FR2685415A1 - Mechanical coupling device, with determinable coupling - Google Patents

Abstract

Coupling device (1) intended to provide a mechanical connection with controlled damping (shock-absorption) between a holding piece (2) and a held piece (3), characterised by the fact that it includes pressure means (4, 5; 14, 15) capable of immobilising the said coupling device (1) via contacts (7, 17) on at least one of the said pieces (2, 3) and of exerting a given pressure on these contacts (7, 17). Application to bearings.

Description

MECHANICAL COUPLING DEVICE,
WITH DETERNINABLE COUPLING.

The present invention relates to a coupling device intended to ensure a mechanical connection with controlled damping between a holding part and a maintained part.

Already known are such coupling devices, which must ensure the holding of a part held vis-à-vis a holding part, while having an action on the transmission of vibrations between these two parts, action consisting in general, to dampen the amplitude of the transmitted vibrations, with damping which can vary depending on the frequency. This action can also consist in modifying the value of the resonant frequencies of one or both parts, by modifying the vibrating mass and its distribution by means of a modification of the coupling between these parts.

This makes it possible to attenuate or shift in frequency annoying vibrations, such as those at a resonant frequency of a part, without having to increase the size of this part to modify the resonant frequencies.

Thus, in the automobile industry, it is known, to deal with the problem of the vibrations of the steering wheel shaft relative to the steering column in which it can turn, to install needle bearings in this column, which carry this tree. These bearings, with rubber bodies, came into force and glued to the internal wall of the column.

However, the internal diameter of this column being poorly defined, the crushing of the elastic body of the bearings is poorly defined, and it follows that the coupling between the column and the shaft is poorly controlled, which results in incorrect filtering of the vibrations transmitted by the column to this tree. In addition, the bearing needles induce unpleasant vibrations on the steering wheel.

The present invention aims to solve these problems.

To this end, the coupling device according to the invention, intended to ensure a mechanical connection with controlled damping between a holding part and a maintained part, is characterized in that it comprises pressure means capable of blocking said device coupling by contacts on at least one of said parts and exerting on these contacts a determined pressure.

It is thus possible to have a coupling, between the holding part and said coupling device, which is known and responds, precisely, to the need for frequency damping, allowing manufacturing on an industrial scale.

The coupling device according to the invention advantageously comprises other pressure means capable of blocking, in at least one direction, by means of other contacts, the other part with respect to said coupling device and to exert on these other contacts a determined pressure.

There are thus, on the side of this other part, the possibilities offered by said coupling device on the side of the first part.

In particular, said pressure means may include a flexible tongue, which deforms to apply the determined pressure. This application of pressure is thus carried out by means of a very simple part, which may be in one piece with the or other elements of this coupling device.

If necessary, said pressure means may include pressure adjustment means, pressing on said tongue. It is thus possible to compensate for a variation in pressure due to a play which can vary from one room to another.

Said pressure means may include parts made of elastic material, spring or equivalent, which, after force insertion into a housing of said coupling device, then exert a known force generating said pressure. These parts are, for example, cylindrical for a housing of this shape but can have any other shape.

Advantageously, a body is integral with several of said tabs, substantially angularly distributed on a cylindrical contact surface of said body with one of said coupled parts and respectively pressed elastically against this surface under the action of adjustment parts made of elastic material resting on the body.

In order to mechanically maintain said coupling device independently of the pressure exerted on said part, a retractable lug may be provided to make said coupling device captive with respect to one of said parts. Advantageously, said lug is integral with said tongue. This takes advantage of its ability to move to make it retract and then return the lug when it is positioned on the
v piece.

The pressure means may also include a flexible beam arranged to transmit said determined pressure to a said associated contact, integral with the beam. The beam, secured by its two ends to the other elements of the coupling device, plays the role of the tongue indicated above. As the beam is not cantilevered, it has, for equivalent volume of material, a higher resistance to bending, that is to say that, at a given resistance, it suffices to less material. In addition, the beam is less likely to be broken when the device is put in place.

Advantageously, said pressure adjusting means comprise pressure adjusting parts made of elastic material, preferably made of elastomeric material, housed in housings of the device and arranged to elastically repel the contact of the beam towards one of said parts.

The elastic material can be disposed, in a quasi-continuous manner, substantially in a circle and repel the contacts of the beams, which are regularly distributed angularly and arranged alternately to exert pressure on one and the other of said parts.

