FR3060086A1 - TORSION DAMPER AND MOTOR VEHICLE - Google Patents

Abstract

The present invention relates to a torsion damper (1) comprising: - a first element (11, 5), - a second element (5, 11) intended to be rotatably mounted relative to the first element (11, 5) around an axis of rotation X, - a turbine (17) riveted to the second element (5, 11), the torsion damper (1) also comprises: - axial retaining means between on the one hand the first element (11, 5) and on the other hand an assembly comprising the second element (5, 11) and the turbine (17), the axial retaining means comprising at least one projecting element axially coupled to one of the first element (11, 5). ) or the assembly and at least one housing formed in the other of the first element (11, 5) or the assembly, the, at least one housing being configured to receive the projecting element with a set of predefined assembly allowing rotation between the assembly and the first element (11, 5).

Description

Technical area

The invention relates to the field of torque transmission devices of the torsion damper type intended to equip motor vehicle transmissions and in particular torsion dampers comprising a turbine.

Technological background

Explosion engines do not generate constant torque and exhibit acyclisms caused by successive explosions in their cylinders. These acyclisms generate vibrations which are liable to be transmitted to the gearbox and thus to generate shock, noise and noise, which are particularly undesirable. In order to reduce the undesirable effects of vibrations and improve the driving comfort of motor vehicles, it is known to equip motor vehicle transmissions with torsional dampers.

Torsion dampers generally include a primary element and a secondary element that can move in rotation with respect to each other about an axis of rotation. The torsion dampers also include elastic damping means disposed between the primary element and the secondary element to dampen acyclisms. In addition, the torsional dampers can also include a turbine which makes it possible to transmit a torque via a hydraulic transmission which acts in parallel with the mechanical torque transmission.

The turbine must be coupled in rotation with an element of the torsion damper, for example the input element or an intermediate element such as a veil, a guide washer or a phasing washer. Such a coupling must be reliable for axially retaining the turbine and must allow the rotation of the assembly formed by the turbine and the movable element relative to the other elements of the torsion damper. A solution of the state of the art to obtain such a result is to use a weld at the level of fixing rivets between the turbine and the element to which the turbine is fixed as described in document US 2009139821.

However, such a solution is relatively expensive because it requires specific assembly lines allowing such welds to be made at the rivets.

It is therefore necessary to find an inexpensive solution allowing a reliable fixing of the turbine on an element of the torsion damper while allowing rotation between the various elements of the torsion damper.

To this end, the present invention relates to a torsion damper comprising:

- a first element,

a second element intended to be rotatably mounted relative to the first element about an axis of rotation X,

- a turbine riveted to the second element,

- axial retaining means between on the one hand the first element and on the other hand an assembly comprising the second element and the turbine, the axial retaining means comprising at least one projecting element axially coupled to one of the first element or of the assembly and at least one housing formed in the other of the first element or of the assembly, the, at least one, housing being configured to receive the projecting element with a predefined mounting clearance allowing rotation between the whole and the first element.

According to a further aspect of the present invention, the housing is formed by a circumferential groove and the projecting element is produced by tabs arranged on a circular washer.

According to a further aspect of the present invention, the circumferential groove is formed in the first element and the tabs are oriented towards the inside of the circular washer.

According to a further aspect of the present invention, the circular washer comprises at least two legs.

According to a further aspect of the present invention, the circular washer comprises axial pads intended to come into complementary housings of the second element.

According to a further aspect of the present invention, the projecting element is produced by a circumferential collar provided on the first element and the housing is produced by a shoulder formed on retaining rivets between the turbine and the second element.

According to a further aspect of the present invention, the collar is made of material with the first element.

According to a further aspect of the present invention, a retaining rivet comprises:

- a central cylindrical rod,

- a first head with a diameter larger than the rod fixed to a first end of the rod,

a second head with a diameter larger than the rod fixed to a second end of the rod, the second head comprising a shoulder so that the head comprises a proximal portion whose axial height corresponds to the axial height of the projecting element added to the predefined mounting clearance and an end portion of diameter greater than the diameter of the proximal portion, the housing being formed between the end portion of the head and the assembly comprising the second element and the turbine, said assembly being intended to be maintained between the first and second heads of the rivet.

According to a further aspect of the present invention, the torsion damper comprises at least three retaining rivets distributed around the axis X.

