GB2341582A

GB2341582A - A steering wheel arrangememt

Info

Publication number: GB2341582A
Application number: GB9920121A
Authority: GB
Inventors: Homayoun Karimi
Original assignee: MG Rover Group Ltd
Current assignee: MG Rover Group Ltd
Priority date: 1998-09-19
Filing date: 1999-08-26
Publication date: 2000-03-22
Also published as: GB9920121D0; GB9820342D0

Abstract

A steering wheel arrangement in which a steering wheel (1) presents spaced ends (5, 6) to an occupant of a motor vehicle and the steering wheel (1) is rotatable about a mounting end (2) secured to a dashboard (3). The spaced ends (5, 6) being coupled to orientation means whereby upon detection of a motor vehicle collision, the spaced ends (5, 6) are rotated about the mounting end (2) into a predetermined orientation more acceptable for occupant impact collision.

Description

2341582 - 1 A STEERING WHEEL ARRANGEMENT The present invention relates to

a steering wheel arrangement.

Traditionally, steering wheels have comprised a round wheel secured through a steering column to the chassis of a motor vehicle. Inherently, such a traditional assembly provides a fixed obstacle in front of a vehicle occupant during a collision and therefore is potentially dangerous. Of particular concern is the lower edge of such a traditional steering wheel which abuts a vehicle driver's abdomen and can cause severe injury.

One solution to such a steering wheel collision problem is to couple the steering wheel directly to the dashboard and eliminate the lower perimeter of the steering wheel. Thus, so-called split cone steering wheel configurations have been proposed. In such circumstances, the steering wheel is coupled as indicated previously directly to the dashboard using electromagnetic sensors to determine rotation of the steering wheel and provide a controlled response in terms of road wheel turning. Thus, there is no direct contact between the steering wheel and the vehicle chassis and the whole assembly of steering wheel and dashboard can deform together in order to reduce the potential injury to a vehicle occupant.

Clearly, a steering wheel is designed to rotate in order to turn a motor vehicle and in particular it will be appreciated that just prior to a motor vehicle collision there is a good possibility that the vehicle driver will attempt to swerve to avoid an obstacle and therefore turn the steering wheel significantly. Unfortunately, in such circumstances, even with a split cone steering wheel, one of the edges of the cone will be located adjacent to an occupant's abdomen and therefore may precipitate the injuries described above.

It is an object of the present invention to provide a steering wheel arrangement which substantially removes the above-mentioned problems.

1 In accordance with the present invention, there is provided a steering wheel arrangement for a vehicle, the arrangement comprising a steering wheel defining two spaced ends rotatable about a mounting end of that steering wheel, the spaced ends being coupled to pull wires and said pull wires being associated with orientation means, such as a retractor mechanism, in order to pull the said pull wires upon detection of a vehicle collision such that said spaced ends associated therewith are rotated about the mounted end into a predetermined orientation.

Typically, the predetermined orientation is with said respective spaced ends level or. centralised relative to a vehicle occupant.

The steering wheel may be of a split cone type or alternatively defining, in cross-section, a rectangular channel shape or split oval shape, both of which normally taper towards the mounting end.

Normally, the retractor mechanism will comprise a pyrotechnic device arranged to pull upon the pull wires about a pulley arrangement in order to return the respective spaced ends to the predetermined orientation.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawing in which a symbolic pictorial representation of a steering wheel arrangement is illustrated.

In the drawing, a steering wheel arrangement is illustrated in symbolic pictorial perspective. Thus, a steering wheel 1 is mounted through a mounting end 2 to a dashboard 3. The steering wheel 1 presents a front edge 4 to an occupant with respective spaced grip ends 5, 6 to allow the occupant to grip the steering wheel 1. The steering wheel 1 rotates in the direction of arrow heads A about the mounting end 2. As described previously, this mounting end 2 is associated with appropriate detection means such that an electronic control mechanism can reciprocally turn vehicle road wheels according to rotation of the steering wheel 1 in the direction of arrow heads A. Typically, rotation of the steering wheel 1 in the direction of arrow heads A will not be linear with regard to road wheel turning through the electronic control mechanism in order that complete rotation of the steering wheel 1 is not necessary to turn from left to right full road wheel lock.

The purpose of mounting the steering wheel 1 through the mounting end 2 directly to the dashboard 3, rather than to a vehicle chassis, is to reduce the rigidity of the steering wheel as presented to an occupant of a vehicle. Thus, the steering wheel 1 and the dashboard 3 will combine as an assembly which deforms together upon impact with that occupant in order to provide a more sympathetic engagement therebetween under impact load. It will, however, also be appreciated that typically the steering wheel 1 will be associated with an air bag deployment mechanism 7, normally located about the mounting end 2 in order to present an air bag upon detection of a motor vehicle collision to an occupant gripping the steering wheel through the spaced grip ends 5, 6.

In accordance with the present invention, the front edge 4 of the steering wheel 1, it will be noted, does not constitute a complete circular perimeter. Thus, below the spaced grip ends 5, 6 there is a free space and this free space ensures that the steering wheel, during a collision impact, does not abut a vehicle occupant's lower abdomen and precipitate injuries thereby. However, it will be appreciated that the steering wheel 1 generally will be rotated in the direction of arrow heads A by the occupant and in particular during a motor vehicle collision the steering wheel 1 may be severely turned in order to attempt to avoid an obstacle. In such circumstances, either of the spaced grip ends 5, 6 may be lower than the normal balanced or centralised configuration typical with the road wheels parallel for forward motion. With one of the spaced grip ends 5, 6 in such a turned position, it will be appreciated that the end 5, 6 could engage an occupants' abdomen and therefore cause injury during a collision impact.

