Tool for removing a blind fastener and associated method

EP4747027A1Pending Publication Date: 2026-05-27AIRBUS ATLANTIC (SAS)
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Patent Information

Authority / Receiving Office
EP · EP
Patent Type
Applications
Current Assignee / Owner
AIRBUS ATLANTIC (SAS)
Filing Date
2024-07-08
Publication Date
2026-05-27

AI Technical Summary

Technical Problem

Dismantling blind fasteners in aeronautical assemblies is complex and error-prone, requiring multiple operators and risking damage to mechanical parts due to the sensitivity of existing methods, which limits disassembly rate and reliability.

Method used

A tool comprising an anti-rotation member and interface member with a cutting device, allowing single-operator disassembly by preventing rotation of the female part and ensuring precise positioning, while a stabilizing member maintains coaxiality and evacuation recesses manage debris, facilitating safe and efficient removal.

Benefits of technology

The tool enables faster, more reliable, and error-free disassembly of blind fasteners, doubling the disassembly rate and reducing operator burden, with improved safety and reduced risk of damage to mechanical parts.

✦ Generated by Eureka AI based on patent content.

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    Figure EP2024069242_23012025_PF_FP_ABST
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Abstract

The invention relates to a removal tool (5) for removing a blind fastener securing a first mechanical part to a second mechanical part, the removal tool (5) comprising: an anti-rotation member (51) comprising a passage opening (510) extending along a tool axis (X5) and a gripping surface (511) configured to cooperate with the female portion of the blind fastener (1) from upstream in order to prevent it from rotating about the fastening axis (XI), an interface member (7) connected to the anti-rotation member (51), the interface member (7) comprising a main body (77) with a through-cavity (4) which extends along the tool axis (X5) and which has an upstream opening (4A) configured to receive a cutting device (6) comprising a cutting member (61), the interface member (7) comprising an alignment groove (43) configured to guide the cutting member (61) into the passage opening (510) of the anti-rotation member (51).
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Description

Tool for removing a blind fastener and associated method

[0001] The present invention relates to the field of mechanical fasteners in the aeronautical field for producing an assembly, in particular, so-called "blind" fasteners, that is to say, mounted only from one side of the assembly. More specifically, the invention relates to a tool for dismantling a blind fastener.

[0002] As is known, an aircraft comprises a fuselage which is made by assembling several mechanical parts. It is known to use blind fasteners to connect the mechanical parts together, for example, rivets. Such blind fasteners allow rapid assembly with few constraints, in particular, in terms of accessibility.

[0003] With reference to the, the securing of a first mechanical part P1 to a second mechanical part P2 is shown by means of a blind fastener 1 in order to form an assembly. For example, the mechanical parts P1, P2 are aeronautical panels which must be assembled together. The blind fastener 1 usually comprises a female part 2 and a male part 3 inserted into the female part 2. When installing the blind fastener 1, a rotation is applied to the male part 3 which screws into the female part 2 to form a bulb 22 on the downstream side C2, in contact with the second mechanical part P2. The mechanical parts P1, P2 are thus linked and held, on the upstream side C1 by the imprinted head 21 of the female part and, on the downstream side C2, by the bulb 22 as illustrated in the.

[0004] During maintenance operations, for example to bring the fasteners used up to standard or to correct a problem on an isolated part of a panel, the blind fasteners 1 must be dismantled. When dismantling a blind fastener 1, the male part 3 is first dismantled. For example, the male part 3 can be dismantled by releasing the thread of the male part 3 on the downstream side C2 and driving the male part 3 towards the upstream side C1, usually with a drift.

[0005] Only the female part 2 must then be removed, this being still retained by its head with imprints 21 and its bulb 22. The removal of the female part 2 is critical in the life phase of a panel composed of several mechanical parts P1, P2, the slightest roughness or scratch being able to lead to a non-conformity generating high costs. It is known to use a drill to machine the female part 2 in order to break its crown. This operation is complex given that the female part 2 is driven in rotation with the cutting member of the drill. Also, it is necessary for a second operator to immobilize in rotation the female part 2 from the downstream side C2 when a first operator carries out the drilling operation. This removal method is therefore very sensitive to human errors, due to the multiplicity of operators involved.Indeed, a slip or misalignment may force the scrapping of one of the previously connected mechanical parts P1, P2. Dismantling the female part 2 also has the disadvantage of requiring a low dismantling rate.

