FR2764079A1 - OPTICAL FIBER CABLE - Google Patents

Abstract

A fiber optic cable (100) includes a cylindrical housing (30), a central structural support member (16), and at least one fiber optic tube (14). The optical fiber tube (14) includes at least one optical fiber (10). A single layer of solid, water-resistant material (50) is applied to the surface of the structural support member (16) and to the surface of the fiber optic tube (s) (14) to protect the fiber (s) optics (10) for the penetration of moisture.

Description

"Fiber optic cable"

  The present invention relates to a fiber optic cable

  and a method for constructing a fiber optic cable

  ques. Figure 1 illustrates a conventional fiber optic cable

  than. The conventional fiber optic cable has a

  reality of free tubes 14, each containing at least one optical fiber 10. The free tubes 14 are arranged around a central reinforcing element 16, which is positioned in the center of the fiber optic cable. Each of the free tubes 14 is filled with a gel 12 to prevent the optical fibers from being damaged by penetration of moisture. Intermediate tubes 20, not containing optical fibers 10, can also be positioned around the element of

  central reinforcement 16. The intermediate tubes 20 are available

  to help maintain the free tubes 14 in a concentric configuration around the reinforcing member

central 16.

  The spaces between the free tubes 14 and the inner tubes

  20 are filled with material 18. The material

  riau 18 also fills the spaces between the tubes

  bres 14 and the central reinforcement element 16, and those between the central reinforcement element 16 and the intermediate tubes 20. The material 18, which is a gel-like material,

  prevents the penetration of external moisture.

  A film 22 is wrapped around the outer surfaces of the free tubes 14 and the intermediate tubes 20 to

  isolate the filling material 18 from the ex-environment

  dull. Additional fiber 24 can be wrapped around

  of film 22. An inner coating 26 is also applied

  qué on the outer surface of the film 22 to protect the optical fibers 10 from the outside environment. In addition to

  the protection of the optical fibers 10, the inner coating

  Laughter 26 communicates to the fiber optic cable a predetermined required compressive force. The inner lining 26 comprises a cylindrical void 26a, as shown in FIG.

  2, to keep the tubes free 14, the intermediate tubes

  diaries 20, and the central reinforcing element 16.

  A tension wire 28 is wrapped around the outer surface of the inner covering 26 to impart to the fiber optic cable a required tensile strength. Typically, the tension wire 28 is wrapped around the inner lining 26 so that

  that multiple layers of tension wire 28 are formed

  mées. A fiber, a strip or a bonding film addition-

  nel is wrapped around the layer of tension wire if-

  killed the outermost, so that the pieces

  of tension wire 28 in the layers be pressed tightly

  one against the other. An outer coating is applied to the outer surface of the tension thread

  28 to protect the internal components of the cable. The re-

  outer garment 30 is made of a suitable material

  for the installation environment of the fiber optic cable

  ques. The conventional fiber optic cable described above suffers from a number of drawbacks. Use

  gel 18 filler and additive film

  tional 22 and fiber 24 to prevent the ingress of moisture increases the outside diameter and the cost of the fiber optic cable. In addition, the inner lining, which is annular, as shown in Figure 2, must be thick to ensure that the fiber optic cable has the predetermined required compressive strength. This

  also increases the outside diameter and weight of the cable

fiber optic.

  In addition, the use of additional fiber, film, or bonding tape to press the pieces of tension wire 28 against each other gives rise to other problems. Using a film increases the

  cost of producing a long cable. The use of the fi-

  link bre decreases the linear speed, because the

  no application of the bonding fiber should be infe

  lower than that of the tension fiber. As a result, the appli-

  cation and extrusion of the tension wire must be carried out

killed separately.

  Therefore, an object of the present invention is to solve the problems described above. Therefore, the present invention provides a fiber optic cable comprising: a cylindrical housing;

  a sensitive structural support element

  lying in the center of the cylindrical housing; at least one fiber optic tube positioned around

  of the structural support element, the fiber optic tube

  having at least one optical fiber and being filled

  a suitable material to protect the optical fibers

  be the penetration of moisture; and a single layer of solid, water-resistant material applied to the surface of the structural support member and to the surfaces of all the fiber optic tubes, so that any voids inside the housing are filled , to protect optical fibers

moisture penetration.

  The use of a single layer of solid, water-resistant material prevents water from entering the fiber optic tubes without unnecessarily increasing the

  diameter and weight of the fiber optic cable. The material

  strong and water resistant also increases advantageously

  the cable's compressive strength. The use

  A single layer of solid, water-resistant material further reduces the cost of producing the cable to

optical fiber.

  Preferably, the fiber optic cable comprises

  plus a tension wire wrapped around the outer surface

  layer of solid, water-resistant material to impart resistance to the fiber optic cable

tensile.

  Such an optical fiber cable has the additional advantage of

  tional to have increased tensile strength.

