CA2029591C - Connector holders - Google Patents

Abstract

A planar connector holder for optical fibers with a storage facility for coiled fiber, a mounting region at the front end region of the holder for connectors with an end of each connector facing forwardly. The holder has a connector uard to shield the forward facing ends of the connectors. The shield is located in front of the mounting region to define a space for other optical fibers to be connected to the forward facing ends of the connectors.
Provision is made for limiting the minimum bend radius of fibers as they enter into this space and then laterally of the holder through an inlet to the space.

Description

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'_ CONNECTOR HOLDERS
This invention relates to connector holders for optical fibers.
Connector holders for optical fibers are known 5 primarily through publications in patent specifications, but also in a few commercially available designs. In U.S.
Patent 4,792,203, for example, a holder structure is described in which a storage space is provided for optical fibers entering the structure from an incoming cable and 10 optical connectors are mounted on an arm located at the one side of the holder and to which the optical fibers are connected. Other optical fibers exit from the other ends of the connectors and also pass through the storage space of the holder before proceeding as distribution fibers to 15 telecommunications equipment in a customer's premises. A
plurality of such holders are mounted in a housing and are pivotally attached so as to be movable into a withdrawn or use position within the housing or an access position pivoted at the front of the housing for maintenance pur-20 poses.
In a further structure, such as described inGerman Offenlegungschrift 2735106, a housing carries a tray which is pivotally mounted for movement in and out of the housing. Incoming optical fibers are stored within the 25 tray and are connected to pigtail fibers also stored within the tray. The pigtail fibers extend from the tray to pig-tail connectors mounted at the rear of the housing.
Holders are known that are mounted in a distribution frame with the connectors mounted at a front end region of the holders so as to be located at the front of a distribution frame with one end of each connector facing forward for ease of connection of additional fibers These known holders have connector guards which extend 35 across the front end region of the connectors so that with the holders in use, the guards deflect any light beam exiting from a connector to which a fiber is not connected at the front of the connector 5 9 ~

The holders are constructed so as to provide for 10 minimum bend radius of the fibers passing through the hold-ers whereby attenuation is not significantly increased during use of the fibers.
The present invention seeks to provide a con-nector holder which has improved pathways for optical 15 fibers taking into account that there should be minimum bend radius requirements so as to avoid significant attenuation in use.
Accordingly, the present invention provides a planar connector holder for connecting a plurality of in-20 coming optical fibers to outgoing optical fibers, theholder having:- a front end region and a rear end region;
a storage facility for the storage of a plurality of coiled lengths of fiber with the coils in planes of the holder; a mounting region for a plurality of optical connectors, the 25 mounting region disposed at the front end region of the holder with the storage facility disposed between the mounting region and the rear end region of the holder with the mounting region comprising a plurality of connector mounting positions disposed in a series which extends from 30 mounting position to mounting position along the front end region of the holder for location of connectors in the mounting positions with an end of each connector facing forwardly from the front end region of the holder; a con-nector guard provided to shield the forward facing end of 35 each connector while being disposed forwardly in front of the mounting region to provide a space between the guard and the mounting region for other optical fibers to extend to the forward facing ends of the connectors, an inlet .~

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formed at one side of the holder and forwardly of the mounting region for passage of said other optical fibers into said space; and means for limiting the minimum bend radius of said other optical fibers as they extend in the 5 space from the forwardly facing ends of the connectors and laterally of the holder through the inlet.
Thus in use, with the other optical fibers con-nected to the forward facing ends of the connectors, these fibers are controlled in position by the minimum bend 10 radius limiting means as they change in direction so as to extend laterally of the holder and through the inlet. These optical fibers are hence unable to bend below the minimum bend radius while in the space between the guard and the mounting region. Preferably, the minimum bend radius 15 limiting means comprises a plurality of convex surface elements spaced apart laterally of the holder whereby the optical fibers may pass from their respective connectors and between the convex surface elements so as to be sup-ported upon respective convex surfaces for limiting the 20 minimum bend radius.
For the purpose of directing the other optical fibers away from the front of the holder in use so as to make the holder more accessible, one side of the guard is provided with a convex minimum bend radius limiting surface 25 provided at the inlet, the convex surface extending out-wardly from the space while curving rearwardly of the holder.
One embodiment of the invention will now be described, by way of example, with reference to the accom-30 panying drawings, in which:-Figure 1 is an isometric view showing a plurality of connector holders according to the embodiment assembled into a distribution frame, a part only of the assembly being shown;
Figure 2 is a cross-sectional view through the assembly taken along line II-II in Figure l;

