GB2157791A

GB2157791A - Friction clutch with disengageable snap connection

Info

Publication number: GB2157791A
Application number: GB08509934A
Authority: GB
Inventors: Hans-Walter Riese
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Sachs AG
Priority date: 1984-04-19
Filing date: 1985-04-18
Publication date: 1985-10-30
Also published as: GB8509934D0; FR2563298A1; DE3414836A1; BR8501865A; GB2157791B; FR2563298B1

Abstract

A friction clutch has a snap connection for the transmission of a pull release movement. The snap connection consists of a tube piece with spring tongues 13 which engage in a ring 17 which is fixedly arranged on the release elements, e.g. levers or diaphragm fingers of the clutch. The spring tongues 13 slide inward with taper 15 on a taper 24 and engage behind the edge 18. The groove 19 forming the edge 18 is elongated and contains an axially and radially loose sleeve 20. To release the snap connections, further push-in movement of the spring tongues 13 causes the tapered ends of the tongues to slide into the sleeve 20 and thus take this sleeve with them until ends 22 on the tongues abut an edge 21 of a circlip 23. Following each abutment, an extraction movement is carried out in the direction of the arrow G. <IMAGE>

Description

SPECIFICATION Friction clutch with disengageable snap connection The invention relates to a friction clutch with snap connection in the release system to simplify fitting in the assembly of engine and gear, consisting inter alia of a tube piece arranged on the gear side with spring tongues pointing in the direction towards the clutch, which tongues end in an external taper which terminates in a surrounding edge divided by longitudinal slots which on insertion movement engages behind a counter-edge in an internal groove of a clutch ring, to transmit the pulling release movement.

Clutch constructions with pulled release system are coming into use in rising numbers.

"Pulled release system here signifies that for the release movement of the clutch the release member is moved away from the clutch in the direction towards the gear. Now however in fitting of engine and gear engagement of the release member behind the release elements of the clutch is necessary. If this fitting operation is to be simple, special precautions must be taken. Thus by way of example it is known from German Publication Specification No. 2,613,952 to provide the release system on the gear side with a tube piece which comprises longitudinally arranged spring tongues having an external taper on their end facing the clutch, the external taper terminating at its larger diameter in a surrounding edge.Now the tube piece is introduced together with the gear and the release member, in the assembly of gear and engine, through the opening of the internal race ring of a release bearing, the spring tongues being compressed by the taper surfaces and thus able to engage behind the inner race ring. The operation of separation of this snap connection is guaranteed in that the tube piece has a severance point between the release bearing and the gear. Thus in a dismantlement following the assembly the forward part of the tube piece remains with its spring tongues in the release bearing.

It is the problem of the present invention, in a friction clutch with pulled release system, to produce a snap connection in which not only is the assembly of engine and gear facilitated, but also the dismantlement proceeds easily to the same extent, without the necessity of a part of the snap connection remaining behind in the other part.

In accordance with the invention this problem is solved by the characteristic of the main claim. Due to the arrangement of a radially and axially loose sleeve in the prolonged internal groove it is possible to carry out the disengagement operation quite simply. For this purpose the tube piece is inserted in the assembly direction, that is thus contrarily of the release direction, further into the ring on the clutch so that the spring tongues slide with their external taper into the internal diameter of the sleeve, so that on a subsequent movement of the spring tongues in the release direction the sleeve together with the spring tongues can slide as far as the counter-edge of the ring, whereby it becomes possible for the spring tongues to slide past the counter edge and thus to depart from the ring in the release direction.Thus the snap connection is disengaged again in a quite simple manner. It is merely to be ensured that the sleeve is arranged on the stop lying opposite to the counter-edge in a renewed fitting operation.

In accordance with the Sub-Claims this stop edge is formed by a circlip. Furthermore it is advantageous to make the internal diameter of the circlip smaller than the diameter of the external taper on the end face of the spring tongues in the position inserted into the sleeve. Thus the circlip serves at the same time as axial stop for the spring tongues in their movement contrary to the release direction for the initiation of the dismantlement of the snap connection.

The invention will next be explained in greater detail by reference to an example of embodiment. Individually: Figure 1 shows the longitudinal section through a representation of principle of a friction clutch; Figures 2 and 3 show enlarged representations of the individual parts of the snap connection.

