Gantry crane and associated method of erection

Abstract

The invention relates to a gantry crane (30) and to the associated method of erection, the gantry crane (30) comprising: - a frame (40) comprising at least three first members (32); - a longitudinal rail (50) supported by the frame (40); and - at least three second members (34) extending between opposite first end (34a) and second end (34b) portions, each second member (34) being connected to the frame (40) by means (48) of rigid connection of the second member to the frame and of continuous rotational movement of the second member relative to the frame between a first position in which the second member (34) makes an angle of less than 90° with the first plane (XY) and a second position in which the second member (34) is substantially perpendicular to said first plane (XY).

Description

Description Title: LIFTING GANTRY AND ASSOCIATED ASSEMBLY METHOD technical field

[0001] This disclosure relates to a lifting gantry and a method for assembling this lifting gantry. Previous technique

[0002] For lifting a heavy mechanical part, it is known to use a lifting gantry equipped with a lifting device, such as a hoist, capable of being connected, directly or indirectly, to the mechanical part to be lifted.

[0003] The lifting gantry comprises two legs extending from the ground in a first direction, typically vertical. The legs are connected by a beam from which the lifting device is suspended. In some cases, the lifting device is fixed to the beam, preventing any movement of the device along the beam. In other cases, the beam forms a rail along which the lifting device can move.

[0004] The gantry beam is positioned at a sufficient distance from the ground to allow the mechanical component to be lifted to a desired height. Due to the beam's weight, assembling it on the gantry legs at such a distance requires either heavy machinery, which is not available everywhere, or excessive human strength, necessitating the intervention of several operators and posing a risk to their physical safety.

[0005] Furthermore, the gantry known from prior art is not sufficiently rigid and stable to lift and move heavy mechanical parts, which endangers operators working near the gantry, especially those working under it. Summary

[0006] This disclosure improves the situation.

[0007] To this end, a lifting gantry is proposed comprising: - a frame comprising at least three first uprights extending parallel to a foreground and each comprising a first end portion and a second end portion opposite each other, each of the first and second end portions of one of the first uprights being connected to another respective first upright; - a longitudinal rail supported by the frame and extending parallel to said foreground and on which is articulated in longitudinal movement as a lifting device for a mechanical part; and - at least three second uprights extending between a first end portion and a second end portion opposite each other, the first end portion of each second upright being rotationally articulated on the frame around an axis parallel to the first plane, each second upright being further connected to the frame by means of rigid connection of the second upright to the frame and of continuous rotational movement of the second upright relative to the frame between a first position in which the second upright forms an angle of less than 90° with the first plane and a second position in which the second upright is substantially perpendicular to said first plane.

[0008] In a practical example, the first uprights are initially placed on a support at a distance from the ground and then connected to each other to form the frame. In a subsequent step, a second upright is rotationally connected to the frame at its first end, with the second end facing the ground. It is understood that in this position, corresponding to the first position, the second upright forms an angle of less than 90° with the first plane. The same operation is repeated for each second upright. After connecting all the second uprights to the frame, the rigid connection and movement mechanisms are activated so that the second uprights move to their second position, which corresponds to a service position—that is, the position of the uprights when the lifting gantry is operational.

[0009] Thanks to the rigid connection and movement of the second uprights, the frame can be raised to a desired height, including a height that allows operators to work underneath the gantry without using external lifting equipment or manual labor. Furthermore, the gantry can be installed anywhere without the need to transport heavy machinery and without endangering the health of the installation workers.

[0010] Furthermore, the presence of at least three initial uprights increases the gantry's resistance to loads lifted in service, particularly the weight of said mechanical part.

[0011] Finally, the presence of at least three second uprights improves the stability of the gantry, particularly in their second position, which improves the safety of any operator working under the gantry.

[0012] Advantageously, the first plane extends substantially parallel to the ground on which the gantry is installed, both in the first position and in the second position of the second uprights.

[0013] According to one aspect of the invention, the rigid connection and continuous movement means are specific to each second upright and independent of the rigid connection and continuous movement means of the other second uprights.

[0014] The rigid connection and continuous movement means of each second upright thus allow the respective second upright to be moved between the first position and the second position independently of the rigid connection and continuous movement means of the other second uprights.

[0015] According to one aspect of the invention, the means for rigid connection and continuous movement include a rack and pinion winch connected to every second upright.

[0016] The rack and pinion winch can be manual or motorized. In the manual version, it is equipped with an operating element, such as a crank, which allows the operator to easily control the movement of the second upright between the first and second positions without requiring significant physical effort. In the motorized version, the operator can control this movement without exerting any physical effort. In some cases, the motorized rack and pinion winch can be controlled remotely.

[0017] The rack and pinion winch has sufficient lifting capacity to allow the second respective upright to be moved between the first and second positions despite the high weight of the frame, which is around 150 kg.

[0018] According to one aspect of the invention, the gantry further comprises a plurality of stiffeners, each stiffener connecting one of the first uprights to one of the second uprights.

[0019] According to the invention, each second upright is connected to the first two uprights. Also, the number of stiffeners is doubled compared to the number of second uprights.

[0020] According to the invention, each stiffener comprises a rigid connecting bar of constant length. It connects the first end portion of a second upright to a first upright.

[0021] The multiple stiffeners improve the stability of the gantry and increase its resistance to lifted loads. Once fixed at both ends, the stiffeners also create a fixed connection between the first and second uprights. In this mounting position, rotation of the second upright around its axis is no longer permitted.

[0022] According to one aspect of the invention, the second end portion of each second upright comprises a lifting member configured to move the respective second upright substantially perpendicular to the foreground when the second uprights are in the second position.

[0023] Thanks to the lifting elements, the height of the frame above the ground can be adjusted. This allows the height to be set so that, when the gantry is used to install the lifted mechanical part in a designated space, the frame's height above the ground ensures that the part is aligned with that space before installation. This is the case, for example, when fitting an axle into a bogie bore.

[0024] According to one aspect of the invention, the second end portion of each second upright comprises a rolling element.

[0025] The rolling element facilitates the movement of each second upright on the ground, so that a single operator is able to move each second upright on the ground to connect its first end portion to the frame.

[0026] According to one aspect of the invention, the first uprights, the second uprights, the rail and the means for rigid connection and continuous movement each form a unit piece, these pieces being connected by removable links.

[0027] Since the connections are removable, the gantry can be disassembled and stored compactly, allowing it to be easily transported by land, sea or air.

[0028] According to one aspect of the invention, the portal comprises four first uprights and four second uprights arranged to form a general cubic structure.

[0029] The presence of four second uprights further increases the stability of the gantry in the second position of the second uprights.

[0030] According to one aspect of the invention, each first upright and the rail have a weight less than or equal to 50 kg. Preferably, each first upright and the rail have a weight less than or equal to 40 kg. For example, each upright and the rail may have a weight less than or equal to 36 kg.

[0031] Each first piece and the rail can thus be transported by only two operators while respecting the legal provisions which set the maximum load that an operator can carry at 25 kg.

[0032] In another respect, a method for assembling a lifting gantry is proposed, comprising: a) assembly of the frame by connecting each of the first and second end portions of one of the first uprights to another respective first upright; b) assembly of the rail on the frame; c) connection to the frame of the first end portion of each second upright, the first end portion of each second upright being articulated in rotation on the frame around an axis parallel to the foreground; d) connection of each second upright to a first upright by means of said rigid connection and continuous movement means; e) movement of each second upright in rotation around the axis parallel to the foreground between the first position obtained in step d) and the second position by actuation of the rigid connection and continuous movement means.

[0033] As previously mentioned, for assembling the frame, the first uprights are placed on the support at a distance from the ground and then connected to each other. According to the invention, the support can comprise a plurality of independent support elements such as trestles, preferably as many support elements as there are first uprights. The first end portion of each first upright can thus rest on one of the support elements, and the second end portion of each first upright on another of the support elements.

[0034] Advantageously, the height of the support elements is less than or equal to 1 m, preferably between 0.8 m and 1 m. Operators therefore do not have to exert significant physical effort to place the first uprights on the individual support elements.

[0035] Thanks to the means of rigid connection and movement of the second uprights, the assembly process of the gantry according to the invention does not require the use of heavy machinery, and the use of human force is limited to that used to arrange the first uprights on the unit support elements and to assemble the rail on the frame.

[0036] According to one aspect of the invention, the gantry assembly method further comprises the connection between each first upright and each second upright of the respective stiffener after the movement of each second upright between the first position and the second position.

[0037] Since the connection of the stiffeners is subsequent to the movement of each second upright into the second position, it is possible to use rigid stiffeners.

[0038] According to one aspect of the invention, the method further comprises the installation of each lifting element after the movement of each second upright between the first position and the second position.

