Improvements relating to lock assemblies

Abstract

 A lock assembly (10) comprising a lock (20) for location within a closure and fixable relative to the closure, such that a first end portion (28) of the lock protrudes from an exposed side of the closure, and a cover member (78) that is adapted to at least impede access to the protruding, first end portion of the lock, wherein the cover member is fixable relative to the lock, by means of cooperating formations of the cover member and the lock.

Description

[0001] This invention relates to lock assemblies, and in particular to improving the security of such assemblies.

[0002] A common type of lock is a cylinder lock, which comprises an elongate barrel of substantially uniform cross-section that is suitable for fitting in a door or other closure, the barrel having a centrally located cam that is operated by movement of a key in the lock between open and locked positions. A cylinder lock has a cross-sectional profile that is shaped to closely match the shape of an opening within a door. When fitted within a door in this manner, at least one end of the lock cylinder is accessible from a side of the door. In the case of a conventional double cylinder lock, the lock extends through the entire thickness of the door, such that it is accessible from each side of the door.

[0003] The barrel of a conventional cylinder lock has a reduced thickness in the region of the centrally located cam, and hence this is a point of weakness in conventional cylinder locks. This area is typically weakened further by the presence of a fixing hole in this region, which enables fixation of the lock to an internal cavity within a door or other closure by way of a bolt or screw. It has been found that the application of a moment of sufficient magnitude to the protruding end of a conventional cylinder lock of this type will cause a reliable shear of the lock at the weakened central region.

[0004] There has now been devised an improved lock assembly which overcomes or substantially mitigates the above-mentioned and/or other disadvantages associated with the prior art.

[0005] According to a first aspect of the invention, there is provided a lock assembly comprising a lock for location within a closure and fixable relative to the closure, such that a first end portion of the lock protrudes from an exposed side of the closure, and a cover member that is adapted to at least impede access to the protruding, first end portion of the lock, wherein the cover member is fixable relative to the lock, by means of cooperating formations of the cover member and the lock.

[0006] The lock assembly according to the invention is advantageous principally because the cover member is adapted to at least impede access to the protruding, first end portion of the lock, which may reduce the risk of the lock being forcibly removed from the closure, for example by application of a moment of sufficient magnitude to the protruding, first end portion of the lock to cause a shear of the lock at a weakened central region. Furthermore, the cover member being fixable relative to the lock, by means of cooperating formations of the cover member and the lock, reduces the risk that the cover member will be removed from the closure by persons attempting unauthorised entry.

[0007] The present invention is particularly advantageous where the lock includes a weakened region, for example due to the presence of particular fixing arrangements or a cam for actuation of a bolt mechanism. The lock will typically be a cylinder lock, and in particular a double cylinder lock, which comprises a first lock cylinder integrally joined to a second lock cylinder. The first and second lock cylinders are preferably separately actuatable, and preferably include a cam therebetween for actuation of a bolt mechanism. In particular, a spine preferably extends along the length of the double cylinder lock, with the first and second lock cylinders being mounted to the spine, and the cam mounted between the first and second lock cylinders.

[0008] The lock preferably includes a body that is adapted for location within a bore in the closure, most preferably with a close fit, such that the first end portion of the lock protrudes from the bore on the exposed side of the closure. In presently preferred embodiments, the lock is actuatable from both sides of the closure, in which case a second end portion of the lock is accessible on a protected side of the closure. The bore in the closure is preferably therefore a through-bore, extending between the exposed and protected sides of the closure.

[0009] The lock is preferably fixable relative to the closure by a fixing that is inaccessible from the exposed side of the closure, when the closure is in a closed and locked configuration. In particular, the fixing is preferably inaccessible to persons attempting unauthorised opening of the closure. The fixing may be located within the closure, eg within an internal cavity, the fixing may be located on a protected side of the closure, or a combination of these fixings may be provided.

[0010] A type of lock for which the present invention is particularly advantageous is a lock that includes a fixing in a central region of the lock, where the presence of the fixing causes the central region to be weakened. In particular, the fixing typically comprises a threaded bore within the lock, with which a threaded fastener is engaged. Where the lock is a double cylinder lock, as described above, the fixing is typically adjacent to the cam for actuation of a bolt mechanism, and in particular in the part of the spine adjacent to the cam.