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Figure 3 is an isometric view to a larger scale upon an upper side of one of the connector holders with a cover in an open position;
Figure 4 is a view similar to Figure 3 with the 5 cover in a closed position;
Figure 5 is an isometric view upon the underside of the connector holder;
Figure 6 is a cross-sectional view of part of the connector holder taken along line VI-VI in Figure 3;
Figure 7 is an end view of the connector holder in the direction of arrow VII in Figure 3;
Figure 8 is an isometric view of a connector holder, similar to Figure 4, but showing the connector holder located in a rearward operative position in the 15 distribution frame with parts of the distribution frame also shown; and Figure 9 is a view similar to Figure 8 but show-ing the connector holder moved to a forward connector access position.
As shown in Figure 1 an optical fiber distribu-tion frame 10 holds two vertical banks 12 of planar con-nector holders 14 for connecting a plurality of incoming optical fibers to outgoing optical fibers. As shown in Figures 1 and 2, the distribution frame comprises a rear 25 wall 16 and remote side walls 18 which extend from the rear to an open front of the frame. Between the side walls 18 are two other walls 20 which extend forwardly from the rear wall 16 and lie in parallel relationship to the side walls 18. In each bank 12, a side wall 18 and its corresponding 30 wall 20 define between them receiving stations for the connector holders 14. The two walls 20 are spaced apart as shown in Figure 2 to provide a storage channel 22 for optical fibers leading from front end regions of the con-nectors as will be described. The distance between the 35 walls 20 is sufficient to ensure that where loops of fiber are to be disposed within the storage channel then these loops will not have a bend radius below a desired minimum.
Each of the connector holders 14 is insertable into a ~ 9 1 respective receiving station from the front of the distri-bution frame and is locatable in two positions in the res-pective station, i.e. in a rearward operative position as shown in Figure 2 and in full outline in Figure 1, and a 5 forward connector access position as shown in chain-dotted outline in Figure 1.

Holders in the right-hand bank 12 in Figure 1 are of opposite hand to those in the left-hand bank 12. In the following description, a holder for accommodation in the left-hand bank will be described with the underst~n~;ng 20 that the holders in the right-hand bank are of opposite hand.
Each tray 14 of the left-hand bank is of planar configuration as shown in Figure 3 and has a planar base 24 (Figure 6) in the plane of the holder, the base 24 being 25 bordered by side walls 26 which extend to both sides of the base in the depth direction of the holder. At a front end region of the holder is provided a mounting region 28 for optical connectors 30 to be positioned laterally spaced from one another across the width of the holder from one 30 side wall 26 to the other. On one side of the base and between the side walls 26 there is provided a storage com-partment 31 (Figures 5 and 6) for incoming optical fibers stored within a tube 32 which is one of a plurality of tubes 32 forming the core of an incoming optical cable (not 35 shown). The storage compartment 31 extends between the mounting region 28 and a rear end wall 34 of the holder, the rear end wall extending between the side walls 26. The compartment 31 is provided with a cover 36 which covers substantially the whole of the compartment 31 except the surrounding edges. The cover 36 is movable at right angles to its plane between an inner operative position as shown in Figure S and a slightly retracted position (not shown) 5 in which it stands upwardly from the walls 26 to enable the tube 32 to be passed laterally between edges of the cover and ends of the walls 26 during assembly of the tube into the compartment. The cover is mounted upon a central structure shown at 38 in Figure 5 and is locatable in its 10 operative and retracted positions by latches 40. Localized I flanges 42 extend inwardly into recesses in the cover 36 so ! as to distort the gap around the cover so as to render it impossible for a tube to be removed with the cover in its operative position.
On the other side of the holder as shown in Figures 3 and 6, there is a second compartment 44 provided.
This compartment also extends from the mounting region to the rear end 34 of the holder. The base 24, as shown in Figure 6, extends downwardly at its front end 46 so as to 20 define one side of a recess 48 which extends from side-to-side of the holder, the recess being provided to accom-modate the connectors 30 in their side-by-side positions.
Each con-nector 30 is held by a connector mount 49 which is provided 25 with a forwardly facing foot 50 (Figure 6) which is to be disposed under an overhanging surface 52 at a front side of the recess. The other end of each connector mount has a flexible latch 54 which is received through a hole 56 in the base of the recess, the latch then engaging beneath the 30 inclined side 46 to hold the connector mounts in position.

