A removable, blind-type fastening device, an assembly comprising at least one such fastening device, and a method for dismantling such a fastening device.

Abstract

A removable, blind-type fastening device, an assembly comprising at least one such fastening device, and a method for disassembling such a fastening device. The invention relates to a fastening device for holding at least two first and second parts together. This fastening device comprises a tubular body (54) that passes through the first and second parts, an expanding nut (56), and a screw (58) housed in the tubular body (54) and cooperating with the expanding nut (56). To facilitate disassembly of the fastening device, the screw (58) has at least one feature, such as a recess (82) positioned on its transverse face (F72), to prevent rotation using a first tool, and the expanding nut (56) has at least one feature, such as a flat (70), to allow unscrewing using a second tool.The invention also relates to an assembly comprising at least one such assembly device and a disassembly method. Figure 5.

Description

Title of the invention: Detachable blind-type fixing device, assembly comprising at least one such fixing device and method for dismantling such a fixing device

[0001] The present application relates to a removable blind-type fixing device, to an assembly comprising at least one such fixing device and to a method of dismantling such a fixing device.

[0002] According to an embodiment visible in Figures 1 to 3 and described in document EP2647851, a blind-type fixing device 10, configured to keep first and second parts 12, 14 assembled, comprises a tubular body 16, an expanding nut 18 and a screw 20. The first and second assembled parts 12, 14 each comprise a through hole 12.1, 14.1, for housing the tubular body 16, and a bearing surface 12.2, 14.2, the bearing surface 12.2 of the first part 12 comprising a chamfer 12.3 around the through hole 12.1.

[0003] The tubular body 16 comprises a main part 22 which extends between first and second ends 22.1, 22.2, a detachable part 24 which comprises a lateral face 24.1 of hexagonal cross-section as well as a breakable junction zone 26 connecting the main part 22 and the detachable part 24. The tubular body 16 comprises a through-orifice 28 over its entire length which has a reduction in diameter 28.1 frustoconical at the second end 22.2 of the main part 22. The first end 22.1 of the main part 22 comprises a frustoconical shape flared towards the second end 22.2. The tubular body 16 comprises, at the second end 22.2 of the main part 22, a frustoconical head 30 configured to be housed in the chamfer 12.3 of the first part 12 in operation.

[0004] The expanding nut 18 extends between first and second ends 18.1, 18.2, the second end 18.2 cooperating with the first end 22.1 of the main part 22 of the tubular body 16 in operation. The expanding nut 18 comprises an initially smooth lateral face 32 as well as a through hole 34 which connects the first and second ends 18.1, 18.2. The expanding nut 18 can deform and expand so as to form a bulb 36 (visible in FIGS. 2 and 3) bearing against the bearing surface 14.2 of the second part 14 when the expanding nut 18 is subjected to a compressive force between its first and second ends 18.1, 18.2.

[0005] The through hole 34 has a tapped section 34.2 near the first end 18.1 of the expanding nut 18.

[0006] The screw 20 comprises a rod 38 which extends between first and second ends 38.1, 38.2, a head 40 of hexagonal section for screwing the screw 20 as well as a breakable junction zone 42 connecting the rod 38 and the head 40. The rod 38 comprises a threaded section 44, which extends from the first end 38.1, configured to cooperate with the tapped section 34.2 of the expanding nut 18 and to be screwed therein. The second end 38.2 of the rod 38 comprises a frustoconical shape configured to cooperate with the diameter reduction 28.1 of the tubular body 16.

[0007] The method of mounting such a fixing device comprises a step of inserting the device into the through holes 12.1, 14.1 of the first and second parts 12, 14 to be assembled from the bearing surface 12.2 until the frustoconical head 30 of the tubular body 16 is housed in the chamfer 12.3 of the first part 12. The first end 22.1 of the main part 22 is located projecting relative to the bearing surface 14.2 of the second part 14.

