Electric primer with reduced RF and ESD hazard
AssigneeOlin Corporation
InventorGeorge C. Mei
Life of this patent
Estimating the term…
Abstract
An electric primer using an intrinsic conductive pyrotechnic mixture is improved by the addition of a carbon layer between the inner and outer electrodes and the mixture. The carbon layer provides a parallel resistive current path between the electrodes in addition to the path through the conductive mixture. The addition of a carbon layer also increases the operable temperature range of the primer. The high energy firing threshold of the intrinsically conductive pyrotechnic mixture and the additional dissipative current path through the carbon layer coact to further reduce the sensitivity of the primer to RF radiation and ESD hazards.
Claims17
In an automatic airbag inflator utilizing a gas generator in an automobile passive restraint system, an electric primer operative at nominal vehicle battery voltage for igniting a propellant in said gas generator comprising:
- a cup shaped outer electrode having a central bore therethrough;
- an inner button shaped electrode having a terminal portion extending through said bore;
- an insulator sleeve spaced between and separating said electrodes;
- a layer of carbon over said inner electrode and a portion of said insulator sleeve and a portion of said outer electrode so as to form a resistance path through said layer between said electrodes;
- and
- an intrinsic conductive pyrotechnic mixture within said cup shaped outer electrode and over said layer, said mixture consisting essentially of a powdered metal fuel, an alkaline chlorate oxidizer, and a sensitizer fuel, said mixture reacting exothermically when said nominal battery voltage is applied between said electrodes through said carbon layer and said mixture to ignite said propellant in said gas generator.
An electric primer adapted for use in a automobile airbag inflator to ignite a propellant in a gas generator, said primer comprising:
- a cup shaped outer electrode;
- an inner electrode;
- an insulator space between and separating said electrodes;
- an intrinsically conductive pyrotechnic mixture consisting essentially of a powdered metal fuel, an alkaline chlorate oxidizer, and a sensitizer fuel within said outer electrode communicating between said electrodes;
- and
- a layer of carbon disposed between said mixture and said electrodes and over said insulator communicating with said mixture and said electrodes.
An electric primer comprising:
- a cup shaped outer electrode;
- an inner electrode;
- an insulator spaced between and separating said electrodes;
- an intrinsically conductive pyrotechnic mixture consisting essentially of a powdered metal fuel, an alkaline chlorate oxidizer, and a sensitizer fuel within said outer electrode communicating between said electrodes;
- and
- a layer of carbon disposed between said mixture and said electrodes and over said insulator and communicating with said mixture and said electrodes, said mixture being about 27% by weight titanium and 68% by weight potassium chlorate.
Dependencies are inferred from the claim text.