GB2434403A

GB2434403A - Cylinder lock reinforcement arrangements

Info

Publication number: GB2434403A
Application number: GB0621387A
Authority: GB
Inventors: Stephen Spencer
Original assignee: SELECT ENGINEERING ASIA
Current assignee: SELECT ENGINEERING ASIA
Priority date: 2006-01-24
Filing date: 2006-10-27
Publication date: 2007-07-25
Anticipated expiration: 2026-10-27
Also published as: GB0621387D0; GB2434403B; GB0601377D0

Abstract

A cylinder lock reinforcement device 202 comprising a plate having an open-ended cutaway portion 204 and a face defining an abutment portion laterally spaced therefrom. The open-ended cutaway portion 204 is operable to accommodate a portion of a cylinder lock 102, in use. Preferably a slot formed in the housing section 106 of the cylinder lock receives the portion 204 and any unauthorized pulling on the lock causes the plate to abuts the rear of a handle assembly 306. A post 308 extending from the assembly 306 can engage a formation 206 to prevent forced rotation of the lock. A door handle backing plate can be formed with a recess to receive the device 202 and securing means attaching the backing plate can extend through aperture 208 to resist rotation. Devices 202 can be used on both ends of the lock with a bolt extending between them.

Description

IMPROVEMENTS RELATING TO CYLINDER LOCKS

The present invention relates to improvements relating to cylinder locks, particularly to a cylinder lock reinforcement device, a lock assembly, a lock kit and method of installing the same.

Cylinder locks are known in the art and usually comprise a barrel portion which is generally cylindrical, and a housing portion extending radially from the barrel portion. The barrel portion is formed of two coaxial barrels, between which is a gap in which a rotatable cam is situated. In use, a key is inserted into a keyhole at an end of the barrel portion and turned. This turning motion rotates a cylinder within the barrel and thus rotates the cam which operates a secondary locking mechanism.

A problem with such locks is that they have an inherent weak point where the gap in the barrel portion is situated. This can result in the lock being vulnerable to tampering, particularly by exerting a torsional force along the longitudinal axis of the barrels, which can result in the cylinder lock shearing at the weak point which may render the lock useless and allow unauthorised entry to the previously locked area.

The torsional vulnerability of cylinder locks has been known for some time in the art and various attempts have been made to address the problem. For example, it is known to add a sleeve over the end of the cylindrical lock, routed into the face of a door, to thereby prevent torsional force being administered thereto. However, a further vulnerability of cylindrical locks has recently been discovered.

It has recently been found that it may be possible to screw an object into the keyhole of a cylindrical lock and use the object as an anchor to exert a force parallel with the longitudinal axis of the cylindrical lock. This can result in the lock being removed longitudinally from its position, either to such an extent that a torsional force may be applied to the lock and the lock sheared as stated above or the lock removed entirely.

It is an object of aspects of the present invention to address the above or other problems.

According to a first aspect of the present invention there is provided a cylinder lock reinforcement device comprising a plate having an abutment portion and an open-ended cutaway portion laterally spaced from the abutment portion, wherein the open ended cutaway portion is operable to accommodate a portion of a cylinder lock, in use.

Preferably, the abutment portion comprises at least one abutment face.

Preferably, the abutment portion and cutaway portion are arranged such that, when the plate is arranged about a cylinder lock, the abutment face is generally perpendicular to a longitudinal axis of the cylinder lock.

Usually, cylinder locks have a generally constant cross section. However, advantageously and preferably, the reinforcement plate, when arranged about a cylinder lock, provides an increased cross-sectional area to the cylinder lock at the point where the plate is arranged.

Advantageously, this prevents a cylinder lock being displaced longitudinally from its housing.

Preferably, the plate further comprises rotation prevention means. Preferably, the rotation prevention means comprises a lobe which extends, preferably perpendicularly, from the abutment face. Preferably, the rotation prevention means is operable to abut or engage with a rear portion of a handle, for example a door handle, in use.