In accordance with the present invention, when a vehicle collision 10 impact is detected, the steering wheel 1 is rotated back to a predetermined orientation to achieve best engagement with an occupant during an impact for reduced injury to that occupant. Typically, as illustrated in the drawing, this will be with the spaced grip ends 5, 6 in a level or centralised configuration. However, it will be appreciated that alternative arrangements for the spaced ends 5, 6 could be envisaged dependent upon a particular vehicle geometry and expected occupant impact orientation to the steering wheel front edge 4. This rotation of the spaced ends 5, 6 upon detection of a collision is precipitated by the orientation mechanism 8 which acts upon the steering wheel 1.

The orientation mechanism 8 typically will comprise a retractor acting through respective pull wires 9, 10 coupled through the steering wheel 1 to be associated with a respective spaced end 5, 6. Thus, upon detection of a vehicle collision, the pull wires 9, 10 will be pulled by the retraction mechanism such that the steering wheel 1 is rotated about the mounting end 2 to achieve the desired predetermined orientation for occupant impact.

Thus, the orientation means 8 most overcome both steering wheel turn resistance and the occupant's grip. Normally, the pull wires 9, 10 will be drawn or retracted through a pulley mechanism 11 as the steering wheel 1 is rotated in the direction of arrow heads A.

Upon detection of a vehicle collision, the pull wires 9, 10 will be retracted to equalise their length relative to the pulley 11 and thereby turn the steering wheel to the predetermined orientation.

Clearly, it is necessary for the return to the predetermined orientation to be relatively rapid. Thus, a pyrotechnic device will act as the retractor mechanism power force. As an alternative to a pyrotechnic device, a motor powered winder could be used, but it will be appreciated that the speed of such a winder may be significantly lower than a pyrotechnic device and therefore less acceptable.

Normally, the steering wheel 1 as illustrated in the drawing will comprise, in cross-section, a half circle at the front edge 4. However, it is essentially providing the spaced ends 5, 6 to be gripped by the occupant for convenient rotation of the steering wheel 1 that is the requirement. Thus, the steering wheel 1 can assume a variety of cross-sections in order to present the spaced ends 5, 6 to an occupant. For example, these crosssections may be an open rectangle or similar open channel cross- section.

Normally, for convenience the steering wheel will taper from the front end to the mounting to facilitate easy mounting to the dashboard.

Electromagnetic devices may be used to determined rotation of the steering for translation by an electronic control device to produce road wheel turning.

As illustrated in the drawing, normally the steering wheel 1 win be presented in a downward configuration with an arch between the spaced ends 5, 6. However, it will also be appreciated that the steering wheel could be provided in an upturned configuration but that there is additional possibility of occupant abdominal injury or the retractor mechanism lifts or turns the steering wheel to reduce injury. Clearly, in such circumstances, the operational function of the steering wheel in terms of road wheel turning may be disabled in order that these movements of the steering wheel are acceptable.

It will be appreciated that a steering wheel is a highly visible component within a motor vehicle interior. Thus, as illustrated in the drawing, the steering wheel, in accordance with the present invention, may include cut-out sections from its notional shape envelope in order to provide an aesthetically pleasing design. For example, in the drawing, the steering wheel 1 has a notionally split cone shape envelope but a back section is removed to improve appearance but also reduce weight and increase dashboard instrument visibility. Furthermore, the spaced grip ends 5, 6 are more clqarly defined by respective grip cut-outs 14, 15 and to allow the 10vehicle driver to more easily turn the wheel 1. Clearly, these cut-out 14, 15 portions will also weaken the steering wheel 1 so that deformation under impact load is facilitated

Claims

-9CLAIMS

1. The steering wheel arrangement for a vehicle, the arrangement comprising a steering wheel defining two spaced ends rotatable about a mounting end of the steering wheel, the spaced ends being coupled to pull wires and said pull wires being associated with an orientation means in order to pull said pull wires upon detection of a vehicle collision such that the spaced ends associated therewith are rotated about the mounting end into a predetermined orientation.

2. An arrangement as claimed in Claim 1, wherein the predetermined orientation is with the spaced ends level and centralised relative to the vehicle occupant.

3. An arrangement as claimed in Claim 1 or 2, wherein the steering wheel comprises a split cone or rectangular channel or split oval shape.

4. An arrangement as claimed in any preceding claim, wherein the steering wheel tapers from a front edge incorporating the spaced ends to the mounting end in order to facilitate securing such a mounting end within a dashboard of a motor vehicle.

5. An arrangement as claimed in any preceding claim, wherein the orientation means comprises a retractor mechanism including a pyrotechnic device arranged to pull the pull wires about a pulley arrangement in order to rotate the steering wheel about the mounting end into the predetermined orientation.

6. An arrangement as claimed in any preceding claim, wherein the steering wheel includes cut out portions in order to facilitate deformation upon impact collision with an occupant.

7. A steering wheel arrangement as hereinbefore described with reference to the accompanying drawing.

8. A motor vehicle including a steering wheel arrangement as claimed in any preceding claim.