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The present invention relates to a safety lock and the key for operating the same.

In particular, the lock described herein is a cylinder lock of the type comprising:

- a lock body or stator;

- a cylinder or rotor, rotatably mounted in the lock body and having a passage for introduction of a key;

- a plurality of blocking pins, each of which is mounted in the cylinder in a fixed position along its own axis, with the possibility of rotation about the above axis, and is designed to be engaged by the operating key and rotate about its own axis into a pre set operative position following upon introduction of the key into the cylinder; and

- a blocking member carried by the cylinder and projecting therefrom in an operative position of engagement of a respective seat in the lock body, said blocking member being free to retract into a position of disengagement from the aforesaid seat when the blocking pins rotate into the pre-set operative positions following upon introduction of the operating key.

The aforesaid pins each comprise at least one projecting eccentric finger, and, on the other hand, the operating key has at least one groove designed to receive the eccentric fingers of the pins, which is shaped so as to get the pins to rotate into the aforesaid pre-set operative positions, following upon introduction of the key into the cylinder.

A safety system of the type referred to above is known from the European patent EP1019601 filed in the name of the present applicant. The aim of the present invention is to improve known systems of the type referred to above, both from the operating standpoint and from the security standpoint .

The above object is achieved via a locking system according to Claim 1.

The claims provided in what follows form an integral part of the technical teaching presented herein .

Further characteristics and advantages of the invention will emerge clearly from the ensuing description with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

- Figure 1 illustrates the safety lock and the key for operating the lock according to an embodiment of the system described herein, in an axonometric view;

- Figure 2 is a sectional view, according to a longitudinal plane of section, of the safety lock of Figure 1 with the key inserted therein;

- Figure 3 is a sectional view, according to a plane of cross section parallel to the plane of Figure 2, of the safety lock of Figure 1 with the key inserted therein;

- Figure 4 is a sectional view, according to a longitudinal plane of section, of the safety lock of

Figure 1 with the operating key inserted therein;

- Figure 5 is a top plan view of the operating key of the system of Figure 1;

- Figure 5A illustrates a detail of the key illustrated in Figure 5 in a cross-sectional view according to the plane A-A illustrated in Figure 5;

- Figure 6 is a schematic illustration of the mode of operation of the key represented in Figure 5 inserted into the safety lock of Figure 1; - Figure 7 is a schematic illustration of the mode of operation of the key represented in Figure 5 inserted into a safety lock according to the prior art;

- Figure 8 is a schematic illustration of an attempt to use an operating key according to the prior art in the safety lock of Figure 1.

In the ensuing description, various specific details are illustrated aimed at enabling an in-depth understanding of the embodiments. The embodiments may be provided without one or more of the specific details, or with other methods, components, or materials, etc. In other cases, known structures, materials, or operations are not illustrated or described in detail so that various aspects of the embodiments will not be obscured.

The references used herein are provided merely for convenience and hence do not define the sphere of protection or the scope of the embodiments.

As mentioned at the start, the safety system described herein comprises a cylinder lock and the key for operating the same.

Reference will be made hereinafter, for the purposes of description of the invention, to the embodiment illustrated in the figures that envisages a European cylinder. In any case, the principles that will be delineated may equally be applied also to cylinder locks of some other type, as will emerge clearly in what follows.

In Figure 1, the reference number 10 designates as a whole a cylinder lock mounted in a door 3 of a dwelling (illustrated only partially) and associated to a key 100 having a grip 102 and a plate-like body 104 with two opposite faces 105 and two longitudinal edges 107.

In various embodiments, as in the one illustrated, the cylinder lock 10 comprises a body 2 or stator traversed by a cylindrical passage 2A within which a rotor or cylinder 4 is rotatably mounted about an axis of rotation I.

Figure 1 illustrates how the body 2 is made up of two parts 2’ , 2’’ that are the same as one another and symmetrical with respect to a plane of symmetry P orthogonal to the axis of rotation I. In particular, the half 2’’ of the body 2 is provided with a cylinder that is the same as and symmetrical with respect to the cylinder 4, for engagement of a key on the side of the door opposite to the one illustrated on which the cylinder 4 is provided.

