ENHANCED SECURITY STRUCTURE

Description

Technical field of the invention

[0001] The present invention relates to a reinforced security structure and a method of manufacturing such a structure. Technological background

[0002] Securing a sensitive site, whether military, industrial or otherwise, is primarily achieved through physical and access barriers, one of the purposes of which is to allow for enhanced control of the entry and exit of individuals. These barriers are generally made of metal or metal alloys and can take the form of grilles, turnstiles, gates, etc. However, these barriers can be subject to attacks using cutting tools for malicious purposes.

[0003] To improve their resistance to these attacks, technical solutions exist and offer structures with bars or thick steel plates. However, these solutions are heavy, impractical to install and can prove impractical to use.

[0004] For more specific devices, such as vertical window bars, there are already solutions for increasing cutting resistance using a shaft that can rotate freely within a hollow tube. When a cutting tool comes into contact with the shaft, the movement of the tool then causes the shaft to rotate, reducing the tool's penetration power.

[0005] For example, GB-D0-9001311 describes a shaft housed in a tube and configured to rotate freely. The tube is welded at each end to plates for attachment to a frame. The shaft is then axially locked by the frame.

[0006] Document US-A-4669239 describes a window grille composed of vertical bars. Each of these bars comprises a hollow casing within which is housed a core extending along the length of the bar. This core comprises a shaft surrounded by a plurality of ceramic elements, the assembly being able to rotate freely. The shaft also passes through the frame of the grille and is axially retained, once the grille is mounted, by the wall in which the window is arranged.

[0007] Documents US-A1-2018 / 347227, US-B2-7736085 or US-A-2125807 propose further security structures.

[0008] However, these solutions are not suitable for all security structures, particularly structures with bars with one end free, as may be the case for an arm / comb turnstile or even a fence. Indeed, there is nothing to prevent the rotating shaft from being removed through this free end, which constitutes a flaw.

[0009] Also, an objective of the invention is therefore to propose an improved security structure which does not have, at least, one of the aforementioned drawbacks. Summary of the invention

[0010] A safety structure is therefore proposed comprising a base fitted with a longitudinal axis and at least: a hollow tube provided with a longitudinal axis substantially perpendicular to the longitudinal axis of the base, with one end fixed in the base and with a free end, the hollow tube being formed from a given material, a shaft housed inside the hollow tube and having a longitudinal axis coinciding with that of the hollow tube, the shaft being furthermore made from a material of higher hardness than that of the material forming the hollow tube, and means of cooperation between the hollow tube and the shaft configured to allow the shaft to rotate freely around its longitudinal axis and to retain the shaft axially relative to the hollow tube so as to prevent its withdrawal by the free end.

[0011] Thus, thanks to the invention, security is enhanced. Indeed, the axial retention of the shaft in the hollow tube prevents its removal during a malicious act, making it mandatory to use a cutting tool to force the security structure. Use made difficult, again thanks to the invention, due to the improvement in cutting resistance. Indeed, the higher hardness of the shaft material compared to that of the hollow tube material causes heating and accelerated wear of the cutting tools. In addition, since the shaft can rotate freely on itself in the hollow tube, the point of attack of the cutting tool will not be stable, which reduces its penetration force into the structure, increasing the time required to cut the structure. This then allows surveillance personnel to intervene in time to put an end to the break-in attempt.

[0012] The structure according to the invention may comprise one or more of the following characteristics, taken in isolation from each other or in combination with each other: the means of cooperation between the hollow tube and the shaft comprise, to retain the shaft axially relative to the hollow tube, at least one retaining means extending radially; the means of cooperation between the hollow tube and the shaft comprise, to allow the shaft to rotate about its longitudinal axis, at each end of the shaft: o at least one bearing mounted on an external wall of the shaft, o a ring mounted on an external surface of the bearing and against an internal wall of the hollow tube; at least one retaining means is in contact with at least one of the rings and advantageously on the side of the free end; the means of cooperation between the hollow tube and the shaft comprise, at each end of the shaft, to allow the shaft to rotate freely about its longitudinal axis, at least one bearing mounted on an external wall of the shaft and against an internal wall of the hollow tube;at least one retaining means is in contact with at least one of the bearings, and advantageously on the free end side; a first retaining means is located as close as possible to the base and a second retaining means is located on the free end side; the safety structure comprises an intermediate body housed in an annular space defined by an external wall of the shaft and an internal wall of the hollow tube, the intermediate body being configured to increase the coefficient of friction between the shaft and a blade of a cutting tool. the shaft is made of a metallic or metallic alloy material; the shaft is made of steel with a Vickers hardness of between 40 and 70 kg f / mm 2< , and preferably between 60 and 65 kg f / mm 2< . ;

[0013] The invention also relates to a method of manufacturing a security structure as described above, the method comprising the steps of: a) inserting the shaft inside the hollow tube by its free end, the shaft being provided with a first part of the means of cooperation with the hollow tube, first part configured to allow the shaft to rotate freely around its longitudinal axis, b) producing a second part of the means of cooperation with the shaft, second part configured to retain the shaft axially relative to the hollow tube so as to prevent its withdrawal by the free end (12).

