Electric heating apparatus with housing

• US 20050056637A1
• Filed: 04/30/2004
• Published: 03/17/2005
• Est. Priority Date: 09/11/2003
• Status: Active Grant

• Current Assignee: Catem GmbH & Co., KG
• Original Assignee: Catem GmbH & Co., KG
• Inventors: Bohlender, Franz, Walz, Kurt
• Granted Patent: US 7,012,225 B2
• Time in Patent Office: Days
• US Class Current: 219/536
• CPC Class Codes: F24H 3/0429 For vehicles
• CPC Class Codes: F24H 9/1872 PTC
• 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 3/50 heating conductor arranged in metal tubes, the radiating surface having heat-conducting fins

Abstract

Electric heating apparatus and manufacturing method for an electric heating apparatus, wherein prefabricated constructional units are used. The prefabricated constructional units consist of PTC heating elements fastened to contact sheets by means of a lacquer. This simplifies production and enhances protection against corrosion.

Claims

1. An electric heating apparatus comprising:

a housing which has openings on elongate housing faces, and a layered structure including at least one PTC heating element, a radiator element, first and second contact sheets for power supply and a resilient element, the PTC heating element being arranged between the first and second contact sheets and the layered structure being kept clamped in the housing by the resilient element,

wherein

the first contact sheet is provided with a lacquer layer at the side facing the PTC heating element, and the space between the PTC heating element and the first contact sheet is sealed via lacquer pressed out of said space.

2. The electric heating apparatus according to claim 1, wherein the lacquer is an electrically non-conductive silicone lacquer.

3. The electric heating apparatus according to claim 1, wherein the lacquer has a viscosity lower than 900 mPa.S.

4. The electric heating apparatus according to claim 3, wherein the lacquer has a viscosity of about 800 mPa.S.

5. The electric heating apparatus according to claim 1, wherein the first contact sheet is made from aluminum.

6. The electric heating apparatus according to claim 1, wherein the second contact sheet is made from brass.

7. The electric heating apparatus according to claim 1, wherein the second contact sheet is tin-plated.

8. The electric heating apparatus according to claim 1, wherein an opening is provided in the housing for inserting the resilient element.

9. The electric heating apparatus according to claim 1, wherein a resilient channel formed in the housing for receiving the resilient element.

10. The electric heating apparatus according to claim 1, further comprising positioning means for pre-fixing the elements of the heating apparatus in the housing.

11. The electric heating apparatus according to claim 10, wherein the positioning means in the housing simultaneously forms a groove for guiding the resilient element during insertion.

12. The electric heating apparatus according to claim 1, wherein the elongate faces of the housing are mechanically reinforced by at least one transverse strut.

13. The electric heating apparatus according to claim 12, wherein the struts in the elongate faces of the housing have the shape of a grid structure.

14. The electric heating apparatus according to claim 13, wherein the grid structure has at least one longitudinal strut in the area of the PTC heating elements.

15. The electric heating apparatus according to claim 1, wherein said housing is made from plastics.

16. The electric heating apparatus according to claim 1, wherein the housing comprises two half-shells.

17. The electric heating apparatus according to claim 16, wherein the half-shells of the housing can be put together.

18. The electric heating apparatus according to claim 17, further comprising locking pins or locking noses which, when the half-shells of the housing are put together, effect a locking of the two half-shells.

19. The electric heating apparatus according to claim 17, wherein the half-shells are configured such that they separate the housing approximately in the middle between the elongate faces of the housing.

20. The electric heating apparatus according to claim 19, wherein respectively opposite projections provided on the separation line of the half-shells, which will engage each other when the half-shells are assembled.

21. The electric heating apparatus according to claim 1, wherein the resilient element is configured such that it transmits the clamping forces essentially onto the reinforced longitudinal sides of the housing.

22. The electric heating apparatus according to claim 1, wherein the resilient element consists of a sheet member with resilient segments projecting therefrom.

23. The electric heating apparatus according to claim 21, wherein each of the resilient segments extends into the edge portions of the longitudinal sides of the resilient member.

24. The electric heating apparatus according to claim 22, wherein the resilient member is made integral with the resilient segments.

