Patent Number: 6,169,947

Title: Vehicle occupant protection system

Abstract: If a seat belt is not fastened, then a first switch is turned on and a second switch is turned off, and a fastened status detector outputs an impact decision level signal to a switch, which selects a signal from a first impact decision level output unit. Thus, when the speed of a motor vehicle is about 16 km/h or higher immediately prior to a collision, an air bag is inflated upon the collision. If the seat belt is fastened, then the first switch is turned off and the second switch is turned on, and the fastened status detector outputs an impact decision level signal, selecting a signal from a second impact decision level output unit. Thus, when the speed of the motor vehicle is about 24 km/h or higher immediately prior to a collision, the air bag is inflated upon the collision. If both the first and second switches are turned on or off due to a failure, the fastened status detector outputs the impact decision level signal, inflating the air bag when the vehicle speed of the motor vehicle immediately prior to a collision becomes greater than about 16 km/h, as is the case with the seat belt being not fastened. Even when the fastened state of the seat belt cannot be detected, therefore, vehicle occupants are protected safely by a vehicle occupant protection system.

Inventors: Fukui; Tsutomu (Tochigi-ken, JP), Koyota; Nobuhiro (Utsunomiya, JP), Isonaga; Kazutomo (Utsunomiya, JP), Kamiji; Koichi (Tochigi-ken, JP)

Assignee: Honda Giken Kogyo Kabushiki Kaisha

International Classification: B60R 21/01 (20060101); G05D 001/00 ()

Expiration Date: 01/02/2018