TECHNICAL FIELD

The present invention relates generally to vehicle airbags and, in particular, relates to a roof-mounted primary airbag with a support airbag.

BACKGROUND

It is known to provide an inflatable vehicle occupant protection device, such as an airbag, for helping to protect an occupant of a vehicle. One particular type of airbag is a frontal airbag inflatable between an occupant of a front seat of the vehicle and an instrument panel of the vehicle. Such airbags may be driver airbags or passenger airbags. When inflated, the driver and passenger airbags help protect the occupant from impacts with parts of the vehicle such as the instrument panel and/or a steering wheel of the vehicle.

Passenger airbags are typically stored in a deflated condition in a housing that is mounted to the vehicle instrument panel. An airbag door is connectable with the housing and/or instrument panel to help enclose and conceal the airbag in a stored condition. Upon deployment of the passenger airbag, the airbag door opens to permit the airbag to move to an inflated condition. The airbag door opens as a result of forces exerted on the door by the inflating airbag.

Driver airbags are typically stored in a deflated condition in a housing that is mounted on the vehicle steering wheel. An airbag cover is connectable with the housing and/or steering wheel to help enclose and conceal the airbag in a stored condition. Upon deployment of the driver airbag, the airbag cover opens to permit the airbag to move to an inflated condition. The airbag cover opens as a result of forces exerted on the cover by the inflating driver airbag.

There are trends in the auto industry to make vehicles more spacious. Styling has been making the instrument panel smaller and thus farther away from the occupant. Looking further into the future, driverless, autonomous vehicles are even more spacious. Autonomous vehicles have been contemplated for some time, and now their adaption on a large scale is approaching. Autonomous vehicles can eliminate some of the structure.

With these realities as a backdrop, the paradigm of occupant safety systems must shift. In the past, the necessity of a vehicle operator/driver lent to a somewhat standard vehicle passenger cabin configuration. In the U.S., the driver is a front seat, left side, forward facing occupant within reach of the vehicle controls and instrumentation (steering wheel, pedals, instrument panel, console, etc.). This driver configuration helps dictate the layout of the remainder of the vehicle—front seat, forward-facing passenger-side occupant, rear seat (second row, third row, etc.) forward-facing occupants. Accordingly, in the past, occupant safety systems were typically designed with this passenger cabin layout and the associated occupant positions and orientations in mind.

The autonomous vehicle eliminates the operator/driver, which eliminates the necessity of their being positioned and oriented in the conventional manner. Vehicle manufacturers are free to utilize passenger cabin space as they see fit without being constrained to predetermined passenger arrangements, such as all forward-facing occupants, or vehicle structural configurations, such as steering wheel/instrument panel configurations, center console configurations, foot well pedal controls, etc.

This presents the challenge of not only where to locate airbag systems, but also finding a reaction surface against which to position the airbag so that it can absorb impacts. Typically, instrument panel and steering wheel mounted frontal airbags utilize those structures as a reaction surface against which the airbag rests so that it can oppose, cushion, and absorb the impact energy of an impacting occupant and provide a desired ride-down effect. In the autonomous vehicles, however, the vehicle may not have an instrument panel or steering wheel at all, and the occupants can be positioned and oriented outside the traditional manner. This can make it difficult or impossible to utilize traditional structures in the vehicle as reaction surface.

SUMMARY

In one example, a restraint system for helping to protect an occupant of a vehicle having a roof and a cabin with a seat for the occupant includes a primary airbag having a stored condition within the roof and being inflatable to a deployed condition extending into the cabin on a first side of the seat. A support airbag has a stored condition within the roof and is inflatable to a deployed condition on a second side of the seat opposite the first side. Tethers connect the primary airbag and the support airbag such that occupant penetration into the primary airbag pulls the support airbag into engagement with the seat.

In another example, a restraint system for helping to protect an occupant of a vehicle having a roof and a cabin with a seat for the occupant includes a primary airbag having a stored condition within the roof and being inflatable to a deployed condition extending into the cabin on a first side of the seat. A support airbag has a stored condition within the roof and is inflatable to a deployed condition on a second side of the seat opposite the first side. A first inflator provides inflation fluid to the primary airbag. A second inflator provides inflation fluid to the support airbag. Tethers connect the primary airbag and the support airbag such that occupant penetration into the primary airbag pulls the support airbag into engagement with a seatback of the seat to restrict movement of the primary airbag away from the occupant.

Other objects and advantages and a fuller understanding of the invention will be had from the following detailed description and the accompanying drawings.

