IE20200237A1 - Locking assembly - Google Patents

Abstract

locking assembly for a door or window having a casing; and a locking mechanism located within the casing. the locking mechanism has a cam follower engageable with a cylinder lock and moveable between first and second positions. The cam follower has at least one charmel formed therein, and the casing has a motion limiter configured to engage the at least one charmel and limit motion of the cam follower. The locking assembly is more resistant to attacks which seek to actuate the locking mechanism by breaking through the skin of the door or window.

Description

Field of Invention The invention relates to locking assemblies for windows and doors, and more specifically to a locking assembly which is more resistant to brute force attacks.

Background Many existing locking assemblies for windows and doors, such as mortice locks and multi—point locks (MPLS), are typically morticed (recessed) into the door or window leaf.

This hides the locking mechanism and thus provides both aesthetic and security benefits, since only the face edge of the locking assembly is accessible when the door or window is open. At all other times, the remainder of the locking assembly and the locking mechanism therein is completely hidden and inaccessible. To make the locking assembly easy to install, the locking assembly is supplied preassembled and is configured to be inserted into a mortice or recess in the door or window leaf. The locking assembly can then be actuated (locked and unlocked) by a handle which extends through the surface of the door or window leaf, and/or by a key which can be inserted through an aperture in the door or window leaf. Such locking assemblies have become widely adopted for exterior doors of all varieties, such as wooden and composite doors in which mortices are cut and in extruded uPVC, aluminium and steel doors in which the casing can be received within the extrusion profile or in which mortices can also be formed.

Summary of Invention Advances in such locking assemblies have focussed on improving the locking mechanism’s resistance to attacks such as lock picking, lock snapping, drilling and bumping, among others. A result of this increase in security is that attackers have found new ways to overcome existing locking assemblies. In some extreme cases, it is possible to drill through or destroy part of the door or window surface in order to access the locking mechanism recessed within the door or window leaf. Attackers have then found it possible to manipulate or bypass the locking mechanism in the locking assembly.

The present invention attempts to resolve and/or ameliorate one or more of the problems with looking mechanisms for windows and doors and/or provide a valuable alternative.

According to a first aspect of the invention, there is provided a locking assembly for a door or window. The locking assembly may comprise a casing. The locking assembly may comprise a locking mechanism. The locking mechanism may be located within the casing. The locking mechanism may comprise a cam follower. The cam follower may be engageable with a cylinder lock. The cam follower may be moveable between first and second positions. The cam follower may comprise at least one channel therein.

The casing may comprise at least one motion limiter. The at least one motion limiter may be configured to engage the at least one channel and limit motion of the cam follower.

The first and second positions may correspond to locked and unlocked states of the locking mechanism. The assembly described above is advantageous, since it provides a simple and secure mechanism to limit the motion of the cam follower and thus ensure efficient and secure operation of the locking assembly.

The at least one motion limiter may comprise a rail. The rail may project internally from the casing. The rail may be straight. The rail may be curved. The rail may be integrally formed in the casing. For example, the rail may be formed by a stamping or moulding process. The rail may be formed so that the rail and the casing are a continuous surface e.g. with no slots or openings therein. This configuration is advantageous, since without any openings in the casing, it is not possible to access the cam follower from the outside of the casing. Thus a potential method of attacking the locking assembly is prevented.

The cam follower may comprise a first and second channel. The first and second channels may be located on opposing sides of the cam follower. The first and second channels may be curved or they may be straight. The casing may comprise first and second motion limiters. The first and second motion limiters may be configured to engage the first and second channels. Placing first and second channels on opposing sides of the cam follower results in smooth motion of the cam follower with respect to -‘I M&C PB156677lE the motion limiters. Compared to some existing locking mechanisms, the cam follower experiences less wobble or play, and thus is easier for a user to move e.g. via a cylinder lock.

The casing may comprise a first casing portion and a second casing portion. The first and second casing portions may be connectable to each other by any suitable means.

In some embodiments, the first and second casing portions are connected to each other with mechanical fasteners.

The first casing portion may comprise the first motion limiter. The second casing portion may comprise the second motion limiter. Such a configuration is simpler to manufacture and reduces the need for additional parts.

The first and second casing portions may overlap in a region adjacent to the cam follower.

