Gas inflator apparatus

• US 5,078,422 A
• Filed: 10/22/1990
• Issued: 01/07/1992
• Est. Priority Date: 04/30/1990
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: OEA Incorporated (Autoliv Incorporated)
• Inventors: Butt, Ronald J., Hamilton, Brian K.
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): GRAYSAY, TAMARA L
• Application Number:
  US07/601,365
• Time in Patent Office: 442 Days
• Field of Search: 280/727, 280/728, 280/731, 280/732, 280/734, 280/735, 280/736, 280/737, 280/741, 280/742
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/26035 triggered by mechanical means
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators

Abstract

A gas inflator apparatus for deploying inflatable devices, particularly automobile air bags, which provides an initial flow rate of gas into the air bag, followed by a delayed maximum flow rate to fully deploy the air bag, the apparatus particularly having the capability to program the delay by monitoring certain environmental conditions, namely pressure, and additionally providing temperature compensation for variations in ambient conditions, all of which optimize performance of the gas inflator apparatus over a wider range of operating conditions. A single electrical signal is sent to the gas inflator apparatus upon the sensing of an impact. The signal actuates an electro-explosive device which allows stored gas in the gas inflator apparatus to begin flowing into the air bag. Mechanical elements monitor the differential pressure between a pressure related to the pressure in the housing which stores the gas and a reference pressure. Upon achievement of a programmed differential pressure, the mechanical elements ignite a gas generator propellant, the combustion of which augments the flow rate into the air bag to ensure full inflation thereof.

Claims

1. An apparatus for inflating an inflatable container in which a time delay is provided and wherein a gas propellant is activated without direct use of an electric signal to increase the inflation rate, comprising:

first means for continuing gas and having a wall;

electro-explosive device means for creating a path for gas from said first means to the inflatable container, wherein said electro-explosive device means is electrically activated;

propellant means positioned within said first means; and

bistable pressure-sensing means having a first stable position and a second stable position and connected, directly or indirectly, to said first means, wherein said bistable pressure-sensing means controls activation of said propellant means and wherein said propellant means is activated after a delay dependant upon at least one factor and without electrical activation thereof to increase the flow of gas into the inflatable container.

2. An apparatus, as claimed in claim 1, further including temperature compensating means.

3. An apparatus, as claimed in claim 2, wherein said temperature compensating means reduces said delay as the ambient temperature decreases.

4. An apparatus, as claimed in claim 2, wherein said temperature compensating means increases said delay as the ambient temperature increases.

5. An apparatus, as claimed in claim 1, wherein said bistable pressure-sensing means monitors a differential pressure between a first pressure related to the pressure of the gas in said first means and a reference pressure.

6. An apparatus, as claimed in claim 5, wherein at least a portion of said bistable pressure-sensing means moves from said first stable position to said second stable position when said reference pressure exceeds said first pressure by a predetermined amount to initiate activation of said propellant means.

7. An apparatus, as claimed in claim 6, wherein said bistable pressure sensing means includes diaphragm means deflected in one position in said first stable position and deflected is an opposite position in said second stable position.

8. An apparatus, is claimed in claim 6, wherein said bistable pressure sensing means includes retaining means and projectile means, said first stable position being retention of said projectile means by said retaining means and said second stable position being the release of said projectile means by said retaining means.

9. An apparatus, as claimed in claim 6, wherein said bistable pressure sensing means includes retention pin means and projective means, said first stable position being retention of said projectile by said retention means and said second stable position being the breaking of said retention means to release said projectile means.

10. An apparatus, as claimed in claim 6, wherein movement of said bistable pressure-sensing means from said first to said second stable position propels firing mass means into contact with ignition means to activate said propellant means.

11. An apparatus, as claimed in claim 10, wherein said ignition means includes at least one of the following:

pyrotechnic booster proximate to said propellant means and at least one percussion primer adjacent to said pyrotechnic booster, wherein said firing mass means is aligned with and impacts said percussion primer to activate said pyrotechnic booster and said propellant means.

12. An apparatus, as claimed in claim 1, wherein said bistable pressure sensing means includes temperature sensing means.

13. An apparatus for inflating an inflatable container, comprising:

first enclosure means containing compressed gas under a first pressure;

first barrier means for providing a barrier between said first enclosure means and the inflatable container;

means for removing said first barrier means, wherein said compressed gas in said first enclosure means begins to flow said first enclosure means into the inflatable container;

a combustible material positioned within said first enclosure means;

pressure-sensing means connected, directly or indirectly, to said first enclosure means for controlling ignition of said combustible material, wherein said combustible material is ignited after a delay dependent upon at least one factor; and

temperature compensating means connected, directly or indirectly, to said first enclosure means, wherein said temperature compensating means automatically adjusts said delay based upon the ambient temperature.

