GB2246289A

GB2246289A - A vehicle seat

Info

Publication number: GB2246289A
Application number: GB9016424A
Authority: GB
Inventors: Tony Jonsson; Ingemar Stig
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1990-07-26
Filing date: 1990-07-26
Publication date: 1992-01-29
Also published as: GB9016424D0

Abstract

A structural element for a vehicle seat consists of two parts which abut to define a hollow elongate element. The two parts define projecting flange portions which project outwardly from the rest of the hollow element. The flange portions are interconnected by spot welding or by punch rivets. In a preferred embodiment, one part comprises a flat plate and the other part comprises a channel, the side walls of the channel carrying outwardly directed flange portions. The edges of the flat plate are secured to the outwardly directly flange portions. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO A VEHICLE SEAT.

The present invention relates to a vehicle seat and relates to a structural element for use in creating a vehicle seat.

It is desirable for a vehicle seat, and particularly the back of a vehicle seat, to be relatively strong. The reason for this is that a seat can be subjected to severe forces during an accident involving the motor vehicle. For example, if a person travelling behind the seat in question is not restrained by a safety belt, in the event that an accident arises, that person may travel forwardly, relative to the seat, at a rapid rate, and may impinge with the back of the seat.

The back of the seat should be strong enough to withstand the force of such an event, since otherwise the back of the seat will move forwardly under the force applied to the seat from the rear, thus serving to apply further compressional force to the person occupying that seat, who will be restrained in position by the seat belt.

Also it is to be appreciated that it has been proposed to mount the retractor reel for a safety belt actually in the back of the seat at a position adjacent the shoulder of the person wearing the safety belt, in order to obviate the use of a pillar loop and a floormounted safety belt. This provides a desirable cost saving, in that the cost of the pillar loop will not be incurred, and also minimises the length of safety belt, since the length of belt extending from the floor to the pillar belt need not be provided. Thus further reduces the cost of the safety belt assembly and also reduces problems that arise from the elasticity of the safety belt.However, if the retractor reel for a safety belt is to be mounted in the seat of the motor vehicle, it is to be clearly understood that the seat of the motor vehicle must be strong enough to withstand the forces applied thereto when an accident arises.

It is thus desired that the back of the seat of a motor vehicle should be as strong as possible, but yet should be manufactured in an economic and convenient manner.

It has been proposed previously to utilize structural elements in the back of a seat in the form of an open lTUfl section channel. A problem with a channel of this type is that the channel may well not be sufficiently strong to withstand the forces that may be applied to the seat, unless the channel is made very thick, thus leading to a heavy weight and a significant price.

It has been proposed previously, as illustrated in cross-section in Figure 1, to provide a structural element for a motor vehicle seat in the form of a closed box profile, comprising two inter-nested "U" section profiles which are seam welded. Two such profiles 1,2 are illustrated in Figure 1, these profiles being seam welded together at points 3,4. Production of such a beam is slow and expensive.

The present invention seeks to provide an improved motor vehicle seat and an improved element for use in manufacturing a motor vehicle seat.

According to this invention there is provided a structural element for a vehicle seat, the structural element comprising two parts, the two parts abutting to define a hollow elongate element, the two parts defining projecting flange portions which project outwardly from the rest of the hollow element, the flange portions being inter-connected.

Preferably the flange portions are interconnected by spot welding.

Conveniently the flange elements are interconnected by means of punch-rivets.

In one embodiment one part comprises a flat plate and the other part comprises a channel element, the side walls of which carry outwardly directed flange portions.

Preferably at least one of the flanges is substantially co-planar with one side of the element.

Conveniently the structural element defines a central cavity which is substantially rectangular, one of the side walls of the cavity being formed of two inclined portions which are not parallel with the opposed side of the cavity.

Preferably the cavity is substantially rectan gular, two cooperating flanges being defined by the two parts substantially at the centre of one of the short sides of the cavity.

The invention also relates to a vehicle seat including at least one structural element as described above.

In order that the invention may be more readily understood, an so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 2 is a cross-sectional view of one elongate element for use in manufacturing a motor vehicle seat in accordance with the invention; FIGURE 3 is a diagrammatic view of a motor vehicle seat in accordance with the invention; FIGURE 4 is a cross-sectional view taken on the line A-A of Figure 3; FIGURE 5 is an enlarged view of the structural element illustrated in Figure Jl; FIGURE 6 illustrates the deformation of a box beam; and FIGURE 7 illustrates, in cross-section a punch rivet between two flanges.

Referring now to Figures 2 to 7 of the drawings, Figure 2 illustrates, in cross-section, an elongate element 5. The elongate element 5 is formed of two metal parts, namely a channel component 6, which presents a base 7, two parallel side walls 8,9, extending orthogonally to the base, and which terminate with two outwardly directed flanges 10,11 and a plate 12 having the opposed edges 1R,14 thereof aligned with the flanges 10 and 11. The edges 13,14 of the plate 12 are secured to the flanges 10 and 11 by means of spot welds 15,16. The resultant structure is relatively cheap to manufacture, but possesses a significant degree of strength. The production, utilizing spot welding, is much cheaper and quicker than utilizing seam welding as in the prior art arrangement illustrated in Figure 1.

