GB2460452A

GB2460452A - Improvements in and relating to optical fibre patch panels

Info

Publication number: GB2460452A
Application number: GB0809869A
Authority: GB
Inventors: Richard Dempster; Kenneth George Hodge; Edward Anthony Mcginley
Original assignee: Brand Rex Ltd
Current assignee: Leviton Manufacturing UK Ltd
Priority date: 2008-05-30
Filing date: 2008-05-30
Publication date: 2009-12-02
Anticipated expiration: 2028-05-30
Also published as: GB0809869D0; GB2460452B

Abstract

A patch panel (1) has a plurality of optical fibre outlets (21 to 26 inclusive and 31 to 36 inclusive) mounted on a front face of a tray (2), the tray being mounted so as to be withdrawn (in a direction 1 W) from the patch panel. The tray is arranged so that at least a portion (50) of the tray is moveable by pivoting (3P) and or hinging (in the direction of 4D) to a position (4H) for easy access. A benefit of the invention is that an installer may easily access optical fibres and optical fibre cables within the tray for installation or maintenance purposes.

Description

Improvements in and relating to optical fibre patch panels The present invention relates to the management of optical fibres in optical fibre patch panels.

According to a first aspect of the present invention, there is provided a patch panel having a plurality of optical fibre outlets mounted on a front face of a tray, the tray being mounted so as to be withdrawn from the patch panel, at least a portion of the tray moveable by pivoting and or hinging, to a position for easy access.

A benefit of the invention is that a user may easily access optical fibres and optical fibre cables within the tray for installation or maintenance purposes.

Preferably the tray is arranged so that when the at least a portion of the tray is in the position for easy access, the portion of the tray is spaced at a distance from a front face of a similar tray mounted to the patch panel below the withdrawn tray.

A benefit of the hingeable portion of the tray being spaced at a distance from a front face of the tray below is that it is not necessary to remove any optical fibre connectors plugged into the outlets of the tray below before moving the portion to the position for easy access.

* 2Y Preferably the patch panel is arranged for the interconnection of a plurality of optical fibres, the patch panel comprising a plurality of trays each arranged for the storage of lengths of optical fibres. * * * 0* *

Preferably the patch panel is arranged for the interconnection of optical fibres.

* * 2.5 Preferably the tray is arranged to be withdrawn to a first position by pivoting about a * first axis.

Preferably the tray is arranged to be withdrawn to a second position by a linear movement.

Preferably the linear movement is in a direction perpendicular to the first axis.

Preferably the tray further comprises a lid hingeably mounted to the tray, the lid arranged to be openable at least when the tray is in the second position.

Preferably the patch panel has a hingeable portion of the tray that is arranged to be moveable to the position for easy access by hinging about a perpendicular axis substantially perpendicular the direction of linear movement.

Preferably the first axis is substantially vertical and the perpendicular axis for hinging is substantially horizontal.

Preferably the patch panel is provided with a releasable latch that is arranged to be released to a first position to allow the tray to hinge about the perpendicular axis to a first hinged position.

Preferably the releasable latch is arranged to be released to a second position to allow the tray to hinge to a second hinged position.

Preferably each of the outlets has a longitudinal axis along which an optical fibre connector is connected to the outlet, the longitudinal axis being at an angle of less than 85 degrees to a plane of the front face.

Preferably each of the outlets is aligned to face at least partly in a direction towards the first axis.

Preferably the hingeable portion of the tray is connected to a non-hinging portion of the tray by a hinge, the hinge being formed by a reduced thickness portion of a base of the tray along the perpendicular axis.

Preferably the patch panel further comprises a non-hinging portion that at least partly remains within and supported by the patch panel.

Preferably the tray is mounted so as to be withdrawn from a front face of the patch panel, the front face of the patch panel facing the same direction as the front face of 2Q the tray. *. S

* S. S

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*..* : According to a second aspect of the invention there is provided a patch panel having a plurality of optical fibre outlets mounted on a front face of a tray, the tray being arranged to receive an optical fibre cable having a plurality of optical fibres at an entry, the tray having a splicing block and a store for optical fibre between the entry and the splicing block and a further store for optical fibre between the splicing block and the outlets.

A benefit is that an installer is able to carefully manage excess fibre lengths without risk of damage to the fibres.

