Airbag initiator cover attachment apparatus and method

• US 7,077,428 B2
• Filed: 07/07/2003
• Issued: 07/18/2006
• Est. Priority Date: 07/07/2003
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Brisighella, Dario, Parks, Brent, Barker, Kent
• Primary Examiner(s): Dickson, Paul N.
• Assistant Examiner(s): To, Toan C.
• Application Number:
  US10/614,155
• Publication Number:
  US 20050006887A1
• Time in Patent Office: 1,107 Days
• Field of Search: 280/736, 280/741, 280/728.2, 280/737, 102/202, 102/202.1, 102/202.2, 102/202.3, 102/202.5, 102/530, 102/531, 403/359.1
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

An airbag module has an inflator activated via an electrical connector. The inflator includes an initiation assembly having an initiator and a receptacle that retains the connector. The initiator may have a single, center pin. The initiator may be encased by a body and cover, which may be attached together by molding, vibratory welding, electromagnetic welding, or snap fitting. The connector may have projections that extend from a main body to facilitate retention of the connector by a collar, washer, a retainer attached to the body, or by the inflator housing. The body may be seated in a collar having an annular ridge that presses into the body to form a seal. The connector may have a rib designed to mesh with splines of the receptacle to enable engagement of the connector with the receptacle in multiple orientations, while preventing relative rotation between the connector and the initiator after assembly.

Claims

1. An initiation assembly for an inflator for a pyrotechnic device, the initiation assembly comprising:

an initiator comprising a center pin disposed to convey an activation signal to trigger ignition of a quantity of ignition material;

a body disposed to encircle at least a portion of the initiator; and

a cover attached to the body through a method selected from the group consisting of snap fitting, vibratory welding, and electromagnetic welding to encircle at least a portion of the initiator, wherein the body is part of a receptacle defined by the initiation assembly for receiving a connector, the receptacle comprising a retainer attached to the body, wherein the receptacle comprises a plurality of splines shaped to mate with at least one rib of the connector such that the connector is engageable with the retainer in at least three orientations, wherein the splines and the rib mesh to prevent rotation of the connector between the orientations.

2. The initiation assembly of claim 1, wherein the initiator further comprises a header eyelet encircling at least a portion of the center pin and a bridge wire that electrically couples the center pin and the header eyelet together such that passage of the activation signal through the bridge wire ignites the bridge wire to ignite the ignition material.

3. The initiation assembly of claim 2, wherein the cover is attached to the body to electrically insulate the initiator.

4. The initiation assembly of claim 1, wherein the body and the cover are formed from polymeric materials and the cover comprises a rim, wherein the rim is ultrasonically welded to the body.

5. The initiation assembly of claim 1, wherein the body is press fit into place to prevent moisture entry into the inflator and to prevent inflation gases from exiting the inflator through a region encircling the body.

6. The initiation assembly of claim 1, wherein the connector engages the initiator to enable transmission of the activation signal from the connector to the initiator.

7. The initiation assembly of claim 6, wherein the receptacle is disposed within a housing of the inflator, wherein the housing is shaped to retain the body, the housing comprising an inside diameter through which the connector is insertable, wherein the connector comprises at least one projection and the housing is disposed to engage the projection when the connector engages the initiator to restrict withdrawal of the connector from the initiator.

8. The initiation assembly of claim 6, wherein the receptacle comprises a collar shaped to retain the body, the collar comprising an inside diameter disposed to receive the connector, the connector comprising at least one projection, wherein the collar is disposed to engage the projection when the connector engages the initiator to restrict withdrawal of the connector from the initiator.

9. The initiation assembly of claim 6, wherein the retainer is formed of a polymer and has a generally annular shape, wherein the connector comprises at least one projection and the retainer is disposed to engage the projection when the connector engages the initiator to restrict withdrawal of the connector from the initiator.

10. An inflator for an airbag module for protecting an occupant of a vehicle from impact, the inflator comprising:

a housing;

an initiator retained within the housing, the initiator comprising a quantity of ignition material and a center pin disposed to convey an activation signal to trigger ignition of the ignition material; and

a cover disposed to encircle at least a portion of the initiator through a method selected from the group consisting of snap fitting, vibratory welding, and electromagnetic welding, further comprising a body that is part of a receptacle defined by the initiation assembly for receiving a connector, the receptacle comprising a retainer attached to the body, wherein the receptacle comprises a plurality of splines shaped to mate with at least one rib of the connector such that the connector is engageable with the retainer in at least three orientations, wherein the splines and the rib mesh to prevent rotation of the connector between the orientations.

11. The inflator of claim 10, wherein the body disposed to encircle at least a portion of the initiator, wherein the initiator further comprises a header eyelet encircling at least a portion of the center pin and a bridge wire that electrically couples the center pin and the header eyelet together such that passage of the activation signal through the bridge wire ignites the bridge wire to ignite the ignition material.

12. The inflator of claim 11, wherein the body and the cover are formed from polymeric materials and the cover comprises a rim, wherein the rim is ultrasonically welded to the body.

13. The inflator of claim 11, wherein a region encircling the body is sealed to prevent moisture entry into the inflator and inflation gas exit out of the inflator via one of a press fit, an o-ring, and an annular ridge disposed to press into the body.

14. A method for manufacturing an initiation assembly for a pyrotechnic device, the initiation assembly comprising a body, a cover, and an initiator comprising a quantity of ignition material that ignites in response to receipt of an activation signal, the method comprising:

disposing the body to encircle at least a portion of the initiator;

disposing the cover to encircle at least a portion of the initiator; and

attaching the cover to the body through a method selected from the group consisting of snap fitting, vibratory welding, and electromagnetic welding, wherein the body is part of a receptacle defined by the initiation assembly for receiving a connector, the receptacle comprising a retainer attached to the body, wherein the receptacle comprises a plurality of splines shaped to mate with at least one rib of the connector such that the connector is engageable with the retainer in at least three orientations, wherein the splines and the rib mesh to prevent rotation of the connector between the orientations.

15. The method of claim 14, wherein the initiator further comprises a header eyelet encircling at least a portion of the center pin and a bridge wire that electrically couples the center pin and the header eyelet together such that passage of the activation signal through the bridge wire ignites the bridge wire to ignite the ignition material, wherein disposing the body to encircle at least a portion of the initiator comprises positioning the body to cover an outer diameter of the header eyelet.

16. The method of claim 14, wherein the body and the cover are formed from polymeric materials and the cover comprises a rim, wherein attaching the cover to the body comprises ultrasonically welding the rim to the body.