Patent Description:
Cylinders for locks comprise a fixed part, or stator, which must be coupled to the door leaf of installation, and a moving part, or rotor, which is designed to move a cam that interacts with the sliding latch and the spring latch of the lock, thus allowing closing and opening.

Interposed between the rotor and the stator are coded pins that immobilize them reciprocally: only via the insertion of a coded key is it possible to align the pins so as to release the rotor from the stator, thus allowing the movement of the cam.

In some cylinders, on the side intended to be installed inside the environment delimited by the door leaf that carries the cylinder proper, a knob which is directly connected to the cam may be provided.

In this manner, from inside it will always be possible to actuate the sliding latch (or latches) and the spring latch, by way of a movement of the knob, while from outside such condition will be subordinated to the insertion of the key with the correct coding into the respective seat of the rotor.

This type of cylinder is liable to intrusion actions, which are carried out using a drill in which a small-diameter drill bit is fitted: the tool will be inserted by the intruder into the seat for the key, in order to perforate the bottom of the seat and access the end portion of the knob (the portion connected to the cam).

At this point it will be possible, using a tool the end of which can be coupled to the end portion of the knob through the seat and the hole made, to move the cam, thus resulting in the opening (retraction of the sliding latches and spring latch).

Such intrusion actions are particularly effective (allowing the illintentioned individual to remain in the environment to which he has been able to gain access by virtue of the intrusion perpetrated) in that they leave a trace that is hard to detect from outside. In fact the hole made is small in diameter and therefore it does not cause serious damage to the accommodation seat of the key: once he has entered, therefore, the intruder can close the door behind him, with no evident signs of intrusion being perceptible from outside. <CIT> relates to an anti-intrusion cylinder of the type comprising a fixed stator, provided with a cavity inside which can rotate at least one rotor that is integral, at a central portion thereof, with an actuation cam for at least one sliding latch, said at least one rotor, at one end, being coupled to a movement knob and, at the other, comprising a seat for a coded key, said seat being intercepted by a plurality of coding pins, wherein said at least one rotor is constituted by two coaxial half-rotors between which is interposed a longitudinal plug that can be coupled indirectly to said cam.

<CIT> relates to a cylinder lock for increased security, that contains an inner ball to protect the closing lever from an attack by drilling.

The aim of the present invention is to solve the above mentioned drawbacks, by providing an anti-intrusion cylinder that is protected against intrusion actions carried out with a drill through the insertion seat of the key.

Within this aim, an object of the invention is to provide an anti-intrusion cylinder that guards against intrusion actions that are carried out with a drill and are adapted to leave traces that are hard to detect.

Another object of the invention is to provide an anti-intrusion cylinder that offers high standards of security.

A still further object of the present invention is to provide an anti-intrusion cylinder that is low cost, easily and practically implemented and safely applied.

This aim and these and other objects which will become better apparent hereinafter, are achieved by an anti-intrusion cylinder of the type comprising a fixed stator, provided with a cavity inside which can rotate at least one rotor that is integral, at a central portion thereof, with an actuation cam for at least one sliding latch, said at least one rotor, at one end, being coupled to a movement knob and, at the other, comprising a seat for a coded key, said seat being intercepted by a plurality of coding pins, characterized in that said at least one rotor is constituted by two coaxial half-rotors between which is interposed a longitudinal plug that can be coupled to said cam, the end head of said plug, which constitutes the end wall of the seat for accommodating said key, having a convex shape structure preferably chosen from among conical, hemispherical, pyramidal, hemi-ellipsoidal and the like, said longitudinal plug comprises, at its end tip opposite from said head , means of detachable coupling, directly or indirectly, to the half-rotor that is integral with said actuation knob , and it comprises detachable coupling means that are constituted by an end profile of shape and dimensions complementary to those of a respective receptacle facing the half-rotor that is associated with said knob, elastic means forcing said end profile into said receptacle for a mutual coupling.

Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the anti-intrusion cylinder according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings, wherein:.

With reference to the figures, an anti-intrusion cylinder is generally designated by the reference numeral <NUM>.

The anti-intrusion cylinder <NUM> comprises a fixed stator <NUM> provided with a cavity <NUM> inside which can rotate at least one rotor <NUM>, 4a, 4b that is integral, at a central portion thereof, with an actuation cam <NUM> for at least one sliding latch.

