GB2237350A - Clutch control device - Google Patents

Abstract

In a clutch control device of the kind comprising a cable (504) hooked onto and wound around a rotatable element (533, 600) carried by a support (551), the support (551) comprises a bearing shoulder (10) for resilient moans (20) urging an intermediate bush (30) towards a coupling element (40) fixed to the cable (504). The bush (30) is telescopically mounted relative to the element (40) with the intervention of disengageable locking means (50) between the parts. The bush (30) is shaped to receive a second section (Fig 4) of a control linkage. The control device is particularly applicable to an automobile vehicle. The shoulder (10) may be replaced by a ring (Fig 9) bolted to the support and the locking means may comprise pawls (Fig 10). <IMAGE>

Description

CLUTCH CONTROL DEVICE The invention relates to a clutch control device, in particular for an automobile vehicle, of the kind comprising, for operating a declutching element adapted to act on the declutching device of a clutch, a cable hooked onto and wound on a rotatable element and adapted to cooperate with a non-rotatable element through the intermediary of complementary ramps provided on the elements, and a support for the rotatable element adapted to be fastened to a fixed part.

A device of this kind is described in FR-A-1 587 732 and EP-A-O 322 265, the support being fixed to the non-rotatable element in the case of FR-A-1 587 732 whilst it is separate from the latter in the case of EP-A-O 322 265.

A mounting or assembly problem arises with this kind of construction since the cable comprising the control device has to be connected subsequently to an operating element such as a clutch pedal.

In practice, especially in the case of an automobile vehicle, on the assembly line it is easier initially to mount the control linkage, of which the cable forms part, onto the operating element and then onto the control device fixed to the engine-gearhox assembly.

Moreover it is imperative, taking into account the various manufacturing tolerances, to set the control linkage to the correct length, in particular when a wear adjuster is provided, so as to avoid the length of the cable (which requires a certain travel, variable from one embodiment to another) impairing the travel of the wear adjuster.

Furthermore it is preferable that the cable should be permanently under tension.

The object of the present invention is to provide a control device, comprising a cable connected to a rotatable element, which meets these requirements and thus facilitates mounting of the linkage, whilst allowing in a simple and economical manner the setting of the correct length of the cable under tension, and providing other advantages as will be hereinafter described.

According to the invention a declutching device of the kind described above is characterized in that the support for the movable element comprises a bearing shoulder for elastic means urging an intermediate bush towards a coupling element which is fixed to the cable; the said intermediate bush is mounted telescopically relative to the coupling element with the intervention of disengageable locking means between the said parts, and the intermediate bush is shaped to receive a second section of a control linkage.

As a result of the invention, and in particular the aforesaid elastic means, the device for setting the length of the control linkage under tension, is integrated into the control device and may be assembled with the second section already mounted in advance on the operating element.

This second section may comprise a cable and/or linking rods.

Alternatively it may comprise a hydraulic element.

Furthermore, as a result of the disengageable locking means, subsequent dismounting is possible. Advantageously the locking means comprise gripping means for this purpose.

In one embodiment of the invention, the lockinq means comprise a sleeve adapted to cooperate with balls wedged in by tapered bearing surfaces or with pawls, the sleeve comprising, externally, a gripping shoulder.

Traction on the sleeve frees the balls, or the pawls, and the coupling element.

In another embodiment, in the storage position, when the control linkage is not assembled, retractable holding means are provided to hold the bush in position. These means may be a retractable catch mounted on the intermediate bush and bearing on a shoulder of the support for the control device. Alternatively the bush may be held indirectly by pinching.

Thus during storage, it is possible to hold the elastic means in position under tension then, after mounting the elements of the linkage, to retract the holding means.

