GB2392651A

GB2392651A - An air bag for a motor vehicle

Info

Publication number: GB2392651A
Application number: GB0220524A
Authority: GB
Inventors: Gregor C Whelan; Marcus J Ward; Tim Scott
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2002-09-04
Filing date: 2002-09-04
Publication date: 2004-03-10
Also published as: GB0220524D0

Abstract

A motor vehicle (100) comprises at least one air bag (11, 12) arranged to inflate in a substantially transverse direction when deployed so as to lie between a windscreen (105) of the vehicle and a front seated passenger (5). The air bag may be mounted close to the top, bottom or side edge of the windscreen for inflation in a substantially vertical downwards, upwards or horizontal direction respectively. Preferably there is at least one further air bag mounted in an instrument panel (111) for inflation in a substantially vertical upwards direction, the air bag being arranged to break out of a panel located in the upper surface of the instrument panel. One preferable embodiment comprises a first air bag mounted close to the top edge of the windscreen and a second air bag mounted in the instrument panel. The volume of one of the air bags may be larger than the other with the second air bag overlying part of the first.

Description

239265 1

A motor vehicle This invention relates to motor vehicles and in particular to a motor vehicle having an airbag to protect a front seated passenger.

It is well known to provide a motor vehicle with an airbag to provide protection for a front seated passenger in which the airbag is stored in a dashboard or instrument panel of 5 the motor vehicle. When the airbag is energised it inflates rapidly towards the passenger to reduce the possibility of contact between the passenger and the instrument panel or windscreen of the motor vehicle.

It is a problem with such a prior art arrangement that if the passenger is out of position

during inflation of the airbag as can occur if the passenger is leaning forward or if the 10 passenger is not wearing a safety belt then the force of the rapidly inflating airbag can itself cause injury to the passenger.

It is an object of this invention to provide a motor vehicle providing improved protection for a front seated occupant and in particular providing reduced risk to an out of position occupant. 15 According to a first aspect of the invention there is provided a motor vehicle having a body structure defining a passenger compartment, a windscreen attached to part of the body structure, an instrument panel attached to part of the body structure, seating at the front of the passenger compartment for at least one passenger and at least one airbag for providing protection to the or each front seated passenger wherein the or each airbag is 20 arranged to inflate in a substantially transverse direction when deployed so as to lie between the windscreen of the motor vehicle and the or each front seated passenger.

There may be at least one airbag mounted close to a top edge of the windscreen for inflation in a substantially vertical downward direction so as to overlie at least part of the windscreen when deployed.

Altematively, there may be at least one airbag mounted close to a lateral edge of the 5 windscreen for inflation in a substantially horizontal transverse direction so as to overlie at least part of the windscreen when deployed.

As yet another altemative, there may be at least one airbag mounted close to a bottom edge of the windscreen for inflation in a substantially vertical upward direction so as to overlie at least part of the windscreen when deployed.

10 There may be at least one further airbag mounted in the instrument panel for inflation in a substantially vertical upward direction when deployed.

The or each airbag may be arranged to break out of a panel located in an upper surface of the instrument panel.

Preferably, the motor vehicle may have a first airbag mounted close to a top edge of 15 the windscreen for inflation in a substantially vertical downward direction and a second airbag mounted in the instrument panel for inflation in a substantially vertical upward direction. Preferably, the first and second airbags may be arranged to interact when inflated.

The inflated volume of one of the first and second airbags may be less than the 20 inflated volume of the other of the first and second airbags.

( - 3 The first airbag, when inflated, may overlie an upper portion of the windscreen and the second airbag, when inflated, may overlie a lower portion of the windscreen and an upper portion of the instrument panel.

The second airbag may overlie part of the first airbag when both airbags are fully 5 inflated.

