Inflatable restraint system with gas augmentation

• US 5,509,686 A
• Filed: 05/04/1992
• Issued: 04/23/1996
• Est. Priority Date: 05/04/1992
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Shepherd, Jeffrey A., Donegan, Michael W.
• Primary Examiner(s): Focarino, Margaret A.
• Assistant Examiner(s): English, Peter C.
• Application Number:
  US07/878,712
• Time in Patent Office: 1,450 Days
• Field of Search: 280/740, 280/728, 280/736, 280/738, 280/742, 280/728.1, 222/3
• US Class Current: 280/738
• CPC Class Codes: B60R 21/30 with means to draw ambient air into the flow line and mix such air with the inflation fluid

Abstract

An air bag assembly for an inflatable passenger vehicle restraint system comprises an inflatable air bag, a thrust neutral inflator for generating pressure gas and a reaction canister. The inflator has a cylindrical casing with a plurality of holes on opposite sides for discharging the gas to inflate the air bag. The reaction canister houses the inflator and has a part-cylindrical bottom wall terminating in upstanding side walls which operatively connect the inflator to the air bag. A plurality of aspiration holes are formed in the reaction canister side walls. A part-cylindrical baffle is mounted in the canister between the inflator and the bottom wall and has an outlet to direct gas discharged from the inflator away from the walls and to the air bag. Ambient air is aspirated through the aspirator holes upon gas delivery from the inflator discharge ports to augment the volume of gas delivered to the air bag. The aspirator holes also serve as pressure relief vents for the air bag.

Claims

1. An air bag assembly comprising:

an inflatable air bag having a central opening;

a thrust neutral inflator for generating pressure gas and having a cylindrical casing with a plurality of diametrically opposed gas discharge holes for discharging the gas in diametrically opposed directions to inflate the air bag;

a reaction canister housing the inflator and having a part-cylindrical bottom wall terminating in upstanding side walls and including end walls closing the ends of the side and bottom walls, and the inflator being mounted on the end walls, and the side and end walls defining a canister gas discharge opening remote from the inflator and having the central opening of the air bag mating therewith so that gas discharged from the inflator travels upwardly through the canister and out through the canister discharge opening into the air bag via the central opening;

a plurality of aspiration holes continuously communicable with ambient air and located in the reaction canister side walls adjacent the gas discharge holes of the inflator such that gas discharged from the inflator is directed at the aspiration holes; and

a cylindrical baffle which is mounted in the canister surrounding the inflator and remote and separate from the canister discharge opening and the air bag, the baffle being interposed directly between the inflator and the aspiration holes in the reaction canister side walls to prevent discharging inflator gas from communicating out through the aspiration holes to the ambient air, the baffle being spaced from the inflator and the aspiration holes and having a baffle outlet to direct gas discharged from the inflator away from the aspiration holes and upwardly through the canister and out through the canister discharge opening and into the air bag so that the baffle provides directional thrust from the thrust neutral inflator to enable the use of a thrust neutral inflator with a canister having a plurality of aspiration holes for ambient air aspiration, whereby upon air bag deployment, the directional thrust creates a pressure drop around the baffle such that ambient air is aspirated in through the aspiration holes to augment the volume of gas delivered to the air bag by the inflator.

2. The air bag assembly of claim 1, wherein the baffle includes cylindrical end portions flanking the outlet which engage the ends of the inflator casing.

3. An air bag assembly comprising:

an inflatable air bag;

a thrust neutral inflator for generating pressure gas and having a cylindrical casing with a plurality of diametrically opposed gas discharge holes for discharging the gas in diametrically opposed horizontal directions to inflate the air bag;

a reaction canister housing the inflator and having walls defining a canister outlet for operatively connecting the inflator to the air bag for delivering gas therethrough;

a plurality of aspiration holes continuously communicable with ambient air and located in the reaction canister walls adjacent the gas discharge holes of the inflator such that gas discharged from the inflator is directed at the aspiration holes; and

a baffle which is mounted in the canister between the inflator and the reaction canister walls to prevent discharging inflator gas from communicating out through the aspiration holes to the ambient air, the baffle being spaced from the inflator and the aspiration holes to the ambient air and having a baffle outlet to direct gas discharged from the inflator away from the aspiration holes to the canister outlet and a pair of longitudinal wing-like flaps bordering said baffle outlet, whereby upon air bag deployment, pressure drops around the baffle and ambient air is aspirated in through the aspiration holes to augment the volume of gas delivered to the air bag and said wing-like flaps are operable to reduce losses caused by turbulent gas flow.

4. The air bag assembly of claim 3, wherein the baffle is part-cylindrical, is rigid, and is closely spaced from the inflator casing a distance of about 3-5 mils.