Airbag Patents Reveal Long History of Safety Improvement Attempts

Airbag patents show researchers probed ways to make the devices more durable and the explosive propellant inside them more stable for decades before Takata Corp. products designed to save lives started killing people.

The patents, some from as early as 1985, were intended to improve the ammonium nitrate propellants that help inflate the bags and strengthen their metal housing.

The applications provide ammunition for lawyers seeking to show the Japanese supplier could have acted sooner to head off defects linked to at least five deaths globally after airbags have deployed with too much force, said Jason Turchin, a lawyer who represented a driver injured by a Takata airbag in a 2006 Chrysler sedan.

Takata executives are being second-guessed by lawyers, U.S. regulators and members of Congress as recall numbers climb beyond 10 million involving at least 10 global automakers. Takata said last week it still doesn’t fully understand the root cause of failures that have also injured hundreds of people. The Tokyo-based company said it has been aware since 2005 of a flaw on airbags made as early as 2000.

A Bloomberg News review of the patents studied by Turchin as well as several others shows that Takata researchers have been aware of the instability of ammonium nitrate and other risks for more than a dozen years.

Turchin cites two patents, one from 1985 and another from 1989, that address the possibility airbag housings can degrade at high temperatures and otherwise be at risk of rupturing or breaking apart. At least seven applications from Takata cite those two patents, according to a patent search by Innography Inc., an Austin, Texas-based maker of software to analyze patent portfolios.

Honda Motor Co., Toyota Motor Corp. and Ford Motor Co. were among automakers last week that agreed to seek independent testing of Takata airbags and expanded recalls based on evidence showing new risks for models not included in earlier safety actions. Honda expanded U.S. recalls by 2.6 million, to about 5.4 million, for driver’s side airbags.