FR2604760A1 - PANEL FASTENING ASSEMBLY COMPRISING A CAPTIVE MEMBER - Google Patents

Abstract

THE INVENTION RELATES TO A CAPTIVE FIXING ORGAN ASSEMBLY FOR A PANEL. IT RELATES TO A SET IN WHICH A THREADED ANKLE 11 CAN BE RETAINED IN A VIROLE 22 PLACED IN THE HOLE OF A PANEL BY COOPERATION OF ELASTIC TABS 26, 27 OF THE VIROLE 22 WITH A THROAT 35 SHAPED AT THE END OF THE ANKLE 11. THIS LATTER CAN BE HELD IN THE EXIT POSITION WHEN THE TABS ARE PLACED IN THE THROAT, BUT CAN ALSO BE PUSHED INWARDS, THE TABS SLIPING ALONG ITS STEM 36. APPLICATION TO THE RETAINING TO THE PANELS.

Description

The present invention relates to assemblies with

  The invention relates to a captive fastener for a panel, and more specifically to an improved assembly with an attachment member intended for an aircraft and ensuring the retention of the head and the rod of an anchor of the fastener assembly to be disengaged.

  of an opening formed in a panel in an aircraft

  nave, in a first position, while allowing the thrust of the ankle to a second position in

  which the head is in abutment against the panel of the aircraft

  nave and the rod enters the opening formed in this panel and can be connected to a complementary assembly

  housing mounted on an infrastructure of the aircraft.

  Panel fasteners for aircraft are

  well known. Usually, these bodies ensure the

  of a panel to an aircraft by introduction, by an opening formed in the panel of the aircraft, of a housing member fixed to the panel, on the hidden side thereof, which

  is screwed to the stem of the fastener, the head extended

  being in abutment with the panel on the accessible side thereof. Devices have already been suggested to prevent separation of the panel fastener when this member is unscrewed and separated from the housing member. In some applications, the panels may be formed of composite materials, and such materials may easily crack or disintegrate when the load applied to the panel fastener assembly is not distributed over the entire area surrounding the hole. . U.S. Patent No. 4,285,380 discloses a panel fastener having a nut which is formed on a stud, the nut having a tapped hole and being mounted on a ferrule assembly itself disposed in a sign. The nut is intended to cooperate by screwing with a stud mounted on an infrastructure panel. In

  first position, the nut is kept away from the

  water, outwardly, by a retaining ring placed in the ferrule assembly and retained in a groove near the nose of the nut. When the nut is pushed inwardly of the panel, the retaining ring disposed in the ferrule assembly moves along the rod of the nut until it abuts against the head of the nut. the nut and

  hold the latter on the panel, in an indi-

  dull, and until the nut is removed from the panel.

  The ring moves along the stem until it re-enters the throat near the nose of

the nut.

  Clearly, the ferrule assembly described in this patent requires a number of carefully machined elements and the installation in a panel 16 relatively

  thick. It also requires the formation of a relative hole

  made in the panel, for the housing of the en-

seems to ferrule.

  U.S. Patent No. 4,324,517 discloses a panel fastener assembly for

  to connect a sign to a sign board

  frastructure. This assembly comprises a nut having a

  and attached to a ferrule assembly mounted in the

  neau. A housing unit is attached to the infra-

  structure. The ferrule assembly comprises a retaining ring

  naked in a groove formed in the body of the nut when it is in the withdrawn position or outwardly spaced away from the housing assembly. As shown in FIGS. 5 and 8 of this patent, the panel fastener assembly consists of precisely machined elements. In addition, as shown in Figure 1 of this patent, the panel 4 must be relatively thick so

  that it allows the setting up of the assembly with ferrule.

  Thus, in the two aforementioned patents, it is necessary that elements are machined accurately and mounted as subsets. These subassemblies require that the panel in which they are mounted be relatively

  thick, and they increase the weight of the installation. cer-

  some panels, for example those of vehicle doors and the like, must be relatively thin and of low weight. Thus, the fastener assemblies that are used in these panels must be very small and very light. The achievements of these two patents are thick and heavy and increase the weight of the installation. This is very undesirable, especially when editing in

  aircraft whose payload is reduced.

  A panel fastener assembly allows

  both the attachment of a panel to an infrastructure panel and such that its peg can be retained in external position or withdrawn, without separation of the panel, until it is placed in cooperation with a fastener, such as a dowel , carried by the infrastructure panel, is therefore necessary. Such a fastener assembly must be light, must have a relatively small number of elements, must be easy to manufacture and mount and must, however, give great mechanical strength and

  high rigidity at installation.

