Device for fastening a pipe to a holder

Description

[0001] The technical field of the invention is that of fixing devices and more particularly the fixings between a tube and a support, this support could, for example, be a crosspiece of an airplane seat structure. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] Cylindrical beams or tubes are fastened to supports, whether metal or not, by tightening a simple screw passing through these two elements. The screw therefore only exerts pressure at its head and threads, which has the effect of "pinching" the support around the tube and does not distribute the tightening over its entire periphery. This simple radial tightening of the tube in the support induces poorly distributed pressure on its periphery and thus an ovalization of the latter. This results in poorly controlled tightening torque as well as grinding noises when a force is exerted due to the play between the tube and the support induced by this tightening method. The assembly then loses rigidity and therefore does not ensure optimal transmission of forces.

[0003] This is even more troublesome when this attachment concerns a seat where squeaking noises appear when a user sits or manipulates the seat. GB2200401A discloses a known attachment device. SUMMARY OF THE INVENTION

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

[0005] The device for fixing a tube to a support according to the invention comprises the tube, the support, a through screw and a nut, the support receiving the tube in a cylindrical housing pierced transversely by an orifice, the tube having two holes arranged opposite each other, the screw passing through the orifice and the two holes and securing the tube and the support, it is characterized in that the cylindrical housing of the support has a longitudinal slot arranged opposite the orifice, the slot having two internal edges arranged on the side of the housing and two external edges arranged on the side opposite the housing, the nut comprising at least one inclined face, each external edge having an angle transmission cooperating with the inclined face of the nut.Tightening the screw on the nut causes the edges of the slot to tighten on the tube, the cylindrical housing closes on the tube allowing contact of the entire surface of the housing on the surface of the tube and thus better distributing the forces.

[0006] According to a first embodiment, the inclined face is conical. In this case, the nut can be circular and therefore space-saving. Each angle transmission will then be semi-conical in shape.

[0007] According to a second embodiment, the nut has two inclined faces arranged opposite each other. The two inclined faces provide a bearing surface across the entire thickness of the support. The angle transmissions will then be flat in shape.

[0008] Advantageously, the tube and the cylindrical housing have a circular cross-section. A circular cross-section of the tube and the cylindrical housing makes it easier to mount the tube, which can be inserted in any position, and thus to tighten the cylindrical housing onto the tube. However, a tube and a housing with an oval cross-section make it possible to lock the tube in rotation.

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

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

[0011] Advantageously, the tube is made of composite material. Composite materials are lighter and more resistant and particularly suitable for aeronautical applications.

[0012] Advantageously, the support is a stock. The support has a curved shape in the form of an elbow and the attachment can be made indifferently at each end or at the location of the elbow.

[0013] Advantageously, the stock constitutes an element of a seat. The seat could, for example, be an airplane seat.

[0014] Seat comprising a fixing device with at least one of the preceding characteristics. In this case the seat consists of at least two crosspieces connected by at least one tube, preferably three tubes. BRIEF DESCRIPTION OF THE FIGURES

[0015] The figures are presented for information purposes only and in no way limit the invention. [ Fig. 1 ] is a section of a device for fixing a tube in a support according to the state of the art; [ Fig. 2 ] is a side view of a support with a fixing device according to the invention; [ Fig. 3 ] is a rear view of the Figure 2 ; [ Fig. 4] is a partial section of the side of the device according to the invention; [ Fig. 5 ] is a perspective view of a device according to the invention; [ Fig. 6 ] is a side view of another bracket with a nut; [ Fig. 7 ] is a side view of the support of the Figure 6 with the screw, nut and tube. DETAILED DESCRIPTION

[0016] The figures are presented for information purposes only and in no way limit the invention.

[0017] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0018] Throughout the description we will call the illustrated XY plane "side". Figure 2 , the front being arranged on the left side of this figure.

[0019] The state-of-the-art fixing device of the Figure 1comprises a support 1, a tube 2 and a screw 3. The tube 2 is inserted into a cylindrical housing 10 provided for this purpose in the support 1 of thickness e. A screw 3 secures the assembly by passing through the tube 2 through two holes 20 arranged opposite each other, and the support 1 through an orifice 11 and a tapped hole 12.

[0020] This simple screw therefore only exerts pressure at the level of its head and its threads, which has the effect of "pinching" the support around the tube and does not distribute the tightening over the entire periphery of the latter. We can see here that the connection only holds at the level of the two holes 20, hence significant stresses at this location which can deform the tube 2. This deformation, an ovalization of the tube 2, results in poorly controlled tightening torque, play between the tube and the support induced by this tightening method, the assembly then loses rigidity and therefore does not ensure optimal transmission of forces.