The terms "entry" and "outlets" are used in the opposing sense, so that an outlet may be an entry and the entry may be an outlet.

Hence, an optical fibre cable received in the tray at the entry, may be used to bring optical signals to the outlets, or may be used to receive optical signals input at the outlets, or may be used to transmit information in both directions. In most practical applications, the mode of use of an optical fibre will be determined by connections made at an end remote from the patch panel.

Preferably the store for optical fibre comprises a drum within which the fibre may be placed.

A benefit of the drum is that a single turn or a multiple number of turns of fibre may be accommodated to allow for the storage of different lengths of fibre.

Preferably the tray is provided with a labyrinth arranged to guide the optical fibres such that the fibres are constrained to at least a curved path between the incoming and the outlets.

A benefit of the bend radii of the fibres being controlled within the guides in the labyrinth is to avoid the macro-bending phenomena which causes optical losses when optical fibres are bent at too small a radii.

Preferably the curved path or pathway in the labyrinth is arranged in such a way that there is only one possible routing for an optical fibre passing through the tray.

A benefit of having only one pathway is that an installer is presented with a logical and efficient way of laying the excess lengths of fibre either side of the splice into the assembly. A further benefit of the pathway system being arranged in this way is to aid the technician in tenninating and installing the product by encouraging the use of a .. 2t2 simple and repeatable method of managing multiple fibre splices and excess lengths of *. fibre. *SS. e..

: Preferably the curved path is provided with at least two reversals of direction.

Preferably a minimum path length is at least one and a half times a length of a width of the tray plus a length of the tray.

* 1 Preferably in an alternative embodiment, a minimum path length is twice a length of width of the tray plus a length of the length of the tray.

Preferably the labyrinth is further arranged so that an additional length of each fibre may be accommodated within the tray, the additional length of each fibre being at least equal to half the minimum length.

Preferably the tray is arranged to be withdrawably mounted to a patch panel, so that when withdrawn the fibre pathway is positioned clear of the patch panel.

Preferably the tray is when withdrawn, the fibre pathway is arranged to be positioned clear of optical fibres and optical fibre connectors connected to outlets of a similar tray mounted within the patch panel above the withdrawn tray.

Specific embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:-Figure 1 is a perspective front view of a patch panel according to a first embodiment of the present invention; Figure 2 is a perspective view of the patch panel shown in Figure 1, with a lower tray in a second fully extended position having been first moved to a first pivoted position; Figure 3 is another perspective view of the patch panel shown in Figure 1, with the upper tray in a second fully extended position; Figure 4 is a perspective view of the patch panel shown in Figure 1, with an upper tray in a fully extended and hinged position, but with a fixed lid and a hinged lid omitted from the tray for clarity; * .20 * * * : : e. Figure 5 is a perspective view of a plurality of patch panels according to the invention S..... mountedinarack; * . . * Figure 6 is a is a perspective view of the tray for the patch panel shown in Figure 1.

* Figure 7 is a plan view of the tray shown in Figure 6; *. S... * S

Figure 8 is a scrap view of the tray shown in Figure 1 with a lid shown in an open position; Figure 9 is a scrap view of a hinge for the lid shown in Figure 8; Figure 10 is a scrap side view of the tray shown in Figure 1; and Figure 11 is a scrap view of a latch for the tray shown in Figure 1, the latch shown in a first, latched position.

From Figure 1, a patch panel 1 is shown having a plurality of trays 2, 3 which are shown in a fully inserted or closed position 1 C within a panel housing 4. The trays are retained securely in the closed position 1 C by securing feature, screw 5 (only one shown). The panel housing 4 is provided with adjustable mounting lugs 6 and 7 for mounting the panel to a suitable support, such as frame 8, 8' shown in Figure 5. The adjustable lugs 6, 7 are adjustably secured to the housing with screws 9 through slots.

Each of the trays 2 and 3 is provided with a plurality of optical fibre outlets 21 to 26 and 31 to 36 respectively mounted on a front face 20 and 30 respectively of each of the trays. In the closed position 1C a plane 1P of the front faces of the trays are substantially aligned with each other and on or parallel with a plane 1Q of the mounting brackets 6 and 7.

