Abstract:
The invention relates to a vehicle steering wheel which comprises a steering wheel skeleton consisting of a steering wheel rim having an interior space, and of a hub and at least one spoke connecting the hub with the steering wheel rim. The vehicle steering wheel further comprises at least one additional mass fastened to the steering wheel skeleton and constructed as a separate part. The at least one additional mass is intended for reducing vibration and is provided in the interior space of the steering wheel rim. At least one flexible clip is provided which engages on the additional mass and holds the additional mass against the steering wheel skeleton.

Description:
TECHNICAL FIELD 
     The invention relates to a vehicle steering wheel. 
     BACKGROUND OF THE INVENTION 
     Standard vehicle steering wheels may be provided with separate additional masses to be fastened at desired sites on the steering wheel skeleton. These additional masses are intended to increase the inert mass of the vehicle steering wheel as a whole and to largely prevent vibrations. Additional masses have generally hitherto been fastened to the hub. 
     As slight modifications to the steering wheel also lead to a different coordination of the steering wheel with respect to the inert masses of its individual parts, slightly lighter or heavier additional masses are to be able to be fastened to the steering wheel skeleton quickly and simply, without a reconstruction of the steering wheel being required. Such a fine coordination of the individual parts of a steering wheel is also appropriate if with the same steering wheel skeleton different embodiments are to be produced (e.g. with additional facings or function switches). 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides a vehicle steering wheel, in which the additional mass for reducing vibration can be arrested quickly and simply on the steering wheel skeleton. This is achieved in a vehicle steering wheel which comprises a steering wheel skeleton consisting of a steering wheel rim having an interior space, and of a hub and at least one spoke connecting the hub with the steering wheel rim. The vehicle steering wheel further comprises at least one additional mass for reducing vibration fastened to the steering wheel skeleton and constructed as a separate part. The at least one additional mass is provided in the interior space of the steering wheel rim. At least one flexible clip is provided which engages on the additional mass and holds the additional mass against the steering wheel skeleton. This clip makes possible a simple, rapid clipping of the additional mass on the steering wheel skeleton. As through the clip a separate part is available for fastening the additional mass to the steering wheel skeleton, the additional mass can also be constructed slightly differently and hence also with a slightly altered weight, without a different clip being required. By using such a clip, the additional mass is preferably also to be pressed in a prestressed manner against the steering wheel skeleton. The prestressing is to be selected such that no vibrations can occur between the additional mass and the steering wheel skeleton. For this purpose, it can be advantageous if in addition also a form-fitting connection is provided between the additional mass and the clip. This form-fitting connection prevents a faulty positioning of the additional mass and the clip with respect to each other on installation. 
     Preferably, a further form-fitting connection is present between the clip and the steering wheel skeleton. This also facilitates the exact positioning of the clip on the steering wheel skeleton on installation. Furthermore, such an additional form-fitting connection serves for the additional securing of the clip on the steering wheel skeleton. 
     The above-mentioned form-fitting connections can be formed for example by a recess and a corresponding projection, which projects into the recess. 
     According to the preferred embodiment, several additional masses are fastened to the steering wheel rim by means of clips. The accommodating of the additional mass takes place here advantageously in the steering wheel itself, if the latter has a hollow profile which is open in cross-section. The clip presses the additional mass into the interior of this hollow profile and closes it. Thereby, the additional mass does not project outwards with respect to the steering wheel rim, or only projects slightly, and also does not prevent the process of encasing with foam. 
     The clip which embraces the steering wheel rim can be secured in addition by a shell-shaped hard panel or cover visible from outside, which presses together the free ends or edges of the clip. In this connection, the clip has a dual function by not only fastening the additional mass but also the visible panel to the steering wheel rim. The visible panel is preferably a plastic panel or a panel of a different material such as aluminum, wood or composite material and is arranged on the inner face of the steering wheel rim in steering wheels having a particularly high-quality appearance. Its fastening can also be achieved according to one design by a clip connection, by the panel, the clip and the foam casing of the steering wheel being coordinated with each other such that with a steering wheel which is already encased in foam, possibly even already covered with leather, the panel is clipped onto the clip. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a top view onto a diagrammatically illustrated steering wheel skeleton according to the invention, with additional masses fastened thereon, 
     FIG. 2 shows a cross-section through a steering wheel rim, encased in foam and covered with leather, of a steering wheel according to the invention in accordance with a first embodiment, 
     FIG. 3 shows a cross-section through a steering wheel rim, encased in foam and covered with leather, of a steering wheel according to the invention in accordance with a second embodiment, 
     FIG. 4 shows a cross-section through a steering wheel rim, encased in foam and covered with leather, of a steering wheel according to the invention in accordance with a third embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1, a steering wheel skeleton is illustrated, consisting of a steering wheel rim  3 , a steering wheel hub  5  and several spokes  7  connecting steering wheel rim  3  and steering wheel hub  5 . Several additional masses are arranged, uniformly distributed across the periphery of the steering wheel rim  3 , to increase the inertia of the steering wheel and hence to reduce the vibrations in driving operation. The additional masses can be seen in the following figures; in FIG. 1 only clips  9  can be seen, which each serve for arresting one additional mass on the steering wheel rim  3 . 
