EP3816370B1 - Device and method for securing a foot of structure to be dismantled by cutting - Google Patents

Description

The present invention relates to a device for securing a foot of a structure for its dismantling by cutting, as well as a pylon structure comprising at least one such securing device. It also relates to a method for securing and dismantling a foot of a structure.

It applies more specifically to the dismantling of heavy structures, such as large generally metallic pylons. These can be electricity pylons, carriers of high voltage power lines, telecommunications pylons, antenna carriers, etc. This type of pylon, with one or more ground anchoring feet, can be complex to uninstall. One solution is to disassemble the structure by successive cuts of its foot(s) and by extraction of each upper section resulting from a cut using a lifting device such as a crane or a helicopter.

This operation is particularly delicate and risky. In particular, each cutout at the foot of the structure weakens the resulting upper section to be extracted, which is subjected to the winds until it is recovered by the lifting device. This is the reason why such an operation generally requires the prior installation of a device for securing each foot of the structure for its dismantling by cutting.

The document KR 101 5369 596 B1 represents the state of the art closest to the subject matter of claim 1.

• une portion inférieure munie de moyens de fixation au pied de structure en dessous d'une zone de découpe du pied de structure ; et
• une portion supérieure munie de moyens de fixation au pied de structure au-dessus de la zone de découpe.

The invention thus applies more particularly to a device for securing a foot of a structure for its dismantling by cutting, comprising:

• a lower portion provided with means for fixing to the foot of the structure below a cut-out area of the foot of the structure; And
• an upper portion provided with means of attachment to the foot of the structure above the cutout zone.

A solution known today, for dismantling by cutting in a secure manner a foot of a metal structure shaped as an angle iron, consists in using a set of four steel plates to be bolted to the wings of the angle iron above and below the cutting area.

• perçage de huit trous dont deux sur une première aile de la cornière au-dessus de la zone de découpe, deux sur une deuxième aile de la cornière au-dessus de la zone de découpe, deux sur la première aile de la cornière en dessous de la zone de découpe et deux sur la deuxième aile de la cornière en dessous de la zone de découpe,
• découpe de l'une des deux ailes de la cornière dans la zone de découpe à l'aide d'une disqueuse thermique,
• mise en place et fixation en vis-à-vis par boulonnage de deux plaques d'acier contre les deux faces de l'aile découpée, à l'aide de deux boulons en portions inférieures des deux plaques et deux boulons en portions supérieures,
• découpe de l'autre des deux ailes de la cornière dans la zone de découpe,
• mise en place et fixation en vis-à-vis par boulonnage de deux autres plaques d'acier contre les deux faces de l'autre aile découpée, à l'aide de deux autres boulons en portions inférieures des deux autres plaques et deux autres boulons en portions supérieures.

More specifically, for the disassembly by helicopter of an electric pylon structure, it is usual to proceed as follows for each of its ground anchor angle feet:

• drilling of eight holes, two of which on a first wing of the angle above the cut-out area, two on a second wing of the angle above the cut-out area, two on the first wing of the angle below the cutout area and two on the second flange of the angle below the cutout area,
• cutting of one of the two wings of the angle iron in the cutting area using a thermal grinder,
• installation and fixing facing each other by bolting two steel plates against the two faces of the cut wing, using two bolts in the lower portions of the two plates and two bolts in the upper portions,
• cutting of the other of the two wings of the angle iron in the cutting area,
• installation and fixing facing each other by bolting two other steel plates against the two faces of the other cut-out wing, using two other bolts in the lower portions of the two other plates and two other bolts in higher portions.

Approximately 5 to 10 minutes before the arrival of the helicopter, the upper bolts are removed by operators. A pin connected to a cord can be placed on each foot at the location of one of the bolts removed if the weather conditions (i.e. the force of the wind) jeopardize the maintenance of the upper section of the structure to be hoisted.

When the helicopter begins to take the weight of the upper section before lifting, instructions are given to the operators to pull on the cords to extract the pins and allow the helicopter to be hoisted.

But this approach has several drawbacks. First of all, it requires the presence of several operators in the vicinity of the structure during the winching of its cut-out upper section, which is not without risk. In addition, it may happen that pins get stuck due to the heavy loads they are subjected to. At least one operator must then climb onto the structure to extract each jammed pin by force. On the contrary, the pins can prove to be ineffective and/or slip before the arrival of the helicopter, which jeopardizes the maintenance of the cut upper section.

