ABSORPTION OF INNER STRESSES AND INNER SEALING FOR MOUNTING IN A FIBER OPTIC CONNECTION BOX TECHNICAL FIELD

The present invention generally relates to a connector assembly for cables, in particular for fiber optic cables, which can be mounted in fiber optic connection boxes, in particular vertical or horizontal type for aerial mounting, underground, wall or pole mounting, and wherein the connector assembly is adapted to absorb and/or release inner stresses exerted on the fiber optic cable while simultaneously ensures sealing between the connector assembly and the fiber optic cable, as well as between the connector assembly and the fiber optic connection box.

PRIOR ART

Fiber optic connection boxes, also referred to as junction boxes, are known by the skilled person for their use in aerial installations, wall, pole or duct mounting. Such connection boxes can be installed as terminal boxes, bypass nodes, network end points and so. Such connection boxes are commonly manufactured in plastic materials by injection molding, and are designed to endure environmental conditions such as rain, corrosion, extreme heat and cold, in such a way that inner components of the connection box remain isolated from the outside.

There are different kinds of connection boxes depending on the specific use and type of mounting, for example vertical type or horizontal type, cap-type, etc. which are known by the skilled person.

Generally speaking, a cap-type connection box comprises a base with an O-ring, a base with a cable holding system, a back plate (also referred to as base plate), a plurality of trays for connection and bypass of fiber optic cables, a cover or dome that is mounted on the base with O-ring in order to close hermetically the connection box, and several passages, ducts and bypass connectors.

A cap-type connection box mentioned above is known, for example, from the International Patent Application WO2012/155359A1, which discloses a connection box having a base, a dome or cover, and a plurality of ducts for fiber optic cables for bypassing fiber optic cables. As it can be seen in Fig. 7 of said document, ducts are tubes protruding from the base to allow passage of the fiber optic cables.

Another cap-type connection box similar to the one mentioned above is known from the Mexican Patent application MX/a/2013/000227, which discloses a connection box having, among other elements, an end surface and several cylindrical hollow tubes for passage of the fiber optic cables.

Connection boxes of the prior art described above suffer from many drawbacks and troubles, just to mention a few: they do not guarantee a tight seal of the connection box, are difficult to handle, and hinder the passage of the fiber optic cable through the tube or cylindrical duct; in addition the cable installed in said tubes or cylindrical ducts is subject to inner damage and breakage at the free end of the cable because there is no absorption or dissipation of the inner stresses generated in the cable since the tube or duct which the cable passes through is a rigid element that is formed as a molded or extruded part of the base of the connection box.

In the state of the art, improvements to this type of connection boxes are also known. For instance, an improvement to a connection box, in particular to the tubes or ducts for connection of the cables thereof, is known from the Chinese Patent CN201637902U, which discloses, among other elements, a connection box including a base, a plurality of access tubes for fiber optic cable which are mounted in the base, and a lock nut. In further detail it can be observed that an access tube comprises a threaded section in each of its ends as well as a flange intermediate to both threaded sections, so that a threaded section passes through the base and is fixed with a fixing nut, and the other threaded section is used for screwing in the lock nut once the cable is passed through. According to an embodiment of this prior art document, it can also be provided a washer and a seal between the tube and nut to produce a sealing to the fiber optic cable. According to a second embodiment, it is provided a nut which has a ring protruding from said nut in order to produce a seal to the fiber optic cable. Whatever the case is, it is produced a seal between the tube and lock nut assembly to the fiber optic cable in the outer section of the connection box while facilitating assembly and disassembly of the cable through the tube and base.

Nevertheless, despite these improvements in the assembly of the tube in the base and the sealing to the fiber optic cable, there are numerous deficiencies both in the assembly of the access tube as in the sealing to the fiber optic cable, and there are also drawbacks in functioning of the connection box once installed, such as deficient sealing to the fiber optic cable which affects air tightness of the connection box, internal damage in the fiber optic cable because there is no absorption or dissipation of inner stresses unavoidable when the connection box is in use, breakage of the fiber optic cable at the free end protruding from the lock nut, among others.

As a consequence of the above, other kind of problems arise such as the need for inspection and frequent replacement of the sealing materials and, in the worst case, of the fiber optic cables; presence of humidity and/or dirt is detected inside the connection box; it is requested the use of multiple complex tools for assembly and disassembly of the connection box and its components, as well as the need to install further sealing elements such as shrinkable sleeves, which increases installation costs; at least two technicians are needed for carrying out assembly of the components of the connection box and it is further requested high level skills of the technicians.

On the other hand, in the state of the art, attempts to solve the problem of absorbing inner stresses produced in the fiber optic cable are also known.