The invention will now be described by way of example with reference to the accompanying drawing of which: Fig. 1 is a cut-away side view of part of a motor vehicle; Fig.2 is a view similar to that of Fig.1 but showing the inflation of a prior art airbag;

10Fig.3 is a view similar to Fig.1 but showing an airbag assembly according to one embodiment of the invention in a partially inflated state; and Fig.4 is a view similar to that of Fig.3 but showing the airbag assembly in a fully inflated state.

With reference to Fig.1 there is shown a motor vehicle 100 having a body structure 15including two vehicle support pillars or A-posts 101, two support pillars or B-posts 102 and a roof 107. A windscreen 105 is supported along its lateral edges by the two A-posts 101 along it top edge by a header rail (not shown) at the front of the roof 107 and along its bottom edge by part of the body structure in the form of a bulkhead 109.

The motor vehicle 100 is fitted with a primary or active safety system in the form of two 20 safety belt assemblies, one for each of the front seated occupants.

Each of the safety belt assemblies comprises of a safety belt in the form of safety belt webbing 110 extending from a retractor mechanism 104 through a safety belt guide 103 to

( - 4 a buckle 108 and through the buckle 108 to a fixed mount 106 secured to part of the body structure 101 of the motor vehicle 100. The buckle 108 is releasably attachable to a latching means 112 fixed to part of the body structure.

The retractor mechanism 104 allows the safety belt webbing 110 to be fed out and 5 retracted back into the retractor mechanism 104 and includes a locking means (not shown) to prevent the safety belt webbing 110 from being fed out in the event of a collision.

It will be appreciated that only one front seated occupant is shown but seating and a safety belt assembly is provided for at least two front seated occupants. One of the front seated occupants is a driver of the motor vehicle and the other occupants are passengers.

10 In addition to the active safety system fitted to the motor vehicle 100 the motor vehicle also includes a passive or supplementary safety system in the form of a passenger airbag assembly stored in a housing (not shown) in a dashboard or instrument panel 111 attached to the bulkhead 109.

With particular reference to Fig.2 there is shown a motor vehicle as previously 15 described having a prior art airbag 6 and for which identical parts are given the same

reference numeral.

In the event of a collision with another object of sufficient severity a sensor (not shown) indicates to a controller (not shown) that the airbag 6 needs to be deployed. The airbag 6 may be deployed before the actual collision occurs or may be inflated when a 20 collision has been detected to be occurring.

As previously mentioned, the airbag 6 is stored in a housing within the instrument panel 111 and is concealed from view before deployment by a flap or break-out panel fomming part of the instrument panel 111.

- 5 When the controller receives the signal indicating that the airbag 6 needs to be deployed it sends a further signal to a gas generator (not shown) connected to the airbag 6 to fire the gas generator and so inflate the airbag 6. The inflation of the airbag 6 causes it to be rapidly inflated and it breaks out through the break-out panel and inflates rapidly 5 towards the front seated passenger 5 as indicated by the arrow 'X' on Fig.2. It will be appreciated that the direction of the force produced by this inflation is substantially horizontal and is considerable.

In the event that the passenger 5 is located close to the instrument panel 111, at the time of initial inflation, the airbag 6 will react forcefully against the passenger 5 and push 10 them rearwardly. Such a violent interaction between the passenger 5 and the airbag 6 is undesirable because it can cause direct injury to the passenger 5 due to the actual contact between the airbag 6 and the passenger 5 or indirect injury due to the rapid rearward movement of the passenger 5.

With particular reference to Figs 3 and 4 there is shown a motor vehicle which is in 15 most respects the same as that previously described with respect to Fig.1 and for which identical parts are identically numbered but which is fitted with two airbags according to a preferred embodiment of the invention.

As before the motor vehicle 100 has a body structure defining a passenger compartment, a windscreen 105 is attached to part of the body structure, an instrument 20 panel 111 is attached to part of the body structure in the form of the bulkhead 109, seating is provided at the front of the passenger compartment for a front seated passenger 5. The two airbags in the form of first and second airbags 11, and 12 are provided to give protection to the front seated passenger 5 in the event of a collision.