[0014] The method according to the invention may comprise one or more of the following characteristics, taken in isolation from each other or in combination with each other: the second part of the means of cooperation between the hollow tube and the shaft comprises at least one retaining means made extending radially; the retaining means is made by punching on the hollow tube; the retaining means is made by inserting a circlip or a stop ring against the hollow tube; the second part of the means of cooperation between the hollow tube and the shaft comprises a first retaining means and a second retaining means, the first retaining means being made by punching on the hollow tube and the second retaining means being made by inserting a circlip or a stop ring against the hollow tube. Brief description of the figures

[0015] The invention will be better understood with the aid of the following description, given solely by way of example and with reference to the appended drawings in which: There figure 1 represents a schematic view of a security structure according to the invention, The figure 2 represents a partial schematic sectional view of a safety structure according to the invention, The figure 3 represents a partial schematic sectional view of another embodiment of a safety structure according to the invention, The figure 4 represents a schematic front view of an example of application of the security structure according to the invention, in the particular case of a comb turnstile. Detailed description of the invention

[0016] There figure 1shows an example of a safety structure 1. The safety structure 1 chosen to illustrate the present description is in the form of a comb. The term "comb" means a plurality of hollow tubes 10 fixed to a base 2 provided with a longitudinal axis Y. Each hollow tube 10 is provided with a longitudinal axis X, perpendicular to the Y axis of the base 2 and is provided with a free end 12. It is understood that each hollow tube 10 is fixed by one of its ends, for example the end 11, to the base 2 while the other end 12 is left free. Each hollow tube 10 is fixed in the base 2 at its end 11, for example by welding. Each hollow tube 10 is further formed from a given material. In this embodiment, the hollow tubes 10 are substantially parallel to each other.This example of safety structure 1 is non-limiting and could be substituted by any safety structure comprising at least one hollow tube 10 provided with a free end 12.

[0017] Reference is now made to the figure 2 and to the figure 3 , each showing a partial sectional view of an embodiment of the safety structure 1.

[0018] The safety structure 1, in addition to at least one hollow tube 10 provided with a longitudinal axis X and a free end 12 fixed in the base 2, comprises a shaft 20 housed inside the hollow tube 10 and cooperation means 30 between the hollow tube 10 and the shaft 20.

[0019] The shaft 20 has a longitudinal axis X' which substantially coincides with the longitudinal axis X of the hollow tube 10. It is understood that the shaft 20 preferably has a radial dimension and a longitudinal dimension which are substantially smaller than the radial and longitudinal dimensions of the hollow tube 10 so that it can be easily housed inside the hollow tube 10 without protruding therefrom. The shaft 20 is also made of a material of higher hardness than that of the material forming the hollow tube 10.

[0020] Advantageously, the shaft 20 is in the form of a solid cylinder. The shaft 20 may be made of a metallic material or a metallic alloy, and advantageously a steel. The material forming the shaft 20 may have a Vickers hardness (HV) of between 40 and 70 kg f / mm 2 < (kilogram-force per square millimeter), and advantageously between 60 and 65 kg f / mm 2 < .

[0021] A high hardness value improves the abrasion resistance of the steel. Also, within the scope of the invention, a Vickers hardness of at least 40 kg f / mm 2< , and advantageously at least 60 kg f / mm 2< , is suitable. At the same time, to limit the risk of deformation or breakage of the shaft, a maximum Vickers hardness of 70 kg f / mm 2< , and advantageously 65 kg f / mm 2< , is suitable.

[0022] The cooperation means 30 between the hollow tube 10 and the shaft 20 of the safety structure 1 are configured to allow the shaft 20 to rotate freely about its longitudinal axis X' and to retain the shaft 20 axially relative to the hollow tube 10. In other words, the cooperation means 30 comprise at least two parts: a first part to allow the shaft 20 to rotate freely about its longitudinal axis X' and a second part to retain the shaft 20 axially relative to the hollow tube 10. It is understood that the cooperation means 30 between the hollow tube 10 and the shaft 20 prevent the withdrawal of the shaft 20 by the free end 12 of the hollow tube 10.