If a retaining or maintained part has an irregular surface, there is advantageously provided a ring interposed between those of the beams intended to cooperate with one of said parts and comprising a sliding surface, for sliding on the contacts of said beams, and surfaces support to take support on said part and transmit said determined pressure to it.

Advantageously also, said housings are arranged to receive said pressure adjustment parts of suitable shapes, depending on the desired pressure at said contacts.

Said contacts can be substantially arranged in a circle. They can then be brought into contact with a holding part with a substantially circular section. Said contacts may be able to block in translation one of said parts relative to the other part. This avoids the need for additional parts if such blocking is necessary.

Likewise, said contacts may be capable of allowing the rotation of one of said parts relative to the other part. We can thus make a landing.

In the body of this device, cavities can be distributed in a substantially uniform manner. Such an arrangement facilitates the manufacture of a molded body, by distributing the masses and allowing uniform cooling. It also increases the radial elasticity of the body of the coupling device and thus distributes the radial forces. It may be useful for the coupling device according to the invention to comprise a part that is less deformable than the rest of said coupling device and capable of coming into contact with both said retaining piece and said piece held under the action of a movement bringing said parts together. This less deformable part thus provides protection preventing the crushing of said coupling device in the event of high radial stress.

The invention will be better understood using the description of the preferred embodiment of a coupling device according to the invention and of several alternative embodiments, with reference to the drawing, in which FIG. 1 is an axial view of a bearing according to
the invention, FIG. 2 represents, in perspective form, a
part of said bearing, comprising a part
protective toric and Figures 3 to 7 are respectively axial views
from first to fifth
variant of the bearing of
Figure 1.

The coupling device 1, intended to ensure a mechanical connection with controlled damping between a holding part 2, shown in dotted lines, and a maintained part 3, also shown in dotted lines, is shown in FIG. 1, which is a sectional view perpendicular to the axis of this device.

In this exemplary embodiment, this coupling device 1 is a bearing ensuring the connection between a holding part 2 which is a steering column forming a cylindrical tube containing this coupling device 1, while the maintained part 3 is a cylindrical shaft AX axis, controlled in rotation by a steering wheel not shown.

The bearing 1 comprises a plastic body 1C with a low coefficient of friction on the material constituting the shaft 3 and has a generally hollow cylindrical shape with an axis AX, the external radial wall 1E of which has a diameter slightly less than the internal diameter of the steering column 2, while its internal wall 1I has a diameter slightly greater than that of the shaft 3.

First pressure means comprise a first flexible tongue 4 attached to the rest of the body 1C by a connection end 4R, first tongue disposed at the level of the external wall 1E and which, in this example, is oriented circumferentially to the axis
AX, and a first pressure adjustment means consisting of a first adjustment piece 5, cylindrical in this example, made of elastic material with an axis parallel to the axis
AX, housed by force in a first cavity 6 opening axially and limited by the first tongue 4, located between the axis AX and this first tongue 4, and pressing radially at the free end 4L thereof. Such an assembly exists in three places that are angularly distributed with respect to the axis AX.

The first tab 4 has a first contact 7 which is applied to the internal face 21 of the steering column 2 under the effect of a radial deformation of this first tab 4 due to the first elastic adjustment part 5.

A lug 8, of rectangular section of length parallel to the axis AX, located on the free end 4L of the first tongue 4, projects radially outside the diameter of the external wall 1E and has a face 8E opposite to the axis AX at a distance from this axis AX greater than the internal radius of the steering column 2, while said distance from the face 8E to the axis AX can become less than this internal radius of the steering column 2 by depressing radial of this lug 8 and corresponding recoil of the first tongue 4 in the first cavity 6. The steering column 2 has a through hole 2T of size corresponding to the rectangular section of the lug 8, capable of receiving it. Such an arrangement exists three times, at each of the first tabs 4. The lug 8 comprises axially, relative to the axis AX, therefore at the level of the width of its circumferential section, a bevel shape facilitating the introduction axial of the three lugs 8 in the steering column 2.

The body 1C has cavities 9, together which include the first cavities 6 and second cavities 16 defined below, substantially evenly distributed in the volume of this body 1C, extending axially and circularly to the axis AX, in layers alternating, used to balance the masses and avoid uneven cooling during molding. In addition, they contribute to the deformability of the body 1C and they make it possible to reduce the mass.

