Resistance heating device

• US 6,084,219 A
• Filed: 10/10/1997
• Issued: 07/04/2000
• Est. Priority Date: 02/05/1997
• Status: Expired due to Term

• Current Assignee: Winter, Josef
• Original Assignee: Winter, Josef
• Inventors: Winter, Josef
• Primary Examiner(s): Leung, Philip H.
• Assistant Examiner(s): ROBINSON, DANIEL LEON
• Application Number:
  US08/948,421
• Time in Patent Office: 998 Days
• Field of Search: 219/539, 219/541, 219/543, 219/552, 219/203, 219/219, 338/306, 338/307, 338/308, 338/309, 338/22 R
• US Class Current: 219/539
• CPC Class Codes: H05B 2203/016 Heaters using particular connecting means
• CPC Class Codes: H05B 2203/02 Heaters using heating elements having a positive temperature coefficient
• CPC Class Codes: H05B 3/14 the material being non-metallic
• 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
• CPC Class Codes: H05B 3/845 specially adapted for reflecting surfaces, e.g. bathroom - or rearview mirrors

Abstract

A flat resistance heating device with a heating layer including of a material having a positive resistance/temperature coefficient to which current or voltage can be applied via electrodes. In order to reduce the current uptake in the switch-on phase and hence to reduce the risk of a burn-through effect, the individual heating elements of the resistance heating device have a meniscus shape, so that they heat more rapidly in the narrow region when switched on and hence reduce the current uptake.

Claims

1. A resistance heating device, comprising:

a substrate;

at least a first and second electrode arranged on a surface of said substrate;

a heating layer comprising a plurality of PTC elements which extend between said at least said first and second electrode,

wherein at least one of said plurality of PTC elements comprises a width which tapers continuously from a contact area with said first electrode to a center point between said first and second electrode, and subsequently broadens continuously to a contact area with said second electrode.

2. A device according to claim 1, further comprising:

an adhesive layer arranged on said heating layer.

3. A device according to claim 1, wherein said substrate comprises an electrically insulating substrate.

4. A device according to claim 1, wherein said at least one of said plurality of PTC elements comprises a meniscus shape.

5. A device according to claim 4, wherein said plurality of PTC elements are substantially parallel to each other and comprise a constant heating capacity per unit area of said heating layer.

6. A device according to claim 4, further comprising:

at least two main feed lines each having an L-shape connecting said at least said first and second electrode,

wherein a corner region of said L-shape is round.

7. A device according to claim 1, wherein said at least one of said plurality of PTC elements comprises a trapezoidal shape.

8. A device according to claim 1, wherein said plurality of PTC elements are substantially parallel to each other.

9. A device according to claim 5, wherein said plurality of PTC elements are substantially parallel to each other and comprise a constant heating capacity per unit area.

10. A device according to claim 1, further comprising:

at least two main feed lines each having an L-shape connecting said at least said first and second electrode.

11. A device according to claim 10, wherein a corner region of said L-shape is round.

12. A device according to claim 1, further comprising:

at least two main feed lines each having a T-shape having a first limb, a second limb, and a third limb,

wherein said first limb and said second limb comprise tapered ends, and

wherein an intersection of said first limb, said second limb, and said third limb comprises a round shape.

13. A method of making a resistance heating device including a substrate, comprising the steps of:

arranging at least a first and second electrode on a surface of said substrate; and

applying a plurality of PTC elements which extend between said at least said first and second electrode,

wherein at least one of said plurality of PTC elements comprises a width which tapers continuously from a contact area with said first electrode to a center point between said first and second electrode, and subsequently broadens continuously to a contact area with said second electrode.

14. A method according to claim 13, further comprising the step of:

applying an adhesive layer on said plurality of PTC elements.

15. A method according to claim 13, wherein said substrate comprises an electrically insulating substrate.

16. A method according to claim 13, further comprising the step of:

forming said at least one of said plurality of PTC elements to have a meniscus shape.

17. A method according to claim 16, further comprising the step of:

arranging said plurality of PTC elements substantially parallel to each other and to have a constant heating capacity per unit area.

18. A method according to claim 16, further comprising the step of:

connecting at least two main feed lines each having an L-shape to said at least said first and second electrode,

wherein a corner region of said L-shape is round.

19. A method according to claim 13, further comprising the step of:

forming said at least one of said plurality of PTC elements to have a trapezodial shape.

20. A method according to claim 13, further comprising the step of:

arranging said plurality of PTC elements substantially parallel to each other.

21. A method according to claim 20, wherein said step of arranging arranges said plurality of PTC elements to have a constant heating capacity per unit area of said heating layer.

22. A method according to claim 13, further comprising the step of:

connecting at least two main feed lines each having an L-shape to said at least said first and second electrode.

23. A method according to claim 22, wherein a corner region of said L-shape is round.

24. A method according to claim 13, further comprising the step of:

connecting at least two main feed lines each having a T-shape having a first limb, a second limb, and a third limb,

wherein said first limb and said second limb comprise tapered ends, and

wherein an intersection of said first limb, said second limb, and said third limb comprises a round shape.

25. A system for heating an object with a resistance heating device including a substrate, comprising:

means for arranging at least a first and second electrode on a surface of said substrate; and

means for applying a plurality of PTC elements which extend between said at least said first and second electrode,

wherein at least one of said plurality of PTC elements comprises a width which tapers continuously from a contact area with said first electrode to a center point between said first and second electrode, and subsequently broadens continuously to a contact area with said second electrode.

26. A system according to claim 25, further comprising:

means for applying an adhesive layer on said plurality of PTC elements.

27. A system according to claim 25, wherein said substrate comprises an electrically insulating substrate.

28. A system according to claim 25, further comprising:

means for forming said at least one of said plurality of PTC elements to have a meniscus shape.

29. A system according to claim 28, further comprising:

means for arranging said plurality of PTC elements substantially parallel to each other and to have a constant heating capacity per unit area of said heating layer.

30. A system according to claim 25, further comprising:

means for forming said at least one of said plurality of PTC elements to have a trapezodial shape.

31. A system according to claim 25, further comprising:

means for arranging said plurality of PTC elements substantially parallel to each other.

32. A system according to claim 31, wherein said means for arranging arranges said plurality of PTC elements to have a constant heating capacity per unit area of said heating layer.

33. A system according to claim 25, further comprising:

means for connecting at least two main feed lines each having an L-shape to said at least said first and second electrode.

34. A system according to claim 33, wherein a corner region of said L-shape is round.

35. A system according to claim 25, further comprising:

means for connecting at least two main feed lines each having an L-shape to said at least said first and second electrode,

wherein a corner region of said L-shape is round.

36. A system according to claim 25, further comprising:

means for connecting at least two main feed lines each having a T-shape having a first limb, a second limb, and a third limb,

wherein said first limb and said second limb comprise tapered ends, and

wherein an intersection of said first limb, said second limb, and said third limb comprises a round shape.