FR2577629A1 - Dowel for fastening objects against a hollow partition with the aid of a screw - Google Patents

Abstract

Dowel of the type allowing the fastening of an object, with the aid of a fastening screw, against and outside a hollow partition comprising two parallel plain walls 4a, 4b spaced from one another by a distance d, one of the two walls being pierced with a hole through which the dowel is inserted from the outside between the two walls 4a, 4b to the inside 6 of the partition 3 and which allows the passage of the fastening screw, characterised in that it comprises means for holding this dowel 1 inside 6 the partition 3, facing the hole. The dowel according to the invention is held in place facing the hole when it is in place inside the hollow partition.

Description

Dowel for fixing objects using a screw against

a hollow partition.

  The present invention relates to an ankle for

  be inserted inside a hollow partition, and

  putting to fix objects outside of and against

  this hollow wall using a fixing screw.

  The present invention also relates to a method of fixing an object to a partition using such a dowel. Anchors for fixing objects against partitions are already known, and more particularly anchor pins for fixing objects on plaster partitions, on plant panels and other soft, hollow or insulating materials. Known devices provide dowels which have four anchoring branches which deviate behind the wall of the hollow partition until they are completely flattened as the fixing screw is screwed on these dowels. These anchoring branches prevent on the one hand that the dowel does not rotate with the fixing screw, and on the other hand that the dowel does not come out of the hollow partition when the wall is particularly fragile, or that the tightening

  of the screw must be particularly important.

  However, these known devices do not allow main-

  hold the dowel opposite the hole drilled in the wall when the dowel is fully inserted inside

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  of the hollow partition which is inaccessible from the outside.

  Indeed when the ankle has completely crossed the

  nothing holds it anymore, and it falls inside

  interior of the hollow partition, unless you have previously introduced the screw into the dowel, when the latter

  was in the hole. However, the latter solution

  tion is inconvenient, especially when the object is large. In addition, these known pegs do not

  are not permanently applied against the wall inside the

  inside of the hollow wall, and the anchor branches

  cannot perform their function properly,

  at the very beginning of the screwing. Finally, if we remove the screw, for example to change it, the ankle is lost at

  inside the partition and it is necessary to rein-

  produce a new dowel, which is not always possible in cases where the object cannot

to be moved.

  The present invention aims to overcome these drawbacks, by proposing a dowel allowing the fixing of objects, using a fixing screw, against and outside a hollow partition comprising two parallel flat walls spaced one on the other by a distance d, one of the two walls being pierced with a hole through which the dowel is inserted from the outside inside the partition, that is to say between the two flat walls , this hole also authorizing the passage of the fixing screw, the dowel according to the invention comprising means for holding this dowel inside

  the hollow partition opposite said hole.

  Thus, the ankle according to the invention is maintained in

  place next to the hole when it is in place at the

  inside of the hollow partition between the two walls, and is not likely to fall or be irretrievably lost

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  in the interior empty space of the front hollow wall

  the introduction of the fixing screw in this dowel.

  The means for holding this ankle according to the invention

  tion are an integral part thereof, and are elastic means allowing the deformation of the anchor according to the invention having an overall length greater than the distance d, preferably elastic compression means exerting a compression preload according to the longitudinal axis of the anchor when the latter is in place inside the hollow partition and facing the hole before the introduction of the fixing screw into the anchor. These elastic means have the function of pressing the dowel inside the hollow partition against at least one of the two walls and preferably against the two walls with a restoring force such as the static friction of the dowel against the internal surface of this wall prevents the ankle subjected to its weight from sliding and therefore keeps it

next to the hole.

  The elastic means are preferably arranged at each of the ends of the dowel according to the invention and exert elastic forces in opposite directions along the longitudinal axis of the dowel. However, these elastic means can be arranged at only one of the ends of the dowel, then exerting elastic forces along the longitudinal axis of the dowel which press the other end of the dowel against the corresponding wall inside the partition. dig. These holding means can also be arranged on the median part of the ankle, substantially in the middle, tending to separate the two ends from one another and to press them against the walls inside.

of the hollow partition.

  Thus, the compression preload applied when the anchor is in place inside the partition is due to the fact that the anchor has a total length when empty, that is to say before its insertion between the two walls, greater at the distance d which separates these two walls. Ankles of different lengths are therefore provided

  vacuum for different types of hollow partitions.

