Device for attaching a tube to a holder

Abstract

The device for attaching a tube (2) to a holder (1) according to the invention comprises a tube (2), a holder (1), a through bolt (3) and a nut (4), the holder (1) receiving the tube (2) in a cylindrical housing (10) transversely penetrated by an opening (11), the tube (2) having two holes (20) arranged opposite each other, the bolt (3) passing through the opening (11) and the two holes (20) and rigidly attaching the tube (2) to the holder (1); characterized in that the cylindrical housing (10) of the holder has a longitudinal slot (100) arranged opposite the opening (11), the slot (100) having two inner edges (103) arranged on the lateral faces of the housing and two outer edges (104) arranged on the opposite lateral faces of the housing, the nut (4) comprising at least one angled face (40, 41), each outer edge (104) having a bevel gear (1010, 1020) engaging with the angled face (40, 41) of the nut (4). Tightening the bolt (3) on the nut (4) causes the edges of the slot (100) to tighten onto the tube (2), the cylindrical housing (10) closing on the tube (2), thus allowing the entire surface of the housing to come into contact with the surface of the tube and allowing a better distribution of the forces.

Description

TECHNICAL FIELD

[0001] The technical field of the invention is that of attachment devices, and more particularly the attachment between a tube and a holder, for example, which can be a cradle of a seat structure of an aircraft. BACKGROUND

[0002] Attaching a cylindrical beam or tube to a holder, whether or not metallic, is done by simple bolting through the two elements. Thus, the bolt exerts pressure only at its head and its thread, which has the effect of "squeezing" the holder around the tube and does not distribute the tightening over its entire periphery. This simple radial tightening of the tube in the holder results in a poorly distributed pressure on its periphery, thus causing its ovalization. When a load is applied due to the clearance between the tube and the holder resulting from this tightening mode, this results in a poorly controlled tightening torque and a piercing noise. The assembly then loses rigidity and does not ensure optimal load transmission.

[0003] This is even more troublesome when this attachment involves a seat, in which piercing noises occur when the user sits down or manipulates the seat. SUMMARY

[0004] The invention provides a solution to the problems discussed previously by allowing a better distribution of the forces over the entire periphery of the tube and thus improving the rigidity of the attachment.

[0005] The device for attaching a tube to a holder according to the invention comprises a tube, a holder, a through bolt and a nut, the holder receiving the tube in a cylindrical housing traversed by a port, the tube having two perforations facing each other, the bolt passing through the port and the two perforations and fixing the tube and the holder, characterized in that the cylindrical housing of the holder has a longitudinal slot facing the port, the slot having two inner edges provided on the lateral faces of the housing and two outer edges provided on the opposite sides of the housing, the nut comprising at least one inclined face, each outer edge having a crank cooperating with the inclined face of the nut. The tightening of the bolt to the nut results in the edges of the slot being tightened to the tube, the cylindrical housing closing on the tube, allowing the entire surface of the housing to be in contact on the surface of the tube and thus better distribute the load.

[0006] According to a first embodiment, the inclined face is conical. In this case, the nut can be circular and thus have small overall dimensions. The shape of each crank will then be semi-conical.

[0007] According to a second embodiment, the nut has two inclined faces facing each other. These two inclined faces provide a bearing surface over the entire thickness of the holder. The shape of the crank will then be planar.

[0008] Advantageously, the tube and the cylindrical shell have a circular cross section. The circular cross section of the tube and the cylindrical shell facilitates the installation of the tube which can be inserted anywhere, thereby fastening the cylindrical shell to the tube. However, a tube and a shell having an elliptical cross section allow the tube to be rotatably blocked.

[0009] Advantageously, the holder is metallic. The metal allows a certain flexibility which allows the holder to deform to enclose the tube and return to its initial shape if the tube has to be removed from the holder.

[0010] Advantageously, the tube is metallic. The metal is strong enough while remaining flexible enough.

[0011] Advantageously, the tube is composite. The composite material is lighter and stronger and is particularly suitable for aeronautical applications.

[0012] Advantageously, the holder is a cradle. The holder has a curved shape in the form of a bend and can be attached at each end or at the bend location.

[0013] Advantageously, the cradle constitutes an element of a seat. For example, the seat can be an aircraft seat.

[0014] The seat comprises an attachment device having at least one of the aforementioned characteristics. In this case, the seat is composed of at least two cradles connected by at least one tube, preferably three tubes. BRIEF DESCRIPTION OF DRAWINGS

[0015] These drawings illustrate by way of example, not by way of limitation, the present application.

[0016] Figure 1 is a cross-sectional view of a device for attaching a tube in a holder according to the prior art;

[0017] Figure 2 is a side view of a holder having an attachment device according to the application;

[0018] Figure 3 is Figure 2 a rear view;

[0019] Figure 4 is a partial cross-sectional view of a side of a device according to the application;

[0020] Figure 5 is a perspective view of a device according to the application;

[0021] Figure 6 is a side view of another holder with a nut;

[0022] Figure 7 is a side view of the holder of Figure 6 with a bolt, a nut and a tube. DETAILED DESCRIPTION

[0023] These figures are set out by way of indication and not limitation of the object of the application.

[0024] Unless otherwise stated, identical elements appearing in different figures are given a single reference number.

[0025] Throughout the description, Figure 2 The plane XY shown in Figure 1 will be called the "side face", the front being arranged on the left-hand side of the figure.

