Mounting device with decoupling and splash protection function

Abstract

The invention relates to a fastening device (1) for attaching an element to be fastened to a support element of a structure, in particular to a wall of an armored vehicle, wherein the fastening device (1) comprises a body part (4) that can be connected to the support element and a head part (5) that can be connected to the element to be fastened, wherein the body part (4) and the head part (5) are coaxial, a melting area (6) that is configured to break under a predetermined load and connect the head part (5) to the body part (4), characterized in that it has retaining means (7, 9) which are designed such that, upon breakage of the melting area (6), they inseparably connect the body part (4) and the head part (5) to each other and keep them in direct contact with each other.

Description

[0001] The technical scope of the invention includes fastening devices that enable the fastening of an element to be fastened to a support element of a structure.

[0002] The fastening device according to the present invention is particularly suitable for military purposes, especially for fastening equipment to an inner wall of an armored vehicle.

[0003] It is known that equipment inside an armored vehicle is usually attached to the vehicle's inner wall using fastening devices that include spacers or supports.

[0004] For example, the French patent FR2670842 is known, which describes a fastening device comprising a spacer that is clamped against the wall of a vehicle by means of a nut and a screw, the shank of which passes through the spacer and the end of which interacts with a threaded hole of the equipment to be fastened.

[0005] Also known is the French patent FR2859451, which describes a fastening device with which two components can be connected at a certain distance from each other, wherein the device comprises a tubular spacer and a fastening element, such as a screw or a bolt, which penetrates the spacer.

[0006] However, if an explosive device, such as a mine, is detonated near the structure, these fastening devices transfer the entire force acting on the structure's wall to the equipment attached to that wall, potentially causing it to break. Furthermore, the resulting impact on the structure's wall is so severe that the elements of these fastening devices can shear off, violently hurling the equipment into the interior of the structure, where it then acts as a dangerous projectile.

[0007] To partially overcome these disadvantages, French patent FR3036145 provides for the use of a fastening accessory comprising two parts separated by a weak zone calibrated for fracture. Thus, if a load applied to the accessory exceeds the permissible load level in the weak zone, the accessory breaks. Such a fracture limits the transmission of the load to the structure to which the accessory is attached.

[0008] Furthermore, this patent provides for equipping this extension with a flexible connection that restrains the portion of the extension that could be ejected in the event of a fracture of the weakened zone. Thus, in the event of a fracture of the weakened zone, both parts of the extension remain firmly connected and at an appropriate distance from each other. Such a flexible connection therefore prevents a part of the attachment from being ejected in the event of a fracture of the weakened zone, which could injure a person in the vicinity of the attachment or damage nearby equipment.

[0009] However, such a fastening device comprises several parts, in particular a flexible connection that must be integrated into the two parts of the attachment, making its manufacture relatively complicated. Furthermore, this flexible connection cannot hold the part of the attachment that interacts with the equipment in position after the weakened zone breaks. This allows the equipment to move relative to the wall and, depending on the length of the flexible connection, could strike a person or other equipment near the wall.

[0010] The object of the present invention is therefore to propose a fastening device which, under normal mechanical loads, provides a fastening function equivalent to fastening by supports or a spacer, which makes it possible to decouple the element to be fastened from the supporting element in the event of an event such as a mine explosion without damaging the element to be fastened and the surrounding parts, which retains its fastening function after decoupling and is easy to manufacture.

[0011] Application WO 03 / 004958 A2 discloses a military vehicle in which a seat is attached to a floor via a fastening device according to the preamble of claim 1.

[0012] The invention thus relates to a fastening device for attaching an element to be fastened to a support element of a structure, in particular to a wall of an armored vehicle, wherein the fastening device comprises a body part that can be connected to the support element and a head part that can be connected to the element to be fastened, wherein the body part and the head part are arranged coaxially, wherein a melting area configured to break under a predetermined load connects the head part to the body part, wherein the fastening device has retaining means designed such that, upon breakage of the melting area, they inseparably connect the body part and the head part to each other and keep them in direct contact with each other, characterized in that the retaining means comprise a chamber element fixedly connected to the body part and a piston element fixedly connected to the head part.wherein the chamber-forming element defines a cavity in the body part and has a radial wall extending transversely to the axis of the body part and the head part, wherein the radial wall comprises the melting area, the piston element has an axial shaft penetrating the radial wall, and a radial flange formed around the shaft and received in the cavity, wherein the chamber element and the piston element are configured such that, in the event of a fracture of the melting area, the rod can slide into the cavity and the flange is held in the cavity by bearing against the radial wall.

