Single-station splicing unit and method

An example single-station splicing unit is provided that includes a housing, an alignment element, a first electrode, and a second electrode. The housing includes an interior space and at least one cover configured to be interlocked with the housing to enclose the interior space. The alignment element is disposed within the interior space of the housing. The first electrode is disposed on one side of the housing, and the second electrode is disposed in the housing on an opposing side from the first electrode and in a facing relationship with the first electrode. The housing is configured to receive fibers in an opposing and abutting relationship to splice the fibers, and the housing remains secured to the fibers after splicing.

BACKGROUND

In the fiber optic industry, fusion splicing can be used to fuse or weld two fiber ends together. Traditional fusion splicing generally involves the use of a high-precision, high-maintenance, two-station fusion splicer to create an electric arc that creates a reliable joint between the two fiber ends. The fusion splicing process generally involves the steps of aligning the cleaved fiber ends, generating and controlling a high-voltage arc to melt the fiber ends together, and providing mechanical protection to the completed splice.

Alignment of the cleaved fiber ends and using the electric arc to melt the fiber ends together is typically performed in a main station of the fusion splicer. Providing mechanical protection to the completed splice is generally performed by means of a consumable, heat-shrinkable protective sleeve that must slid over the splice by the user and fixed in position in the splicer's secondary station (e.g., a small oven) to shrink the protective sleeve over the splice. The protective sleeve generally includes a heat shrink tubing, a hot melt glue tube through which the spliced fiber is routed, and a rigid strength member (e.g., a metal rod or formed ceramic).

The protective sleeve must be fed onto one of the fiber ends prior to splicing, and operators occasionally forget to do so. If the protective sleeve is not positioned on the fiber end prior to splicing, once the fibers are spliced, the only option is to break the splice and start over. In addition, the completed splice must be handled carefully when it is removed from the main station of the fusion splicer, covered over by the protective sleeve, then placed inside the secondary station to apply the protective sleeve. Damage to the splice can occur during the delicate transfer of the spliced fibers between the main and secondary stations. A high level of skill and experience is therefore generally needed to splice fibers.

Traditional fusion splicers can also be expensive due to their high precision, and may necessitate constant cleaning and regular maintenance in the form of arc calibration and periodic replacement of the tungsten electrodes. The electrodes can wear down after approximately 1,000 cycles because the high-voltage arc formed during splicing can blast away a small amount of material with each discharge, gradually reducing the sharpness of the electrode point, and reducing the accuracy of the arc path within the splicing chamber. Although tungsten provides a high melting and boiling point for the electrodes, lasting longer than other metals, the expensive nature of tungsten results in an added expense to electrode replacement.

SUMMARY

Embodiments of the present disclosure provide an exemplary single-station splicing unit that allows for precise and cost-efficient fiber splicing. The splicing unit includes a housing and an alignment element disposed within the housing. The alignment element assists with precisely aligning the fiber ends prior to fixedly clamping the fibers within the housing. The splicing unit includes a pair of electrodes disposed within the housing that creates the high-voltage arc to splice the fiber ends when the splicing unit is placed within a fusion splicer. The housing remains on the fibers after using the fusion splicer to protect the spliced fibers without the need for an oven station or a protective sleeve. The housing covers the completed splice after use, and clamps to the fiber coating and/or buffer. The combination of the housing and the mechanical rigidity of the alignment element prevents flexural loads on the housing from being transmitted to the splice. The splicing unit therefore provides a single-station fusion splicing process by performing the splice inside of a protective housing or consumable unit, significantly simplifying the splicing process and preventing or reducing potential mistakes by the operator.

In accordance with embodiments of the present disclosure, an exemplary splicing unit is provided. The splicing unit includes a housing, an alignment element, and first and second electrodes. The housing includes an interior space and at least one cover configured to be interlocked with the housing to enclose the interior space. The alignment element is disposed within the interior space of the housing. The first electrode is disposed on one side of the housing. The second electrode is disposed in the housing on an opposing side from the first electrode and in a facing relationship with the first electrode. The housing is configured to receive fibers in an opposing and abutting relationship to splice the fibers, and the housing remains secured to the fibers after splicing.

The housing can include alignment protrusions extending from a bottom surface of the housing. The alignment element can include complementary notches configured to engage with the alignment protrusions of the housing to orient the alignment element within the housing. The housing can include first and second upwardly directed extensions protruding from a bottom surface of the housing, the upwardly directed extensions configured to support a coated section of the respective fibers. As discussed herein, “coated section” refers to a coated and/or a buffered section of the fiber. An uppermost point of each of the first and second upwardly directed extensions can include a groove formed therein and extending the length of the first and second upwardly directed extensions. The groove can be configured complementary to an outer diameter of the coated section of the respective fibers.