  Similarly, the holding means may be produced according to different embodiments depending on the

  hollow partition (material, thickness ...) and use

  tion that we want to make of the ankle (construction

fixed, aeronautical ...).

  An anchor according to the invention comprises anti-

  back to the end of this plug which is opposite the hole when the latter is in place inside the hollow partition, the function of which is to prevent the plug according to the invention from coming out of the hollow partition through the hole when it was placed in

  the interior of this hollow partition between the two walls.

  An anchor according to the invention also comprises

  anchoring means securing this ankle to the wall

  its by avoiding that it rotates simultaneously with the fixing screw when this screw is rotated along its axis to introduce it into the dowel by screwing. Preferably, part of the elastic means for holding the ankle according to the invention constitute the non-return means and the anchoring means and have the triple function of holding the ankle, of preventing it from coming out through the hole. of the hollow partition, and to block the ankle in rotation against the

partition.

2577629

  According to one embodiment of the invention, a che-

  city according to the invention is symmetrical with respect to one and only one plane P perpendicular to its longitudinal axis

of symmetry.

  In a method of fixing an object according to the invention using a fixing screw and a dowel according to the invention, the dowel is held opposite the hole by said holding means before positioning

  of the object and the introduction of the fixing screw.

  Thus, a dowel according to the invention can be used on a building site in an easy way and does not require any special assembly tool. In addition, when the fixing screw is dismantled, the anchor according to the invention is again held between the two walls, and it is not necessary to reintroduce a new anchor to

reassemble a fixing screw.

  The following description referring to the appended figures

  will allow a better understanding of the invention, and more particularly describes an embodiment of a dowel according to the invention, made of plastic, by

  example, and more particularly intended for buildings

fixed tions.

  Figure 1 is a partial schematic view in pers-

  pective of a hollow partition on which an object is fixed by a fixing screw and a dowel according to

the invention.

  Figure 2 is a schematic elevational view of a

ankle according to the invention.

  Figure 3 is a schematic top view of a

ankle according to the invention.

  Figures 4a, 4b, 4c are schematic views through

  perspective drawings illustrating different stages of the process of fixing an object against a partition

  hollow using a dowel according to the invention.

  An anchor 1 according to the invention is an element of the device.

  positive for fixing an object 2 against and outside a hollow partition 3 having two walls 4a, 4b

  parallel planes. This hollow partition 3 can possibly-

  Lement also include longitudinal members 5 of rigidifi-

  cation or insulation perpendicular to the walls 4a, 4b planes or other known elements constituting such a hollow partition 3, such as sleepers, grooves, ribs, etc. The two parallel planar walls 4a, 4b are spaced

  from each other by a distance d and delimit an es-

  inner space 6 of the hollow partition 3, located between these two walls 4a, 4b. The wall 4a is the wall against which the object 2 is fixed; this wall 4a is therefore pierced with at least one hole 7 through which the pin 1 is inserted from the outside between the two walls 4a, 4b

  inside 6 of the partition 3 and which also allows

  ment the passage of a fixing screw 8. Thus, the fixing

  tion of the object 2 is done using the fixing screw 8

  which crosses the object 2 pierced with at least one diameter hole

  meter less than the hole 7 in the wall 4a that the screw 8 also passes through, this fixing screw 8 being screwed into a dowel 1 located behind the wall 4a, in

  the interior space 6 of the hollow partition 3.

  The thickness of the partition 3 is equal to the sum of the distance d and the thicknesses of the walls 4a, 4b. The dimensions can have all the possible values, and for example, the distance d is 20 millimeters, and the walls 4a, 4b both have a thickness of

  1 millimeter, which gives the partition 3 a thick-

22 millimeter.

  In the following, the index a will relate to the parts of the plug 1 according to the invention or of the partition 3 located

  on the side of the wall 4a pierced with the hole 7 when the sleeve

  city 1 is in place inside 6 of the partition 3, and the index b will relate to the parts of the ankle 1

  or of the partition 3 located on the side of the wall 4b.

  An anchor 1 according to the invention is generally cylindrical.

  dric and symmetrical of revolution around an axis 9.