Compartment 31 has an inlet 58 at its forward end, the inlet 58 being laterally open at position 60 i.e. at an edge of a side 26, so as to permit the tube 32 to be in-35 serted into the opening 60 and into the inlet. Further-more, the two compartments are connected at the rear wall 34 of the connector by interconnecting passage 62 (see ,~.

Figure 7) to enable the tube 32 to pass from one com-partment to the other.
In the other compartment 44, a splice block 64 (Figure 3) is provided for connecting incoming optical 5 fibers to pigtail fibers, the other ends of the pigtail fibers being provided by the connectors 30.
Each holder 14 also comprises a connector guard 66 mounted at its front end.

Guard 66 has two sides 68 and 70 and a front 72 which extends across the width of the holder. The two sides 68 and 70 are hinged so as to be movable between an upper connector guarding position in the plane of the holder as shown in Figure 3 and a downward position removed 15 from the guarding position as shown in Figure 9.

The guard is pivoted in front of the mounting 20 region 28 upon two forward extensions 74 of the side walls 26 at positions 76 and is normally retained in the guarding position by domed protrusions 78 on free ends of the arms 74, the domed protrusions extending into holes in the side walls 68 and 70. To move the guard 66 into and out of the 25 guarding position, downward or upward pressure on the front of the guard is sufficient so as to cause the extensions 74 to flex inwardly and cause the protrusions 78 to move into or out of the respective holes in the side walls 68 and 70.
A space defined between the mounting region 28 and the 30 front 72 of the guard has an inlet provided between the front 72 and an arcuate extension 80 of the side wall 70.
The arcuate extension 80 extends laterally sideways from the side 70 and the holder and provides a means for limit-ing the minimum bend radius of fibers extending from the 35 space while allowing them to pass rearwardly of the holder.
The arcuate extension 80 is spaced slightly rearwardly of the front 72 of the guard to provide the inlet.

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Means for limiting the m i n; mum bend radius of optical fibers in the space is provided for ends of fibers as they extend from forward facing ends of the connectors 30 when they change direction to pass through the inlet.
5 The means for limiting the minimum bend radius at this position comprises a plurality of arcuate vanes 82 which are disposed in spaced positions across the width of the holder and are supported each by one end upon a flange 84 ext~n~ing rearwardly from the front 72. The vanes 82 10 extend upwardly from flange 84 and are suitably positioned - relative to respective mounting positions for the con-nectors 30 so that ends of optical fibers in the space and ext~n~;ng to the connectors 30 engage against a convex surface of a respective vane as it changes direction 15 towards the inlet. With the convex surface of each vane formed to provide a desirable minimum bend radius for the fibers, then no undue rech~nical stresses or attenuation will take place in fibers engaging these surfaces-.
In use, a plurality of the fibers described above 20 are located complete with connectors and fibers into the left-hand bank shown in Figure 1 and holders 14 of opposite hand also replete with fibers and connectors are received in the receiving stations in the right-hand bank. As shown in Figures 1 and 2, a storage channel 86 is provided at the 25 forward edge on each side wall 18, each storage channel 86 opening forwardly for receiving a plurality of tubes con-taining fibers. The left-hand channel 86 contains and guards tubes 32 for incoming fibers from a single incoming optical cable (not shown). The tubes 32 extend one to each 30 of the receiving stations in the left-hand bank and is therefore associated with a respective holder 14. As shown in Figure 5 which shows the underside of a tray in the left-hand bank 12, a respective tube 32 passes through the inlet 58 and is disposed beneath the cover 36 in a series 35 of coils around the center of the tray in the compartment 31.
The tube then passes along an arcuate passageway 88 at the rear of the compartment 31 and through the inter-~ ~ ~ $ ~ ~ ~

