Externally vented airbag assembly

• US 5,351,977 A
• Filed: 11/03/1992
• Issued: 10/04/1994
• Est. Priority Date: 11/03/1992
• Status: Expired due to Fees

• Current Assignee: TRW Inc. (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Grace, Gregory B.
• Primary Examiner(s): FERRITER, KARIN L
• Application Number:
  US07/970,916
• Time in Patent Office: 700 Days
• Field of Search: 280/739, 280/736, 280/731, 280/738, 280/743, 280/728 R
• US Class Current: 280/738
• CPC Class Codes: B60R 21/2032 the inflator or inflatable member not being rotatable with the steering wheel; Arrangements using the steering column or steering wheel rim for storing, supplying or evacuating the inflation gas or for storing the inflatable member
• CPC Class Codes: B60R 21/237 characterised by the way they are folded
• 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

Abstract

An airbag assembly (12/112) is incorporated into a vehicle (10) that includes a steering assembly (16/116) and a firewall (18). The firewall (18) at least partially defines an occupant compartment (20) and separates the occupant compartment (20) from an external environment (22). In one embodiment, the steering assembly (16) includes a steering column (50) defining an inlet passageway (71) and a separate exhaust passageway (73). The passageways (71) and (73) communicate separately with an airbag (30) through a mouth portion (32) of the airbag. The inlet passageway (71) communicates with an inflator (40), and the exhaust passageway (73) communicates with the external environment (22). Inflation fluid travels through the inlet passageway (71) into the airbag (30), and inflation fluid is vented through the outlet passageway (73) to the external environment (22). In another embodiment, the airbag (130) includes a mouth portion (132) which defines a fluid inlet opening and another portion (134) which defines one or more separate exhaust vents (136). Each exhaust vent (136) communicates with an exhaust passageway (173) in a steering column (150) to vent inflation fluid to the external environment (22).

Claims

1. In combination, a vehicle and an airbag assembly;

said vehicle comprising a steering assembly and a firewall;

said firewall partially defining an occupant compartment and separating said occupant compartment from an external environment;

said steering wheel assembly being positioned at least partially within said occupant compartment;

said airbag assembly being mounted on said steering assembly;

said airbag assembly comprising an airbag and an inflator which supplies inflation fluid to said airbag to inflate said airbag into said occupant compartment;

said steering assembly comprising a steering column defining an inlet passageway which communicates with said airbag and a separate exhaust passageway which communicates with said airbag separately and independently of said inlet passageway;

said inlet passageway communicating with said inflator whereby inflation fluid travels through said inlet passageway into said airbag; and

said exhaust passageway communicating with said external environment whereby at least a certain portion of said inflation fluid is vented to said external environment.

2. The combination set forth in claim 1 wherein said airbag includes a mouth portion which defines an opening and said airbag defines a chamber which is closed except for said opening.

3. The combination set forth in claim 2 wherein said steering assembly further comprises a steering shaft and a steering wheel;

said steering shaft is rotatable relative to said steering column and controls the steering of said vehicle during operation of said vehicle;

said steering wheel is fixedly coupled to said steering shaft; and

said steering wheel includes a hub and said airbag is coupled to said hub.

4. In combination, a vehicle and an airbag assembly;

said vehicle comprising a steering assembly and a firewall;

said firewall partially defining an occupant compartment and separating said occupant compartment from an external environment;

said steering assembly being positioned at least partially within said occupant compartment;

said steering assembly comprising a steering column defining an exhaust passageway which communicates with said external environment;

said airbag assembly being mounted on said steering assembly;

said airbag assembly comprising an airbag including a mouth portion which defines a fluid inlet opening and another portion which defines one or more exhaust vents;

said airbag assembly further comprising an inflator which supplies inflation fluid into said fluid inlet opening to inflate said airbag into said occupant compartment; and

each of said exhaust vents communicating with said exhaust passageway to vent inflation fluid from said airbag to said external environment.

5. The combination set forth in claim 4 wherein said airbag defines a chamber which is closed except for said fluid inlet opening and said exhaust vents.

6. The combination set forth in claim 5 wherein said steering assembly further comprises a steering shaft and a steering wheel;

said steering shaft is rotatable relative to said steering column and controls the steering of said vehicle during operation of said vehicle;

said steering wheel is fixedly coupled to said steering shaft; and

said steering wheel includes a hub and said airbag and said inflator are coupled to said hub.

7. The combination set forth in claim 6 wherein:

said hub defines a set of channels which communicate with said exhaust passageway; and

said portion of said airbag defining said exhaust vents is coupled to said hub in such manner that each of said exhaust vents communicates with one of said channels whereby inflation fluid will travel through said exhaust vents, into said channels, into said exhaust passageway, and subsequently exhaust to said external environment.