  This axis 9 of symmetry of the pin 1 coincides with the axes of symmetry of the fixing screw 8, of the hole 7 of the wall 4a and of the hole of the object 2 when the pin 1

  is in place, inside 6 of the hollow partition 3.

  The reference 9 will therefore designate sometimes the axis of symmetry of the pin 1, sometimes the common axis of the pin 1,

of hole 7, of the hole of object 2.

  A plug 1 according to the invention has a middle part 10 and two ends 11. The plug 1 also has a longitudinal internal bore 12 along the axis 9,

  in which the fixing screw 8 is introduced and screwed.

  An anchor 1 according to the invention is such that it comprises

  door means 13 for holding this pin 1 inside 6 of the partition 3 and facing the hole 7

  of the wall 4a by which the screw 8 is introduced.

  These holding means 13 are advantageously elastic means 13 allowing the deformation of the

  pin 1 along its longitudinal axis 9, and preferably

  elastic means 13 for compression,

  that is to say elastic means specially for-

  intended to be compressed from their resting state.

  An anchor 1 according to the invention has its overall length

  at rest, i.e. its overall length before in-

  setting between the two walls 4a, 4b of the hollow partition 3, greater than the distance d which separates these two walls 4a, 4b. Using the example mentioned above where the distance d is 20 millimeters, a dowel 1 adapted to this example of hollow partition will have

  an overall length at rest greater than 20 milli-

  meters, for example equal to 25 millimeters. This length must also not be too great, otherwise the pin 1 could not be inserted between the

  walls 4a, 4b inside 6 of the partition 3.

  This is why different plugs 1 having different lengths are provided so as to be adapted to the different types of hollow partition 3 on the market. In

  the example above, the elastic means 13 de.com-

  pressure can be compressed along axis 9 by at least

  five millimeters. It is clear that only one type of che-

  city, for example of length equal to 25 millimeters, may be suitable for several thicknesses of partition, for example for the two partitions whose distance d is

  between 18 millimeters and 24 millimeters.

  Thus, the same type of ankle can be adapted to more

  several types of partitions and between five and ten types of wall plugs are provided for all the different types

of hollow partitions.

  Thus, when the plug 1 is in place inside the partition 3 opposite the hole 7 and at least before the screw 8 is introduced, the elastic means 13

  are compressed and exert a precon-

  compression strap along axis 9. The function of

  these elastic means 13 is therefore to press inside

  laughter of the partition 3 the dowel 1 against the two walls 4a, 4b, with a restoring force such that the static friction of the dowel 1 against the internal surfaces 14a, 14b of the walls 4a, 4b prevents the sliding of the dowel 1 subjected to its weight, now this

9 2577629

  pin 1 opposite hole 7. In the embodiment

  tion of the invention, shown in the figures,

  elastic means 13 are arranged at each of the ends

  moths lia, lib of the pin 1 and exert elastic restoring forces along the axis 9 of opposite directions when the pin 1 is in place inside 6 of

  the partition 3, before the introduction of the screw 8 for fixing

ankle 1.

  As illustrated in FIG. 4c, the elastic means 13 located at the end 11a of the dowel 1 bear on the wall 4a, and the elastic means 13 located at

  the end llb are supported on the wall 4b.

  However, the elastic means 13 can be arranged at one of the ends 11a or 11b of the pin 1, preferably the end 11b, and exert elastic restoring forces along the axis 9 which press the other end 11b or 11a, preferably the end 11a, against the corresponding wall 4b or 4a, preferably against the wall 4a opposite the hole 7 inside 6

of the partition 3.

  Similarly, the elastic means 13 can be disposed on the middle part 10 of the pin 1 and exert elastic return forces of opposite directions along the axis 9 when the pin 1 is in place inside 6 of the partition 3 before the introduction of the screw 8 for fixing in the dowel 1. In this case, the elastic means 13 tend to separate the two ends 11a,

  ilb from each other in the axial direction.

