SK28696A3 - A device and method for terminating or splicing of optical fibre - Google Patents

Abstract

A device for terminating or splicing at least two tubes (12, 13) carrying optical fibres (14, 15) surrounded by reinforcing fibres (17), which device comprises first (1) and second parts (3) which can be secured together during the termination or splicing such that a portion of an optical fibre within each tube extends through aligned apertures in the parts, and such that the reinforcing fibres of each of the tubes are gripped between the secured parts.

Description

Termination device and method of use

Areas of technology

The present invention relates to fibers.

-1or optical fiber splicing enhancements in optical splicing

BACKGROUND OF THE INVENTION

Telecommunication systems using optical fibers often use cables containing a large number of optical fibers. When the signal path approaches an individual customer, a central office or other interface, it is necessary to provide a connection to individual optical fibers or fiber distribution groups. This generally entails fiber configuration configurations performed by knotting and their arrangement into suitable connections to the other fiber. This and the overall fiber handling must be. carefully to avoid excess or stress on the fibers, or any other purpose. However, during their installation and operation, optical fibers can be subjected to considerable axial forces. An example of one way a person installing a certain amount of optical fibers can provide a path for each individual fiber to locate it in a bundle is to pull the end portion of the fiber and notice which fiber is moving.

Optical fibers are provided with different protection. For example, the optical fibers may be surrounded by one or more packages that provide some protection both from physical damage and loss of light and provide the fiber with a certain amount of stiffness. Optical fibers are often routed in so-called transport tubes, which provide additional

Further protection may be provided by additional reinforcing material, in a fibrous form, secured between the outer tube and the inner optical fiber. The reinforcement may comprise thin, high-strength, flexible fibers, for example, fibers sold under the brand name Kevlar, which are stretched longitudinally within the outer transport tube.

Where fiber optic connections are to be made, it is customary to cut the outer transport tube and fold out the reinforcing fibers so that the internally wrapped fibers are further drawn into the connection device. (Additional short lengths of transport tubes may be provided around wrapped fibers extending from the cut protective tubes and reinforcing fibers.)

When making splices containing optical fibers, it is very important to avoid kinking, as this can negatively affect light transmission and eventually permanently damage these fibers. As a result, it is desirable to terminate the slit guard tube and reinforcing fibers surrounding the central optical fiber so that any axial tension on the fiber tube is transferred to the respective box or other structure in which the tube is terminated or bonded and not contained within the fiber inside the oven. Consequently, the techniques of splicing or terminating coaxial or other metal cables should not be automatically expected to be suitable for the purpose of splicing or terminating optical fiber cables.

Optical fibers guided in the transport tubes are sometimes provided in the form of connecting cables, i. generally shorter fiber lengths, usually factory pre-assembled with a connector at one or both ends. Connecting cables or (terminals) of short length are preferably used when connecting different parts of a network rather than connecting the fibers of different parts of the network directly

-3 one to another. Their use minimizes work with major fiber lengths.

It is an object of the present invention to provide efficient optical fiber terminating means that keep tubes and reinforcing fibers containing optical fibers against high axial forces, but leave the inner optical fibers unloaded and free to move to join or terminate them. In particular, the present invention provides for joining or terminating at least two (occasionally two, three, four, or even up to about twelve) side-by-side optical fiber tubes. For example, the transmitting and receiving fibers, or the main and backup fibers, could be coupled or terminated in pairs.

SUMMARY OF THE INVENTION

The present invention provides for joining at least two terminating devices or tubes surrounded by reinforcing fibers, a portion that can be fixed or joined so that each tube is aligned with the axes and the reinforcing fibers are clamped by the parts.

The first connected terminated in the case

There, carrying optical fibers comprising the first and second together when terminating a portion of the optical openings between the fibers within these portions fixed therein and the second portion may preferably be mechanically to a partition or the like where the tubes are to be or, for example, to another pair of these. parts of the connection.

wherein the first and second portions comprise alloyed screw threads, the portions are preferably made of a metallic or polymeric material. Where these portions comprise matched fit elements, the portions preferably comprise an electrically insulating material and are preferably made of a polymeric material.

Preferably, the fused portions are such that they can be re-entered, i.e., the screw or mating connection can be reopened after they have been made. Preferably, such a device can be installed and reopened by the installer on site without tools.

The present invention also provides a method for terminating or joining two optical fiber-carrying tubes, each with reinforced fibers surrounding the optical fiber, within the apparatus of the invention, the method comprising:

(a) removing part of each pipe end and exposing part of the optical fiber and reinforcing fibers;

b) passing a portion of the optical fiber and exposed reinforcement fibers from each tube through the opening in the first part of the device,

c) fastening a second portion of the device relative to the first portion such that the optical fiber portions are passed through the respective apertures in these portions and the optical fiber reinforcement fibers are clamped between the first and second portion of the device.

