GB2236826A

GB2236826A - Actuating assembly for clutch release bearing

Info

Publication number: GB2236826A
Application number: GB9021686A
Authority: GB
Inventors: Jacques Feigler
Original assignee: Valeo SE
Current assignee: Valeo SE
Priority date: 1989-10-13
Filing date: 1990-10-05
Publication date: 1991-04-17
Anticipated expiration: 2010-10-05
Also published as: FR2653194A1; GB9021686D0; DE4032374C2; GB2236826B; DE4032374A1; FR2653194B1

Abstract

An actuating assembly for coupling a clutch release bearing in traction to the diaphragm (11) of a clutch of an automotive vehicle, includes an actuating member (16) carrying a coupling member (20) and including a flange (18) having two distinct openings (22A, 22B) separated by a bridge portion (32). The coupling member (20) has two arms (121A, 121B) which are arranged to hook one over the other, and which extend through the openings (22A, 22B) in the flange. The portion of the flange (18) having the openings (22A, 22B) is at least partly deformed. This deformation is in a direction radially away from the axis, to form a curved portion (132) concave radially inwards. <IMAGE>

Description

1 AN ACTUATING ASSEMBLY FOR A CLUTCH RELEASE BEARING, IN PARTICULAR FOR AN

AUTOMOTIVE VEHICLE, AND A CLUTCH RELEASE BEARING OF SUCH AN ASSEMBLY

The present invention relates generally to the coupling of a clutch release bearing to the diaphragm of a clutch, where the clutch release bearing is arranged to act in traction on the diaphragm. It is applicable in the case in which, to this end, an actuating assembly is used which is of the kind described in the specifications of French published patent applications Nos. FR 2 624 935A and FR 2 630 174A. It is also applicable to a clutch release bearing of or for such an assembly.

The arrangement described in the above mentioned specification FR 2 630 174A will first be described with reference to Figures 1 and 2 of the accompanying drawings, which are identical to Figures 1 and 3 of specification No. FR 2 630 174A. In these Figures, the actuating assembly includes an actuating member 16, which is here made of pressed steel plate and which has a collar portion 17 adapted for bearing against the diaphragm 11 of the clutch, on the side of the latter opposite to the clutch release bearing, which is indicated at 10. The actuating member 16 here has a curved transverse profile, and, integrally with the collar portion 17, a projecting flange 18 which extends through a central opening 15 in the diaphragm 11, between the latter and the striker or nose portion 13 of the clutch release bearing. The actuating assembly also includes a coupling piece 20 which is resiliently deformable in the radial direction. The coupling piece 20 has a ring portion which extends within the flange 18 of the actuating member 16, between the latter and the nose portion 13, and is adapted to couple the clutch release bearing 10 to the actuating member by a simple snap action, at least in the

1 2 axial direction which corresponds to the exertion of a tractive force on the diaphragm 11 by the clutch release bearing 10. This direction is that indicated by the arrow F in Figure 1, i.e. going from the collar portion 17 towards the coupling piece 20.

The ring portion of the coupling piece 20 is interrupted by a gap defined between two integral arms 21A and 21B, each of which extends through a respective opening 22A, 22B formed in the flange 18, the coupling piece itself being carried by this flange. The openings 22A and 22B are circumferentially separated from each other by a bridge portion 32, and each opening 22A or 22B extends over a distance greater than the diameter of the round wire from which the coupling piece 20 is formed, by an amount which is as great in the circumferential as in the axial direction.

The arms 21A and 21B are arranged to hook resiliently one over the other, in such a way that the coupling piece 20 is closed on itself with its two arms then bearing against the bridge portion 32 as can be seen from Figure 2.

The part of the flange 18 that includes the openings 22A and 22B is radially deformed towards the axis of the assembly, in a curve which is convex in the inward radial direction. That arrangement gives satisfaction, and necessitates forming this re-entrant curve in the press. In some cases, it may be desirable to improve still further the precision and geometric quality of the internal bore of the flange, especially as regards its generally frusto conical section, which forms a frusto conical surface for the coupling piece and which is formed in its middle zone for engagement by the latter.

R 1 3 High precision in the bore of the flange is generally difficult to achieve because of the re-entrant part mentioned above, as this prevents any corrective operations.

An object of the present invention is to overcome these drawbacks and so to improve both the geometric quality and the manufacturing precision of the internal bore of the flange of the actuating member.

