FIBER OPTIC STRAIN RELIEF AND ASSOCIATED ASSEMBLIES

Abstract

A strain relief for a fiber optic assembly is provided including a base, a forward cable channel, a rear cable channel aligned with the at least one forward cable channel along a longitudinal axis, and an offset post disposed between the at least one forward cable channel and the at least one rear cable channel. Each of the forward cable channel and the rear cable channel includes a first post and a second post extending from the base. The offset post is disposed along the longitudinal axis, such that when an optical cable is installed into the strain relief the optical cable bends around the offset post out of the longitudinal axis.

Claims

1. A strain relief for a fiber optic assembly, the strain relief comprising: a base; at least one forward cable channel; at least one rear cable channel aligned with the at least one forward cable channel along a longitudinal axis, wherein the at least one rear cable channel is spaced apart from the at least one forward cable channel longitudinally at a first distance; and at least one offset post disposed between the at least one forward cable channel and the at least one rear cable channel, wherein each of the at least one forward cable channel and the at least one rear cable channel comprises a first post and a second post extending from the base, and wherein the first post is spaced apart from the second post laterally at a second distance, and wherein the at least one offset post is disposed along the longitudinal axis, such that when an optical cable is installed into the strain relief the optical cable bends around the at least one offset post out of the longitudinal axis.

2. The strain relief of claim 1, wherein the at least one forward cable channel comprises a plurality of forward cable channels, the at least one rear cable channel comprises a plurality of rear cable channels, and at least one the offset post comprises a plurality of offset posts, and wherein the strain relief is configured to receive a plurality of optical cables.

3. The strain relief of claim 2, wherein the plurality of offset posts form at least one offset cable channel.

4. The strain relief of claim 2, wherein the second post of a first cable channel of the plurality of forward cable channels is the first post of a second cable channel of the plurality of forward cable channels.

5. The strain relief of claim 1 further comprising: a wall extending along at least a portion of a perimeter of the base, wherein the first post or the second post of the at least one forward cable channel or the at least one rear cable channel is integral to the wall.

6. The strain relief of claim 1, wherein the first post or the second post is planar.

7. The strain relief of claim 1, wherein the base is configured to be selectively attached to the fiber optic assembly.

8. The strain relief of claim 1, wherein the second distance comprises about 2 mm.

9. The strain relief of claim 1, wherein the strain relief comprises a monolithic plastic component.

10. A fiber optic assembly comprising: a connection base; a plurality of optical connection holders; and a strain relief comprising: a base; at least one forward cable channel; at least one rear cable channel aligned with the at least one forward cable channel along a longitudinal axis, wherein the at least one rear cable channel is spaced apart from the forward cable channel longitudinally at a first distance; and at least one offset post disposed between the at least one forward cable channel and the at least one rear cable channel, wherein each of the at least one forward cable channel and the at least one rear cable channel comprises a first post and a second post extending from the base, and wherein the first post is spaced apart from the second post laterally at a second distance, wherein the at least one forward cable channel and the at least one rear cable channel are aligned about a longitudinal axis; and wherein the at least one offset post is disposed along the longitudinal axis, such that when an optical cable is installed into the strain relief the optical cable bends around the at least one offset post out of the longitudinal axis.

11. The strain relief of claim 10, wherein the at least one forward cable channel comprises a plurality of forward cable channels, the at least one rear cable channel comprises a plurality of rear cable channels, and at least one the offset post comprises a plurality of offset posts, and wherein the strain relief is configured to receive a plurality of optical cables.

12. The strain relief of claim 11, wherein the plurality of offset posts form at least one offset cable channel.

13. The strain relief of claim 11, wherein the second post of a first cable channel of the plurality of forward cable channels is the first post of a second cable channel of the plurality of forward cable channels.

14. The strain relief of claim 10 further comprising: a wall extending along at least a portion of a perimeter of the base, wherein the first post or the second post of the at least one forward cable channel or the at least one rear cable channel is integral to the wall.

15. The fiber optic assembly of claim 10, wherein the first post or the second post is planar.

16. The fiber optic assembly of claim 10, wherein the base is integral to the fiber optic assembly.

17. The fiber optic assembly of claim 10, wherein the base is configured to be selectively attached to the fiber optic assembly.

