WO2006106223A2

WO2006106223A2 - Hinge device for an opening on a structure such as an insulated container door

Info

Publication number: WO2006106223A2
Application number: PCT/FR2006/000734
Authority: WO
Inventors: François Clavier
Original assignee: Lamberet Constructions Isothermes
Priority date: 2005-04-05
Filing date: 2006-04-04
Publication date: 2006-10-12
Also published as: WO2006106223A3; EP1866510B1; ATE468461T1; EP1866510A2; DE602006014378D1; FR2883902A1; FR2883902B1

Abstract

The inventive hinge device (1) comprises a body (2) containing first and second bores (9, 11) which are embodied therein in such a way that they are longitudinally oriented, parallel to each other, remote from each other and are assigned to respective axes (10, 12). The body is pivotally mounted on the door around the first axis (10) and on the structure around the second axis (12). Said hinge device (1) also comprises a first pin (32) movably mounted in a longitudinal direction in the bore between an extended position, in which it is projected outside of the bore to a first longitudinal end (38) of the body, and a second retracted position, in which it is arranged in the bore, means for displacing the pin between the extended and retracted position thereof and means (31, 35, 37) for holding said pin in the extended position.

Description

DEVICE FOR JOINING AN OPENING ON A STRUCTURE, SUCH AS AN ISOTHERMAL CONTAINER DOOR

The present invention relates to a hinge device of an opening on a structure, an opening provided with such a hinge device, and an isothermal container comprising an open box and a hinged door on the box by such a device. .

Arrangements for articulating an opening on a structure having a body which comprises first and second parallel bores are already known; each of these bores receives a longitudinal axis and allows one to pivot the device relative to the opening and the other the pivoting of the device relative to the structure. Such a device is for example described in EP 0 801 197. These devices have many advantages, particularly related to the possibility of pivoting the opening of a large angle, for example 270 °.

Mounting the opening on the structure is done in two steps. In a first step, the hinge devices are placed in the openings of the opening and then an axis is inserted into a longitudinal housing of the opening aligned with the reservations and the first bores. In a second step, the opening thus equipped is approached to the structure, and the hinge devices are placed in reservations provided in the structure. Finally, an axis is inserted into a longitudinal housing of the structure aligned with the reservations and the second bores. This editing is inconvenient, and requires a large space and specific tools for its implementation. It can also be difficult to achieve. Indeed, during the second step, it is necessary to maintain the opening against the structure in the correct position where the housing of the structure and the second bores are aligned, while inserting the axis, which is relatively long. This is all the more difficult in cases where the opening is heavy and its large dimensions, or when the structure is not at ground level. This mounting problem is particularly encountered in the case of isothermal container doors to be shipped on refrigerated vehicles, which are massive and made of thick layers of thermally insulating materials. In addition, the known devices do not guarantee a satisfactory level of tamper when the opening is closed, because they have apparently outside the structure of the screws or other fastening means which can be easily released. In addition, the known devices can not be disassembled without the use of specific tools.

Furthermore, the document US Pat. No. 4,455,711 describes a single-axis articulation device comprising a hollow cylinder in which one or two sliding rods are engaged. A resilient V-shaped actuator makes it possible to bias the rod or rods towards their deployed position, but also to keep the rod or rods in the retracted position by locking them in radial grooves of the cylinder. The elastic actuator protrudes outside the hollow cylinder, which has the following drawbacks:

- large footprint;

- Risk for a user to hit the elastic actuator when it holds the rods in retracted position, which could lead to the movement of the actuator and inadvertent tripping of the system, the rods found in the deployed position;

- risk of catching dust or other soiling, the hinge device thus poorly meet the standards of hygiene, especially in the application to refrigerated containers.

In addition, this device would be poorly suited for use in a vertical position, in which the upper rod would tend to fall by compressing the elastic actuator, the rod may then retract and no longer ensure the connection with the other party of the articulation device. This problem is accentuated in the application to vehicles, because of jolts that can be exerted on the hinge device.

The present invention aims to remedy the drawbacks mentioned above, by providing a hinge device allowing a very great ease of introduction of the opening on the structure. Another object of the invention is to allow the disassembly of the entire structure - opening without specific tools.

Yet another object of the invention is to provide an inviolable hinge device when the door is closed.