The at least one rotor <NUM>, 4a, 4b, at one end, is coupled to a movement knob <NUM> and, at the other end, comprises a seat <NUM> for a coded key <NUM>.

The seat <NUM> is intercepted by a plurality of coding pins <NUM>, which are adapted to be accommodated temporarily in respective coding recesses on the surface of the key <NUM>, when the latter is inserted into the seat <NUM> in order to execute opening and/or closing operations.

According to the invention, the at least one rotor <NUM>, 4a and 4b is constituted by two coaxial half-rotors 4a and 4b, between which is interposed a longitudinal plug <NUM> that can be coupled, indirectly, to the cam <NUM>.

The end head <NUM> of the plug <NUM>, which constitutes the end wall of the seat <NUM> for accommodating the key <NUM>, has a convex shape structure preferably chosen from among conical, hemispherical, pyramidal, hemi-ellipsoidal and the like.

The convex shape makes it possible to guard against the perpetration of an intrusion action that entails the insertion of a drill bit into the seat <NUM> for the axial drilling of the plug <NUM> and gaining access to the half-rotor 4b from outside (with consequent ability to control the rotations of the cam <NUM> in a similar manner to what would happen from inside using the knob <NUM>).

In fact a drill bit, when it encounters the convex surface, will be deflected, thus allowing drilling only on surfaces other than those of the plug <NUM>, thus defeating the intrusion attempt.

With particular reference to an embodiment of undoubted practical and applicative interest, the longitudinal plug <NUM> can advantageously comprise, at its end tip opposite from the head <NUM>, means of detachable coupling to the half-rotor 4b that is integral with the actuation knob <NUM>.

Such detachable coupling means can conveniently be constituted by an end profile <NUM> of shape and dimensions complementary to those of a respective receptacle <NUM> that is present on the half-rotor 4b associated with the knob <NUM>.

Suitable elastic means (by way of example these may be a helical spring <NUM> that has an axial action) will be provided to force the end profile <NUM> into the receptacle <NUM> for a mutual coupling, unless external actions (adapted to bring about the decoupling) are carried out to force the elastic means.

It should be noted that the receptacle <NUM> present on the half-rotor 4b associated with the knob <NUM> is constituted by a cavity <NUM>, facing the end face of the half-rotor 4b proper: in particular on a collar <NUM>, accommodated inside the half-rotor 4b, inside which the end tip <NUM> opposite from the head <NUM> of the plug <NUM> can slide. The collar <NUM> is provided with coupling means, more precisely the receptacle <NUM> (in which the end profile <NUM> can engage) is provided on the collar <NUM>.

With particular reference to a form of execution of undoubted practical interest, the end head <NUM> of the plug <NUM> can advantageously comprise (or be constituted by) material with a high surface hardness.

For example, the head <NUM> can preferably be constituted by a tempered steel, a casehardened steel, a hardened steel, a nitrided steel, a cyanided steel, a steel covered with at least one substance chosen from among silica, diamond, ceramic materials, stony materials, a metal alloy covered with at least one substance chosen from among silica, diamond, ceramic materials, stony materials and the like.

The high surface hardness of the head <NUM>, combined with its convex shape structure, will pose an exceptionally difficult obstacle to drilling carried out with a drill bit which is inserted into the seat <NUM> for the key <NUM>.

In fact it will be very difficult to nick the surface of the head <NUM>, making it substantially impossible to cut into it by getting a stable purchase for a drill bit, which will necessarily be deflected, as a result of the convex shape structure.

With particular reference to the implementation solutions proposed by way of non-limiting example in the accompanying figures, the half-rotor 4a, in which the seat <NUM> for accommodating the key <NUM> is provided, comprises, at its end wall, a bushing <NUM> inside which the head <NUM> of the plug <NUM> can be translated axially, according to a preset stroke and forced by an elastic element that has an axial action <NUM>.

In order to ensure the necessary security against intrusion actions of the conventional type (with lockpicks and the like), it should furthermore be noted that the seat <NUM> for the key <NUM> will positively be intercepted by a plurality of transverse coding pins <NUM>, which are adapted to abut against a respective surface of the coded key <NUM> of the type of a flat key and/or a punched key.