  A dowel 1 according to the invention comprises non-return means 15 at the end 11a of the dowel 1 opposite the hole 7 when the latter is in place inside the partition 3, the function of which is to 'prohibit. the pin 1 to come out of the partition

  3 through hole 7 when it was installed inside

  tieur 6 of this partition 3, while authorizing this establishment of the pin 1 between the two walls 4a, 4b by the hole 7 of the wall 4a. These non-return means may consist for example of clipping means or other non-return device, but are preferably constituted by the part of the elastic means 13 located at the end 11a, which then have

  at least two functions: a first function consists

  both to keep the pin 1 inside 6 of the partition 3 opposite the hole 7, and a second function of preventing the pin 1 from coming out of the interior space 6 through the hole 7, while allowing complete insertion of plug 1 between the two

walls 4a, 4b.

  A dowel according to the invention also comprises anchoring means 17 of this dowel 1 against the partition 3 securing in rotation the dowel 1 to the partition 3 and preventing it from turning around the axis 9 when

  the fixing screw 8 is introduced into this pin 1.

  We will now more particularly describe the

  elastic retaining means 13 by compression.

  A dowel 1 according to the invention has at least one of its ends 11, at least two branches 16 of elongated shape, extending the middle part 10, these two

  branches constituting the elastic means 13 of com-

  pressure. Preferably, the ankle 1 has at least one of its ends 11, four branches 16 extending the middle part 10, these branches 16 being two by two facing each other, arranged 1111 2577629 symmetrically with respect to the axis 9. The branches 16 extend from the end 11 substantially in the direction of the axis 9 while gradually moving away from it,

  each of the branches 16 being curved with concavity in turn

  born outwards, so that each of these branches 16, parallel to the axis 9 at the end 11, is inclined relative to the axis 9 at the free end 20 of this branch 16. A peg 1 according to the invention preferably comprises four branches 16a at the end lla of this pin 1 and four branches 16b at the other

end 11b of the plug 1.

  The branches 16a have three functions. A first function

  tion which consists of constituting a part of the elastic compression means 13. A second function which consists in constituting the non-return means 15 preventing the pin 1 from coming out through the hole 7 under the effect of the branches 16b constituting the second part of the elastic means 13. A third function which consists in constituting the means d anchoring 17 of the pin 1 against the wall 4a pierced with the hole 7, blocking this pin 1 in rotation, the solid friction of the branches 16a against the wall 4a preventing this pin 1 from rotating around the axis 9 when one introduces the screw 8 for fixing by screwing into the bore 12 of this pin 1. During the implementation of the method of fixing the object 2 by the screw 8 and the pin 1, the branches 16a can perform these

  different functions simultaneously or successively.

  The plug 1 must be inserted through the hole 7; this is why the branches 16b advantageously have, at rest, a transverse size smaller than the diameter of the hole 7. On the other hand, the branches 16a have a transverse size larger than the diameter of the hole 7

12 2577629

  that these branches 16a tighten on the passage of this hole 7, then position themselves by elasticity around the hole 7 when they are fully inserted in

  the interior space 6 of the partition 3. Thus, the branches

  ches 16a of the end 11a of the pin 1 are, at rest, more curved towards the outside with respect to the axis 9 and deviate more quickly from this axis 9 than

  the branches 16a of the other end 11a of the plug 1.

  According to another embodiment of the pin 1 according to

  the invention, branches 16a and 16b are similar.

  The dowel 1 then has the following symmetries: the dowel 1 is, as already mentioned above, symmetrical in revolution about the axis 9 which coincides with the axis of the fixing screw 8 when the latter is introduced into ankle 1, and ankle 1 is

  more symmetrical with respect to a plane P perpendicular to

area at axis 9.

  The branches 16a, 16b of a dowel 1 according to the invention are preferably made of rigid plastic material but deformable in an elastic manner in the direction of the bending of these branches 16a, 16b and notably undeformable in the direction of the traction and the compression of these branches 16a, 16b. In addition, the branches 16a, 16b advantageously include grooves 18 and / or ribs, in particular longitudinal, providing locally or globally to each of these

  branches 16a, 16b the elastic and elastic properties

  deur appropriate to the various movements and functions

that they perform.

  Each of the branches 16a, 16b also includes

  tagging a flat 19 & its free end 20.

  This flat 19 comes into contact with the internal surfaces

13 2577629

  14a, 14b of the walls 4a, 4b when the pin 1 is in place inside the partition 3, making it possible to guide the movements of the branches 16a, 16b in bending

  avoiding a twisting movement of these branches.

