Floating nut system and method of assembling two parts using said system

Abstract

A floating nut system and a method of assembling two parts using the system. A floating nut system (1) intended to assemble a part (2) and a part (3), the part (2) comprising an opening (4) having an axis of revolution (A1), the floating nut system comprising a nut device (7) and at least one elastomeric holder device (6) comprising a cylinder (8) intended to be introduced into an opening (9) made in the part (3) and a collar (11) surrounding the cylinder; the nut device (7) comprises a cylinder (13) having an axis of revolution (A3) and a gasket (15) intended to press the collar against the part (3) when the screw (5) is screwed into the cylinder (13); the cylinder (8) is configured to deform when the screw (5) is screwed in such that the axis of revolution (A1) and the axis of revolution (A3) become substantially coincident. The elastomeric holder arrangement makes it possible to reduce the mass of the floating nut system.

Description

Technical Field

[0001] The present invention relates to a floating nut system with reduced mass and to a method of assembling two parts using said system. Background Art

[0002] When one part needs to be assembled with another, there may be misalignment between the two parts due to assembly tolerances. The most common way to accommodate this misalignment is to use a floating nut, which consists of a metal nut held in a metal holder. Prior to assembly, this metal holder can be installed in a hole in one of the parts using a process such as cold expansion or by riveting it to one of the parts.

[0003] Therefore, this type of floating nut requires a difficult operation to install the floating nut. When the number of floating nuts is large, the installation time may be long and the operation is very difficult. For example, in the case of the ventral fairing of an aircraft, about 4,000 floating nuts may be installed.

[0004] This collection of floating nuts therefore represents a very significant quality. Summary of the Invention

[0005] The object of the present invention is to propose a floating nut system of reduced mass for assembling two parts to be assembled.

[0006] To this end, the invention relates to a floating nut system intended for assembling a first part and a second part, the first part comprising a first opening intended for the passage of a screw, the first opening having a first axis of revolution.

[0007] According to the present invention, the floating nut system comprises a nut device and at least one elastomeric holder device, the holder device comprising:

[0008] - a first hollow cylinder having a second axis of revolution and an outer diameter substantially equal to the diameter of a second opening made in the second part, the first cylinder being intended to be introduced into the second opening via a first end of the first cylinder,

[0009] - a first collar protruding on the outer surface of the first cylinder around the second end of the first cylinder, the diameter of the first collar being intended to be greater than the diameter of the second opening;

[0010] The nut assembly includes:

[0011] - a second hollow cylinder having a third axis of revolution parallel to the second axis of revolution and an inner surface comprising a thread intended to cooperate with the screw when the screw is screwed in,

[0012] - a washer fastened to the second cylinder, extending completely around it, the diameter of the washer being intended to be greater than the diameter of the second opening, the washer being embedded in the first collar, the washer being intended to press the first collar against the second part when the screw is screwed into the thread;

[0013] The first cylinder is configured to deform when the screw is screwed in, such that the first axis of revolution and the third axis of revolution become substantially coincident when the screw is screwed into the thread.

[0014] Thus, by means of the elastomeric retainer, the floating nut system has a reduced mass while accommodating misalignments between the two parts to be assembled.

[0015] Furthermore, the retaining device comprises a second collar, which protrudes on the outer surface of the first cylinder around the first end of the first cylinder, the diameter of the second collar being configured to be larger than the diameter of the second opening, the second collar being elastically deformable so that, on the one hand, when the user forces the retaining device through the second opening parallel to the second rotation axis, the second collar bends against the first cylinder so as to pass through the second opening, and, on the other hand, after the retaining device has passed through the second opening, the second collar unbends.

[0016] The second collar is intended to be clamped between the first and second parts when the screw is screwed into the thread.

[0017] According to one embodiment, the second collar includes a plurality of fins protruding around the first end of the first cylinder.

[0018] Advantageously, the outer surface of the first cylindrical body has a plurality of longitudinal grooves parallel to one another, each of these grooves being positioned so as to be aligned with one of the fins, each groove being intended to accommodate said fin when it is bent in alignment with the groove, so that the second collar can pass through the second opening when the user forces the retaining device through the second opening parallel to the second axis of rotation.

[0019] Furthermore, the nut device comprises a tapered portion fastened to the second cylindrical body, the tapered portion having the shape of a frustum with a small base connecting the tapered portion to the first end of the second cylindrical body and a large base intended to face the first opening.