For this purpose, and according to a first aspect, the invention relates to a device for articulating an opening on a structure, comprising a body in which are formed a first and a second longitudinal bores. substantially parallel and spaced from each other, respectively having a first and a second axis, the body being intended to be mounted on the one hand on the opening, pivotally about the first axis, and secondly on the structure, pivotally about the second axis, characterized in that it further comprises:

at least one first rod movably mounted in longitudinal translation in a bore between an extended position, in which the first rod projects in part from the bore at a first longitudinal end of the body and a retracted position, in which the first rod is housed in said bore;

- Actuating means for moving the first rod between the deployed and retracted positions;

- Means for holding the first rod in its deployed position; and - elastic return means housed in the same bore as the first rod and able to urge said first rod towards its deployed position.

In practice, for mounting the hinge device on the opening or on the structure, the rod is placed in the retracted position. Then, once the hinge device is in place, the rod is moved to its deployed position where it forms the pivot axis and ensures the maintenance of the device on the opening or the structure. This assembly is very simple.

In addition, the passage of the rod to the deployed position is automatically under the action of elastic return means. And, since these means are housed in the bore, the aforementioned disadvantages are avoided.

It should be noted that the actuating and holding means are preferably separate return means. Thus, even if the return means are housed in the bore, and therefore difficult to access, it is possible for a user to move and lock the rod. The fact that these different means can be distinct also avoids unwanted movement of the rod under the action of elastic means.

According to one possible embodiment, the hinge device comprises a second rod mounted in the same bore as the first rod, said second rod being movable in longitudinal translation between an extended position, in which the second rod is partly projecting out of said boring bore. a second longitudinal end of the body and a retracted position, wherein the second rod is housed in said bore, the device further comprising actuating means for moving the second rod between the deployed and retracted positions and means for holding the second rod in its extended position. For example, the device comprises elastic return means housed in the same bore as the second rod and able to urge said second rod towards its deployed position.

These elastic return means may comprise a spring housed in the bore receiving the two rods, between the two rods, said spring being supported at its first longitudinal end portion on one end of the first rod and at its second longitudinal end portion on a end of the second stem.

To facilitate assembly, the device may comprise means for holding at least one rod in its retracted position. According to one possible embodiment, the means for holding the rod in the extended and / or retracted position comprise a screw capable of being engaged, on the one hand, in a longitudinal oblong opening formed in the body opposite the bore receiving said rod. and, secondly, in a through hole formed in said rod. The screw makes a clamping of the rod against the bore at one or the other end of the opening, which thus correspond to one of the retracted position of the rod and the other to the extended position.

For example, it is in the second bore that the first rod is engaged.

The body may comprise a central strip extended laterally of a first side by a first column in which the first bore is formed and a second side by a second column in which is formed the second bore, said first and second columns being located in the same half-plane defined by the central band.

The first column may comprise a longitudinal rib projecting opposite the second column; the first and / or second column may comprise two adjacent faces inclined towards one another forming a longitudinal protrusion of substantially triangular section, said protuberance being located on the side of the first and / or second column substantially opposite the central strip; . According to a second aspect, the invention relates to an opening, such as a door, intended to be articulated to a structure and comprising an amount in which are provided a longitudinal axis housing and at least one reservation located along the axis of the housing, the opening comprising at least one hinge device as previously described, the body of said hinge device being placed partly in the reservation so that the first axis of the body is substantially coincident with the axis of the housing.

According to a possible embodiment, the opening comprises at least two reservations located along the axis of the housing one above the other, at least two hinge devices each placed in one of the reservations so that the first axes of the two bodies are substantially coincident with the axis of the housing, and a pin engaged in the housing and in the first bore of each of the two articulation devices, the articulation devices being fixed on the spindle by fixing means in a position such that the second axes of the two bodies are substantially aligned. At least one sleeve can be engaged in the housing formed in the upright, around the spindle, the sleeve being made of a material for facilitating rotation of the spindle in the housing, and having at least one of its ends longitudinal a shoulder located outside the housing against a transverse face of a reservation, the shoulder being interposed between the body of the hinge device and said transverse face. By limiting the friction, it facilitates the rotation of the pin integral with the body of the hinge device in the housing. The opposite configuration, in which the sleeve is inserted into the first bore and the pin fixed in the housing of the opening, is also conceivable.

According to a third aspect, the invention relates to an isothermal container, can be embedded on a vehicle, comprising a box having an opening surrounded by a frame and at least one hinged door on the frame by at least one hinge device as previously described.

