Title of Invention	"FRICTION CLUTCH, IN PARTICULAR FOR MOTOR VEHICLE OF THE TYPE COMPRISING AN IMPROVED SHOCK ABSORBER"
Abstract	The invention concerns a friction clutch (10) comprising a shock absorber (12) including coaxial rotating input (16) and output (22) elements, a first coupling element (12A) integral in rotation with the rotating input element (16), a second coupling element (12B) integral with the rotating output element (22), damping means (19) including resilient members (30) with circumferential effect borne by the first (12A)and second (12B) coupling elements, and means (36) for limiting the angular displacement between the rotating input (16) and output (22) elemenls. The limiting means (36) include complementary angular limitation stops (39, 40) provided on a radially inner contour (42) of the first coupling element (12A) and on a limiting member (37) integral in rotation with ihe second coupling element (12B).

Title of Invention

"FRICTION CLUTCH, IN PARTICULAR FOR MOTOR VEHICLE OF THE TYPE COMPRISING AN IMPROVED SHOCK ABSORBER"

Abstract

The invention concerns a friction clutch (10) comprising a shock absorber (12) including coaxial rotating input (16) and output (22) elements, a first coupling element (12A) integral in rotation with the rotating input element (16), a second coupling element (12B) integral with the rotating output element (22), damping means (19) including resilient members (30) with circumferential effect borne by the first (12A)and second (12B) coupling elements, and means (36) for limiting the angular displacement between the rotating input (16) and output (22) elemenls. The limiting means (36) include complementary angular limitation stops (39, 40) provided on a radially inner contour (42) of the first coupling element (12A) and on a limiting member (37) integral in rotation with ihe second coupling element (12B).