[0039] According to the invention, in a retracted position of each lifting element, the second end portion of each second upright is in contact with the ground on which the gantry is put into service, while in a deployed position of each lifting element, the second end portion of each second upright is separated from the ground by a distance equal to a deployment length of each lifting element.

[0040] In one variant, the lifting devices can be pre-mounted on each second upright and be movable on it from a waiting position to a service position.

[0041] This document also relates to a method of mounting an axle in a bore of a bogie mounted on the landing gear of an aircraft, the landing gear being in a deployed position, the bore of the bogie extending in a substantially horizontal direction, referred to as the axle installation direction, between a first open end and a second open end, the method comprising: a) providing a movable supporting structure including axle displacement means movable in a direction substantially parallel to the axle installation direction, b) installing the axle on the axle displacement means, c) aligning the axle axis with the bore axis, d) inserting the axle into said bogie bore by moving the axle displacement means in the direction substantially parallel to the axle installation direction.

[0042] Because the axle is inserted into the bogie bore in the direction of its installation, which is essentially horizontal, the mounting method allows the axle to be installed in the bogie bore without removing the bogie from the landing gear. The axle can even be installed under the aircraft wing. This simplifies and speeds up the axle installation process, thereby reducing aircraft downtime costs.

[0043] The process may include a step prior to step d) comprising introducing the axle in a horizontal position, for a given time, for example one hour, into a tank filled with liquid nitrogen.

[0044] Introducing the axle into the tank filled with liquid nitrogen cools it to a temperature of approximately -200°C, causing it to contract and facilitating its insertion into the bore. Once in the bore, the axle's temperature rises to ambient temperature, causing it to expand. the axle, leading to an increase in its external diameter until it self-locks at room temperature in the bore.

[0045] In one respect, step c) includes: - the positioning of a reference mark on the movable supporting structure such that the axis of the bore intercepts said reference mark, and - the positioning of the axle so that its axis is aligned according to the direction of installation with the said reference mark.

[0046] Thanks to the positioning of the reference mark so that it is intercepted by the axis of the bogie bore, the alignment between the axle axis and the reference mark also implies that the axle axis is aligned with the bore axis. The axle can therefore be easily inserted into the bore without risk of collision between the axle and the bore during this insertion.

[0047] The reference point can be arranged in a vertical plane including the direction of installation, this plane corresponding to a lifting plane of the axle axis.

[0048] With the reference mark positioned in the lifting plane of the axle axis, it is only necessary to adjust the position of the axle axis in a substantially vertical direction to align the reference mark and said axle axis, which allows the alignment of the axle axis with the axis of the bogie bore.

[0049] The method may include mounting a laser beam device in the bogie bore so that the axis of the laser beam is coaxial with the axis of the bogie bore.

[0050] Depending on the aspect, the laser beam will be visible on the marker. As the axis of the laser beam is coaxial with the axis of the bogie bore, alignment between the marker and the laser beam ensures alignment between the bore axis and the marker.

[0051] According to one aspect, step d) is preceded by a step comprising the fitting of a sleeve around a first end of the axle which is arranged opposite the bore of the bogie according to the direction of installation of the axle.

[0052] The sleeve can be made of a flexible material, such as plastic. This sleeve helps to cushion any collisions that may occur between the axle and the bogie bore during step d).

[0053] This document also relates to an installation for implementing a method of mounting an axle in a bore of a bogie mounted on the landing gear of an aircraft, the landing gear being in a deployed position, the bore extending in a substantially horizontal direction, referred to as the axle installation direction, between a first open end and a second end open, the installation comprising: - a mobile supporting structure, - means for aligning the axis of the bogie bore with the axle axis, - means of moving the axle into an insertion position in the bogie bore and of mounting the axle in the bogie bore.

[0054] The installation allows the axle to be mounted in the bore in a nearly horizontal orientation. Therefore, there is no need to remove the landing gear bogie to install the axle. The installation can be positioned under the aircraft wing to allow the axle to be mounted directly in that position. This simplifies axle installation and reduces its cost.

[0055] The installation may also include a tank filled with liquid nitrogen.

[0056] The tank filled with liquid nitrogen cools the axle before it is inserted into the bore. This causes the axle to contract, facilitating its insertion. Once in the bore, the axle's temperature rises to ambient temperature, causing it to expand and allowing for a tight fit within the bogie bore without the need for additional fasteners.

[0057] The alignment means may include a marker carried by the movable supporting structure and a laser beam device shaped to be installed in the bogie bore so that the axis of the laser beam is coaxial with the axis of the bogie bore.

[0058] The position of the marker can be adjusted so that the laser beam intercepts it. Since the laser beam axis is coaxial with the axis of the bogie bore, the installation allows for easy alignment of the marker and the bore axis.

[0059] The installation may further include means for moving the reference frame comprising at least one rolling element configured to move the supporting structure along a horizontal plane, and at least one lifting element for the supporting structure configured to move the supporting structure in translation along a substantially vertical direction.

[0060] Thanks to the rolling element and the lifting device, the marker can be moved along the horizontal plane and in the substantially vertical direction until the laser beam intercepts the marker, which ensures alignment between the marker and the bore axis.

[0061] According to one aspect, the load-bearing structure comprises an upper frame supported by a plurality of vertical uprights, the upper frame supporting the means for moving the axle into a position of insertion into the bogie bore and mounting the axle in the bogie bore.

[0062] The axle movement means are arranged in particular so that, once the reference mark is aligned with the bore axis, the axle movement means move in a direction substantially parallel to the bore axis. This allows for easy alignment of the axle with the bore.

[0063] According to one aspect, the means of movement include a rail carried by the upper frame and a hoist mounted to move in translation on the rail according to the direction of installation of the axle.

[0064] The hoist allows the axle to be lifted to the alignment position between the axle axis and the bore axis. Since the hoist is mounted with a linear movement along the rail in the direction of axle installation, the axle is directly inserted into the bore by means of this hoist movement once the axle is aligned with the bogie bore axis.

[0065] The reference point can be fixed relative to the rail and arranged in a plane including the direction of installation of the axle and the direction of translational movement of the hoist on the rail.

[0066] Since the marker is fixed relative to the rail, movements of the supporting structure by means of the rolling element and the lifting device do not change the relative position of the marker with respect to the rail.

[0067] The hoist can be configured so that in the raised position, the axle is necessarily positioned with its axis aligned with the reference mark.

[0068] Alignment between the axle and the reference mark is achieved by positioning the hoist in the raised position. This makes alignment between the axle and the reference mark easy and minimizes the risk of error. Brief description of the drawings

[0069] Other features, details, and advantages will become apparent upon reading the detailed description below and analyzing the attached drawings, on which: Fig. 1

[0070] [Fig. 1] is a schematic perspective view of a lifting gantry according to the invention in a low service position. Fig. 2

[0071] [Fig. 2] is a schematic perspective view of the lifting gantry of Figure 1 in a high service position. Fig. 3

[0072] [Fig. 3] is a schematic perspective view of a rigid linkage and continuous displacement means installed on the lifting gantry of Figure 1. Fig. 4

[0073] [Fig. 4] is a schematic perspective view of a frame of the lifting gantry of figure 1 arranged on a support. Fig. 5

[0074] [Fig. 5] is a schematic side view of the lifting gantry of figure 1 in another position. Fig. 6

[0075] [Fig. 6] is a schematic perspective view of an axle mounting installation on a bogie installed on an aircraft landing gear, the installation including the gantry of Figure 1. Fig. 7

[0076] [Fig. 7] is a schematic view of the installation and landing gear of figure 6 and viewed from a different orientation. Fig. 8

[0077] [Fig. 8] is a schematic perspective view of the gantry in Figure 1 when it is part of the installation in Figures 6 and 7. Fig. 9

[0078] [Fig. 9] is a schematic perspective view of an axle support from the installation in Figures 6 and 7. Fig. 10

[0079] [Fig. 10] is a schematic perspective view of a tank from the installation of figures 6 and 7. Fig. 11

[0080] [Fig. 11] is a schematic perspective view of the axle support in Figure 9 supporting the axle and inserted into the tray in Figure 10. Fig. 12

[0081] [Fig. 12] is a schematic perspective view of the axle support in Figure 9 supporting the axle, and of the tray in Figure 10. Fig. 13

[0082] [Fig. 13] is a schematic perspective view of a laser of the installation of figures 6 and 7 and a detail of the bogie. Fig. 14

[0083] [Fig. 14] is a schematic perspective view of a detail of the bogie when the axle supported by the axle support is inserted into the bore of the bogie. Description of the implementation methods

[0084] In this description, the various elements will be defined in the three perpendicular directions of space. In particular, an orthonormal coordinate system will be used, comprising a first direction X, a second direction Y, and a third direction Z, all orthogonal to each other. The first direction X and the second direction Y are substantially horizontal, forming between them a substantially horizontal XY plane. The third direction Z is substantially vertical and forms an XZ plane with the first direction X, as well as a YZ plane with the second direction Y. The XZ and YZ planes are substantially vertical.

