FR3062168A1 - DEVICE FOR EXTRACTING A TURBOREACTOR BLOWER BLADE BLADE - Google Patents

Abstract

The invention relates to a device for extracting a shim (20) interposed between a fan blade (11) of a turbojet engine and a cell bottom (14) of a turbojet fan disk and having a body longitudinal axis (21) terminated by an axial retention shoe (22), said device comprising a sliding hammer extractor (100) equipped with a gripping tool (300) of the shim. The gripping tool (300) comprises a transverse body (310) with a C-section comprising: - two axial walls (311, 312) extending in planes parallel to the longitudinal body (21) of the wedge, - a wall radial joint (313) extending between the two axial walls, - an opening formed between the axial and radial walls for transversely receiving the wedge retention shoe, and - a retaining rim (314, 315) extending to the end of each of the axial walls (311, 312) to form a contact surface with the retention shoe.

Description

@ Holder (s): SAFRAN AIRCRAFT ENGINES.

©) Extension request (s): ® Agent (s): CABINET CAMUS LEBKIRI Limited liability company.

® DEVICE FOR EXTRACTING A BLADE OF A TURBOREACTOR BLOWER.

FR 3,062,168 - A1 (57) The invention relates to a device for extracting a block (20) interposed between a blade (11) of a fan of a turbojet engine and a bottom of a cell (14) of a fan disc of the turbojet engine and comprising a longitudinal body (21) terminated by an axial retention shoe (22), said device comprising a sliding hammer extractor (100) equipped with a tool for gripping (300) the wedge. The gripping tool (300) comprises a transverse body (310) with a C section comprising:

- two axial walls (311, 312) extending in planes parallel to the longitudinal body (21) of the wedge,

- a radial wall (313) extending between the two axial walls,

an opening formed between the axial and radial walls to receive the wedge retention shoe transversely, and

- A retaining rim (314, 315) extending at the end of each of the axial walls (311,312) to form a contact surface with the retention shoe.

318

DEVICE FOR EXTRACTING A TURBOREACTOR BLADE BLADE BLADE

TECHNICAL AREA

The present invention relates to a device for extracting a shim mounted in a cell of a turbojet fan disc. The invention finds applications in the field of aircraft turbojet blowers and, in particular, in the field of maintenance of turbojet blowers.

STATE OF THE ART

In the field of aeronautics, it is known that a turbojet fan 10 generally comprises, as shown in FIG. 1, a disc 16 at the periphery of which are formed a plurality of teeth 15 spaced circumferentially from one another, and each extending substantially axially, that is to say parallel to the axis of rotation X of the fan. Two teeth 15 directly consecutive in the circumferential direction form a cell 14. The disc 16 therefore comprises a plurality of cells 14 distributed over its circumference. Each cell 14 is a cavity housed between two consecutive teeth 15 and intended to receive the foot 20 of a fan blade 11. Each cell 14 has a bottom 14a, at the junction of the two consecutive teeth, and radial walls 14b each formed by a tooth 15.

In known manner, each tooth 15 is provided with an enlarged head so as to ensure the retention of the blades radially. Consequently, the transverse dimension between the radial walls 14b of a cell 14 is narrowed with respect to the transverse dimension of the bottom 14a of the cell. This narrowing of the transverse dimension of the cell 14 allows the passage of the stilt 13 of the blade 11 whose section is narrowed relative to that of the blade root 12. The assembly cell 14 and blade 11 is therefore of the dovetail type.

It is also known that the fan 10 comprises, between the lower end of each blade root 12 and the bottom of the cell 14, a shim 20 associated with the blade concerned. This wedge 20 makes it possible to block the blade 10 in the internal radial direction (that is to say the direction extending from the circumference of the disc 16 towards the axis X) and to press the foot 12 against the teeth 15 The wedge 20, a partial view of which is shown in FIG. 2, comprises a longitudinal body 21 terminated by a shoe for axial retention of the associated blade. The retention shoe 22 is intended to be in abutment against a retention ring 17 carried by the fan disc 16.

It is known, moreover, in the field of aeronautical maintenance, to regularly disassemble the various parts of an aircraft to ensure their maintenance. The turbojet blowers are therefore regularly dismantled by maintenance operators in order to be cleaned and checked. During these dismantling, maintenance operators must extract each block from its cell.

