GB2464490A

GB2464490A - Impact failing actuating lever for clamping device of adjustable steering column

Info

Publication number: GB2464490A
Application number: GB0818958A
Authority: GB
Inventors: James Peter Bentley; John Lowe; Raj Sikotra
Original assignee: NSK Steering Systems Europe Ltd
Current assignee: NSK Steering Systems Europe Ltd
Priority date: 2008-10-16
Filing date: 2008-10-16
Publication date: 2010-04-21
Anticipated expiration: 2028-10-16
Also published as: GB0818958D0; GB2464490B

Abstract

The actuating lever 1 for a clamping device for an adjustable steering column of a vehicle is formed in two parts 2,3 with a part and/or zone 5 of a frangible material that is designed to fail in the event of an overload by impact of the driver or occupant of the vehicle during a collision. The part/zone 5 may have a known shear strength and may be used as an interface between the two parts 2,3 of the actuating lever 1. The frangible material 5 may have one section cut away to weaken the connection between the two parts 2,3 in order to effect the softening of any breakaway peak load. The lever 1 may be rotatable about an axis that has the clamping device attached to it. The lever 1 may have one part 3 forming a free end that can be gripped by the driver to release and engage the clamping device. The part/zone 5 designed to fail may include one or more shear pins 6 that may be provided of different section to provide a pre-calculated shear strength. The shear pins 6 may be integral to one of the parts 2,3 of the lever 1 or may be over-moulded on the other part 2,3. The lever 1 may be in the form of a pressed lever. The device is intended to reduce injury, in particular knee injuries, and inhibit loads on the actuating lever 1 in the event of car crash.

Description

ACTUATING LEVER FOR CLAMPING DEVICE

FOR ADJUSTABLE STEERING COLUMN

This invention relates to an actuating lever for a clamping device for an adjustable steering column of a vehicle.

Vehicle steering columns which are adjustable in a rake and/or reach direction normally are retained in a desired position by means of a releasable clamping device. The clamping device is operated by an actuating lever coupled to the clamping device and controlled by the vehicle driver.

The actuating lever is often a sturdy component that is designed to withstand repeated operations. The lever also has to be sufficiently robust to sustain a degree of unintended loads that may be categorised as abuse.

However, with these considerations, the lever can become strong enough to be the source of driver or occupant injury in the event of a collision of the vehicle.

It is desirable that loads on the lever in a specified direction should cause the lever to break or bend, to prevent driver or occupant injury.

A known form of lever is disclosed in WO 03018384, the lever disclosed incorporating a buckling point which tends to change the shape of the lever in the event of an impact.

According to the present invention, there is provided an actuating lever for a clamping device for an adjustable steering column of a vehicle, the lever itself including a part and/or zone of a material designed to fail in the event of an overload by impact of an occupant of the vehicle during a vehicle collision, thereby serving to inhibit or reduce injury, said part or zone including frangible material.

Preferably, the part or zone of frangible material is of a known shear strength. This part or zone can therefore be used as an interface between two parts of the actuating lever.

The invention also extends to an adjustable steering column assembly for a vehicle incorporating such an actuating lever.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:-Fig. 1 is a diagrammatic side view of an actuating lever for a clamping device for an adjustable steering of a vehicle, Fig. 2 is a diagrammatic view illustrating one form of connection between two parts of the actuating lever, Fig. 3 shows another possible way of connecting the two parts of the lever, Fig. 4 shows another possibility, and Fig. 5 is a view similar to Figure 1 of a variant.

Referring to the drawings, an actuating lever 1 for a clamping device (not shown) of an adjustable steering column assembly is shown. The lever 1 is formed in two parts 2,3 and is rotated about an axis 4. The clamping device is connected via the axis 4. The part 3 of the lever 1 forms the free end of the lever which is the part of the lever gripped by the driver to release and clamp the clamping device when adjustment of the steering column is desired.

The lever 1 is designed to be strong enough to withstand repeated operations and is also designed to be sufficiently robust to sustain a degree of unintended loads that may be categorised as abuse.

However, in order to permit the lever to break to prevent driver or occupant injury in the event of vehicle crash, a part or zone 5 is provided between the two parts 2,3 of the lever, this part or zone 5 including frangible material of a known shear strength.

This part or zone 5 may include one or more shear pins 6.

The or each shear pin 6 therefore acts as a form of "fuse" material that would fail when a force of a predetermined value is applied to it.

By using identical shear pins 6 (or other similar means) or by using pins of different section, the "fuse rating" can be carefully adjusted to achieve the desired reaction upon impact.

Arrow A in Fig. 1 shows the direction of rotation of the lever 1 and Arrow B indicates the general direction and location of where a load could be expected to be applied by the knee of a driver or by another occupant of the vehicle in the event of vehicle crash which is sufficient to cause the frangible material to shear.

Fig. 2 shows a version of moulded actuating lever where the shear pins are incorporated as an integral part of one or other side 2, 3 of the lever 1.

Fig. 3 shows a version where the grip part 3 of the lever is over-moulded on the part 2, whilst Fig. 4 shows the basic form of a pressed lever with the shear pins 6 between the parts 2 and 3.

Fig. 5 shows a variation of the example shown of the profile of part of the lever of Fig. 1. By the dotted lines, it can be seen that at least one section 7 of the underlying material at the zone 5 can be cut away, thereby weakening the connection between the two parts 2, 3. This is intended to have the effect of softening the breakaway peak load.

It will be appreciated that the present actuating lever provides a breakaway facility for knee protection of the driver in the event of a vehicle collision.

Claims

Claims 1. An actuating lever for a clamping device for an adjustable steering column of a vehicle, the lever itself including a part and/or zone of a material designed to fail in the event of an overload by impact of an occupant of the vehicle during a vehicle collision, thereby serving to inhibit or reduce injury, said part or zone including frangible material.
2. An actuating lever according to claim 1, wherein the part or zone of frangible material is of a known shear strength.
3. An actuating lever according to claim 2, wherein the part or zone of frangible material is used as an interface between two parts of the actuating lever.
4. An actuating lever according to claim 3, wherein the frangible material has at least one section which is cut away, thereby weakening the connection between the two parts of the lever in order to effect the softening of any breakaway peak load.
5. An actuating lever according to any one of the preceding claims, wherein it is rotatable about an axis, with the clamping device being connectable via the axis.
6. An actuating lever according to any one of the preceding claims, wherein the lever has one part which forms a free end that can be gripped by a driver to release and clamp the clamping device.
7. An actuating lever according to any one of the preceding claims, wherein the part and/or zone of the material designed to fail includes one or more shear pins.
8. An actuating lever according to claim 7, wherein shear pins may be provided of different section to provide a pre-calculated shear strength.
9. An actuating lever according to claim 2 and claim 7 or 8, wherein the or each shear pin is incorporated as an integral part of one or other part of the lever.
10. An actuating lever according to claim 3 or any one of claims 4 to 9 as appendant to claim 3, wherein one part of the lever is over-moulded on the other part.
11. An actuating lever according to claim 3 or any one of claims 4 to 9 as appendant to claim 3, wherein the lever is in the form of a pressed lever.
12. An adjustable steering column assembly for a vehicle incorporating an actuating lever according to any one of the preceding claims.