FR2741918A1 - FRICTION CLUTCH - Google Patents

Abstract

The invention relates to a friction clutch comprising a cover (6), an annular spring (7) mounted so as to be able to pivot therein and requesting a pressure plate (11), connected to the cover in a non-rotating manner but nevertheless with possibility of limited axial offset. To ensure forced retention of the pressure plate during a pivoting movement of the annular spring, there are provided between the annular spring and the pressure plate retaining brackets (15) which, at least under the action of a centrifugal force, are connected by friction, (at 16b, 21) with a component (6) movable axially with respect to the pressure plate (11).

Description

FRICTION CLUTCH

  The present invention relates to a friction clutch, particularly for vehicles, comprising a device that dampens the oscillations of the pressure plate, occurring in particular during the clutching and disengaging processes, so that unpleasant noises can also be eliminated. In particular, the invention relates to a friction clutch comprising a casing and an annular spring, mounted so as to be pivotable thereon and which solicits a pressure plate, connected to the casing without the possibility of relative rotation but nevertheless with the possibility of axial displacement. limited, and o is provided, for a forced retention of the pressure plate during a pivoting movement of the annular spring, retaining brackets between the annular spring and the pressure plate. The object of the present invention is to create a friction clutch of the type defined above, in which, with as little expense as possible, the oscillations occurring at least temporarily during the clutching and disengaging processes can be prevented. by simple and inexpensive means, without adversely affecting the function of the

the friction clutch.

  According to the invention, this result is obtained by the fact that retaining brackets are used to produce a friction damping which at least reduces the axial oscillations of the pressure plate. The frictional connection which is provided by the retaining stirrups is then established at least when centrifugal forces act on the retaining stirrups which bear against a moving part axially by

compared to the pressure plate.

  The arrangement according to the invention makes it particularly easy for the means already provided in friction clutches and in the form of retaining brackets can be used for damping oscillations of the

pressure plate.

  In a particularly advantageous manner, the friction connection can be provided between the retaining brackets and the housing. The retaining stirrups can then bear directly against the housing or there may be a corresponding intermediate layer formed for example of a friction material or a sliding material. The areas of the housing supporting the retaining brackets may be advantageously arranged so as to be oriented at least approximately parallel to the axis of rotation of the friction clutch. These support zones can be

  created by crankcase wall portions.

  It may be advisable for the retaining brackets to be attached to the pressure plate and to engage axially behind the outer edge region of the annular spring on the opposite side of the pressure plate. Advantageously, the retaining stirrups are formed of spring steel and then the stirrups can be installed with prestressing in the friction clutch and particularly advantageously so that the pressure plate is pushed dynamically against

the annular spring.

  A particularly advantageous arrangement of the retaining stirrups can be obtained when these have a shape which ensures elastic radial retention in the mounting state in the friction clutch. The retaining brackets can then be installed with a radial preload in the friction clutch and lean against the housing. It may be advisable for the friction action between the retaining brackets and the housing to occur at the axial height of the outer edge of the annular spring. This friction action can, however, also occur in another place and for this purpose the retaining stirrups must be arranged in correspondence. Thus such retaining brackets may also comprise fins formed unitarily and which bear elastically against a component movable relative to the pressure plate, such as the clutch housing. These fins can then rest in a radial direction, or even if they are curved in correspondence with the base body of the retaining yoke, also laterally or in a circumferential direction of the friction clutch. against the corresponding component, and in particular to produce a

friction damping.

  The invention furthermore converts a friction clutch which is arranged, in association with a flywheel having two masses of inertia, between a drive motor and a transmission, the motor-side inertia mass being connected through of bolts with the crankshaft of the engine and at least the second mass of inertia, carrying the friction clutch with the aid of a clutch disk, has recesses allowing the passage of a tool for actuating the bolts ; in this regard, for disassembly of the flywheel with two masses of inertia, the friction clutch and the clutch disc are separated from the second mass of inertia and then the recesses of the second mass of inertia are brought axially in coincidence with the bolt heads by rotating correspondingly the second mass of inertia and then the bolts are loosened to

  using a tool engaged through the recesses.

  The tool for actuating the bolt heads can then be arranged in such a way that it is always ensured that, during unscrewing, the heads of the bolts can penetrate properly into the recesses provided in the

second mass of inertia.

