Hybrid gas generator for a side airbag applied to motor vehicle safety

• US 20030047924A1
• Filed: 08/01/2002
• Published: 03/13/2003
• Est. Priority Date: 09/12/2001
• Status: Active Grant

• Current Assignee: Livbag Snc
• Original Assignee: Livbag Snc
• Inventors: Rigault, Francois A., Perotto, Christian, Lebaudy, Franck, Martin, Bernard
• Granted Patent: US 6,874,813 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• 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

The present invention relates to a hybrid gas generator (1), used for motor vehicle safety to inflate an airbag, comprising, on the one hand, a body (2) containing an ignition device (16) and, on the other hand, a reservoir (3) connected to the body and containing a pressurized gas (31), together with initially closed-off discharge orifices (10), characterized in that the body possesses:

i) a first pyrotechnic charge (14) capable of generating a quantity of gas which, coupled to the volume of gas (31) contained in the reservoir, allows the airbag to be inflated in a time period of less than 50 milliseconds,

ii) a second pyrotechnic charge (13) capable of generating, after combustion of the first pyrotechnic charge, a quantity of gas sufficient to keep the airbag inflated for a time period of several seconds.

Claims

1. Hybrid gas generator (1), used for motor vehicle safety to inflate an airbag, comprising, on the one hand, a body (2) containing an ignition device (16) and, on the other hand, a reservoir (3) connected to the body and containing a pressurized gas (31), together with initially closed-off discharge orifices (10), characterized in that the body possesses:

i) a first pyrotechnic charge (14) capable of generating a quantity of gas which, coupled to the volume of gas (31) contained in the reservoir, allows the airbag to be inflated in a time period of less than 50 milliseconds,

ii) a second pyrotechnic charge (13) capable of generating, after combustion of the first pyrotechnic charge, a quantity of gas sufficient to keep the airbag inflated for a time period of several seconds

2. Generator (1) according to claim 1, characterized in that the reservoir (3) is of elongate cylindrical shape.

3. Generator (1) according to claim 2, characterized in that the body (2) and the reservoir (3) are each produced in a separate cylindrical element.

4. Generator (1) according to claim 2, characterized in that the body (2) and the reservoir (3) are produced in the same one-piece tube.

5. Generator (1) according to claim 4, characterized in that a perforated piece forming a nozzle is placed at the junction between the body (2) and the reservoir (3).

6. Generator (1) according to any one of claims 2 to 4, characterized in that the reservoir (3) has one end closed off by means of a metal piece (7) having at least one axial gas exit channel (8).

7. Generator (1) according to claim 6, characterized in that a gas diffuser (9) is mounted on the closed-off end of the reservoir (3).

8. Generator (1) according to claim 1, characterized in that the first pyrotechnic charge is produced in the form of loose cubes (14).

9. Generator according to either of claims 1 and 8, characterized in that the second pyrotechnic charge is produced in the form of a cylindrical block (13) provided with a central channel capable of containing the first pyrotechnic charge (14).

10. Generator (1) according to claim 1, characterized in that the pressurized gas (31) housed in the reservoir (3) is chosen from the group consisting of helium, argon, oxygen, nitrous oxide or a mixture of all or some of the latter.