[0085] Now a lifting gantry 30, or supporting structure, will be described with reference to figures 1 and 2. In these figures, the gantry is placed on a floor S which extends along the XY plane, without this being limiting.

[0086] The portal frame comprises a plurality of first uprights 32 and a plurality of second uprights 34.

[0087] The first uprights extend parallel to a first plane. In Figures 1 and 2, the plurality of first uprights 32 extend substantially parallel to the XY plane, which is substantially horizontal, while the plurality of second uprights 34 extend along the Z direction, which is substantially vertical. For this reason, and for the sake of semantic simplification, in what follows the first uprights will be called "horizontal uprights" and the second uprights will be called "vertical uprights".

[0088] Advantageously, the frame comprises at least three horizontal posts 32 and at least three vertical posts 34. In the present case, the frame comprises four horizontal posts and four vertical posts arranged to form a general cubic structure. In particular, to form such a cubic structure, the horizontal posts are parallel in pairs, with two horizontal posts extending along the X direction and two horizontal posts extending along the Y direction.

[0089] Each horizontal upright 32 comprises a first end portion 32a and a second end portion 32b, which are opposite each other. Each end portion 32a, 32b is adapted to connect two horizontal uprights 32 together. In particular, each portion The end portions 32a, 32b of the horizontal uprights 32 are connected to another respective horizontal upright. In the example of Figures 1 and 2, each of the end portions 32a, 32b of the horizontal uprights extending substantially parallel to the X direction is connected to one of the end portions of a respective horizontal upright extending substantially parallel to the Y direction.

[0090] Two horizontal uprights 32 are advantageously connected to each other by a removable link. For this purpose, each end portion of the horizontal uprights can, for example, be provided with at least one connector 36 or at least one bore (not visible).

[0091] Each bore extends in a plane substantially parallel to the XY plane and passes through the horizontal member 32 in which it is contained, in a direction substantially perpendicular to the direction of extension of that member. Thus, for example, for horizontal members 32 extending substantially in the X direction, a bore made in one of their end portions extends substantially in the Y direction.

[0092] Each connector 36 extends from its respective end portion along the direction of extension of the horizontal upright 32 to which this end portion is connected. According to a non-limiting embodiment of the invention, each connector 36 comprises two mounting tabs 36a, 36b arranged opposite each other. Each mounting tab 36a, 36b comprises a hole (not visible in the figures). The holes in the two mounting tabs 36a, 36b are aligned with each other.

[0093] To connect two horizontal uprights 32, the horizontal upright 32 with the bore is positioned between the mounting tabs 36a, 36b of the connector on the other horizontal upright 32 so that the holes in the mounting tabs and the bore are aligned. A removable connecting element 38, such as a rod, can then be positioned to pass through the two holes in the connector 36 and the bore. The two horizontal uprights 32 are thus connected and held in position relative to each other.

[0094] When all the horizontal uprights 32 are connected, they form an upper frame 40 of the portal frame 30. The frame 40 supports a rail 50 extending along a longitudinal direction 50 substantially parallel to the XY plane. In Figures 1 and 2, the longitudinal direction corresponds to the Y direction, although this is not a limiting factor. The rail 50 will be described in more detail later.

[0095] Each end portion 32a, 32b is further adapted to connect the horizontal uprights 32 to the vertical uprights 34 as explained below. To this end, each end portion of the horizontal uprights 32 may include at least one connector 36 as described above, but extending substantially parallel to the Z direction.

[0096] The vertical posts 34 support the upper frame 40 of the portal, as clearly shown in Figures 1 and 2. In the non-limiting example of the figures, each vertical post 34 is arranged opposite another vertical post 34 along the first direction X, and opposite another vertical post 34 along the second direction Y.

[0097] Each vertical upright 34 comprises a first end portion 34a and a second end portion 34b opposite each other.

[0098] The first end portion 34a is adapted to be connected to at least two horizontal uprights. More precisely, the first end portion 34a is adapted to be connected to one of the end portions 32a, 32b of at least two horizontal uprights.

[0099] Preferably, the connection between the first end portion 34a of each vertical upright 34 and the respective horizontal uprights 32 is removable. For this purpose, each first end portion 34a of the vertical uprights 34 comprises one or more connectors 36 similar to that described previously, and / or one or more bores (not visible). In the non-limiting example shown in the figures, the first end portion 34a of each vertical upright 34 comprises a bore (not visible), a connector 36 extending substantially along the first X direction, and a connector 36 extending substantially along the second Y direction.

[0100] In this configuration, to connect one of the vertical uprights 34 to one of the horizontal uprights 32, the vertical upright 34 is positioned between the mounting tabs of the connector 36 of the respective horizontal upright, which extends substantially parallel to the Z direction. Specifically, the vertical upright 34 is positioned between the mounting tabs of this connector 36 so as to align the holes in the mounting tabs with the bore passing through the vertical upright. A removable connecting element 38, for example similar to that used to connect two horizontal uprights 32, can then be positioned to pass through the two holes in the connector and the bore of the vertical upright. The vertical upright 34 and the horizontal upright 32 are thus directly connected to each other by the removable connecting element 38 and held in position relative to each other.

[0101] Advantageously, each vertical upright 34, directly connected to its respective horizontal upright 32 by the removable connecting element 38, is rotationally articulated on the frame 40 about an axis parallel to the plane parallel to the horizontal uprights 32, in this case the XY plane. The axis of rotation of each vertical upright 34 is, for example, aligned with the removable connecting element 38, which allows each vertical upright 34 to be directly connected to its respective horizontal upright 32. As will be detailed later, each vertical upright 34 can thus be moved between a first position in which the respective vertical upright forms an angle of less than 90° with the frame 40, and a The second position, visible in Figures 1 and 2, corresponds to the service position of each vertical upright 34. The "service position" of each vertical upright 34 is understood to be the position of each upright when the gantry 30 is operational, that is, when it can be used to lift a mechanical part. In Figures 1 and 2, in the service position, the vertical uprights 34 extend substantially perpendicularly to the XY plane, that is, along the Z direction.

[0102] The second end portion 34b is positioned on a lower area, relative to the Z direction, of the respective vertical upright 34. The second end portion 34b thus forms a foot for each vertical upright 34. As can be seen in Figures 1 and 2, each foot 34b can be equipped with a rolling element 42 and a lifting device 44 for the gantry.

[0103] The rolling element 42 is, for example, a wheel that allows the gantry to be moved along the XY plane. Preferably, the wheel 42 is capable of rotating around an axis substantially parallel to the respective vertical upright by an angle of 360°. The gantry can thus be easily moved in all directions within the XY plane, even by a single operator.

[0104] Advantageously, wheel 42 includes a stop brake which blocks the movement of the wheel, and therefore the movement of the gantry in the XY plane, when it is actuated.

[0105] The lifting element 44 is, for example, a jack. Preferably, the lifting element 44 is connected to the foot 34b in a removable manner.

[0106] The lifting mechanism 44 is configured to move between a retracted position, visible in Figure 1, and an extended position, visible in Figure 2. This allows the gantry 30 to be moved substantially perpendicularly to the plane parallel to the horizontal uprights. In this case, the lifting mechanism allows the gantry to be moved along the Z-axis. The gantry 30 can thus be moved from a first lower position, or minimum height position, visible in Figure 1, to a second upper position, or maximum height position, shown in Figure 2.

[0107] The lifting device 44 is configured to be able to lift the gantry 30 continuously from a first low position or minimum height position, visible in figure 1, to a second high position or maximum height position, shown in figure 2.

[0108] The lifting device can be operated manually. In one configuration, the lifting device 44 of each leg 34a is operated independently of the lifting devices 44 of the other legs 34a. In another configuration, the gantry 30 can include synchronous lifting devices of all the vertical uprights 34 of in order to allow the simultaneous lifting of all 34b feet together and by a single command.

[0109] The gantry 30 is therefore mobile in the three perpendicular directions of space X, Y, Z thanks to the rolling element 42 and the lifting device 44.

[0110] The frame 30 may also include a plurality of stiffeners 46. In this case, each stiffener 46 includes a connecting bar, but this is not a limitation. The connecting bar 46 is, for example, a rigid bar of constant length.