According to a further aspect of the present invention, the first element corresponds to an output element formed by a hub intended to be coupled in rotation with a gearbox.

According to a further aspect of the present invention, the first element comprises a single part ensuring the function of axial thrust seat on one side and the other of the hub to allow the mounting of bearings, thrust washers or thrust with needles.

According to a further aspect of the present invention, the second element corresponds to a veil or a guide washer or a phasing washer.

According to a further aspect of the present invention, the torsion damper comprises a first spring and a second spring mounted in series, the first spring being disposed between an input element and the second element, the second spring being disposed between said second element and a veil linked to the first element corresponding to an output element.

According to a further aspect of the present invention, the first element corresponds to a guide washer and the second element corresponds to the hub.

The present invention also relates to a motor vehicle comprising a torsional damper according to one of the preceding claims

Other characteristics and advantages of the invention will emerge from the following description, given by way of example and without limitation, with reference to the appended drawings in which:

FIG. 1 represents a schematic perspective view cut in a radial direction of a torsion damper according to a first embodiment of the present invention,

FIG. 2 represents a schematic perspective view cut in a radial direction of part of a torsion damper according to the first embodiment,

FIG. 3 represents a schematic view in radial section of a torsion damper according to the first embodiment,

FIG. 4 represents a schematic view in radial section of a torsion damper according to a second embodiment,

FIG. 5 represents a schematic perspective view of a portion of a torsion damper according to a third embodiment,

FIG. 6 represents a schematic perspective view of a portion of a torsion damper according to the third embodiment,

FIG. 7 represents a schematic view in radial section of a torsion damper according to the third embodiment,

FIG. 8 represents a schematic perspective view of a portion of a torsion damper according to a fourth embodiment,

- Figure 9 shows a schematic sectional view of a portion of a torsion damper according to a fifth embodiment.

In all the figures, identical elements or ensuring the same function bear the same reference numbers.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment or that the features apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments.

In the following description, the terms internal and external are defined with respect to the axis of rotation X of the torsion damper, an external element being either distant from the axis of rotation X or oriented opposite to the axis of rotation X while an internal element is either located near the axis of rotation X or is oriented towards the axis of rotation X.

FIG. 1 represents a schematic perspective view cut along a radial plane of a torsion damper 1. In the present case, the torsion damper 1 comprises a first element corresponding for example to an output element, produced here by a hub 5. The hub 5 comprises a central part of cylindrical shape. Flanges or slots may be provided around the central part to allow the arrangement and / or maintenance of the other elements of the torsion damper 1 around the hub 5.

The torsion damper 1 also comprises a second element corresponding here to a guide washer 11 intended to be rotatably mounted relative to the hub 5 along the axis X of the torsion damper 1. The guide washer 11 is intended to be fixed to a turbine 17, for example by rivets 19.

The torsion damper 1 also comprises an input element, produced here by a disc holder 3 of a clutch device. The disc holder 3 can be fixed to an input web 15 rotatably mounted relative to the hub 5 along the axis of rotation X of the torsion damper 1. The disc holder 3 comprises for example a central part 3a in perforated disc shape in the center and a peripheral part 3b of cylindrical shape which extends axially from the periphery of the central part of the disc holder. The disc holder 3 can be riveted on the entry veil 15 at its central part 3a.

The torsional damper 1 also comprises an elastic element intended to filter acyclisms between the input element 3 and the output element 5. The elastic element is for example intended to be placed in a housing of the washer. guide 11.

The elastic element is produced here by a first helical spring called external spring 7 and a second helical spring said internal spring 9. The two external helical springs 7 and internal 9 are arranged in series, their series connection is achieved by the washer guide 11. The helical springs 7 and 9 may comprise several parts arranged in parallel, for example in three parts, the different parts are for example arranged in dedicated housings of the guide washer 11 which ensures the paralleling of the different parts of a spring 7, 9.

In the present case, the guide washer 11, better visible in FIG. 2, comprises a first 1a and a second 1 lb housings to receive respectively the first 9a and the second 9b parts of the internal spring 9 (the guide washer can include a third housing and the spring (s) can (come) t include a third part on the part not shown (in Figure 2) of the torsion damper 1). The guide washer 11 is also a phasing washer and includes two other housings 11c and lld to receive the first 7a and the second 7b, respectively, part of the external spring 7.