Alternatively or additionally, the plate may further comprise anchoring means operable to allow the plate to be anchored to a surface. The anchoring means may comprise at least one aperture which may extend through the plate.

The aperture may be generally circular in cross-section and may be internally threaded. The anchoring means may comprise a plurality of apertures for examples 2 or 3.

Preferably, the plate is generally rectangular, preferably having major and minor edges. Preferably, the cutaway portion extends inwardly from an edge of the plate, preferably, a minor edge thereof. Preferably, the cutaway portion comprises two generally parallel side walls.

Preferably, the side walls of the cutaway portion are generally parallel with edges of, preferably opposite edges of, the plate.

Preferably, the cutaway portion is generally "U" shaped.

Preferably, the cutaway section extends from a first edge of the plate toward a second, preferably opposite, edge of the plate. Preferably, the cutaway portion extends at least 30% toward a second edge of the plate from the first edge, more preferably at least 40% and most preferably at least 50%.

Preferably, the plate comprises locating means operable to allow the plate to locate relative to a door or door handle, in use. Preferably, the locating means comprises a nick which is preferably generally semi-circular.

Preferably, the locating means extends inward from an edge of the plate, preferably a minor edge, preferably an edge opposite the cutaway portion.

Preferably, the plate is formed from a rigid material which is preferably a rigid metallic metal such as steel,

for example.

Preferably, the plate has a thickness between about 0.5 and 5mm, more preferably, between about 1 and 3mm and most preferably about 2mm.

Preferably, the length of the major edge of the plate is between about 20 and 45mm, more preferably between about 25 and 40mm and most preferably between about 30 and 35mm.

Preferably, the length of the minor edge of the plate is between about 10 and 35mm, more preferably between about and 30mm and most preferably between about 20 and 25mm.

In use, the lock reinforcement device may be arranged about a cylinder lock.

According to a second aspect of the present invention there is provided a lock assembly comprising at least one cylinder lock reinforcement device and a cylinder lock, the at least one cylinder lock reinforcement device comprising a plate having an abutment portion and an open ended cutaway portion laterally spaced from the abutment portion, wherein a portion of the cylinder lock is accommodated in the cutaway portion.

Preferably, the plate is arranged generally perpendicular to a longitudinal axis of the cylinder lock.

Preferably, the cylinder lock comprises a barrel portion and a housing portion. Preferably, a portion of the housing portion of the cylinder lock is accommodated in the cutaway portion. Preferably, the housing portion extends radially frora the barrel portion.

Preferably, the assembly further comprises a handle. The handle may comprise an aperture generally equal in size to the cross sectional area of a cylinder lock. Preferably, the handle comprises an abutment surface which preferably laterally surrounds the aperture. Preferably, the abutment surface is arranged to abut the abutment portion of the plate upon longitudinal movement of the cylinder lock.

Preferably, the abutment surface comprises a recess section that is preferably adapted, in use, to accommodate the plate of the cylinder lock reinforcement device.

Preferably, the recess section has a generally constant cross-section, for example, the recess section may have a uniform depth which may be between about 2mm and about 15mm, more preferably, between about 3mm and about 8mm.

Advantageously, the plate may be accommodated in the recess section thus preventing torsional movement of the plate and thus also the lock.

Preferably, the cylinder lock comprises plate engaging means which preferably comprise at least one channel.

Preferably, the plate engaging means are situated on the housing portion. Preferably, the channel is of a depth and width to allow at least one edge and more preferably at least two edges of the cutaway portion of the plate to engage therewith, preferably in a friction fit manner.

Preferably, the plate engaging means are located at a position toward a longitudinal end of the cylinder lock.

In one embodiment, the plate engaging means may comprise two channels located at positions toward opposite longitudinal ends of the cylinder lock. In this embodiment, the assembly may comprise two cylinder lock reinforcement devices which may be situated toward generally opposite ends of the cylinder lock. The two cylinder lock reinforcement devices may be bridged by at least one anchor, each of which may be a bolt, for example, to afford an increased structural rigidity to the assembly. In one embodiment, the two cylinder lock reinforcement devices may be bridged by at least two anchors.

