FR2786832A1 - Friction clutch, esp for motor vehicle, with wear take-up mechanism - Google Patents

Abstract

The friction clutch, having a wear take-up mechanism with meshing external teeth and a endless screw (63) between its pressure plate and thrust assembly, The mechanism is located in a housing with a support which has two side plates (65, 66) with holes (61) for a spindle (67) on which the screw is mounted. The holes in the side plates are offset axially relative to one another so that the spindle and screw are set at an angle. The ends of the plates are also angled so that the axes of the holes lie perpendicular to them.

Description

The present invention relates to a friction clutch mechanism.

  The invention relates more particularly to a friction clutch, in particular for a motor vehicle, and relates more particularly to a clutch equipped with a device for compensating for wear due in particular to the wear of or friction linings, such so-called wear take-up device operating progressively

wear of the lining (s).

  The invention relates to a clutch mechanism of the type 1o described and shown in French patent application No. 96.15865 of December 23, 1996. French patent application No. 98.01453 of February 5, 1998 also describes other examples of realization and improvements of a clutch mechanism comprising a

wear take-up device.

  L In these documents, the friction clutch mechanism is of the type comprising a cover, a pressure plate linked in rotation to the cover while being able to move axially relative to the latter, support means carried by the plate pressure, axially acting engagement means acting between the cover and the support means, and a wear take-up device comprising on the one hand means with ramps integral in rotation with external teeth and placed between the pressure plate and the support means for constituting a pressure plate of variable thickness between its friction face and the support means and comprising, on the other hand, a cassette carried by the cover and which comprises: - a piece forming a support generally U-shaped with a central core and two lateral wings each provided with a hole for the rotational mounting of a crew; - Said equipment, which comprises an endless screw, cooperating with the toothing of the ramp means on which is mounted a transverse axis, of generally tangential orientation relative to the central axis of the mechanism, passing through at least one hole of the one of the lateral wings of the support, and which comprises a ratchet wheel secured axially and in rotation to the worm and of which a first lateral face is adjacent to the worm; - an elastic take-up means acting on the second lateral face of the body of the ratchet wheel to permanently urge it elastically; and - an elastic member provided with an elastic control tongue carried by a return of the elastic member and provided with a pawl

  which are suitable for cooperating with the ratchet wheel.

  Such a clutch generally comprises a reaction plate, 10 optionally in two parts to form a damping flywheel or a flexible flywheel, fixed in rotation on a first shaft, usually a driving shaft such as the crankshaft of an engine with internal combustion, and supporting by its external periphery a cover to which is attached, with axial mobility, at least one pressure plate which is integral in rotation with the cover and the reaction plate. The declutching means can consist of helical springs, or two Belleville washers mounted in series, and they are subjected to the action of declutching levers forming the means.

declutchers.

  A friction disc usually carrying friction linings at its outer periphery, which is rotatably integral with a shaft, usually a driven shaft such as the input shaft of the powertrain gearbox, is interposed between the pressure plate and the reaction plate so as to be clamped axially between them when the clutch is in the engagement position to transmit the torque from the drive shaft to the driven shaft. Alternatively, the friction disc has a single friction lining. The friction lining (s) are resiliently coupled to a hub integral in

rotation of the driven shaft.

  During the lifetime of such a clutch, the friction lining (s) as well as the counter-materials, pressure and reaction plates, wear out which causes a variation in the axial position of the pressure plate and that of the axially acting engagement means and the clutch release bearing, resulting in a variation in the clamping force between the friction disc on the one hand and, on the other hand, the pressure and reaction plates due to changes in the working conditions of the clutch means, and the force required to disengage is affected. By providing such a clutch with a wear take-up device, these drawbacks are avoided, the clutch means as well as the clutch release bearing usually in constant support on the clutch means, occupying the same position when the clutch is in

o position of engagement.

