The present invention relates to an break-in resistant lock. In particular, the invention makes it possible to define a cylinder lock with radial coding that is adapted to guard against being opened using the tampering technique known as "lock bumping". The present invention can also be applied to locks with traditional coding, however.

This technique entails inserting a key with the right shape for entering the hole of the rotor of the cylinder, but lacking the necessary coding, and using a percussion tool to apply knocks to the head of the key, while also applying a torque on the head in the direction required to open the lock.

The percussion will cause a movement of the pins (and of the corresponding counterpins, if any) along the respective channels, with subsequent restoration of the initial conditions by the action of the elastic means present in those channels.

During the stroke of the pins (and of the counterpins), these will assume the configuration for opening the lock for at least a moment.

After the application of numerous knocks in sequence, it is possible to obtain a momentary condition in which the pins (and the counterpins) are all correctly aligned for the lock to be opened. When this condition is achieved, the torque applied will be sufficient to cause the rotation of the rotor (which is now free to rotate) with respect to the stator and, therefore, open the lock.

This tampering technique is becoming extremely widespread and preventive measures are known and adopted on cylinders for keys with traditional coding (i.e. where the coded teeth are provided on a perimetric edge).

In locks with traditional coding, the length of the channels that host the pins (and the counterpins) is generally appreciably longer than 10 mm and therefore the space available makes it possible to adopt pins (and counterpins) that are conveniently contoured and/or subdivided and which are adapted to prevent being opened with the lock bumping technique. In cylinders with radial coding, the length of the channels that host the pins (and the counterpins) is appreciably shorter than the radius of the stator (they occupy the radial space between the aperture for inserting the key into the rotor and the rotor itself) and therefore it is not possible to adopt the conventional contrivances applied in locks with traditional coding.

For manufacturers of locks, the problem is even more important in that the adoption of specific pins and/or counterpins to prevent lock bumping in locks with traditional coding, but which cannot be used in locks with radial coding, implies problems of a logistic nature (more space needed in warehouses, different provisioning procedures, reduced versatility of components, etc).

The aim of the present invention is to solve the above mentioned drawbacks by providing a break-in resistant lock that is protected against the tampering technique known as "lock bumping".

Within this aim, an object of the invention is to provide a break-in resistant lock of the type with a cylinder with radial coding which is provided with components that are adapted to prevent tampering using the technique known as "lock bumping".

Another object of the invention is to provide a break-in resistant lock that is provided with components that are adapted to prevent tampering using the technique known as "lock bumping" and which are adapted to be applied equally on cylinders with traditional coding and/or on cylinders with radial coding.

Another object of the present invention is to provide a break-in resistant lock that is of 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 a break-in resistant cylinder lock of the type comprising a stator which is provided with a substantially cylindrical longitudinal cavity for accommodating a rotor with a longitudinal seat for the insertion of a key, said rotor and said stator comprising a plurality of channels, which are substantially aligned and facing when the cylinder is in the locked configuration, said channels accommodating respective pins, counterpins and optional elastic means that are adapted to prevent the rotation of the rotor in the stator in the absence of the key from said longitudinal seat, characterized in that at least one of said counterpins comprises at least one external bushing which is provided with at least one respective through hole at the head and at least one contoured inner insert that can slide within said bushing and which is provided with a protruding terminal projection with shape and dimensions that are complementary to those of the said through hole of the said bushing in order to slide within said hole.

Further characteristics and advantages of the invention will become better apparent from the description of a preferred, but not exclusive, embodiment of the break-in resistant lock according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is a cross-sectional front elevation view taken along a transverse plane of a break-in resistant lock according to the invention; Figure 2 is a cross-sectional front elevation view, taken along a transverse plane, of the lock of Figure 1 with a respective key inserted;

Figure 3 is a cross-sectional front elevation view, taken along a transverse plane, of the lock of Figure 1 with the respective key inserted during opening; Figure 4 is a cross-sectional front elevation view, taken along a transverse plane, of the lock of Figure 1 with a false key inserted;

Figure 5 is a cross-sectional front elevation view, taken along a transverse plane, of the lock of Figure 1 with a false key inserted when an external pulsed percussive action is applied to the head of the key in order to attempt tampering using the lock bumping technique; Figure 6 is a cross-sectional front elevation view taken along a transverse plane of a variation of a break-in resistant lock according to the invention in which the respective key is inserted;

Figure 7 is a cross-sectional front elevation view taken along a transverse plane of a variation of a break-in resistant lock according to the invention;

Figure 8 is a cross-sectional rear view taken along a transverse plane of a variation of a break-in resistant lock according to the invention;

Figure 9 is a cross-sectional front elevation view, taken along a transverse plane and partially exploded, of the lock of Figure 1 with a respective key inserted;

Figure 10 is a cross-sectional view taken along the line X-X in Figure

6;

Figure 11 is a cross-sectional front elevation view taken along a transverse plane of a further version of a break-in resistant lock according to the invention;

Figure 12 is a cross-sectional front elevation view, taken along a transverse plane, of the lock of Figure 11 with a false key inserted, during the application of a percussive action to the head of the key in order to attempt tampering (an attempt at lock bumping).