Preferably, the at least one channel extends generally perpendicularly to a longitudinal axis of the cylinder lock.

According to a third aspect of the present invention there is provided a lock kit comprising: -at least one cylinder lock reinforcement device comprising a plate having an abutment portion and an open ended cutaway portion laterally spaced from the abutment portion, wherein the cutaway portion is operable to accommodate a portion of a cylinder lock; and -a cylinder lock.

Preferably, the kit further comprises a handle which preferably comprises an abutment surface.

Preferably, the abutment surface comprises a recess section that is preferably adapted, in use, to accommodate the plate of the cylinder lock enforcement device.

The kit may comprise at least two cylinder lock reinforcement devices.

According to a fourth aspect of the present invention there is provided a method of fitting a cylinder lock reinforcement device to a cylinder lock comprising the step of accommodating a portion of a cylindrical lock in an open ended cutaway portion of a plate of a cylindrical lock reinforcement device, the plate further comprising an abutment portion laterally spaced from the cutaway portion.

According to a fifth aspect of the present invention there is provided a door handle backing plate comprising a recess section, which recess section is adapted, in use, to accommodate a cylinder lock reinforcement device, the cylinder lock reinforcement device comprising a plate having an abutment portion and an open-ended cutaway portion laterally spaced from the abutment portion, wherein the open ended cutaway portion is operable to accommodate a portion of a cylinder lock, in use.

Advantageously, the lock reinforcement device does not require any routing of the door to which it is to be attached.

Advantageously, the lock reinforcement device may be retrofitted to existing cylinder locks, preferably cylinder locks of grade 4 or above (i.e. with resistance to the lock being removed longitudinally. The method may also include the step of creating plate engaging means on the cylinder lock which may comprise the step of milling, filing or routing a channel in the cylinder lock, preferably in a housing portion thereof.

The method may further comprise the step of anchoring the cylinder lock reinforcement device to a door, a handle or a further cylinder lock reinforcement device.

All of the features disclosed herein may be combined with any of the above aspects, in any combination.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 shows a perspective view of a cylinder lock adapted to receive a lock protecting plate; Figure la shows an enlarged view of a portion of Figure 1; Figure 2 shows a perspective view of a lock protecting device; Figure 3 shows a sectional side view of a first embodiment of a lock protection assembly in situ; Figure 4 shows a sectional view of a second embodiment of a lock protection assembly in situ; and Figure 5a shows a rear side perspective view of a back plate of a door handle for use with a lock protection assembly; and Figure 5b shows a cross sectional view of the back plate of figure 5a.

Referring to figure 1 there is shown a perspective view of a cylinder lock 102, which comprises a barrel section 104 and a housing section 106. The barrel section is divided into two discrete barrels 108, 110, which are aligned coaxially with a gap 111 therebetween. The two barrels 108, 110 are held rigidly in place by virtue of the housing section 106, which extends radially away from each barrel 108, 110 and spans the gap 111. The housing section 106 is generally "11" shaped in cross section and comprises a cutaway portion 112, which extends across the width thereof, perpendicular to the longitudinal axis thereof. The cutaway portion 112 forms part of the gap 111. The barrels 108, 110 house rotatable cylinders 114 operated by inserting a key (not shown) into a keyhole 116 and rotating in a manner known in the art. Rotation of the cylinder 114 causes a cam member (not shown) to rotate within the gap 111 between the two barrels and engage with further locking members (not shown) in a manner known in the art.

Adjacent to the cutaway portion 112 is a cylindrical aperture 118, which extends through the width of the housing portion 106, perpendicular to the longitudinal axis thereof. This aperture 118 may be internally threaded and may be used to secure the cylinder lock 102 to a surface, such as an internal cavity in a door. The gap 111, the cutaway portion 112 and the aperture 118 are generally radially aligned and result in a reduction in structural rigidity which results in weak point in the lock 102 in the region of the gap 111, cutaway portion 112 and the aperture 118. This weak point may make the lock 102 vulnerable to shearing as a result of the application of a torsional force to the lock 102.