  Other features and advantages of the invention will be highlighted later in the

  description, given by way of non-limiting example, in

  1 represents a friction clutch provided with a retaining clip arranged in accordance with the invention and which is mounted on a flywheel with two masses of inertia, FIG. 2 represents a retaining clip. in an elevational view taken along arrow II of FIG. 1, FIG. 3 is a side elevational view of FIG. 2, FIG. 4 is a plan view of FIG. 3, FIG. 1, and FIG. 6 shows the arrangement of a pivot support for holding an annular clutch spring on a cover, FIG. 7 is a partial sectional view of another arrangement according to the invention. 8 is an enlarged sectional view of the retaining element, which is shown in section in FIG. 7, FIG. 8 showing the relaxed position of this retaining element, FIG. 9 is a plan view of the reel element held according to the arrow IX of FIG. 7, and FIG. 10 is an elevational view in

  Correspondence to arrow X in Figure 9.

  In Figure 1 is shown a friction clutch 1 which is mounted on what is called a flywheel with two masses of inertia 2. The flywheel with two masses of inertia 2 consists of a mass of primary inertia 3 , which can be coupled to the crankshaft of an engine, and of a secondary mass of inertia 5, which can rotate in a limited manner with respect to the primary mass of inertia by means of a bearing 4 and on which is

attached the friction clutch 1.

  With regard to the arrangement and mode of operation of the flywheel with two masses of inertia 2, reference is made to the German patent application DE-OS 44 14 584, the disclosed content of which is thus integrated into the

this patent application.

  The friction clutch 1 comprises a cover 6 on which is pivotally held an annular spring acting as a lever with two arms. The annular spring 7 comprises tongues 7a, oriented radially inwards, to actuate the friction clutch and an outer base body 7b, of annular shape, connected unitarily to the tongues 7a and which serves as a storage battery. energy. The annular spring 7 is rotatably mounted between a pivoting support 8 on the lid side and a pivoting support 9 provided on the side of the annular spring which is opposite the lid. In the embodiment shown, the pivoting supports 8, 9 are constituted by wire rings which are axially connected to the cover 6 by means of rivets 10 which extend radially in the base body 7b, axially through the annular spring. Inside the lid 6, there is provided a pressure plate 11, which is connected to the lid 6 by means of elements 12 in the form of elastic blades, without the possibility of relative rotation but

  however with possibility of limited axial offset.

  In the exemplary embodiment shown, the elements 12 in the form of elastic blades are connected to the rivets 10 and serve simultaneously to support axially the pivot supports 8, 9 and the annular spring 7. By their other end, the elements 12 in form of resilient blades, are non-rotatably connected to the pressure plate 11, and in particular in a manner similar to that shown in Figure 1 of the aforementioned German patent application DE-OS 44 14 584. The lid clutch 6, also called "casing", firmly connected to the secondary mass of inertia 5, is also firmly connected to a component 13 in the form of a hollow cylinder, particularly advantageously by bolting, as has been described in the application of German patent DE-OS 44 14 584. The component 13 in the form of a hollow cylinder surrounds the secondary mass of inertia 5 and is firmly connected thereto. The friction linings of a clutch disc 14 are clamped axially between the pressure plate 11 and the secondary inertia mass 5, forming a back pressure plate. The friction clutch 1 further comprises retaining brackets 15, which are firmly connected to the pressure plate 11 and which engage by means of a hook-shaped zone 16 behind the outer edge of the annular spring. 7 on the side of this

  the last one opposite the pressure plate 11.

  Advantageously, there are provided three retaining brackets 15 of this kind which are distributed at equal intervals on the

around the pressure plate 11.

  The retaining brackets 15 are arranged such that, in the mounted state, they exert a clamping force on the annular spring 7, so that the pressure plate is applied against the underside of the annular spring 7. The outer edge of the annular spring 7 is thus elastically clamped between the bearing zones 16a of the hook-shaped portions 16 of the retaining stirrups 15 and the bosses 17 of the pressure plate 11. As shown in FIG. contact of the support portions 16a and bosses 17 are advantageously axially aligned with the annular spring 7 disposed between them. However, these contact zones can also be shifted in a radial direction and in this respect, however, because of the axial prestressing of the elastic stirrups 15, the annular spring 7 is subjected to a torque which has an influence on the force exerted by this spring. ring 7 on the support bosses 17 of the

pressure plate 11.