  To increase the tensile strength of the cable, it is preferred that two layers of tension wire be formed

  around the outer surface of the solid material and re-

  water resistant. To prevent the generation of a rotational force,

  a first layer of tension wire is formed in winding

  the tension wire around the solid and resistant material

  both with water in a first direction, and a second layer is formed by wrapping the tension thread around the

  solid and water resistant material in an op-

asked.

  Preferably, the tension wire is coated with a poly-

  mother to keep tension wire tightly wound

  around the solid and water-resistant material and for

  catch moisture from entering the tension wire.

  The polymer can be a polymer which becomes adhesive

  when subjected to heat treatment.

  Preferably, the tension thread comprises a fiber or

  a strip having a high tensile modulus and a resistance

  high tance. In particular, the tension wire can include

  take an aramid fiber or a fiber based on glass.

  To reduce the weight of the cable and increase its service life, the fiber optic tubes are preferably formed

of plastic.

  Preferably, at least one empty tube is also placed.

  positioned around the structural support element, to

  maintain the fiber optic tubes under a configura-

  predetermined tion around the structured support element

  rel. Preferably, the predetermined configuration is a

concentric configuration.

  The fiber optic tubes can be filled with a water resistant gel; We prefer that the solid and water resistant material

  either applied by extrusion to the structural support element

  turel and fiber optic tubes, to ensure it

  be applied regularly.

  The solid, water-resistant material includes

  preferably a polyethylene or chloride chloride resin

  nyle. The present invention also extends to a fiber optic cable comprising: a cylindrical housing; a plurality of optical fiber tubes positioned in the housing, each optical fiber tube containing at least one optical fiber;

  a layer of tension wire surrounding the thread tubes

  optical fibers, the tension wire being coated with a polymer so that the pieces of tension wire in the

  layer adhere to each other.

  The polymer preferably comprises a polymer which

  comes adhesive when subjected to heat treatment

  than. The present invention will now be described by way of

  example with reference to the accompanying drawings, in the-

  which: Figure 1 is a sectional view of a conventional self-supporting, non-metallic fiber optic cable;

  Figure 2 is a sectional view of an inner lining

  laughing to protect free tubes in conventional self-supporting, non-metallic fiber optic cable; Figure 3 is a sectional view of a fiber cable

  self-supporting and non-metallic optics according to a realization

  preferred station of the present invention; Figure 4 is a perspective view in section of an inner coating for protecting free tubes in the self-supporting, non-metallic fiber optic cable according to the preferred embodiment of the present invention; and

  Figure 5 is a sectional view of the inner lining

  laughing to protect the free tubes according to the embodiment

  preferred of the present invention.

  FIG. 3 illustrates a fiber optic cable 100 se-

  lon the invention. The optical fiber cable 100 includes a central reinforcing element 16. The central reinforcing element

  16 is positioned in the center of the optical fiber cable 100.

  It communicates to the optical fiber cable 100 a tensile strength, which is necessary for the installation of the cable. It also plays the basic role around which free tubes 14 and intermediate tubes 20 are

  centered. The central reinforcing element 16 is formed of a ma-

  water resistant material to prevent moisture from penetrating

  enter the spaces between the free tubes 14 and the element

central reinforcement 16.

  As mentioned above, a fiber optic cable according to the invention also comprises a plurality of

  free tubes 14. As illustrated in FIG. 3, the free tubes

  bres 14 are positioned around the central reinforcing element 16. The free tubes 14 are formed of material

  very robust plastic. Each free tube 14 con-

  holds at least one optical fiber 10. The optical fibers 10 are preferably coated with colored acrylic, for the purpose of

  facilitate identification. The free tubes 14 are replaced

  folds of a gel 12 to prevent optical fibers 10

  to be damaged by the penetration of moisture.

  A fiber optic cable 100 according to the invention may also comprise intermediate tubes 20. The intermediate tubes 20 are present to keep the free tubes 14 in a concentric configuration around the central reinforcing element 16. The intermediate tubes

  are also positioned around the return element

fort central 16.

  An interior coating 50 is applied to the surfaces.

  these external free tubes 14 and intermediate tubes

  diaries 20. The internal coating 50 fills the spaces between the free tubes 14 and the central reinforcing element 16, as well as the spaces between the free tubes 14 and the intermediate tubes 20. The internal coating 50 protects the optical fibers 10 from the outdoor environment. It also constitutes a surface around which a tension wire 52 can be wound. The internal coating is preferably formed from polyethylene or vinyl chloride resin. As shown in Figures 4 and 5, the inner lining 50 is introduced evenly into the spaces between the free tubes 14. This increases

  compression characteristics and decreases its thickness

application.

  In a preferred embodiment, at least one tension wire

  sion 52 is wrapped around the outer surface of the re-

  inner garment 50. The tension wire 52 communicates to the optical fiber cable 100 a required tensile strength. The tension wire 52 is preferably wound

  so that two layers of tension thread are formed

  mées on the inner coating 50. In particular, it is preferred that a first layer is formed by winding the tension wire 52 around the inner coating 50 in

  a first direction, and that the second layer is formed

  méée by winding the tension wire 52 around the coating

  interior 50 in an opposite direction. This winding em-

  fishing generation of a rotational force.