14. An apparatus, as claimed in claim 13, wherein said pressure-sensing means monitors a differential pressure between a second pressure related to said first pressure and a reference pressure.

15. An apparatus, as claimed in claim 14, wherein said pressure-sensing means initiates ignition of said combustible material when said reference pressure exceeds said second pressure by a predetermined amount.

16. An apparatus, as claimed in claim 14, wherein said pressure-sensing means includes at least retaining means and projectile means.

17. An apparatus, as claimed in claim 16, wherein said retaining means releases said projectile means when said reference pressure exceeds said second pressure by a predetermined amount to initiate ignition of said combustible material.

18. An apparatus, as claimed in claim 17, wherein said retaining means in part of said temperature compensating means.

19. An apparatus, as claimed in claim 18, wherein said retaining means reduces the pressure differential required to release said projectile means as the ambient temperature decreases.

20. An apparatus, as claimed in claim 18, wherein said retaining means increases the pressure differential required to release said projectile means as the ambient temperature increases.

21. An apparatus, as claimed in claim 17, wherein said projectile means impacts ignition means to ignite said combustible material.

22. An apparatus, as claimed in claim 21, wherein said ignition means includes at least one of the following:

pyrotechnic booster proximate to said combustible material and at least one percussion primer adjacent to said pyrotechnic booster, wherein said projectile means impacts said percussion primer to ignite said combustible material.

23. An apparatus, as claimed in claim 16, wherein said pressure-sensing means is positioned within second enclosure means connected to said first enclosure means.

24. An apparatus, as claimed in claim 23, wherein said pressure-sensing means separates said second enclosure means into first and second chambers, said first chamber being in communication with said first enclosure means and under said second pressure, said second pressure being substantially equal to said first pressure in the static state, and said second chamber containing compressed gas at said reference pressure.

25. An apparatus, as claimed in claim 24, wherein said pressure-sensing means is positioned in tube means connecting said first and second chambers.

26. An apparatus, as claimed in claim 25, wherein said retaining means releases said projectile means when said reference pressure exceeds said second pressure by a predetermined amount to initiate ignition of said combustible material.

27. An apparatus, as claimed in claim 26, wherein said retaining means is part of said temperature compensating means.

28. An apparatus, as claimed in claim 27, wherein said retaining means reduces the pressure differential required to release said projectile means as the ambient temperature deceases.

29. An apparatus, as claimed in claim 27, wherein said retaining means increases the pressure differential required to release said projectile means as the ambient increases.

30. An apparatus, as claimed in claim 14, wherein said pressure sensing means includes diaphragm means.

31. An apparatus, as claimed in claim 30, wherein said diaphragm means moves from a first position to a second position when said reference pressure exceeds said second pressure by a predetermined amount to initiate ignition of said combustible material.

32. An apparatus, as claimed in claim 31, wherein said diaphragm means is part of said temperature compensating means.

33. An apparatus, as claimed in claim 32, wherein a smaller pressure differential is required to move said diaphragm means from said first position to said second position as the ambient temperature decreases.

34. An apparatus, as claimed in claim 32, wherein a larger pressure differential is required to move said diaphragm means from said position to said second position as the ambient temperature increases.

35. An apparatus, as claimed in claim 30, wherein said pressure sensing means is positioned within second enclosure means connected to said first enclosure means.

36. An apparatus, as claimed in claim 35, wherein said diaphragm means separates said second enclosure means into first and second chambers, said first chamber being in communication with said first enclosure means and under said second pressure, said second pressure being substantially equal to said first pressure in the static state, and said second chamber containing compressed gas at said reference pressure.

37. An apparatus, as claimed in claim 36, wherein said diaphragm means moves from a first position to a second position when said reference pressure exceeds said second pressure by a predetermined amount to initiate ignition of said combustion material.

38. An apparatus, as claimed in claim 37, wherein said diaphragm means is part of said temperature compensating means.

39. An apparatus, as claimed in claim 38, wherein a smaller pressure differential is required to move said diaphragm means from said first position to said second position as the ambient temperature decreases.

40. An apparatus, as claimed in claim 38, wherein a larger pressure differential is required to move said diaphragm means from said first position to said second position as the ambient temperature increases.

41. An apparatus, as claimed in claim 13, wherein said temperature compensating means reduces said delay as the ambient temperature decreases.

42. An apparatus, as claimed in claim 13, wherein said temperature compensating means increases said delay as the ambient temperature increases.