- 6 Both of the airbags 11, 12, when deployed, are arranged to inflate in a substantially vertical direction, when deployed, so as to lie between the windscreen 105 of the motor vehicle 100 and the front seated passenger 5.

The term transverse as meant herein means that the airbags inflate substantially 5 parallel to the windscreen of the motor vehicle so that they do not inflate directly at an occupant. The temm substantially vertical as meant herein means that the airbags inflate either in a predominately upward direction or in a predominately downward direction.

The first airbag 11 is mounted close to a top edge of the windscreen 105 for inflation in a substantially vertical downward direction so as to overlie an upper part of the windscreen 10105. The first airbag 11 is stored in a housing (not shown) attached to a header rail (not shovvn) extending across the top edge of the windscreen 105 and is concealed from view prior to inflation by a headlining (not shown) fitted to an inner side of the roof 107 of the motor vehicle 100. The headlining has a breakout panel formed in it through which the first airbag 11 can be deployed when required.

15An electronic controller (not shown) and a sensor (not shown) are used to determine when the first airbag 11 needs to be deployed and the electronic controller is connected to a gas generator (not shown) mounted within the A-post 101 to provide gas to inflate the first airbag11. The airbag 11 may be deployed before the actual collision occurs or may be inflated when a collision has been detected to be occurring depending upon the type of 20 sensors used.

The second airbag is mounted in a housing (not shown) within the instrument panel 111 for inflation in a substantially vertical upward direction.

The instrument panel 111 has a break-out panel (not shown) formed in an upper surface so that the second airbag 12 can break out of the upper surface of the instrument 25 panel 111 when it is inflated.

- 7 The electronic controller is also connected to a gas generator (not shown) mounted within the instrument panel 111 to provide gas to inflate the second airbag 12.

Although according to the preferred embodiment shown and described herein the motor vehicle has a first airbag mounted close to a top edge of the windscreen for inflation 5 in a substantially vertical downward direction and a second airbag mounted in the instrument panel for inflation in a substantially vertical upward direction, it is envisaged that a motor vehicle could alternatively be fitted with either a airbag mounted dose to a top edge of the windscreen for inflation in a substantially vertical downward direction so as to overlie at least part of the windscreen when deployed or an airbag mounted in the 10 instrument panel for inflation in a substantially vertical upward direction when deployed.

In addition the motor vehicle could be fitted with one airbag in the instrument panel for deployment in a substantially upward direction and one airbag mounted near to a lateral edge of the windscreen for deployment in a transverse direction horizontally across the motor vehicle.

15 It will be further appreciated that the motor vehicle could be fitted with a small volume airbag mounted in the instrument panel for deployment in an upward direction and a second larger airbag also mounted in the instrument panel for deployment in an upward direction. The smaller airbag in this case forms a support for the larger airbag and can be used to open a door covering both of the airbags.

20 In all cases an important feature is that the direction of inflation is essentially vertical or, in other words, the forces of expansion due to inflation are not directed towards the passenger. This greatly reduces the risk of an airbag causing injury to a passenger when it Is inflated, particularly if the passenger is out of position at the time of inflation. It will however be appreciated that the primary airbag 11 does inflate in both an upward direction 25 and a direction towards the occupant, however the large forces during initial inflation are

( - 8 directed upwardly because the airbag is deployed through an upwardly facing aperture in the instrument panel.

Operation is as follows when the motor vehicle 100 is involved in a collision, of severity greater than a pre-determined magnitude, the electronic controller is operational to 5 send signals to both of the gas generators causing the first and second airbags 11 and 12 to be deployed by filling them with gas.

The first airbag 11 breaks out of its containment and expands rapidly in a downward direction such that the force of the expanding gas is directed substantially vertically as indicated by the arrow 'Z' on Fig.3. Simultaneously, the second airbag 12 breaks out of its 10 containment and expands in an upward direction such that the force of the expanding gas is directed substantially vertically as indicated by the arrow At' on Fig. 3.

