The present invention relates to a method of manufacturing a wheel, particularly for use on vehicles, which has a recess for association of the rim to the wheel disc without the need for additional steps in the method of manufacturing the wheel, as well as to a wheel and a wheel disc thus con- figured.

Description of the Prior Art Conventional stamped-steel wheels, known since decades ago, comprise a cylindrical wheel rim defining an inner wall and a substantially circular stamped wheel disc associated to the rim by fixation to an intermedi- ate point of its inner wall. Unmistakably, the main characteristics of this type of conventional wheel are the low manufacture cost and the little attractive appearance. So, with the passing of time and the sophistication of the motor- vehicle consuming market, especially light-weight commercial and utility automobiles, the use of these conventional wheels has been reduced to low- cost vehicles or vehicles with more professional vocation, in which the use of wheel cast from light-metal alloys, which have a more elaborate appearance and a much higher manufacture cost, is not desirable or economically feasi- ble.

With a view to associate the low manufacture cost with the at- tractive appearance, wheels have been developed with the stamped disc having the maximum diameter of the wheel, and the wheel rim being associ- ated to this disc at its back surface. Stylistically, these wheels are much more attractive than the conventional stamped wheels, and their manufacture cost continue to be reduced, so that they have a great potential of penetration into the consumer market.

In spite of having an advantageous appearance, the question of centering the rim during its association to the disc presented difficulties when compared with conventional stamped wheels. It was necessary to position the rim very carefully to fix it to the disc, which, as a rule, was effected by welding in order to avoid the manufacture of concentric wheels, the use of

which is prohibited because they cause unsolvable vibrations when the vehi- cle moves.

In order to facilitate this perfectly centered fixation between the disc and the rim, a number of solutions have proposed, generally constituted by concentric channels or recesses made in the disc by adequate cutting tools, wherein the free end of the rim was fitted correctly positioned to be welded. With a view to make this preliminary fitting more precise, rims have been developed with their free end being specifically prepared by using a cutting tool.

In spite of achieving their objectives, all of these solutions devel- oped for overcoming the problem of centering the rim resort to additional steps of manufacture, incurring a higher production cost due to the need for additional machinery and personnel in operation, wear of the cutting tools and waste of material, in addition to the time spent in producing the wheel.

Moreover, it is always to remind that the larger the number of steps for manufacturing a component, the greater the chances of the piece of work presenting manufacture flaws.

In this regard, document US 4,610, 482 discloses a wheel pro- vided with a rim associated to the upper surface of a disc on which a step of mechanical shaping to remove material is carried out, forming a cavity in the region where the rim is associated. Additionally, in this wheel the rim also undergoes a similar process of shaping its free end by means of a cutting tool, which brings about a perfect fitting between them both. Besides, a sur- face is configured, which serves as a stop for indicating a perfect fitting.

However, as expected, this wheel has a considerably high manufacture cost, due to the large number of manufacture steps required for making it.

With a view to providing a wheel that could be easy to center, without the need to resort to additional manufacture steps, a wheel has been proposed and disclosed in patent application PI 9916810, corresponding to the Brazilian national phase of case PCT US99/30165, published under number WO00/38936, which discloses a wheel rim the free end of which is turned inwards, defining a flange. The flange surface that will touch the disc

should be completely parallel to the corresponding disc surface, which brings about a correct centering, although less effective than that disclosed in the North-American document discussed in the preceding paragraph. Similar solutions may further be found in document US 2001/0038238.

Thus, a wheel provided with means for centering the rim on the disc without the need for additional manufacture steps for making it is some- thing that had not so far been developed.

Obiectives of the Invention The present invention has the objective of providing a method of manufacturing a wheel, especially for use on an automotive vehicle, com- prising a disc to which a wheel rim is associated, the disc being provided with a centering element for fixing the rim in the correct position, without the need for any additional manufacture step to provide it with this element. Also, the invention has the objectives of providing a wheel and a wheel disc obtained by the manufacture method disclosed herein.

Brief Description of the Invention The objectives of the present invention are achieved by means of a method of manufacturing a wheel, particularly for use on automotive vehi- cles, the wheel comprising a wheel rim and a wheel disc associable to each other, the method comprising the steps cited below : (i) a step of shaping the wheel disc; (ii) a step of shaping the wheel rim; the steps (i) and (ii) may or may not be carried out simultaneously ; (iii) a step of association of at least one first centering element comprised by the wheel disc and at least one second centering element com- prised in the wheel rim; and (iv) a step of final association between the wheel disc and the wheel rim.

