Malfunction preventive system for use in an air bag incorporating a sensor for detecting the collision speed of a vehicle

• US 3,921,129 A
• Filed: 03/14/1973
• Issued: 11/18/1975
• Est. Priority Date: 05/10/1971
• Status: Expired due to Term

• Current Assignee: Shizuo Sumida
• Original Assignee: Shizuo Sumida
• Inventors: Sumida, Shizuo
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Nowicki, Joseph E.
• Application Number:
  US05/341,195
• Time in Patent Office: 979 Days
• Field of Search: 340/52R,52H,61,262 180/91,103,104 280/15AB 317/31,33R 200/61.45M
• US Class Current: 180/274
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558

Abstract

A malfunction preventive system for use in an air bag system which incorporates a sensor for detecting the collision speed of a vehicle, prevents the actuation of electrical circuits incorporated therein in case the sensor circuit and collision detecting means are not in normal conditions. This system further incorporates several other simulating and failure detecting means or circuits to detect the failures in several components associated therewith, thereby completely preventing the possibility of incurring a danger to human life and personal injury erroneous explosive inflation of an air bag, caused by the mal-function of failure in the system.

Claims

1. A malfunction preventive system for use in an air bag system of a vehicle, comprising:

an electrical power source;

an electrical sensor means for detecting a collision speed of said vehicle and consisting of a combination of a coil and a magnet and generating a collision signal at the time of detecting the collision speed of said vehicle;

a priming or ignition plug for actuating an air bag;

a first switching means connected to the coil of said electrical sensor means and adapted to be brought to an ON position in response to the collision signal from said electrical sensor means, said first switching means being connected between said plug and power electrical power source;

failure detecting means adapted to detect failures in at least said electrical sensor means, said priming or ignition plug, and said first switching means and to generate a failure signal;

a relay, said relay, said first switching means, said plug, and said electrical power source being connected in series, said relay being adapted to electrically disconnect said plug from said electrical power source in response to the failure signal fed from said failure detecting means; and

indicating or alarming means connected to said electrical power source and adapted to be actuated in response to a failure signal fed from said failure detecting means, whereby, In case of said failure detecting means detecting failures, said relay electrically disconnects said electrical power source and said plug, and simultaneously said indicating or alarming means is actuated.

2. A malfunction preventive system as defined in claim 1, wherein said system further comprises a simulation means for generating a simulation signal, and a key switch having OFF, ON and START positions, said simulation means being connected to said START position of said key switch and to said coil, and said START position being provided for driviNg a starter motor of an engine, whereby said simulation means may feed the simulation signal to said coil at the time of starting said engine.

3. A malfunction preventive system as defined in claim 2, wherein said relay is adapted to connect said plug with said electrical power source in response to said simulation signal.

4. A malfunction preventive system as defined in claim 3, wherein said simulation means includes means for stopping the feeding of said simulation signal by said relay after said plug has been connected with said electrical power source.

5. A malfunction preventive system as defined in claim 1, wherein said first switching means includes two switching elements connected in series.

6. A malfunction preventive system for use in an air bag system incorporating a sensor for detecting a collision speed of a vehicle, comprising:

an electrical power source;

a fuse;

an electrical sensor means for generating a collision signal and consisting of a coil and a magnet;

a priming or ignition plug adapted to actute said air bag;

a first switching means connected to said coil of said electrical sensor means and adapted to be turned ON in response to said collision signal from said electrical sensor means;

a relay having a switching device with ON and OFF positions, said switching device being connected in series with said electrical power source, said first switching means and said plug and operative to turn ON or OFF the electrical connection of said plug with said first switching means, and an electric magnet adapted to bring said switching device to the ON position, said electric magnet of said relay being connected via said fuse to said electrical power source;

a failure detecting means for detecting failures in at least said electrical sensor means, said priming or ignition means, and said first switching means and generating a failure signal;

a second switching means adapted to be actuated in response to said failure signal from said failure detecting means, whereby said fuse will be blown when said second switching means is activated;

a simulation means adapted to feed a simulation signal similar to said collision signal to said coil of said electrical sensor means, prior to the starting of said vehicle; and

a third switching means adapted to be actuated in response to said simulation signal and forming a circuit by being connected via said fuse and said electric magnet of said relay to said electrical power source.