According to a second aspect of the invention, there is provided a locking assembly for a door or window. The locking assembly may comprise a casing. The casing may comprise first and second casing portions. The locking assembly may comprise a locking mechanism. The locking mechanism may be located within the casing. The locking mechanism may comprise a cam follower. The cam follower may be engageable with a cylinder lock. The cam follower may be moveable between first and second positions. The first and second casing portions may overlap in a region adjacent to the cam follower.

Having the first and second casing portions overlap is advantageous, since it prevents an attacker from inserting a lever into the seam between the two casing portions. By preventing such access in a region adjacent to the cam follower, unauthorised access to the cam follower is prevented.

According to any aspect of the invention, the first and second casing portions may comprise first faces and second faces. The second faces may extend perpendicularly from the first faces. The second faces may be configured to overlap in the region adjacent to the cam follower.

The second faces may form or extend across a rear edge or face of the casing. For example, the second faces may form or extend across a rear edge or face of the casing in the region of overlap. The second faces may both extend across the full width of the rear face of the casing.

According to a third aspect of the invention, there is provided a sleeve for a locking assembly, the sleeve being configured to be fittable over a casing of a locking assembly and impede or block access to the casing.

The locking assembly of the first or second aspect may further comprise a sleeve according to the third aspect.

According to a fourth aspect of the invention, there is provided locking assembly for a door or window. The locking assembly may comprise a casing. The locking assembly may comprise a locking mechanism. The locking mechanism may be located within the casing. The locking mechanism may comprise a cam follower. The cam follower may be engageable with a cylinder lock. The cam follower may be moveable between first and second positions. The locking assembly may comprise a sleeve according to the third aspect of the invention.

Providing a sleeve is advantageous, because the sleeve can cover any openings or seams in the casing, and thus prevents access to the interior of the casing and to the cam follower.

According to any aspect of the invention, the sleeve may be configured to be fittable over the casing and receive the casing therein.

The sleeve may comprise at least one connection means for connecting the sleeve to the casing. In some embodiments, the sleeve may comprise a connection means on a first and second surface. The sleeve may comprise a connection means on a front and/or rear face of the sleeve. The sleeve may be provided with a connection means on two faces, three faces, or four or greater faces. The sleeve may be provided with multiple connection means on one or more surfaces. The or each connection means may comprise connector apertures for receiving a mechanical fastener therethrough.

The connector apertures may be located so that one or more of the mechanical —1 M&C PB156677|E fasteners connecting the first and second casing portions, extend through a connector aperture of the sleeve. Such a configuration reduces the need for additional fasteners, and retains the sleeve securely in position.

The sleeve may be configured so that, when fitted over the casing, the sleeve covers a seam or aperture in the casing. For example, the sleeve may cover a seam between first and second casing portions. The sleeve thus obscures potential points for attacking a locking assembly.

The sleeve may be configured so that in use the sleeve is located between a casing of a locking assembly and a surface (e.g. an internal surface) of a door or window leaf.

For example, the sleeve may be configured to fit over a casing and within a mortice or recess in a door or window e.g. in which the locking assembly is located.

The sleeve may be continuously formed e.g. the sleeve may be formed from a single component which is shaped to conform to the casing. Thus, the sleeve may form a continuous outer surface.

The sleeve may be formed by any suitable process, such as bending, stamping, drawing, moulding and/or extrusion. The sleeve may be formed from a metal. For example, the sleeve may comprise steel. The sleeve may be formed from a plastics material. The plastics material may be a reinforced plastics material, such as a fibre reinforced plastics material.

The casing and the sleeve may each comprise a lock aperture for receiving a cylinder lock therethrough. The sleeve may comprise a first lock aperture on a first face and a second lock aperture on a second face. This arrangement aids simple alignment of the sleeve. Furthermore, since a lock cylinder would typically extend through the locking assembly and extend therefrom, the lock cylinder prevents removal of the sleeve.

The sleeve may be substantially cuboidal. The sleeve may comprise at least one open face. The sleeve may be configured so that the casing is insertable into the sleeve via the at least one open face. In such embodiments, assembly of the locking mechanism can be completed by inserting the assembled casing into the sleeve and optionally securing the sleeve in position.

