WO2005039940A1

WO2005039940A1 - A seat belt arrangement

Info

Publication number: WO2005039940A1
Application number: PCT/SE2004/001530
Authority: WO
Inventors: Ola BOSTRÖM; Yngve Håland
Original assignee: Autoliv Development Ab
Priority date: 2003-10-28
Filing date: 2004-10-22
Publication date: 2005-05-06
Also published as: GB0325148D0; GB2407537A

Abstract

A seat belt arrangement (3) for use by the occupant of vehicle seat (1), the seat having at least one free side with no support to prevent lateral movement of the seat occupant during an impact includes a seat belt mount (11). The mount is configured so that the seat belt (10) emerging from the mount, which is on the free side of the seat, is substantially vertical. Part of the belt (10) as it passes the neck of the seat occupant presents a relatively large area in contact with the neck of the seat occupant, thus minimising the risk of neck injuries occurring.

Description

"A SEAT BELT ARRANGEMENT"

THE PRESENT INVENTION relates to a seat belt arrangement and more particularly relates to a seat belt arrangement provided to protect the occupant of the seat in a motor vehicle.

One conventional seat belt arrangement provided to protect a seat occupant in a motor vehicle is a so-called "3-point" seat belt arrangement. Such an arrangement typically incorporates a mount for a seat belt which is mounted on or at least associated with part of the side of the vehicle which is adjacent to the relevant seat. The mount may comprise a retractor, and may optionally include a belt guide. The seat belt emerges from the mount at a point above the seat on one side of the seat, which is the side closest to the side of the vehicle which is immediately adjacent the seat. In use, the seat belt extends diagonally across the chest or upper torso of the seat occupant, a tongue slideably mounted on the seat belt being received in a buckle to releasably receive the tongue which is mounted securely in position on the other side of the seat. The seat belt then passes across the lap of the seat occupant, the end of the seat belt being secured to an anchor point on the said one side of the vehicle seat.

Statistics shows that for a standard 3-point belt of this type a seat occupant is not very likely to become injured in the neck region due to interaction between the seat belt and the neck. It is believed that the reason for this is that the diagonally extending part of the seat belt passes adjacent that side of the neck of the occupant which is closest to the adjacent side of the vehicle. For the seat occupant to become injured in the neck area due to interaction with the belt the seat occupant must, during an accident, move towards the adjacent side of the vehicle with a substantial velocity. However, the very presence of the side of the vehicle immediately adjacent the seat occupant provides a degree of support for the seat occupant and prevents this rapid movement.

It has been proposed to provide a 3-point seat belt for a seat which is not adjacent the side of a vehicle such as, for example, the middle seat in a rear row of seats. A 3-point seat belt of this type is usually provided with a seat belt mount which is formed with or supported by the roof of the vehicle. The mount is located above the seat and to one side of the seat, possibly being located slightly rearwardly of the backrest of the seat. Typically the mount includes a retractor having a spool which rotates about a horizontal axis, so that the mount is unobtrusive. The seat belt emerges from the mount and passes diagonally across the chest or torso of the seat occupant to a buckle provided on the other side of the seat, with part of the belt then passing across the lap of the seat occupant to an anchorage. If no air-bags or other supports are provided which may act to prevent lateral movement of the seat occupant during an accident, or, in other words, if the side of the seat occupant on which the seat belt mount is provided is a "free" side, it would be possible for the seat occupant to move during an impact, with a substantial velocity, towards the free side of the seat, with a risk that the side edge of the belt would engage the neck of the seat occupant and give rise to injuries. There is a growing interest in the provision of a second seat belt for use with a conventional 3-point belt, the second belt comprising a single diagonally extending strap which crosses over the diagonal strap of the 3-point belt system. The seat belt arrangements of this type are known as "3+ 2-point" belt system. If a belt system of this type is used it is quite common for the 3-point belt of the system to be mounted in a conventional way, with the seat belt mount on or associated with the side of the vehicle, with the secondary or 2-point belt incorporating a seat belt mount which is provided above the inboard side of the seat, that is to say the side of the seat which is remote from the adjacent side of the vehicle. The side of the seat is a "free" side of the seat, in that there is no support to prevent lateral movement of the seat occupant during an impact situation provided on that side of the seat. Consequently with an arrangement of this type there is a risk that the seat occupant may move, with a substantial velocity, towards that side of the seat which is the free side of the seat, there again being the risk that the seat belt may cause injury to the neck of the seat occupant

