ELECTRONIC SENSOR FOR TRIGGERING SAFETY DEVICES DURING THE CRASH OF VEHICLES

• US 3,870,894 A
• Filed: 02/20/1973
• Issued: 03/11/1975
• Est. Priority Date: 02/19/1972
• Status: Expired due to Term

• Current Assignee: Gunter Hirschmann, Heinz Gawlick, Karl-Egon Flach, Uwe Brede, Walter Kreibich
• Original Assignee: Gunter Hirschmann, Heinz Gawlick, Karl-Egon Flach, Uwe Brede, Walter Kreibich
• Inventors: Brede, Uwe, Flach, Karl-Egon, Gawlick, Heinz, Hirschmann, Gunter, Kreibich, Walter
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Smith, William J.
• Application Number:
  US05/334,023
• Time in Patent Office: 749 Days
• Field of Search: 307/1R,9,121 340/52H 180/82,91 280/15AB 102/70.2
• US Class Current: 307/9.1
• 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: G01P 15/0891 with indication of predetermined acceleration values G01P15/135 takes precedence
• CPC Class Codes: G01P 15/0907 of the compression mode type

Abstract

An electronic sensing system for triggering the activation of a safety mechanism of a vehicle during a vehicle collision. The system includes a piezoelectric transducer providing an output indicative of shock acceleration of the vehicle, an evaluating and safety circuit for processing the output of the transducer in accordance with predetermined dynamic deformation characteristics of the vehicle and for providing a triggering output signal to an ignition circuit for activating the safety mechanism such as an air bag system. The evaluating and safety circuit provides a triggering output signal depending upon whether at least one of a predetermined threshold value has been attained by the output signal of the transducer and that the value is maintained for a predetermined delay period.

Claims

1. An electronic sensing system for triggering the actuation of a safety mechanism during a vehicle collision comprising acceleration pickup transducer means responsive to vehicle shock acceleration for providing an output signal indicative thereof, evaluating and safety triggering circuit means for processing the output signal of the transducer means in accordance with predetermined dynamic deformation characteristics of the vehicle, said evaluating and safety circuit means including threshold means providing first and second threshold values and for providing triggering output signal upon the output signal of said transducer means exceeding the first and second threshold values, and ignition circuit means responsive to the triggering signal for actuating the safety mechanism.

2. A sensing system according to claim 1, wherein said threshold value means includes delay means providing the second threshold value in the form of a predetermined delay period corresponding to the predetermined deformation characteristics of the vehicle, said delay means being arranged before said ignition circuit means for providing a triggering output signal to said ignition circuit means.

3. A sensing system according to claim 2, wherein said delay means is responsive to a signal of said transducer means exceeding the first threshold value and being present for said predetermined delay period for providing the triggering output signal.

4. A sensing system according to claim 1, wherein said evaluating and safety circuit means includes filtering means for filtering the signal of said transducer means.

5. A sensing system according to claim 1, wherein said evaluating and safety circuit means includes filtering means for filtering the signal of said transducer means, said threshold means including triggering means responsive to the filtered signal for providing an output signal upon exceeding the first threshold value and delay means responsive to the output of the triggering means for a predetermined time period corresponding to the second threshold value for providing a triggering output signal.

6. A sensing system according to claim 2, wherein said delay means provides a predetermined delay period in the range of 1 to 50 ms.

7. A sensing system according to claim 6, wherein the predetermined delay period is in the range of 3 to 6 ms.

8. A sensing system according to claim 1, wherein said threshold means includes integrator means for integrating the signal of said transducer means for providing a triggering signal.

9. A sensing system according to claim 1, wherein said threshold means includes triggering means responsive to the output of said transducer means for initiating a triggering signal, said triggering means forming an integrator means.

10. A sensing system according to claim 1, wherein said transducer means is a piezoelectric transducer means having a natural frequency in the range of 10 to 100kilohertz.

11. A sensing system according to claim 1, wherein said transducer means is a piezoelectric transducer means including a piezoelectric pellet and means for biasing an impact mass toward said piezoelectric pellet.

12. A sensing system according to claim 11, wherein said biasing means includes cup spring means and screw means, said screw means being adjustable for varying the force of said cup spring means on said impact mass.

13. A sensing system according to claim 1, wherein said sensing system is arranged for connection with a primary power source, said sensing system including a reserve power source.

14. A sensing system according to claim 13, wherein the primary power source is the electrical means of the vehicle, and the reserve power source is a capacitor means.

15. A sensing system according to claim 1, further comprising control circuit means for controlling the operability of the sensing system and for indicating the functional operability thereof.

16. A sensing system according to claim 15, wherein the control circuit means includes logic switching circuit means.

17. A sensing system according to claim 16, wherein the logic switching circuit means comprises a quadruple NAND-gate logic element.

18. A sensing system according to claim 16, wherein said control circuit means includes means for controlling the voltage level of said sensing system.

19. A sensing system according to claim 18, wherein said means for controlling the voltage level includes a Zener diode.

20. A sensing system according to claim 1, wherein said ignition circuit means includes switching means connected to capacitor means and resistor means, said switching means being responsive to the triggering signal of said evaluating and safety circuit means for connecting the output of said capacitor means as the output of said ignition circuit means for actuating the safety mechanism.

21. A sensing system according to claim 20, wherein said switching means is an integrated circuit component having a thyristor characteristic in the anode-cathode path thereof and the characteristic of an exact trigger diode in the control circuit thereof.

22. A sensing system according to claim 1, wherein the evaluating and safety circuit means includes amplifier means serving as an impedance amplifier for amplifying the output of said transducer means.

23. A sensing system according to claim 1, wherein said sensing system is an integrated circuit module.

24. A sensing system according to claim 5, wherein said sensing system is arranged for connection with a primary power source and said sensing system includes a reserve power source.

25. A sensing system according to claim 24, further comprising control circuit means for controlling the operability of said sensing system and for indicating the functional operability thereof.

26. A sensing system according to claim 25, wherein the control circuit means includes means for controlling the voltage level supplied by said power source means to said sensing system.

27. A sensing system according to claim 26, wherein said evaluating and safety circuit means includes amplifier means for amplifying the output of said transducer means and for providing an amplified output signal to said filtering means.

28. A sensing system according to claim 8, wherein said integrator means is provided with the second threshold value corresponding to the predetermined deformation characteristics of the vehicle, said integrator means providing a triggering signal in response to the integration of the signal of said transducer means attaining said predetermined threshold value.

29. A sensing system according to claim 28, wherein said sensing system is arranged for connection with a primary power source and said sensing system includes a reserve power source.

30. A sensing system according to claim 29, further comprising control circuit means for controlling the operability of said sensing system and for indicating the functional operability thereOf.

31. A sensing system according to claim 30, wherein the control circuit means includes means for controlling the voltage level applied by said power source means to said sensing system.

32. A sensing system according to claim 31, wherein said ignition circuit means includes switching means connected to capacitor means and resistor means, said switching means being responsive to the output of said integrator means for connecting the output of said capacitor means as the output of said ignition circuit means for actuating the safety mechanism.

33. A sensing system according to claim 32, wherein said evaluating and safety circuit means includes amplifier means for amplifying the output of said transducer means and providing an amplified signal to the integrator means.