connection passage 62 (see Figure 7). The tube then con-tinues into the storage compartment 44 and is held in posi-tion by a strain relief at position 90 The tube itself then 5 terminates adjacent to this position and fibers 91 (Figure 2) extending from the tube, extend in coils around the com-partment 44 and terminate in the splice block 64. In the splice block 64, the fibers from the tube 32 are spliced to pigtail fibers 92 which also proceed in coils around the 10 compartment 44 and other ends of the pigtail fibers are joined to the optical connectors 30 mounted in the mounting region 28 as shown in Figure 3. After connecting the .
fibers in this way, a hinged cover 94 is positioned over the compartment 26 so as to close it for instance as shown 15 in Figure 8.
Each holder 14 in the right-hand bank 12 (Figure 2) has its connectors 30 also forming parts of pigtails with pigtail fibers 92 as discussed for the left-hand bank.
The pigtail fibers 92 are spliced in the splice block 64 in 20 the right-hand bank to distribution fibers 96 which extend into the end of a tube 98 in the compartment 44. The tube 98 then proceeds from the compartment 44 in the holders in the right-hand bank into the other storage compartment 31 of the holder before continuing out from the holder through 25 the inlet 58. The tubes 98 are then accommodated within the right-hand storage channel 86 as shown in Figure 2 and proceed to terminal equipment in a customer's premises.
Patch cords are then provided between the two banks of holders. Each patch cord comprises a tube pro-30 tected fiber 100 and connectors 102 at each end of thefiber. Connectors in the holders in the right-hand bank 12 are selectively connected to connectors in the right-hand bank by use of the patch cords. Hence any connector 30 in one bank may be selectively connected to any connector 30 35 in the other bank. With all of the connectors in the rear-ward operative positions in their respective receiving stations as shown in Figures 1 and 8, the guards 66 of the holders are held in their connector guarding positions in . . j .