For instance, from the Chinese Patent CN202977875U it is known a connector assembly comprising, among other elements, a connector having a threaded end section, on which a nut is screwed. Connector assembly further comprises a tubular seal and a crimping ring which comprises a crimping block at the end thereof. Crimping ring has a plurality of notches which are able to engage with protrusions provided in the threaded section to prevent rotation once the connector assembly is closed.

Similarly, it is known in the state of the art to provide a connector assembly in which a threaded section is provided, at its end engaging with the lock nut of the assembly, with a plurality of resilient blades which bend over the cable such that they can absorb vibrations and, possibly, inner stresses of the cable. Connector assemblies having these features are known, for example, from patent documents US2013/0183848A1, US2014/0065873A1 and CN203036139U.

Another solution to the problem of absorbing inner stresses in the fiber optic cable is known, for example, from patent US3796504, which discloses a collar having four teeth and a circumferential edge, wherein the teeth bend in direction towards the cable to absorb vibrations of the cable whereas the edge produces a seal to the outer surface of the cable.

Once again, despite the attempts for improving connector assemblies, drawbacks and disadvantages still exist because the elements used for absorbing inner stresses of the fiber optic cable on the one hand, only absorb a minor amount of the inner stresses since there is poor contact with the cable surface and, on the other hand, they do not guarantee fluid tight seal. Indeed, in the state of the art it is known that provision of elements for absorbing inner stresses impairs sealing capacity of the connector assembly and vice versa. BRIEF DESCRIPTION OF THE INVENTION

In view of the deficiencies and disadvantages present in the state of the art, it is a first object of the present invention to overcome the drawbacks and problems related to the absorption of inner stresses while simultaneously ensuring a tight seal of a connector assembly for fiber optic cables.

A further object of the present invention is to provide a connector assembly that is easy to manufacture, easy to assemble and disassemble in a base of a fiber optic connection box.

A further object of the invention is to provide a method of assembling a connector for fiber optic cable of easy execution and that secures a tight seal of the connector assembly as well as absorption of inner stresses generated on the fiber optic cable.

To solve the deficiencies and disadvantages of the prior art and to give solution to the objects of the invention, it is proposed a connector assembly for fiber optic cables in which, firstly, the distance between the base plate of the connection box and free end of the cable lying outside the connector assembly is increased in order to reduce likelihood of damage and breakage of said free end and, secondly, means for sealing and absorption of inner stresses generated on the fiber optic cable when the latter passes through the connector assembly are provided.

In this way, a first component of the connector assembly of the present invention consists in a main body comprising, on its outer side, a first thread section, a second thread section and a nut section intermediate to said first and second thread sections. Main body further comprises, on its inner side, a cavity formed by a first tubular section, a conical section adjacent the first tubular section, a second tubular section adjacent the conical section, and a circumferential recess formed in the second tubular section. Advantageously, main body further comprises a recess in the form of a circumferential notch which is formed in a back face of the nut section, wherein said annular recess faces a front face of a base plate of the fiber optic connection box when the main body is mounted on the base plate.

In addition, advantageously, the first inner tubular section of the main body is provided with a plurality of grooves or channels extending at least partially along the length of the first tubular section.

In addition, advantageously, a ring-shaped seal (also known as O-ring) can be provided which is mounted on the main body, and is at least partially accommodated in the annular recess such that said ring-shaped seal provides a seal to the front face of the base plate of the connection box.

A second component of the connector assembly consists in a fixing nut comprising an inner thread section which can be screwed in the first outer thread section of the main body to fasten said main body to the base plate.

As previously mentioned, main body is formed with a cavity which is also adapted to at least partially allow insertion of a third component of the connector assembly which consists in a sub-assembly comprising an insert and a cable seal. This insert and seal subassembly is able and is designed, on the one hand, to absorb inner stresses exerted on a cable passing through the same and, on the other hand, to simultaneously generate a tight seal to the surface of said cable.

According to the above, insert is manufactured from a plastic material, in particular a plastic made of, or that comprises, nylon. In addition, plastic insert is manufactured making use of injection molding techniques.

On the other hand, cable seal is manufactured from a rubber-based material, in particular Buna-N, or a silicone-based material. Such a cable seal is manufactured making use of compression-molding techniques.

The insert according to the invention is designed in such a manner that it comprises a main tubular body, a second tubular body adjacent the main tubular body and which includes an inner circumferential cavity, as well as a plurality of fingers which are flexible and elastically deformable; said fingers protrude from the second tubular body in a longitudinal direction of the insert. In addition, advantageously the main tubular body is provided with a plurality of longitudinal and circumferential projections which respectively serve for guiding insertion of the insert into the main body and prevent relative rotation of the insert with respect to the main body, and on the other hand to increase structural strength of the insert, in particular of the main tubular body.