  In the known design of the cassette of the wear take-up device mentioned above, the control tongue is capable of being actuated by an actuator belonging to the clutch engagement means and it cooperates, like the pawl, with the teeth of the ratchet wheel. The worm cooperates with the teeth of the toothing belonging to the ring-shaped ramp means placed between the support means of the engagement means and the pressure plate. The worm cooperates with the teeth and with the rotational drive means comprising the elastic take-up means, which are made operational by the wear of or friction linings when the clutch is engaged. The worm is

  mounted tangentially with respect to its associated toothing.

  In the various embodiments proposed in the documents mentioned above, the elastic take-up means acting on the second lateral face of the body of the ratchet wheel in order to urge it permanently elastically is a helical compression spring which is crossed by the axis cross-section of the crew. The take-up helical spring is thus mounted compressed between the lateral face opposite the ratchet wheel and a lateral face opposite belonging to one of the lateral wings of the piece forming a support in the form of U, directly or with the interposition of a forming element

support washer.

  It may be desirable to decrease the number of components.

  The object of the invention is to propose an improvement to a clutch mechanism of the type mentioned above by proposing a new design which further simplifies the design of the cassette by reducing the number of components and by facilitating the various assembly operations. To this end, the invention provides a clutch mechanism characterized in that the elastic member constitutes said support-forming part and comprises said lateral wings. Thanks to the invention, the number of parts is reduced and the cassette is lighter and therefore more

lo easy to balance.

  According to other characteristics of the invention - the elastic member forming a support comprises at least one tab for fixing it to the cover; - The elastic member forming a support comprises a tab of z5 fixing a radial orientation which extends, in a plane perpendicular to the central axis of the mechanism, from the central core; - The elastic member forming a support comprises two opposite legs for fixing transverse orientation, each of which extends, in a plane perpendicular to the central axis of the mechanism, from one of the lateral wings;

  - The elastic member is a piece of cut and folded sheet metal.

  Other characteristics and advantages of the invention will appear

  on reading the following detailed description for understanding

  which will be referred to the accompanying drawings in which: - Figure 1 is a front view of a clutch mechanism equipped with a wear take-up device according to the teachings of the invention, with partial cutaway to show in particular the cooperation of the teeth of the ramp means with the crew of the cassette; - Figure 2 is a detail view on a larger scale of the upper part of Figure 1; - Figure 3 is a detail view in section along line 3-3 of Figure 2 - Figure 4 is an enlarged view, along arrow F4, of Figure 2 which illustrates, in partial section, I arrangement of the wear take-up device cassette; - Figure 5 is a schematic perspective view, along arrow F5 of Figure 2, which shows on a larger scale the single piece forming a support and elastic member of the cassette of the wear take-up device; - Figure 6 is a sectional view along line 6-6 of the figure; and o10 - Figure 7 is a view similar to that of Figure 5 which illustrates an alternative embodiment of the single piece which incorporates the spring

  take-up in the form of an elastic catch-up blade.

  In the following description, identical components,

  similar or analogous are designated by the same numbers of

reference.

  The figures represent a clutch mechanism equipped with a wear take-up device of the type described and represented in the two previously mentioned patent applications, the content of which should be referred to for more details, this content to be considered to be an integral part of this

description.

  Referring in particular to FIGS. 1 to 3, a friction clutch mechanism is seen, in particular for a motor vehicle, of axis of axial symmetry XX, which constitutes a unitary assembly and which mainly comprises a pressure plate 51 intended to cooperate by its front transverse face 11 with a friction disc (not shown in the figures) which carries at its outer periphery friction linings and which cooperates itself with a reaction plate (not shown) which is intended to be wedged in rotation on a driving shaft, such as the crankshaft of the internal combustion engine. In

  variant, the friction disc carries a single friction lining.

  The friction disc is integral in rotation with a driven shaft such as the input shaft of the gearbox and it is interposed, by means of or its friction linings, between the pressure plate 51, 11 and the reaction plate so as to be clamped axially between them when the clutch is in the engagement position

  to transmit the torque from the drive shaft to the driven shaft.

  Conventionally, the friction linings are mounted on an axially elastic support rigidly or resiliently coupled to

  a hub locked in rotation on the drive shaft.

  Thanks to this arrangement, the friction disc assists the diaphragm during the clutch release operation. As a variant, the support is partially embedded in a friction lining and

lo is therefore axially rigid.

