This invention relates generally to systems and methods for reducing vehicle-collision injuries and damage and concerns more specifically such systems and methods that are particularly suitable for use with large vehicles, such as truck trailers, for preventing smaller vehicle from under-riding them.
Deployable interior airbags have been effective for protecting passengers inside vehicles and have, therefore, become mandatory equipment for vehicles. As an extension of this, it has been suggested to place deployable airbags on exteriors of vehicles for absorbing impact energy of colliding vehicles and thereby reducing damage to the vehicles. For example, each of U.S. Pat. No. 4,441,751 to Wesley; U.S. Pat. No. 5,725,265 to Baber; and U.S. Pat. No. 6,106,038 to Dreher describes a system for reducing collision damage by deploying an airbag on an exterior of a vehicle. The airbag system of Baber is mentioned as being particularly suitable for use with trucks and truck trailers. This system involves placing an airbag on a truck, which is depicted in FIG. 7. The airbag is inflated when a possible collision is perceived, by radar for example. This patent mentions that the invention described therein particularly helps a vehicle colliding with the principal truck on which the airbag is mounted, since an airbag inflates to cushion the colliding vehicle. The patent mentions both side and rear collisions and mentions that this system reduces liability claims for trucks.
Although the system described in U.S. Pat. No. 5,725,265 and the other prior-art patents mentioned above have advantages, they also present some difficulties. One such difficulty involves sensing that a collision is about to take place with enough certainty and lead time that an airbag has time to deploy in time to do some good. Several of the above-described prior-art patents suggest using radar or sonar (see U.S. Pat. 6,106,038 to Dreher and U.S. Pat. No. 5,725,265 to Baber), presumably to sense that a collision is imminent and trigger deployment of the airbag in time to provide a useful cushion. However, as can be imagined, such non-con tact and imprecise sensing can be risky, sometimes triggering an expensive, unnecessary and dangerous airbag deployment.
Thus, it is an object of this invention to provide an airbag system, method and vehicle with such an airbag system, that provides a precise, reliable sensing of an imminent collision, while at the same time providing sufficient lead time for allowing an airbag enough time to inflate and cushion the impact of the colliding vehicle.
Large vehicles, such as truck cabs and trailers, pose a particular problem for motorists of smaller vehicles because the smaller vehicles, such as normal-size cars, can under-ride the larger vehicles. Such under-ride collisions are particularly dangerous for the occupants of the smaller vehicles because they can be thereby, decapitated, even though they may be wearing seat belts and are not driving at high speeds. To prevent such under-riding, some trucks have installed under-ride guards, or bumpers, mounted at their sides and back. These under-ride guards can have various shapes and forms, but quite often are simply rigid vertical and horizontal bars extending downwardly from the bottoms of truck trailers. Again, such under-ride guards can be at sides and backs of truck trailers. Although under-ride guards tend to reduce under-ride injuries, they are often not sufficiently strong to prevent under-ride during high-speed collisions. Another problem is that the under-ride guards themselves cause damage to smaller cars, because they, by their nature, are formed as rigid protrusions. Therefore, it is an object of this invention to provide an under-ride protection system that has added strength while also cushioning the impact of a collision.
U.S. Pat. No. 3,907,353 to Dinitz suggests using adjustable bumpers on vehicles having elevated bodies, with the adjustable bumpers including energy absorbers, or dissipaters. A disadvantage of such a system is that the adjustable bumper is unduly complicated and the dissipaters make it unduly bulky. Further, in order to make the bumper adjustable, one must make compromises between strength and functionality. It is therefore an object of this invention to provide an under-ride protection system that is not unduly complicated, bulky, non-functional or weak.
According to principles of this invention, an external vehicle airbag system for being mounted on a road-traveling principal vehicle includes an airbag to be inflated for absorbing the energy of a colliding vehicle and preventing the colliding vehicle from under-riding the principle vehicle. In this regard, the vehicle airbag system includes an airbag mount for mounting the airbag at a bottom side of the principal vehicle, substantially laterally inwardly spaced from a lateral-side periphery of the principal vehicle. The airbag system further includes a sensor for being mounted on the principal vehicle at a position more laterally outward, in the direction of the lateral-side periphery, than is the airbag. The sensor senses an imminent impact of the principal vehicle with the colliding vehicle and, in response thereto, inflates the airbag. Thus, as the colliding vehicle impacts the principle vehicle laterally, the airbag inflates below the principal vehicle, along the bottom thereof toward the lateral periphery, to thereby counter and absorb energy from the colliding vehicle to prevent its under-riding. In one embodiment, the sensor is positioned about at the lateral-side periphery and includes a rigid under-ride guard.