Figure 3 illustrates a seat in accordance with the invention comprising a squab 17 and a back 18.

Figure 4 is a cross-sectional view of the back 18. It can be seen that located adjacent each side of the back is a vertically extending elongate structural element 19,20, these two elements effectively being mirrorimages of each other. The element 20 is shown in an enlarged form in Figure 5.

The element 20 is formed of two metal parts which are secured together, the parts presenting abutting flanges similar to those present in Figure 2. Thus the element 20 consists of a first Dart 21 presenting a substantially horizontal wall 22 terminating at one end with a flange portion 23, and being connected, at its other end, by means of a 900 corner 24, to a depending wall 25 which merges, at its lower end, with an inwardly directed downwardly inclined portion 26 which terminates with a vertically depending flange 27. The second part 28 of the element 20 comprises a horizontally extending flange portion 29 located beneath and abutting the flange portion 23, the flange portion 29 terminating at a corner 30 which extends to a downwardly extending portion 31, extending in spaced parallelism with the portion 25. The portion 31 merges with a downwardly and inwardly inclined portion 32 which again terminates with a downwardly extending vertical flange 33 aligned with and adjacent the flange 27.

It is to be noted that the two parts, when located adjacent one another as illustrated in Figure 5, define an elongate element having a substantially rectangular cavity therein. The two abutting flanges 23,29 are secured together by means of spot welds or the like, and the two depending flanges 27,33 are inter-connected in a similar way.

It is to be noted that the flange 23 is aligned with the uppermost wall 22 of the elongate element 20 when in the position illustrated in Figure 5. As can be seen from Figure 4 this facilitates the fabrication of the seat with a flat back 34, since the co-aligned flanges 23,29 extend substantially parallel with the back of the seat.

The downwardly and inwardly inclined portions 32,33 are inclined downwardly at an angle to the horizontal, as indicated, and the downwardly extending flanges 27,33 are located substantially centrally of the rectangular cavity. This arrangement provides an improved ability to resist deformation.

Figure 6 illustrates, in solid lines, a conventional rectangular beam 35, showing, in dotted lines, a typical deformation pattern for the beam. It will be understood that the arrangement of the- downwardly inclined portions 26,32 and the associated centrally located vertical flanges 27,33 will help resist deformation of this type, thus effectively increasing the operational strength of the elongate element. Also, having the flanges 27 and 33 located substantially at the centre of one of the short sides of the rectangular element helps the element resist deformation when exposed to a torque perpendicular to the beam and perpendicular to the long side walls 25,31.

Whilst reference has been made to the flanges being inter-connected by means of spot welding, it is to be apDreciated that the flanges may be inter-connected by means of punch-rivets. In forming a punch-rivet an appropriate die is located adjacent one flange, such as the flange 27' as illustrated in Figure 7, and a punch is located adjacent the cooperating flange 33'. The punch then oDerated to form a recess 36 in the flange 33', deforming the material of flange 33' and also deforming the material of the flange 27' into a cavity formed by the die. The result is that the two flanges are securely inter-locked due to the inter-engagement of the deformed regions of the flanges.

Whilst the invention has been described with reference to specific embodiments, it is to be appreciated that many modifications may be effected without departing from the scope of the invention as defined by the following claims.

Claims

CLAI:

1. A structural element for a vehicle seat, the structural element comprising two parts, the two parts abutting to define a hollow elongate element, the two parts defining projecting flange portions which project outwardly from the rest of the hollow element, the flange portions being inter-connected.

2. A structural element according to Claim 1 wherein the flange portions are inter-connected by spot welding.

3. A structural element according to Claim 1 wherein the flange elements are inter-connected by means of punch-rivets.

14. A structural element according to any one of the preceding Claims wherein one part comprises a flat plate and the other part comprises a channel element, the side walls of which carry outwardly directed flange portions.

5. A structural element according to any one of Claims 1 to 3 wherein at least one of the flanges is substantially co-planar with one side of the element.

6. A structural element according to any one of Claims 1 to 3 or Claim 5 wherein the structural element defines a central cavity which is substantially rectangular, one of the side walls of the cavity being formed of two inclined portions which are not parallel with the opposed side of the cavity.

7. A structural element according to any one of Claims 1 to 3, 5 or 6 wherein the cavity is substantially rectangular, two cooperating flanges being defined by the two parts substantially at the centre of one of the short sides of the cavity.

8. A vehicle seat including at least one structural element according to any one of the preceding Claims.

9. A structural element substantially as herein described with reference to and as shown in Figure 2 of the accompanying drawings.

10. A structural element substantially as herein described with reference to and as shown in Figures 4 and 5 of the accompanying drawings.

11. A vehicle seat substantially as hereinbefore described with reference to and as shown in Figures 4 and 5 of the accompanying drawings.

12. Any novel feature or combination of features disclosed herein.