EP2894279A1

EP2894279A1 - Security device for lock cylinders

Info

Publication number: EP2894279A1
Application number: EP14382005.8A
Authority: EP
Inventors: Ricardo Beitia Molina
Original assignee: Metalurgica Cerrajera de Mondragon SA
Current assignee: Metalurgica Cerrajera de Mondragon SA
Priority date: 2014-01-09
Filing date: 2014-01-09
Publication date: 2015-07-15

Abstract

The present invention relates to a security device for lock cylinders comprising a cylinder body which is formed by a cylindrical body (1) from which a radial prolongation (2) comprising two side faces (2') and a lower area (2") extends along the entire length of its generatrix, where the cylindrical body (1) is split by inner cavity (3) partially affecting the radial prolongation (2) without reaching the lower area (2") thereof, there being in the radial prolongation (2), in correspondence with the inner cavity (3), a weakened central area (5), comprising a security element (6) having a U-shaped laminar configuration, being able to be inserted by pressure and fitted in a recess (7) which the side faces (2') and the lower area (2") of the radial prolongation (2) have, such that said security element (6) runs along the weakened central area (5) of the radial prolongation (2), where the configuration of the security element (6) corresponds with the configuration of the recess (7).

Description

Technical Field of the Invention

The present invention relates to a security device for lock cylinders applicable in the locksmith industry, and more specifically in the field of locks for doors or accesses, which allows increasing the resistance of the lock given that the weakened central area of the cylinder body where the cam is located is reinforced, which makes breaking it by hitting, bending or pulling on it more difficult, and even in the event that the lock is forced open by breaking the cylinder in said central area, the lock is protected to prevent the immediate removal of the cylinder whereby unauthorized accesses to a specific enclosure are prevented in any case, all this by means of a simple, easy-to-assemble and low cost solution.

Background of the Invention

Today cylinder bodies for locks, also known as cylinders, are known to consist of a cylindrical body from which a radial prolongation emerges in the lower portion thereof, such that both the cylindrical body and part of the radial prolongation are affected by an inner cavity in which a cam is housed, such that the cavity splits the cylinder into two portions, one portion corresponding with the outside of the door and another inner portion corresponding with the inside of the door. In the closed lock position, the cam projects from the transverse contour of the cylinder body, whereas in the open position, the cam remains within the contour of the cylinder body. The central area which is in the radial prolongation, located in correspondence with the inner cavity, in turn has a rather small width and it tends to have a threaded hole for fixing the cylinder body to the door or access in which it is to be installed, usually by means of a screw. Ultimately, as the result of the presence of the inner cavity and of the fixing hole, said central area is weakened in response to actions performed to force open the lock.
It is common that at least one of the ends of the cylindrical body of such locks has an opening, usually known as keyhole, for introducing a key to operate the lock, for going from the closed position to the open position and vice versa. A plurality of locking tumblers or any other locking means, each of which is operated by means of a spring is in turn housed in the radial prolongation, where said locking tumblers collaborate with the corrugated profile or ridges of the corresponding key.
The cylinder body is usually longer than the door width, so once assembled the ends thereof project slightly from the two inner and outer faces of the door, having the drawback that any thief can act on the projecting end with a tool capable of producing a torque, impact or bending force on the cylinder, thus causing it to break at the weakened central area or cavity. Once broken, the cylinder body or half of the broken cylinder body is removed simply by pulling for the purpose of acting on the rotary cam for driving the mechanism to open the door and access the enclosure.
Sometimes a so-called protective shield, which also has decorative purposes, is provided for protecting the portion projecting from the cylinder.
Today there are different security devices and systems to prevent breaking the cylinder or at least make breaking it more difficult, as well as anti-removal devices, for the purpose of preventing removal if the cylinder ultimately breaks.
Some solutions are based exclusively on preventing removal, without offering reinforcement to the weakened central area, such as for example the slot envisaged for fitting on a flange located in the shield described in GB-2434403-A . The main drawback of this device is that in a situation to force open the lock, it is not effective once the shield is successfully removed; it is always easier to remove the shield of the lock than to remove the cylinder body. Once the shield is removed, the device does not prevent breaking the cylinder body.
On the other hand, there are solutions based on arranging outer reinforcement elements between both portions separated by the cavity, but said solutions are expensive and hard to implement as they require an additional element which must be provided during manufacture in many cases, with the subsequent cost increase. In most of these cases, they are complex parts envisaged to be used together with a cylinder body manufactured for that purpose, where the assembly is likewise complicated because it requires fixing inserts by means of specific fixing elements located in specific spaces for that purpose, such as the lock cylinders described in UK patent document nos. GB-2494737-A and GB-2375795-B , in European patent application nos. EP-2128359-A1 and EP-1707710-A1 , or in German patent application no. DE-19744065-A1 , for example.
Other solutions contemplate directly manufacturing the cylinder in two independent halves that are connected with one another by means of an attachment and reinforcement part internally linking both parts in addition to defining the attachment section, incorporating the fixing hole. As in the preceding case, these solutions are expensive, complex and rather unreliable, in addition to being ineffective in preventing the removal of the cylinder body once the link between the two portions forming the cylinder has been broken. An example of this solution is described in UK patent no. GB-2372535-B .
The solutions described in the preceding paragraph include the solution described in the Spanish invention patent no. ES-2197745-B1 which describes an anti-removal cylinder body for a lock comprising a plurality of linear filiform elements, where each filiform element fits in a specific groove provided for that purpose and the ends thereof are inserted in a pair of holes that must be made previously in the cylinder body, such that each filiform element acts as a reinforcement in a single direction. The drawbacks of this solution include the need to make a plurality of grooves and holes in specific positions in the cylinder body itself, with the cost that it entails, in addition to the assembly difficulty due to the need to arrange a plurality of independent security elements in a plurality of holes and grooves that must be made in the radial prolongation, with the subsequent weakening of the cylinder body that it entails, as it has a plurality of drill holes and grooves in different positions, weakening the resistance thereof. On the other hand, the fact that a plurality of security elements must be arranged translates into the assembly having lower resistance, since for the assembly to achieve a specific resistance value it is necessary to provide all the elements, or at least as many elements as the number of directions to be reinforced, such that forgetting or failing to place only one of said elements according to a direction results in said direction not having reinforcement, whereby in response to an action in which a thief tries to move the cylinder in different directions, he/she will finally break it since it will not be reinforced in all directions.
Ultimately, in view of the foregoing, there is no optimal solution allowing the combined effect of preventing breakage and hindering removal by means of a simple, low cost, easy-to-install and easy-to-assemble element.

