Passenger protection apparatus

• US 4,384,734 A
• Filed: 03/12/1981
• Issued: 05/24/1983
• Est. Priority Date: 03/25/1980
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Yasui, Toshio
• Primary Examiner(s): Peters, Jr., Joseph F.
• Assistant Examiner(s): McGiehan, Donn
• Application Number:
  US06/242,828
• Time in Patent Office: 803 Days
• Field of Search: 280/735, 280/734, 280/728, 180/268, 180/274, 180/282, 307/10 R, 340/52 H
• US Class Current: 280/735
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves

Abstract

A passenger protection system comprises an air bag operating circuit having a G sensor and a squib, and a back-up circuit connected in parallel to the operating circuit. A terminal of the parallel circuit including the air bag operating circuit and the back-up circuit is connected to the body earth through a battery mounted in the automobile, and the other terminal thereof is grounded through a diode, thus making it possible to supply power to squib for expansion of the air bag even if the G sensor is short-circuited on the occasion of an automobile collision.

Claims

1. A passenger protection system for use in an automobile having a key switch and a battery including two terminals one of which is connected to a body earth comprising:

a detector switch,

a responsive element connected in series with said detection switch,

a capacitor and a first diode,

said detection switch and said responsive element making up an operating circuit,

said capacitor and said first diode making up a back-up circuit,

said operating circuit and said back-up circuit making up a closed loop circuit,

the junction point of said operating circuit and said capacitor being connectable to the other of said battery terminals through said key switch,

a second diode for connecting the junction point of said operating circuit and said first diode to a body earth,

wherein said back-up circuit includes a negative voltage generator circuit connected in parallel to said capacitor for applying a voltage pulse to said capacitor.

2. A passenger protection system including an air bag operating circuit having a collision sensor for detecting the acceleration of the automobile body at the time of collision connected in series with a squib for expanding the air bag, and a back-up circuit having a back-up capacitor and a first diode connected in series with said back-up capacitor, said back-up circuit being connected in parallel to said operating circuit, said passenger protection system comprising means for connecting the junction point of said operating circuit and said back-up capacitor to an automobile-carried battery through an ignition switch, a second diode inserted between the junction point of said operating circuit and said first diode and the automobile body earth, and a negative voltage generator circuit connected in parallel to said back-up capacitor for applying a high voltage pulse to said capacitor.