Seat weight sensor

• US 7,246,850 B2
• Filed: 09/08/2005
• Issued: 07/24/2007
• Est. Priority Date: 09/08/2004
• Status: Expired due to Fees

• Current Assignee: Joyson Safety Systems Acquisition, LLC
• Original Assignee: TK Holdings Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Steele, Ryan N.
• Primary Examiner(s): WHITE, RODNEY BARNETT
• Application Number:
  US11/220,545
• Publication Number:
  US 20060061159A1
• Time in Patent Office: 684 Days
• Field of Search: 297/217.2, 297/463.1, 297/463.2, 280/735
• US Class Current: 297/217.2
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015
• CPC Class Codes: G01G 19/445 in a horizontal position

Abstract

A seat weight sensor for detecting the load upon a vehicle seat. The seat weight sensor includes a seat rail positioned under the vehicle seat. A lever arm is mounted to the vehicle seat. One end of the lever arm has one or more stationary fingers and a free finger. The stationary fingers are rigidly mounted to the seat rail. The lever arm bends in relation to the force placed upon the seat that in turn places the free finger in motion. A sensor is mounted to the seat rail and is configured to measure the change in motion of the free finger when a force is placed upon the seat.

Claims

1. A seat weight sensor, comprising:

a seat rail positioned under a vehicle seat;

a lever arm, wherein a first end of the lever arm includes a free finger and one or more stationary fingers, wherein the one or more stationary fingers are mounted to the seat rail such that the end of the stationary fingers cannot move vertically and a second end of the lever arm, rigidly mounted to the seat rail;

a sensor, mounted to the seat rail;

a plunger, connected to the free finger, wherein the plunger is positioned within a housing so that its movement is restricted to the vertical axis; and

one or more magnets positioned inside the plunger, wherein the sensor detects changes in a magnetic field created by the magnets when the plunger is put in motion by the free finger.

2. A seat weight sensor as claimed in claim 1, wherein the sensor is a Hall Effect sensor.

3. A seat weight sensor as claimed in claim 1, wherein the lever arm is composed of an elastic material.

4. A seat weight sensor, comprising:

a seat rail positioned under a vehicle seat;

a lever arm, wherein a first end of the lever arm includes a free finger and one or more stationary fingers, wherein the one or more stationary fingers are mounted to the seat rail such that the end of the stationary fingers cannot move vertically and a second end of the lever arm, rigidly mounted to the seat rail; and

a sensor, mounted to the seat rail, wherein a first pin attaches the second end of the lever arm to the seat rail so that the lever arm may pivot relative to the rail and a second pin attaches the second end of the lever arm to the seat rail at a corner of the vehicle seat.

5. A seat weight sensor as claimed in claim 4, further comprising:

a plunger, connected to the free finger, wherein the plunger is positioned within a housing so that its movement is restricted to the vertical axis; and

one or more magnets positioned inside the plunger, wherein the sensor detects changes in a magnetic field created by the magnets when the plunger is put in motion by the free finger.

6. A seat weight sensor as claimed in claim 5, wherein the magnets are configured to provide a magnetic field to be measured by the sensor.

7. A seat weight sensor as claimed in claim 4, wherein when force is applied at the second pin, the lever arm will pivot around the first pin.

8. A seat weight sensor, comprising:

a seat rail positioned under a vehicle seat;

a lever arm, wherein a first end of the lever arm includes a free finger and one or more stationary fingers, wherein the one or more stationary fingers are mounted to the seat rail such that the end of the fingers cannot move vertically and a second end of the lever arm, rigidly mounted to the seat rail;

one or more of displacement sensors mounted to the seat rail, wherein the displacement sensors are used to detect the position of the free finger;

a plunger, connected to the free finger, wherein the plunger is positioned within a housing so that its movement is restricted to the vertical axis; and

one or more magnets positioned inside the plunger, wherein the sensor detects changes in a magnetic field created by the magnets when the plunger is put in motion by the free finger.

