GB2318824A

GB2318824A - Euro-cylinder door locks

Info

Publication number: GB2318824A
Application number: GB9622872A
Authority: GB
Inventors: Matthew Cubitt; Jeffrey Lee Crowder
Original assignee: Anglian Windows Ltd
Current assignee: Anglian Windows Ltd
Priority date: 1996-11-02
Filing date: 1996-11-02
Publication date: 1998-05-06
Anticipated expiration: 2016-11-02
Also published as: GB9622872D0; GB2318824B

Abstract

A Euro-cylinder lock wherein a rupturable formation, conveniently in the form of a notch (20), is provided in the barrel flange (12) to the interior side of the screwhole (18) by which the lock is fixed in the door.

Description

Eur > Cylinder Door Locks This invention relates to a Euro-cylinder door lock.

Many modern doors, especially doors of plastics material such as PVCU, or aluminium doors, are fitted with Eurocylinder door locks.

A Euro-cylinder door lock, as far as relevance to the present invention is concerned, includes a flanged metal alloy barrel having a cutout at or adjacent the centre of its length wherein is located a key-rotatable lock bolt actuator and also having, in the flange in line with the cut-out, a screwhole enabling fixing of the barrel within a door. Such a Euro-cylinder door lock is hereinafter referred to as a Euro-cylinder lock of the kind described.

When fitted, the ends of the barrel protrude by about 6 mm at both the interior and exterior faces of the door. Both on said door interior and exterior, an apertured faceplace is secured over the protruding end of the barrel, such that the end face of the Euro-cylinder lock containing the key-receiving slot is approximately flush with the exterior face of said faceplate. The faceplates are both secured by screws inserted from the door interior and passing completely through the door stile into internal screwthreads in the external faceplate, so that the screws are not visible on the exterior sides. The same faceplates are assembled with the door handles, which fit quite closely against the faces of the faceplates and accept the protruding ends of the spindle.

However, it has been found, in relation to the Eurocylinder door lock as thus far described, whether or not the lock has anti-drill pins, that by levering away the handle and the faceplate on the exterior side of a locked door, and then striking the protruding end of the barrel hard, as with a hammer, especially in a direction normal to the axis of the fixing screw, in which the thickness of material is least, the barrel can be ruptured through the screwhole and bolt actuator cut-out. The same effect can sometimes be achieved by forcibly twisting the exposed end of the lock barrel with a wrench. The broken off portion of the barrel on the exterior side can then be removed, giving sufficient access to the bolt actuator and lock interior to enable the lock mechanism to be manipulated, permitting the door to be unlocked and opened. Furthermore, because Euro-cylinder locks are manufactured in a fixed range of standard lengths, sometimes the end of the barrel may project by about 1 mm or so beyond the face of the faceplate on the exterior side of the door, possibly enabling a potential intruder to rupture the lock barrel with the aid of a screwdriver and hammer, without even first levering off the exterior handle and faceplate.

It is an object of the invention to provide a solution to this security problem.

According to the invention, there is provided a Euro-cylinder lock of the kind described, wherein, to one side of the screwhole, the barrel is provided with a weakening formation such that the barrel, if subjected to a lateral impact or lateral twisting at one of its ends, will rupture in line with the formation in preference to breaking in line with the screwhole.

According to a further aspect of the invention, there is provided a door having a Euro-cylinder lock having a rupturable formation as aforesaid, wherein the Eurocylinder lock is fixed within the door so that the rupturable formation is positioned to the interior side of the screwhole fixing.

Commonly, the cut-out in the barrel for the bolt actuator is positioned to one side of the centre of the length of the barrel, to a small extent, so that it will usually be apparent to the lock fitter which way round the lock has to be fitted within the door. However, the barrel may be marked to indicate its interior and exterior ends if desired, especially if the cut-out for the bolt actuator is substantially central along the barrel. It may also be desirable to mark the barrel because, hitherto, the same Euro-cylinder lock may have been required to be fitted either way round, depending on the type of door. The invention will require the production of two different Euro-cylinder locks in place of one Eurocylinder lock which has hitherto been used different ways round in different circumstances, because no security advantage is gained if the lock is fitted within the door with the rupturable formation to the exterior side of the screwhole fixing.

