WO1995021753A1

WO1995021753A1 - A safety device in a motor vehicle to protect the head of a person

Info

Publication number: WO1995021753A1
Application number: PCT/SE1995/000136
Authority: WO
Inventors: Yngve Håland
Original assignee: Autoliv Development Ab
Priority date: 1994-02-11
Filing date: 1995-02-10
Publication date: 1995-08-17
Also published as: GB2286564B; GB2286564A; GB9402725D0

Abstract

A safety arrangement in the motor vehicle comprises a curtain (6) initially retained within the roof (4) of the motor vehicle. A wire (7) extends from a fixed point across the bottom of the curtain to a piston associated with a gas generator (10) and a cylinder (9). The gas generator is activated in response to a side impact, applying tension to the wire (7), pulling down the curtain (6) so that the curtain occupies a position between the head of a person in the vehicle and the window, thus minimising movement of the head.

Description

A safety device in a motor vehicle to protect the head of a person.

THE PRESENT INVENTION relates to a safety arrangement and more particularly relates to a safety arrangement mounted in a motor vehicle such as a motor car.

Many safety arrangements have been proposed to be included in a motor vehicle such as a motor car in order to reduce the risk of injury to a person present in the car if an accident arises. Some of the safety devices are specifically intended to reduce the risk of injury in the case that a specific type of accident should arise.

For example, safety devices have been proposed previously which are intended to minimise the risk of injury to a person in a motor vehicle if the motor vehicle is subjected to a side impact. A side impact can arise if the driver of the vehicle loses control and the side of the vehicle impacts a stationary object (such as a tree or a building) or another vehicle, and also a side impact can arise, especially at a cross-roads, if another vehicle collides with the vehicle in question.

Investigations of such accidents have shown that life-threatening injuries are received mainly by the head, the chest and abdomen/pelvis. Research has found that the chest and abdominal/pelvic injuries can be significantly reduced by a combination of a side air-bag for the chest and abdomen and padding in the pelvic/thigh area. It has been found that life-threatening injuries to the head are often caused by impacts to objects which are external to the motor vehicle in question, like a tree or building with which the vehicle has effected a side impact, or the front part of another vehicle that has crashed into the vehicle in question, for example at a cross-roads. It has been concluded that the risk of head injuries would be reduced if the head could be retained within the outer profile of the motor vehicle during a side collision.

Research has also shown that in side impacts there are quite a lot of neck injuries. Various tests have shown that the maximum moment of the force applied to the neck by the head during lateral flection occurs relatively early, when the head is rotated by not more than 10 to 20°.

It has been proposed to provide an air-bag specifically to protect the head of an occupant of a motor vehicle during a side impact. In one such prior arrangement the air-bag was initially mounted within part of the seat, emerging from the side of the seat, when inflated, to occupy the space between the torso and the head of the person sitting in the seat, and the adjacent door of the vehicle.

Another prior arrangement is shown in DE-A- 4,238,427 where an air-bag is provided mounted in the roof of the motor vehicle which, when inflated, lies between the window, forming part of the door of the vehicle, and the head of the person within the vehicle. A restraint is provided located between the air-bag and the window to retain the air-bag in position in the event that the window should break. Similarly, in DE-A-4,137,749 an air-bag is provided which, in the uninflated state, is mounted within the lower part of the door of a motor vehicle, the air-bag, when inflated, being located between the body and head of a person sitting in a motor vehicle, and the door of the motor vehicle. A retracted net is provided which is initially mounted on part of the door adjacent the window, but which moves to an extended position in which the net is located between the air-bag and the window to retain the air-bag in position should the window break.

A disadvantage with a side air-bag adapted to restrain the head of a person sitting in a motor vehicle is that if the head of the person is initially "out of position" (for example, is leaning towards the window) , the air-bag, during inflation, can impact the head and move it laterally very swiftly, away from the window. This can impart significant injuries to the neck.

The present invention seeks to provide an improved safety arrangement.

According to this invention there is provided a safety device in a motor vehicle to protect the head of a person sitting in the motor vehicle, the safety device comprising a curtain, the curtain initially being located in the body of the motor vehicle adjacent a side door, means being provided to pull the curtain to occupy a position between the head of a person in the motor vehicle and the side door of the motor vehicle in response to a side impact so that the head of the occupant of the vehicle may directly engage the curtain to restrict movement of the said head. Preferably as the curtain is pulled to occupy said position, the curtain does not move laterally towards said person.

Preferably the curtain is pulled down by a device which responds to a sensor which senses a side impact. Conveniently the device comprises a piston within a cylinder associated with a gas generator adapted to move the piston along the cylinder. Advantageously the device is connected to a wire, the wire being connected to the curtain to pull the curtain in response to a side impact. Advantageously the wire extends from the device to the lower edge of the curtain, then extending across the lower edge of the curtain and terminating at a fixed position.

