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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; and

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

a first pin is slidably mounted in a first cavity that gives out onto the aforesaid passage on a first side; and

a second pin is mounted in a second cavity that gives out onto the aforesaid passage on a second side opposite to the first side.

The operating key has a body, mounted on which is a ring, which is mobile with its own axis with respect to the body of the key and is designed, when the key is inserted into the aforesaid passage, to be engaged at diametrally opposite points by the aforesaid first and second pins in the cylinder. The ring defines a pre-set distance such as to set the first and second pins in a relative position in which they enable free rotation of the cylinder within the lock body.

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, in particular from the security standpoint.

The above object is achieved via a safety system according to Claim 1. Moreover constituting a subject of the present invention are a safety lock according to Claim 9 and an operating key according to Claim 11. 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 top plan view of the operating key of the system of Figure 1;

- Figure 4 illustrates a detail of the key represented in Figure 3 in a cross-sectional view according to the plane A-A appearing in Figure 3;

- Figure 5 is a sectional view, according to a transverse plane of section, of the safety lock of Figure 1 with the key inserted therein;

- Figure 6 illustrates the mode of operation of the key represented in Figure 3 inserted in a safety lock according to the prior art; and

- Figure 7 illustrates 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 operating 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 two pins 16, 18 mounted in the cylinder 4 within respective holes, which are made on opposite sides with respect to the passage 8 and give out into the passage.

As for the pins 6, the pin 16 is able to slide along its own axis and co-operates with a corresponding counterpin 22 slidably mounted radially in the body 2 and recalled by a spring 14' against the pin 16. The counterpin 22 pushed by the spring inserts into the hole of the cylinder 4 within which the pin 16 is housed, thus preventing rotation of the cylinder.

On the other hand, the pin 18 is mounted in the respective hole substantially without the possibility of moving along its own axis.

The pins 16 and 22 define a particular blocking condition that cannot be disabled simply by a notch made on the key, like the aforesaid cavities 103.

In fact, the pin 16 has a length that is not sufficient, following upon insertion of a key provided with a corresponding notch that engages it, for it to be brought flush with the interface between the cylinder 4 and the stator body 2 so as to unblock the cylinder, in the way that has been described above for the pins 6 and 12.

In this case, the body of the key must present an appropriate projecting portion.

This portion is defined by a cylindrical ring 30, carried by the body 104 of the key, which is mobile with its own axis in a direction transverse to the longitudinal plane defined by the body 104.

During insertion, the ring 30 is free to move in a transverse direction with respect to the key, so as to centre itself within the passage 8 so as not to hinder the key while it is being inserted.

As will emerge clearly in what follows, with the description of how it is mounted on the key, the ring 30 is moreover free to rotate about its own axis, this facilitating insertion of the key into the passage 8.

On the other hand, as will be seen also in what follows, the ring 30 may also have the possibility of moving in the longitudinal direction of the key, once again in order not to hinder insertion of the key into the passage 8.

When the key is inserted, the ring 30 will be engaged by the pin 18, on one side, and by the pin 16, on the opposite side.

The pin 18 has a length such as to act on the ring

30 by contrast, pushing it against the pin 16 and getting it to project from the key on the side of the aforesaid pin 16.

The ring 30 defines a distance between the pin 18 and the pin 16 that is such as to set the latter flush with the cylinder 4, and to set, accordingly, the pin 22 outside of the cylinder in a position of non interference (Figure 5) .

In particular, the ring 30 has a cylindrical outer surface that defines a first diameter, provided on which is a circumferential groove 32 that defines with its bottom a second diameter, smaller than the first diameter .

Accordingly, at least one between the pin 16 and the pin 18 - in the solution illustrated the fixed pin 18 - is provided with a shaped tip 18A facing the passage 8 and configured for engaging the groove 32, moving into contact with its bottom.

In the embodiment illustrated, the aforesaid pre- set distance is represented by the distance between the bottom of the groove 32, on the side engaged by the pin 18, and the outer surface of the ring 30, on the side engaged by the pin 16.

