Ruggedized fiber optic connector assembly

Robust fiber optic connector assembly.

Background of the invention

Field of the Invention

The present invention relates, in general, to a robust fiber optic connector assembly, also referred to as an "optical fiber" plug. More specifically, the present invention relates to a robust fiber optic connector assembly incorporating a retention body, or glued body, which is configured to both retain a fiber optic cable, preferably having one or more resistant members, as well as for coupling with a fiber optic receptacle or, alternatively, another fiber optic connector assembly.

Technical background of the invention

Fiber optic is used to an increasing extent for a variety of broadband applications, including voice, video and data transmission. As a result, fiber optic communications networks include a number of interconnection points, in which multiple optical fibers are interconnected. Fiber optic communications networks also include a number of connection terminals, the examples of which include, but are not limited to network access point closures (NAPs), aerial closures, low-level closures, pedestals, optical network terminals (ONTs), network interface devices (NIDs) and multi-port devices. In certain cases, the connection terminals include connector ports, which typically open through an external wall of the connection terminals, which are used to establish optical connections between optical fibers that are terminated from a distribution cable and optical fibers. respective of one or more connection lines with preconnector, extended distribution cables, cord cables, or branch cables, collectively referred to as "connection lines". The connection terminals are used to easily extend fiber optic communications services to a subscriber. In this regard, fiber optic communications networks are being developed that provide “fiber to the node” (FTTC), “fiber to the building's connection” (FTTB), “fiber to the home” (FTTH) and fiber to the establishment ”(FTTP), referred to generically as“ FTTx ”.

A conventional connector port that opens through an external wall of a connection terminal typically includes a receptacle that is configured to receive optical fiber with connector on the inner side of the terminal, and a connection line with connector on the outer side of the terminal. One of the coupling bushes is mounted on the end of an optical fiber that is optimally interconnected to at least one optical fiber of the distribution cable within the connection terminal. The other coupling bushing is mounted on the end of an optical fiber of a connection line that is inserted into the receptacle from the outer side of the connection terminal. An alignment sleeve of the receptacle typically aids in the alignment of the bushings, and guide pins of the bushings or other means of alignment can further assist in the precise alignment of multiple fiber bushings.

In particular, a plug mounted at one end of the connection line is coupled with a side of a corresponding receptacle. Typically, the plug includes a substantially cylindrical plug body, and a fiber optic connector that includes a plug socket disposed within the plug body. The end of the plug body is open, or is provided with one or more holes, such that the socket is accessible within the plug body, for example for cleaning. The bushing is mounted on the end of one or more optical fibers of the connection line, such that the coupling of the plug with the receptacle aligns the optical fibers of the connection line with the respective optical fibers terminated from the distribution cable inside the connection terminal. In the process of coupling the plug with the receptacle, the socket is inserted into one end of the alignment sleeve housed within the receptacle. As a result of the construction of a conventional plug, the alignment sleeve is received to a minimum extent within the open end of the plug body when the socket is inserted into the alignment sleeve. As an alternative to the above, the plug mounted at the end of the connection line is coupled with a plug mounted at the end of another connection line or another receptacle not associated with a connection terminal, such as the one associated with an establishment, a house, a building, etc.

Several different types of conventional connectors have been developed, the examples of which include, but are not limited to SC, ST, LC, MTP, MT-RJ and SC-DC. The size and shape of the socket of each of these connectors are somewhat different. Correspondingly, the size and shape of the sleeve body and the alignment sleeve are somewhat different. As a result, in conventional practice, different plugs and receptacles are used in combination with different bushings. In this regard, the receptacles generally define internal cavities of different sizes and characteristics that correspond to alignment sockets and plug bodies of different sizes and, in turn, different sockets arranged within the plug bodies and alignment sleeves.