Description of the Invention

The present invention relates to a security device for lock cylinders which allows reinforcing the inner area of the cylinder body, i.e., area which is located in correspondence with the inner cavity, against any of the common methods to force open a lock, i.e., by hitting, bending and pulling on it.
According to the invention, a security element links both areas of the cylinder body separated by said cavity, whereby the removal of the cylinder body is prevented even in the event that said body has been intentionally broken from the outside in order to access the interior of the corresponding home or enclosure, which is extremely difficult as indicated in the preceding paragraph. Given its simplicity, the device is highly reliable.
The device proposed by the invention comprises a cylinder body which is formed by a cylindrical body from which a radial prolongation comprising two side faces and a lower area extends along the entire length of its generatrix.
The cylindrical body is in turn split by an inner or central cavity splitting it into two portions, one portion corresponding with the outer face of the door and the other portion with the inner face. The cavity partially affects the radial prolongation without reaching the lower area thereof, there being in the radial prolongation, in correspondence with the inner cavity, a mechanically weakened central area, such that said central area is indeed weakened in response to any act of vandalism.
According to the invention the security device comprises a security element having a U-shaped laminar configuration, being able to be inserted by pressure and fitted in a slot- or cavity-like recess which the side faces have, partially affecting said faces, and the lower area of the radial prolongation has, not necessarily along the entire length thereof, but rather a specific area surrounding the weakened central area.
Therefore, the security element runs along the weakened central area of the radial prolongation, where the configuration of the security element corresponds with the configuration of the recess.
As indicated above, there are basically three ways to force open a lock cylinder with an end projecting from the plane of the door: by hitting, bending and pulling on it. The most popular way is by hitting it, in response to which the particular laminar configuration, with a specific thickness, of the security element significantly reinforces the lock cylinder. In other words, the invention clearly reinforces the cylinder in the weakest portion thereof, considerably improving its resistance against being hit, bent and pulled on, while at the same time prevents, or at least greatly complicates, the removal of the cylinder in the event that the cylinder of the lock ends up being broken in the weakest portion thereof with ill intention.
Even though a preferred embodiment of the invention contemplates the implementation thereof in cylinder bodies having a cylindrical configuration with radial prolongation, the application of the security device of the invention in cylinder bodies of any profile and configuration type is contemplated.
The possibility that the security element comprises a pair of lobes at each end is contemplated, where each lobe has an end hole intended for housing a lug projecting from the recess of the radial prolongation, such that when the security element is fitted in the recess, each lug is housed in an end hole of the security element.
Therefore, in addition to snap-fitting the security element in the recess, a more stable and secure fixing between the security element and the lock cylinder is achieved, the lugs being fitted in the end holes located in the lobes of the security element.
The weakened central area usually has a threaded hole for fixing to a door. In such case, the security element comprising two central holes that face the ends of the threaded hole when the security element is fitted in the recess is contemplated, the security element, the lock cylinder and the door thus being completely fixed and linked together, which makes forcing open the lock even more difficult, increasing the effectiveness of the device.
The possibility that the security element does not project from the side faces and from the lower area of the radial prolongation when it is fitted in the recess is contemplated, whereby better integration and protection of the security element are achieved. The security element is coupled by pressure in the cylinder, i.e., it is pushed against the cylinder, it opens as it is being applied on the radial prolongation and closes when it coincides with the recess having the same geometry

