Device for retaining a vehicle steering wheel safety module

Abstract

A device for retaining a safety module mounted on a vehicle steering wheel structure, comprising: at least one latching element, at least one elastic element that is arranged so as to engage with the latching element in order to retain the safety module on the steering wheel structure,
the elastic element comprising a contact portion arranged such that, when there is a movement of mounting the safety module on the steering wheel structure, it comes into contact with a guide track arranged on an actuation face of the latching element located facing the elastic element,
wherein the guide track is arranged on a first side of the latching element, and in that the actuation face has at least one offset arranged between the guide track and a second side of the latching element.

Claims

1. A retaining device of a safety module mounted on a vehicle steering wheel structure, comprising: at least one latching element rigidly connected to one of the safety module or the steering wheel structure, at least one elastic element rigidly connected to the other of the safety module or the steering wheel structure, and arranged so as to engage with the latching element in order to retain the safety module on the steering wheel structure, the elastic element comprising a contact portion arranged such that, when there is a movement of mounting the safety module on the steering wheel structure, the contact portion comes into contact with a guide track arranged on an actuation face of the latching element located facing the elastic element, the guide track being arranged to deform the elastic element to a released position of the latching element, during the movement of mounting carried out in a mounting direction, wherein the guide track is arranged on a first side of the latching element, and in that the actuation face has at least one offset arranged between the guide track and a second side of the latching element, wherein the latching element comprises two ribs, and wherein the guide track is formed on only one of the two ribs.

2. The retaining device according to claim 1, wherein the offset is defined to leave a strictly positive gap between the elastic element and the second side of the latching element during the movement of mounting.

3. The retaining device according to claim 1, wherein, in a cutting plane normal to the mounting direction and in a direction defined by a force exerted by the elastic element on the latching element, the first side has a first length, greater than a second length of the second side.

4. The retaining device according to claim 1, wherein, in at least one cutting plane normal to the mounting direction the latching element has an H-shaped section, with a first flange of the H arranged on the first side and a second flange of the H arranged on the second side, the first flange having a first length greater than a second length of the second flange.

5. The retaining device according to claim 1, wherein the elastic element comprises a deformable portion connected to the contact portion, and wherein the second side is arranged between the deformable portion and the first side.

6. The retaining device according to claim 5, wherein, during the movement of mounting, a distance between the deformable portion and a point of contact between a contact path and the contact portion is less than 40 mm.

7. The retaining device according to claim 1, wherein the elastic element is arranged to be deformed in bending during the movement of mounting, and wherein a bending direction is normal to the mounting direction.

8. The retaining device according to claim 1, wherein the latching element is formed of plastic and/or polymer material.

9. The retaining device according to claim 1, wherein the latching element is formed by an injection molding process.

10. The retaining device according to claim 1, wherein the latching element is rigidly connected to the safety module.

11. The retaining device according to claim 1, wherein the guide track is arranged to provide a linear contact with the contact portion.

12. The retaining device according to claim 1, comprising two latching elements and one or two elastic elements.

13. The retaining device according to claim 1 in combination with a vehicle steering wheel.

14. The retaining device according to claim 1 in combination with a motor vehicle.

15. The retaining device according to claim 1, further comprising a space between the two ribs.

16. The retaining device according to claim 1, wherein the elastic element is configured to only contact the only one of the two ribs during mounting.

17. The retaining device according to claim 1, wherein the guide track is formed on an exterior surface of the only one of the two ribs.

Description

DESCRIPTION OF THE FIGURES

(1) Other features and advantages of the present invention will become more apparent upon reading the following detailed description of an embodiment of the invention, which is provided by way of example but in no manner limited thereto, and illustrated by the attached drawings, in which:

(2) FIG. 1 shows an exploded view of a steering wheel comprising a steering wheel structure, a safety module and a device for retaining the safety module on the steering wheel structure according to the invention,

(3) FIG. 2 shows a side view of a latching element and an elastic element of the retaining device of FIG. 1;

(4) FIG. 3 shows a top view in cross-section of the retaining device of FIG. 1, with, in the left-hand part, the elastic element of the retaining device of FIG. 1 in a retaining position, and in the right-hand part, the elastic element of the retaining device of FIG. 1 in a released position or being mounted of the safety module of FIG. 1;

(5) FIG. 4 depicts a perspective view of the latching element of the retaining device of FIG. 1.