which they lie directly in front of the connectors 30, either by the fact that the guards are sufficiently close together to prevent their hinging movement out of these positions or by some frame member which prevents movement.
To enable the patch cords to be connected to connectors 30 of any particular holder, then the holder needs to be drawn forwardly from its fully operative posi-tion shown in Figure 8 to its forward connector access position shown in Figure 9. In the connector access posi-10 tion, the mounting region 28 of a holder is substantially aligned with the fronts 72 of the other holders, so that the particular guard 66 of the holder projects forwardly sufficiently for it to be pivoted downwards and out of the guarding position. This is the position shown in Figure 9.
15 Hence with selected holders in their forward connector access positions from one bank 12 to the other, the patch cords may be connected between appropriate connectors 30 between the two banks. Superfluous lengths of the tube protected fiber 100 of the patch cords are then passed 20 rearwardly into the storage channel 22 in which they are allowed to hang freely as loops 103 of surplus material (Figures 1, 2 and 8) by extending over horizontal support brackets 104 extending outwardly into the storage channel 22 from both of the walls 20. As may be seen from Figure 25 8, each of the brackets 104 has a convex surface member 106 which ensures that the fibers 100 in being supported by the surface member do not attain a bend radius below a desired minimum. When all of the connectors 30 of any particular holder have had their patch cords connected to them, then 30 the guard 66 is pivoted upwardly into the connector guard-ing position shown in Figures 3 and 8 and the particular holder is then moved backwardly into the frame so as to assume its rearward fully operative position once more. In this position, as shown in Figure 8, the tube protected 35 fibers 100 pass from the connectors 102 around respective vanes 82 of the guard 66, around the arcuate extensions 80 as they move from the inlet to the space forwardly of the mounting regions 28, and then beneath a bracket 108 which '~ 2029591 is a lateral extension at a remote end of the extension 80.With each of the holders in its rearward fully operative position as shown in Figure 8, the flange 108 forms a part of a corralling arrangement which also comprises a split 5 ring 110 formed as a lateral extension from the associated wall 20. Each of the fibers 100 then passes over the bracket 104 and descends as a free loop 103 in the storage channel 22.
In the assembled condition, the minimum bend 10 radius of each of the tube covered fibers 100 is controlled partly by the vanes 82 as the fibers extend from the con-nectors 102 and then around the arcuate extension 80 before proceeding over the convex surface member 106. As any of the holders is subsequently drawn forwardly to its con-15 nector access position, for instance as shown in Figure 9,the guard 66 is still in the guarding position during this movement. The forward movement draws surplus material from the corresponding loops 103 of the tube enclosed fiber 100 as the fibers move through the split ring 110 by being 20 drawn forward by the holder. The forward movement of the fibers 100 is resisted by the weight of the loops 103 and also by frictional engagement with the tube covered fibers 100 with the surfaces which they engage. However while this resistance is present, no undue bending of the fiber 25 takes place as at each critical position where the fiber is bent or is likely to become bent, a minimum bend radius element is present to prevent any undue formation of any restrictive bend radius. Thus the vanes 82 particularly and also the arcuate extension 80 and the element 106 pre-30 vent any tendency to produce mechanical failure in thefibers or to tension the fibers in such a way that attenua-tion of a signal could take place.
In a modification of the above embodiment (not shown) each of the banks 12 of holders is serviced by tubes 35 32 from an incoming cable. The outgoing fibers from the front ends of connectors 30 pass around the arcuate exten-sion 82 as in the embodiment and into the storage channel 22. However, these particular tube covered fibers then proceed directly through the customer's premises to the customer's telecommunications equipment. Hence in the modification, these outgoing fibers replace the looped patch cords of the embodiment. However, when moving 5 holders forwardly into the forward connector access posi-tions, the minimum bend radius provisions which have been described above with regard to the first embodiment operate in the way discussed in the first embodiment to prevent any undue bending of the fibers.

Claims (5)

1. A planar connector holder for connecting a plurality of incoming optical fibers to outgoing optical fibers, the holder having:-a front end region and a rear end region;
a storage facility for the storage of a plurality of coiled lengths of fiber with the coils in the planes of the holder;
a mounting region for a plurality of optical connectors, the mounting region disposed at the front end region of the holder with the storage facility disposed between the mounting region and the rear end region of the holder with the mounting region comprising a plurality of connector mounting positions disposed in a series which extends from mounting position to mounting position along the front end region of the holder for location of connectors in the mounting positions with an end of each connector facing forwardly from the front end region of the holder;
a connector guard provided to shield the forward facing end of each connector while being disposed forwardly in front of the mounting region to provide a space between the guard and the mounting region for other optical fibers to extend to the forward facing ends of the connectors, an inlet at one side of the holder and forwardly of the mounting region for passage of said other optical fibers into said space;
and means for limiting the minimum bend radius of said other optical fibers as they extend in the space from the forward facing ends of the connectors and laterally of the holder through the inlet.

2. A planar connector holder according to claim 1 wherein the means for limiting the minimum bend radius comprises a plurality of convex surface elements which are spaced apart laterally of the holder for laterally supporting said other optical fibers upon said convex surfaces as they extend to the inlet from connectors when mounted in respective mounting positions.

3. A planar connector holder according to claim 1 wherein the connector guard is movable into and out of a connector guarding position in which it is disposed forwardly in front of the mounting region, and the means for limiting the minimum bend radius of the other fibers is provided upon the connector guard.

4. A planar connector holder according to claim 3 wherein the means for limiting the minimum bend radius comprises a plurality of convex surface elements which are carried by the connector guard, and with the connector guard in the guarding position, the convex surface elements are spaced apart laterally of the holder for laterally supporting said other optical fibers upon said convex surfaces as they extend to the inlet from connectors when mounted in respective mounting positions.

5. A planar connector holder according to either claim 3 or claim 4 wherein one side of the guard is provided with a convex minimum bend radius limiting surface at the inlet, the convex surface extending outwardly from the space while curving rearwardly of the holder.