Inflatable air bag safety device for motor vehicles

• US 5,161,820 A
• Filed: 05/21/1991
• Issued: 11/10/1992
• Est. Priority Date: 05/23/1990
• Status: Expired due to Term

• Current Assignee: Audi AG (Volkswagen AG)
• Original Assignee: Audi AG (Volkswagen AG)
• Inventors: Vollmer, Elmer
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): DICKSON, PAUL N
• Application Number:
  US07/703,689
• Time in Patent Office: 539 Days
• Field of Search: 280/730, 280/731, 280/732, 280/735, 180/273, 180/272, 340/666, 340/667
• US Class Current: 280/730.1
• CPC Class Codes: B60R 21/01524 using electric switches

Abstract

An improved inflatable passenger side air bag safety device for motor vehicles for detecting the presence or absence of a passenger positioned on or in front of a particular passenger vehicle seat. The safety device comprises a control unit for the intelligent triggering of the propellant charge for the air bag when a triggering event is detected, such as an impending collision, and the presence of a passenger is also detected. The control unit receives signals from a pair of switches, electrically connected in parallel to one another, including a first seat switch for detecting the presence or absence of a sitting passenger and a second foot switch for detecting the presence or absence of a standing, kneeling, or sitting passenger in the region in front of the vehicle seat. In the preferred embodiment both switches are flat, contact type switches, each having a broad surface area and are activated when subjected to the weight of a passenger from above. An acceleration sensor is also connected to the control unit for signaling the event of an impending collision. In an alternate embodiment the foot switch is a condenser-type switch in the form of a metallic screen interwoven within the floor carpet and detects fluctuations in the magnetic and electric fields corresponding to the presence or absence of a passenger positioned over the floor carpet. The air bag associated with the vehicle seat is caused to be activated during a triggering event if either of the seats switch and/or foot switch are activated by a passenger.

Claims

1. In a passenger side inflatable air bag safety device for use in motor vehicles of the type in which a control unit is provided for the intelligent triggering of a propellant charge associated with the inflatable air bag to provide a protective cushion for the passenger when two conditions have been satisfied including a first condition where a collision of a sufficient severity is occurring and a second condition where a passenger is present in a vehicle seat, and in which determination of the first condition is accomplished by an acceleration sensor connected to said control unit to sense the magnitude and direction of an impending collision of the motor vehicle and determination of the second condition is accomplished by a switch disposed in said vehicle seat for determining the presence or absence or a passenger seated on said vehicle seat, the improvement comprising:

a) means for detecting the presence of a person standing, kneeling or sitting on a floor mat region in front of said passenger vehicle seat;

b) said detecting means is disposed in association with a floor mat and sends a signal to said control unit when a passenger is present in said floor mat region so that said control unit will activate the ignition of the propellant charge for said passenger side air bag upon satisfaction of said first condition;

c) said detecting means is electrically connected in parallel with said first seat switch so that said detecting means signals said control unit independently of said first seat switch; and

d) said control unit includes a safety override means for triggering the propellant charge of said passenger side air bag for an operation condition where said detecting means does not confirm the presence of a passenger in the region adjacent said passenger seat and said first seat switch does not confirm the presence of a passenger seated on said vehicle seat when said acceleration sensor has signaled said control unit of an impending collision above a preselected severity level.

2. An improved passenger side inflatable air bag safety device as in claim 1 wherein said detecting means includes a flat, mat-shaped, mechanical actuable contact switch having a contact surface area sufficient to span said floor mat region in front of said passenger seat.

3. An improved passenger side inflatable air bag safety device as in claim 2 wherein:

a) said mechanical actuable contact switch includes means for measuring the force and pressure exerted on said contact switch and permitting said contact switch to close after a pre-set threshold force or pressure value is surpassed.

4. An improved passenger side inflatable air bag safety device as in claim 3 wherein said force and pressure measuring means includes at least one recognition sensor to distinguish between force and pressure distribution patterns associated with a passenger, and force and pressure distribution patterns associated with articles placed on said floor mat region.

5. An improved passenger side inflatable air bag safety device as in claim 4 wherein said contact switch is disposed under a floor carpet covering associated with said floor mat region.

6. An improved passenger side inflatable air bag safety device as in claim 4 wherein said contact switch is formed into a floor carpet covering associated with said floor mat region.

7. An improved passenger side inflatable air bag safety device as in claim 1 wherein:

a) said detecting means includes a tri-layer contact switch of the type having at least two spaced apart, contact surfaces interposed by a elastically deformable and electrically insulating layer, said tri-layer contact switch completing an electrically conductive pathway when said contact surfaces are brought together under the weight of a passenger; and

b) said contact surfaces having a surface area sufficient to span said floor mat region in front of said passenger seat.

8. An improved passenger side inflatable air bag safety device as in claim 7 wherein:

a) said tri-layer contact switch includes means for measuring the force and pressure exerted on said tri-layer contact switch and permitting said tri-layer contact switch to close after a pre-set threshold value is surpassed.

9. An improved passenger side inflatable air bag safety device as claim 8 wherein said force and pressure measuring means includes at least one recognition sensor to distinguish between force and pressure distribution patterns associated with a passenger and force and pressure distribution patterns associated with articles placed on said floor mat area.

10. An improved passenger side inflatable air bag safety device as in claim 9 wherein said contact switch is disposed under a floor carpet portion associated with said floor mat region.

11. An improved passenger side inflatable air bag safety device as in claim 9 wherein said contact switch is formed onto a floor carpet portion associated with said floor mat region.

12. An improved passenger side inflatable air bag safety device as in claim 1 wherein:

a) said detecting means includes a condenser switch comprising a pair of electrodes connected to a sheet surface of interconnecting metallic elements for running an electrical current therethrough;

d) said condenser switch detecting changes in the electric and magnetic fields adjacent said floor mat region which correspond to the presence or absence of a passenger positioned thereover; and

c) said condenser switch having a surface area sufficient to span said floor mat region in front of said passenger seat.

13. An improved passenger side inflatable air bag safety device as in claim 12 wherein:

a) said metallic elements are in the form of a metallic screen; and

b) said metallic screen is formed into a floor carpet portion associated with said floor mat region.

14. An improved passenger side inflatable air bag safety device as in claim 13 wherein said floor carpet is removable by lifting up sideways.

15. An improved passenger side inflatable air bag safety device as in claim 12 wherein:

a) said metallic elements are in the form of metallic loops; and

b) said metallic loops are formed into a floor carpet portion associated with said floor mat region.

16. An improved passenger side inflatable air bag safety device as in claim 15 wherein said floor carpet is removable by lifting up sideways.