Arrangement for branching a telecommunications cable containing several stranded elements with optical fibers

• US 6,181,861 B1
• Filed: 02/10/1998
• Issued: 01/30/2001
• Est. Priority Date: 02/14/1997
• Status: Expired due to Fees

• Current Assignee: Nexans Deutschland Industries AG & Co. KG (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Grajewski, Franz, Freckmann, Hans-Holger, Wielgolaski, Zbigniew, Wenski, Wolfgang, Stieb, Werner, Teschner, Wolfgang
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): CONNELLY, MICHELLE R
• Application Number:
  US09/021,217
• Time in Patent Office: 1,085 Days
• Field of Search: 385/53-56, 385/100, 385/105-107, 385/134-137, 385/58, 385/51, 385/139
• US Class Current: 385/135
• CPC Class Codes: G02B 6/501 underground installation of connection boxes
• CPC Class Codes: H02G 9/10 in cable chambers, e.g. in manhole or in handhole

Abstract

In an arrangement for producing a branch in a telecommunications cable (1) containing several stranded elements with optical fibers, at least one stranded element is cut, the optical fibers of the stranded element are spliced to the optical fibers of a branch line (2), and the branched area is protected with a sleeve (3). The branch line (2) comprises a number of optical fibers, each of which is loosely arranged by itself in a small plastic tube (10). A predetermined length of the tube (10) is removed from approximately the middle of the optical fiber elements, and each optical fiber (13) from which the tube (10) has been removed is stored in a cassette (12). The cassettes (12) are stored in a container (5). The sleeve housing (4) is stored in a container (5). The sleeve housing (4) with the cassettes (12) and the branch line (2) with the optical fibers (13) located in the tube (10) are a unit which is prefabricated at the factory.

Claims

1. An arrangement for connecting to a main cable containing several stranded elements, each with a plurality of optical fibers therin, comprising:

(a) a housing;

(b) at least two splice cassettes in the housing; and

(c) a branch-off cable entering the housing in a fluid tight manner and having at least two optical fibers adapted for splicing to the optical fibers of the main cable to create a branched area to be protected to a sleeve, the sleeve for the branched area is buried undergound, each optical fiber protected by a separate pair of tubes made of polymeric material, a portion of each optical fiber not located within its pair of tubes and being stored in a respective one of the at least two splice cassettes in the housing thereby acting as excess length being adapted to be connected to a subscriber connection cable, wherein the branch-off cable and the housing with the cassettes comprise a prefabricated unit.

2. An arrangement as claimed in claim 1, wherein several of the pairs of tubes with optical fibers therein are combined into a bundle.

3. An arrangement as claimed in claim 2, wherein each bundle is helically wrapped with a tape or thread.

4. An arrangement as claimed in claim 3, wherein the tapes or threads are of different colors to identify the bundles.

5. An arrangement as claimed in claim 2, wherein each bundle is surrounded by a protective conduit.

6. An arrangement as claimed in claim 5, wherein the protective conduit is a corrugated plastic conduit.

7. An arrangement as claimed in claim 5, wherein a gap between each bundle and its protective conduit is sealed against lengthwise water propagation.

8. An arrangement as claimed in claim 5, wherein the protective conduit is at least 5 m in length.

9. An arrangement as claimed in claim 5, wherein the housing is a hooded sleeve with several openings in a bottom part, one of the openings contains the protective conduit, and other of the openings are provided to insert subscriber connection cables.

10. An arrangement as claimed in claim 9, wherein the openings in the bottom part of the housing have a circular cross section.

11. An arrangement as claimed in claim 1, further including a container in which the housing is stored, the container is an underground container.

12. An arrangement as claimed in claim 1, wherein the housing is prefabricated so that ends of the optical fibers of the branch-off cable can be connected by means of conventional splicing to the optical fibers to be branched off from the main cable.

13. An arrangement as claimed in claim 1, wherein the portion of each optical fiber is stored as an uncut slack length in its cassette.

14. An arrangement as claimed in claim 1, wherein the optical fiber of the branch-off cable protruding from the housing is at least 5 m in length.

15. An arrangement as claimed in claim 1, wherein each optical fiber of the branch-off cable has a length in a range of about 10 to 15 m and each tube in its respective pair of tubes has a length in a range of 4 to 6 m.

16. An arrangement as claimed in claim 1, wherein each pair of tubes enters its respective one of the at least two splice cassettes thereby protecting its optical fiber.

17. An arrangement for branching a telecommunications cable containing several stranded elements, each with a plurality of optical fibers therein, comprising:

at least one stranded element being cut, the optical fibers of the stranded element are spliced to optical fibers of a branch line to create a branched area which is protected with a sleeve, each optical fiber of the branch line is arranged in a pair of casings so that a portion of the optical fiber is not contained therein, the portion of the optical fiber is stored in a cassette, the cassettes are located in a sleeve housing which can be opened, and the sleeve housing is located in a container, wherein the container includes;

a) upper and lower holders provided on opposite sides of an inside wall of the container and at different levels;

b) the sleeve housing attached to the lower holder by a bottom part; and

c) the sleeve housing is secured with a rod, one end of which is screwed to the holder.

18. An arrangement as claimed in claim 17, wherein the rod has a turning aid at an end opposite from the lower holder.

19. An arrangement as claimed in claim 18, wherein the turning aid is chosen from a group consisting of a square on an external surface of the rod, a hexagon on an external surface of the rod, a square on a front end of the rod, a hexagon on a front end of the rod, and a transverse bore.

20. An arrangement as claimed in claim 17, wherein the sleeve housing is a hooded sleeve.

21. An arrangement as claimed in claim 20, wherein a handle is provided at an end of the hooded sleeve which faces away from the bottom part.

22. An arrangement as claimed in claim 17, wherein the holders are bolted to supports.

23. An arrangement as claimed in claim 17, wherein the container is made of concrete and comprises several superimposed segments.