Filter for a gas generator

• US 10,099,648 B2
• Filed: 03/23/2015
• Issued: 10/16/2018
• Est. Priority Date: 03/28/2014
• Status: Active Grant

• Current Assignee: Autoliv Development AB (Autoliv Incorporated)
• Original Assignee: Autoliv Development AB (Autoliv Incorporated)
• Inventors: Louboutin, Dominique
• Primary Examiner(s): Brown, Drew J
• Application Number:
  US15/129,972
• Publication Number:
  US 20170136984A1
• Time in Patent Office: 1,303 Days
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

A filter for a pyrotechnical gas generator includes a filtering material and a protection screen. The protection screen forms at least one sealed loop arranged so as to surround at least a part of a charge of propergol of the pyrotechnical gas generator in such a manner as to protect this at least one part of the filtering material from a pressure wave from the ignition of the propergol charge.

Claims

1. A pyrotechnical gas generator comprising:

a housing;

a combustion chamber in the housing;

a filter including a filtering material; and

a protection screen, the protection screen forms at least one sealed loop arranged to surround at least a part of a charge of the pyrotechnical gas generator in such a manner as to protect at least a part of the filtering material from a pressure wave from ignition of the charge

wherein the filtering material has a height and the protection screen covers the filtering material at a midpoint of the height,

wherein the filter has a first axial end adjacent a first end of the housing and a second axial end adjacent a second end of the housing such that the first and second axial ends of the filter are held to the housing at contact zones to maintain positioning of the filter within the housing, and

wherein the protection screen is radially spaced from both the first end of the housing and the second end of the housing.

2. The pyrotechnical gas generator according to claim 1, wherein the filtering material is arranged at least in part around the protection screen, and that the sealed loop is arranged in such a manner as to resist an expansion force greater than an expansion force of the filtering material.

3. The pyrotechnical gas generator according to claim 1, wherein the protection screen is a support piece different from the filtering material.

4. The pyrotechnical gas generator according to claim 1, wherein the protection screen is a solid band.

5. The pyrotechnical gas generator according to claim 4, wherein the solid band is advantageously free of holes over a length of the sealed loop.

6. The pyrotechnical gas generator according to claim 1, wherein the filtering material is attached to the sealed loop.

7. The pyrotechnical gas generator according to claim 1, wherein the filtering material has a cylindrical shape with a first height, and that the protection screen protects the filtering material on a second height greater than or equal to one half of the first height.

8. The pyrotechnical gas generator according to claim 1, wherein the pyrotechnical gas generator comprises an electro-pyrotechnical igniter with at least one radial vent arranged for igniting the charge, the protection screen is arranged facing this at least one radial vent.

9. The pyrotechnical gas generator according to claim 1, wherein the filtering material is a metallic wire and/or a metallic fabric and/or a metallic knit fabric and/or an unfolded metal and/or a metallic, stamped sheet.

10. The pyrotechnical gas generator according to claim 1, in combination with a safety module.

11. The pyrotechnical gas generator according to claim 1, in combination with an automobile.

12. The pyrotechnic gas generator of claim 1, wherein a sidewall of the housing includes at least one vent and the protection screen is radially disposed between the igniter and the at least one vent.

13. A pyrotechnical gas generator comprising:

a housing;

a combustion chamber in the housing;

a charge in the combustion chamber for creating inflation gases for an airbag,

an igniter designed for igniting the charge, the igniter axially extending within the housing;

a filter comprising a filtering material and a protection screen, the protection screen forms at least one sealed loop arranged so as to surround at least a part of the charge in such a manner as to protect at least a part of the filtering material from a pressure wave from the ignition of the charge,

wherein the protection screen is radially positioned between the igniter and the filtering material, and

wherein the protection screen is radially spaced from both the first end of the housing and the second end of the housing.

14. The pyrotechnical gas generator according to claim 13, wherein the igniter comprises at least one radial vent, and that the protection screen comprises a solid band arranged facing this at least one vent.

15. The pyrotechnical gas generator according to claim 13, further comprising at least one discharge nozzle and that the filtering material is arranged between the charge and the at least one discharge nozzle.

16. The pyrotechnic gas generator of claim 13, in combination with a safety module.

17. The pyrotechnic gas generator of claim 13, in combination with an automobile.

18. The pyrotechnic gas generator of claim 13, wherein a sidewall of the housing includes at least one vent and the protection screen is radially disposed between the igniter and the at least one vent.

19. A pyrotechnical gas generator comprising:

a housing having a first axial end and a second axial end;

a combustion chamber within the housing;

a charge in the combustion chamber for creating inflation gases for an airbag,

an igniter for igniting the charge, the igniter axially extending in the housing;

a filter comprising a filtering material and a protection screen, the protection screen forms at least one sealed loop arranged so as to surround at least a part of a charge in such a manner as to protect at least a part of the filtering material from a pressure wave from the ignition of the charge, the protection screen radially positioned between the igniter and the filtering materials,

wherein a sidewall of the housing includes at least one vent and the protection screen is radially disposed between the igniter and the at least one vent, and

wherein the protection screen is radially spaced from both the first axial end of the housing and the second axial end of the housing.