Reduced airbag deployment skewness with non-symmetric gas output inflators

• US 5,967,551 A
• Filed: 07/23/1996
• Issued: 10/19/1999
• Est. Priority Date: 12/18/1992
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Newkirk, John C., Thompson, Mark A., Rose, Larry D., Green, David J., Ravenberg, Michael J., Davis, Terry R., Lauritzen, Donald R.
• Primary Examiner(s): CULBRETH, ERIC D
• Application Number:
  US08/685,160
• Time in Patent Office: 1,183 Days
• Field of Search: 280/740, 280/741, 280/742, 280/736
• US Class Current: 280/740
• CPC Class Codes: B60R 21/2171 specially adapted for elongated cylindrical or bottle-like inflators with a symmetry axis perpendicular to the main direction of bag deployment, e.g. extruded reaction canisters B60R21/2176 takes precedence
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid

Abstract

An improvement in inflatable restraint air bag module assemblies with non-symmetric gas output inflators wherein a diffuser of specific design and in cooperation with the reaction canister results in reduced air bag deployment skewness.

Claims

1. An inflatable restraint air bag module assembly comprising:

an inflatable air bag having an inflation gas inlet opening,

an elongated non-symmetric gas output inflator having a longitudinal length and at least one inflation gas outlet port at one end thereof to emit inflation gas upon actuation,

an elongated open-mouthed reaction canister forming a housing for said air bag and said inflator, said reaction canister including first and second opposed longitudinal sides and first and second opposed parallel lateral ends and forming a mouth for the deployment of said air bag therethrough, and

an inflation gas diffuser including a lace member interposed between the at least one inflator gas outlet port and the air bag gas inlet opening, the face member including a gas flow through area comprising at least one inflation gas passage aperture for conveying inflation gas from said inflator to said air bag,

wherein the reaction canister sides and ends each include sections extending beyond said diffuser towards the reaction canister mouth, said diffuser cooperating with the extending sections of the reaction canister sides and ends to define a cavity for housing said air bag when in a stored, uninflated condition,

wherein a sufficient portion of the diffuser gas flow through area is adjacent one of a) the extending section of the reaction canister first end, b) the extending section of the reaction canister second end, and c) the extending sections of the reaction canister first and second ends, such that upon actuation of said inflator, said diffuser and said reaction canister cooperate whereby said air bag deploys from said reaction canister in a non-skewed manner without the flow of inflation gas through said diffuser being significantly restricted,

wherein the inflator end having the at least one inflation gas outlet port is adjacent the reaction canister first end and the sufficient portion of the diffuser gas flow through area includes a first area adjacent the reaction canister first end and a second area adjacent the reaction canister second end, and

wherein the first area comprises at least 60% of the total of the first and the second areas.

2. The inflatable restraint air bag module assembly of claim 1 wherein the diffuser face portion additionally comprises at least one inflation gas passage aperture interposed between the first and the second areas.

3. An inflatable restraint air bag module assembly installation comprising:

an inflatable air bag having an inflation gas inlet opening,

an elongated non-symmetric gas output hybrid inflator having a longitudinal length and at least one inflation gas output port at one end thereof to emit inflation gas upon actuation,

an elongated open-mouthed reaction canister forming a housing for said air bag and said inflator, said reaction canister including first and second opposed longitudinal sides and first and second opposed parallel lateral ends and forming a mouth for the deployment of said air bag therethrough, and

an inflation gas diffuser including a face member interposed between the at least one inflator gas outlet port and the air bag gas inlet opening, the face member including a gas flow through area comprising a plurality of inflation gas passage apertures for conveying inflation gas from said inflator to said air bag,

wherein the reaction canister sides and ends each include sections extending beyond said diffuser towards the reaction canister mouth, said diffuser cooperating with the extending sections of the reaction canister sides and ends to define a cavity for housing said air bag when in a stored, uninflated condition,

wherein the module assembly is installed in a central region of a vehicle dashboard, between an upper portion and a lower portion of the vehicle dashboard, with said air bag having a direction of deployment generally directly towards an oppositely seated vehicle occupant,

wherein a sufficient first portion of the diffuser gas flow through area is adjacent the reaction canister first end and a sufficient second portion of the diffuser gas flow through area is adjacent the reaction canister second end such that upon actuation of said inflator, the extending sections of the reaction canister sides and ends and the first and second end adjacent portions of the diffuser gas flow through area cooperate to provide at least about 70% of the gas flow passing into said air bar at the reaction canister mouth is parallel to the reaction canister first and second ends whereby said air bag deploys from said reaction canister in a non-skewed manner without the flow of inflation gas through said diffuser being significantly restricted, and

wherein the reaction canister first end is adjacent the inflator end having the at least one inflation gas outlet port and wherein the first portion of the diffuser gas flow through area comprises at least 60% of the total of the first and the second end adjacent portions of the diffuser gas flow through area.

4. The inflatable restraint air bag module assembly installation of claim 3 wherein the first end adjacent portion of the diffuser gas flow through area comprises no more than about 75-80% of the total gas flow through area of the diffuser.

5. The inflatable restraint air bag module assembly installation of claim 3 wherein the second end adjacent portion of the diffuser gas flow through area comprises no more than about 30-40% of the total gas flow through area of the diffuser.