In some embodiments, the at least one cover can include first and second covers configured to close over and crimp a coated section of the respective fibers at proximal and distal ends of the housing. In some embodiments, the at least one cover can include a third cover disposed between the first and second covers, the third cover configured to close over and seat an exposed section of the respective fibers within a groove formed in the alignment element. Each of the first, second and third covers can be pivotably connected to a main body section of the housing with a respective hinge.

First and second outer walls of the housing can include a slot formed therein, the slots configured to slidably receive the respective first and second electrodes. Each slot includes a first opening facing outwardly away from the interior space of the housing, and a second opening facing inwardly towards the interior space. A body of the first and second electrodes can be exposed through the first opening formed in the slots of the housing for electrical contact with contacts of a fusion splicer. A pointed extension of the first and second electrodes can extend into the interior space of the housing through the second opening formed in the slots of the housing.

The alignment element can include an elongated body with a notched area creating a space aligned with a position of the first and second electrodes. The alignment element can include a top surface with a groove formed therein, the groove configured to receive exposed sections of the fibers. Ends of the exposed sections of the fibers can be configured to be positioned in an abutting relationship in the notched area of the alignment element. The at least one cover can include an extension complementary to the groove formed in the top surface of the alignment element, the extension configured to seat the exposed sections of the fibers within the groove of the alignment element.

In accordance with embodiments of the present disclosure, an exemplary splicing system is provided. The splicing system includes a fusion splicer and a splicing unit configured to be positioned within the fusion splicer. The splicing unit includes a housing, an alignment element, and first and second electrodes. The housing includes an interior space and at least one cover configured to be interlocked with the housing to enclose the interior space. The alignment element is disposed within the interior space of the housing. The first electrode is disposed on one side of the housing. The second electrode is disposed in the housing on an opposing side from the first electrode and in a facing relationship with the first electrode. The housing is configured to receive fibers in an opposing and abutting relationship to splice the fibers, and the housing remains secured to the fibers after splicing. The fusion splicer can include a cradle configured to receive the splicing unit. The fusion splicer can include electrical contacts configured to electrically connect with the first and second electrodes of the splicing unit.

In accordance with embodiments of the present disclosure, an exemplary method of fusion splicing optical fibers is provided. The method includes positioning a first fiber and a second fiber in an opposing and facing relationship within an interior space of a housing of a splicing unit. Each of the first and second fibers includes a coated section and an exposed section. The splicing unit includes an alignment element disposed within the interior space, and first and second electrodes disposed on opposing sides of the housing. The method includes positioning ends of the exposed sections of the first and second fibers in an abutting relationship. The method includes interlocking a cover with the housing to enclose the exposed section of the first and second fibers within the interior space of the housing and to maintain the position of the first and second fibers within the housing. The method includes creating a voltage arc between the first and second electrodes to splice the ends of the exposed sections of the first and second fibers. The housing remains secured to the first and second fibers after splicing.

DETAILED DESCRIPTION

FIGS.1-2are perspective and detailed views of an exemplary single-station splicing unit100(hereinafter “splicing unit100”) of the present disclosure. The splicing unit100includes a housing102, an alignment element104disposed within the housing102, and electrodes106,108forming an electrode pair disposed within the housing102. The components of the splicing unit100allow for the entire splicing process to take place in a single station. In particular, the splicing unit100can be placed within a cradle of a fusion splicer such that electrical contacts (e.g., wiping contacts) of the fusion splicer touch and make an electrical connection with the electrodes106,108on opposing sides of the splicing unit100to generate the high-voltage arc within the splicing unit100. The high-voltage arc splices the fiber ends within the housing102, and the housing102remains permanently fixed to the fibers to act as a protective layer to the splice. The splicing process is thereby significantly simplified and reduces the potential for damage to the splice.

The housing102can be fabricated from a molded plastic (e.g., polypropylene, or the like) to provide protection to the completed splice, while permitting flexibility in the necessary areas for using the splicing unit100. With reference toFIGS.1-3, the housing102includes a main body section110(e.g., a base) defining an elongated structure extending between opposing proximal and distal ends112,114. The housing102includes three covers116,118,120each pivotably connected to the main body section110by respective living hinges122,124,126. The covers116,118can be separated from each other by a gap128, and the covers118,120can be separated from each other by a gap130. Each of the covers116,118,120is therefore capable of being pivoted relative to the main body section110independently from the other covers116,118,120. The material of the housing102allows for flexing of the hinges122,124,126during operation of the covers116,118,120. The covers116,118,120are configured to interlock with an outer wall138of the main body section110to enclose the interior space of the main body section110. For example, the main body section110can include a groove into which the covers116,118,120can be snapped into to maintain the closed position of the covers116,118,120.