  The pressure plate 51 is integral in rotation with a cover 52 by means of tangential tongues 9 which are axially elastic and which at the same time constitute return means, in the axial direction, of the front pressure plate 51 towards the z5 rear cover 52. As a variant, the tongues are oriented

  radial by being axially elastic.

  The tongues 9 are fixed by riveting from one of their ends to the cover 52 and at their other end to a lug of the pressure plate 51 and they allow an axial movement of the

  pressure plate 51 with respect to the cover 52.

  The cover 52 is a metal piece of stamped sheet metal which

  has a bottom 13 of transverse orientation perpendicular to the axis X-

  X, centrally perforated and means for fixing it to a tray

  reaction, possibly divided to form a damping flywheel.

  Here, the cover 52 is generally in the form of a hollow plate and it has at its external periphery a radial flange 152 forming the means for fixing the cover to the reaction plate, said flange being provided with holes for the passage of fixing members. , such as

  screw, from the cover to the reaction plate.

  An annular skirt 32 of axial orientation connects the bottom 13 to the

  rim 152 and is open at the tabs 9.

  The pressure plate 51, while being integral in rotation with the cover 52, is therefore axially displaceable relative to the latter under the stress of axially acting engagement means controlled by declutching means which are here constituted by a diaphragm 53 mounted articulated on the cover 52, for example by means of balusters carried by the bottom 13 of the cover 52 with a central hole. The columns offer secondary support to the diaphragm 53 opposite a secondary support carried by the cover. The diaphragm 53, forming elastic means with axial action, has a frustoconical shape in the free state and comprises a peripheral part in the form of a Belleville washer 50 by means of which the diaphragm bears on the internal face of the bottom 13 of the cover. 52 for action on the pressure plate 51 and clamping of the friction linings between the pressure 51 and reaction plates. The washer 50 is extended towards the center by a central part fragmented into radial fingers by blind slots, including the adjoining bottoms at the periphery of the Belleville washer 50 constitute enlarged orifices crossed by the aforementioned balusters. Here, the orifices are crossed axially by

  tabs 26 produced by cutting and folding the bottom 13 of the cover 52.

  The legs carry a ring crown (not referenced) of frustoconical shape carrying the secondary support for the internal periphery of the Belleville washer 50 of the diaphragm 53 and this, opposite a support

  primary formed here by stamping the bottom 13 of the bottom 52.

  To disengage the clutch, here one presses on the internal end of the fingers of the diaphragm 53 with the aid of a disengaging stop not shown in order to cancel the load exerted by the diaphragm 53 on the

pressure plate 51.

  Thus, the diaphragm 53, by the internal periphery of its Belleville washer 50, is pivotally or pivotally mounted between the

  primary and secondary supports carried by the bottom 13 of the cover 52.

  By the external periphery of its Belleville washer 50, the diaphragm 53 is in contact with support zones 14, described in detail below, forming support means and which are carried by the pressure plate 51. To maintain, when the clutch is engaged or engaged, the axially acting clutch means 53 in an axial position which is independent of the wear of the friction linings, and to a lesser extent of the wear of the pressure and reaction plates 51 of which the faces, called friction faces forming friction tracks, wear out in contact with or friction linings of the friction disc, it is provided

  a wear take-up device.

  According to a known general design, the wear take-up device comprises a cassette 10 and means 54 to

ramps 56.

  More specifically, the ramp means consist of a ring 54 of cut and stamped sheet metal so as to have ramps 56 arranged circumferentially, the ring 54 with ramps 56 also having bearing zones 14 formed by the upper edge rounded stamped in arcs of a circle which are centered on the axis XX of the clutch and which are placed radially on the outside with respect to the

ramps 56 (see Figures 2 and 3).

  The pressure plate 51 has here, produced from molding, on its rear transverse face turned towards the bottom 13 of the cover 52, studs 57 distributed circumferentially at a distance from each other which corresponds to that which separates circumferentially two consecutive ramps 56, the pads 57 being intended to cooperate each with a corresponding ramp 56. These pads 57 thus form

counter ramps.