M&C PB156677|E The sleeve may comprise first and second open faces. The sleeve may comprise a tab portion. The tab portion may extend across a portion of one of the open faces. The tab portion may be configured to prevent removal of the sleeve through the othenNise open face. The tab may be provided with a connection means. The open surface may be configured so that the casing extends from the sleeve through the open surface. Thus, the sleeve can be configured to protect specific regions or areas of the casing. The sleeve need not cover the full exterior of the casing. One of the open surfaces may correspond to the front surface of the locking mechanism. Such configurations save on material costs and still provide the desired improved security.

Brief Description of the Drawings Embodiments of the invention will now be described by way of example only with reference to the following figures, in which: Figure 1 shows a perspective view of a locking assembly; Figure 2 is a magnified view of the region A of Figure 1; Figure 3 is a magnified view of a first casing portion viewed from an inner side; Figure 4 is the magnified view of the region A of Figure 1, with the first casing portion removed; Figure 5 is a magnified view of a second locking assembly; Figure 6 is an exploded view of the second locking assembly; Figure 7 is a magnified view of a third locking assembly; and Figure 8 is a perspective view of a sleeve for a locking assembly.

Specific Description Turning now to Figure 1, there is shown a perspective view of a locking assembly 1.

The locking assembly 1 has a casing 4, a locking bolt 5 and a latch bolt 7. The casing 4 is configured to be recessed into a door or window leaf (not shown). Inside the casing 4 is a locking mechanism (not shown) which is operable by a user to extend and retract the locking bolt 5 and latch bolt 7. The locking mechanism is engaged with a spindle follower 9, which receives a spindle (not shown) from a handle assembly (not shown).

M&C PB156677lE Figure 2 is a magnified view of region A of Figure 1, and shows a lower portion of the locking assembly 1. The casing 4 is formed from a first casing portion 41 and a second casing portion 43. The first and second casing portions are connected to each other via mechanical fasters 45. In the embodiment shown, the mechanical fasteners 45 are SCFBWS.

The locking assembly has a lock aperture 11 which is shaped to receive a lock cylinder (not shown) therein. Adjacent to the lock aperture 11 is a first motion limiter 13 and stop guide 15. The first motion limiter 13 and the stop guide 15, when viewed from the exterior of the casing 4, are depressions in the exterior surface of the casing 4. In the embodiment shown, the lock aperture 11 is shaped to receive a standard euro cylinder lock, although the lock aperture 11 may be shaped to receive any other form of lock cylinder.

Turning now to Figure 3 there is shown the interior side of the first casing portion 41 in the region A. The first motion limiter 13 projects from the internal face of the first casing portion 41. The first motion limiter 13 forms a rail. in the embodiment shown, the rail is a straight or linear rail. Adjacent to the first motion limiter 13 is the stop guide 15, which also projects from the internal face of the first casing portion 41. The stop guide 15 has a castellated shape with a pair of recesses 16 separated by walls 17.

The first motion limiter 13 and the stop guide 15 are formed integrally with the first casing portion 41, for example, by a stamping process or other suitable forming technique. The casing 4 is preferably formed from steel and the first motion limiter 13 is stamped into the first casing portion 41. The first casing portion 41, the first motion limiter 13 and the stop guide 15 are thus all continuously formed i.e. there are no openings or slots in the first casing portion 41 needed to form the first motion limiter 13 or stop guide 15. Since both the first motion limiter 13 and the stop guide 15 project from the inner surface, they provide a structure which is engageable from the inside of the casing 4.

Turning now to Figure 4, there is shown the same view of region A as shown in Figure 2, but with the first casing portion 41 removed to show the interior of the casing 4. The second casing portion 43 is formed in the shape of a shallow tray and defines the depth of the casing 4. Within the casing 4 is a locking mechanism, which includes a drive M&C PB156677lE plate 20, which operates similarly to known drive plates within locking mechanisms.

The locking mechanism further has a cam follower 25 located adjacent to the lock " aperture 11. Also shown is a lifter arm 21, which has a slot 22 therein which engages a tooth 23 provided on the cam follower 25. At the opposite end (not shown) the lifter arm is connected to or engageable with further parts of the locking mechanism.

The cam follower 25 is formed from two parts, a cam follower body 26 and a restrictor arm 27. The cam follower body has a channel 29 formed therein. The channel 29 extends laterally across the cam follower body 26 to define a length, extends into the cam follower body 26 to define a depth, and extends in a vertical direction to define a width of the channel 29. The width and depth of the channel 29 correspond with the width of the first motion limiter 13, and the height of the first motion limiter 13 (i.e. how far the first motion limiter projects from the planar surface of the first casing portion).

