GB2045184A

GB2045184A - Steering wheel assembly

Info

Publication number: GB2045184A
Application number: GB7944383A
Authority: GB
Original assignee: Petri AG
Current assignee: Petri AG
Priority date: 1979-01-08
Filing date: 1979-12-24
Publication date: 1980-10-29
Also published as: DE2900403A1; GB2045184B; FR2445788B1; DE2900403C2; FR2445788A1; BR7908628A

Abstract

An automotive steering wheel assembly, e.g. for a steering column steeply inclined to the vehicle floor, comprises a hub (1), a ring (2) and spokes (3, 4), connecting the hub and the ring, the spokes being located in plane or defining a dished structure, wherein the spokes (3, 4) are pre-bent laterally in a direction extending substantially parallel to the tangent to the ring in the region in which the spoke is connected to the ring. <IMAGE>

Description

SPECIFICATION Steering wheel assembly for automotive vehicles The present invention relates to a steering wheel assembly for automotive vehicles. More particularly, the present invention relates to a steering wheel assembly for use in steering arrangements in which the steering column is steeply inclined relative to the floor of the vehicle. Generally, the assembly of the present invention is of the type which comprises a steering wheel assembly for automotive vehicles, particularly suitable for steering arrangements in which the steering column is steeply inclined to the floor of the vehicle, the assembly comprising a hub, a ring and spokes connecting the hub and the ring, the spokes being located in an imaginary flat or horizontal plane or defining a dished structure so as to form a substantially frusto-conical jacket between the hub and the ring.

In a number of types of automative vehicles, such as heavy goods vehicles and light passenger transport vehicles, such as minibuses, and vehicles having box or flat platforms, the steering column is often installed at an angle of about 65" (or greater) to the floor of the vehicle for design reasons. In such vehicles, the steering wheel itself is generally located in a horizontal, or substantially horizontal plane. Conventional safety measures utilised in steering wheel assemblies to prevent injury to the driver if the vehicle is involved in an accident are at best inadequately effective if the steering wheel extends substantially horizontally.This is true both in arrangements wherein the wheel hub is in the form of collapsible telescopic sections and in arrangements in which the steering wheel ring and spokes are suitably shaped and made from suitable materials so as to act as deformable energyabsorbing devices. Impact forces occurring in directions substantially parallel to the spokes of the wheel, which will frequently occur in the case of horizontally disposed steering wheels, prevent the spokes from acting as energy absorption devices.

Accordingly the entire steering wheel assembly acts as a rigid system which resists the deformation of the steering wheel rim or ring.

The present invention seeks to provide a steering wheel assembly for automotive vehicles which can receive and absorb impact energy forces irrespective ofthe direction in which the impact force acts and also which, if subjected to a force acting at right angles to the steering column, that is to say, parallel to the plane of the steering wheel rim or ring, acts as an energy absorption device so as to protect the driver.

According to the present invention, there is provided a steering wheel assembly for automotive vehicles, particularly suitable for steering arrangements in which the steering column is steeply inclined to the floor of the vehicle, the assembly comprising a hub, a ring and spokes connecting the hub and the ring, the spokes being located in an imaginary flat or horizontal plane or defining a dished structure so as to form a substantially frusto-conical jacket between the hub and the ring, wherein the spokes are pre-bent laterally in a direction extending substantially parallel to the tangent of the ring in the region in which the spoke is connected to the ring.

Such a steering wheel assembly appears to permit impact energy to be absorbed irrespective of the direction of the impact force. Moreover, if the impact forces occur in the plane of the steering wheel rim or ring, both the spokes of the steering wheel and the steering wheel ring play their part in energy absorption. Nevertheless, the normal effectiveness of the steering wheel spokes which act as deformable energy absorbing elements if the force is directed at right angles to the plane of the steering wheel ring is not impaired so that the present assembly may be usefully employed in any vehicle steering arrangement.

The desired sequence of deformation of the spokes and the ring on impact may be selected in dependence upon the installation in which the assembly is to be used. Thus, if the installation includes a steeply angled steering column, both the spokes and the steering wheel ring may have a higher bending moment in a direction parallel to the steering spindle than in the transverse direction. To achieve this, the ring and the spokes may have a substantially elliptical cross section and are so mounted on the steering wheel ring that the minor axis of the ellipse extends tangential or substantially tangential (spoke) or radial (steering wheel ring) relative to the circumference of the steering wheel dish. Accordingly, a preferred manner of deformation depending on the installation in which the assembly is to be used can be achieved.