It may thus be desirable to provide a device for securing a foot of the structure which makes it possible to overcome at least some of the aforementioned problems and constraints.

• une portion inférieure munie de moyens de fixation au pied de structure en dessous d'une zone de découpe du pied de structure ; et
• une portion supérieure munie de moyens de fixation au pied de structure au-dessus de la zone de découpe ;

dans lequel ces deux portions sont distinctes et :

• l'une des portions inférieure et supérieure est solidaire d'un bras de liaison de gond ; et
• l'autre des portions inférieure et supérieure est solidaire d'une bague de réception par insertion du bras de liaison de gond.

A device for securing a foot of a structure for its dismantling by cutting is therefore proposed, comprising:

• a lower portion provided with means for fixing to the foot of the structure below a cut-out area of the foot of the structure; And
• an upper portion provided with means for fixing to the foot of the structure above the cutout zone;

in which these two portions are distinct and:

• one of the lower and upper portions is secured to a hinge connecting arm; And
• the other of the lower and upper portions is secured to a receiving ring by insertion of the hinge connecting arm.

It should first be noted that a hinge connection is, in a manner known per se and accepted, a sliding pivot connection, abutting against a base of a hinge connection arm, between this hinge connection arm and a receiving ring into which it fits. Thus, it is the insertion of the hinge connecting arm in the receiving ring which ensures the maintenance of the upper section of the foot of the structure after cutting and before lifting. And the dismantling operation by lifting, in particular using a crane or a helicopter, can be done without pins and without the intervention of operators on the ground by simply sliding the hinge link arm in the reception to get out.

Optionally, the integral portion of the hinge link arm includes a hinge base and the hinge link arm that extends up or down from the hinge base.

Also optionally, a securing device according to the invention may further comprise wedges to compensate for an inclination of the foot of the structure with respect to a desired verticality of the main axes of the hinge connecting arm and of a cylindrical hole of the receiving ring.

Also optionally, an operating clearance of several millimeters, in particular 6 to 10 mm, is provided between the diameter of the hinge connecting arm and that of the inside of the receiving ring in which it is designed to fit. insert.

Also optionally, each of the fastening means comprises at least one bolt.

Also optionally, a securing device according to the invention may further comprise a retaining ring and means for fixing this retaining ring to a portion of the hinge connecting arm extending beyond the retaining ring. reception in which it is inserted for maintaining this insertion.

A pylon structure is also proposed comprising several feet fixed to the ground and, for each foot, at least one securing device according to the invention.

Optionally, a pylon structure according to the invention may more precisely comprise four feet shaped as angle irons and two securing devices according to the invention arranged respectively on the two flanges of each angle iron.

• sélection d'une zone de découpe sur le pied de structure ;
• mise en place et fixation d'un dispositif de sécurisation au-dessus et en dessous de la zone de découpe sélectionnée ;
• découpe du pied de structure dans la zone de découpe sélectionnée ;
• démontage par élévation de la partie de pied de structure située au-dessus de la zone de découpe ;

dans lequel :

• la fixation est réalisée à l'aide d'un dispositif de sécurisation selon l'invention de telle sorte que la bague de réception soit traversée par le bras de liaison de gond ; et
• le démontage se fait de manière à désengager le bras de liaison de gond de la bague de réception.

A method for securing and dismantling a foot of a structure is also proposed, comprising the following steps:

• selection of a cutting area on the structure foot;
• installation and fixing of a securing device above and below the selected cutting area;
• cutting of the foot of the structure in the selected cutting area;
• disassembly by elevation of the structural foot part located above the cutout zone;

in which :

• the attachment is made using a securing device according to the invention such that the receiving ring is crossed by the hinge connecting arm; And
• dismantling is done in such a way as to disengage the hinge link arm from the receiving ring.

• la fixation du dispositif de sécurisation comporte la fixation par boulonnage de la bague de maintien à la portion du bras de liaison de gond s'étendant au-delà de la bague de réception dans laquelle il est inséré ; et
• le démontage comporte une étape préalable de retrait de la bague de maintien par déboulonnage, par exemple dans un délai prédéterminé avant l'élévation de la partie de pied de structure située au-dessus de la zone de découpe.