The second tubular body of the insert is designed in such a manner that it has the shape of an annular circumferential body projecting from the main tubular body and thereby having an outer diameter greater than the outer diameter of the main tubular body.

In addition, the flexible fingers of the insert are designed such that they comprise a base portion adjoining the second tubular body and a gripping portion projecting radially inwardly at an angle relative the longitudinal axis of the insert. Such flexible fingers are further arranged in a polar symmetrical pattern in the circumference of the second tubular body, and spaced apart by gaps such that application of a radial compressive force on the fingers causes a radial deformation inwardly in such a way that the fingers overlap to one another maintaining a cylindrical shape between the gripping portions of the fingers.

On the other hand, cable seal is designed in such a way that it comprises a tubular body having an outer circumferential recess on one of its ends, and an inner circumferential recess on the other end.

Thus, cable seal can be snap-fitted in a hollow inner space essentially formed by the plurality of fingers and inner circumferential cavity of the insert, such that the part comprising the inner circumferential recess of cable seal is at least partially accommodated in the inner circumferential cavity of the insert, and the part comprising the outer circumferential recess of the cable seal at least partially contacts with the gripping portion of the flexible fingers of the insert.

In this manner, the radially inwardly deformation caused to the plurality of flexible fingers likewise causes radially inwardly deformation of, at least, the part having the outer circumferential recess and a portion of the tubular body of the cable seal thus creating a fluid-tight seal to the surface of a fiber optic cable passing through the insert and seal sub- assembly.

Connector assembly of the present invention further comprises a fourth component which consists in an extension nut comprising, on its outer side, a tubular section, a nut section arranged approximately intermediate in the tubular section, and a thread section. In addition, extension nut is designed in such a way that it defines, in its inner side, a cavity formed by a thread section, a first conical section adjacent the thread section, a first tubular section adjacent the first conical section, a second conical section adjacent the first tubular section, and a second tubular section adjacent the second conical section.

According to the present invention, inner thread section of the extension nut can be screwed in the second outer thread section of the main body, advantageously with the insert and cable seal sub-assembly at least partially introduced in the main body. In addition, inner cavity of the extension nut is designed in such a way that it is able to cause radially inwardly deformation (as previously discussed) of at least a portion of the insert and cable seal sub-assembly when said extension nut is screwed in the main body as mentioned above.

In this way, there is provided a first area of the connector assembly which is able to absorb inner stresses and to produce a sealing to the fiber optic cable.

Connector assembly according to the present invention further comprises a fifth component which consists in a lock nut comprising, on its outer side, a tubular section and a nut section adjacent the tubular section. In addition, lock nut is designed in such a way that it defines an inner cavity formed by a thread section, a conical section adjacent the thread section, and a cylindrical section adjacent the conical section. Inner thread section of the lock nut can be screwed in the outer thread section of the extension nut for closing the connector assembly.

Advantageously, according to a preferred embodiment of the invention, inner thread section of the lock nut can be screwed alternatively in the second outer thread section of main body. To this end, it is necessary to dispense with the extension nut; to put it another words, lock nut replaces the extension nut. However, design of inner cavity of the lock nut is also able to cause radially inwardly deformation of the insert and cable seal sub-assembly needed to absorb inner stresses and to produce the sealing to the fiber optic cable, as discussed above.

Connector assembly, according to a preferred embodiment, further comprises a sixth component which consists in an elastically deformable ferrule, which can be mounted in a hollow space formed between the extension nut and lock nut. Ferrule is designed in such a way that it comprises a center tubular section or body and two slope end sections or bodies each adjacent to each end of the center tubular section or body, and an inner bore passing through the center and end sections or bodies with an even diameter, that is to say in the form of a cylindrical body.

In addition, said ferrule, when introduced in the hollow space formed between the extension nut and lock nut, is able to at least partially absorb vibrations as well as tension stresses and shear stresses exerted on the fiber optic cable when the latter is in use, thus reducing damage to the cable.

Furthermore, advantageously, ferrule is made from an elastically deformable material such that it is able to produce a seal in the hollow space formed between the extension nut and lock nut to the fiber optic cable. To this end, ferrule is manufactured from a silicone based material, in particular manufactured by compression molding.

Advantageously, at least one of the main body, fixing nut, extension nut and lock nut is manufactured from a metal material, in particular a metal selected from the group comprising steel, bronze, brass, in particular tin plated brass, and aluminium. These components are manufactured preferably through automated machining processes, though it is conceivable to employ techniques such as die casting. Alternatively, these components may be manufactured from a plastic material comprising, or made of, nylon, and manufactured through injection molding techniques.

In accordance with the above, there is provided a second area of the connector assembly that is able to absorb inner stresses and to produce a sealing to the fiber optic cable, which improves both the tight seal and the absorption of inner stresses generated on the cable.

