole in a manner which would allow it to loosen a fastener received through the fastener hole.
It is to be understood that reference to the lock cylinder preventing the handle from moving from the first position is not intended to require the handle to be held completely stationary with no "wobble". In some arrangements the first position may therefore be considered to be a range of positions in which the bolt remains extended, the lock cylinder being arranged to prevent the handle from moving out of that range of positions.
It is to be understood that the term "lock assembly" is used to describe any assembly which can provide a mechanical locking function. Accordingly, a night latch assembly may be considered to be a lock assembly, but a portion therefor (for instance the lock case assembly) may be considered to be a lock assembly in of itself.
Optionally:

the lock assembly further comprises an additional fastener hole extending through the housing and intersecting the rear surface; and
the additional fastener hole is located in a position in which it is blocked when the handle is in the first position, and exposed to allow the insertion or removal of a fastener therethrough when the handle is in a different position.

The additional fastener hole may allow the lock assembly to be attached to the door, in a manner which requires it to be unlocked in order to be removed, with greater strength and/or stability. This, in turn, can make the lock assembly harder to remove with brute force.
As an alternative, the lock assembly may comprise a single fastener hole, or may have other fastener holes which are not blocked or exposed depending on the position of the handle. Such arrangements may not provide the advantage above, but may nonetheless be sufficient for the needs of some situations and they may provide other advantages such as being attachable to a door more quickly.
The handle may be rotatable to a third position, the additional fastener hole being exposed when the handle is in the third position.
As an alternative, the fastener hole and additional fastener hole may both be exposed when the handle is in the second position. In such an arrangement the handle may be movable substantially only between the first and second positions.
Optionally, with the handle in the second position the fastener hole is exposed and the additional fastener hole is blocked, and with the handle in the third position the fastener hole is blocked and the additional fastener hole is exposed.
In such an arrangement, to remove the lock assembly from a door it would be necessary to move the handle to two different positions. This may increase the complexity of the task facing a person who is attempting to force the handle to move so as to access the fastener holes and remove the lock from the door.
As an alternative, both fastener holes may be exposed when the handle is in the second position and/or when the handle is in the third position. In some contexts this may provide a benefit in terms of allowing the lock assembly to be removed more easily when it is unlocked, which may compensate for the potentially reduced resistance to being forced.
The first position of the handle may be between the second and third positions of the handle, movement of the handle between the second and third positions requiring movement of the handle through the first position.
This may be advantageous in that a person trying to force the handle from the first position to the second and third positions would need to force the handle in two different directions, and force it out of or past the first position twice. This may be particularly difficult to achieve.
As an alternative, the second position may be between the first position and the third position, or the third position may be between the first position and the second position. As another alternative, the handle may be rotatable through 360 degrees at which point it may be possible to move the handle from any one position to either of the other two positions directly.
The handle may also be coupled to the bolt such that rotation of the handle from the first position to the third position retracts the bolt.
The lock assembly may therefore be opened, to open the door, either by rotating the handle (when unlocked) from the first position to the second position or from the first position to the third position. This may make the lock assembly more user-friendly, and/or may make the lock assembly more applicable to different doors that open in different directions (e.g. doors that open anticlockwise when viewed in from above and doors that open clockwise when viewed from above).
As an alternative, movement of the handle from the third position may expose the additional fastener hole but may not retract the bolt to allow the door to be opened.
When the or each fastener hole is blocked, it may be blocked by a part of the handle.
This may allow a particularly simple (and thus cheap, compact and/or robust) mechanism to be used to enable rotation of the handle to block or expose the fastener hole(s).
As an alternative, the lock assembly may have one or more blocking members which are separate to the handle, movement of the handle between positions moving the or each blocking member between positions in which it does and does not block the or one of the (or both of the) fastener hole(s).
When the or each fastener hole is blocked, it may be substantially entirely obscured from view.
This may make it particularly difficult to access the or each fastener hole with the handle in the first position, even with specialised tooling. Instead or as well, the or each fastener hole being substantially entirely obscured from view may mean that a person cannot identify where the or each fattener hole is. This may make it even harder for someone to force access to the or each fastener hole, as the person may not know where they need to force access in order to remove the lock assembly.
The lock housing may have an overhang portion positioned to overlie an end face of said door, the overhang portion having a further fastener hole extending therethrough.
The presence of a further fastener hole may allow the lock assembly to be fixed to the door with greater strength and/or stability, making it harder to forcibly remove the lock assembly as discussed above. The further fastener hole being provided through the overhang portion may mean that when the door is closed the further fastener hole is blocked by the door frame or by a keep in which the bolt is receivable. Thus, a fastener received through the further fastener hole may contribute to the strength and stability of the mounting of the lock assembly to the door (and may make the lock assembly harder to detach by force), with that fastener not being removable until the lock is unlocked (and the door opened).
In some embodiments the faceplate surface may extend over part of the overhang portion or may extend over the entire overhang portion.
Optionally:

