Preterminated fiber optic cable

• US 5,121,458 A
• Filed: 04/05/1991
• Issued: 06/09/1992
• Est. Priority Date: 04/05/1991
• Status: Expired due to Fees

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Nelson, John C., Nilsson, Richard C.
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US07/681,156
• Time in Patent Office: 431 Days
• Field of Search: 385/100-105, 385/135
• US Class Current: 385/100
• CPC Class Codes: G02B 6/4472 Manifolds
• CPC Class Codes: G02B 6/4473 Three-way systems
• CPC Class Codes: G02B 6/4476 with heat-shrinkable elements

Abstract

A predetermined optical fiber cable has a main trunk cable comprising a plurality of optical fibers disposed therein and multiple drop cables spliced to the trunk cable at various branch points, the preterminated fiber optic cable being completely assembled at the time of manufacture and is easily installed thereafter. At each branch point an optical fiber cable splice closure is utilized for protecting the optical fibers and splices from moisture and mechanical damage, providing a strong anchoring point for the optical fiber drop cable, and insuring that the minimum fiber bend radius is not violated. The splice closure is cylindrical in shape and has a cavity providing room for the splices and for excess optical fiber storage. Because the splice closure is relatively small (an outer diameter of no greater than 4 inches and a length of no greater than 7 inches), the preterminated fiber optic cable, after manufacture, may be wound in reels for installment without incurring cable or fiber damage and, further, may be depolyed within standard PVC piping having a 4 inch inner diameter. The preterminated fiber optic cable may also be preconnectorized.

Claims

1. A preterminated fiber optic cable assembly, comprising:

a trunk cable having a predetermined length and having first and second ends, said trunk cable further having an access point being positioned along the length of said trunk cable, said trunk cable including;

optical fiber buffering means having a length substantially equal to said predetermined length and having first and second ends, at least one optical fiber of substantially said predetermined length disposed within and enclosed by said buffering means, said fiber having first and second ends substantially coincident with the first and second ends of said trunk cable, and at least one splicing optical fiber having first and second ends and a first portion extending between its first end being coincident with said trunk cable first end and said access point, said first portion being disposed within and enclosed by said buffering means and a second portion extending from said access point to its second end, said second portion being disposed outside of said buffering means;

at least one drop cable having first and second ends, said drop cable including;

jacketing means having first and second ends, said jacketing means first end being substantially coincident with said drop cable first end, and at least one optical fiber having first and second ends substantially coincident with said drop cable first and second ends, said fiber having a first fiber portion extending between its first end and said second end of said jacketing means, said first fiber portion being disposed within and enclosed by said jacketing means, and a second fiber portion extending between said jacketing means second end and the fiber'"'"'s second end, said second fiber portion being disposed outside of said jacketing means, the fiber'"'"'s second end being spliced to said splicing optical fiber second end; and

a splice closure including;

a splice closure body having a cavity dimensioned for encompassing an uncoiled, substantially linear length of said trunk cable extending therethrough, said trunk cable length including at least said access point, and for further encompassing said splicing optical fiber second portion and said splice, and opening means extending into said cavity for receiving said drop cable second fiber portion.

2. A preterminated fiber optic cable assembly as described in claim 1, wherein said splice closure has a cylindrical shape having first and second ends, said splice closure first and second ends each comprising opening means for receiving said trunk cable whereby said uncoiled, substantially linear length of said trunk cable extends between said first and second end receiving means.

3. A preterminated fiber optic cable assembly as described in claim 2, wherein said cylindrical splice closure has an outer diameter of less than 4 inches.

4. A preterminated fiber optic cable assembly as described in claim 2, wherein said cylindrical splice closure has a length of less than 8 inches.

5. A preterminated fiber optic cable assembly as described in claim 2, wherein said drop cable receiving means comprises a plurality of drop cable entrance channels extending between said first and second ends of said cylindrical splice closure and said cavity.

6. A preterminated fiber optic cable assembly as described in claim 1, wherein said drop cable comprises at least one strength member and said splice closure comprises means for securing said strength member to said splice closure.