The step of shaping the wheel disc comprises making the first centering element and the step of shaping the wheel rim comprises making the second centering element.

Also, the objectives of the present invention are achieved by means of a wheel, particularly for use on automotive vehicles, comprising a

wheel disc and a wheel rim that are associable to each other, obtained by the method of manufacturing a wheel as defined above, the wheel disc compris- ing a first centering element made in the step of shaping the wheel disc, and the wheel rim comprising a second centering element made in the step of shaping the wheel rim.

Further, the objectives of the present invention are achieved by means of a wheel disc, particularly for use on a wheel designed for automo- tive vehicles, as defined above and obtained by a method as defined above, comprising a second centering element made in the step of shaping the wheel disc.

The present invention has the advantage of enabling one to manufacture a stamped wheel composed of a disc and a rim, which may be easily arranged in a centered or concentric way, by virtue of the existence of centering elements. The centering elements are made during the mechanical shaping of the rim and the rim, subsequent manufacture steps being dis- pensed with, which results in lower manufacture costs for the wheel, lower sale price on the consumer market and the consequent greater penetration into the market.

Brief Description of the Drawings The present will now be described in greater detail with reference to an embodiment represented in the drawings. The figures show: Figure 1-a schematic cross-section view of a stamped steel wheel of the prior art; Figure 2-a schematic view of the wheel illustrated in figure 1 in an intermediate step of its manufacture method, before the completion; Figure 3-a schematic cross-section view of the wheel disc and wheel rim of stamped steel of the present invention, before its association; and Figure 4-a schematic cross-section view of the wheel of the present invention, after the definitive association between disc and rim.

Detailed Description of the Figures According to a preferred embodiment and as can be seen in fig-

ures 3 and 4, the integrated wheel 1 of the present invention comprises a substantially circular wheel disc 3, to which a substantially cylindrical or trun- cated-cone-shaped wheel rim 2. The rim 2 has a first free end 8 (see com- plete description below), which has a first wheel flange (not shown). Prefera- bly, the rim 2 is substantially truncated-cone-shaped.

The wheel flange of the rim is protuberant and has a substantially J-shaped curved profile, its free tip being substantially perpendicular to the rest of its body.

In the preferred embodiment, the rim is made from already-used carbon steel, being obtained by a mechanical shaping lamination step. How- ever, this rim 2 evidently may be made in other ways, as well as built from materials other than carbon steel, and may have shapes other than the cylin- drical or truncated-cone shapes. The only requirement is that the rim enable one to build the wheel described.

The first free end of the rim 8, already mentioned above, extends from its side wall 20 and defines a substantially annular surface. In the pre- ferred embodiment, this free end 8 is slightly facing the inside of the rim 2 and has a substantially pointed end, configuring a centering element 5, which preferably has an annular projection of triangular cross-section. It is in reality an angle piece, constituted by the disc 2 itself, without the need for any other step of mechanical shaping. However, it may have other shapes, amounts and/or configurations, as for example, segmented, or any other shape that enable it to function, which will be explained later.

The wheel disc 3, in turn, is preferably substantially cylindrical, being preferably made from carbon steel by the stamping process. The wheel disc 3 has an end region 6 that embraces its free end, from which a second wheel flange analogous to that of the rim 2 projects.

The disc 3 further has an association region 7 adjacent to the end region 6, which comprises a centering element that is preferably a re- cess having a substantially triangular cross-section 4, thus cooperating with the projection 5 of the rim 2. Of course, the association region 7 may be lo- cated at another point 3, for instance close to its end, or positioned in a more

central way, without the wheel 1 configured according to these possibilities being out of the protection scope defined in the claims of the present applica- tion.

Preferably, the recess 4 is substantially annular, however it may be segmented or have other shape/geometry or amount; the only basic re- quirement is the obligatoriness of cooperating with the projection 5, that is to say, the projection 5 and the recess 4 should totally cooperate with each other.

Another requirement is that both the recess 4 and the projection 5 are absolutely concentric with the rest of the disc 3 and the rim 2, respec- tively. This condition is indispensable to characterize these two elements as centering element, since, in case the association between the disc 3 and the rim 2 have been effected in an eccentric way, the resultant wheel 1 is inher- ently unbalanced, and so it may not be used, otherwise vibrations and loss of security of the vehicle equipped with it will occur. In short, a wheel 1 with ec- centric association between the disc 3 and the rim 2 is a product that should be obligatorily rejected or reworked.