  The longitudinal bore 12 along the axis 9 of a dowel 1 according to the invention advantageously includes a thread 21 making it possible to associate a threaded screw 8

to this peg 1.

  In a method of fixing an object 2 to a hollow partition 3 by a fixing screw 8 and a dowel 1,

  the pin 1 is held opposite the hole 7 inside the

  térieur 6 of the partition 3 by the means 13 for holding before the positioning of the object 2 against the partition 3

  and the introduction of the fixing screw 8 in the sleeve

city 1.

  According to such a method, an elastic deformation is imposed

at pin 1 along its axis 9.

  A fixing method according to the invention comprises the following steps: a step of introduction into the interior 6 of the partition 3 between the walls 4a, 4b of the end llb and of the middle part 10 of the dowel 1, l end 11b coming into contact with wall 4b; - a step of inserting the pin 1 inside 6

  of the partition 3 during which the end is introduced

  miter lla through the hole 7 of the wall 4a inside 6 of the partition 3 by deformation of the plug 1 according to

  its axis 9, the pin 1 then being entirely invisible

  crimped inside 6 of the partition 3 and held facing the hole 7 by the means 13 for holding;

14 2577629

  - A step of positioning the object 2 against the wall 4a; - A step of introducing the fixing screw 8 through the hole of the object 2 and through the hole 7 of the wall 4a in the pin 1; - a step of screwing and tightening the screw 8 of

  fixing in which the pin 1 is hand-

  held inside 6 of the partition 3 by the non-return means 15 and anchored against the wall 4a by the anchoring means 17, the object 2 being pressed against the partition 3 by tightening the screw 8 of

fixation in the ankle 1.

  During the insertion step of the ankle 1 inside

  laughing 6 of the partition 3, the branches 16a come closer

  fall transversely from the axis 9 to the passage of the hole 7

  and the branches 16b are deformed in flexion by spreading

  both from axis 9 transversely and sliding on

  the internal surface 14b of the wall 4b.

  At the end of this insertion step, and after the free ends 20 of the branches 16a are introduced into the interior space 6 of the partition 3 through the hole 7, the branches 16a move away from the axis 9 transversely under the effect of the branches 16b which approach the axis 9, transversely, of

  so that mechanical balance is reached.

  In a fixing method according to the invention, a dowel 1 is inserted inside 6 of the partition 3 between the walls 4a, 4b through the hole 7, starting by introducing the end 11b of this dowel 1 through the hole 7, in the direction of the arrow F1 in FIG. 4a, then the middle part 10 and the end 11a of the pin 1 are introduced by pushing from the outside according to the arrow F2 in FIG. 4b on this end 11a , so that the branches 16b bend in flexion by moving away from the axis 9 transversely and sliding on the internal surface 14b of the wall 4b while the

  branches 16a narrow towards the transverse axis 9-

  ment to go through hole 7. When branches 16a

  have passed hole 7, they deviate from axis 9 trans-

  versally under the effect of the branches 16b which remain

  tighten, so that the mechanical balance is reached, the pin 1 being inserted in the interior space 6 of the partition 3, its branches 16a, 16b being spaced transversely from the axis 9 relative to their initial rest position, and being in contact with the internal surfaces 14a, 14b of the walls 4a, 4b, as shown in FIG. 4c. The solid friction of the branches 16a, 16b against the walls 4a, 4b then keeps the dowel inside the partition 3 in

look from hole 7.

  Subsequently, the screw 8 is introduced into the hole of the object 2 and then, through the hole 7, into the bore 12 of the dowel 1 which has a thread 21 on which the thread of the screw 8 is screwed . During the screwing of the screw 8, the branches 16a perform both their function of non-return means and of anchoring means against the wall 4a. When tightening the screw 8, these

  branches 16a bend more and more, exerting a re-

  resistance to clamping more and more important, while the pin 1 moves according to the arrow F3 of FIG. 1, the branches 16b returning more and more towards their initial position of rest that they can

  reach if the tightening is large enough.

  However, the dimensions of the anchor 1 are advantageously

  -goodly planned so that the branches 16b remain permanently, even after tightening the fixing screw 8, in contact with the surface 14b. In this way, even if a possible creep and / or plastic deformation

  branches 16a appeared when tightening or using

  sation of the object 2 and of the partition 3, the dowel 1 will again be held opposite the hole 7 after

  disassembly of the screw 8 and the partition 3.