Optionally:

• the fixing of the securing device comprises the fixing by bolting of the retaining ring to the portion of the hinge connecting arm extending beyond the receiving ring in which it is inserted; And
• the dismantling includes a preliminary step of removing the retaining ring by unbolting, for example within a predetermined period before the elevation of the structural foot part located above the cutout zone.

• [Fig.1] la figure 1 représente en perspective la configuration générale partielle d'un pied de structure équipé de deux dispositifs de sécurisation selon un mode de réalisation de l'invention,
• [Fig.2] la figure 2 représente schématiquement une coupe horizontale de structure de pylône à quatre pieds d'ancrage au sol tels que celui de la figure 1,
• [Fig.3] la figure 3 est une vue de côté partielle de la structure de pylône de la figure 2, et
• [Fig.4] la figure 4 illustre les étapes successives d'un procédé de sécurisation et de démontage d'un pied de structure, selon un mode de réalisation de l'invention.

The invention will be better understood with the aid of the following description, given solely by way of example and made with reference to the appended drawings in which:

• [ Fig.1 ] there figure 1 shows in perspective the general partial configuration of a structure foot equipped with two securing devices according to one embodiment of the invention,
• [ Fig.2 ] there figure 2 schematically represents a horizontal section of a pylon structure with four ground anchoring feet such as that of the figure 1 ,
• [ Fig.3 ] there picture 3 is a partial side view of the pylon structure of the figure 2 , And
• [ Fig.4 ] there figure 4 illustrates the successive steps of a method for securing and dismantling a foot of a structure, according to one embodiment of the invention.

The structural foot 10 partially illustrated in the figure 1 is shaped as an angle iron with two longitudinal flanges 12A and 12B. It is for example metallic and constitutes one of the elements of an electric pylon structure for its anchoring to the ground.

A first securing device 14A for its removal by cutting is fixed on either side of a cutting zone Z on the wing 12A. More precisely, a lower portion of this securing device 14A, consisting of a hinge base 16A and a hinge connecting arm 18A which extends upwards from the hinge base 16A, is fixed on an outer face of the wing 12A by bolting (not visible on the figure 1 ) of the hinge base 16A below the cutout zone Z. A wedge 20A, for example a wedge wedge, may be provided between the wing 12A and the hinge base 16A to adjust the orientation of the latter by so as to ensure the verticality of the 18A hinge link arm. An upper portion of the securing device 14A, comprising a receiving ring 22A by insertion of the hinge connecting arm 18A, is fixed to the same outer face of the wing 12A by bolting above the cutout zone. Similarly, a wedge 24A, for example a wedge wedge, may be provided between the wing 12A and the receiving ring 22A to adjust the orientation of the latter in accordance with that of the hinge link arm 18A. These two portions are formed in separate parts and are connected together only by inserting the hinge connecting arm 18A into a corresponding cylindrical through hole of the receiving ring 22A.

In a preferred concrete embodiment, the hinge base 16A is a steel part having a lateral foot for fixing to the wing 12A, pressed against the wedge 20A, and an upper hollow part spaced apart from the wing 12A and in profile flattened hollow cylinder to receive a corresponding flattened lower end of the hinge link arm 18A. The lateral foot of the hinge base 16A takes for example the form of a plate integral with lateral reinforcements extending from the hollow profile of the upper receiving part of the hinge connecting arm 18A. This plate is pierced with at least one hole, for example at least two, to achieve the fixing by bolting against the wing 12A.

The hinge connecting arm 18A is itself a cylindrical steel tube, the lower end of which is fixed in the upper hollow part of the hinge base 16A by insertion and bolting. It is advantageously sized so that, when it is inserted into the receiving ring 22A, it resists shearing and bending against any pressure exerted by the upper section resulting from a cutout of the foot of the structure 10. It is also sufficiently long above beyond the receiving ring 22A to oppose any tilting of this upper section.

The receiving ring 22A is a steel part having a lateral foot for attachment to the wing 12A, pressed against the wedge 24A, and a lower part spaced with respect to the wing 12A comprising the cylindrical hole through which the connecting arm passes of hinge 18A. The lateral foot of the ring 22A takes for example the form of an extension in the form of a plate upwards in which is drilled at least one hole, for example at least two, to carry out the fixing by bolting against the wing 12A.

The separated parts of the hinge base 16A and of the receiving ring 22A make it possible to release the cutout zone Z which is situated between the two fixing plates by bolting of the hinge base 16A and of the receiving ring 22A.