This particular type of key <NUM> (i.e. a flat and/or punched key) in fact currently offers among the highest standards of security against nondestructive attempts at tampering (lock-picking carried out according to many and varied methods).

It should be noted that, with particular reference to an embodiment of proven functionality and effectiveness, the head <NUM> of the plug <NUM> can conveniently comprise a rotatable cavity <NUM> for accommodating an element of the type of a ball <NUM>, a slug with the front, with a convex or similar shape, directed outward.

In this manner the head <NUM>, in addition to deflecting a drill bit by virtue of the convex shape, and in addition to being difficult to damage owing to its high surface hardness, will tend to be entrained in rotation by the drill bit which will therefore not succeed in any case in carrying out an effective abrasive action, thus making it, effectively, substantially impossible to drill the plug <NUM> through the seat <NUM>.

In order to ensure the possibility of the ball-type element <NUM> to rotate inside the cavity <NUM>, it will be necessary to provide containment end lips in the cavity <NUM> which impede the egress of the ball <NUM>.

Advantageously the present invention solves the above mentioned problems, by providing an anti-intrusion cylinder <NUM> that is protected against intrusion actions carried out with a drill through the insertion seat <NUM> of the key <NUM>.

This is obtained by virtue of the particular characteristics of construction of the plug <NUM> (designed to couple the half-rotors 4a and 4b to the cam <NUM>), the head of which that faces the seat <NUM> in fact has a convex shape structure (designed to deflect a drill bit). Furthermore such head <NUM> can be made with material with high surface hardness (difficult to damage with a drill bit) and it can comprise a rotatable end insert (which would be entrained in rotation by the drill bit, making any attempt at drilling futile).

Positively the anti-intrusion cylinder <NUM> according to the invention guards against intrusion actions that are carried out with a drill and are adapted to not leave visible traces. In fact only intrusion actions of the destructive kind (such as for example the total drilling of the rotor <NUM>, 4a, 4b) could make it possible to open the cylinder <NUM>: but it is not possible to gain access to the knob <NUM> from the outside through holes made on the bottom of the seat <NUM> (which are not visible from outside), as seen above.

Conveniently the anti-intrusion cylinder <NUM> has high standards of security, requiring in fact the use of a flat key (or a punched key) and therefore an arrangement of the coding pins <NUM> that is particularly secure and effective.

Positively the anti-intrusion cylinder <NUM> according to the invention is easily and practically implemented and is low cost: such characteristics make the cylinder <NUM> according to the invention a technical innovation that is certain to be safe in use.

The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be interchanged with other, different characteristics, existing in other embodiments.

In practice, the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.

Claim 1:
An anti-intrusion cylinder of the type comprising a fixed stator (<NUM>), provided with a cavity (<NUM>) inside which can rotate at least one rotor (<NUM>, 4a, 4b) that is integral, at a central portion thereof, with an actuation cam (<NUM>) for at least one sliding latch, said at least one rotor (<NUM>, 4a, 4b), at one end, being coupled to a movement knob (<NUM>) and, at the other, comprising a seat (<NUM>) for a coded key (<NUM>), said seat (<NUM>) being intercepted by a plurality of coding pins (<NUM>), wherein said at least one rotor (<NUM>, 4a, 4b) is constituted by two coaxial half-rotors (4a, 4b) between which is interposed a longitudinal plug (<NUM>) that can be coupled indirectly to said cam (<NUM>),
characterized in that the end head (<NUM>) of said plug (<NUM>), which constitutes the end wall of the seat (<NUM>) for accommodating said key (<NUM>), has a convex shape structure preferably chosen from among conical, hemispherical, pyramidal, hemi-ellipsoidal and the like,
in that said longitudinal plug (<NUM>) comprises, at its end tip (<NUM>) opposite from said head (<NUM>), means of detachable coupling, directly or indirectly, to the half-rotor (4b) that is integral with said actuation knob (<NUM>),
and in that it comprises detachable coupling means that are constituted by an end profile of shape and dimensions complementary to those of a respective receptacle (<NUM>) facing the half-rotor (4b) that is associated with said knob (<NUM>), elastic means (<NUM>) forcing said end profile into said receptacle for a mutual coupling.