GB2308361A - Improved optical fibre cleaver - Google Patents

Abstract

An optical fibre cleaver 10 has location means 11 for an end of an optical fibre. The cleaver 10 also includes a clamping means 13 and a tensioned clamping means 14, as well as having a curved anvil 15 and a diamond blade 16. The clamping means 14 is tensioned so that such clamping means 14 is attempting to move away from the diamond blade 16. The cleaver also has an operating means 17 which is operated by pushing downwardly thereon. Once the fibre 12 has been clamped in position then the operating means 17 is operated and the diamond blade 16 is brought down towards the anvil 15 and nicks the fibre 12, the fibre breaking off by the tensioned clamping means 14 moving away from the diamond blade 15. In such position of use, the operating means 17 returns to its original position and, in so doing, causes member 18 to move downwardly via linkage 19. Such downward movement of member 18 contacts the end region of the fibre offcut and by continuing its downward movement causes said offcut 21 to be forced into the container 20 acting as a sharps bin located in the cleaver 10. Upward movement of the operating means 17 permits the cut end of the optical fibre to be removed.

Description

IMPROVEMENTS IN OR RELATING TO CLEAVING TOOLS The present invention concerns improvements in or relating to cleaving tools. More particularly, the present invention is concerned with an optical fibre cleaving tool.

There are several optical fibre cleaving tools on the market. Such cleaving tools are used for producing flat square ends to optical fibres which are subsequently joined together.

When joining optical fibres together, either using mechanical splices, or by fusing them together, the fibres must have very flat square ends to ensure a good optical joint.

There is an increasing use of optical fibres in many industries, particularly in connection with telecommunications. In order to ensure that information may be passed down said optical fibres, it is necessary to have a good optical joint between ends of such fibres.

The current method of producing flat square ends of optical fibres is by use of a cleaving tool. Such tool includes a channel member for location of the end of the optical fibre therein, clamping means for clamping the fibre in position, tensioning means for tensioning the fibre, an anvil and a diamond blade. In operation, the fibre is tensioned over a curved anvil and then the fibre is nicked with a diamond blade. As the fibre is under tension, the fibre breaks at the point of nicking by the diamond blade and a flat end of the fibre is obtained. In order to obtain good results, the tension in the fibre, the position of the blade and the clamping of the fibre need to be accurately controlled.

Current optical fibre cleaving tools are available which can consistently produce flat cleaved fibre ends with end angles of less than 0.5 from square.

Before the fibre can be cleaved, all of the protective coating needs to be removed leaving the bare usually 125m diameter glass fibre. Once cleaved, a portion of the fibre is left on the cleaver which is typically 20 to 60 mm of 125corm diameter glass. This is the piece of fibre left over after cleaving has been effected and is known as fibre offcut.

Currently such offcut has to be removed by hand and disposed of safely. When operating the cleaver, if such offcuts are not disposed of safely, they can cause problems by possibly damaging the operator or a third party if the offcuts are not safely collected. Usually, a sharps bin is utilised in which the offcuts are disposed.

However, this can be a difficult operation to carry out because of the small size of the fibre offcut and the fact that the operator usually has his hands full holding both the cleaver and the cleaved fibre.

It is an object of the present invention to provide a cleaving tool, particularly suitable for cleaving optical fibres, which incorporates means for safely disposing of the fibre offcut.

According to the present invention there is provided a cleaving tool comprising locating means for locating an end of a length of elongate material, suitably optical fibre, therein, anvil means on which the material may rest, clamping and tensioning means for clamping and tensioning said elongate material on either side of said anvil means, in the direction of travel, a diamond blade means which, in use, will nick the elongate material at a selected point, operating means for operating said cleaving tool and means within said cleaving tool for safely disposing of the end of the material cut off during said cleaving operation.

The present invention will be further described in respect of cleaving of optical fibres, but it will be clear that the device of the invention may also be utilised in connection with other elongate material of similar nature.

In a preferred embodiment, the means for safely removing the optical fibre off cut will operate automatically to cause such offcut to be ejected into a container located within the body of the cleaving tool.

Thus, in a preferred method of operation, an end of an optical fibre, after the protective coating has been removed therefrom, is located in a channel member of a cleaving tool in accordance with the invention. Such tool is suitably provided with operating means, suitably in the form of a button type member, which when operated will cause the fibre to be clamped in position over the anvil means and the offcut end of the fibre is clamped and tensioned. When the diamond blade is operated, the tensioning means, which is tensioned so as to cause the offcut to be pulled away from the point at which the fibre is nicked by the diamond blade, is caused to operate and then further operation of the operating means of the cleaving tool of the invention causes the fibre offcut to be removed from the channel member and located in a container within the cleaving tool.Such means for safe removal of the offcut operates automatically and in synchronism. Thereafter, the cleaving tool is then ready for further use.

It will thus be seen that the cleaving tool in accordance with the present invention automatically disposes of optical fibre offcuts in a safe manner by appropriate use of the operating means. It is intended that the cleaving tool will be of appropriate size so that same can be hand held and carried around by the user. Moreover, the operating means can be operated by either a left-handed or right-handed operator. The casing of the cleaving tool is suitably formed of cast metal and will have an opening, suitably in the form of a channel, so as to guide the end of the optical fibre into the location means provided in the cleaving tool.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic section through an optical fibre cleaver in accordance with the present invention in its first position of operation; Fig. 2 is the same section through the cleaver in its second position of operation; and Fig. 3 is the same section through the cleaver in its third position of operation.

