Interbay fiber optic storage unit

[0002] The present invention is directed to fiber optic connector systems and in particular to a storage unit for mounting to a rack containing a plurality of fiber optic connector housings containing connector panels.

[0003] Fiber optic cables are used for transmitting voice, data, and video communications. In some installations, a large number of fiber optic cables must be interconnected with other fiber optic cables extending throughout the user's facility. For large systems, storage racks are often used. A storage rack is a vertical rack that supports itself on the floor and holds a number of fiber optic connector panels in housings, with the housings spaced one above the other. The connector panels have large number of apertures for various connectors/adapters used in connecting the optical fibers. Some of the systems also contain electronics that must be interconnected with the fiber connector panels. In some cases, massive amounts of optical fiber are required to be stored and routed from the front and back of the frame. Care must be taken in storage of the optical fibers to avoid bending the optical fibers more than a specified radius (the bend radius), usually 1.25-1.50 inches.

[0004] In this invention, a storage unit mounts to at least one of the vertical sides of the storage rack. Each storage unit has a pair of longitudinal extending parallel rails, each of the rails having a front and a back. The rails are connected to each other and spaced apart, defining openings between the rails to allow the passage of optical fibers from the front to the back. The rails also carry hubs to allow for storage of slack optical fibers. The hubs are longitudinally spaced along the rails. Some of the hubs protrude rearward from the rails and some of the hubs protrude forward from the rails.

[0005] In the preferred embodiment, the hubs are mounted to spacers that interconnect and maintain the rails in parallel. Both the rails and the spacers preferably have curved portions that join the front and the back and prevent excessive bending of the optical fibers.

[0006] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

[0007] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0008] FIG. 1 is a front elevational view showing portions of two storage racks having storage units constructed according to the present invention;

[0009] FIG. 2 is a top view of the storage racks of FIG. 1;

[0010] FIG. 3 is a partial isometric view of one of the storage units

[0011] FIG. 4 is partial exploded isometric view as seen from the back and top of one of the storage units, with the end cap not being shown;

[0012] FIG. 5 is a partial isometric view of the storage unit with an end cap according to the present invention; and

[0013] FIG. 6 is a partial side view of a second embodiment of the storage units according to the present invention.

[0014] Referring to FIG. 1, an optical fiber storage rack 11 is shown. Rack 11 is a frame that supports a number of connector housing 13 in bays, one above the other. A typical rack 11 may be about seven feet in height and hold nine connector housings 13. Connector housings 13 are conventional patch panels with connector panels 14 that interconnect a large number of optical fibers 15. Rack 11 has two longitudinal frame members 17 that are spaced apart and interconnected to each other with lateral braces 18. A top view of frame members 17 and a lateral brace 18 is shown in FIG. 2, with two connector housings 13 attached to the frame members 17. Numeral 19 references the back side of rack 11, while numeral 21 references the front side.

[0015] A storage unit 23 is mounted to each lateral side of rack 11 in the preferred embodiment, as illustrated in FIG. 1. Referring again to FIG. 2, each storage unit 23 has a pair of longitudinally extending rails 25,27 that are parallel to and attached to frame members 17. Each rail 25,27 has a back flange 26, a front flange 28, and a connecting wall 30 that are perpendicular to flanges 26,28 (see FIG. 3). Outer rail 25 is identical to inner rail 27, except for being the mirror image when installed. The corners 31 between flange 26 and connecting wall 30 and between flange 28 and connecting wall 30 are curved at a desired minimum radius to avoid excessive bending of fibers 15, preferably 1.25 to 1.50 inch. Flanges 26,28 of the rails 25,27 are fastened to the frames members 17 of rack 11, creating a hollow column 22, allowing a fiber optic cable stub (not shown) to be run up the side of the rack 11 if required. As best seen in FIG. 2, frame members 17 have a longer front flange 17athan back flange 17b. The front flange 28 of storage unit 23 is shorter than the back flange 26 (see FIGS. 3 and 4), thereby allowing the flanges 26,28 of storage unit 23 to mate with the flanges of the frame members 17. However, other configurations (i.e., flange 17ais shorter than flange 17band flange 28 is longer that flange 26.) are possible as well.

[0016] As shown more clearly in FIGS. 3 and 4, a plurality of spacers 33 are located between connecting walls 30 of rails 25,27. Spaces 33 are spaced longitudinally along rails 25,27. For example, there may be nine spacers 33 evenly spaced along the storage units 23. As shown in FIG. 4, each spacer 33 is formed in two symmetrical halves 33a,33bfor ease in manufacturing and assembly. Spacer half 33ahas upper and lower guide plate flanges 35athat are spaced longitudinally apart from each other and joined by a mounting plate 37a. Guide plate flanges 35aand mounting plate 37aare integrally formed with each other. A curved corner 36ais located at the junction of each guide plate flange 35awith mounting plate 37a. Corners 36aare preferably curved at the same radius as corners 31 to avoid excessive bending the optical fibers. Similarly, spacer half 33bhas upper and lower guide plate flanges 35bthat are spaced longitudinally apart from each other and joined by a mounting plate 37b. A curved corner 36bis located at the junction of each guide plate flange 35bwith mounting plate 37b.