The first and second portions are secured together such that the reinforcing fibers surrounding the optical fiber are clamped between the portions. To this end, the second portion is preferably positioned to surround at least a portion of the first portion. Another possibility is that the second part can be adjusted within the second part. The first and second portions are preferably hollow and preferably also generally cylindrical.

Where the second portion surrounds at least a portion of the first portion, the method preferably also comprises folding the reinforcing fibers over the outer surface of the first portion before placing the second portion therethrough.

One of the first or second portions, preferably both, is preferably adapted to be. mechanically fixed to a partition or the like, where the tubes are to be terminated or connected to another pair of these parts in the case of joining.

In some applications where the second portions are secured over the first portion, it may be desirable to use a cylindrical portion, such as, for example, a clamping sleeve in addition to the first and second fused portions. The clamping sleeve may be positioned to extend within the first portion over the optical fiber portions and within the reinforcement fibers after the reinforcement fibers have been folded over the exterior of the first portion. The second part is then placed on the first part and attached thereto. The housing may locate and internally support the reinforcing fibers, and provide additional protection to portions of the optical fiber. Preferably, the housing has an outwardly directed flange at one end that projects beyond the wall thickness of the first portion. In this case, the housing also aids in the correct alignment of the first portion to the optical fibers, as its outwardly directed flanges can abut and determine the location of the ends of the tubes surrounding the optical fibers. Where the housing has outwardly extending flanges at one end, these are preferably small enough that the second portion fits over the housing flanges and engages and is fastened to the first portion.

When the first and second portions comprise screw threads for fastening them together, they are preferably provided with nut portions that allow both portions to be screwed together by a wrench. Preferably, the threaded alloyed surfaces are arranged such that the reinforcing fibers are clamped between them.

Preferably, only two encapsulated optical fibers are bonded together. Surprisingly, it has been found that sufficient axial load transfer can be achieved

The reinforcing fibers surrounding the optical fibers into the first and second portions of the device of the present invention (and then into a partition or the like) without the portions being fastened together so tightly as to cause damage. Instead of the screw threads or the interlocking fit, other plated surfaces comprising interlocking bevels or bayonet fastenings may be mentioned. These surfaces may be screw threaded if desired. In some embodiments of the present invention where two or more optical fibers are to terminate side by side, the first and second portions comprise a single opening through which both the optical fibers and their respective surrounding tubes and their reinforcing fibers pass. In a preferred embodiment of the invention, one of the first and second portions comprises a projecting portion comprising open channels into which coated optical fibers projecting from the truncated transfer tube can be placed. The open channel configuration facilitates the installer to see and arrange the optical fibers while the reinforcing fibers are folded over the truncated tube and the first portion (or the remaining portion of the first portion where the protruding portions protrude from the first portion).

Overview of the figures in the drawing

An embodiment of the invention will be further described by reference to the accompanying drawings, in which:

Fig. 1 is an exploded, side view of the device of the present invention.

Fig. 2 is a side cross-sectional view of the apparatus of FIG. 1, in an unfolded form.

-ΊObr. 3 is a side view of the device of FIG.

and 2 in use.

Fig. 4/5 shows a perspective view of the first and second parts, respectively, of the second device according to the invention.

Fig. 6/7 show a cross-section of FIG. 4 and 5, respectively.

Fig. 8 is a cross-sectional view of the parts of FIG. 4 to 7 installed in a box.

Fig. 9 is a perspective view of the fiber optic tube passage of the configuration of FIG. 8th

Fig. 10 shows a perspective view of a first part of a third device.

Fig. 11/12 are perspective views of first and second portions, respectively, of one embodiment of the present invention.

Fig. 13/14 show perspective views (Fig. 14 partially transparent) of the assembled first and second parts of yet another embodiment according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a device which comprises a first part 1 for receiving the tube and an optical fiber with reinforcing fiber, a cylindrical part (clamping sleeve) 2 and a second part 2 ·

The first part 1 has an inner bore or hole 4 into which

Two tubes, head 5 and part 6 with external threads, can be inserted.

The housing 2 has a diameter such that it fits inside the bore 4 in the part 4, but also outwardly facing the flange 7, arranged so that it protrudes through the wall thickness of the part 1 and thus limits the penetration of the housing into the part 1. a nut 8 and an elongated part 9 with a bore 10 therein. The nut part 8 has a threaded recess 11 inside which is flush with the part 5 with the external threads of the first part 1.

In use, the ends of each of the transport tubes 12 and 13 surrounding the fiber-reinforced optical fibers are removed and exposed to the optical fibers 14, 15 (which may be wrapped or otherwise protected) and the reinforcing fibers 16, 17.

