Telecommunications distribution elements

An optical fiber distribution element includes a chassis defining an interior; a movable tray slidably movable from within the chassis to a position at least partially outside the chassis, the tray defining a front end and a rear end; a slide mechanism which connects the movable tray to the chassis; at least one hingedly mounted frame member within the tray which hinges about an axis perpendicular to the direction of movement of the movable tray; and a cover mounted adjacent the rear end of the tray and movable between an access position and an operational position when the tray is in the open position, only the operational position of the cover allowing the tray to move from the open position to the closed position, the access position al lowing access to the at least one hingedly mounted frame member, and the cover in the access position preventing the tray from moving from the open to the closed position.

FIELD OF THE INVENTION

The present invention relates to telecommunications distribution systems, e.g., optical fiber distribution systems, which may include a rack and elements which populate the rack, wherein such fiber optic elements can include fiber terminations, patching, fiber splitters, and fiber splices.

BACKGROUND OF THE INVENTION

Optical fiber distribution systems may include fiber terminations and other equipment which is typically rack mounted. Various concerns exist for the optical fiber distribution systems, including density, ease of use and mounting, and cable management. There is a continuing need for improvements in the telecommunications distribution area, especially optical fiber distribution.

SUMMARY OF THE INVENTION

One implementation of a system in accordance with the examples of the disclosure includes a building block element mountable to a rack or other structure. The element includes a chassis and a movable tray. The tray is movably mounted to the chassis with a slide mechanism that allows the tray to slide relative to the chassis, wherein the tray may house equipment for fiber terminations, patching, splitting, and splicing.

The elements can be stacked in a column with each tray slideable in a horizontal direction. In the case of a column of elements, a selected tray is pulled outward to access the desired tray.

In an example embodiment of a fiber optic distribution element, one side of each element can be for patch cables, and the opposite side can be for cable termination of an incoming cable, such as a distribution cable or a feeder cable. The elements can be configured as desired and form building blocks for an optical fiber distribution system. When the elements are mounted in a column in a rack, the cables can be placed in vertical cable guides to enter and exit the selected element. An example rack may be front accessible. However, the elements shown and described can be used in other racks, frames, cabinets, or boxes including in arrangements where rear access is desirable or useful.

According to an aspect of the disclosure, the disclosure is directed to an optical fiber distribution element that includes a chassis defining an interior; a movable tray slidably movable from within the chassis to a position at least partially outside the chassis, the tray defining a front end and a rear end; a slide mechanism which connects the movable tray to the chassis; at least one hingedly mounted frame member within the tray which hinges about an axis perpendicular to the direction of movement of the movable tray; and a cover mounted adjacent the rear end of the tray and movable between an access position and an operational position when the tray is in the open position, only the operational position of the cover allowing the tray to move from the open position to the closed position, the access position allowing access to the at least one hingedly mounted frame member, and the cover in the access position preventing the tray from moving from the open to the closed position.

DETAILED DESCRIPTION

Referring now toFIGS.1-11, various embodiments of an optical fiber distribution element10are shown. The element10can be individually mounted as desired to telecommunications equipment including racks, frames, or cabinets. The element10can be mounted in groups or blocks which can form a stacked arrangement. In one embodiment, a vertical stack of elements10can populate an optical fiber distribution rack.

Each element10can hold fiber terminations or other fiber components including fiber splitters and/or fiber splices.

The example depicted optical fiber distribution element10that is going to be referenced for describing the inventive features of the disclosure is a drawer-based dedicated splice element that includes, within its tray, cable management structures for guiding cabling to and from hinged splice frames (also referred to herein as splice trays).

As shown, the element10includes a chassis20and a movable tray24. Tray24is movable with a slide mechanism30. Slide mechanism30provides for synchronized movement for managing the cables extending to and from tray24. Entry points36on either side of chassis20allow for fixation of the input and output cables associated with each element10. U-shaped radius limiters38associated with each slide mechanism30move in synchronized movement relative to chassis20and tray24to maintain fiber slack, without causing fibers to be bent, pinched, or pulled.

Further details relating to such slide mechanisms that can be used in the distribution element10are described and illustrated in PCT Publication No. WO 2019/201878, the entire disclosure of which is hereby incorporated by reference.

Referring specifically toFIG.1, as noted above, the depicted optical fiber distribution element10that is going to be referenced for describing the inventive features of the disclosure is a dedicated splice element that includes, within its tray, cable management structures for guiding cabling to and from the hinged splice frames.

In the depicted element, incoming outside plant (OSP) cabling50(e.g., 250 micron/900 micron optical fibers) may be directed to pivotally mounted splice frames52(may also be referred to as splice trays or pivot trays). Within the splice trays52, each fiber of the OSP cable50may be spliced to a pigtail54(i.e., outgoing cabling) that may lead to another element or other points in the network such as other equipment or customer dwellings.

