Airbag ingniter with integral sensitivity identification

• US 5,602,359 A
• Filed: 08/14/1995
• Issued: 02/11/1997
• Est. Priority Date: 08/14/1995
• Status: Expired due to Fees

• Current Assignee: ICI Americas Inc (Astrazeneca PLC)
• Original Assignee: ICI Americas Inc (Astrazeneca PLC)
• Inventors: Hambro, Roger S., Chatley, Glenn R.
• Primary Examiner(s): TUDOR, HAROLD JAY
• Application Number:
  US08/514,615
• Time in Patent Office: 547 Days
• Field of Search: 102/202.5, 102/202.14, 102/530, 102/531, 102/293, 280/741, 376/451, 376/452
• US Class Current: 102/202.5
• CPC Class Codes: F42B 3/103 Mounting initiator heads in initiators; Sealing-plugs
• CPC Class Codes: F42B 35/00 Testing or checking of ammunition apparatus for measuring the energy of projectiles G01L5/14

Abstract

In a set of airbag igniters, each igniter has a mounting ring connected to and surrounding a portion of its body. Each igniter is supported in a retainer having an X-ray permeable wall surrounding the mounting ring. The mounting ring has a radially outwardly facing surface having a pattern of annular grooves hidden from visual inspection by the wall of the retainer. The pattern of grooves is the same for all of the igniters in the set having the same sensitivity, and any two igniters in the set having different sensitivities have different patterns of grooves. The grooves are inspected automatically by X-rays.

Claims

1. In an airbag igniter having an igniter body, a pyrotechnic charge and electrical means for causing ignition of said charge, the improvement comprising a ring attached to the igniter body and surrounding a portion of the igniter body, and a pattern of annular grooves in the ring, the pattern of annular grooves indicating the sensitivity of the electrical means, in which the ring is a mounting ring having an outwardly facing surface, in which the pattern of annular grooves is formed in said outwardly facing surface, and including a supporting retainer having a wall and means securing the mounting ring in fixed relation to the retainer whereby the pattern of grooves is hidden from visual inspection by said wall of the supporting retainer, and in which said wall of the supporting retainer is X-ray permeable, whereby said grooves can be inspected automatically by means of an X-ray source and X-ray detection means.

2. In a set of airbag igniters each comprising an igniter body, a pyrotechnic charge and electrical means for causing ignition of said charge, in which the electrical means of at least one of the igniters in the set has a sensitivity different from the sensitivity of the electrical means of at least one other igniter in the set, the improvement comprising a pattern of annular grooves on each of said igniters, the pattern of annular grooves being the same for all of the igniters in the set having the same sensitivity, and any two igniters in the set having different sensitivities having different patterns of annular grooves, in which each igniter in the set has a mounting ring connected to its igniter body and surrounding a portion of its igniter body, a supporting retainer having a wall surrounding the mounting ring, and means securing the mounting ring in fixed relation to the retainer, the mounting ring having a radially outwardly facing surface, in which the pattern of annular grooves for each igniter in the set is formed in said outwardly facing surface, whereby the pattern of grooves is hidden from visual inspection by said wall of the supporting retainer, and in which said wall of the supporting retainer is X-ray permeable, whereby said grooves can be inspected automatically by means of an X-ray source and X-ray detection means.

3. A method of distinguishing different airbag igniters in a set of airbag igniters each comprising an igniter body, a pyrotechnic charge and electrical means for causing ignition of said charge, in which the electrical means of at least one of the igniters in the set has a sensitivity different from the sensitivity of the electrical means of at least one other igniter in the set, wherein a pattern of annular grooves is provided on each of said igniters, the pattern of annular grooves being the same for all of the igniters in the set having the same sensitivity, and any two igniters in the set having different sensitivities having different patterns of annular grooves, in which each igniter in the set has a mounting ring connected to its igniter body and surrounding a portion of its igniter body, a supporting retainer having a wall surrounding the mounting ring, and means securing the mounting ring in fixed relation to the retainer, the mounting ring having a radially outwardly facing surface, in which the pattern of annular grooves for each igniter in the set is formed in said outwardly facing surface, whereby the pattern of grooves is hidden from visual inspection by said wall of the supporting retainer, and in which said wall of the supporting retainer is X-ray permeable, comprising the step of inspecting said grooves by positioning said igniters in the path of X-rays between an X-ray source and X-ray detection means.