  In the exemplary embodiment shown, the retaining stirrups 15 are fixed on the radially outer circumferential surface of the pressure plate 11, and in particular in the embodiment shown by means of screw connections 18. retaining 15 could also be connected in a similar manner to a pressure plate, as is

  known for example from the United States patent US-

  3.640.364, that is to say via a radially oriented zone which is fixed by riveting on the corresponding pressure plate. The riveting can then be used simultaneously for fixing the elements in the form of elastic blades establishing the rotating connection between the pressure plate and the housing. In addition, the retaining stirrups according to the invention can also be connected individually to the elements in the form of an elastic blade which establish the non-rotating connection between the corresponding pressure plate and

the housing.

  As shown in FIG. 2, the retaining stirrups 15 comprise, in a foot zone 20, a hole-shaped recess 19 for a fastening means 18. The hook-shaped zone 16, arranged after the zone 20, is arranged such that it rests, at least under the effect of a centrifugal force, against an area 21 of the wall of the cover or housing 6. Advantageously, however, the retaining brackets 15 are arranged in such a way that they are mounted with a certain radial prestressing in the friction clutch 1, the portions 16b of the hook-shaped zone 16 then pressing elastically against the axially oriented wall zone 21. It is thus ensured that there is always a frictional connection between the pressure plate 1il or the retaining stirrups and the housing 6. In the embodiment shown, the support between the stirrups 15 and the housing 6 is established at the axial height of the outer edge region of the annular spring 7. This support can however be established also in another place and in this respect the retaining stirrups 16 must be profiled in correspondence. Thus, for example, a retaining stirrup 15 may, as shown in FIG. 2, also comprise arms 22 formed in one piece and able to bear against the casing 6 with prestressing. In the exemplary embodiment shown, the wall zones 21, against which the retaining stirrups 15 bear radially, are oriented axially exactly. These wall zones 21 can however - by considering them in the axial direction of the clutch - be oriented also by a determined angle such that, during an axial shift of the pressure plate 11, for example during a process of the friction clutch 1, the radial prestressing of the retaining stirrups is modified, for example undergoing, in the case of a clutch, an increase or a

  decrease in case this is more appropriate.

  The extent of the wall zones 21 against which the retaining stirrups 15 are based is dimensioned such that this support, or the frictional connection, is advantageously manifested throughout the duration of the friction clutch 1. This therefore means that, also in the case where the friction linings of the clutch disc 14 are worn, there is a force-conjugate connection or a friction-coupling connection between the stirrups of

retainer 16 and housing 6.

  The support of the zones 16b of the retaining stirrups 15 against the casing 6 can be effected either directly, as shown in FIG. 1, or indirectly. For example, a friction or sliding material, that is to say an intermediate layer which can be carried by the casing 6 and / or by the shims 15, can be arranged between the bearing zones 21 and the retaining stirrups 15. different

retaining brackets 15.

  It may also be wise for the retaining stirrups 15 to be provided with a coating at least in the area of the contact portions 16b. This coating may be formed for example by a phosphate layer or a hard nickel layer. Where appropriate, the housing 6 may also comprise a coating corresponding at least to the zones cooperating with the

retaining brackets 15.

  The retaining stirrups 15 arranged as elastic stirrups, ensure that, during an actuation of the friction clutch 1, the pressure plate 11 axially undergoes a forced offset under the effect of the annular spring 7. Under the the effect of the frictional connection existing between the retaining stirrups 15 and the casing 6, it is ensured that the axial oscillations of the pressure plate occurring during the clutching and disengaging processes are damped, so that one is ensured a correct separation between the friction linings of the clutch plate 14 and the friction surfaces of the pressure plate 11 and the backing plate 5. In addition, the retaining brackets 15 can eliminate noise which could be produced for example by abutment bosses 17 against the annular spring 7 when

  oscillations of the pressure plate 11.

  The arrangement of the retaining stirrups 15 according to the invention thus makes it possible to obtain a simple and inexpensive solution for a damping of the axial oscillations of the pressure plate 11, and especially over the entire service life of the friction clutch. 1. Thus, thanks to the simple and elegant arrangement of the friction clutch according to the invention, so-called switching rattles are avoided under the effect of axial oscillations of the pressure plate. In addition, the friction damping with a view to eliminating axial oscillations of the pressure plate 11 can be modified, for example increased, during an increase in the speed of rotation by means of a corresponding arrangement of the stirrups. of restraint with respect to

their elasticity.