Referring now also to figure la, the housing portion 106 comprises a channel 120 which extends therearound, perpendicular with the longitudinal axis of the housing portion 106. The channel is approximately 2mm wide and 2mm deep and situated at about 10mm from an end of the lock 102.

In an alternate embodiment, as will be discussed with respect to figure 4, the cylinder lock 102 may comprise a further channel, similar to the channel 120, situated toward the opposite longitudinal end of the lock 102.

Referring now to figure 2 there is shown a perspective view of a lock protecting device comprising a plate 202, which is generally rectangular in shape. The plate 202 comprises a cutaway section 204 extending perpendicularly from a central region of one of the minor walls thereof to a position between a half and a third way therethrough.

The aperture 204 is generally "0" shaped. Generally opposite the cutaway section 204 is a nick 206 extending inwardly from the other minor wall. In use, as will be discussed with regard to figures 3 and 4, the nick 206 serves to locate the plate 202.

The distance between the walls of the cutaway section 204 and the depth of the plate 202 are such that the groove 120 of the cylinder lock 102 accommodates the outer edges of the aperture 204 in a friction fit manner. The plate further comprises a circular aperture 208 extending therethrough toward a bottom corner thereof. In the present embodiment, the plate is formed of 2mm thick steel, and measures approximately 33 x 20mm. The cutaway section 204 is approximately 7mm wide by approximately 20mm deep.

Referring now to figure 3, there is shown a first embodiment of a lock protection assembly. The lock protection assembly comprises a cylinder lock 102 having a lock protecting plate 202 frictionally fitted into the channel 120 thereof. The lock assembly is accommodated on a door 302 and a longitudinal end of the lock 102 extends through an aperture 304 in a handle 306. On the inner side of the handle 306 are two bars 308 which house the fixing means (usually screws) that fix the handle 306 to the door 302. The nick 206 locates over a lower one of these bars 308, thus rotational movement of the plate 202 and lock 102 is prevented. The handle 306 is formed of reinforced or strengthened materials such as steel and cannot therefore be easily removed from the door 302.

Between the two barrels 108, 110 is a rotatable cam member 109 which, upon rotation, operates further locking members (not shown). As discussed in the preamble, cylinder locks known in the art may be vulnerable to attack by inserting an anchor into the keyhole 116 and pulling the cylinder lock 102 along its longitudinal axis, which can result in the cylinder lock shearing in two (usually at its weakest point: proximal to the aperture 118), or simply being removed longitudinally in its entirety. However, in the assembly of figure 3, it can be seen that such an attempt would result in the cylinder lock only moving a short distance before the plate 202 abuts a rear face of the handle 306 thereby preventing further longitudinal movement of the cylinder lock. Further, even if the lock were sheared, its removal would be prevented by virtue of the plate 202. Thus access to the cam 109 is denied.

Advantageously, the plate 202 may be retro fitted to an existing cylinder lock by simply milling or filing a channel 120 onto an existing cylinder lock 102 and frictionally fitting the plate 202 about the groove 120.

Figure 4 shows a second embodiment of a lock assembly comprising a cylinder lock 102 having two lock protecting plates 202 fitted into two channels 120 toward opposite ends of the lock 102. The second embodiment of the lock assembly comprises two handles 306 situated on an inner and outer face of a door 302.

A bolt 402 extends from the first plate 202 to the second plate 202 and is secured in place by a nut 404.

The outer side "A" of the door 302 is also known as the "at risk" side of the door, hence screws 406 extend through the handle 306 on the inner side "B" of the door 302 into the bars 308 of the handle 306 on the outer side "A" of the door 302. In this manner, no screw heads (a possible point of attack) are visible on the at risk side "A" of the door.

Advantageously, the bolt 402 provides further structural rigidity to the lock assembly and may negate the need for the aperture 120 (thus providing even further structural rigidity). Additionally, in a further alternative embodiment (not shown) a further bolt 402 and nut 404 may be added to secure the two plates together via a further aperture in the plate. This would serve to further increase the structural rigidity of the lock.