Optionally but advantageously, an operating clearance of several millimeters, in particular from 6 to 10 mm, for example 8 mm, is provided between the outer diameter of the hinge connecting arm 18A and that of the cylindrical hole intended to receive it in the receiving ring 22A. This play facilitates the separation, by vertical lifting, of the lower and upper portions of the securing device 14A.

Optionally but also advantageously, the securing device 14A comprises a retaining ring 26A and means for fixing this retaining ring 14A by bolting around an upper portion of the hinge connecting arm 18A which extends above beyond the receiving ring 22A. This retaining ring 26A fulfills a function of securing the insertion of the hinge connecting arm 18A into the receiving ring 22A.

A second securing device 14B is fixed on either side of the cutout zone Z on the wing 12B. It is identical to the first and comprises elements 16B, 18B, 20B, 22B, 24B and 26B respectively identical to elements 16A, 18A, 20A, 22A, 24A and 26A.

There picture 2 schematically represents a horizontal section of a pylon structure with several anchoring feet fixed to the ground and at least one securing device such as that of the figure 1 per foot.

More precisely, it illustrates the case of a metal electrical pylon with four feet anchored to the ground, referenced respectively 10 ₁ , 10 ₂ , 10 ₃ and 10 ₄ . Each of these feet is identical to foot 10 of the figure 1 , that is to say in the form of an angle iron with two wings: 12A, and 12B ₁ for the foot 10 ₁ , 12A ₂ and 12B ₂ for the foot 10 ₂ , 12A ₃ and 12B ₃ for the foot 10 ₃ , 12A ₄ and 12B ₄ for foot 10 ₄ . Two securing devices identical to those 14A, 14B of the figure 1 are respectively arranged and fixed on the two wings of each foot, i.e. eight securing devices 14A ₁ , 14B ₁ , 14A ₂ , 14B ₂ , 14A ₃ , 14B ₃ , 14A ₄ and 14B ₄ respectively fixed to the eight wings 12A ₁ , 12B ₁ , 12A ₂ , 12B ₂ , 12A ₃ , 12B ₃ , 12A ₄ and 12B ₄ of the four feet 10 ₁ , 10 ₂ , 10 ₃ and 10 ₄ .

The secure structure illustrated on the figure 2 can be subjected to constraints such as a wind coming from the right and exerting a pressure distributed frontally on the securing devices 14A2, 14B2, 14A3, 14B3 surrounded (ie front face subjected to the wind). This wind is likely to tilt the structure at an angle α illustrated in the picture 3 (according to side view A of the figure 2 ) after cutting anchoring feet along a horizontal plane P chosen in the cutout zone Z of each foot.

This possibility of tilting is notably facilitated by the functional play between the hinge link arm and the receiving ring of each of the constrained securing devices 14A2, 14B2, 14A3, 14B3, but it is also limited by the lengths and constructions of the four hinge link arms concerned. In particular, their sizing to counter the effects of the wind depends on the distance D between the structure feet at the level of the securing devices, generally called the "blueprint" of the pylon, on the configuration and weight of the upper section at the cutting plane P It is within the reach of those skilled in the art to calculate the maximum acceptable stresses likely to be exerted on the structure for a maximum acceptable time after cutting in order to size the various elements of each securing device accordingly. These calculations will therefore not be detailed.

It will also be noted that the picture 3 makes it possible to visualize an angle β defining the angular difference of each ground anchor foot with respect to the vertical. This gap is generally referred to as the "fruit" of the pylon. It is this gap that justifies the addition of wedge wedges for each securing device, the hinge connecting arm and the inner axis of the receiving ring must advantageously be oriented vertically to facilitate dismantling by vertical lifting, possibly by helicopter .

A method for securing and dismantling a foot of a structure such as that of the figure 1 will now be detailed with reference to the figure 4 .

During a first step 100, the cutting zone Z is selected on the foot of the angle structure 10. Two holes are dug on the first wing 12A of the angle iron above the cutout zone Z, two on the second wing 12B of the angle iron above the cutout zone Z, two on the first wing 12A of the angle iron below the Z cutout area and two on the second wing 12B of the angle iron below the Z cutout area.