The guide washer 11 may comprise several parts coupled together in rotation. The guide washer 11 here comprises three parts 110, 111 and 112. The first part 110 extends radially from a first side of the internal 9 and external 7 springs.

The first part 110 may include curved zones intended to partially surround the internal spring 9 and / or the external spring 7.

The second part 111 extends radially from a second side of the internal spring 9. The first part 110 and the second part 111 form the housings 11a and 11b intended to receive respectively the first 9a and the second 9b parts of the internal spring 9 The second part 111 may comprise an opening 11a facing the central axis of the internal spring 9. The width of the opening 111a is less than the diameter of the internal spring 9 so that the internal spring 9 is in contact with a internal zone and an external zone of the second part 111. The internal and external zones allow the internal spring 9 to be held in position in the housing 11a, 1 lb. The first part 110 and the second part 111 are for example coupled by a cooperation of complementary shape, in particular by crimping, embedding or snap-fastening (the complementary shapes are not visible in FIGS. 1 and 2).

The third part 112 extends radially on a second side of the external spring 7. The first part 110 and the third part 112 form the housings 11c and lld intended to receive the external spring 7. The first part 110 and the third part 112 can be coupled at a peripheral portion located on the outer side of the outer spring 7, for example by crimping complementary shapes. The first part 110 comprises for example openings 110a and the third part 112 comprises for example projecting elements 112a of a shape complementary to the openings 110a of the first part 110 which are inserted or fitted into the openings 110a to the assembled state of the torsion damper 1.

The external spring 7 is also constrained by the entry veil 15. In fact, the entry veil 15 is configured to come into contact with one end of the external spring 7 so that a rotation of the disc holder 3 causes the compression of the external spring 7. The veil 15 has for example substantially the general shape of a perforated disc in the center and comprises openings intended to receive the various parts 7a, 7b of the external spring 7.

The torsional damper 1 also comprises an outlet veil 16 coupled in rotation with the hub 5, for example by welding. The outlet veil 16 is configured to come into contact with one end of the internal spring 9. The outlet veil 16 has for example a shape of a perforated disc in the center and includes openings intended to receive the different parts 9a, 9b of the internal spring 9.

Thus, in operation, a rotation of the disc carrier 3 causes the rotation of the inlet web 15 which compresses the external spring 7. The external spring 7 then rotates the guide washer 11, which causes a firstly the compression of the internal spring 9 and secondly the rotation of the turbine 17. The internal spring 9 then rotates the outlet web 16 which causes the hub 5 to rotate.

The torsion damper 1 can also comprise a pendulum device 13 comprising weights mounted movably on an element of the torsion damper 1, for example the guide washer 11, to improve the filtration of acyclisms. The weights are for example arranged on a peripheral part of the guide washer 11 and can move over a few millimeters or centimeters. The pendulum device 13 is for example fixed to the guide washer 11 by rivets 20.

The torsion damper 1 also comprises axial retaining means between on the one hand the assembly comprising the guide washer 11 and the turbine 17 and on the other hand the hub 5. The axial retaining means comprise at least one element projecting axially coupled to one of the hub 5 or of the assembly comprising the guide washer 11 and the turbine 17 and at least one housing formed in the other of the hub 5 or of the assembly comprising the guide washer 11 and the turbine 17. The at least one housing being configured to receive the projecting element with a predefined mounting clearance allowing the rotation between on the one hand the assembly comprising the guide washer 11 and the turbine 17 and d on the other hand the hub 5.

According to a first embodiment shown in FIGS. 1 to 3, the turbine 17 is fixed to the guide washer 11 by fixing rivets 19. In addition, as is better visible in the sectional view of FIG. 3, the rivets 19 include a shoulder 19a so as to form a housing intended to receive an element 5a of the hub 5 projecting outwards. The housing is formed by the space located between the shoulder 19a of the rivet 19 on the one hand and an internal end of the guide washer 11, and more particularly the first part 110 of the guide washer 11, on the other hand .