[0011] In presently preferred embodiments, the lock is fixable relative to the closure by a fixing at a second end portion of the lock, on a protected side of the closure. In particular, in a presently preferred embodiment, the lock has a body that is adapted for location within a bore in the closure, and the lock comprises formations at the protruding, first end portion of the lock that extend outwardly from the body of the lock, the outwardly-extending formations having dimensions that prevent passage of the protruding, first end portion of the lock through the bore in the closure.

[0012] The assembly is preferably provided with a securing member engageable with a second end portion of the lock, on a protected side of the closure. In particular, the second end portion of the lock is preferably adapted to protrude from the protected side of the closure, and the securing member preferably has dimensions that prevent passage of the securing member, and hence the protruding, second end portion of the lock, through the bore in the closure.

[0013] A cover member is preferably also provided on the protected side of the closure, in order to at least partially conceal the protruding, second end portion of the lock and any securing member, and preferably also provide a mount for a handle sub-assembly, as described below.

[0014] The securing member preferably has an aperture therethrough, the aperture being shaped to correspond to the profile of the second end portion of the lock. The securing member is preferably secured by fasteners engageable with both the securing member and the lock, for example engaging recesses in the lock.

[0015] The use of a lock that includes a fixing in a central region enables accurate positioning of the lock relative to a bolt mechanism of the closure. It is thought that the present invention substantially mitigates the weaknesses of this type of lock. However, a lock without a fixing in a central region may be used, such as that described in GB 2440743. In this arrangement, one or more spacers may be provided, for positioning between the outwardly-extending formations of the protruding, first end portion of the lock, and the adjacent surface of the closure and/or the cover member. The one or more spacers are preferably selectively engageable with the lock, such that a number of spacers may be used that provides appropriate positioning of the lock relative to the closure, and in particular the bolt mechanism of the closure.

[0016] The cover member is adapted to at least impede access to the protruding, first end portion of the lock, which may reduce the risk of the lock being forcibly removed from the closure. For example, the cover member may be particularly adapted to impede application of a moment of sufficient magnitude to the protruding, first end portion of the lock to cause a shear of the lock at a weakened central region.

[0017] The cover member is preferably adapted to at least partially enclose the protruding, first end portion of the lock. The cover member preferably comprises an enclosing wall that is adapted to extend about at least the lateral surfaces of the protruding, first end portion of the lock. The enclosing wall is preferably continuous, and preferably prevents unauthorised access to the lateral surfaces of the protruding, first end portion of the lock, at least. The cover member is preferably adapted to provide access to an end surface of the lock to enable actuation of the lock. The cover member preferably includes an opening, which enables access to an end surface of the lock. The end surface of the lock is preferably positioned, with a close fit, within the opening.

[0018] The cover member preferably comprises a face plate, and a peripheral skirt that extends into abutment with the surface of the closure. A rear surface of the cover member is preferably adapted to lie flush with the surface of the closure and, in particular, the skirt is preferably adapted to be in substantially continuous contact with the surface of the closure. The face plate is preferably orientated generally perpendicularly to the surface of the closure, and the face plate preferably has a flat exterior surface. In presently preferred embodiments, the cover member includes a raised portion, within which the protruding, first end portion is accommodated.

[0019] The cover member preferably forms a mount for both the lock and a handle sub-assembly, such that the cover member has a lock portion and a handle portion. The lock portion and the handle portion are preferably separated by a weakened region of the cover member, such that forced removal of the handle portion from the surface of the closure would cause the handle portion to shear from the lock portion. This feature prevents forced removal of the handle portion acting as a lever to also remove the lock portion, and hence enable access to the protruding, first end portion of the lock. The weakened region is preferably formed by one or more regions of the cover member that have a reduced thickness relative to the adjacent regions of the cover member. These one or more regions of reduced thickness are preferably arranged in a plane, about which the handle portion would shear from the lock portion. For example, the cover member may be provided with one or more grooves arranged in a shear plane.

[0020] The cover member is preferably fixable relative to the lock by means of at least part of the cover member being interposed between the lock and the surface of the closure. In particular, the lock preferably comprises formations at the protruding, first end portion of the lock that extend outwardly from the body of the lock, and at least part of the cover member is preferably adapted to be interposed between those formations and the surface of the closure.