[0021] On the clamping device according to the invention illustrated in figures 3 to 5 , the support 1 comprises a cylindrical housing 10 with a longitudinal slot 100 which divides the housing 10 into two branches 101 and 102. Here, the branch 101 is flexible so that it can close on the other branch 102. The slot 100 has an internal edge 103 and an external edge 104.

[0022] Each of the two branches 101 and 102 ends with an angle transmission 1010 and 1020, placed projecting on an external edge 104 of the slot 100. The nut 4 has two inclined faces 40 and 41 intended to cooperate with the angle transmissions 1010 and 1020 and inclined towards the threaded part of the nut 4. These angle transmissions 1010 and 1020 extend over the entire thickness e of the support 1. On the figures 6 And 7 , both branches 101 and 102 are flexible.

[0023] The cylindrical housing 10 also comprises an orifice 11 arranged opposite the longitudinal slot 100 (cf. Figure 6 ). The tube 2 is also pierced with two holes 20 arranged face to face.

[0024] The nut 4 is in the form of a segment of the length of the thickness e of the support 1. One of its sides has two inclined faces 40 and 41. The inclination of the faces 40 and 41 is substantially identical to that of the angle transmissions.

[0025] We will now describe the assembly of the tube 2 on the support 1. The tube 2 is inserted into the cylindrical housing 10 of the support 1, once the holes 20 are opposite the orifice 11, the screw 3 is inserted into the orifice 11, the holes 20 and the longitudinal slot 100.

[0026] Once the screw 3 is inserted, the nut 4 is screwed onto the end of the screw 3 according to arrow V. Tightening the nut 4 will bring it closer to the angle transmissions 1010 and 1020 (arrow E), once its inclined faces 40 and 41 are in contact with the angle transmissions 1010 and 1020 (arrow C), the bringing together of the nut 4 of the support will cause the inclined faces 40, 41 to bear on each of the angle transmissions 1010 and 1020. The increasingly important support of the inclined planes 40, 41 as the nut 4 is tightened will cause the two branches 101 and 102 to gradually close until the tube 2 is sufficiently tightened (arrow F).

[0027] In the example of the figures 6 And 7 , the two branches 101 and 102 are flexible, which allows better tightening of the tube 2.

[0028] Other forms of support or nut are possible, for example one can have a nut with a hollow conical face which cooperates with two half-cones projecting on the external edges 104 of the slot 100.

[0029] This fastening device is particularly well suited for aircraft seats with structural elements, such as crossbars and beams. The crossbars have a beam passage area and the assembly is secured by means of a screw passing through openings in the beam and the crossbar. The crossbar thus corresponds to the support and the beam to the tube.

[0030] Typically, airplane seats have several individual seats separated by armrests. Each seat is separated from the next by a crossbar, so for example, there are four crossbars for three seats. The crossbars are connected to each other by one or more tubes or beams. For example, there may be one tube at the seat, one at the backrest, and one at the intersection of the seat and backrest.

Claims

1. A device for attaching a tube (2) onto a holder (1), comprising the tube (2), the holder (1), a through screw (3) and a nut (4), the holder (1) receiving the tube (2) in a cylindrical housing (10) transversely pierced by a port (11), the tube (2) having two piercings (20) facing each other, the screw (3) passing through the port (11) and the two piercings (20) and securing the tube (2) and the holder (1), characterised in that the cylindrical housing (10) of the holder (1) has a longitudinal slot (100) facing the port (11), the slot (100) having two inner edges disposed on the side of the housing (10) and two outer edges disposed on the side opposite the housing (10), the nut (4) including at least one inclined face (40, 41), each outer edge having a bell crank (1010, 1020) cooperating with the inclined face (40, 41) of the nut (4).

2. The attachment device according to claim 1, characterised in that the inclined face is conical.

3. The attachment device according to claim 1, characterised in that the nut (4) has two inclined faces (40, 41) facing each other.

4. The attachment device according to one of the preceding claims, characterised in that the tube (2) and the cylindrical housing (10) have a circular cross-section.

5. The attachment device according to one of the preceding claims, characterised in that the holder (1) is metallic.

6. The attachment device according to one of the preceding claims, characterised in that the tube (2) is metallic.

7. The attachment device according to one of claims 1 to 5, characterised in that the tube (2) is of composite material.

8. The attachment device according to one of the preceding claims, characterised in that the holder (1) is a bracket.

9. The attachment device according to the preceding claim, characterised in that the bracket is a component of a seat.

10. A seat comprising an attachment device according to one of the preceding claims.