[0020] In addition, the floating nut system includes an annular member having an axis of rotation coinciding with the second axis of rotation, the annular member being embedded in the first cylinder, the thickness of the annular member being substantially intended to be equal to the thickness of the second part that is easily assembled with the first part by the floating nut system, and the annular member being configured not to deform when the first cylinder is deformed.

[0021] Furthermore, the first collar has a circular rim, the first collar having a cylindrical wall on the circular rim, the cylindrical wall having a free end intended to be pressed against the second part when the screw is screwed into the thread.

[0022] The invention also relates to a method of assembling a first part and a second part using a floating nut system as specified above.

[0023] According to the present invention, the method comprises the following steps:

[0024] - a step of introducing the first cylindrical body into the second opening via the first end of the first cylindrical body;

[0025] - a step of introducing a screw into the first opening;

[0026] - a first deformation step of shear deforming the first cylindrical body until the first axis of revolution substantially coincides with the third axis of revolution of the second cylindrical body;

[0027] - a step of introducing the screw into the second cylindrical body;

[0028] - the step of screwing the screw into the thread of the inner surface of the second cylinder;

[0029] - A second deformation step of compressively deforming the first cylinder until the washer presses the first collar against the second part.

[0030] Additionally, the step of introducing the first cylinder comprises:

[0031] - a sub-step of elastically deforming and bending the second collar against the first cylinder when the second collar passes through the second opening;

[0032] - A sub-step of unbending the second loop after the second loop has passed through the second opening.

[0033] Furthermore, the first deformation step comprises:

[0034] - a sub-step of introducing the screw into the tapered portion;

[0035] - A sub-step of deforming the first cylinder as the screw gradually enters the tapered portion until the screw enters the second cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings will make it easy to understand how the invention can be implemented. In the drawings, like reference numerals represent similar elements.

[0037] Figure 1 Depicts a perspective view of the floating nut system.

[0038] Figure 2A radial section is shown through the floating nut system and through the two parts to be assembled.

[0039] Figure 3 The assembly method using the floating nut system is schematically depicted.

[0040] Figure 4 A radial section through the floating nut system and through the two parts to be assembled is shown before the first cylinder is introduced into the second opening.

[0041] Figure 5 A radial section through the floating nut system and through the two parts to be assembled is shown at the beginning of the introduction of the first cylinder into the second opening.

[0042] Figure 6 Depicted is a radial section through the floating nut system and through the two parts to be assembled during the introduction of the first cylinder into the second opening.

[0043] Figure 7 A radial section through the floating nut system, through the two parts to be assembled, and through the screw is depicted during its introduction into the first opening.

[0044] Figure 8 A radial section through the floating nut system, through the two parts to be assembled, and through the screw is depicted at the beginning of screwing the screw into the thread of the second cylinder.

[0045] Figure 9 Depicted is a radial section through the floating nut system, through the two parts to be assembled, and through the screw just when the screw has been completely screwed into the thread of the second cylinder. DETAILED DESCRIPTION

[0046] Figure 1 and Figure 2 A floating nut system 1 intended for assembling a first part 2 and a second part 3 is depicted.

[0047] Without limitation, the first part 2 and the second part 3 may each correspond to a metal sheet to be assembled. The first part 2 and the second part 3 may also correspond to a ventral fairing of an aircraft to be assembled.

[0048] The first part 2 comprises a first opening 4 intended to pass the screw 5. The first opening 4 has a first axis of revolution A1.

[0049] The first opening 4 can be produced by a tool before the first part 2 is placed relative to the second part 3 .

[0050] The floating nut system 1 comprises at least one elastomeric holder device 6 and a nut device 7. The holder device 6 holds the nut device 7.

[0051] The holder device 6 comprises a first hollow cylindrical body 8. The first cylindrical body 8 has a second axis of revolution A2. The outer diameter D1 of the first cylindrical body 8 is substantially equal to the diameter of the second opening 9 made in the second part 3. Like the first opening 4, the second opening 9 can be made by a tool before the first part 2 is placed relative to the second part 3.

[0052] The first cylindrical body 8 is intended to be introduced into the second opening 9 via a first end 10 of the first cylindrical body 8 .

[0053] The holder device 6 further comprises a first collar 11. The first collar 11 protrudes on the outer surface 80 of the first cylindrical body 8 around the second end 12 of the first cylindrical body 8. The diameter D2 of the first collar 11 is intended to be greater than the diameter of the second opening 9.

[0054] The nut device 7 comprises a second hollow cylinder 13 having a third axis of revolution A3 parallel to the second axis of revolution A2. The inner surface 14 of the second cylinder 13 comprises a thread. The thread is intended to cooperate with the screw 5 when the screw 5 is screwed into said thread.