Full Text	Friction clutch, in particular for a motor vehicle, of the type comprising an improved damper The present invention concerns a friction clutch, in particular for a motor vehicle, of the type comprising an improved damper. In a motor vehicle, the function of a friction clutch is to transmit a torque between an input rotary element and an output rotary element, by friction gripping between the pressure and reaction plates rotationally connected with an engine flywheel. In general, the input element is formed by a friction disc and the output element is rotationally connected, with or without angular clearance, to a hub rotationally connected with a gearbox input shaft. Another function of the friction clutch is to provide continuity of the torque transmitted and to filter the Vibrations coming from the engine, in particular by virtue of damping means comprising elastic members and friction means. A friction clutch is already known in the prior art, in particular for a motor vehicle, of the type having a damper comprising: - substantially coaxial input and output rotary elements, - a first coupling element, of general shape of revolution, rotationally fixed to the input rotary element, - a second coupling element, of general shape of revolution, rotationally fixed to the output rotary element, - damping means comprising circumferential-effect elastic members carried by the first and second coupling elements, and - means of limiting the angular movement between the input and output rotary elements. A damper generally comprises a damper plate interposed between two guide washers. These guide washers are normally connected together rotationally. It should be noted that the damper is said to be "symmetrical" when the friction disc (input element) is fixed to the damper plate. In this case, the first coupling element is formed by the damper plate and the second coupling element is formed by the guide washers of the damper. In addition, the damper is said to be "asymmetric" when the friction disc is fixed to one of the guide washers. In this case, the first coupling element is formed by the guide washers and the second coupling element is formed by the damper plate. Normally the elastic members are housed in windows provided in the first and second coupling elements. In many cases, the angular movement between the input and output rotary elements is limited by the elastic members. This is because, when the torque is transmitted between the first and second coupling elements, the elastic members are able to be compressed up to a compression limit defining a maximum angular movement angle. However, the use of the elastic members up to their compression limit reduces their service life. The aim of the invention is in particular to increase the service life of the elastic members by providing a motor vehicle clutch comprising angular movement limitation means independent of the elastic members. To this end, an object of the invention is a clutch of the aforementioned type comprising a damper able to pass the maximum engine torque, the limitation means of which comprise complementary angular limitation stops formed on the one hand on a radially internal contour of the first coupling element and on the other hand on a limitation member rotationally fixed to the second coupling element. The complementary angular limitation stops are conformed so as to define a movement limitation angle between the input and output rotary elements preventing the elastic members reaching their compression limit. When the movement angle reaches the limitation angle, the torque is then transmitted directly from the first coupling element to the limitation member, rotationally fixed to the second coupling element, by means of the limitation stops. The excess torque, referred to as over-torque, then no longer passes through the elastic members. Thus, during the functioning of the clutch, the elastic members never reach their compression limit, which increases their service life. It is in fact known that the engine torque may exhibit over-torques that are not filtered by the friction clutch. In the case of the present invention, the over-torque passes not through the second coupling element but through the limitation member, unlike the known solutions of the prior art. It is thus possible to advantageously size the second coupling element. A clutch according to the invention can also comprise one or more of the following characteristics: - the limitation member is annular in shape overall; - the limitation stops are delimited on the one hand by radial projections formed on the internal contour of the first coupling element and on the other hand by radial projections formed on a radially external contour of the limitation member; - the input and output rotary elements being able to move angularly with respect to each other in direct and retrograde directions, the angular movement in the direct direction is limited by a predetermined direct angle with respect to an idle position and the angular movement in the retrograde direction is limited by a predetermined retrograde angle with respect to the idle position; - the first coupling element is a damper plate and the second coupling element is a guide washer; - the clutch comprises two guide washers, coupled together by axial fingers extending through orifices formed in the limitation member in order to couple the limitation member with the guide washers; - the orifices of the limitation member coincide angularly with the radial projections of this limitation member; - the axial fingers are rivets; - the first coupling element is a guide washer and the second coupling element is a damper plate; - the damper plate and the limitation member are conformed in a single piece; - radial projections are formed on the one hand on an internal contour of the damper plate and on the other hand on a radially external contour of the limitation member, so that these radial projections cooperate with each other without clearance; - the input rotary element is a friction disc of the clutch; and - the limitation member is rotationally connected, with or without angular clearance, to a hub rotationally connected with an input shaft of a gearbox of the motor vehicle. The invention will be better understood from a reading of the following description, given solely by way of example and made with reference to the accompanying drawings, in which: - figure 1 is an exploded perspective view of a clutch according to a first embodiment of the invention; - figure 2 is a front view of a damper plate of the clutch of figure 1 and of the associated limitation member; - figure 3 is a half-view in axial section of a clutch according to a second embodiment of the invention; - figure 4 is a half-view in axial section of a clutch according to a third embodiment of the invention. Figures 1 and 2 depict a friction clutch, in particular for a motor vehicle, according to a first embodiment of the invention. The friction clutch comprises a friction device 10 intended to transmit a torque between an engine flywheel rotationally fixed to a driving shaft, such as the crankshaft of a motor vehicle engine, and a driven shaft such as the input shaft of a motor vehicle gearbox. The friction device 10 is provided with a main damper 12 and a predamper 14. The main damper 12 is coupled in series with the predamper 14 between a general input rotary element 16 and a general output rotary element 18. The general input rotary element 16 is a friction disc able to be rotationally connected with the engine flywheel by gripping between pressure and reaction plates rotationally connected with the engine flywheel and actuated by engagement means. The general output rotary element is a hub 18, annular in shape overall, rotationally connected with the input shaft of the motor vehicle gearbox. For this purpose, the hub 18 is provided with internal longitudinal flutes rotationally connecting it with one end of the input shaft of the gearbox. The main damper 12 and the predamper 14 are each provided with substantially coaxial input and output rotary elements. It should be noted that the input element of the predamper 14 is normally formed by the output element of the main damper 12. The main damper 12 comprises first 12A and second 12B coupling elements, of general shape of revolution, respectively rotationally connected to the input and output rotary elements of the damper 12. The first 12A and second 12B coupling elements are coupled together by damping means 19. Likewise, the predamper 14 comprises first 14A and second 14B coupling elements, of general shape of revolution, respectively rotationally connected to the input and output rotary elements of this predamper 14. The first 14A and second 14B coupling elements are coupled together by damping means 20. In a conventional manner, the output rotary element of the main damper 12 is formed by the second coupling element 12B. The first coupling element 14A of the predamper 14 is fixed, for example by riveting, to this second coupling element 12B of the main damper. According to the embodiment described with reference to figure 1, the input element of the main damper 12 is the general input element of the friction device 10, that is to say the friction disc 16. The output element of the predamper 14 is the general output element of the friction device 10, that is to say the hub 18. Thus, when a torque is transmitted from the friction disc 16 to the hub 18, it first of all passes from the first 12A to the second 12B coupling element of the main damper 12 through the damping means 19. According to the first embodiment of the invention, the main damper 12 is of the symmetrical type. In this case, the first coupling element 12A is a damper plate 21 (fixed to the friction disc 16) of the main damper 12, and the second coupling element 12B is formed by two guide washers 22 of the main damper 12 between which the damper plate 21 is housed, coaxially with these. The guide washers 22 are coupled together by axial fingers 24, preferably rivets. The first coupling element 14A of the predamper 14 is generally formed by two guide washers fixed to one of the corresponding guide washers 22 of the main damper, for example by riveting. The guide washers 14A of the predamper 14 surround a damper plate forming the second coupling element 14B of the predamper 14. This damper plate 14B is rotationally connected to 'the hub 18 by means of internal flutes cooperating with external flutes on the hub 18. The damping means 19 of the main damper 12 comprise circumferential-effect elastic members 30, such as high-stiffness helical springs. The elastic members 30 are housed in windows 32 in the damper plate 21 and in windows 34 in the guide washers 22. These elastic members 30 participate in the transmission of the rotation torque between the damper plate 21 and the guide washers 22. The damping means 19 also comprise two friction washers 35, each arranged between the damper plate 21 and a corresponding guide washer 22. The friction washers 35 are rotationally connected with the damper plate 21 by means of folded lugs 35P cooperating with notches 32E formed in contours of the windows 32 in the damper plate 21. Each friction washer 35 also comprises a friction face 35F cooperating with the corresponding guide washer 22. Thus, when the damper plate 21 and the guide washer 22 move angularly with respect to each other, a friction is generated between the friction washers 35 and the guide washers 22. It is also possible to dispose a washer with no lug in place of the friction washer 35 with a lug. Teeth,are then provided, the shape of which is conjugate with that of the limitation member 37, on a radially internal contour of the said washer. In order to increase the service life of the elastic members 30, the main damper 12 comprises means 36 of limiting the angular movement between the friction disc 16 and the guide washers 22 independent of the elastic members 30. The limitation means 36 comprise a limitation member 37, annular in shape overall, rotationally connected with the guide washers 22. For this purpose, the rivets 24 coupling together the guide washers 22 of the main damper extend through orifices 38 formed in the limitation member 37. It should be noted that this limitation member 37 is rotationally connected with the hub 18, with an angular clearance allowing an angular movement between the guide washers 22 and this hub 18 by means of the predamper 14. The limitation means 36 also comprise complementary angular limitation stops 39, 40 formed on the one hand on a radially internal contour 42 of the damper plate 21 and on the other hand on a radially external contour 44 of the limitation member 37 (see in particular figure 2). The limitation stops 39, 40 are delimited on the one hand by radial projections 