Vehicle having a roof mounted inflatable cushion

Abstract: A vehicle passenger safety restraint arrangement where an inflatable cushion (4) mounted in a vehicle roof (6) is operatively connected to an inflator (8) which inflates the inflatable cushion (4) in the event of an accident. The inflator (8) is conveniently positioned in the roof space adjacent to the front reinforcement rail (24) and can be attached to the rail (24) by a deformable bracket (26) so as to soften the impact if a passenger collides with the inflator (8) during an accident.

Description: The present invention relates to motor vehicle safety restraint apparatus, and in particular to safety restraint apparatus which protects vehicle passengers by deploying an inflatable cushion in the event of a accident. The safety of vehicle passengers is an important consideration in the interior design of most modern automotive vehicles. When a vehicle suffers an accident, a vehicle passenger can undergo multiple collisions with the interior surfaces of the vehicle. The interior trim of the vehicle can be designed to cushion the impact of such collisions, and in addition, inflatable cushions can be provided which inflate within the interior of a vehicle in order to restrain the passengers in the event of an accident. However, inflators used to inflate side cushions are normally mounted on a roof supporting pillar. Since inflators are normally hard objects, this can make it difficult to design the interior trim of a pillar so that the trim will effectively absorb the energy of internal collisions. It is known from WO 96/07563 to position an inflator in the roof of a vehicle, behind the B-pillar. The inflator is rigidly supported and, in the event of a collision of the driver's head with the roof, serious head injury may result. The document EP-A-0903270 according to the preamble of claim 1 describes a vehicular headlining that includes an integrated head protection restraining apparatus. The apparatus is in the form of several inflatable gas bags that are stowed folded in a trough shaped receiving body in the border of the headlining,and form, together with the headlining a pre-assembled module. Inflators for the gas bags are stowed under the rear edge of the headlining. The present invention provides a motor vehicle comprising a passenger compartment, an inflatable cushion, and an inflator to inflate the inflatable cushion in the event of an accident, the passenger compartment having a roof comprising an exterior roof panel, the roof including a front edge, a side edge and a roof lining, the inflatable cushion being provided along said side edge and being arranged to inflate downwards into the passenger compartment in the event of an accident; characterised in that the roof has a front reinforcement member therein along a front edge arranged to provide an adjacent recess within the roof; the inflator is provided adjacent to the reinforcement member within said recess and resides between the exterior roof panel and the interior roof lining; and the inflator is attached to the front reinforcement member by means of a deformable member and positioned so that in the event of an accident it is not constrained by either the reinforcement member or the roof panel, the deformable member being long enough to ensure that the inflator can move past the reinforcement member and into contact with the exterior roof panel when a sufficiently large upward force is applied to the inflator. The inflator can therefore conveniently be positioned in the space created in many vehicles by the presence of the front reinforcement member between the roof panel and the interior roof lining of a vehicle. Since the inflator is not placed against a structural pillar supporting the vehicle roof, the lining of the structural pillars may be optimised to absorb the internal collisions without being constrained by taking into account the presence of an inflator. The deformable member may be a bracket formed from sheet metal secured at one point to the inflator and at another point to the reinforcement member. The deformable member may for example be welded to the inflator at one end and screw mounted to the reinforcement member at the other end. So as to make most efficient use of the recess space adjacent to the front reinforcement member, the inflator may have a long axis which is aligned substantially parallel to the front reinforcement member. The inflator may be cylindrical, or any other elongate shape which can conveniently fit in the recess space. In a preferred embodiment, the inflator is operatively connected to the inflatable cushion via a tube smoothly curving though approximately 90 degrees, the tube being aligned with the axis of the cylinder at one end and with a side edge of the vehicle roof at the other end. The curved tube allows the folded cushion and the inflator to be aligned generally perpendicular to one another, the smoothness of the curvature being important to reduce the sudden transfer of momentum of fast flowing gas to the tube. The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of part of the body of a vehicle with an inflatable cushion and an inflator according to the invention; Figure 2 shows a cross sectional view through the line A-A in Figure 1; and Figure 3 shows a perspective view of an inflator with a deformable mounting bracket suitable for use in the present invention. In Figure 1, a vehicle body 2 is shown where an inflatable cushion 4 in the uninflated state is folded up along a line running close to a side edge of the roof 6. The inflatable cushion 4 is operatively connected to an inflator 8 by a rigid tube 10 which curves through approximately 90 degrees. In the event of an accident, the inflator 8 forces gas into the inflatable cushion 4 which inflates in a downward direction, between an interior side of the vehicle and a vehicle passenger, the cushion helping to restrain the passenger during the accident. The inflator 8 is cylindrical in shape, typically 20 cm long with a diameter of 3.5 cm, and is located within the roof 6, with the axis of the inflator 8 aligned almost parallel to the front edge of the roof. These dimensions are given by way of illustration and do not limit the invention in any way. Since the inflator 8 is situated towards the front of the vehicle rather than on a roof supporting pillar 12, the lining of the supporting pillars 12 can be optimised to absorb the impact of a collision. Referring now to Figure 2, the inflator 8 resides between an exterior roof panel 20 and interior roof lining 22, and is attached to a front reinforcement member 24 by a deformable bracket 26. Because of the space available in this area of the roof, the inflator 8 can be positioned some distance away from both the roof panel 20 and the reinforcement member 24, as indicated in Figure 2. This means that in the event of an accident, the inflator 8 is not constrained by either the reinforcement member 24 or the roof panel 20, both of which are relatively inflexible in comparison to the deformable bracket 26. If an accident occurs and the head of a passenger collides with the inflator 8, the bracket 26 will deform and allow the inflator 8 to move upwards towards the roof panel 20, thereby absorbing some of the energy of the collision and reducing the force experience by the passenger. The deformable bracket 26 is long enough to ensure that the inflator 8 can move past the reinforcement member 24 and into contact with the roof panel 20 when a sufficiently large upward force is applied to the inflator 8. This is desirable since the roof panel 20 is more flexible than the reinforcement member 24, and will deform to some extent. In Figure 3, the deformable bracket 26 is shown welded to the inflator 8 at one end, the other end having bolt holes 32 and 34 for mounting to the reinforcement member 24. The bracket 26 is formed from a blank of sheet steel, and is shaped with a plurality of non parallel fold lines 36 which enable the inflator 8 to be orientated with a slight downward slant in the direction of the inflatable cushion 4. The fold lines 36 also have the effect of concentrating the stresses on the bracket 26 in the event of an impact, so that the bracket will deform in a predictable fashion. It will thus be appreciated that the present invention provides considerable advantages in the interior safety design of vehicles, particularly in the event of passenger collisions with the inflator used for side impact inflatable cushions.