[0008] Next, the screw 20 is screwed in, the tubular body 16 being immobilized in rotation by means of a tool which cooperates with the detachable part 24 of the tubular body 16. The frustoconical shape of the second end 38.2 of the rod 38 of the screw 20 being in abutment against the reduction in diameter 28.1 of the tubular body 16, the expanding nut 18 is compressed between its first and second ends 18.1, 18.2, its second end 18.2 being in contact with the first end 22.1 of the main part 22 of the tubular body 16. The screwing then causes the expansion of the expanding nut 18 which then forms a bulb 36. When the latter is formed, the screwing causes the bulb 36 to be pressed against the bearing surface 14.2 of the second part 14. From then on, the first and second parts 12 and 14 are compressed between the bulb 36 and the truncated head 30 of the tubular body 16.As soon as the desired tightening torque is reached, the junction zone 42 breaks firstly and then, under the effect of a complementary movement of the installation tool, the breakable junction zone 26 breaks secondly. The fixing device 10 is then correctly tightened. As illustrated in [Fig. 3], the tubular body 16 and the screw 20 are flush with the bearing surface 12.2 of the first part 12. .

[0009] This embodiment makes it possible to automate the assembly with a single tool configured to lock the tubular body 16 in rotation and screw the screw.

[0010] To disassemble such a fixing device, one solution consists of destroying the frustoconical shape of the second end 38.2 of the rod 38 using a drill. This solution is not satisfactory because the risks of damaging the bearing surface 12.2 of the first part 12 are significant due to the fact that the tubular body 16 and the screw 20 are flush with said bearing surface 12.2 of the first part 12. According to another drawback, the machining of the screw 20 generates debris which pollutes the environment if it is not collected. Finally, even if the frustoconical shape of the second end 38.2 of the rod 38 is destroyed, the expanding nut 18 can remain connected to the tubular body 16 to the extent that the second end 18.2 of the expanding nut can still be nested on the first end 22.1 of the main part 22 of the tubular body 16.

[0011] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0012] To this end, the invention relates to a fixing device for holding together at least first and second parts which each comprise a through hole and a bearing surface at which the through hole opens, said fixing device comprising a tubular body, an expanding nut and a screw. The tubular body is configured to be housed in the through holes of the first and second parts and extends between first and second ends, the first end of the tubular body cooperating with the expanding nut, the second end of the tubular body having a head configured to bear against the bearing surface of the first part.The expanding nut extends between first and second ends and has at least one threaded section and an axis of revolution, the expanding nut being configured to expand so as to form a bulb when it is subjected to a compressive force between its first and second ends. The screw comprises a rod which extends between first and second ends and has an axis of revolution as well as an end face at its first end, the rod comprising a threaded section which cooperates with the threaded section of the expanding nut, the second end of the rod comprising an enlarged shape bearing against the tubular body.

[0013] According to the invention, the screw has at least one shape positioned at the transverse face of the rod and configured to cooperate with a first tool in order to immobilize the screw in rotation around its axis of revolution relative to the first tool. In addition, the expanding nut comprises at least one shape configured to cooperate with a second tool in order to immobilize the expanding nut in rotation around its axis of revolution relative to the second tool.

[0014] This solution does not generate any debris during disassembly, reduces the risk of damage to the first and second parts and allows the tubular body and the expanding nut to be safely separated. This fixing device allows disassembly of the assembled parts without risk of damage so that it is not necessary to re-machine the bores of the assembled parts.

[0015] According to another characteristic, the expanding nut comprises a lateral face connecting the first and second ends of the expanding nut as well as at least one flat positioned on the lateral face.

[0016] According to another characteristic, the lateral face comprises several regular flats- evenly distributed around the axis of revolution of the expanding nut.

[0017] According to another characteristic, each flat is positioned close to the first end of the expanding nut.

[0018] According to another characteristic, the rod comprises an imprint, coaxial with the axis of revolution of the screw, which opens at the level of the transverse face and has a bottom as well as a lateral face connecting the bottom and the transverse face, the lateral face comprising at least one flat.