[0013] Such a fastening device can have a function to hold an element to be fastened in its position relative to a support element, a decoupling function between the element to be fastened and the support element thanks to the presence of a melting area, as well as a splash guard function for the element to be fastened and a function to maintain its position after decoupling through the presence of holding devices.

[0014] The decoupling function prevents the complete transfer of shock or impact energy via the fastening device to the element being fastened in the event of an event such as a mine explosion.

[0015] The retaining devices prevent the body part and head part from separating after decoupling; that is, they prevent the head part from being flung a certain distance from the body part. Thus, the splash guard function prevents the attached element from colliding with the surroundings of the fastening device after decoupling.

[0016] Particularly in the event of a fracture of the melted area, the head part is held essentially coaxial to the body part and its axial deflection is limited by the radial wall of the chamber against which the flange can strike.

[0017] Preferably, the melting area has at least one reduced section calibrated for fracture.

[0018] The reduced cross-section can be defined, for example, by at least one of the following means: notch, groove, slot, slot, fillet or similar.

[0019] Advantageously, the chamber-forming element is an element that defines a cylindrical cavity, the piston-forming element is a cylindrical element with a cylindrical rod and a cylindrical flange, and the melting area is an annular area, wherein the diameter of the annular zone is larger than the diameter of the rod and smaller than the diameter of the flange.

[0020] Preferably, the diameter of the rod is slightly smaller than the diameter of the annular region, and the diameter of the flange is slightly smaller than the diameter of the cavity. This allows for better guidance of the movement of the piston-forming element relative to the chamber-forming element in the event of a rupture of the fusible region.

[0021] The chamber element can have multiple vents configured to allow air to escape from the cavity.

[0022] Depending on their number, dimensions and positioning, such vent openings allow the control of the movement speed of the piston-forming element relative to the chamber-forming element after decoupling between the head and body parts.

[0023] At least one mechanical element can be arranged within the cavity in such a way as to dampen the movement of the head part relative to the body part in the event of a fracture of the fused area.

[0024] The presence of at least one such mechanical element thus enables a progressive and controlled displacement of the head section after its decoupling from the body part.

[0025] Preferably, the device has a first fastening area at one of its axial ends, which is firmly connected to the body part, in particular a male area, and a second fastening area at its other axial end, which is firmly connected to the head part, in particular a female area, wherein the first and the second fastening area are coaxial.

[0026] The first mounting area can be a male rod with or without threads, and the second mounting area can be a female bore with or without internal threads.

[0027] Such fasteners are releasable fasteners that allow the element to be fastened to be removed from the fastening device, as well as the fastening device to be removed from the supporting element. Furthermore, the arrangement of these fasteners allows the element to be held at a distance from the supporting element, with the fastening device positioned between the element to be fastened and the supporting element.

[0028] The device can be made of plastic or metal.

[0029] Advantageously, the device is a one-piece part that can be manufactured using 3D printing or an additive manufacturing process.

[0030] This allows the fastening device to be manufactured easily and quickly. Such manufacturing techniques enable a high degree of adaptability or even custom manufacturing.

[0031] The present invention will be better understood with reference to the following description of a particular embodiment and the accompanying drawings, wherein the drawings: [ Fig. 1] shows a longitudinal sectional view of a fastening device according to the invention, which is attached to a wall and carries equipment; [ Fig. 2] shows a fastening device according to the invention in longitudinal section in its configuration before the fracture of the melting area; [ Fig. 3] shows the fastening device Fig. 2 in longitudinal section after the fracture of the fused area; and [ Fig. Figure 4 shows a perspective view of the fastening device. Fig. 3 after the break.

[0032] Referring first to Fig. It can be seen that the fastening device 1 according to the present invention is designed to fasten an element 2, such as armored vehicle equipment, to a support element 3 of a structure, such as an inner wall of an armored vehicle, wherein the fastening device 1 is arranged between the equipment 2 and the wall 3. In other words, in the mounted state, the fastening device 1 projects from the wall 3. The fastening device 1 has the form of a longitudinal part extending along a longitudinal axis X, which is said to be orthogonal to the wall 3 to which the device 1 is attached.