  The group shown in Figure 1 - consisting of the friction clutch 1, the disc

  clutch 14 and flywheel with two masses of inertia 2 -

  may, as described in the previously mentioned German patent application DE-OS 44 14 584, be transported or shipped in this condition and be fixed integrally on the crankshaft of an engine in the assembly line of the factory of automobile manufacturing. Disassembly of the complete unit by means of a corresponding bolting tool can be carried out in a similar manner to the assembly and in this respect, however, it is necessary initially to bring the openings, provided for a passage of the bolting or dismounting tool. in the annular spring 7 of the clutch disk 14 and the second mass of inertia, in at least substantially aligned positions

axial to reach the bolts.

  However, it may also be advantageous for the dismantling of the two flywheel 2 of the crankshaft of an engine, initially the clutch 1 is separated or removed from the secondary mass of inertia 5, so that also the clutch disc 14 can be removed. Provided that the springs of the damper 24, arranged between the two masses of inertia 3 and 5 and being compressible in a circumferential direction, do not push the two masses of inertia 3 and 5 into a defined initial position where the recesses 5a provided in the secondary mass of inertia 5 do not come to be placed axially substantially in alignment with the heads of bolts 23, it is necessary if necessary to rotate the

  secondary mass of inertia 5 of a corresponding angle.

  As soon as the sets of holes 5a of the secondary inertia mass 5 and the bolt heads 23 are arranged at least approximately in mutually aligned positions, it is possible to loosen the bolts with a corresponding tool 25 which is shown in FIG. 5 and which is engaged in the holes 5a. It is advisable in this regard that the bolting tool has an outline that is at least approximately adapted to the diameters or contours of the recesses 5a so that it can be assured that, upon unscrewing the bolts 23a, their heads 23 It is particularly advantageous if the bolting tool 25 has in the region of recesses 5a a section which is tangential to a circle having a diameter approximately less than or equal to the circle tangent to the outer contour of a bolt head 23. To avoid jamming between the bolt heads 23 and the secondary mass of inertia 5, the bolt heads 23 and / or the recesses 5a may comprise chamfers that constitute surfaces

introductory assistance.

  The mounting system shown in FIG. 6 for pivotal mounting of an annular spring 107 on a housing or cover 106 can also be used in

  a friction clutch 1 such as that of FIG.

  The pivoting support located on the cover side is constituted by fingerprints 108 in the form of bristles which are created in the cover 106 in the circumferential direction between the retaining means 110. The retaining means 110 form one and the same piece with the The retaining means 110 arranged in the form of tabs are formed from the material of the lid 106 in a manner similar to that described in the German patent application DE-OS 44 20 251 and in the application. filed in the United States under serial number 08 / 264,557. According to the invention, however, it is not necessary to use any additional support means, such as for example the wire ring 9 of FIG. 1, since the end zones 110a of the holding means 110 are profiled directly. to support the annular spring 107. To ensure correct support and pivoting of the annular spring 107 on the holding means 110, the annular spring 107 comprises, in the region of the recesses 107a, through which the support means extend axially. 110, 197b form of curved or rounded around which the holding means or the lugs 110 or their support zone a, are arranged or curved. The parts 110b of the tabs 110 which engage under the annular spring 107 or its annular base body 107c are arranged such that the annular spring 107 can pivot correctly relative to the lid, and this also when the clutch disk (14 in Figure 1) is worn. For this purpose, in the exemplary embodiment shown and in the case of a new friction clutch and also a new clutch disk, there exists between the zones 10b and the base body 107c an angle 112. This Angle 112 permits the conical modification of the annular spring 107 necessary during the service life of the friction clutch and which allows compensation of the wear on the friction linings.

friction of the clutch disc.

  In the case of an arrangement of a pivoting support in accordance with FIG. 6, it is advisable for the tabs 110 to be connected to the cover 106 so that the zones 110a which engage under the annular spring 107 are loaded or pushed by a determined force in the direction of the pivot support 108 on the cover side. In this regard reference is made to the patent applications already cited as well as to United States Patent 4,781,820. According to this prior art, the holding means 110 are connected to the actual base body of the cover by means of parts of this cover acting as torsional elastic zones or flexural elastic zones, which makes it possible to compensate a wear in the area of the pivot bearings of the annular spring. An arrangement of an annular spring pivot bearing 107 in accordance with FIG. 6 has the advantage that by simply bending or folding the end zones 110a of the lugs 110, the annular spring 107 can be pivotally mounted on the cover 106. During the folding process of the holding members 110, the base body 107c of the annular spring 107 serves as a supporting part in

  thus constituting practically a folding tool.