[0019] According to another characteristic, the imprint comprises several flats regularly distributed around the axis of revolution of the screw.

[0020] According to another characteristic, the head is configured to allow it to be immobilized in rotation or to be driven in rotation with a tool.

[0021] According to another characteristic, the head of the tubular body extends between first and second transverse faces, the second transverse face being configured to bear against the bearing surface of the first part. In addition, the head comprises a first section of prismatic section which extends from the first transverse face as well as a second section, which extends between the first section and the second transverse face, of section greater than that of the first section.

[0022] The invention also relates to an assembly comprising at least first and second parts as well as at least one fixing device according to one of the preceding characteristics in order to hold the first and second parts assembled.

[0023] The invention also relates to a method for dismantling a fixing device according to one of the preceding characteristics. This dismantling method comprises a step of unscrewing a first element, among the screw and the expanding nut, relative to a second element different from the first element, among the screw and the expanding nut, by immobilizing in rotation the second element using a first tool and by pivoting the first element using a second tool.

[0024] According to another characteristic, the method comprises a step of unscrewing the expanding nut relative to the screw by immobilizing the screw in rotation using the first tool, which cooperates with the imprint of the screw, and by pivoting the expanding nut using the second tool which cooperates with the flats of the expanding nut.

[0025] According to another characteristic, prior to the step of unscrewing the expandable nut relative to the screw or at the start of this unscrewing step, the disassembly method comprises a step of unlocking the expandable nut relative to the tubular body by immobilizing the tubular body in rotation using a third tool, which cooperates with the head of the tubular body, and by pivoting the expandable nut using the second tool.

[0026] Other characteristics and advantages will emerge from the description of the invention which will follow, description given by way of example only, with reference to the attached drawings among which:

[0027] [Fig.l] is a longitudinal section of a fixing device illustrating an embodiment of the prior art,

[0028] [Fig.2] is a section of an assembly including a fixing device in progress assembly illustrating an embodiment of the prior art,

[0029] [Fig.3] is a section of an assembly comprising a fixing device at the end of assembly illustrating an embodiment of the prior art,

[0030] [Fig.4] is a perspective view from a first viewing angle of a device for attachment illustrating an embodiment of the invention,

[0031] [Fig.5] is a perspective view from a second viewing angle of the device of fixing visible on [Fig.4],

[0032] [Fig.6] is a perspective view of the fixing device visible in [Fig.4] at the disassembled state,

[0033] [Fig.7] is a section of an assembly comprising a fixing device illustrating an embodiment of the invention,

[0034] [Fig.8] shows sections illustrating different stages of a dismantling process of the fixing device visible in [Fig.4],

[0035] [Fig.9] is a longitudinal section of a fixing device and a tool of disassembly illustrating a step of a disassembly process, and

[0036] [Fig. 10] is a longitudinal section of the fixing device and the disassembly tooling visible in [Fig.9] illustrating another step of the disassembly process.

[0037] According to an embodiment visible in [Fig.7], an assembly 46 comprises at least first and second parts 48, 50 as well as at least one fixing device 52 holding the first and second assembled parts 48, 50. The first and second assembled parts 48, 50 each comprise a through hole 48.1, 50.1 as well as a bearing surface 48.2, 50.2 at which the through hole 48.1, 50.1 opens. The bearing surface 48.2 of the first part 48 may comprise a chamfer around the through hole 48.1.

[0038] The fixing device 52 comprises a tubular body 54 passing through the first and second parts 48, 50, an expanding nut 56 as well as a screw 58 housed in the tubular body and cooperating with the expanding nut 56.

[0039] According to an embodiment visible in Figures 4 to 6, the tubular body 54 comprises a tubular part 60 which extends between first and second ends 60.1, 60.2, a head 62 which extends between first and second transverse faces 62.1, 62.2 (the second end 60.2 of the tubular part 60 being connected to the second transverse face 62.2) as well as a through orifice T60 which opens at the level of the first end 60.1 of the tubular part 60 and the first face transverse 62.1 of head 62.

