Split end plate fuse assembly

• US 5,270,679 A
• Filed: 02/08/1993
• Issued: 12/14/1993
• Est. Priority Date: 02/08/1993
• Status: Expired due to Fees

• Current Assignee: Gould Electronics Incorporated (Eternal Materials Co., Ltd.)
• Original Assignee: Gould, Inc. (Transdigm Group Incorporated)
• Inventors: Gulbrandsen, David P.
• Primary Examiner(s): Broome, Harold
• Application Number:
  US08/014,842
• Time in Patent Office: 309 Days
• Field of Search: 337/251, 337/252, 337/253, 337/248, 337/254, 439/620, 439/621, 439/622, 29/623
• US Class Current: 337/252
• CPC Class Codes: H01H 69/02 Manufacture of fuses
• CPC Class Codes: H01H 85/153 Knife-blade-end contacts
• CPC Class Codes: H01H 85/18 Casing fillings, e.g. powder
• CPC Class Codes: Y10T 29/49107 Fuse making

Abstract

A terminal assembly for a fuse using multiple end plate pieces to collar a terminal element around a neck portion, the end plate pieces being attached to a housing.

Claims

1. An electrical fuse terminal assembly comprising

an end plate assembly, and

a terminal element received in said end plate assembly,

said end plate assembly comprising two or more end plate pieces abutting each other along abutting portions of abutting edges and having substantially the same plate thickness along said abutting edges, said abutting edges defining a terminal hole which receives said terminal element,

said terminal element comprising a base portion and a terminal connection portion, said base portion comprising two parallel overlap portions spaced a distance by a neck portion, said distance being substantially equal to the plate thickness of the end plate pieces, and said neck portion fitting within said terminal hole and being collared by said end plate pieces,

said abutting edges fitting between said overlap portions, the portions of the edges defining said hole being covered by a said overlap portion.

2. The electrical fuse terminal assembly of claim 1 wherein said neck portion is of the same cross-sectional shape and size as said terminal hole.

3. The electrical fuse terminal assembly of claim 1 wherein said end plate assembly is generally square.

4. The electrical fuse terminal assembly of claim 1 wherein the abutting portions of the abutting edges comprise coordinating overlap surfaces such that the end plate pieces abut each other in overlapping fashion.

5. The electrical fuse terminal assembly of claim 1 wherein the abutting portions of the abutting edges comprise coordinating tongue and groove features such that the end plate pieces abut each other in tongue-in-groove fashion.

7. The electrical fuse terminal assembly of claim 1 wherein the abutting portions of the abutting edges are flat surfaces that are perpendicular to the faces of the plate pieces.

8. The electrical fuse terminal assembly of claim 2 wherein said terminal hole is non-circular such that said terminal element is restrained from rotating within said terminal hole.

9. The electrical fuse terminal assembly of claim 8 wherein said terminal hole is generally polygonal.

10. The electrical fuse terminal assembly of claim 9 wherein said terminal hole is regularly polygonal such that said terminal element may be received in said terminal hole in a plurality of angular orientations.

11. The electrical fuse terminal assembly of claim 10 wherein said terminal hole is generally square.

12. The electrical fuse terminal assembly of claim 1 wherein the base portion of the terminal element further comprises one or more fusible element contact areas.

13. The electrical fuse terminal assembly of claim 12 wherein contact areas have crowned surfaces.

14. The electrical fuse terminal assembly of claim 12 wherein said fusible element contact areas comprise a plurality of axially spaced concentric surfaces.

15. The electrical fuse terminal assembly of claim 12 wherein said fusible element contact areas comprise the side surfaces of a square projection on said base portion.

16. The electrical fuse terminal assembly of claim 1 wherein the terminal connection portion of the terminal element is a blade.

17. The electrical fuse terminal assembly of claim 15 wherein said blade is notched.

18. The electrical fuse terminal assembly of claim 17 wherein said blade has a hole through it.

19. The electrical fuse terminal assembly of claim 1 wherein the terminal connection portion of the terminal element is one or more threaded receptacles.

20. The electrical fuse terminal assembly of claim 1 wherein the terminal connection portion of the terminal element has a plurality of pin engagement holes.

6. The electrical fuse terminal assembly of claim wherein the abutting portions of the abutting edges are flat surfaces at nonperpendicular angles to the faces of the plate pieces.

