GB1576754A

GB1576754A - Motor vehicle safety steering mechanism

Info

Publication number: GB1576754A
Application number: GB1884377A
Authority: GB
Original assignee: Ustav Pro Vyzkum Motorovych Vozidel
Current assignee: Ustav Pro Vyzkum Motorovych Vozidel
Priority date: 1976-05-05
Filing date: 1977-05-05
Publication date: 1980-10-15
Also published as: CS196596B1; FR2350241B1; DE2718974A1; DD129766A1; FR2350241A1

Description

(54) MOTOR VEHICLE SAFETY STEERING MECHANISM (71) We, . USTAV PROVYZKUM MOTOROVYCh VOZIDEL, a Czechoslovak Corporation, of No. 12 Lihovaska, Praha 9, Czechoslovakia, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention concerns a motor vehicle safety steering mechanism comprising a steering wheel, a steering shaft which is one part or a plurality of parts connected together by one or more joints, the shaft being connectible at its lower end to the steering gear of the vehicle, a console enabling the shaft to be mounted at its upper end to the body of the vehicle.

The safety steering mechanism should in the case of an impact of the driver against the steering wheel allow such a distortion that does not allow the development of a greater force acting against the chest than is tolerable for the human body. This force acting against the chest of the driver is according to the valid regulations ECE UNO in the case of an impact of the human body against the steering wheel not allowed to exceed 1135 kp.

The above mentioned requirement is in known embodiments of the steering mechanism solved by means of deformation elements arranged mostly on the steering wheel shaft. The deformation elements may be represented by the individual parts of the control steering mechanism. There are also used disengageable mechanisms where the disengageable member is at the same time an absorbent element. Another solution is presented by a telescopic shaft of the steering wheel that in the form of grooves guarantees the transfer of the twisting moment that is secured against an axial displacement in the ordinary conditions by means of a shear pin that has suitable dimensions and that in the case of exceeding a predetermined axial force breaks and enables an axial movement in the grooves.

The steering wheel shaft or a greater number of components are in the most recently known constructions fixed to the body by means of a console or of consoles.

The steering wheel shaft or its parts are practically always guided in a direction that is different from the direction of the force that causes the impact against the steering wheel. A jamming or sticking of the steering wheel shaft, that goes through the console in the place of its mounting, occurs therefore in the case of an impact of the driver against the steering wheel. The jamming or sticking of the steering wheel shaft in the console effects a corresponding increase of the tolerable force affecting the body of the driver. The sticking of the steering wheel shaft takes place at its mounting points the more if the angle between the impact force and the axis of the steering wheel shaft is greater. These disadvantages are also evident in the steering mechanism where the console is on its walls provided with lightening holes that nevertheless does not allow a sufficient deformation of the console in the direction of the impact force action without preventing an increase of the force affecting the chest of the driver over 1135 kp.

The elimination of the damping effect of the absorption element, that will be used, if need be, in the steering mechanism, forms a further unfavourable effect of the steering wheel shaft getting stuck.

According to the invention there is provided a motor vehicle safety steering mechanism comprising a steering wheel, a steering wheel shaft which is one part or a plurality of parts connected together by one or more joints, the shaft being connectible at its lower end to the steering gear of the vehicle, a console enabling the shaft to be mounted at its upper end on the body of the vehicle, the console including longitudinally extending vertical side walls and a longitudinally extending upper wall adjoining each side wall, the vertical side walls of the console being provided with pressed portions and/or lightening holes to decrease the stiffness of the console, each vertical wall being provided with a portion projecting upwardly clear of the upper wall of the console, there being a steering lock housing including a vertical wall extending transversely across the front edges of the vertical walls of the console near the upper end of the steering wheel shaft, the housing being secured to the console only by means connected to the transverse wall being secured to the portions projecting upwardly from the vertical walls of the console.

The vertical walls of the console may be provided with stamped slots or with cutouts arranged one behind the other. The direction of the stamped slots or of the cutouts arranged one behind the other preferably forms an angle of 45 +10 with that component of the impact force which is perpendicular to the axis of the steering wheel shaft.