[0040] According to one configuration, the tubular part 60 comprises a cylindrical lateral face F60 which has a diameter substantially equal to or slightly smaller than those of the through holes 48.1, 50.1 of the first and second parts 48, 50. The through orifice T60 is smooth.

[0041] The first end 60.1 of the tubular part 60 has a truncated cone shape which flares out towards the second end 60.2.

[0042] The through-orifice T60 comprises a widening, such as a chamfer or a counterbore, at its end opening at the first transverse face 62.1 of the head 62.

[0043] According to one embodiment, the head 62 comprises a first section 64.1 of prismatic section, in particular hexagonal, which extends from the first transverse face 62.1 as well as a second section 64.2, which extends between the first section 64.1 and the second transverse face 62.2, of circular section and greater than that of the first section 64.1. This second section 64.2 forms a false washer. The latter allows a better distribution of the forces on the first or second part 48, 50 and a better holding of the fixing device in a setting tool. Of course, the invention is not limited to this geometry (hexagonal) for the head 62. Whatever the embodiment, the head 62 is configured to allow it to be immobilized in rotation or to be driven in rotation with a tool.

[0044] In operation, the second transverse face 62.2 of the head 62 is configured to be pressed against the bearing surface 48.2 of the first part 48. The first section 64.1 is used to immobilize the tubular body 54 in rotation with a tool.

[0045] Of course, the invention is not limited to this embodiment for the tubular body 54. The latter could be identical to those of the prior art. Whatever the embodiment, the tubular body 54 is configured to be housed in the through holes 48.1, 50.1 of the first and second parts 48, 50. It comprises a tubular part 60 which extends between first and second ends 60.1, 60.2 and has an axis of revolution A54, the first end 60.1 cooperating with the expanding nut 56 and having a flared shape in the direction of the second end 60.2, the second end 60.2 having a head 62 configured to bear against the bearing surface 48.2 of the first part 48.

[0046] The expanding nut 56 extends between first and second ends 56.1, 56.2, the second end 56.2 being in contact with the first end 60.1 of the tubular portion 60 of the tubular body 54 in operation. The expanding nut 56 includes a side face 66 as well as a through hole 68 which connects the first and second ends 56.1, 56.2. The expanding nut 56 is configured to deform and expand so as to form a bulb B56 (visible in [Fig.7]) when the nut expandable 56 is subjected to a compressive force between its first and second ends 56.1, 56.2. In operation, the bulb B56 bears against the bearing surface 50.2 of the second part 50.

[0047] Before deformation, the lateral face 66 has a diameter substantially equal to that of the lateral face F60 of the tubular body 54.

[0048] The through hole 68 has a threaded section 68.1 which extends from the first end 56.1 of the expanding nut 56.

[0049] With the exception of its lateral face 66, the expanding nut 56 may be identical to those of the prior art. Whatever the embodiment, the expanding nut 56 extends between first and second ends 56.1, 56.2 and comprises a through hole 68 which opens at the first and second ends 56.1, 56.2. This through hole 68 has at least one threaded section 68.1 and an axis of revolution A56. The second end 56.2 of the expanding nut 56 cooperates with the first end 60.1 of the tubular part 60 of the tubular body 54 in operation. The expanding nut 56 is configured to deform and expand to form a bulb B56 when subjected to a compressive force between its first and second ends 56.1, 56.2.

[0050] According to a feature of the invention, the expanding nut 56 comprises at least one shape configured to cooperate with a tool in order to immobilize the expanding nut 56 in rotation about its axis of revolution A56 relative to the tool. According to one embodiment, the lateral face 66 of the expanding nut 56 comprises at least one flat 70. According to one configuration, the lateral face 66 comprises several flats 70 regularly distributed around the axis of revolution A56 of the expanding nut 56. By way of example, the lateral face 66 comprises six flats. Of course, the invention is not limited to this geometry for the expanding nut 56. Whatever the embodiment, the expanding nut 56 is configured to cooperate with a tool in order to immobilize it in rotation about its axis of revolution A56 relative to the tool.