21. An electrical fuse comprising

a hollow housing comprising a first opening,

a first terminal assembly affixed to said housing at said first opening and covering said first opening, said first terminal assembly comprising

a first end plate assembly, and

a first terminal element received in said first end plate assembly, and

one or more fusible elements connected to said first terminal element and disposed within said housing,

said first end plate assembly comprising two or more end plate pieces abutting each other along abutting portions of abutting edges and having substantially the same plate thickness along said abutting edges, said abutting edges defining a terminal hole which receives said terminal element,

said first terminal element comprising a base portion and a terminal connection portion, said base portion comprising two parallel overlap portions spaced a distance by a neck portion, said distance being substantially equal to the plate thickness of the end plate pieces, and said neck portion fitting within said terminal hole and being collared by said end plate pieces,

said abutting edges fitting between said overlap portions, the portions of the edges defining said hole being covered by a said overlap portion.

22. The fuse terminal assembly of claim 21 wherein said neck portion is of the same cross-sectional shape and size as said terminal hole.

23. The electrical fuse of claim 21 wherein

said housing further comprises a second opening opposing said first opening,

said electrical fuse further comprises a second terminal assembly affixed to said housing at said second opening and covering said second opening, said second terminal assembly comprising

a second end plate assembly, and

a second terminal element affixed to said second end plate assembly, and

said one or more fusible elements interconnect said first and second terminal elements.

24. The electrical fuse of claim 23 wherein said housing is ceramic, and further comprising arc-quenching fill material contained within said housing.

25. The electrical fuse of claim 23 wherein said housing is generally square.

26. The electrical fuse of claim 25 wherein said first and second end plate assemblies are generally square.

27. The electrical fuse of claim 26 wherein said terminal hole is generally square.

28. The electrical fuse of claim 27 wherein said end plate assemblies carry tabs for mounting a blown fuse indicator on said fuse.

29. The electrical fuse of claim 21 wherein said first end plate assembly is affixed to said housing by screws.

30. The electrical fuse of claim 23 wherein said first and second end plate assemblies are affixed to said housing by screws.

31. The method of making an electrical fuse comprising the steps of

providing first and second terminal elements,

each of said terminal elements comprising a base portion and a terminal connection portion,

said base portion comprising two parallel overlap portions spaced a distance by a neck portion and further comprising one or more fusible element contact areas,

electrically conductively attaching one or more fusible elements to said fusible element contact areas of said first and second terminal elements so as to interconnect said first and second terminal elements to form a subassembly,

inserting abutting edges of a first set of two or more end plate pieces between the overlap portions of said first terminal element so as to collar said first terminal element around its neck portion,

providing a hollow housing,

said housing having a cavity and a first and a second opening at opposing ends in communication with said cavity,

disposing said subassembly in said cavity by inserting said subassembly through said first opening, second terminal first, until said first set of end plate pieces contact said housing and said second terminal element protrudes through said second opening,

affixing said first set of end plate pieces to said housing,

inserting abutting edges of a second set of two or more end plate pieces between the overlap portions of said second terminal element so as to collar said second terminal element around its neck portion, and

affixing said second set of end plate pieces to said housing.

32. The method of claim 31 further comprising filling said cavity with arc-quenching fill material.

33. The method of claim 32 wherein said step of filling said cavity comprises injecting loose fill material through fill holes in said end plate pieces after said first and second sets of end plate pieces have been affixed to said housing.

34. The method of claim 32 wherein said step of filling said cavity is performed before said second terminal element is collared by said second set of end plate pieces.

35. The method of claim 33 wherein said arc-quenching fill material is solid fill and further comprising soaking said loose fill material with a liquid bath of binder material which wicks into said loose fill material and cures to bind said loose fill material.

36. The method of claim 34 wherein said arc-quenching fill material is solid fill, and wherein said filling includes filling with loose fill material and soaking said loose fill material with a liquid bath of binder material which wicks into said loose fill material and cures to bind said loose fill material.

37. The method of claim 35 wherein said solid fill comprises quartz sand and cured sodium silicate.

38. The method of claim 36 wherein said solid fill comprises quartz sand and cured sodium silicate.

39. The method of claim 31 wherein said step of attaching fusible elements to said fusible element contact areas comprises welding.

40. The method of claim 31 wherein said step of attaching fusible elements to said fusible element contact areas comprises soldering.