[0017] Spacers 33 are secured on top of flanges 26,28 of rails 25,27 with fasteners (e.g., screws, rivets, etc.) 39. The forward edges of guide plate flanges 35babut the rearward edges of guide plate flanges 35ato define upper and lower guide plates that extend around and between the connecting walls 30 and corners 31. Mounting plates 37a,37bare on top of vertical flanges 28,26, respectively (see FIG. 1). This configuration defines openings 41 through the storage unit 23, which are shown in FIG. 1.

[0018] Hubs 43a,43bare mounted to each mounting plate 37a,37bof each spacer 33 with a bracket 49 and a retainer plate 47, as illustrated in FIG. 3. Referring to FIG. 4, one of the hubs 43bprotrudes from mounting plate 37bat the back 19 of rack 11, while the other hub 43aprotrudes forward from mounting plate 37aat the front 21. Each hub 43a,43b, is shown as a cylinder having a radius as specified above to avoid excessive bending of the optical fibers to be wrapped around and stored on the hubs 43a,43b. Hubs 43a,43bmay be in two separate halves, separated from each other, however. As illustrated in FIG. 6, hub 43ahas a hub axis 45 that is co-axial with the hub axis of hub 43bmounted to the same spacer 33 but on the opposite side of storage unit 23. However, the hubs 43a,43bneed not be attached to both sides of each of the spacers 33, thereby allowing hubs not to be aligned on the front 21 and the back 19 of the storage unit 23. Rather, the spacers 33 may not have the hubs 43a,43b, the brackets 49, and the retainer plates 47 attached.

[0019] To attach the hubs 43a,43bto the spacers 33, one end of the bracket 49 is mounted to the spacer 33 using fasteners (e.g., screws, rivets, etc.), the hubs 43a,43bare slid over the bracket 49, and a retainer plate 47 is attached to the other end of the bracket 49, thereby securing the hubs between the spacer 33 and the retainer plate 47. In the embodiment illustrated in the figures, the retainer plate 47 is generally triangular in shape with rounded corners, however, other configurations (e.g., square, rectangular, oval, etc.) may be used. The retainer plates 47 are generally mounted in a plane parallel to the mounting plates 37.

[0020] In operation, a storage unit 23 is mounted to each side of rack 11 as shown in FIG. 1 (a second rack 16 may then be attached to the free side of each of the storage units 23, depending on the user's need and space availability). While installing the optical fibers 15, excess slack will be wrapped around the various hubs 43a,43b. The installer may extend fibers through the large openings 41, to allow the optical fibers to be routed from front 21 to back 19 of the storage unit 23, depending on the location of the connectors to be used and the needs of the installer, etc.

[0021] In the embodiment shown in FIGS. 1 and 2, an end cap 29 secures to flanges 26,28 of outer rail 25 when another rack is not attached to that side of the storage unit 23 to also define a hollow column 22 (see FIG. 2) and to make the end look more aesthetically pleasing. The end cap 29 preferably has end storage hubs 60. While only two end storage hubs are shown in FIG. 1, any number of end storage hubs 60 can be attached along the length of the end cap 29, which may or may not extend along the entire length of the storage unit 23. Alternatively, as shown in FIG. 6, the end cap 29 may not have any end storage hubs 60, but rather be radiused to prevent the excessive bending of the fibers if the fibers 15 are routed around the end cap 29.

[0022] The end storage hubs 60 have a central cylindrical element 62, which is attached to the end cap 29 with a fastener 68 (e.g., screw, rivet, etc.). The central cylindrical element 62 has an end piece 66 that includes a plurality of flanges 64 that help to retain the optical fibers on the hub 60. While the flanges 64 are shown to be comprised of four narrow, individual flanges, the end piece 66 and flanges 64 could be of any configuration, such as the single flange 47 on the front 21 and rear 19 of storage unit 23. The central cylindrical elements 62 have a radius that is greater than the desired minimum radius described above. The central cylindrical elements 62 may also be made of several components (e.g., two separate pieces that form an oval in cross-section) as long as the optical fibers 15 cannot violate the minimum radius when wrapped around them.

[0023] The end storage hubs 60 provide extra routing and storage options for the installers and the users of the storage units 23. The optical fibers 15 can be routed around the end cap 29 in going from front 21 to back 19 (or vice versa), rather than through the opening 41 in the center of the storage unit 23. An example of such routing is shown in FIGS. 1 and 2.

[0024] The invention has significant advantages. By providing hubs on both the front and the back, additional storage for optical fiber slack is provided. The large openings between the spacers and hubs provide convenient access between the front and back. The curved portions of the spacers and the rails prevent excessive bending of the optical fibers.