  The friction clutch 201 shown in part in FIG. 7 is realized, independently of the particular arrangement of the retaining means 215, in a manner similar to the friction clutch 1 of FIG. 1 and it can be mounted, also in a manner similar to this clutch, so that it is not necessary to

  redo a detailed description.

  The retaining means 215, which axially connect the annular spring 207 to the pressure plate 211, comprise a base body 207 of annular shape which, in the embodiment shown, acts in the manner of a membrane or a flexible spring, as well as arms 217, starting from the outer edge of the base body 216 and forming retaining elements which ensure the connection of the pressure plate 211 axially with the annular spring 207. As shown in Figure 9, there is provided in this embodiment, four retaining elements 217 distributed at equal intervals around the periphery. FIG. 8 shows that, in the relaxed state, that is to say not mounted, retaining means 215, the annular base body 216 is arranged in the manner of an annular spring. In addition, it can be seen that the arms or retaining elements 217 are radially offset or pivoted in the direction of the axis of rotation of the clutch 201 relative to the position they occupy in the clutch 201 in accordance with FIG. FIGS. 7 and 8 also show that, when assembling the annular spring 207, the casing 206 and the pressure plate 211, the annular base body 216, acting as an elastic ring, changes its conicity. , and in particular in the direction of a decrease in taper while against the arms 217 are spaced radially from the axis of rotation of the clutch 201 by pivoting and are supported radially

  outside against the pressure plate 211.

  The retaining means 215 arranged as an elastic ring or a retaining ring are made such that, in the mounted state, they exert a clamping force on the annular spring 207, which makes the pressure plate 211 is applied against the lower side of the annular spring 207. The elastic ring 216 forms a bearing zone 218 of annular profile, which is located on the side of the spring

  annular 207 which is opposed to the pressure plate 211.

  The bearing zone 218 may extend over a complete circle, but it is also possible for it to consist of several sector-shaped zones, in which case at least in part of the circumferential extent of the legs 217 There must be bearing zones through which the retaining ring 215 rests against the annular spring 207. The contact areas of the bearing portions 218 and the bosses 219 of the pressure plate with the annular spring 207 are advantageously arranged, at least approximately, in respective axial alignment and in this respect, as shown in Figure 7, there may also exist a radial offset. FIG. 7 also shows that the areas of contact between the retaining ring and the annular spring 207 are slightly offset radially inward with respect to the contact zones between the

  bosses 219 and the annular spring 7.

  During assembly of the friction clutch 201, and before the annular spring 207 is pivotally attached to the clutch housing 206, the elastic ring 215 is placed in the housing 206. This housing 206 has a annular support zone 206a, against which the tabs 220 formed radially inwards on the annular base body 216 can bear axially. In the new-state condition of the friction clutch 201, the depression plate 211 occupies the axial position shown in FIG. 7 so that the ring-shaped base body 207a of the annular spring 207 is substantially clamped in a flat layout. As can be seen from a comparison of FIGS. 7 and 8, at least in the new state of assembly of the friction clutch 201, an axial clamping of the annular base body 216 between the annular spring is obtained. 207 and the bearing zones 206a of the casing 206. The force exerted axially by the annular base body 216 is added to the force exerted by the

annular spring 207.