The restrictor arm 27 is movably connected to the cam follower body 26 by a biasing mechanism (not shown), such as a spring, which biases the restrictor arm 26 into the position shown. The restrictor arm 27 is moveable, relative to the cam follower body 26, in a single direction. The direction is perpendicular to the length of the channel 29 and the motion axis of the cam follower 25 (described below). The restrictor arm 27 has a foot 30 at a first end located closest to the lock aperture 11 and a projection 31 located at a second, opposite end. The projection 31 is configured to engage the recesses 16 of the stop guide 15.

Not shown in Figures 3 and 4 is a second motion limiter with the same structure as the first motion limiter 13. The second motion limiter is provided on the second casing portion 43, and is located opposite to the first motion limiter 13. The cam follower body 26 has a second channel on the opposite side to the channel 29. The channel 29 and second channel are parallel. The second channel receives the second motion limiter to further constrain the motion of the cam follower 25 in use.

In use, a cylinder lock, such as a euro profile lock cylinder, will be located in the lock aperture 11. The cylinder lock can be fixed in position by inserting a mechanical fastener through a hole in the lock cylinder as is known in the art. The first and second casing portions 41, 43 have lock tabs 28 which extend perpendicularly from the inner surfaces of the first and second casing portions 41, 43 and allow a mechanical fastener -1 M&C PB156677lE to extend through the casing 4 to engage the lock cylinder. The mechanical fastener can engage a faceplate (not shown) on the exposed front face of the locking assembly and a connection means 35 on the rear face of the casing 3.

Cylinder locks have a cam which is rotatable relative to the body of the cylinder lock.

The cam follower 25 is configured to receive the cam and be moved by the rotation of the cam. In Figure 4, the cam follower 25 is in a first position corresponding to an unlocked state of the locking mechanism. A user will rotate the cam anti-clockwise via a key (the skilled person will appreciate that the directions are for descriptive purposes only). The cam engages the foot 30 of the restrictor arm 27, and as the cam rotates, lifts the restrictor arm 27. The projection 31 of the restrictor arm 27 is raised out of a recess 16 of the stop guide 15 so that it is positioned above the walls 17.

As the cam continues to rotate, it engages a drive surface 33 of the cam follower body 26. The cam follower 25 is then pushed laterally by the cam toward the front face of the casing 4 (i.e. to the left as pictured). The cam follower 25 is limited to a single axis of motion by the first motion limiter 13 and the second motion limiter received within the channels 29. The cam follower 25 thus moves linearly. As the rotation of the cam completes, the cam disengages the foot 30 of the restrictor arm 27, which thus returns to its default position relative to the cam follower body 26. The projection 31 thus drops into the respective recess 16, having been lifted and moved laterally over the central wall 17 by the cam rotation. The restrictor arm 27 and the stop guide 15 thus form a mechanism to prevent the cam follower 25 being manipulated laterally between first and second positions by attackers not using a key. The cam follower 25 comes to rest in a second position, corresponding to a locked state of the locking mechanism. in order to unlock the locking mechanism, a key is inserted into the lock cylinder and the DFOCSSS reversed.

The embodiment is advantageous, since as shown in Figures 2 and 3, the first casing portion 41 is a continuous surface. The first motion limiter 13 and the stop guide 15 are formed integrally into the first casing portion 41, and thus provide the necessary motion guide and anti-attack mechanism for the locking mechanism. The same configuration is used on the rear face (not shown) of the casing to form a second motion limiter. -1 M&C PB156677lE Conventionally, the motion of the cam follower 25 and the function of the stop portion are provided by slots or suitable shaped apertures in casing, which receive projections provided on the cam follower. Such an arrangement is shown for descriptive purposes in Figure 5. Although the conventional configuration is able to limit the cam follower 25 to the desired axis of motion, an attacker could drill through the surface of the door and manipulate the cam follower 25 directly using a thin tool such as a screwdriver. By inverting the configuration in the manner disclosed herein, access to the cam follower 25 is prevented, since there are no apertures or slots in the outer continuous surface of the casing 4 through which the cam follower 25 is accessible.