18. The fiber optic assembly of claim 10, wherein the second distance comprises about 2 mm.

19. The fiber optic assembly of claim 10, wherein the strain relief comprises a monolithic plastic component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the written description, it is believed that the specification will be better understood from the following written description when taken in conjunction with the accompanying drawings, wherein:

[0015] FIG. 1 is a schematic diagram of an exemplary FTTx network according to an example embodiment;

[0016] FIG. 2 is a perspective view of a fiber optic assembly according to an example embodiment;

[0017] FIG. 3 illustrates a top down view of the fiber optic assembly of FIG. 2 with the lid open to show internal features according to an example embodiment;

[0018] FIG. 4 illustrates a top down view of a fiber optic assembly with the lid open to show internal features according to an example embodiment;

[0019] FIG. 5 illustrates a perspective view of the fiber optic assembly of FIG. 2 with the lid open to show internal features according to an example embodiment; and

[0020] FIG. 6 illustrates a top down view of a strain relief associated with the fiber optic assembly according to an example embodiment.

[0021] The embodiments set forth in the drawings are illustrative in nature and not intended to be limiting of the scope of the detailed description or claims. Whenever possible, the same reference numeral will be used throughout the drawings to refer to the same or like feature. The drawings are not necessarily to scale for ease of illustration an explanation.

DETAILED DESCRIPTION

[0022] The present disclosure is provided as an enabling teaching and can be understood more readily by reference to the following description, drawings, examples, and claims. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the embodiments described herein, while still obtaining the beneficial results. It will also be apparent that some of the desired benefits of the present embodiments can be obtained by selecting some of the features without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations are possible and can even be desirable in certain circumstances and are a part of the present disclosure. Therefore, it is to be understood that this disclosure is not limited to the specific compositions, articles, devices, and methods disclosed unless otherwise specified. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

[0023] The claims set forth below are incorporated by reference into this Detailed Description section.

[0024] Terms like forward, rear, front, back, top, bottom, side, etc. are relative terms used for convenience and ease of explanation and are not intended to be limiting.

[0025] In an FTTx network, fiber optic cables are used to carry optical signals to various distribution points and, in some cases, all the way to end subscribers. For example, FIG. 1 is a schematic diagram of an exemplary FTTx network 10 that distributes optical signals generated at a switching point 12 (e.g., a central office of a network provider) to subscriber premises 14. Optical line terminals (OLTs; not shown) at the switching point 12 convert electrical signals to optical signals. Fiber optic feeder cables 16 then carry the optical signals to various local convergence points 18, which act as locations for splicing and making cross-connections and interconnections. The local convergence points 18 often include splitters to enable any given optical fiber in the fiber optic feeder cable 16 to serve multiple subscriber premises 14. As a result, the optical signals are “branched out” from the optical fibers of the fiber optic feeder cables 16 to optical fibers of distribution cables 20 that exit the local convergence points 18.

[0026] At network access points closer to the subscriber premises 14, some or all of the optical fibers in the distribution cables 20 may be accessed to connect to one or more subscriber premises 14. Drop cables 22 extend from the network access points to the subscriber premises 14, which may be single-dwelling units (SDU), multi-dwelling units (MDU), businesses, and/or other facilities or buildings. A conversion of optical signals back to electrical signals may occur at the network access points or at the subscriber premises 14.

[0027] There are many different network architectures, and the various tasks required to distribute optical signals (e.g., splitting, splicing, routing, connecting subscribers) can occur at several locations. Regardless of whether a location is considered a switching point, local convergence point, network access point, subscriber premise, or something else, fiber optic equipment is used to house components that carry out one or more of the tasks. The fiber optic equipment may be assemblies that include drawers, trays, or modules to facilitate the tasks. The term “fiber optic assembly” will be used in this disclosure to generically refer to such equipment (or at least portions thereof). Typically such equipment is located at the switching points 12 in an FTTx network, although this disclosure is not limited to any particular intended use. Further, although an FTTx network 10 is shown in FIG. 1, the same considerations apply with respect to other types of telecommunication networks or environments, such data centers and other enterprise network environments. Like switching points (central offices), data centers may include fiber optic equipment having drawers, trays, modules or the like. In some cases subscriber premises 14 may have one or more SDUs or MDUs having drawers, trays, or modules.