the lock assembly is a night latch assembly, the night latch assembly having a lock case assembly and a cylinder assembly configured for mutual engagement via a tail bar; and
the lock housing, bolt and handle are provided by the lock case assembly.

A night latch assembly may be a type of lock assembly in which one or more of the advantages discussed above are of particular benefit. For example, night latch assemblies are often the lock of choice for the main door of residential premises, which are relatively frequent targets for intruders who enter through a window and wish to leave by the door.
The lock cylinder may be provided by the cylinder assembly. As an alternative, the lock cylinder may be provided by the lock case assembly. In embodiments where the lock cylinder is provided by the lock case assembly, the cylinder assembly may not comprise a lock cylinder. Such an assembly could nonetheless be referred to as a cylinder assembly due to its resemblance (e.g. in shape and/or intended location on a door) to the cylinder assembly of a conventional night latch assembly.
The lock case assembly may comprise the lock cylinder and the cylinder assembly may comprise an additional lock cylinder.
The presence of lock cylinders in both the lock case assembly and the cylinder assembly can allow a door comprising the lock assembly to be unlocked/opened from either side by someone in possession of a key. In contrast, if only a single lock cylinder was provided then a user may only be able to do so on one side of the door, which may mean that the door would be always locked, or always unlocked, from the other side.
The additional lock cylinder may be arranged to selectively prevent rotation of the handle from the first position. Thus, the handle may be prevented from moving from the first position (thereby preventing the lock case assembly from being removed from the door) from either side of the door.
As an alternative, the additional lock cylinder may be coupled to the bolt such that rotation of the lock cylinder by a key can retract the bolt, but the additional lock cylinder may not have any effect on the ability of the handle to move.
According to a second aspect of the present invention there is provided a method of fitting a lock assembly to a door, the method comprising:

rotating a handle of the lock assembly from a first position to a second position, thereby (a) retracting a bolt of the lock assembly relative to a faceplate surface of the lock assembly and (b) exposing a fastener hole which extends through the housing and intersects a rear surface of the housing;
with the rear surface of the housing presented to a face of the door and the handle in the second position, inserting a fastener through the exposed fastener hole and tightening the fastener to secure the rear surface of the lock housing on said face of the door;
rotating the handle from the second position to the first position, thereby (a) extending the bolt relative to the faceplate surface and (b) blocking the fastener hole and the fastener inserted therethrough; and
locking a lock cylinder of the lock assembly so as to prevent rotation of the handle from the first position.

A lock assembly fitted to a door according to this method may be beneficially difficult to remove from the door when the door is locked, in corresponding fashion to the first aspect of the invention. More specifically, with rotating the handle from the first position to the second position exposing the fastener hole, and locking of the lock cylinder preventing rotation of the handle from the first position, in order to expose the fastener hole so as to remove the fastener one must first unlock the lock cylinder so that the handle will move. Thus, without being able to unlock the locking cylinder an intruder would be unable to remove the lock assembly in order to use the door.
Instead or as well, this method may be advantageously quick to perform, in comparison to methods in which the lock assembly is attached to the door via a mounting plate.
The fastener may be a screw which threadedly engages the door. As an alternative, the fastener may be a screw or bolt which threadedly engages a mounting plate attached to the door.
In some embodiments of the method, the rear surface of the housing may be presented to the door and then the handle may be rotated from the first position to the second position. In other embodiments of the method, the handle may be rotated from the first position to the second position and then held there while the rear surface of the housing is presented to the door.
The method may further comprise, with the rear surface of the lock housing secured on the face of the door using the fastener through the fastener hole but before locking of the lock cylinder:

rotating the handle from the first position to a third position, thereby (a) retracting the bolt relative to the faceplate surface and (b) exposing an additional fastener hole which extends through the housing and intersects the rear surface;
inserting a fastener through the additional fastener hole and tightening the fastener to further secure the rear surface of the lock housing on said face of the door; and
rotating the handle from the second position to the first position, thereby (a) extending the bolt relative to the faceplate surface and (b) blocking the additional fastener hole and the fastener inserted therethrough.

A lock assembly fitted to a door according to such a method may be even more difficult to remove from the door when the door is locked, in corresponding fashion to embodiments of the first aspect of the invention in which the lock assembly has an additional fastener hole.
Optionally:

the lock assembly is a night latch assembly which has a lock case assembly and a cylinder assembly;
the lock housing, bolt and handle are provided by the lock case assembly; and
the method comprises attaching the lock case assembly and cylinder assembly to opposite faces of the door, the lock case assembly and cylinder assembly engaging one another via a tail bar running through a thickness of the door.

A night latch assembly may be a type of lock assembly in which one or more of the advantages discussed above are of particular benefit. For example, as discussed above night latch assemblies are often the lock of choice for the main door of residential premises, which are relatively frequent targets for break-ins in which an intruder enters through a window and wishes to leave by the door.
The lock assembly may be a lock assembly according to the first aspect of the invention.
According to a third aspect of the present invention there is provided a door comprising a lock assembly according to the first aspect of the invention and/or a lock assembly fitted using a method according to the second aspect of the invention.
It may be particularly difficult for an intruder to remove the lock assembly from the door while the door is locked, for instance for one or more of the reasons discussed above.
It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. Additionally, a method of the invention may incorporate any of the features described with reference to an apparatus of the invention and vice versa.

Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

Figure 1 is an exploded view of part of a door according to an embodiment of the invention viewed from inside a building;
Figure 2 is an exploded view of the part of the door of Figure 1, viewed from outside the building;
Figure 3 is a perspective view of a lock case assembly of the part of a door of Figures 1 and 2;
Figure 4 is a front view of the lock case assembly of Figure 3, along with a keep, with a handle of the lock case assembly in a second position;
Figure 5 is a front view of the lock case assembly and keep of Figure 4, with the handle of the lock case assembly in a third position.