In a way in itself known, the body 2 has a threaded hole 22 for engagement of a screw for fixing the lock to the door.

In what follows reference will be made to the cylinder 4 and to the part 2’ of the body 2 that receives it, but it is clear that what has been described applies identically also to the second half 2’’ of the body 2 and to the cylinder received therein.

As mentioned above, the present invention can also be applied to cylinder locks of a non-European type, and hence also to locks that include a single rotatable cylinder accessible only on one side of the door.

Moreover, the drawings do not show the usual rotatable door bolt, which is connected in rotation to the cylinder 4 and is set in the space 2C defined between the two parts 2', 2’’ of the stator, for control of opening and closing of the door.

Provided in the cylinder 4 is a passage 8, which extends axially through the cylinder, for introduction of the key 100.

According to the traditional technique, in the cylinder 4 there may be provided a first series of blocking pins 6, positioned in succession along the axis of rotation I and slidably mounted within respective radial holes that are made in the cylinder 4 and give out into the passage 8. Once again according to the traditional technique, the blocking pins 6 co operate with corresponding counterpins 12 slidably mounted radially in the body 2 and recalled by springs 14 against the blocking pins 6.

The blocking pins 6 have end tips designed to co- operate with a shaped profile of the key 100, which in the example illustrated is defined by a plurality of cavities 103 made on one or both of the faces 105 of the key 100.

By way of said shaped profile, the key authorized to open the lock is able, once it has been introduced into the passage 8, to cause axial displacement of the blocking pins 6 into the operative positions illustrated in Figure 3, where they do not project beyond the outer surface of the cylinder 4, so that they do not prevent rotation of the cylinder 4 with respect to the body 2.

The pins mentioned above are not in any case essential for the solution described herein, and it is in fact also possible to envisage embodiments without such pins .

As mentioned at the start, the lock described herein is moreover provided with a series of blocking pins 16, which are also positioned in the cylinder in succession along the axis of rotation I and are mounted within respective holes having axes orthogonal to the axial plane in which the passage 8 is defined and giving out onto the passage 8. In various preferred embodiments, as in the one illustrated, the pins 16 are mounted within respective radial holes made in the cylinder 4. In various preferred embodiments, as in the one illustrated, the pins 16 are provided on the opposite side of the passage 8 with respect to the blocking pins 6 described above.

Each of the blocking pins 16 is mounted in a fixed position along its own axis, with the possibility of rotation about the latter.

The modalities of mounting of the pins 16 in the cylinder 4 may be multiple. In various preferred embodiments, as in the one illustrated (Figures 2 and 3), the aforesaid pins have a height equal to the depth of the holes in which they are arranged, so that their opposite ends are respectively flush with the outer surface of the cylinder 4 and in contact with the bottom of the respective hole. In this way, the pins 16 are blocked with respect to any movement in their own axial direction.

The pins 16 are designed to co-operate with a secondary blocking member 18 slidably mounted in the cylinder 4 in a direction transverse to a plane containing the axis of rotation I.

The secondary member 18 is, in particular, mobile between an operative position in which it projects out of the outer surface of the cylinder 4 engaging a seat 24 made on the inner wall of the body 2 that delimits the cylindrical passage 2A, and an inoperative position in which it is, instead, completely contained within the cylinder 4.

The outer surface of the pins 16 is configured for enabling or preventing re-entry of the member 18 into the inoperative position referred to, according to the orientation that the pins themselves assume with respect to their own axes.

In particular, in each pin the aforesaid lateral surface has for practically all of its perimetral extension, dimensions such as to prevent the member 18 from going back into the cylinder 4, thus constraining it in the aforesaid operative position, where it engages with the seat 24.

Instead, in a precise position of its own outer contour, each pin 16 has a profile shaped so as to provide sufficient space for the member 18 to be able to go completely back into the cylinder 4, moving into the aforesaid inoperative position.

In particular, in various preferred embodiments, as in the one illustrated, each pin 16 is provided with an axial groove 16A, which is configured for receiving a corresponding nose 18B of the blocking member 18 so as to enable the latter to go completely back into the cylinder 4.