46 formed on the internal contour 42 of the damper plate 21 and on the other hand by radial projections 48 formed on the external contour 44 of the limitation member 37. The orifices 38 of the limitation member 37 preferably coincide angularly with the radial projections 48, in order to reduce the radial size of the limitation member 37. This is because this arrangement makes it possible to reduce the radial dimension of the limitation member 37 between the projections 48. In general, the damper plate 21 and the limitation member 37 are able to move angularly with respect to each other in direct D and retrograde R directions, depicted in figure 2. The angular movement in the direct direction D is limited by a predetermined direct angle A1 with respect to an idle position depicted in figure 2 and the angular movement in the retrograde direction R is limited by a predetermined retrograde angle A2 with respect to the idle position depicted in figure 2. In figures 3 and 4, the elements analogous to those in figures 1 and 2 are designated by identical references. According to the second embodiment, described with reference to figure 3, the main damper 12 is of the asymmetric type, that is to say the friction disc 16 is fixed to one of the guide washers 22. The guide washers 22 are coupled to each other by means of lugs 60 formed on the guide washer 22 carrying the friction disc 16. These lugs 60 are folded towards the other guide washer 22 and cooperate with corresponding notches formed on this other guide washer 22. The limitation means 36 comprise complementary angular limitation stops formed on the one hand on radially internal contours of the guide washers 22 and on the other hand on a radially external contour of the limitation member 37. It should be noted that the limitation member 37 and the damper plate 21 are conformed in a single piece. According to the third embodiment, described with reference to figure 4, radial projections 62 are formed on the one hand on an internal contour of the damper plate 21 and on the other hand on a radially external contour of the limitation member 62, so that its radial projections 62 cooperate with each other without clearance. The limitation member 37 is thus rotationally fixed to the damper plate 21. It should be noted that the invention is not limited to the embodiments described above. In particular, the invention can apply to a friction device comprising a symmetrical main damper and not having any predamper. In this case, the limitation member 37 is rotationally connected without angular clearance with the hub 18. CLAIMS 1. Friction clutch (10), in particular for a motor vehicle, of the type comprising a damper (12) able to pass the maximum engine torque, comprising: - substantially coaxial input (16) and output (22; 37) rotary elements, - a first coupling element (12A), of general shape of revolution, rotationally fixed to the input rotary element (12), - a second coupling element (12B), of general shape of revolution, rotationally fixed to the output rotary element (22; 37), - damping means (19) comprising circumferential-effect elastic members (30) carried by the first (12A) and second (12B) coupling elements, and - means (36) of limiting the angular movement between the input (16) and output (22; 37) rotary elements, characterised in that the limitation means (36) comprise complementary angular limitation stops (39, 40) formed on the one hand on a radially internal contour (42) of the first coupling element (12A) and on the other hand on a limitation member (37) rotationally fixed to the second coupling element (12B). 2. Clutch (10) according to claim 1, characterised in that the limitation member (37) is annular in shape overall. 3. Clutch (10) according to claim 2, characterised in that the limitation stops (39, 40) are delimited on the one hand by radial projections (46) formed on the internal contour (42) of the first coupling element (12A) and on the other hand by radial projections (48) formed on a radially external contour (44) of the limitation member (37). 4. Clutch (10) according to any one of the preceding claims, characterised in that, the input (16) and output (22; 37) rotary elements being able to move angularly with respect to each other in direct (D) and retrograde (R) directions, the angular movement in the direct direction (D) is limited by a predetermined direct angle (A1) with respect to an idle position and the angular movement in the retrograde direction (R) is limited by a predetermined retrograde angle (A2) with respect to the idle position. 5. Clutch (10) according to any one of claims 1 to 4, characterised in that the first coupling element (12A) is a damper plate (21) and the second coupling element (12B) is a guide washer (22). 6. Clutch (10) according to claim 5, characterised in that it comprises two guide washers (22), coupled together by axial fingers (24) extending through orifices (38) formed in the limitation member (37) in order to couple the limitation member (37) with the guide washers (22). 7. Clutch (10) according to claims 3 and 6 taken together, characterised in that the orifices (38) of the limitation member (37) coincide angularly with the radial projections (48) of this limitation member (37). 8. Clutch (10) according to claim 6 or 7, characterised in that the axial fingers (24) are rivets. 9. Clutch (10) according to any one of claims 1 to 4, characterised in that the first coupling element (12A) is a guide washer (22) and the second coupling element (12B) is a damper plate (21). 10. Clutch (10) according to claim 9, characterised in that the damper plate (21) and the limitation member (37) are conformed in a single piece. 11. Clutch (10) according to claim 9, characterised in that radial projections (62) are formed on the one hand on an internal contour of the damper plate (21) and on the other hand on a radially external contour of the limitation member (37), so that these radial projections (62) cooperate with each other without clearance. 12. Clutch (10) according to any one of the preceding claims, characterised in that the input rotary element (16) is a friction disc of the clutch. 13. Clutch (10) according to any one of the preceding claims, characterised in that the limitation member (37) is rotationally connected, with or without, angular clearance, to a hub (18) rotationally connected with an input shaft of a gearbox of the motor vehicle.