Detailed Description

Figure 1 shows a part of a door 2 according to an embodiment of the invention, in exploded view generally from the front. Figure 2 shows the same exploded view of the part of the door 2, but generally from the back. Referring to Figures 1 and 2, the door 2 has a leaf 4, and a lock assembly in the form of a night latch assembly 6 which is secured to the leaf 4 via screws 8, 10, 12. The door 2 of this embodiment is a wooden door to a building such as a house. It has a first face 14 which faces outside the building, a second face 16 which faces inside the building, and an end face 17. In Figures 1 and 2 the door 2 is shown along with part of a frame 18 which has supports a keep 20. The frame 18 and keep 20 are not material to the present invention, therefore will not be described in detail.
The night latch assembly 6 comprises a cylinder assembly 22, a mounting plate 24 and a lock case assembly 26. The cylinder assembly 22 has a housing 28 which defines a handle lip 30 descending from its front, and two pairs of threaded holes 32, 34 at its rear. Inside the housing 28 of the cylinder assembly 22 is a lock cylinder 36, and extending rearwards from the rear of the housing 28 is a tail bar 38 which is rotationally coupled to the lock cylinder 36. In this particular embodiment the tail bar 38 forms part of the cylinder assembly, but in other embodiments the tail bar (where present) may be part of the lock case assembly 26 or may be a stand-alone component. By placing the correct key into the lock cylinder 36 and rotating the key, the lock cylinder 36 and thus the tail bar 38 can be rotated.
The mounting plate 24 has a base 40 which defines a generally flat and planar rear face 42 for engaging the second face 16 of the door 2, with a projection 44 extending rearward therefrom. The projection 44 has an aperture 54 and a pair of screw holes 56 extending therethrough. A further pair of screw holes 58 run through the base 40 of the mounting plate 24.
The screw holes 56 on the projection 44 of the mounting plate 24 are configured for alignment with the threaded holes 32 of the cylinder assembly 22, and the screw holes 58 in the base 40 of the mounting plate 24 are configured for alignment with the threaded holes 34 of the cylinder assembly 22. When the cylinder assembly 22 and the mounting plate 24 are correctly positioned on their respective sides of the door, screws 8 can run from respective head ends, through the holes 56, through the leaf 4 of the door and into the threaded holes 32. Equally, screws 10 can run from respective head ends, through the holes 58, through the leaf 4 and into the threaded holes 34. The screws 8, 10 can threadedly engage with their respective threaded holes 32, 34 in the cylinder assembly 22, thereby attaching the cylinder assembly 22 and mounting plate 24 to one another as discussed later.
The lock case assembly 26 is shown in isolation in Figure 3, which will now be referred to in combination with Figures 1 and 2. The lock case assembly 26 has a housing 60 (an example of a lock housing) with a rear surface 64 configured for mounting to the second face 16 of the door 2. The housing 60 also has a faceplate surface 46 relative to which a bolt 65 of the lock case assembly 26 can extend and retract. The bolt 65 is shown extended in Figures 1 to 3.
The housing 60 of the lock case assembly 26 also has an overhang portion 48 which is positioned to overlie the end face 17 of the door 2 when the lock case assembly 26 is fitted to the door 2. In this embodiment the faceplate surface 46 extends over the overhang portion 48 (as well as around the bolt 65 and over the entire of one side of the housing 60). The overhang portion 48 has a pair of fastener holes in the form of screw holes 50.
The rear surface 64 of the housing 60 defines a shallow recess 66 into which a protrusion 68 extends. The protrusion 68 has an aperture 70 configured to receive the end of the tail bar 38, and is coupled to the bolt 65 such that rotation of the protrusion 60 can retract the bolt 65. Accordingly, with the tail bar 38 received in the aperture 70, turning the lock cylinder 36 of the cylinder assembly 22 with a key (not shown) can retract the bolt 65 so that the door 2 can be opened.
Figures 1 to 3 show the handle 62 in a first position. In this embodiment the handle 62 is biased to the first position by a spring (not visible). The handle 62 is rotatable clockwise from the first position to a second position, and is rotatable anticlockwise from the first position to a third position. Figure 4 shows the lock case assembly 26 (in conjunction with the keep 20) with the handle 62 in the second position, and Figure 5 shows the lock case assembly 26 (in conjunction with the keep 20) with the handle 62 in the third position. Figures 4 and 5 will now be referred to in combination with Figures 1 to 3.