DETAILED DESCRIPTION OF EMBODIMENT(S)

(6) FIG. 1 shows a vehicle steering wheel that generally comprises a rim 10, connected to a hub 20 by branches 30. A safety module 40 is provided to be mounted on the hub 20 and typically comprises an airbag. Conventionally, the vehicle steering wheel is mounted on a steering column or gear to be pivotable about a hub axis AM.

(7) The safety module 40 must be held on the hub 20 while being able for example to be movable relative to the hub 20 in order to actuate an audible warning (for example in the direction of the axis AM, or another direction), and the vehicle steering wheel comprises for this purpose a retaining device 50 formed in particular by: two hooks 52 rigidly connected to the safety module 40 and arranged to pass at least partially through passage holes 21 provided in the hub 20, two elastic rods 51 rigidly connected to the hub 20 and arranged opposite each passage hole 21 to engage with one of the hooks 52.

(8) As shown in FIG. 1, each elastic rod 51 comprises a contact portion 51-1, arranged to come into contact with the hook 52 of the safety module 40, a deformation portion 51-2, which allows the elastic rod to deform in particular during mounting, and also to maintain and return the contact portion 51-1 into the retaining position, and an anchoring portion 51-3, which will be engaged or fixed with the hub 20.

(9) As regards the hooks 52, they are formed directly on the housing of the safety module 40, and may be formed from a plastic material (for example polyamide, preferably with a filler material such as glass fibers). It may be provided, as shown in FIG. 1, to form the hooks 52 with ribs, to facilitate molding operations (better cooling, less deformation or shrinkage, etc.).

(10) In other words, the hub 20 forms a structure of the steering wheel 100, on which the safety module 40 may be held by an elastic element (the elastic rod(s) 51) arranged so as to engage with a latching element (the hook(s) 52).

(11) As shown in FIG. 2, once the safety module 40 is mounted on the hub 20: each elastic rod 51 (rigidly connected to the hub 20) can prevent any movement of the hook 52 (rigidly connected to the safety module 40) towards the top of FIG. 2. In FIG. 2, the part of the elastic rod 51 engaged with the hook 52 occupies a retaining position PR, occupied naturally.

(12) It can also be noted that FIG. 2 shows the hook 52 seen from the side that the latter has an actuation face FA inclined relative to the vertical of FIG. 2 to allow mounting of the safety module 40 on the hub 20.

(13) Indeed, before the mounting of the safety module 40, therefore before taking up the retaining position PR engaged with the hook 52, the contact portion 51-1 in dotted lines shown at the bottom of FIG. 2 of the elastic rod 51 occupies the free position PL, and bars the hook 52 from going through before the mounting. To allow the mounting, the actuation face FA of the hook 52 is arranged to deform the elastic rod 51 during a vertical relative movement between the two parts, so that the contact portion 51-1 of the elastic rod 51 moves as shown by the arrows in FIG. 2, to the released position PD, to then be automatically returned to the retaining position PR due to the elastic return force exerted by the rest of the elastic rod (in particular the deformation portion 51-2 deformed and tensioned during the movement of the contact portion 51-1. However, it should be noted that the contact portion 51-1 and even the anchoring portion 51-3 can also deform and participate in the return to the retaining position PR).

(14) In this implementation, to perform the mounting, the safety module 40 is moved in a mounting direction that is parallel to the hub axis AM, but other mounting directions may be envisaged.

(15) FIG. 3 shows a sectional top view of the retaining device of FIG. 1, with, in the left-hand portion, the elastic rod 51 in a retaining position PR. Indeed, the left part represents the vehicle steering wheel with the mounted safety module, that is to say with the elastic rod 51 engaged under the hook 52, to retain it. It may be noted that the elastic rod is kept rigidly connected to the hub 20 by three attachment portions 22 of the hub 20, engaged with the anchoring portion 51-3 of the elastic rod 51.