Full Text

Friction clutch, in particular for a motor vehicle, of the type comprising
an improved damper
The present invention concerns a friction clutch, in particular for a motor vehicle, of the type comprising an improved damper.
In a motor vehicle, the function of a friction clutch is to transmit a torque between an input rotary element and an output rotary element, by friction gripping between the pressure and reaction plates rotationally connected with an engine flywheel.
In general, the input element is formed by a friction disc and the output element is rotationally connected, with or without angular clearance, to a hub rotationally connected with a gearbox input shaft.
Another function of the friction clutch is to provide continuity of the torque transmitted and to filter the Vibrations coming from the engine, in particular by virtue of damping means comprising elastic members and friction means.
A friction clutch is already known in the prior art, in particular for a motor vehicle, of the type having a damper comprising:
- substantially coaxial input and output rotary elements,
- a first coupling element, of general shape of revolution, rotationally fixed to
the input rotary element,
- a second coupling element, of general shape of revolution, rotationally fixed
to the output rotary element,
- damping means comprising circumferential-effect elastic members carried
by the first and second coupling elements, and

- means of limiting the angular movement between the input and output rotary elements.
A damper generally comprises a damper plate interposed between two guide washers. These guide washers are normally connected together rotationally.
It should be noted that the damper is said to be "symmetrical" when the friction disc (input element) is fixed to the damper plate. In this case, the first coupling element is formed by the damper plate and the second coupling element is formed by the guide washers of the damper.
In addition, the damper is said to be "asymmetric" when the friction disc is fixed to one of the guide washers. In this case, the first coupling element is formed by the guide washers and the second coupling element is formed by the damper plate.
Normally the elastic members are housed in windows provided in the first and second coupling elements.
In many cases, the angular movement between the input and output rotary elements is limited by the elastic members. This is because, when the torque is transmitted between the first and second coupling elements, the elastic members are able to be compressed up to a compression limit defining a maximum angular movement angle.
However, the use of the elastic members up to their compression limit reduces their service life.
The aim of the invention is in particular to increase the service life of the elastic members by providing a motor vehicle clutch comprising angular movement limitation means independent of the elastic members.
To this end, an object of the invention is a clutch of the aforementioned type

comprising a damper able to pass the maximum engine torque, the limitation means of which comprise complementary angular limitation stops formed on the one hand on a radially internal contour of the first coupling element and on the other hand on a limitation member rotationally fixed to the second coupling element.
The complementary angular limitation stops are conformed so as to define a movement limitation angle between the input and output rotary elements preventing the elastic members reaching their compression limit.
When the movement angle reaches the limitation angle, the torque is then transmitted directly from the first coupling element to the limitation member, rotationally fixed to the second coupling element, by means of the limitation stops. The excess torque, referred to as over-torque, then no longer passes through the elastic members.
Thus, during the functioning of the clutch, the elastic members never reach their compression limit, which increases their service life.
It is in fact known that the engine torque may exhibit over-torques that are not filtered by the friction clutch.
In the case of the present invention, the over-torque passes not through the second coupling element but through the limitation member, unlike the known solutions of the prior art.
It is thus possible to advantageously size the second coupling element.
A clutch according to the invention can also comprise one or more of the following characteristics:
- the limitation member is annular in shape overall;
- the limitation stops are delimited on the one hand by radial projections

formed on the internal contour of the first coupling element and on the other hand by radial projections formed on a radially external contour of the limitation member;
- the input and output rotary elements being able to move angularly with
respect to each other in direct and retrograde directions, the angular
movement in the direct direction is limited by a predetermined direct angle
with respect to an idle position and the angular movement in the retrograde
direction is limited by a predetermined retrograde angle with respect to the
idle position;
- the first coupling element is a damper plate and the second coupling
element is a guide washer;
- the clutch comprises two guide washers, coupled together by axial fingers
extending through orifices formed in the limitation member in order to couple
the limitation member with the guide washers;
- the orifices of the limitation member coincide angularly with the radial
projections of this limitation member;
- the axial fingers are rivets;
- the first coupling element is a guide washer and the second coupling
element is a damper plate;
- the damper plate and the limitation member are conformed in a single piece;
- radial projections are formed on the one hand on an internal contour of the
damper plate and on the other hand on a radially external contour of the
limitation member, so that these radial projections cooperate with each other
without clearance;
- the input rotary element is a friction disc of the clutch; and

