Single-sensing airbag system with zero power consumption in the "key-off" s t

• US 5,170,066 A
• Filed: 02/19/1991
• Issued: 12/08/1992
• Est. Priority Date: 02/19/1991
• Status: Expired due to Fees

• Current Assignee: Continental Automotive GmbH (Continental AG), Siemens AG
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Huber, Anton S.
• Primary Examiner(s): Gaffin, Jeffrey A.
• Application Number:
  US07/657,704
• Time in Patent Office: 658 Days
• Field of Search: 180/274, 180/282, 280/734, 280/735, 307/10.1, 340/436
• US Class Current: 307/10.1
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves

Abstract

When the key-operated ignition switch is turned on, the electronic activation device, which contains a solid state deceleration sensor and crash data processing and diagnostic electronics, is energized so that it is on alert to give a deployment signal to the firing squib when a crash for which the airbag should be deployed is detected by the electronic activation device. When the ignition switch is turned off, the electronic activation device is disconnected from the battery so that it does not drain the battery, but the squib can still be fired by an associated electromechanical crash sensor. There are two circuits which employ these general principles in particular ways.

Claims

1. In an automotive vehicle that is powered by a motor, that has a deployable restraint for an occupant of the vehicle, and that has an electrical system which is powered by a battery and includes a first electrical circuit having an on-off switch for turning the motor on and off and a second electrical circuit, including a firing squib, for deploying the restraint at the incipiency of a crash for which the restraint should be deployed by igniting the firing squib by conducting electric current from the battery to the firing squib, the improvement in which said second electrical circuit comprises an electromechanical crash sensor switch that is sufficiently sensitive to operate from an open condition to a closed condition at the incipiency of any crash for which said restraint should be deployed, an electronic activation device that is energized from said battery when the on-off switch is on but not when the on-off switch is off and that when so energized is sufficiently sensitive to give a deployment signal for commanding deployment of the restraint at the incipiency of any crash for which the restraint should be deployed but when not so energized is incapable of giving said deployment signal, a first coupling circuit comprising a first coupling switch through which the firing squib and said electromechanical crash sensor switch are coupled with the battery and which is closed when said electronic activation device is not energized but is open when said electronic activation device is energized, and a second coupling circuit comprising a second coupling switch through which the firing squib and said electromechanical crash sensor switch are coupled with said battery and which is open when said electronic activation device does not give said deployment signal but is closed when said electronic activation device gives said deployment signal.

2. In an automotive vehicle that is powered by a motor, that has a deployable restraint for an occupant of the vehicle, and that has an electrical system which is powered by a battery and includes a first electrical circuit having an on-off switch for turning the motor on and off and a second electrical circuit, including a firing squib, for deploying the restraint at the incipiency of a crash for which the restraint should be deployed by igniting the firing squib by conducting electric current from the battery to the firing squib, the improvement in which said second electrical circuit comprises an electromechanical crash sensor switch that is less sensitive than an electronic activation device that is a part of said second electrical circuit and that operates from an open condition to a closed condition at the incipiency of any crash to which it is sensitive, said electronic activation device is energized from the battery when the on-off switch is on but not when the on-off switch is off, and when so energized, is sufficiently sensitive to give a deployment signal for commanding deployment of the restraint at the incipiency of any crash for which the restraint should be deployed, but when not so energized is incapable of giving said deployment signal, a first coupling circuit through which the firing squib and said electromechanical crash sensor switch are continuously coupled with the battery, and a second coupling circuit comprising two series-connected coupling switches through which said firing squib is coupled with said battery, one of said two series-connected coupling switches being open when said electronic activation device does not give said deployment signal but being closed when said electronic activation device gives said deployment signal, and the other of said two series-connected coupling switches being an electromechanical velocity change switch which operates from open to closed at the incipiency of a deceleration indicative of a velocity change which is greater than deceleration experienced by the vehicle during non-crash deceleration but which is less than deceleration which causes said electromechanical crash sensor switch to operate from open condition to closed condition.