Safety devices

Abstract

A security device wherein an elongated metallic body has at least one end attachable to a lock unit, the body having at least one track extending longitudinally on a surface thereof, the material of the track comprising particles of a hard, cut-resistant material dispersed in a self-fluxing matrix having a lower melting point than that of the body and comprising one of nickel, iron and cobalt in a composition with chromium, silicon and boron, the or each track being welded to the elongated body.

Description

[0001] This invention relates to security devices, and more particularly to the use of cut-resistant materials in elongated elements that form essential components in security devices. One object of the invention is to provide an element that is so difficult to cut that thieves are deterred or prevented from breaking open a device secured by the element. The invention particularly relates to security devices in which at least one end of an elongated body can be attached to a lock unit.

[0002] Examples of well-known cut-resistant materials include cermet, tungsten carbide, titanium carbide, titanium nitride, and titanium carbon nitride. It is known to use a material such as tungsten carbide to form a wear-resistant layer on a surface. Such layers can be formed by flame spraying and / or laser cladding. Typically, tungsten carbide particles are dispersed in a self-fluxing matrix or alloy based on nickel, iron, or cobalt in a composition with chromium, silicon, and boron, as discussed in a conference paper titled "High temperature erosion wear of cermet particles reinforced self-fluxing alloy matrix HVOF sprayed coatings," published in Materials Science in September 2015. Products bearing such layers or coatings are available from various companies, such as ASB Industries Inc.from Barburton, Ohio, USA, B&B Precision Engineering from Huddersfield, UK, and Oerlikon Metco from Pfäffikon, Switzerland.

[0003] Reference is also made to US Patent Nos. 4,136,230 and 4,561,272, US Published Application No. 2005 / 0092038 and European Patent Publications Nos. 2740,553, 2808,107 and 3,974,552, all of which disclose the use of tungsten carbide in an alloy matrix.

[0004] The present invention is based on the concept of reinforcing an operative component of a locking device with a cut-resistant material. According to the invention, a security device comprises a metallic, elongated body which can be attached to a lock unit at at least one end. The body has at least one track of a material of the type mentioned above extending longitudinally on its surface and metallurgically bonded thereto. The material of the track comprises particles of a hard, cut-resistant material dispersed in a self-fluxing matrix with a lower melting point than that of the body and comprising one of the elements nickel, iron, and cobalt in a composition with chromium, silicon, and boron.The traces are typically applied to the elongated body by welding, preferably laser welding or laser cladding, but plasma arc welding or brazing can also be used. The lower melting point prevents melting of the elongated body while enabling the metallurgical bond. Tungsten carbide is the preferred cut-resistant material, but other materials such as silicon carbide, cubic boron nitride, or industrial or synthetic diamond can also be used.

[0005] Preferred matrices used as trace material in the devices according to the invention are based on nickel or cobalt, ideally with a hardness of approximately 50 to 60 HRC (Rockwell C hardness). Nickel-based matrices with optional inclusion of iron are particularly preferred. In the matrix forming the traces in the elements according to the invention, the hardness of the cut-resistant particles is preferably in the range of 2,500 to 3,000 Hv (Vickers hardness), and that of the matrix is ​​500 to 600 Hv.

[0006] The base material of the elongated body is usually steel, typically a hardened, low-carbon steel. A preferred material is a low-carbon case-hardened steel hardened to 58-60 HRC.

[0007] The matrix with the dispersed particles can be in solid or powder form. In solid form, it is supplied as a rod or wire that must be melted during trace application. This can lead to increased heating at the application area, resulting in migration of the body material into the traces. A preferred application method uses a powder form that is applied directly to the body and welded to form the traces. Migration of the material from the elongated body into the matrix should be kept to a minimum, preferably to no more than 10 percent by volume of the trace material.

[0008] The particles in the matrix that form the tracks in the elements according to the invention are preferably spherical and typically vary in size from 50 to 160 µm. The particles can also be in cast and crushed form. In this form, the dimensions of the particles typically vary between 50 and 200 µm. In some embodiments, a mixture of spherical and crushed particles could also be used. The size variation of the particles determines the density of the particles in the matrix, but particles that are too small may melt or disintegrate when the tracks are applied to the body, and particles that are too large may not be retained. The particles typically comprise 40 to 65 percent by volume of the track material.

