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US 2004/0200371 A1Published application
Heating element and method of making same for use as an igniter for pyrothecnic charges
AssigneeHIRTENBERGER-SCHAFFLER AUTOMOTIVE ZUNDERGES. m.b.H
InventorMarkus Forsthuber
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Abstract
A heating element for the ignition of a pyrotechnic charge, e.g. for firing an air bag, has increased stability with respect to transient pulses and electrostatic discharge as a result of a selection of this mass, specific resistance and specific heat capacity. In particular the mass is 1.0×10−9 kg to 4.0×10−9 kg, the specific resistance is 1×10−6 Ωm to 2×10−6 Ωm and the specific heat capacity is 100 W/(kg.K) to 400 W/(kg·K).
Claims13
A heating element for igniting a pyrotechnic charge comprising
- a base body, a structured strip shaped resistance layer on said base body, and contact fields overlapping said resistance layer at ends thereof for applying a current pulse to the heating element, wherein the heating element has a mass of 1.0×10−9 kg to 4.0×10−9 kg, a specific resistance of 1×10−6 Ωm to 2×10−6 Ωm and a specific heat capacity of 100 W/(kg.K) to 400 W/(kg·K).
A method of making a heating element for igniting a pyrotechnic charge, comprising the steps of:
- depositing a glass or glass ceramic on a base body to form a glass or glass ceramic layer;
- applying to said glass or glass ceramic layer a resistance layer in the shape of a strip;
- structuring said resistance layer with a programmable layer;
- and
- applying to ends of said resistance layer respective contact fields enabling electrical excitation of the resulting heating element, said heating element having a mass of 1.0×10−9 kg to 4.0×10−9 kg, a specific resistance of 1×10−6 Ωm to 2×10−6 Ωm and a specific heat capacity of 100 W/(kg.K) to 400 W/(kg·K).
2 more elements
Dependencies are inferred from the claim text.