The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 04, 1992
Filed:
Apr. 18, 1991
Mitsuhiko Masegi, Nukata, JP;
Akira Kondo, Okazaki, JP;
Masahito Mutoh, Toyota, JP;
Koichi Fujita, Nagoya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
Air bags are located at different positions within a vehicle. Squibs serve to fire and activate the air bags respectively. An acceleration detecting device is provided in common to the squibs for detecting an acceleration of the vehicle upon a collision of the vehicle and executing a switching operation in response to the detected vehicle acceleration. Constant-current circuits supplied with an electric power from a vehicle battery feed constant electric currents for a firing operation to the squibs respectively in response to the switching operation of the acceleration detecting device. An energy storage device serves to feed a backup electric power to the constant-current circuits when the supply of the electric power from the vehicle battery is cut off. Each of the constant-current circuits includes a first transistor for feeding an electric current to the related squib, a first resistor for detecting a level of the electric current fed to the squib, a second transistor conducting an electric current with a level which depends on the electric current level detected by the first resistor, and a second resistor for generating a voltage which depends on the electric current conducted by the second transistor and for controlling the first transistor in response to the generated voltage.