[0021] In presently preferred embodiments, the lock has a flange extending outwardly from a body of the lock, and at least part of the cover member is adapted to be interposed between the flange and the surface of the closure. The body of the lock preferably has a generally constant profile, such that the body has a close fit within a bore in the closure. The flange preferably has a first, inner surface, which is preferably orientated substantially perpendicular to the longitudinal axis of body, and is preferably flat. The flange preferably has a second, outer face, which is tapered. The flange may extend around part, but not all, of the lock body. Most preferably, the flange is formed integrally with the body of the lock, for example by a casting manufacturing process.

[0022] The part of the cover member that is adapted to be interposed between the lock and the surface of the closure preferably has the form of one or more retention members that extend from an interior surface of the cover member, into a space between the lock, and most preferably the outwardly-extending formations of the protruding, first end portion of the lock, and the surface of the closure. Most preferably, these one or more retention members are disposed on at least opposing lateral sides of the lock. The one or more retention members may be adapted to at least partially accommodate the body of the lock with a close fit, and hence extend into a space between the outwardly-extending formations of the protruding, first end portion of the lock, and the surface of the closure. For example, the cover member may comprise a back plate, with an opening formed therein that is adapted to at least partially accommodate the body of the lock with a close fit.

[0023] In addition to the cover member being secured relative to the closure by means of the cooperating formations of the cover member and the lock, the cover member is preferably fixable relative to the closure by additional fixing arrangements. In particular, the cover member preferably includes formations adapted to engage with fixing members, such as threaded bolts, which extend from a protected side of the closure. In presently preferred embodiments, the cover member includes one or more sleeves having threaded interior surfaces, which are adapted to receive threaded fixing members extending from the protected side of the closure.

[0024] The cover member preferably forms a mount for a handle sub-assembly, such that the cover member has a lock portion and a handle portion. The handle sub-assembly preferably comprises at least one handle, and a connecting shaft that connects the handle to the bolt mechanism of the closure. The handle is preferably rotatably mounted to the cover member, eg within a corresponding opening. In presently preferred embodiments, the handle sub-assembly comprises a handle on each side of the closure, connected by a connecting shaft. In this arrangement, a cover member is preferably also provided on the protected side of the closure, in order to provide a mount for the handle on that side of the closure, and preferably also to at least partially conceal the protruding, second end portion of the lock and any securing member, as described above.

[0025] The handles and the connecting shaft are preferably coupled for rotation relative to the cover member(s), and in particular each handle is preferably fixable to one end of the connecting shaft. The fixing between the handle on the exposed side of the closure, and the connecting shaft, is preferably inaccessible in the installed configuration of the assembly. This fixing may, for example, be enclosed by the cover member on the exposed side of the closure in the installed configuration of the assembly. In these embodiments, the assembly is preferably arranged with only the fixing between the handle on the protected side of the closure and the connecting shaft being accessible, from the protected side of the closure, in the installed configuration of the assembly. The assembly is preferably therefore arranged such that the fixing between the handle on the exposed side of the closure, and the connecting shaft, is assembled before the handles are mounted to the cover members, and then the fixing between the handle on the protected side of the closure, and the connecting shaft, is assembled after the handles are mounted to the cover members.

[0026] The connecting shaft is preferably received within a co-axial bore of a connection end portion of the handle. The connecting shaft is preferably received within the co-axial bore with a close fit, and preferably has a non-circular cross-sectional shape. The connecting shaft preferably comprises a series of formations, which define a series of fixing points for at least one of the handles, such that the separation between the handles is variable. Most preferably, the connecting shaft includes a series of formations at each end, which define a series of fixing points for each handle. Each series of fixing points is preferably adapted to be engaged by a fixing member associated with the handle, at any one of a plurality of different positions. In presently preferred embodiments, the series of fixing points comprises a series of threaded bores, each adapted to be engaged by a threaded fastener that is also engaged with a threaded bore of the handle.

[0027] According to a further aspect of the invention, there is provided a closure including a lock assembly as described above. The closure is typically a door, with open and closed configurations. The closure preferably includes a bolt mechanism, with which the lock assembly cooperates in order to provide locked and unlocked configurations of the closure. In particular, the bolt mechanism preferably includes a bolt that is movable between an extended position, in which the bolt engages a keep and prevents opening of the closure, and a retracted position, in which the bolt disengages a keep and allows opening of the closure. The keep with which the bolt engages is typically provided in a frame of the closure, eg a door frame.