Fig. 1 shows quite generally a friction clutch 1 between an internal combustion engine (not shown) and a gear (not shown). The friction clutch 1 is a part of the flywheel 4 which is connected fast in rotation with the crank shaft 8. The friction clutch 1 is partially surrounded by the stationary engine housing 5. Adjoining the engine housing 5 the gearbox 6 extends, the major number of parts of the release system being arranged in the gearbox 6. Starting from the friction clutch 1, the gear input shaft 7 extends centrally thereof. Around the gear input shaft 7 there is arranged the release member 3 which is connected through the release fork 9 and a linkage 10 with the clutch pedal in the motor vehicle. On a movement of the release fork 9 in the clockwise direction a movement of the release member 3 takes place in the direction of the arrow F, the friction clutch 1 being engaged.On a movement of the release fork 9 in the counter-clockwise direction a movement of the release member 3 takes place in the direction of the arrow G, the friction clutch 1 being disengaged. This movement is transmitted from the release member 3 through a snap connection characterised generally by 2 to the diaphragm spring 11 of the friction clutch 1. It is readily possible to provide release leavers in place of the dia phragm spring 11.

The snap connection 2 is represented in enlarged form in Figs. 2 and 3 and will be explained in greater detail by reference to these Figures in connection with Fig. 1. Fig. 2 shows the longitudinal section through the snap connection 2. This consists of a tube piece 1 2 which is arranged axially fixedly in the release system 3 in a manner not further described. The tube piece 12 comprises a plurality of spring tongues 1 3 distributed on the circumference and separated from one another by longitudinal slots 14. The spring tongues 1 3 extend in the direction towards the friction clutch 1, that is in the direction of the arrow F.In the operational position as represented in Fig. 2 the spring tongues 1 3 engage with an edge 1 6 behind a counteredge 1 8 of a ring 1 7 which is at least axially fixedly connected with the spring tongues 1 3.

The release force is transmitted by these two edges 1 6 and 1 8 in the direction of the arrow G from the release member 3 to the diaphragm spring 11. The function of assembling and dismantling the snap connection 2 is advantageously explained in connection with the discussion of Fig. 3. Fig. 3 shows an enlarged representation of the snap connection 2 according to Fig. 2. The spring tongue 1 3 has an external taper 1 5 in its end region, which taper begins with the diameter E at the end face 22 and has an increase of diameter in the direction of the arrow G.This increase of diameter terminates at the latest at the edge 1 6 where the spring tongues 1 3 are reduced to a smaller diameter than the maximum diameter of the external taper 1 5. This end region of each spring tongue 1 3 has an axial extent according to A. This reaches from the end face 22 to the edge 16. The counterpart of the spring tongues 1 3 is formed as a ring 1 7. This has an internal taper 24 in its end region directed towards the gear. This internal taper narrows in the direction of the arrow F to a value corresponding to the internal diameter D.The internal diameter D is adjoined by a counter-edge 1 8 which represents the one axial limitation of an internal groove 1 9. The internal groove 1 9 has a larger diameter than the diameter D. In the assembling of gear and engine the tube piece 1 2 with its spring tongues 1 3 leading is moved in the direction towards the ring 1 7.

Since the ring 17 is arranged fixedly on the diaphragm spring 11, the spring tongues 1 3 can slide with their external taper 1 5 radially inwards on the internal taper 24 of the ring 17, with elastic deformation. As soon as the edge 1 6 of the spring tongues 1 3 engages behind the counter-edge 18 in the internal groove 19, the spring tongues 1 3 snap radially outwards and thus render possible a force transmission in the direction of the arrow G by way of the two annular faces formed by the edge 1 6 and by the counter-edge 18. The annular face formed by the edge 1 6 is here interrupted by the longitudinal slots 14.