7. A preterminated fiber optic cable assembly as described in claim 1, wherein said drop cable comprises an armored jacket and said splice closure further comprises a grounding strap having first and second ends, said grounding strap first end being connected to said armored jacket and said grounding strap second end being connected to said splice closure body.

8. A preterminated fiber optic cable assembly as described in claim 1, wherein said trunk cable further comprises a central strength member and further wherein said trunk cable buffering means comprises a plurality of buffer tubes disposed around said central strength member, said buffer tubes encapsulating said optical fibers.

9. A preterminated fiber optic cable assembly as described in claim 2, wherein said splice closure further comprises first and second means secured to said splice closure first and second ends for clamping said trunk cable to said splice closure.

10. A preterminated fiber optic cable assembly as descried in claim 9, wherein said first and second clamping means each comprise first and second halves having means for being secured to said splice closure body and being dimensioned for cooperative engagement with said buffering means of said trunk cable whereby said uncoiled, substantially linear length of said trunk cable extending through said cavity remains in a fixed position relative to said splice closure body.

11. A preterminated fiber optic cable assembly as described in claim 10, wherein said first and second clamping means are secured to said splice closure body at said first and second ends of said splice closure.

12. A preterminated fiber optic cable assembly as described in claim 9, wherein said trunk cable buffering means comprises a single buffer tube encompassing said optical fibers and further wherein said trunk cable further comprises at least one strength member extending longitudinally with said buffer tube.

13. A preterminated fiber optic cable assembly as described in claim 12, wherein said first and second clamping means each comprise first and second halves having means for being secured to said splice closure body and being dimensioned for cooperative engagement with said trunk cable strength member whereby said uncoiled, substantially linear length of said trunk cable extending through said cavity remains in a fixed position relative to said splice closure body.

14. A preterminated fiber optic cable assembly as described in claim 1, wherein a portion of said drop cable second fiber portion is encompassed by a transport tube.

15. A preterminated fiber optic cable assembly as described in claim 1, wherein said preterminated fiber optic cable assembly comprises a plurality of drop cables, each drop cable first end having a connector attached thereto.

16. A preterminated fiber optic cable assembly as described in claim 1, wherein said preterminated fiber optic cable assembly comprises a plurality of drop cables and means for strapping said plurality of drop cables to said trunk cable.

17. A preterminated fiber optic cable assembly as described in claim 1, wherein said preterminated fiber optic cable assembly further comprises means for covering said splice closure.

18. A preterminated fiber optic cable assembly as described in claim 17, wherein said covering means comprises a heat-recoverable wrap.

19. A preterminated fiber optic cable assembly as described in claim 18, wherein said covering means further comprises a non-adhesive wrap disposed between said splice closure and said heat-recoverable wrap.

20. A preterminated fiber optic cable assembly as described in claim 1, wherein said preterminated fiber optic cable assembly further comprises at least one conductor for electricity.

22. A preterminated fiber optic cable assembly as described in claim 1, wherein at least a portion of said drop cable second fiber portion is coiled within said splice closure cavity.

23. A preterminated fiber optic cable assembly as described in claim 22, wherein said splice closure is comprised of substantially symmetrical first and second halves, said splice closure first and second halves having means for being secured together, and further wherein said splice closure further comprises a retaining bracket extending into said splice closure cavity for retaining said drop cable optical fiber second portion in one of said splice closure halves.

24. A preterminated fiber optic cable assembly as described in claim 1, wherein said splice closure further comprises a splice holder in said splice closure cavity for holding said splice and preventing any splice movement.

25. A preterminated fiber optic cable assembly as described in claim 1, wherein said trunk cable further comprises a disconnect point disposed along the length of said trunk cable, said disconnect point being encapsulated by a heat-recoverable patch.

21. A preterminated fiber optic cable assembly as described in claim I, wherein said splicing optical fiber second portion is coiled within said splice closure cavity.