On the side of the internal wall 1I of the bearing 1 turned towards the shaft 3, are installed second pressure means comprising a second flexible tongue 14, attached to the rest of the body 1C by a connection end 14R, arranged circumferentially with respect to the 'axis
AX, associated with a second cylindrical adjustment part 15 of elastic material housed by force in a second cavity 16 opening axially and limited by this second tongue 14 and located radially like this second tongue 14, but more distant from the axis AX than that -this, this second adjustment part 15 pressing radially towards the axis AX, on the second tongue 14 near its free end 14L. Such an assembly exists in three places angularly distributed with respect to the axis AX, and in this example, located angularly staggered relative to the first pressure means 4 and 5, that is to say approximately offset by 60 degrees relative to the arrangement of these.

The second tongue 14 comprises, near its free end 14L, a second contact 17 coming into contact with the shaft 3 under the effect of the radial deformation of this second tongue 14 due to the second adjustment part 15.

The axial length of the body 1C as well as of the various pressure means is adapted as a function of the forces exerted, so as not to exceed a pressure liable to damage elements.

FIG. 2 represents, in perspective form, a partial view of the bearing 1 cut along a plane passing through the axis AX. This bearing 1 further comprises, with respect to its representation in FIG. 1, a hollow cylindrical toric part 20 having substantially the same general shape as the body 1C, comprising an external cylindrical wall 20E of diameter slightly smaller than that of the external wall 1E, and an internal cylindrical wall 20I of diameter slightly greater than that of the internal wall 1I.

The purpose of this toric part 20 is to avoid excessive radial crushing of the bearing 1. It is made of a material resistant to crushing, and has an axial length adapted to enable it to resist radial crushing.

This O-ring piece 20 is axially blocked by means of deformable fixing lugs 21, two of which are shown, three in this example, forming part of the body 1C and located substantially in the axial extension of the external wall 1E, equally spaced radially and axially elongated. Their length is slightly greater than the axial length of the toric body 20, and their free end has a hook 22 facing the axis AX. The toric body 20 comprises, in its external wall 20E, three notches 20L, two of which are shown, which can receive one of the lugs 21, the hook 22 of which then bears on the radial face 20R of the toric body 20 opposite the body 1C.

The operation of such a bearing 1 is as follows. The toric part 20 is fixed to the body 1C by means of the lugs 21, then the assembly is introduced into the steering column 2. Depending on whether or not the first and second adjustment parts 5 and 15 have already been installed, it may or may not be necessary to first introduce the toroidal part 20 in order to allow, if necessary, access to the first and second cavities 6 and 16. The bevelled shape of the lugs 8 allows their simultaneous axial introduction into the steering column 2, of which the internal wall crushes them until they are each housed in one of the three holes 2T, where they resume their initial shape, thus blocking the bearing 1 in translation and in rotation relative to this steering column 2 The release of the bearing 1 can be carried out by simultaneously crushing the three lugs 8 and pulling axially on the bearing 1 by means of a hook passing through a cavity 9 or passing through the bearing 1 in the middle if the shaft 3 is not not implemented. It will be noted that the extraction can be facilitated by providing a bevel in the hole 2T, opposite the bevel of the lug 8, making it possible to release the latter by axial support on the bearing 1, then axial traction preceded by a rotation for avoid locking the lug 8. Similarly, one can provide another bevel, at the other width of the section of the lugs 8, or at one of the lengths of said section, possibly associated with a homologous bevel of the hole 2T, allowing respectively to release the lug 8 from the hole 2T by axial traction or by rotation then axial withdrawal of the bearing 1.

The adjustment parts 5 and 15 can, as indicated above, be installed before introduction of the bearing 1 or after, and may be changed according to vibration tests in order to adjust the pressure they exert respectively on the internal face 21 of the steering column 2 and on the shaft 3.

The adjustment of the contact pressure on the first or second contacts 7 and 17 could obviously be carried out using other means, for example by replacing the adjustment parts 5 and 15 with a screw with increasing radial section towards the head of this screw, pressing by its threads on a surface of suitable shape of the respective tongues 4 or 14, located near the free end 4L or 14L or else distant from it to make the amplifying lever of displacement in rotation around the end of 4R or 14R connection of the tongue, the screwing of such a screw increasing the diameter it occupies in the corresponding cavity 6 or 16 and thus increasing the pressure on the associated contact 7 or 17. Similarly, the adjustment parts 5 and 15 may not exist if an adjustment is not necessary, because the desired pressure is known, the tongues 4 and 14 then having a slightly projecting shape relative to the concerned wall of the horn. ps 1C, as they apply themselves on the steering column 2 and the shaft 3 respectively and exert the desired pressure due to their flexibility. The length, circumferential in this example, of these tabs 4 and 14, between their connection end 4R or 14R with the rest of the body 1C and the associated point of contact 7 or 17, then determines the suitability of the tab 4 or 14 to maintain a substantially constant pressure if the internal diameter of the steering column 2 or the diameter of the shaft 3 has manufacturing differences from one part to another.