[0023] In reference to the figure 2, the first part of the cooperation means 30 comprises at each end 22, 24 of the shaft 20 at least one bearing 40 mounted on an external wall 26 of the shaft 20 and a ring 50 mounted on an external surface 42 of the bearing 40 and against an internal wall 14 of the hollow tube 10.

[0024] The bearings 40 may be, without limitation, ball bearings, roller bearings, needle bearings or tapered bearings.

[0025] Each ring 50 comprises an internal surface 52 configured to cooperate with the external surface 42 of the bearing 40. Advantageously, the internal surface 52 is configured to have a minimum of friction with the external surface 42. For this, the internal surface 52 of each ring 50 is bored.

[0026] Advantageously, each ring 50 is tightly mounted with the hollow tube 10 so that the ring 50 cannot rotate inside the hollow tube 10.

[0027] Each ring 50 may be secured to the shaft 20 with a bolt / washer assembly 70 so as to axially hold the bearing 40 between the shaft 20 and the ring 50.

[0028] Advantageously, the rings 50 are made of a non-corrodible material so as to avoid blocking of the shaft 20 due to rust for example. In a non-limiting manner, the rings 50 may be made of plastic material such as polyamide 6-6 (PA66), polytetrafluoroethylene (PTFE) or made of metal such as titanium.

[0029] There figure 3shows another embodiment in which the first part of the cooperation means 30 comprises at least one bearing 40', different from the bearing 40. The bearing 40' is mounted on the external wall 26 of the shaft 20 and against the internal wall 14 of the hollow tube 10. In this way, an external surface 42' of the bearing 40' can be in contact with the internal wall 14 of the hollow tube 10. It is then understood that this bearing 40' has a radial dimension greater than the radial dimension of the shaft 20 and substantially less than or equal to the internal radial dimension of the hollow tube 10. In other words, in the case of a hollow tube 10 and a shaft 20 both cylindrical, the diameter of the bearing 40' is greater than that of the shaft 20 and substantially less than or equal to the internal diameter of the hollow tube 10.

[0030] The second part of the cooperation means 30 comprises, to axially retain the shaft 20 relative to the hollow tube 10, at least one retaining means 32, 32' which extends radially. It is understood that this retaining means 32, 32' extends towards the inside of the hollow tube 10. In a non-limiting manner, this retaining means 32, 32' may be a stop formed by an annular groove on the hollow tube 10. Alternatively, the retaining means 32, 32' may be a circlip or a stop ring mounted against the hollow tube 10, and in particular against the internal wall 14 of the hollow tube 10. It is understood that at least one retaining means 32, 32' is located between the free end 12 of the hollow tube 10 and the other end 11 of the hollow tube fixed in the base 2.

[0031] Advantageously, at least one retaining means 32, 32' is in contact with at least one of the rings 50 or at least one of the bearings 40'.

[0032] Advantageously, a first retaining means 32 is located as close as possible to the base 2 while a second retaining means 32' is located on the side of the end 12, in particular between the first part of the cooperation means 30, understood to be in contact with the ring 50 or the bearing 40', and the free end 12. In this way, the axial movement of the shaft 20 inside the hollow tube 10 is minimal. Indeed, the shaft 20 is retained on the one hand on the side of the free end 12 of the hollow tube 10 and on the other hand on the side of the base 2. It is understood by the term "as close as possible" that the first retaining means 32 defined on the hollow tube 10 is located at the surface of the base 2, when the hollow tube 10 is fixed in the base 2.

[0033] Advantageously, the free end 12 of the hollow tube 10 is closed by a plug, not shown, so as to protect access to the interior of the hollow tube 10 from the free end 12.

[0034] In the embodiments presented by the figures 2 And 3 , the safety structure 1 comprises an annular space 60 defined by the external wall 26 of the shaft 20 and the internal wall 14 of the hollow tube 10.

[0035] Advantageously, the safety structure 1 comprises, housed in the annular space 60, an intermediate body configured to increase the coefficient of friction between the shaft 20 and the blade of the cutting tool. This has the advantage of creating heating of the cutting tool when it comes into contact with the body, which makes it possible to damage the cutting tool and / or slow down the cutting of the safety structure 1. In other words, the intermediate body constitutes a brake on the cutting.

[0036] Advantageously, the intermediate body is made of a material chosen in a non-limiting manner from glass, ceramic, steel or wood, or a combination of the aforementioned materials. These materials have the characteristic of increasing the coefficient of friction.

[0037] The material making up the intermediate body is advantageously in particulate form, that is to say it is in powder form or in the form of balls for example, and fills the annular space 60. In this way, the intermediate body does not prevent the rotation of the shaft 20 around its longitudinal axis X'.

