Steering Wheel Frame for an Automobile Vehicle or the Like

The present invention relates to steering wheels which comprise an annular rim connected by a plurality of radial arms to a hub for fixing to a steering shaft.

It is well known that automobile vehicle steering wheels must be light and easy to use and moreover have a low polar inertia and great strength so as not to break under the action of vibrations due to the motion of the vehicle or under the effect of a shock or the like. For this purpose, they are usually formed by a metal frame preferably composed of wire or tube which is covered with a polyurethane foam or the like affording an attractive appearance and comfort for the driver.

In order to render them lighter, it has been proposed, as described in the U.S. Pat. No. 4,448,091, to form the rim by means of a tube curved into the shape of a ring and bent at its ends so as to constitute a radial arm for fixing to the hub. Unfortunately, such a steering wheel has only one radial arm, which does not afford the comfort required by the vehicle drivers, and moreover the steering wheel is often insufficiently strong.

It has also been proposed, as described in the United Kingdom patent 1,571,902, to form the rim by means of a hollow tube and to connect it by solid arms to a hub moulded onto the ends of these arms. The steering wheel may in this way have the desired number of radial arms, but its weight and size are increased.

An object of the present invention is to provide a steering wheel frame which both satisfies the requirements of lightness, low polar inertia and strength and provides the steering wheel with the number of radial arms considered preferable for the comfort of the driver.

The invention therefore provides a steering wheel frame comprising a tubular peripheral rim which is connected to a moulded metal hub for fixing to a steering shaft, by a plurality of radial arms, wherein the rim comprises at least two curved tubes in the form of substantially complementary portions of a ring and inwardly and downwardly bent at their ends so as to form steering wheel spokes having axially extending end portions which are progressively crushed and moulded in substantially longitudinal lateral bosses of the hub.

According to another feature of the invention, the two adjacent spokes of two successive curved tubes are moulded side by side in each of the bosses of the hub so as to form a radial arm.

Preferably, a reinforcing tube is mounted inside the end portion of each of the steering wheel spokes and is progressively crushed with said end portion.

Such a steering wheel not only benefits from the qualities of lightness of the tubes constituting the rim and the radial arms but also has great strength owing to both the presence of a plurality of radial arms and the cooperation of the bosses of the hub with the progressively crushed end portions on which these bosses are moulded.

The following description of an embodiment, given by way of a non-limitative example and shown in the accompanying drawings, will bring out the features and advantages of the invention.

In these drawings:

FIG. 1 is a top plan view, with a part cut away, of a steering wheel frame according to the invention.

FIG. 2 is a sectional view taken on line 2--2 of FIG. 1.

FIG. 3 is a bottom view of the hub of the steering wheel in the direction of arrow F of FIG. 2.

FIG. 4 is a sectional view taken on line 4--4 of FIG. 2.

FIG. 5 is a sectional view taken on line 5--5 of FIG. 3.

As shown in the drawings, the steering wheel frame to which the invention relates comprises a peripheral tubular rim 1 which is formed by a plurality of curved tubes, in the shape of substantially complementary portions of a ring disposed in side by side relation. In the illustrated embodiment, the rim 1 is formed by two tubes, respectively 2 and 4, which are curved with the same radius of curvature, one of the tubes, namely the tube 2, extending in more than a semi-circumference whereas the other, namely the tube 4, occupies the complementary sector. Each of these tubes 2 and 4 is bent at its ends so as to form inwardly and downwardly extending spokes respectively 6-7 and 8-9.

The adjacent spokes 6-8 or 7-9 of the two tubes in this way comprise, starting at the rim portion 2, 4, oblique and convergent portions 6a and 8a on one hand, and 7a and 9a on the other, which are extended by rectilinear and parallel portions 6b, 8b and 7b, 9b which have first of all an oblique portion, then a bent portion and then a substantially vertical portion. Placed inside the end portion of each of the spokes is a reinforcing tube 10 whose outside diameter is such that it is closely applied against the inner surface of each of the tubes 6, 7, 8 and 9. This reinforcing tube 10 extends throughout the vertical portion of the tube and inside the bent portion which connects this vertical portion to the oblique portion (FIG. 2).

The whole of the reinforcing tube 10 and vertical end portion 12 of the corresponding spoke has a progressively crushed section so that the spoke is closed in a sealed manner at its lower end. The crushed end portion 12, however, retains a curved section in the shape of a haricot bean, as shown more particularly in FIG. 4, its thickness being gradually reduced down to the contact between the walls. Moulded on the end portions 12 of the two adjacent spokes 6-8 or 7-9 is a boss 14 in one piece with a hub 16 for fixing the steering wheel on a steering shaft (not shown). The bosses 14, namely two in number in the illustrated embodiment, project laterally and longitudinally upwardly relative to the hub 16. Each of them surrounds the vertical end portion 12 of the two adjacent spokes 7-9 or 6-8 and the bent portion of these tubes. The two tubes are in this way completely embedded in the hub material, preferably a light metal such as aluminum or an aluminum alloy, the tubes being isolated from each other but maintained very close to each other. They can in this way constitute the frame of the same radial arm of the steering wheel which is thus firmly fixed to the hub. The hub 16 of course includes in the conventional manner an axial aperture 18 whose upper part is provided with inner splines 20 which cooperate with corresponding splines on the steering wheel shaft, and a conical clamping part 22. Preferably, as shown in FIG. 2, the conical part 22 is formed in an annular extension 24 of the hub 16 and a ring 26 of harder metal, for example steel, is mounted on the extension 24, when clamping the assembly on a steering column, so as to reinforce it. Preferably, as shown, the extension 24 has a double conical outer shape and the ring 26 is reduced in section in its median part so that its inner surface fits this double conical shape. A finger portion 28 extends from the lower part of the hub 26 and is in one piece with the latter and constitutes a return finger portion for the flashing direction indicator. This return finger portion extends vertically downwardly, i.e. in a direction opposed to that of the bosses.

The whole of the hub has a particularly compact shape and a relatively small size in the transverse direction while it permits a strong and reliable connection of the radial arms thereto. This narrow shape facilitates the mounting of the steering wheel, especially in the case where the hub must be inserted in a sleeve of the dashboard which defines an aperture of small diameter.

It will be clear that the hub 16 may have any desired number of bosses 14, that is to say, the number of radial arms of the steering wheel may exceed two and vary in accordance with the type of comfort desired by the driver.