The main body section110includes a hollow interior with a substantially planar or flat bottom surface132at the center of the main body section110. Outer walls138,140extend substantially perpendicularly on opposing sides of the bottom surface132. The main body section110includes two protrusions134,136extending substantially perpendicularly from the bottom surface132. The protrusions134,136are spaced from each other and can include a rounded top surface. In some embodiments, the protrusions134,136can be disposed near the gaps128,130. The protrusions134,136can assist in aligning and maintaining the position of the alignment element104when the alignment element104is positioned within the housing102by insertion of the protrusions134,136into complementary openings or notches formed in the alignment element104.

The main body section110includes upwardly directed extensions142,144extending from the bottom surface132on opposing sides of the main body section110. The extension142can extend from the bottom surface132at or near the protrusion134and up to the proximal end112, and the extension144can extend from the bottom surface132at or near the protrusion136and up to the distal end114. Each extension142,144can define a substantially V-shaped configuration. In some embodiments, the uppermost point of the extensions142,144can define a U-shaped groove146,148configured and dimensioned to receive or cradle the coated section150,152of the respective fibers154,156.

Each of the covers116,118,120can define a substantially planar configuration and includes an extension158,160,162extending substantially perpendicularly from the inner surface of the respective cover116,118,120. The extensions158,160,162can be oriented substantially parallel to a longitudinal axis passing along the length of the housing102. The extension158can extend from and between the outer proximal and distal edges of the cover116, the extension160can extend from and between the outer proximal and distal edges of the cover118, and the extension162can extend from and between the outer proximal and distal edges of the cover120. Each extension158,160,162can define a substantially V-shaped configuration, with the uppermost point of the extensions158,160,162defining a U-shaped groove164,166,168.

The grooves164,168can be complementary to the grooves146,148such that when the covers116,120are closed over the main body section110, the grooves146,148,164,168can substantially surround and crimp opposing sides of the coated section150,152of the respective fibers154,156to maintain the position of the fibers154,156relative to the housing102. When the central cover118is closed over the main body section110, the groove166can at least partially receive and impart downward pressure on the exposed glass section170,172of the respective fibers154,156to ensure the exposed glass sections170,172are properly aligned and seated within the alignment element104.

The housing102includes two downwardly directed slots174,176formed in the outer walls138,140on opposing sides of the main body section110. The slots174,176can be substantially centrally positioned between the proximal and distal ends112,114, and are configured and dimensioned to at least partially receive the respective electrodes106,108. In some embodiments, the depth of the slots174,176can be dimensioned to partially receive the respective electrodes106,108, such that at least a portion of the electrodes106,108extends above the top surface of the main body section110(see, e.g.,FIG.2).

In some embodiments, the depth of the slots174,176can be dimensioned to completely receive the respective electrodes106,108such that the electrodes106,108do not extend above the plane defined by the top surface of the main body section110(e.g., the electrodes106,108are aligned with the top surface of the main body section110, the electrodes106,108are disposed below the top surface of the main body section110, or the like). The depth of the slots174,176can be selected to ensure alignment of the electrodes106,108with the ends182,184of the fibers154,156. The housing102includes a U-shaped cutout178(e.g., opening) at each inner surface of the outer walls138,140and extending into the hollow space formed by the slots174,176, and a U-shaped cutout180(e.g., opening) at each outer surface of the outer walls138,140and extending into the hollow space formed by the slots174,176.

The U-shaped cutout180can be dimensioned generally greater than the U-shaped cutout178. For example, the width of the U-shaped cutout180can be dimensioned greater than the width U-shaped cutout178to provide a greater exposed surface area of the electrodes106,108at the outer surfaces. In some embodiments, the height of the U-shaped cutouts178,180can be substantially equal. In some embodiments, the height of the U-shaped cutout180can be dimensioned greater than the height of the U-shaped cutout178. The greater exposed surface area of the electrodes106,108at the outer surfaces ensures reliable electrical contact with corresponding contacts of the fusion splicer.

With reference toFIGS.1,2and4, the alignment element104can be fabricated from a molded zirconia ceramic or a similar micron-precision material. The material of fabrication can provide mechanical rigidity to the structure supporting the fibers154,156, and allows for a high precision alignment product at a low cost for high volume production. The alignment element104includes an elongated body186extending between proximal and distal ends188,190. The body186includes a substantially flat bottom surface192and a substantially flat top surface194.

