Airbag vent valve and system

• US 6,273,463 B1
• Filed: 04/19/2000
• Issued: 08/14/2001
• Est. Priority Date: 04/19/2000
• Status: Expired due to Fees

• Current Assignee: Leslie D. Peterson, Richard E. Zimmermann
• Original Assignee: Leslie D. Peterson, Richard E. Zimmermann
• Inventors: Peterson, Leslie D., Zimmermann, Richard E.
• Primary Examiner(s): CULBRETH, ERIC D
• Application Number:
  US09/552,124
• Time in Patent Office: 482 Days
• Field of Search: 280/738, 280/739, 137/852, 137/855, 137/857.XC, 137/899, 137/351, 137/524, 137/512, 137/512.1 XC
• US Class Current: 280/739
• CPC Class Codes: B60R 21/276 with means to vent the inflation fluid source, e.g. in case of overpressure B60R21/30 takes precedence; venting means on inflatable member walls B60R21/239
• CPC Class Codes: F16K 15/161 with biasing means in addition to material resiliency, e.g. spring
• CPC Class Codes: Y10T 137/7839 Dividing and recombining in a single flow path

Abstract

An energy absorbing airbag system includes one or more vent valve assemblies for controlling the release of airbag inflation gases to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event. Each vent valve assembly includes a cantilever spring that is flat in an unstressed condition and that has a free end portion. The cantilever spring is secured to an exterior surface of the airbag housing and flexed to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against a vent port or a closure covering the vent port to seal the vent port until inflation gas pressure within the airbag reaches a preselected value determined by the preset force whereupon the free end portion of the cantilever spring is lifted from the vent port by the inflation gases within the airbag to vent the inflation gases from within the airbag. The resilience of the cantilever spring maintains a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event by causing the cantilever spring to vent gases through the vent port whenever the pressure of the inflation gases reaches the preselected value and by causing the cantilever spring to close the vent port whenever the pressure of the inflation gases falls below the preselected value.

Claims

1. A vent valve assembly for controlling the release of airbag inflation gases in an energy absorbing airbag system to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event, comprising:

a cantilever spring that is flat or substantially flat in an unstressed condition and has an upper major surface and a lower major surface;

the cantilever spring having a first end and a second free end portion;

means for securing the cantilever spring to an exterior surface of an airbag housing and flexing the cantilever spring to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against an exterior vent port surface, that completely surrounds and defines an exterior periphery of an airbag housing vent port, to cover and seal the vent port until inflation gas pressure within an airbag housed within the airbag housing reaches a preselected value determined by the preset force whereupon the second free end portion of the cantilever spring is lifted from the vent port by the gas pressure exerted on the second free end portion of the cantilever spring by the inflation gases within the airbag to vent the inflation gases from within the airbag; and

the resilience of the cantilever spring maintaining a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event;

by causing the cantilever spring to vent gases at a rate generally proportional to pressure exerted on the free end of the cantilever spring by the inflation gases within the airbag to vent the inflation gases more quickly as the pressure of the inflation gases within the airbag increases above the preselected value during a ride-down portion of an energy absorbing event and to vent gases less quickly as the pressure of the inflation gases within the airbag above the preselected value decreases during a ride-down portion of an energy absorbing event;

by causing the cantilever spring to close and seal the vent port whenever the pressure of the inflation gases within the airbag drops below the preselected value during a ride-down portion of an energy absorbing event; and

by causing the cantilever spring to reopen and vent inflation gases from the vent port whenever the pressure of the inflation gases within the airbag again exceeds the preselected value during a ride-down portion of an energy absorbing event.

2. The vent valve assembly according to claim 1, wherein:

the means for securing and flexing the cantilever spring is a mounting block for securing the cantilever spring to an airbag housing;

the mounting block has a spring mounting surface to which a portion of the cantilever spring adjacent the first end of the cantilever spring is secured;

the spring mounting surface is inclined relative to the exterior vent port surface of an airbag housing, when the mounting block in secured to the airbag housing, at an angle which causes the lower major surface of the cantilever spring to be inclined to the exterior vent port surface at an acute angle and to contact the vent port surface intermediate the mounting block and the vent port and which causes the cantilever spring to be flexed and pressed against the vent port surface with the preset force.

3. The vent valve assembly according to claim 2, wherein:

the means for securing and flexing the cantilever spring includes flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port.

4. The vent valve assembly according to claim 3, wherein:

the flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port is an adjustable force exerting means which can be adjusted to exert a selected downward force on the upper major surface of the cantilever spring intermediate the spring mounting surface of the mounting block and the free end portion of the cantilever spring.

5. The vent valve assembly according to claim 1, wherein:

the means for securing and flexing the cantilever spring includes flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port.

6. The vent valve assembly according to claim 1, wherein:

the cantilever spring has a longitudinal center line extending from the first end of the cantilever spring to the second end portion of the cantilever spring;

the means for securing and flexing the cantilever spring includes a pivot mounting means depending from the cantilever spring for pivotally mounting the cantilever spring intermediate the first end of the cantilever spring and the second end portion of the cantilever spring and for allowing the cantilever spring to pivot about an axis which extends generally perpendicular to the longitudinal centerline and generally parallel to the major surfaces of the cantilever spring; and

the means for securing and flexing the cantilever spring includes flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port.