As illustrated, the optical fibre cleaver in accordance with the invention is generally referenced 10.

Such cleaver 10 has location means 11 for an end 12 of an optical fibre, from which the fibre has been stripped of all protective coatings. The cleaver 10 also includes a clamping means 13 and a tensioned clamping means 14 as well as having a curved anvil 15 and a diamond blade 16.

The clamping means 14 is tensioned by a suitable spring arrangement so that the clamping means 14 is attempting to move away from the diamond blade 16 as illustrated in Fig. 1. The cleaver also has an operating means 17 which is operated by pushing downwardly thereon.

In the position of use shown in Fig. 1, the end of the optical fibre 12 is located in the locating means 11 suitably in the form of a channel.

In the position of use as shown in Fig. 2, the operating means 17 has been depressed and clamping means 13 and 14 then clamp the end of the fibre 12 in position and the diamond blade is brought down towards the anvil 15 and nicks the fibre 12. The fibre now breaks off by the tensioned clamping means 14 moving away from the diamond blade 16.

In the position of use shown in Fig. 3, the operating means 17 is allowed to return to its original position. In so doing, said means 17 causes member 18 to move downwardly via linkage 19. Such downward movement of member 18, contacts the end region of the fibre offcut and by continuing its downward movement causes said offcut 21 to be forced into the container 20 acting as a sharps bin located in the cleaver 10. Such upward movement of operating means 17 permits the cut end of the optical fibre to be removed, said cut end having an end angle of less than 0.5 from square.

The fibre offcut 21 is safely disposed of in the container 20 of the cleaver 10. In order to assist the location of such fibre offcut in the container 20, suitable roller means 22 are provided which causes the fibre offcut to bend round same and thereby ensures the location of such fibre offcut 21 in the container 20.

In order to prevent the fibre/offcut 21 from breaking as it is forced into the container 20, an angled deflector may be provided which pushes the fibre around the clamping means 14 thus ensuring the bend radius of the offcut does not exceed that which would cause it to break.

The cleaving tool in accordance with the invention is compact and is easily held in the hand, and can be operated by either a left-handed or right-handed operator. Moreover, the cleaving tool of the present invention does not require to be located on any fixed surface in order to be operational and simple location of an end of an optical fibre in the cleaving tool of the invention will ensure that an appropriate flat cleaved fibre end is produced and the fibre offcut is safely disposed of. Such action is achieved in an automatic manner by operation of the operating means.

In order to facilitate location of the fibre end in the cleaving tool of the present invention, the outer casing of the cleaving tool can be provided with a channel portion which directs the fibre end into its correct location in the cleaving tool.

The cleaving tool of the present invention can be used over and over again, each operation of the operating means causing the required flat cleaved fibre end to be produced and its associated fibre offcut to be safely disposed of.

Whilst the present invention has been described in relation to producing flat cleaved fibre ends of optical fibres, it is also possible for such device to be used in connection with producing other cleaved ends of similar material.

It is to be understood that appropriate modifications can be effected in respect of the various integers forming the cleaving tool of the present invention and the mode of the operation thereof can be varied as required.

Claims (9)

1. A cleaving tool comprising locating means for locating an end of a length of elongate material, suitably optical fibre, therein, anvil means on which the material may rest, clamping and tensioning means for clamping and tensioning said elongate material on either side of said anvil means, in the direction of travel, a diamond blade means which, in use, will nick the elongate material at a selected point, operating means for operating said cleaving tool and means within said cleaving tool for safely disposing of the end of the material cut off during said cleaving operation.

2. A cleaving tool as claimed in claim 1, in which the means for safely removing the end of the material cut off during the cleaving operation, operates automatically to cause such offcut to be ejected into a container located within the body of the cleaving tool.

3. A cleaving tool as claimed in claim 1 or 2, in which the operating means comprises a button-type member.

4. A cleaving tool as claimed in claim 1, 2 or 3, in which the locating means comprises a channel member.

5. A cleaving tool as claimed in any preceding claim, in which the casing of the cleaving tool is formed of cast metal.

6. A cleaving tool as claimed in claim 5, in which the casing has an opening in the form of a channel so as to guide the end of the elongate material into the location means.

7. A cleaving tool as claimed in any preceding claim, substantially as hereinbefore described with reference to the accompanying drawings.

8. A method of operating a cleaving tool as claimed in any preceding claim, comprising locating an end of an optical fibre, after the protective coating has been removed therefrom, in a channel member of said cleaving tool, operating said operating means to cause the fibre to be clamped in position over the anvil means and the offcut end of the fibre to be clamped and tensioned, operating the diamond blade so as to nick said fibre, operating said tensioning means so as to cause the offcut to be pulled away from the point at which the fibre is nicked by the diamond blade, further operating the operating means to cause the fibre offcut to be removed from the channel member and to be located in a container within the cleaving tool.

9. A method as claimed in claim 8, substantially as hereinbefore described with reference to the accompanying drawings.