In order that the invention may be more fully understood, embodiments in accordance therewith will now be described by way of example with reference to the accompanying drawings, in which: - Figure 1 is a view in axial section identical to Figure 12 in EP-A-O 322 265 - Figure 2 is a view in cross-section identical to Figure 13 in the above-mentioned document - Figure 3 is a diagramnatic view identical to Figure 14 in the above-mentioned document - Figure 4 is a diagrammatic view of the second section of the linkage according to the invention ;; - Figure 5 is a view, of an axial section corresponding to that shown in Figure 2, of the storage position of the control device according to the invention, the second section having been mounted - Figure 6 is a view showing the retractable catch according to the invention - Figure 7 is a view similar to Fiqure 5 after retraction of the retractable catch, the clutch being in the engaged position - Figure 8 is a view similar to Figure 7, the clutch being in the disengaged position ; - Figure 9 is a partial view, similar to Figure 7, of a second embodiment; and - Figure 10 is a partial view, similar to Figure 9, of a third embodiment.

The control device described by way of example is similar to that described in EP-A-O 322 265, the disclosure of which is considered as incorporated into the present description.

Referring to this prior disclosure and in particular to the arrangment shown in Figures 1 to 3 herein it will be noted that the driving element comprises a part 531 equipped with ramp means, in this case helicoidal, for cooperation with complementary ramp means carried by a driven element 532, with the interposition of balls 570. The element 531 comprises an operating element 600 which is free to rotate.

This element 600 is connected to a flange 533 bearing a toothed pawl 601 which passes through an opening 602 for engagement with teeth carried by the element 531. A spring 603 bears on the elements 600-533.

The flange 533 is pivotably mounted on the element 600 which is recessed for this purpose. A spring 604 is interposed axially between the element 60n and a shoulder 605 on the driven element, in order to allow continuous bearing of the declutching element 1 (in the form of a thrust bearing) against the diaphragm 500, which is mounted for pivoting about the cover 610 of the clutch by means of luqs 611 extending from the cover.

The diaphragm 500, which forms part of the declutching device of the clutch, bears on a pressure plate 612 in order to clamp a friction disc (not shown) between the said plate 612 and a reaction plate (not shown) fixed to the driving shaft of the automobile vehicle.

The friction disc is fixed in rotation to the input shaft of the gearbox 615. Reference number 616 indicates an intermediate part fixed on the gearbox and on which the flange 552 becomes engaged and centred as a result of bosses 617.

The flange 552 of the support means 551 comprises an axial return 620 on which the internal race of an angular contact ball bearing becomes engaged, the external race of the bearing being constituted by the driving element itself.

Elastic means 512 connect the thrust bearing 1 to a flange 520 of the driven element 532, and consist here of a corrugated washer bearing on the flange 520 and equipped with axial lugs passing through the central opening in the flanges 520, 511, each of them comprising at its end a hook bearing on the flange 511 (Figure 8 in document FR-A-2 337 231).

The support means 551, hereinafter called the support for the control device support, adapted to be fixed on the gearbox 615, comprise a cover 554, a base with a wall 553, and the flange 552, and means for clipping together, in the form of hooks and teeth provided on the cover 554 and the wall 553, both advantageously made of plastic material, are shown at 630.

In the clutch engaged position (Figure 3), the pawl 601 is not in contact with the teeth of the driving element 531, because it bears on a stop 631, in the form of a sloping edge of the wall 553, as a result of the action of the spring 604. The stop 631 thus allows the flange 533, or pawl carrier, to be raised.

In the declutching position, the action of the cable 504, reinforced by that of the spring 603 equipped with a central lug covering the groove in the pivoting flange 533 and two lateral flanges bearing on the said flange on either side of the groove 535 for the cable 504 to pass through, allows the pawl 601 to pivot. The spring 603 comprises an opening for hooking on the head 505 of the cable 504, which is fixed to the latter, to pass through.

The flange 533 (Figure 2) comprises a groove 535 for the cable 504 to pass through and wind round and the head 505, of course, bears on the shoulder formed at the end of the groove 535. Where it emerges from the said groove 535 the cable 504 extends substantially tangentially. The spring 603 comprises a substantially radial leg cooperating with a groove in the element 600.

For pivoting the flange 533 is equipped on both sides of its groove 535 with circular studs 632 cooperating with the outer periphery of the element 600, which is provided with a recessed flat portion connected by a ramp to the main part of the outer periphery of the element 600.