[0028] FIG. 2 is a perspective view of a fiber optic assembly 100 according to an example embodiment. The fiber optic assembly 100 may include a connection base, or base 102, providing a volume to make one or more optical connections between optical fibers, such as but not limited to splice connections, splitter connections and/or patch connections. In some embodiments, a lid 104 may be provided to enclose at least a portion of the volume between the base 102 and the lid 104. The base 102 and lid 104 may be formed or plastic, metal, or other suitable material.

[0029] In an example embodiment, the fiber optic assembly 100 may include one or more ports 106, to provide entry of an optical cable into the volume. In the depicted example, the fiber optic assembly 100 includes two ports disposed at opposite ends of the fiber optic assembly 100. To enable access to the volume of the fiber optic assembly where a lid 104 is provided, a hinge 108 may be disposed between the base 102 and the lid 104. The hinge 108 may be configured to enable the lid 104 to transition between an open position and a closed position, where access to the volume is prevented in the closed position and enabled in the open position. additionally or alternatively, snap features, screws, or other suitable components may be included to selectively remove the lid 104 from the base 102.

[0030] In some example embodiments, the fiber optic assembly 100 may include connection features 110. The connection features 110 may be configured to enable one fiber optic assembly to attach to a second fiber optic assembly 100. For example, the base 102 of the fiber optic assembly 100 may have to longitudinal sides each including a connection feature 110. The connection feature 110 of the first longitudinal side may be complementary to the connection feature 110 of the second longitudinal side, such as a dove tail joint. When the connection features 110 of a first longitudinal side of a first fiber optic assembly 100 slide longitudinally into the complementary connection feature 110 of a second side of a second fiber optic assembly 100. The connection features 110 may connect the two fiber optic assemblies 100 to each other. In some example embodiments, the connection features 110 of the receiving longitudinal side, may have a flare or funnel shape to encourage alignment of the connection features 110 as the fiber optic assemblies are connected. Other connection features, such as snap features, tabs, or the like are also contemplated to enable expandability of the fiber optic assemblies 100.

[0031] FIG. 3 illustrates a top down view of the fiber optic assembly 100 with the lid 104 open to show internal features according to an example embodiment. In some example embodiments, the lid 104 may include structural features 115 to increase the strength and or rigidity of the lid 104. The structural features 115 may be integral to the lid 104, such as formed during a common molding process. The structural features 115 may be raised patterns of material disposed on one or both sides of the lid 104, for example lines, triangles, honeycomb, or any other suitable pattern. Additionally, or alternatively, the lid 104 may include one or more closure features 107, such as detents or protrusions, configured to engage complementary closure features disposed on the base 102. The closure features 107 may be configure to limit or resist opening of the fiber optic assembly 100.

[0032] Turning to the internal features of the base 102, the base 102 may include one or more optical connection holders 122. For example, the base 102 may include one or more splice holders or adapter holders. The optical connection holders 122 may limit or restrict movement of optical connections between optical cables, thereby preventing damage or signal attenuation at the optical connection. In addition to the optical connection holders 122, the base 102 may also include one or more cable routing features configured to route incoming and outgoing optical cables to align the optical connections, as well as to provide storage for cable slack. The cable routing features may include one or more bend radius protectors 124 configured to enable a change in the direction of the routing of an optical cable while ensuring that the optical cable does not exceed a minimum bend radius. The minimum bend radius may be predetermined to limit or prevent damage to the optical cable or signal attenuation due to excessive bend radii. The cable routing features may also include one or more cable retention features 126. The cable retention features 126 may include one or more projections that are substantially parallel with the base 102. The projections may extend from a side wall of the base 102 and/or the bend radius protectors 124. The cable retention features 126 may be configured to maintain the optical cable proximate to the base 102 and/or to limit or prevent uncoiling of the routed optical cable. In some example embodiments, the cable retention features 126 may include a access feature configured to transition the optical cable from outside the cable retention features 126 to inside the cable retention features 126, for example the access feature may be a gap provided in the retention feature. In some example embodiments the gap may be angled relative to the direction of routing the optical cable to further resist inadvertent removal of the optical cable.

[0033] The base 102 may include one or more strain reliefs 120. The strain reliefs 120 may be provided proximate to one or more of the ports 106, such as to provide axial strain protection to the optical cable routed into the fiber optic assembly 100. The strain reliefs 120 may limit or prevent axial force applied to the optical cable from outside of the fiber optic assembly from being translated to the optical connections hosed therein. The strain reliefs 120 are discussed below, in FIGS. 5 and 6, in greater detail.