26. A splice closure for use with a preterminated fiber optic cable assembly comprising a trunk cable having a predetermined length and first and second ends, said trunk cable further having an access point being positioned along the length of said trunk cable, said trunk cable comprising optical fiber buffering means of said predetermined length and having first and second ends, at least one optical fiber of said predetermined length disposed within and enclosed by said buffering means, said optical fiber having first and second ends coincident with the first and second ends of said trunk cable, and at least one splicing optical fiber having first and second ends and having a first portion extending between the splicing optical fiber'"'"'s first end being coincident with said trunk cable first end and said access point, said first portion being disposed within and enclosed by said buffering means, and a second portion extending between said access point and the splicing optical fiber'"'"'s second end, said second portion being disposed outside of said buffering means, and at least one drop cable having first and second ends, said drop cable comprising jacketing means having first and second ends, said jacketing means first end being coincident with said drop cable first end, and at least one optical fiber having first and second ends coincident with said drop cable first and second ends, the drop cable optical fiber further having a first fiber portion extending between its first end and said jacketing means second end, said first fiber portion being disposed within and enclosed by said jacketing means, and a second fiber portion extending between said jacketing means second end and the second end of the drop cable optical fiber, said second fiber portion being disposed outside of said jacketing means, second end being spliced to said splicing optical fiber second end, said splice closure comprising:

a splice closure body having a cavity dimensioned for encompassing an uncoiled, substantially linear length of said trunk cable extending therethrough, said trunk cable length including at least said access point, and for further encompassing said splicing optical fiber second portion and said splice; and

means extending into said cavity for receiving said drop cable second fiber portion.

27. A splice closure as described in claim 26, wherein said splice closure has a cylindrical shape having first and second ends, said first and second ends each comprising means for receiving said trunk cable whereby said uncoiled, substantially linear length of said trunk cable extends between said first and second end receiving means.

28. A splice closure as described in claim 27, wherein said cylindrical splice closure has an outer diameter of less than 4 inches.

29. A splice closure as described in claim 27, wherein said cylindrical splice closure has a length of less than 8 inches.

30. A splice closure as described in claim 27, wherein said drop cable receiving means comprises a plurality of drop cable entrance channels extending between said first and second ends of said cylindrical splice closure and said cavity.

31. A splice closure as described in claim 26, wherein said drop cable comprises at least one strength member and said splice closure comprises means for securing said strength member to said splice closure.

32. A splice closure as described in claim 26, wherein said drop cable comprises an armored jacket and said splice closure further comprises a grounding strap having first and second ends, said grounding strap first end being connected to said armored jacket and said grounding strap second end being connected to said splice closure body.

33. A splice closure as described in claim 27, wherein said splice closure further comprises first and second means located at said splice closure first and second ends for clamping said trunk cable to said splice closure.

34. A splice closure as described in claim 33, wherein said first and second clamping means each comprise first and second halves having means for being secured to said splice closure body and being dimensioned for cooperative engagement with said buffering means of said trunk cable whereby said uncoiled, substantially linear length of said trunk cable extending through said cavity will remain in a fixed position relative to said splice closure body.

35. A splice closure as described in claim 34, wherein said trunk cable is a loose tube design optical fiber cable and wherein said first and second clamping means halves are dimensioned for cooperative engagement with the buffer tubes of said loose tube design optical fiber trunk cable.

36. A splice closure as described in claim 34, wherein said trunk cable is a monotube design optical fiber cable having at least one strength member and wherein said first and second clamping means halves are dimensioned for cooperative engagement with said at least one strength member of said monotube design optical fiber trunk cable.

37. A splice closure as described in claim 26, wherein said splice closure is comprised of substantially symmetrical first and second halves, said first and second halves comprising means for being secured together, and further wherein said splice closure further comprises a retaining bracket extending into said splice closure cavity for retaining said drop cable second fiber portion in one of said halves.

38. A splice closure as described in claim 26, wherein said splice closure further comprises a splice holder in said splice closure cavity for holding said splice and preventing any splice movement.