The optical fibers 14, 15 and reinforcing fibers 16, 17 are inserted through the bore 4 in the first part 1. The reinforcing fibers 16, 17 are then folded over the outer bore part of the first part 1 of the device. The closing sleeve 2 is inserted into the first part 1 of the device via the optical fibers 14, 15 inside the reinforcing fibers 16, 17. This thus determines the location of the first part 1 relative to the cut tubes 12, 13 because their ends abut against the outwardly directed flange Z The second part 2 of the device is then placed over the optical fibers 14, 15 so that they pass through the bore

The second part 3 is then screwed onto the first part 1 of the device, clamping and separating the reinforcing fibers 16, 17 between the screw thread portions of the first and second parts 1, 3 of the device.

Looking now at the second device of the present invention in FIG. 4-9, the first part 21 of the device is shown in FIG. 4. It is generally cylindrically shaped on its outer surface, but includes an annular ridge 22, groove 24 and collar 26 adjacent to each other. These serve together to form an arrangement that can cooperate with a partition

-9 (described later). The portion 21 also includes a portion of the tube 28 extending from the collar 26 and having, on its outer surface, partially along its length, a ridge of small profile 20. This provides a portion of the snap fit mechanism of the device described later. The cylindrical bore 32 extends through the entire portion 21 to pass the fiber optic tubes in use.

Fig. 5 shows the second part 33 of the first embodiment device. It comprises a cylindrical portion 34 having an annular groove of a small profile 38 on its outer surface. The groove 38 engages with the ridge 40 of the first portion. The second portion 33 also has an aperture 36 extending its length to pass optical fibers and is provided with an end wall 42.

Each of the portions 21 and 33 is integrally molded and each is made of a polymer material, such as a high strength polymer. Polymers that may be useful include fluoropolymers, for example, the Kevlar trademark. The portions 21 and 33 are preferably molded.

In cross-sections FIG. 6 and 7, the emerging features of portions 21 and 33 can also be seen. As shown in these figures, some dimensions of these portions are as follows:

Fig. 6 - Part 21

Diameter d (hole 32 in first section 21)

Total length 1 (first part 21)

Diameter d ₂ (inner diameter of cuff 26 on part 21)

Height h ^ (ridge 30)

4.5 mm

20,0 mm

5,2 mm

0.28 mm

-10Off, 7 - Part. 33

Diameter d ₃ (Inner Diameter 18) 8.33 mm Diameter d (Inner Diameter For Part 21 Inlet) 10.2 mm Diameter d _s (Output Diameter For Optical Fibers And Reinforcing Seams) 4.5 mm Height (Height 18). ) 0.76 mm thickness t _x (end wall 40) 1.0 mm

The images are drawn approximately four times larger than their actual size (unless otherwise indicated).

Fig. 8 shows part 21 in some compartment 42. Part 33 is not shown for clarity. The ridge 22 on the portion 21 must be small enough to pass through the opening of the compartment, and then an additional portion 44 is required to engage the ridge 22 on the insert side in the compartment to retain the portion 21 in the compartment 42. Thus, the device of this aspect of the invention has two interlocking housing parts, a first interlocking fit of the two parts of the device together and a second interlocking fit to the tray or the like, which makes the installation particularly easy.

Fig. 9 shows the position of the devices 21 and 33 adjacent to the compartment 42 with the fiber optic cables 44 extending therethrough. A weight 24 (10 kg) is shown to illustrate the installation test. Fibers installed in this way can withstand a weight of 10 kg without loops or other damage.

Fig. 10 is a perspective view of a first portion of yet another embodiment of the present invention. The same parts are designated with the same reference numerals as the embodiment shown in FIG. 4.6 and 8. This portion will cooperate with the same second portion 33 shown in Figs. 5 and 7, the ridge 30 ^{1 of the} part 21 ^T fits into the bearing with the groove 38 of the part 33.

The difference between the two embodiments is the shape of the ridge 22 ¹ . In the embodiment of FIG. 10 and 12, ^one portion 22 is shorter in one transverse dimension than in the other. This could be inserted into the compartment or the like in any suitable manner, for example, it could be inserted through an opening in the compartment which is intermediate in size between the further and shorter dimensions of the part 22 ¹ . and then simply rotated to keep it in place, with some suitable locking means to prevent reverse rotation.

Fig. 11 illustrates a first portion of a third embodiment of the present invention; and FIG. 12 illustrates a cooperating second portion of this embodiment. In this case, instead of the ridge 30 on the outer surface of the first portion engaging the groove 38 in the second portion (as shown in the previous figures), the four projecting portions 50 spaced equidistantly around the outer surface of the first portion 2 cooperate with equally spaced apertures 52. in the overall cylindrical second portion 33. Again, the collaboration is an interlocking fit. As before the termination of the first portion 21 remote from the protruding parts ILQ », it can be configured for easy connection to a partition, board or the like. Again, the parts are of the same material and preferably made in the same manner as the embodiment in the previous figures.