- the limitation member is rotationally connected, with or without angular
clearance, to a hub rotationally connected with an input shaft of a gearbox of
the motor vehicle.
The invention will be better understood from a reading of the following description, given solely by way of example and made with reference to the accompanying drawings, in which:
- figure 1 is an exploded perspective view of a clutch according to a first
embodiment of the invention;
- figure 2 is a front view of a damper plate of the clutch of figure 1 and of the
associated limitation member;
- figure 3 is a half-view in axial section of a clutch according to a second
embodiment of the invention;
- figure 4 is a half-view in axial section of a clutch according to a third
embodiment of the invention.
Figures 1 and 2 depict a friction clutch, in particular for a motor vehicle, according to a first embodiment of the invention.
The friction clutch comprises a friction device 10 intended to transmit a torque between an engine flywheel rotationally fixed to a driving shaft, such as the crankshaft of a motor vehicle engine, and a driven shaft such as the input shaft of a motor vehicle gearbox.
The friction device 10 is provided with a main damper 12 and a predamper 14. The main damper 12 is coupled in series with the predamper 14 between a general input rotary element 16 and a general output rotary element 18.
The general input rotary element 16 is a friction disc able to be rotationally

connected with the engine flywheel by gripping between pressure and reaction plates rotationally connected with the engine flywheel and actuated by engagement means.
The general output rotary element is a hub 18, annular in shape overall, rotationally connected with the input shaft of the motor vehicle gearbox. For this purpose, the hub 18 is provided with internal longitudinal flutes rotationally connecting it with one end of the input shaft of the gearbox.
The main damper 12 and the predamper 14 are each provided with substantially coaxial input and output rotary elements. It should be noted that the input element of the predamper 14 is normally formed by the output element of the main damper 12.
The main damper 12 comprises first 12A and second 12B coupling elements, of general shape of revolution, respectively rotationally connected to the input and output rotary elements of the damper 12. The first 12A and second 12B coupling elements are coupled together by damping means 19.
Likewise, the predamper 14 comprises first 14A and second 14B coupling elements, of general shape of revolution, respectively rotationally connected to the input and output rotary elements of this predamper 14. The first 14A and second 14B coupling elements are coupled together by damping means 20.
In a conventional manner, the output rotary element of the main damper 12 is formed by the second coupling element 12B. The first coupling element 14A of the predamper 14 is fixed, for example by riveting, to this second coupling element 12B of the main damper.
According to the embodiment described with reference to figure 1, the input element of the main damper 12 is the general input element of the friction device 10, that is to say the friction disc 16. The output element of the predamper 14 is the general output element of the friction device 10, that is to

say the hub 18.
Thus, when a torque is transmitted from the friction disc 16 to the hub 18, it first of all passes from the first 12A to the second 12B coupling element of the main damper 12 through the damping means 19.
According to the first embodiment of the invention, the main damper 12 is of the symmetrical type. In this case, the first coupling element 12A is a damper plate 21 (fixed to the friction disc 16) of the main damper 12, and the second coupling element 12B is formed by two guide washers 22 of the main damper 12 between which the damper plate 21 is housed, coaxially with these.
The guide washers 22 are coupled together by axial fingers 24, preferably rivets.
The first coupling element 14A of the predamper 14 is generally formed by two guide washers fixed to one of the corresponding guide washers 22 of the main damper, for example by riveting.
The guide washers 14A of the predamper 14 surround a damper plate forming the second coupling element 14B of the predamper 14. This damper plate 14B is rotationally connected to 'the hub 18 by means of internal flutes cooperating with external flutes on the hub 18.
The damping means 19 of the main damper 12 comprise circumferential-effect elastic members 30, such as high-stiffness helical springs.
The elastic members 30 are housed in windows 32 in the damper plate 21 and in windows 34 in the guide washers 22. These elastic members 30 participate in the transmission of the rotation torque between the damper plate 21 and the guide washers 22.
The damping means 19 also comprise two friction washers 35, each arranged between the damper plate 21 and a corresponding guide washer 22. The