Currently, to extract a blower block, maintenance operators use a tool called a “sliding hammer extractor”. This sliding hammer extractor 100, shown in FIG. 3, comprises a rod 110 on which slides, between two stops 151-152, a hammer 120. One end 112 of the rod 110, provided with the stop 152, is integral with a handle 130 allowing the gripping of the tool by the maintenance operator. The opposite end 111 of the rod 110, provided with the stop 151, is equipped with a rod 40 of shape and dimension adapted to be inserted into an orifice 23 preexisting in the wedge 20.

In the maintenance phase, the operator must insert the rod 40 into the orifice 23 of the wedge 20 and pull the wedge 20 axially out of the cell 14 by actuating the hammer sliding along the rod 110 between the two stops 151 -152. However, given the environment which is a driving environment with a limited space, the operator finds it difficult to maneuver the tools. The operator must therefore be patient and careful to insert the pin 40 into the hole 23 of the hold and then to axially pull the hold out of the socket. The operation of removing a wedge 20 is therefore relatively long. As this operation must be repeated as many times as there are shims on the blower, a significant loss of time is caused by the difficulty of the operation.

In addition, the rod 40 has a section defined by the section of the orifice 23 of the wedge. However, this section of the rod 40 is insufficient to withstand the forces induced by the use of the sliding hammer extractor, which has the consequence of causing plastic deformations of the rod 40 which then tends to remain blocked in the tools. The rod 40 must therefore be replaced regularly, which generates costs and a waste of time.

In addition, as the contact surface between the rod 40 and the shim 20 is small (that is to say at most equal to the circumference of the orifice 23), the forces induced by the use of the extractor sliding hammer also cause plastic deformation of the shim 20, which requires replacement of the shim and generates additional costs.

Given all these difficulties, it is common for maintenance operators to use other, unsuitable tools, to remove the shims from the fan blades. However, the use of non-compliant tools can lead to damage to the neighboring parts of the block in the blower.

There is therefore a real need for a specific device for extracting the blades of fan blades which is more manageable and more efficient than conventional devices.

SUMMARY OF THE INVENTION

To respond to the problems mentioned above of the sliding hammer extractor equipped with a rod, the applicant proposes a device for extracting a fan blade wedge in which the sliding hammer extractor is equipped with a hold tool which at least partially envelops said hold.

In the description which follows, the extraction device of the invention is described with reference to an orthonormal reference frame linked to the fan of the turbojet engine, in which the axis X corresponds to the axis of rotation of the fan, the axis Y corresponds to the radial axis of the fan and the Z axis corresponds to the transverse axis of said fan.

According to a first aspect, the invention relates to a device for extracting a shim interposed between a fan blade of a turbojet engine and a cell bottom of a fan disc of the turbojet engine and comprising a longitudinal body terminated by a axial retention shoe, said device comprising a sliding hammer extractor equipped with a tool for gripping the wedge. The device is characterized by the fact that the gripping tool comprises a transverse body with a C section comprising:

- two axial walls extending in planes parallel to the longitudinal body of the hold,

- a radial wall extending between the two axial walls,

an opening formed between the axial and radial walls to receive the wedge retention shoe transversely, and

- a retaining rim extending at the end of each of the axial walls to form a contact surface with the retention shoe.

Due to its shape, this gripping tool allows the axial forces induced by the sliding hammer to be distributed over several surfaces, which limits the risks of deformation of the tool and the shim.

Advantageously, the opening formed between the axial and radial walls has dimensions adapted so that at least one of said walls is in contact with the retention shoe. The contact surface between the shim and the gripping tool is thus increased.

Advantageously, the transverse body of the gripping tool comprises, on an external face of the radial wall, fixing means capable of integrally fixing said transverse body on the sliding hammer extractor. These fastening means make it possible to secure the sliding hammer extractor and the gripping tool.

In certain variants, the fastening means comprise first fastening elements secured to the transverse body and second fastening elements secured to the sliding hammer extractor, the first and second fastening elements being fitted one into the other. others and assembled by means of a pin.

Advantageously, the gripping tool comprises at least one protective element mounted on an internal face of a retaining rim. This protective element protects the wedge during the extraction of the wedge.

In some variants, the protective element is a plate of elastic material bonded to a surface intended to be in contact with the retention shoe. These variants allow the protection element to be easily changed when it is worn.

Advantageously, the gripping tool comprises a protective layer covering at least partially the internal faces of the radial and axial walls. This protective layer protects the wedge from blows and vibrations caused by the sliding hammer within the gripping device.