Preferably, the cylinder 4 comprises springs 27 provided for recalling the member 18 against the seat 24.

In the light of what has been said above, in the lock described herein a blocking condition is determined in which the member 18 engages the respective seat 24 and is blocked in this position by the pins 16 so that rotation of the cylinder 4 is prevented .

To disable the above blocking mode, the individual pins 16 must be oriented so as to set the grooves 16A facing the corresponding noses 18B of the blocking member 18. In this position of the pins 16, the member 18 is in fact free to move into a position of disengagement from the seat 24, as a result of a rotation imparted on the cylinder 4 by the key 100.

In this regard, preferably the seat 24 and the corresponding end of the blocking member 18 have shaped profiles, for example curved or rounded, to determine an action of thrust on the blocking member towards the inside of the cylinder 4 by the walls of the seat 24, as a result of the rotation imparted on the cylinder 4 by the key 100.

Rotation of the pins 16 into the respective operative positions referred to in which the blocking member 18 is allowed to move completely back into the cylinder 4, is obtained by introducing the authorized key 100.

With reference now to the prior art, this rotation of the pins 16 is induced by introducing the authorized key in so far as the latter has a shaped longitudinal groove, engaged within which is, for each pin, an eccentric finger projecting from the pin within the passage for introduction of the key.

With reference to the figures, in the safety system described herein, instead, each blocking pin comprises a pair of eccentric fingers 16B, 16'B of different lengths, and the authorized key has a pair of longitudinal grooves of different depths, for selectively receiving one and the other eccentric finger of each pin.

The two grooves 106, 106' are shaped so as to guide simultaneously and in a co-ordinated way the two fingers 16B, 16'B of each pin so as to get it to rotate up to the pre-set operative position, following upon introduction of the authorized key into the cylinder 4.

For an initial stretch starting from the tip of the key, the two grooves 106, 106' overlie one another and are of different widths so that the deeper groove 106 is contained within the lateral dimension of the shallower groove 106' , as may be seen in the top plan view of Figure 5.

In particular, in various preferred embodiments, as in the one illustrated, both of the grooves have respective initial portions 106A, 106Ά, which are contained in one another and are characterized by a profile decreasing in width starting from the tip of the key towards the grip 102, thus defining a lead-in portion to facilitate insertion of the fingers 16B, 16'B of the pins 16.

The portion 106A of the deeper groove 106 narrows more rapidly than does the portion 106Ά of the shallower groove 106' and converges into a subsequent portion 106B, of constant width, in a position where the shallower groove 106' still presents, instead, the lead-in portion 106Ά.

The groove 106 proceeds with the portion 106B up to the end of its extension.

The lead-in portion 106' proceeds further in the axial direction of the key, containing the portion 106B within its own lateral dimension.

Further on, in a region where the two grooves 106, 106' still overlie one another, the portion 106Ά converges into a portion 106' C, which is also widened so as to contain the portion 106B of the groove 106, but has a substantially constant width.

Starting from the position where the two grooves separate, the groove 106' finally procedes with a third portion 106' B having a constant width substantially equal to the width of the portion 106B of the groove 106.

The two portions 106B and 106' B extend alongside one another along the key according to distinct paths and without crossing over for an intermediate stretch, and then instead they cross over at the end of the portion 106B where the groove 106 terminates.

The groove 106' proceeds beyond the groove 106, terminating further forwards.

Preferably, the eccentric fingers 16B, 16'B are arranged in diametrally opposite positions with respect to the axis of the corresponding pin. In the embodiment illustrated, the grooves 106, 106' are made on each face 105 of the body of the key in order to enable the key to operate indifferently in the two opposite orientations about its own longitudinal axis. It is in any case clear that the two grooves 106, 106' may also be provided on just one of the two faces.

Incidentally, it should moreover be noted that in general the operating key 100 may present a body having a shape different from the plate-like body of the solution illustrated. Hence, in general, the grooves

106, 106' will be arranged on the side (or sides) of the body of the key that is (are) to co-operate with the blocking pins 16 of the cylinder lock.