  As shown in FIGS. 7 to 10, the retaining elements 217, which are prestressed in the radial direction, bear radially against outer zones 221 of the pressure plate 211. The arms 21 axially essential, comprise in the exemplary embodiment shown, two outer branches 222, 223, which are connected to each other, at their opposite ends to the base body 216 of annular shape, through A transverse connection 224. From this transverse connection 224 again part a tongue 225, which is oriented axially in the direction of the annular base body 216. The free end 226 bears, with radial prestressing, against parts 225 of the casing 206. The portions 227 are located, in the embodiment shown in FIG. 7, in the region of an axially oriented wall 228. 206. As can be seen in a comparison of FIGS. 7 and 8, the tongues 225 protrude radially from the branches 222, 223 in the unmounted state of the elastic ring 215, whereas on the other hand, in the mounted state of this ring. elastic, the tabs 225 associated respectively with the two branches 222, 223 are situated, at least approximately, in the same plane as said branches 222, 223. The tongue end 226 is provided with a curved profile and is placed in connection friction with the housing 206. It is thus ensured that there is still a frictional connection between the pressure plate 211 or the annular spring 207 and the casing 206. The axial connection between the retaining element or the elastic ring 215 and the pressure plate 211 is established via a connection 229 by conjugation of forms. For this purpose, the branches 217 comprise, at their free end directed towards the pressure plate 211, tabs 230 which cling axially below the radially outer regions of the pressure plate 211. As shown in FIGS. 8 and 10, the tongues 230 extend in an axial direction before mounting the elastic ring 215 in the clutch 201. As soon as the pressure plate 211 has been put into place in the housing 206 and a corresponding clamping of the annular spring 207, for example at least the axial offset of the pressure plate 211, the tongues 230 are bent radially inward so as to axially clamp the pressure plate 211 with the spring

  annular 207 by means of the elastic ring 215.

  The structural arrangement can, however, be made in such a way that corresponding zones 230, directed radially inwards, are already provided before mounting the elastic ring 216. The arm 217 or the branches 222, 223 must then have a corresponding radial elastic deformation capacity, which makes it possible to axially guide zones 230, directed radially inwards, above corresponding zones of the pressure plate 211 and, after a determined position has been reached, to make them

  again retract radially inward.

  Between the retaining element 215 and the casing 206,

  there is also an anti-tamper

  rotation. This anti-rotation security system 231 is created by means of arms 232 which are carried by the retaining element 215 and which engage in corresponding recesses of the casing 206. As shown in FIGS. 8 and 9, these arms 232 are formed, in the exemplary embodiment shown, on the radial inner edge of the base body 215 of annular shape, and in particular, considering a circumferential direction, in the zone

tongues 225.

  Friction hysteresis occurring as a result of friction between tabs 226 and housing 206 produces at least the same effects as the frictional action acting as described in FIG. 1. between the retaining brackets 15

and the housing 6.

  As shown in particular in FIG. 8, the retaining element 215 comprises, radially outside the bearing zones 218, zones 233 in the form of hooks or arcs, which are arranged in such a way that the parts 207b of the annular spring which are located radially outside the bearing zones 218 can be displaced by pivoting, in order to disengage the friction clutch 201, without coming to bear against the aforementioned zones 233. The annular base body 216 of the retaining element 215 occupies, in the mounting state in the friction clutch, also a corresponding arrangement which allows a pivotal movement of the annular spring 207. The shaped zones 233 arcs are located between the ring-shaped base body 216 and

branches 222, 223.

  In a variant of Figures 7 to 10, it would also be possible to use several retaining elements distributed around the periphery. In the exemplary embodiment considered, one could use four such retention elements, distributed for example with a respective offset of 90 on the periphery. Such an arrangement can be demonstrated by means of FIG. 9 when the areas of the annular base body 216 which extend in a circumferential direction between the branches 222, 223 or the arms are removed from this figure. 217. The tongues 232 and the lid 206 are then advantageously mutually adapted so that the corresponding retaining elements

  blocked or supported radially outward.

  This radial blocking could also be established by a combination of shapes between the retaining elements and the annular spring 207. For this purpose, for example tongue-like zones, similar to the tabs 232, could engage in corresponding recesses of the annular spring 207 or could be applied against corresponding support contours of this spring

Annular 207.

  The friction occurring between the zones 226 and 227 is a function of the force acting on the tongues 225 under the effect of the centrifugal force occurring during the rotation of the clutch 201. This therefore means that the friction damping

  increases as the rotational speed increases.

  Because the base body 216 of annular profile is arranged in the manner of an annular spring,

  this one can have a characteristic force-

  race that is not linear. By means of a corresponding choice of this spring characteristic curve or a corresponding position of installation of the ring-shaped base body 216 in the new state of the clutch, it is thus possible to act on the clamping force exerted on the pressure plate 211 during the service life of the friction clutch. Also the evolution of the disengagement force of the friction clutch 201 is influenced by the basic body 216 in

annular spring shape.

  The claims filed with the application for

  patents are drafting proposals that have no prejudicial effect for obtaining future patent protection. The Applicant still reserves to claim other characteristics highlighted

  until now only in the description and / or

on the drawings.