(16) The right-hand part of FIG. 3 shows the vehicle steering wheel with the safety module 40 being mounted. In this FIG. 3, the mounting direction (parallel to the hub axis AM, that is, the line z) is normal to the plane of FIG. 3. FIG. 3 shows the mounting in particular when the contact portion 51-1 is in the released position PD. In this released position PD, no part of the contact portion 51-1 shown in solid lines hinders the actuation face FA, so that the hook 52 can freely pass through the passage hole 21 (note that a gap is shown between the contact portion 51-1 in solid lines and the hook 52 for clarity's sake, although in reality, there is no gap).

(17) In addition, in thin mixed lines, the contact portion 51-1 is shown at any instant of the mounting, in a mounting position PM.

(18) At this moment, the contact portion 51-1 is in contact with the actuation face FA at a point of contact PC.

(19) According to the invention, this point of contact PC is located on a guide track arranged on a first side 52-1 of the hook 52, and preferably on the side of the hook 52 furthest from the deformation portion 51-2 of the elastic rod 51. In other words, the point of contact PC is located as close as possible to the free end of the elastic rod 51. Consequently, the leverage generated between the point of contact PC and the deformation portion 51-2 (to deform the elastic rod 51) is as large as possible, which guarantees a minimum mounting force.

(20) Furthermore, in order to guarantee that no parasitic contact between the elastic rod 51 and the rest of the actuation face FA occurs during mounting, the actuation face FA comprises an offset between the first side 52-1 of the hook 52 and a second side 52-2 of the hook 52. In the cutting plane of FIG. 3, normal to the mounting direction (hub axis AM, or z axis of FIG. 3), it may be noted that the hook 52 has in the direction x a first length of the first side greater than a second length of the second side 52-2.

(21) Consequently, a gap j may be noted between the contact portion 51-1 and any point on the actuation face other than the point of contact PC of the guide track (here, the gap j is indicated positive at the second side level 52-2, but there is positive gap between the contact portion 51-1 and the actuation face FA at any point between the point of contact PC and the second side 52-2).

(22) In other words, the offset provided on the actuation face FA causes an asymmetrical section of the hook 52 (here the ribs of the hook 52 form an H with flanges of different lengths as clearly shown by the uneven cross-hatched parts, but it is possible to provide other shapes, such as for example an actuation face FA without ribs, simply with a slope, a recess or a relief to form the offset and guarantee the gap j).

(23) In other words, due to the offset, the actuation face FA has two inclinations: a first slope relative to the mounting direction in order to progressively deform the elastic rod 51 during the mounting of the safety module, and a second slope relative to the direction y of FIG. 3, to guarantee the gap j at every point off of the guide track.

(24) In the embodiment shown, the point of contact PC remains on the first side 52-1 of the hook the entire time, all along the mounting, so that in the plane yz of FIG. 3, a projection of the path from the point of contact PC is a straight line parallel to the axis z.

(25) It is also possible to provide for forming the rib of the first side 52-1 with a dome or an edge or at least a reduced surface area to have a linear or even spot contact between the contact portion 51-1 and the hook 52, at the actuation face FA, so as to control the position of the point of contact, and at the very least limit as much as possible any movement of the point of contact during mounting upwards along the y-axis, which would result in the leverage acting on the bending or deformation of the elastic rod 51 and would increase the mounting forces.

(26) In conclusion, thanks to the offset provided on the actuation surface FA of the hook 52, the guide track (on which the point of contact PC moves during the mounting of the safety module) ensures: the lowest possible mounting force due to the leverage being as large as possible a variation in the mounting force without a sudden or abrupt increase, due to the absence of parasitic contact which would cause the leverage to vary and/or decrease sharply.

(27) As shown in FIG. 4, the offset provided on the actuation face FA guarantees that the path of the point of contact PC: follows the curve T1, located on the first side 52-1 of the hook 52, and does not deviate during mounting to approach the second side 52-2 in order to follow the curve T2, and does not leave the second side 52-2 of the hook 52 at a given moment of the mounting to follow the curve T3.

(28) The curves T2 and T3 return to significantly decrease the leverage which acts to tighten the spring, a contact between the contact portion 51-1 and the hook 52 on these curves would be able to significantly increase the force necessary to deform the elastic rod 51, which would make mounting more difficult. With the offset that guarantees that the contact path follows the curve T1, the forces remain as low as possible, and do not vary suddenly.

(29) It will be understood that various modifications and/or improvements which are obvious to a person skilled in the art may be made to the different embodiments of the invention described in the present description without departing from the scope of the invention.