GB2144070A - Optical fibre cable preparation tool - Google Patents

Abstract

A positioning barrel C rotatably supports a cutter A which, when the whole tool is passed onto a fibre optic cable for preparation purposes, is closed onto the protective cable sheath when an adjusting screw E is rotated. The screw E is rotated until resistance is felt, the cutter is then rotated by a key D causing the sheath to be cut evenly, the screw is retightened followed by further rotation of the cutter. Tightening of the screw and rotation of the cutter is continued until the sheath is almost fully parted which coincides with the cutter being in the fully closed position. The parted and unwanted section of the sheath may then be eased away from the cable assembly and withdrawn by careful manipulation of the whole tool. <IMAGE>

Description

SPECIFICATION Optical fibre cable preparation tool Figure (1) shows a full size cross section through the assembly.

The purpose of the tool is to allow the careful removal of the tubular protection sheath from around the optical fibre core of telecommunication cable.

Cutter (A), connecting shaft (B) and rotation key (D), form one effective cutter assembly which freely rotates in positioning barrel (C).

For operation, the whole assembly is pushed over the exposed cable protection sheath and down to the strip back position under the wire braiding. The cutter adjusting screw (E) is rotated clockwise until resistance is felt-indicating cutter penetration. The cutter assembly is then rotated to facilitate even cutting. The adjustable screw is retightened followed by further rotation of the cutter assembly.

The above process of tightening and cutting is continued until the protection sheath is almost fully parted at the cutting point. This position coincides with the cutter attaining its fully closed state, thus preventing over penetration (see Fig. 2).

Slight bending movements accompanying tool withdrawal facilitate parting of the sheath with the spent portion being discarded through the hollow shaft (B).

Items B, C, D, and E are manufactured from (so 970 PT. 1 1972080 M 40).

The cutter item A is manufactured from (BS 4659 BD3 KE. 970) tool steel hardened and tempered to 55/60 Rockwell C.

1. A multipart, hollow-section hand tool with rotating cutter for the purpose of removing the layer or layers of protective sheathing from fibre optic telecommunication cable as part of the process of making connection with a connection device for the purpose of rendering the cable operational.

2. A handtool according to claim 1, in which the depth of annular cut into the protective sheathing may be controlled by the dimensions of the radially fully compressed tool steel cutter. These dimensions are predetermined by jig controlled precision machining of the cutter.

3. A handtool according to claim 1, in which the depth of annular cut into the protective sheathing may be controlled by means of two adjustable locknuts which are fitted to cutter adjusting screw E as indicated in drawing Fig. 1. The locknuts predetermine the length of travel of the cutter adjusting screw which in turn fixes the maximum radial compression of the precision machined tool steel cutter.

4. A handtool according to claim 1, and claims 2 or 3 in which the piece of spent sheathing is held captive by the tool after cutting thus permitting recovery of the same piece of spent sheathing by means of a steady pull on the complete handtool which in turn exposes the optical fibre component of the cable assembly ready for further connection processing.

5. A handtool substantially as described in which support bushes may be inserted into connecting shaft B directly behind the cutter A for the purpose of supporting cable assemblies of differing diameters to afford a high level of accuracy to the depth of cut described in previous claims.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Optical fibre cable preparation tool Figure (1) shows a full size cross section through the assembly. The purpose of the tool is to allow the careful removal of the tubular protection sheath from around the optical fibre core of telecommunication cable. Cutter (A), connecting shaft (B) and rotation key (D), form one effective cutter assembly which freely rotates in positioning barrel (C). For operation, the whole assembly is pushed over the exposed cable protection sheath and down to the strip back position under the wire braiding. The cutter adjusting screw (E) is rotated clockwise until resistance is felt-indicating cutter penetration. The cutter assembly is then rotated to facilitate even cutting. The adjustable screw is retightened followed by further rotation of the cutter assembly. The above process of tightening and cutting is continued until the protection sheath is almost fully parted at the cutting point. This position coincides with the cutter attaining its fully closed state, thus preventing over penetration (see Fig. 2). Slight bending movements accompanying tool withdrawal facilitate parting of the sheath with the spent portion being discarded through the hollow shaft (B). Items B, C, D, and E are manufactured from (so 970 PT. 1 1972080 M 40). The cutter item A is manufactured from (BS 4659 BD3 KE. 970) tool steel hardened and tempered to 55/60 Rockwell C. CLAIMS

1. A multipart, hollow-section hand tool with rotating cutter for the purpose of removing the layer or layers of protective sheathing from fibre optic telecommunication cable as part of the process of making connection with a connection device for the purpose of rendering the cable operational.

2. A handtool according to claim 1, in which the depth of annular cut into the protective sheathing may be controlled by the dimensions of the radially fully compressed tool steel cutter. These dimensions are predetermined by jig controlled precision machining of the cutter.

3. A handtool according to claim 1, in which the depth of annular cut into the protective sheathing may be controlled by means of two adjustable locknuts which are fitted to cutter adjusting screw E as indicated in drawing Fig. 1. The locknuts predetermine the length of travel of the cutter adjusting screw which in turn fixes the maximum radial compression of the precision machined tool steel cutter.

4. A handtool according to claim 1, and claims 2 or 3 in which the piece of spent sheathing is held captive by the tool after cutting thus permitting recovery of the same piece of spent sheathing by means of a steady pull on the complete handtool which in turn exposes the optical fibre component of the cable assembly ready for further connection processing.

5. A handtool substantially as described in which support bushes may be inserted into connecting shaft B directly behind the cutter A for the purpose of supporting cable assemblies of differing diameters to afford a high level of accuracy to the depth of cut described in previous claims.