  The subject of the invention is a simplified assembly with a panel fastener, intended for fixing a

panel on an infrastructure.

  It also concerns an improved assembly with

  a panel fastener having an anchor secured to

  a panel and which can be held in position

  tance of the panel and then pushed back so that it comes together

  with a fastener carried by an infrastruc-

ture.

  It also concerns an improved assembly with

  a panel mounting member having a sleeve mounted in a panel and providing strength and rigidity to the hole formed in the panel so that the life of the panel is increased and the load is well distributed throughout the area surrounding the hole, the sleeve cooperating with an anchor fixed to the panel so

  that the ankle can be held in position

the panel.

  These different characteristics are obtained by using a captive fastener assembly of panel according to the invention, intended to connect a panel to

  an infrastructure. The fastener assembly comprises

  takes a threaded dowel, a ferrule assembly attached to the panel and a housing assembly attached to the infrastructure. The threaded pin passes into the ferrule assembly and cooperates with the housing assembly so that the panel is connected to the infrastructure. The ankle has an enlarged head at a first end, an intermediate portion forming a body and a nose. at the other end. A throat

  is formed between the nose and the body of the ankle. The in-

  seems to ferrule has a sleeve placed in a hole

  formed in the panel, the sleeve having several tongues

  the elastics protruding inwards and formed from the body of the sleeve, the tongues moving outwardly upon insertion of the nose into the

  sleeve until the nose passes beyond the tabs, -

  these then penetrating into the groove and resuming their original position turned inward so that the ankle is held in the extended position relative to the panel, the ankle can however be pushed back to a position in which the tabs move along from the body of the ankle, until the head of the

  ankle abut against the panel. Thus, the

  city is retained in the panel and remains in position

  extracted when the panel is separated from the infrastructure.

  The sleeve therefore ensures the coating and reinforces

  hole which has good mechanical strength and

  duration of use-is increased because of the elimination of

  nation of usury. This provision is particularly

  well with relatively thin or

  composite materials, since the insallation of the sleeve does not

  does not stop a large hole and the load is

  spread over the entire area around the hole.

  Other features and advantages of the invention

  will be better understood by reading the description

  which will follow of embodiments, made with reference to the accompanying drawings in which: Figure 1 is a side elevation in partial section of a panel fastener assembly

  according to the invention, associated with a panel and an infrared

structure;

  Figure 2 is an exploded perspective of the

  seems to fastening member of Figure 1, according to the invention

  tion; Figure 3 is a perspective of the sleeve of Figure 1, shown alone, before installation; Figure 4 is a bottom view of the sleeve of Figure 3; Figure 5 is a side elevation, partly in longitudinal section, showing the peg of the panel of Figure 1, inserted into the sleeve thereof; Figure 6 is a side elevation in partial longitudinal section of the elements of Figures 1 to 4 in their final mounting position; Figure 7 is a side elevation partly in longitudinal section, of a variant of the figures panel

1 to 5;

  Figure 8 is a partial longitudinal sectional elevation of the pin of Figure 6, when in place; Figure 9 is a perspective similar to Figure 3, showing a variant of the sleeve according to the invention; Figure 10 is a section along line X-X of Figure 1; Figure 11 is a section through a longitudinal plane of a ferrule assembly variant according to the invention; Figure 12 is a longitudinal sectional view, similar to Figure 5 but without the dowel, showing the mounting of the ferrule assembly of Figure 11; and FIG. 13 is a longitudinal section of the

  washer of the assembly of Figure 12, shown alone.

  Referring first to FIG. 1, there is shown a panel fastener assembly 10 in cooperation with a construction panel 21 and an infrastructure 18. A ferrule assembly 22 is shown mounted in a milled aperture 20 aligned with the hole 33 formed in the panel 21, according to the invention. The assembly 10 comprises a threaded pin 11 intended to pass through the assembly 22 to

  ferrule and to come cooperate with a 12 housing set.

  The pin 11 can be tapped, as indicated by

  threads 13, and can cooperate with a threaded stud 14 hand-

  held in the housing set 12.

  As shown in FIG. 3, a set 22 to

  ferrule is shown before it is installed in the opening.

  Thus, the ferrule assembly 22 (or sleeve) comprises a body 23 of generally cylindrical and thin-walled shape, having a hole 24 and a flange.