With reference now to operation of the lock, it will be noted that, with introduction of the key into the passage 8, the lead-in portion 106A can engage always and only the longer finger 16B of each pin since the other, shorter, finger 16'B is not able to reach the walls of the corresponding groove 106.

Moreover, the longer finger 16B can be engaged only by the portion 106A in so far as this is contained within the lateral dimension of the lead-in portion 106Ά and hence the longer finger 16B can never reach the walls of the portion 106Ά.

Accordingly, the lead-in portion 106Ά may, instead, engage always and only the shorter finger 16' B of each pin 16.

The lead-in portion 106A intervenes on the longer finger 16B of each pin 16, rotating the latter so as to set it according to an orientation such as to enable insertion of the two fingers 16B, 16'B into the subsequent portions 106B and 106'C, 106'B of the respective grooves associated thereto.

The same function is performed by the lead-in portion 106Ά on the shorter finger 16'B of each pin 16.

Consequently, whether it is one or the other of the two fingers 16B, 16'B of each pin that is engaged first by the groove associated thereto, the pin will in any case be set in the correct orientation to guide the fingers 16B into the portions 106B and 106'C, 106'B.

The portions 106B and 106'C, 106'B are shaped according to respective profiles that are correlated with one another.

In the first place, for each position assumed by each pin 16 along the key, the portions 106B and 106' C, 106' B of the two grooves are configured for exerting on the individual pin, through the fingers 16B, 16' B, concordant angular momenta so as to set the pin in rotation .

Moreover, the aforesaid portions globally follow respective paths that co-operate to bring each pin 16 into the pre-set operative position referred to above when the key reaches the end-of-travel position within the lock.

In this position of the key, the pins 16 come to occupy different positions along the two grooves 106, 106' and will all be oriented in their pre-set operative positions.

As compared to the solution according to the prior art, the two grooves 106, 106' and the corresponding fingers 16B, 16'B of the pins 16 that co-operate with them, afford a series of advantages.

In the first place, the grooves 106, 106' define two reference points for each pin that make it possible to guide it and position it precisely notwithstanding the manufacturing tolerances.

On the other hand, the two fingers provided for each pin are able to stabilise it during insertion of the key, thus limiting the stresses that would tend instead to bring the pin out of alignment. This contributes to reducing wear of the pins and of the other components that interface with them and consequently improving reliability of the lock.

In view of the foregoing, as compared to the solution according to the prior art, the safety system described herein is characterized as a whole by a more precise and reliable operation.

The means described moreover provide a new type of opening code that is additional to the codes already existing for the type of lock in question.

In effect, only the authorized key provided with the two grooves 106, 106' will be able to position the pins in the pre-set operative positions and hence operate the lock.

Figure 8 illustrates schematically how an operating key according to the prior art that is provided with a single groove is in no way able to rotate and orient the pins 16 properly in so far as the fingers 16B, 16'B of these pins - in the case illustrated, the shorter fingers 16' B - move into positions where they interfere with the groove, not even allowing complete insertion of the key.

On the other hand, in the case where an attempt at burglary were made with a key that has been tampered withprovided with a single widened groove so as to enable the insertion of the key into the lock, the key would be completely inserted but would not be able to orient the pins 16 in their pre-set operative positions .

On the other hand, as illustrated in Figure 7, the authorized key described herein is able to turn a lock according to the prior art that is provided with blocking pins, each having a single eccentric finger in so far as it is able to orient the aforesaid pins in their operative positions via one of its two grooves 106, 106' - in the case illustrated, the deeper groove

106.

For the manufacturer of the safety system described herein, there is hence the advantage of being able to provide the new model of key both for the new lock described herein and for the lock according to the prior art.

Finally, it is pointed out that the pairs of eccentric fingers provided on the pins 16 all project into the passage 8 for insertion of the key and together occlude it so as to render it difficult to access using burglary tools. Preferably, these pins are made of a high-strength material, for example hardened steel, to withstand attempts at effraction.

Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary, even significantly, with respect to what has been illustrated herein purely by way of non-limiting example, without thereby departing from the scope of the invention, as defined by the annexed claims .