Hybrid inflating assembly using a projectile

• US 5,653,463 A
• Filed: 01/04/1996
• Issued: 08/05/1997
• Est. Priority Date: 06/30/1995
• Status: Expired due to Fees

• Current Assignee: Daewoo Electronics (Government of South Korea)
• Original Assignee: Daewoo Electronics (Government of South Korea)
• Inventors: Jeong, Jae-Ho
• Primary Examiner(s): Dickson, Paul N.
• Application Number:
  US08/582,737
• Time in Patent Office: 579 Days
• Field of Search: 280/737, 280/741, 280/736, 222/5, 102/530, 102/531
• US Class Current: 280/737
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators

Abstract

A hybrid inflator for an airbag system using a projectile is disclosed. The projectile includes a rod portion and a stop end portion larger in diameter than the rod portion, a plurality of grooves functioning as a passageway of the gas flow are formed on the rod portion, and an end of the rod portion tapers to a point. The inflator includes an actuator assembly in which the projectile and a propellant are retained. The actuator assembly is secured to a container storing a pressured gas so that a portion of the actuator assembly projects into the container. A blocking cap isolates the container from the actuator assembly. When the airbag system initiates activating, projectile ruptures a circular upper surface of the blocking cap and a burst disk and the hot combustion gases tear away portions of side wall of the blocking cap. The combustion gases are introduced in the container through the torn portions of side wall of the blocking cap and are mixed with the pressured gas to raise the pressure and temperature of the container. Consequently, an air pressure is generated which is sufficient to inflate the airbag.

Claims

1. An inflator for an airbag system in an automotive vehicle comprising:

pressured container means having a first opening and a second opening opposite to said first opening for storing gas under pressure;

blocking means for blocking a gas flow toward an airbag in a normal state in which the airbag is kept deflated, said blocking means being secured to said container means to close said first opening provided at one end of said container means;

projectile means located coaxially opposite to said blocking means for being launched by burning a propellant and rupturing said blocking means to inflate the airbag;

hollow guiding means for containing said projectile means and guiding said projectile means toward said blocking means, said guiding means having a chamber for receiving said projectile means and moving said projectile means toward said blocking means and being coupled with said container means through said second opening which is provided at another end of said container means opposite to said one end thereof so that a portion of said guiding means is received inside said container means;

hollow casing means being coaxially coupled with one end portion of said guiding means outside said container means and retaining a propellant to generate combustion gases;

sealing means for sealing said second opening through which said guiding means is coupled so that the gas under pressure can be stored within said container means, said sealing means being hermetically coupled with an inner wall of said container means to cover said guiding means; and

ignition means for igniting said propellant, said ignition means being disposed in said chamber inside said casing means adjacent to said propellant,

wherein said projectile means includes a rod portion and a stop end portion larger in diameter than said rod portion, an end of said rod portion tapers to a point to rupture said blocking means easily, and a plurality of grooves functioning as passageways for gas flow are formed on said rod portion along a longitudinal direction thereof,

wherein said guiding means includes, at an end portion thereof opposite to said blocking means, a ring portion through which said rod portion passes but said stop end portion does not pass, and said ring portion is connected with a body of said guiding means by a plurality of poles, whereby hot combustion gases generated by burning of said propellant tear away portions of a side wall of said sealing means through spaces formed between said poles, and said combustion gases are mixed with the gas under pressure stored in said container means.

2. The inflator as claimed in claim 1, wherein said sealing means has a hollow cylindrical shape of which one end is closed and the other end is open and is hermetically welded to the inner wall of said container means.

3. The inflator as claimed in claim 1, wherein said container means is threadedly engaged with said guiding means and said casing means is also threadedly engaged with said guiding means.

4. The inflator as claimed in claim 1, wherein said blocking means is a disk formed of a domed central portion and a flat portion extended around said central portion, and said flat portion is hermetically welded to said container means.

