AIR CUSHION ACTUATION AND FAILURE WARNING CIRCUIT

• US 3,622,974 A
• Filed: 05/11/1970
• Issued: 11/23/1971
• Est. Priority Date: 05/11/1970
• Status: Expired due to Term

• Current Assignee: Arden G. Gillund, Frederick A. Best, Trevor O. Jones
• Original Assignee: Arden G. Gillund, Frederick A. Best, Trevor O. Jones
• Inventors: Best, Frederick A., Gillund, Arden G., Jones, Trevor O.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/035,980
• Time in Patent Office: 561 Days
• Field of Search: 340/52H,53 280/150 200/61.45 180/103,104
• US Class Current: 280/735
• CPC Class Codes: B60R 21/0173 Diagnostic or recording means therefor

Abstract

A control circuit for actuating an inflatable air cushion in a motor vehicle including an electrically fired actuator connected between a pair of SCR'"'"''"'"'s which are triggered from respective vehicle deceleration sensors. A storage capacitor is discharged through the SCR'"'"''"'"'s and actuator upon a deceleration of predetermined magnitude and duration. Failure warning circuitry is provided for simulated operation of the sensors and for detecting the voltage at a junction in the control circuit to determine whether various components of the control circuit are functioning properly, and if not, to provide an indication to the operator of the vehicle.

Claims

1. In a passenger conveyance provided with a safety device adapted to be actuated by electrically operated actuator means, a control circuit for operating said actuator means comprising, a storage capacitor, means for charging said capacitor, first and second normally open switch means, means including said first switch means connecting one side of said actuator to said capacitor, means including said second switch means connecting the other side of said actuator means and to a reference potential, means including first and second normally open sensor switch means responsive to acceleration of said conveyance of a predetermined magnitude for actuating said first and second normally open switch means, to thereby discharge said capacitor and operate said actuator means, failure warning circuit means for diagnosing a malfunction in said control circuit prior to charging of said capacitor and comprising indicator means, means for applying a test current to the series network of said actuator means and said normally open switch means, said test current being of a magnitude less than that required to operate said actuator means, means for simulating closure of said first and second sensor means in sequence, means for sampling the voltage at a junction in said circuit after closure of each of said sensor means and providing a logic output indicative of a malfunction in the control circuit, and means responsive to said logic output for controlling the energization of said indicator means.

2. In a motor vehicle provided with an inflatable safety device adapted to be inflated by electrically operated actuator means, a source of voltage, and an ignition switch connected thereto;

a control circuit for operating said actuator means comprising;

first and second normally nonconductive semiconductor switch means each having a control electrode and adapted to be rendered conductive by a pulse applied to said control electrode, said first and second semiconductor switch means being connected to opposite sides of said actuator means to form a series network connected at one end thereof to a reference potential, a storage capacitor connected in parallel with said series network, first and second monostabLe switch means actuable to apply said pulse to the control electrode of said first and second semiconductor switch means respectively, first and second normally open sensor switch means responsive to deceleration of said vehicle, first and second integrator means connected respectively with said first and second normally open switch means for respectively actuating said first and second monostable switch means, failure warning circuit means energizable through said ignition switch and comprising means for supplying a test current to said series network for a predetermined interval of time, said test current being of a magnitude less than that required to operate said actuator means, means for simulating closure of said first and second sensor means including a pair of transistors connected across respective ones of said sensor switch means, timing means for generating a plurality of individual output pulses in sequence, means connecting said transistors to said timing means to render said transistors conductive in response to generation of respective ones of said output pulses, failure detection logic means connected to said timing means for sampling the voltage at a junction between said detector means and said second semiconductor switch means prior to simulated closure of said first sensor switch means and subsequent to simulated closure of each of said sensors switch means and for providing a logic output indicative of a malfunction in the control circuit, indicator means, means responsive to said logic output for controlling the energization of said indicator means, means responsive to the expiration of said predetermined time interval for connecting said capacitor to said ignition switch, means responsive to an engine running condition, means responsive to a charge condition of said capacitor, means for inhibiting operation of said timing generator when either said capacitor is charged or said engine is not running.