Apparatus for connecting adjustable reach steering column to impact actuated means

Abstract: A vehicle steering column (1) incorporates a device (2) to allow manual reach adjustment of the steering column. Means (3) is provided to pull the steering wheel away to one side of the driver in the event of an impact of the vehicle. Two legs (6, 7) one connected to the steering column assembly and the other to the pulling cable (3) each have along one edge ramps (6a, 7a) and opposite edges have serrated portions (6b, 7b). One leg is inverted relatively to the other so that they mate with ramps of one leg nesting in valleys defined by the ramps of the other leg. A shear element (8) secures the legs normally. The legs are located by two guide rails (9) in a serrated block assembly (10) with its serrations (10a) lying closely adjacent but normally clear of serrations (6b, 7b). Upon vehicle impact, the cable (3) is pulled and the leg (7) tries to separate from the other leg (6), the shear element (8) breaks and the serrations on the legs lock into the serrations of the serrated block assembly (10). Further pulling continues to pull the whole assembly.

Description: This invention relates to an apparatus for connecting an adjustable reach steering column to means for moving, in use, the steering column away from a driver in the event of an impact of the vehicle in which the steering column is mounted. A means is known which is designed to pull a steering wheel column away from the driver in the event of an impact of the vehicle, the means acting in such a manner to pull the steering wheel to one side of the driver. DE-A-3 642 437 discloses an apparatus for connecting an adjustable reach steering column to means which moves the steering column away from the driver in the event of vehicle impact. The apparatus has a part for connection to the steering column to allow axial adjustment and another part for connection to the means for moving the steering column away from the driver. The apparatus incorporates a locking device which acts to prevent relative axial movement between the steering column and the first part upon actuation of said means upon vehicle impact, thereby to allow said means to act as intended on the steering column. According to the present invention, there is provided an apparatus for connecting an adjustable reach steering column to means for moving, in use, the steering column away from a driver in the event of an impact of the vehicle in which the steering column is mounted, the apparatus having a first part for connection to the steering column in such manner as to allow axial adjustment of the steering column relative to said first part and a second part for connection to said means, and the two parts incorporating a locking device which acts to prevent relative axial movement between the steering column and said first part upon actuation of said means upon vehicle impact thereby to allow said means to act as intended on the steering column; characterised in that said first part and said second part are in the form of two flat legs, each leg having serrations along at least part of the length of one edge thereof and ramp portions along the opposite edge, the legs being so arranged that, when one of the legs is inverted relatively to the other, the two parts mate together by means of their ramps in the event of said impact. A shear element can be provided interconnecting the two legs to keep them normally in a nesting relationship with one another. It is therefore the outer edges of the two legs which are provided with the serrations and the two legs are mounted in a serrated block assembly and located by guide rails. The serrated block assembly is of such dimensions that its serrations and the serrations on the two legs do not normally interfere with one another, i.e. there is a small clearance between them. The block assembly is fixed so that, upon vehicle impact, the second part is pulled by said means and this causes the shear element to shear, thereby allowing the ramps of the leg of the first part to ride up over the ramps of the leg of the second part thereby to engage the serrations of the two legs with the serrations of the block assembly. Thus the first and second parts, along with the steering column to which the first part is connected, is caused to be pulled by said means. 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:- Figure 1 is a plan view of a vehicle steering column incorporating manually operable means to adjust the reach of the steering column, Figure 2 is a side view of the steering column shown in Figure 1 incorporating an apparatus according to the present invention, Figure 3 is an end view viewed generally on the line III-III in Figure 2, Figure 4 is an enlarged side view of the apparatus according to the invention before activation caused by impact of the vehicle, Figure 5 is a diagrammatic sectional view taken on the line V-V in Figure 4, and Figure 6 is a view of part of the apparatus shown in Figure 4 after activation caused by vehicle impact. Referring to the drawings, a vehicle steering column 1 incorporates a device 2 which allows the steering column to be manually adjustable by the driver in terms of reach to obtain the most comfortable position of the steering wheel for the driver concerned. This adjustable reach apparatus is known and will not be described further. Also known is a means to pull the steering wheel away to one side of the driver in the event of an impact of the vehicle. Again, it is not necessary to describe details of this further, save for the fact that part of the means is a cable 3 which is connected at one end to the steering column 1 and which is pulled by another part of the means in the event of vehicle impact. In Figures 2 and 4, the cable 3 is pulled to the left. The apparatus according to the present invention incorporates a first part which is anchored to the steering column assembly and, in the embodiment illustrated, is anchored to a lock handle bolt 4 of a lock handle 5 and a second part which is anchored to the pulling cable 3. In more detail, as best viewed in Figures 4 to 6, the apparatus comprises two legs 6 and 7 which are substantially identical. Each leg has along one edge a series of ramps 6A, 7A, respectively. The opposite edges of each leg have serrated portions 6B and 7B, respectively. As shown in Figure 4, when one leg is inverted relatively to the other, the two legs will mate with the ramps 6A nesting in valleys defined by the ramps. The two legs are held together in nesting relationship by a shear element 8 welded or otherwise secured to the legs. The legs are located by two guide rails 9 in a serrated block assembly 10 with its serrations 10A lying closely adjacent but normally clear of the serrations 6B and 7B along part of the length of the serrations on the legs 6 and 7. The serrated block assembly 10 is fixed in a bracket 11 which is welded or otherwise joined to an outer tube 12 forming part of the steering column itself. The tube 12, bracket 11 and the block assembly 10 is normally allowed to be adjustable in a linear direction over some 60 mm and because of the clearance, which is about 0.5 mm either side of the leg serrations 6A and 7B, the assembly of the tube, bracket and block can be adjusted over the legs 6 and 7 as, for example, shown by an alternative position indicated in dashed lines in Figure 4. At all times, however, the serrations 10A lie close to some of the serrations 6B and 7B. As already mentioned, one end of the leg 7 is attached to one end of the crash pull cable 3 and the end of the leg 6 remote from the end of the leg 7 just mentioned is anchored to the lock handle bolt 4. Referring to Figure 6, when the vehicle experiences impact, the means for moving the steering column away from the driver is activated by sudden pulling on the cable 3. The leg 7, with its ramps which are at about 45°, tries to separate from the leg 6. The shear element 8 breaks and the leg splines or serrations 6B and 7B lock into the splines or serrations of the serrated block assembly 10. Further pulling effort by the cable 3 continues to pull the whole assembly coupled to the steering column, including the two legs, the block assembly 10, the bracket 11, the tube 12 and the lock handle bolt 4.