5. The inflator as claimed in claim 1, wherein an end of said casing means extending toward said guiding means is sealed by a sealing disk, said sealing disk and inner walls of said casing means define a cavity in which said propellant and said ignition means are disposed successively, and said ignition means is located adjacent to said propellant.

6. The inflator as claimed in claim 1, wherein said container means is cylindrical and has-opposite ends which are curved toward the inside of said container means, said first opening is formed at one curved end of said container means, said second opening is formed at the other curved end thereof coaxial with said first opening, and a flange portion is secured to the outer circumference of said container means and includes a plurality of mounting openings.

7. The inflator as claimed in claim 6, wherein a circular flat plate is coupled to the one curved end of said container means including said first opening to define a chamber, said chamber being communicated with said container means through said first opening, and said flat plate includes a plurality of exhaust openings through which said chamber is communicated with the airbag.

8. The inflator as claimed in claim 1, wherein said grooves are extended straight.

9. The inflator as claimed in claim 1, wherein said grooves are spirally extended.

10. An inflator for an airbag system in an automotive vehicle comprising:

pressured container means having a first opening and a second opening opposite to said first opening for storing gas under pressure;

blocking means for blocking a gas flow toward an airbag in a normal state in which the airbag is kept deflated, said blocking means being secured to said container means to close said first opening provided at one end of said container means;

projectile means located coaxially opposite to said blocking means for being launched by burning a propellant and rupturing said blocking means to inflate the airbag;

hollow guiding means for containing said projectile means and guiding said projectile means toward said blocking means, said guiding means having a chamber for receiving said projectile means and moving said projectile means toward said blocking means and being coupled with said container means through said second opening which is provided at another end of said container means opposite to said one end thereof so that a portion of said guiding means is received inside said container means;

hollow casing means being coaxially coupled with one end portion of said guiding means outside said container means and retaining a propellant to generate combustion gases;

sealing means for sealing said second opening through which said guiding means is coupled so that the gas under pressure can be stored within said container means, said sealing means being hermetically coupled with an inner wall of said container means to cover said guiding means; and

ignition means for igniting said propellant, said ignition means being disposed in said chamber inside said casing means adjacent to said propellant,

wherein said projectile means includes a rod portion and a stop end portion larger in diameter than said rod portion, an end of said rod portion tapers to a point to rupture said blocking means easily, and a plurality of grooves functioning as passageways for gas flow are formed on said rod portion along a longitudinal direction thereof,

wherein said sealing means has a hollow cylindrical shape of which one end is closed and the other end is open and is hermetically welded to the inner wall of said container means,

wherein said guiding means includes, at an end portion thereof opposite to said blocking means, a ring portion through which said rod portion passes but said stop end portion does not pass, and said ring portion is connected with a body of said guiding means by a plurality of poles, whereby hot combustion gases generated by burning of said propellant tear away portions of a side wall of said sealing means through spaces formed between said poles, and said combustion gases are mixed with the gas under pressure stored in said container means,

wherein said container means is threadedly engaged with said guiding means and said casing means is also threadedly engaged with said guiding means,

wherein said blocking means is a disk formed of a domed central portion and a flat portion extended around said central portion, and said flat portion is hermetically welded to said container means,

wherein an end of said casing means extending toward said guiding means is sealed by a sealing disk, said sealing disk and inner walls of said casing means define a cavity in which said propellant and said ignition means are disposed successively, and said ignition means is located adjacent to said propellant,

wherein said container means is cylindrical and has opposite ends which are curved toward the inside of said container means, said first opening is formed at one curved end of said container means, said second opening is formed at the other curved end thereof coaxial with said first opening, and a flange portion is secured to the outer circumference of said container means and includes a plurality of mounting openings,

wherein a circular flat plate is coupled to the one curved end of said container means including said first opening to define a chamber, said chamber being communicated with said container means through said first opening, and said flat plate includes a plurality of exhaust openings through which said chamber is communicated with the airbag.