  25 of circular general shape, at a first end.

  Two tabs or tabs 26, 27 (see also FIG. 4) are cut into the thin-walled body 23 and protrude inwardly as shown in FIG. 4. These tabs 26, 27 are circumferentially disposed around the body 23 and are diametrically opposite each other. The body 23 is obviously formed of a material

  suitable, that is to say of a metallic material

  both cutting the tabs in the rest of the body 23, with some elasticity. Thus, as indicated in FIG. 4, a thrust exerted on the tabs 26, 27 towards the outside, that is to say in the opposite direction to that of the longitudinal axis of the body 23, brings the tabs towards

  outside at the level of the rest of the body 23.

  Referring again to Figure 1; the body 23, having the shape shown in Figure 3, is inserted into the hole 33, in the direction of the arrow 28 until the flange 25 enters the hole 29 formed on the surface of the panel 21 so that the outer surface of the flange 25

  is at the outer surface of the panel.

  The other end such as the end 31 of Figure 1, is deformed so that it is pushed against the opening formed in the surface 32 of the panel 21, so that it

  takes the configuration of this opening.

  The threaded pin 11 (Figure 2) has a nose 34, an annular groove 35 adjacent the nose 34 and a rod 36 of generally cylindrical shape. An enlarged head 37 is disposed at the end of the rod 36 and is intended to abut against the end 31 of the ferrule assembly 22, when the rod is screwed onto the threaded stud 14 of the assembly 12 of housing as described below. A countersunk hole 19 formed in the infrastructure panel 18 is aligned with the hole 33 of the top panel 21. Although at least one of these panels 18, 21 may be formed of a

  composite material or can be relatively thin,

  door which suitable sign can obviously be fixed by

implementation of the invention.

  The housing assembly 12 (FIG. 2) comprises a hooking support 16 or a housing, a cylinder 60 and

  A threaded stud 14. As shown in Figure 1, the end

  The lower barrel 60 is crimped around the base 62 'of the stud 14 and is deformed inwards so that it cooperates with the stud 14 and connects the barrel 60 to the barrel 60. As shown in FIG. 2, the threaded stud 14 has a protrusion 110 having flattened areas 111, 112 (see also Fig. 10). As indicated in FIG. 1, the barrel 60 has a peripheral wall 113

  turned inwards and whose configuration is

  logue that of the projection 110 (Figure 10). It's about

  of a feature preventing rotation of the stud

  14 in the barrel 60 so that the stud 14 and the barrel 60 can cooperate and be locked relative to each other, behaving as a one-piece element. The barrel 60 has tabs 63 which penetrate into two slots 64 formed in the hooking support 16 so that the barrel 60 is connected to the support 16. The slots 64 have a circumferential dimension greater than the width of the tabs 63 so that the cylinder 60 and the threaded stud 14 can rotate in a limited amount relative to the support 16 attachment. The latter is fixed to the infrastructure 18 (FIG. 6) in any suitable manner, for example by rivets 17 passing through holes 17 '(FIG. 2) of the support 16.

  12 housing and support 16 as a set of ele-

  individual elements, a single element can obviously be used.

  The tapped anchor It is represented on the

  gure 1 in its position of separation of the stud, outlet relative to the panel 21. The pin 11 is fixed by the

  tongues 26, 27 which penetrate the groove 35.

  The assembly of the assembly 22 is obviously made before the introduction of the pin 11. This assembly is shown in Figure 5 in which the pin 11 is

  introduced into the assembly 22 in the direction of the arrow 41.

  The nose 34 moves at the tongues 26, 27 and

  pushes them outwards, that is to say

  The nose 34 thus moves beyond the tongues 26, 27 until the tongues penetrate into the groove 35 and return to their original position shown in FIG. 4, if although they elastically hold the ankle 11 in

  the groove 35 and keep it in the extended position

  Figure 1. The ankle 11 can then be moved

  in the direction of arrow 42 (Figure 1) to the position

  Final mounting assembly shown in Figure 6, wherein the pin 11 is screwed onto the stud 14 of the housing assembly 12. When the pin 11 is moved from the position of Figure 1 to that of Figure 6, the tabs 26, 27 move along the frustoconical portion 40 of the pin 11 and along the rod 36 until the head 37 comes into contact with the end 31 of the assembly 22 as shown in Figure 6. The tongues 26, 27 and surround the pin 11 between the head 37 and the rest of the rod 36. When unscrewed

  of the threaded stud 14, the ankle 11 can thus be moved

  in the direction of the arrow 28 (Figure 1) from the position of Figure 6 to that of Figure 1, the tongues 26, 27 returning along the rod 36 until they enter the groove 35 as shown in FIG.