Claims: A motor vehicle comprising a passenger compartment, an inflatable cushion (4), and an inflator (8) to inflate the inflatable cushion (4) in the event of an accident, the passenger compartment having a roof (6) comprising an exterior roof panel (20), the roof including a front edge, a side edge and a roof lining (22), the inflatable cushion (4) being provided along said side edge and being arranged to inflate downwards into the passenger compartment in the event of an accident; characterised in that the roof has a front reinforcement member (24) therein along a front edge arranged to provide an adjacent recess within the roof (6); the inflator (8) is provided adjacent to the reinforcement member (24) within said recess and resides between the exterior roof panel (20) and the interior roof lining (22); and the inflator (8) is attached to the front reinforcement member (24) by means of a deformable member (26) and positioned so that in the event of an accident it is not constrained by either the reinforcement member (24) or the roof panel (20), the deformable member (26) being long enough to ensure that the inflator (8) can move past the reinforcement member (24) and into contact with the exterior roof panel (20) when a sufficiently large upward force is applied to the inflator (8). A motor vehicle as claimed in claim 1, wherein the deformable member is a bracket (26) formed from sheet metal secured at one point to the inflator (8) and at another point to the front reinforcement member (24). A motor vehicle as claimed in claim 1 or 2, wherein the deformable member (26) has a plurality of fold lines (36) where the stress will be concentrated in the event of an impact. A motor vehicle as claimed in any previous claim, wherein the inflator (8) has a long axis which is aligned substantially parallel to the front reinforcement member. A motor vehicle as claimed in any previous claim, wherein the inflator is operatively connected to the inflatable cushion via a tube (10) curving through approximately 90 degrees.

Inventors: FLAVELL TREVOR ANTHONY, GREY JASON JOHN, JONES IAIN RAYMOND, KENYON RACHAEL, ROOTE ANDREW, FLAVELL, TREVOR ANTHONY, GREY, JASON JOHN, JONES, IAIN RAYMOND, KENYON, RACHAEL, ROOTE, ANDREW
Applicants: JAGUAR CARS, JAGUAR CARS LIMITED
Application year: 2000
Main classification: B60R21
IPC codes: B60R21