GB2372535A

GB2372535A - Security double profile cylinder lock

Info

Publication number: GB2372535A
Application number: GB0215081A
Authority: GB
Inventors: Bruce Patrick Mccarthy
Original assignee: Security Products UK Ltd
Current assignee: Security Products UK Ltd
Priority date: 2002-06-29
Filing date: 2002-06-29
Publication date: 2002-08-28
Anticipated expiration: 2022-06-29
Also published as: GB0215081D0; GB2372535B

Abstract

A double profile lock cylinder is formed from two separate housing parts (10, 11), in each of which is a cylinder core and associated tumbler pins, driver pins and springs. The housing parts are secured together by a joining element (17) which has respective arms (18, 19) received within respective recesses (16) in the housing parts. Respective stoppers (15) which close the drillings (14) in which the driver pins and springs are received extend through respective bores (24) through the arms (18, 19) to secure the two housing parts together via the joining element (17). The joining element (17) is of a material which is deformable/bendable and break-resistant to enable the lock cylinder to resist an impact attack attempting to snap the housing parts apart. One of the cylinder cores could be operable by a thumb turn instead of being part of a pin tumbler lock.

Description

LOCK This invention relates to a lock commonly known in the Trade as either a profile cylinder, a profiled double-locking cylinder or a double profiled lock cylinder.

A known lock of the above-mentioned type is in the form of a single component defining two housings respectively for two key operable rotatable cylinder cores and associated tumblers and springs. Said housings are integrally connected by a lower web through which is provided a threaded fixing hole, and between the facing ends of the respective housings is a space or slot for a cam, with a floating clutch to connect it to a selected one of the cylinder cores upon key insertion. However such a lock is susceptible to attack, for example by impacting it with a chisel at the outer end thereof, resulting in the snapping of the housing across the fixing hole, thereby allowing the two halves of the housing to be removed.

Various other forms of such a lock are known where the housings are formed in two separate components, which are connected together by a bridging member or arm. Examples of this construction are shown in EP 0 792 981, EP 0 438 654 and NL 7800771. However even with this two-part construction it is still possible for the bridging member or arm to snap, and there is the added need to provide it with means for securing it to the separate components, such as lateral pins.

An object of the invention is to provide an improved double profile lock cylinder.

Accordingly to the invention there is provided a double profile lock cylinder comprising two separate housing parts having received therein two rotatable cylinder cores respectively with, for at least one of the cores, associated tumbler pins, driver pins and springs, and a joining element which connects together said two housing parts, the joining element being of a bendable, break-resistant material, such that, in use, application of force to either end of the lock cylinder to snap it apart is resisted and absorbed by the joining element by the bending thereof.

Preferably the ductile joining element is formed from mild steel or plastics material, and more preferably is in one piece. Conveniently the housing parts are of brass. An attack on the lock cylinder at an end thereof thus causes the joining element to deform by bending, but not to break or fracture, thereby retaining the connection together of the housing parts.

Desirably the joining element is secured to the housing parts by plug means extending into respective bores containing, for said at least one of the cores, said springs and driver pins. Advantageously the joining element has two arms received in respective recesses in the housing parts, and said plug means of each housing extend into respective openings provided through said arms. More preferably the plug means are stoppers. The joining element has, between said arms, a thickened portion which is received between the housing parts and spans a region between the housing parts at which is disposed a cam which can be coupled to either one of the cylinder cores by a floating clutch. In one embodiment both cores have respective associated tumbler pins, driver pins and springs, but alternatively in another embodiment the pins and springs would be omitted for one of the housing parts and core therein, that core being rotatable by means of a manually operable member integral with or connected to the core outside of the housing part. Desirably the member would be a thumb turn.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partly exploded top perspective view of part of a lock cylinder of the invention, Figure 2 is a partly exploded underneath perspective view of the part of the lock cylinder of Figure 1, and Figure 3 is a perspective view of a joining element shown in Figures 1 and 2.

Shown in Figures 1 and 2 are two brass housing parts 10,11 respectively of a double profile lock cylinder of the invention. Each housing part is of substantially conventional form comprising a hollow cylindrical portion 12 from the outer surface of which an extension portion 13 integrally radially extends. Extending radially through the extension portion 13 in an equispaced arrangement along the length thereof are a number of circular section drillings 14, which as shown in Figure 2 break through the outer end of the portion 13 as well as breaking through the inner end thereof into the hollow interior of the portion 12.

For each housing part, a conventional pin tumbler lock cylinder core is received in the hollow cylindrical portion 12, the core containing the pin tumblers, with associated conventional driver pins being received in the drillings 14 and biased towards the cylinder core by respective associated coiled compression springs, in the normal manner. In this way the drivers normally extend across the interface between the rotatable cylinder core and the extension portion 13 so as to prevent rotation of the core. However when the correct key is inserted into the cylinder core the pin tumblers force the driver pins clear of said interface, against their spring bias, with the result that the cylinder core can be rotated to operate the lock.