The inflated volume of the first airbag 11 is less than the inflated volume of the second airbag 12 and so it is inflated more rapidly than the second airbag 12. This ensures that the first airbag 11 is fully inflated before the second airbag 12 and is able to adopt its 15 correct position overlying an upper portion of the windscreen 105 before the second airbag 12 adopts its fully inflated position overlying a lower portion of the windscreen 105 and an upper portion of the instrument panel 111.

This is important because the first and second airbags 11 and 12 are shaped so as to cooperate with one another and in particular the second airbag 12 is designed to overlie 20 part of the first airbag 11 when both airbags 11, 12 are fully inflated (as shown in Fig.4).

If a load is applied by contact between the passenger and one of the airbags this load will be partially transferred to the other airbag and the two airbags are designed to interact with each other to provide the best possible protection. By using two airbags it is possible to obtain very fast coverage of the upper portion of windscreen by using a relatively small

( - 9 -

upper airbag and then use the second airbag to provide a slower inflating and hence less aggressive protection for the lower portion of the windscreen and the instrument panel.

During inflation of the first and second airbags 11 and 12 the force of the expanding gas is not directed at the passenger but is directed towards the other of the airbags. In this 5 way, if a passenger is leaning forward or is sitting too close to the instrument panel, the forces applied from the rapidly expanding airbags are less likely to injure the passenger than is the case when the airbag expands directly towards the passenger.

It Will be appreciated that the invention has been described with respect to a specific embodiment of the invention but alternative embodiments or modifications to the 10 embodiment can be produced without departing from the scope of the invention as set forth in the accompanying claims.

It will for example be appreciated that the motor vehicle could be fitted with a bench front seat and the invention could be used to provide protection to more than one passenger sat upon the seat.

Claims

l - 10 CLAIMS

1. A motor vehicle having a body structure defining a passenger compartment, a windscreen attached to part of the body structure, an instrument panel attached to part of the body structure, seating at the front of the passenger compartment for at least one passenger and at least one airbag for providing protection to the or each front seated passenger wherein the or each airbag is arranged to inflate in a substantially transverse direction when deployed so as to lie between the windscreen of the motor vehicle and the or each front seated passenger.

2. A motor vehicle as claimed in claim 1 in which there is at least one airbag mounted close to a top edge of the windscreen for inflation in a substantially vertical downward direction so as to overlie at least part of the windscreen when deployed.

3. A motor vehicle as claimed in claim 1 in which there is at least one airbag mounted close to a lateral edge of the windscreen for inflation in a substantially horizontal transverse direction so as to overlie at least part of the windscreen when deployed.

4. A motor vehicle as claimed in claim 1 in which there is at least one airbag mounted close to a bottom edge of the windscreen for inflation in a substantially vertical upward direction so as to overlie at least part of the windscreen when deployed.

5. A motor vehicle as claimed in any of claims 1 to 4 in which there is at least one further airbag mounted in the instrument panel for initial inflation in a substantially vertical upward direction when deployed.

6. A motor vehicle as claimed in claim 5 in which the or each airbag is arranged to break out of a panel located in an upper surface of the instrument panel.

7. A motor vehicle as claimed in any of claims 1 to 6 in which the motor vehicle has a first airbag mounted close to a top edge of the windscreen for inflation in a

- 11 substantially vertical downward direction and a second airbag mounted in the instrument panel for inflation in a substantially vertical upward direction.

8. A motor vehicle as claimed in claim 7 in which the inflated volume of one of the first and second airbags is less than the inflated volume of the other of the first and second airbags.

9. A motor vehicle as claimed in claim 5 or in claim 6 in which the first airbag, when inflated, overlies an upper portion of the windscreen and the second airbag, when inflated, overlies a lower portion of the windscreen and an upper portion of the instrument panel.

10. A motor vehicle as claimed in claim 7 in which the second airbag overlies part of the first airbag when both airbags are fully inflated.

11. A motor vehicle substantially as described herein with reference to the accompanying drawing.