The present invention relates to a locking device with high resistance to abrasion, drilling and cutting.

The definition of locking device, in the present discussion, is understood to comprise cylinders for locks and doors and corresponding protectors, locks in general (including electronic ones and/or combination locks), padlocks, padlock chains, safes, mechanical anti-theft devices for bicycles, motorcycles and motor vehicles and the like.

Locking devices have reached excellent levels of protection against numerous techniques of forcing (picking, bumping etc.) and therefore they ensure good security against possible non-destructive violation attempts from ill-intentioned individuals.

Unfortunately however, the use is increasingly frequent of destructive forcing methods: the reason for such tendency is the greater usability (moreover at low cost) of battery-powered tools (therefore easily transported and usable anywhere) with high power levels.

By using battery-powered drills on which tools of high hardness (drill bits coated in titanium nitride and the like) are fitted, it is possible to pierce practically any locking device in a fairly short time instead; by using angle grinders, on which diamond abrasive disks are fitted, it is possible to cut practically any locking device in a fairly short time.

The widespread nature of such battery-powered tools means that any locking device is to be considered liable to destructive forcing and therefore is intrinsically non-secure.

The aim of the present invention is to solve the above mentioned drawbacks, by providing a locking device with high resistance to abrasion, drilling and cutting, i.e. of a type adapted to abrade and/or damage the drill bits or the cutting disks of power tools used for forcing.

Within this aim, an object of the invention is to provide a locking device with high resistance to abrasion, drilling and cutting, i.e. of the type adapted to withstand for particularly long times, for example as long as a few hours, an attempt at destructive forcing perpetrated with a power tool, for example a drill and/or an angle grinder.

Another object of the invention is to provide a locking device with high resistance to abrasion, drilling and cutting, of the type that can be visually identified, in order to constitute a strong deterrent for anyone wanting to carry out a destructive forcing by way of power tools and the like.

Another object of the present invention is to provide a locking device with high resistance to abrasion, drilling and cutting, which 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 a locking device with high resistance to abrasion, drilling and cutting, which is characterized in that it comprises, on at least one of its outer surfaces, at least one layer of a protective material that comprises a plurality of diamonds and at least one binder, the volumetric density of said diamonds in said protective material being comprised between 10 carats/cm ³ and 50 carats/cm ³ .

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 locking device with high resistance to abrasion, drilling and cutting, according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a schematic perspective view of a safe with high resistance to abrasion, according to the invention;

Figure 2 is a schematic perspective view of a protector for lock cylinders with high resistance to abrasion, according to the invention;

Figure 3 is a schematic perspective view of a lock with high resistance to abrasion, according to the invention;

Figure 4 is a schematic perspective view of a padlock and a chain with high resistance to abrasion, according to the invention;

Figure 5 is a schematic perspective view of a lock cylinder with high resistance to abrasion, according to the invention;

Figure 6 is an enlarged schematic view of a surface of a locking device according to the invention.

With reference to the figures, the reference numeral 1 generally designates a locking device with high resistance to abrasion, drilling and cutting.

The device 1 comprises, on at least one of its outer surfaces, at least one layer 2 of a protective material that comprises a plurality of diamonds 3 and at least one binder 4.

In such layer 2 of protective material, the volumetric density of the diamonds 3 is advantageously comprised between 10 carats/cm ³ and 50 carats/cm ³ .

In practice such layer 2 of protective material comprises a mass of diamond crystals 3 with random orientation, such crystals being selected starting from natural or synthetic diamond powder 3, of pre-established granulometry: this mass of diamond crystals is conveniently mixed with suitable quantities of binder 4 and then compacted at very high temperatures and pressure levels.

The layer 2 of protective material, in at least one of the possible applications of the present invention, can be sintered.

The protection conferred by the layer 2 of protective material relates to the protection action against mechanical abrasion, cutting and drilling, but also against corrosion and the oxidation and degenerative effects that can be produced by saline mists.

It should be noted that, preferably, for reasons of containment of costs, the diamond crystals 3 will be synthetic (industrial diamonds). The layer 2 thus provided is very dense, of variable thickness between 0.1 mm and 15 mm, and has the hardness, resistance to abrasion, and thermal conductivity of diamond 3.

Such characteristics of the layer 2 make it possible to adopt materials with reduced hardness and mechanical performance to provide the surfaces of the locking device onto which the layer 2 will be coupled.

The adoption of easily-deformable metals for the production of cylinders, protectors for cylinders, locks (in particular the box-like body that delimits it), padlocks (and chains), and anti-theft devices for vehicles, safes and the like makes it possible to appreciably limit the production costs thereof, since such metals are more easily workable when cold and do not require thermal and/or thermochemical and/or electrochemical treatments for their stabilization.

It follows from this therefore that the layer 2 can be deposited on less expensive locking devices 1 than those currently on the market, while still ensuring mechanical performance against abrasion, cutting and drilling that is decisively superior than all conventional locking devices.

It should be noted that the at least one layer 2 has a surface density of diamonds 3 greater than 0.5 carats/cm ² .