The rivets 19 comprise, for example, a central cylindrical rod, a first head with a diameter larger than the rod fixed to a first end of the rod and a second head with a diameter wider than the rod fixed to a second end of the rod. In addition, the second head comprises the shoulder 19a so that the second head comprises a proximal portion (oriented towards the rod) whose axial height Δ1 corresponds to the axial height Δ2 of the projecting element 5a added to the play of predefined assembly and an extreme portion (oriented opposite the rod) of diameter greater than the diameter of the proximal portion. The housing is formed between the end portion of the second head and the assembly comprising the guide washer 11 and the turbine 17. The assembly is intended to be held between the first and the second heads of the rivet 19.

The protruding element is for example produced by a circular flange 5a which comes integrally with the hub 5. In addition, the axial width of the housing is slightly greater than the axial width of the flange 5a so as to allow rotation of the 'assembly formed by the guide washer 11 and the turbine 17 around the hub 5. The number of rivets 19 can be variable but preferably at least three rivets 19 distributed around the axis of rotation X are necessary to allow the maintenance between the guide washer 11 and the turbine 17 as well as the rotation of the assembly around the hub 5.

According to a second embodiment shown in FIG. 4, the projecting element is produced by an elastic retaining ring 20, also called a circlip, disposed in a groove 5b formed in the hub 5. The elastic retaining ring 20 is then intended to be positioned in the housing formed at the shouldered rivet 19. In addition, the axial width Δ1 of the housing formed at the shouldered rivet 19 is slightly greater than the axial width Δ3 of the elastic retaining ring 20 of so as to allow the rotation of the assembly formed by the guide washer 11 and the turbine 17 around the hub 5. The torsion damper 1 is moreover similar to the torsion damper 1 of the first embodiment described in the Figures 1 to 3.

According to a third embodiment shown in FIGS. 5 to 7, the torsion damper 1 comprises a circular washer 21 (visible in FIG. 5) intended to be coupled in rotation to the turbine 17 and to the guide washer 11. The circular washer 21 has a general shape of a perforated disc in the center. The circular washer 21 comprises tabs 210 disposed on the inside of the circular washer 21, projecting inwards and intended to come into a circumferential groove 5c formed on the external part of the hub 5. The axial width Δ4 of the groove 5c, for example equal to 2mm, is greater than the axial width Δ5 of the tabs 210, for example equal to 1.6mm, so as to allow the rotation of the circular washer 21 and therefore of the turbine 17 and of the guide washer 11 relative to the hub 5. The circular washer 21 comprises at least two tabs 210, six in the example of FIG. 5. The circular washer 21 is intended to be clipped into the groove of the hub 5. To facilitate snap-fastening of the circular washer 21, internal notches 212 can be formed on either side of the tabs 210 of the circular washer 21 to allow greater axial flexibility of the tabs 210. The internal notches 212 in fact allow obtaining make longer, for example 11mm, and more flexible legs. The length of the legs 210 is for example substantially equal to the radial width of the circular washer 21 at the sections without legs 210. The circular washer 21a for example an internal diameter of 62mm and an external diameter of 73mm.

As shown in FIG. 6, the circular washer 21 can also include axial studs 213 intended to come into complementary housings of the guide washer 11 to facilitate the positioning of the circular washer 21 during the mounting of the torsional damper 1 The axial studs 213 are for example of cylindrical shape and the complementary housings are for example made by cylindrical holes.

The circular washer 21 also includes a plurality of holes 211 distributed around the central axis of the circular washer 21 to receive, for example, fixing rivets 23 visible in the sectional view of FIG. 7. In fact, the circular washer 21 is ίο intended to be riveted with the turbine 17 and the guide washer 11 as shown in Figure 7 (the turbine 17 is not shown in Figure 7). Thus, the turbine 17, the guide washer 11 and the circular washer 21 are fixed together by fixing rivets 23, for example by twelve rivets 23, and the assembly comprising the turbine 17, the guide washer 11 and the circular washer 21 is rotatably mounted relative to the hub 5 by the combination of the tabs 210 of the circular washer 21 and of the groove 5c of the hub 5.

This embodiment therefore differs from the first two embodiments by the use of an additional circular washer 21 to allow the rotary mounting of the guide washer 11 and of the turbine 17 relative to the hub 5. In addition, the rivets 23 used for fixing the guide washer 11, the turbine 17 and the circular washer 21 can be fixing rivets without a shoulder. The torsional damper 1 is moreover similar to the torsional damper 1 of the first two embodiments.