[0051] According to one arrangement, each flat 70 is positioned close to the first end 56.1 of the expanding nut 56. The flats all have the same length (dimension taken in a direction parallel to the axis of revolution A56 of the expanding nut 56) and are positioned between two transverse planes.

[0052] The screw 58 comprises a rod 72 which extends between first and second ends 72.1, 72.2, a head 74 of hexagonal section for screwing the screw 58, as well as a breakable junction zone 76 connecting the rod 72 and the head 74. The rod 72 comprises a threaded section 78, which extends from the first end 72.1, configured to cooperate with the tapped section 68.1 of the expanding nut 56 and to be screwed therein. The second end 72.2 of the rod 72 comprises an enlarged shape 80 configured to bear against the tubular body 54.

[0053] With the exception of the first end 72.1 of its rod 72, the screw 58 could be identical to the screws of the prior art. Whatever the embodiment, the rod 72 of the screw 58 extends between first and second ends 72.1, 72.2 and has an axis of revolution A72 as well as an end face F72, at its first end 72.1, substantially perpendicular to the axis of revolution A72. The rod 72 comprises a threaded section 78, which extends from the first end 72.1, configured to cooperate with the tapped section 68.1 of the expanding nut 56 and screw therein, the second end 72.2 of the rod 72 comprising an enlarged shape 80 configured to bear against the tubular body 54.

[0054] According to a feature of the invention, the screw 58 has at least one shape positioned at the end face F72 and configured to cooperate with a tool in order to immobilize in rotation about its axis of revolution A58 the screw 58 relative to the tool. According to one embodiment, the rod 72 comprises a recess 82, coaxial with the axis of revolution A58 of the screw 58, which opens at the end face F72 and has a bottom 82.1 as well as a lateral face 82.2 connecting the bottom 82.1 and the end face F72, the lateral face 82.2 comprising at least one flat. According to one arrangement, the recess 82 comprises several flats regularly distributed around the axis of revolution A58 of the screw 58. According to one arrangement, the recess 82 comprises six flats and has a hexagonal cross-section. Each flat extends between the end face F72 and the bottom 82.1. Of course, the invention is not limited to this geometry for the imprint 82.Whatever the embodiment, the screw 58 is configured to cooperate with a tool in order to immobilize it in rotation around its axis of revolution A58 relative to the tool.

[0055] According to one method of operation, the fixing device 52 is mounted using substantially the same mounting method as for the fixing devices of the prior art visible in FIGS. 1 to 3

[0056] Thus, a mounting method comprises a step of inserting the device into the through holes 48.1, 50.1 of the first and second parts 48, 50 to be assembled from the bearing surface 48.2 of the first part 48 until the head 62 of the tubular body 54 is in abutment against the bearing surface 48.2 of the first part 48. The first end 60.1 of the tubular body 54 is located projecting relative to the bearing surface 50.2 of the second part 50.

[0057] Next, the screw 58 is screwed with a first tool, the tubular body 54 being immobilized in rotation thanks to a second tool which cooperates with the head 62 of the tubular body 54. The second section 64.2 of the head 62, which forms a false washer, limits the risks of damage to the first part 48 with the second tool.

[0058] When screwing the screw 58, the expanding nut 56 is compressed between its first and second ends 56.1, 56.2, its second end 56.2 being in contact with the first end 60.1 of the tubular part 60 of the tubular body 54. This screwing thus causes the expansion of the expanding nut 56 which then forms a bulb B56. When the latter is formed, the screwing causes the bulb B56 to be pressed against the bearing surface 50.2 of the second part 50. From then on, the first and second parts 48 and 50 are compressed between the bulb B56 of the expanding nut 56 and the head 62 of the tubular body 54. As soon as a desired tightening torque is reached, the breakable junction zone 76 of the screw 58 breaks. The fixing device 52 is then correctly tightened.