Consequently in a 3-point seat belt as provided for a seat not adjacent the side of a vehicle, and with a "3+ 2-point" belt system there is a risk of neck injuries arising.

The present invention seeks to provide an improved seat belt arrangement.

According to this invention there is provided a seat belt arrangement for use by the occupant of a vehicle seat, the seat having at least one free side, the seat belt arrangement incorporating a seat belt having a seat belt mount, the mount being located above and to one side of the seat, said one side of the seat being a free side, the seat belt emerging from the mount, the mount being configured so that the part of the seat belt that emerges from the mount is vertical, +/- 15°, part of the belt being provided with a connector to engage a co-operating connector adjacent the other side of the seat.

A seat has a free side if that side of the seat is not provided with a separate support which acts to restrain the occupant of the seat from lateral movement during an impact. Examples of support which might be present include the side of the vehicle itself, or an air-bag, or other deployable device which, in response to an accident situation, becomes positioned adjacent the side of the seat to provide a support or restraint prevent, or at least reducing the risk of, the seat occupant from moving laterally.

Preferably the mount is configured so that the part of the seat belt emerging from the mount is substantially vertical.

Conveniently the mount incorporates a retractor, the retractor having a substantially vertical axis. Advantageously the seat belt mount incorporates a guide slot through which the seat belt emerges, the guide slot being substantially vertical.

In one embodiment the seat belt is a 2-point seat belt, the free end of the seat belt being provided with said connector to engage the co-operating connector adjacent the other side of the seat.

In an alternative embodiment the seat belt is a 3-point seat belt, part of the belt between the mount and an anchor point provided adjacent the said one side of the seat being provided with the said connector to engage said co-operating connector adjacent the other side of the seat.

Conveniently the said connector is a tongue on the belt and the co-operating connector adjacent the other side of the seat is a buckle adapted releasably to engage the tongue.

Preferably the seat belt mount is a roof mount. Alternatively the seat belt mount is formed integrally with the seat.

An embodiment of the invention may include both a 3-point belt and 2-point belt. Preferably the belt is provided with at least one region thereof which has a low elastic tension force such that 1 kN tension applied to that region of the belt will cause an extension of at least 15 mm per metre.

Conveniently at least one side of the seat belt is provided with the area of low elastic tension force.

Preferably two opposed sides of the seat belt are provided with the low elastic tension force. In order that the invention may be more readily understood, and 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 1 is a diagrammatic view of a seat belt arrangement in accordance with the invention;

FIGURE 2 is a view of part of the seat belt used in the seat belt arrangement of Figure 1;

FIGURE 3 is a diagrammatic view of an alternative embodiment of the invention; and FIGURE 4 is a diagrammatic view of another embodiment of the invention.

Referring initially to Figure 1 of the accompanying drawings a seat belt arrangement is provided, the seat belt arrangement being a so-called "3+ 2-point" belt arrangement.

The seat belt arrangement is provided to give protection for the occupant of the seat 1, the seat 1 being located adjacent a side 2 of the vehicle. The seat belt arrangement incorporates a conventional 3-point belt 3, the 3-point belt 3 incorporating a mount 4 which is at least partially mounted on the side 2 of the vehicle, from which part of the belt 5 emerges. The part 5 of the belt is configured to extend diagonally across the chest or torso of an occupant of the seat 1. A tongue 6 is mounted on the belt, to be releasably engaged by a buckle 7 which is mounted securely in position at a point on the other side of the seat 1, that is to say the side of the seat which is remote from the side 2 of the vehicle. This may be considered to be the "in-board" side of the seat. This is a "free" side of the seat, since no support is provided on this side of the seat to prevent lateral movement of the seat occupant. The safety belt 3 incorporates a further part 8 which extends from the tongue 6 across the lap of the seat occupant to an anchor point 9 provided on the in-board side of the seat 1 adjacent the side 2 of the vehicle. This 3-point safety belt is conventional.