Finally, according to a fourth aspect, the invention relates to a structure comprising at least one upright and an opening hinged to the upright by at least one hinge device, said hinge device comprising a body in which are formed a first and a second longitudinal bores substantially parallel and spaced from each other, respectively having a first and a second axis, the body of the hinge device being intended to be mounted on the one hand on the opening, pivotally about the first axis and secondly on the upright, pivotally about the second axis. The upright comprises at least one longitudinal housing and at least one first rod movably mounted in longitudinal translation in said housing, between an extended position, in which the first rod partially projects out of the housing and is adapted to cooperate with the second bore and a retracted position, wherein the first rod is housed in said housing, and in that the structure comprises actuating means for moving the first rod between the extended and retracted positions, means for holding the first rod in its deployed position and elastic return means housed in said housing and able to urge said first rod towards its deployed position.

This fourth aspect corresponds to an inverted configuration, in which the rods are not provided on the hinge device, but in the structure itself.

For a good understanding, the invention is described below with reference to the appended figures representing, by way of non-limiting example, a possible embodiment of the invention. Figure 1 is an exploded perspective view of a hinge device according to the invention, comprising two rods;

Figure 2 is a perspective view of the device of Figure 1, in the mounted position, the rods being in the deployed position;

Figure 3 is a cross section of the body of the device of Figure 1;

Figure 4 is a partial perspective view of a frame on which is intended to be mounted the hinge device;

Figures 5 and 6 are partial perspective views of a door equipped with the hinge device of Figure 1, showing respectively the outer and inner faces of the door;

Figure 7 is a perspective view of the outer face of two doors associated with a frame by hinge devices according to that of Figure 1, the doors being in the closed position; and

Figure 8 is an enlarged view of detail A of Figure 7. The hinge device 1 comprises a body 2 made of metal, for example aluminum. The body 2 has a length that can be example of the order of 13 cm, a maximum transverse dimension can be for example of the order of 4 cm, and a mass close to 0.2 kg. It has the same section over its entire length.

The body 2 comprises a central strip 3, of a width that may be close to 8 mm, extended laterally by a first side by a first column 4 and by a second side by a second column 5, the two columns 4, 5 being located in the same half-plane defined by the central strip 3. Between the two columns 4, 5 is thus formed a longitudinal groove 6, on the side of a first face of the central strip 3, said inner face 7. On the opposite of the inner face 7, the outer face of the central strip forms, with the adjacent faces of the columns 4, 5, the outer face 8 of the body 2. The outer face 8 is curved and curved.

In the first column 4 is formed substantially centrally a first cylindrical bore 9, of longitudinal axis 10, and of diameter of about 8 mm. In the second column 5 is formed substantially centrally a second cylindrical bore 11, of longitudinal axis 12, and of the order of the order of 8 mm diameter. The axes 10, 12 are situated substantially at the same distance from the central strip 3.

The contour of the first column 4 comprises, when it runs from the inner face 7 of the central strip 3 to the outer face 8 of the body 2:

a first face 13 in a cylinder portion, substantially concentric with the first bore 9, extending over an angle of approximately 30 °, and connected to the central strip 3 by a fillet 14; - In the extension of the first face 13 substantially tangentially, a second substantially planar face 15, then a third face 16 substantially flat and parallel to the central strip 3. The second and third faces 15, 16 are thus inclined one to the other and form a longitudinal protuberance 17 of substantially triangular section, located opposite the outer face 8 of the body 2;

- In the extension of the third face 16, a fourth face 18 substantially flat, inclined towards the outer face 8;

- A fifth and a sixth faces 19, 20 substantially planar and parallel to the second face 15, spaced from one another and connected at their ends by a rounded 21. The fifth and sixth faces 19, 20 thus define a rib 22 extending from the first column 4 a distance of the order of 11 mm, opposite the second column 5, and forming with the central band 3 an angle of 50 °;

a seventh face 23 in a quarter of a cylinder, connecting the rib 22 to the outer face 8 of the body 2. With the exception of the rib 22, the outline of the first column 4 is generally in a cylinder of diameter 1, 5 cm.