A steering wheel assembly in accordance with the invention has the above-described favourable properties irrespective of further modifications which may be made. Thus, it is substantially irrelevant whether or not two or a larger number of spokes are provided and whether or not the spokes are regularly or irregularly spaced apart. It is also possible to provide an equiaxial pre-bending, orto provide the spokes in pars, the spokes in each pair being bent in opposite directions. In this latter case, the spokes are located offset relative to one another. For this purpose, the spokes, at least at one end, for example, on the steering wheel hub, may be mounted in a vertically offset manner or may additionally be bent vertically at right angles to the lateral pre-bend. If the spokes are in pairs, such vertical bending may be effected in opposite directions.In this manner, obstruction of the spokes by one another when they buckle on impact is reliably prevented. Thus, the full deformation path of the spokes may be utilised for absorbing energy. The spokes may be so arranged that, in their undeformed state, the bending regions of pairs of spokes overlap one another with a slight clearance, whereby a common covering may be provided over at least the overlap region.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure lisa section through a part of a steering wheel assembly in accordance with the present invention; and Figure 2 is a plan view of the assembly shown in Figure 1.

In the drawings, there is shown a steering wheel hub 1, a steering wheel ring 2 provided with a covering 2a and spokes 3 and 4 of the steering wheel which connect the hub 1 to the ring 2. As shown, four spokes are provided which are in pairs, the spokes in each pair being slightly spaced from on another. The spokes, as can best be seen in Figure 2, are each pre-bent laterally in a direction extending substantially parallel to the tangent to the circumference of the steering wheel ring at the point at which the spoke is connected to the ring. The spokes, in their bent regions are offset relative to one another in that the mountings of the spokes on the hub 1 are at different levels. The spokes thus extend out of the hub at different setting angles.If an accident occurs, thereby setting up impact forces acting, for example, substantially in the direction denoted by the arrow P in Figure 2, a material deformation ofthespokes occurs at both their conncting points to the hub and to the steering wheel ring as well as in the region in which the spokes have been pre-bent. By providing the bend in a lateral direction, it is ensured, as far as possible, that portions of the spokes will not become bent upwardly in an uncontrolled manner in the event of an accident. The desired deformation of the spokes may be made more certain if the spokes have a higher resistance to bending in the direction parallel to the steering column than in the plane of the steering wheel ring. For this purpose, the spokes are preferably made elliptical in shape and are so mounted on the steering wheel that the major axis of the ellipse extends parallel, or substantially parallel, to the steering column. Figure 2 further shows, in broken lines, the deformation of the steering wheel, and more particularly the spokes, after an impact has occurred.

Claims

1. A steering wheei assembly for automotive vehicles, particularly suitable for steering arrangements in which the steering column is steeply inclined to the floor of the vehicle, the assembly comprising a hub, a ring and spokes connecting the hub and the ring, the spokes being located in an imaginary flat or horizontal plane or defining a dished structure so as to form a substantially frusto-conical jacket between the hub and the ring, wherein the spokes are pre-bent laterally in a direction extending substantially parallel to the tangent to the ring in the region in which the spoke is connected to the ring.

2. A steering wheel assembly as claimed in claim 1, wherein the spokes and the steering wheel ring each have a higher bending moment in a direction extending parallel to the steering column than in the transverse direction.

3. A steering wheel assembly as claimed in claim 2, wherein the spokes and the steering wheel ring are each elliptical in cross section.

4. A steering wheel assembly as claimed in any one of claims 1 to 3, wherein the spokes are arranged in pairs, the spokes in each pair being pre-bent in opposite directions and being offset from one another.

5. A steering wheel assembly as claimed in claim 4 wherein the spokes are each mounted on the steering wheel hub, their points of mounting on the hub being vertically offset from one another, the spokes extending from the hub at differing angles.

6. A steering wheel assembly as claimed in claim 4, wherein the spokes are also bent vertically at right angles to the lateral pre-bending, in mutually opposite directions.

7. A steering wheel assembly as claimed in any one of claims 4 to 6, wherein each spoke, in its undeformed state, overlaps at least one other spoke in its bend region, the overlapping portions being provided with a common covering.

8. A steering wheel assembly constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.