FLUID SUPPLY DEVICE FOR VEHICLE SAFETY SYSTEM

• US 3,649,045 A
• Filed: 01/27/1970
• Issued: 03/14/1972
• Est. Priority Date: 01/27/1970
• Status: Expired due to Term

• Current Assignee: Ensign Bickford Aerospace Co.
• Original Assignee: Francis N. Wrobel, William M. Smith
• Inventors: Smith, William M., Wrobel, Francis N.
• Primary Examiner(s): Betts, Kenneth H.
• Application Number:
  US05/006,163
• Time in Patent Office: 777 Days
• Field of Search: 280/15AB 23/281 102/34.5,37.7,39,40 222/5
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 2021/335 Connections between collision detecting means and inflators using pyrothechnic transmission lines
• 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
• 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 3/04 for producing gas under pressure generators of inflation fluid especially adapted for vehicle air bags B60R21/26

Abstract

A multistage pyrotechnic gas generator for deploying a passenger confinement of a vehicle safety system comprises a support member having an ignition inlet and first and second stage compartments mounted on the support and having separate gas outlets, the first and second stage compartments containing gas-generating pyrotechnic material. The gas-generating pyrotechnic material in each stage comprises distinct primary and secondary pyrotechnic charges ignitable sequentially. The primary pyrotechnic charge of the first stage is in communication with the ignition inlet while the secondary pyrotechnic charge of each stage is disposed between the primary charge and the gas outlet for ignition by the primary charge. The pyrotechnic material used in the secondary charge of each stage has a cooling effect on the temperature of the gas generated by the primary charge and gas generation is controlled by the inclusion of time delay lines between the primary charges of adjacent stages to assure sequenced ignition of the gas-generating stages.

Claims

1. A multistage pyrotechnic gas generator for deploying a passenger confinement of a vehicle safety system comprising a support member having an ignition inlet;

first and second stage compartments mounted on said support, each compartment having a separate gas outlet;

first and second stage gas-generating material within said first and second stage compartments respectively, each stage of said gas-generating material comprising distinct primary and secondary pyrotechnic charges, the primary pyrotechnic charge of said first stage being in communication with said ignition inlet, the secondary pyrotechnic charge of each stage being disposed between the primary charge and the gas outlet for ignition by only its respective primary charge, said secondary charge being effective to reduce the temperature of the gas generated by the primary charge, the secondary charge of said first stage being pyrotechnically isolated from the secondary charge of said second stage.

2. The gas generator of claim 1 wherein the support member includes a generally cylindrical support column extending axially of the generator and a compartment-retaining member secured to the support column, the compartments including cylindrical charge-confining wall portions assembled in coaxial alignment, said portions confining said secondary charges having a plurality of circumferentially spaced gas outlets, the gas generator including time delay means disposed between the primary charges of said first and second stages to effect ignition of said second stage subsequent to ignition of said first stage.

3. The gas generator of claim 1 wherein the first and second stage compartments are stacked in overlying relationship and the primary and secondary charges of each stage are disposed coaxially.

4. The gas generator of claim 1 wherein the primary and secondary charges are arranged concentrically with the secondary charges being disposed outwardly of the primary charges.

5. The gas generator of claim 1 wherein each compartment includes primary and secondary charge containers in stacked overlying relationship, said containers providing communication therebetween for ignition of the secondary charge by the primary charge.

6. The gas generator of claim 1 including a pyrotechnic delay column of predetermined burning rate extending longitudinally of said support member and interconnecting primary charges of immediately adjacent gas-generating stages.

7. The gas generator of claim 1 wherein the primary pyrotechnic charge consists essentially of black powder and the secondary charge is an endothermic pyrotechnic material.

8. The gas generator of claim 7 wherein the secondary charge includes ammonium nitrate.

9. The gas generator of claim 1 including an auxiliary fluid supply reservoir and fluid flow control means for opening the reservoir upon ignition of the pyrotechnic gas generator.

10. The gas generator of claim 9 wherein the reservoir is a rupturable gas cylinder and the fluid flow control means is a punch for rupturing the cylinder, said punch and cylinder being relatively movable for rupturing the cylinder upon ignition of the gas generator.

11. The gas generator of claim 1 wherein the support member includes a generally cylindrical support column having an opening for receiving a pyrotechnic igniter and an axial cavity communicating with said opening, said generator including an auxiliary fluid supply reservoir supportably mounted within said cavity for release of fluid therefrom upon actuation of the igniter.

12. The gas generator of claim 1 including a cylindrical housing having gas diffusing vent means, the support member including a base portion for the first stage secured at one end of the housing, said base portion providing a cup-shaped canister for the primary charge of the first stage, the first stage compartment further including a second cup-shaped canister for the secondary charge disposed in overlying supported relationship to said base and having gas outlet ports communicating with said vent means, and retaining means for maintaining said cup-shaped canisters in secure assembled relationship with the support member and the housing.