The handle 62 is coupled to the bolt 65 whereby rotation of the handle 62 from the first position to the second position retracts the bolt 65 (and conversely rotation of the handle 62 from the second position to the first position extends the bolt 65). The handle 62 is also coupled to the bolt 65 whereby rotation of the handle 62 from the first position to the third position retracts the bolt 65 (and conversely rotation of the handle 62 from the third position to the first position extends the bolt 65). Accordingly, a user can unlock the door 2 by moving the handle 65 in either direction. In the present embodiment the range of motion of the handle 62 is limited to the approximately 90 degrees through which it can travel between the second position and the third position. The handle is thus only able to between the second and third positions via the first position.
The lock case assembly 26 also has a lock cylinder 52, which in this embodiment is provided on the handle 62. Whereas the lock cylinder 36 of the cylinder assembly 22 is operable via a key to retract the bolt 65 (via the tail bar 38 as described above), the lock cylinder 52 of the lock case assembly 26 is operable via a key to prevent rotation of the handle 62 from the first position. A user can therefore secure the handle 62 in the first position, preventing it from being rotated to the second or third position and thus preventing the door from being opened from that side of the door. Securing the handle 62 in the first position does not, however, affect the ability to retract the bolt 65 by operating the lock cylinder 36 of the cylinder assembly 22. Thus, with the handle 62 secured in the first position a user could still open the door 2 by using a key to operate the lock cylinder 36 of the cylinder assembly 22. Equally, operation of the lock cylinder 36 of the cylinder assembly 22 does not have any effect on the ability (or inability) of the handle 62 to move between positions.
The lock case assembly 26 also has a fastener hole 72a and an additional fastener hole 72b, each of which runs through the housing 60 and intersects the rear surface 64. Screws 12 pass through the fastener holes 72a, 72b and threadedly engage the wood of the door, holding the housing 60 (and thus the lock case assembly 26) on the door.
It is noteworthy that both fastener holes 72a, 72b are located in positions in which they are blocked by part of the handle 62 when the handle is in the first position. Indeed, with the handle 62 in the first position both fastener holes 72a, 72b (and the screws 12 running through them) are substantially entirely obscured from view by the handle 62. However, both fastener holes 72a, 72b are located in positions in which they are exposed (to allow the insertion or removal of the corresponding screw 12) when the handle 62 is in a different position. More particularly, in this embodiment the fastener hole 72a is exposed when the handle 62 is in the second position, and the additional fastener hole 72b is exposed when the handle 62 is in the third position.
It should be noted that with the handle 62 in the second position the additional fastener hole 72b is blocked, and with the handle 62 in the third position the fastener hole 72a is blocked. In other words, moving the handle 62 from the first position to the second position exposes only the fastener hole 72a, and moving the handle from the first position to the third position exposes only the additional fastener hole 72b. Accordingly, removing both screws 12 so as to remove the lock case assembly 26 from the door 2 would require the handle to be moved both from the first position to the second position (to remove the screw 12 from the fastener hole 72a) and from the first position to the third position (to remove the screw 12 from the additional fastener hole 72b). Neither movement is possible while the lock cylinder 52 is locked.
A method of fitting the night latch assembly 6 to the door 2 will now be described with continued reference to Figures 1 to 5. A first step of the method is to drill a main hole 74 and two additional holes 76 in the leaf 4 of the door 2. In this case each hole 74, 75 is a through-hole, passing through both the first and second faces 14, 16. The main hole 74 is around 32mm in diameter, being sized to accommodate the projection 44 and the rear parts of the cylinder assembly 22 which provide the screw holes 32, while the additional holes are considerably smaller (around 6mm), each being sized to accommodate a part of the cylinder assembly 22 which provides one of the screw holes 34.
After drilling of the holes 74, 76 in the door, the cylinder assembly 22 is presented to the first face 14 of the door and the mounting plate 24 is presented to the second face 16 of the door. The projection 44 of the mounting plate 24 is then inserted into the main hole 74, which snugly receives the projection. The mounting plate 24 is then rotated about the projection 44 until it reaches the required orientation, with the screw holes 58 aligned with the additional holes 76 and the aperture 54 towards the bottom of the projection 44. With the projection 44 snugly received in the main hole 74, the door 2 supports the mounting plate 24 without assistance from the fitter.