[0006] The invention thus aims to eliminate these drawbacks, by allowing a higher dismantling rate and increased reliability. PRESENTATION OF THE INVENTION

[0007] The invention relates to a tool for dismantling a blind fastener securing a first mechanical part and a second mechanical part, the blind fastener having been introduced from upstream to downstream into an opening of the first part then into an opening of the second part from an upstream side, the blind fastener extending along a fastening axis, the blind fastener comprising a female part extending into the openings and a male part inserted into the female part in order to deform it to secure the mechanical parts, the dismantling tool comprising: an anti-rotation member comprising a passage opening extending along a tool axis and a gripping surface configured to cooperate with the female part of the blind fastener from upstream in order to prevent its rotation around the fastening axis, an interface member connected to the anti-rotation member,the interface member comprising a main body comprising a through housing extending along the tool axis which comprises an upstream mouth configured to receive a cutting device comprising a cutting member, the interface member comprising an alignment groove configured to guide the cutting member in the passage opening of the anti-rotation member.,

[0008] Thanks to the invention, a blind fastener can be dismantled quickly and easily by a single operator. This advantageously makes it possible to increase the rate of dismantling of blind fasteners, while reducing the difficulty of the task for the operator. The use of an anti-rotation member associated with an interface member makes it possible to prevent any rotation from the same side by the same operator while ensuring precise and secure positioning. The cutting member is advantageously not likely to damage any of the mechanical parts.

[0009] According to one aspect, the disassembly tool comprises a stabilizing member configured to bear on the first mechanical part. This makes it possible to guarantee coaxiality between the fixing axis and the tool axis in order, in particular, to avoid damaging the first mechanical part and to allow precise disassembly.

[0010] In one aspect, the stabilizing member comprises at least three support arms, the distal ends of the arms defining a plane orthogonal to the device axis. Three arms are sufficient to provide stabilization.

[0011] According to one aspect, the anti-rotation member is screwed to the interface member. Preferably, the anti-rotation member comprises a threaded portion, and the interface member comprises an internally threaded portion configured to receive the threaded portion of the anti-rotation member. This makes it possible to simply secure the two members, and to easily disassemble them in the event of repair. In addition, this makes it possible to use the same interface member for different anti-rotation member jigs, and vice versa, thus allowing simple adaptation of the disassembly tool.

[0012] According to one aspect, the stabilizing member is screwed to the interface member. Preferably, the stabilizing member comprises a threaded portion, and the interface member comprises an external threaded portion configured to receive the threaded portion of the support member. According to another aspect, the stabilizing member can be slid onto the interface member and limited in translation by the anti-rotation member. This makes it possible to simply secure the two members, and to easily disassemble them in the event of repair. In addition, this makes it possible to use the same interface member for different stabilizing member templates, and vice versa, thus allowing simple adaptation of the disassembly tool.

[0013] In one aspect, the main body of the interface member has a plurality of evacuation recesses, preferably extending radially relative to the tool axis. Preferably, the evacuation recesses are distributed circumferentially around the device axis. This allows chips to be evacuated from the blind fastener throughout the disassembly operation, and thus avoids pauses necessary for cleaning the disassembly tool, thereby increasing the disassembly rate.

[0014] The invention also relates to an assembly of a cutting apparatus comprising a cutting member and a disassembly tool as presented previously, the cutting apparatus being introduced at least partially into the through-housing, the cutting member extending into the alignment groove of the disassembly tool.

[0015] According to one aspect, the cutting apparatus comprises a micrometric stop. This makes it possible to adjust the travel of the cutting tool, so as not to damage the first mechanical part during the disassembly operation, by cutting only the imprinted head of the female part of the blind fastener.

[0016] According to one aspect, the cutting apparatus is secured to the disassembly tool, preferably by screwing. This allows for greater safety of use, and reduces the risk of accidents linked to potential slippage of the cutting apparatus or the disassembly tool. This also makes it easier and faster to repeat the disassembly operation from one mechanical part to another, thus increasing the disassembly rate.

[0017] The invention also relates to a method of using an assembly presented previously for dismantling a blind fastener securing a first mechanical part and a second mechanical part, the blind fastener having been introduced from upstream to downstream into an opening of the first part then into an opening of the second part from an upstream side, the blind fastener extending along a fastening axis, the blind fastener comprising a female part extending into the openings and a male part inserted into the female part in order to deform it to secure the mechanical parts, the male part of the fastener having been previously removed, the cutting member being set back in the dismantling tool, the method comprising steps consisting of: Making the gripping surface of the anti-rotation member cooperate with the female part of the blind fastener from the upstream side in order to prevent its rotation around the fastening axis,Move the cutting member downstream so that it cuts an upstream end of the female part of the blind fastener.