During a following step 102, the two hinge bases 16A and 16B are respectively fixed by bolting to the two wings 12A and 12B of angles under the cut-out zone Z thanks to the four holes previously drilled under this zone Z, if necessary with interposition of wedges 20A and 20B corners.

During a following step 104, the two receiving rings 22A and 22B are respectively fixed by bolting to the two wings 12A and 12B of angles above the cut-out zone Z thanks to the four holes previously drilled above this zone Z if necessary with the interposition of corner wedges 24A and 24B. The two receiving rings 22A and 22B are positioned above the two hinge bases 16A and 16B so that their respective holes intended to receive the two hinge connecting arms 18A and 18B are coaxial.

During a following step 106, the two hinge connecting arms 18A and 18B are respectively inserted into the coaxial holes of the elements 16A, 22A and 16B, 22B. They are respectively fixed by bolting their lower ends into the two hinge bases 16A and 16B. At the end of this step 106, the positioning and fixing of the securing devices 14A and 14B above and below the cutout zone Z can be considered as completed.

The next step 108 is a step of cutting the foot of the structure in the cutting zone Z while the securing devices 14A and 14B are put in place and fixed so that their two receiving rings 22A and 22B are respectively crossed by their two hinge link arms 18A and 18B.

During an optional step 110, the two fasteners are secured by respective bolting of the two retaining rings 26A and 26B around the portions of the hinge connecting arms 18A and 18B extending beyond the receiving rings 22A and 22B in which they are inserted. This optional step is proposed after step 108 of cutting, but it could also be executed before. It makes it possible to pass from a "stacked" state of the two sections of the structure foot 10 after cutting such as that illustrated for step 108, to a "secure" state of the two sections of the structure foot 10 after cutting such as that shown for step 110.

For a dismantling operation by helicopter winching, approximately 5 to 10 minutes before the arrival of the helicopter, the two retaining rings 26A and 26B are unbolted and removed if necessary by at least one operator during an optional step 112 Even in the event of bad weather, ie in the event of wind tending to tilt the upper section to be dismantled resulting from the cutting, the maintenance of the latter is not jeopardized thanks to the cooperation between the hinge link arms 18A, 18B and the retaining rings 22A and 22B in which they remain engaged during the arrival of the helicopter.

During this time, the operator(s) on the ground can move away from the dismantling area since their presence is no longer required for the rest of the operations.

Thus, when the helicopter begins to take on the weight of the upper section before lifting, no more operator on the ground is forced to remain in the area. The lifting operation of the upper section (step 114) can begin. Dismantling is done in such a way as to disengage the hinge connecting arms 18A, 18B from the receiving rings 22A, 22B by vertical elevation of the latter with the upper section.

Note that the complete process of figure 4 allows faster and more secure execution than that of the known solution presented previously. In particular, it does not require the use of pins and cords.

It is clear that a securing device such as the one described above makes it possible to envisage the effective and secure dismantling of any heavy structure to be cut in sections which must successively be removed using a machine connected to the ground such as a crane or a flying machine such as a helicopter. Such a securing device can also be limited in weight, in manufacturing costs and be reused on several construction sites.

It will also be noted that the invention is not limited to the embodiment described above.

Thus, for example, the securing devices 14A and 14B could be mounted in an inverted direction on the outer faces of the wings 12A and 12B of the foot of the structure 10 in angle iron. In other words, the base and the hinge connecting arm 16A, 18A, respectively the base and the hinge connecting arm 16B, 18B, could be turned over and constitute the upper portion of the securing device 14A, 14B respectively. The receiving ring 22A, respectively the receiving ring 22B, could be turned over and constitute the lower portion of the securing device 14A, respectively 14B. This configuration is however less advantageous because the upper section which is airlifted and evacuated is generally then placed on the ground without any particular precautions. This has the effect of risking rapid damage to the male part of the securing device (ie the hinge connecting arm), whereas in the configuration of the figure 1 , 3 And 4 this risk does not exist and allows reuse of the security device.