[0009] In most embodiments of the invention, a plurality of separate tracks extend across the surface of the body, typically three or four. However, in one particular embodiment, the tracks extend contiguously side by side to completely cover the body. In other embodiments, the tracks may be applied in different directions so that they intersect on the surface of the elongated body. In some embodiments, the track or tracks may be compressed into the body after application to substantially restore the original cross-section. At the end or ends of the body to be received in a locking unit, this compression may be limited to the respective end portion.The track or tracks normally extend the entire length of the elongated body, but may terminate short of one or each end of the body to leave an end portion for receipt in an opening of matching cross-section in the lock unit.

[0010] In devices according to the invention, tracks made of a material similar to that of the track(s) on the elongated body can also be applied to the locking unit. Particularly when one end of the body is adapted to enter an opening in the unit, a track made of the material can be metallurgically bonded to the locking unit around the perimeter of the opening.

[0011] The dimensions of the or each track on the elongated body in elements according to the invention vary depending on the dimensions of the particular body. However, for a body with a circular cross-section and a diameter of up to 5 cm, a typical maximum thickness of the track is no more than 2 mm, preferably no more than 1 mm, and a typical width is in the range of 3 to 10 mm.

[0012] In all embodiments of the invention, the finished product may be plated, coated, or encapsulated in a polymeric material, preferably a low-pressure plant-based polymer, to provide corrosion resistance and durability, as well as to conceal the position and structure of the reinforcement traces.

[0013] Devices according to the invention can be used in a variety of portable security devices such as bicycle and motorcycle locks, e.g. padlocks and D-locks or U-locks as described in European Patents Nos. 3193405 and 3584394, as well as in door locks, safes and catalytic converter locks, which are cited as examples of many other applications.

[0014] The invention will now be described by way of example with reference to the accompanying schematic drawings, in which: Fig. is a perspective view of the locking portion of a device incorporating a security element according to the invention; The Fig. illustrate the forms of tungsten carbide dispersed in the matrix in lane 8 of the Fig. ; Fig. is a perspective view of elongated bodies in embodiments of the invention; Fig. shows cross-sections of elongated bodies in embodiments of the invention; The Fig. show how the present invention can be used in products, and Fig. is a micrograph showing a cross-section of a track associated with a security element in a device according to the invention.

[0015] Fig. shows two housing elements 2A and 2B secured together by an elongated safety element 4. The element 4 consists of a solid rod 6 of metal, typically steel, with a track 8 welded thereto. The material of the track comprises a hard, cut-resistant material such as tungsten carbide in a self-fluxing matrix or low-melting point alloy as mentioned above. At one end, the element 4 is mounted in a slot 10 on the housing element 2A for pivotal movement about an axis 12 mounted in the element 2A. At the other end, the element is received in a slot 14 where it is held by a locking mechanism (not shown) operated by a removable key 16. When the rod is secured in position as shown, the rod passes through the recess between the housing elements 2, with little space between the rod and the base of the recess.This space is inaccessible to conventional cutting mechanisms, so the underside of the rod 2 is protected by the housing elements 2, as shown. When the other end of the rod is released by the locking mechanism, it can rotate clockwise, as shown, to allow the housing elements to separate. Of course, the locking mechanism could also be operable merely to release the end of the rod from the housing element 2B, enabling it to be pulled directly out of the slot 14. In this case, the rod could be rigidly attached to the housing element 2A.

[0016] The self-fluxing matrix is ​​based on nickel in combination with chromium, silicon, and boron. A preferred composition includes 15% chromium, 3% boron, 4.5% silicon, 0.65% carbon, and 3% iron, with the remainder being nickel, although some ceramic is usually included as well.

[0017] Fig. shows spherical particles of tungsten carbide (WC) embedded in a nickel-based matrix of the type Fig. The dispersion is random, and the smaller particles tend to occupy the spaces between the larger ones. The particle size varies in the range of 50 to 160 µm in diameter. The matrix is ​​nickel-based and contains silicon and boron. Composites made from such particles in this matrix are available from Stoody Industrial Welding Supply, Inc. in San Diego, California, USA. The WC particle content in the matrix is ​​approximately 65 percent by volume. Fig. shows cast and crushed particles of WC in the same nickel-based matrix as in Fig. As you can see, the density of the particles is higher than in Fig. and is around 80%.