As shown, the incoming cabling50may follow a path from an exterior of the element10, through U-shaped movable radius limiters38, to the interior pivot trays52. After the splice operation, the outgoing cabling54may follow a similar path, where the cabling54is routed through U-shaped radius limiters38at the opposite side of the elements10. As shown, the incoming cabling50may be provided with strength members that are secured to the sides of the elements via cable fixation devices60such as those described in PCT Publication No. WO 2019/201878, which has been incorporated herein by reference.

Referring now toFIGS.2-11, certain inventive interior features of the trays24of elements such as the element10shown inFIG.1will be described.

FIGS.2-3illustrate the details of a cover portion62of the tray24that is configured to protect the pivotally mounted splice frames52provided along a center portion of the tray24. As shown, the cover62is hinged adjacent a back end64of the tray24and is openable in a front-to-back direction, where the cover62is pivotally liftable from a front end66of the cover62. A flexible latch68provided at the front66of the cover62is used to keep the cover62closed by being snap-fit into a latch opening70provided at a front end72of the tray24. A latch grip74can be elastically moved by a user in a front-to-back direction to free a latch lip76from the latch opening70before pivotally lifting the cover62.

The arrangement of the cover62where the hinge is positioned at the back end64of the tray24provides a safety feature for protecting the splice trays52and the fibers therein within the tray24. Each of the splice frames or trays52first must be pivoted down before the cover62itself can be brought down and snapped to a closed position. When the cover62is at an open position, slideable closure of the tray24is prevented by contact of the cover62with the chassis20of the distribution element10. And, since closure of the cover62requires closure of each of the splice trays52, accidental closure of the tray24and pinching or damaging any of the fibers within the splice trays52is prevented or at least limited.

Without the cover62, if the tray24was closed with any of the splice trays52in an open position, a front edge of the top of the chassis20of the element10might damage the trays52or the fibers therein. To prevent such a closure and the potential resulting damage, cover62is configured to prevent movement of tray24to the closed position when cover62is not in the closed position itself as noted above. The closed position of the cover62may also be referred to as the operational position, and the open position of the cover62may be referred to as the access position where the splice trays52may be accessed.

A hinge78of the cover62and a hinge receiver80of the tray24may be configured such that the cover62remains or is locked in an open position when pivoted open. According to one example configuration, the hinge78of the cover62may utilize a square or other polygonal shaped cross-section where sharp edges of the cross-section provide temporary stops within the hinge receiver80to enable the cover62to remain open when brought to an open position. In such an example, the hinge78of the cover62and the hinge receiver80of the tray24provide a self-supporting locking system to keep the cover62in an open position without the need for further structures or features.

As also shown inFIG.2, the cover62may be used to house a card82(i.e., identification card) that can be used to write or provide connectivity information thereon regarding the distribution element10. The card82is removably mounted to a card slot84provided on the cover62via tabs86provided around the perimeter of the card slot84. Even though the card82is removable from the cover62, the cover62provides access to the card82such that distribution information can be written on the card82without removal from the cover62.

FIG.4shows the tray24ofFIGS.2-3without the cover62or the hinged splice frames52to illustrate the details of inventive cable management structures90within the tray24.

As shown, a cable management structure90is provided at each of the right and left sides92,94of tray24. The cable management structures90are for guiding cabling to and from the hinged splice trays52.

According to one example embodiment as depicted, the cable management structure90may be provided as a removable insert. As such, if the cable management insert90is damaged in any way, the insert may be replaced with another. In other embodiments, the cable management structure may be integrally molded with the tray of the distribution element10.

In the depicted embodiment, each cable management insert90extends in a front-to-back direction, on opposing sides of the flip trays52. A series of curved radius limiters96are provided for guiding cabling to and from the splice trays52.

In the depicted example, each cable management insert90defines a double layered cable routing channel defined by a lower channel98and an upper channel100, wherein cable management fingers102separate the lower channel98from the upper channel100. According to an example configuration as shown inFIG.1, the lower channel98may be used for 250 micron or 900 micron optical fibers50and the upper channel100may be used for the pigtails54. The dual layered construction provides a physical separation between two different types of cabling and may provide extra protection to the smaller 250 micron or 900 micron optical fibers50in the lower channel98. As shown, the upper channel100is also provided with cable retention fingers104extending into and partially covering the upper channel100for retaining the pigtails54within the upper channel100.

Now referring toFIGS.5and6, details on the locking feature for pivotally mounting the splice frames52to the tray24are illustrated.