Thus the clutch control device, for operating the declutching element 1 adapted to act on the declutching device 500 of the clutch, comprises a support 551 for the declutching element which is adapted to be fastened to a support which is fixed in translation, control means carried by the support and comprising an element 531 which can be rotated and here is fixed in translation, adapted to be subjected to the action of operating means, in this case comprising the cable 504 wound and hooked by its head on the flange 533 of the rotatable element.

These control means also comprise a driven element 532 which is movable in translation and fixed in rotation by the intermediary of a tangential tongue 553. It is this part which carries the thrust bearing 1.

Complementary ramp means are provided on the said elements, with the intervention of balls 570, for entrainment of the driven element by the driving element and axial displacement of the driven element relative to the support 551.

The driving element and the driven element are hollow and are mounted coaxially, the driving element 531 comprising engagement means at its outer periphery for engagement with the cable 504.

The driven element is mounted in the axial extension of the driving element, being connected in rotation to the support 551 by means for connection in rotation. In Figure 1 these means consist of a tangential tongue 563 fixed to a transverse part 562 of the driven part 532 as well as to the support 551.

The driving element 531 comprises on its inner periphery a support portion 520 for the coupling of the thrust bearing 1. Thus rotation of the driving element entrains an axial displacement of the driven element due to the ramp means and to the balls 537.

According to the invention the support 551 for the movable element 531, 600, 533 comprises a bearing shoulder 10 for elastic means 20 driving an intermediate bush 30 towards a coupling element 40 fixed to the cable 504. The intermediate bush 30 is mounted telescopically relative to the coupling element 40 with the intervention of disengageable locking means 50 between the said elements.

The bush 30 is shaped for the reception of a second section 60 of the linkage, the first section of which is constituted by the cable 504.

The second section f;0 (Figure 4) is adapted to be connected to a clutch pedal 61 which constitutes the operating element for the clutch.

This section in this case comprises a cable 63 sliding inside a guide tube 64 interposed between two fixed points, whilst the cable 63 comprises at its end a shouldered rod 65 comprising a hole 66.

Thus on the assembly line the second section 60 is mounted in advance on the pedal 61, whilst the control device is fixed by means of its support 551 to the gearbox.

A retractable catch 70 is engaged in a groove 71 in the bush 30.

The catch 70 bears on the shoulder 10 and during storage (linkage not assembled) allows the elastic means 20 to he maintained in a compressed state, these means in this case being in the form of a coiled spring bearing on the shoulder 10, and more specifically on the surface of the latter facing towards the coupling element 40 and facing away from the outer surface on which the catch 70 bears.

This catch 70 (Figure 6) consists of a resilient pin substantially in the form of an inturned loop. Alternatively a retaining pin or a circlip may be provided.

The rod 65 is likewise mounted on the bush 30 by means of a catch 67 similar to the catch 70, this catch engaging in the hole 66. The coupling element 40 consists of a smooth rod comprising a shoulder 42 and fixed to the cable 504.

In the clutch engaged position and during storage this rod bears by means of its shoulder, in a manner described below, on a shoulder 41 comprised by the support 551, which is in the form of a casing.

This support is equipped with a hollow shaft 2 aligned with the rod 40 and acting as a guide for the spring 20 which bears on a shoulder 31 comprised by the bush at its lower end. The hollow shaft 2, which can also be seen in Figure 1, is closed partly by the cover 554 (Figure 1) of the casing.

It will be understood that due to the said cover easy mounting is possible, in particular of the bush 30 and the spring 20. This bush 30, forming a traction bush, is equipped near its lower end with housings 32 comprising a tapered bearing surface for the reception of balls 33 adapted to cooperate with the smooth rod 40.

The housings 32 are in the form of grooves having a tapered bearing surface sloping towards the axis of the assembly and directed towards the end piece 40, the said tapered bearing surfaces connecting with a spherical portion adapted to the dimension of the associated ball 33, the said portion connecting with a vertical portion. The ball 33 is mounted with play, relative to the said spherical portion, and is adapted to be wedged by the tapered portion. A sleeve 51, housed inside the bush 30 and centred and guided by the latter, acts as a cage for the balls 33. This sleeve, at its end furthest from the balls 33, comprises a shoulder 52 overlapping the bush 30 and bearing on the end of the bush, the sleeve 51 constituting an extraction sleeve. This shoulder also acts as a bearing for the shouldered rod fi5.

