Inflator

• US 7,073,820 B2
• Filed: 12/16/2004
• Issued: 07/11/2006
• Est. Priority Date: 12/17/2003
• Status: Expired due to Fees

• Current Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: McCormick, David M.
• Primary Examiner(s): Dunn, David R.
• Application Number:
  US11/014,642
• Publication Number:
  US 20050134031A1
• Time in Patent Office: 572 Days
• Field of Search: 280/736, 280/740, 280/741, 280/742, 102/530, 102/531
• US Class Current: 280/741
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

An inflator (10) for a vehicle occupant restraint system. The inflator (10) includes a housing (12) having apertures (13) formed therealong to enable fluid communication between an interior of the housing (12) and an exterior of the housing. A first baffle (14) is positioned in the housing interior. The baffle (14) is spaced apart from the housing (12) to define a fluid channel (33) therebetween in communication with the housing apertures (13). The baffle (14) includes a first opening (17) for fluid communication between an interior of the baffle (14) and the fluid channel (33), and an open end portion for fluid communication between the baffle interior and the baffle exterior. A spacer (18) positioned in the housing interior cavity defines an enclosure (18c) and includes an aperture (19) formed therein for fluid communication between the enclosure (18c) and the open end portion of the baffle. A gas generant (30) is positioned within the spacer enclosure (18c). The gas generant (30) may be a smokeless gas generant composition. An initiator (20) is coupled to the housing (12) for initiating combustion of the gas generant (30) upon activation of the inflator. The inflator (10) provides a continuous, tortuous fluid path through the fluid channel (33) for cooling inflation gases. In addition, the use of a smokeless gas generant composition allows the inflator (10) to operate without the need for a filter to remove particulate materials from the inflation gas.

Claims

1. An inflator comprising:

a housing defining a housing interior cavity, the housing including at least one housing aperture formed therealong to enable fluid communication between the interior cavity and an exterior of the housing;

a first baffle positioned in the housing interior cavity, at least a portion of the first baffle being spaced apart from the housing to define a fluid channel therebetween in communication with the at least one housing aperture, the first baffle defining a first baffle interior cavity, the first baffle including a first opening to enable fluid communication between the first baffle interior cavity and the fluid channel;

a spacer positioned in the housing interior cavity, the spacer defining an enclosure, the spacer having at least one spacer aperture formed therein to enable fluid communication between the enclosure and the first baffle interior cavity;

a quantity of a gas generant composition contained within the spacer enclosure; and

an initiator in fluid communication with the gas generant composition and operatively coupled to the housing so as to enable fluid communication between the initiator and the spacer enclosure upon activation of the inflator, for initiating combustion of the gas generant composition upon activation of the inflator.

2. The inflator of claim 1 wherein the spacer has a base portion and a wall extending from the base portion, the base portion and the wall defining the enclosure, and wherein the spacer aperture is formed in the base portion.

3. The inflator of claim 1 further comprising a second baffle positioned in the first baffle interior cavity, at least a portion of the second baffle being spaced apart from the first baffle to define a second fluid channel extending between the first baffle and the second baffle, the second fluid channel being in communication with the first opening of the first baffle, the second baffle defining a second baffle interior cavity, the second baffle including at least one second baffle aperture formed therealong to enable fluid communication between the second baffle interior cavity and the second fluid channel.

4. The inflator of claim 3 wherein the second baffle is positioned coaxially with the first baffle.

5. The inflator of claim 4 wherein at least a portion of the second baffle is positioned in the first baffle interior cavity.

6. The inflator of claim 1 wherein the spacer includes a groove for receiving a portion of the first baffle therein, for positioning and securing the first baffle within the housing.

7. The inflator of claim 3 wherein the spacer includes a groove for receiving a portion of the second baffle therein, for positioning and securing the second baffle within the housing.

8. The inflator of claim 3 wherein at least a portion of the second baffle is positioned within the first baffle interior cavity.

9. The inflator of claim 1 wherein the initiator extends into the spacer enclosure.

10. The inflator of claim 1 wherein the gas generant composition is a smokeless gas generant composition.

11. The inflator of claim 1 wherein a portion of the housing includes a groove for receiving a portion of the baffle therein, for positioning and securing the baffle within the housing.

12. The inflator of claim 1 further comprising a quantity of a second gas generant composition positioned in the baffle interior cavity, wherein activation of the initiator ignites the first gas generant composition and ignition of the first gas generant composition ignites the second gas generant composition.

13. The inflator of claim 12 wherein the second gas generant composition is a smokeless gas generant composition.

14. The inflator of claim 1 further comprising an autoignition material positioned in the spacer enclosure proximate the gas generant composition.

15. The inflator of claim 1 further comprising a rupturable, fluid-tight seal positioned to seal the spacer aperture.

16. An airbag system comprising at least one airbag and an inflator coupled to the airbag so as to enable fluid communication with an interior of the airbag upon activation of the inflator, the inflator including:

a housing including at least one housing aperture formed therealong to enable fluid communication between an interior of the housing and an exterior of the housing;

a baffle positioned in the housing interior, at least a portion of the baffle being spaced apart from the housing to define a fluid channel therebetween in communication with the at least one housing aperture, the baffle including a first opening to enable fluid communication with the fluid channel;

a spacer positioned in the housing interior, the spacer defining an enclosure, the spacer having at least one spacer aperture formed therein to enable fluid communication between the enclosure and an interior of the baffle;

a quantity of a gas generant composition contained within the spacer enclosure; and

an initiator in fluid communication with the gas generant composition for initiating combustion of the gas generant composition upon activation of the inflator.

17. The airbag system of claim 16 further comprising a crash event sensor in operative communication with the inflator, thereby actuating the airbag system in the event of a collision.

18. The airbag system of claim 16 wherein the gas generant composition is a smokeless gas generant composition.

19. A vehicle occupant restraint system comprising:

a safety belt assembly including a first housing and a safety belt extending from the first housing, and an air bag system including at least one airbag and an airbag inflator coupled to the airbag so as to enable fluid communication with an interior of the airbag for inflating the airbag in the event of a collision, the inflator comprising;

a second housing including at least one housing aperture formed therealong to enable fluid communication between an interior of the second housing and an exterior of the second housing;

a first baffle positioned in the second housing interior, at least a portion of the baffle being spaced apart from the second housing to define a fluid channel therebetween in communication with the at least one housing aperture, the baffle including a first opening to enable fluid communication with the fluid channel;

a spacer positioned in the second housing interior, the spacer defining an enclosure, the spacer having at least one spacer aperture formed therein to enable fluid communication between the enclosure and an interior of the baffle;

a quantity of a gas generant composition contained within the spacer enclosure; and

an initiator in fluid communication with the gas generant composition for initiating combustion of the gas generant composition upon activation of the inflator.

20. The vehicle occupant restraint system of claim 19 wherein the gas generant composition is a smokeless gas generant composition.