Each of the optical fibre outlets is arranged so that an axial axis 1A of each of the outlets is at an angle 1G to the plane IP. The angle 1G being less than 90 degrees.

Hence when connectors, such as connectors 10, 11, 12 and 13 are connected to an optical fibre outlet, a projection 1J of the connector from the plane 1P is less than it would otherwise be if the axis 1A was perpendicular to the plane 1P'. Further, it can be seen from Figure 5, that optical fibres 14, 15, 16 and 17 that are terminated in the connectors 10, 11, 12 and 13 respectively may more easily be led through a convenient aperture 18 alongside the frame 8'. It is important that optical fibres 14 to 17 are not bent through a bend radius less than an acceptable bend radius. S..

:::.: In a preferred embodiment the angle 1G is preferably in the range from 70 degrees to degrees.

* In a particular embodiment an optimal value for the angle I G has been found to be approximately 80 degrees.

However, to meet the requirements of particular installations, the angle 1 G may range from approximately 30 degrees.

*SSS.S * S In a particular case of an optical fibre patch cable having a fibre diameter of say 2mm, such an acceptable bend radius would be 30mm minimum and preferably no less than 35mm. For certain types of fibres, such as single-mode fibres, a larger minimum bend radius is preferable, such as 35mm.

Within the tray, a typical primary coated optical fibre would have a diameter of approximately 250 micro metres and the minimum bend radius would be 30mm minimum and preferably no less than 35mm. If the fibres were protected by a buffer coat the typical diameter would be either say 600 or 900 micro metres, but since the optical fibre inside is the same size, the minimum bend radius would be 30mm minimum and preferably no less than 35mm.

The frame 8, 8' and the aperture 18 are within a suitable structure such as cabinet 9 which provides protection and means for controlling the optical fibres leading to and from the patch panel 1. The means for control is arranged so that the fibres are not bent through a smaller radius than a permitted minimum radius.

In use, to access one of the trays 2 or 3, each of the trays is mounted so as to be able to be withdrawn from the patch panel. This is shown in Figure 2, where the tray 2 is shown in a partially withdrawn position 2W. In the partially withdrawn position 2W, the face 20 of the tray 2 has been rotated about a vertical axis 2V of pivot pin 40, so that it is at an angle 2R to the plane lQ. The tray is prevented from being rotated further by a stop comprising the abutment of front face 20 or 30 against edge 41 of front facing wall 42 of the housing 4.

From Figure 2, it can be seen that in the particular embodiment shown the angle 2R is substantially 90 degrees.

Although in other embodiments not shown herein, it should be noted that the angle 2R may be less than 90 degrees, or greater than 90 degrees. For example in one other particular embodiment the angle is 60 degrees, while in another particular embodiment the angle is 150 degrees. *

Once pivoted to the position shown in Figure 2, the tray 2 is then moveable by sliding S outwards to a fully extended position 3E as shown in Figure 3. S... * S S S. *

Once in the fully extended position, an accessible portion 50 of the tray with an openable lid 51 is positioned such that the lid may be opened without movement of the lid being obstructed by optical fibres connected to sockets in a front face of a *..

* * further patch panel positioned above the present patch panel.

The optical fibres and connectors such as optical fibres 14 to 17 and connectors 10 to 13 do not extend further from the front of the patch panel than a side edge 54 of the lid 51. The tray further comprises a portion 52 with a lid 53 which does not normally need to be openable. Figure 11 shows clip feature 56 where a clip (not shown) on the lid 53 engages portion 52.

When lid 51 is opened, latch 60 shown in Figure 11, may be operated in the direction of arrow I IR against a return spring (not shown in Figure II) to allow the portion 50 to hinge about hinge 55 with respect to the portion 52 until sloping abutting face 61 abuts the abutment 62 formed on portion 52.

Since portion 52 is extending substantially horizontally from the front face of the patch panel, when portion 50 is hinged, it hangs downwards under the effect of gravity to hinged position 4H. The abutment of the sloping face 61 and abutment 62 ensure that the portion 50 is held at a preferred angle to the vertical, so that in this position easy access is provided to an installer for the installation of optical fibres to an inside space 4S of the tray 2.

The hingeable portion 50 of the tray 2 when hinged, is moved to the position for easy access by hinging in the angular direction 4D about a perpendicular axis 6H. The perpendicular axis 6H is substantially perpendicular to the direction of linear movement 3T that occurs when the tray is being withdrawn fully from the patch panel.

