SEAT OCCUPANCY RESPONSIVE AIR CUSHION ACTUATION AND MONITORING CIRCUIT

• US 3,767,002 A
• Filed: 08/10/1972
• Issued: 10/23/1973
• Est. Priority Date: 08/10/1972
• Status: Expired due to Term

• Current Assignee: Arden G. Gillund
• Original Assignee: Arden G. Gillund
• Inventors: Gillund, Arden G.
• Primary Examiner(s): Betts, Kenneth H.
• Application Number:
  US05/279,542
• Time in Patent Office: 439 Days
• Field of Search: 280/15AB 180/91,103,100,102 340/52H,278
• US Class Current: 280/735
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means

Abstract

A circuit for actuating respective air cushions for the driver and passengers of a vehicle in the event of a collision includes relay contacts connected in the series network for firing the squib which controls inflation of the passenger cushion. When the seat is occupied by a passenger, a seat sensor disables the relay controlling the contact and the series network is armed. If no passenger occupies the seat the relay is energized to open circuit the series network and prevent inflation of the passenger cushion in the event of a collision. Monitoring circuitry indicates to the driver if a malfunction occurs such as the series network being armed while no passenger is present or the series network being open circuited while a passenger is present.

Claims

1. In a passenger conveyance provided with a source of direct current potential, the combination of:

seat occupancy responsive switch means;

an inflatable cushion located in said vehicle to arrest forward motion of an occupant of the vehicle, said cushion adapted to be actuated by electrically operated actuator means, first and second normally open acceleration responsive switch means connected to opposite sides of said actuator means to form a series network;

means for connecting said series network across said source;

voltage divider means adapted to be connected with said source for normally establishing a predetermined voltage at a monitoring junction in said series network;

relay means comprising a relay coil, and first and second normally closed contact means operable by said relay coil;

means connecting said first normally closed contact means in series between said actuator means and said second acceleration responsive switch means whereby said series network is open circuited when said relay coil is energized;

relay control means responsive to operation of said seat occupancy responsive switch means for connecting said relay coil to said source during seat vacancy and for disconnecting said relay coil from said source during seat occupancy;

means including said relay control means connecting said second normally closed contact means between said source and said junction whereby the voltage at said junction changes from said predetermined voltage in the event said relay coil is disabled during seat vacancy; and

means connected with said junction for detecting and indicating said change from said predetermined voltage.

2. In a motor vehicle provided with a source of direct current potential;

an ignition switch connected in series with said source;

first and second inflatable cushions adapted to be actuated by first and second electrically operated actuator means, said first and second cushions being located in said vehicle to arrest forward motion of the driver of the vehicle and a passenger of the vehicle respectively, the combination of;

an actuation circuit for operating said first and second actuator means and comprising first and second normally open acceleration responsIve switch means connected to opposite sides of said first actuator means to form a series network;

means for connecting said series network across said source;

relay means comprising a relay coil and first and second normally closed contact means operable by said relay coil, switch means responsive to occupancy of the vehicle by a passenger, relay control means connected with said seat occupancy responsive switch means for controlling energization of said relay coil whereby said relay coil is enabled in response to seat vacancy and is disabled in response to seat occupancy;

means connecting said first normally closed contact means in series with said second actuator means between said first and second acceleration responsive switch means whereby said second actuator means is disabled in response to seat vacancy;

voltage divider means adapted to be connected with said source for normally establishing a predetermined voltage at a monitoring junction in said series network;

indicator means;

means responsive to a change in voltage from said predetermined voltage at said monitoring junction for energizing said indicator means;

means including said relay control connecting said second normally closed contact means between said source and a junction between said first normally closed contact means and said second acceleration responsive switch means whereby the voltage at said monitoring junction changes from said predetermined voltage in the event said relay coil is disabled during seat vacancy.

3. The circuit defined in claim 2 wherein said relay means further includes normally open contact means operable by said relay coil;

a resistor connected in series with said normally open contact means across said first normally closed contact means whereby the voltage at said monitoring junction changes from said predetermined voltage in the event said first normally closed contact means does not close in response to disabling of said relay coil.

4. The circuit defined in claim 3 further including a diode interconnecting said second actuator means with said second normally closed contact means to provide a current path between said second actuator means and said second acceleration responsive switch means in parallel to said first normally closed contact means and wherein said means connecting said second normally closed contact means with said source includes a second diode poled to prevent current flow through said first mentioned diode or second normally closed contact means to said relay coil.