As it can be appreciated, connector assembly according to the present invention, once installed with a fiber optic cable passing therethrough, increases the distance between the base plate of the connection box and the free end of the fiber optic cable lying outside the connector assembly, such that the stress spot is transferred and/or distributed in a more stable inner area of the connector assembly. In addition, the provision of the ferrule and insert and cable seal sub-assembly allows ensuring a reliable fluid tight seal given that there are two sealing areas between the components of the connector assembly and the fiber optic cable.

The present invention also provides a method of forming a connector assembly in a base plate of a fiber optic connection box, wherein the method comprises the steps of:

- providing a main body;

- providing a fixing nut;

- fixing the main body through an opening in the base plate by means of the fixing nut;

- providing a sub-assembly comprising an insert and a cable seal, wherein the cable seal is mounted at least partially inside the insert;

- at least partially introducing the insert and cable seal sub-assembly in a cavity of the main body;

- providing an extension nut;

- providing a lock nut;

- positioning in sequence, from a distal end of the fiber optic cable in a direction towards the proximal end thereof, the lock nut and the extension nut;

- passing the distal end of the cable through the main body to a position in which a substantial portion of the distal end of the cable protrudes from the base plate and main body;

- sliding the insert and cable seal sub-assembly on the cable until at least partially introducing said sub-assembly in the main body;

- screwing in the extension nut to the main body; and

- screwing in the lock nut to the extension nut.

Advantageously, according to a preferred embodiment, the method further comprises providing an elastically deformable ferrule, which is mounted on the fiber optic cable after mounting of the lock nut and before mounting the extension nut. In addition, the method further comprises sliding the ferrule to be at least partially introduced in the extension nut such that the ferrule is deformed when the lock nut is screwed in the extension nut, thus forming a fluid tight seal to the fiber optic cable.

Advantageously, according to a preferred embodiment, the method further comprises providing an O-ring, which is mounted between the main body and the base plate in order to form an annular seal therebetween.

Consequently, according to the present invention, there is provided a method of forming a connector assembly that ensures, on the one hand, absorption of inner stresses and, on the other hand, tight seal between the connector assembly and a fiber optic cable installed therethrough.

Further objects and their solutions will be apparent to those skilled in the art on the basis of the reading the present specification with the aid of the enclosed drawings which show in an illustrative, non limitative manner details and features of embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

Figure 1 is a side view of the connector assembly according to the present invention mounted in a base plate.

Figure 2 is a side-perspective view of the connector assembly shown in Figure 1. Figure 3 is a front-perspective view of the connector assembly shown in Figure 1. Figure 4 is a back-perspective view of the connector assembly shown in Figure 1. Figure 5 is a front-perspective view of the connector assembly according to the present invention where the base plate and fiber optic cable have been omitted.

Figure 6 is a back-perspective view of the connector assembly according to the present invention where the base plate and fiber optic cable have been omitted.

Figure 7 is a top-perspective view of the main body of the connector assembly according to the present invention.

Figure 8 is a back-perspective view of the main body of the connector assembly according to the present invention.

Figure 9 is top view of the main body of the connector assembly according to the present invention. Figure 10 is a cross-sectional view of the main body shown in Figure 9.

Figure 11 is a top-perspective view of the fixing nut of the connector assembly according to the present invention.

Figure 12 is a front view of the fixing nut shown in Figure 11.

Figure 13 is a side view of the fixing nut shown in Figure 11.

Figure 14 is a cross-sectional view of the fixing nut shown in Figure 13.

Figure 15 is a perspective view of the O-ring of the connector assembly according to the present invention.

Figure 16 is a front-perspective view of the extension nut of the connector assembly according to the present invention.

Figure 17 is a back-perspective view of the extension nut of the connector assembly according to the present invention.

Figure 18 is a top view of the extension nut shown in Figure 16.

Figure 19 is a cross-sectional view of the extension nut shown in Figure 18.

Figure 20 is a front-perspective view of the insert of the connector assembly according to the present invention.

Figure 21 is a back-perspective view of the insert of the connector assembly according to the present invention.

Figure 22 is a top view of the insert shown in Figure 20.

Figure 23 is a cross-sectional view of the insert shown in Figure 22.

Figure 24 is a front view of the insert of the connector assembly according to the present invention.

Figure 25 is a back-perspective view of the cable seal according to the present invention.

Figure 26 is a front-perspective view of the cable seal of the connector assembly according to the present invention.

Figure 27 is a top view of the cable seal shown in Figure 25.

Figure 28 is a cross-sectional view of the cable seal shown in Figure 27.

Figure 29 is a front-perspective view of the insert and cable seal sub-assembly of the connector assembly according to the present invention.