  The ring 54 with ramps 56 is placed axially between the diaphragm 53 and the pressure plate 51 so that the studs 57 receive the ramps 56 and that the diaphragm 53 cooperates with the bearing zones 14 which thus constitute the means of support, here split but which can be continuous in a variant, via which

  the diaphragm 53 acts on the pressure plate 51.

  At least one of the bearing zones 14 of the ring 54 with ramps 56 is extended at its external periphery by a flange parallel to the axis of the clutch ending in a transverse return, which extends radially towards the outside in a plane perpendicular to the axis XX of the clutch, which is provided at its outer periphery with a toothing 59, so that the bearing zones 14 can be continuous and that the flange is centered by a extra thickness 157 of the pressure plate 51. It is the extra thickness 157 which carries the studs 57 replaced in a variant by

  counter-ramps possibly attached to the pressure plate.

  According to a known general design, the cassette 10 of the wear take-up device 10, 54 comprises an assembly comprising a ratchet wheel 60 with inclined teeth secured to an axis 67 which also carries an endless screw 63 whose thread and not are adapted to the toothing 59 with which the worm is brought to cooperate under the conditions which will be described below, the worm 63 extending generally tangentially with respect to the toothing 59 which here is in

  o shape of annular sector with teeth.

  In accordance with the teachings of the invention, the equipment 60, 63, 67 is rotated by a single piece forming a support 72 which, as a variant (FIG. 7) incorporates an elastic take-up means acting on the ratchet wheel and which also constitutes the elastic control member of the wear take-up device capable of cooperating with the ratchet wheel 60. With this arrangement, the support of the prior art is eliminated, the number of parts is reduced and the weight of the

  cassette. Assembly operations are reduced.

  The part 72 is a cut and folded sheet metal part which, to constitute a part forming a support for the cassette, is in the general shape of a U having a central core 73 and two lateral wings.

  parallel 74 intended to support the axis 67.

  To this end, each of the side wings 74 has a circular hole 75 adapted to receive the axis 67. In the arrangement illustrated in the figures, and as can be seen in particular in Figures 2 and 3, the parallel side wings are parallel to the axis XX of the mechanism and arranged symmetrically on either side of an axial plane of symmetry

  corresponding to section line 3-3 in Figure 2.

  The upper central core 73 (considering the figures) in the form of a plate is of tangential orientation, parallel to the axis X-X and

  is located radially outside with respect to axis 67.

  For fixing the cassette 10 by means of the single piece 72 forming a U-shaped support, it comprises a first front fixing tab 168 which extends at right angles from the front edge o10 of the core central 73, which extends radially outward in a transverse plane perpendicular to the axis XX and which is intended to be fixed, by a rivet 155 passing through a hole 36 of the tab 168, on a range 154 of the outer edge 152 of the cover 52, the said area being offset axially forwards with respect to the rear bottom 13 of the

cover 52.

  In the example illustrated in the figures, the part 72 forming a support for the crew 60, 63, 67 of the cassette 10 also comprises two

  rear side fixing lugs 371.

  Considering FIGS. 2, 4 and 5, the two symmetrical and opposite lateral legs 371 each extend transversely towards the outside with respect to the median vertical plane of general symmetry of

  the part 72, in a common transverse plane perpendicular to the axis X-

  X and parallel to the plane of the front leg 168.

  : .5 Each of the rear lateral fixing lugs 371 extends transversely outwards from the rear vertical edge 40

a side wing 74.

  Each of the two rear fixing lugs 371 has a

  hole 372 for the passage of a rivet 373 for fixing.

  According to a known design, the cassette 10 is received at the outer periphery of the pressure plate 51 which is locally notched for housing the cassette 10 (see FIGS. 3 and 4) and reduction of

axial dimensions.

  A housing 110 for the cassette 10 is formed in excess thickness, here by press deformation, at the level of the range 154 of the rim 152

cover 52.

  The housing 110 is delimited by the pad 154 secured to a central orientation core and it protects the cassette 10 by being open to the

beach level 154.