It is thus possible, with this bearing 1, to separately adjust the mechanical coupling between this bearing 1 and the steering column 2, on the one hand, and the shaft 3 on the other hand, which, as the man of the art knows profession, allows to modify the amplitude and the frequency of the vibrations coming from an external disturbing element linked to the steering column 2, since it is put in mechanical connection with a more or less important mass, representing a part more or less significant of the mass of the shaft 3, according to the coupling, and of variable geometry as a function of said coupling.

The pressure on the second contacts 17 is kept below a limit corresponding to the acceptable friction torque.

The equal and alternate arrangement of the various cavities 9 prevents the body 1C from having angularly localized zones resistant to radial compression, the constituent material of which would be destroyed in the event of crushing, due to the limited size of the volume concerned. In particular, it can be seen in FIG. 1 that the material circumferentially separating two cavities 9 adjacent to an outer layer is located radially substantially along the middle of a cavity of the inner layer, and vice versa, so that said material, in the event radial crushing, crushes the associated cavity, which avoids localization of the stresses.

The toric body 20, integral for convenience with the body 1C, limits the crushing dynamics of this body 1C, while not rubbing on the shaft, in normal operation. This avoids possible deterioration of the body 1C due to an attempt to force an anti-theft radial finger blocking the shaft 3, too great a torque on the steering wheel having the effect of tending to pivot this shaft 3 around an axis parallel to the axis AX but decentered because passing through the point of contact of the finger, located on the periphery of this shaft 3. Therefore, this shaft 3, pivoting around this offset axis, crushes one side of the bearing 1 and would risk destroying it in the absence of the toric body 20.

The five alternative embodiments of the bearing 1 represented in FIGS. 3 to 7 comprise elements having a function similar to that of elements of the bearing 1 and which bear the same reference, preceded by a hundred figure from 1 to 5 indicating the variant rank.

In order not to unnecessarily overload the description, only the particular characteristics of the variants are described.

In FIG. 3, the first variant comprises a bearing 101 with a body 101C of generally tubular and substantially full shape comprising three beams 104 angularly distributed equally, elongated according to an arc of a circle of center AX, of width equal to the axial length of the body 101C .

The beams 104, projecting externally from the rest of the body 101C, are connected thereto, at their two ends angularly spaced, by radial lugs 104R1 and 104R2.

At mid-length, the beams 104 each carry a lug 108.

Three recesses 130 on the internal face of the body 101C, in, and even beyond, three angular sectors containing the beams 104, avoid contact between the body 101C and the part 3. The above contact takes place in the remaining sectors, where the legs 104R1 and 104R2 are not likely to deform the body 101C. This avoids the application of an uncontrolled pressure exerted by the external part 2 (not shown) on the part 3.

A housing 106, delimited by the beam 104 and the rest of the body 101C, can receive an adjustment piece 105 of elastic material, such as rubber or elastomer, making it possible to adjust the pressure of the contacts 107. In its absence, it is the resistance to bending of beams 104 and their deformation which determine the above pressure.

The second variant, shown in FIG. 4, comprises a bearing 201 with a body 201C of generally tubular shape.

 I1 is also provided three beams, 204, oriented like the beams 104, but they are, for their part, integrated into the body 201C, only their contacts 207 and the pins 208 projecting externally to the tubular form.

With a regular angular distribution, the three beams 204 alternate one by one with three other beams 214, arranged like the beams 204 but located on the internal side of the body 201C.

The beams 214 are set back with respect to the internal face of the body 201C, except at their mid-length, where they have a protuberance 217 serving as sliding contact with the part 3. On the side of the beams 204 and 214 opposite their contact 207 , 217, housings 206, 216 contain, as above, adjustment pieces 205 and 215 of elastic material. Between the six sectors containing the housings 206, 216, arranged in an arc, six housings 209 are provided.

The third variant, shown in FIG. 5, comprises a bearing 301 whose tubular body 301C has, on the outside, the shape of the body 201C and comprises beams 304 carrying contacts 307 and lugs 308.