  In addition, although two tabs are

  In FIGS. 1 to 5, a number of tabs greater than two may of course be used. In addition, although the tabs 26, 27 are represented in the same

  plan, this provision being preferable so that the man-

  chon can be mounted in relatively thin panels, it is not necessary that the tabs are in the same plane. It is preferable that

  tongues 26, 27 are both circumferentially

  the outer surface of the body 23 and preferably

  in diametrically opposed positions so that the weight of the ankle 11 which is applied to them is well distributed. In addition, although tabs have been

  circumferential with reference to FIGS. 1 to 5, those

  they can be placed vertically. This arrangement is indicated in FIG. 7 on which identical references designate elements similar to those of FIGS. 1 to 6, the infrastructure panel 18 and the housing assembly 12 being removed for the convenience of the

  representation. Thus, a sleeve assembly 50 is

  is flanged 51 (flange 25-like) and a thin-walled hollow cylindrical body 52 (similar to the body 23) having a deformed end 53 (end-like 31). Several tabs-three of which are visible on the

  FIG. 6, for example the tabs 54 to 56, are

  52. Each tongue 54 to 56 is inwardly directed towards the central axis of the assembly 50 as shown in FIG. 7, and downwardly in the direction of

  arrow 41 'as shown. Another identical tongue

  The tab 54 to 56 is facing outwardly of the body 52 (this tab not being visible) can be formed in the wall of the body 52 so that four regularly distributed tabs are placed at the circumference of the body 52, in positions diametrically opposed, for

  reasons indicated above. Obviously, several lan-

  This type of watch can be used and it is not

  necessary that they are in the same plane.

  The mounting of the pin 11 in Figure 7 is identical to the mounting of the pin 11 of all of Figures 1 to 6. Thus, the pin 11 is inserted into the assembly 50 in the direction of the arrow 41 ', the nose 34 penetrating the assembly 50 and pushing the tabs 54 to 56 outwards, because of their own elasticity, until the nose 34 protrudes from these tongues 54 to 56. At this moment, the latter return elastically to the position shown in Figure 8, in the groove, and tighten the pin 11 and hold it in the position shown in Figure 8. Obviously, the pin 11 can then be pushed inwards, further,

  so that she comes to cooperate with a housing complex.

  carried by an infrastructure panel as described above.

  with reference to all of Figures 1 to 6, and

  it can be separated and removed from this set of boxes.

  as previously described with reference to the

embodiment of Figures 1 to 6.

  We now refer to the two modes of

  tion; the rotation of the threaded pin 11 causes its

  screwed together with the threaded stud 14 of the

  seems 12 of housing. Preferably, the pin 11 and the threaded stud 14 have double threads so that the time and displacement necessary for the removal and placing

  in place of the panel be reduced.

  The barrel 60 may comprise projections 70 (FIG.

  gure 1) facing inwards and cooperating by friction

  with the outer surface 61 of the threaded pin 11, when it is screwed onto the threaded stud 14, if

  although the ankle 11 is firmly locked on the

  housing 12 when the panel 21 is attached to the infrastructure 18. In the preferred embodiment,

  these projections 70 are preferably made by deformation

  It can be used from the outside of the barrel 60, but any suitable device for frictionally locking the internal surface of the barrel 60 and the external surface 65 of the peg 11 can be used, for example in the form of a material insert. plastic introduced by the side of the

barrel 60.

  As previously described, the ferrule assembly 22

  may be at the surface 30 of the panel 21.

  However, in some applications, the thickness of the panel 21 and sealing criteria may require the use of a liner 66 between the panel 21 and

infrastructure 18.

  It can thus be noted that the invention relates to a

  together in which a restraint and restraint device

  your ankle in the out position is made in one

  single piece and its mounting is simple and easy. The lan-

  can be cut quickly and easily or

  formed by deep drawing in the body of the sleeve.

  Thus, no precise machining of elements is necessary. The sleeve may have a machined construction in one piece or may be formed of a stamped soldered metal element. Thus, the sleeve can be made in one piece and the tabs can be cut into the sleeve, or the sleeve can be made from a flat member which is then shaped and rolled into an open cylinder or of a split ring as shown in FIG. 9. Thus, the sleeve 71 has been

  formed from a flat material, numerical references

  identical to those in Figure 3 designating

  elements similar to those of the sleeve 22 of this figure.

