Fiber optic cable splice closure

• US 4,805,979 A
• Filed: 09/04/1987
• Issued: 02/21/1989
• Est. Priority Date: 09/04/1987
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Krenz, Dean C., Smith, Russell P., Bossard, Ronald G.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Epps, Georgia Y.
• Application Number:
  US07/093,339
• Time in Patent Office: 536 Days
• Field of Search: 350/96.20, 350/96.21, 350/96.22
• US Class Current: 385/135
• CPC Class Codes: G02B 6/4446 Cable boxes, e.g. splicing boxes with two or more multi fibre cables
• CPC Class Codes: G02B 6/44465 Seals
• CPC Class Codes: G02B 6/4477 with means for strain-relieving to interior strengths element
• CPC Class Codes: G02B 6/44785 Cable clamps
• CPC Class Codes: G02B 6/483 Installation of aerial type

Abstract

A fiber optic splice closure for protecting the splice made into a transmission cable, containing a plurality of fibers which are to remain unsevered, comprises a base to which the cable is anchored and in which slack fibers in the uncut cable are looped and stored free of transverse barriers. The seal is made with the cables and the base by a mating cover provided with a second area to receive splice trays and slack fibers selected from the cable for splicing.

Claims

1. A splice closure assembly for a branch-line fiber optic cable splice which fiber cable comprises an outer sheath, a plurality of optical fibers and a strength member, said assembly comprising

a pair of mating shell-like closure members including base means and cover means for defining a three dimensional chamber, said base means and cover means each having a mating surface having opposed arcuate wall portions defining at least a pair of cable entry ports when assembled,

anchor means within said base means and disposed in generally aligned relationship with said entry ports for securing a strength member of a said fiber optic cable to said base means,

said chamber having length, width and depth dimensions to afford a first open storage area for at least one loop of optical fiber therein without deleterious effect on said optical fiber,

retaining means supported by said base means for positioning said at least one loop of optical fiber in said base means, and

said cover means affording means for receiving and storing at least one splice tray supported from said base means and spaced from said first storage area.

2. A splice closure assembly according to claim 1 wherein the width and length of said chamber are at least twice the minimum bending radius of the fibers affording a looping of slack fiber within said chamber.

3. A splice closure assembly according to claim 1 wherein said mating surfaces of said base means and cover means have means for retaining a sealing strip therebetween to form an hermetic seal for said chamber.

4. A splice closure assembly according to claim 3 wherein:

a mastic sealant material is wrapped on a said fiber cable and cooperates with said arcuate wall portions for forming a seal for a said cable in said entry ports.

5. A splice closure assembly according to claim 4 wherein means are provided for strain relief on a said fiber cable adjacent said entry ports.

6. A splice closure assembly according to claim 1 wherein said anchor means comprises a member secured in said base means and comprising means defining a surpentine path in which a said strength member is forced to anchor the same.

7. A splice closure assembly according to claim 1 wherein said base means is generally rectangular and said anchor means is positioned generally centrally of said base means affording said first storage area about said anchor means, and comprising support means for supporting a splice tray to said base means.

8. A splice closure assembly according to claim 7 wherein said support means are incorporated with said anchor means.

9. A splice closure assembly according to claim 1 comprising adapter plate means adapted to fit between said base means and cover means to increase the size of said first storage means and multiply the number of said entry ports.

10. A splice closure assembly according to claim 6 wherein said anchor means comprises a pair of similar members adapted to be stacked in said base means to accommodate multiple strength members.

11. A splice closure assembly according to claim 6 wherein said anchor means comprises support means for supporting a splice tray in spaced relationship to said base means.

12. A splice closure assembly according to claim 9 wherein said adapter plate means comprises means for retaining a sealing strip for making sealing engagement with said mating surface of said base means and said cover means.

13. A splice closure kit for fiber optic cable splices comprising

a generally rectangular base with a mating surface surrounding a central cavity defining a first storage area,

a mating cover for attachment to said base, said cover having a mating surface surrounding a cavity defining a second storage area, said cover and base having cooperating arcuate wall means in said mating surfaces defining cylindrical cable entry ports into said first storage area,

a strength member anchor adapted to be attached to said base in said first storage area and disposed in generally aligned relationship with said entry ports,

a splice tray adapted to be secured to said base and be received in said second storage area,

sealing cord of a mastic sealant for fitting between said mating surfaces of said base and cover to seal the same, and

sealing tape for wrapping a said cable to seal the entry ports when said base and cover are in mating engagement.