     In FIG. 2, a greatly enlarged view through a steering wheel in the region of the steering wheel rim, the steering wheel rim  3  of the skeleton is illustrated as an open hollow section. The hollow section is open to the rear face of the steering wheel (at the bottom in the drawings). From this side, an additional mass  11  is inserted into the hollow section. The additional mass is adapted in its shape to the inner face of the hollow section, so that no transverse movements can occur between the steering wheel rim  3  and the additional mass  11 . The additional mass of forged steel is accommodated almost completely in an interior space  3   a  (see FIG. 2) inside the steering wheel rim  3 . Only two lateral extensions  13  surround the free edges  15  of the steering wheel rim  3  and serve for the additional fixing of the additional mass  11  on the steering wheel rim  3 . The arresting of the additional mass  11  on the steering wheel rim  3  takes place by a clip  9  bent in a C-shape, which can be clipped from outside onto the steering wheel rim  3  which is not yet encased in foam and not yet covered with leather. The clip is formed from a wide band of spring steel and presses the additional mass  11  under prestressing into the interior of the steering wheel rim  3 . So that the steering wheel rim  3  is positioned exactly to the clip  9  and the latter is positioned exactly to the additional mass  11 , and so that the sites on the periphery of the steering wheel rim  3  on which the additional mass  11  is to be fastened are preset, form-fitting connections are provided between the steering wheel rim  3  and the clip  9  and also between the clip  9  and the additional mass  11 . The form-fitting connections are formed by respectively at least one projection  17  on the front face of the steering wheel rim  3  and also one projection  19  on the additional mass  11  and also by recesses  21  and  23  in the clip  9 , into which the projections  17  and  19 , respectively, project. Also in FIG. 1 the projections  17  can be seen. 
     Steering wheels having a high-quality appearance can have panels  25 , visible from outside, of plastic, aluminum, wood or composite material, which for example have an imitation of wood on the outside. A panel  25  of plastic, arranged on the inner face of the steering wheel rim, is shown in FIG. 2. A panel  25 , which covers a segment of the steering wheel rim on the inner face, sits on the periphery of the steering wheel rim on the inner face in the region of each clip  9 . The panel  25  has outer edges  27 , which are directed towards each other. These edges  27  each grasp an associated, outwardly bent edge  29  of the clip  9 . Thereby, a form-fitting connection results between the free edges of the clip  9  and the edges  27  of the panel  25 . The panel  25  endeavors to press the edges  29  together and thus serves as an additional arresting of the clip  9 . The clip  9  in turn serves to arrest the panel  25 , because the panel  25  does not require an additional arrangement for its arresting on the steering wheel rim. 
     As can be additionally seen from FIG. 2, the shape of the clip  9  is largely adapted to the outer contour of the steering wheel rim  3  and also to the additional mass  11 , so that there is effected an extensive abutment of the clip  9  against the steering wheel rim  3  on the front face and against the additional mass  11  on the rear face. 
     The steering wheel rim  3  together with the clips and additional masses  11  arranged thereon is surrounded by a foamed sheathing  31 , adjoining which externally is a leather covering  33  in the embodiment which is shown. The leather covering  33  has ends  35  towards the panel  25 , which are deflected into the interior of the foam casing of the steering wheel rim. 
     The production of the illustrated steering wheel is explained hereinbelow in detail. After the production of the steering wheel skeleton, the additional masses  11  are fastened by means of the clips  9  to the sites marked by the projections  17 . In so doing, firstly each additional mass  11  is pressed into the hollow interior of the steering wheel rim  3 . Then the clip  9  is put in place, the projections  17 ,  19  engaging into their recesses  21  and  23 , respectively. Then the steering wheel is encased in foam and covered with leather. Finally, the panels  25  are inserted from the inner face of the steering wheel rim, with the edges  27 ,  29  forming a latching connection, for which reason the panels only have to be clipped onto the clips. 
     The embodiment illustrated in FIG. 3 corresponds substantially to the one previously explained, the parts already explained having the reference numbers which have already been introduced, increased by the number  100 . Other than with the embodiment shown in FIG. 2, the additional mass  111  is accommodated completely within the hollow interior of the steering wheel rim  103 . It can also be pushed fully into this hollow interior. So that the elastic clip  109  lies with a prestressing against the additional mass  111 , it has a projection  141  with which it contacts the additional mass  111 . A further projection  143  serves to provide a prestressing in a transverse direction. As a further difference to the embodiment shown in FIG. 2, in this embodiment no panel is provided and hence also no additional securing for the clip  109 . 
     The embodiment illustrated in FIG. 4 corresponds substantially to the one shown in FIG.  3  and already explained. Here, also, the reference numbers already used are used again, however again increased by the number  100 . In contrast to the embodiment shown in FIG. 3, the clip  209  further embraces the steering wheel rim  203 , so that it engages more securely on the steering wheel rim  203  of the skeleton. 
     For the fine adjustment of the steering wheel, additional masses of different weight can also be arranged on the steering wheel skeleton by the same clips. The additional masses are only constructed slightly longer or shorter, so that a type of modular system results, which by simple means permits an optimum coordination of the steering wheel with respect to its inert masses.