[0038] In one variant, the intermediate body can be fixed directly to the shaft 20, for example in the form of a covering.

[0039] We are finally interested in the figure 4which illustrates an example of application of the security structure 1 as described above. The example presented here is a comb turnstile 100. It is understood that this “comb” is comparable to the security structure 1 described previously.

[0040] In the turnstile 100, a base 2 can be distinguished which is fixedly mounted and a base 3 which is configured to rotate along an axis of rotation coinciding with its longitudinal axis Y'. In the case of the turnstile 100 described here, it comprises a fixed comb and at least one comb rotating around the longitudinal axis Y' of the base 3. In the example of the figure 4 , there are in particular three rotating combs. In use, the hollow tubes 10 of the different combs of the turnstile 100 are oriented horizontally, that is to say they are substantially parallel with the ground.

[0041] However, it is also possible to use the safety structure 1 as described with vertically oriented hollow tubes 10, for example in a fencing application.

[0042] The invention also relates to a method of manufacturing a safety structure 1 as described above. This manufacturing method comprises at least the following steps: a) inserting the shaft 20 inside the hollow tube 10 by its free end 12, the shaft 20 being provided with a first part of the means of cooperation 30 with the hollow tube 10 configured to allow the shaft 20 to rotate freely around its longitudinal axis X', b) producing a second part of the means of cooperation 30 with the shaft 20 configured to retain the shaft 20 axially relative to the hollow tube 10.

[0043] It is understood that the cooperation means 30 between the hollow tube 10 and the shaft 20 prevent the withdrawal of the shaft 20 by the free end 12 of the hollow tube 10.

[0044] Prior to step a), a step consisting of mounting at least one bearing 40, 40' at each end 22, 24 of the shaft 20 can be carried out.

[0045] Following the mounting of at least one bearing 40, and still prior to step a), a step consisting of mounting, at each end 22, 24 of the shaft 20, a ring 50, between the internal wall 14 of the hollow tube 10 and the external surface 42 of the bearing 40 can be carried out.

[0046] In step b), the second part of the cooperation means 30 between the hollow tube 10 and the shaft 20 comprises at least one retaining means 32, 32' which extends radially relative to the hollow tube 10.

[0047] Advantageously, the retaining means is produced by punching on the hollow tube 10. Alternatively, the retaining means is produced by inserting a circlip or a stop ring against the hollow tube 10.

[0048] Advantageously, the second part of the cooperation means 30 between the hollow tube and the shaft 20 comprises a first retaining means 32 and a second retaining means 32'. The first retaining means 32 and the second means 32' can both be produced by punching on the hollow tube 10. Alternatively, the first retaining means 32 is produced by punching on the hollow tube 10 while the second retaining means 32' is produced by inserting a circlip or a stop ring against the hollow tube 10, in particular inside the hollow tube 10.

[0049] Prior to step b) and in parallel with step a), an intermediate body can be inserted into the annular space 60 defined between the shaft 20 and the internal wall 14 of the hollow tube 10. For this, the intermediate body is advantageously inserted while the shaft 20 is partially introduced into the hollow tube 10, that is to say before the end 22 of the shaft 20 is inserted inside the hollow tube 10. Alternatively, the intermediate body can be fixed around the shaft 20 before the shaft 20 is inserted into the hollow tube.

[0050] After step a), and before or after step b), the free end 12 of the hollow tube 10 is advantageously plugged using a stopper so as to protect access, from the free end 12, to the interior of the hollow tube 10, and in particular to the shaft 20.

[0051] It is clear that the safety structure as described above provides enhanced security. Indeed, the axial retention of the shaft in the hollow tube prevents its removal during a malicious act, making it necessary to use a cutting tool to force the safety structure.

[0052] Another advantage is to improve the cutting resistance of the safety structure by making it difficult to use a cutting tool. Indeed, the higher hardness of the shaft material compared to that of the hollow tube material causes heating and accelerated wear of the cutting tools. In addition, since the shaft can rotate freely on itself in the hollow tube, the cutting tool's attack point will not be stable, which reduces its penetration force into the structure, increasing the time required to cut the structure. In addition, when present, the intermediate body housed in the annular space allows for increased heating of the cutting tools, contributing to a further improvement in cutting resistance.

[0053] Furthermore, the safety structure according to the invention is suitable for countering all types of cutting tools, and in particular cutting tools such as grinders or chainsaws which include rotating discs capable of rotating at high speed (between 4000 and 7000 rpm). Indeed, when bearings are mounted on the shaft, the latter can rotate at high speed.