Figure 30 is a cross-sectional view, in perspective, of the sub-assembly shown in

Figure 29.

Figure 31 is a front view of the sub-assembly in cross-section shown in Figure 30. Figure 32 is a top-perspective view of the lock nut of the connector assembly according to the present invention.

Figure 33 is a back-perspective view of the external lock nut shown in Figure 32. Figure 34 is a front-perspective view of the external lock nut shown in Figure 32. Figure 35 is a top view of the external lock nut shown in Figure 32.

Figure 36 is a cross-sectional view of the external lock nut shown in Figure 35.

Figure 37 is a top-perspective view of the ferrule of the connector assembly according to the present invention.

Figure 38 is a top view of the ferrule shown in Figure 37.

Figure 39 is a cross-sectional view of the ferrule shown in Figure 38.

Figure 40 is a side-perspective view of a first stage of assembly of the connector assembly in a base plate of a connection box for fiber optic cables according to the present invention.

Figure 41 is a cross-sectional view of a second stage of assembly of the connector assembly according to the present invention.

Figure 42 is a cross-sectional view of a third stage of assembly of the connector assembly according to the present invention.

Figure 43 is a cross-sectional view of a fourth stage of assembly of the connector assembly according to the present invention.

Figure 44 is a cross-sectional view of a fifth stage of assembly of the connector assembly according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in the drawings, reference numeral 1 designates a connector assembly for a fiber optic cable C, wherein the connector assembly 1 can be mounted on a base plate P of a fiber optic connection box.

In Figures 1 to 4 there is shown the connector assembly 1 mounted on the base plate P (represented only partially for the sake of simplicity) of the fiber optic connection box, wherein a fiber optic cable C is installed through the connector assembly 1 and base plate P.

In these Figures 1-4, connector assembly 1 is shown in an assembled or closed state with the elements visible to an observer, where reference numeral 100 designates a main body, reference numeral 200 designates a fixing nut, reference numeral 300 designates an O-ring, reference numeral 400 designates a lock nut, and reference numeral 600 designates an extension nut, which are described in further detail below. In addition, as it can be observed in Figures 1 and 2, for example, a distal end of cable C protrudes from both the base plate P and the fixing nut 200 (i.e. at the right side of the drawing), while a proximal end of cable C protrudes from the lock nut 400 (i.e. at the left side of the drawing).

Figures 5 and 6 show the connector assembly 1, in accordance with Figures 1 to 4, with the difference in the fiber optic cable C and the base plate P have been omitted for clarity purposes. It can be seen that connector assembly 1 defines a hollow space through which the fiber optic cable C is able to pass.

With reference now to Figures 7 to 10, details of main body 100 according to the present invention are shown. Main body 100 comprises, on its outer side, a first outer thread section 101, a nut section 102, and a second outer thread section 103, wherein the nut section 102 is arranged intermediate to the first and second thread sections 101 and 103; and further comprises, on its inner side, a cavity (configured similar to a through- hole) formed by a first tubular section 104, a conical section 106, a second tubular section 107, and a circumferential recess 108.

As it can be seen for example in Figure 10, conical section 106 is arranged intermediate and adjacent the first tubular section 104 on the one hand, and the second tubular section 107 on the other hand, such that a diameter of the first tubular section 104 is substantially smaller than a diameter of the second tubular section 107. Likewise, circumferential recess 108, which is formed in the second tubular section 107 and adjacent an end of the main body 100, has a diameter greater than the second tubular section 107.

In Figures 8 and 10 it can be seen that the main body 100 further comprises an annular recess 109 in a back face of the thread section 102 that faces a front face of the base plate P (see for example Figures 1 to 3). Such annular recess 109 has the function of accommodating a sealing element to produce a seal to a surface of said base plate P, as described herein below.

In addition, as it can be seen in Figures 8 and 10, the first inner tubular section 104 is provided with a plurality of longitudinal grooves or channels 105 extending longitudinally, at most, as much as the length of said first inner tubular section 104. Particularly, as observed in Figure 8, longitudinal channels 105 are arranged in an even number, for instance there are provided 6 longitudinal channels, and in a symmetrical pattern around the circumference of said first tubular section 104.

In relation now to Figures 11 to 14, there is shown a fixing nut 200, which comprises an inner thread 201. Said inner thread 201 can be screwed in the first outer thread section 101 of main body 100 for fixing said main body 100 in the base plate P.

Figure 15 shows an O-ring 300 which, according to a preferred embodiment of the invention, can be mounted on the main body 100 such that it is at least partially received in the annular recess 109 thereby providing a seal to a front face of the base plate P of connection box (see for example Figures 41 to 44).