According to a fourth embodiment shown in Figure 8, the legs 210 'of the circular washer 21 have a different shape from the legs 210 of the third embodiment. The legs 210 ′ have a V shape, the base of the V protruding inwardly to come to be positioned in the groove 5c of the hub 5. The branches of the V extend for example in a tangential direction and the ends of the branches are connected to the rest of the circular washer 21. A V-shaped opening is made in the circular washer 21 on the outer part and adjacent to the legs 210 '. This V shape makes it possible to obtain flexible lugs which make it possible to clip the circular washer into the groove 5c of the hub 5.

The axial width A4 of the groove 5c is greater than the axial width Δ5 of the tabs 210 'so as to allow the rotation of the circular washer 21 and therefore of the turbine 17 and of the guide washer 11 relative to the hub 5. L torsional damper 1 is also similar to the third embodiment. Other forms of flexible legs can also be envisaged in the context of the present invention.

According to a fifth embodiment shown in Figure 9, the turbine 17 can be riveted to the hub 5, the guide washer 11 'is then rotatably mounted relative to the turbine 17 and to the hub 5. In this case, the means of axial retention comprise for example a circular washer 21 'and rivets 23 configured to axially retain said circular washer 21' with the turbine 17 and the hub 5. The turbine 17 and the circular washer 21 'are arranged on either side of 'a collar 5d of the hub 5. The external radius r2 of the circular washer 21' is greater than the external radius rl of the collar 5d of the hub 5 on which the turbine 17 and the circular washer 21 'are fixed so that the space between the turbine 17 and the circular washer 21 'forms a housing intended to receive one end of the guide washer 11' which forms the projecting element. The housing has an axial width Δ6 greater than the axial width Δ7 of the end of the guide washer 11 'to allow the rotation of the guide washer 11' relative to the hub 5. In this embodiment, the circular washer 21 'can be devoid of legs and can be a simple washer having the shape of a perforated disc in the center. In addition, in this embodiment, the elastic element disposed between the input element, that is to say the disc holder 3 and the output element, that is to say the hub 5 comprises a single helical spring 10 disposed in a housing of the guide washer 11 'which is rotatably coupled with the disc holder 3. The guide washer 11' comprises for example a first part 1 a and a second part ll'b. The first part 1a is for example similar to the internal part of the first part 110 of the guide washer 11, that is to say the part intended to form the housing of the internal spring 9 of the first embodiment , and the second part ll'b is for example similar to the second bed part of the guide washer 11 of the first embodiment.

A pendulum device 13, for example similar to the pendulum device of the first embodiment, is also disposed on the guide washer 11 '. The torsion damper 1 also comprises an outlet veil 16 coupled in rotation to the hub 5 and intended to come to bear on one end of the helical spring 10.

In operation, the rotation of the disc holder 3 causes the rotation of the guide washer 11 'which compresses the helical spring 10. The rotation of the guide washer 11' can also cause the movement of the weights of the pendulum device 13 coupled to the guide washer 11 '. The compression of the helical spring 10 then causes the hub 5, and therefore the turbine 17, to rotate via the outlet web 16.

It should also be noted that in the various embodiments described above, a single piece formed by the hub 5 performs the function of the axial abutment seat on one side and on the other of the hub 5, that is to say say at the level of a first abutment seat 5e situated on a first axial side of the hub 5 and of a second abutment seat 5f situated on a second side of the hub 5 opposite the first side, to allow the mounting of bearings, thrust washers or needle thrust washers. The fact that the two abutment seats 5e and 5f are produced in a single piece makes it possible to reduce the tolerances and to optimize the operation of the torsion damper 1 and / or to reduce its manufacturing cost (by reducing the tolerances of hub manufacturing 5).

Furthermore, it should be noted that the present invention is not limited to the embodiments of the torsion damper 1 described above but extends to other types of torsion damper 1. In particular, the turbine 17 can be fixed by riveting to other elements of the torsion damper 1 other than the guide washer 11 or the hub 5 such as, for example, a web, such as the inlet web 15, or a phasing washer. In addition, the number of elements of the torsion damper 1 can also be different (no pendulum device, several of guide washer, a different number of springs or an elastic element of different shape such as flexible blades for example) . In addition, the characteristics of the various embodiments can be combined so that, for example, the fifth embodiment can comprise two springs or, conversely, the other embodiments can comprise only one spring.