With reference to Figure 1 of the prior art, a conventional connector 10 includes a plug housing 12, in which an crimping body 14 is included axially including two halves 14a, 14b and a crimping tape 16 during assembly. A thermal retraction 18 is also used, as described in more detail below. Collectively, the crimping body 14 and crimping tape 16 both retain a connection line 20 and a connector sub-assembly 22 (i.e., a pre-assembled bushing support module), where the connector sub-assembly 22 retains a bushing 24. Specifically, a rod 25 of the connector sub-assembly 22 is secured between the two halves 14a, 14b of the crimping body 14. As a result, an optical fiber of the connection line 20 and the bushing 24 are optimally connected. The thermal retraction 18 is arranged around an end portion of the plug housing 12 and an end portion of the connection line 20, thereby providing some tension retention and relief force, and a flexible environmental seal . As illustrated, the connection line 20 is an individual fiber connection line and the bushing 24 is an individual termination bushing, although other types of connection lines, optical fibers and bushes could be used with other types of connectors. This inner assembly is partially housed within a coupling nut 26 that is externally threaded, such that the connector 10 is configured to engage with the internal thread of an alignment sleeve of a receptacle (not shown), thus aligning and optically coupling the socket 24 of the connector 10 and a socket of the receptacle. As described above, guide pins or other alignment means can aid in more precise alignment of multi-fiber bushes. For example, the end of the plug housing 12 and the alignment sleeve and / or the receptacle may be keyed. The connector 10 also includes one or more silicone O-rings 28 that seal the connector 10 and the receptacle, when connected together, and a sleeve 30 that relieves the tension in the connection line 20. Finally, the connector 10 incorporates one or more dust caps 32, 34, which are used to selectively protect the socket 24 and the exposed end of the plug housing 12. Preferably, the largest of the dust caps 34, also referred to as "traction cap" is internally threaded, such that it is configured to engage with the outer thread of the coupling nut 26. Finally, the traction cap 34 is secured to the sleeve 20 through a plastic collar 36 or other retaining means, such that the traction cap 34 cannot be easily lost. The connector 10 provides a hardened connector for deployment on the outer side of the plant and incorporates an integral traction eyelet 38 designed for tensile stress.

However, until now there is an unresolved need for an alternative (or additional) retention method to deal with otherwise incompatible rugged connection line members, such as robust fiber reinforced plastic (GRP) members and the like. The manipulation and coupling of the two halves 14a, 14b of the crimp body 14 described above often apply excessive tension and endanger the optical fiber (which typically has a diameter of approximately 250 µm) during termination. In addition, the crimp design alone is not robust enough to meet tensile stress requirements, the use of an adhesive being necessary. This adhesive rigidly fixes the connector sub-assembly, eliminating the ability to compensate for radial deviation due to manufacturing tolerances. This radial deviation can be compensated, however, by "flotation" of the adapter, in a plug-to-plug arrangement, but there is no such flotation element. Therefore, manufacturing tolerances become much stricter. Still further, this crimping design, which incorporates the thermal retraction 18 is based on a hard stop of the plug housing 12 against the coupling nut 26 and, ultimately, the thermal retraction 18 proper to maintain the connection line 20 and the connector sub-assembly 22 in the same position during the process and use. In a high temperature environment, and due to improper mooring during the application of thermal retraction 18, the plug housing 12 is allowed to move axially and change position. Until now there is also an unresolved need for an alternative retention method that does not allow multiple ways (i.e., two opposite 180 degree modes) to mount the connector components, with mooring and verification by an operator being necessary to ensure that the connector sub-assembly 22 is properly oriented. Sometimes, this requires cutting a good connector when the orientation of the extreme face angle is incompatible, resulting in scrap cuts.

US-A1-5129023 describes a connector with the features of the preamble of claim 1.

US-B1-6224270 describes a fiber optic connector having a bushing fixed to a tubular member, that is, a bushing support The assembly, that is, the plug, the bushing and the tubular member are movable with respect to the cylindrical tube by spring. The cylindrical tube does not engage and retains an optical cable.

Another prior art is known from US-A1-2005 / 0069264.

Summary of the invention

In one embodiment of the present invention, a robust fiber optic connector assembly includes a substantially hollow plug housing; and a retention body disposed within the substantially hollow plug housing; wherein the retention body includes a first portion that is configured to engage and retain an optical cable comprising an optical fiber and one or more robust members; wherein the retention body includes a second portion that is configured to engage and retain a connector subset comprising an optical bushing; wherein the second portion of the retention body includes a pair of opposite elastic snap hooks that are configured to engage with a corresponding pair of opposite recesses of the connector sub-assembly; and in which the optical fiber and the optical bushing are optimally coupled.