In relation now to Figures 16 to 19, there are shown details of the extension nut 600 according to the present invention. Extension nut 600 is designed in such a way that it comprises, on its outer part, a tubular section 601, a nut section 602 arranged approximately intermediate the tubular section 601 (see for example Figure 18), and a thread section 603, and it further comprises, on its inner part, a cavity (configured similar to a through hole) formed by a thread section 604, a first conical section 605 adjacent the first thread section 604, a first tubular section 606 adjacent the first conical section 605, a second conical section 607 adjacent the first tubular section 606, and a second tubular section 608 adjacent the second conical section 607.

As it can be seen, for example in Figure 19, a diameter of the first inner tubular section 606 is substantially smaller than a diameter of the second inner tubular section 608.

Inner thread section 604 is able and is intended to be screwed in the second outer thread section 103 of main body 100, thus forming a hollow space into which a first sealing and stress-absorbing member can be introduced, as described below.

With reference now to Figures 20 to 24 there are shown details of an insert 700 according to the present invention, which is made in particular of a plastic material, for example made of, or that comprises, nylon. Insert 700 comprises a main tubular body 701, a second tubular body 702 adjacent the main tubular body 701 and which includes an inner circumferential cavity 706, and a plurality of flexible and elastically deformable fingers 703, wherein said fingers 703 project from the second tubular body 702 in a longitudinal direction of the insert 700.

As it can be seen, for example in Figures 20, 21 and 22, main tubular body 701 is provided with a plurality of protrusions 704 arranged around the circumference of main tubular body 701 and extending longitudinally, at most, as much as the length of said main tubular body 701, as well as a plurality of circumferential protrusions 705 formed on said main tubular body 701 and spaced apart from each other. Said longitudinal protrusions 704 are formed correspondingly (that is to say in position and quantity) with the longitudinal channels 105 of main body 100 such that together they guide insertion of insert 700, particularly of main tubular body 701, into the first inner tubular section 104 of main body 100. Likewise, said longitudinal protrusions 704 are able to prevent rotation of insert 700 relative the main body 100, which is particularly advantageous when screwing the extension nut 600 in the main body 100, as described below.

On the other hand, the circumferential protrusions 705 increase structural strength of the insert 700, in particular of the main tubular body 701, and improve fastening of the insert 700 in the main body 100 given that said circumferential protrusions 705 can be adjusted tightly to the surface of the first inner tubular section 104 of main body 100.

Continuing with Figures 20 to 23, it can be seen that the second tubular body 702 is designed in the form of a circumferential annular body projecting concentrically from an end of the main tubular body 701 and has an outer diameter greater than the outer diameter of main tubular body 701. In addition, making reference to Figure 23, the second tubular body 702 comprises the circumferential cavity 706 in an inner part thereof.

On the other hand, making reference to Figures 20, 23 and 24, it can be seen that the flexible fingers 703 of insert 700 are designed in such a manner comprising a base portion 703a adjoining the second tubular body 702 and a gripping portion 703b, wherein said gripping portion 703b of each finger projects extending radially inwardly at an angle a with respect to a longitudinal axis of the insert when seen from the front (see Figure 24). In addition, as seen in Figure 24, said flexible fingers 703 are arranged in a symmetrical polar pattern in the circumference of the second tubular body 702 and spaced apart by respective gaps 703c, such that the application of a radial compressive force (see for example Figures 42 to 44) onto the fingers 703 causes a radially inwardly deformation of the fingers so that they overlap to one another maintaining a cylindrically- shaped space between the gripping portions 703b.

As it can be seen for example in Figures 21 to 23, base portion 703 a is shaped including a step 703d. Said step 703d is intended to contact the circumferential recess 108 of main body 100, such that only the flexible fingers 703 remain outside the main body 100 when the insert 700 is introduced butt up against said main body 100 (see for example Figures 41 to 44).

In relation now to Figures 25 to 28, there are shown details of a cable seal 800 according to the present invention, which is preferably made of a rubber-based material, in particular of Buna-N, or a silicone-based material. Cable seal 800 comprises a tubular body 801, which is manufactured by using compression molding techniques known in the art. Said seal 800 is formed with an outer circumferential recess 802 at one of its ends, and with an inner circumferential recess 803 at the other end.

In relation now to Figures 29 to 31, there is shown the cable seal 800 snap fitted in a hollow inner space essentially formed by the plurality of fingers 703 and the inner circumferential cavity 706 of insert 700, in such a way that the portion comprising the inner circumferential recess 803 of cable seal 800 is at least partially accommodated inside the inner circumferential cavity 706 of insert 700 whereas the portion comprising the outer circumferential recess 802 of cable seal 800 contacts at least partially with an inner face of the gripping portion 703b of the fingers 703 of insert 700 (see for example Figure 31).