Thus, the use on the one hand of axial retaining means such as shouldered rivets or of an assembly comprising rivets 23 and a circular washer 21, 21 ′ to fix the turbine 17 to an element of the torsion damper 1 and on the other hand a combination comprising a projecting element and a housing with a mounting clearance between the projecting element and the housing to allow rotation between the projecting element and the housing makes it possible to obtain a reliable fixing of the turbine 17 to an element of the torsion damper 1 without the need to carry out a welding or any other costly assembly step which reduces manufacturing costs.

Claims (15)

1. Torsional damper (1) comprising: - a first element (11, 1Γ, 5), - a second element (5, 11, 11 ') intended to be rotatably mounted relative to the first element (11, 1Γ, 5) about an axis of rotation X, - a turbine (17) riveted to the second element (5, 11, 1Γ), characterized in that the torsion damper (1) also comprises: - axial retaining means between on the one hand the first element (11, 1Γ, 5) and on the other hand an assembly comprising the second element (5, 11, 1Γ) and the turbine (17), the retaining means axial comprising at least one projecting element axially coupled to one of the first element (11, 1Γ, 5) or of the assembly and at least one housing formed in the other of the first element (11, 1Γ, 5) or of the assembly, the, at least one, housing being configured to receive the projecting element with a predefined mounting clearance allowing rotation between the assembly and the first element (11, H ', 5). 2. torsion damper (1) according to claim 1 wherein the housing is formed by a circumferential groove (5c) and the projecting element is produced by lugs (210, 210 ') arranged on a circular washer (21) . 3. torsion damper (1) according to claim 2 wherein the circumferential groove (5c) is formed in the first element (5) and the tabs (210, 210 ') are oriented towards the inside of the circular washer (21 ). 4. Torsional damper (1) according to claim 2 or 3 wherein the circular washer (21) comprises at least two legs (210, 210 '). 5. Torsional damper (1) according to one of claims 2 to 4 wherein the circular washer (21) comprises axial pads (213) intended to come in complementary housings of the second element (11). 6. torsion damper (1) according to claim 1 wherein the projecting element is produced by a circumferential flange (5a) formed on the first element (5) and the housing is produced by a shoulder (19a) formed on retaining rivets (19) between the turbine (17) and the second element (11). 7. torsion damper (1) according to claim 6 wherein the flange (5a) is made of material with the first element (5). 8. Torsional damper (1) according to claim 6 or 7 in which a retaining rivet (19) comprises: - a central cylindrical rod, - a first head with a diameter larger than the rod fixed to a first end of the rod, - a second head with a diameter larger than the rod fixed to a second end of the rod, the second head comprising a shoulder (19a) so that the head comprises a proximal portion whose axial height corresponds to the axial height of the projecting element added to the predefined mounting clearance and an extremal portion of diameter greater than the diameter of the proximal portion, the housing being formed between the extremal portion of the head and the assembly comprising the second element (11) and the turbine (17 ), said assembly being intended to be maintained between the first and second heads of the rivet (19). 9. Torsional damper (1) according to one of claims 6 to 8 comprising at least three retaining rivets (19) distributed around the axis X. 10. Torsional damper (1) according to one of the preceding claims wherein the first element (5) corresponds to an output element formed by a hub (5) intended to be coupled in rotation with a gearbox. 11. Torsional damper (1) according to claim 10 wherein the first element (5) comprises a single piece ensuring the function of axial stop seat on one side and the other of the hub (5) to allow the mounting of bearings, thrust washers or needle thrust. 12. Torsional damper (1) according to one of the preceding claims wherein the second element corresponds to a veil or a guide washer (11) or a phasing washer. 13. Torsional damper (1) according to one of the preceding claims comprising a first spring (7) and a second spring (9) mounted in series, the first spring (7) being disposed between an input element (3) and the second element (11), the second spring (9) being disposed between said second element (11) and a web (16) linked to the first element (5) corresponding to an outlet element. 14. Torsional damper (1) according to claim 1 wherein the first element corresponds to a guide washer (1Γ) and the second element corresponds to the hub (5). 15. Motor vehicle comprising a torsion damper (1) according to one of the preceding claims. 1/4