[0054] Furthermore, the manufacturing process of the safety structure is easy and quick to implement by inserting the shaft into the hollow tube and providing axial retention of the shaft.

[0055] The process also has the advantage of being able to adapt to existing safety structures equipped with hollow tubes. This allows them to be reinforced and also reduces infrastructure costs.

Claims

1. A reinforced structure (1) comprising a base (2, 3) with a longitudinal axis (Y, Y') and at least: - a hollow tube (10) having a longitudinal axis (X) substantially perpendicular to the longitudinal axis (Y, Y') of the base (2, 3), an end (11) fixed in the base (2, 3) and a free end (12), said hollow tube being made of a given material, - a shaft (20) housed inside the hollow tube (10) and having a longitudinal axis (X') coinciding with that of the hollow tube, said shaft also being made of a material having a higher hardness than that of the material forming the hollow tube, characterised in that it further comprises: - means of cooperation (30) between the hollow tube (10) and the shaft (20) configured to allow the shaft to rotate freely about its longitudinal axis (X') and to retain the shaft axially with respect to the hollow tube so as to prevent its removal by the free end (12).

2. The reinforced structure (1) according to claim 1, characterised in that the means of cooperation (30) between the hollow tube (10) and the shaft (20) comprise, in order to retain the shaft axially with respect to the hollow tube, at least one radially extending retaining means (32, 32').

3. The reinforced structure (1) according to claim 2, characterized in that the means of cooperation (30) between the hollow tube (10) and the shaft (20) comprise means for allowing the shaft to rotate about its longitudinal axis (X'), at each end (22, 24) of the shaft: - at least one bearing (40) is mounted on an outer wall (26) of the shaft, - a ring (50) mounted on an outer surface (42) of the bearing (40) and against an inner wall (14) of the hollow tube.

4. The reinforced structure (1) according to claim 3, characterised in that said at least one retaining means (32, 32') is in contact with at least one of the rings (50), advantageously on the side of the free end (12).

5. The reinforced structure (1) according to claim 2, characterised in that the means of cooperation (30) between the hollow tube (10) and the shaft (20) comprise at each end (22, 24) of the shaft, to allow the shaft to rotate freely about its longitudinal axis (X'), at least one bearing (40') is mounted on an outer wall (26) of the shaft and against an inner wall (14) of the hollow tube.

6. The reinforced structure (1) according to claim 5, characterised in that said at least one retaining means (32, 32') is in contact with at least one of the bearings (40'), advantageously on the side of the free end (12).

7. The reinforced structure (1) according to any one of claims 3 or 5, characterised in that a first retaining means (32) is located as close as possible to the base (2, 3) and that a second retaining means (32') is located on the side of the free end (12).

8. The reinforced structure (1) according to any one of claims 1 to 7, characterised in that it comprises an intermediate body housed in an annular space (60) defined by an outer wall (26) of the shaft (20) and an inner wall (14) of the hollow tube (10), said intermediate body being configured to increase the coefficient of friction between the shaft (20) and a blade of a cutting tool.

9. The reinforced structure (1) according to any one of claims 1 to 8, characterised in that the shaft (20) is made of a metal or metal alloy material.

10. The reinforced structure (1) according to claim 9, characterised in that the shaft (20) is made of steel with a Vickers hardness of between 40 and 70 kgf / mm2, and preferably between 60 and 65 kgf / mm2.

11. A method of manufacturing a reinforced structure (1) according to any one of claims 1 to 10, said method comprising at least the steps consisting of: a) inserting the shaft (20) into the hollow tube (10) by its free end (12) said shaft being provided with a first part of the means of cooperation (30) with the hollow tube, which first part is configured to allow the shaft to rotate freely about its longitudinal axis (X'), b) achieving a second part of the means of cooperation (30) with the shaft, which second part is configured to retain the shaft axially with respect to the hollow tube so as to prevent it being withdrawn by the free end (12).

12. The method according to claim 11, wherein the second part of the means of cooperation (30) between the hollow tube (10) and the shaft (20) comprises at least one radially extending retaining means (32, 32').

13. The method according to claim 12, wherein said at least one retaining means is produced by punching on the hollow tube.

14. The method according to claim 12, wherein said at least one retaining means is achieved by inserting a circlip or retaining ring against the hollow tube (10).

15. The method according to the combination of claims 13 and 14, wherein the second part of the means of cooperation (30) between the hollow tube (10) and the shaft (20) comprises a first retaining means (32) and a second retaining means (32'), the first retaining means (32) being achieved by punching on the hollow tube and the second retaining means (32') being achieved by inserting a circlip or a retaining ring against the hollow tube.