Fuse links and dual element fuse

• US 5,252,942 A
• Filed: 01/08/1992
• Issued: 10/12/1993
• Est. Priority Date: 01/08/1992
• Status: Expired due to Term

• Current Assignee: Cooper Industries, Inc. (Eaton Corporation PLC.)
• Original Assignee: Cooper Industries, Inc. (Eaton Corporation PLC.)
• Inventors: Gurevich, Leon
• Primary Examiner(s): Broome, Harold
• Application Number:
  US07/817,759
• Time in Patent Office: 643 Days
• Field of Search: 337/163, 337/164, 337/165, 337/166, 337/158, 337/159, 337/160, 337/161, 337/162, 337/290, 337/291, 337/292, 337/293, 337/294, 337/295, 337/401, 337/402, 337/416, 337/417
• US Class Current: 337/163
• CPC Class Codes: H01H 85/055 Fusible members
• CPC Class Codes: H01H 85/10 with constriction for localised fusing H01H85/11 takes precedence

Abstract

A hollow electrical circuit protector preferably coated with an insulative coating which will maintain its structure and not be conductive when said circuit protector blows. The electrical circuit protector has at least one weak spot cross-sectional area and is generally adapted to be part of a dual element fuse link with ribbon-like fuse links on opposite sides thereof. Also provided are the ribbon like fuse links, one with a guide and the other with an integral washer.

Claims

1. A dual element fuse link comprising a first fuse link section, said first fuse link section having a first end and a second end;

a second fuse link section, said second fuse link section having a first end and a second end;

a third fuse link, said third fuse link section, having a proximal end and a distal end, and said third fuse link having a hollow body defining an interior chamber, said body and said chamber of said third fuse link defining at least one weak spot;

said first fuse link section first end being electrically connected to said third fuse link proximal end; and

said second fuse link section first end being electrically connected to said third fuse link section distal end.

2. The dual element fuse link of claim 1 wherein said body and chamber of said third fuse link define at least two weak spots.

3. The dual element fuse link of claim 1 wherein a support structure is mounted in said chamber.

4. The dual element fuse link of claim 3 wherein said support structure is a washer means having a diameter dimension larger than a corresponding diameter dimension of said chamber.

5. The dual element fuse link of claim 2 wherein said body has a body distal end, a body proximal end, and a central body portion between said body proximal and distal ends, said body proximal end having a thickness being less than a thickness of said central body portion, a proximal end body thickness being less than said central body thickness, and weak spot cross-sectional areas provided adjacent said distal and proximal body ends.

6. The dual element fuse link of claim 5 wherein an outer face of at least one of said body distal and proximal ends is substantially flat.

7. The dual element fuse link of claim 5 wherein said outer face of both of the body distal and proximal ends are substantially circular and substantially flat.

8. The dual element fuse link of claim 2 wherein said body has first and second body sections, said first section has a first base and a first apex, said first base having a larger diameter than a diameter of said first apex, said first apex outer surface being said proximal end outer face, a main first body section between said first base and said first apex, said main first body section converging from said first base to said first apex, a bore defined by said first section, said first section bore having a first closed end adjacent an interior face of said first apex and a first open end opening through said first base.

9. The dual element fuse link of claim 8 wherein said bore first closed end being smaller than said bore first open end.

10. The dual element fuse link of claim 8 wherein said first base is substantially cylindrical and the outer surface of said main first body section forms a shoulder with said base.

11. The dual element fuse link of claim 10 wherein said first main body section is substantially frustro-conical, said bore has at least a major portion thereof which is substantially frustro-conical with a base of the frustro conical bore being the first open end of the bore.

12. The dual element fuse link of claim 11 wherein a base cross-sectional area of the main section wall adjacent said shoulder is approximately at least 1.75 times the cross-sectional area of the weak spot adjacent said apex.

13. The dual element fuse link of claim 12 wherein the bore is substantially frustro-conical.

14. The dual element fuse link of claim 12 wherein the bore is conical.

15. The dual element fuse link of claim 8 wherein said second body section is substantially identical to said first body section and said second body section is substantially symmetrically and electrically attached to said first body section.

16. The dual element fuse link of claim 15 wherein said first and second body sections are welded at their respective bases.

17. The dual element fuse link of claim 10 wherein said second body section is substantially identical to said first body section and said second body section is substantially symmetrically and electrically attached to said first body section.

18. The dual element fuse link of claim 17 wherein said first and second body sections are welded at their respective bases.

19. The dual element fuse link of claim 12 wherein said second body section is substantially identical to said first body section and said second body section is substantially symmetrically and electrically attached to said first body section.