In some variants, the protective layer is a layer of elastic material bonded to the internal faces of the axial and radial walls. These variants allow you to easily change the protective layer when it is worn.

In some embodiments, the gripping tool has a lateral stop mounted at a transverse end of the transverse body to transversely hold the retention shoe in said tool. This lateral stop facilitates the installation of the gripping tool around the retention shoe.

In some variants, the lateral stop is provided with a protective cap.

Advantageously, at least one of the retaining flanges has one end in the form of a radiating nipple capable of being inserted at least partially in a groove situated at the junction of the longitudinal body and the wedge retention shoe. This end in the shape of a radiated nipple makes it possible to limit the clearance between the wedge and the transverse body.

BRIEF DESCRIPTION OF THE FIGURES

Other advantages and characteristics of the invention will appear on reading the description, illustrated by the figures in which:

- Figure 1, already described, shows an exploded perspective view of a portion of a jet engine fan for an aircraft, of a design known from the prior art;

- Figure 2, already described, shows an enlargement of part of a blade hold of the fan of Figure 1;

- Figure 3, already described, shows a side view of a blade hold extraction tool according to the prior art;

- Figure 4 shows a side view of the blade hold extraction device according to the invention;

- Figures 5A and 5B show perspective views of the gripping tool of the device of Figure 4, respectively, alone and mounted around a wedge;

- Figures 6A, 6B and 6C show different views of the gripping tool of Figures 5A-5B during its manufacture;

- Figures 7A and 7B show side views, on one side and on the other side, of the gripping tool of Figures 5A-5B when said tool is mounted on a block.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT

An exemplary embodiment of a device for extracting fan blade wedges according to the invention is described in detail below, with reference to the accompanying drawings. This example illustrates the characteristics and advantages of the invention. It is however recalled that the invention is not limited to this example.

In the figures, identical elements are identified by identical references. For reasons of readability of the figures, the size scales between the elements represented are not respected.

FIG. 4 schematically represents an example of a device for extracting wedges according to the invention during the operation of extracting a wedge. More precisely, FIG. 4 represents:

- part of a blower disc 16 with a cell 14 in which a shim 20 is housed, and

- an extraction device 200 adapted to extract the shim 20 from the socket 14.

The extraction device 200 comprises a sliding hammer extractor 100 and a gripping tool 300 of the wedge 20.  The sliding hammer extractor conventionally comprises a gripping handle 130, a rod 110 and a sliding hammer 120 capable of sliding along the rod 110.  One end 112 of the rod 110 is secured to the handle 130.  This end 112 is equipped with an external stop 212 which can be a projecting element around the rod 110 or which can be formed by a face of the handle 130, as in the example of FIG. 4.  One end 111 of the rod 110, opposite the end 112, is provided with an internal stop 211, located near the tool for gripping the wedge 300.  The internal stop 211 may be formed by a protruding element around the rod 110 or by a part of an attachment device 350 provided for attaching the gripping tool 300 to the sliding hammer extractor 100, as described more in detail later.

The gripping tool 300, mounted integrally at the end 111 of the sliding hammer extractor 100, is designed to at least partially envelop the retention shoe 22 of the wedge 20 so as to provide a maximum surface area of resumption of axial forces induced by the sliding hammer extractor. An example of a gripping tool 300 is shown in FIGS. 5A and 5B. In FIG. 5A, the gripping tool 300 is shown alone, that is to say neither mounted on the shim, nor mounted on the sliding hammer extractor 100. In FIG. 5B, the gripping tool 300 is shown mounted around the wedge retention shoe.

This gripping tool 300 comprises a transverse body 310 designed to be inserted transversely around the retention shoe 22 of the wedge 20. This transverse body 310 can be made of a metal or an alloy, for example Inconel® which has the advantage of being very resistant and therefore capable of withstanding the forces applied to the gripping tool during the extraction of the wedge.

The transverse body 310 is a hollow part, the cross section of which is substantially in the form of a C. The transverse body 310 comprises two axial walls 311 and 312 which extend along the axis X, in XZ planes substantially parallel to the plane containing the longitudinal body 21 of the wedge 20. It also has a radial wall 313 which extends radially between the two axial walls 311, 312, in a plane YZ substantially perpendicular to the plane of the longitudinal body 21 of the wedge. The radial wall 313 forms, with each of the two axial walls 311, 312, a substantially right angle. Thus, the axial wall 311 forms the upper surface of the transverse body 310 and the axial wall 312 forms its lower surface. The radial wall 313 forms the bottom of the transverse body 310. Each of the axial walls 311, 312 ends in a retaining rim, respectively 314 and 315, formed opposite the radial wall 313, in a plane substantially parallel to the plane YZ of the radial wall 313. In other words, the transverse body 310 forms a sort of straight, hollow block, with two full axial faces 311-312, two transverse faces 317, 319 open, a full radial face 313 and a partial radial face (constituted retaining edges 314-315).