[0059] A method for dismantling the fixing device 52 is described with reference to FIGS. 8 to 10. This dismantling method comprises a step of unscrewing a first element, among the screw 58 and the expanding nut 56, relative to a second element different from the first element, among the screw 58 and the expanding nut 56, by immobilizing the second element in rotation using a first tool and by pivoting the first element using a second tool. According to one operating mode, the tubular body 54 can be immobilized prior to the unscrewing step to unlock the expanding nut 56.

[0060] According to a preferred embodiment visible in Figures 8 to 10, the disassembly method comprises a step of unscrewing the expanding nut 56 relative to the screw 58 by immobilizing the screw 58 in rotation using the first tool 84, which cooperates with the imprint 82 of the screw 58, and by pivoting the expanding nut 56 using the second tool 86 which cooperates with the flats 70 of the lateral face 66 of the expanding nut 56. By way of example, the first tool 84 is a male hexagonal key and the second tool 86 is a socket wrench.

[0061] According to one embodiment, prior to the step of unscrewing the expanding nut 56 relative to the screw 58 or at the start of this unscrewing step, the disassembly method comprises a step of unlocking the expanding nut 56 relative to the tubular body 54 by immobilizing the tubular body 54 in rotation using a third tool 88, which cooperates with the first section 64.1 of the head 62 of the tubular body 54, and by pivoting the expanding nut 56 using the second tool 86. For example, the third tool 88 is a socket wrench. This unlocking step becomes necessary if the imprint 82 of the screw 58 is not sufficient to unlock the expanding nut 56 at the start of the unscrewing step due to the significant pressure forces exerted by the expanding nut 56 on the tubular body 54.

[0062] As illustrated in [Fig.9], firstly, the third tool 88 is fitted onto the head 62 of the tubular body 54. Next, the first tool 84 is inserted into the recess 82 of the screw 58, as illustrated in [Fig.9] and parts (A) and (B) of [Fig.8], and the second tool 86 is fitted onto the expanding nut 56 by making it cooperate with the flats 70, as illustrated in parts (C) and (D) of [Fig.8]. [Fig.8]. The third tool 88 immobilizing the tubular body 54 in rotation, the second tool 86 is then rotated, as illustrated in [Fig.9]. Then, the expanding nut 56 is unscrewed with the second tool 86 while keeping the screw 58 immobile in rotation thanks to the first tool 84, as illustrated in part (D) of [Fig.8] and [Fig. 10],

[0063] At the end of the unscrewing step, the expanding nut 56 is separated from the screw 58. From then on, the tubular body 54 and the screw 58 can be removed from the through holes 48.1, 50.1 of the first and second parts 48, 50.

[0064] This operating mode does not generate any debris and allows the tubular body 54 and the expanding nut 54 to be safely separated.

[0065] According to an embodiment visible in figures 9 and 10, the same tool 90 supports the first and second tools 84, 86, the tool 90 comprising a support 92, a fixed connection 94 connecting the support 92 and the first tool 84 as well as a pivoting connection 96 which connects the support 92 and the second tool 86.