With this type of arrangement, it is known to have the drillings extending through the complete length of the extension portion 13, with these drillings being closed at their open exterior ends respectively by respective stoppers 15, these fitting in the open ends of the bores and being inserted so that their respective outer ends lie flush with the outer exterior surface of the portion 13, as shown for the right hand housing part 11 in Figure 2, thereby retaining the springs, drivers and pin tumblers in position within the housing part. The stoppers can be a friction fit within the drillings 14. Alternatively they could be secured by adhesive, screw-threadedly engaged, or held in place by any other suitable means.

Extending centrally through each extension portion 13, parallel to the axis of the cylindrical portion 12 is a circular recess or bore 16. Whilst the outer or front end of each portion 13 is closed, the bore 16 breaks through the opposite flat end surface of the extension portion 13, as shown for the bore in housing part 11 in Figure 1. As can be seen from the Figures, the bores 16 are disposed only a short way from the free outer surfaces of the respective portions 13. In other words with the disposition of the housing parts as shown in Figures 1 and 2, these bores 16 are just inwards of the respective lower external surfaces of the portions 13. Although conveniently each bore will extend to the position of the drilling 14 which is nearest the front surface of the housing part, this is not essential as will be described below.

The two identical housing parts of the embodiment of the invention shown in the drawings are connected together by the use of a joining element 17 shown in detail in Figure 3. Whilst the housing parts 10,11 would normally be of brass, the joining element 17 is of a material which is flexible/ductile so that it can bend and is resistant to breaking when a force is applied to the lock cylinder as will be described hereinafter. Typically therefore the joining element would be of mild steel, but it may be possible to make it of plastics material. It will be appreciated, however, that other suitable materials could be used, provided that these are able to deform and resist fracture when said above-mentioned force is applied to the lock cylinder.

The joining element 17, which in this embodiment is in one piece, has two cylindrical arms 18,19 respectively extending co-axially from a central, thickened portion 20, this portion 20 having the exterior of its lower part 21 shaped generally to match the outer profiles of the respective lower parts of the extension portions 13, as shown best in Figure 2. The remaining, upper outer surface 22 of the portion 20 is flat so as, on assembly, to lie parallel to the flat exterior under surfaces of the extension portions 13 as shown in Figure 2. Extending centrally through the portion 20 is a circular threaded screw hole 23 having its axis parallel to the plane of the undersurface 22.

Finally with regard to the joining element 17, it can be seen from the drawings that each arm is provided with a number of circular bores 24 extending diametrically completely therethrough. The number of bores and the arrangement thereof depends upon the length of each arm, namely upon how many of the drillings 14 the arm extends through. Thus in the example illustrated the arm extends substantially the full length of each housing part and thus extends through all of the six drillings 14. Accordingly the arm itself is provided with six bores 24 arranged to form respective continuations of the drillings 14 when the joining element 17 connects the two housing parts together, in use as will be described hereinafter. However if the arm were shorter and extended through only three of the drillings, then clearly only three bores 24 would be provided. The respective opposite sides of the portion 20 from which the arms 18,19 extend are flat, so that, as will be described, the flat generally annular surface of the part 20 around each arm can abut the corresponding flat surface of the extension portion 13 around the bore 16 therein.

Accordingly it will be appreciated from Figures 1 and 2 that on assembly the respective arms 18,19 of the joining element 17 are inserted into the respective bores 16 of the housing parts 10,11 respectively in the orientation shown in Figures 1 and 2, so that the surface 21 generally matches the lower profiles respectively of the extension portions 13, this providing the orientation for the screw hole 23 as shown in Figures 1 and 2, namely generally horizontal where the housing parts are upright/vertical. As can be seen from Figures 1 and 2, the respective housing parts are moved towards one another so that said flat surfaces of the respective extension portions 13 around their respective bores 16 at the respective opening ends thereof abut the respective generally annular surfaces of the portion 20 from which the arms 18,19 extend.

With the housing parts 10,11 abutting respective opposite sides of the portion 20, each arm will be received in its associated bore 16 with its respective circular bores 24 aligned with the drillings 14 in said extension portions 13. With the respective cylinder cores inserted into the portions 12 of the housing parts, the pin tumblers, driver pins and springs can then be inserted up into each of the drillings 14 through the respective open ends thereof shown in Figure 2 for the left hand housing part 10, these drillings then being closed by insertion of the stoppers 15 into the positions shown in Figure 2 for the right hand housing part 11. It will be appreciated that with the position of the bores 16 as shown in the illustrated embodiment, the majority of the stoppers will lie within the bores 24 thereby tightly connecting together the two housing parts 10,11 by way of the joining element 17. This is a particularly convenient way of securing the joining element to the housing parts and it is in contrast to previous proposals where lateral pins have been used. With the present arrangement no additional drillings are required for such pins given that the drillings for the pin tumblers, drivers and springs are anyway required for the pin tumbler lock arrangements, with the stoppers being required to close the drillings in the normal manner. Thus the use of the stoppers additionally to securely fix together the joining element and the housing parts is particularly convenient and effective, additionally easing assembly.