39. A method of making a preterminated fiber optic cable assembly utilizing a trunk cable having a predetermined length and having first and second ends, said trunk cable further having an access point and a disconnect point each being positioned along the length of said trunk cable, said trunk cable comprising optical fiber buffering means of said predetermined length and having first and second ends, at least one optical fiber of said predetermined length disposed within and enclosed by said buffering means, said optical fiber having first and second ends coincident with the first and second ends of said trunk cable, and at least one splicing optical fiber having first and second ends and having a first portion extending between the fiber'"'"'s first end being coincident with said trunk cable first end and said access point and a second portion extending between said access point and the fiber'"'"'s second end being coincident with said disconnect point, said splicing optical fiber being disposed within and enclosed by said buffering means, at least one drop cable having first and second ends, said drop cable comprising jacketing means having first and second ends, said jacketing means first end being coincident with said drop cable first end, and at least one optical fiber having first and second ends coincident with said drop cable first and second ends and having a first fiber portion extending between said first end of the drop cable optical fiber and said jacketing means second end, said first fiber portion being disposed within and enclosed by said jacketing means, and a second fiber portion extending between said jacketing means second end and said second end of the drop cable optical fiber, said second fiber portion being disposed outside of said jacketing means, and a splice closure, comprising a splice closure body having a cavity dimensioned for encompassing an uncoiled, substantially linear length of said trunk cable extending therethrough, and means extending into said cavity for receiving said drop cable second fiber portion, said method comprising the steps of:

removing a portion of said buffering means at said access point of said trunk cable so that said splicing optical fiber is accessible;

removing said splicing optical fiber second portion from within said buffering means so that said splicing optical fiber second portion is disposed outside of said buffering means;

splicing said splicing optical fiber second end to said drop cable optical fiber second end; and

enclosing said splice, said splicing optical fiber second portion, and said uncoiled, substantially linear length of said trunk cable with said splice closure, said trunk cable disconnect point being disposed outside of said splice closure.

40. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said method further comprises the step of encapsulating said splice closure with a heat-recoverable wrap.

41. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said method further comprises the steps of encapsulating said splice closure with a non-adhesive wrap and encapsulating said non-adhesive wrap with a heat-recoverable wrap.

42. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said preterminated fiber optic cable assembly comprises a plurality of drop cables and said method further comprises the step of strapping said plurality of drop cables to said trunk cable.

43. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said method further comprises the step of attaching a connector to said at least one drop cable first end.

44. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said trunk cable buffering means comprises at least one buffer tube and said trunk cable further comprises an outer jacket encapsulating said buffer tube and further wherein said method further comprises, before said buffering means removing step, the step of removing the portion of said outer jacket along said uncoiled, substantially linear length of said trunk cable.

45. A method of making a preterminated fiber optic cable assembly as described in claim 44, wherein said trunk cable further comprises an armored jacket disposed between said outer jacket and said buffer tube and wherein said method further comprises, after said outer jacket removing step, the step of removing the portion of said armored jacket along said uncoiled, substantially linear length of said trunk cable.

46. A method of making a preterminated fiber optic cable assembly as described in claim 45, wherein said trunk cable further comprises an inner jacket disposed between said armored jacket and said buffer tube and further wherein said method further comprises, after said armored jacket removing step, the step of removing said inner jacket along said uncoiled, substantially linear length of said trunk cable.

47. A method of making a preterminated fiber optic cable assembly as described in claim 46, wherein said trunk cable further comprises radial strength yarns disposed between said inner jacket and said buffer tube and further wherein said method further comprises, after said inner jacket removing step, the step of removing said radial strength yarns along said uncoiled, substantially linear length of said trunk cable.

48. A method of making a preterminated fiber optic cable assembly as described in claim 45, wherein said method further comprises the step of connecting a grounding strap between said armored jacket and said splice closure body.

49. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said method further comprises, after said splicing step, the step of clamping said trunk cable to said splice closure.

50. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said splice closure further comprises a splice holder disposed in said splice closure cavity and further wherein said method further comprises, after said splicing step, the step of securing said splice to said splice holder.

51. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said drop cable further comprises a strength member and said method further comprises the step of securing said strength member to said splice closure.

52. A method of making a preterminated fiber optic cable assembly as described in claim 39, wherein said method further comprises, before said splicing step, the step of applying transport tubing to said drop cable second fiber portion.