20. The dual element fuse link of claim 19 wherein said first and second body sections are welded at their respective bases.

21. The dual element fuse link of claim 8 wherein the first and second body sections are composed of an eutectic solder having a melting point of from about 90°

C. to about 119°

C. and a lead content of less than about 2.0 percent by weight, and the interior of the fuse is coated with a flux coating and an insulative silicone rubber coating is a silicone rubber coating surrounding said third fuse link section and said silicone coating being U.V. curable and having a melting point of great than 150°

C.

22. The dual element fuse link of claim 21 wherein said first main body section is substantially frustro-conical, said bore has at least a major portion thereof which is substantially frustro-conical with a base of the frustro conical bore being the first open end of the bore.

23. The dual element fuse link of claim 22 wherein a base cross-sectional area of the main section wall adjacent said shoulder is approximately at least 1.75 times the cross-sectional area of the weak spot adjacent said apex.

24. The dual element fuse link of claim 23 wherein said second body section is substantially identical to said first body section and said second body section is substantially symmetrically and electrically attached to said first body section.

25. A fuse link strip comprising

a one-piece strip having a plurality of substantially flat first fuse links having opposite first and second ends,

each first fuse link having a plurality of spaced weak spots located along the length thereof,

first and second strip feed means interconnecting adjacent first fuse links,

said strip feed means extending from opposing sides of said first fuse link adjacent said first fuse link first end,

said second strip feed means extending from opposing sides of said first fuse link adjacent said fuse link second end,

at least one partial second fuse link electrically connected to at least one first fuse link end,

said second fuse link having a body with a body first end and a body second end, a bore formed in said body, said bore having a closed end adjacent said body first end and a second open end opening through said body second end, and said body first end attached to said first fuse link end.

26. The fuse link strip of claim 25 wherein said second fuse link has a conical body section with a base and an apex, said body base having a larger diameter than a diameter of said apex, said bore having a first closed end adjacent an interior face of said first apex and a second open end opening through said base and said first fuse link first end being electrically attached to the apex of said second fuse link.

27. The fuse link strip of claim 26 wherein said bore first closed end being smaller than said bore second open end.

28. The fuse link strip of claim 27 wherein said base is substantially cylindrical and the outer surface of said body section forms a shoulder with said base.

29. The fuse link strip of claim 28 wherein a thickness of the main section wall adjacent said shoulder is approximately at least 1.75 times as thick as a weak spot adjacent said apex.

30. The fuse link strip of claim 28 wherein said second fuse link is substantially composed of solder.

31. The fuse link strip of claim 30 wherein said solder has a melting point of from about 90°

C. to about 150°

C., and has a lead content of less than 2% by weight.

32. A cylindrical fuse comprising:

a tubular casing, said tubular casing being an electrical insulating material, and said tubular casing having a proximal end and a distal end;

a first terminal attached to said proximal end of said tubular casing;

a second terminal attached to said distal end of said tubular casing;

at least one dual element fuse link disposed within said casing, said at least one dual element fuse link having a first ribbon-like fuse link section, said first fuse link section having a first end and a second end;

a second ribbon-like fuse link section, said second fuse link section having a first end and a second end;

a third fuse link section, said third fuse link section having a proximal end and a distal end, and said third fuse link section having a body defining an interior chamber, said body and said chamber defining at least one weak spot;

said first fuse link section first end being electrically connected to said third fuse link section proximal end; and

said second fuse link section first end being electrically connected to said third fuse link section distal end;

said first fuse link section second end electrically attached to said first terminal,

said second fuse link section second end being electrically attached to said second terminal, said first, second and third fuse link sections being spaced from the interior of said casing.

33. The fuse of claim 32, wherein said third fuse link section includes an insulating coating or housing surrounding said fuse link body and is attached to said first and second fuse link sections, said coating or housing being such that it remains substantially intact when at least one of said third fuse link section proximal and distal ends electrically separates from at least one of said corresponding ends of said first and second fuse links;

are quenching filler within said casing surrounding and in contact with said first, second and third fuse link sections.

34. The fuse of claim 32 wherein the body and the chamber define at least two weak spots.

35. The fuse of claim 33 wherein a support structure is mounted in said chamber.

36. The fuse of claim 35 wherein said support structure is a washer means having a diameter dimension larger than a corresponding diameter dimension of said chamber.

37. The fuse of claim 32 wherein the chamber is shaped as a pair of cones joined at their bases with opposite apex ends of the cones being adjacent the ends of the body, said weak spots being adjacent said body ends and a cross-sectional area of said body adjacent said joined chamber bases being at least 1.75 times greater than cross-sectional areas of said weak spots which are adjacent said apex ends.

