Ammunition and explosives – Igniting devices and systems – Electrical primer or ignitor
Reexamination Certificate
1999-08-13
2001-05-15
Miller, Edward A. (Department: 3641)
Ammunition and explosives
Igniting devices and systems
Electrical primer or ignitor
C102S202500, C102S202900, C149S018000, C149S093000, C149S105000
Reexamination Certificate
active
06230624
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an igniter, and particularly relates to an ignition material for an igniter for inflating an inflatable vehicle occupant protection device.
BACKGROUND OF THE INVENTION
An inflatable vehicle occupant protection device, such as an air bag, is inflated by inflation gas provided by an inflator. The inflator typically contains ignitable gas generating material. The inflator further includes an igniter to ignite the gas generating material.
The igniter contains a charge of ignition material. The igniter also contains a bridgewire which is supported in a heat transferring relationship with the ignition material. When the igniter is actuated, an actuating level of electric current is directed through the bridgewire in the igniter. This causes the bridgewire to become resistively heated sufficiently to ignite the ignition material. The ignition material then produces combustion products which, in turn, ignite the gas generating material.
SUMMARY OF THE INVENTION
The present invention is an electrically actuatable igniter which comprises a body, a pair of electrodes associated with the body, a heating element electrically connected between the electrodes, and an ignition droplet covering and adhering to the heating element. The ignition droplet comprises a particulate primary pyrotechnic material and a secondary pyrotechnic material. The secondary pyrotechnic material has a melting point below the autoignition temperature of the primary pyrotechnic material. The secondary pyrotechnic material is in the form of a continuous, solid matrix containing and adhering together the particles of the primary pyrotechnic material.
The ignition droplet is made by forming a precursor mixture of the particles of the secondary pyrotechnic material and the particles of the primary pyrotechnic material. The secondary pyrotechnic material is in a molten state and the particles of the primary pyrotechnic material are dispersed in the molten state secondary pyrotechnic material. The amount of secondary pyrotechnic material is an effective amount to disperse the particles of primary pyrotechnic material. The precursor mixture is positioned on the heating element. The precursor mixture is allowed to cool, solidifying the secondary pyrotechnic material.
In an embodiment of the present invention, the particles of the secondary pyrotechnic material, the particles of the primary pyrotechnic material, and a liquid carrier, in which neither pyrotechnic material is soluble, are blended together to form a viscous slurry. The slurry is deposited onto the heating element, and is heated to a first temperature to drive off the solvent. The slurry is then heated to a second temperature to melt the secondary pyrotechnic material and form the precursor mixture in which the particles of the primary pyrotechnic material are dispersed in the molten secondary pyrotechnic material.
In another embodiment of the present invention, the particles of the secondary pyrotechnic material are heated to a temperature effective to melt the particles of the secondary pyrotechnic material. The particles of the primary pyrotechnic material are dispersed in the melt of the secondary pyrotechnic material to form the precursor mixture. The precursor mixture of the primary and secondary pyrotechnic materials is deposited on the heating element and is allowed to cool, solidifying the secondary pyrotechnic material.
REFERENCES:
patent: 3134329 (1964-05-01), Zeman
patent: 3686934 (1972-08-01), Farrand et al.
patent: 3906858 (1975-09-01), Craig et al.
patent: 4134780 (1979-01-01), Barnett
patent: 4747892 (1988-05-01), Spencer
patent: 5210153 (1993-05-01), Manser et al.
patent: 5341742 (1994-08-01), Alford et al.
patent: 5385098 (1995-01-01), Lindqvist et al.
patent: 5431104 (1995-07-01), Barker
patent: 5648634 (1997-07-01), Avory et al.
patent: 5711531 (1998-01-01), Avory et al.
patent: 5717158 (1998-02-01), Capellos et al.
patent: 5821446 (1998-10-01), Chatley
patent: 5939660 (1999-08-01), Fogle et al.
patent: 5945627 (1999-08-01), Arpin et al.
patent: 6085659 (2000-07-01), Beukes et al.
Chatley, Jr. Glenn R.
Sampson William P.
Miller Edward A.
Tarolli, Sundheim, Covell Tummino & Szabo L.L.P.
TRW Inc.
LandOfFree
Igniter having a hot melt ignition droplet does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Igniter having a hot melt ignition droplet, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Igniter having a hot melt ignition droplet will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2509492