In accordance with the invention, there is provided an actuating assembly for the actuation, in traction by a clutch release bearing, of the diaphragm of a clutch, the actuating assembly being of the kind comprising, firstly, an actuating member including a collar portion for engagement on the diaphragm and, integral with the said collar portion, a flange adapted to extend through the said diaphragm via the central opening of the latter; and secondly, extending in the form of a ring within the said flange, a coupling piece which is deformable resiliently in the radial direction and adapted for attachment to the clutch release bearing by simple snap-fitting of the latter at least in the axial direction going from the collar portion towards the said coupling piece, the said flange having two distinct openings, for the passage of a respective arm of the coupling piece through each said opening, the said openings being separated from each other by a bridge portion, wherein the portion of the flange having the said openings is at least partly deformed, deformation being radially away from the axis of the assembly to define a curved portion which is concave towards the said axis.

The concave curved position offers no obstacle to any corrective operation such as a turning operation, so that 4 the geometry and accuracy of the flange bore can be made to be of a high order. In particular, the frusto conical surface itself can be made with high precision, especially as regards its location. The same is however also true for the internal surfaces of the cylindrical portions which form extensions of the frusto conical surface, on either side of the latter. All this assists easy assembly and fitting of the actuating assembly.

Preferably, it is the bridge portion that is partly radially deformed, so that it has an incurved shape. This facilitates pre-positioning of the coupling piece before being snap-fitted together with the clutch release bearing.

The curved portion is preferably formed in the terminal cylindrical portion defining the free end of the flange, and also in a part of the frusto-conical surface of the latter and of the bridge portion.

A major preferred feature of the invention is that the fingers of the diaphragm define a clearance facing the openings in the flange. This arrangement facilitates fitting of the coupling piece.

As will be understood, the arrangement according to the invention was in no way obvious, because during fitting of the clutch release bearing an obstacle was to be expected, due to the fact that the coupling piece conventionally has an axial orientation portion extending along the outside of the flange.

Because of the clearance mentioned above, the diaphragm may be brought very close to the flange without detriment to the fitting of the clutch release bearing; and the curved portion enables the coupling piece to be fitted while still j k 1 permitting the latter to engage on the axial base of the openings beyond the radius of curvature joining the ring portion of the coupling piece to its axial portion.

The description of a preferred embodiment of the invention, which follows, is given by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a view in axial cross section of an actuating assembly, identical to that shown in Figure 1 of French published patent application No. FR 2 630 174A and shown in position between the diaphragm of a clutch and the clutch release bearing which is adapted to act on the diaphragm; Figure 2 is a partial view shown in circumferential cross section, identical to Figure 3 of the same document FR 2 630 174A; Figure 3 is an end view of the actuating member in accordance with the invention; Figure 4 is a view in axial cross section of an actuating member in accordance with the invention, mounted on the diaphragm and equipped with its coupling piece; and Figure 5 is a partial view as seen in the direction of the arrow 5 in Figure 4.

For simplicity, the same reference numerals will be used for those elements that are common to the present invention and to the prior art as described above with reference to Figures 1 and 2.

In the present example, the clutch release bearing 10 includes a striker or nose portion 13 for acting on the clutch diaphragm 11. The nose portion 13 comprises an 6 extension of the inner ring of a ball bearing. On the outer periphery of the nose portion 13 there is a transverse shoulder 14 which constitutes a thrust surface. The shoulder 14 delimits a groove, within which the coupling piece 20, carried by the actuating member 16, lies after being snap-fitted to the clutch release bearing 10. The coupling piece 20 is resiliently deformable in the radial direction, and cooperates with the internal bore of the flange 18. With regard to the diaphragm 11, it will be noted that its central portion is formed with radial fingers which are separated by slots (see Figure 5), and that the diaphragm has a central opening 15 radially inward of its fingers.

In Figures 3 to 5, in order to hold the actuating assembly 12, which is, like that of Figures 1 and 2, provided for the actuation, by a clutch release bearing 10, of the diaphragm 11 in a tractive mode, the collar portion 17 of the actuating member 16 has radial fingers 25 distributed over its outer periphery. The fingers 25 are directed axially in the same direction as the flange 18 of the actuating member. Each finger 25 extends through a respective one of the radial slots which separate the radial fingers of the diaphragm. Each finger 25 of the actuating member 16 carries a retaining finger 40, extending circumferentially and cantilevered from the corresponding radial finger 25 in line with the engagement collar portion 17 and generally parallel to the latter. The retaining fingers 40, cooperating with the collar portion 17, ensure that the assembly is held axially on the diaphragm in the manner described in the above mentioned specification No. FR 2 624 935A.