Referring now to FIG. 13 and 14, the first portion 21 ^{111 is} seated inside, and is snap fit, with the second portion 33 ¹¹¹ . The snap fit is secured by four spaced holes on the portions 21, ¹¹¹ , cooperating with four equally spaced projections on the inner surface of the surrounding portions 33, ¹¹¹ (see Fig. 14). As before, the common aperture (designated 58 in this case) extends through both parts 21 ¹¹¹ and 33 ¹¹¹ . The two interconnecting cables (with the truncated outer pipe) to be terminated pass through the opening 58 and then are reinforcing braids

The surrounding filaments themselves folded over the outer surface of the portion 21 ^xxx and within the portion 33 ^xxx so that they are trapped between these portions. For the sake of clarity, the interconnecting cables, which are of course inserted and reinforcing fibers located between portions 21 ^xxx and 33 ^xxx, are not shown. before setting and storing the part 33 ^xxx through part 21 ^xxx . In this embodiment, a special feature is provided on the inner portion 21 ^xxx in the form of an elongated protrusion 62 extending beyond the end 64 of the common aperture 58 through the portions 21 ^xxx and 33 ^xxx . This protrusion comprises two open channels 66 for receiving respective fibers from a pair of connecting cables that have been separated at this point from the surrounding reinforcing fibers. The fibers may be wrapped (primary or optionally with an auxiliary wrap) in the channels 66, but are not surrounded by reinforcing fibers. The channels 66 may be resized to accommodate the fibers in the transport tubes, if desired. The channels 66 provide additional support to the fibers. The open channel configuration also makes it easy for the installer to sort and arrange the fibers related to each other.

Using the apparatus of the invention, the ends of each tube containing the optical fibers and the exposed optical fiber (which may be coated or otherwise protected) and the reinforcing fibers are removed. Optical and reinforcing fibers are passed through openings in the first of two parts of the device (generally designated as 1 or 21). The reinforcing fibers are then folded over the first part 1 or 21 and then the second part 13 or 33 passes through the optical fibers and is mounted (e.g., screwed, snap-fit or otherwise) to the first part, thereby retaining the reinforcing fibers between the parts i or 21 and 13 or 33 of the device of the present invention.

The connection (s) described above was seen as having sufficient resistance to axial forces resulting from:

-13 from further pulling of the package (for example, by testing with a weight of 10 kg) but not resulting in kinking of the optical fibers. It is surprising that the two tubes can be terminated or joined in this way, because the axial pull on the tubes is likely to be laterally offset from one or the other fiber axis and would be expected to lead to an unacceptable micro-movement or other fiber deformation.

Generally, the method of the invention will be used to terminate pairs of tubes at a partition or frame, other part of a cable, or a splitter housing. The partition, frame or other portion may comprise a plate with an opening or slot through which the fibers pass and the tubes are terminated. The fibers passing through the plate will not be loaded by axial tension on the tubes, as this load will be absorbed by the plate.

Claims (7)

PATENT CLAIMS A device for terminating or joining at least two optical fiber-carrying tubes surrounded by reinforcing fibers, comprising first and second portions, which may be. fastened together during termination or bonding such that a portion of the optical fiber within each tube extends axially through the aligned holes in these portions and so that the reinforcing fibers from each tube are clamped between the fixed portions. The device according to claim 1, wherein the first and second portions are provided with zinc-plated screw threads or interlocking portions, or equivalents thereof, to effect fastening together. Device according to claim 1 or 2, wherein the respective parts are detachably fastened to each other. Device 1 or 3, wherein the first and second parts are hollow and generally cylindrical. The apparatus of any preceding claim, wherein the first portion comprises a projecting portion configured to extend beyond the molded portions of the portions that grip the reinforcing fibers, the projecting portion comprising channels arranged to receive fibers projecting beyond the terminated tubes and the reinforcing fibers. A method of terminating or joining at least two optical fiber-carrying tubes, each with reinforcing fibers surrounding the optical fiber, within the apparatus of any preceding claim, the method comprising: (a) removing part of the end of each pipe and exposing part of the optical fiber and reinforcing fibers; (b) passing a portion of the optical fiber and exposed reinforcement fibers from each tube through the opening in the first part of the device; and c) securing a second portion of the device relative to the first portion such that the optical fiber portions are passed through the respective apertures in those portions and the optical fiber reinforcement fibers are clamped between the first and second portion of the device. The method of claim 5, using the apparatus of claim 4, which also includes the step of adjusting the fibers in the channels of the projecting member.