9. A seat weight sensor system, comprising:

a vehicle seat;

one or more seat rails positioned under the vehicle seat;

one or more lever arms, wherein a first end of the lever arm includes an free finger and one or more stationary fingers, wherein the one or more stationary fingers are mounted to the seat rail such that the end of the fingers cannot move vertically and a second end of the lever arm, rigidly mounted to the seat rail;

a sensor mounted to the seat rail, wherein the sensor detects changes in the movement of the free finger when a force is applied to the seat and generates an electric signal;

a processor, configured to receive and convert the electrical signal into a force value;

a plunger, connected to the free finger, wherein the plunger is positioned within a housing so that its movement is restricted to the vertical axis; and

one or more magnets positioned inside the plunger, wherein the sensor detects changes in a magnetic field created by the magnets when the plunger is put in motion by the free finger.

10. A seat weight sensor for a vehicle, comprising:

a lever arm, wherein the first end of a lever arm includes a free finger and one or more stationary fingers, wherein the one or more stationary fingers are mounted to a seat track of a vehicle seat such that the end of the fingers cannot move vertically and a second end of a lever arm is mounted to the vehicle such that the second end cannot move vertically;

a sensor, wherein the sensor detects changes in the movement of the free finger when a force is applied to the seat;

a plunger, connected to the free finger, wherein the plunger is positioned within a housing so that its movement is restricted to the vertical axis; and

one or more magnets positioned inside the plunger, wherein the sensor detects changes in a magnetic field created by the magnets when the plunger is put in motion by the free finger.

11. A seat weight sensor for a vehicle as claimed in claim 10, further comprising:

a sensor mounted to the seat track, wherein the sensor detects changes in the movement of the free finger when a force is applied to the seat.

12. A seat weight sensor for a vehicle as claimed in claim 10, further comprising:

a sensor mounted to the one or more stationary fingers, wherein the sensor detects changes in the movement of the free finger when a force is applied to the seat.

13. A seat weight sensor for a vehicle as claimed in claim 10, wherein the magnets are configured to provide a magnetic field to be measured by the sensor.

14. A seat weight sensor for a vehicle as claimed in claim 10, wherein the sensor is a Hall Effect sensor.

15. A seat weight sensor for a vehicle as claimed in claim 10, wherein the lever arm is composed of an elastic material.

16. A seat weight sensor system, comprising:

a vehicle seat;

one or more of lever arms, wherein the first end of a lever arm includes a free finger and one or more stationary fingers, wherein the one or more stationary fingers are mounted to a seat track of the vehicle seat such that the end of the fingers cannot move vertically and a second end of a lever arm is mounted to the vehicle such that it cannot move vertically;

a sensor mounted to the seat track, wherein the sensor detects changes in the movement of the free finger when a force is applied to the seat; and

a processor, configured to receive and convert the electrical signal into a force value;

a plunger, connected to the free finger, wherein the plunger is positioned within a housing so that its movement is restricted to the vertical axis; and

one or more magnets positioned inside the plunger, wherein the sensor detects changes in a magnetic field created by the magnets when the plunger is put in motion by the free finger.

17. A seat weight sensor system according to claim 16, further comprising:

a sensor mounted to the one or more stationary fingers, wherein the sensor detects changes in the movement of the free finger when a force is applied to the seat.

18. A seat weight sensor comprising:

a lever arm, wherein a first end of the lever arm includes a free finger and a second end of the lever arm is rigidly mounted to a vehicle mount positioned between a vehicle floor and a vehicle seat; and

a sensor mounted to the vehicle, wherein the sensor detects changes in the movement of the free finger when a force is applied to the seat;

a plunger, connected to the free finger, wherein the plunger is positioned within a housing so that its movement is restricted to the vertical axis; and

one or more magnets positioned inside the plunger, wherein the sensor detects changes in a magnetic field created by the magnets when the plunger is put in motion by the free finger.