Thus, the transverse body 310 surrounds, at least in part, four sides of the retention shoe 22. This surrounding of the retention shoe 22 makes it possible to maximize the surfaces of the gripping tool in contact with the shim 20. In particular, for maximize the contact surfaces, the opening made between the axial and radial walls of the transverse body has dimensions adapted so that at least one of said walls is in contact with the retention shoe. In fact, each contact surface between the gripping tool and the retention shoe is a surface for taking up the axial forces induced by the sliding hammer extractor 100. However, the larger the surface for taking up the axial forces, the more the risk of plastic deformation of the wedge and / or of the gripping tool, during the extraction of the wedge, is low. The transverse body 310 of the gripping tool according to the invention has a shape and dimensions making it possible to maximize this contact surface. Embodiments described later make it possible to further increase this contact surface.

The shape of the transverse body 310 described above also allows said transverse body 310 to slide transversely around the retention shoe 22. The gripping tool 300 is therefore relatively easy to install around the retention shoe of the wedge. 20 even in a restricted environment such as a turbojet fan environment.

In certain embodiments of the invention, faces of the transverse body 310, for example the surfaces in contact, or likely to be in contact, with the retention shoe 22 or other elements of the fan, are covered with a protective layer 360. In the example of FIGS. 5A-5B, the protective layer 360 is a layer of protective material bonded to the internal faces of the axial walls 311 -312 and radial 313 as well as to the contour of the retaining rim 315 Those skilled in the art will understand that the protective layer can also cover the contour of the retaining rim 314 and / or the external faces of the axial and radial walls. The protective layer 360 can be, for example, an elastomer layer which not only has the advantage of protecting the shim and the neighboring elements in the blower, but also has the advantage of having a roughness greater than the roughness of the material. in which the walls of the transverse body are manufactured, which makes it possible to avoid any sliding of the wedge inside the transverse body 310. Thus, during the disassembly of the wedge 20, the retention shoe 22 of the wedge is maintained inside the transverse body 310, not only axially and radially by the walls 311-313 and retaining edges 314-315 of the transverse body, but also transversely by the elastomer layer 360.

In certain variants, such as that shown in FIG. 6A, the elastomer layer 360 is cut to the dimensions of the faces of the transverse body to be covered and then fixed by gluing on said faces. This manufacturing method allows a simple and rapid change of the elastomeric layer when it is worn.

In certain embodiments of the invention, a protective element 370 is integrated inside the transverse body 310. This protective element 370 can be, for example, a plate of elastic material, of the elastomer type, fixed inside of the transverse body 310, on the retaining rim 314 on the upper surface of the fan disc 16, as shown in FIGS. 5A-5B. This protective element 370, of a thickness greater than the thickness of the protective layer 360, forms a flexible contact surface intended to absorb the vibrations and the shocks generated between the transverse body and the wedge during the axial force exerted. by the sliding hammer 120 to extract said wedge. This protective element 370 thus makes it possible to protect the shim 20, and the fan disc 16, during the disassembly of said shim.

In some variants, the protective element 370 is fixed to the internal face of the retaining flange 314 by gluing. In other variants, such as that shown in FIG. 6B, the retaining rim 314 forms, inside the transverse body, a trough 316 designed to receive the protective element 370. The protective element 370 can then be previously cut to the dimensions of the chute 316 and slid transversely to the hollow of said chute, as shown in Figure 6B. It can also be glued inside the trough 316. Whatever the variant of attachment, the protective element can be easily and quickly changed in the event of wear.