With particular reference to an embodiment that makes it possible to obtain an optimal resistance to abrasion, to cutting and to drilling, it should be noted that the at least one layer 2 can positively have the following densities of diamonds 3 :

- surface density greater than 0.9 carats/cm ² ,

- volumetric density comprised between 20 carats/cm ³ and 25 carats/cm ³ .

Note that one carat corresponds to 0.2 grams.

In order to increase the resistance to abrasion (cutting, drilling) of the device 1 according to the invention, it should be noted that it will similarly be possible to coat the respective faces 1 a thereof with two or more layers 2, optionally selecting layers 2 with different densities.

It should be noted that the binder 4 used will conveniently comprise at least one component chosen from among:

- metallic powders, preferably chosen from among cobalt, aluminum, copper, brass, iron, steel, tin, nickel, tungsten, silver, and metallic alloys;

- ceramic powders;

- resin powders, preferably chosen from among aramid, epoxy, phenolic, and polyamide.

According to the type of layer 2 that it is desired to obtain, different binders can be adopted that require a different and specific sintering process.

In order to increase the resistance of the layer 2, the technician can proceed to increase the granulometry of the diamonds 3 : the greater the granulometry, the better the resistance will be to abrasion (cutting, drilling) ofthe layer 2.

Specifically, it should be noted the diamonds 3 used will preferably be industrial diamonds and will advantageously have a granulometry, understood as the average granule diameter, comprised between 50 μιη and 1000 pm, preferably greater than 100 μηι.

The greater the granulometry of the diamonds 3 in the layer 2, the better the resistance will be to abrasion (cutting, drilling) of the locking device 1 that will comprise such layer 2.

It should be noted that, from an applicative point of view, the locking device 1 can be positively constituted by a cylinder for locks, by a lock, by a protector for cylinders and the like, on the outer surface la of which is arranged the at least one layer 2 of a protective material that comprises a plurality of diamonds 3 and at least one binder 4.

As regards the cylinder, it should be noted that the layer 2 can be deposited on the front faces l a thereof (at least the face intended to be directed toward the outside when the cylinder is installed in the respective lock), although the possibility is not ruled out of providing a complete coating of the cylinder in order to ensure protection against transverse attacks as well (for example holes drilled diagonally with respect to the surface of the installation door in order to reach the cylinder while avoiding the outer face la).

Regarding protectors for cylinders, the layer 2 will need to be extended to the entire surface l a or, at least, to the corresponding portion that is exactly aligned with the front face of the underlying cylinder.

For locks, the layer 2 will be used to coat the entire box-like containment body and/or specific portions thereof; however, the possibility is not ruled out of adopting internal components of the lock that are conveniently coated with the layer 2.

For padlocks, chains and anti-theft devices for vehicles in general, obviously the layer 2 will need to constitute a coating as extended as possible in order to reduce (or even eliminate) the areas that are liable to be damaged by a destructive attack (drilling, cutting and abrasion).

Finally it should be noted that for safes (and safe deposit boxes in general) the layer 2 will be arranged on all the outer surfaces l a so as to define a form of protective shield against destructive attacks (drilling, cutting and abrasion).

It should be noted that the at least one layer 2 can be advantageously deposited on the surface l a to be coated and sintered directly thereon by way of a thermomechanical treatment such as laser sintering, localized direct melting and the like.

In such case, the adhesion of the layer 2 to the faces la of the locking device 1 will be ensured by the fact that it is directly sintered thereon, with consequent stable coupling without discontinuities at the interface surface.

Alternatively, the at least one layer 2 can positively be coupled to the surface l a to be coated only at the end of the corresponding sintering process. In this second case, the coupling can be done by way of a technique chosen from among adhesive bonding, mechanical interference, welding, brazing, and interposition of mechanical coupling elements.

The cohesion of the layer 2 to the faces la on which it is arranged in the respective device 1 will depend, in this second case, on the quality of the coupling performed.

Advantageously the present invention solves the above mentioned problems, by providing a locking device with high resistance to abrasion, drilling and cutting, i.e. of a type adapted to abrade and/or damage the drill bits or the cutting disks of the power tools used for forcing: in fact the presence of the diamond crystals 3 in the layer 2 ensures that (having high hardness) they will damage the tools used for forced entry before they can undermine the layer 2.

Conveniently the locking device 1 is adapted to resist for particularly long times, for example as long as a few hours, an attempt at destructive forcing perpetrated with a power tool, for example a drill and/or an angle grinder. In such period of time in fact, the tools used for forcing will be damaged, with consequent need to replace them in order to continue. An increase in the time necessary for forcing implies a higher probability of catching the ill-intentioned individuals in the act (for example by the forces of law and order, alerted by the protracted noise produced with the power tools).

Profitably the locking device 1 is of the visually identifiable device, in order to constitute a strong deterrent to anyone wishing to carry out a destructive forcing by way of power tools and the like.

In fact the layer 2 has an appearance that is appreciably different from that of the metals usually used, and therefore the ill-intentioned individual, after having seen the presence of the layer 2, will tend to abandon the forcing owing to the extreme difficulty that he/she would encounter in order to damage the layer 2. Positively the locking device 1 is easily and practically implemented and is low cost: such characteristics make the device 1 according to the invention an innovation that is 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.