17 2577629

Claims (24)

  1. Anchor of the type allowing the fixing of an object, using a fixing screw (8), against and outside a hollow partition (3) comprising two walls (4a, 4b ) parallel planes spaced from each other by a distance d, one of the two walls being pierced with a hole (7) through which the dowel is inserted from the outside between the two walls (4a, 4b) at the interior (6) of the partition (3) and which allows the passage of the fixing screw (8), characterized in that it comprises means (13) for holding this pin (1) inside (6)   of the partition (3), opposite the hole (7).   2. Dowel according to claim 1, characterized in that it comprises non-return means (15) at the end (11a) of the dowel (1) opposite the hole (7) when the latter is in place inside the   partition (3), the function of which is to prohibit the   city (1) to emerge from the partition (3) through the hole (7) when it has been placed inside (6) of this partition (3), while allowing the establishment   of the dowel (1) inside (6) of the partition (3).   3. Dowel according to any one of the claims   1 and 2, characterized in that it comprises means for anchoring (17) this pin (1) against the partition   (3) securing in rotation the ankle (1) to the wall   sound (3) preventing it from turning around the axis (9) when the fixing screws (8) are introduced into this ankle (1).   4. Dowel according to any one of the claims   1 to 3, characterized in that it comprises elastic means (13) allowing the deformation of the ankle (1) along its longitudinal axis (9).   5. Dowel according to any one of the claims   1 to 4, characterized in that its overall length   while at rest before being inserted between the two walls (4a, 4b) of the hollow partition (3) is greater than the   distance d which separates these two walls (4a, 4b).   6. Dowel according to any one of the claims   1 to 5, characterized in that the holding means (13) are elastic compression means (13) exerting a compression preload along the axis (9), when the pin (1) is in place at the interior   of the partition (3), opposite the hole (7), before the introduction   duction of the fixing screw (8) in the plug (1).   7. Dowel according to any one of the claims   1 to 6, characterized in that the holding means (13) consist of elastic means (13) whose function is to press inside the partition   (3) this ankle (1) against at least one of the two pa-   kings (4a, 4b), with a restoring force such as the static friction of the ankle (1) against the surface   internal (14a, 14b) of the wall (4a, 4b) prevents slipping   ankle (1) under its weight, now   this pin (1) opposite the hole (7) before the intro   duction of the screw (8) in the dowel (1).   8. Dowel according to any one of the claims   1 to 7, characterized in that the elastic means   (13) are arranged at one end (11) of the sleeve   city (1) and exert elastic return forces along the axis (9), which press the other end (11a) against the corresponding wall (4a), inside (6) of the partition (3).   9. Dowel according to any one of the claims   1 to 8, characterized in that the elastic means (13) are arranged at each of the ends (11a, 11b) 19 2577629   of the pin (1) and exert elastic return forces of opposite directions along the axis (9) when the   pin (1) is in place inside (6) of the enclosure   sound (3), before the introduction of the screw (8) for fixing in the dowel (1).   10. Dowel according to any one of the claims   1 to 9, characterized in that the elastic means   (13) are arranged on the middle part (10) of the che-   city (1) and exert elastic return forces of opposite directions along the axis (9) when the pin (1) is   in place inside (6) of the partition (3) before installation.   production of the fixing screw (8) in the plug (1).   11. Dowel according to any one of the claims   tions 1 to 10, characterized in that it is symmetrical about revolution about an axis (9) which coincides with the axis of the fixing screw (8) when the latter is introduced into the dowel (1) and with the axis of the hole (7), and in that it is symmetrical with respect to a plane (P) perpendicular to the axis (9).   12. Dowel according to any one of the claims   tions 1 to 11, characterized in that it comprises at least one of its ends (11), at least two branches (16) of elongated shape extending the middle part (10),   constituting the elastic compression means (13).   13. Dowel according to any one of the claims   tions 1 to 12, characterized in that it has at least one of its ends (11) four branches (16) extending the middle part (10), these branches (16) being two by two opposite one of the other, arranged   symmetrically with respect to the axis (9).   