In the embodiment of FIGS. 5A and 5B, the gripping tool 300 comprises a lateral stop 340 formed at a transverse end of the transverse body 310. This lateral stop 340 can be, for example, a tongue 341 positioned in the XY plane of the transverse opening 317 of the transverse body 310. This tongue 341 can be fixed, for example by gluing, welding or brazing, on the radial wall 313 of the transverse body 310, as shown in FIGS. 5A5B, or on one of the axial walls 311-312. This lateral stop 340 has the effect of transversely blocking the wedge 20 in the transverse body 310, in particular when installing the gripping tool 300 around the wedge 20. With this lateral stop, the maintenance operator can install easily the gripping tool around the retention shoe 22 by sliding said gripping tool 300 around the retention shoe until said shoe is in abutment against the lateral stop 340. Once the gripping tool 300 in placed around the retention shoe 22, the maintenance operator can actuate the sliding hammer 120 along the rod 110 so as to generate axial forces on the gripping tool. These axial forces are then transmitted to the shim by the surfaces of the gripping tool which are in contact with said shim and, in particular, by the inner faces of the retaining flanges 314-315.

In certain variants, such as that shown in FIG. 6C, the lateral stop 340 comprises a protective tip 342. This protective tip 342 can be, for example, a piece cut from an elastic material, such as the elastomer, and glued to the tongue 341. The protective end piece 342 can be glued to the outside face of the tongue 341 to protect the elements surrounding the wedge 20 or to the inside face of said tongue 341 to protect the wedge itself. Two protective caps 342 can also be glued on either side of the tongue 341 to protect both the wedge and the elements surrounding the wedge. Whatever the location of the protective end piece 342 on the tongue 341, the adhesive bonding makes it easy and quick to exchange the protective end piece when it is worn.

FIGS. 7A-7B show side views of the gripping tool 300 installed around the retention shoe 22 of the wedge 20. These figures show the gripping tool 300 with its transverse body 310 which envelops the shoe axially and radially retention 22. Indeed, the retention shoe 22 is held radially between the axial walls 311 and 312 and axially between the radial wall 313 and the retaining flanges 314 and 315. The clearance between the axial walls 311-312 and the shoe retention 22 is reduced to the maximum so as to allow only a slight radial movement of the shim in the gripping tool, which makes it possible to maximize the surface for taking up the axial forces of the gripping tool.

According to certain embodiments of the invention, at least one of the retaining flanges, for example the retaining flange 315 on the underside of the blower disc 16, has one end in the form of a radiating stud 318, that is to say one end whose section is sloping and rounded. More specifically, the end in the shape of a radiated nipple 318 - as shown in FIGS. 5A-5B - has an internal face 318a straight and radial and an external face 318b sloping, forming a rounded angle 318c with the internal face 318a. By its sloping shape, the radiated nipple 318 is able to be inserted at least partially in a groove 24 located at the junction of the longitudinal body 21 and the retention shoe 22 of the wedge 20, which has the effect of minimizing the clearance between the axial walls 311-312 and the retention shoe 22.

The slope of the external face 318b of the radiated stud 318 are chosen as a function of the dimensions of the groove 24 so as to allow transverse sliding of the radiated stud 318 in the groove 24 and an axial and radial blocking of said stud in said groove. The radiated nipple 318 thus allows optimum placement of the gripping tool 300 around the wedge 20. It also serves as a key during the insertion of the gripping tool around the wedge. The radiated nipple 318 also offers an additional contact surface between the gripping tool and the shim, which further improves the distribution of the axial forces between the gripping tool and the shim.

FIGS. 7A-7B also show that the retention shoe 22 is protected, during the application of the axial forces, by the protective layer 360 and by the protective element 370. In fact, when the sliding hammer 120 of the device d extraction is actuated, it generates axial forces between the transverse body 310 and the shim 20 which have the effect of pulling the shim 20 out of the cell 14. The presence of the protective layer 360 and the protective element 370 can absorb shocks and vibrations between the wedge and the transverse body and thus avoid any damage to the wedge.

In addition, as shown in FIGS. 4 and 7A-7B, the gripping tool 300 comprises fixing means making it possible to connect the transverse body 310 with the sliding hammer extractor 100. These fixing means secure the transverse body 310 with the sliding hammer extractor 100. These fixing means can also constitute the internal stop 211 on which the sliding hammer 120 comes to bear when it is activated by the maintenance operator.

In the example of FIGS. 7A-7B, the fastening means are a fastening device 350 comprising first fastening elements 351-352 and second fastening elements 353 designed to fit one into the other, for example by month. The first attachment elements 351-352, for example two stirrups 351 and 352 positioned in two parallel planes, are integral with the transverse body 310. They can be manufactured in one piece with the transverse body 310 or fixed to said transverse body by any known fixing means. The second attachment elements 353, for example a stirrup 353 positioned in an intermediate plane between the stirrups 351 and 352, is fixed to the end 111 of the rod 110 of the sliding hammer extractor 100, for example, by clipping or branching. Each of the first and second attachment elements 351-353 has an orifice, aligned radially with the orifices of the other first and second attachment elements.