Although not shown in the drawings, with the joining element securely fixed in place it can be seen that the thickened portion 20 spans the region between the housing parts, and at the part of this region generally between the portions 12 there is disposed a conventional type of cam which is connected, in use, via, for example, a floating clutch to a selected one of the cylinder cores depending upon which of said cores is operated by the key of the lock, rotation of the cylinder core then causing rotation of the cam to actuate a bolt or other locking means in the normal manner. It will be appreciated that the screw hole 23 is for reception of a fixing screw to secure the lock cylinder in position to a door or similar pivotal wing. Whilst as stated, stoppers are known with this type of arrangement to plug the open ends of the drillings, it will be appreciated that the stoppers 15 shown in the drawings may require specific lengthening and shaping so as appropriately to be received in the bores 24 as well as in the drillings 14.

In an alternative embodiment of the invention, one of the housing parts is associated with a thumb turn or similar manually operable member instead of the pin tumbler lock construction described. Typically the thumb turn is disposed outside of the housing part and is connected to a core closely rotationally received in the interior portion 12 of the hosing part, the core being connectible to the cam by a floating clutch or other suitable component.

Accordingly, at one side of the door or other pivotable wing the thumb turn is manually angularly movable, such movement effecting corresponding angular movement of the core connected to the thumb turn, so as to turn the cam and actuate the bolt of the lock. Alternatively, the thumb turn and core may be integral. The drillings 15 would remain despite the absence of the pins and springs, and the arm in the housing part associated with the thumb turn would receive the stoppers 15 through the bores 24 as described for the first embodiment.

In operation, the lock cylinder of the present invention provides improved attack resistance as compared to known arrangements in that if an impact force is applied to an outer end of either of the housing parts 10,11, for example at a position between the housing part and its associated cylinder core, this force will be transmitted through the housing part to the joining element 17 which, as described, is constructed of a material which is fracture resistant. As a consequence the force is absorbed by the element 17 as a bending and not a breaking force, so that the element 17 deforms/bends without causing the two interconnected housing parts of the lock cylinder to snap apart. Thus a disadvantage of known double profile lock cylinders is overcome.

Claims

CLAIMS 1. A double profile lock cylinder comprising two separate housing parts having received therein two rotatable cylinder cores respectively with, for at least one of the cores, associated tumbler pins, driver pins and springs, and a joining element which connects together said two housing parts, the joining element being of a bendable, break-resistant material, such that, in use, application of force to either end of the lock cylinder to snap it apart is resisted and absorbed by the joining element by the bending thereof.
2. A lock cylinder as claimed in Claim 1, wherein the joining element is secured to the housing parts by plug means extending into respective bores, the ones of the bores associated with said one of the cores containing the springs and driver pins.
3. A lock cylinder as claimed in Claim 2, wherein the joining element has two arms received in respective recesses in the housing parts.
4. A lock cylinder as claimed in Claim 3, wherein said plug means of each housing part extend into respective openings provided through said arms.
5. A lock cylinder as claimed in any one of Claims 2 to 4, wherein the plug means are stoppers against which said springs associated with said one of the cores bear respectively.
6. A lock cylinder as claimed in either Claim 3 or Claim 4, wherein the arms extend from opposite sides of a central thickened portion which has at least part of its external profile to match or substantially to match at least part of the profile adjacent thereto of each of the housing parts.
7. A lock cylinder as claimed in Claim 6, wherein the thickened portion is disposed between the housing parts and spans a region between the housing parts at which is disposed a cam.
8. A lock cylinder as claimed in Claim 7, wherein the cam can be coupled to either of the cylinder cores via a floating clutch.
9. A lock cylinder as claimed in any one of Claims 6 to 8, wherein a threaded hole for a fixing screw extends through said thickened portion.
10. A lock cylinder as claimed in any one of the preceding claims, wherein the joining element is of mild steel.
11. A lock cylinder as claimed in any one of the preceding claims, wherein the joining element is in one piece.
12. A lock cylinder as claimed in any one of the preceding claims, wherein the housing parts are of brass.
13. A lock cylinder as claimed in any one of the preceding claims, wherein both cores have tumbler pins, drive pins and springs associated therewith respectively.
14. A lock cylinder as claimed in any one of claims 1 to 12, wherein said one of the cores has said associated tumbler pins, drive pins and springs, and the other of the cores has no associated tumbler pins, drive pins and springs, and is angularly movable, in use, by a manually operable member at the outside of its housing part.
15. A lock cylinder as claimed in claim 14, wherein the manually operable member is a thumb turn.
16. A double profiled lock cylinder substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.