  As can be seen in particular in FIGS. 5 and 6, each of the lateral wings 74 extends axially towards the rear beyond its edge 40 by a horizontal arm 42, each arm 42 extending itself by a return 71 which s 'extends transversely inward in a substantially tangential plane. The returns 71 are intended to constitute control stops whose role will be explained later, the free ends 69 of the returns 71 facing each other being located at a sufficient distance to allow, without interfere with it, the actuator travel during clutch and declutching operations. The actuator 55 is constituted by a protuberance (or appendage) which comprises the diaphragm 53 radially projecting at its

outer periphery.

  In accordance with the teachings of the invention, the returns 71 are integrated into the part 72 from which they originate by cutting and folding to

o from the side wings 74.

  The central core 73 of the part 72 is extended towards the rear, then obliquely radially inwards by an oblique extension 84 delimited in particular by notches 82 and 83 which gives a certain elasticity to the extension 84 which is cut out centrally to form two extension arms. At the free end, radially inside, of the extension 84 is formed a return 85 in the form of a tangential orientation bar which itself extends forward in a tangential plane by a control tab 76 which globally extends

  in a lower plane parallel to the plane of the upper central core 73.

  A cutout 77 formed in extension 84 divides it into two branches or arms and, thanks to this cutout 77 and notches

  79 and 80 formed in the central core 73, an anti-ratchet is produced

  back 78 in the form of a blade. The free end of the pawl 78 extends generally in a transverse plane perpendicular to the plane of the upper central core 73, the pawl blade 78 extending

  radially inwards from the upper central core 73.

  As can be seen precisely in Figure 6, the control tongue 76 and the pawl 78 are slightly inclined respectively with respect to the tangential plane of the central core 73 and the plane

transverse perpendicular.

  The pawl 78 is offset with respect to the tongue 76, the free ends of the pawl 78 and the tongue 76 being circumferentially offset around the geometric axis of the axis 67 of the wheel

ratchet 60.

  The cassette also comprises, according to a known arrangement, an elastic take-up means 86 constituted by a helical spring of

  compression interposed between a lateral wing 74 and the ratchet wheel 60.

  The ratchet wheel 60 is delimited laterally by a first lateral face 200 adjacent to the worm 63 and by a second face

  lateral 202 on which the helical compression spring 86 acts.

  The shape and dimensions of the take-up spring 86 are such that it permanently resiliently urges the ratchet wheel 60, that is to say that it urges the latter from right to left in

1o considering Figure 4.

  The ratchet wheel 60 is thus implanted globally between the screw

  endless 63 and the take-up spring 86.

  The ratchet wheel 60 is in line with the non-return pawl 78 which, by cooperation with the inclined teeth of the ratchet wheel 60, prevents the ratchet wheel 60 from turning, as well as the worm 63, in the direction

  contrary to that of clockwise when considering figure 3.

  The part 72 forming a support (carrying the ratchet wheel 60, the worm 63) and the axis 67 being integral with the cover 52, the diaphragm 53 moves relative to this part during the declutching and re-clutch operations. The diaphragm 53 carries at its periphery a radial appendage 55 constituting the actuator which extends radially to cooperate with the extension 84 of the elastic member 72, more precisely with a rounded zone 184 connecting the main part of the extension in two branches 84 at the return bar 85 (see

figure 6).

  It is understood that, thanks to this arrangement, during the tilting of the diaphragm 53 during declutching and re-clutching operations, the actuator 55 moves the extension 84 from the right to the left considering FIG. 6, and that the tongue of control 76, by cooperation with the teeth of the ratchet wheel 60, is caused to turn the ratchet wheel 60 clockwise, and therefore to turn the screw 63 by compressing the catching spring 86. On the return, when the actuator 55 is moved from left to right considering figure 3, the elasticity of the extension 84 of the elastic member 72 and the inclination of the teeth of the ratchet wheel 60 cause the tongue 76 to be moves up on the teeth which are kept fixed in rotation

by the non-return pawl 78.