Fig. 3 further shows the components which render possible the simple operation of disengagement of the snap connection 2. For this purpose the internal groove 1 9 is of prolonged formation in the direction of the arrow F and has parallel with the counter-edge 1 8 an edge 21 formed by a circlip 23. In the axial space between the end face 22 of the spring tongues 13 and the edge 21 of the circlip 23 a sleeve 20 is arranged which is made with slight radial play in relation to the internal groove 1 9 and has an internal diameter d. Thus this sleeve 20 in the operational position of the snap connection 2 is arranged loosely.The longitudinal extent of the individual parts according to Figs. 2 and 3 is such that the overall length of the internal groove 1 9 has the dimension L, the axial extent of the sleeve 20 is formed in accordance with B and the spring tongues 1 3 have the dimension A between the end face 22 and the edge 16. For satisfactory function of the snap connection 2 it is necessary that the dimension L is made at least slightly greater than the sum of the dimensions A and B.

Thus it is ensured that the sleeve 20 is arranged axially loosely in the operational position of the snap connection 2. For the disengagement of the snap connection 2 now the tube piece 1 2 is moved with the spring tongues 1 3 leading further into the ring 1 7 in the direction of the arrow F, that is in the direction of the original assembly. In this movement the spring tongues 1 3 slide by means of their external taper 1 5 into the internal diameter d of the sleeve 20. This push-in movement can advantageously be defined exactly in that the spring tongues 1 3 come to abut with their end face 22 on the edge 21 of the circlip 23.For this purpose the circlip 23 in the installed condition has an internal diameter C which is made smaller than the diameter E of the external taper 1 5 at the end face 22 when the spring tongues 1 3 are in the position driven into the sleeve 20. Following the abutment of the end faces 22 on the edge 21 a rearward movement of the tube piece 1 2 in the direction of the arrow G, that is in the release direction, takes place.

The spring tongues 1 3 clamped into the internal diameter d of the sleeve 20 move the sleeve 20 with them in the direction of the arrow G. Due to the formation of the internal diameter d of the sleeve 20 being equal to or smaller than the internal diameter D in the ring 1 7 at the inner end of the internal taper 24, which diameter also inwardly limits the counter-edge 18, it is now possible during the extraction movement in the direction of the arrow G and after the abutment of the sleeve 20 on the counter-edge 18 of the ring 17, to withdraw the spring tongues 1 3 through the opening D of the ring 17. The sleeve 20 is then situated in the internal groove 1 9 of the counter-edge 1 8. If re-assembly is next intended, the sleeve 20 is again brought to abut on the edge 21 according to Fig. 3. If d is made smaller than D, in this case the sleeve 20 is automatically shifted in the direction F by the external taper 1 5 of the spring tongues 1 3 and thus the engagement space is cleared.

It would appear to be superfluous to point out that the diameter E at the end face 22 of the spring tongues 13, in the substantially relaxed position according to Fig. 3, must be made smaller than the internal diameter d of the sleeve 20.

Due to the arrangement of the sleeve 20 in the internal groove 19, which is made correspondingly long, it is thus possible to separate the snap connection 2 again in a simple manner without any tool. After the separation operation a fresh assembly operation can be carried out immediately.

Claims

1. Friction clutch with snap connection in the release system for the simplification of fitting in assembly of engine and gearing, consisting inter alia of a tube piece arranged on the gear side with spring tongues pointing in the direction towards the clutch which end in an external taper which terminates in a surrounding edge separated by longitudinal slots which in the insertion movement engages behind a counter-edge in an internal groove of a ring on the clutch for the transmission of the pulling release movement, characterised in that the internal groove (19) is of prolonged formation in the clutch direction (arrow F), an axially and radially loosely guided sleeve (20) is arranged therein which is supported on an edge (21) at a distance from the counter-edge (18) which has an internal diameter (d) equal to or less than the internal diameter (D) of the counter-edge (18) of the ring (17), which has a length (B) which is greater than the axial extent of the external taper (15), while the axial extent of the internal groove (L) is made at least slightly greater than the length of the sleeve (B) and the length (A) of the external taper (15) from the end face (22) of the spring tongues (13) to the edge (16).

2. Friction clutch according to Claim 1, characterised in that the edge (21) is formed by a circlip (23) inserted into the ring (17).

3. Friction clutch according to Claims 1 and 2, characterised in that the internal diameter (C) of the circlip (23) is made smaller than the diameter (E) of the external taper (15) on the end face (22) of the spring tongues (13) in the position driven into the sleeve (20).

4. Friction clutch with snap connection in the release system as claimed in claim 1, substantially as described herein with reference to and as illustrated by the example shown in the accompanying drawings.