Thus, as will have been understood, the sleeve 51 together with the balls 33 mounted in their housings 32 form part of the disengageable locking means 50.

The device operates in the following manner.

In a first stage in which the support 551 is fixed on the gearbox and the section 60 is mounted on the pedal 61, the end piece 65 is mounted in the bush 30, by means of the stop 67 engaged in the hole 66 and passing through the sleeve 51, which comprises through holes for this purpose, from side to side.

It will be noted that the cable 504 with its rod 40 has previously been mounted telescopically on the bush 30, the rod 40 being adapted to pass inside the bush 30 and the sleeve 51. In this configuration the balls 33 are not wedged. The bush 30 is immobilised by the catch 70.

It will also be noted that the element 600 bears against a shoulder 631' as a result of the action of the preload spring 604, and that the flange 533 is raised by means of a spring 700, in this case a leaf spring, fixed to the element 600 and bearing on the flange 533 at the end of the latter near the pawl 601. The spring 603' having a similar configuration to the spring 603, but without the central branch, serves only for the connection in rotation of the flange 533 to the element 600.

In the storage position the bush 30 is substantially in the position which it occupies in the maximally declutched position (clutch disengaged). After the section 60 has been mounted, the catch 70 is removed and this allows decompression of the spring 20 and wedging of the balls 33, subsequently of the first declutching operation (Figure 8), between the rod 40 and the tapered bearing surfaces in their associated housings 32, together with an axial movement of the bush 30 relative to the rod 40 allowed by the housing 32. In this position the flange 533 is still raised.

Thus on considering Figures 5 and 7, it can be seen that the part 30 has descended by the distance A which allows the section 60 to be set to the correct length, the section 60 being preferably under a slight tension, and the pedal 61 then coming to bear on a fixed stop 68.

It will be noted that the size of the cable 504 is chosen dependent on the circumferential distance separating the shoulder 41 from the stop 631', the length of the cable being such that in this position the pawl 601 is raised by the spring 700, whilst the element 40 bears against the shoulder 41 and the element 600 against the stop 631' of the support 551.

It will be understood that the stop 631' is a simple shoulder, and that the stop 631' and the shoulder 41 advantageously replace the stop in the form of a wedge 631 in Figure 1. The distance, taking into account the presence of the flange 533, between the said stop 631' and the said shoulder 41 can easily be calculated, the cable 504 being slightly stretched in the case of the configuration shown in Figure 7.

During declutching, the cables 63, 504 are pulled and the traction bush 30 is displaced, as can be seen in Figure 8, the pawl 601 becoming engaged with the driving element 531 and the element 600 becoming moved and leaving its stop 631'.

To disassemble, it suffices to pull on the extraction sleeve 51, and more specifically to pull on the shoulder 52 forming gripping means, in order to pull on the balls 33, unwedging them and thus unlocking the assembly. It will be noted that the end piece 65 may be demounted by removal of the catch 67 before or after having pulled on the shoulder 52.

The pulling action on the sleeve 51 is then continued for a distance such that it can allow replacement of the catch 70, after which it becomes easily possible, optionally, to detach the section 60.

Thus by means of the invention, the control device for the declutching element 1 can easily be mounted on and demounted from the second section 60 of the linkage. Moreover, thanks to the elastic means 20, a setting to the correct length, under tension, of the second section can easily be performed and the disengageable locking means 50 allow a subsequent easy disassembly.

The present invention is not limited to the examples described.

In particular, as shown in Figure 9, the sleeve 151 may be centred by the hollow shaft 2 and surround the bush 30 with a clearance. The sleeve 151 comprises on its inner periphery a transverse return 152, and an axial return 153 in order to follow the contour of the end of the bush 3n, the return 153 acting as a cage for the balls 33. This sleeve 151 is provided with rectangular openings 154 through each of which bolts supporting a ring 161 pass, the said bolts also passing through the hollow shaft 2. Thus, as will have been understood, the ring 161 constitutes the shoulder 10 shown in Figure 5 and is thus connected by the bolts 160 to the support 551.