8. In combination, a vehicle and an airbag assembly;

said vehicle comprising a firewall which partially defines an occupant compartment and separates said occupant compartment from an external environment;

said airbag assembly being coupled to said vehicle;

said airbag assembly comprising an airbag that defines a chamber which is closed except for a fluid inlet opening and one or more separate exhaust vents;

said airbag assembly further comprising an inflator which supplies inflation fluid into said fluid inlet opening to inflate said airbag into said occupant compartment; and

each of said exhaust vents communicating with said external environment separately and independently of said fluid inlet opening whereby said inflation fluid is vented to said external environment.

9. The combination set forth in claim 8 wherein said vehicle further comprises a steering assembly positioned at least partially within said occupant compartment and wherein said airbag assembly is mounted to said steering assembly.

10. The combination set forth in claim 9 wherein said steering assembly comprises a steering column defining an exhaust passageway between said exhaust vents and said external environment.

11. An airbag assembly comprising an airbag and an inflator;

said airbag having a portion defining a fluid inlet opening and a portion defining one or more exhaust vents;

said inflator being positioned to supply inflation fluid into said fluid inlet opening to inflate said airbag during a deployment process;

said airbag being folded in a pre-deployment folding pattern in which said exhaust vents are blocked during early stages of said deployment process and are subsequently unblocked to vent said inflation fluid during latter stages of said deployment process;

said pre-deployment folding pattern consisting essentially of a mushroom-shaped fold and a pair of accordion pleats separated by said mushroom-shaped fold, said mushroom-shaped fold substantially blocking said inflator so that during said early stages of said deployment process said pair of accordion pleats are forced by said mushroom-shaped fold in a direction radially outward from an axis defined by the direction of fluid flow into said airbag.

12. An airbag assembly comprising an airbag and an inflator;

said airbag having a portion defining a fluid inlet opening and a portion defining one or more exhaust vents;

said inflator being positioned to supply inflation fluid into said fluid inlet opening to inflate said airbag during a deployment process;

said airbag being folded in a pre-deployment folding pattern in which said exhaust vents are blocked during early stages of said deployment process and are subsequently unblocked to vent said inflation fluid during latter stages of said deployment process

said pre-deployment folding pattern consisting essentially of a mushroom-shaped fold and a pair of accordion pleats separated by said mushroom-shaped fold;

said mushroom-shaped fold being formed from a passenger-contacting portion of said airbag and includes a top and a stem;

a central section of said passenger-contacting portion forms said top of said mushroom-shaped fold;

sections of said passenger-contacting portion adjacent said central section overlapping to form said stem of said mushroom-shaped fold;

said top being positioned immediately adjacent said inflator and said stem extends outwardly from said inflator;

said accordion pleats being formed from remaining portions of said airbag; and

said accordion pleats being positioned outwardly from said top of said mushroom-shaped fold and on either side of said stem of said mushroom-shaped fold.

13. In combination, a vehicle and an airbag assembly;

said vehicle comprising a steering assembly and a firewall;

said firewall partially defining an occupant compartment and separating said occupant compartment from an external environment;

said steering assembly being positioned at least partially within said occupant compartment;

said airbag assembly being mounted on said steering assembly;

said airbag assembly comprising an airbag and an inflator which supplies inflation fluid to said airbag to inflate said airbag into said occupant compartment, said airbag including a mouth portion which defines an opening and said airbag defining a chamber which is closed except for said opening;

said steering assembly comprising (i) a steering column comprising an inlet casing, an outlet casing, and a shaft housing, said inlet casing defining an inlet passageway which communicates with said airbag, said exhaust casing defining an exhaust passageway which also communicates with said airbag, (ii) a steering shaft which is surrounded by said shaft housing and which is rotatable relative to said steering column to control the steering of said vehicle during operation of said vehicle, and (iii) a steering wheel which is fixedly coupled to said steering shaft and which includes a hub to which is coupled said airbag, said hub including a plurality of ports allowing said inlet passageway and said exhaust passageway to communicate with said chamber of said airbag;

said inlet passageway communicating with said inflator whereby inflation fluid travels through said inlet passageway into said airbag; and

said exhaust passageway communicating with said external environment whereby at least a certain portion of said inflation fluid is vented to said external environment.

14. The combination set forth in claim 13 wherein said inflator is mounted to a portion of said inlet casing and an opening is provided in said inlet casing so that said inflator may communicate with said inlet passageway.

15. An airbag assembly comprising an airbag and an inflator;

said airbag having a portion defining a fluid inlet opening and a portion defining one or more exhaust vents;

said inflator being positioned to supply inflation fluid into said fluid inlet opening to inflate said airbag during a deployment process;

said airbag being folded in a pre-deployment folding pattern in which said exhaust vents are blocked during early stages of said deployment process and are subsequently unblocked to vent said inflation fluid during latter stages of said deployment process;

said pre-deployment folding pattern comprising a mushroom-shaped fold and a pair of accordion pleats separated by said mushroom-shaped fold, said mushroom-shaped fold substantially blocking said inflator so that during said early stages of said deployment process said pair of accordion pleats are forced by said mushroom-shaped fold in a direction radially outward from an axis defined by the direction of fluid flow into said airbag.