Furthermore, the present embodiment achieves this effect without a significant increase in cost, or manufacturing complexity. For example, the present embodiment avoids fixing a plate over the slots in the casing or fixing additional components to the inside of the casing. . The motion limiter 13 and stop portion 15 in the current embodiment can be formed into the casing 4 in the same process as forming the casing portions 41, 43 from a blank and thus does not require any significant additional tooling or additional fixing steps.

Turning now to Figures 5 and 6, there is shown a second embodiment of the invention, wherein description of like parts and components will not be repeated. Shown is a locking assembly 100, which has a casing 104 formed of a first casing portion 141 and a second casing portion 143.

The first casing portion 141 has a first face 144 and a second face 145. The second face 145 extends perpendicularly from the first face 144. The second casing portion 143 has a first face 144 and a second face 145. The second faces 145 are formed integrally with the first faces 144 and are connected by an edge 146. The edge 146 can be formed by bending the second face 145 relative to the first face 144 to provide a continuous surface.

The first and second casing portions 141, 143 of the locking assembly 100 are connected to each other in the same manner as the locking assembly 1 of Figures 1 to 4. However, the first and second casing portions 141, 143 of the locking assembly differ in that both casing portions are provided with second faces 145. When assembled, the second faces 145 form the rear face of the casing 104. In the embodiment shown, the second face 145 of the first casing portion 141 is configured to M&C PB156677|E overlap the second face 145 of the second casing portion 143. Thus, there is a double layer formed in the rear face of the casing 104. This region of overlap is located adjacent to the cam follower 125. As shown, both second faces 145 extend across the full width of the rear face of the casing 104. The rear face is a face of the casing 104 that is opposite to a front face of the casing, wherein the front face is a face from which a locking bolt and/or a latch bolt (not shown in Figures 5 and 6) extend.

As shown in Figure 2, the first casing portion 41 and second casing portion 43 are butted together and fixed using mechanical fasteners 45. This forms a seam 47 between the two casing portions. Returning to Figures 5 and 6, the seam between the first and second casing portions 141, 143 is located beneath the edge 146 of the first casing portion.

This embodiment is advantageous, since the seam between first and second casing portions 141, 143 of the locking assembly 100 cannot be accessed or attacked. One method of attacking conventional locking assemblies is to destroy the door surface behind the casing, and force a lever or tool into the seam between casing portions. By applying a suitable force to the lever, the casing portions can be prised apart, and attackers can access the inside of the casing to manipulate a camfollower and thus unlock the locking mechanism. In the current embodiment, access to the seam is prevented, and thus there is no position for an attacker to apply a lever or force. if an attacker attacks the locking assembly 100 from the opposite side, a tool could be inserted into the seam between the two second faces 145. However, because of the second face 145 of the second casing portion 143, access to the interior of the casing and thus to the cam follower 125 is still prevented.

Turning now to Figures 7 and 8, a further embodiment is shown, wherein description of like components will not be repeated. Shown is a locking assembly 200 which has a sleeve 301. As shown in Figure 7, the sleeve 301 closely conforms to the exterior surface of the casing 204 of the locking assembly.

The sleeve has a lock aperture 311 which is aligned (e.g. coaxial) with the lock aperture 211 of the casing 204. The sleeve 301 is also provided with connection means 335. The connection means 335 are apertures through which mechanical fasteners can be inserted. The connection means 335 may be positioned to align with the M&C PB156677|E mechanical fasteners 245 connecting the casing portions, thus avoiding the need for additional mechanical fasteners to secure the sleeve 301 over the casing 204.

The sleeve 301 is approximately cuboidal, and has first and second open faces 303, 304. The first open face 303 is configured so that the sleeve 301 can be slid onto the casing 204. The second open face 304 is configured to ease installation and so that the sleeve 301 does not obstruct any of the locking mechanism within the casing 204. A tab portion 305 is provided in the second open face 304. The tab portion 305 has a connection means 335 to prevent the sleeve 301 from being removed by an attacker by pulling the sleeve 301 toward the rear of the casing 204.

The sleeve 301 can be formed to have a continuous outer surface. For example, the sleeve 301 can be formed from a single sheet which is bend or moulded into shape.

The sleeve 301 may be formed from metal, such as steel, aluminium or titanium, or a plastics material or reinforced plastics material such as a fibre reinforced plastics material such as glass-reinforced plastic (GRP). The sleeve 301 extends around the casing 204 and obscures and prevents access to any apertures or seams in the casing or between casing portions.