[0111] Each connecting bar 46 links one of the horizontal uprights 32 to one of the vertical uprights 34. In particular, each connecting bar 46 can be positioned between each free connector 36 located on the second end portion of the vertical upright 34 and one of the free connectors 36 located on the end portions of the horizontal uprights 32. A "free connector" is defined as a connector that has not yet been used to link two uprights 32, 34 together. In this case, each vertical upright 34 is connected to two horizontal uprights 32. The number of connecting bars 46 is thus doubled compared to the number of vertical uprights 34.

[0112] As can be seen in Figures 1 and 2, each connecting bar 46 extends substantially diagonally between one of the vertical uprights 34 and one of the horizontal uprights 32. The connecting bar 46 has two ends, each advantageously including a hole (not visible in the figures) that allows the connecting bar 46 to be connected to the connectors 36 of the vertical uprights 34 and horizontal uprights 32 that it joins. In particular, a removable connecting element 38, for example similar to that used to join two horizontal uprights, can be used to connect each connecting bar 46 between the respective vertical uprights 34 and horizontal uprights 32.

[0113] The multiple stiffeners 46 improve the stability of the gantry and increase its resistance to lifted loads. Each stiffener 46 also creates a fixed connection between one of the horizontal uprights 32 and one of the vertical uprights 34.

[0114] The gantry 30 further includes means for rigidly connecting each vertical post 34 to the frame 40 and for continuously rotating each vertical post 34 relative to the frame 40. Advantageously, each vertical post 42 has its own rigid connection and continuous movement means, independent of the rigid connection and continuous movement means of the other vertical posts.

[0115] In the figures, the means of rigid connection and continuous movement include a plurality of winches 48.

[0116] Each winch 48 is arranged between a vertical post 34 and a horizontal post 36. Preferably, all the winches 48 extend along the same plane, in particular the XZ plane or the YZ plane. In other words, each winch 48 is arranged between each of the vertical posts 34 and only each of the horizontal posts 36 extending substantially parallel in a single direction. For example, in Figures 1 and 2, four winches are installed, each winch connecting the first end portion 34a of the respective vertical upright 34 and one of the end portions of the horizontal uprights 32 extending substantially parallel to the first direction X. All the winches 48 therefore extend along the XZ plane in the example of Figures 1 and 2. Conversely, in these figures, no winch 48 is installed between the respective vertical upright 34 and the horizontal uprights 32 extending substantially along the second direction Y.Therefore, no winch 48 extends along the YZ plane in the example of figures 1 and 2.

[0117] The winch 48 allows the respective vertical upright 34 to rotate around an axis parallel to the plane parallel to the horizontal uprights 32, specifically around an axis parallel to the direction of extension of the horizontal upright 32 to which the winch 48 connects it. Thus, as previously indicated, each vertical upright 34 can be moved between the first position in which the respective vertical upright forms an angle of less than 90° with the frame 40, and the service position visible in Figures 1 and 2.

[0118] As stated above, each winch 48 is independent of the other winches 48. This allows each vertical upright 34 to be moved between the first position and the second position, or service position, independently of the other vertical uprights 34.

[0119] As shown in Figure 3, each winch 48 can be a rack and pinion winch. In some cases, the rack and pinion winch is a manual winch equipped with an actuating element, such as a crank, which allows the operator to easily control the movement of the second respective upright between the first and second positions without requiring significant physical effort. In other cases, the rack and pinion winch is motorized, allowing the operator to control this movement without any physical effort and even remotely.

[0120] It is noted that the means of rigid connection and continuous movement can allow the vertical uprights to be arranged in a multitude of positions between the first position and the service position.

[0121] As indicated above, the gantry 30 further includes a longitudinal rail 50. The rail is connected to the upper frame 40, preferably by a removable type connection, similar to that used to connect the horizontal uprights together.

[0122] Advantageously, the rail 50 extends substantially transversely to at least one of the horizontal uprights. Advantageously, the rail 50 is connected to two horizontal uprights 32. For example, in Figures 1 and 2, the rail 50 is connected to two horizontal uprights 32 arranged opposite each other in the Y direction. The rail 50 comprises a first end portion 50a and a second end portion 50b. Each of the first and second end portions 50a, 50b is provided with a locking element 52 for the rail 50 that can be moved between a locking position and an unlocking position of the rail 50. The first end portion 50a of the rail may further comprise a first hole 51a and a second hole 51b.

[0123] The rail 50 advantageously has an H-shape. Thanks to the H-shape, a lifting device for a mechanical part can be articulated in longitudinal movement on the rail 50. The lifting device includes, for example, a trolley 54 carrying a hoist connected to a hoist 56. The hoist 56 can thus be connected to the rail 50 via the trolley 54.

[0124] The trolley 54 is mounted to be moved in translation along the longitudinal direction of the rail 50, in this case the direction substantially perpendicular to the X direction. The hoist 56 is then fixed to the movements of the trolley 54 along the rail 50.

[0125] The hoist 56 includes a chain (not shown) that can be moved approximately along the Z-axis between a low and a high position. This allows, as will be detailed later, the mechanical part to be moved from the ground to a desired installation height.

[0126] In some cases, the lifting device further includes a hooking device 57, visible in Figures 11 and 12, which is connected to one end of the hoist chain 56.

[0127] The gantry may further include a contact arm 58 with another mechanical part, called a receiving part, into which the lifted mechanical part is to be installed. Advantageously, the contact arm 58 is removably connected to one of the vertical uprights 54.

[0128] As particularly visible in Figures 1 and 2, the contact arm extends in an L-shape from one of the vertical uprights 54 of the gantry 30. On a first portion 58a of the L-shape, the contact arm 58 extends substantially parallel to the Y direction and is substantially aligned along the X direction with the horizontal upright 32 located in contact with the first end portion 50a of the rail 50. On a second portion 58b of the L, the contact arm 58 projects from the gantry 30 substantially parallel to the Y direction. Advantageously, the second portion 58b of the L is located laterally by relation to rail 50, which prevents the contact arm 58 from interfering with the movement of the mechanical part lifted during its installation in the receiving room.

[0129] As can be seen in the enlarged detail of Figure 3, the second part 58b of the L is connected to a support block 58c of the receiving piece. The support block 58c extends substantially parallel to the third direction Z. Advantageously, the support block 58c includes a substantially concave bearing face 58d against which the receiving piece makes contact. The support block 58c may further include a strap 58e. The strap 58e is, for example, positioned adjacent to the bearing face 58d. The strap 58e allows the receiving piece to be fixed to the support block so as to limit the relative movements between the receiving piece and the gantry 30 during the mounting of the mechanical part lifted into the receiving piece.

[0130] Advantageously, the 30 gantry is primarily made of steel or aluminum to limit its weight. Preferably, each of the uprights and the rail weighs 50 kg or less, and even more preferably 40 kg or less. For example, each of the uprights and the rail could weigh 36 kg or less.

[0131] The arrangement of each component in the gantry 30, as described above and illustrated in Figures 1 and 2, corresponds to an operational position of the gantry. It should be noted, however, that each component of the gantry 30 is a unit component connected to the others by removable links, as described above. A "unit component" is understood to be a structurally independent component. The gantry can thus be in a disassembled position, in which each unit component is separated from the others and can assume any position in space. Furthermore, in the disassembled position of the gantry, all the unit components can be arranged to occupy a smaller volume compared to the volume occupied by the gantry in the operational position. The components can therefore be stored compactly, which facilitates their movement from one location to another, whether by land, sea, or air.

[0132] It should also be noted that, thanks to the rigid connection and continuous movement of each vertical post 34, the height of the gantry 30, and in particular the distance of the frame 40 from the ground S, can be increased without the need for external lifting equipment or human force. The lifting device 44 on each leg also contributes to this objective. Furthermore, the gantry 30 can be installed and adjusted anywhere without the need to transport heavy machinery and without endangering the health of the operators installing it.

[0133] It is also noted that the presence of at least three initial uprights increases the gantry's resistance to loads lifted in service, particularly the weight of the lifted mechanical part.

[0134] Finally, it should be noted that thanks to the presence of at least three vertical supports 34, the stability of the gantry 30 is improved, which helps to limit the risk of gantry failure and consequently increases the safety of any operator working under the gantry 30. Similarly, when the lifted part is to be installed in the receiving room, the stability of the gantry 30 allows for rapid installation of the mechanical part in the lifted room. In particular, the installation time can be approximately 30 seconds.

[0135] A method for assembling gantry 30 will now be described.

[0136] The process initially involves assembling the frame. This step is carried out by connecting each of the first and second end portions of one of the horizontal uprights to another respective horizontal upright, as explained above.