In a typical installation, such as that shown in Figure 5, where the tray when in the fully closed position 1C is lying in a substantially horizontal plane, the first axis 2V is substantially vertical and the perpendicular axis 6H for hinging is substantially horizontal.

From Figure 4, it can be seen that portion 52 and lid 53 extend sufficiently from the plane 1 P so that any connectors and optical fibres connected to the front faces above or below do not have to be displaced to open lid 51 or hinge the portion 50 about hinge 55. Hence the row of connectors 4C and the optical fibres 4F connected to the *. : connectors do not have to be displaced or disconnected to gain easy access to the inside space 4S. *S..

Indeed, in a preferred installation, since the optical fibres 4F are led away to the side * : , of the patch panel at 4F', for example to pass through an aperture 18 as shown in Figure 5, the hinged portion 50 may normally be moved to the hinged position 4H shown in Figure 4 without significantly displacing any optical fibres.

** **** * In a particular embodiment of the invention it has been found that a suitable extension 4E of the tray portion 52 is approximately 50 mm, and a suitable angle 4G at which the tray portion 50 hangs when hinged downwards is approximately 60 degrees.

A benefit of the extension 4E, is that a tray 2 or 3 can be withdrawn for easy access to work on the fibres within the tray in inside space 4S without disconnecting any of the fibre patch cords connected to similar trays above or below the tray being withdrawn.

Further the tray may be withdrawn for inspection of the fibres within the tray, without disconnecting any of the fibre patch cords connected to the outlets of the tray itself, as shown in Figure 5.

In other particular embodiments, it has been found that a suitable minimum value for the angle 40 is 30 degrees and that a suitable maximum value is 90 degrees.

However, in particularly cramped installations, it has been found advantageous for the tray portion 50 to hang approximately vertically from the hinge.

To permit the installer to select an optimum angle for the particular conditions of an installation, in a further embodiment not shown herein, the latch 60 is arranged so that it provides for alternative abutment positions, so that in the fuily engaged position the tray portion 50 is co-planar with tray portion 52, and in the first hinged position the portion 50 is retained at a first angle 4G' and in a second hinged position the tray is retained at a second angle 40", the second angle 4G' being greater than the first angle 40'.

In a yet further embodiment not shown herein, the latch may be moved to a fully retracted position, where the tray portion 50 hangs freely, hence substantially vertically from the hinge 55.

The tray is arranged to be withdrawn to the second position shown in Figure 4 by a linear movement in the direction of arrow 3T.

The hingeable portion of the tray 50 is connected to the non-hinging portion 52 of the * :2Q tray by the hinge 55, and in a preferred embodiment, the hinge 55 is formed by a reduced thickness portion of the base 75 of the tray 2 along the perpendicular axis 6H. S...

When the tray 2 is fully extended from the patch panel, the non-hinging portion 52 at least partly remains within and is supported by the patch panel housing 4 and pivot 40.

Hence the hinged portion is well supported along the axis 611 by the hinge to facilitate the easy installation of fibres.

S.....

* The tray is arranged so that when at least a portion of the tray, the hinged portion 50, is in the position 4H for easy access as shown in Figure 4, the said portion of the tray, portion 50 is spaced at the distance 4E from the front face 30 of a similar tray 3 mounted to the patch panel 1 below the withdrawn tray 2.

From the scrap views of the lid 51 and tray portion 50 shown in Figures 8 and 9, hinges 70 and 71 can be seen to retain the lid hingeably to the tray. To ensure that an installer has unrestricted easy access to the inside space 4S, at least one of the hinges is provided with a cam portion 72 which as the lid is opened resiliently deflects latch protrusion 73 so as to retain the lid in an open position. When an installer applies a force in the direction of arrow 9C to close the lid 51, a small radius on the cam portion 72 enables the latch protrusion 73 to be deflected in the direction 9D so as to release the lid.

If the open lid is an inconvenience to the installer, in a particular embodiment the hinges 70 and 71 are arranged so that the installer may temporarily remove the lid 51 from the tray portion 50.

In an alternative embodiment, the hinges 70 and 71 are arranged so that once fitted, it is not normally possible to remove the lid 51 from the tray portion 50.