The cylinder assembly 22 is then applied to the first face 14 of the door 2. The tail bar 38 and the rear parts of the housing 28 that provide the threaded holes 32 are inserted into the main hole 74. The screw holes 32 terminate within the main hole 74 whereas the tail bar 38 extends through the aperture 54 in the mounting plate, all the way through the hole 74, and projects past the second face 16. At the same time, the parts of the housing 28 which provide the threaded holes 34 are inserted into respective additional holes 76, within which they terminate.
With the cylinder assembly 22 and mounting plate 24 so positioned, they are held in place by the door 2 and protected from shifting out of position by knocks or the like. The cylinder assembly 22 and mounting plate 24 are then attached to one another using screws 8, 10. Screws 8 are inserted through screw holes 56 of the mounting plate 24, through the main hole 74 and into respective screw holes 32 of the cylinder assembly 22. Screws 10 are inserted through screw holes 58 of the mounting plate 24, through respective additional holes 76 and into respective screw holes 34 of the cylinder assembly 22. The screws 8, 10 engage their respective threaded screw holes 32, 34, attaching the cylinder assembly 22 and mounting plate 24 together. As the screws 8, 10 are tightened, they draw the cylinder assembly 22 and mounting plate 24 towards one another until they are secured on their respective faces 14, 16 of the door 2 and clasp the door 2 therebetween.
After the cylinder assembly 22 and mounting plate 24 are secured on their respective faces 14, 16 of the door, the lock case assembly 26 is attached to the door 2. The lock case assembly 26 is presented to the door 2 with its rear face 64 facing the second face 16 of the door 2. The aperture 70 in the protrusion 68 is aligned with, and then slid onto, the tail bar 38. This brings the rear face 64 of the housing 60 of the lock case assembly 26 into abutment with the second face 16 of the door 2, with the rear face 64 of the lock case assembly 26 entirely overlying the mounting plate 24 and shielding it from view. Placing the lock case assembly 26 against the second face 16 of the door also inserts the base 40 of the mounting plate 24 into the recess 66 and inserts the protrusion 68 into the cavity 50.
With the lock case assembly 26 so positioned it is moved over the face 16 of the door 2, with the base 40 of the mounting plate 24 moving within the recess 66 and the protrusion 68 moving within the cavity, so as to find the location where the tail bar 38 experiences the least resistance to rotation. In this position the tail bar 38 rotationally couples the lock cylinder 36 of the cylinder assembly 22 and the handle 62 of the lock case assembly 26, so that rotation of either one retracts the bolt 65, with least friction and wear.
The lock case assembly 26 is then secured to the door 2 in this position. First, the handle 62 is moved from the first position to the second position (having first operated the lock cylinder 52 to allow the handle 62 to move, if necessary) so as to expose the fastener hole 72a. A screw 12 is then inserted through the fastener hole 72, threadedly engaged with the wood of the door 2, and tightened to secure the rear surface 64 of the housing 60 on the second face 16. The handle 62 is then released, at which point it moves back to the first position and blocks the fastener hole 72a (along with the screw 12 received therethrough). The handle 62 is then moved to the third position so as to expose the additional fastener hole 72b. The other screw 12 is then inserted through the additional fastener hole 72b, threadedly engaged with the wood of the door 2, and tightened to secure the rear surface 64 of the housing 60 on the second face 16 more firmly and stably. At that point the handle can be released, allowing it to move back to the first position again. Where an even more solid connection between the lock case assembly 26 and the door 2 is required, further screws (not shown) can be driven through the screw holes 50 in the overhang portion 48, into the end face 17 of the door 2.
Once the lock case assembly 26 and door 2 have been attached together, the lock cylinder 52 is then locked to secure the handle 62 in the first position, either for testing purposes or during use of the night latch assembly 6.
Whilst the invention has been described in relation to a lock assembly which takes the form of a night latch assembly, the invention is also applicable to other types of lock assembly. For example in another embodiment the entire lock assembly may be of the same structure and general function as the lock case assembly of the embodiment described above, but there may be no provision for unlocking or opening the door from the opposite side thereof.
Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