[0055] The nut device 7 further includes a washer 15 secured to the second cylindrical body 13. The washer 15 extends completely around the second cylindrical body 13, or in other words, protrudes around the second cylindrical body 13. The diameter D3 of the washer 15 is intended to be greater than the diameter of the second opening 9. The washer 15 is embedded in the first collar 11. In addition to embedding, additional fixing means for fixing the washer to the collar can be provided, such as overmolding, gluing, or any other equivalent means. The washer 15 is intended to deform the first cylindrical body 8 by pressing the first collar 11 against the second part 3 when the screw 5 is screwed into the thread.

[0056] The first cylindrical body 8 is configured to deform as the screw 5 is screwed in, such that the first axis of rotation A1 and the third axis of rotation A3 become substantially coincident when the screw 5 is screwed into the thread. Without limitation, the configuration that enables the first cylindrical body 8 to deform may depend on the material of the holder device 6 and the wall thickness of the first cylindrical body 8.

[0057] The nut device 7 may be made of a metal material, such as stainless steel or aluminum.

[0058] Advantageously, the holder device 6 further comprises a second collar 16, which protrudes on the outer surface 80 of the first cylindrical body 8 around the first end 10 of the first cylindrical body 8. The diameter D4 of the second collar 16 is configured to be larger than the diameter of the second opening 9. The second collar 16 is configured to be elastically deformable so that, on the one hand, when the user forces the holder device 6 to pass through the second opening 9 ( Figure 5 and Figure 6 ), the second collar is bent against the first cylinder 8 so as to pass through the second opening 9, and on the other hand, the second collar is bent when it passes through the second opening 9 ( Figure 7 ) and then release the bend.

[0059] The second collar 16 is intended to be clamped between the first part 2 and the second part 3 when the screw 5 is screwed into the thread.

[0060] The second collar 16 clamped between the first part 2 and the second part 3 enables the first cylindrical body 8 to be retained in the second opening 9 during the method (described below) of assembling the first and second parts 2, 3. Thus, the first cylindrical body 8 cannot escape from the second opening 9 during said assembly method.

[0061] According to one embodiment, the second collar 16 comprises a plurality of fins 17 protruding around the first end 10 of the first cylindrical body 8 .

[0062] The outer surface 80 of the first cylindrical body 8 may have a plurality of longitudinal grooves 18 that are parallel to each other. Each groove 18 is positioned to align with each fin 17. Each groove 18 is intended to accommodate the fin 17 when the fin 17 aligned with the groove 18 is bent, so that when the user forces the retaining device 6 (or the floating nut system 1) through the second opening 9 parallel to the second axis of rotation A2, the second collar 16 can pass through the second opening 9. Figure 6 The moment of introduction of the floating nut system 1 is shown, during which the fins are bent into these grooves 18 , allowing the holder device 6 to pass through the second opening 9 .

[0063] Advantageously, the nut device 7 comprises a tapered portion 19 fastened to the second cylindrical body 13. The tapered portion 19 has the shape of a frustum of a cone having a small base 21 and a large base 22. The small base 21 connects the tapered portion 19 to the first end 20 of the second cylindrical body 13. The large base 22 is intended to face the first opening 4 when the first cylindrical body 8 is introduced into the second opening 9. The tapered portion 19 allows the free end of the screw 5 to be guided towards the second cylindrical body 13 so that the screw 5 can be screwed into the thread of the second cylindrical body 13.

[0064] The floating nut system 1 may further include an annular member 23 having an axis of rotation that coincides with the second axis of rotation A2 when the first cylindrical body 8 is undeformed. The annular member 23 is embedded in the first cylindrical body 8. The annular member 23 has a thickness D5 that is substantially equal to the thickness of the second part 3 that is easily assembled with the first part 2 using the floating nut system 1. The annular member 23 is configured to remain unchanged when the first cylindrical body 8 is deformed. The annular member allows the first cylindrical body 8 to maintain its cylindrical shape at the second opening 9.

[0065] The first collar 11 may have a circular rim 24. The first collar 11 may have a cylindrical wall 25 on the circular rim 24. The cylindrical wall 11 has a free end 26 intended to be pressed against the second part 3 when the screw 5 is screwed into the thread.

[0066] The present invention also relates to a method for using a floating nut system 1 ( Figure 3 ) to assemble the first part 2 and the second part 3.