[0137] In a practical example of assembling the frame 40, shown in Figure 4, the horizontal uprights 32 are arranged on a support 200 at a distance from the ground S. The support 200 comprises, for example, a plurality of unit support elements 210. Each unit support element is, for example, a trestle. Advantageously, the number of unit support elements is equal to the number of horizontal uprights 32 in the frame 30. The first end portion of each horizontal upright 32 can thus rest on one of the unit support elements 210, and the second end portion of each horizontal upright can rest on another of the unit support elements 210.

[0138] Advantageously, the height of the unit support elements 210 is less than or equal to 1 m, preferably between 0.8 m and 1 m. Operators handling the parts of the gantry 30 therefore do not have to exert significant physical effort to position the first uprights 32 on the unit support elements 210. Advantageously, all the unit support elements 210 have the same height.

[0139] After assembling the frame, the rail 50 and the vertical uprights 34 are connected to the frame 40. When connecting the rail 50 and the vertical uprights 34 to the frame, the latter is advantageously held on the support 200.

[0140] The order of connection of the rail 50 and the vertical uprights 34 to the frame 40 is indifferent, the rail 50 can be assembled on the frame 40 before the connection of the vertical uprights 34, or vice versa.

[0141] As previously stated, the vertical uprights 34 are connected to the frame by their first end portion such that each vertical upright 34 is pivotally articulated on the frame about an axis parallel to the plane parallel to the horizontal uprights 32, in this case the XY plane. After connecting the respective vertical upright 34 to the frame 40, the foot 34b of the vertical upright 34 is oriented towards the ground S, with the rolling element 42 in contact with the ground S. Since the height of the unit support elements 210 on which the frame 40 rests is less than 1 meter, in this configuration the vertical uprights 34 are in the first position described above, that is, the position in which the angle that the vertical uprights 34 form with the frame is less than 90°.This avoids having to use support means for the frame 40 at a sufficient height to be able to connect the vertical uprights 34 directly in their service position, which in this case is substantially parallel to the direction Z.

[0142] The method further comprises connecting each vertical member 34 to one of the horizontal members 32 via the rigid and continuously moving connecting means, as explained above. In one example, all the rigid and continuously moving connecting means are connected to the respective vertical members 34 and horizontal members 32 after all the vertical members 34 have been connected to the frame 40. Alternatively, immediately after connecting one of the vertical members 34 to the frame, the rigid and continuously moving connecting means associated with that vertical member 34 are installed.

[0143] As previously stated, the means for rigid connection and continuous movement can be winches 48, in particular rack and pinion winches. In the figures, the winches 48 will be mounted between the vertical uprights 34 and only the horizontal uprights 32 substantially parallel in a single direction, as shown above. As also explained, in this configuration, the actuation of each winch 48 imparts a rotational movement to the respective vertical upright 34 around a direction parallel to the direction of extension of the horizontal upright 32 to which this vertical upright 34 is connected by the winch. This allows the vertical uprights 34 to be easily moved from the initial position to the service position, visible in Figures 1 and 2.

[0144] As shown in Figure 5, the process finally includes the movement of each second upright in rotation around the corresponding axis between the first position obtained and the service position by actuation of the rigid linkage means and continuous movement.

[0145] Advantageously, before activating the winches 48 to position the vertical uprights 34 in their service position, the movements in the XY plane of the wheels 42 belonging to two vertical uprights 34 located on one side of the gantry 30 relative to the rail 50 are locked. To do this, the brake of the wheels 42 belonging to two vertical uprights 34 located on said first side of the gantry 30 is activated.

[0146] Following the locking of the wheels 42 of the vertical uprights 34 located on the first side of the gantry 30 relative to the rail 50, the winches 48 associated with the two vertical uprights 34 located on a second side of the gantry 30 relative to the rail 50 are actuated, preferably synchronously. This second side is opposite the first side of the gantry 30. Activating the brake on the wheels 42 of the first side of the gantry 30 prevents the actuating of the winches 48 associated with the two vertical uprights 34 located on the second side of the gantry 30 from causing a translation of the entire gantry 30 in the XY plane. The winches 48 associated with the two vertical uprights 34 located on the second side of the gantry 30 are actuated until the vertical uprights 34 of this second side of the gantry 30 reach their operating position in the Z direction.

[0147] Once the vertical posts 34 located on the second side of the gantry 30 are placed in their service position substantially parallel to the Z direction, the stiffeners 46 connecting the horizontal posts 32 and the vertical posts 34 located on the second side of the gantry 30 can be installed. Since the stiffeners 46 are rigid, once installed, rotation of the respective vertical post 34 around its axis is no longer permitted.

[0148] After unlocking the movement of the wheels 42 associated with the vertical uprights 34 on the first side of the gantry 30, the steps of actuation of the stop brakes, actuation of the winches and installation of the connecting bars can then be carried out on the opposite sides of the gantry 30 with respect to the rail 50. This allows the vertical uprights 34 located on the first side of the gantry 30 to be placed in the service position along the Z direction.

[0149] Once all the vertical uprights 34 are in the service position, the lifting element 44 of each leg 34b can be installed on the respective vertical upright 34. Similarly, the contact arm 58 can be connected to the corresponding vertical upright 34.

[0150] To complete the gantry assembly, the trolley 54 and the hoist 56 are installed. To install the trolley 56 in the rail, at least one of the locking elements 52 of the rail 50 is moved to the unlocked position. This allows the trolley 56 to be inserted into the rail. Once the trolley 54 is inserted into the rail 50, the locking element 52 is returned to the locking position of the rail 50 to prevent the trolley from 54 does not leave the rail 50 during its translation along the longitudinal direction of the rail. The hoist 56 is suspended from the trolley.

[0151] It is noted that thanks to the means of rigid connection and movement of the second uprights, the assembly process of the gantry according to the invention does not require the use of heavy machinery, and the use of human force is limited to that used to arrange the first uprights on the unit support elements and to assemble the rail on the frame.

[0152] An example of the use of the gantry will now be described.

[0153] The gantry 30 can be part of an installation 10 for mounting an axle 12 in a bore 14 of a bogie 16, visible in figures 6 and 7. The bogie 16 is preferably mounted on a landing gear 18 of an aircraft, for example an airplane.

[0154] The bogie 16 has an elongated shape and extends between two open ends 20. The bogie 16 has in particular a substantially cylindrical shape with axis A. Advantageously, the bogie 16 is made of titanium.

[0155] The bogie 16 comprises a plurality of bores 14. In the example of figures 6 and 7, the bogie 16 comprises two bores 14, but this number is not limiting, the bogie 16 may comprise a single bore or more than two bores.

[0156] Each bore 14 extends between a first open end 14a and a second open end 14b, such that the bore 14 is a through bore. Each bore 14 has, for example, a substantially cylindrical cross-section with axis B, the axis B being substantially perpendicular to the axis A of the bogie 16. Advantageously, each open end 20 of the bogie 16 communicates with one of the bores 14.

[0157] In Figures 6 and 7, the landing gear 18 is in a deployed position, that is, a normal operating position of the landing gear 18 in which the landing gear wheels, not shown, are in contact with the ground. In this deployed position, the axis A of the bogie 16 extends substantially parallel to the first direction X and the axis B of each bore 14 extends substantially parallel to the second direction Y.

[0158] The axle 12 has an elongated tubular shape, with a substantially cylindrical cross-section, extending between a first end 12a and a second end 12b. Advantageously, a cavity 22 extends inside the axle 12 between the first end 16a and the second end 16b. The axle 12 therefore comprises an outer wall and an inner wall, the inner wall defining the cavity 22 of the axle. The cavity 22 is preferably substantially cylindrical with axis C. When the axle is mounted in the bore of the bogie, the B axis of the bogie bore and the C axis of the axle are coaxial, as illustrated in figures 6 and 7.

[0159] The axle 12 comprises a first end part 12c, a central part 12d and a second end part 12e. The central part 12d extends between the first and second end parts 12c, 12e. The first end part 12c and the second end part 12e extend between the central part 12d and, respectively, the first end 12a and the second end 12b of the axle 12.

[0160] A first bore 24, visible in Figure 11, passes substantially radially through the outer wall of the axle 12. The first bore 24 is located on the first end portion 12c of the axle 12. A second bore, similar to the first bore but not visible in the figures, is preferably located on the second end portion 12e of the axle 12. As will be detailed, the second bore allows the axle 12 to be oriented and held in position within an axle support 60, which will be described in detail with reference to Figure 9. Advantageously, the first bore and the second bore are aligned along an axis parallel to the axis C of the axle. On the central part 12d of the axle 12, a third bore 26, illustrated in figure 12, passes through the inner and outer walls of the axle 12. The third bore 26 is arranged at approximately 90° around the axis C relative to the first bore 24.The third bore is advantageously equidistant from the first and second ends 12a, 12b of the axle 12.