In the example of FIGS. 7A-7B, the fastening device 350 further comprises a pin 240, for example a rod, intended to pass through both the orifices of the first and second fastening elements 351-353 so securing said first fastening elements with said second fastening elements and, consequently, the sliding hammer extractor with the gripping tool. The pin 240 is made of a metal or an alloy such as Inconel® offering sufficient strength to avoid any deformation during the extraction of the wedge.

These fixing means make it possible, when the sliding hammer 120 is actuated between the stops 211-212, to transmit the axial force of said sliding hammer on the stops to the retaining flanges 314-315 of the transverse body 310. The retaining flanges 314-315 being in contact with the retention shoe 22 of the wedge, the transmission of the axial forces to the retaining edges makes it possible to extract the wedge from the cell 14.

Those skilled in the art will understand that the gripping tool 300 which has just been described can be easily mounted on a commercial sliding hammer extractor or any other known device allowing an axial tensile force and which can be inserted in an environment of reactor fan. This gripping tool ensures optimal retention of the retention shoe 22 of the wedge 20 and offers a maximum contact surface between said wedge and said gripping tool so that the extraction forces are distributed as well as possible. This gripping tool also offers protection of the hold and surrounding elements in order to avoid any damage during the hold extraction operation.

Although described through a certain number of examples, variants and embodiments, the device for extracting a fan blade wedge according to the invention includes various variants, modifications and improvements which will become apparent on reading 'skilled in the art, it being understood that these variants, modifications and improvements are part of the scope of the invention, as defined by the claims which follow.

Claims (10)

1. Device for extracting a shim (20) interposed between a blade (11) of the fan of a turbojet engine and a bottom of the cell (14) of a fan disk of the turbojet engine and comprising a longitudinal body (21 ) terminated by an axial retention shoe (22), said device comprising a sliding hammer extractor (100) equipped with a gripping tool (300) of the wedge, characterized in that said gripping tool (300) comprises a transverse body (310) with C section comprising: - two axial walls (311,312) extending in planes parallel to the longitudinal body (21) of the hold, - a radial wall (313) extending between the two axial walls, an opening formed between the axial and radial walls to receive the wedge retention shoe transversely, and - a retaining rim (314, 315) extending at the end of each of the axial walls (311, 312) to form a contact surface with the retention shoe. 2. Extraction device according to claim 1, characterized in that the opening formed between the axial and radial walls has dimensions adapted so that at least one of said walls (311-313) is in contact with the retention shoe. . 3. Extraction device according to claim 1 or 2, characterized in that the transverse body (310) of the gripping tool comprises, on an external face of the radial wall, fixing means (350) capable of fixing integrally said transverse body on the sliding hammer extractor. 4. Extraction device according to claim 3, characterized in that the fixing means (350) comprise first attachment elements (351-352) integral with the transverse body (310) and second attachment elements (353 ) integral with the sliding hammer extractor, the first and second fastening elements being nested one inside the other and assembled by means of a pin (240). 5. Extraction device according to any one of claims 1 to 4, characterized in that the gripping tool (300) comprises at least one protective element (370) mounted on an internal face of a retaining rim . 6. Extraction device according to claim 5, characterized in that the protective element is a plate of elastic material bonded to a surface intended to be in contact with the retention shoe. 7. Extraction device according to any one of claims 1 to 6, characterized in that the gripping tool (300) comprises a protective layer (360) covering at least partially the internal faces of the radial and axial walls, the protective layer being a layer of elastic material bonded to the internal faces of the axial and radial walls. 8. Extraction device according to any one of claims 1 to 7, characterized in that the gripping tool comprises a lateral stop (340) mounted at a transverse end (317) of the transverse body to transversely maintain the shoe. retention in said tool. 9. Extraction device according to claim 8, characterized in that the lateral stop (340) is provided with a protective tip (342). 10. Extraction device according to any one of claims 1 to 9, characterized in that at least one of the retaining flanges (314, 315) has one end (318) in the form of a radiated stud capable of being inserted into the less partially in a groove (24) located at the junction of the longitudinal body and the wedge retention shoe. 1/3 100