[0018] Fig. shows an elongated security element with a substantially square cross-section, but any suitable cross-section may be used. The single track 8 may be duplicated on one or more other sides of a body with a polygonal cross-section, but the invention is normally embodied in elements in the form of an elongated body with a circular cross-section. Fig. Examples are shown in which tracks in different structures are applied to different solid bodies; four with one, four, six or eight linear tracks and three with four, six or eight spiral tracks. Cross sections of similar bodies are shown in Fig. As you can see, it is possible to place tracks very close together, even contiguously, or so that they overlap and completely envelop the body.

[0019] As mentioned above, the track(s) applied to an elongated body in devices according to the invention can be compressed into the body to substantially restore the body's original cross-section. This has the advantage that the positioning of the tracks can be concealed or disguised. A further advantage is that the tracks can extend to one or both ends of the body, which can then be received in a locking or other unit designed to accommodate the body's original shape.

[0020] The present invention can be implemented in well-known security devices. One such device is the D-lock or U-lock, commonly used on bicycles and motorcycles. Fig. shows how the "D" or "U" section 20 may be reinforced by the application of tracks 22 welded thereto as described above. In the illustrated reinforced body, the tracks may terminate short of the ends of the section, thereby enabling the ends to be received in openings in the locking bar 24 of the original product that have the same cross-section as the unreinforced section. The bar itself may also be reinforced by one or more tracks 26. In a preferred feature applicable to all embodiments of the invention, additional tracks 28 may be welded around the points where the section ends are received in the bar or lock unit. Of course, if the tracks 22 are compressed into the section 20, they may extend to the ends and into the locking bar 24.It is therefore understood that the invention can also be subsequently used on existing products.

[0021] Another known security device that can be enhanced with the present invention is a padlock. As in Fig. As shown, traces 30 of the WC dispersed matrix may be welded to the padlock body 32 in addition to the traces 34 welded to the shackle 36.

[0022] The Fig.The micrograph shown illustrates the bonding between a track 38 and an elongated member or body 40 in a device according to the invention with minimal migration of the track material into the body material. As can be seen, tungsten carbide particles (shown in white) of a variety of sizes are distributed throughout the self-fluxing matrix or alloy (shown in gray), which has displaced some of the body material while being applied, either through compression or softening of the material during the application process. While the distribution of the particles is random, the concentration is clearly sufficient to ensure resistance to any severing attempt. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 4136230

[0003] US 4561272

[0003] US 2005 / 0092038

[0003] EP 2740553

[0003] EP 2808107

[0003] EP 3974552

[0003] EP 3193405

[0013] EP 3584394

[0013] Cited non-patent literature

[0000] “High temperature erosion wear of cermet particles reinforced self-fluxing alloy matrix HVOF sprayed coatings” in September 2015

[0002]