[0161] As will be detailed later, particularly with reference to Figure 12, the first and second end portions 12c, 12e advantageously have a cross-section substantially smaller than a cross-section of the central portion. By "cross-section" is meant an external section of the axle 12 obtained by projection onto the XZ plane when the axle 12 extends substantially parallel to the second Y direction. Preferably, the cross-section of the central portion 12d of the axle 12 has a dimension substantially equal to that of the bore 14, so that the axle 12 can be inserted into the bore 14 as will be explained later.

[0162] Preferably, axle 12 is made of metal, for example steel.

[0163] We now describe installation 10 with reference to the figures.

[0164] Installation 10 includes the gantry 30 described above. Figure 6 illustrates the gantry 30 in use and at the end of the mounting of an axle 12 in a bore 14 of a bogie 16. In this configuration, the contact arm 58 of the gantry is advantageously in contact with the bogie. More precisely, the bogie 16 comes into contact with the bearing face 58d and is held in this position by means of the strap 58. e . The relative movements between the bogie 16 and the gantry 30 during the mounting of the axle 12 in the bore 14 are thus limited.

[0165] Installation 10 further includes means for aligning the axis B of the bogie bore with the axle axis C. These alignment means may include a marker 110, visible in Figures 6 to 8, and a laser beam device 120, visible in Figure 13.

[0166] The marker 110 is located on one face of a target 112 carried by the gantry 30. In particular, the target is suspended from one of the holes 51a, 51b provided in the first end part 50a and the second end part 50b of the rail 50. In particular, the target 112 is connected to one of the holes 51a, 51b of the first and second end parts of the rail by means of a suspension element 114. Advantageously, a length of the suspension element 114 is chosen such that the marker 110 and the axis C of the axle 12 are aligned in the Z direction when the axle 12 is carried by the hoist 56 and the chain of the hoist 56 is in the raised position.

[0167] The marker 110, for example, has a cross shape with a first line substantially parallel to the Z direction and a second line substantially parallel to the X direction when the target 112 is suspended from the rail.

[0168] The laser beam device 120 is a device that emits a laser beam. The laser beam device 120 is designed to be installed in the bogie bore. More specifically, the laser beam device 120 is designed so that, when installed in the bore, the axis of the laser beam is coaxial with the axis B of the bogie bore 14.

[0169] Advantageously, the laser beam has the same shape as the reference 110. For example, the laser beam has a cross shape with a first ray substantially parallel to the Z direction and a second ray substantially parallel to the X direction when the laser beam device 120 is installed in the bore 14.

[0170] As seen in Figure 13, the laser beam device 120 includes a bore 122 located at a substantially central position of the laser beam device 120 in the Y direction. This bore 122 receives, when the laser beam device 120 is installed in a final position in the bore, a position-holding rod 130.

[0171] To identify the final position of the laser in the bore, the installation may further include a guiding tool 140, visible in Figure 13. The guiding device is configured to be located on the open end 20 of the bogie 16, which communicates with the bore 14 in which the axle 12 will be installed. The guiding device includes a hole 142 having a shape and dimensions substantially equal to those of the bore 122 of the laser beam device 120. When the laser beam device 120 is in its In its final position in bore 14, the hole 142 in the guide tool 140 and the bore 122 in the laser beam device are aligned. The positioning rod 130 can then be inserted into the bore 122 of the laser beam device 120 through the hole 142 in the guide tool 140.

[0172] As shown in Figure 14, the guide tool 140 also serves to identify the final position of the axle 12 in the bore 14, similarly to the identification of the final position of the laser beam device. In particular, the hole 142 in the guide tool 140 is substantially the same shape and size as the third bore 26 of the axle 12. When the axle 12 is in its final position in the bore 14, the hole 142 in the guide tool 140 and the third bore 26 of the axle are aligned.

[0173] The positioning rod 130 also serves to hold the axle 12 in its final position in the bore 14. In particular, when the hole 142 of the guide tool 140 and the third bore 26 of the axle are aligned, the positioning rod 130 can be inserted into the bore 26 of the axle 12 through the hole 142 of the guide tool 140.

[0174] The installation 10 may further include an axle support 60, shown in Figure 9. Advantageously, the axle support 60 is made of metal, for example stainless steel for its thermal and mechanical properties.

[0175] The axle support 60 comprises two half-collars 62, a collar support 64, and a rocker arm 66. Each of these parts of the axle support 60 will be described below with respect to its position in Figure 9 according to the orthonormal coordinate system formed by the X, Y, and Z directions. It should be noted, however, that the axle support 60 is advantageously demountable, as these parts are advantageously separable from one another. Thus, in a disassembled position of the axle support, not shown, these parts of the axle support are isolated from one another and can assume any position in space.

[0176] The two half-collars 62 are preferably identical. Therefore, the same references will be used to describe the same parts of both half-collars.

[0177] Each half-collar consists of a block comprising a front face 62a, a rear face 62b (visible in Figure 7), a first side face 62c, and a second side face 62d (visible in Figure 7). The front face 62a and the rear face 62b are opposite and substantially parallel to each other. In Figure 9, the front face 62a and the rear face 62b extend substantially parallel to the XZ plane. Preferably, the front face 62a and the rear face 62b are identical. The side faces 62c and 62d are opposite and substantially parallel to each other. In Figure 9, the side faces extend substantially parallel to the YZ plane. Preferably, the two side faces 62c and 62d are identical.

[0178] Each side face 62c, 62d connects the front face 62a and the rear face 62b of each half-collar 62. Advantageously, a shoulder (not visible in the figures) exists between the front face 62a and each side face 62c, 62d, as well as between the rear face 62b and each side face of the half-collar 62c, 62d. Each shoulder allows each half-collar 62 to be fitted into the collar support 64, as will be explained later.

[0179] Each half-collar 62 further comprises a flat face 62e and a concave face 62f. The flat face 62e and the concave face 62f connect the front faces 62a and rear faces 62b of each half-collar 62. Advantageously, the flat face 62e and concave face 62f are substantially perpendicular to the lateral faces 62c, 62d of the respective half-collar 62.

[0180] The flat face 62e is substantially rectangular and opposite the concave face 62f. The concave face 62f has a concavity. Two substantially flat edges 62g extend over the concave face 62f between each end of the concavity and the respective lateral face 62c, 62d of the half-collar.

[0181] The substantially flat edges allow the two half-collars 62 to be stacked so that their concaves face each other. In particular, to stack the two half-collars 62, the substantially flat edges 62g of the concave face 62f of one of the half-collars 62 are brought into contact with the substantially flat edges 62g of the concave face 62f of the other half-collar 62. The two half-collars 62 thus form a collar through which passes an opening 63 for receiving the axle 12. As can be seen from Figure 9, this opening 63 for receiving the axle 12 is delimited by the concaves of the two half-collars. Advantageously, a shape and dimension of the receiving orifice 63 of the axle 12 are substantially equal to the cross-section of the central part 12d of the axle 12. The axle 12 can thus be held locked between the two half-collars 62 as will be detailed.

[0182] The collar support 64 comprises a support surface 64a and four connecting segments 64b.

[0183] The support surface 64a is flat. In Figure 9, the support surface extends substantially parallel to the XY plane. The support surface comprises a top face 64aa and a bottom face 64ab. The top face 64aa includes a bearing area (not visible) and a peripheral area 65.

[0184] The bearing area has a shape and dimensions substantially equal to the flat face of one of the half-collars 62. The bearing area is thus designed to receive the flat face 62e of one of the half-collars 62 as a support. The peripheral area 65 surrounds the bearing area. The peripheral area 65 preferably has a substantially rectangular loop shape.

[0185] The support surface 64a is configured to support the collar formed by the two half-collars 62 as previously indicated.

[0186] Each connecting segment 64b has a substantially flat shape comprising an outer face 64ba, an inner face 64bb, and two lateral edges 64bc. Each connecting segment 64b extends substantially perpendicularly to the support surface 64a. In this case, each connecting segment 64b extends substantially parallel to the third direction Z.

[0187] As can be seen in Figure 9, the four connecting segments 64b are arranged on the peripheral area 65 of the support surface 64a. The connecting segments 64b are advantageously arranged opposite each other in pairs along the first direction X. The connecting segments are also advantageously arranged opposite each other in pairs along the second direction Y. Preferably, the connecting segments 64b are separated from each other along the direction X or along the direction Y by distances such that one of the lateral edges 64bc and the inner face 64bb of each connecting segment 64b are in contact with one of the shoulders arranged between the lateral faces 62c, 62d and the front face 62a or rear face 62b of each half-collar 62.Each half-collar 62 is thus fitted into the axle support 60 between the four connecting segments 64b, which prevents the collar from moving along the first direction X and along the second direction Y when the collar is installed on the support surface 64a.