Claims

Claims

1. Fastening device for holding together at least first and second parts (48, 50) which each comprise a through hole (48.1, 50.1) and a bearing surface (48.2, 50.2) at which the through hole (48.1, 50.1) opens, said fastening device comprising a tubular body (54), an expanding nut (56) and a screw (58); the tubular body (54) being configured to be housed in the through holes (48.1, 50.1) of the first and second parts (48, 50) and extending between first and second ends (60.1, 60.2), the first end (60.1) of the tubular body (54) cooperating with the expanding nut (56), the second end (60.2) of the tubular body (54) having a head (62) configured to bear against the bearing surface (48.2) of the first part (48); the expanding nut (56) extending between first and second ends (56.1, 56.2), having at least one threaded section (68.1) and an axis of revolution (A56), the expanding nut (56) being configured to expand so as to form a bulb (B56) when it is subjected to a compressive force between its first and second ends (56.1, 56.2); the screw (58) comprising a rod (72) which extends between first and second ends (72.1, 72.2) and has an axis of revolution (A72) as well as an end face (F72) at its first end (72.1), the rod (72) comprising a threaded section (78) which cooperates with the threaded section (68.1) of the expanding nut (56), the second end (72.2) of the rod (72) comprising an enlarged shape (80) bearing against the tubular body (54); characterized in that the screw (58) has at least one shape, at the transverse face (F72) of the rod (72), configured to cooperate with a first tool (84) in order to immobilize in rotation around its axis of revolution (A72) the screw (58) relative to the first tool (84) and in that the expanding nut (56) comprises at least one shape configured to cooperate with a second tool (86) in order to immobilize in rotation around its axis of revolution (A56) the expanding nut (56) relative to the second tool (86).

2. Fastening device according to the preceding claim, characterized in that the expanding nut (56) comprises a lateral face (66) connecting the first and second ends (56.1, 56.2) of the expanding nut (56) as well as at least one flat (70) positioned on the lateral face (66).

3. Fixing device according to the preceding claim, characterized in that the lateral face (66) comprises several flats (70) regularly distributed around the axis of revolution (A56) of the expanding nut (56).

4. Fastening device according to one of claims 2 to 3, characterized in that each flat (70) is positioned close to the first end (56.1) of the expanding nut (56).

5. Fixing device according to one of the preceding claims, characterized in that the rod (72) comprises an imprint (82), coaxial with the axis of revolution (A58) of the screw (58), which opens at the level of the transverse face (F72) and has a base (82.1) as well as a lateral face (82.2) connecting the base (82.1) and the transverse face (F72), the lateral face (82.2) comprising at least one flat.

6. Fixing device according to the preceding claim, characterized in that the imprint (82) comprises several flats regularly distributed around the axis of revolution (A58) of the screw (58).

7. Fixing device according to one of the preceding claims, characterized in that the head (62) is configured to allow it to be immobilized in rotation or to be driven in rotation with a tool.

8. Fixing device according to the preceding claim, characterized in that the head (62) of the tubular body (54) extends between first and second transverse faces (62.1, 62.2), the second transverse face (62.2) being configured to bear against the bearing surface (48.2) of the first part (48) and in that the head (62) comprises a first section (64.1) of prismatic section which extends from the first transverse face (62.1) as well as a second section (64.2) which extends between the first section (64.1) and the second transverse face (62.2), of section greater than that of the first section (64.1).

9. Assembly comprising at least first and second parts (48, 50) as well as at least one fixing device according to one of the preceding claims for holding the first and second parts (48, 50) assembled.

10. Method for dismantling a fixing device according to one of claims 1 to 8, characterized in that the dismantling method comprises a step of unscrewing a first element, among the screw (58) and the expanding nut (56), relative to a second element different from the first element, among the screw (58) and the expanding nut (56), by immobilizing in rotation the second element using a first tool (84) and by pivoting the first element using a second tool (86).

11. Disassembly method according to the preceding claim, characterized in that the method comprises a step of unscrewing the expanding nut (56) relative to the screw (58) by immobilizing the screw (58) in rotation using the first tool (84), which cooperates with the imprint (82) of the screw (58), and by pivoting the expanding nut (56) using the second tool (86) which cooperates with the flats (70) of the expanding nut (56).

12. Disassembly method according to the preceding claim, characterized in that, prior to the step of unscrewing the expanding nut (56) relative to the screw (58) or at the start of this unscrewing step, the disassembly method comprises a step of unlocking the expanding nut (56) relative to the tubular body (54) by immobilizing the tubular body (54) in rotation using a third tool (88) which cooperates with the head (62) of the tubular body (54) and by pivoting the expanding nut (56) using the second tool (86).

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