  The operation of the play take-up device which has just been described is known and will not be detailed. If necessary, reference may be made to the content of the French patent applications mentioned

  previously whose parts of the corresponding description must

  be considered as part of the present application, knowing that during the declutching operation, the return or arming stroke 10 of the control tongue 76 is limited by the abutment of the extension 84, more precisely of the rounded area 184 against

  returns 71 which have the role of sparing the elastic member 72.

  The worm 63 and the ratchet wheel 60 can be made in one piece and be forced into the axis 67 carried by the part 72. The axis 67 passes through the holes 75 of the wings 74 and it is integral of the worm gear 63-ratchet wheel monobloc assembly 60 which is immobilized axially by the left lateral wing 74 by considering FIG. 4 towards which the crew is permanently pushed axially by the

take-up spring 86.

  In order to give great flexibility to the pawl 78, it is possible to thin the corresponding sheet metal part of the part 72 from which the pawl 78 is cut. As illustrated in the figures, it is also possible to stiffen the tongue 76 by a boss or a rib produced in the form of a stamping, which makes it possible to bring the

constraints towards the center. According to the variant illustrated in Figure 7, the single piece 72 forming

  support and elastic member also comprises an elastic blade 186 which constitutes the elastic means for taking up the cassette 10 which replaces the helical spring according to the design described above

  known previously mentioned.

  The ratchet wheel 60 is delimited laterally by a first lateral face 200 adjacent to the worm 63 and by a second lateral face 202 on which acts the elastic take-up means constituted here by an elastic blade 186 produced integrally with the part 72. The elastic blade 186 has a rooting portion 204 which connects it to the rear vertical edge 40 of the lateral wing 74 which faces laterally the second lateral face 202 of the ratchet wheel 60. The elastic blade 186 s' generally extends in a tangential plane and is located radially below the side tab

neighboring fixing 371.

  From its rooting edge 204, the elastic blade 86 extends transversely towards the inside of the cassette, and therefore of the part 72, in the direction of the second lateral face 202 of the ratchet wheel 60 with a profile curved so that its free end in contact with the second lateral face 202 of the ratchet wheel 60 is substantially parallel to this lateral face 202 and perpendicular to I5 the axis 67. Thanks to the blade 186, it is better to control than with the spring 86, the elastic action exerted by the elastic take-up means on the

ratchet wheel 60.

  More specifically, the free end 208 of the elastic take-up blade 186 has a curved profile, the convex face of which cooperates with the lateral face 202 of the ratchet wheel 60 and it is shaped like a fork, the two parallel branches of which are spaced apart. 'from one another to allow the passage of the corresponding section of the axis

transverse 67 of the crew.

  The shape and dimensions of the elastic take-up blade 186 are such that it permanently urges the wheel to

ratchet 60.

  The ratchet wheel 60 is thus implanted globally between the screw

  endless 63 and the elastic catching blade 86.

  Due to the production in the form of a single piece 72 of the 3o support of the cassette 10 of the elastic member and of the elastic take-up means, the cassette 10 is particularly simple and economical to produce, its weight is reduced and the assembly operations are simplified.

  In the figures, we see at 8 a ring with holes 19.

  The ring 8 is intended to protect the cassette 10 when the clutch mechanism is not mounted by its cover on the reaction plate or a part integral with the reaction plate, the skirt 32 being able to be fixed for example by snap-fastening or crimping. The ring 8 has at its outer periphery tabs shown in dotted lines and introduced by a bayonet-type mounting under stop tabs 5 which has at its inner periphery the bottom 13 of the cover 52, the tabs 5 being directed lo radially towards the inside. The ring 8 is thus interposed between the fingers of the diaphragm and the legs 5 alternating regularly with

legs 26.

  The assembly is done using one or more tools engaging the holes 19, to rotate the ring 8 in one direction or the other relative to the cover 52, in order to assemble or disassemble this one. After fixing the cover 52 on the reaction plate or a

  part integral with it, the ring 8 is dismantled.

  For more details, see document FR98 / 01769 filed on February 13, 1998, the content of which is considered to be

annexed to the present invention.