[0033] As from the Fig. As can be seen in Figures 1 to 4, the fastening device 1 according to the present invention comprises a body part 4 and a head part 5, which are connected to each other by a fused area 6. Thus, the fastening device 1 is a one-piece part, i.e., manufactured from a single piece. This part can be made from any material suitable for load bearing, preferably plastic or metal, the choice of material and the dimensions of the part depending on the loads that the part must withstand. Since the part is a single piece without joints or welds, it can be manufactured by 3D printing or by an additive manufacturing process.

[0034] Body part 4 is designed to be attached directly to the wall 3 or another supporting element and to come into direct contact with it. Generally, body part 4 comprises a comb-like element 7 and a first attachment area 8.

[0035] In the illustrated embodiment, the chamber element 7 has the overall shape of a cylindrical, tubular body of revolution extending along the longitudinal axis X. This body is closed at one of its axial ends by a circular bottom wall 70, the diameter of which corresponds to the diameter of the cylindrical side wall 71 of the body. The other axial end of the body has an annular radial wall 72 that extends radially into the interior of the body. The radial wall 72 is parallel to and opposite the bottom wall 70. The radial wall 72 has a fracture-calibrated reduced cross-section 6 near its junction with the head section 5, this reduced cross-section 6 forming the melting zone 6.This melting area 6 is an annular region with a diameter D1 that is smaller than the inner diameter D2 of the cylindrical side wall 71 and whose central axis is coaxial with the longitudinal axis X. The reduced section 6 can be formed by two circumferential grooves 60, 61, with the same center point and the same diameter, which are formed on both sides of the radial wall 72.

[0036] It should be emphasized that melting zone 6 can be a region of reduced thickness, a region with at least one slit, or any other fatigue zone that can break under a predetermined load.

[0037] An annular circumferential wall 73 can be formed around the side wall 71 of the body near the bottom wall 70, with this wall 73 extending in a transverse plane of the body. The bottom wall 70, the side wall 71, and the radial wall 72 define a cylindrical cavity 74 in the chamber-forming element 7.

[0038] Flat surfaces (not shown) can be provided on the cylindrical side wall 71, which serve as bearing surfaces for a key or a screw tool and thus facilitate the fastening of the device 1 to the wall 3.

[0039] In the illustrated embodiment, the first fastening area 8 is fixedly connected to the outer surface of the base wall 70. This first fastening area 8 is designed in the form of a cylindrical stud 80 extending coaxially to the longitudinal axis X, with an annular groove 81 formed between the stud 80 and the base wall 70. This stud 80 can have an external thread that can engage with a corresponding thread in a receptacle of the wall 3. Thus, in the assembled state, the male stud 80 is received in the receptacle of the wall 3, particularly by screwing it in, and the outer surface of the base wall 70 rests against the wall 3.

[0040] The head section 5 is designed to receive and support the equipment 2 to be attached to the wall 3. Generally, the head section 5 comprises a piston element 9 and a second mounting area 10.

[0041] The piston element 9 has the overall shape of an axial rod 90 with a radial flange 91. The rod 90 is a cylindrical rotary rod extending along the longitudinal axis X and has a first axial end that is received in the cavity 74 and a second axial end that is located outside the cavity 74. Thus, the rod 90 penetrates the radial wall 72 and is connected to the radial wall 72 over its entire circumference. In other words, the connection area between the rod 90 and the radial wall 72 is an annular connection area whose diameter corresponds to the diameter D3 of the rod 90. The diameter D3 of the rod 90 is therefore smaller than the diameter D1 of the melting area 6. The connection area is located near the first axial end of the rod 90, where the flange 91 is located.

[0042] The flange 91 has the shape of a disc that projects radially outwards from the cylindrical surface of the rod 90. The diameter D4 of the flange 91 is thus larger than the diameter D3 of the rod 90, smaller than the inner diameter D2 of the cylindrical side wall 71, and larger than the diameter D1 of the melting area 6. The flange 91 extends in a plane orthogonal to the longitudinal axis X and parallel to the plane of the radial wall 72.

[0043] In the Fig. In the embodiment shown in Figures 2 to 4, the axial rod 90 is a solid rod. In the embodiment shown in Fig. In the embodiment shown in Figure 1, a receptacle 92 is incorporated into the rod 90 coaxially to the longitudinal axis X, opening outwards on the side of the second axial end of the rod 90. This receptacle 92 is a cylindrical receptacle or bore extending between the second axial end of the rod 90 and the connection area between the rod 90 and the radial wall 72. This receptacle 92 may or may not be threaded. If it is threaded, this receptacle 92 is designed to receive a screw-like fastening element 20, which allows the device 2 to be reliably held on the head 5.