Description of the Drawings

To complement the description that is being made and for the purpose of aiding to better understand the features of the invention according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description in which the following has been depicted with an illustrative and non-limiting character:

Figure 1 shows a schematic top perspective view of a preferred embodiment of the security element comprising the security device of the invention, where said security element has been removed from its service position in the recess incorporated in the radial prolongation of the lock.
Figure 2 shows a schematic profile view and a cross-section of the device of the invention as depicted in Figure 1, i.e., with the security element removed.
Figure 3 shows a schematic profile view of the device with the security element already assembled in its position, as well as two top and bottom plan views and two cross-sections along the section lines indicated in the profile view.
Figure 4 shows a schematic top perspective view, although from a viewpoint different from that of Figure 1, of the device of the invention, where the security element is depicted as being placed in its service position, i.e., housed in the recess of the radial prolongation.

Preferred Embodiment of the Invention

In view of the described drawings it can be observed how in one of the possible embodiments of the invention the security device for lock cylinders proposed by the invention comprises a cylinder body which is formed by a cylindrical body (1) from which a hollow radial prolongation (2) comprising two side faces (2') and a lower curved area (2") extends along the entire length of its generatrix.
The cylindrical body (1) is split by the inner or central cavity (3) partially affecting the radial prolongation (2) without reaching the lower area (2") thereof, there being in the radial prolongation (2), in correspondence with the inner cavity (3), a mechanically weakened area (5). Said weakened central area (5) is formed as a solid central attachment section having a small width and a threaded hole (11) for fixing to the door by means of the corresponding screw, such that said central area (5) is to some extent weakened in response to any act of vandalism.
In turn there is housed in the inner cavity (3) a rotary cam (4) through which a plurality of teeth (9) which are housed inside the radial prolongation (2) is operated in closing and opening by means of the corresponding key, when it is introduced in the openings made for such purpose located at the ends (8) of the cylinder body, specifically in a rotor (10) which can rotate with respect to said cylinder body when operated by the key.
According to the invention the security device comprises a security element having a U-shaped laminar configuration, being able to be inserted by pressure and fitted in a recess (7) which the side faces (2') and the lower area (2") of the radial prolongation (2) have.
Therefore, the security element (6) runs along the weakened central area (5) of the radial prolongation (2), where the configuration of the security element (6) corresponds with the configuration of the recess (7).
As can be seen in the embodiment depicted in the drawings, the security element (6) comprises a pair of lobes (6') at each end, where each lobe (6') has an end hole (6") intended for housing a lug (7') projecting from the recess (7) of the radial prolongation, such that when the security element (6) is fitted in the recess (7), each lug (7') is housed in an end hole (6") of the security element.
Likewise, the lugs (7') preferably have a beveled edge to facilitate the operation of inserting the security element (6) in the recess (7).
The weakened central area (5) usually has a threaded hole (11) for fixing to a door. In such case, the security element (6) comprising two central holes (6"') that face the ends of the threaded hole (11) when the security element (6) is fitted in the recess (7) is contemplated, the security element, the lock cylinder and the door thus being completely fixed and linked together, which makes forcing open the lock even more difficult, increasing the effectiveness of the device.
As seen in Figures 3 and 4, the security element (6) preferably does not project from the side faces (2') and from the lower area (2") of the radial prolongation (2) when it is fitted in the recess (7), whereby better integration and protection of the security element are achieved. The security element is coupled by pressure in the cylinder, i.e., it is pushed against the cylinder, it opens as it envelopes the radial prolongation and closes when it coincides with the recess having the same geometry.
The security element (6) is therefore perfectly integrated in the structure of the cylinder body which makes the removal of the cylinder from its positioning in the corresponding lock difficult even if the cylinder is intentionally broken, with respect to its central area (5), acting as highly reliable security elements. In such situation, the security element (6) keeps both portions of the cylinder body linked and attached to one another through the central area (5), acting as an attachment element to prevent removal if it breaks. Additionally, though unnecessary, fixing the security element (6) by means of central holes (6") on the radial prolongation (2) of the cylinder body is contemplated, although it is preferably assembled by pressure.
According to a preferred embodiment, the security element (6) is symmetrical with respect to a longitudinal plane splitting the radial prolongation (2) into two equal halves and passing through the axis of the cylindrical body (1), taking the position of the security element (6) when it is fitted in the recess (7) as reference.
Likewise, it is contemplated that the security element (6) is symmetrical with respect to a plane transverse to the axis of the cylindrical body (1) passing through half of the inner cavity (3), taking the position of the security element (6) when it is fitted in the recess (7) as reference.
Nevertheless, the security element (6) may or may not be symmetrical with respect to a plane transverse to the axis of the cylindrical body (1) passing through half of the inner cavity (3), taking the position of the security element (6) when it is fitted in the recess (7) as reference. Symmetry or asymmetry depends on the length of the outer and inner portions of the cylinder, which are not always of the same length.
Finally, it is also contemplated that the security element (6) is not symmetrical with respect to a plane transverse to the axis of the cylindrical body (1), taking the position of the security element (6) when it is fitted in the recess (7) as reference.
The security element (6) preferably has a flexible clip configuration and consists of a U-shaped steel sheet. The security element thus performs the function of a spring acting like a highly elastic clip that is coupled by pressure on the cylinder.
In view of this description and set of drawings, the person skilled in the art will understand that the embodiments of the invention which have been described can be combined in many ways within the object of the invention. The invention has been described according to several preferred embodiments thereof, but for the person skilled in the art it will be evident that multiple variations can be introduced in said preferred embodiments without exceeding the object of the claimed invention.