[0188] A portion of the end of each connecting segment opposite the support surface is pierced by a hole (not visible in the figures). Advantageously, the holes in the connecting segments 64b arranged opposite each other along the X direction are aligned. These holes allow the collar support 64 and the rocker arm 66 to be connected as will be detailed below.

[0189] The rudder 66 comprises a front part 66a and a rear part 66b.

[0190] The front part 66a comprises a first arm 68 and two plates 70. The first arm 68 extends substantially along the X direction. In the non-limiting example shown in Figure 9, the plates 70 are separated from each other along the Y direction by a distance substantially less than the distance separating two connecting segments 64b along the Y direction. Thus, the two plates 70 can be positioned between the four connecting segments 64b. Each plate has two holes (not visible in the figures) which are arranged opposite each other along the Y direction to the holes passing through the connecting segments 64b when the plates are positioned between these segments 64b. Thus, a rod 72 can pass through the holes in the two plates 70 and two segments 64b arranged opposite each other along the Y direction. Each rod 72 therefore allows the collar support 64 and the rocker arm 66 to be connected.

[0191] The rear part 66b of the rudder pedal comprises an arm 74, a push bar 76 and an end portion 78. The arm 74 and the push bar 76 extend substantially in the X direction, while the end portion 78 extends substantially in the Z direction. The end portion 78 is connected to a guide cylinder 80 arranged substantially opposite the push bar 76 in the Z direction and extending substantially in the Y direction.

[0192] The front 66a and rear 66b parts of the lifting beam 66 are connected to each other by a cross member 82 which extends substantially in the Y direction. The cross member 82 includes, on one end near the front part 66a of the lifting beam, a piece 83 extending substantially in the Z direction and including an opening 84. The opening 84 allows the attachment of the attachment device 57 of the hoist. The axle support 60 can thus be moved along the Z direction by means of the movement of the hoist chain 56, and in translation along the extension direction of the rail 50 when the hoist 56 follows the movement of the carriage 54. On another end, near the rear part 66b of the lifting beam 66, the cross member 82 is pierced by a through hole (not visible in the figures) which passes substantially along the Z direction of the cross member 82. As can be seen in Figure 9, this through hole is adapted to receive a rod 86.

[0193] As particularly visible in figures 11 and 12, when the axle 12 is received in the orifice 63 of the collar formed by the two half-collars 62, the axle is arranged so that the guide cylinder 80 is inserted into the cavity 22 of the axle 12 and the rod 86 is inserted into the second bore arranged on the second end part 12e of the axle 12. This arrangement allows, on the one hand, the axle to be held in position in the axle support 60, and on the other hand, ensures that the axle 12 is oriented in a position which ensures that when the axle 12 arrives in its final position in the bore 14, the bore 26 and the hole of the guide tool are aligned and facing each other.

[0194] The installation 10 further includes a tank 90 shown in figures 6, 10, 11 and 12. The tank 90 includes a vessel 92 and a plurality of substantially vertical uprights 94.

[0195] Tank 92, for example, has the shape of a rectangular parallelepiped, but other shapes are possible. In the figures, tank 92 is delimited by two longitudinal walls 92a, two transverse walls 92b, a lower wall 92c, and an upper wall 92d. The longitudinal walls 92a extend along two planes that are substantially parallel to each other and along the YZ plane. The transverse walls 92b extend along two planes that are substantially parallel to each other and along the XZ plane. The lower wall 92c and the upper wall 92d extend along two planes that are substantially parallel to each other and along the XY plane.

[0196] As can be seen from Figures 11 and 12, an interior 95 of the tank 92 is hollow. The interior of the tank 94 advantageously has a length and width greater than, respectively, the length and width of the axle 12, which allows, as will be detailed, the axle to be inserted into the container 90.

[0197] Each longitudinal wall has a thickness that defines a longitudinal edge 96 of the tank. Similarly, each transverse wall has a thickness that defines a transverse edge 98 of the tank.

[0198] As clearly shown in Figure 11, the lifting arms 68 and 74, as well as the push bar 76, are longer than the width of the tank 92. Therefore, the arms 68 and 74 and the push bar 76 rest on the longitudinal edges 96 of the tank 92 when the axle 12 and the axle support 60 are positioned inside the tank. This prevents the axle support 60 from touching the bottom of the tank 92 when it is positioned inside the tank.

[0199] As clearly shown in Figure 10, the upper wall 92d of the tank comprises a plurality of removable covers 99, so as to define an open and a closed position of the tank 92. In the closed position, the covers 99 are arranged on the tank, so as to prevent access to the interior 95 of the tank 92. In the open position, all the covers 99 are removed from the tank 92, which allows access to its interior 95.

[0200] Advantageously, one or more of the covers 99 have a shape adapted to allow passage of the axle support 60, in particular the arms 68, 74 and the push bar 76, when the axle 12 is inserted into the tank. These covers, whose shape allows passage of the axle support 60, make it possible to define a third position of the tank 92, called the axle cooling position. In the axle cooling position 12, all the covers 99 are arranged on the tank 92, except for the covers whose shape allows passage of the axle support 60. This makes it possible to seal the tank 92 as much as possible when the axle 12 is inside, while allowing the arms 68, 74 and the push bar 76 to rest on the longitudinal edges 96 of the tank 92, so as to limit heat transfer to the outside.

[0201] Tank 92 is intended to be filled with liquid nitrogen in the axle cooling position.

[0202] The tank 92 is supported by a plurality of substantially vertical uprights 94. These uprights extend substantially parallel to the Z direction from the lower face 92d of the tank. In the figures, the container 90 comprises four uprights 94 substantially vertical supports placed under each intersection between the longitudinal and transverse walls. Of course, the 90-unit container could include more than four supports.

[0203] Advantageously, each vertical upright includes a foot equipped with a rolling element 97, such as a wheel. The wheel 97 allows the container 90 to be moved in the XY plane. The container can thus be easily positioned under the gantry 30, as shown in Figure 6.

[0204] The gantry 30 can then be used to implement a method for mounting the axle 12 in the bogie 16 using the installation shown in Figure 6. In what follows, we will describe in particular the method for mounting the axle in one of the axle bores B of the bogie. In what follows, a direction along the axle bore B will be referred to as the "axle installation direction".

[0205] The process initially involves the supply of the mobile gantry 30.

[0206] In some cases, the gantry 30 will already be mounted and it will only be necessary to move it along the XY plane until the support face 58d, which is connected to the contact arm 59 of the gantry 30, comes into contact with the bogie 16 installed in the landing gear 18. The strap 58e of the support block 58c will then be arranged around the bogie 16 to block the relative movements of the gantry 30 with respect to the bogie 16.

[0207] In other cases, the gantry 30 is not pre-assembled. The gantry 30 is then assembled according to the assembly procedure described above.

[0208] After the gantry is assembled, it is in the operational position and can be moved along the XY plane until the support face 58d, which is connected to the contact arm 58 of the gantry 30, comes into contact with the bogie 16 installed in the landing gear 18.

[0209] The process further includes a step of installing the axle on the axle movement means. As previously stated, the axle movement means include the rail 50, the trolley 52, and the hoist 54.

[0210] Initially, the step of installing the axle 12 on the means of moving the axle 12 allows the axle 12 to be positioned on the axle support 60. In particular, the hooking device 57 of the hoist is connected to the axle, which is moved suspended from the hoist 56 until it is installed on one of the half-collars 62 already arranged on the support surface 64a of the axle support 64.

[0211] The other half-collar 64 and the rocker arm 66 can then be installed so as to lock the axle 12 in the opening 63, in accordance with the configuration described above with reference to Figures 9 and 11. In particular, when the axle 12 is received in the opening 63 of the collar formed by the two half-collars 62, the axle 12 is arranged so that the cylinder guide 80 is inserted into the cavity 22 of the axle 12 and the rod 86 is inserted into the second bore arranged on the second end part 12e of the axle 12. As previously stated and clearly visible in figure 12, the axle 12 will be blocked in the orifice 63 by its central part 12d.

[0212] Once the axle support 60 is correctly installed around the axle 12, the hooking device 57 of the hoist 56 is hooked onto the opening 84 located near the front part 66a of the lifting beam 66 of the axle support 60. Then, the chain of the hoist 56 is gradually moved from its lower position to its upper position. The configuration of the axle support ensures that the assembly formed by the axle and the axle support is held at its center of gravity, which allows the axle 12 to be maintained in a position substantially parallel to the horizontal plane XY during its movement by the axle movement means.

[0213] Moving the hoist chain to the high position allows the axle axis C to be aligned with the bore axis B, so that the axle extends in the direction of axle installation.

