Heating element

• US 6,686,562 B1
• Filed: 08/18/2000
• Issued: 02/03/2004
• Est. Priority Date: 08/20/1999
• Status: Expired due to Fees

• Current Assignee: Wet Automotive Systems AG (Gentherm Incorporated)
• Original Assignee: Wet Automotive Systems AG (Gentherm Incorporated)
• Inventors: Weiss, Michael, Hugenschmidt, Markus, Schuller, Ferdinand
• Primary Examiner(s): Jeffery, John A.
• Application Number:
  US09/642,167
• Time in Patent Office: 1,264 Days
• Field of Search: 219/217, 219/543, 219/528, 219/549, 219/544, 297/180.12, 338/292, 338/288, 338/289, 338/283, 338/295, 338/293, 338/280
• US Class Current: 219/217
• CPC Class Codes: H05B 2203/002 Heaters using a particular layout for the resistive material or resistive elements
• CPC Class Codes: H05B 2203/007 using multiple electrically connected resistive elements or resistive zones
• CPC Class Codes: H05B 2203/011 Heaters using laterally extending conductive material as connecting means
• CPC Class Codes: H05B 2203/013 Heaters using resistive films or coatings
• 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
• CPC Class Codes: H05B 3/36 heating conductor embedded in insulating material
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

A heating element comprises a heating film having an electrically nonconductive support layer and a conductive layer. The conductive layer of the present invention comprises a metallic layer or material that is deposited onto the support layer. The heating element system is suitable for integration into the seating surface or backrest surface of an automotive vehicle which may also comprise additional components such as upholstered units and sensors to facilitate the comfort of the occupant of the vehicle.

Claims

1. A heating element having a heating film comprising:

(a) a flexible electrically nonconductive support layer including a polymeric material;

(b) a flexible electrically nonconductive cover layer including a polymeric material; and

(c) a substantially metallic conductive layer substantially sandwiched between the cover layer and the support layer for forming the heating film wherein;

i) the film includes one or more outer edges defining a periphery of the film;

ii) the film includes a plurality of recesses forming a conductive path for guiding current through the conductive layer, each of the plurality of recesses extending into the film from the one or more outer edges of the film;

iii) the film includes at least one slit extending through the film and extending substantially entirely along the conductive path internal of the one or more edges, the slit forming the conductive path into a plurality of conductive strips extending along the conductive path, the slit extending from adjacent a first end of the conductive path to adjacent a second end of the conductive path; and

(d) a first contact area and a second contact area, the first contact area and the second contact area being in electrical communication with the conductive path for electrically connecting the path to a power source; and

wherein the heating film is located below a cover layer of a seat of an automotive vehicle and wherein the support layer and a cover layer are integrally joined at the boundaries of the at least one slit.

2. The heating element according to claim 1, wherein the support layer comprises a material selected from the group consisting of plastic, polyester, polyimide, polyamide, polypropylene, polycarbonate, and paper and wherein one of the portions of the conductive layer is applied to the support layer by means selected from the group consisting of vacuum evaporation, sputtering, and electroplating.

3. The heating element according to claim 2, wherein the conductive layer comprises a metallic material selected from the group consisting of copper, aluminum, silver, gold, and nickel.

4. The heating element according to claim 3, wherein the heating film has a thickness in a range between 10 and 30 μ

m, and the conductive layer has a thickness in a range between 0.05 and 10 μ

m.

5. The heating element according to claim 1, having at least two conductive paths consisting of substantially the same overall length and at least two conductive strips consisting of substantially the same overall length.

6. The heating element according to claim 1, wherein at least one of the plurality of recesses runs perpendicular to the directions of mechanical extension load.

7. The heating element according to claim 6, wherein the at least one slit includes a plurality of slits and at least one of the plurality of slits runs perpendicular to the directions of mechanical extension load.

8. The heating element according to claim 7, wherein the thickness of the conductive path varies over the length of the conductive path whereby the power per surface area is locally adjusted.

9. The heating element according to claim 1, wherein the support layer and a cover layer are integrally joined at the boundaries of at least one recess.

10. The heating element according to claim 1, wherein the support layer and a cover layer completely overlap the at least one slit.

11. The heating element according to claim 1, wherein the support layer and a cover layer completely overlap at least one recess.

12. The heating element according to claim 11, wherein the conductive layer is adapted to be connected a source of electrical power.