Conveniently the wire is guided by guide means.

The gas generator and cylinder means may be located on the "B"-Post of the motor vehicle, on the door sill of the motor vehicle or in the roof of the motor vehicle.

Preferably the curtain is initially retained in a recess provided at least partly in the roof of the motor vehicle.

Advantageously the recess is provided at least partly in the "A"-Post of the motor vehicle.

Conveniently the curtain is formed from a polyamide fabric.

Advantageously the curtain, when in said position, is located no more than 80 millimetres from said window. Preferably the curtain, when in said position,is located between 30 and 50 millimetres inside the said window.

Conveniently a locking mechanism is provided to retain the curtain in the said position.

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 schematic elevational view of a safety device in accordance with the invention ready for use,

FIGURE 2 is a view corresponding to Figure 1 showing the safety device in use,

FIGURE 3 is a sectional view taken on the line A-A of Figure 2,

FIGURE 4 is a view corresponding to Figure 2 illustrating a modified embodiment of the invention, and

FIGURE 5 is a view corresponding to Figure 2 illustrating yet another modified embodiment of the invention.

Referring initially to Figure 1 of the accompanying drawings, part of a motor vehicle is illustrated comprising a door 1 which is provided with a window 2. The door is the front door of the motor vehicle and is surrounded by the "A"-Post 3, part of the roof 4 of the vehicle and the "B"-Post 5.

A curtain 6 is provided which is made of a polyamide fabric, such as is typically used for the manufacture of an air-bag. The curtain 6 is initially in a folded or retracted state within an appropriate cavity formed partly in the roof 4 and partly in the "A"-Post 3. One edge of the curtain is secured to the cavity and the opposed edge of the curtain is connected to a steel wire 7. One end 7' of the steel wire is secured to the "A"-Post 5. The steel wire 7, in an initial condition of the apparatus as shown in Figure 1, emerges from the end of the cavity retaining the curtain 6 which is adjacent the "B"-Post 5, and passes a guide means in the form of a guide peg 8, the wire being connected to a piston present within a tube 9 which is associated with a gas generator 10.

The gas generator is associated with a sensor 5 adapted to sense a side impact. When the gas generator is activated by the sensor the piston is moved down the tube 9, thus applying tension to the wire 7.

Referring to Figure 2 it can be seen that when tension is applied to the wire 7, the wire moves downwardly as indicated by the arrow 11, thus withdrawing the curtain 6 from its initial position, so that the curtain is then stretched tightly in position across the upper part of the window 2.

If reference is made to Figure 3, it can be seen that the curtain 6 is spaced from the glass of the window 2, the preferred spacing being between 30 and 50 millimetres. The minimum spacing is 25 millimetres, and the maximum preferred spacing is 80 millimetres. If the spacing is less than 25 millimetres there is an appreciable risk that the curtain may be deflected so that the head of a person sitting near the curtain will impact on the window. If the spacing is more than 80 millimetres, there is an appreciable risk that when the curtain is activated it will engage the head of a person sitting near the window, or it will move the head of such a person laterally towards the centre of the vehicle.

The recess 11 that initially accommodated the curtain 6 is visible in Figure 3.

It can be seen, from the phantom figure of a person 12 in Figure 3, that when the curtain 6 is in the extended position, the head 13 of the person 12 will directly engage the curtain and will be restrained by the curtain. A locking mechanism L associated with the gas generator and piston arrangement ensures that the wire 7 is retained in position when the piston has moved to its full extent, thus retaining tension within the curtain 6.

The curtain 6 will thus directly engage the head 13, whilst the head is still typically between 30 and 50 millimetres away from the interior of the side window 2, thus ensuring that the head only moves a minimal extent. Since the curtain is maintained in position by the locking mechanism L, the curtain will provide protection should a second side impact occur or if the vehicle rolls over.

It is to be noted that during a side impact, if the impact occurs in the lower part of the door 1, the upper part of the door can actually move outwardly. The curtain, in the described embodiment of the invention, is connected to parts of the frame of the vehicle, and is not connected to the door. Thus the curtain is connected to part of the roof and part of the "A"-Post, whilst the remaining components are mounted on the "B"-Post. It is found that typically these parts are not subject to the same degree of deformation as is the door of the vehicle. Thus, even if the door is deformed, the curtain will be in the desired position.

