Vehicle seat weight sensor

• US 6,161,891 A
• Filed: 10/21/1999
• Issued: 12/19/2000
• Est. Priority Date: 10/21/1999
• Status: Expired due to Term

• Current Assignee: CTS Corporation
• Original Assignee: CTS Corporation
• Inventors: Blakesley, Patrick B.
• Primary Examiner(s): Dayoan, D. Glenn
• Assistant Examiner(s): BLANKENSHIP, GREGORY A
• Application Number:
  US09/422,382
• Time in Patent Office: 425 Days
• Field of Search: 296/65.01, 296/65.13, 296/65.14, 296/68.1, 280/273, 280/735, 177/144, 177/136, 177/211, 177/199, 177/DIG. 6, 177/210, 33/DIG. 13
• US Class Current: 296/65.01
• 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: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress

Abstract

A vehicle seat weight sensor for sensing the weight of an occupant in a vehicle seat. The sensor includes a substrate that has a first and second end. The substrate is located between the seat bottom and the vehicle floor. Strain gauge resistors are located on the substrate for generating an electrical signal in response to the substrate being stressed by the weight of the seat occupant. The electrical signal changes as a function of the weight of the seat occupant. Several mounting configurations to the vehicle seat are shown.

Claims

1. A vehicle seat weight sensor for sensing weight of an occupant in a vehicle seat, the seat having a seat back, a seat bottom and a seat bracket connected to a vehicle floor, a lower slide rail, and an upper slide rail coupled to the seat bracket and a seat pan attached to the upper rail, the vehicle seat weight sensor comprising:

a) a substrate, having a first and second end, the first end attached to the lower slide rail and the second end attached to the seat bracket such that forces applied to the seat bottom are transferred from the lower slide rail to the seat bracket through the substrate;

b) a plurality of strain gauge resistors, located on the substrate, for generating an electrical signal in response to the substrate being stressed, the electrical signal changing magnitude as a function of the weight of the occupant; and

c) a first fastener connected between the first end and the lower slide rail and a second fastener connected between the second end and the seat bracket.

2. The vehicle seat weight sensor according to claim 1, wherein the substrate has a neck down region for concentrating the forces onto the strain gauge resistors.

3. The vehicle seat weight sensor according to claim 1, wherein the substrate has apertures at the first and second ends of the substrate.

4. The vehicle seat weight sensor according to claim 1, wherein the electrical signal is used to control activation of an airbag.

5. A vehicle seat weight sensor for sensing weight of an occupant in a vehicle seat for use by an airbag control system, the seat having a seat back, a seat bottom and a seat bracket connected to a vehicle floor, a lower slide rail, and an upper slide rail coupled to the seat bracket and a seat pan attached to the upper rail, the improvement comprising:

at least one generally horizontally elongated substrate, having a first and second end, said first end attached to said lower slide rail and said second end attached to said seat bracket such that a portion of forces applied to said seat bottom are transferred from said lower slide rail to said seat bracket through said substrate;

a neckdown region formed in said substrate between said first and second ends for concentrating said forces thereon;

a plurality of strain gauge resistors, located on said neckdown region of said substrate, for generating an electrical signal in response to said substrate being stressed, said electrical signal changing magnitude as a function of the weight of said occupant; and

fastener means, connected between said first end and said lower slide rail and between said second end and said seat bracket for connecting said substrate to said seat.

6. A vehicle seat weight sensor for sensing weight of an occupant in a vehicle seat for use by an airbag control system, the seat having a seat back, a seat bottom and a seat bracket connected to a vehicle floor, a lower slide rail, and an upper slide rail coupled to the seat bracket and a seat pan attached to the upper rail, the sensor comprising:

a) at least one generally horizontally elongated substrate, disposed between said seat bottom and said vehicle floor such that a portion of the weight of said occupant on said seat bottom is transferred from said seat bottom to said vehicle floor through said substrate, said substrate having a first and a second end;

b) a neckdown region formed in said substrate between said first and second ends for concentrating the weight of said occupant thereon; and

c) a plurality of strain gauge resistors, located on said neckdown region of said substrate, for generating an electrical signal in response to said substrate being stressed by the weight of said occupant, said electrical signal changing magnitude as a function of the weight of said occupant.

7. The vehicle seat weight sensor according to claim 6, wherein the substrate is located between said upper slide rail and said seat pan.

8. The vehicle seat weight sensor according to claim 6, wherein the substrate is located between said lower slide rail and said seat bracket.

9. The vehicle seat weight sensor according to claim 6, wherein the substrate is located between said lower seat rail and said vehicle floor.