[0028] By "exposed side of the closure" is meant that side of the closure that is exposed to unauthorised persons, and hence for which it is desired to provide greater security against unauthorised access, eg the side of a door on the exterior of a building. The protected side of the closure is that side of the closure for which less security against unauthorised access, if any, is required, for example because the protected side of the closure is only exposed to authorised persons, eg the side of a door on the interior of a building.

[0029] Preferred embodiments of the invention will now be described in greater detail, by way of illustration only, with reference to the accompanying drawings, in which

Figure 1 is a front perspective view of a first embodiment of a door handle and lock assembly according to the invention;

Figure 2 is a rear perspective view of the door handle and lock assembly;

Figure 3 is an exploded, perspective view of the door handle and lock assembly;

Figure 4 is a first cut-away view of the door handle and lock assembly;

Figure 5 is a second cut-away view of the door handle and lock assembly;

Figure 6 is a third cut-away view of the door handle and lock assembly; and

Figure 7 is a front perspective view of a second embodiment of a door handle and lock assembly according to the invention.

[0030] Figures 1 and 2 show a first embodiment of a door handle and lock assembly according to the invention, which is generally designated 10. The assembly 10 is shown in its installed configuration, but with the door to which it is installed having been omitted from the drawings. Figure 3 is an exploded view of the assembly 10.

[0031] The assembly 10 is described below with respect to the door to which it is installed, which will have an "exposed side" and a "protected side". The exposed side of the closure is that side of the closure that is exposed to unauthorised persons, and hence for which it is desired to provide greater security against unauthorised access, eg the side of a door on the exterior of a building. The protected side of the closure is that side of the closure for which less security against unauthorised access, if any, is required, for example because the protected side of the closure is only exposed to authorised persons, eg the side of a door on the interior of a building.

[0032] The door handle and lock assembly 10 comprises a double cylinder lock 20, a handle sub-assembly 50, an exposed mount 70 and a protected mount 90. The exposed mount 70 is fixed to the exposed side of a door, and the protected mount 90 is fixed to the protected side of a door. The double cylinder lock 20 and the handle sub-assembly 50 each extend between the exposed and protected mounts 70,90, through separate through-bores in the door, in the installed configuration, as discussed in more detail below.

[0033] The double cylinder lock 20, also commonly referred to as a "Euro cylinder lock" or else a "Euro" lock, that is shown in the drawings is of a type that does not require a fixing hole in a mid-region of the lock 20, as described in GB 2440743. This configuration of lock 20 reduces the weakness at the mid-region of the lock 20, and hence reduces the risk of the lock 20 being forcibly sheared. It is noted that the present invention is thought to provide sufficient security that a double cylinder lock 20 having a fixing hole in its mid-region may be used (see the second embodiment shown in Figure 7). However, the use of a double cylinder lock 20 of the type described in GB 2440743 provides even greater security.

[0034] The cylinder lock 20 comprises two lock cylinders 22 and 24 arranged coaxially. A lower spine portion 26 connects the lock cylinders 22 and 24 and is integrally formed therewith, such that the spine 26 and cylinders 22 and 24 form a single member. A conventional locking pin arrangement (not visible in Figures 1-3) is housed within each of the cylinders 22,24.

[0035] The respective end faces 28 and 30 of the cylinders 22 and 24 face in opposing directions and are each provided with an opening in order to allow insertion of a key. In a central region of the lock 20, a cam 32 is interposed between the cylinders 22 and 24. The cam 32 has a central drum, which is mounted coaxially with the cylinders, and a locking arm extending radially therefrom. The spine 26 has a notch or recess, within which the locking arm of the cam 32 sits when in an inoperative, unlocked, condition. Upon operation of the lock 20, the locking arm of the cam 32 rotates to actuate an aligned element within a bolt mechanism of the door (not shown).

[0036] A flange 40 is integrally formed with the cylinder 22 on the exposed side of the door, towards the end face 28 thereof. The flange 40 has a substantially flat rear face plate which extends in a plane substantially perpendicular to the longitudinal axis of the cylinder lock 20. The opposing face of the flange 40 is obliquely oriented and is tapered towards the surface of the cylinder 22, such that an incline is formed leading up to a discontinuity or step formed by the face of the rear face plate. The rear face of the flange 40 is parallel with the end face 28 of the cylinder 22, but facing in an opposing direction.

