Air bag start device

• US 6,698,791 B1
• Filed: 06/05/2002
• Issued: 03/02/2004
• Est. Priority Date: 10/11/2000
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Furui, Takashi
• Primary Examiner(s): Ellis, Christopher P.
• Assistant Examiner(s): Sharma, Rashmi
• Application Number:
  US10/148,833
• Time in Patent Office: 636 Days
• Field of Search: 280/735, 280/741, 280/734
• US Class Current: 280/735
• 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

A two-stage ignition type air bag actuator having first-stage inflators and second-stage inflators, comprising power supply 11 for supplying power to the igniting devices for the inflators, a mechanical acceleration switch 12 disposed between the common junction of the respective igniting devices 4, 5, 7, and 8 and the power supply 11, and a forcible igniting mechanism 15 disposed in parallel with the mechanical acceleration switch 12 for electrically connecting or disconnecting the common junction and the power supply 11.

Claims

1. In an air bag actuator for inflating at least one two-stage ignition type air bag, having first-stage inflators, and second inflators which are ignited simultaneously with said first-stage inflators or after a predetermined time has elapsed since said first-stage inflators are ignited, comprising:

power supply means for supplying a current necessary for igniting said inflators;

a mechanical acceleration switch, which is disposed between the common junction of a first-stage igniting device provided for every one or more first-stage inflators and a second-stage igniting device provided for one or more second-stage inflators, and opens or closes depending on the acceleration of a vehicle;

one or more first switching means connected in series with said first-stage igniting device for every said first-stage igniting device;

one or more second switching means connected in series with said second-stage igniting device for every said second-stage igniting device;

an acceleration sensor for detecting how far the acceleration is applied to the vehicle, and for outputting a signal corresponding to the acceleration;

an ignition judging means, connected to the control terminals of said first switching means and said second switching means, for controlling ON-OFF of said first switching means and said second switching means in response to the signal inputted from said acceleration sensor; and

forcible igniting means, disposed between said common junction of the igniting devices and said power supply means in parallel with said mechanical acceleration switch, for electrically connecting or disconnecting said common junction and said power supply means in response to the signal from said ignition judging means.

2. The air bag actuator according to claim 1, wherein said forcible igniting means comprises:

forcible ignition switching means disposed between the common junction of the igniting devices and the power supply means in parallel with the mechanical acceleration switch;

closure detecting means for detecting said mechanical acceleration switch is opened or closed, and for holding a signal output indicative of the closure of said mechanical acceleration switch for a predetermined time after it has opened after the closure; and

logical means, having its input portions connected to the ignition judging means and said closure detecting means and having its output portion connected to said forcible ignition switching means, for turning ON said forcible ignition switching means only when a signal instructing the ignition of the second-stage inflators is outputted from said ignition judging means, and a signal indicative of the closure of said mechanical acceleration switch is outputted from said closure detecting means.

3. The air bag actuator according to claim 1, wherein a one-way conducting element, disposed at the common junction of the first-stage igniting device provided for every one ore more first-stage inflators, and the second-stage igniting device provided for every one or more second-stage inflators, for passing a current only in one direction, and

wherein, with respect to a first junction and a second junction which are partitioned by the one-way conducting element at said common junction of the igniting devices, a current is passed only from said first junction to said second junction, and one or more said first-stage igniting devices and said mechanical acceleration switch are connected to said first junction, while one or more said second igniting devices and said forcible igniting means are connected to said second junction.