With reference to the figures, the reference numeral 1 generally designates a break-in resistant lock and the reference numeral 6 generally designates the respective key.

The lock 1 according to the invention is a cylinder lock that comprises a stator 2 which is provided with a substantially cylindrical longitudinal cavity 3 for accommodating a rotor 4 with a longitudinal seat 5 for the insertion of a key 6.

The rotor 4 and the stator 2 comprise a plurality of channels 7, which are substantially aligned and facing when the cylinder is in the locked configuration. The channels 7 accommodate respective pins 8, counterpins 9 and optional elastic means 7a.

The pins 8 and counterpins 9 are adapted to prevent the rotation of the rotor 4 in the stator 2 (more precisely inside its cavity 3) in the absence of the key 6 from the longitudinal seat 5.

At least one of the counterpins 9 will advantageously comprise at least one external bushing 10 which is provided with at least one respective through hole 11 at the head and at least one contoured inner insert 12 that can slide within the bushing 10 and which is provided with a protruding terminal projection 13 with shape and dimensions that are complementary to those of the through hole 11 of the bushing 10: the end protrusion 13 will be able to slide within the hole 11 and, in general, the inner insert 12 will be able to slide axially within the bushing 10 (by the action of external forces applied by the key 6 and in contrast with the thrust exerted by the elastic means 7a).

With particular reference to an embodiment of undoubted practical and applicative interest, each pin 8 can conveniently comprise an end head 14 with a larger diameter and a cylindrical main body 15 with a smaller diameter.

The rotor portion of the channel 7 comprises a first segment 16, proximate to the longitudinal seat 5 (adapted to temporarily accommodate the key 6), which has a shape and dimensions that are complementary to those of the cylindrical main body 15, for the sliding accommodation thereof, and a second segment 17, proximate to the stator 2, which has a shape and dimensions that are complementary to those of the end head 14, for the sliding accommodation thereof.

It is convenient to note that the stator portion of the channel 7 can usefully comprise an outer part 18 with a larger diameter and an inner part 19 with a smaller diameter.

The bushing 10, in turn, will conveniently comprise a cylindrical main element 20 with shape and dimensions that are complementary to those of the part with a smaller diameter 19 and a protruding lip 21, arranged at the base of the bushing 10, which has a shape and dimensions that are complementary to those of the part with a larger diameter 18. In this manner, the variations in diameter of the channel 7 will define steps that act as abutment shoulders against which ridges of the pin 8 and of the counterpin 9 will abut, for the purpose of preventing them from protruding from the respective seat (within which they can slide along the axis of the channel 7), thus ensuring the necessary stability of the lock 1 according to the invention.

With particular reference to an implementation that is particularly efficient and secure against effraction (in particular effraction using the lock bumping technique), the counterpins 9 can advantageously be a plurality, each one slideably accommodated in a respective channel 7. In such case, the initial front 22 of each pin 8, aligned with a respective counterpin 9 in a common channel 7, will, in the configuration of total insertion of the key 6 into the longitudinal seat 5, abut against respective coded recesses 23 of the key 6.

It should be noted that the channels 7 are provided in a radial direction and are defined entirely between the stator 2 and the rotor 3.

With particular reference to an embodiment of particular practical and applicative interest, the channels 7 adapted to accommodate the pins 8 and the counterpins 9 according to the invention are a plurality and provided in a radial direction and are mutually spaced apart according to a distribution chosen from longitudinal, angular and combinations thereof.

Purely for the purposes of non-limiting example, Figure 6 shows an embodiment that comprises three channels 7 which are provided with pins 8 and counterpins 9 according to the invention, while Figure 7 and Figure 8 show locks 1 according to the invention in which the channels 7 provided with pins 8 and counterpins 9 according to the invention are two in number, while also showing the presence of a third channel 24 that accommodates pins 25 and counterpins 25a which is of the conventional type (showing how the embodiment according to the invention can be integrated in conventional solutions in order to offer the necessary protection against tampering).

According to an alternative embodiment, the channels 7 can conveniently be provided along a plane of symmetry of a frame 26 that contains the stator 2 and the rotor 3 and are advantageously defined within the stator 2, the rotor 3 and an expansion 27 of the frame 26. More often, the frame 26 will be an integral part of the stator 2, as can clearly be seen in Figure 11 and in Figure 12.

The present invention also extends its protection to include a kit constituted by a lock 1 and by the related key 6.

In such case the lock 1 will comprise a break-in resistant cylinder which is provided with a stator 2 which is provided with a substantially cylindrical longitudinal cavity 3 for accommodating a rotor 4 with a longitudinal seat 5 for the insertion of the respective key 6, in conformance with the characteristics of the lock 1 described up to this point.

In such lock 1, the rotor 4 and the stator 2 will comprise a plurality of channels 7, which are substantially aligned and facing when the cylinder is in the locked configuration.