The illustrated seat belt arrangement incorporates a secondary or 2-point safety belt 10. The 2-point safety belt 10 is mounted by means of a roof mount 11 which is secured to or formed with the roof 12 of the vehicle. The roof mount 11 incorporates a retractor mechanism and has a guide slot 13 through which the secondary belt 10 emerges from the mount. The retractor may incorporate a spool which rotates about a vertical axis. The slot 13 is shown to be vertical. The slot 13 may be inclined by up to 10° on either side of the vertical, but it is preferred for the slot 13 to be substantially vertical. Thus, the secondary belt 10, as it emerges from the mount, is constrained to be vertical or substantially vertical. The free end of the belt 10 is provided with a tongue 14 to be releasably engaged by a buckle 15 which is securely mounted in position on or adjacent the in-board side of the seat 1. The secondary belt 10 may thus be positioned to extend across the chest or torso of an occupant of the seat 1, crossing with the diagonally extending part 5 of the 3-point safety belt 3.

Because the secondary belt 10 is constrained to be substantially vertical as it leaves the mount, the belt 10 tends to remain substantially vertical as it passes the neck of the seat occupant. The belt, where it passes the neck will present a relatively large area in contact with the neck in contrast to many prior proposed arrangements where it is the edge of the belt, which may be relatively sharp, that is in contact with the neck, as the belt, in such prior arrangements, tends to have a large surface area in contact with the shoulder of the seat occupant.

Thus, should the seat occupant move towards the free side of the seat during an impact situation, the risk of the belt causing injury to the neck of the seat occupant is nrinimised.

It has been found that the risk of injury may further be rninimised if a belt is used that has a low elastic tension force, at least in the region of the belt which will lie adjacent the neck of a seat occupant when the belt is in use. The belt may have a low elastic tension force across the whole of its width, or may alternatively have a low elastic tension force in the area of the belt that is likely to be in contact with the neck. Thus the low elastic tension force may be provided in one or both side edges of the belt.

Figure 2 illustrates part of the belt 10 of the embodiment shown in Figure 1. The belt 10 has a central region 16 which is of conventional form, and two edge regions 17,18 which each have a low elastic tension force. In each region of low elastic tension force, the belt is formed so that one kN tension provides at least 15 mm of elongation per metre of webbing.

In deteπnining the low elastic tension force of a region of the safety belt, that region of the safety belt is tested in isolation from the remaining regions of the safety belt. Thus, the low elastic tension force applies solely to the two opposed side edges of the safety belt shown in Figure 2 and not the central region 16, meaning that the safety belt, taken as a whole, would not necessarily have the property that one lk of tension would provide 15 mm of elongation per metre over the entire width of the belt. Whilst the invention has been described, with reference to Figure 1, in connection with a "3+ 2-point" belt arrangement, in an alternative embodiment of the invention, a 3-point belt is provided for use by the occupant of the seat which has two free sides, exemplified by the central seat of a row of three seats.

Referring to Figure 3 of the drawings, a row of three seats 20,21,22 is illustrated. The central seat 21 is provided with a 3-point seat belt arrangement 23. The seat belt arrangement incorporates a mount 24 which is secured to or formed integrally with the roof 25 of the vehicle. The mount 24 includes a retractor arrangement, with the axis of the retractor being vertical. A guide slot 25 is provided which is substantially vertical +/-15⁰, (most preferably +/-10⁰) and part of the safety belt 23 emerges from the vertical slot 25 to pass adjacent the neck of the seat occupant. As in a conventional 3-point safety belt arrangement, the belt 23 carries a tongue 27 to releasably engaged by a buckle 28 provided adjacent the side of the seat which is remote from the seat belt mount, there being an anchorage 29 for the free end of the belt at a point on the same side of the seat as the seat belt mount.

