Seat heater with occupant sensor

• US 20080073130A1
• Filed: 09/27/2006
• Published: 03/27/2008
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Cubon, Michael M., Bulgajewski, Edward F.
• Granted Patent: US 7,500,536 B2
• Time in Patent Office: Days
• US Class Current: 177/136
• 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: H05B 2203/005 using multiple resistive elements or resistive zones isolated from each other
• CPC Class Codes: H05B 2203/017 Manufacturing methods or apparatus for heaters
• CPC Class Codes: H05B 2203/029 Heaters specially adapted for seat warmers
• CPC Class Codes: H05B 3/34 flexible, e.g. heating nets or webs

Abstract

The present invention relates to a combination heater and occupant sensor device that may be used in an automobile seat. The device will heat a seat and sense the mass of an occupant in the seat. The device provides the ability to combine occupant sensors with a seat heater without damaging the sensors or obtaining incorrect sensor readings. The sensor results may be processed and used to control air bag deployment, for example, or to indicate if the seat belt of an occupied seat is not being employed. To provide flexibility of the device during use, the device may be formed on a polymer substrate and configured to include apertures throughout. In addition, in the heating portion of the device, conductive material may be blended in a polymer and the device may be configured to limit conductor cracking after repeated flexing of the device thus extending the life of the device.

Claims

1. A device to produce heat and to sense mass for use in a vehicle seat comprising:

an electrically insulative substrate defining a first and second side,

a heater portion disposed on the first side of the substrate, the heater portion including a layer of conductive material forming at least one buss extending across the first side of the substrate, the heater portion further including a plurality of traces connected to the at least one buss, and

a sensor portion disposed on the second side of the substrate, the sensor portion including at least one sensor.

2. The device of claim 1 further comprising a resistive layer disposed over the layer of conductive material of the heater portion, whereby the resistive layer has an increasing resistance in response to an increasing temperature.

3. The device of claim 1 wherein the layer of conductive material comprises a conductive polymer and a material chosen from the group consisting of copper, gold, silver, aluminum, carbon, or graphitic materials.

4. The device of claim 1 wherein the traces comprise conductive material flakes mixed with a conductive polymer.

5. The device of claim 1 wherein the substrate includes a plurality of apertures that are configured to limit elongation of the layer of conductive material.

6. The device of claim 5 wherein the apertures include intersecting elongated slots.

7. The device of claim 6 wherein the apertures are aligned in rows and ranks offset with respect to each other.

8. The device of claim 1 wherein at least some of the traces include spurs extending outwardly from the traces.

9. The device of claim 1 further comprising a chemical resistive laminate disposed across the sensor portion.

10. A combination heater and mass sensor device for use in a vehicle comprising:

a heating portion comprising;

a nonconductive substrate;

a plurality of apertures formed through the substrate;

a layer of conductive material forming a buss and extending across the substrate, the buss forming at least one nonconductive area, and a plurality of traces extending outwardly from the buss, the plurality of traces positioned adjacent to at least some of the apertures;

a layer of resistive material disposed on the conductive material; and

a sensing portion disposed on the resistive material layer, comprising a plurality of sensors configured to be disposed in the at least one nonconductive area, each sensor comprising a first substantially flexible electrical contact, a second substantially flexible electrical contact, and a layer of dielectric material disposed between the first and second electrical contacts.

11. The device of claim 10 wherein the resistive layer comprises a positive temperature coefficient material.

12. The device of claim 10 wherein the conductive layer comprises a conductive polymer and a material chosen from the group consisting of copper, gold, silver, aluminum, carbon, or graphitic materials.

13. The device of claim 10 wherein the apertures include intersecting elongated slots substantially normal to each other.

14. The device of claim 13 wherein the apertures are aligned in rows and ranks offset with respect to each other.

15. The device of claim 14 wherein at least some of the traces include spurs extending outwardly from the traces.

16. The device of claim 15 wherein at least some the spurs include branches extending outwardly from the spurs.

17. The device of claim 10, further comprising a second buss disposed adjacent to the first buss, the second buss forming at least one nonconductive area.

18. A device to produce heat and to sense mass for use in a vehicle seat comprising:

an electrically insulative substrate made of a polymeric film;

a conductive layer screen printed onto a first side of the substrate,

a resistive layer configured across the conductive layer, the conductive layer and resistive layer being adapted to generate heat when subjected to an electrical power source; and

a sensor disposed on a second side of the substrate, the sensor comprising a first substantially flexible electrical contact, a second substantially flexible electrical contact, and a layer of dielectric material disposed between the first and second electrical contacts.

19. The device of claim 18 further including a plurality of sensors disposed on the second side of the substrate.

20. The device of claim 19, wherein the resistive layer comprises a positive temperature coefficient material.