OCCUPANT RESTRAINT SYSTEM

• US 3,807,755 A
• Filed: 11/13/1972
• Issued: 04/30/1974
• Est. Priority Date: 11/13/1972
• Status: Expired due to Term

• Current Assignee: William T. Mason Jr
• Original Assignee: William T. Mason Jr
• Inventors: Mason, William T. Jr.
• Primary Examiner(s): Betts, Kenneth H.
• Assistant Examiner(s): Silverstrim, John P.
• Application Number:
  US05/305,918
• Time in Patent Office: 533 Days
• Field of Search: 280/15AB 73/147 222/3 181/47R
• US Class Current: 280/736
• 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

Abstract

An inflator of a vehicle occupant restraint system provided with a source of pressure fluid to inflate a cushion. A manifold receives the pressure fluid from the source and includes a nozzle through which the fluid accelerates to a supersonic flow. The nozzle has a throat that provides for the formation of a normal shock wave within the throat. A passage portion of the manifold is of generally uniform cross-sectional area and receives the supersonic fluid and the normal shock wave from the nozzle. A converging nozzle receives the fluid flow from the passage portion and has a throat for trapping the normal shock wave upstream therefrom to prevent the normal shock wave from traveling downstream of the passage portion and to decelerate the fluid flow to subsonic. A diffuser or apertured outlet portion receives the subsonic fluid from the converging nozzle and communicates the subsonic flow to an inflatable occupant restraint cushion.

Claims

1. In a vehicle occupant restraint system having a source of pressure fluid and an inflatable cushion, a manifold communicating the source and cushion and comprising:

nozzle means receiving pressure fluid from the source for accelerating the pressure fluid to supersonic fluid flow, said nozzle means having a throat providing for the formation of a normal shock wave within said throat;

a passage portion of generally uniform crosssectional area for receiving the supersonic fluid flow and normal shock wave from said nozzle;

a converging nozzle receiving the fluid flow from said passage portion and having a throat for trapping the normal shock wave upstream therefrom to prevent the normal shock wave from traveling downstream of said passage portion and to decelerate the fluid flow to a subsonic fluid flow; and

an outlet portion receiving the subsonic fluid flow from said converging nozzle and communicating the subsonic fluid flow to the cushion.

2. In a vehicle occupant restraint system having a source of pressure fluid and an inflatable cushion, a manifold communicating the source and cushion and comprising:

a converging-diverging nozzle receiving the pressure fluid from the source for accelerating the pressure fluid to a supersonic flow, said converging-diverging nozzle having a throat providing for the formation of a normal shock wave within said throat;

a passage portion having a generally uniform cross-sectional area greater than the cross-sectional area of said throat of said converging-diverging nozzle receiving the supersonic fluid flow and the normal shock wave from said converging-diverging nozzle;

a converging nozzle receiving the fluid flow from said passage portion and having a throat with a cross-sectional area greater than the cross-sectional area of said throat of said converging-diverging nozzle for trapping the normal shock wave upstream therefrom to prevent the normal shock wave from traveling downstream of said passage portion and to decelerate the fluid flow to a subsonic fluid flow; and

an outlet portion having a generally uniform cross-sectional area equal to or greater than the cross-sectional area of said passage portion and receiving the subsonic fluid flow from said converging nozzle amd communicating the subsonic flow to the cushion.

3. In a vehicle occupant restraint system having a source of pressure fluId and an inflatable cushion, a manifold communicating the source and the cushion and comprising:

a first nozzle associated with said source of fluid pressure to receive the pressurized fluid therefrom, said first nozzle having a converging portion through which the pressurized fluid accelerates to a sonic fluid flow, said first nozzle having a throat to provide for the formation of a normal shock wave within said throat, said first nozzle having a diverging portion for expanding the fluid flow and through which said sonic fluid flow accelerates to a supersonic fluid flow;

a passage portion having a generally uniform cross-sectional area greater than the cross-sectional area of said throat of said first nozzle and adapted to receive the supersonic fluid flow and normal shock wave;

a second nozzle having a converging portion terminating in a throat having a cross-sectional area greater than the cross-sectional area of said throat of said first nozzle and less than the cross-sectional area of said passage portion, said second nozzle receiving the fluid flow from said passage portion and contracting the fluid flow to trap the normal shock wave in the downstream end of said passage portion to prevent the normal shock wave from traveling downstream of said passage portion and to decelerate the fluid flow to a subsonic fluid flow, said second nozzle having a diverging portion receiving and passing the subsonic fluid flow; and

an outlet portion having a generally uniform cross-sectional area equal to or greater than the cross-sectional area of said passage portion and receiving the subsonic fluid flow from said second nozzle, said outlet portion having a plurality of exit openings for communicating the subsonic fluid flow to the cushion.