×

Vehicle air bag apparatus

  • US 5,135,254 A
  • Filed: 04/18/1991
  • Issued: 08/04/1992
  • Est. Priority Date: 04/18/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. A vehicle air bag apparatus comprising:

  • first and second air bags located at different positions within a vehicle for protecting occupants of the vehicle;

    first and second squibs for firing and activating the first and second air bags respectively;

    acceleration detecting means provided in common to the first and second squibs for detecting an acceleration of the vehicle upon a collision of the vehicle and executing a switching operation in response to the detected vehicle acceleration;

    first and second constant-current circuits supplied with an electric power from a vehicle battery and feeding constant electric currents for a firing operation to the first and second squibs respectively in response to the switching operation of the acceleration detecting means; and

    energy storage means for feeding a backup electric power to the first and second constant-current circuits when the supply of the electric power from the vehicle battery to the first and second constant-current circuits is cut off;

    wherein each of the first and second constant-current circuits comprises a first transistor for feeding an electric current to the related squib, a first resistor for detecting a level of the electric current fed to the squib, a second transistor conducting an electric current with a level which depends on the electric current level detected by the first resistor, and a second resistor for generating a voltage which depends on the electric current conducted by the second transistor and for controlling the first transistor in response to the generated voltage to control the electric current fed to the squib.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×