14. Dowel according to any one of the claims   tions 1 to 13, characterized in that at least one of its ends (11), the branches (16) extend   from the end (11) substantially in the direction   tion of the axis (9) progressively deviating therefrom, each of the branches (16) being curved with a concavity facing outwards so that each of these branches (16), parallel to the axis (9 ) at the end (11), or inclined relative to the axis (9) at the free end (20) of this branch (16).   15. Anchor according to any one of the claims   tions 1 to 14, characterized in that it comprises four branches (16a) at one end (11a) and four branches (16b) at the other end (11b), the branches (16a) at one end (11a) of the ankle (1) being at rest more curved towards the outside, deviating more quickly from the axis (9) than the branches (16b) of the other end (11b) of the ankle (1).   16. Dowel according to any one of the claims   1 to 15, characterized in that the four branches   (16b) from the end (11b) constitute the elastic means   compression ticks (13), and the four branches (16a) of the end (11a) constitute the elastic compression means (13), non-return means (15) and anchoring means (17) of the dowel (1) to the wall (4a) drilling the hole (7).   17. Anchor according to any one of the claims   tions 1 to 16, characterized in that the branches (16a, 16b) are made of rigid plastic material but elastically deformable in the direction of bending of these branches (16a, 16b) and notably deformable in. the meaning of   the traction of the compression of these branches (16a, 16b). 21 2577629   18. Dowel according to any one of the claims   1 to 17, characterized in that the branches (16a, 16b) have grooves (18) and / or ribs,   particularly longitudinal, providing locally or globally   balance at each of the branches (16a, 16b) the properties   elastic and stiffness appropriate.   19. Dowel according to any one of the claims   tions 1 to 18, characterized in that its longitudinal bore (12) along the axis (9) comprises a thread (21) making it possible to associate a threaded screw (8) at the ankle (1).   20. Method for fixing an object (2) on a wall   its hollow (3) by a fixing screw (8) and a sleeve   city (1) according to any one of claims 1 to   19, characterized in that the plug (1) is held opposite the hole (7) inside (6) of the partition   (3) by the means (13) for holding before positioning it   ment of the object (2) against the partition (3) and the introduction   tion of the fixing screw (8) in the dowel (1).   21. The fixing method according to claim 20,   characterized in that an elastic deformation is imposed   ankle tick (1) along its axis (9).   22. Fastening method according to any one of   Claims 20 and 21, characterized in that it comprises   the following steps: - a step of introduction into the interior (6) of the partition (3) between the walls (4a, 4b) of the end (llb)   and from the middle part (10) of the ankle (1), the   mite (11b) coming into contact with the wall (4b).   - a step of inserting the ankle (1) into the   térieur (6) of the partition (3) during which one introduces 22 2577629   the end (11a) through the hole (7.) of the wall (4a) inside (6) of the partition (3) by deformation of the pin (1) along its axis (9), the pin ( 1) being   then fully inserted inside (6) of the enclosure   sound (3) and held opposite the hole (7) by the holding means (13); - a step of positioning the object (2) against the wall (4a);   - a step of introducing the screw (8)   fixing by the hole of the object (2) and by the hole (7) of the wall (4a) in the dowel (1); - A step of screwing and tightening the fixing screw (8) during which the pin (1) is held inside (6) of the partition (3) by the non-return means (15) and anchored against the wall (4a) by the anchoring means (17), the object (2) being pressed   against the partition (3) by tightening the screw (8) ankle fixation (1).   23. Fastening method according to any one of   claims 20 to 22, characterized in that when   the step of inserting the dowel (1) inside (6) of the partition (3), the branches (16a) approach transversely from the axis (9) when the hole (7) passes; and   that the branches (16b) are deformed in flexion by spreading   both from the axis (9) transversely and sliding on   the internal surface (14b) of the wall (4b).   24. Fastening method according to any one of   claims 20 to 23, characterized in that at the end   of the step of inserting the plug (1) inside (6) of the partition (3), and after the free ends (20) of the branches (16a) are introduced into the space   interior (6) of the partition (3) through the hole (7), the branches   ches (16a) deviate from the axis (9) transversely under the effect of the branches (16b) which approach the axis (9), transversely, so that the mechanical equilibrium is reached.