Likewise, housings 306 contain adjustment parts 305.

On the internal side, the body 301C is similar to the body 101C and has three recesses 330 arranged like the recesses 130.

The three circular sectors containing the internal contacts 317 between the recesses 330 each comprise a housing 316 angularly extending beyond the sector considered and larger angularly than the housing 306.

Each housing 316 and the associated contact 317 delimit a beam 314 pushed back towards the axis AX by an adjustment piece 315 contained in the corresponding housing 316.

Relative to the body 201C, the contacts 317 have a significantly greater angular length than those of the contacts 217.

The fourth variant, shown in FIG. 6, has the same elements as those of the second variant, here identified with the hundred 4.

It further comprises an internal tubular ring 440, externally in contact with the internal contacts 417 and the internal face of which comprises a plurality of small protrusions 441 intended to bear on the part 3. Thus, in the case where the surface of the part 3 is too irregular to allow sliding without appreciable friction of the contacts 417, the ring 440 plays the role of a sleeve replacing the part 3 to slide relative to the body 401C while transmitting, due to its plastic deformation, the pressure exerted by the contacts 417 on the part 3. The ring 440 also makes it possible to increase the axial rigidity of the bearing 401.

It makes it possible to improve the coefficient of friction, to control the resistive friction torque and to compensate for the geometry defects of the shaft 3.

It can be integral with the shaft 3 or movable relative thereto, in both directions: sliding and rotation.

It allows an axial displacement of the shaft 3 during the adjustments and the operation of the vehicle comprising the shaft 3, with a controlled sliding force.

In addition, the internal geometry of this ring 440 can be of any other shape, for example: support point similar to contact 217 in FIG. 4, or to contact 117 in FIG. 3, or 317 in FIG. 5 with similar geometry. elements 314, 315, 316. The interior shape can also be triangular.

The fifth variant, represented in FIG. 7, comprises a body 501C, the elements of which are identical to those of the fourth variant and are referenced in the same way, but with the hundred 5. However, unlike the fourth variant, the pieces of adjustment 505 and 515 do not completely fill the housings 506 and 516 over their entire angular length.

The shape shown of the adjustment pieces 505 and 515 is fictitious because it is that of their state in the absence of radial compression, that is to say that this shape projects radially from the corresponding housing 506, 516 on the side of the associated beam 504, 514 which flexes under the effect of the pressure applied by the elastic material, for example an elastomer.

In this example, the adjustment pieces 505, 515 have substantially the same shape and are arranged in the same way, a sole 505S, 515S being supported on the face of the interior side of the housing 506, 516 associated and a foot 505P, 515P, angularly less extended. that the sole 505S, 515S, being supported on its opposite face. This identical arrangement, instead of being alternated, of the adjustment pieces 505 and 515 avoids assembly errors.

The sole 515S has an angular length greater than that of the contact 517 of the beam 514, which avoids an irregular deformation of the latter, which could have degraded the coefficient of friction of the contact 517.

As for the contacts 507, they are in this example, if the lugs 508 are received in a cavity of the part 2 of a shape other than that of a circular groove, fixed with respect to the part 2, so that an irregular deformation of the beam 504 by the foot 505P does not present any drawback.

The choice of a determined angular width of the feet 505P, 515P makes it possible to adjust the contact pressure of the contacts 507 and 517. The adjustment parts 505, 515, and the preceding ones, can also be constituted by springs. These springs are, for example, with turns or flexible leaves, made of metal or another material having sufficient rigidity.

The embodiment example above concerned a rotary shaft. I1 is quite obvious that parts maintained 3 having a different movement, such as translation, relative to the holding part 2, can be associated with such a coupling device 1, by adapting the position and the number of first and second contacts. 7 and 17. The cavities 9 then play the role of free passage of air, thus avoiding overpressures due to the displacement of parts associated with the steering column. Likewise, the second contacts 17 can play the role of the lugs 8, by blocking the axial movement of the bearing 1 in a groove in the shaft 3, the release being able to be carried out according to the principles set out for that of the lugs 8.

It will also be noted that such a bearing 1, by its identical design for the first and second contacts, can be fixed to one or the other of the coupled parts 2 and 3.

It is even possible not to block this bearing 1 in rotation, which will then tend to slide in rotation relative to the part 2 or 3 with which it has the least friction.

