GB2193603A

GB2193603A - A splice protection assembly

Info

Publication number: GB2193603A
Application number: GB08619397A
Authority: GB
Inventors: Alan Kershaw
Original assignee: Plessey Co Ltd
Current assignee: Plessey Co Ltd
Priority date: 1986-08-08
Filing date: 1986-08-08
Publication date: 1988-02-10
Also published as: GB8619397D0

Abstract

A splice protection assembly in which spliced cables (15) are held directly by respective spigots 3 in internal bores 7 which are partially collapsed when the spigots 3 are secured with a sleeve member 1 holding them at displaced positions. The spigots 3 have two parts with the internal bore, the first part 9 entering the sleeve and the second part 11 limiting entry by the first part 9 by abutting an end of the sleeve 1. <IMAGE>

Description

SPECIFICATION A splice protection assembly The present invention relates to a splice protection assembly and more particularly but not exclusively to splice protection assemblies used with optical fibres.

Optical fibres which are spliced require protection to protect the brittle junction between the fibres breaking when bent or exposed to tensile stress. This protection usually involves anchoring a cover or sheath over the fibre splice at displaced positions along the length of each fibre from the splice such that a portion of each fibre is held rigidly in its position after assembly and any applied tension to them is not transmitted to the splice location.

A common type of splice protection is of a "piggy-back" configuration comprising a sheath of crimpable material such as polythene with a rigid reinforcing bar adhered to the sheath. The sheath being crimped to the fibre.

These prior splice protection assemblies have been expensive in terms of cost of assembly and space required. The assemblies have also been found to be susceptible to damage during installation and operation.

It is an objective of the present invention to provide a splice protection assembly which is relatively easy to assemble and provides good protection from tensile stress damage and damage due to collisions during installation.

According to the present invention there is provided a splice protection assembly for protecting a cable splice comprising a sleeve member and two spigot members each spigot member having an internal bore to accommodate a respective cable end and having a two part construction, a first part to enter the sleeve member and a second part to limit the entry of the first part into the sleeve, the sleeve being secured onto each spigot substantially securing them and partially collapsing the internal bore of each spigot substantially fixing each cable into its respective spigot.

Preferably, the first parts of the spigots should span the length of the sleeve member when both are inserted.

The sleeve member and spigots may be secured by crimping or thermal deformation thus ensuring collapse of the spigot internal bore.

The second part of the spigot member may abut the sleeve to prevent further entry of the first part into the sleeve.

The spigots and sleeve member may be made of plastics or metal..

A method of constructing a splice protection assembly according to the present invention is also provided including threading each cable through its respective spigot, passing one cable through the sleeve member, splicing the cables, bringing the sleeve member over the splice, inserting the first part of each spigot into the sleeve and securing the sleeve member to each spigot such that the internal bore of the spigot partially collapses securing the cable.

An embodiment of the present invention will now be described by way of example only with respect to the accompanying drawings in which: Figure 1 illustrates in front elevation a splice protection assembly according to the present invention; Figure 2 shows an end elevation of the splice protection assembly as illustrated in Figure 1; and, Figure 3 shows a perspective view of a completely assembled splice protection assembly as illustrated in Figure 1.

Consider Figures 1 to 3, the splice protection assembly comprises a sleeve member 1 and two end stepped spigots 3 each having a bore 7 to accommodate an optical fibre. The internal diameter 5 of the sleeve 1 is substantially the same as that of a first spigot part 9 and the spigot 3 having a second part 11 of larger diameter. When assembled the splice protection assembly thus has a respective optical fibre cable 15 passing through bore 7 in each spigot 3 inserted into sleeve 1 such that each second part 11 of the spigot 3 abuts respective ends of the sleeve 1. The optical fibres being spliced at some position within the sleeve 1. The ends of the sleeve 1 are crimped 17 onto the spigots 3 such that the spigots 3 are rigidly held within the sleeve 1 and the bore 7 in the spigot 3 partially collapsed gripping the optical fibre cable 15 passing there through.The assembly thus crimps directly to the optical cable 15.

A typical method of producing a splice protection assembly according to the present invention would include the following steps: (1) threading the optical fibre cables 15 to be spliced through respective spigots 3; (2) threading one of the optical fibre cables 15 through the sleeve 1; (3) effecting a splice of the optical fibres; (4) locating the sleeve 1 and spigots 3 such that the sleeve 1 is over the splice and the first part 9 of each spigot 3 is inserted into the sleeve 1 until the second part 11 abuts an end of the sleeve 1; (5) crimping the ends of the sleeve member 1 to respective spigots 3 such that each spigot is substantially held in the sleeve 1 and the bore 7 in each spigot 3 partially collapses gripping the optical fibre cable 15.

It will be appreciated that several types of material may be used to fabricate sleeve member 1 and spigots 3 including metals and plastics materials and also dependent upon the material used specific dimensions such as spigot wall thicknesses may be altered to allow effective crimping etc. The length of the spigot 3 first part 9 is important as this provides support for the optical fibre in the assembly and ideally the first parts 9 of each spigot should constitute a large proportion of the length of the sleeve member 1. The thickness of the wall 21 of the spigot 3 along with that of the sleeve 1 are important to ensure collapse of the bore 7 and thus securing of the optical cable 15.

Although, crimping has been defined as the securing method other techniques such as thermal deformation may be used with suitable types of material.

Claims

1. A splice protection assembly for protecting a cable splice comprising a sleeve member and two spigot members each spigot member having an internal bore to accomodate a respective cable end and having a two part construction, a first part to enter the sleeve member and a second part to limit the entry of the first part into the sleeve, the sleeve being secured onto each spigot substantially securing them and partially collapsing the internal bore of each spigot substantially fixing each cable in to its respective spigot.

2. A splice protection assembly as claimed in claim 1 wherein the first parts of the spigots span the length of the sleeve member when both are inserted into the sleeve.

3. A splice protection assembly as claimed in claim 1 or 2 wherein the spigots and sleeve are secured by crimping the two together thus collapsing the internal bore of each spigot.

4. A splice protection assembly as claimed in claim 1 or 2 wherein the spigots and sleeve are secured by thermal deformation thus collapsing the internal bore of each spigot.

5. A splice protection assembly as claimed in any preceding claim wherein the second part of each spigot member abuts an end of the sleeve to prevent further entry of the first part into the sleeve.

6. A splice protection assembly as claimed in any preceding claim wherein the sleeve member is constructed of a metal.

7. A splice protection assembly as claimed in claim 1 or 2 wherein the sleeve member is constructed of a plastics material.

8. A splice protection assembly as claimed in any preceding claim wherein the spigot members are constructed of a metal.

9. A splice protection assembly as claimed in any one of claims 1 to 7 wherein the spigot members are made of a plastics material.

10. A method of constructing a splice protection assembly including threading each cable through a respective spigot member, passing one cable through a sleeve member, splicing the cables, bringing the sleeve member over the splice, inserting first parts of each spigot into the sleeve and securing the sleeve member to each spigot such that the internal bore of the spigot partially collapses securing the cable.

11. A method of constructing a splice protection assembly as claimed in claim 10 wherein the sleeve member is hecured to the spigots by crimping.

12. A method of constructing a splice protection assembly as claimed in claim 10 wherein the sleeve member is secured to the spigots by thermal deformation.

13. A splice protection assembly substantially as hereinbefore described with reference to the accompanying drawings.

14. A method of constructing a splice protection assembly substantially as hereinbefore described with reference to the accompanying drawings.