7. A malfunction preventive system as defined in claim 1, wherein said indicating or alarming means consists of:

a lamp (54) having two terminals, one of which is grounded and the other of which is ungrounded;

a buzzer (55) having two terminals;

a resistor (F) connected to one of said two terminals of said buzzer (55);

a fuse (20), said buzzer, resistor and fuse being connected in series via a contact (26) to said electrical power source (23);

a transistor (53) whose emitter is connected to said contact (26) and whose collector is connected to the other of said two terminals of said buzzer and to the ungrounded terminal of said lamp;

a diode (E) connected to the same terminal of said buzzer as said resistor; and

a second switching means (22) having a gate which is connected to said diode (E), said second switching means being connected to the base of said transistor.

8. A malfunction preventive system as defined in claim 1, wherein said failure detecting means includes means for detecting a failure in the circuit from said coil to said first switching means.

9. A malfunction preventive system as defined in claim 8, wherein said first switching means includes two gated switching elements and said detecting means for detecting failure in the circuit from said coil to said first switching means, consists of:

two sensing coil portions (3 and

     4) each having a pair of coils (5, 6 and 7,

     8), said coils being connected in comMon at one terminal each thereof to a contact (27) of a key switch, corresponding ones in each of said pair of coils being connected to each other; and

two voltage comparators (11 and

     12) whose outputs are connected to gate said two switching elements (13 and

     14).

10. A malfunction preventive system as defined in claim 1, further including a G-sensor connected in parallel with said first switching means and wherein said failure detecting means includes means for detecting short-circuiting in said G-sensor.

11. A malfunction preventive system as defined in claim 1, further including means for inflating said air bag, including a pressure switch and wherein said failure detecting means includes means for detecting failure in said pressure switch.

12. A malfunction preventive system as defined in claim 1, wherein said failure detecting means includes means for detecting incorrect position of said magnet.

13. A malfunction preventive system as defined in claim 10, wherein said G-sensor includes input and output terminals and two contacts (38 and 39) which are open in normal conditions and two resistors (40 and 41) connected in parallel to said contacts, respectively, said detecting means comprising:

a contact (26) connected via a fuse (20) to the input terminal of said G-sensor;

a switching element having a gate electrode, said switching element being (21) connected to said relay; and

a transistor (45) whose base is connected to the output terminal of said G-sensor and whose collector is connected to the gate electrode of said switching element (21) and whose emitter is connected to ground.

14. A malfunction preventive system as defined in claim 11, wherein said pressure switch (32) includes input and output terminals, and wherein said detecting means comprises:

a fuse connected in series with said electrical power source and said input terminal of said pressure switch; and

a second switching means (22) whose gate is connected to the output terminal of said pressure switch, said second switching means being connected via said fuse (20) to said electrical power source.

15. A malfunction preventive system as defined in claim 12, wherein said failure detecting means for detecting an incorrect position of a magnet, consists of:

a key switch;

a fuse;

two magnets;

a bumper switching means (33) having input and output terminals and two contacts (58 and

     57) normally connecting said output terminal to ground and adapted to open in the event of an incorrect position of said magnets, while the input terminal of said bumper switching means is connected via said fuse (20) and a contact (25) of said key switch (24) to said electrical power source (23);

a first transistor (63) whose base is connected to the output terminal of said bumper switching means (33) and whose emitter is grounded; and

a second transistor (53) whose base is connected to the collector of said first transistor, said second transistor being connected to switch said indicating means.

16. A malfunction preventive system as defined in claim 1, wherein said failure detecting means includes means for detecting shortcircuiting or open-circuiting of said ignition plug.

17. A malfunction preventive system as defined in claim 1, further including a G-sensor connected in parallel with said first switching means, means for inflating said air bag including a pressure switch, and wherein said failure detecting means includes means for detecting a failure in the circuit from said coil to said first switching means, means for detecting short-circuiting in said G-sensor, means for detecting failure in said pressure switch, means for detecting incorrect position of said magnet, and means for detecting short-circuiting or open-circuiting of said ignition plug.