In this manner, the radially inwardly deformation caused on the plurality of flexible fingers 703 also causes radially inwardly deformation of, at least, the portion having the outer circumferential recess 802 and a portion of the tubular body 801 of cable seal 800.

In relation now to Figures 32 to 36, there are shown details of the lock nut 400 according to the present invention. Lock nut 400 comprises, on its outer part, a tubular section 401 and a nut section 402, and on its inner part it comprises a cavity (configured similar to a through hole) formed by a thread section 403, a conical section 404, and a cylindrical section 405, wherein the conical section 404 is arranged intermediate and adjacent the thread section 403 and the cylindrical section 405.

In use, said inner thread section 403 of the lock nut 400 can be screwed in the outer thread section 603 of extension nut 600 in order to close the connector assembly 1, as described below.

Alternatively, according to a preferred embodiment of the invention, inner thread section 403 can be screwed in the second outer thread section 103 of main body 100. To this end, connector assembly consists in a simplified form thereof (not shown in the drawings) which does not include the extension nut 600 but the lock nut 400 is screwed directly on the main body 100. However, this simplified form of the connector assembly is also able to produce a radially inwardly deformation of the insert 700 and cable seal 800 by means of the conical section 404 of lock nut 400 which thereby has the same or substantially the same design as the first conical section 605 of the extension nut 600 (see for example Figures 19 and 36).

In relation now to Figures 37 to 39, there are shown details of a ferrule 500, which is made of a silicone-based material, and which is manufactured preferably through compression molding. Said ferrule 500 comprises a center tubular section or body 501 and two slope end sections or bodies 502 each adjacent to each end of the center tubular section or body 501, and an inner bore 503 passing through the center 501 and end sections or bodies 502 with an even diameter, that is to say in the form of a cylindrical body.

Ferrule 500 is designed such that it can be introduced in a hollow space formed between the extension nut 600 and lock nut 400 (see Figure 43), and elastically deformed when said lock nut 400 is screwed tightly in the extension nut 600 (see Figure 44), described below.

In Figure 40 there is shown the connector assembly 1 exploded wherein the first outer thread section 101 of main body 100 is partially passed through an opening in the base plate P and the fixing nut 200 is partially screwed in the first outer thread section 101. It is also seen that lock nut 400, ferrule 500, extension nut 600, and sub-assembly of insert 700 and cable seal 800 are mounted on the fiber optic cable C, and said cable C has been passed through main body 100 and, therefore, also through base plate P such that a distal end of the cable C protrudes from both the base plate P and the fixing nut 200.

In relation now to Figures 41 to 44, a method of forming a connector assembly 1 in a base plate P of a fiber optic connection box according to the present invention will be described.

According to the method of the present invention, the main body 100, fixing nut 200, O-ring 300, lock nut 400, ferrule 500, extension nut 600, insert 700 and cable seal 800 are provided according to the present invention. Optionally, O-ring 300 and ferrule 500 may also be provided.

Subsequently, main body 100 is fixed in the opening of the base plate P with the aid of the fixing nut 200. Optionally, O-ring 300 may be installed such that it is at least partially received in the main body 100, in particular in the annular recess 109 (see for example Figure 10), and abutting against a front face of base plate P, as described above.

In a subsequent step of the method, cable seal 800 is at least partially mounted inside the insert 700, thus forming the sub-assembly 700-800 previously described (see for example Figures 29 to 31).

Said sub-assembly 700-800, according to an embodiment of the invention, can be at least partially introduced in the cavity of main body 100. Alternatively, according to another embodiment of the invention, said sub-assembly 700-800 is introduced in main body 100 in a subsequent step as described below.

Subsequently, there are positioned in sequence, starting from a distal end of the fiber optic cable C in a direction towards a proximal end thereof, the lock nut 400 and the extension nut 600. Optionally, according to a preferred embodiment of the invention, ferrule 500 can be positioned after positioning the lock nut 400 and before positioning the extension nut 600. In addition, optionally according to an embodiment of the invention, sub-assembly 700-800 can be positioned in the cable C after positioning the extension nut 600 (this applies for the embodiment of the method in which the sub-assembly has not been introduced in the main body 100 yet).

Then, distal end of cable C is passed through either the sub-assembly 700-800 and main body 100 fixed in the base plate P according to an embodiment of the invention or directly through the main body 100 (given that the sub-assembly 700-800 is already positioned in the cable C) according to another embodiment of the invention, to a position in which a substantial portion of the distal end of said cable C protrudes from the base plate P and main body 100.

Subsequently, while maintaining the fiber optic cable C in a substantially fixed manner, according to an embodiment of the invention, sub-assembly 700-800 is slid until it is at least partially introduced in the cavity of main body 100.

