Gas generator for air bag and air bag apparatus

• US 6,997,475 B2
• Filed: 08/30/2004
• Issued: 02/14/2006
• Est. Priority Date: 11/29/1999
• Status: Expired due to Term

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Yabuta, Mikio, Watase, Takefumi
• Primary Examiner(s): Ilan, Ruth
• Application Number:
  US10/928,136
• Publication Number:
  US 20050029786A1
• Time in Patent Office: 533 Days
• Field of Search: 280/736, 280/741, 280/737, 102/530, 102/531
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• 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

Abstract

A gas generator for an air bag capable of easily and unfailingly closing a gas discharging port formed in a housing. An amount of accommodated gas generating agent can be varied and the gas generating agent can be ignited and burnt unfailingly even by ignition devices having normal output. The gas generator has sealing structures as small as possible and a simple structure, and can be manufactured easily. Activation performance and activation timing can be adjusted at multiple stages. For instance, the air bag housing may be provided at its peripheral wall with a plurality of gas discharging ports, an ignition device to be actuated upon impact, and a gas generating agent to be ignited and burnt by the ignition device, wherein the gas discharging ports are arranged in the axial direction of the housing to form a gas discharging port line. Other configurations are also disclosed.

Claims

1. A gas generator for an air bag comprising, in a cylindrical housing which is longer in the axial direction than in the radial direction, an ignition means to be actuated upon the impact, and a gas generating means to be ignited and burnt by the ignition means,

wherein a combustion chamber for accommodating the gas generating means and a filter means accommodating chamber for accommodating a filter means are formed in the housing adjacent to each other in the axial direction and these chambers communicate with each other,

wherein the combustion chamber accommodating the gas generating means is separated from the filter means accommodating chamber by a partitioning member having a through-hole, and

wherein the cylindrical housing comprises a cylindrical diffuser shell provided at its peripheral wall with a plurality of gas discharging ports, and closure shells for closing the opposite end openings of the peripheral wall, the closure shell closing the opening in the filter means accommodating chamber side comprises an annular portion connected to an opening edge of the diffuser shell, a circular portion projecting from the annular portion toward the filter means accommodating chamber, and a screw portion projecting from the annular portion out of the housing, and the circular portion abuts against an inner peripheral surface of the filter means to support the filter means.

2. A gas generator for an air bag according to claim 1, wherein a filter supporting member which has an inner peripheral wall of an annular portion projecting into a hollow portion of the filter means and an outer peripheral wall fitted into the housing is disposed on the filter means in the combustion chamber side, and the filter means is supported by and fixed to the inner peripheral wall of the filter means supporting member and the circular portion of the closure shell.

3. A gas generator for an air bag comprising, in a cylindrical housing which is longer in the axial direction than in the radial direction, an ignition means to be actuated upon the impact, and a gas generating means to be ignited and burnt by the ignition means,

wherein a combustion chamber for accommodating the gas generating means and a filter means accommodating chamber for accommodating a filter means are formed in the housing adjacent to each other in the axial direction, the gas generating means accommodated in the combustion chamber is pressed and/or held towards the filter means accommodating chamber side by an inwardly flange-shaped plate member fitted into the combustion chamber, and the plate member is slidable in the axial direction of the housing, and

wherein the cylindrical housing comprises a cylindrical diffuser shell provided at its peripheral wall with a plurality of gas discharging ports, and closure shells for closing the opposite end openings of the peripheral wall, the closure shell closing the opening in the filter means accommodating chamber side comprises an annular portion connected to an opening edge of the diffuser shell, a circular portion projecting from the annular portion toward the filter means accommodating chamber, and a screw portion projecting from the annular portion out of the housing, and the circular portion abuts against an inner peripheral surface of the filter means to support the filter means.

4. A gas generator for an air bag according to claim 3, wherein a filter supporting member which has an inner peripheral wall of an annular portion projecting into a hollow portion of the filter means and an outer peripheral wall fitted into the housing is disposed on the filter means in the combustion chamber side, and the filter means is supported by and fixed to the inner peripheral wall of the filter means supporting member and the circular portion of the diffuser shell.