[0214] Alignment of axes B and C of bore 14 and axle 12 can be achieved using the laser beam device and the marker. Specifically, as explained above, the laser beam device 120 is installed in bore 14 of the bogie so that axis B of bore 14 is aligned with the laser beam emitted by the laser beam device 120. As previously stated, when installing the laser beam device 120 in bore 14, the guide tool 140 can be used to determine the final position of the laser beam device 120 within the bore 14, and the rod 130 can be used to lock the laser beam device 120 in this final position.

[0215] Furthermore, as previously mentioned, the hoist chain 56 is configured so that, in its raised position, the axle axis C is necessarily aligned with the reference mark 110. Therefore, to ensure that the axle axis C and the bore axis B are aligned, the process may include a step of aligning the laser beam with the reference mark 110. For this purpose, the reference mark 110 is initially mounted on the hole 51a of the first end section 50a of the rail. The gantry 30 is then moved along the Y direction by means of the running elements 42, and along the Z direction by means of the lifting elements 44, until the laser beam and the reference mark 110 coincide. The continuous vertical movement of the gantry 30 allows for a precise coaxial adjustment of the axis C with the XY plane containing the axis B.

[0216] If the marker 110 and the emitted laser beam have a cross shape, the laser beam and the marker 110 are coincident when the vertical line of the marker 110 and the vertical ray The laser beams are aligned, and the horizontal line of marker 110 and the horizontal ray of the laser beam are aligned. After this initial alignment between the vertical line and ray, and between the horizontal line and ray, marker 110 is removed from hole 51a of the first end section 50a of rail 50 and moved through hole 51b of the second end section 50b of rail. If, in this position, the laser beam and the marker are not coincident, the gantry is moved again along the Y and Z directions until they are coincident, as explained above.

[0217] With the laser beam aligned with axis B of bore 14, the alignment between the laser beam and reference mark 110 implies that axis B and reference mark 110 are also aligned. Reference mark 110 is then positioned in a vertical plane encompassing the installation direction of axle 12. As reference mark 110 and the hoist are supported by rail 50, the vertical plane encompassing the axle installation direction and reference mark 110 also corresponds to a lifting plane for axis C of axle 12.

[0218] Note that the marker 110 is fixed relative to the rail. In other words, when the gantry 30 moves along the Y and Z directions, the relative position of the marker 110 with respect to the rail does not change. Indeed, the marker 110 and the rail 50 move as a unit with the gantry 30. The rolling elements 42 and the lifting elements 44 therefore constitute not only means of moving the gantry 30, but also means of moving the marker 110.

[0219] Once the axle axis C and the bore axis B of the bore 14 are aligned, the method involves inserting the axle 12 into the bogie bore 14, as shown in Figure 14. Specifically, to insert the axle into the bore, the hoist is connected to the axle support 60, particularly to the opening 84 as previously described. The carriage 54 then moves in the direction of axle installation, which causes the hoist 56 and the axle 12 to move in the same direction. The carriage 54 and the hoist 56 are moved in the direction of axle 12 installation until the final position of the axle 12 in the bogie 16 is determined using the guide tool 140 as previously described. Once in the final position, the axle 12 is fixed in the bore by means of the retaining rod 130.

[0220] To improve axle mounting in the bore, a thermal differential mounting method can also be used. For this purpose, as shown in Figure 11, the axle-axle support assembly is inserted into the tank 92 of the container 90. In particular, the axle 12 is inserted into the tank 92 in a horizontal position, i.e., along the XY plane. The tank 92 is then placed in its axle cooling position. As shown below, in the axle cooling position, all the covers 99 are arranged on the tank 92, with the exception of the lids whose shape allows the axle support 60 to pass through. The tank 92 is then filled with liquid nitrogen. The liquid nitrogen cools the axle to approximately -200°C, causing the axle 12 to contract. To reach this temperature, the axle is kept in the tank 90 filled with liquid nitrogen for, for example, 1 hour. When the axle is removed from the tank 90, the contraction caused by the low temperatures facilitates its insertion into the bore 14. Once in the bore 14, the axle's temperature increases, causing it to expand and its external diameter to increase until it self-tightens at ambient temperature within the bore.

[0221] To improve the thermal differential assembly, the bogie bore 14 can be heated to a specific temperature, for example, +100 °C. This causes the bore to expand, facilitating the insertion of the axle 12 into the bore 14. Once in the bore, the temperature of the bore 14 decreases to ambient temperature, causing the bore to contract and thus tightening the axle within the bore 14.

[0222] To heat the bore 14, heating means, such as for example a resistor (not shown), can be placed in the bore 14. Optionally, a temperature sensor (not shown) can also be introduced into the bore 14 to control its heating.

[0223] Advantageously, before introducing the axle 12 into the bore 14, a sleeve 150, visible in figures 6 and 14, is arranged around the end of the axle 12 which is arranged opposite the bore 14 according to the direction of installation of the axle, in this case the first end 12a of the axle. In other words, the sleeve 150 is positioned around the end portion of the axle 12 that passes completely through the bore 14, in order to place the axle 12 in its final position within the bore 14. The sleeve 150 prevents direct collisions between the axle 12 and the bore 14, and also limits the misalignment of the axle axis C and the bore axis B, which can be caused by the difference in cross-section between the first end portion 12c and the central portion 12d of the axle. The sleeve 150 is advantageously removed after the axle 12 has been installed in the bore 14.

[0224] As shown in Figure 12, when axle 12 is introduced into the tank 90 filled with liquid nitrogen, sleeve 150 can be installed around the first end of axle 12 after the axle 12 has been extracted from the tank 90.

Claims

Demands

1. Lifting gantry (30) comprising: - a frame (40) comprising at least three first uprights (32) extending parallel to a first plane (XY) and each comprising a first end portion (32a) and a second end portion (32b) opposite, each of the first and second end portions (32a, 32b) of one of the first uprights (32) being connected to another respective first upright (32); - a longitudinal rail (50) supported by the frame (40) and extending parallel to said foreground (XY) and on which is articulated in longitudinal movement a lifting device for a mechanical part; and - at least three second uprights (34) extending between a first end portion (34a) and a second end portion (34b) opposite, the first end portion (34a) of each second upright (34) being rotationally articulated on the frame (40) about an axis parallel to the first plane (XY), each second upright (34) being further connected to the frame (40) by means (48) of rigid connection of the second upright to the frame and of continuous rotational displacement of the second upright relative to the frame between a first position in which the second upright (34) forms an angle of less than 90° with the first plane (XY) and a second position in which the second upright (34) is substantially perpendicular to said first plane (XY).

2. A gantry (30) according to the preceding claim, wherein the rigid connection and continuous displacement means (48) are specific to each second upright (34) and independent of the rigid connection and continuous displacement means (48) of the other second uprights (34).

3. Gantry (30) according to any one of claims 1 or 2, wherein the rigid connection and continuous displacement means (48) comprise a rack and pinion winch connected to every second upright (34).

4. A gantry (30) according to any one of the preceding claims, further comprising a plurality of stiffeners (46), each stiffener connecting one of the first uprights (32) to one of the second uprights (34).

5. A gantry (30) according to any one of the preceding claims, wherein the second end portion (34b) of each second post includes a lifting member (44) configured to move the respective second post (34) substantially perpendicular to the first plane (XY) when the second posts (34) are in the second position.

6. Gantry (30) according to any one of the preceding claims, wherein the second end portion (34b) of each second upright (34) comprises a rolling element (32).

7. A gantry (30) according to any one of the preceding claims, wherein the first uprights (32), the second uprights (34), the rail (50) and the means (48) for rigid connection and continuous movement each form a unit piece, these pieces being connected by removable links.

8. A portal frame (30) according to any one of the preceding claims, comprising four first uprights (32) and four second uprights (34) arranged to form a general cubic structure.

9. A method for assembling a lifting gantry (30) according to any one of the preceding claims, comprising: a) assembling the frame (40) by connecting each of the first and second end portions (32a, 32b) of one of the first uprights (32) to another respective first upright (32); b) assembling the rail (50) onto the frame (40); c) connecting to the frame (40) the first end portion (34a) of each second upright (34), the first end portion (34a) of each second upright (34) being rotationally articulated on the frame (40) about an axis parallel to the first plane (XY); d) connecting each second upright (34) to a first upright (32) by means of said rigid connection and continuous movement means (48);e) displacement of each second upright (34) in rotation around the axis parallel to the first plane (XY) between the first position obtained in step d) and the second position by actuation of the rigid connection and continuous displacement means (48).

10. A method according to the preceding claim for mounting a gantry according to claim 4, further comprising the connection between each first upright (32) and each second upright (34) of the respective stiffener (46) after the displacement of each second upright (34) between the first position and the second position.

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