It can be appreciated here that, on the one hand, the sub-assembly 700-800 is guided inside the main body 100 because the longitudinal protrusions 704 follow the path defined by the longitudinal channels 105 of main body 100 and, on the other hand, it is ensured that the sub-assembly 700-800 is positioned butt up against the main body 100 when step 703d of insert 700 is received in the circumferential recess 108 of main body 100.

In a subsequent step of the method, extension nut 600 is screwed in the main body 100 to a position in which the first conical section 605 of extension nut 600 contacts with a distal end of insert 700, as shown in Figure 41.

Subsequently, as it can be appreciated in Figure 42, a further screwing-in of the extension nut 600 in the main body 100 is so produced as to cause a radially inwardly deformation of a portion of sub-assembly 700-800 thus creating a seal to the surface of the fiber optic cable C. It will be understood here that the sub-assembly 700-800 is kept in a substantially fixed position (that is to say hindered from rotating) and stable inside the main body 100 due to the combined action of the longitudinal 704 and circumferential 705 protrusions of the insert 700.

Then, as shown in Figure 43, both the ferrule 500 and lock nut 400 are brought into proximity to the extension nut 600 such that at least a portion of the center tubular section 501 and one of the end sections 502 are at least partially introduced in the cavity of the extension nut 600 such that an edge of the end section 502 contacts with the second conical section 607, and an edge of the other end section 502 contacts with conical section 404 of lock nut 400.

As it can be seen in Figure 44, lock nut 400 is screwed in the extension nut 600 thus causing deformation of the ferrule 500 in the hollow space formed by said extension nut 600 and said lock nut 400. In this way, ferrule 500 is deformed such that it at least partially protrudes out of the lock nut 400 thus ensuring a tight seal to the fiber optic cable C.

Thus, as it can be seen in Figure 44, connector assembly 1 allows to obtain a greater distance d than can be obtained with connector assemblies from the prior art. With these features, connector assembly of the present invention allows transferring and distributing the stress spot to a more stable inner zone of the connector assembly. In addition, connector assembly of the present invention presents two seal and stress-absorption areas, namely, a first seal and stress-absorption area provided by means of the insert and cable seal sub-assembly, and a second seal and stress-absorption area provided by means of the ferrule.

In the context of the present invention, terms "comprises", "comprising", "includes", "including", "has" and their conjugates should be understood as "including but not limited to". Likewise, terms "consists of and "consisting of should be understood as "including and limited to".

In addition, in the context of the present invention, the term "distal" should be understood as a position away from a technician installing the connector assembly in the base plate of the connection box, that is to say a position close to the connection box but away from the technician. Conversely, the term "proximal" should be understood as a position close to the technician installing the connector assembly, that is to say a position away from the connection box.

Likewise, it should be understood that other materials may be used for the components of the connector assembly of the present invention than those described in the present specification without departing from the spirit and scope of the invention.

Reader will appreciate that the features of the present invention described as independent or separate embodiments may also be provided in combination in a single embodiment without departing from the spirit and scope of the present invention. Conversely, features of the invention described or shown as a single embodiment for the purpose of brevity and simplicity may also be provided as independent or separate embodiments, which should be considered as included within the scope of the present disclosure.

Although the invention has been described and exemplified with the help of exemplary drawings showing embodiments of the invention, it will be understood that modifications and variations thereof will be apparent to a skilled person. Consequently, it is intended that such modifications and variations be included within the spirit and scope of the present invention as claimed in the enclosed claims.

LIST OF REFERENCES

1 connector assembly

100 main body

101 first outer thread section

102 nut section

103 second outer thread section

104 first inner tubular section

105 longitudinal grooves or channels

106 conical section

107 second inner tubular section

108 circumferential recess

109 annular recess

200 fixing nut

201 inner thread section

300 ring-shaped seal (O-ring)

400 lock nut

401 tubular section

402 nut section

403 inner thread section

404 conical section

405 cylindrical section

500 ferrule

501 center tubular section or body

502 slope end sections or bodies

503 through bore

600 extension nut

601 outer tubular section

602 nut section

603 outer thread section

604 inner thread section

605 first conical section

606 first inner tubular section 607 second conical section

608 second inner tubular section

700 insert

701 main tubular body

702 second tubular body

703 plurality of flexible and elastically deformable fingers

703a base portion of finger

703b gripping portion of finger

703c gaps

703d step

704 longitudinal protrusions

705 circumferential protrusions

706 inner circumferential cavity

800 cable seal

801 tubular body

802 outer circumferential recess

803 inner circumferential recess

C fiber optic cable

d distance between the base plate and a free end of cable outside the connector assembly

P base plate

a angle of radial projection of the gripping portions 703b of fingers 703 relative a longitudinal axis of the insert