13. A heating element having a heating film comprising:

(a) a flexible electrically nonconductive support layer including a polymeric material selected from a polyester or a polyimide;

(b) a flexible electrically nonconductive cover layer including a polymeric material selected from a polyester or a polyimide; and

(c) a substantially metallic conductive layer substantially sandwiched between the cover layer and the support layer for forming the heating film wherein;

i) the film includes one or more outer edges defining a periphery of the film;

ii) the film includes a plurality of recesses forming a conductive path for guiding current through the conductive layer, the conductive path having a first end and a second end, each of the plurality of recesses extending into both the support layer and the cover layer of the film from adjacent the one or more outer edges of the film;

iii) the film includes at least one slit extending through the film and extending along the conductive path internal of the one or more edges, the slit forming the conductive path into a plurality of conductive strips extending along the conductive path; and

iv) the film includes a first plurality of connection points adjacent the first end of the conductive path and a second plurality of connection points adjacent the second end of the conductive path;

the first and second plurality of connection points electrically connecting the plurality of conductive strips such that the potential for each of the conductive strips is substantially uniform along the conductive path; and

(d) a first contact area and a second contact area, the first contact area and the second contact area respectively being in electrical communication with the first end and the second end of the conductive path for electrically connecting the first end and the second end to a power source.

14. The heating element according to claim 13, wherein the heating film has a thickness in a range between 10 and 30 μ

m, and the conductive layer is at least partially formed of copper and has a thickness in a range between 0.05 and 10 μ

m and wherein the film is located beneath a cover layer of a seat of an automotive vehicle.

15. The heating element according to claim 14, wherein one of the portions of the metallic conductive layer comprises a metallic material and the heating film has a ductility greater than the ductility of the metallic material and wherein the other portion of the metallic conductive layer is covered by a cover layer.

16. The heating element according to claim 15, having at least two conductive paths consisting of substantially the same overall length and at least two conductive strips consisting of substantially the same overall length.

17. The heating element according to claim 15, wherein at least one of the plurality of recesses runs perpendicular to the directions of mechanical extension load and the at least one slit runs perpendicular to the directions of mechanical extension load.

18. The heating element according to claim 15, wherein the support layer and a cover layer are integrally joined at the boundaries of the at least one slit and the support layer and the cover layer are integrally joined at the boundaries of at least one of the plurality of recesses.

19. The heating element according to therein claim 15, wherein the support layer and a cover layer completely overlap the at least one slit.

20. A heating element having a heating film comprising:

(a) a flexible electrically nonconductive support layer including a polymeric material selected from a polyester or a polyimide;

(b) a flexible electrically nonconductive cover layer including a polymeric material selected from a polyester or a polyimide; and

(c) a substantially metallic copper conductive layer substantially sandwiched between the cover layer and the support layer for forming the heating film, the conductive layer having a thickness between 0.05 and 1 micrometer, the heating film having a thickness between 20 and 150 micrometers for achieving high stability and functionality, wherein;

i) the film includes one or more outer edges defining a periphery of the film;

ii) the film includes a plurality of recesses forming a conductive path for guiding current through the conductive layer, the conductive path having a first end and a second end, each of the plurality of recesses extending into both the support layer and the cover layer of the film from adjacent the one or more outer edges of the film;

iii) the film includes a plurality of slits extending through both the support layer and the cover layer of the film and extending substantially entirely along the conductive path internal of the one or more edges, the plurality of slits forming the conductive path into a plurality of conductive strips extending along the conductive path, the plurality of slits extending from adjacent the first end of the conductive path to adjacent the second end of the conductive path; and

iv) the film includes a first plurality of connection points adjacent the first end of the conductive path and a second plurality of connection points adjacent the second end of the conductive path, the first and second plurality of connection points electrically connecting the plurality of conductive strips such that the potential for each of the conductive strips is substantially uniform for each of the plurality of conductive strips along the conductive path and each of the conductive strips are substantially the same length; and

v) the heater film is sized to fit within a seat of an automotive vehicle;

(d) a first contact area and a second contact area, the first contact area and the second contact area respectively being in electrical communication with the first end and the second end of the conductive path for electrically connecting the first end and the second end to a power source, the first contact area being adjacent the first end of the conductive path and the second contact area being adjacent the second end of the conductive path;

wherein the heating film is located below a cover layer of a seat of an automotive vehicle.

21. The heating element according to therein claim 20, wherein the support layer and a cover layer are integrally joined at the boundaries of at least one of the plurality of slits and the support layer and a cover layer are integrally joined at the boundaries of at least one of the plurality of recesses.