Multiple stage airbag gas generator

• US 5,839,754 A
• Filed: 06/06/1996
• Issued: 11/24/1998
• Est. Priority Date: 06/08/1995
• Status: Expired due to Fees

• Current Assignee: Honda R&D Company Limited (Honda Motor Company)
• Original Assignee: Honda R&D Company Limited (Honda Motor Company), Nippon Koki Co., Ltd. (NOF Corporation)
• Inventors: Schwarz, Wolfgang, Kishimoto, Junichi, Kuscher, Gerd, Klober, Martin, Schneider, Karl-Heinz, Honda, Kiyoshi, Schluter, Klaus, Feuerstake, Eugen, Kobayashi, Seiichiroh
• Primary Examiner(s): English, Peter C.
• Application Number:
  US08/659,493
• Time in Patent Office: 901 Days
• Field of Search: 280/736, 280/741, 280/742, 280/740, 280/737, 102/531, 102/530
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

After the pressure of the gas in a first chamber reaches the maximum value, the cover for the air bag is broken up. The cover is broken at the pressure of the maximum value, and there is almost no waste of the gas energy. Thus, the cover can be broken up by the small amount of the gas energy and the heat losses are extremely reduced, so that the amount of the gas generating agents are made small. Also, the cover is broken by the burning of the first chamber and the air bag is inflated at the first stage by expansion and inertia of the gas. There is provided a mechanical timing for ignition delay, and then the bag is fully inflated by the burning of a second chamber. Therefore, the bag can be desirably inflated.

Claims

1. A gas generating apparatus for an automobile air bag having a cover;

comprising a first chamber containing first gas generating agents;

an igniter which is actuated when an automobile crash is detected to ignite said first gas generating agents;

first passage means communicating said first chamber with said air bag and metallic foil covering said first passage means;

a second chamber containing second gas generating agents extending about said first chamber;

gas bores communicating said second chamber with said first chamber;

second passage means communicating said second chamber with said air bag and metallic foil covering said second passage means;

said igniter upon being actuated causing said first gas generating agents in said first chamber to ignite to generate a first gas rupturing the metallic foil covering said first passage means and a portion of said first gas flowing into said air bag through said first passage means, and a further portion of said first gas flowing into said second chamber to ignite the second gas generating agents to generate a second gas rupturing the metallic foil covering said second passage means and flowing into said air bag, said first passage means being differently sized relative to the gas bores between said first and second chambers and the positioning of the rupturable metallic foil over said first and second passage means causing said cover to be torn open to facilitate expansion of said air bag after the first gas in said first chamber has reached a maximum pressure and said second gas in said second chamber reaches a maximum pressure after said cover has been torn open and at a time delay caused by a difference in the sizes between the first passage means and the gas bores between said first and second chambers.

2. A gas generating apparatus according to claim 1, wherein said igniter has an igniter housing (35), said first chamber (30) being disposed annularly around said igniter housing (35).

3. A gas generating apparatus according to claim 1, wherein said second passage means comprises gas bores (15) formed in an outer wall of the second chamber.