The contour of the second column 5 comprises, when it runs from the inner face 7 of the central strip 3 to the outer face 8 of the body 2: - a first face 24 in cylinder portion, substantially concentric with the second bore 11, extending at an angle of about 50 °, and connected to the central strip 3 by a fillet 25;

- A second and a third substantially flat faces 26, 27, inclined towards each other to form a longitudinal protuberance 28 of substantially triangular section whose tip is directed substantially opposite the outer face 8 of the body 2;

a fourth cylinder-side face 29, substantially concentric with the second bore 11, extending at an angle of approximately 30 ° to the outer face 8. With the exception of the protrusion 28, the contour of the second column 5 is generally in a cylinder whose diameter may be of the order of 1.5 cm.

In the third face 16 of the first column 4, substantially mid-length of the body 2, is provided an orifice 30 opening into the first bore 9. In the first face 24 or the second face 26 of the second column 5 are formed two aligned longitudinal oblong apertures 31, arranged on either side of the orifice 30, symmetrically with respect to a median transverse plane of the body 2.

The hinge device 1 also comprises first and second cylindrical rods 32, 33 intended to be engaged in the second bore 11. The diameter of the rods is slightly smaller than the diameter of the second bore 11, to allow a sliding assembly along the the axis 12, and the length of the rods is less than the half-length of the body 2, for example of the order of 5 cm. The rods 32, 33 are for example made of stainless steel. Finally, the hinge device 1 comprises a helical spring 34 of diameter smaller than the diameter of the second bore 11.

The spring 34 and the rods 32, 33 are mounted longitudinally in the second bore 11, the spring being located between the rods 32, 33 and bearing on the flat transverse end faces 32a, 33a of the rods 32, 33 located at In the vicinity of their end face 32a, 33a, the rods 32, 33 each comprise a through orifice 35, 36 in which is intended to be engaged a screw 37 inserted through the corresponding oblong opening 31. . Each of the rods 32, 33 is movable in translation in the second bore 11, along the axis 12, between:

a retracted position, in which each rod is housed inside the bore 11 and does not protrude beyond the body 2. In this position, the through-orifice 35, 36 of the rods 32, 33 is located in the vicinity of the end of the corresponding oblong opening 31 close to the orifice 30. The spring 34 is compressed between the two rods and, by pressing on the faces 32a, 33a, urges the rods to the opposite one of the other towards the outside of the body 2. The maintenance of the rods 32, 33 in this retracted position, despite the action of the spring 34, is ensured by the tightening of the screws 37; and an extended position (see FIG. 2) in which the first and second rods protrude outside the body 2, respectively at first and second longitudinal ends 38, 39 of the body 2. In this position, the through hole 35, 36 rods 32, 33 is located near the end of the corresponding oblong opening 31 close to the longitudinal ends 38, 39 of the body 2. The spring 34 is in the rest position or slightly compressed between two rods 32, 33. The rods 32, 33 are held in this extended position by tightening the screws 37.

We now describe the mounting of the hinge device 1 on the opening and the structure for which it is intended.

The opening is here an isothermal container door 40. The door 40, partially shown in FIGS. 5 and 6, has an inner face 41 and an outer face 42. It comprises an upright 43 in which are formed a housing 44 of longitudinal axis and at least two reservations situated along the housing axis 44, one above the other. A hinge device 1 is placed in each of the reservations, so that the axis 10 of the first bore 9 is substantially coincident with the axis of the housing 44 and that, when the axes 10, 11 are arranged in the plane of the gate 40, the outer face 8 of the body 2 is located on the side of the outer face of the door 40. A pin, not shown, is then engaged in the housing 44 and in the first bore 9 of each of the two hinge devices 1. The spindle is for example made of stainless steel. A screw 45 is then inserted into the orifice 30 of each articulation device 1 and into a facing orifice formed in the spindle in order to secure the spindle and the articulation device 1. The two orifices formed in the spindle are aligned parallel to the axis of the spindle, so that, once the two hinge devices secured to the spindle by the screws 45, the second pins 12 of said hinge devices are substantially merged. Thus, synchronized pivoting is provided at the two articulation devices. A sleeve is provided in the housing 44 around the spindle. The sleeve is a wear part, and it also facilitates the rotation of the pin in the housing 44, and thus the rotation of the hinge device 1 relative to the door 40. It is for example made of plastic , but may also be made of any material having a low coefficient of friction with the parts adjacent thereto and are movable relative thereto. The sleeve comprises a shoulder located between the hinge device 1 and the transverse face of the reservation, to avoid friction between these two elements.

The door assembly 40 and hinge device 1 is then mounted on the structure, here constituted by a frame 46 intended to be placed around the opening of the box of the isothermal container.