For merely descriptive purposes, the recess 4 located in the disc 3 will be called first centering element, and the projection 5 of the rim 2 will be called second centering element.

After the correct positioning between the recess 4 and the pro- jection 5, preferably fitted to each other, a definitive fixation of association between the rim 2 and the disc 3 is necessary, so that the wheel 1 can be stabilized. Preferably, this fixation is effected by welding, by depositing a weld cord 9, but one may evidently use other joining elements such as screws, rivets, adhesives, etc. In short, both the first the second centering element play the role of a template, facilitating the correct positioning be- tween the disc 3 and the rim 2 prior to definitive fixation between them.

By way of description only, the wheel flange located on the disc 3 constitutes the region where its diameter is maximum. The two wheel flanges 4 and the side wall 20 of the rim 2 define a groove (not shown), into which a tire (not shown) is placed, so that the side wall of the tire close to the its

opening is propped by the two wheel flanges. Due to the fact that the flanges have the profiled described above, and since they project from the end region of the rim 2 and of the disc 3, they are substantially annular in shape.

Additionally, in spite of not being detailed in the figures, the disc 3 has a central region associable to a wheel hub of the vehicle, preferably by means of at least one bore for inserting a wheel screw. Further optionally, a concentric bore is foreseen, to enable one to position the tip of the vehicle axle (not shown). Further preferably, but not obligatorily, esthetic and func- tional windows are provided, characterized so as to contribute to the ventila- tion of the brakes and to the esthetic aspect of the wheel 1.

The method of manufacturing the wheel 1 of the present inven- tion comprises a number of steps, which are listed below : (i) step of shaping the wheel disc 3, which, as already mentioned, is preferably but not obligatorily carried out by stamping; (ii) step of shaping the wheel rim 2, which, as already mentioned, is pref- erably but not obligatorily carried out by lamination ; (iii) step of associating the first centering element (s) 4 comprised on the wheel disc 3 and the second centering element (s), comprised on the wheel rim 2; and (iv) step of final association between the wheel disc 3 and the wheel rim 2.

In the method described here, both the first and the second cen- tering elements, which are preferably the recess 4 and the projection 5, are made during the process of shaping the disc 3 and the rim 2, respectively.

This means that, in the preferred case, the recess 4 is foreseen in the stamping piece that will form the disc 3, while the projection 5 is foreseen in on the lamination equipment that will form the rim 2. Evidently, there is no obligatory order for shaping the disc 3 and the rim 2; they may be shaped at the same time or, which is probably more common, both steps occur inde- pendently, producing the discs 3 and the rims 2, which only then will be joined two by two, to facilitate the carrying-out of the subsequent steps (iii) and (iv).

The step (iii) of associating the disc and the rim comprises posi-

tioning and fitting the projection 5 into the recess 4, positioning the rim 2 on the disc 3 concentrically, so as not to require any other means for correctly positioning both components.

Finally, the step (iv) of final association between the disc 3 and the rim 2 preferably comprises welding these components to each other by means of a welding cord 9. Evidently, other procedures may be used in this step, as for instance, effecting this fixation by means of screws, rivets, fitting, using adhesives or necessary or required other means.

Preferably, but not obligatorily, the step (i) of the method of manufacturing wheels described here shape the wheel disc 3, the recess 4 of which is located in a substantially intermediate association region 7 of the disc 3, as already described before.

Also preferably, the step (ii) of the method of manufacturing wheels described here shapes a wheel rim 2, the projection 5 of which is lo- cated in a free end region of the rim 2, which has also been mentioned be- fore. However, this positioning of the projection 5 is not obligatory.

Figures 1 and 2 show an integrated wheel 100 of the prior art, composed by a rim 200 and a disc 300 associated to each other by means of a welding cord 9. As can be seen in the drawings, a manufacture work is necessary to made the recess 400 and the rim projection 200. Figure 2 shows the portion of material that should be removed from the wheel during its manufacture, under number 500, achieved by using a cutting tool. The disadvantages of this system may be verified above, in the section"descrip- tion of the prior art".

A preferred embodiment having been described, it should be un- derstood that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which include the possible equivalents.