friction washers 35 are rotationally connected with the damper plate 21 by means of folded lugs 35P cooperating with notches 32E formed in contours of the windows 32 in the damper plate 21. Each friction washer 35 also comprises a friction face 35F cooperating with the corresponding guide washer 22. Thus, when the damper plate 21 and the guide washer 22 move angularly with respect to each other, a friction is generated between the friction washers 35 and the guide washers 22.
It is also possible to dispose a washer with no lug in place of the friction washer 35 with a lug. Teeth,are then provided, the shape of which is conjugate with that of the limitation member 37, on a radially internal contour of the said washer.
In order to increase the service life of the elastic members 30, the main damper 12 comprises means 36 of limiting the angular movement between the friction disc 16 and the guide washers 22 independent of the elastic members 30.
The limitation means 36 comprise a limitation member 37, annular in shape overall, rotationally connected with the guide washers 22.
For this purpose, the rivets 24 coupling together the guide washers 22 of the main damper extend through orifices 38 formed in the limitation member 37.
It should be noted that this limitation member 37 is rotationally connected with the hub 18, with an angular clearance allowing an angular movement between the guide washers 22 and this hub 18 by means of the predamper 14.
The limitation means 36 also comprise complementary angular limitation stops 39, 40 formed on the one hand on a radially internal contour 42 of the damper plate 21 and on the other hand on a radially external contour 44 of the limitation member 37 (see in particular figure 2).
The limitation stops 39, 40 are delimited on the one hand by radial projections

46 formed on the internal contour 42 of the damper plate 21 and on the other hand by radial projections 48 formed on the external contour 44 of the limitation member 37.
The orifices 38 of the limitation member 37 preferably coincide angularly with the radial projections 48, in order to reduce the radial size of the limitation member 37. This is because this arrangement makes it possible to reduce the radial dimension of the limitation member 37 between the projections 48.
In general, the damper plate 21 and the limitation member 37 are able to move angularly with respect to each other in direct D and retrograde R directions, depicted in figure 2. The angular movement in the direct direction D is limited by a predetermined direct angle A1 with respect to an idle position depicted in figure 2 and the angular movement in the retrograde direction R is limited by a predetermined retrograde angle A2 with respect to the idle position depicted in figure 2.
In figures 3 and 4, the elements analogous to those in figures 1 and 2 are designated by identical references.
According to the second embodiment, described with reference to figure 3, the main damper 12 is of the asymmetric type, that is to say the friction disc 16 is fixed to one of the guide washers 22.
The guide washers 22 are coupled to each other by means of lugs 60 formed on the guide washer 22 carrying the friction disc 16. These lugs 60 are folded towards the other guide washer 22 and cooperate with corresponding notches formed on this other guide washer 22.
The limitation means 36 comprise complementary angular limitation stops formed on the one hand on radially internal contours of the guide washers 22 and on the other hand on a radially external contour of the limitation member 37.

It should be noted that the limitation member 37 and the damper plate 21 are conformed in a single piece.
According to the third embodiment, described with reference to figure 4, radial projections 62 are formed on the one hand on an internal contour of the damper plate 21 and on the other hand on a radially external contour of the limitation member 62, so that its radial projections 62 cooperate with each other without clearance. The limitation member 37 is thus rotationally fixed to the damper plate 21.
It should be noted that the invention is not limited to the embodiments described above.
In particular, the invention can apply to a friction device comprising a symmetrical main damper and not having any predamper. In this case, the limitation member 37 is rotationally connected without angular clearance with the hub 18.