In other words, the aforesaid distance corresponds to the diameter defined by the bottom of the groove 32 plus half of the difference between the outer diameter of the ring 30 and the diameter defined by the bottom of the groove 32.

The pre-set distance in question is the same also in the case where it is the pin 16, instead of the fixed pin 18, that is provided with a shaped tip as indicated above.

In the case, instead, where both the pin 18 and the pin 16 are provided with such a tip, the aforesaid pre-set distance corresponds precisely to the diameter defined by the bottom of the groove 32.

With reference now to how the ring 30 is mounted on the key, preferably it is mounted on a cylindrical pin 31, within a through opening 112 made on the body 104 of the key.

The ring 30 has a diameter considerably larger than the pin 31 and is mobile within the opening 112 orthogonally to the longitudinal plane identified by the body 104.

Preferably, the opening 112 has a width - measured in the transverse direction - substantially corresponding to the width of the ring 30, taking into account the tolerances necessary for enabling the ring to move freely in a direction transverse to the body of the key.

In this way, the ring 30 is guided laterally in the above movement by the walls of the opening 112 and is substantially fixed in position with respect to a direction transverse to the longitudinal direction of the body of the key.

Preferably, the opening 112 is constituted by an axial slit made on the tip of the body 104 of the key.

In view of the foregoing, it will be understood that the degree of the movement, in the transverse and longitudinal directions referred to above, to which the ring 30 may be subject with respect to the key, is a function of the difference between the inner diameter of the ring and the outer diameter of the cylindrical pin 31.

In various preferred embodiments, as in the one illustrated, the ring 30 is positioned in an axial direction of the key parallel to and not coinciding with the direction in which the shaped profile defined by the cavities 103 is located.

On the other hand, the pin 22 is positioned in the lock body 2 aligned to the counterpins 12.

The pin 16 that is in contact with the pin 22 at an end thereof is consequently mounted in the cylinder 4 oriented with its own axis inclined with respect to the axis of the pin 22 so that its opposite end is able to reach the ring 30 in the passage 8.

The pin 18 is, instead, positioned in the cylinder 4 with its own axis parallel to the axis of the pin 22.

In various preferred embodiments, as in the one illustrated, the ring 30 is set along a plane of symmetry of the body of the key orthogonal to the longitudinal plane identified by the latter.

In this way, the ring 30 can operate indifferently for both of the two opposite orientations of the key about its own longitudinal axis.

It is in any case clear that it is also possible to envisage embodiments in which the key is provided with two rings 30, which are each to operate for a respective orientation of the key.

As compared to the solution according to the prior art, the safety system described herein affords a greater protection against non-authorized duplications of the key and, in general, is able to counter more effectively possible attempts at burglary.

In particular, it should be noted that the ring

30, with the corresponding groove 32 and the pins 16 and 18, determine a pre-set distance that cannot be directly detected from an examination of the key alone, given that it depends also upon the shaped tip that is designed to engage the groove 32, which may be provided on one or both of the pins 16 and 18.

On the other hand, it will be noted that 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 ring 30 and corresponding groove 32 will be able to position the pin 16 in the pre-set operating position and hence operate the lock.

Figure 7 illustrates schematically how an operating key according to the prior art that is provided with a ring without groove is not able in any way to position the pin 16 properly flush with the cylinder 4 in so far as in this case the distance defined by the ring between the pin 18 and the pin 16 is greater than the pre-set distance referred to above, so that the pin 16 is brought outside of the cylinder thus preventing rotation thereof.

On the other hand, as illustrated in Figure 6, the authorized key described herein may also be able to operate a lock according to the prior art, the blocking pins of which are without a shaped tip designed to engage the groove 32 of the ring 30 of the key in so far as in this case the outer diameter of the ring 30 corresponds, instead, to the pre-set distance specifically envisaged for operating the lock according to the prior art.

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.

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 .