[0034] FIG. 4 illustrates a top down view of a fiber optic assembly 100′ with the lid open to show internal features according to an example embodiment. The depicted fiber optic assembly 100′ is similar to the fiber optic assembly 100 discussed above. However, the fiber optic assembly 100′ is configured to hold twice as many optical connections and route the associated increase in optical cable. As such the fiber optic assembly 100′ is approximately twice the width of the fiber optic assembly 100, discussed above.

[0035] FIG. 5 illustrates a perspective view of the fiber optic assembly 100 discussed above in reference to FIGS. 2 and 3. The perspective view of the fiber optic assembly 100 provides a view of the profile of features of the strain relief 120. The strain relief 120 may include one or more cable channels configured to receive one or more optical cables therein. The cable channels may have a generally rectangular shape having a substantially planar bottom surface and two opposing planar wall extending upward from the base 102. In an example embodiment, the cable channels may be configured to receive non-round optical cables, such as Pixian or “butterfly” optical cables. In some embodiments, the cable channels may be configured for an interference or friction fit of Pixian optical cables, for example the cable channels may have a width of approximately two (2) mm and a height of approximately three (3) mm corresponding to the outer dimensions of a Pixian optical cable. In further embodiments, the cable channels may have a width of approximately two (2) mm and a height of approximately six (6) mm, enabling two Pixian optical cables to be inserted into a cable channel in a stacked configuration.

[0036] The strain relief 120 may be integral to the fiber optic assembly 100 or a portion of the fiber optic assembly 100, such as the base 102. In such an embodiment the strain relief 120 may be formed in a common mold process with the base 102. Alternatively, the strain relief 120 may be selectively removable from the fiber optic assembly 100, such that strain reliefs for different optical cable types may be inserted into the fiber optic assembly 100. The different strain reliefs may be strain reliefs 120 discussed herein with one or more different cable channel widths or heights based on the width or height of the intended optical cable.

[0037] Turning now to FIG. 6 a top down view of the strain relief 120 associated with the fiber optic assembly 100 is illustrated to show routing of an optical cable 140. The strain relief 120 may include a base 121 and two cable channels that are substantially aligned with one another along a longitudinal axis A. The two cable channels include a forward cable channel 131 and a rear cable channel 133. The rear cable channel 133 is spaced apart from the forward cable channel 131, longitudinally, at a first predetermined distance. The strain relief 120 may also include an offset post 134 disposed between the forward cable channel 131 and the rear cable channel 133. Each of the forward cable channel 131 and the rear cable channel 133 includes a first post 130a,132a and a second post 130b,132b, respectively, extending outward from the base 121. The first post 130a,132a is spaced apart from the second post 130b,132b, laterally, at a second predetermined distance. For example, the second predetermined distance may be approximately the outer diameter of the intended optical cable 140, such as about two (2) mm in the case of Pixian cable. The correspondence between the width of the cable channels 131,133 and the outer diameter of the optical cable 140 may enable a toolless interference or friction fit in the cable channels 131, 133. The offset post 134 is disposed along the longitudinal axis, such that when the optical cable 140 is installed into the strain relief 120 the optical cable bends around the offset post 134 out of the longitudinal axis A. When an axial force is applied to the optical cable 140, the optical cable 140 is pulled laterally against the offset post 134, which increases a friction applied to the optical cable 140, thereby resting axial movement. The strain relief 120 may be configured to correspond and cooperate with the width of the optical cable 140 including a protective cable jacket, such as two (2) mm in width for Pixian cable. As such, valuable installation time may be saved by not having to strip the optical cable and install a buffer tube prior to installation, which is the case in traditional strain relief of Pixian cable, as well as other optical cable types.

[0038] The posts 130, 132 may have a generally rectangular prism shape, e.g. the posts 130, 132 may be elongated in the longitudinal direction parallel with the longitudinal axis A of the cable channels 131,133. The rectangular prism may include generally planar sidewalls. A rectangular prism shape of the posts 130,132 is discussed herein, however other posts shapes are also contemplated, such as cylindrical, ellipsoid, or other suitable shapes. In some embodiments, the posts 130, 132 may include corners configured to bite into the protective cable jacket of the optical cable 140 to further resist axial movement of the optical cable 140 in the cable channels 131, 133 when a axial force is applied. In alternative embodiments, the edges of the posts 130,132 may be rounded.