7. The vent valve assembly according to claim 6, wherein:

the flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port is an adjustable force exerting means which can be adjusted to exert a selected upward force on the lower major surface of the cantilever spring intermediate the pivot axis and the first end of the cantilever spring.

8. The vent valve assembly according to claim 6, wherein:

the flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port is an adjustable force exerting means which can be adjusted to exert a selected downward force on the upper major surface of the cantilever spring intermediate the pivot axis and the free end portion of the cantilever spring.

9. The vent valve assembly according to claim 1, wherein:

the means for securing the cantilever spring to the airbag housing is adapted to form the exterior vent port surface of the airbag housing.

10. A vent valve assembly for controlling the release of airbag inflation gases in an energy absorbing airbag system to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event, comprising:

a cantilever spring that is flat or substantially flat in an unstressed condition and has an upper major surface and a lower major surface;

the cantilever spring having a first end and a second free end portion;

means for securing the cantilever spring to an exterior surface of an airbag housing and flexing the cantilever spring to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against a closure means for sealing an exterior vent port surface, that completely surrounds and defines an exterior periphery of an airbag housing vent port, to cover and seal the vent port until inflation gas pressure within an airbag housed within the airbag housing reaches a preselected value determined by the preset force whereupon the closure means and the second free end portion of the cantilever spring are lifted from the vent port by the gas pressure exerted on the second free end portion of the cantilever spring through the closure means by the inflation gases within the airbag to vent the inflation gases from within the airbag; and

the resilience of the cantilever spring maintaining a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event;

by causing the cantilever spring and closure means to vent gases at a rate generally proportional to the pressure exerted on the free end of the cantilever spring, through the closure means, by the inflation gases within the airbag to vent the inflation gases more quickly as the pressure of the inflation gases within the airbag increases above the preselected value during a ride-down portion of an energy absorbing event and to vent the inflation gases less quickly as the pressure of the inflation gases within the airbag decreases above the preselected value during a ride-down portion of an energy absorbing event;

by causing the cantilever spring, through the closure means to close and seal the vent port whenever the pressure of the inflation gases within the airbag drops below the preselected value during a ride-down portion of an energy absorbing event; and

by causing the cantilever spring, through the closure means, to reopen and vent inflation gases from the vent port whenever the pressure of the inflation gases within the airbag again exceeds the preselected value during a ride-down portion of an energy absorbing event.

11. The vent valve assembly according to claim 10, wherein:

the means for securing the cantilever spring to the airbag housing is adapted to form the exterior vent port surface of the airbag housing.

12. An energy absorbing airbag system with a vent valve assembly for controlling the release of airbag inflation gases to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event, comprising:

an airbag housing for housing an inflatable airbag;

a vent valve assembly including a cantilever spring that is flat or substantially flat in an unstressed condition and has an upper major surface and a lower major surface;

the cantilever spring having a first end and a second free end portion;

means securing the cantilever spring to an exterior surface of the airbag housing and flexing the cantilever spring to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against an exterior vent port surface, that completely surrounds and defines an exterior periphery of an airbag housing vent port, to cover and seal the vent port until inflation gas pressure within the airbag housed within the airbag housing reaches a preselected value determined by the preset force whereupon the second free end portion of the cantilever spring is lifted from the vent port by the gas pressure exerted on the second free end portion of the cantilever spring by the inflation gases within the airbag to vent the inflation gases from within the airbag; and

the resilience of the cantilever spring maintaining a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event;

by causing the cantilever spring to vent gases at a rate generally proportional to the pressure exerted on the free end of the cantilever spring by the inflation gases within the airbag to vent the inflation gases more quickly as the pressure of the inflation gases within the airbag increases above the preselected value during a ride-down portion of an energy absorbing event and to vent gases less quickly as the pressure of the inflation gases within the airbag above the preselected value decreases during a ride-down portion of an energy absorbing event;

by causing the cantilever spring to close and seal the vent port whenever the pressure of the inflation gases within the airbag drops below the preselected value during a ride-down portion of an energy absorbing event; and

by causing the cantilever spring to reopen and vent inflation gases from the vent port whenever the pressure of the inflation gases within the airbag again exceeds the preselected value during a ride-down portion of an energy absorbing event.

13. The energy absorbing airbag system according to claim 12, wherein:

the means for securing and flexing the cantilever spring is a mounting block securing the cantilever spring to the airbag housing;

the mounting block has a spring mounting surface to which a portion of the cantilever spring adjacent the first end of the cantilever spring is secured;

the spring mounting surface is inclined relative to the exterior vent port surface of the airbag housing at an angle which causes the lower major surface of the cantilever spring to be inclined to the exterior vent port surface at an acute angle and to contact the vent port surface intermediate the mounting block and the vent port and which causes the cantilever spring to be flexed and pressed against the vent port surface with the preset force.