In the case of an impact of the driver against the steering wheel, there takes place a deformation of the console and at the same time a displacement of the steering wheel shaft in conformity with the afforded damping of the deformation energy so that the console does not develop any rise of a peak value of the force during the course of the impact that should exceed the limit prescribed by the regulations.

The possibility of the steering wheel shaft getting stuck in a mounting supported by the console is diminished in the case of deformation of the console by an impact beacuse the component of the impact which acts perpendicularly to the shaft axis is diminished. It is therefore possible to use, in the case of the displacement of the steering wheel shaft, the deformation element that may be introduced into the lower part of the steering wheel shaft. An advantage of the safety steering mechanism according to the invention is the ease of manufacture and the low purchase cost.

An embodiment of a safety steering mechanism is by the way of illustration shown in the accompanying drawings where: Figure 1 shows a side view of the safety steering mechanism, Figure 2 is a plan view of the Figure 1, Figure 3 is an axonometric view of an alternative embodiment of the console of the safety steering mechanism, and Figure 4 is a schematic representation of the console of the safety steering mechanism with marked stamped slots extending parallel to the individual components of the impact force.

Referring to Figure 1, there is shown a steering wheel 1 fixed on the upper shaft part 2 of a steering wheel shaft assembly.

The upper shaft part 2 is connected by means of an upper joint 3 with a lower steering wheel shaft part 4. The lower steering wheel shaft part 4 is connected by means of a lower joint 5 with a steering gear 6. The lower steering wheel shaft part 4 is provided with a telescopic member 7 in which may be situated a deformation member. The upper steering wheel shaft part 2 is supported in bearings 8 carried by a console 9. The console 9 includes vertical spaced side walls 10 adjoining a cross wall 11. The walls 10 are provided with a pair of lug portions 12 to serve a purpose to be described later. At the moment of impact of the driver against the steering shaft the vertical side walls 10 are adapted to enable the console 9 to deform to an extent sufficient to absorb forces which act on the drivers chest. To this end the walls 10 are provided with lightening holes 13 and pressed portions in the form of ridges 14 which extend radially through the lightening holes 13. While ridges have been shown the portions could equally well comprise stamped slots or cut-outs. In the embodiment shown in Figures 1 and 2, two such ridges are provided extending at an angle of 45"f10" to the axis of the shaft part 2. The ridges 14 and the lightening holes 13 serve to reduce the rigidity of the console in the impact direction.

The embodiments shown in Figure 1 to 3 also include a housing for a steering lock, the embodiment shown in Figure 3 being similar to that shown in Figures 1 and 2 except that here only one lightening hole 13 is provided in each vertical side wall 10 but as in Figures 1 and 2 the ridges 14 extend at an angle of 45"f100 to the axis of the shaft part 2.

The housing comprises a transverse vertical wall 15 and a horizontal cross-wall 16 bent at right angles to the transverse wall 15. The cross-wall 16 is formed with a pair of bent-up vertical lugs 17 which are secured to the lug portions 12 on the vertical side walls 10 of console 9. This arrangement of fixing the housing of the steering lock to the console 9 in a plane which is parallel to the axis of steering wheel shaft 2, means that the outside of the forefront edges of the walls 10 of console 9 do not substantially increase the stiffness of the console.

The embodiment shown in Figure 4 differs from that shown in Figures 1 and 2, and 3 in that two ridges 14' and 14" are provided in each vertical wall 10 the first of these ridges, 14', extending in a direction parallel to the axis of the steering wheel shaft part 2 and opening at its lower end into a lightening hole 13, while the second of these ridges, 14", extends in a direction perpendicular to the axis of the shaft part 2.

As shown in Figure 4 the impact force P can be resolved into a component P0 extending in the direction of the axis of the shaft part 2, and hence parallel to the ridge 14', and a component Pk extending perpendicular to the component P0 and hence parallel to the ridge 14". A decrease in the stiffness of the console in the direction of the component P0 is achieved by the ridge 14" while a decrease in the stiffness of the console in the direction of the component Pk is achieved by the ridge 14'.