Referring now to figures 5a and Sb there is shown a back plate of a door handle for use with a lock protection assembly of the present invention. Figure 5a shows a rear side of the back plate 502, whereas figure 5b shows a cross-sectional view of the back plate 502 through line A-A' of figure 5a.

The back plate 502 is generally rectangular having arcuate opposite minor walls 504. Extending through the plate 502 toward longitudinally opposite ends thereof are two circular apertures 506. As shown in figure 5b, the apertures 506 flare toward a front face 508 of the back plate 502 to accommodate countersunk screws (not shown), in use. Toward the centre of the back plate 502 is a circular aperture 510 through which a door handle (not shown) extends, in use. Surrounding the aperture 510 is a generally rectangular recess 512, cut into a rear face 514 of the back plate 502. The rectangular recess 512 accommodates a portion of a door handle housing (not shown), in use.

Toward an elongate end of the plate 502, between the aperture 510 and the aperture 506 is a further aperture 516, being of a shape and size to accommodate a cylinder lock, such as the lock 102. Situated between the aperture 516 and the aperture 506 is a U" shaped recess section 518 cut into the rear face 514. The recess section 518 has a generally constant cross section as shown in figure 5b.

As can be seen in figure 5a, the lower edge of the recess section 518 incorporates the aperture 506.

In use, a cylinder lock, such as lock 102 and a lock protecting device 202 may be fitted to the plate 502 such that the lock 102 extends through the aperture 516 and the lock protecting device 202 is accommodated in the recess 518. In this configuration the screw (not shown) extending through the aperture 506 adjacent to the recess 518 is accommodated in the notch 208 of the device 202.

Use of cylinder lock 102 and lock protecting device 202 in conjunction with a back plate 502 as described above provides extra strength to the lock 102, and extra resistance to tampering.

A lock protection assembly made in accordance with the present invention facilitates a lock which is less liable to fail during an attempt to gain unauthorised entry to the surface to which it is affixed.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification

(including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features

disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS

1. A cylinder lock reinforcement device comprising a plate having an abutment portion and an open-ended cutaway portion laterally spaced from the abutment portion, wherein the open ended cutaway portion is operable to accommodate a portion of a cylinder lock, in use.

2. A cylinder lock reinforcement device as claimed in claim 1, wherein the abutment portion and cutaway portion are arranged such that, when the plate is arranged about a cylinder lock, the abutment face is generally perpendicular to a longitudinal axis of the cylinder lock.

3. A cylinder lock reinforcement device as claimed in either of claim 1 or claim 2, wherein the plate further comprises rotation prevention means.

4. A cylinder lock reinforcement device as claimed in claim 3, wherein the rotation prevention means comprises a lobe which extends from the abutment face.

5. A cylinder lock reinforcement device as claimed in either of claim 3 or clam 4, wherein the rotation prevention means is operable to abut or engage with a rear portion of a handle.

6. A cylinder lock reinforcement device as claimed in any preceding claim, wherein the plate further comprises anchoring means operable to allow the plate to be anchored to a surface.

7. A cylinder lock reinforcement device as claimed in claim 6, wherein the anchoring means comprises at least one aperture that extends through the plate.

8. A cylinder lock reinforcement device as claimed in any preceding claim, wherein the cutaway portion extends inwardly from an edge of the plate.

9. A cylinder lock reinforcement device as claimed in any preceding claim, wherein the cutaway portion comprises two generally parallel side walls.

10. A cylinder lock reinforcement device as claimed in any preceding claim, wherein the cutaway portion is generally "U" shaped.

11. A cylinder lock reinforcement device as claimed in any preceding claim, wherein the cutaway section extends from a first edge of the plate toward a second opposite edge of the plate.

12. A cylinder lock reinforcement device as claimed in claim 11, wherein the cutaway portion extends at least 30% toward a second edge of the plate from the first edge.

13. A cylinder lock reinforcement device as claimed in any preceding claim, wherein the plate comprises locating means operable to allow the plate to locate relative to a door or door handle, in use.