  The sleeve assembly 50 of FIG. 7 may also be a

split ring.

  As the tabs only cover one surface

  of the sleeve and as the sleeves

  Due to the rigidity of the mounting holes, lightweight sleeves can be mounted in very thin and / or very light panels of any type of material, even

  composite materials. Thus, the excess weight is eliminated.

  The tabs of the two sliding embodiments

  feel or slide along the body of the ankle up to

  what they are in abutment against the nose of it.

  Thus, the tabs replace the various elements used

  to perform these functions in the prior art.

  such as the ferrule assemblies of the aforesaid U.S. Patent Nos. 4,324,517 and 4,285,380.

  the tongues of the two embodiments preferably have

  diametrically opposed positions, the force of ap-

  the ankle on the tabs of the sleeve is

  also, while the sleeve provides the coating and the reinforcement of the mounting hole which thus has a good mechanical strength and the duration of use

is lying down.

  Although the ferrule assemblies 22 and 50 have been described as comprising a cylindrical portion 23 or 52 to

  thin wall that can be deformed or flared in the opening

  With the milling angle 20, this flaring may be undesirable in the case of panels formed of certain materials. Thus, as indicated in FIG. 11, a ferrule assembly 150 can be made with characteristics similar to those of the assembly 23 of FIG. 3, the references of FIG. 11 identical to those of FIG. 3 denoting elements like. In this variant of the invention, the flange 25 is removed and the body 151 has a flared portion 152, formed before its upper end as shown, this portion being adapted to fit into the opening 20 of Figure 1. The assembly 150 to ferrule

  FIG. 11 has tabs 26 and 27 as previously described.

  demtene but it can include obviously tongues similar to those of the embodiment of Figures 7 and 8 and can be in the form of a split ring as in the embodiment of Figure 9. In addition, the assembly 150 to ferrule can be formed from a flat metal

  stamped which is rolled in the form of a cylinder with

  slit between its free ends as

shown in Figure 9.

  In the embodiment of FIG.

  The ring 150 is installed on the panel 21 (FIG. 12) using a washer 153 as shown in detail in FIG. 13. The washer 153 is preferably circular and may have a flat top wall 154. , a flat bottom wall 155 and a cylindrical outer peripheral wall 156. The inner circular wall 157 may be inclined downwards and outwards,

  level of an inclined wall 158, with respect to the longitudinal axis

  tudinal of the washer 153. The latter can be formed

stainless steel.

  As shown in Figure 12, the ferrule assembly 150 is placed in the hole 33 of the panel 21 with the flared portion 152 abutting the countersunk opening 20, with the configuration thereof. The washer 153 is placed in the hole 29 formed on the hidden side 30 of the panel 21. The lower end 161 of the ferrule assembly 150

is set against the puck 153.

  The use of the washer 153 is particularly

  Efficiently effective in the overall panel fastener assembly of FIG. 1, when used with composite materials. The washer 153 has a bearing surface 154 against the surface 29 of the panel 21 which is wider than in the known assemblies. As the washer 153 always has the same thickness, the crimping of the end 161 of the assembly 150 quickly and easily forms a lip resting against the washer 153, now this one

  on the panel 21 regardless of the thickness thereof.

  Although we have described a particular set of

  housing, any suitable set can be used.

  Of course, various modifications may be made by those skilled in the art to the assemblies which have just been described solely as non-limiting examples.

  without departing from the scope of the invention.

Claims (22)