[0037] Towards the end face 30 on the protected side of the door, an elongate groove or indentation 34 is provided on each side of the spine 26. The groove 34 is elongate in shape, extending in a direction parallel with the longitudinal axis of the lock 20. More specifically, the grooves 34 have parallel side walls and curved edges, forming an oval indentation in each side of the spine 26.

[0038] The spine 26 is also provided with a rounded lower face that extends the length of the cylinder lock 20. A series of formations 36 is visible at each end of this lower face, which are the ends of the sockets for the locking pins within the cylinder lock 20.

[0039] On the protected side of the door, the end of the cylinder lock 20 is fixed to a securing plate 38. The securing plate 38 is formed of a rectangular block having a substantiality flat rear face, which is adapted to abut the adjacent surface of the door in the installed configuration. The front and rear faces of the securing plate 38 are separated by a peripheral, side face that is provided with bevelled edges. The securing plate 38 has a central aperture extending therethrough, through which the end of the cylinder lock 20 extends. The shape of the central aperture corresponds to the sectional profile of the body of the cylinder lock 20, such that there is a relatively close fit between the cylinder lock 20 and the securing plate 38.

[0040] In addition, the securing plate 38 is provided with internal, threaded bores that extend through the securing plate 38 between the peripheral, side face and the walls of the central aperture. The threaded bores extend from opposing sides of the securing plate 38 towards the central aperture. The positioning of the bores is arranged to correspond to the positions of the grooves 34 within the spine 16 of the cylinder lock 20. The securing plate 38 is fixed to the end of the cylinder lock 20 by screws that are engaged with the threaded bores of the securing plate 38, and are received within the grooves 34 in the spine 26 of the lock 20.

[0041] As shown in Figure 3, the cylinder lock 20 is positioned with respect to the exposed mount 70 by means of one or more shims 42 (four shims 42 are shown in Figure 3). Each shim 42 is generally planar in form, and has opposing and substantially parallel front and rear faces. The depth of each shim 42 is significantly smaller than the width or height of the shim. Each shim 42 is provided with a cut-away portion, which is open at the lower edge of the shim 42. The cut-away portion of each shim 42 has a shape that corresponds to the profile of the body of the cylinder lock 20, such that each shim 42 may be slidably engaged with the body of the cylinder lock 20, with a relatively close fit.

[0042] As discussed above, the double cylinder lock 20 and the handle sub-assembly 50 each extend between the exposed and protected mounts 70,90, through separate through-bores in the door, in the installed configuration. The exposed and protected mounts 70,90 each comprise a face plate 72,92, and a peripheral skirt 74,94 that extends perpendicularly from the edge of the mount 70,90 into abutment with the respective surface of the door. The face plates 72,92 are substantially planar, and the skirts 74,94 each have a constant depth, such that the abutment edges of the skirts 74,94 are in contact with the respective surfaces of the door along their entire extent.

[0043] The exposed mount 70, which is located on the exposed side of the door, comprises an opening towards its upper end that accommodates the shaft 56 of the handle assembly 50, and a raised housing 76 towards its lower end that accommodates the end of the cylinder lock 20 that includes the flange 40. The raised housing 76 has a side wall that defines a generally rectangular enclosure for accommodating the end of the cylinder lock 20, and a front face defined by a separate cover plate 78. The cover plate 78 includes a circular opening, which exposes the end face 28 of the cylinder lock 20, in the installed configuration. The cover plate 78 also includes rearwardly extending fastening arms, with outwardly projecting end portions, which resiliently engage a rearwardly facing shoulder on the interior surface of the side wall, in order to fasten the cover plate 78 to the side wall of the raised housing 76. This arrangement is shown most clearly in the cut-away view of Figure 5.

[0044] As shown in Figures 2, 4 and 5, the exposed mount 70 also includes a back plate 80 that extends between interior surfaces of the skirt 74, behind the raised housing 76. The back plate 80 includes an opening with a shape that corresponds to the profile of the body of the cylinder lock 20, such that the cylinder lock 20 extends through the opening in the back plate 80 with a close fit. The flange 40 of the cylinder lock 20, and the one or more shims 42, are disposed within the space between the cover plate 78 of the raised housing 76 and the back plate 80, and these parts of the cylinder lock 20 have greater dimensions than the opening in the back plate 80, thereby preventing passage of the flange 40 or the one or more shims 42 through the opening in the back plate 80. In particular, the cylinder lock 20 and the shims 42 are arranged with the shims 42 sandwiched between the flange 40 of the cylinder lock 20 and the front surface of the back plate 80.