Claims

[1] A security device wherein an elongated metallic body has at least one end attachable to a lock unit, the body having at least one track extending longitudinally on a surface thereof, the material of the track comprising particles of a hard, cut-resistant material dispersed in a self-fluxing matrix having a lower melting point than that of the body and comprising one of nickel, iron and cobalt in a composition with chromium, silicon and boron, the or each track being welded to the elongated body. [2] The safety device of claim 1, wherein the matrix includes a ceramic material. [3] A safety device according to any one of the preceding claims, wherein the material of the cut-resistant particles comprises at least one of the following materials: tungsten carbide, silicon carbide and an industrial or synthetic diamond. [4] Safety device according to one of the preceding claims, wherein the cut-resistant particles have a spherical shape. [5] A safety device according to claim 4, wherein the particle size varies in the range of 50 to 160 µm. [6] Safety device according to one of claims 1 to 3, wherein the particles are in cast and crushed form. [7] Safety device according to claim 6, wherein the dimensions of the particles vary between 50 and 200 µm. [8] A safety device according to any one of the preceding claims, wherein the particles comprise 40 to 65% of the trace material. [9] A safety device according to any one of the preceding claims, wherein a plurality of tracks extend contiguously side by side to completely cover the body. [10] A security device according to any one of the preceding claims, wherein a plurality of said tracks cross each other on the surface of the elongate body. [11] A safety device according to any one of the preceding claims, wherein the at least one track has a maximum thickness of 2 mm. [12] A safety device according to any one of the preceding claims, wherein the at least one track has a width in the range of 3 to 10 mm. [13] A safety device according to any one of the preceding claims, wherein the elongated body has a circular, square or polygonal cross-section. [14] A security device according to any one of the preceding claims, wherein at least one end of the elongate body is attachable to the lock unit by entering an opening therein, and wherein a track of material comprising particles of a hard, cut-resistant material dispersed in a self-fluxing matrix comprising one of nickel, iron and cobalt in a composition with chromium, silicon and boron is metallurgically bonded to the lock unit around the perimeter of the opening. [15] A safety device according to claim 14, wherein the material of the cut-resistant particles in the track around the opening comprises at least one of tungsten carbide, silicon carbide and an industrial or synthetic diamond. [16] A safety device according to any one of the preceding claims, wherein the elongate body is encapsulated in a layer of polymeric material. [17] A padlock comprising a security device according to any one of the preceding claims, wherein the elongate member is the shackle of the padlock. [18] A D-lock comprising a security device according to any one of the preceding claims, wherein each end of the element is adapted to engage a locking bar. [19] A security device, wherein an elongated metallic body has at least one end attachable to a lock unit, the body having at least one track extending longitudinally on a surface thereof, the material of the track comprising particles of a hard, cut-resistant material dispersed in a self-fluxing matrix having a lower melting point than that of the body and comprising one of nickel, iron and cobalt in a composition with chromium, silicon and boron, the or each track being brazed to the elongated body. [20] A safety device according to claim 19, wherein the matrix includes a ceramic material. [21] A safety device according to claim 19 or 20, wherein the material of the cut-resistant particles comprises at least one of the following materials: tungsten carbide, silicon carbide and an industrial or synthetic diamond. [22] A safety device according to any one of claims 19 to 21, wherein the cut-resistant particles have a spherical shape. [23] A safety device according to claim 22, wherein the particle size varies in the range of 50 to 160 µm. [24] A safety device according to any one of claims 21 to 23, wherein the particles are in cast and crushed form. [25] A safety device according to claim 24, wherein the dimensions of the particles vary between 50 and 200 µm. [26] A security device according to any one of claims 21 to 25, wherein the particles comprise 40 to 65% of the trace material. [27] A safety device according to any one of claims 19 to 26, wherein a plurality of tracks extend contiguously side by side to completely cover the body. [28] A security device according to any one of claims 19 to 26, wherein a plurality of said tracks cross each other on the surface of said elongate body. [29] A security device according to any one of claims 19 to 28, wherein the at least one track has a maximum thickness of 2 mm. [30] A safety device according to any one of claims 19 to 29, wherein the at least one track has a width in the range of 3 to 10 mm. [31] A safety device according to any one of claims 19 to 30, wherein the elongated body has a circular, square or polygonal cross-section. [32] A security device according to any one of claims 19 to 31, wherein at least one end of the elongate body is attachable to the lock unit by entering an opening therein, and wherein a track of material comprising particles of a hard, cut-resistant material dispersed in a self-fluxing matrix comprising one of nickel, iron and cobalt in a composition with chromium, silicon and boron is metallurgically bonded to the lock unit around the perimeter of the opening. [33] A safety device according to claim 32, wherein the material of the cut-resistant particles in the track around the opening comprises at least one of tungsten carbide, silicon carbide and an industrial or synthetic diamond. [34] A safety device according to any one of claims 19 to 33, wherein the elongated body is encapsulated in a layer of polymeric material. [35] A padlock comprising a security device according to any one of claims 19 to 34, wherein the elongate member is the shackle of the padlock. [36] A D-lock comprising a security device according to any one of claims 19 to 34, wherein each end of the element is adapted to engage a locking bar.

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