The frame 46, shown in Figures 4 and 7, has an inner face and an outer face 47. It comprises two uprights 48 in each of which are formed two reservations 49 located one above the other along a vertical axis 50. Each reservation 49 has two transverse faces 51 from each of which extends, in the amount 48, an axis housing 50. A sleeve 52, made of plastic or any other material facilitating rotation, is engaged in each housing. It comprises at one of its longitudinal ends a shoulder 53 located outside the housing, against the corresponding transverse face 51 of the reservation 49. As before, the sleeve is a wear part, and it also facilitates rotation.

Two doors 40 as previously described are intended to be articulated each to a post 48 of the frame 46. The rods 32, 33 of the two hinge devices 1 of a door 40 are placed in their retracted position. For this, the user loosens the screws 37, moves the rods inwardly of the first bore 9 by compressing the spring 34 (by pushing the rods with the fingers from the outside of the body 2 or by pulling them by means of the screws 37, through the oblong openings 31), then tighten the screws 37 to maintain the rods 32, 33 in their retracted position.

The door 40 is then approached to the frame 46 and the hinge devices 1 placed in the reservations 49, so that the axis 12 of the second bore is substantially coincidental with the axis 50. Then the user loosens the screws 37. Under the action of the spring 34, the rods 32, 33 are moved to their deployed position and enter the slots formed on either side of the reservations 49. Finally, the user tightens the screws 37 to maintain the rods in their deployed position. The spring 34 automatically brings the rods into their positron deployed as soon as the screws 37 are loosened, without the user having to move the rods himself. It also allows the maintenance of the rods in the deployed position in case the screws 37 come to loosen.

It should be noted that the dimensions of the hinge device 1 are designed so that the rods 32, 33 protrude out of the body 2 sufficiently to firstly ensure a very good maintenance of the hinge device in the frame 46. and on the other hand form a satisfactory pivot axis.

The invention thus provides a hinge device whose implementation is particularly easy and does not require a specific tool but a simple screwdriver. The same is true of dismantling. Another advantage lies in the fact that the frame and door assembly is put in place on the container at the end of the process. In addition, following an accident, the door can be easily replaced in after-sales service.

When the door 40 is closed (FIGS. 7 and 8), the visible face of the hinge device 1, outside the isothermal container, is the outside face 8 of the body 2. The fastening means (screws 45 and 37) are not accessible from the outside, which reinforces the inviolability of the container. In addition, the aesthetics of the container is improved.

The inclined faces 15, 16 of the first column 4 and 26, 27 of the second column 5 as well as the rib 22 allow on the one hand to sequence the pivoting with respect to the axes 10, 12. On the other hand, these elements serve stop for limiting the movement of the door 40 relative to the frame 46.

In the fully open position, the doors 40 are adjacent to the side faces of the container (opening 270 °) which is advantageous in terms of space.

It goes without saying that the invention is not limited to the embodiment described above by way of example but that it encompasses all variants. One can imagine that the articulation about the first axis of pivoting also involves retractable rods, these rods can be mounted movable either in the hinge device or in the opening.

Claims

1. A device for hinging an opening (40) on a structure (46), comprising a body (2) in which are arranged first and second bores (9, 11) substantially parallel longitudinal and spaced one of the other, respectively having a first and a second axis (10, 12), the body (2) being intended to be mounted on the one hand on the opening (40), pivotally about the first axis (10) , and secondly on the structure (46), pivotally about the second axis (12), characterized in that it further comprises: at least one first rod (32) mounted to move longitudinally in a bore between an extended position, in which the first rod (32) partially projects out of the bore at a first longitudinal end (38) of the body (2) and a retracted position, in which the first rod (32) is housed in said bore; actuating means for moving the first rod between the deployed and retracted positions; holding means (31, 35, 37) of the first rod (32) in its deployed position; and elastic return means (34) housed in the same bore as the first rod (32) and able to urge said first rod (32) towards its deployed position.

2. articulation device according to claim 1, characterized in that it comprises a second rod (33) mounted in the same bore as the first rod (32), said second rod (33) being movable in longitudinal translation between a extended position, in which the second rod (33) partially protrudes out of said bore at a second longitudinal end (39) of the body (2) and a retracted position, in which the second rod (33) is housed in said bore, the device further comprising actuating means for moving the second rod (33) between the extended and retracted positions and holding means (31, 36, 37) of the second rod (33) in its position deployed.