[0045] In addition, the exposed mount 70 includes a region of reduced strength, immediately above the raised housing 76 and the back plate 80. In particular, the skirt 74 of the exposed mount 70 includes v-shaped grooves 79 that extend across the width of its interior surface, on each side of the interior of the exposed mount 70, immediately above the back plate 80.

[0046] The handle sub-assembly 50 comprises front and rear handles 52,54, which are connected by a shaft 56 that extends through openings in the exposed and protected mounts 70,90, and through a corresponding through-bore in the door to which the door handle and lock assembly 10 is installed. As shown most clearly in Figures 4 and 6, the handles 52,54 are each mounted within the openings in the upper portion of the mounts 70,90, for rotation relative to the mounts 70,90. In particular, a connection portion of each handle 52,54 is cylindrical in form, with a threaded exterior surface and a reduced diameter relative to the adjacent portion of the handle 52,54, such that a rearwardly facing shoulder is defined. These connection portions are adapted to extend through the openings in the upper portions of the mounts 70,90, such that the shoulders of the handles 52,54 and associated washers abut the outer surfaces of the mounts 70,90, and the threaded surfaces of the connection portions are disposed to the rear of the face plates 72,92 of the mounts 70,90. A circlip and an associated washer secures each handle 52,54 to the associated mount 70,90, such that the handle 52,54 is rotatable relative to the mount 70,90.

[0047] The shaft 56 connects the handles 52,54 of the handle sub-assembly 56, and is adapted to connect the handle sub-assembly 50 to the bolt mechanism of the door (not shown). The shaft 56 has a generally square cross-section, with bevelled edges, and is received at each end within a correspondingly shaped, co-axial bore 58 formed in the connection portion of each handle 52,54. The shaft 56 is received within the bore 58 of each handle 52,54 with a close fit, such that the handles 52,54 and shaft 56 are coupled for simultaneous rotation.

[0048] A series of circular recesses 60 is formed at each end of the shaft 56, aligned along one of the faces of the shaft 56. The handle 52 that is mounted to the exposed mount 70, and hence positioned on the exposed side of the door, includes a radial, threaded bore in its connection portion. A screw 62 is engaged with the threaded bore in the connection portion of the handle 52, and extends into one of the recesses 60 at that end of the shaft 56. The outer end of the screw 62 is depressed relative to the threaded surface of the connection portion of the handle 52.

[0049] In addition, the handle 54 that is mounted to the protected mount 90, and hence positioned on the protected side of the door, includes a radial, threaded bore in a portion of the handle 54 that is adjacent to the connection portion, and hence is accessible in the installed configuration. A screw 62 is engaged with the threaded bore in the handle 54, and extends into one of the recesses 60 at that end of the shaft 56. The outer end of the screw 62 is depressed relative to the threaded surface of the connection portion of the handle 52.

[0050] The exposed and protected mounts 70,90 also include an arrangement for fixing the mounts 70,90 to the door. In particular, the face plate 92 of the protected mount 90 includes two apertures 96, one at the lower end of the face plate 92 and one positioned just below the handle sub-assembly 50. Each aperture 96 has a tapered side wall, and is adapted to accommodate the head of a corresponding bolt. A sleeve 98 extends rearwardly from each aperture 96, and projects beyond the skirt 94 at the protected end of the mount 90. Corresponding sleeves 78, each with a threaded internal surface, project from the rear surface of the face plate 72 of the exposed mount 70. The sleeves 78,98 are located, in the installed configuration, within each end of two through-bores that extend through the door (not shown in the Figures). A threaded bolt with an enlarged head (not shown in the Figures) is engaged with the exposed and protected mounts 70,90 through these apertures 96 and corresponding sleeves 78,98. In particular, the shaft of each threaded bolt extends through the corresponding aperture 96 and sleeve 98 of the protected mount 90, through the corresponding through-bore in the door, and into threaded engagement with the corresponding sleeve 78 of the exposed mount 70. The enlarged heads of the threaded bolts are accommodated within the apertures 96, such that the enlarged heads are flush with the surface the face plate 92 of the protected mount 96. The threaded bolts secure the exposed and protected mounts 70,90 to the surfaces of the door.

[0051] As discussed above, the door in which the door handle and lock assembly 10 is installed has through-bores for the threaded bolts, the cylinder lock 20 and the shaft 56 of the handle sub-assembly 50. The through-bore for the cylinder lock 20 is generally keyhole shaped in profile, and adapted to receive the body of the cylinder lock 20 with a close fit.