A lock assembly (26) comprising:
a lock housing (60) having a rear surface (64) for mounting to a face of a door (2) and a faceplate surface (46) for facing towards a keep of a door frame;

a bolt (65) extendable and retractable relative to the faceplate surface (46);

a handle (62) rotatable from a first position to a second position, the handle (62) being coupled to the bolt (65) such that rotation of the handle (62) from the first position to the second position retracts the bolt (65);

a lock cylinder (52) arranged to selectively prevent rotation of the handle from the first position; and

a fastener hole (72a, 72b) extending through the housing and intersecting the rear surface (64),

wherein the fastener hole (72a, 72b) is located in a position in which it is blocked when the handle (62) is in the first position, and exposed to allow the insertion or removal of a fastener therethrough when the handle (62) is in the second position.
A lock assembly according to claim 1 wherein:
the lock assembly further comprises an additional fastener hole extending through the housing and intersecting the rear surface; and

the additional fastener hole is located in a position in which it is blocked when the handle is in the first position, and exposed to allow the insertion or removal of a fastener therethrough when the handle is in a different position.
A lock assembly according to claim 2 wherein the handle is rotatable to a third position, the additional fastener hole being exposed when the handle is in the third position.
A lock assembly according to claim 3 wherein with the handle in the second position the fastener hole is exposed and the additional fastener hole is blocked, and with the handle in the third position the fastener hole is blocked and the additional fastener hole is exposed.
A lock assembly according to claim 3 or 4 wherein the first position of the handle is between the second and third positions of the handle, movement of the handle between the second and third positions requiring movement of the handle through the first position.
A lock assembly according to any one of claims 3 to 5 wherein the handle is also coupled to the bolt such that rotation of the handle from the first position to the third position retracts the bolt.
A lock assembly according to any preceding claim wherein when the or each fastener hole is blocked, it is blocked by a part of the handle.
A lock assembly according to any preceding claim wherein when the or each fastener hole is blocked, it is substantially entirely obscured from view.
A lock assembly according to any preceding claim wherein the lock housing has an overhang portion positioned to overlie an end face of said door, the overhang portion having a further fastener hole extending therethrough.
A lock assembly according to any preceding claim wherein:
the lock assembly is a night latch assembly, the night latch assembly having a lock case assembly and a cylinder assembly configured for mutual engagement via a tail bar; and

the lock housing, bolt and handle are provided by the lock case assembly.
A lock assembly according to claim 10 wherein the lock case assembly comprises the lock cylinder and the cylinder assembly comprises an additional lock cylinder.
A method of fitting a lock assembly (26) to a door (2), the method comprising:
rotating a handle (62) of the lock assembly (26) from a first position to a second position, thereby (a) retracting a bolt (65) of the lock assembly (26) relative to a faceplate surface (46) of the lock assembly (26) and (b) exposing a fastener hole (72a, 72b) which extends through a lock housing (60) of the lock assembly (26) and intersects a rear surface (64) of the lock housing (60);

with the rear surface (64) of the lock housing (60) presented to a face of the door (2) and the handle (62) in the second position, inserting a fastener (12) through the exposed fastener hole (72a, 72b) and tightening the fastener (12) to secure the rear surface (64) of the lock housing (60) on said face of the door (2);

rotating the handle (62) from the second position to the first position, thereby (a) extending the bolt (65) relative to the faceplate surface (46) and (b) blocking the fastener hole (72a, 72b) and the fastener (12) inserted therethrough; and

locking a lock cylinder (52) of the lock assembly (26) so as to prevent rotation of the handle from the first position.
A method according to claim 12 further comprising, with the rear surface of the lock housing secured on the face of the door using the fastener through the fastener hole but before locking of the lock cylinder:
rotating the handle from the first position to a third position, thereby (a) retracting the bolt relative to the faceplate surface and (b) exposing an additional fastener hole which extends through the housing and intersects the rear surface;

inserting a fastener through the additional fastener hole and tightening the fastener to further secure the rear surface of the lock housing on said face of the door; and

rotating the handle from the second position to the first position, thereby (a) extending the bolt relative to the faceplate surface and (b) blocking the additional fastener hole and the fastener inserted therethrough.
A method according to claim 12 or 13 wherein:
the lock assembly is a night latch assembly which has a lock case assembly and a cylinder assembly;

the lock housing, bolt and handle are provided by the lock case assembly; and

the method comprises attaching the lock case assembly and cylinder assembly to opposite faces of the door, the lock case assembly and cylinder assembly engaging one another via a tail bar running through a thickness of the door.
A door comprising a lock assembly according to any one of claims 1 to 11 and/or a lock assembly fitted using a method according to any one of claims 12 to 14.