  In FIGS. 1 and 2, two other housings are also seen with closed bottoms and holes for mounting, here pre-balancing rivets, as a variant of pre-balancing mass for pre-balancing the cover with its cassette 10 as described in this

document FR98 / 01769.

  Thanks to the cassette 10, according to the invention, lighter than that of the

  aforementioned document and therefore easier to balance.

  The reference 25 indicates a braking tab carried by the pressure plate and acting on the ramps 56 to press the ring

  54 against the pads 57 and make the system insensitive to vibrations.

  Circlips can be provided to block the axis 67. As a variant, the ring 54 is distinct from the toothing 59 belonging for example to an intermediate part linked in rotation with the ring 54, with the possibility of axial displacement. For example two tongues 9 of the same set have an extension for pinching the intermediate piece and wedging

  axially the intermediate part linked in rotation to the ring 54 by a connection of the mortise tenon type allowing an axial displacement of the ring 54. As a variant, this connection is produced by tongues of the type of tongues 9.

  For more details, refer to document FR98 / 11991 filed on September 23, 1998 and therefore the content is considered to be

  annexed to the present invention. In this case, you can remove the non-return pawl.

Claims (9)

  1. Friction clutch mechanism, in particular for a motor vehicle, of the type comprising a cover (52), a pressure plate (51) linked in rotation to the cover (52) while being able to move axially relative to the latter , support means (14) carried by the pressure plate (51), clutch means (53) with axial action acting between the cover (52) and the support means (14), and a take-up device wear comprising firstly means (54) with ramps (56) integral in rotation with an external toothing (59) and placed between the pressure plate (51) and the support means (14) to constitute a pressure plate (51, 54) of variable thickness between its friction face (11) and the support means (14) and comprising, on the other hand, a cassette (10) carried by the cover (52) and which comprises: - a part (72) forming a generally U-shaped support with a central core and two lateral wings (74) each provided with a hole (75) for the rotational mounting of a crew (67, 63, 60); - Said equipment which comprises an endless screw (63), cooperating with the toothing (59) integral in rotation with the means (54) with ramps (56) on which is mounted a transverse axis (67), of generally tangential orientation by relative to the central axis (XX) of the mechanism, passing through at least one hole (75) in one of the lateral wings (74) of the support, and which comprises a ratchet wheel (60) axially and rotationally integral with the worm (63); - an elastic take-up means (86) acting on the ratchet wheel (60); and - an elastic member (72) provided with an elastic control tongue (76) carried by a return (85) of the elastic member (72) and provided with a non-return pawl (78) which are suitable for cooperate with the ratchet wheel (60), characterized in that said elastic member constitutes said part (72)   forming a support and comprises said lateral wings (74).   2. Mechanism according to the preceding claim, characterized in that the elastic member (72) forming a support comprises at least one   tab (168, 371) for fixing to the cover (52).   3. Clutch mechanism according to the preceding claim, characterized in that the elastic member (72) forming a support comprises a fixing lug (168) of radial orientation which extends, in a plane perpendicular to the central axis (XX) of the mechanism, from the soul central (73).   4. Mechanism according to one of claims 2 or 3, characterized   l0 in that the elastic member (72) forming a support comprises two opposite fixing lugs (371) of transverse orientation each of which extends, in a plane perpendicular to the central axis (X-X) of the   mechanism, from one of the side wings (74).   5. Mechanism according to any one of the claims   previous, characterized in that the elastic member (72) is a part in cut and folded sheet metal.   6. Mechanism according to claim 5 characterized in that the elastic member (72) incorporates an elastic take-up means (186)   acting on the ratchet wheel (60).   7. Mechanism according to claim 6 characterized in that the   elastic catch-up means is an elastic blade (186).   8. Mechanism according to any one of claims 1 to 7,   characterized in that the toothing (59) belongs to the means (54) to   ramps (56) consisting of a ring (54) of cut and stamped sheet metal.   9. Mechanism according to any one of claims 1 to 7,   characterized in that the teeth (59) belong to an intermediate piece linked in rotation with axial mobility, to a ring (54) with ramps (56) made of cut and stamped sheet metal constituting the means (54) to ramps (56).