25. The electric heating apparatus according to claim 1, further comprising at least one resilient segment for generating clamping forces is provided at each PTC heating element position for a frictional clamping action.

26. The electric heating apparatus according to claim 25, wherein at least two resilient segments are provided for each PTC heating element position.

27. The electric heating apparatus according to claim 1, wherein the heating apparatus comprises an auxiliary heater for automotive vehicles.

28. A constructional unit for an electric heating apparatus, comprising:

a housing which has openings on elongate housing faces, and a layered structure including at least one PTC heating element, a radiator element, first and second contact sheets for power supply, and a resilient element, the PTC heating element being arranged between the first and second contact sheets and the layered structure being kept clamped in the housing by the resilient element,

wherein

the constructional unit is formed from the first contact sheet and a PTC heating element, the first contact sheet being provided with a lacquer layer at the side facing the PTC heating element, and the space between the PTC heating element and the first contact sheet being sealed via lacquer pressed out of said space.

29. The constructional unit according to claim 28, wherein the lacquer is an electrically non-conductive silicone lacquer.

30. The constructional unit according to claim 28, wherein the lacquer has a viscosity lower than 900 mPa.S.

31. The constructional unit according to claim 28, wherein the lacquer has a viscosity of about 800 mPa.S.

32. The constructional unit according to claim 28, wherein the first contact sheet is made from aluminum.

33. The constructional unit according to claim 31, wherein the second contact sheet is made from brass.

34. The constructional unit according to claim 29, wherein the second contact sheet is tin-plated.

35. The constructional unit according to claim 28, wherein the unit is for an auxiliary heater for automotive vehicles.

36. A method for producing an electric heating apparatus that includes:

a housing having two half-shells with openings on elongate faces of the housing, and a layered structure including at least one PTC heating element, a radiator element, first and second contact sheets for power supply, and a resilient element, the layered structure being kept clamped by the resilient element in the housing, the method comprising;

fastening a PTC heating element to the first contact sheet via a lacquer,

inserting the first contact sheet with the PTC heating element fastened thereto and the second contact sheets into a first half-shell of the housing, and attaching the second half-shell of the housing to the first half-shell.

37. The method according to claim 36, wherein the lacquer is an electrically non-conductive silicone lacquer.

38. The method according to claim 36, wherein the lacquer has a viscosity lower than 900 mPa.s.

39. The method according to claim 36, wherein the lacquer has a viscosity of about 800 mPa.S.

40. The method according to claim 36, wherein the fastening of the PTC heating element via the lacquer only withstands small mechanical loads.

41. The method according to claim 36, wherein the resilient element is inserted through an opening of the assembled housing to effect clamping of the layered structure.

42. The method according to claim 36, wherein, along with the insertion of the resilient element, the lacquer is pressed out of the area between the PTC heating elements and the contact sheet via the contact pressure generated by the resilient element.

43. The method according to claim 36, wherein the lacquer pressed out of the area between the PTC heating element and the contact sheet seals said area against penetrating moisture.

44. The method according to claim 36, wherein the first contact sheet is made from aluminum.

45. The method according to claim 36, wherein the second contact sheet is made from brass.

46. The method according to claim 36, wherein the second contact sheet is tin-plated.

47. The method according to claim 36, wherein an auxiliary heating unit for automotive vehicles is produced.

48. An auxiliary electric heater for automotive vehicles, comprising:

a housing which has elongate housing faces having openings formed therein, and

a layered structure including

at least one PTC heating element,

a radiator element,

first and second contact sheets, and

a resilient element, the PTC heating element being arranged between the first and second contact sheets and the layered structure being clamped in the housing by the resilient element,

wherein

the first contact sheet is provided with a lacquer layer at a side thereof facing the PTC heating element, and wherein

a space between the PTC heating element and the first contact sheet is sealed via lacquer pressed out of the space.

49. The electric heating apparatus according to claim 48, wherein the lacquer is an electrically non-conductive silicone lacquer.

50. The electric heating apparatus according to claim 48, wherein the lacquer has a viscosity lower than 900 mPa.S.

51. The electric heating apparatus according to claim 50, wherein the lacquer has a viscosity of about 800 mPa.S.