The coupling piece 20, being resilient in the radial 4 1 -1 7 direction, extends in a plane which is substantially perpendicular to the axis of the assembly, and is made of round wire. It is open between two generally-radial arms 121A and 121B, which are integral extensions of the ring, and each of which passes through a respective one of two separate openings 22A and 22B formed through the flange 18, so as to extend radially outwards beyond the flange 18. That part of the flange 18 that includes the openings 22A and 22B for accommodating the arms 121A and 121B is deformed at least partly away from the axis of the assembly, to form a curved portion 132 which is concave towards the axis of the assembly. Although it would be possible to deform the two openings 22A and 22B, in Figures 3 to 5 it is the bridge portion 32 that is locally deformed in the radial direction away from the axis of the assembly, this bridge portion being partly curved inwards as is best seen in Figures 3 and S.

The flange 18 includes a frusto conical section 124, and two cylindrical portions 130 and 131 which extend on either side of the section 124. The portion 130 has the larger diameter, and is joined to the collar portion 17 through a curved section, while the cylindrical portion 131 defines the free end of the flange 18, being chamfered and having the smaller diameter. In this example, the local curved portion 132 (see Figure 4) includes part of the bridge portion 32, as well as the whole of the cylindrical portion 131 in the axial alignment of the bridge portion 32. It may of course include the whole of the bridge portion 32. Part of the section 124 is also affected by the curved portion 132.

The coupling piece 20 also includes at least one radially extending lug 23, which is itself in engagement with an 8 aperture 24 of the flange 18, this.aperture being wider in the circumferential direction than the openings 22A and 22B. In the present example, there are two supplementary radial lugs 23, in the form of approximately semicircular local deformations of the circular part of the coupling piece. Two corresponding apertures 24 are provided, each one at approximately 1200 from the openings 22A and 22B.

The lugs 23 are in contact with only one of the lateral or circumferential edges of the apertures 24, so as to enable the coupling piece 20 to expand during snap fitting with the clutch release bearing 10. In order to increase the elasticity of the coupling piece 20 when in an open state, each of the two arms 121A and 121B is provided with a local deformation, indicated at 122A and 122B respectively, which. increases its length. After fitting, the loops extend above the clutch release bearing 10. These loops reduce the rigidity of the coupling piece, which facilitates both snap fitting and gripping.

More precisely, on the outside of the flange 18 the arms 121A and 121B have two curved portions beyond the loops 122A and 122B, so that the ends of the arms, which are offset axially with respect to the coupling piece 20, extend together in a plane which is parallel to the generally circular ring portion of the coupling piece between the clutch release bearing 10 and the diaphragm 11. The end of the arm 121B forms an oblique hook 30 so that the arm can be hooked resiliently on the straight part of the arm 121A beyond the loops.

Referring now to Figures 4 and 5, each of the arms 121A and 121B, has an axial orientation portion 125 which, after passing through the openings 22A and 22B when the clutch 1 7 i 1 9 release bearing has been mounted, is in contact with the outer surface of the flange 18, and more particularly with the outer surface of the cylindrical portion 131 of the latter. The axial orientation portion 125 of the arm is extended in a first radial portion 126 and then in an inclined, second radial portion 127 in the plane of Figure 4 and including the loop 122A, 122B. The portions 126 are closer to each other than are the portions 127, and allow the diaphragm 11 to tilt.

An S-shaped bend 128 connects the two portions 126 and 127 of each arm together, these portions being parallel with each other in each of the two arms 121A and 121B. The portion 127 comprises two radial portions which are offset axially and which are parallel with each other, these radial portions being connected through the inclined portion 129 of a loop 122A, 122B. The inclined portion 129 thus generally defines a turn of a helical spring, while the loops constitute a spring of the clothes- peg type.

It is important to note that the diaphragm defines a clearance or recess 200 facing the openings 22A and 22B. For reasons of symmetry, two further recesses are provided in the region of the lugs 23. As is best seen in Figure 5, the recess 200 is defined by shortening the appropriate fingers 8 of the diaphragm at their inner periphery, so that they thus have an increased diameter. This makes it possible to fit the coupling member 20 with ease, in spite of the presence of the curved portion 132 which serves to advantage for prepositioning the arm portion 125 before the clutch release bearing is fitted. The inner diameter of the portion 125 may in practice be equal to the outer diameter of the cylindrical portion 130 that is of larger diameter, the dimensions being chosen having regard to the size of the curved portion 132.