[0018] According to one aspect, the method comprises a preliminary step to the engagement of the gripping surface consisting of making the cutting tool engage the blind fastener. Preferably, the cutting tool projects a few millimeters from the anti-rotation member.

[0019] In one aspect, the method includes stabilizing the position of the tool axis so that it is coaxial with the attachment axis.

[0020] In one aspect, the main body of the interface member having a plurality of discharge recesses, the method of use includes discharging cutting waste through the discharge recesses. PRESENTATION OF FIGURES

[0021] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0022] This is a schematic representation of a sectional view of a blind fastener connecting two mechanical parts.

[0023] This is a schematic representation of a sectional view of a disassembly tool according to one embodiment of the invention.

[0024] This is a schematic representation of an exploded sectional view of the disassembly tool.

[0025] This is a schematic representation of a positioning step of a cutting device comprising a disassembly tool

[0026] This is a schematic representation of a step of moving the drill bit of the cutting device into the blind fastener to be removed.

[0027] This is a schematic representation of a step in removing the drill bit from the blind fastener.

[0028] This is a schematic representation of a step in removing the female part of the blind fastener.

[0029] It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention if necessary. DETAILED DESCRIPTION OF THE INVENTION

[0030] The invention relates to a tool for removing a blind fastener from an assembly, hereinafter referred to as a "fastener". A blind fastener is by definition a fastener that is mounted from only one side of the assembly, for example, a rivet.

[0031] With reference to the, the joining of a first mechanical part P1 to a second mechanical part P2 by means of a fastener 1 is shown in order to form an assembly. For example, the mechanical parts P1, P2 are aeronautical panels which must be assembled together.

[0032] In this example, the first mechanical part P1 has an opening O1 and the second mechanical part P2 has an opening O2 which are aligned along a fixing axis X1 which is oriented from upstream to downstream. Upstream thus corresponds to the side of the first mechanical part P1 while downstream corresponds to the side of the second mechanical part P2.

[0033] With reference to the, the fastener 1 was introduced along the fastening axis X1 from upstream to downstream into the opening O1 of the first mechanical part P1 then into the opening O2 of the second mechanical part P2 from an upstream side C1 to a downstream side C2. The fastener 1 usually comprises a female part 2, having an outside diameter D2, and a male part 3 inserted into the female part 2. The male part 3 is made integral with the female part 2, usually by a thread of the male part 3 complementary to a tapping formed in the female part 2. The male part 3 is inserted into the female part 2 in order to deform it to secure the mechanical parts P1, P2.

[0034] The female part 2 has, at its upstream end, a head with impressions 21 comprising impressions used to hold it and prevent its rotation during the installation of the fixing 1, in particular, during the installation of the male part 3. In this example, the head with impressions 21 comprises impressions, for example, pyramidal teeth. It goes without saying that the impressions could have different shapes.

[0035] Indeed, when installing the fastener 1, a rotation is applied to the male part 3 which screws into the female part 2 from the upstream side C1 until it exerts a traction upstream at the downstream end of the female part 2. Due to its shape and configuration, the downstream end of the female part 2 deforms to form a bulb 22 on the downstream side C2, in contact with the second mechanical part P2. The mechanical parts P1, P2 are thus linked and held, on the upstream side C1 by the imprinted head 21 of the female part and, on the downstream side C2, by the bulb 22 as illustrated in.

[0036] When dismantling a fastener 1, the male part 3 is first dismantled. This dismantling step is known to those skilled in the art and will not be presented in detail. For example, the male part 3 can be dismantled by releasing the thread of the male part 3 on the downstream side C2 and driving the male part 3 towards the upstream side C1, usually with a drift. Only the female part 2 must then be removed, the latter still being retained by its imprinted head 21 and its bulb 22.

[0037] A disassembly tool 5 will now be presented according to an embodiment of the invention allowing rapid and simple disassembly of the female part 2 of the fixing 1.

[0038] With reference to the, there is shown a disassembly tool 5 according to an embodiment of the invention. The disassembly tool 5 extends along a tool axis X5 from upstream to downstream, and comprises from upstream to downstream an interface member 7, a stabilizing member 52 as well as an anti-rotation member 51. The stabilizing member 52 is optional and will be presented later.