14. The energy absorbing airbag system according to claim 13, wherein:

the means for securing and flexing the cantilever spring includes flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port.

15. The energy absorbing airbag system according to claim 14, wherein:

the flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port is an adjustable force exerting means which can be adjusted to exert a selected downward force on the upper major surface of the cantilever spring intermediate the spring mounting surface of the mounting block and the free end portion of the cantilever spring.

16. The energy absorbing airbag system according to claim 12, wherein:

the means for securing and flexing the cantilever spring includes flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port.

17. The energy absorbing airbag system according to claim 12, wherein:

the cantilever spring has a longitudinal center line extending from the first end of the cantilever spring to the second end portion of the cantilever spring;

the means for securing and flexing the cantilever spring includes a pivot mounting means depending from the cantilever spring for pivotally mounting the cantilever spring intermediate the first end of the cantilever spring and the second end portion of the cantilever spring and for allowing the cantilever spring to pivot about an axis which extends generally perpendicular to the longitudinal centerline and generally parallel to the major surfaces of the cantilever spring; and

the means for securing and flexing the cantilever spring includes flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port.

18. The energy absorbing airbag system according to claim 17, wherein:

the flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port is an adjustable force exerting means which can be adjusted to exert a selected upward force on the lower major surface of the cantilever spring intermediate the pivot axis and the first end of the cantilever spring.

19. The energy absorbing airbag system according to claim 17, wherein:

the flexure adjusting means for adjusting the flexure of the cantilever spring and the preset force with which the second free end portion of the cantilever spring is pressed against the exterior vent port surface to cover and seal the vent port is an adjustable force exerting means which can be adjusted to exert a selected downward force on the upper major surface of the cantilever spring intermediate the pivot axis and the free end portion of the cantilever spring.

20. The energy absorbing airbag system according to claim 12, wherein:

the exterior vent port surface of the airbag housing is formed by a portion of the means securing the cantilever spring to the airbag housing.

21. The energy absorbing airbag system according to claim 12, wherein:

there are a plurality of vent valve assemblies secured to the airbag housing for controlling the release of airbag inflation gases through a plurality of the airbag housing vent ports.

22. The energy absorbing airbag system according to claim 21, wherein:

internal vent closure means is included within the airbag housing for closing the vent ports to prevent the venting of inflation gases through the vent ports at the initiation of airbag inflation.

23. The energy absorbing airbag system according to claim 22, wherein:

the internal vent closure means is a canister that is slidably mounted within the airbag housing;

the canister includes a sleeve portion slidably received within the airbag housing and an airbag retainer; and

the sleeve portion of the canister has an outer surface, generally conforming in cross section to an interior surface of the airbag housing, that closes the vent ports until the canister is moved a preselected distance within the airbag housing by inflation gases.

24. An energy absorbing airbag system with a vent valve assembly for controlling the release of airbag inflation gases to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event, comprising:

an airbag housing for housing an inflatable airbag;

a vent valve assembly including a cantilever spring that is flat or substantially flat in an unstressed condition and has an upper major surface and a lower major surface;

the cantilever spring having a first end and a second free end portion;

means securing the cantilever spring to an exterior surface of the airbag housing and flexing the cantilever spring to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against a closure means for sealing an exterior vent port surface, that completely surrounds and defines an exterior periphery of an airbag housing vent port, to cover and seal the vent port until inflation gas pressure within the airbag housed within the airbag housing reaches a preselected value determined by the preset force whereupon the closure means and the second free end portion of the cantilever spring are lifted from the vent port by the gas pressure exerted on the second free end portion of the cantilever spring through the closure means by the inflation gases within the airbag to vent the inflation gases from within the airbag; and

the resilience of the cantilever spring maintaining a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event;

by causing the cantilever spring and closure means to vent gases at a rate generally proportional to the pressure exerted on the free end of the cantilever spring, through the closure means, by the inflation gases within the airbag to vent the inflation gases more quickly as the pressure of the inflation gases within the airbag increases above the preselected value during a ride-down portion of an energy absorbing event and to vent gases less quickly as the pressure of the inflation gases within the airbag above the preselected value decreases during a ride-down portion of an energy absorbing event;

by causing the cantilever spring, through the closure means, to close and seal the vent port whenever the pressure of the inflation gases within the airbag drops below the preselected value during a ride-down portion of an energy absorbing event; and

by causing the cantilever spring, through the closure means, to reopen and vent inflation gases from the vent port whenever the pressure of the inflation gases within the airbag again exceeds the preselected value during a ride-down portion of an energy absorbing event.

25. The energy absorbing airbag system according to claim 24, wherein:

the exterior vent port surface of the airbag housing is formed by a portion of the means securing the cantilever spring to the airbag housing.

26. The energy absorbing airbag system according to claim 24, wherein:

there are a plurality of vent valve assemblies secured to the airbag housing for controlling the release of airbag inflation gases through a plurality of the airbag housing vent ports.

27. The energy absorbing airbag system according to claim 26, wherein:

internal vent closure means is included within the airbag housing for closing the vent ports to prevent the venting of inflation gases through the vent ports at the initiation of airbag inflation.