FIG.5illustrates a prior art version of a locking feature110provided between a tray such as the tray24shown inFIGS.2-4and a hinged splice frame52therein for pivotally mounting the splice frame52within such a tray24.

As shown in the example ofFIG.5, each frame mounting location112within the tray24defines hinge openings114and a flexible ramped tab116positioned between the hinge openings114. Hinge pins118defined on each splice tray52are configured to be horizontally slidably inserted into the hinge openings114while a retention tab120defined on the splice tray52slides over and pushes down on the flexible ramped tab116. Once the flexible ramped tab116is cleared, the retention tab120is locked in against a stop surface122defined by the ramped tab116. In this manner, the splice trays52are limited from removal unless the ramped tab116is flexed down and the hinge pins118are slid.

FIG.6illustrates an improved version of a locking feature130provided between the tray24ofFIGS.2-4and the hinged splice frames52. In the version ofFIG.6, a flexible ramped tab132is provided with flexibility along a horizontal plane defined by a bottom surface/wall134of the tray24, which is in a perpendicular direction relative to the flex direction shown for the version of the tab116inFIG.5. As shown inFIG.6, in the improved locking feature130, the flexible ramped tab132is provided within an aperture136defined by the bottom wall134of the tray24. Edges138defining the aperture136provide positive stops for the flexible ramped tab132so as to limit over-flexing of the ramped tab132. In this manner, the flexible ramped tab132has a limit in its travel and is not as susceptible to breaking off.

In contrast, in the version of the locking feature110inFIG.5, the flexible ramped tab116is not limited in its travel since the ramped tab116is not provided with any positive stops. Thus, repetitive flexing of the ramped tab116inFIG.5might result in faster deformation or failure of the tab116versus the ramped tab132shown inFIG.6which is provided with a positive stop.

Referring now toFIG.7, details relating to example tube holders140that are configured to be mounted within the tray24ofFIGS.2-4that can frictionally support fiber carrying tubes50is discussed.

As shown, the tube holders140may be mounted so as to align with the channels of the movable U-shaped radius limiters38of the distribution elements10. The tube holders140may be configured for tubes holding 250 micron fibers or for tubes holding 900 micron fibers, depending on the application. The tube holders140include friction members142which limit the amount of sliding movement of cables50passing through the tube holders140, to assist with cable management. Friction members142grip lightly on the cables50in the tube holders140to reduce or eliminate sliding movement of the cables50therein.

Such tube holders140may also be positioned at various locations within the trays24for guiding of cabling in the preferred paths. As shown in an example layout inFIG.7, one of the tube holders140ais positioned to lead fiber carrying tubes50toward the cable management insert90.

As also shown, a second tuber holder140bmay be positioned and may also cooperate with a channel144defined at the back64of the tray24to lead fiber carrying tubes to an opposite side of the tray24to provide for a side-switching concept. The second tube holder140bthat is shown to be provided at the rear64of the tray24can be mounted at either the right side92or the left side94of the tray24and may bypass the splice frames52on one side and lead fiber carrying tubes to the opposite side depending upon the connectivity need.

FIG.8illustrates another version of a tray24bsimilar to the tray24ofFIGS.2-4that includes a further cable management wall150on both sides of the tray24bfor guiding cabling within the tray24b. For example, the cable management walls150can cooperate with the cable channel144at the back64of the tray24band guide fiber holding tubes extending from an opposite side of the tray24btoward the radius limiters96defined by the cable management insert90when a side-switching operation is performed. Each cable management wall150is provided with a cable retention finger152for retaining the cables.

FIGS.9-10illustrate a retainer160configured to be mounted within a tray such as the tray24ofFIGS.2-4. The retainer160is configured to hold a plurality of cable termination units162in a stacked arrangement. The example retainer160has the same mounting interface as the above-discussed tube holders140and can be mounted at various locations within the tray24. In the depicted embodiment, each retainer160is shown to hold four cable termination units162in a stacked arrangement. Other numbers are certainly possible depending upon connectivity need. The cable termination units162allow termination of cables inside the trays24. A cable channel164is defined for receiving the cable. Strength members may be tied down or clamped within each cable termination unit162for securing the cables.

FIG.11illustrates an example of another cable retention feature170having inventive aspects. The cable retention feature170is shown to be used at both sides of the tray24adjacent to the back end64for transitioning cabling50(FIG.1) from the U-shaped cable radius managers38to the main body of the tray24. In one example, the cable retention feature170is formed from two flexible fingers172that provide a push-through design. The flexible fingers172allow cabling50surrounded by corrugated tubes51(i.e., flex tubes) or pigtails to be pushed through and retained thereunder.

Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.