EP1549981A1

EP1549981A1 - Cable guide

Info

Publication number: EP1549981A1
Application number: EP03797317A
Authority: EP
Inventors: Hendrikus Petrus Gijsbertus Van Der Steen; Marcel Peter Meijer
Original assignee: FCI SA; Framatome Connectors International SAS
Current assignee: FCI SA
Priority date: 2002-09-19
Filing date: 2003-09-16
Publication date: 2005-07-06
Also published as: WO2004027484A1; AU2003299050A1; NL1021492C2

Abstract

The invention relates to a cable guide (1) providing a passage (2) for guiding at least a portion of a cable, wherein the passage (2) defines a centre line (3) extending between a proximal end (4) and a distal end (5) of this passage (2). The centre line (3) is at least partly defined along an imaginary helix such that the centre line (3) at the distal end (5) deflects away from an imaginary plane through the centre line (3) at the proximal end (4). The helical shape of the cable guide (1) avoids bending of the cable with a curvature beneath the minimum bend radius before the cable degrades, while the distal end (5) of the passage (2) provided by the cable guide (1) may point in any direction on the surface of an imaginary cylinder defined by the helix. The invention also relates to a cable comprising such a cable guide (1) and to a method for guiding a cable.

Description

Cable guide

The invention relates to a cable guide providing a passage for guiding at least a portion of at least one cable, said passage defining a centre line extending between a proximal end and a distal end of said passage. It is well known that fibre optical cables are susceptible to mechanical stress in that the signal transmission quality may significantly decrease if these stresses are too high. However, optical cables need to be guided or routed in various directions in spaces that are often severely limited or restricted. As a result significant curvature or bending of these optical cables is often unavoidable.

US 5,640,476 discloses a guide sleeve for a fibre optical cable partially curved along its length with a radius of curvature not less than the minimum bend radius, of the fibre optical cable. The cable may be inserted in and removed from the guide sleeve by means of a slot extending along the length of the sleeve.

However, the guide sleeve according to the prior art comprises several limitations with regard to e.g. the routing or guiding directions of cables.

It is an object of the invention to provide an improved cable guide wherein the limitations of the prior art cable guides are substantially reduced. This object is achieved by providing a cable guide characterised in that said centre line is at least partly defined along an imaginary helix such that said centre line at said distal end deflects away from an imaginary plane through said centre line at said proximal- end. The helical shape of the cable guide avoids bending of the cable with a curvature beneath the minimum bend radius before the cable degrades, while the distal end of the passage provided by the cable guide may point in any direction on the surface of an imaginary cylinder defined by the helix. Thus, a horizontally placed fibre ribbon may be guided vertically with an optimum bending and twisting of the cable to minimise the internal stress of the optical fibre. The cable guide introduces at most the same level of stress in the cable as a normal bending radius. This is important for the life time because a higher level of stress in the bare fiber causes a higher deterioration and shortens the product life time.

In a preferred embodiment of the invention the centre line deflects away such that the centre line at said proximal end is substantially perpendicular to the centre line at said distal end. This provides the possibility to guide a cable in a restricted space, such as behind a backpanel . However, a shorter passage may be applied as well, wherein the part of the cable near the distal end is not guided by the cable boot .

In a preferred embodiment of the invention the cable guide comprises a housing at the proximal end providing a further passage for the cable substantially aligned to said centre line of said passage. Preferably the housing comprises hinging means for opening the housing. The housing or cable guide may comprises cable tie means for mounting the cable to said housing or cable guide. These features provide the possibility of releasably pre-mounting of the cable guide to the cable. The cable guide thus is field installable, i.e. the cable guide can be mounted at the moment the guide direction for, the cable is known. Moreover, re-routing of the cable, i.e. guiding the cable in a direction different from a previous direction, can be performed easily by applying a cable guide with the hinging means and/or cable tie means .

In a preferred embodiment of the invention the cable guide is adapted to be mounted to a connector for the cable. The cable may be a flat fibre optical cable.

It should be appreciated that the embodiments, or aspects thereof, may be combined.

The invention also relates to a cable comprising a cable guide as described above. Cables may be provided with cable guides that are releasably mounted to these cables, as a result of which a guide or routing direction does not have to be decided upon prior to installing the cable. Moreover, rerouting of cables is less complex. The invention also relates to a method for guiding a cable using a cable guide as described above.

The invention also relates to a method for guiding a cable from a first direction to a second direction, deflecting away from said first direction using such a cable guide, comprising the steps of: releasing said cable pointing in said first direction from said cable tie means; - orienting said cable guide or a second cable guide such that said distal end points in said second direction; attaching said cable by said cable tie means in accordance with said passage.

The embodiments of the invention will be described into more detail below with reference to the attached drawing of which

Figs. 1A-E show a cable guide according to an embodiment of the invention in various stages of use;

Fig. 2 shows a backpanel wherein various cable guides are employed; Fig. 3 provides a geometrical clarification of the invention.

Figs. 1A-E show a cable guide 1 according to an embodiment of the invention in various stages of use.

As shown in Fig. 1A a cable guide 1 comprises a passage 2 defining a centre line 3 extending between a proximal end 4 and a distal end 5, and a housing 6. Housing 6 is located at the proximal end 4 of the passage 2. Housing 6 comprises a first part 7 and a second part 8 that are connected via hinging means 9. In Fig. 1A housing 6 is shown in an opened state. Housing 6 provides a further passage 10 substantially aligned to the centre line 3 of the passage 2. Moreover housing 6 comprises cable tie means 11 attached to the housing 6 by further hinging means 12. Cable tie means 12 may be closed by applying locking means 13, such as a pin adapted to co-operate with the cable tie means 11.