[0067] The assembly method comprises the following steps:

[0068] - a step E1 of introducing the first cylinder 8 into the second opening 9 via the first end 10 of the first cylinder 8 ( Figure 4 、 Figure 5 and Figure 6 );

[0069] - Step E2 of introducing the screw 5 into the first opening 4 ( Figure 7 );

[0070] - a first deformation step E3 of shear deformation of the first cylindrical body 8 until the first axis of revolution A1 substantially coincides with the third axis of revolution A3 of the second cylindrical body 13 ( Figure 8 );

[0071] - Step E4 of introducing the screw 5 into the second cylindrical body 13 ( Figure 8 );

[0072] - Step E5 of screwing the screw 5 into the thread of the inner surface 14 of the second cylindrical body 13;

[0073] - a second deformation step E6 of deforming the first cylinder 8 in compression until the washer 15 presses the first collar 11 against the second part 3 ( Figure 9 ).

[0074] The step E1 of introducing the first cylindrical body 8 may comprise:

[0075] - Sub-step E11 of causing the second collar 16 to elastically deform and bend against the first cylinder 8 when the second collar 16 passes through the second opening 9 ( Figure 5 and Figure 6 );

[0076] - Sub-step E12 of unbending the second collar 16 after it has passed through the second opening 9 ( Figure 7 ).

[0077] The first deformation step E3 may include:

[0078] - Sub-step E31 of introducing the screw 5 into the conical portion (19) Figure 7 );

[0079] - Sub-step E32 of deforming the first cylindrical body 8 as the screw 5 gradually enters the conical portion 19 until the screw 5 enters the second cylindrical body 13 ( Figure 8 ).

[0080] Therefore, the first cylindrical body 8 is susceptible to deformation due to two mechanical stresses. The first mechanical stress is a shear stress. The deformation of the first cylindrical body 8 caused by the shear stress can cause the first axis of rotation A1 and the third axis of rotation A3 of the second cylindrical body 13 to substantially coincide. The shear stress is caused by the movement of the washer 15 driven by the screw 5. The screw 5 is guided toward the second cylindrical body 13 by the tapered portion 19 of the nut assembly 7 so that it can be screwed into the cylinder. The second mechanical stress is a uniaxial compressive stress. When the screw 5 is fully screwed into the second cylindrical body 13, deformation of the first cylindrical body 8 due to the uniaxial compressive stress occurs. The uniaxial compressive stress is in a direction parallel to the third axis of rotation A3. Therefore, the uniaxial compressive stress is applied by the washer 15. As the screw 5 is screwed into the second cylindrical body 13, it pulls the washer 15 toward the second part 3. The washer 15 thus applies a compressive stress to the first cylindrical body 8.

[0081] The floating nut system 1 offers many advantages:

[0082] - The mass of the floating nut system is reduced compared to the mass of floating nuts of the prior art.

[0083] - The floating nut system enables to reduce factory assembly time.

[0084] - The floating nut system can be used where a small or large degree of float is required, that is, the floating nut system can be used where the misalignment between the two parts to be assembled is small or large.

[0085] - The floating nut system can be used in a wide range of configurations, such as for aircraft ventral fairings, aircraft nacelles, etc.

[0086] - The floating nut system is highly repairable as it can be quickly and easily replaced if necessary.

[0087] - The floating nut system provides isolation and thus filtering of vibrations imposed by the assembled parts.

[0088] - Floating nut system avoids galvanic corrosion problems.

Claims

1. A floating nut system intended for assembling a first part (2) and a second part (3), the first part (2) comprising a first opening (4) intended for passing a screw (5), the first opening (4) having a first axis of rotation (A1), It is characterized in that The floating nut system comprises a nut device (7) and at least one elastomeric holder device (6), The holding frame device (6) comprises: a hollow first cylindrical body (8) having a second axis of revolution (A2) and an outer diameter (D1) substantially equal to the diameter of a second opening (9) made in the second part (3), the first cylindrical body (8) being intended to be introduced into the second opening (9) via a first end (10) of the first cylindrical body (8), a first collar (11) protruding on the outer surface (80) of the first cylindrical body (8) around the second end (12) of the first cylindrical body (8), the diameter (D2) of the first collar (11) being intended to be greater than the diameter of the second opening (9); The nut device (7) comprises: a hollow second cylindrical body (13) having a third axis of revolution (A3) parallel to the second axis of revolution (A2) and an inner surface (14) comprising a thread intended to cooperate with the screw (5) when the screw (5) is screwed in, - a washer (15) fastened to the second cylindrical body (13), said washer (15) extending completely around the second cylindrical body (13), said washer (15) having a diameter (D3) intended to be greater than the diameter of the second opening (9), said washer (15) being embedded in the first collar (11), said washer (15) being intended to press the first collar (11) against the second part (3) when the screw (5) is screwed into the thread; The first cylindrical body (8) is configured to deform when the screw (5) is screwed in, so that when the screw (5) is screwed into the thread, the first axis of revolution (A1) and the third axis of revolution (A3) become substantially coincident.