In another embodiment of the present invention, a robust fiber optic connector assembly includes a substantially hollow plug housing; and a glued leather disposed within the substantially hollow plug housing; wherein the glued body includes a first portion that is configured to engage and retain an optical cable comprising an optical fiber and one or more robust members; wherein the glued body includes a second portion that is configured to engage and retain a connector subset comprising an optical bushing; wherein the second portion of the glued body includes a pair of opposite elastic snap hooks that are configured to engage with a corresponding pair of opposite recesses of the connector sub-assembly; and in which the optical fiber and the optical bushing are optimally coupled.

Additional features and advantages of the present invention according to claim 1 will be indicated in the detailed description that follows, which explains the principles and operations thereof and which will also be apparent to ordinary technicians in the field from the description and / or will be recognized by the practice of the invention, as described. It is understood that the above general description and the following detailed description present exemplary embodiments of the invention, which are intended to provide an overview and a framework for understanding the nature and character of the invention, as claimed. The accompanying drawings are incorporated and constitute a part of this specification, further illustrating and clarifying the exemplary embodiments of the present invention.

Brief description of the drawings

Figure 1 is an exploded perspective and exploded view of a conventional connector.

Figure 2 is a perspective view of an embodiment of the connector assembly of the present invention.

Figure 3 is a fragmentary perspective view of the connector assembly of Figure 2, illustrating the use of a glued body that is configured to retain a connection line, which has one or more robust members, and a subset of connector

Figure 4 is another fragmentary perspective view of another assembly of Figure 2, illustrating the use of a glued body that is configured to retain a connection line, which has one or more robust members, and a connector sub-assembly. .

Figure 5 is an isolated perspective view of the assembled glued body and the connector sub-assembly of Figures 3 and 4.

Figure 6 is an isolated perspective view of the glued body of Figures 3 to 5.

Figure 7 is another perspective view isolated from the glued body of Figures 3 to 5, illustrating the union of a substantially flat connection line incorporating an optical fiber and a pair of robust GRP members with the glued body.

Figure 8 is an isolated perspective view of an end cap used in combination with the connector assembly of Figure 2.

Detailed description of the preferred embodiments

Reference will now be made in detail to the preferred embodiments of the present invention, the examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numbers will be used to refer to similar components or parts.

Referring to Figure 2, the connector assembly 40, also referred to herein as a "plug", of the present invention includes a plug housing 42 containing a connector sub-assembly 44 (ie, a support module of pre-assembled bushing), where the connector sub-assembly 44 carries a bushing 46. The connector sub-assembly 44 and the socket 46 are accessible through an open end of the plug housing 42, such that the socket can be optimally connected to the socket of a receptacle or other connector assembly,

or plug The envelope plugs 48 of the connector assembly 40 are reduced in length compared to the conventional connector 10 (Figure 1) in order to allow two connector sets to be better coupled together, among other things. Any reduced protection that results is compensated for by increasing flexibility in situations that require a more protruding bushing 46. The more protruding bushing 46 also allows for more efficient pre-assembly and termination, including polishing, etc. The keyed configurations of the inner assembly and the bushing housing 42 of the connector assembly 40 require that the connector assembly 40 be mounted in a specific orientation, as described in more detail below. This satisfies the unresolved need for an alternative retention method that does not allow multiple ways (that is, two opposite 180 degree ways) to assemble the connector components, thereby eliminating the requirement of mooring and verification by an operator with the In order to ensure that the connector sub-assembly 44 is oriented properly. The other end of the plug housing 42 is more open compared to the conventional connector 10. This fact and the configuration of the end cap 50 used, described in more detail below, allow a relatively free bending movement of the plug housing 42 relative to a substantially flat connection line 52 incorporating one or more sturdy members of GRP 54 (Figures 3, 4 and 7) or the like, for example. The one or more silicone O-rings 28 (Figure 1) of the conventional Optitap 10 connector can be replaced by an individual O-ring 56 integrally formed and overmoulded, which is disposed within a recessed channel 58 which is manufactured within the outer surface of the plug housing 42. Optionally, the outer surface of the socket housing 42 includes a member of suitable grip surfaces.