In Fig. IB the situation is shown wherein a cable 14 is inserted in the housing 6, or more specifically in the further passage 10, ready to be guided by means of the passage 2 of the cable guide 1. Cable 14 is mounted to the housing 6 in the further passage 10 by locking cable tie means 11 with locking means 13.

In Fig. 1C the situation is shown wherein a portion of the cable 14 is guided by the passage 2 of the cable guide 1. Cable 14 is represented here as a flat fibre optical cable. Centre line 3 is at least partly defined along an imaginary . helix such that this centre line 3 at the distal end 5 deflects away from a plane through said centre line 3 at said proximal end 4. In Fig. 3 this situation is shown in more detail. The level of stress in the cable 14 is low because the change in direction is made by a regular helical cable bend.

In Fig. ID housing 6 is shown in an open state and placed in abutting position against connector 15 and mounted to the cable by cable tie means 11.

In Fig. IE the situation is shown wherein the cable 14 is provided at the side of the housing 6 with the connector 15 ■ comprising a body 16 containing a ferrule with guide pins 17. Housing 6 is adapted to be mounted to the connector 15, by e.g closing housing 6 using the hinging means 9 and subsequent mechanical locking to the connector 15.

In Fig. 2 a backpanel 18 is shown with MPO connectors comprising coupling sleeve means 19. The coupling sleeve means 19 have been provided with a plurality of cable guides 1, none of them comprising a cable 14 here. As is clearly shown, the distal ends 5 of the cable guides 1 point in various directions. As a result, cables 14 may be guided or routed in these various directions by employing these cable guides 1 without degradation of the cable caused by severe bending. Note that in Fig. 2 only the passages 2 of the cable guides 1 are clearly visibly. The cable guides 1 are inserted into the housings 20 of the back panel 18.

Cable guides 1 can be advantageously applied for e.g. re-routing of cables 14 on a backpanel 18. Suppose that the distal end 5' of cable guide 1' shown in Fig. 1 points in a first direction 21 and the distal end 5" of cable guide 1" points in a second direction 22. Further suppose that a rerouting scheme requires the cable 14 (not shown in Fig. 2) guided by the cable guide 5' to be directed in the second direction 22 as well. Such a re-routing procedure may be performed as follows. First, cable guide 5' is released from the connecting means 19 together with the cable 14. Cable 14 is subsequently released from the cable guide 5' by opening the housing 6, hinged by hinging means 9 as shown in Fig. 1A, and opening the cable tie means 11. Next a new cable guide 1" is applied for guiding the cable 14 in the second direction 22 according to the procedure outlined in Figs. 1A-1E. Moreover, a cable 14 with a pre-mounted cable guide 1 can be applied. The direction for the distal end 5 of the passage 2 can be chosen freely upon connection of the cable 14 to the backpanel 18.

In Fig. ^'3A a cable 14 is shown guided over a cylinder 23 having an imaginary helix 24 wherein the distal end 5 of the passage 2 (not shown) deflects away from a plane through the center line 3 at the proximal end 4. Fig. 3B shown an equivalent picture for a flat fibre optical cable 14.

For the purpose of teaching the invention, preferred embodiments of the cable guide have been described above. It will be apparent for the person skilled in the art that other alternative and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the true spirit of the invention, the scope of the invention being only limited by the claims.

Claims

1. Cable guide (1) providing a passage (2) for guiding at least a portion of at least one cable (14) , said passage (2) defining a centre line (3) extending between a proximal end (4) and a distal end (5) of said passage (2) characterised in that said centre line (3) is at least partly defined along an imaginary helix (24) such that said centre line (3) at said distal end (5) deflects away from an imaginary plane through said centre line (3) at said proximal end (4) .

2. Cable guide (1) according to claim 1, wherein said centre line (3) deflects away such that said centre line (3) at said proximal end (4) is substantially perpendicular to said centre line (3) at said distal end (5) .

3. Cable guide (1) according to claim 1 or 2 , wherein said cable guide (1) comprises a housing (6) at said proximal end (4) providing a further passage (10) for said cable (14) substantially aligned to said centre line (3) of said passage (2) .

4. Cable guide (1) according to claim 3, wherein said housing' (6) comprises hinging means (9) for opening said housing (6) .

5. Cable guide according to claim 3 or 4, wherein said housing (6) or said cable guide (1) comprises cable tie means

(11) for mounting said cable (14) to and/or in said housing (6) aήd/or said cable guide (1) .

6. Cable guide (1) according to any of the preceding claims wherein said cable guide (1) is adapted to be mounted to a connector (15) .

7. Cable guide (1) according to one of the preceding claims, wherein said cable (14) is a flat fibre optical cable.

8. Fibre optical cable (14) comprising at least one cable guide (1) according to any of the preceding claims.

9. Method for guiding a cable (14) using a cable guide (1) according to any of the claims 1-7.

10. Method according to claim 9, wherein multiple cables (14) are guided by multiple cable guides (1, i', 1") comprising corresponding passages (2, 2', 2"), said centre lines 3 of said passages (2, 2', 2") deflecting away from said plane in at least a first (21) and a second direction (22) .

11. Method for guiding a cable (14) from a first direction (21) to a second direction (22) , deflecting away from said first direction (21) using a cable guide (1) according to one of the claims 1-5, comprising the steps of: - releasing said cable (14) pointing in said first direction (21) from said cable tie means (11) ; - orienting said cable guide (1) or a second cable guide (!' ; 1") such that said distal end (5) points in said second direction (22) ; attaching said cable (14) by said cable tie means (11) in accordance with said passage (2) .