3. Articulation device according to claim 2, characterized in that it comprises elastic return means (34) housed in the same bore that the second rod (33) and adapted to urge said second rod (33) to its deployed position.

4. Articulation device according to claims 2 or 3, characterized in that the elastic return means comprise a spring

(34) housed in the bore receiving the two rods (32, 33) between the two rods, said spring bearing at its first longitudinal end part on one end (32a) of the first rod (32) and at its second longitudinal end portion on one end (33a) of the second rod (33).

5. articulation device according to one of claims 1 to 4, characterized in that it comprises holding means (31, 35, 36, 37) of at least one rod (32, 33) in its position retracted.

6. articulation device according to one of claims 1 to 5, characterized in that the rod holding means in the extended position and / or retracted comprise a screw (37) adapted to be engaged on the one hand in a longitudinal oblong opening (31) formed in the body (2) facing the bore receiving said rod (32, 33) and secondly in a through hole (35, 36) formed in said rod (32, 33) .

7. Hinge device according to one of claims 1 to 6, characterized in that the first rod (32) is engaged in the second bore (11). ,

8. articulating device according to one of claims 1 to 7, characterized in that the body (2) comprises a central strip (3) extended laterally of a first side by a first column (4) in which is provided the first bore (9) and a second side by a second column (5) in which is formed the second bore (11), said first and second columns (4, 5) being located in the same half-plane defined by the central band (3).

9. articulation device according to claim 8, characterized in that the first column (4) comprises a longitudinal rib (22) projecting opposite the second column (5).

Articulating device according to claim 8 or 9, characterized in that the first and / or second column (4, 5) has two adjacent faces (15, 16, 26, 27) inclined towards one another. another forming a longitudinal protuberance (17, 28) of substantially triangular section, said protuberance (17, 28) being located on the side of the first and / or second column (4, 5) substantially opposite to the central strip (3).

11. Opening, such as a door (40) intended to be articulated to a structure (46) and comprising an amount (43) in which are formed a housing (44) of longitudinal axis and at least one reservation located on along the axis of the housing (44), characterized in that it comprises at least one hinge device (1) according to one of claims 1 to 10, the body (2) of said hinge device (1 ) being placed partly in the reservation so that the first axis (10) of the body (2) is substantially coincident with the axis of the housing (44).

12. Opening according to claim 11, characterized in that it comprises at least two reservations located along the axis of the housing (44) one above the other, at least two hinge devices (1). ) each placed in one of the reservations so that the first axes (10) of the two bodies are substantially merged with the axis of the housing (44), and a pin engaged in the housing (44) and in the first bore ( 9) of each of the two articulation devices (1), the articulation devices (1) being fixed on the spindle by fixing means (45) in a position such that the second axes (12) of the two bodies are substantially aligned.

13. Opening according to claim 11 or 12, characterized in that it comprises at least one sleeve engaged in the housing (44) formed in the upright (43) around the spindle, the sleeve being made of a material allowing facilitating rotation of the spindle in the housing (44), and comprising at least one of its longitudinal ends a shoulder located outside the housing against a transverse face of a reservation, the shoulder being interposed between the body ( 2) of the articulation device (1) and said transverse face.

14. Isothermal container, can be embedded on a vehicle, comprising a box having an opening surrounded by a frame (46) and at least one door (40) articulated on the frame (46) by at least one hinge device (1). ) according to one of claims 1 to 10.

15. Structure comprising at least one upright (48) and an opening (40) articulated on the upright (48) by at least one hinge device (1), said hinge device comprising a body (2) in which are arranged first and second bores (9, 11) substantially parallel and spaced apart from each other, respectively having a first and a second axis (10, 12), the body (2) of the articulation device ( 1) being intended to be mounted on the one hand on the opening (40), pivotally about the first axis (10), and secondly on the upright (48), pivotally about the second axis ( 12), characterized in that the upright (48) comprises at least one longitudinal housing and at least one first rod movably mounted in longitudinal translation in said housing, between an extended position, wherein the first rod partially projects out of the housing and is adapted to cooperate with the second bore (11) and a e retracted position, wherein the first rod is housed in said housing, and in that the structure comprises actuating means for moving the first rod between the extended and retracted position, means for holding the first rod in its deployed position, and elastic return means housed in said housing and able to urge said first rod (32) to its deployed position.