A benefit of the lid 51 and the lid 53 is that it ensures that all the optical fibres are safely retained within the inside space 4S, and cannot get trapped between the tray 2 and a receiving aperture 4R within which the tray is inserted to move the tray into the patch panel to the closed position IC.

From Figures 1 and 2 it can be seen that each tray 2, 3 has an optical fibre cable 81, 82 respectively entering at a rear entry 85 to the patch panel 1. Each of the optical fibre cables 81, 82 are securely retained to their respective trays 2, 3 by compression glands 83, 84. When a tray, such as tray 2 in Figure 3, is withdrawn from the patch panel by being pivoted in the direction 3P and slid forward in the direction 3T, the optical fibre cable 81 is pulled in the direction 3U into the patch panel housing 4 through rear entry * 2*0 85, so that the optical fibre cable 81 follows the curved path 81 C within the housing 4.

* Optical fibre 82 attached to tray 3 is not affected by movement of the tray 2. * **. * *

* : * In a particular embodiment, the optical fibre cable 81, 82 is protected by a sheath, and : the sheath is securely retained by the respective compression gland 83, 84 to the respective tray 2, 3. The sheath may be formed as a part of the cable, or may be a separate flexible conduit or tube containing the optical fibre cable.

****.S * * From Figures 6, 7 and 10, which are views of the tray 2, a hole 80 is provided for as an incoming for the optical fibre cable 81. The optical fibre cable 81 is securely retained to the tray 2 at incoming 80 by a suitable gland 83. The optical fibre contains a plurality of optical fibre elements, each of which is arranged to be coimected to an optical fibre outlet protruding through the front face of the tray 2.

From Figure 6, the tray 2 can be seen to be arranged with upstanding dividing walls 92 to 99 inclusive which are arranged as a labyrinth 100. The labyrinth 100 is arranged to guide each individual optical fibre element such that the fibres are constrained to at least a curved path 102 between the incoming 81 and the outlets 21 -10 -to 26 inclusive. The labyrinth is arranged so that a fibre following the curved path 102 must have at least two reversals of direction 6R and 6S, so as to provide a long path length 7P.

In an embodiment, such as that shown in Figure 7, the labyrinth 100 is arranged such that the minimum length of path length 7P is at least one and a half times a length 7W of width of the tray plus a length 7L of the length of the tray2.

To enable various lengths of optical fibre to be accommodated in the tray, the labyrinth 100 is further arranged so that an additional length 7X and or 7Y of each fibre may be accommodated within the tray as shown in Figure 7.

In a particular embodiment an additional length of each fibre being at least twice the minimum length.

In another particular embodiment of the invention, an additional length of at least 1.5m of each optical fibre connected to each side of a splice connection may be accommodated in the tray.

From the Figures 6, 7 and 10 a slot 45 through which pivot 40 is passed to retain the tray to the housing 4. The slot 45 enables the tray 2 to both pivot about the pivot 40 when the pivot 40 is in the first position 40A and then to slidably move in the direction of arrow 3T until the pivot is in the position 40B.

* From Figure 10 a scrap side view of the tray 2, it can be seen that splice trays 120 and 122 are provided to retain splice joints between a pigtail 123 leading from the optical * * ** fibre outlets and an un-bundled fibre 125 from the cable 81 (not shown in this figure) which enters the tray through hole 80. * * *

S

S * I

Claims

-11 -CLAIMS1. A patch panel having a plurality of optical fibre outlets mounted on a front face of a tray, the tray being mounted so as to be withdrawn from the patch panel, at least a portion of the tray moveable by pivoting and or hinging to a position for easy access.
2. A patch panel as claimed in claim 1, wherein the patch panel is arranged for the interconnection of optical fibres.
3. A patch panel as claimed in any of the preceding claims, wherein the tray is arranged to be withdrawn to a first position by pivoting about a first axis.
4. A patch panel as claimed in claim 3, wherein the tray is arranged to be withdrawn to a second position by a linear movement.
5. A patch panel as claimed in claim 4, wherein the linear movement is in a direction perpendicular to the first axis.
6. A patch panel as claimed in claim 3 or 4, wherein the tray further comprises a lid hingeably mounted to the tray, the lid arranged to be openable at least when the tray is in the second position.
7. A patch panel as claimed in any of claims 4 to 6, wherein a hingeable portion of the tray is further arranged to be moveable to the position for easy access by hinging about a perpendicular axis substantially perpendicular the direction of linear movement. * * * *
8. A patch panel as claimed in any of the preceding claims, wherein the first axis is * substantially vertical and the perpendicular axis for hinging is substantially horizontal.