14. A cylinder lock reinforcement device as claimed in claim 13, wherein the locating means comprises a nick which is generally semi-circular.

15. A cylinder lock reinforcement device as claimed in either claim 13 or 14, wherein locating means extends inward from an edge of the plate.

16. A cylinder lock reinforcement device as claimed in any preceding claim, wherein plate is formed from a rigid material.

17. A cylinder lock reinforcement device as claimed in any preceding claim, wherein the plate has a thickness between about 0.5 and 5mm.

18. A lock assembly comprising at least one cylinder lock reinforcement device and a cylinder lock, the at least one cylinder lock reinforcement device comprising a plate having an abutment portion and an open ended cutaway portion laterally spaced from the abutment portion, wherein a portion of the cylinder lock is accommodated in the cutaway portion.

19. A lock assembly as claimed in claim 18, wherein the plate is arranged generally perpendicular to a longitudinal axis of the cylinder lock.

20. A lock assembly as claimed in either of claim 18 or claim 19, wherein the cylinder lock comprises a barrel portion and a housing portion and wherein a portion of the housing portion of the cylinder lock is accommodated in the cutaway portion.

21. A lock assembly as claimed in either of claim 19 or claim 20, wherein the assembly further comprises a handle.

22. A lock assembly as claimed in either of claim 20 or claim 21, wherein the handle comprises an abutment surface.

23. A lock assembly as claimed in claim 22, wherein the abutment surface is arranged to abut the abutment portion of the plate upon longitudinal movement of the cylinder lock.

24. A lock assembly as claimed in either of claim 22 or claim 23, wherein the abutment surface comprises a recess section that is adapted, in use, to accommodate the plate of the cylinder lock reinforcement device.

25. A lock assembly as claimed in claims 18 to 24, wherein the cylinder lock comprises plate engaging means.

26. A lock assembly as claimed in claim 25 when dependent on any of claims 20 to 24, wherein the plate engaging means are situated on the housing portion.

27. A lock assembly as claimed in claim 26, wherein the plate engaging means comprise a channel and wherein the channel is of a depth and width to allow at least one edge of the cutaway portion of the plate to engage therewith.

28. A lock assembly as claimed in claims 25 to 27, wherein the plate engaging means are located at a position toward a longitudinal end of the cylinder lock.

29. A lock kit comprising: 2].

-at least one cylinder lock reinforcement device comprising a plate having an abutment portion and an open ended cutaway portion laterally spaced from the abutment portion, wherein the cutaway portion is operable to accommodate a portion of a cylinder lock; and -a cylinder lock.

30. A lock kit as claimed in claim 29, wherein the kit further comprises a handle which preferably comprises an abutment surface.

31. A lock kit as claimed in claim 30, wherein the abutment surface comprises a recess section that is preferably adapted, in use, to accommodate the plate of the cylinder lock enforcement device.

32. A lock kit as claimed in claims 29 to 31, wherein the kit comprises at least two cylinder lock reinforcement devices.

33. A method of fitting a cylinder lock reinforcement device to a cylinder lock comprising the step of accommodating a portion of a cylindrical lock in an open ended cutaway portion of a plate of a cylindrical lock reinforcement device, the plate further comprising an abutment portion laterally spaced from the cutaway portion.

34. A door handle backing plate comprising a recess section, which recess section is adapted, in use, to accommodate a cylinder lock reinforcement device, the cylinder lock reinforcement device comprising a plate having an abutment portion and an open-ended cutaway portion laterally spaced from the abutment portion, wherein the open ended cutaway portion is operable to accommodate a portion of a cylinder lock, in use.

35. A cylinder lock reinforcement device substantially as hereinbefore described and with reference to the accompanying drawings.

36. A lock assembly substantially as hereinbefore described and with reference to the accompanying drawings.

37. A lock kit substantially as hereinbefore described and with reference to the accompanying drawings.

38. A method substantially as hereinbefore described and with reference to the accompanying drawings.

39. A door handle backing plate substantially as hereinbefore described and with reference to the accompanying drawings.