The channels 7 accommodate respective pins 8, counterpins 9 and optional elastic means 7a that are adapted to prevent the rotation of the rotor 4 in the stator 2 in the absence of the key 6 from the longitudinal seat 5: in such condition a portion of the pin 8 or of the counterpin 9 will be arranged at the interface between the rotor portion and the stator portion of the respective channel 7, thus preventing the rotor 4 from rotating with respect to the stator 2.

At least one of the counterpins 9 will comprise at least one external bushing 10 which is provided with at least one respective through hole 11 at the head and at least one contoured inner insert 12 that can slide within the bushing 10.

The insert 12 will be provided with a protruding terminal projection 13 with shape and dimensions that are complementary to those of the through hole 11 of the bushing 10 in order to slide within that hole 10.

The key 6 according to the invention will positively comprise at least one contoured superficial recess 23 for accommodating at least one part of the apical (initial) front 22 of a respective pin 8 which can slide within a first segment 16 of the channel 7, a segment 16 proximate to the longitudinal seat 5, in the rotor portion of that channel 7.

It should be noted that, in this case too, the counterpins 9 can be a plurality, each one accommodated slideably in a respective channel 7. The terminal front 22 of each pin 8 aligned with each counterpin 9 will be accommodated in a respective channel 7, abutting, in the configuration that couples the key 6 to the cylinder, on a respective contoured superficial recess 23 of the key 6.

It should furthermore be noted that, in an embodiment of undoubted practical and applicative interest and also of proven efficacy against effraction, the channels 7 can conveniently be a plurality, each one provided in a radial direction.

In such case the channels 7 will be mutually spaced apart according to a distribution chosen from longitudinal, angular and combinations thereof.

Operation of the invention is as follows.

When the key 6 is not inserted, the pin 8 and the counterpin 9 of each channel 7 are pushed by the spring 7a so that the counterpin 9 is located at the surface for interfacing between the stator 2 and the rotor 4, preventing the rotor 4 from rotating within the stator 2.

Such operating situation is shown by way of non-limiting example in the accompanying Figures 1, 7, 8 and 11. When the key 6 is inserted into the longitudinal seat 5, it determines the translation of the pins 8 and of the counterpins 9 within the respective channels 7, until their facing surfaces are aligned proximate to the interface between the stator 2 and the rotor 4 (which corresponds to the surface of the cavity 3). In such situation the rotor 4 will be able to turn freely with respect to the stator 2 by virtue of the action of a moment applied to the head of the key 6.

Such operating situation is shown by way of non-limiting example in the accompanying Figures 2, 3 and 6.

If a false key 6a is inserted (i.e. a key without the necessary coded recesses 23), the pin 8 and the counterpin 9 of the channels 7 will interfere with the interface between the stator 2 and the rotor 4 and therefore will prevent the rotor 4 from rotating and the lock 1 from opening.

Such operating situation is shown by way of non-limiting example in the accompanying Figures 4, 10 and 12 (the latter figure shows the moment when a knock is applied during an attempt at tampering carried out using the lock bumping technique).

If in these conditions (i.e. with the false key 6a) an attempt is made to force or to break the lock using the lock bumping strategy (by applying a moment to the head of the key and striking it in a pulsed manner with a tool) a transfer of motion will occur from the key 6a to the pin 8, which will retreat, pushing (pushing the spring or elastic means 7a) the inner insert 12 of the counterpin 9 back into the channel 7 as well. The bushing 10, however, will not receive the thrust from the pin 8 and therefore will remain in the configuration of interference (i.e. partially accommodated in the stator portion and in the rotor portion of the channel 7), thus preventing the rotor 8 from rotating with respect to the stator 9.

In this manner the lock 1 according to the invention is effectively protected against lock bumping.

Merely for the purposes of non-limiting example, the appearance of the lock 1 according to the invention when a tampering action is applied from outside using the lock bumping technique is shown in Figure 5.

Advantageously the present invention solves the above mentioned problems, by providing a break-in resistant lock 1 that is protected against the tampering technique known as "lock bumping", as exhaustively illustrated.

Conveniently the break-in resistant lock 1 according to the invention can be of the cylinder type with radial coding, marking a major innovation with respect to conventional cylinders with radial coding.

In fact the lock 1 according to the invention, in this case too, will be provided with components that are adapted to prevent tampering using the technique known as "lock bumping", such components being absent from cylinder locks with conventional radial coding.

Positively the break-in resistant lock 1 is provided with components that are adapted to prevent tampering using the technique known as "lock bumping". Such components will usefully be adapted to be applied equally on cylinders with traditional coding and/or on cylinders with radial coding. This constitutes an undoubted advantage for manufacturers, who will have more versatile components (that can be used on any lock), thus minimizing the corresponding space required in warehouses as well.

Positively the present invention makes it possible to provide in a substantially simple manner a break-in resistant lock 1 which is of low cost: such characteristics make the lock 1 according to the invention an 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.

Where the technical features mentioned in any claim are followed by reference numerals and/or signs, those reference numerals and/or signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference numerals and/or signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference numerals and/or signs.