Fault detecting system for vehicle occupants protective apparatus

• US 4,059,822 A
• Filed: 08/11/1975
• Issued: 11/22/1977
• Est. Priority Date: 04/10/1972
• Status: Expired due to Term

• Current Assignee: Nippon Soken, Inc., Toyota Jidosha Kogyo Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Nippon Soken, Inc., Toyota Jidosha Kogyo Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yamada, Takashi, Oishi, Kazuo, Toshioka, Toru
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): Nowicki, Joseph E.
• Application Number:
  US05/603,503
• Time in Patent Office: 834 Days
• Field of Search: 340/52 R, 340/52 H, 340/61, 340/262, 280/735, 180/91, 180/103 A
• US Class Current: 280/735
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• CPC Class Codes: G07C 5/0825 using optical means

Abstract

A fault detecting system adapted for detecting whether a occupants protective apparatus, e.g., an air bag apparatus, seat belt apparatus or rear-end collision preventing apparatus installed in a vehicle, particularly an automobile, is in a normal condition. The system comprises means for detecting the occurrence of a fault or faults in an occupants protective apparatus, means for storing the fact that the occurrence of a fault has been detected by the detecting means, and means for preventing the operation of occupants protective apparatus actuating means as long as the storage means retains its stored content, whereby misoperation of the occupants protective apparatus due to any faulty condition is prevented.

Claims

1. In a vehicle occupants protective apparatus having an operation circuit for radiating an electromagnetic wave, receiving the electromagnetic wave reflected from a target body and combining said radiated wave and said reflected wave to generate a detection signal indicative of a vehicle collision, and an actuating circuit, connected to said operation circuit, for actuating an occupants protector means in response to said detection signal, a fault detecting system comprising:

a first check circuit, connected to said operation circuit, for applying a pseudo signal of fixed frequency thereto to thereby continuously check an occurrence of a fault of said operation circuit;

a second check circuit for checking an occurence of a fault of at least one function of said vehicle occupants protective apparatus;

a logical circuit, connected to said first and second check circuits, for generating an indication signal while at least one of the fault occurrences are being detected by said first and second check circuits;

an indicator means, connected to said logical circuit, for indicating an occurrence of a fault in response to said indication signal;

a timer circuit, connected to said logical circuit, for generating a timer signal representing that duration of said indication signal has exceeded a predetermined time;

a storage means, connected to said timer circuit, for memorizing the generation of said timer signal irrespectively of expiration of said timer signal; and

a prohibition circuit, connected between said storage means and said actuating circuit, for preventing the operation of said actuating circuit while said storage means memorizes the generation of said timer signal, whereby said occupants protector means is maintained irresponsive to said detection signal while at least one fault exists.

2. A fault detecting system for vehicle occupants protective apparatus comprising:

a detecting means for generating a detection signal indicative of a collision of a vehicle;

an actuating means, connected to said detecting means, for actuating a vehicle occupants protective apparatus in response to said detection signals;

a first checking means, connected to said detecting means, for continuously checking an occurrence of a fault of said detecting means;

a second checking means, connected to said vehicle occupants protective apparatus, for continuously checking an occurrence of a fault of said protective apparatus;

an indicating means, connected to said first and second checking means, for indicating at least one of the faults of said detecting means and said protective apparatus;

a timer means, connected to said first and second checking means, for generating a timer signal representing that duration of the occurrence of at least one of the faults is longer than a predetermined time;

a storage means, connected between said timer means and said actuating means, for continuously prohibiting the operation of said actuating means in response to said timer signal, whereby actuation of said protective apparatus is prevented while at least one of the faults exists; and

wherein said detecting means includes an operation circuit for radiating an electromagnetic wave, receiving the electromagnetic wave reflected from a target body and combining said radiated wave and said reflected wave to generate said detection signal, and wherein said first checking means includes a pseudo signal generator for continuously applying a pseudo signal of fixed frequency to said operation circuit to thereby check the operation thereof.

3. A fault detecting system according to claim 2 wherein said operation circuit includes a microwave oscillator using an IMPATT diode.

4. A fault detecting system according to claim 2, wherein said actuating means includes a filament serving as a detonator for inflating a gas bag in said vehicle occupants protective apparatus with compressed gas from a compressed gas vessel, and wherein said second checking means includes a transistor which changes its conductivity in response to burnt-out of said filament.

5. A fault detecting system according to claim 4, wherein said second checking means further includes a switch adapted to switch over when pressure in said compressed gas vessel drops below a predetermined value.

6. A fault detecting system according to claim 2, wherein said indicating means includes an indicator lamp and an astable multivibrator, connected to said lamp, for flickering illumination of said lamp.

7. A fault detecting system according to claim 2, wherein said timer means includes an integration circuit having a resistor and a capacitor.

8. A fault detecting system according to claim 2, wherein said storage means includes a fuse for memorizing the generation of the timer signal.

9. A fault detecting system according to claim 5, further comprising a logical circuit including a NAND gate whose input terminals are connected to said transistor and said switch of said second checking means and whose output terminal is connected to said actuating means, said indicating means and said timer means.