[0026] Figure 1 The prior art attachment device of Figure 1 comprises a holder 1, a tube 2 and a bolt 3. The tube 2 is inserted into a cylindrical housing 10 provided for this purpose in the holder 1, the thickness of which is e. The bolt 3 secures the whole by passing through the tube 2 via two perforations 20 facing each other, and through the holder 1 via a port 11 and a threaded hole 12.

[0027] This simple bolt therefore exerts pressure only at its head and its thread, which has the effect of "squeezing" the holder around the tube, and does not distribute the tightening over its entire periphery. It can be seen here that the connection is maintained only at the two perforations 20, thereby creating significant stresses at this location that can deform the tube 2. This deformation (ovalization of the tube 2) leads to a poorly controlled tightening torque, the clearance between the tube and the holder resulting from this tightening mode, then the assembly loses rigidity and does not ensure optimal load transmission.

[0028] On the fastening device according to the application shown in Figure 2, Figures 3 to 5 The holder 1 comprises a cylindrical housing 10 with a longitudinal slot 100 that divides the housing 10 into two branches 101 and 102. Here, the branch 101 is flexible, in such a way that it can close on the other branch 102. The slot 100 has an inner edge 103 and an outer edge 104.

[0029] Each of the two branches 101 and 102 ends in a crank 1010 and 1020 placed so as to protrude from the outer edge 104 of the slot 100. The nut 4 has two inclined faces 40 and 41 intended to cooperate with the cranks 1010 and 1020 and inclined towards the threaded portion of the nut 4. These cranks 1010 and 1020 extend through the entire thickness e of the holder 1. In Figure 6 and Figure 7 In Figures 1 and 2, the two branches 101 and 102 are flexible.

[0030] The cylindrical housing 10 also comprises a port 11 facing the longitudinal slot 100 (see Figure 2). Figure 6 The tube 2 is also drilled with two perforations 20 facing each other.

[0031] The nut 4 is in the form of a segment having the length of the thickness e of the cage 1. One of its lateral faces comprises two inclined faces 40 and 41. The inclination of the faces 40 and 41 is substantially the same as the inclination of the cranks.

[0032] The assembly of the tube 2 on the cage 1 will now be described. The tube 2 is introduced into the cylindrical housing 10 of the cage 1, once the perforation 20 faces the port 11, the bolt 3 is inserted into the port 11, the perforation 20 and the longitudinal slot 100.

[0033] Once the bolt 3 has been introduced, the nut 4 is tightened onto the end of the bolt 3 according to the arrow V. The tightening of the nut 4 will bring the nut 4 closer to the cranks 1010 and 1020 (arrow E), once its inclined faces 40 and 41 are in contact with the cranks 1010 and 1020 (arrow C), the bringing closer of the nut 4 to the cage will cause the inclined faces 40, 41 to bear on each of the cranks 1010 and 1020. When the nut 4 is tightened, the increasingly important bearing of the inclined faces 40, 41 will cause the progressive closure of the two branches 101 and 102 until the tube 2 is sufficiently tightened (arrow F).

[0034] In the embodiment of Figure 6 and Figure 7 , the two branches 101 and 102 are flexible, which allows better tightening of the tube 2.

[0035] Other forms of cage or nut are possible, for example a nut having a hollow conical face which cooperates with two half-cones which project from the outer edge 104 of the slot 100.

[0036] This attachment device is particularly suitable for use in aircraft seats comprising structural elements such as brackets and beams. The brackets comprise areas for the passage of the beams and the overall attachment is performed by means of bolts which pass through openings provided in the beams and the brackets. The brackets thus correspond to the cage and the beams correspond to the tubes.

[0037] Generally, an aircraft seat comprises several separate places separated by armrests. Each place is separated from the next by a bracket, so that for example for three places there are four brackets. The brackets are connected to each other by one or more tubes or beams. For example, there can be one tube at the seat bottom, one tube at the backrest and one tube at the intersection of the seat and the backrest.

Claims

1. An attachment device for attaching a tube (2) to a holder (1), the attachment device comprising a tube (2), a holder (1), a through bolt (3) and a nut (4), the holder (1) receiving the tube (2) in a cylindrical housing (10) laterally penetrated by a port (11), the tube (2) having two perforations (20) facing each other, the bolt (3) passing through the port (11) and the two perforations (20) and fixing the tube (2) and the holder (1), characterized in that, The cylindrical housing (10) of the cage (1) has a longitudinal slot (100) facing the port (11), the slot (100) having two inner edges provided on lateral sides of the housing (10) and two outer edges provided on opposite lateral sides of the housing (10), the nut (4) comprising at least one inclined face (40, 41), each outer edge having a crank (1010, 1020) cooperating with the inclined face (40, 41) of the nut (4).

2. Attachment device according to claim 1, characterized in that The inclined face is conical.

3. The attachment device of claim 1, wherein, The nut (4) has two inclined faces (40, 41) facing each other.

4. Attachment device according to claim 1 or 2, characterized in that The tube (2) and the cylindrical housing (10) have a circular cross-section.

5. The attachment device according to claim 1 or 2, characterized in that The cage (1) is metallic.

6. Attachment means according to claim 1 or 2, characterized in that The tube (2) is metallic.

7. Attachment means according to claim 1 or 2, characterized in that The tube (2) is composite.

8. Attachment means according to claim 1 or 2, characterized in that The cage (1) is a cradle.

9. Attachment device according to claim 8, characterized in that Said cradle is a component of a seat.

10. A seat comprising an attachment device according to any one of claims 1 to 9.

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