38. The fuse of claim 37 wherein said third fuse link is constructed from an eutectic solder having less than 2.0% lead, a melting point of from about 90°

C. to 150°

C., the housing coating is a U.V. curable silicone rubber coating and the interior is coated with a solder flux coating.

68. The fuse of claim 37 wherein the cones are frusto-conical cones.

69. The fuse of claim 33 wherein the body and the chamber define at least two weak spots.

70. The fuse of claim 32 wherein said third fuse link section includes an insulating coating or housing surrounding said fuse link body and is attached to said first and second fuse link sections, said coating or housing being such that is remains substantially intact when at least one of said third fuse link section proximal and distal ends electrically separates from at least one of said corresponding ends of said first and second fuse links;

are quenching filler within said casing surrounding and in contact with said first, second and third fuse link sections.

71. The fuse of claim 70 wherein said cones are frustro-conical cones.

39. A fuse link comprising a hollow body, said body having a body distal end, a body proximal end and a central body portion between said body distal and body proximal ends defining an interior chamber;

said body having at least one weak spot located adjacent only at least one of said body distal or said proximal ends, wherein said at least one weak spot acts as a circuit interrupter when said fuse link encounters an overload.

40. The fuse link of claim 39 wherein said body and chamber defines at least two weak spots.

41. The fuse link of claim 39 wherein a support structure is mounted in said chamber.

42. The fuse link of claim 41 wherein said support structure is a washer means having a diameter dimension larger than a corresponding diameter dimension of said chamber.

43. The fuse link of claim 40, wherein said body proximal end has a thickness less than a thickness of said central body portion, said distal end has thickness less than a thickness of said central body portion, and at least one weak spot cross-sectional area provided adjacent said distal and proximal body ends.

44. The fuse link of claim 43, wherein an outer face of at least one of said body distal and proximal ends is substantially flat.

45. The fuse link of claim 43, wherein said outer face of both of the body distal and proximal ends are substantially circular and substantially flat.

46. The fuse link of claim 40 wherein said body has first and second body sections, said first section has a first base, and a first apex, said first base having a larger diameter than a diameter of said first apex, said first apex outer surface being said proximal end outer face, a main first body section inclining, said main first body section slanting from said first base to said first apex, a bore defined by said first section, said first section bore having a first closed end adjacent an interior face of said first apex and a first open end opening through said first base.

47. The fuse link of claim 46 wherein said bore first closed end being smaller than said bore first open end.

48. The fuse link of claim 46 wherein said first base is substantially cylindrical and the outer surface of said main first body section forms a shoulder with said base.

49. The fuse link of claim 48 wherein said first main body section is substantially frustroconical, said bore has at least a major portion thereof which is substantially frustroconical with a base of the frustro conical bore being the first open end of the bore.

50. The fuse link of claim 49 wherein a base cross-sectional area of the main section wall adjacent said shoulder is approximately at least 1.75 times the cross-sectional area of the weak spot adjacent said apex.

51. The fuse link of claim 50 wherein the bore is substantially frustro-conical.

52. The fuse link of claim 50 wherein the bore is conical.

53. The fuse link of claim 46, wherein said second body section is substantially identical to said first body section and said second body section is substantially symmetrically and electrically attached to said first body section.

54. The fuse link of claim 53 wherein said first and second body sections are welded at their respective bases.

55. The fuse link of claim 48, wherein said second body section is substantially identical to said first body section and said second body section is substantially symmetrically and electrically attached to said first body section.

56. The fuse link of claim 55 wherein said first and second body sections are welded at their respective bases.

57. The fuse link of claim 50 wherein said second body section is substantially identical to said first body section and said second body section is substantially symmetrically and electrically attached to said first body section.

58. The fuse link of claim 57 wherein said first and second body sections are welded at their respective bases.

59. The fuse link of claim 46 wherein said first and second body sections are substantially composed of solder.

60. The fuse link of claim 59 wherein said solder has a melting point of from about 90°

C. to about 150°

C., a low electrical resistance.

61. The fuse link of claim 39 having an insulative coating or housing surrounding said fuse link.

62. The fuse link of claim 43 having an insulative coating or housing surrounding said fuse link.

63. The fuse link of claim 44 having an insulative coating or housing surrounding said fuse link.

64. The fuse link of claim 45 having an insulative coating or housing surrounding said fuse link.

65. The fuse link of claim 46 having an insulative coating or housing surrounding said fuse link.

66. The fuse link of claim 57 having an insulative coating or housing surrounding said fuse link.

67. The fuse of claim 60 having an insulative coating or housing surrounding said fuse link.