53. A method of making a preterminated fiber optic cable assembly utilizing a trunk cable having a predetermined length and having first and second ends, said trunk cable further having an access point and a disconnect point each being positioned along the length of said trunk cable, said trunk cable comprising optical fiber buffering means of said predetermined length and having first and second ends and a plurality of optical fibers of said predetermined length disposed within and enclosed by said buffering means, said optical fibers having first and second ends coincident with the first and second ends of said trunk cable, at least one drop cable having first and second ends, said drop cable comprising jacketing means having first and second ends, said jacketing means first end being coincident with said drop cable first end, and at least one optical fiber having first and ends coincident with said drop cable first and second ends and having a first fiber portion extending between said drop cable optical fiber'"'"'s first end and said jacketing means second end, said first fiber portion being disposed within and enclosed by said jacketing means, and a second fiber portion extending between said jacketing means second end and said drop cable optical fiber'"'"'s second end, said second fiber portion being disposed outside of said jacketing means, and a splice closure comprising a splice closure body having a cavity dimensioned for encompassing an uncoiled, substantially linear length of said trunk cable extending therethrough, and means extending into said cavity for receiving said drop cable second fiber portion, said method comprising the steps of:

removing a portion of said buffering means at said disconnect point of said trunk cable so that at least one optical fiber is accessible;

cutting said at least one optical fiber at said disconnect point;

encapsulating said disconnect point with a heat-recoverable patch;

removing a portion of said buffering means at said access point of said trunk cable so that said at least one optical fiber is accessible;

removing from within said buffering means the portion of said at least one optical fiber extending between said access point and said disconnect point so that said portion is disposed outside of said buffering means and has an end disposed outside of said buffering means;

splicing said end of said portion of said at least one optical fiber to said drop cable optical fiber second end; and

enclosing said splice, said portion of said at least one optical fiber, and said uncoiled, substantially linear length with said splice closure, said trunk cable disconnect point being disposed outside of said splice closure.

54. A splice closure for use with a preterminated fiber optic cable assembly, said splice closure comprising:

a splice closure body having a cavity dimensioned for encompassing an uncoiled, substantially linear length of a trunk cable extending therethrough, said trunk cable having a plurality of optical fibers, and further for encompassing an optical fiber splice;

means for receiving said uncoiled, substantially linear length of said trunk cable;

means extending into said cavity for receiving an optical fiber from a drop cable;

means for securing a strength member of said drop cable to said splice closure body;

means for connecting an armored jacket of said trunk cable to said splice closure body; and

clamping means for securing said uncoiled, substantially linear length of said trunk cable to splice closure.

55. A splice closure as described in claim 54, wherein said splice closure has a cylindrical shape having first and second ends, and further wherein said trunk cable receiving means comprises first and second trunk cable receiving means disposed at said splice closure first and second ends, whereby said uncoiled, substantially linear length of said trunk cable extends between said splice closure first and second receiving means.

56. A splice closure as described in claim 55, wherein said cylindrical splice closure has an outer diameter of less than four inches.

57. A splice closure as described in claim 55, wherein said cylindrical splice closure has a length of less than eight inches.

58. A splice closure as described in claim 55, wherein said drop cable optical fiber receiving means comprises a plurality of drop cable entrance channels extending between said first and second ends of said cylindrical splice closure and said cavity.

59. A splice closure as described in claim 54, wherein said splice closure further comprises means for electrically connecting said armored jacket of said trunk cable to said splice closure body.

60. A splice closure as described in claim 54, wherein said first and second clamping means each comprise first and second halves having means for being secured to said splice closure body and being dimensioned for cooperative engagement with said uncoiled, substantially linear length of said trunk cable.

61. A splice closure as described in claim 54, wherein said splice closure body is comprised of substantially symmetrical first and second halves, said splice closure first and second halves having means for being secured together.

62. A splice closure as described in claim 61, wherein said splice closure further comprises a retaining bracket extending into said cavity for retaining said drop cable optical fiber in one of said halves.

