Ignition train apparatus for hybrid airbag inflators

• US 5,538,278 A
• Filed: 06/14/1994
• Issued: 07/23/1996
• Est. Priority Date: 06/14/1994
• Status: Expired due to Fees

• Current Assignee: AD Astram Scientific LLC
• Original Assignee: AD Astram Enterprises Of Tempe, AZ
• Inventors: Jones, Clyde L., Blackshire, Robert D., Storch, Milan L.
• Primary Examiner(s): Dickson, Paul N.
• Application Number:
  US08/259,617
• Time in Patent Office: 770 Days
• Field of Search: 280/736, 280/737, 280/741, 280/742, 222/3, 222/5
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators
• CPC Class Codes: F42B 3/045 Hybrid systems with previously pressurised gas using blasting to increase the pressure, e.g. causing the gas to be released from its sealed container

Abstract

An improved hybrid airbag inflator comprises a container for storing a compressed gas having a rupturable wall defining an exit opening. A pyrotechnic gas generator has an output directed into the container for adding heat and mass flow to the compressed gas in the container. The pyrotechnic generator may also have a second output directed into a manifold leading from the container to the airbag, the second output entering the manifold downstream from the inlet nozzles that restrict the flow of compressed gas into the manifold. Adding the second output directly to the manifold increases the energy content of the gas filling the airbag without physically changing the size of the inlet nozzles, thereby allowing a readily controllable staged flow of gases into the airbag.

Claims

1. An apparatus for inflating an inflatable vehicle occupant restraint comprising:

a container for storing a compressed gas, said container including a rupturable wall which is rupturable to define a gas exit opening in fluid communication with said inflatable vehicle occupant restraint;

a pyrotechnic gas generator having a combustion gas outlet directed into said compressed gas container for mixing a gas output of said pyrotechnic gas generator with said compressed gas;

a pyrotechnic delay train having an input end and an output end, said output end adapted to initiate combustion of said pyrotechnic gas generator at a predetermined period after initiation of said input end, said pyrotechnic delay train comprising an ignition charge, a delay column and an output charge, said ignition charge adapted for igniting said delay column, said output charge adapted for igniting said gas generator material, said pyrotechnic delay train further including a primer for initiating said ignition charge; and

an initiator for rupturing said rupturable wall and for initiating said input end of said pyrotechnic delay train, whereby said compressed gas begins to flow substantially immediately after said rupturable wall is ruptured and said pyrotechnic gas generator begins to produce said gas output after a predetermined delay.

2. An apparatus for inflating an inflatable vehicle occupant restraint comprising:

a container for storing a compressed gas, said container including a rupturable wall which is rupturable to define a gas exit opening;

a pyrotechnic gas generator having a combustion gas outlet directed into said compressed gas container for mixing a first portion of a combustion gas output of said pyrotechnic gas generator with said compressed gas;

an initiator for rupturing said rupturable wall and for initiating said pyrotechnic gas generator;

a manifold having an inlet in fluid communication with said gas exit opening, said manifold further including an outlet in fluid communication with said inflatable vehicle occupant restraint;

means for directing a second portion of said combustion gas output from said gas generator directly into said manifold, for heating and increasing pressure of gas within said manifold.

3. The apparatus of claim 2 wherein said manifold inlet is sized for controlling a flow of gas from said compressed gas container into said inflatable vehicle occupant restraint.

4. The apparatus of claim 2 wherein said initiator comprises a pyrotechnic primer capable of producing a high velocity stream of gases and particles for rapturing said rupturable wall.

5. The apparatus of claim 2 wherein said outlet of said gas generator further includes a filter to substantially permit egress of gaseous products only.

6. An apparatus for inflating an inflatable vehicle occupant restraint comprising:

a container for storing a compressed gas, said container including a rupturable wall which is rupturable to define a gas exit opening;

a pyrotechnic gas generator having a combustion gas outlet directed into said compressed gas container for mixing a first portion of a combustion gas output of said pyrotechnic gas generator with said compressed gas;

a pyrotechnic delay train having an input end and an output end, said output end adapted to initiate combustion of said pyrotechnic gas generator at a predetermined period after initiation of said input end;

an initiator for rupturing said rupturable wall and for initiating said input end of said pyrotechnic delay train;

a manifold having an inlet in fluid communication with said gas exit opening, said manifold further including an outlet in fluid communication with said inflatable vehicle occupant restraint, said manifold further including a bypass opening for directing a second portion of said combustion gas output from said gas generator directly into said manifold, for heating and increasing pressure of gas within said manifold.

7. A method for inflating an inflatable vehicle occupant restraint comprising:

rupturing a seal to release a compressed gas from a container into a manifold in fluid communication with said vehicle occupant restraint;

initiating a pyrotechnic delay train; and

initiating, with an output of said pyrotechnic delay train, a pyrotechnic gas generator for producing combustion gas upon initiation;

outputting said combustion gas through a first gas output in said pyrotechnic gas

mixing said combustion gas from said first gas output with said compressed gas in said container;

outputting said combustion gas through a second gas output in said pyrotechnic gas generator; and

mixing within said manifold, said combustion gas from said second gas output with the mixture of said combustion gas from said first gas output and said compressed gas.