[0052] Prior to insertion into the door, the cylinder lock 20 is inserted through the opening in the back plate 80 of the exposed mount 70, with an appropriate number of shims 42 located between the flange 40 and the back plate 80. In addition, the shaft 56 of the handle sub-assembly 50 is fixed within the co-axial bore of the appropriate handle 52, and the handle 52 is mounted to the corresponding aperture in the exposed mount 70.

[0053] The cylinder lock 20 is then inserted into the correspondingly shaped through-bore in the door, and the shaft 56 of the handle sub-assembly 50 is inserted through the corresponding through-bore in the door, from the exposed side of the door. The cylinder lock 20 and the exposed mount 70 are moved into a position in which the flange 40 and any shim(s) 42 abut the back plate 80 of the exposed mount 70, and the skirt 72 of the exposed mount 70 abuts the surface of the door.

[0054] In this configuration, the other end of the cylinder lock 20 and the shaft 56 of the handle sub-assembly 50 will project from the corresponding through bores in the door, on the protected side of the door.

[0055] The securing plate 38 is positioned around the portion of the cylinder lock 20 that protrudes from the door surface, on the protected side of the door. The securing plate 38 is pressed into position against the door surface such that the threaded bores in the side wall of the securing plate 38 align with the grooves 34 in the spine 26. A screw or bolt is inserted and tightened in each threaded bore, so as to fix the securing plate 38 securely to the cylinder lock 20.

[0056] In addition, the other handle 54 of the handle sub-assembly 50 is mounted to the corresponding aperture in the protected mount 90. Once the securing plate 38 is fixed to the cylinder lock 20, the protected mount 90 is positioned over the securing plate 38, such that the shaft 56 of the handle sub-assembly 50 is received within the co-axial bore of the handle 54 mounted to the protected mount 90, and the securing plate 38 is accommodated within the skirt 94 of the protected mount 90. In this configuration, the end of the cylinder lock 20 is received within the corresponding opening in the face plate 92 of the protected mount 90, and the skirt 94 of the protected mount 90 abuts the surface of the door.

[0057] In order to secure the handle sub-assembly 50, a screw 62 is engaged with the threaded bore in the handle 54 mounted to the protected mount 90, until it engages with the recess 60 in the shaft 56 that is aligned with the threaded bore in the handle 54.

[0058] Finally, the exposed and protected mounts 70,90 are secured to the door by means of threaded bolts that extend through corresponding apertures 96 and sleeves 98 of the protected mount 90, through the corresponding through-bores in the door, and into threaded engagement with the corresponding sleeves 78 of the exposed mount 70.

[0059] It is noted that the use of differing numbers of shims 42 enables the installer to adjust the position of the cylinder lock 20 relative to the exposed and protected mounts 70,90, as required. This adjustment may be used to cancel out any engineering tolerances present in the door, the cylinder lock 20, or the exposed and protected mounts 70,90, in order to ensure that the cam 32 of the cylinder lock 20 is located at the position required for correct operation.

[0060] Once installed, the cylinder lock 20 is secured to the door by the securing plate 38, which is on the protected side of the door, and hence inaccessible to anybody attempting unauthorised access through the door. As discussed above, it has been found that, in conventional arrangements, the application of a moment of sufficient magnitude to the protruding end of a cylinder lock will cause a reliable shear of the lock at the weakened central region. However, in this embodiment of the door handle and lock assembly according to the invention, it would be necessary to remove the exposed mount 70 in order to access the protruding end of the cylinder lock 20.

[0061] The engagement between the flange 40 of the cylinder lock 20, and the back plate of the exposed mount 70, provides a secure fixing for the exposed mount 70, which prevents removal of the exposed mount 70 from the door. In addition, the weakened region formed by the v-shaped grooves 79 in the exposed mount 70 means that if the upper part of the exposed mount 70 is prised from the door, the upper part of the exposed mount 70 will separate from the door, rather than acting as a lever that also prises the lower part of the exposed mount 70, which covers the protruding end of the cylinder lock 20, from the door.