  To keep the pieces of tension wire 52 in each layer pressed against each other, the tension wire 52 is heat treated and coated with a material

  adhesive polymer. Typically, the tension wire

  sion 52 is manufactured by applying a high holding tension to a tension fiber, by pre-tensioning the

  tension, by coating the pre-tensioned fiber with poly-

  adhesive mother, then subjecting the coated fiber to a heat treatment. These steps prevent further

  expansion of the tension wire 52. The tension wire 52 includes

  preferably takes a fiber or strip having a resistance

  high tance and a high tensile modulus. For example, an aramid or glass fiber formed from filaments

might be appropriate.

  In another embodiment, the tension wire 52 is not coated with the polymeric material. Instead, a material

  waterproof is added to the tension wire 52 in order to

  fish for possible penetration of moisture.

  An outer coating 30 is applied to the tension wire 52 to protect the various interior components

  of the cable. The outer coating 30 is formed of a material

  riau suitable for the installation environment of the cable to

optical fibers 100.

  Therefore, the present invention provides a fiber optic cable which has improved compression characteristics and a smaller outside diameter. The present invention also provides a fiber optic cable which is lighter and less expensive to manufacture than fibers.

  conventional optics. These advantages are obtained in use.

  sant an interior coating of resin to fill the es-

  paces between the free tubes, the intermediate tubes and the central reinforcing element, and to prevent moisture from entering the free tubes. The resin interior coating eliminates the need for special equipment to apply the conventional gel-like material used

  to prevent penetration of moisture. It also eliminates

  also the need to have a film or fiber that

  turns the filling material and the fiber or the bonding strip which is wrapped around the film or fiber. By

  Therefore, the present invention reduces the number of ma-

  raw materials used and increases productivity and

  process performance. The heat treatment of a po-

  adhesive polymer and the application thereof on the tension thread also bring advantages. This treatment keeps the tension wire tightly wrapped around the inner lining without increasing the diameter of the cable to

optical fibers 100.

Claims (14)

  1. Fiber optic cable (100), characterized in that it comprises: a cylindrical housing (30); a structural support member (16) positioned substantially in the center of the cylindrical housing (30);   at least one optical fiber tube (14) positioned above   tower of the structural support element (16), the optical fiber tube (14) comprising at least one optical fiber   (10) and being filled with a material (12) adapted to protect   manage the optical fibers (10) from the penetration of   you; and a single layer of solid, water-resistant material (50) applied to the surface of the structural support member (16) and to the surfaces of all of the tubes   optical fibers (14), so that all empty inside   inside the housing (30) are filled, to protect the   optical fibers (10) for the penetration of moisture.   2. Fiber optic cable (100) according to claim   1, characterized in that it further comprises a tension wire   sion (52) wrapped around the outer surface of the layer of solid water resistant material (50) to impart resistance to the fiber optic cable (100) tensile.   3. Fiber optic cable (100) according to claim 2, characterized in that two layers of tension wire   (52) are formed around the outer surface of the material.   solid and water-resistant line (50).   4. Fiber optic cable (100) according to claim   3, characterized in that a first layer of tension wire   sion (52) is formed by wrapping the tension wire (52) around the solid, water-resistant material (50) in a first direction and a second layer is formed by wrapping the tension wire (52) around the material solid   and water resistant (50) in the opposite direction.   5. Fiber optic cable (100) according to any one   claims 2 to 4, characterized in that the yarn   tension (52) is coated with a polymer which protects the thread from   tension (52) of moisture penetration and which   holds the tension wire (52) tightly wrapped around the solid, water-resistant material (50). 6. Fiber optic cable (100) according to any one   claims 2 to 5, characterized in that the yarn   tension (52) is coated with a polymer which becomes adhesive   when subjected to heat treatment.   7. Fiber optic cable (100) according to any one   claims 2 to 6, characterized in that the yarn   tension (52) comprises a fiber or a strip having a mo-   high tensile strength and high strength.   8. Fiber optic cable (100) according to any one   claims 2 to 7, characterized in that the yarn   tension (52) includes an aramid fiber or a fiber glass base.   9. Fiber optic cable (100) according to any one   of the preceding claims, characterized in that the   fiber optic tubes (14) are made of plastic tick.   10. Fiber optic cable (100) according to any one   as in the preceding claims, characterized in that it   further comprises at least one empty tube (20) positioned above   round the structural support member (16) to maintain the fiber optic tubes (14) in a predetermined configuration around the structural support member (16).   11. Fiber optic cable (100) according to the claim   tion 10, characterized in that the predetermined configuration   born is a concentric configuration.   12. Fiber optic cable (100) according to any one   as in the preceding claims, characterized in that   the fiber optic tubes (14) are filled with a gel water resistant.   13. Fiber optic cable (100) according to any one   as in the preceding claims, characterized in that   the solid, water-resistant material (50) is applied by extrusion. 14. Fiber optic cable (100) according to any one   as in the preceding claims, characterized in that the solid, water-resistant material (50) comprises a   polyethylene or vinyl chloride resin.