  A captive panel attachment member assembly comprising a peg (11) having an enlarged head at a first end, a nose (34) at the other end, and an intermediate portion forming a body, a groove (35). ) being formed on the ankle between the nose and the body, a panel (21) having a hole (33) containing a retaining device (22) mounted in the panel to maintain it   the ankle in a first position in which   it came out of the panel and in a second position in   which the ankle is intended to cooperate with a   housing appears mounted in an adjacent infra-   structure, said assembly being characterized in that: the retaining device comprises a sleeve (22) mounted in the hole (33) formed in the panel, - the sleeve having a plurality of tabs (26, 27) protruding inwardly therefrom , towards the central longitudinal axis of the sleeve, and are intended to deviate from this central longitudinal axis of the sleeve when the pin (11) is introduced into the sleeve and when the nose comes against the tongues, these   returning to the central longitudinal axis of the man-   chon and penetrating the throat of the ankle when the nose has passed them.   2. An assembly according to claim 1, characterized in that the tongues (26, 27) are formed by cutting the sleeve body.   3. The assembly of claim 1, characterized in that the sleeve is formed of a metallic material and the   tabs are cut in the sleeve.   4. The assembly of claim 1, characterized in that the sleeve (22) is a thin-walled metal member, generally cylindrical in shape and machined in one piece, and the tongues (26, 27) are cut in the wall of this organ.   5. An assembly according to claim 1, characterized in   the tabs (26, 27) are circumferentially around the sleeve.   6. The assembly of claim 1, characterized in that the sleeve has a metal portion (23) forming a thin-walled body of generally cylindrical shape, and the tongues comprise two tongues (26, 27) spaced circumferentially and cut in the body , these tabs being substantially in the same plane and being diametrically opposite.   7. The assembly of claim 1, characterized in that the sleeve (22) has a main body (23), and the tongues (26, 27) protrude inwardly towards the central axis of the body and downwardly in departing from the body of opposite side to the ankle.   8. Assembly according to claim 1, characterized in that the sleeve (50) comprises a metal part   forming a thin-walled body of generally cylindrical shape   and the tabs (54-56) comprise a plurality of tongues spaced circumferentially and cut in   the body, each tongue protruding from the body towards the   the central longitudinal axis of the latter, and   inclined direction opposite the side of the ankle.   9. An assembly according to claim 8, characterized in   four tongues (54-56) are present, the   alternating gullets being diametrically opposed.   10. The assembly of claim 1, characterized in that the sleeve (71) is formed of a cut flat metal element which has been rolled in the form of a cylinder and   which forms a slit between its free ends.   11. The assembly of claim 10, characterized in that the tabs (26, 27) are cut in the sleeve body.   12. The assembly of claim 1, characterized in that it comprises a device (70) of friction associated with the housing assembly and the ankle and intended for prevent their relative rotation.   13. The assembly of claim 1, characterized in that the housing assembly comprises a support member attached to the infrastructure panel, a barrel (60) fixed to the support, and a threaded stud (14) disposed in the barrel of the side of the ankle and intended to cooperate with   this so that the ankle is fixed   on the threaded stud, the cylinder being retained on the threaded stud, a device associated with the stud and barrel-   let preventing their relative rotation.   14. The assembly of claim 13, characterized in that it comprises a device (70) of friction associated with the pin (11) and the stud (14) and intended for   prevent their relative displacement by blocking each other during   that the ankle is screwed on the stud.   15. The assembly of claim 1, characterized in that the panel (21) has an access side and a hidden side, the sleeve (150) having a main body (151) thin wall and generally cylindrical shape having a flared head (152), previously formed at one end and intended to cooperate with a milled opening surrounding the   hole in the access side of the panel.   16. The assembly of claim 15, characterized in that an opening (29) is formed on the hidden side of the panel, around the hole, and a washer (153) is placed in this opening, the lower end of the body (151). )   sleeve being crimped against the washer.   17. Sleeve holding an ankle in the extended position relative to a panel, characterized in that it comprises: a hollow elastic main body (23) of generally cylindrical shape, having a flange (25) at a first end, the flange having a diameter greater than that of the body, and a deformable flange (24) at the other end, and a plurality of tabs (26, 27) cut directly into the material of the body but connected thereto, the tongues being turned towards the inside of the body and having a certain elasticity so that they can be brought back to the level of the rest of the body, then return elastically towards their internal position when they are released. Sleeve according to Claim 17, characterized in that the sleeve (22) is an element machined in a single thin-walled room.   Sleeve according to Claim 17, characterized in that the sleeve (71) is formed of a flat metal member which is rolled into a cylinder and which forms   a slit between its free ends.   20. Sleeve holding an ankle in the extended position relative to a panel, characterized in that it comprises: a hollow elastic main body (151) of shape   generally cylindrical, having a flared portion (152) before   formed at a first end and having a di-   meter greater than that of the main body, and one   deformable tee at the other end, and several tabs (26, 27) directly stamped into the body material but connected thereto, these tongues being turned towards the inside of the body and having an elasticity such that they can be pushed back   at the level of the rest of the body and can return elastically   towards their internal position when they are released   Chees. Sleeve according to claim 20, characterized in that the sleeve (150) is an element machined in one only thin-walled part.   22. Sleeve according to claim 20, characterized in that the sleeve (150) is formed of a flat metal member which is rolled into a cylinder and which forms a slit between its ends.