Referring to FIG. 3, internally, the connector assembly 40 includes a retaining body 60, or glued body, having a pair of elastic snap hooks 62 configured to engage with a recess pair 64 of fabricated elastic snap hooks on opposite sides of the connector sub-assembly 44, so that the elastic snap hooks 62 hold the connector sub-assembly 44 against the glued body 60 once it is "elastically engaged" in position. Each of these elastic snap hooks 62 comprises a protruding "tongue" member having a "hooked" end. Because the tongue members have a degree of flexibility, they deviate out of place or bend as the connector sub-assembly 44 is pressed between them and "elastically fit" back in position when the hooked ends of The tongue members are coupled with recesses 64 of elastic lace hooks. Once the plug housing 42 is secured on the retaining and engaging body by elastic engagement, an inner surface of the plug housing 42 can contact the outer surface of the elastic snap hooks 62, keeping the snap hooks 62 elastic within recesses 64 of elastic lace hooks. Advantageously, the elastic snap hooks 62 or other retention feature of the sub-assembly allow the connector sub-assembly 44 to rotate slightly (± approximately 5 degrees maximum) around the axis of the glued body 60 and the connector assembly 40 , since recesses 64 of elastic lace hooks are slightly oversized with respect to elastic lace hooks 62. The pairs of connectors will self-align below approximately 45 degrees, if there is adequate chamfer and inlet detail, so that the retention feature of the subset allows the connector subset 44 to rotate less than about 45 degrees. This inherent radial flotation reduces the rigor of the manufacturing tolerances involved. This is especially important in an online application, where two connector assemblies are aligned relatively rigidly with respect to each other in order to meet mechanical performance requirements. In such applications, an alignment sleeve disposed between the connector assemblies is often not able to properly fit both connector assemblies, which may have opposite orientations. The rod 25 (figure 1) of the connector sub-assembly 44 is preferably arranged and retained within a bore 66 (figure 6) manufactured at the end of the glued body 60 having the elastic snap hooks 62. This end also includes a pair of alignment blocks 68 that are designed to ensure proper positioning of the connector sub-assembly 44 on the face of the glued body 60.

With reference to Figures 4 and 5, the glued body 60 is coupled with the plug housing 42 (Figure 4) by means of one or more recesses 70 made on the outer surface of the glued body 60 and one or more projections 72 (Figure 4) corresponding manufactured in the inner surface of the plug housing 42. Accordingly, the glued body 60 is "elastically fitted" in position inside the plug housing 42. Again, the selected materials facilitate this and one or both recesses 70 or projections 72 may have complementary angled surfaces. Advantageously, this mechanical retention of the glued body 60 inside the plug housing 42 alleviates the problem of the variation of the position of the end face due to the thermal retraction piston movement. Most importantly, the outer surface of the glued body 60 and the inner surface of the plug housing 42 also include corresponding flattened and raised surfaces. Therefore, the keyed configurations of the glued body 60 and the plug housing 42 of the connector assembly 40 (Figure 4) require that the connector assembly 40 be mounted in a specific orientation. Again, this satisfies the unresolved need for an alternative retention method that does not allow multiple ways (i.e., two opposite 180 degree ways) to mount the connector components, thereby eliminating the requirement of mooring and verification by a operator in order to ensure that the connector sub-assembly 44 is properly oriented. The geometries involved are based on material flexibility and use minor localized interferences between the semi-rigid bodies involved to determine molding tolerances, while maintaining mechanical integrity.

With reference to FIG. 6, the glued body 60 includes a relatively larger diameter portion 74 and a relatively smaller diameter portion 76, the portion of larger diameter 74 being located near the end of the glued body 60 having the snap hooks 62 elastic and the smaller diameter portion 76 being located at a distance from the end of the glued body 60 having elastic snap hooks 62. When the glued body 60 is inserted into the plug housing 42, this larger diameter portion 74 acts as a natural stop as it contacts a ledge 78 fabricated on the inner surface of the plug housing 42 (see Figure 4) . As described above, the rod 25 (Figure 1) of the connector sub-assembly 44 (Figures 2 to 5) is preferably arranged and retained within the bore 66 manufactured at the end of the glued body 60 having the hooks 62 of elastic lace. This end also includes the pair of alignment blocks 68 that are designed to ensure proper positioning of the connector sub-assembly 44 on the face of the glued body 60 in combination with the elastic snap hooks 62.