The security advantage afforded by the present invention is gained because, if a potential intruder does laterally impact or wrench the end of the barrel on the exterior side of the door, as hitherto described, the barrel will only rupture beyond the screwhole fixing, and the portion of barrel on the exterior side of the rupture will remain held by the fixing screw. Although the portion of the barrel may be somewhat loose and wobbly, it will not be possible readily to remove it, so that access to the bolt actuator and the lock mechanism will remain denied.

It is not necessary for the rupturable formation to be positioned a substantial distance to the interior side of the screwhole. In practice, it is convenient to position this formation, in the barrel flange, in line with the end of the cut-out for the bolt actuator on the interior side. This necessitates, for example, a minimum amount of additional machining of the barrel. However, it is not essential for the rupturable formation to be made by machining; it may be produced in any manner convenient to manufacture of the Eurosylinder door lock.

The invention is further described with reference to the accompanying drawings, in which: Figure 1 shows the end of a Euro-cylinder door lock in elevation; Figure 2 shows the lock in side elevation; Figure 3 shows a rupturable notch detail in side elevation; and Figure 4 is a cross-section on the line A-A of Figure 3.

Referring to Figures 1 and 2, the illustrated Euro-cylinder lock, formed of metal alloy, has a barrel with a cylindrical portion 10 and a relatively thick flange 12.

The barrel, at or near the centre of its length, is produced with a cut-out 14 in which a lock bolt actuator 16 is held in place. This actuator is rotatable by means of a key insertable in a keyhole slot (not shown) in each end face of the barrel of the lock.

In line with the centre of the cut-out 14, in the direction of the length of the barrel, is provided an internally screwthreaded hole 18 by means of which the barrel can be fixed within the door, in practice within a cylinder lock and handle spindle casing incorporated in the door during manufacture.

In line with one end of the bolt actuator cut-out 14 is provided a rupturable weakening in the form of a notch 20, the precise nature of which can readily be seen from Figures 3 and 4.

It can readily be understood that, if the lock barrel of Figures 1 and 2 is held fixed at one end, and struck hard laterally at the opposite end, it will rupture at the notch 20, whereat the thickness of material to be ruptured is shown in Figure 4.

This is less than the thickness of material required to rupture in line with the centre of the cut-out 14 and hole ]8, which is where the barrel would break if the notch 20 was not provided.

In use, the above-described Euro-cylinder lock barrel is fined within the lock cylinder and handle spindle casing in the door with the rupturable notch 20 on the interior side of the screwhole 18.

The additional security afforded by this measure has been described in detail hereinbefore.

Claims

claims

1. A Euro-cylinder lock of the kind hereinbefore described, wherein, to one side of the screwhole, the barrel is provided with a weakening formation such that the barrel, if subjected to a lateral impact or lateral twisting at one of its ends, will rupture in line with the formation in preference to breaking in line with the screwhole.

2. A lock according to claim 1, wherein the cut-out in the barrel for the bolt actuator is positioned to a small extent to one side of the centre of the length of the barrel, sothat it is apparent to the lock fitter which way round the lock has to be fined within the door to provide the formation to the interior side of the screwhole fixing.

3. A lock as claimed in claim 1 or claim 2, wherein the barrel is marked to indicate its interior and exterior ends.

4. A lock according to claim 1 or claim 2 or claim 3, wherein the formation is positioned in the barrel flange.

5. A lock according to claim 4, wherein the formation is positioned in line with the end of the cut-out for the bolt actuator on the interior side.

6. A lock according to any of claims 1 to 5, wherein the formation is produced by machining.

7. A lock according to any of claims 1 to 6, wherein the formation is in the form of a straight linear notch.

8. A lock according to claim 7, wherein the notch extends inwardly into the flange from the bolt actuator cut-out.

9. A lock according to claim 7, wherein the notch extends inwardly into the flange from the free edge of the latter.

10. A lock according to claim 8 and claim 9, wherein the flange has two notches in alignment.

11. A door having a Euro-cylinder lock having a rupturable formation as claimed in claim 1, wherein the Euro-cylinder lock is fixed within the door so that the rupturable formation is positioned to the interior side of the screwhole fixing.

12. A Euro cylinder lock as claimed in claim 1 and substantially as hereinbefore described.