Referring back to Figures 1, 2 and 3 it will be seen that by providing the ridges 14 extending at an angle of 45"+10" to the axis of the shaft part 2 a reduction in the stiffness of console 9 in the directions of the impact force components P0 Pk is achieved.

It is not necessary that the pressed portions of the vertical walls 10 be in the form of ridges as shown.

WHAT WE CLAIM IS: 1. A motor vehicle safety steering mechanism comprising a steering wheel, a steering wheel shaft which is one part or a plurality of parts connected together by one or more joints, the shaft being connectible at its lower end to the steering gear of the vehicle, a console enabling the shaft to be mounted at its upper end on the body of the vehicle, the console including longitudinally extending vertical side walls and a longitudinally extending upper wall adjoining each side wall, the vertical side walls of the console being provided with pressed portions and/or lightening holes to decrease the stiffness of the console, each vertical wall being provided with a portion projecting upwardly clear of the upper wall of the console, there being a steering lock housing including a vertical wall extending transversely across the front edges of the vertical walls of the console near the upper end of the steering wheel shaft, the housing being secured to the console only by means connected to the transverse wall being secured to the portions projecting upwardly from the vertical walls of the console.

2. A mechanism as claimed in claim 1, in which the means for securing the housing to the portions includes a horizontal cross-wall bent at right-angles to the transverse wall and formed with a pair of spaced upwardly projecting lugs, each of which is secured to those portions projecting upwardly, from the side walls of the console.

3. A mechanism as-claimed in claims 1 or 2, in which the pressed portions comprise ridges.

4. A mechanism as claimed in claims 1 or 2 in which the pressed portions comprise stamped slots.

5. A mechanism as claimed in claims 1 or 2, in which the pressed portions comprise cut-outs arranged one behind the other.

6. A mechanism according to any of the claims 3 to 5, characterized in that the direction of the ridges, stamped slots or of the cut-outs arranged one behind the other forms an angle of 45"+10" to that component of an impact force which is perpendicular to the axis of the steering wheel shaft.

7. A motor vehicle safety steering mechanism, substantially as described herein with reference to the accompanying drawings.

8. A motor vehicle provided with the safety steering mechanism claimed in any of the preceding claims.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. these ridges, 14", extends in a direction perpendicular to the axis of the shaft part 2. As shown in Figure 4 the impact force P can be resolved into a component P0 extending in the direction of the axis of the shaft part 2, and hence parallel to the ridge 14', and a component Pk extending perpendicular to the component P0 and hence parallel to the ridge 14". A decrease in the stiffness of the console in the direction of the component P0 is achieved by the ridge 14" while a decrease in the stiffness of the console in the direction of the component Pk is achieved by the ridge 14'. Referring back to Figures 1, 2 and 3 it will be seen that by providing the ridges 14 extending at an angle of 45"+10" to the axis of the shaft part 2 a reduction in the stiffness of console 9 in the directions of the impact force components P0 Pk is achieved. It is not necessary that the pressed portions of the vertical walls 10 be in the form of ridges as shown. WHAT WE CLAIM IS:

1. A motor vehicle safety steering mechanism comprising a steering wheel, a steering wheel shaft which is one part or a plurality of parts connected together by one or more joints, the shaft being connectible at its lower end to the steering gear of the vehicle, a console enabling the shaft to be mounted at its upper end on the body of the vehicle, the console including longitudinally extending vertical side walls and a longitudinally extending upper wall adjoining each side wall, the vertical side walls of the console being provided with pressed portions and/or lightening holes to decrease the stiffness of the console, each vertical wall being provided with a portion projecting upwardly clear of the upper wall of the console, there being a steering lock housing including a vertical wall extending transversely across the front edges of the vertical walls of the console near the upper end of the steering wheel shaft, the housing being secured to the console only by means connected to the transverse wall being secured to the portions projecting upwardly from the vertical walls of the console.