In the described embodiment, tension is applied to the wire 7 by a pyrotechnic charge 10 within a gas generator associated with a piston present within a cylinder 9. The piston should have a considerable mass to ensure that it moves the full length of the tube 9, should the burning time of the pyrotechnic charge be insufficient. Typically, the piston will move down the tube by a distance of between 150 and 200 millimetres in a short period of time, typically between 5 and 10 ms. The pyrotechnic charge may be a nitro-cellulose based charge having a mass of typically 1 gram.

In modified embodiments of the invention, alternative means may be used to impart tension to the steel wire 7. For example, a mechanism may be utilised which comprises a compressed spring, the spring being released when a sensor senses a side impact, to impart tension to the wire 7.

Figure 4 of the accompanying drawings illustrates a modified embodiment of the invention which is very similar to the embodiment of Figure 1 save that the gas generator 10 and the tube 9 are located in position in the door sill 14 of the motor vehicle. This may avoid undesirable bulges in the "B"-Post 5. The wire, in the embodiment of Figure 4, is guided not only by the guide pin 8 but also by a further guide pin 15 located at the bottom of the "B"-Post 5. Figure 5 illustrates yet another modified embodiment in which the gas generator 10 and the associated tube 9 are mounted in the roof 4 above the door 1. In this case, the wire 7 is guided not only by the guide pin 8 but also by a further guide pin 16 located at the upper extremity of the "B"-Post 5.

Whilst in the described embodiments of the invention the curtain is described as being made of a thin polyamide fabric, it is to be noted that the curtain may be made of any appropriate fabric, or may be made of a sufficiently strong sheet of polymer material, or may be made in the form of a net.

Whilst in the described embodiments of the invention, the lower edge of the curtain is connected to a wire 7, one end of which is fixed in position, it is to be appreciated that in an alternative embodiment of the invention a wire extending across the bottom of the curtain may have both ends thereof connected to either the same gas generator and piston assembly or two respective gas generator and piston assemblies so that both ends of the wire extending across the bottom of the curtain are pulled downwardly in the event that a side impact should arise.

It is to be appreciated that in further modified embodiments the curtain may initially be retained in the "B"-Post and may be pulled horizontally across the window.

In the described embodiments, as the curtain moves from the initial retracted position to the operative position, the curtain does not move laterally towards the occupant of the vehicle, thus minimising any risk that the head of the occupant of the vehicle will be moved by the operation of the curtain.

Claims

CLAIMS :

1. A safety device in a motor vehicle to protect the head of a person sitting in the motor vehicle, the safety device comprising a curtain, the curtain initially being located in the body of the motor vehicle adjacent a side window in a door, means being provided to pull the curtain to occupy a position between the head of a person in the motor vehicle and the side window of the motor vehicle in response to a side impact so that the head of the occupant of the vehicle may directly engage the curtain to restrict movement of the said head, the curtain, in said position, being at least 25 millimetres from the window.

2. An arrangement according to Claim 1 wherein the curtain is pulled down by a device which responds to a sensor which senses a side impact.

3. A safety arrangement according to Claim 2 wherein the device comprises a piston within a cylinder associated with a gas generator adapted to move the piston along the cylinder.

4. An arrangement according to Claim 2 or 3 where the device is connected to a wire, the wire being connected to the curtain to pull the curtain in response to a side impact.

5. An arrangement according to Claim 4 wherein the wire extends from the device to the lower edge of the curtain, then extending across the lower edge of the curtain and terminating at a fixed position.

6. An arrangement according to Claim 4 or 5 wherein the wire is guided by guide means.

7. An arrangement according to Claim 3 or any Claim dependent thereon wherein the said gas generator and cylinder means are located on the "B"-Post of the motor vehicle.

8. An arrangement according to Claim 3 or any one of Claims 4 to 6 dependent thereon wherein the gas generator and cylinder means are located on the door sill of the motor vehicle.

9. A system according to Claim 3 or any one of Claims 4 to 6 dependent thereon wherein the gas generator and cylinder means are located in the roof of the motor vehicle.

10. An arrangement according to any one of the preceding Claims wherein the curtain is initially retained in a recess provided at least partly in the roof of the motor vehicle.

11. An arrangement according to Claim 10 wherein the recess is provided at least partly in the "A"-Post of the motor vehicle.

12. An arrangement according to any one of the preceding Claims wherein the curtain is formed from a polyamide fabric.

13. An arrangement according to any one of the preceding Claims wherein the curtain, when in said position, is located no more than 80 millimetres from said window.

14. An arrangement according to Claim 13 wherein the curtain, when in said position, is located between 30 and 50 millimetres inside the said window.

15. An arrangement according to any one of the preceding Claims wherein a locking mechanism is provided to retain the curtain in the said position.

16. An arrangement according to any one of the preceding Claims wherein as the curtain is pulled to occupy said position the curtain does not move laterally towards said person.