It is to be appreciated that the mount 24 corresponds directly with the mount 11 described above, and again the seat belt 23 which passes diagonally across the chest or torso of the seat occupant will make a substantial area of contact with the neck of the seat occupant, when in use, thus minimising the risk of injury to the seat occupant. The seat belt of Figure 2 may be used in this embodiment.

Whilst the embodiments of Figure 1 and 3 incorporate the use of seat belt mounts which are the roof-mounted, it is to be appreciated that the precise position of the seat belt mount is not critical. Figure 4 illustrates, by way of example, a further seat belt arrangement in accordance with the invention, which is similar to the embodiment of Figure 1, in that it incorporates a 3-point belt 3 and a secondary or 2-point belt 10. However, in the embodiment of Figure 4, the mount 30 for the 3-point safety belt 3 is formed integrally with the seat 31, and similarly the mount 32 for the secondary or 2-point belt 10 is formed integrally with the seat 31. The seat of Figure 4 may be the central seat in a row of seat and thus both of the mounts 30 and 32 may be configured so that each of the seat belts emerges from the respective mount in a substantially vertical orientation. One or both of the belts may be as shown in Figure 2.

In the present Specification "comprises" means "includes or consists of and "comprising" means "including or consisting of.

Claims

CLAIMS:

1. A seat belt arrangement for use by the occupant of a vehicle seat, the seat having at least one free side, the seat belt arrangement incorporating a seat belt having a seat belt mount, the mount being located above and to one side of the seat, said one side of the seat being a free side, the seat belt emerging from the mount, the mount being configured so that the part of the seat belt that emerges from the mount is vertical, +/- 15°, part of the belt being provided with a connector to engage a co-operating connector adjacent the other side of the seat.

2. A seat belt arrangement according to Claim 1 wherein the mount is configured so that the part of the seat belt emerging from the mount is substantially vertical.

3. A seat belt arrangement according to Claim 1 or Claim 2 wherein the mount incorporates a retractor, the retractor having a substantially vertical axis.

4. A seat belt arrangement according to any one of the preceding Claims wherein the seat belt mount incorporates a guide slot through which the seat belt emerges, the guide slot being substantially vertical.

5. A seat belt arrangement according to any one of the preceding Claims wherein the seat belt is a 2-point seat belt, the free end of the seat belt being provided with said connector to engage the co-operating connector adjacent the other side of the seat.

6. A seat belt arrangement according to any one Claims 1 to 4 wherein the seat belt is a 3-point seat belt, part of the belt between the mount and an anchor point provided adjacent the said one side of the seat being provided with the said connector to engage said co-operating connector adjacent the other side of the seat.

7. A seat belt arrangement according to any one of the preceding Claims wherein the said connector is a tongue on the belt and the co-operating connector adjacent the other side of the seat is a buckle adapted releasably to engage the tongue.

8. A seat belt arrangement according to any of the preceding Claims wherein the seat belt mount is a roof mount.

9. A seat belt arrangement according to any one of the preceding Claims wherein the seat belt mount is formed integrally with the seat.

10. A seat belt arrangement according to any one of the preceding Claims including both a 3-point belt and 2-point belt.

11. A seat belt arrangement according to any one of the preceding Claims wherein the belt is provided with at least one region thereof which has a low elastic tension force such that 1 kN tension applied to that region of the belt will cause an extension of at least 15 mm per metre.

12. A seat belt arrangement according to Claim 11 wherein at least one side of the seat belt is provided with the area of low elastic tension force.

13. A seat belt arrangement according to Claim 11 wherein two opposed sides of the seat belt are provided with the low elastic tension force.