Claims: An apparatus for connecting an adjustable reach steering column (1) to means (3) for moving, in use, the steering column away from a driver in the event of an impact of the vehicle in which the steering column is mounted, the apparatus having a first part (6) for connection to the steering column in such manner as to allow axial adjustment of the steering column relative to said first part and a second part (7) for connection to said means, and the two parts incorporating a locking device (6A,B; 7A,B; 10) which acts to prevent relative axial movement between the steering column and said first part upon actuation of said means (3) upon vehicle impact thereby to allow said means to act as intended on the steering column; characterised in that said first part and said second part are in the form of two flat legs (6, 7), each leg having serrations (6B, 7B) along at least part of the length of one edge thereof and ramp portions (6A, 7A) along the opposite edge, the legs being so arranged that, when one of the legs is inverted relatively to the other, the two parts mate together by means of their ramps in the event of said impact. An apparatus according to claim 1, wherein said first and second parts are substantially identical. An apparatus according to claim 1 or 2, wherein a shear element (8) is provided interconnecting the two legs to keep them normally in a nesting relationship with one another. An apparatus according to claim 1, 2 or 3, wherein the legs are mounted in a serrated block assembly (10) and located by guide rails (9), the serrated block assembly being of such dimensions that its serrations and the serrations on the two legs do not normally interfere with one another. An apparatus according to claim 4, wherein the block assembly (10) is fixed so that, upon vehicle impact, the second part (7) is pulled by said means and this causes the shear element (8) to shear, thereby allowing the ramps of the leg of the first part (6) to ride up over the ramps of the leg of the second part, thereby to engage the serrations of the two legs with the serrations of the block assembly. A vehicle incorporating apparatus according to any one of the preceding claims.

Inventors: BARTON LAURENCE GEORGE, HANCOCK MICHAEL THOMAS, BARTON, LAURENCE GEORGE, HANCOCK, MICHAEL THOMAS
Applicants: TORRINGTON CO, THE TORRINGTON COMPANY LIMITED
Application year: 1992
Main classification: B62D1
IPC codes: B62D1