The bolts 160 serve to hold the bush 30 in position by pinching the sleeve 151 between the hollow shaft 2 and the collar 161. In practice, in the storage position (linkage not assembled), the spring 20 is held compressed by the pinching of the sleeve 151. After the section 60 has been mounted, the bolts 160 are thus slackened.

In order to dismount the assembly it suffices to pull on the collar 157 of the sleeve 151, and then to lock the sleeve 151 again by pinching it.

Thus, as in Figure 5, retractable retaining means are formed which hold the bush 30 when in the storage position; the said means may comprise the retractable catch 70 or alternatively may comprise the bolts 16n for indirectly holding the bush 30 by pinchinq the sleeve 151.

In an alternative embodiment shown in Figure 10, the locking means may comprise pawls; in this case the rod 40 comprises a toothed end 201 with which pawls 202 mounted to rotate on the bush 30 are adapted to cooperate. The pawls pass through the sleeve 251 which also serves in their disengagement. Alternatively, in place of the balls 33, a washer of the "Belleville" type may be provided which is wedged by being deformed, and unwedged with the aid of a sleeve.

The invention is applicable to the devices described in FR-A-1 587 732, the ramp means not being able to comprise balls. Likewise the presence of the pawl is not indispensable; instead the rotatable element may be in one piece as in Figures 4 and 9 of EP-A-O 322 265.

The elastic means may comprise a stack of "Belleville" washers instead of a coiled spring. The gripping means associated with the extraction sleeve may comprise holes for hooking on an extraction tool.

The catch 67 may consist, like the catch 70, of a retaining pin, bolt or the like. Finally, it is possible to reverse the roles of the bush 30 and the coupling element 40, the bush 30 being able to incorporate a nose entering telescopically into the interior of the element 40.

Claims (10)

1. A clutch control device suitable for an automobile vehicle, of the

kind adapted to operate a declutching element adapted to act on the declutching device of a clutch, comprising a cable engaging and wound onto a rotatable element and adapted to cooperate with a non-rotatable element through the intermediary of complementary ramps provided on said elements, and a support for said rotatable element adapted to be fastened to a fixed part, characterized in that said support comprises a bearing shoulder for elastic means adapted to urge an intermediate bush towards a coupling element fixed to the cable, said intermediate bush being mounted telescopically relative to the coupling element, and disengageable locking means being interposed between the parts, the intermediate bush being shaped to receive a second section of a control linkage.

2. A device according to Claim 1, wherein the locking means comprise gripping means.

3. A device according to Claim 1 or Claim 2, wherein the locking means comprise a sleeve coaxial with said bush and provided with a gripping shoulder.

4. A device according to any one of Claims 1 to 3, wherein the locking means comprise balls which are each mounted in a housing having a tapered bearing surface comprised by said bush, and being adapted to cooperate with a smooth part comprised by said coupling element.

5. A device according to any one of Claims 1 to 3, wherein the locking means comprise pawls articulated on the bush and adapted to cooperate with a toothed portion of the coupling element.

6. A device according to Claim 4 or Claim 5, wherein the sleeve which comprises the locking means forms a cage for the balls or for the said pawls.

7. A device according to any one of the preceding claims, wherein the support for said movable element comprises, on the one hand, a bearing shoulder for the coupling element and, on the other hand, a shoulder for an element forming part of the movable element, and the length of the cable is chosen dependent on the distance separating said shoulders.

8. A device according to any one of the preceding claims, wherein, in the storage position, when the control linkage is not assembled, retractable holding means are provided to hold said bush in this position.

9. A device according to Claim 8, wherein a retractable catch is mounted on the intermediate bush and bears on a shoulder of the support.

10. A clutch control device, substantially as hereinbefore described with reference to Figs 4 to 8, Fig 9, or Fig 10 of the accompanying drawings.