63. A splice closure as described in claim 54, wherein said said splice closure further comprises a splice holder in said cavity for holding said splice and preventing any splice movement.

64. A preterminated fiber optic cable assembly comprising:

a slotted core trunk cable having a predetermined length and having first and second ends, said trunk cable further having an access point being positioned along the length of said trunk cable, said trunk cable including;

a longitudinally extending central strength member having at least one groove extending therealong and having a length substantially equal to said predetermined length and having first and second ends, at least one optical fiber of substantially said predetermined length disposed within said groove, said fiber having first and second ends substantially coincident with the first and second ends of said trunk cable, and at least one splicing optical fiber having first and second ends in a first portion extending between its first end being coincident with said trunk cable first end and said access point, said first portion being disposed within said groove and a second portion extending from said access point to its second end, said second portion being disposed outside of said groove;

at least one drop cable having first and second ends, said drop cable including;

jacketing means having first and second ends, said jacketing means first end being substantially coincident with said drop cable first end, and at least one optical fiber having first and second ends substantially coincident with said drop cable first and second ends, said fiber having a first fiber portion extending between its first end and said second end of said jacketing means, said first fiber portion being disposed within and enclosed by said jacketing means, and a second fiber portion extending between said jacketing means second end and the fiber'"'"'s second end, said second fiber portion being disposed outside of said jacketing means, the fiber'"'"'s second end being spliced to said splicing optical fiber second end; and

a splice closure including;

a splice closure body having a cavity dimensioned for encompassing an uncoiled, substantially linear length of said trunk cable extending therethrough, said trunk cable length including at least said access point and for further encompassing said splicing optical fiber second portion and said splice, and opening means extending into said cavity for receiving said drop cable second fiber portion.

65. A method of making a preterminated fiber optic cable assembly utilizing a slotted core trunk cable having a predetermined length and having first and second ends, said trunk cable further having an access point and a disconnect point each being positioned along the length of said trunk cable, said trunk cable comprising outer jacketing means of said predetermined length and having first and second ends and a plurality of optical fibers of said predetermined length disposed within and enclosed by said outer jacketing means, said optical fibers having first and second ends coincident with the first and second ends of said trunk cable, at least one drop cable having first and second ends, said drop cable comprising jacketing means having first and second ends, said jacketing means first end being coincident with said drop cable first end, and at least one optical fiber having first and ends coincident with said drop cable first and second ends and having a first fiber portion extending between said drop cable optical fiber'"'"'s first end and said jacketing means second end, said first fiber portion being disposed within and enclosed by said jacketing means, and a second fiber portion extending between said jacketing means second end and said drop cable optical fiber'"'"'s second end, said second fiber portion being disposed outside of said jacketing means, and a splice closure comprising a splice closure body having a cavity dimensioned for encompassing an uncoiled, substantially linear length of said trunk cable extending therethrough, and means extending into said cavity for receiving said drop cable second fiber portion, said method comprising the steps of:

removing a portion of said outer jacketing means at said disconnect point of said trunk cable so that at least one optical fiber is accessible;

cutting said at least one optical fiber at said disconnect point;

encapsulating said disconnect point with a heat-recoverable patch;

removing a portion of said outer jacketing means at said access point of said trunk cable so that said at least one optical fiber is accessible;

removing from within said outer jacketing means the portion of said at least one optical fiber extending between said access point and said disconnect point so that said portion is disposed outside of said outer jacketing means and has an end disposed outside of said outer jacketing means;

splicing said end of said portion of said at least one optical fiber to said drop cable optical fiber second end; and

enclosing said splice, said portion of said at least one optical fiber, and said uncoiled, substantially linear length with said splice closure, said trunk cable disconnect point being disposed outside of said splice closure.

66. A splice closure for use with a preterminated fiber optic cable assembly, said splice closure comprising:

a splice closure body having a cavity dimension for encompassing an uncoiled, substantially linear length of a trunk cable extending therethrough and for encompassing at least one optical fiber splice;

means for receiving said uncoiled, substantially linear length of said trunk cable; and

means extending into said cavity for receiving an optical fiber form a drop cable.