:.
9. A patch panel as claimed in any of the preceding claims when dependent on claim 7, wherein a releasable latch is arranged to be released to a first position to allow the tray to hinge about the perpendicular axis to a first hinged position.
10. A patch panel as claimed in claim 9 wherein the releasable latch is arranged to be * released to a second position to allow the tray to hinge to a second hinged position.
11. A patch panel as claimed in any of the preceding claims wherein each of the outlets has a longitudinal axis along which an optical fibre connector is connected to the outlet, the longitudinal axis being at an angle of less than 85 degrees to a plane of the front face.
12. A patch panel as claimed in claim 11 when dependent on claim 3, wherein each of the outlets is aligned to face in a direction at least partly towards the first axis.
13. A patch panel as claimed in any of the preceding claims when dependent on claim 7, wherein the hingeable portion of the tray is connected to a non-hinging portion of the tray by a hinge, the hinge being formed by a reduced thickness portion of a base of the tray along the perpendicular axis.

-12 -
14. A patch panel as claimed in any of the preceding claims when dependent on claim 7, wherein the tray further comprises a non-hinging portion that at least partly remains within and supported by the patch panel.
15. A patch panel as claimed in any of the preceding claims wherein the tray is mounted so as to be withdrawn from a front face of the patch panel, the front face of the patch panel facing the same direction as the front face of the tray.
16. A patch panel as claimed in any of the preceding claims wherein the tray is further arranged to receive an optical fibre cable having a plurality of optical fibres at an entry, the tray having a splicing block and a store for optical fibre between the entry and the splicing block and a further store for optical fibre between the splicing block and the outlets.
17. A patch panel as claimed in any of the preceding claims wherein the tray is further arranged so that when the at least a portion of the tray is in the position for easy access, the said portion of the tray is spaced at a distance from a front face of a similar tray mounted to the patch panel below the withdrawn tray.
18. A patch panel having a plurality of optical fibre outlets mounted on a front face of a tray, the tray being arranged to receive an optical fibre cable having a plurality of optical fibres at an entry, the tray having a splicing block and a store for optical fibre between the entry and the splicing block and a further store for optical fibre between the splicing block and the outlets.
19. A patch panel as claimed in claim 18, wherein the store for optical fibre comprises at least an upstanding wall portion within which the fibre may be placed. * ****
20. A patch panel as claimed in claim 18 or 19 wherein the tray is further provided * with a labyrinth arranged to guide the optical fibres such that the fibres are constrained to at least a curved path between the entry and the outlets.
21. A patch panel as claimed in claim 20 wherein the curved path or pathway in the labyrinth is arranged in such a way that there is only one possible routing for an * optical fibre passing through the tray.
22. A patch panel as claimed in claim 21, wherein the curved path is provided with at least two reversals of direction.
23. A patch panel as claimed in claim 22, wherein a minimum path length is at least one and a half times a length of a width of the tray plus a length of the tray.
24. A patch panel as claimed in claim 22, wherein a minimum path length is twice a length of width of the tray plus a length of the length of the tray.
25. A patch panel as claimed in claim 20, the labyrinth is further arranged so that an additional length of each fibre may be accommodated within the tray, the additional length of each fibre being at least equal to half the minimum length.

-13 -
26. A patch panel as claimed in any of the preceding claims, wherein the tray is arranged to be withdrawably mounted to a patch panel, so that when withdrawn the fibre pathway is positioned clear of the patch panel.
27. A patch panel as claimed in claim 26, wherein the tray when withdrawn, is S arranged so that a fibre pathway within the tray is positioned clear of optical fibres and optical fibre connectors connected to outlets of a similar tray mounted within the patch panel above the withdrawn tray.
28. A patch panel substantially as herein described with reference to the accompanying drawings. S.. * . S S. * S...S **5 SI.. * . S S. *I. Sa** S *