The above arrangement ensures that, during fitting of the clutch release bearing 10, with the coupling piece 20 then coming into engagement against the axial base 50 of the openings 22A and 22B (see Figures 2 and 4), this engagement on the base 50 will take place outside the radius of curvature of the coupling piece 20 connecting the portion 125 to the main part of the latter. The recess 200 then allows the portion 125 to move, with the expansion of the coupling piece 20 then taking place satisfactorily by engagement on the base 50. The curved portion 132 allows the coupling piece to be prepositioned. It will be recalled that the free configuration of the coupling piece 20 is such that the arms 121A and 121B are spaced away from each other, so that the diameter of the coupling piece is increased.

After the clutch release bearing 10 has been fitted by a snap fit on to the coupling piece 20, and after the arms 121A and 121B have been resiliently hooked together, the arms are able to bear circumferentially on the bridge portion 32.

For dismantling, the arms 121A and 121B of the coupling piece 20 are merely unhooked, so that the coupling piece then changes from its compressed or closed position to its free or open position.

It will be gathered from the foregoing description and from the drawings that, although the flange 18 is made by pressing, the internal bore of this flange 18 may be formed with high geometrical precision, with the frusto conical internal median surface of the section 124 of the flange being able to be readily formed by turning with very high

11 precision and very good quality, besides being-extremely accurately located. The same geometrical precision can be obtained in the same way in regard to the inner surfaces of the cylindrical portions 130 and 131.

In every case, the bridge portion 32, by projecting towards the outside of the flange, offers no obstacle.

It will be noted that in operation, the coupling piece 20 bears partly on the frusto conical section 124 and partly against the shoulder 14.

The present invention is of course not limited to the embodiments described: for example attachment of the clutch release bearing to the diaphragm may be carried out using a Belleville ring 26 as shown in Figure 1.

The coupling piece 20 may be provided with only one lug 23 extending partly axially in the manner described in specification No. FR 2 624 935A. In a modification, several loops 122A and 122B may be provided on each arm 121A, 121B.

The arms may be identical to the arms 21A, 21B of specification No. FR 2 630 174A, in which case the additional elasticity of the coupling piece 20 may be obtained by reducing the thickness of the lugs 23.

Finally, instead of loops, the arms may be formed with elongations in, for example, a zigzag shape in order to improve the elasticity of the arms.

12

Claims

1. An actuating assembly for the actuation, in traction by a clutch release bearing, of the diaphragm of a clutch, the actuating assembly being of the kind comprising, firstly, an actuating member including a collar portion for engagement on the diaphragm and, integral with the said collar portion, a flange adapted to extend through the said diaphragm via the central opening of the latter; and secondly, extending in the form of a ring within the said flange, a coupling piece which is deformable resiliently in the radial direction and adapted for attachment to the clutch release bearing by simple snap-fitting of the latter at least in the axial direction going from the collar portion towards the said coupling piece, the said flange having two distinct openings, for the passage of a respective arm of the coupling piece through each said opening, the said openings being separated from each other by a bridge portion, wherein the portion of the flange having the said openings is at least partly deformed, such deformation being radially away from the axis of the assembly to define a curved portion which is concave towards the said axis.

2. An actuating assembly-according to Claim 1, wherein the said deformed portion comprises at least part of the bridge portion.

3. An actuating assembly according to Claim 2, wherein the actuating member has a frusto conical section flanked by two cylindrical portions, one of which is a terminal portion of smaller diameter than the other one of the said cylindrical portions and defining the free end of the flange, the terminal portion being deformed radially outwardly with the bridge portion.

1 13

4. An actuating assembly according to Claim 3, wherein a clearance is defined radially between the diaphragm and the said radial openings in the flange.

5. An actuating assembly according to any one of the preceding Claims, wherein the coupling piece includes an axial portion engaging the outer periphery of the flange, whereby the said curved portion of the flange constitutes a pre-positioning means for the said axial portion.

6. An actuating assembly according to any one of the preceding Claims, wherein each arm of the coupling piece includes a loop.

7. An actuating member for an actuating assembly according to any one of the preceding Claims, having two openings separated by a bridge portion, part of which is deformed radially away from the axis of the assembly.

8. An actuating member substantially as described in the foregoing description with reference to Figures 3 to 5 of the accompanying drawings.

1 Published 1991 at The Patent Office. State House. 66/71 High Holborn, London WCIR4,1,p. Further copies maybe obtained from Sales Branch. Unit 6, Nine Mile Point Cwmielinfach, Cross Keys. Newport NPI 7HZ. Printed by Multiplex techniques ltd, St Mary Cray. Kent.