Vehicle seat weight sensor

• US 6,407,347 B1
• Filed: 08/28/2000
• Issued: 06/18/2002
• Est. Priority Date: 10/21/1999
• Status: Active Grant

• Current Assignee: CTS Corporation
• Original Assignee: CTS Corporation
• Inventors: Blakesley, Patrick B.
• Primary Examiner(s): Gibson, Randy W.
• Application Number:
  US09/649,317
• Time in Patent Office: 659 Days
• Field of Search: 738/624.74, 738/626.27, 738/626.39, 738/626.32, 177/211, 177/229, 177/144, 180/273, 280/735
• US Class Current: 177/144
• 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 the weight of an occupant in a vehicle seat, comprising:

a) four substrates, each having a first and second end, one of the substrates mounted at each corner of the seat, the substrate mounted so as to be in a seat weight path between an upper slide rail and a seat pan;

b) at least one strain gage resistor, located on the substrate, for generating an electrical signal in response to the substrate being stressed, the electrical signal changing as a function of the weight of the seat occupant;

c) a plurality of wire harnesses, a wire harness electrically connected to each of the strain gage resistors;

d) a junction box positioned under the seat, the wire harnesses electrically connected to the junction box; and

e) a common wiring harness connected to the junction box, the common wiring harness adapted to be connected to an airbag controller, the common wiring harness providing the electrical signal to the airbag controller.

2. The vehicle seat weight sensor according to claim 1, wherein a first fastener connects the first end to the seat pan and a second fastener connects the second end to the upper slide rail.

3. The vehicle seat weight sensor according to claim 1, wherein the strain gage resistors are disposed on a first surface of the substrate.

4. The vehicle seat weight sensor according to claim 2, wherein the second fastener passes through a clearance aperture in the seat pan.

5. The vehicle seat weight sensor according to claim 2, wherein the substrate has a neckdown region located between the first and second ends for concentrating the stress onto the resistors.

6. A vehicle seat weight sensor for sensing the weight of an occupant in a vehicle seat, comprising:

a) at least three substrates, each having a first and second end, the substrates having a first and second surface, the substrates mounted at corners of the seat, the substrate mounted so as to be in a seat weight path between an upper slide rail and a seat pan;

b) a wheatstone bridge having four strain gage resistors, the wheatstone bridges located on the first surface of the substrate, the wheatstone bridge generating an electrical signal in response to the substrate being stressed, the electrical signal changing as a function of the weight of the seat occupant;

c) at least three wire harnesses, a wire harness electrically connected to each of the strain gage resistors;

d) a junction box positioned between the substrates, the wire harnesses electrically connected to the junction box; and

e) a common wiring harness connected to the junction box, the common wiring harness adapted to be connected to an airbag controller, the common wiring harness providing the electrical signal to the airbag controller.

7. The vehicle seat weight sensor according to claim 6 wherein a first fastener connects the first end to the seat pan and a second fastener connects the second end to the upper slide rail.

8. The vehicle seat weight sensor according to claim 7, wherein the second fastener passes through a clearance aperture in the seat pan.

9. The vehicle seat weight sensor according to claim 6, wherein the substrate has a neckdown region located between the first and second ends for concentrating the stress onto the resistors.