CLAIMS
1. Friction clutch (10), in particular for a motor vehicle, of the type comprising a damper (12) able to pass the maximum engine torque, comprising:
- substantially coaxial input (16) and output (22; 37) rotary elements,
- a first coupling element (12A), of general shape of revolution, rotationally
fixed to the input rotary element (12),
- a second coupling element (12B), of general shape of revolution, rotationally
fixed to the output rotary element (22; 37),
- damping means (19) comprising circumferential-effect elastic members (30)
carried by the first (12A) and second (12B) coupling elements, and
- means (36) of limiting the angular movement between the input (16) and
output (22; 37) rotary elements,
characterised in that the limitation means (36) comprise complementary angular limitation stops (39, 40) formed on the one hand on a radially internal contour (42) of the first coupling element (12A) and on the other hand on a limitation member (37) rotationally fixed to the second coupling element (12B).
2. Clutch (10) according to claim 1, characterised in that the limitation
member (37) is annular in shape overall.
3. Clutch (10) according to claim 2, characterised in that the limitation stops
(39, 40) are delimited on the one hand by radial projections (46) formed on
the internal contour (42) of the first coupling element (12A) and on the other
hand by radial projections (48) formed on a radially external contour (44) of
the limitation member (37).

4. Clutch (10) according to any one of the preceding claims, characterised in
that, the input (16) and output (22; 37) rotary elements being able to move
angularly with respect to each other in direct (D) and retrograde (R) directions,
the angular movement in the direct direction (D) is limited by a predetermined
direct angle (A1) with respect to an idle position and the angular movement in
the retrograde direction (R) is limited by a predetermined retrograde angle
(A2) with respect to the idle position.
5. Clutch (10) according to any one of claims 1 to 4, characterised in that the
first coupling element (12A) is a damper plate (21) and the second coupling
element (12B) is a guide washer (22).
6. Clutch (10) according to claim 5, characterised in that it comprises two
guide washers (22), coupled together by axial fingers (24) extending through
orifices (38) formed in the limitation member (37) in order to couple the
limitation member (37) with the guide washers (22).
7. Clutch (10) according to claims 3 and 6 taken together, characterised in
that the orifices (38) of the limitation member (37) coincide angularly with the
radial projections (48) of this limitation member (37).
8. Clutch (10) according to claim 6 or 7, characterised in that the axial fingers
(24) are rivets.
9. Clutch (10) according to any one of claims 1 to 4, characterised in that the
first coupling element (12A) is a guide washer (22) and the second coupling
element (12B) is a damper plate (21).

10. Clutch (10) according to claim 9, characterised in that the damper plate
(21) and the limitation member (37) are conformed in a single piece.
11. Clutch (10) according to claim 9, characterised in that radial projections
(62) are formed on the one hand on an internal contour of the damper plate
(21) and on the other hand on a radially external contour of the limitation

member (37), so that these radial projections (62) cooperate with each other without clearance.
12. Clutch (10) according to any one of the preceding claims, characterised in
that the input rotary element (16) is a friction disc of the clutch.
13. Clutch (10) according to any one of the preceding claims, characterised in
that the limitation member (37) is rotationally connected, with or without,
angular clearance, to a hub (18) rotationally connected with an input shaft of a
gearbox of the motor vehicle.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=sSKGlNIwqlpqbRL8ZITuuA==&loc=+mN2fYxnTC4l0fUd8W4CAA==

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Patent Number

272945

Indian Patent Application Number

3985/DELNP/2007

PG Journal Number

19/2016

Publication Date

06-May-2016

Grant Date

04-May-2016

Date of Filing

28-May-2007

Name of Patentee

VALEO EMBRAYAGES

Applicant Address

5 AVENUE ROGER DUMOULIN, 80009 AMIENS, FRANCE

Inventors:

#	Inventor's Name	Inventor's Address
1	LEONARDO LAMANA	20 ALLEE DE SUEDE, F-80000 AMIENS, FRANCE.
2	BRUNO GRESSIER	2 PLACE SAINT-JUST, F -80330 LONGUEAU, FRANCE.

PCT International Classification Number

F16D 13/64

PCT International Application Number

PCT/FR2005/051045

PCT International Filing date

2005-12-06

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0453058	2004-12-17	France