[0039] With reference to the, the anti-rotation member 51 extends along the tool axis X5 and comprises a passage opening 510 extending along the tool axis X5, preferably in its center. The passage opening 510 has a diameter D510 of between 2mm and 7mm. In this example, the anti-rotation member 51 is in the form of a cylindrical part having a thickness of between 5mm and 25mm and a diameter of between 5mm and 25mm. Preferably, the anti-rotation member 51 is made of metal, in particular steel.

[0040] The anti-rotation member 51 further comprises a gripping surface 511 (forming a downstream surface of the anti-rotation member 51) configured to cooperate with the imprinted head 21 of the female part 2 from the upstream side C1 in order to prevent its rotation around the fixing axis X1. Preferably, the gripping surface 511 comprises a plurality of grips complementary to the imprints present on the imprinted head 21 of the female part 2, facilitating cooperation between the female part 2 and the disassembly tool 5.

[0041] In this example, the anti-rotation member 51 further comprises a connecting portion 512 extending downstream configured to allow connection with the interface member 7, in particular, by screwing. In this example, the connecting portion 512 is threaded and configured to cooperate with a connecting portion 44, which comprises a thread 73, of the interface member 7.

[0042] Still with reference to the, the disassembly tool 5 comprises a stabilizing member 52 which is positioned between the interface member 7 and the anti-rotation member 51. In this example, the stabilizing member 52 is mechanically connected to the interface member 7, preferably by screwing. Alternatively, the stabilizing member 52 can also be mounted by axial clamping between the anti-rotation member 51 and the interface member 7.

[0043] The stabilizing member 52 is configured to bear against the first mechanical part P1 so as to advantageously stabilize the dismantling tool 5. Preferably, the stabilizing member 52 comprises a circular opening 520 extending along the tool axis X5 so as to form a passage between the anti-rotation member 51 and the interface member 7.

[0044] In this example, the stabilizing member 52 comprises three support arms 522 having a radial component relative to the tool axis X5 so as to ensure stable support. It goes without saying that the number of support arms 522 could be greater. The use of three support arms 522 makes it possible to ensure stable support when the anti-rotation member 51 cooperates with the female part 2 of the fixing 1.

[0045] Still with reference to the, the interface member 7 comprises a through housing 4 extending along the tool axis X5, configured to receive a cutting apparatus 6 (shown in the). In this example, the interface member 7 is shown as a single main body 77, but it goes without saying that it could comprise a plurality of modular bodies assembled together.

[0046] The through-housing 4 comprises an upstream mouth 4A and a downstream mouth 4B. The through-housing 4 comprises, from upstream to downstream, a connection portion 41, a middle portion 42, an alignment groove 43 and a connecting portion 44.

[0047] Preferably, the connection portion 41 of the interface member 7 is configured to receive the cutting apparatus 6 which will be presented subsequently. In this example, the connection portion 41 comprises an upstream thread 76 to allow the cutting apparatus 6 to be screwed in order to allow precise positioning and alignment. The connection portion 41 forms a stable connection interface allowing repeatable connection of cutting apparatuses 6.

[0048] In this example, the middle portion 42, directly downstream of the connection portion 41, is configured to receive a portion of the cutting apparatus 6. Preferably, the middle portion 42 of the interface member 7 comprises a plurality of discharge recesses 75, preferably extending radially relative to the tool axis X5. These discharge recesses 75 advantageously make it possible to discharge the chips of material cut by the cutting apparatus 6 as will be presented later.

[0049] The alignment groove 43 is configured to guide the cutting apparatus 6 in the passage opening 510 of the anti-rotation member 51. In this example, the alignment groove 43 is delimited radially by an annular crown defining, downstream, a transverse wall 430 capable of forming a stop during the mounting of the anti-rotation member 51 in the interface member 7.

[0050] Preferably, the alignment groove 43 has a diameter D43 which is equal to + / - 10% of the diameter D510 of the passage opening 510 of the anti-rotation member 51.

[0051] The interface member 7 further comprises a connecting portion 44, at the downstream end of the interface member 7, mechanically connected to the connecting portion 512 of the anti-rotation member 51.

[0052] In this example, the interface member 7 is connected to the stabilizing member 52 by screwing. In particular, the interface member 7 comprises a second thread 74 formed on an outer surface of the connecting portion 44 of the interface member 7 which cooperates with a tapping 521 formed on an inner surface of the annular opening 520 of the stabilizing member 52.

[0053] The disassembly tool 5 can thus be conveniently assembled by screwing as shown in.