The alignment element104includes a notched area196(e.g., a horizontally oriented cutout) at a central section of the body186. The notched area196creates a gap or separation between two sections of the body186. As illustrated inFIGS.1and2, the notched area196aligns with the electrodes106,108to define a space for creating the fusion arc for splicing the fibers154,156. The proximal and distal ends188,190each include a notch198,200(e.g., a vertically oriented cutout) along the height of the alignment element104. In some embodiments, the notch198,200can define a U-shaped configuration. The diameter associated with the notch198,200is complementary to the protrusions134,136of the housing102, such that when the alignment element104is positioned onto the bottom surface132of the housing102, the protrusions134,136at least partially enter the notches198,200. The combination of protrusions134,136and notches198,200therefore acts as an alignment feature to ensure the proper, centralized position of the alignment element104within the housing102.

Each of the body186halves includes a substantially V-shaped, inwardly directed groove202,204extending the length of the body186. The bottom of the grooves202,204can be dimensioned to precisely align the outer cladding diameter of the exposed sections170,172of the fibers154,156. The groove202extends from and between the proximal end188to the notched area196, and the groove204extends from and between the notched area196and the distal end190.

With reference toFIGS.5and6, each of the electrodes106,108can be fabricated from a metal, such as tungsten. In some embodiments, a lower cost alternative metal to tungsten can be used to fabricate the electrodes106,108without a loss of performance due to the small number of discharge cycles for each electrode106,108. In some embodiments, base metals with a refractory metal plating (such as chromium) can be used to fabricate the electrodes106,108. In some embodiments, the electrodes106,108can be machined, stamped, drawn, cast, or the like, depending on application demands.

Each electrode106,108includes a body206defining a substantially cylindrical configuration with a rounded perimeter edge208and substantially flat front and rear surfaces210,212. In some embodiments, the body206can define a square or rectangular configuration. The dimensions and/or configuration of the body206are complementary to the slot174,176formed in the housing102such that the electrodes106,108can be slid into the respective slots174,176. Each electrode106,108includes a cone-shaped extension214protruding from a central portion of the front surface210, each extension214having a tip216at the distal end. The sharp tip216allows for accurate control of the high-voltage arc formation and location. The larger surface area of the body206(as compared to the extension214) creates a broad outer surface for wiping contact with the fusion splicer.

During use, as shown inFIGS.1and2, the coated sections150,152of the fibers154,156are positioned on the grooves146,148of the housing102. The fibers154,156can be slid towards each other until the ends182,184abut each other with the exposed sections170,172supported in the grooves202,204of the alignment element104. Such alignment can be performed by the fusion splicer. Therefore, the fusion splicer only needs to control the longitudinal placement of the fibers154,156within the splicing unit100, necessitating only 1-axis control (as compared to traditional methods generally necessitating 3-axis control). The grooves202,204receive and support the exposed sections170,172of the fibers154,150such that the ends182,184are suspended within the notched area196in an abutting relationship. Once the ends182,184are aligned relative to each other, the covers116,120can be rotated into the closed position to crimp the coated sections150,152between the extensions142,144and the extensions158,162to stabilize the position of the fibers154,156. The cover118can subsequently be rotated into the closed position to secure the exposed sections170,172within the grooves202,204by the extension160. The configuration of the extension160is complementary to the V-shaped grooves202,204to ensure proper alignment and seating of the exposed sections170,172within the grooves202,204.

After the cover118has been closed and the fibers154,156are locked in the desired position, the splicing unit100can be positioned within the supporting cradle of the fusion splicer. The fusion splicer can be actuated to make electrical contact against the electrodes106,108to create the high-voltage arc within the housing102. The high-voltage arc resulting in splicing of the ends182,182of the fibers154,156. After splicing, the covers116,120can be closed to clamp down on and secure the fibers154,156within the housing102. In some embodiments, closing of the covers116,120can be performed manually by the operator. In some embodiments, the fusion splicer can automatically close the covers116,120after completing the splicer. The housing102acts as the protective sleeve for the spliced fibers154,156and remains permanently attached to the fibers154,156(without the need for a heat-shrinkable protective sleeve). The splicing unit100therefore allows for a single station to be used to splice the fibers154,156.

Such operation shifts the burden of dimensional precision away from the fusion splicer and onto the splicing unit100, reducing the chance of improper splicing of the fibers154,156. The splicing unit100also prevents or reduces damage to the fibers154,156by reducing movement of the fibers154,156between multiple stations. In some embodiments, the splicing unit100can be hermetically packaged to ensure cleanliness prior to splicing. One-time use of the splicing unit100provides a low-cost splicing option (due to the reduced skill level of the operator), and reduces maintenance and cleaning requirements. In some embodiments, the splicing unit100can be removed from the spliced fibers154,156and reused to create another splice. The splicing unit100therefore provides an efficient, low-cost and low-skill option for splicing fibers154,156.