Claims (23)

1. Coupling device (1) intended to ensure a  mechanical connection with controlled damping between a  holding part (2) and a maintained part (3),  characterized by the fact that it includes means for  pressure (4,5; 14,15) able to block said  coupling device (1) by contacts (7,17)  on at least one of said parts (2,3) and to be exercised  on these contacts (7,17) a determined pressure. 2. Coupling device according to claim 1,  in which other pressure means (14,15; 4,5)  are able to block, in at least one direction,  by means of other contacts (17,7), the other part  (3,2) with respect to said coupling device (1) and  to exercise on these other contacts (17,7) a  pressure determined. 3. Coupling device according to one of  claims 1 and 2, wherein said means for  pressure (4,5; 14,15) have a tab  flexible (4.14). 4. Coupling device according to claim 3,  wherein said pressure means (4,5; 14,15)  have pressure adjusting means (5,15)  resting on said tongue (4, 14). 5. Coupling device according to one of the  claims 1 to 4, wherein said means for  pressure (4,5; 14,15) have parts  elastic (5.15). 6. Coupling device according to claim 5,  in which a body (1C) is integral with several  said tabs (4,14), substantially  angularly distributed over a surface of  cylindrical contact of said body (1C) with one  of said coupled parts (2; 3) and respectively  pressed elastically against this surface under  the action of adjusting parts (15) made of material  elastic bearing on the body (1C). 7. Coupling device according to one of  Claims 1 to 6, in which a lug  retractable (8) is capable of capturing said  coupling device (1) with respect to one  said parts (2; 3). 8. Coupling device according to claim 7,  wherein said lug (8) is integral with said  tongue (4.14). 9. Coupling device according to one of  claims 1 to 2, wherein said means for  pressure (104,105) have a flexible beam  (104) for transmitting said determined pressure to  a said associated contact (107) integral with the beam  (104). 10. Coupling device according to claim 9,  wherein said pressure means (504,505  514.515) include adjustment means (505; 515)  pressure. 11. Coupling device according to one of  claims 9 and 10, wherein said beam  flexible (104) comprises, substantially at mid-length,  a retractable lug (108) capable of capturing  said coupling device (1) with respect to one  parts (2; 3). 12. Coupling device according to one of  claims 9 to 11, wherein said contacts  (107) are substantially arranged on a circle. 13. Coupling device according to one of  claims 9 to 12, wherein said means for  pressure control (505; 515) have parts  pressure adjustment in elastic material housed  in housings (506; 516) of the device and  arranged to elastically repel contact  (507; 517) from the beam (504; 514) towards one of the said  pieces (2; 3). 14. Coupling device according to claim 13,  wherein the elastic material (505; 515) is a  elastomer. 15. Coupling device according to claim 2 with  claims 12 and 13, wherein the material  elastic (505; 515) is arranged, almost  continues, substantially in a circle and pushes back  the contacts (507; 517) of the beams (504; 514), which  are regularly distributed angularly and  arranged alternately to exert pressure  on one and the other of said parts (2; 3). 16. Device according to claim 15, in which it  is provided, between beams (314) cooperating with a  same of said parts (3), a recess (330) of a  surface of the device facing said part (3)  and located opposite one of the cooperating beam (304)  with the other part (2). 17. Device according to one of claims 12 to 16,  in which there is provided a ring (540) interposed  between those (514) of the beams (504; 514) intended for  cooperate with one of said parts (3) and  having a sliding surface, for sliding  on the contacts (517) of said beams (514), and  bearing surfaces (541) for bearing on  said part (3) and transmit said pressure to it  determined. 18. Device according to one of claims 13 to 17,  wherein said housings (506; 516) are arranged  to receive said adjustment pieces of  pressure (505; 515) of suitable shapes, function of  the desired pressure at said contacts (507; 517). 19. Coupling device according to one of  claims 1 to 8, wherein said contacts  (7,17) are substantially arranged in a circle. 20. Device according to one of claims 1 to 19,  wherein said contacts (7,17) are adapted to  block in translation one of said parts (3; 2)  relative to the other part (2; 3). 21. Device according to one of claims 1 to 20,  wherein said contacts (7,17) are adapted to  allow rotation of one of said parts (3; 2)  relative to the other part (2; 3). 22. Device according to one of claims 1 to 21,  comprising cavities (9) distributed in a manner  substantially uniform. 23. Coupling device according to one of  Claims 1 to 22, comprising a part (20)  less deformable than the rest (1C) of said device  coupling (1) and able to come into contact with both said holding part (2) and said maintained part (3) under the action of a movement bringing said parts (2,3) closer.