The sleeve 301 provides a simple solution by which manipulation of the cam follower within the casing 204 can be prevented. A range of sleeves can be provided to fit a range of different lock casings, and thus provide a simple, retro-fittable solution which can be applied to a product range without requiring re-design and re-tooling of the existing casings and cam followers. A sleeve can be provided independently of a locking mechanism. Furthermore, a sleeve can be provided to fit locking mechanisms other than those that use cylinder locks. For example, a sleeve can be provided to fit a five lever mortice lock. Thus, in general, sleeves can be fitted to improve the security of any suitable locking mechanism, by resisting attackers who destroy a portion of the door or window leaf in an attempt to access the locking mechanism.

It would be understood by the skilled person that the three embodiments described herein can be combinable in any combination in order to further improve the security of a locking assembly.

Claims (23)

CLAIMS:

1. A locking assembly for a door or window, the locking assembly comprising: a casing; and a locking mechanism located within the casing, the locking mechanism comprising a cam follower engageable with a cylinder lock and moveable between first and second positions; wherein the cam follower comprises at least one channel therein, and the casing comprises at least one motion limiter configured to engage the at least one channel and limit motion of the cam follower.

2. The locking assembly according to claim 1, wherein the at least one motion limiter comprises a rail.

3. The locking assembly according to claim 2, wherein the rail projects internally from the casing.

4. The locking assembly according to claim 2 or 3, wherein the rail is integrally formed in the casing.

5. The locking assembly according to claim 4, wherein the rail is formed by a stamping or moulding process.

6. The locking assembly according to any one of the preceding claims, wherein the cam follower comprises a first and second channel located on opposing sides of the cam follower.

7. The locking assembly according to claim 6, wherein the casing comprises first and second motion limiters configured to engage the first and second channels.

8. The locking assembly according to any one of the preceding claims, wherein the casing comprises a first casing portion and a second casing portion.

9. The locking assembly according to claim 8, wherein the first casing portion comprises the first motion limiter and the second casing portion comprises the second motion limiter.

10. The locking assembly according to claim 8 or 9, wherein the first and second casing portions overlap in a region adjacent to the cam follower.

11. A locking assembly for a door or window, the locking assembly comprising a casing comprising first and second casing portions; and a locking mechanism located within the casing, the locking mechanism comprising a cam follower engageable with a cylinder lock and moveable between first and second positions; wherein the first and second casing portions overlap in a region adjacent to the cam follower.

12. The locking assembly according to either claim 10 or claim 11, wherein the first and second casing portions each comprise: a first face and a second face, each second face extending perpendicularly from a respective first face, wherein the second faces of the first and second casing portions are configured to overlap in the region adjacent to the cam follower.

13. The locking assembly according to claim 12, wherein the second faces form or extend across a rear edge or face of the casing.

14. The locking assembly according to claim 13, wherein the second faces both extend across the full width of the rear face of the casing.

15. A sleeve for a locking assembly, the sleeve being configured to be fittable over a casing of a locking assembly and impede or block access to the casing.

16. The sleeve according to claim 15, comprising at least one connection means for connecting the sleeve to a casing of a locking assembly.

17. The sleeve according to either claims 15 or 16, configured so that when fitted over a casing, the sleeve covers a seam or aperture in the casing.

18. The sleeve according to any one of claims 15 to 17, comprising a lock aperture for receiving a cylinder lock therethrough.

19. The sleeve according to any one of claims 15 to 18, wherein the sleeve is substantially cuboidal, and comprises at least one open face, configured so that a casing is insertable into the sleeve via the at least one open face.

20. The sleeve according to any one of claims 15 to 19, comprising first and second open faces, and further comprising a tab portion extending across a portion of one of the open faces.

21. The sleeve according to any one of claims 15 to 20, wherein the sleeve is configured so that in use the sleeve is located between a casing of a locking assembly and a surface of a door or window leaf.

22. The locking assembly according to any one of claims 1 to 14, further comprising a sleeve according to any one of claims 15 to 21.

23. A locking assembly for a door or window, the locking assembly comprising a casing; and a locking mechanism located within the casing, the locking mechanism comprising a cam follower engageable with a cylinder lock and moveable between first and second positions; and a sleeve according to any one of claims 15 to 21.