[0054] The use of the disassembly tool 5 with a cutting device 6 will now be presented in order to allow the removal of the female part 2 of the fastener 1.

[0055] In this example, the cutting apparatus 6 is generally in the form of a drill. With reference to the, the cutting apparatus 6 extends along a cutting axis X6 and comprises a cutting member 61, for example a rotary drill, the axial position of which along the cutting axis X6 can be modified according to a predetermined displacement stroke. The cutting apparatus 6 comprises a support member 62 in which the cutting member 61 is mounted and which is capable of being driven in rotation along the cutting axis X6. The support member 62 is connected to a rotation drive motor. In this example, the cutting apparatus 6 comprises an adjustment device, in particular a micrometric stop 63, connected to the support member 62, configured to adjust the displacement stroke CD of the cutting member 61 and thus avoid damage. The support member 62 is able to extend into the middle portion 42 of the interface member 7.The micrometric stop 63 is capable of extending into the connection portion 41 of the interface member 7, in particular, by screwing.

[0056] In this example, the cutting member 61 has a cutting diameter D61 which is less than the outer diameter D2 of the female part 2 but greater than the inner diameter D2 of the female part 2. The cutting diameter D61 is less than the diameters D510, D43 in order to allow the cutting member 61 to reach the female part 2 of the fastener 1.

[0057] The method of using a disassembly tool 5 according to the invention will now be presented.

[0058] With reference to Figures 3 and 4, the cutting apparatus 6 is inserted into the disassembly tool 5 through the mouth 4A of the interface member 7, from upstream to downstream. The cutting member 61 is guided by the alignment groove 43 until it extends into the opening 510 of the anti-rotation member 51 of the disassembly tool 5. The micrometric stop 63 is screwed to the connection portion 41 of the interface member 7. The support member 62 extends into the middle portion 42 of the interface member 7 as illustrated in. The tool axis X5 is thus advantageously merged with the cutting axis X6.

[0059] If an operator exerts an axial force on the cutting device 6, the support member 62 can move downstream according to a displacement stroke CD which is determined by the adjustment of the micrometric stop 63. For example, the displacement stroke CD is between 10mm and 30mm.

[0060] Preferably, in the absence of axial force applied by the operator, the cutting member 61 is in the retracted position PR as illustrated in. The downstream end of the cutting member 61 is located at a first distance Da from the gripping surface 511 of the anti-rotation member 51. The first distance Da is less than the displacement stroke CD. For example, the first distance Da is between 10 mm and 20 mm. The downstream end of the cutting member 61 is advantageously retracted into the passage opening 510 during handling of the cutting apparatus 6 assembled with the disassembly tool 5. Any risk of unintentional impact or scratching can thus be avoided.

[0061] Still with reference to the, the disassembly tool 5 is then brought into contact by its gripping surface 511 of the anti-rotation member 51 () with the imprinted head 21 of the female part 2 of the fastener 1 to be disassembled from the upstream side C1. The grips of the gripping surface 511 cooperate with the imprints of the imprinted head 21, so as to advantageously prevent any slipping or skidding of the disassembly tool 5. Preferably, the cutting tool projects a few millimeters from the anti-rotation member and cooperates in a preliminary manner with the blind fastener before the cooperation of the gripping surface 511 of the anti-rotation member 51. This makes it possible to achieve optimal alignment.

[0062] The support arms 522 are brought into contact with the first mechanical part P1, ensuring stability for the disassembly tool 5. The tool axis X5 is thus advantageously merged with the fixing axis X1 and with the cutting axis X6. The alignment of the three axes X1, X5, X6 is advantageously ensured, on the one hand, by the complementary gripping surface 511 of the imprinted head 21 of the female part 2 and, on the other hand, by bringing the support arms 522 of the stabilizing member 52 into contact with the first mechanical part P1.

[0063] With reference to the, the cutting member 61 is rotated and an operator exerts an axial force EFF on the cutting apparatus 6, which moves the cutting member 61 downstream along the movement stroke CD. The cutting member 61 is in the extended position PS as illustrated in the. The downstream end of the cutting member 61 is located at a second distance Db from the gripping surface 511 of the anti-rotation member 51. For example, the second distance Db is between 0.5 mm and 10 mm. The downstream end of the cutting member 61 advantageously projects so as to penetrate the female part 2. During rotation of the cutting member 61, the upstream end of the female part 2, prevented from rotating by the anti-rotation member 51, breaks off into chips which are evacuated by the evacuation recesses 75 of the interface member 7.