  Attachments used in

  secondary claims refer to other bets

  of the subject matter of the main claim by the characteristics of the corresponding secondary claim, but they should not be regarded as a waiver of the

  ancillary claims attached.

  The objects of these secondary claims

  also constitute particular inventions that are of an independent design from the objects of the

  previous secondary claims.

  The invention is also not limited to

  examples of realization given in the description. the

  On the contrary, in the context of the invention, it is possible to envisage numerous variations and modifications, in particular variants, elements and combinations and / or materials which are inventive, for example by combination or modification of certain features, or elements, or operative steps, which have been described in relation

  with those described in the general description, the

  embodiments and claims and that are

  contained in the drawings by driving, by a combination of features to a new object, or new operative steps, or new sequences of operating steps, so far as also relates to methods of manufacture, control and

Implementation.

Claims (14)

  1. Friction clutch comprising a housing, an annular spring pivotally mounted thereon and biasing a pressure plate, which is non-rotatably connected to the housing, but with limited axial offset, and where is provided for a forced retention of the pressure plate during a pivoting movement of the annular spring, the retaining stirrups between the annular spring and the pressure plate, clutch characterized in that the retaining stirrups comprise, at least under the action of a centrifugal force, a connection by friction conjugation with an axially movable component compared to the pressure plate.   2. Friction clutch according to claim 1, characterized in that the connection by friction conjugation is established between the retaining brackets and the housing. 3. Friction clutch according to one of the   1 or 2, characterized in that the   Retaining brackets rest directly on the crankcase. 4. Friction clutch according to claim 3, characterized in that the bearing areas of the housing for the retaining stirrups are created by housing wall areas which are oriented substantially axially. 5. Friction clutch according to one of the   Claims 1 to 4, characterized in that the stirrups   retainers are attached to the pressure plate and engage axially behind the outer edge region of the annular spring on the side opposite the pressure plate.   6. Friction clutch according to one of the   Claims 1 to 5, characterized in that the stirrups   retainers consist of spring steel and are mounted with prestressing, so that the pressure plate is dynamically pushed against the annular spring. 7. Friction clutch according to one of the   Claims 1 to 6, characterized in that the   Retaining brackets are profiled such that they are resiliently biased in a radial direction in the mounting state in the clutch. friction.   8. Friction clutch according to one of the   Claims 1 to 7, characterized in that the stirrups   retainers are mounted with radial prestressing in the friction clutch and bear against the casing.   9. Friction clutch according to one of the   Claims 1 to 8, characterized in that the action of   friction between the retaining brackets and the housing occurs at the axial height of the outer edge of the spring annular.   A friction clutch comprising a housing, an annular spring pivotally mounted thereon and biasing a pressure plate which is non-rotatably connected to the housing, but with the possibility of limited axial displacement, characterized in that the annular spring and the pressure plate are coupled for their movements by means of connecting means and the connecting means comprise a connection by friction conjugation with a component movable axially relative to the pressure plate. 11. Clutch friction according to claim, characterized in that the means of laision are arranged and / or act in accordance with at least one of Claims 2 to 9.   12. Friction clutch, which is arranged in connection with a flywheel having two masses of inertia between a drive motor and a transmission, the mass of inertia located on the motor side being connected by means of bolts to the crankshaft of the motor and at least the second mass of inertia, carrying the friction clutch in association with a clutch disk, having recesses to allow the passage of a tool for actuating the bolts, clutch characterized in that, in in view of disassembling the flywheel with two masses of inertia, initially the friction clutch and the clutch disc are removed from the second mass of inertia, then the recesses provided in the second mass of inertia are brought axially. in alignment with the bolt heads by means of a corresponding rotation of the second mass of inertia and then the bolts are loosened with the aid of a tool engaged through the recesses.   A friction clutch having a housing, an annular spring pivotally mounted thereon and biasing a pressure plate non-rotatably connected to the housing, the annular spring including an annular outer base body from which tongues oriented radially inward and separated from each other by slots opening into adjacent recesses provided in the base body, and further tabs integrally formed with the housing material extend axially through recesses of the housing; annular spring and are curved, on the side of the annular spring which is opposite the housing, so as to maintain this spring with the possibility of pivoting, clutch characterized in that the tabs are bent directly around the areas of the base body of the annular spring which are   adjacent to the corresponding recesses.   14. Friction clutch according to claim 13, characterized in that the annular spring serves as a support tool for folding the end zones of the tabs.