[0062] As discussed above, the door handle and lock assembly 10 shown in Figures 1 to 6 has a double cylinder lock 20 that is of a type that does not require a fixing hole in a mid-region of the lock 20, as described in GB 2440743. This configuration of lock 20 reduces the weakness at the mid-region of the lock 20, and hence reduces the risk of the lock 20 being forcibly sheared. However, the present invention is thought to provide sufficient security that a double cylinder lock 20 having a fixing hole in its mid-region may be used. Figure 7 therefore shows a second embodiment of the door handle and lock assembly according to the invention, which is generally designated 110, in which the cylinder lock 120 is of a type that has a fixing hole 121 in a mid-region of the lock 120, which enables the lock 120 to be accurately positioned relative to the bolt mechanism of the door.

Claims

1. A lock assembly comprising a lock for location within a closure and fixable relative to the closure, such that a first end portion of the lock protrudes from an exposed side of the closure, and a cover member that is adapted to at least impede access to the protruding, first end portion of the lock, wherein the cover member is fixable relative to the lock, by means of cooperating formations of the cover member and the lock.

2. A lock assembly as claimed in Claim 1, wherein the lock is fixable relative to the closure by a fixing at a second end portion of the lock, on a protected side of the closure.

3. A lock assembly as claimed in Claim 1 or Claim 2, wherein the lock has a body that is adapted for location within a bore in the closure, and the lock comprises formations at the protruding, first end portion of the lock that extend outwardly from the body of the lock, the outwardly-extending formations having dimensions that prevent passage of the protruding, first end portion of the lock through the bore in the closure.

4. A lock assembly as claimed in Claim 3, wherein the assembly is provided with a securing member engageable with a second end portion of the lock, on a protected side of the closure, the second end portion of the lock being adapted to protrude from the protected side of the closure, and the securing member having dimensions that prevent passage of the securing member through the bore in the closure.

5. A lock assembly as claimed in any preceding claim, wherein the cover member is adapted to partially enclose the protruding first end portion of the lock and thereby impede application of a moment of sufficient magnitude to the first end portion to cause a shear of the lock at a weakened central region.

6. A lock assembly as claimed in any preceding claim, wherein the cover member comprises a, typically continuous, enclosing wall that is adapted to extend about at least the lateral surfaces of the protruding, first end portion of the lock.

7. A lock assembly as claimed in any preceding claim, wherein the cover member forms a mount for both the lock and a handle sub-assembly, such that the cover member has a lock portion and a handle portion.

8. A lock assembly as claimed in Claim 7, wherein the lock portion and the handle portion are separated by a weakened region of the cover member, such that forced removal of the handle portion from the surface of the closure would cause the handle portion to shear from the lock portion.

9. A lock assembly as claimed in Claim 8, wherein the weakened region is formed by one or more regions of the cover member that have a reduced thickness relative to the adjacent regions of the cover member.

10. A lock assembly as claimed in Claim 8 or Claim 9, wherein the one or more regions of reduced thickness are arranged in a plane, about which the handle portion would shear from the lock portion.

11. A lock assembly as claimed in any preceding claim, wherein the cover member is fixable relative to the lock by means of at least part of the cover member being interposed between the lock and the surface of the closure.

12. A lock assembly as claimed in Claim 11, wherein the lock comprises formations at the protruding, first end portion of the lock that extend outwardly from the body of the lock, and at least part of the cover member is adapted to be interposed between those formations and the surface of the closure.

13. A lock assembly as claimed in Claims 11 or 12, wherein the part of the cover member that is adapted to be interposed between the lock and the surface of the closure has the form of one or more retention members that extend from an interior surface of the cover member, into a space between outwardly-extending formations of the protruding, first end portion of the lock, and the surface of the closure.

14. A lock assembly as claimed in any one of claims 11 to 13, wherein the cover member comprises a back plate, with an opening formed therein that is adapted to at least partially accommodate the body of the lock with a close fit.

15. A lock assembly as claimed in any preceding claim, wherein the cover member is secured relative to the closure by means of the cooperating formations of the cover member and the lock, and the cover member is further fixable relative to the closure by additional fixing arrangements, typically on the protected side of the closure.

16. A lock assembly as claimed in any preceding claim, wherein the cover member forms a mount for a handle sub-assembly, the handle sub-assembly comprising at least one handle, and a connecting shaft that connects the handle to the bolt mechanism of the closure, the fixing between the handle on the exposed side of the closure, and the connecting shaft, being enclosed by the cover member on the exposed side of the closure in the installed configuration of the assembly.

Drawing