[0064] With reference to the, when the operator stops his axial force EFF on the cutting device 6, the cutting member 61 is again in the retracted position PR. The disassembly tool 5 associated with the cutting device 6 can then be moved away from the fastener 1 to disassemble another fastener quickly and similarly.

[0065] With reference to Figures 6 and 7, cutting the upstream end of the female part 2 makes it possible to eliminate its axial retention upstream of the first mechanical part P1. This advantageously makes it possible to separate the imprinted head 21 from the rest of the female part 2 using very little force and quickly without any risk of damage. In addition, since the entire operation takes place on the upstream side C1, only one operator is required to handle the disassembly tool 5 and disassemble the female part 2 from the fastener 1.

[0066] Thanks to the disassembly tool 5 according to the invention, the disassembly of the female part 2 of a fastener 1 is faster, simpler and has better ergonomics. The disassembly rate can advantageously be doubled because it now only requires one operator, compared to two according to the prior art. Finally, quality problems linked to unintentional damage are eliminated.

Claims

Assembly of a cutting apparatus (6) comprising a cutting member (61) and a disassembly tool (5) for a blind fastener (1) securing a first mechanical part (P1) and a second mechanical part (P2), the disassembly tool (5) being mounted in an attached manner by screwing onto the cutting apparatus (6), the blind fastener (1) having been introduced from upstream to downstream into an opening (O1) of the first part (P1) then into an opening (O2) of the second part (P2) from an upstream side (C1), the blind fastener (1) extending along a fastening axis (X1), the blind fastener (1) comprising a female part (2) extending into the openings (O1, O2) and a male part (3) inserted into the female part (2) in order to deform it to secure the mechanical parts (P1, P2),the disassembly tool (5) comprising: an anti-rotation member (51) comprising a passage opening (510) extending along a tool axis (X5) and a gripping surface (511) configured to cooperate with the female part (2) of the blind fastener (1) from the upstream (C1) in order to prevent its rotation around the fixing axis (X1), an interface member (7) connected to the anti-rotation member (51), the interface member (7) comprising a main body (77) comprising a through housing (4) extending along the tool axis (X5) which comprises an upstream mouth (4A) configured to receive a cutting device (6) comprising a cutting member (61), the interface member (7) comprising a connection portion (41), a middle portion (42), an alignment groove (43) and a connecting portion (44), the alignment groove (43) being configured to guide the cutting member (61) in the passage opening (510) of the anti-rotation member (51), the connecting portion (44),at the downstream end of the interface member (7), being mechanically connected by screwing to a connecting portion (512) of the anti-rotation member (51), the cutting device (6) being introduced at least partially into the through-housing (4), the cutting member (61) extending into the alignment groove (43) a stabilizing member (52) configured to bear on the first mechanical part (P1), the stabilizing member (52) being positioned between the interface member (7) and the anti-rotation member (51)., An assembly according to claim 1, wherein the stabilizing member (52) comprises at least three support arms (522) Assembly according to one of claims 1 to 2, in which the main body (77) of the interface member (7) has a plurality of discharge recesses (75), preferably extending radially relative to the tool axis (X5). Assembly according to one of claims 1 to 3, in which the cutting apparatus (6) comprises a micrometric stop (63). Method of using an assembly according to one of claims 1 to 4 for dismantling a blind fastener (1) securing a first mechanical part (P1) and a second mechanical part (P2), the blind fastener (1) having been introduced from upstream to downstream into an opening (O1) of the first part then into an opening (O2) of the second part from an upstream side (C1), the blind fastener (1) extending along a fastening axis (X1), the blind fastener (1) comprising a female part (2) extending into the openings (O1, O2) and a male part (3) inserted into the female part (2) in order to deform it to secure the mechanical parts (P1, P2), the male part (3) of the fastener (1) having been previously removed, the cutting member (61) being set back in the dismantling tool (51),the method comprising steps consisting of:Making the gripping surface (511) of the anti-rotation member (51) cooperate with the female part (2) of the blind fastener (1) from the upstream side (C1) in order to prevent its rotation around the fixing axis (X1),Moving the cutting member (61) downstream so that it cuts an upstream end of the female part (2) of the blind fastener (1)., Method of use according to claim 5, comprising a step of stabilizing the position of the tool axis (X5) so that it is coaxial with the fixing axis (X1). A method of use according to claim 6, the main body (77) of the interface member (7) having a plurality of discharge recesses (75), the method comprising a step of discharging the cutting waste via the discharge recesses (75).