It will more generally appear to those skilled in the art that various modifications can be made to the embodiment described above, in the light of the teaching which has just been disclosed to him. In the detailed presentation of the invention which is made above, the terms used must not be interpreted as limiting the invention to the embodiment set out in the present description, but must be interpreted to include therein all the equivalents whose provision is within the reach of those skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims (10)

1. A device (14A, 14B) for securing a structure foot (10) for its disassembly by cutting, comprising:

   - a lower portion (16A, 18A, 16B, 18B) provided with means for fastening to the structure foot below a cutting area (Z) of the structure foot; and

   - an upper portion (22A, 22B) provided with means for fastening to the structure foot above the cutting area (Z);

   wherein these two portions are two separate pieces and:

   - one of the lower and upper portions (16A, 18A, 16B, 18B, 22A, 22B) is integral with a hinge link arm (18A, 18B) by fastening an end of the hinge link arm to that lower or upper portion; and

   - the other of the lower and upper portions (16A, 18A, 16B, 18B, 22A, 22B) is integral with a receiving ring (22A, 22B) of the hinge link arm,

   the hinge link arm and the receiving ring being shaped for sliding insertion and disengagement of the hinge link arm into the receiving ring.
2. The device (14A, 14B) for securing a structure foot (10) according to claim 1, wherein the portion integral with the hinge link arm (18A, 18B) comprises a hinge base (16A, 16B) and the hinge link arm (18A, 18B) which extends upward or downward from the hinge base.
3. The device (14A, 14B) for securing a structure foot (10) according to claim 1 or 2, further comprising corner wedges (20A, 20B, 24A, 24B) for compensating an inclination (β) of the structure foot (10) with respect to a desired verticality of the main axes of the hinge link arm (18A, 18B) and a cylindrical hole of the receiving ring (22A, 22B).
4. The device (14A, 14B) for securing a structure foot (10) according to any one of claims 1 to 3, wherein an operating play of several millimeters, in particular 6 to 10 mm, is provided between the diameter of the hinge connecting arm (18A, 18B) and that of the inside of the receiving ring (22A, 22B) into which it is designed to fit.
5. The device (14A, 14B) for securing a structure foot (10) according to any one of claims 1 to 4, wherein each of the fastening means comprises at least one nut and bolt.
6. The device (14A, 14B) for securing a structure foot (10) according to any one of claims 1 to 5, further comprising a retaining ring (26A, 26B) and means for fastening said retaining ring to a portion of the hinge link arm (18A, 18B) extending beyond the receiving ring (22A, 22B) into which it is inserted for retention of said insertion.
7. A pylon structure comprising a plurality of feet (10₁, 10₂, 10₃, 10₄) fixed to the ground and, for each foot, at least one securing device (14A₁, 14B₁, 14A₂, 14B₂, 14A₃, 14B₃, 14A₄, 14B₄) according to any of claims 1 to 6.
8. The pylon structure according to claim 7, comprising four feet (10₁, 10₂, 10₃, 10₄) shaped as corner pieces and two securing devices (14A₁, 14B₁, 14A₂, 14B₂, 14A₃, 14B₃, 14A₄, 14B₄) according to any one of claims 1 to 6 arranged respectively on the two wings (12A₁, 12B₁, 12A₂, 12B₂, 12A₃, 12B₃, 12A₄, 12B₄) of each corner piece.
9. A method for securing and disassembling a structure foot (10), comprising the following steps:

   - selection (100) of a cutting area (Z) on the structure foot (10);

   - positioning and fastening (102, 104, 106, 110) of at least one securing device (14A, 14B) above and below the selected cutting area (Z);

   - cutting (108) of the structure foot (10) in the selected cutting area (Z);

   - disassembling (112, 114) by raising the structure foot portion (10) above the cutting area (Z);

   - fastening (102, 104, 106, 110) is performed by means of at least one securing device (14A, 14B) according to any one of claims 1 to 6 in such a way that the receiving ring (22A, 22B) is traversed by the hinge link arm (18A, 18B); and

   - disassembling (112, 114) takes place so as to disengage the hinge link arm (18A, 18B) from the receiving ring (22A, 22B) by sliding the hinge link arm in the receiving ring.
10. The method for securing and disassembling a structure foot (10) according to claim 9 using at least one securing device (14A, 14B) according to claim 6, wherein:

    - fastening (102, 104, 106, 110) of the securing device (14A, 14B) comprises bolting (110) of the retaining ring (26A, 26B) to the portion of the hinge link arm (18A, 18B) extending beyond the receiving ring (22A, 22B) into which it is inserted; and

    - disassembling (112, 114) comprises a preliminary step of removing (112) the retaining ring (26A, 26B) by unbolting, for example within a predetermined period before raising the structure foot (10) part located above the cutting zone (z).

Images