2. The floating nut system according to claim 1, It is characterized in that The holder device (6) further comprises a second collar (16) which projects on the outer surface (80) of the first cylinder (8) around the first end (10) of the first cylinder (8), the diameter (D4) of the second collar (16) being configured to be larger than the diameter of the second opening (9), the second collar (16) being elastically deformable so that, on the one hand, when a user forces the holder device (6) through the second opening (9) parallel to the second axis of rotation (A2), the second collar bends against the first cylinder (8) so as to pass through the second opening (9), and, on the other hand, the second collar unbends after the holder device has passed through the second opening (9). The second collar (16) is intended to be clamped between the first part (2) and the second part (3) when the screw (5) is screwed into the thread.

3. The floating nut system according to claim 2, It is characterized in that The second collar (16) includes a plurality of fins (17) protruding around the first end (10) of the first cylinder (8).

4. The floating nut system according to claim 3, It is characterized in that The outer surface (80) of the first cylindrical body (8) has a plurality of mutually parallel longitudinal grooves (18), each of the longitudinal grooves (18) being positioned to align with each of the fins (17), each of the longitudinal grooves (18) being intended to accommodate the fin (17) when the fin (17) aligned with the longitudinal groove (18) is bent, so that the second collar (16) can pass through the second opening (9) when the user forces the retaining device (6) through the second opening (9) parallel to the second axis of rotation (A2).

5. The floating nut system according to any one of claims 1 to 4, It is characterized in that The nut device (7) comprises a conical portion (19) fixed to the second cylindrical body (13), the conical portion (19) having the shape of a truncated cone having a small base (21) connecting the conical portion (19) to a first end (20) of the second cylindrical body (13) and a large base (22) intended to face the first opening (4).

6. The floating nut system according to any one of claims 1 to 5, It is characterized in that The floating nut system further includes an annular member (23) having an axis of rotation coinciding with the second axis of rotation (A2), the annular member (23) being embedded in the first cylinder (8), the thickness (D5) of the annular member (23) being substantially intended to be equal to the thickness of the second part (3) that is easily assembled with the first part (2) through the floating nut system (1), and the annular member (23) being configured not to deform when the first cylinder (8) is deformed.

7. The floating nut system according to any one of claims 1 to 6, It is characterized in that The first collar (11) has a circular rim (24), the first collar (11) has a cylindrical wall (25) on the circular rim (24), the cylindrical wall (11) having a free end (26) intended to press against the second part (3) when the screw (5) is screwed into the thread.

8. A method for assembling a first part (2) and a second part (3) using a floating nut system (1) according to one of claims 1 to 7, It is characterized in that The method comprises the following steps: - a step (E1) of introducing the first cylindrical body (8) into the second opening (9) via the first end (10) of the first cylindrical body (8); - a step (E2) of introducing a screw (5) into said first opening (4); - a first deformation step (E3) of shear-deforming the first cylindrical body (8) until the first axis of revolution (A1) substantially coincides with the third axis of revolution (A3) of the second cylindrical body (13); - a step (E4) of introducing the screw (5) into the second cylindrical body (13); - a step (E5) of screwing the screw (5) into the thread of the inner surface (14) of the second cylindrical body (13); - A second deformation step (E6) of compressively deforming the first cylindrical body (8) until the washer (15) presses the first collar (11) against the second part (3).

9. The method according to claim 8, It is characterized in that The step (E1) of introducing the first cylindrical body (8) comprises: - a sub-step (E11) of causing the second collar (16) to elastically deform and bend against the first cylinder (8) when the second collar (16) passes through the second opening (9); - A sub-step (E12) of unbending said second collar (16) after said second collar (16) has passed through said second opening (9).

10. The method according to any one of claims 8 and 9, It is characterized in that The first deformation step (E3) comprises: - Sub-step (E31) of introducing the screw (5) into the conical portion (19); - Sub-step (E32) of deforming the first cylindrical body (8) as the screw (5) gradually enters the tapered portion (19) until the screw (5) enters the second cylindrical body (13).

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