In an alternative embodiment, the rod 25 of the connector sub-assembly 44 is arranged and held between the two halves 14a, 14b (figure 1) of the previous crimping body 14 (figure 1) which has now been removed. These are arranged, in turn, inside the bore 66 made at the end of the glued body 60 which has elastic snap hooks 62. As indicated above, these keep the connector sub-assembly 44 centered with respect to the glued body 60 and the plug housing 42. In another alternative embodiment, the two halves 14a, 14b of the previous crimping body 14 are combined in a single crimping retainer (not shown) that is disposed within the bore 66 manufactured at the end of the glued body 60 having the elastic snap hooks 62. Again, this keeps the connector sub-assembly 44 centered with respect to the glued body 60 and the plug housing 42.

Referring to FIG. 7, the glued body 60 also includes a central channel 80 positioned to receive at least one optical fiber 82 of the connection line 52 and a pair of marginal channels 84 positioned to receive robust members of GRP 54 and other members robust connection line 52. The optical fiber 82 (which typically has a diameter of approximately 250 µm) and the pair of robust GRP members 54 are embedded within a connection line sheath 86, as is well known to those of ordinary skill in the art. Although robust members of GRP 54 are illustrated and described here, connection line 52 may also include other types of robust members, or as an alternative. Any robust member of this type can be housed by one or more channels made in the glued body 60. Preferably, the pair of robust GRP members 54 project between approximately 10 mm and approximately 20 mm (and more preferably, approximately 17 mm) in the pair of marginal channels 84 and the marginal channels 84 are filled with an adhesive which serves to adhere the connection line 52 to the glued body 60. The adhesive may be a hardenable epoxy resin with visible light, or an ultraviolet (UV) light or heat-hardenable glue. All material selections depend on tensile strength, temperature exposure range and desired chemical resistance. In the case where a hardenable epoxy resin is used with visible light, the glued body 60 is preferably substantially transparent, such that visible light can reach and harden the epoxy resin. For example, a natural poly imide ether can be used, which also provides a relatively high temperature resistance. This substantially transparent material allows visual feedback during adhesive filling and fiber optic routing processes. Advantageously, the pair of marginal channels 84 separate the adhesive from the central channel 80 and the optical fiber 82. Because the marginal channels 84 are sealed, the material is prevented from flowing into the connector assembly 40 (Figures 2 a 4) during assembly. The connector assembly 40 of the present invention easily meets the desired requirement of 100 lbf of tensile strength, due to the use of the glued body 60 and the adhesive. During assembly, preferably, the connection line 52 is secured first to the glued body 60 and then the connector sub-assembly 44 (figures 2 to 5) is fixed to the glued body 60.

In an alternative embodiment, the pair of marginal channels 84 are configured to accept a pair of wedge type clamps, which are held in position by a pair of unsealed tapes. These wedge-type clamps and non-crimped tapes are subsequently fixed on the robust GRP members 54 by means of crimping, thus securing the connection line 52 to the glued body 60. This represents a non-adhesive solution.

With reference to Figure 8, the end cap 50 described above includes an insertion end 88 that is configured to be inserted tightly into the "rear" end of the plug housing 42 (Figures 2 and 3). The end cap 50 also includes a conical end 90 that is made of a slot opening 92 that is configured to receive the substantially flat connection line 52 (Figure 7), which passes through the end cap 50 and into the housing. plug 42.

As described above, the retaining body 60 of the present invention is coupled to the connector subassembly 44 by means of elastic snap retention hooks 62. In conventional connector assemblies, the movement of the optical fibers and / or of the robust members can cause over time that the connector assembly, including the bushing, protrudes or pushes outward relative to the outer casing of the connector or connector housing , resulting in the connection line being damaged making it incapable of proper interconnection. Stoppers positioned around the projection 72 can prevent the retention body 60, once elastically fitted into position, is removed through the front or connecting end of the plug assembly. Therefore, as the sturdy fibers or members push forward in the retention body 60, the movement of the retention body inside the plug housing 42 beyond a predetermined point can be stopped. By coupling the connector sub-assembly 44 with the retaining body 60, it is also prevented that the connector sub-assembly is projected beyond a

5 predetermined point, providing a connection line capable of adequate interconnection over time. In a form of retention, the plug housing 42, the retention body 60 and its contact points are capable of withstanding forces of up to 50 lbs.

Although the present invention has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be apparent to ordinary technicians in the art that other forms of

10 embodiment and examples can perform similar functions and / or achieve similar results. For example, the coupling of two connector assemblies could be achieved by providing a "female" version of the connector assembly (ie, an output). The coupling order would be plug-output-plug.