Anti-rupture method for liquid propellant gas inflator

• US 5,719,351 A
• Filed: 12/03/1996
• Issued: 02/17/1998
• Est. Priority Date: 12/03/1996
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Johnson, Darrin L., Harris, Bradley D.
• Primary Examiner(s): JOHNSON, STEPHEN
• Application Number:
  US08/770,382
• Time in Patent Office: 441 Days
• Field of Search: 102/530, 102/531, 102/440, 280/741, 280/737
• US Class Current: 102/440
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/276 with means to vent the inflation fluid source, e.g. in case of overpressure B60R21/30 takes precedence; venting means on inflatable member walls B60R21/239

Abstract

An inflator of a vehicle safety restraint system includes a housing having a reservoir of liquid propellant. A combustion chamber is disposed in the housing in communication with the liquid propellant reservoir. A regenerative piston is movably disposed within the housing for separating the liquid propellant reservoir and the combustion chamber. The piston head includes a plurality of injection ports for delivering the liquid propellant to the combustion chamber in a controlled manner. A pressure relieving bore, normally sealed by the piston stem, is disposed in the housing for relieving pressure in the liquid propellant reservoir. Decomposition or combustion within the propellant storage reservoir will move the piston to open the pressure relief bore which depressurizes the liquid propellant and prevents rupture and fragmentation of the inflator.

Claims

1. An inflator of a vehicle safety restraint system, comprising:

a housing, the housing including a reservoir of liquid propellant;

a combustion chamber disposed in the housing in communication with the liquid propellant reservoir;

a swirl retainer located within and enclosing the combustion chamber;

regenerative piston means movably disposed within the housing for separating the liquid propellant reservoir and the combustion chamber, the piston means including a head separating the combustion chamber from the liquid propellant reservoir and a piston stem extending through the housing, the piston head including a plurality of injection ports for delivering the liquid propellant to the combustion chamber in a controlled manner; and

pressure relieving means disposed in the housing for relieving pressure in the liquid propellant reservoir due to combustion and decomposition reactions of the liquid propellant.

2. The inflator of claim 1, wherein the pressure relief means comprises a bore in the housing through which the piston stem extends.

3. The inflator of claim 2, wherein the piston head abuts against the swirl retainer.

4. An inflator of a vehicle safety restraint system, comprising:

a housing, the housing including a reservoir of liquid propellant;

a combustion chamber disposed in the hosing in communication with the liquid propellant reservoir;

a swirl retainer enclosing the combustion chamber, the swirl retainer including an upper section and a lower section connected therewith via a frangible joint;

regenerative piston means movably disposed within the housing for separating the liquid propellant reservoir and the combustion chamber, the piston means comprising a piston including a head separating the combustion chamber from the liquid propellant reservoir and a piston stem extending through the housing, the piston head including a plurality of injection ports for delivering the liquid propellant to the combustion chamber in a controlled manner; and

pressure relieving means disposed in the housing for relieving pressure in the liquid propellant reservoir due to combustion and decomposition reactions of the liquid propellant, the pressure relieving means comprising a bore in the housing through which the piston stem extends, wherein when combustion or decomposition occurs within the liquid propellant reservoir the resulting high pressure will move the piston against the swirl retainer breaking the upper and lower sections of the swirl retainer along the frangible joint, and sliding the upper section, allowing the piston to move in a direction opposite normal operation to open the bore in the housing and relieve the pressure in the inflator.

5. An inflator of a vehicle safety restraint system, comprising:

a housing, the housing including a reservoir of liquid propellant;

a combustion chamber disposed in the housing in communication with the liquid propellant reservoir;

a swirl retainer located within and enclosing the combustion chamber, the swirl retainer including a plurality of grooves along a length thereof;

regenerative piston means movably disposed within the housing for separating the liquid propellant reservoir and the combustion chamber, the piston means comprising a piston including a head separating the combustion chamber from the liquid propellant reservoir and a piston stem extending through the housing, the piston head including a plurality of injection ports for delivering the liquid propellant to the combustion chamber in a controlled manner; and

pressure relieving means disposed in the housing four relieving pressure in the liquid propellant reservoir due to combustion and decomposition reactions of the liquid propellant, the pressure relieving means comprising a bore in the housing through which the piston stem extends, wherein when combustion or decomposition occurs within the liquid propellant reservoir the resulting high pressure will move the piston against the swirl retainer peddling sides of the swirl retainer inwardly to collapse the swirl retainer allowing the piston to move in a direction opposite normal operation to open the bore in the housing and relieve the pressure in the inflator.

6. An inflator of a vehicle safety restraint system, comprising:

a housing, the housing including a reservoir of liquid propellant;

a combustion chamber disposed in the housing in communication with the liquid propellant reservoir;

a swirl tube disposed in the housing in communication with the combustion chamber;

a swirl retainer located within and enclosing the combustion chamber, the swirl retainer including a plurality of fingers along a lower portion thereof;

regenerative piston means movably disposed within the housing for separating the liquid propellant reservoir and the combustion chamber, the piston means comprising a piston including a head separating the combustion chamber from the liquid propellant reservoir and a piston stem extending through the housing, the piston head including a plurality of injection ports for delivering the liquid propellant to the combustion chamber in a controlled manner; and

pressure relieving means disposed in the housing for relieving pressure in the liquid propellant reservoir due to combustion and decomposition reactions of the liquid propellant, the pressure relieving means comprising a bore in the housing through which the piston stem extends, wherein when combustion or decomposition occurs within the liquid propellant reservoir the resulting high pressure will move the piston against the swirl retainer, the fingers will expand allowing the swirl retainer to slide over the swirl tube, allowing the piston stem to move in a direction opposite normal operation to open the bore in the housing and relieve the pressure in the inflator.