[0039] In an case in which the optical cable 140 needs to be removed, such as to reroute or replace the optical cable 140, the optical cable 140 may be lifted out of the cable channels by simply pulling the optical cable 140 up out of the cable channels 131, 133. This toolless removal of the optical cable may greatly reduce time and effort of an installer rerouting or replacing optical cables. In addition, the installer may be less likely to damage the optical cable 140 during removal or caused to simply cut off the cable at the strain relief and reperform any optical connection procedures.

[0040] In an example embodiment, the strain relief 120 may include a plurality of forward cable channels 131, a plurality of rear cable channels 133, and a plurality of offset posts 134 to accommodate a corresponding plurality of optical cables 140. In some such embodiments, the plurality of offset posts 134 form an offset cable channel 135. The optical cable 140 may be routed between offset posts of the offset cable channel 135 in a manner similar to the forward cable channel 131 or the rear cable channel 133, as discussed above. Similarly, adjacent forward cable channels 131 and/or rear cable channels 133 may utilize a common post 130, 132. For example, the second post 130b,132b of a first forward cable channel 131 or rear cable channel 133 may be the first post 130a,132a of a second forward cable channel 131 or rear cable channel 133.

[0041] In some example embodiments, the strain relief 120 may also include a wall 136 extending outward from at least a portion of a perimeter of the base 121. In an example embodiment, wherein the first post 130a,132a or the second post 130a,132a of the forward cable channel 131 or the rear cable channel 133 is integral to the wall 136. The first post 130a,132a, or second post 130b,132b may be fully integrated into the wall 136, or only a portion of the first post 130a,132a or second post 130b,132b may be integrated in the wall 136, such as depicted in FIG. 6.

[0042] The strain relief 120 may be formed of one or more materials, such as plastic, metal, or the other suitable materials. Preferably, the strain relief 120 is formed as a monolithic plastic component, which may be formed by injection molding.

[0043] In an example embodiment, a strain relief for an optical fiber assembly is provided including a base, a forward cable channel, a rear cable channel aligned with the at least one forward cable channel along a longitudinal axis, and an offset post disposed between the forward cable channel and the rear cable channel. Each of the at least one forward cable channel and the at least one rear cable channel includes a first post and a second post extending from the base. The offset post is disposed along the longitudinal axis, such that when an optical cable is installed into the strain relief the optical cable bends around the at least one offset post out of the longitudinal axis.

[0044] In an example embodiment, the strain relief also includes a plurality of forward cable channels, a plurality of rear cable channels, and a plurality of offset posts. The strain relief is configured to receive a plurality of optical cables. In some example embodiments, the plurality of offset posts form at least one offset cable channel. In an example embodiment, the second post of a first cable channel of the plurality of forward cable channels is the first post of a second cable channel of the plurality of forward cable channels. In some example embodiments, the strain relief also includes a wall extending along at least a portion of a perimeter of the base and the first post or the second post of the forward cable channel or the rear cable channel is integral to the wall. In an example embodiment, the first post or the second post is planar. In some example embodiments, the base is integral to the fiber optic assembly. In an example embodiment, the base is configured to be selectively attached to the fiber optic assembly. In some example embodiments, the second distance comprises about 2 mm. In an example embodiment, the strain relief comprises a monolithic plastic component.

[0045] In another example embodiment, a fiber optic assembly is provided including a connection base, a plurality of optical connection holders, and a strain relief. The strain relief including a base, a forward cable channel, a rear cable channel aligned with the at least one forward cable channel along a longitudinal axis, and an offset post disposed between the forward cable channel and the rear cable channel. Each of the at least one forward cable channel and the at least one rear cable channel includes a first post and a second post extending from the base. The offset post is disposed along the longitudinal axis, such that when an optical cable is installed into the strain relief the optical cable bends around the at least one offset post out of the longitudinal axis.

[0046] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the illustrated embodiments. Since modifications, combinations, sub-combinations and variations of the disclosed embodiments that incorporate the spirit and substance of the illustrated embodiments may occur to persons skilled in the art, the description should be construed to include everything within the scope of the appended claims and their equivalents.