Claims

Security device for lock cylinders comprising a cylinder body which is formed by a cylindrical body (1) from which a radial prolongation (2) comprising two side faces (2') and a lower area (2") extends along the entire length of its generatrix, where said cylindrical body (1) is split by an inner cavity (3) partially affecting the radial prolongation (2) without reaching the lower area (2") thereof, there being in the radial prolongation (2), in correspondence with the inner cavity (3), a mechanically weakened central area (5), characterized in that the security device comprises a security element (6) having a U-shaped laminar configuration, being able to be inserted by pressure and fitted in a recess (7) which the side faces (2') and the lower area (2") of the radial prolongation (2) have, such that said security element (6) runs along the weakened central area (5) of the radial prolongation (2), where the configuration of the security element (6) corresponds with the configuration of the recess (7).
Security device according to claim 1, wherein the security element (6) comprises a pair of lobes (6') at each end, where each lobe (6') has an end hole (6") intended for housing a lug (7') projecting from the recess (7) of the radial prolongation, such that when the security element (6) is fitted in the recess (7), each lug (7') is housed in an end hole (6") of the security element.
Security device according to claim 2, wherein the lugs (7') have a beveled edge to facilitate the operation of inserting the security element (6) in the recess (7).
Security device according to any of the preceding claims, where the weakened central area (5) has a threaded hole (11) for fixing to a door, the security element (6) comprising two central holes (6"') that face the ends of the threaded hole (11) when the security element (6) is fitted in the recess (7).
Security device according to any of the preceding claims, wherein the security element (6) does not project from the side faces (2') and from the lower area (2") of the radial prolongation (2) when it is fitted in the recess (7).
Security device according to any of the preceding claims, wherein the security element (6) is symmetrical with respect to a longitudinal plane splitting the radial prolongation (2) into two equal halves and passing through the axis of the cylindrical body (1), taking the position of the security element (6) when it is fitted in the recess (7) as reference.
Security device according to any of the preceding claims, wherein the security element (6) is symmetrical with respect to a plane transverse to the axis of the cylindrical body (1) passing through half of the inner cavity (3), taking the position of the security element (6) when it is fitted in the recess (7) as reference.
Security device according to any of claims 1 to 5, wherein the security element (6) is not symmetrical with respect to a plane transverse to the axis of the cylindrical body (1) taking the position of the security element (6) when it is fitted in the recess (7) as reference.
Security device according to any of the preceding claims, wherein the security element (6) has a flexible clip configuration and consists of a U-shaped steel sheet.