[0044] The second fastening area 10 is firmly connected to the second axial end of the rod 90.

[0045] In the embodiment of the Fig. In sections 2 to 4, this second mounting area 10 has the form of a flange 100, which is rigidly connected to the rod 90 and has an annular projection centered on the longitudinal axis X, forming a seat 101. The flange 100 and the seat 101 are concentric and coaxial with the longitudinal axis X. The diameter of the flange 100 corresponds to the outer diameter of the cylindrical side wall 71. The length of the rod 90 is dimensioned such that the flange 100 is located at a specific distance from the radial wall 72 before the fracture of the melting area 6 and, after the fracture of the melting area 6, can be located near the radial wall 72 or at most in contact with it.

[0046] In the embodiment according to Fig. In this embodiment, the flange 100 is provided with a central circular opening whose diameter corresponds to the diameter of the axial receptacle 92, wherein the diameter of the seat 101 is larger than the diameter of the central opening. In this embodiment, the receptacle 92, in the assembled state, receives a fastening element 20 of the equipment 2, particularly by means of a screw connection; a part of the equipment 2 is received in the opening of the seat 101, and the outer surface of the flange 100 comes into contact with the equipment 2.

[0047] In operation, under normal driving conditions of a vehicle in which the mounting device 1 is installed, the device 1 is screwed or otherwise fastened to the inner wall 3 of the vehicle via the first mounting area 8 of the body part 4, and the equipment 2 is screwed or otherwise fastened to the device 1 via the second mounting area 10 of the head part 5 ( Fig. 1) The melting area 6 of the mounting device 1 is dimensioned to withstand the usual driving loads of the vehicle. Thus, the equipment 2 is reliably and firmly held against the wall 3 under normal driving conditions. Due to the coaxial arrangement of the body part 4 and the head part 5, the device 1 is compact and easy to assemble and disassemble.

[0048] In the event of a violent impact on the vehicle, particularly a mine strike, the vehicle's wall 3 is subjected to stress and deformation. This stress is transferred to the body part 4 of the fastening device 1. Since the melting zone 6 is dimensioned such that it breaks when a certain load limit is exceeded, corresponding to the stress occurring particularly in a mine strike, for example by shearing, the melting zone 6 ( Fig. The head section 5 is then decoupled from the body section 4, i.e., the equipment 2 is decoupled from the vehicle wall 3. Such a separation in the area of ​​the melting zone 6 thus prevents the transfer of the load acting on the wall 3 to the equipment 2 attached to it. Therefore, there is no risk of the equipment 2 being damaged or destroyed by this load.

[0049] When the melting area 6 breaks open, the piston element 9 is displaced relative to the chamber element 7 in the direction of the bottom wall 70 ( Fig. 3 and Fig.4) More precisely, the rod 90 moves into the cavity 74, guided through a central opening 720 that forms after the rupture of the melted area 6 in the radial wall 72. This movement occurs along the longitudinal axis X. The air present in the cavity 74 can dampen the movement of the piston element 9 within the cavity 74. In another embodiment, not shown, the chamber element 7 can have vent openings distributed to allow this air to escape from the cavity 74. In yet another embodiment, not shown, the chamber element 7 could have at least one mechanical element arranged within the cavity 74 to dampen the movement, i.e., controlled braking, of the piston element 9 within the cavity 74.

[0050] The head 5, to which the device 2 is rigidly connected, is prevented from sliding completely out of the cavity 74 of the body part 4 by the retention of the flange 91 within the cavity 74. Since the diameter D4 of the flange 91 is larger than the diameter D1 of the melting area 6, a displacement of the rod 90 towards the radial wall 72 would cause the flange 91 to collide with the radial wall 72 on the side of the cavity 74. This prevents the head 5 from being ejected from the body part 4, thus preventing the equipment 2 from being flung away from the wall 3.The piston element 9, in particular the flange 91, and the chamber element 7, and in particular the radial wall 72 and the position of the melting area 6 on it, form holding devices which under all circumstances prevent the body part 4 and the head part 5 from being separated from each other and keep them in direct contact with each other, without intermediate or additional parts between the body part 4 and the head part 5.

[0051] It is understood that the embodiments described above serve only as examples and are not limiting, and that modifications can be made without derogating from the present invention. For example, the body part 4 and the head part 5 could have non-circular cross-sections. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] FR 2670842

[0004] FR 2859451

[0005] FR 3036145

[0007] WO 03 / 004958 A2

[0011]

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