WO2004053551A1

WO2004053551A1 - Separating device for cutting cables, especially optical waveguides

Info

Publication number: WO2004053551A1
Application number: PCT/IB2003/005842
Authority: WO
Inventors: Ulrich Mühlematter; Leo Bühler; Roger BÄRTSCHI
Original assignee: Schleuniger Holding Ag
Priority date: 2002-12-10
Filing date: 2003-12-10
Publication date: 2004-06-24
Also published as: AU2003302813A1

Abstract

The invention relates to a separating device (1) for cutting cables (3), especially optical waveguides. The inventive separating device (1) allows the individual machining processes (separating and finishing) of cable ends to be carried out in the same operation. Said separating device (1) comprises a separating tool (2) and at least one clamping device (4) and is characterized by the fact that at least one defined or undefined blade (7) preferably a grinding tool (9) or a milling tool is provided on at least one of the lateral faces thereof or next to a separating blade. The cables are retained by at least one clamping device (4) that is fixed to the chassis. In an alternative embodiment, the ferrule that is fastened to the cable is retained by means of a clamping device (4) while the protruding cable end is machined. The delivering movement for machining terminal cable surfaces can be performed by the separating tool (2), the clamping device (4), or both. The cable is separated by the separating tool (2) in a first step and is finished immediately thereafter.

Description

Cutting device and method for cutting cables, in particular optical fibers

The invention relates to a separating device and a method for cutting cables, in particular optical fibers.

It has already been recognized that the surface of a cable end can be optimized by carefully centered cutting or re-cutting and grinding or polishing.

The state of the art includes machines which use the above-mentioned methods, e.g. WO-A2-01 / 71399 discloses the central positioning of an optical waveguide in a ferrule. Applicant's DE-A-10033175 describes a method for achieving good quality of cable end faces by means of several re-cuts (increasingly thin slices are cut off) of the cable end.

Other processes in this area are characterized in that the separation and processing processes of the cable end are carried out in succession in separate steps. For example, a separator and a grinder are placed side by side and an operator inserts the cable end first into the separator and then into the grinder.

definitions

- Central positioning is understood to mean that the inner conductor comes to lie in the longitudinal axis of the cable or in the longitudinal transport axis of the cable. This improves the quality of transmissions over such cable ends, in particular when two cable ends are plugged together in a plug connection

BESTATIGUNGSKOPIE become. For this reason, efforts are being made to position optical fibers centrally in ferrules, for example.

- A ferrule is a continuous holder in which a fiber e.g. is preferably attached centered with adhesive. It is a ferrule in the conventional sense, but also e.g. a connector housing or the like. to understand.

- Under cable in the sense of the invention, due to the finishing operations usually necessary there, in particular optical fibers, such as

To understand POF or fiber optic cable, but the invention is not limited to this, but includes all cables in the conventional sense, including cables that can conduct electrical signals instead of light waves.

- Tools with a defined cutting edge have at least one geometrically defined edge that is suitable for machining (saw, knife, scraping or milling tool, or the like).

- Machining tools with undefined cutting edges using geometrically undefined edges. These are usually applied to a base material in the form of hard material grains and may possibly be conditioned by a dressing process for more precise machining. Typical examples are grinding wheels (with different types of grain binding),

Abrasive and polishing foils or lapping tools. The inventor recognized that the known systems are disadvantageous in the following points:

a) The previous machines for processing cables are each specialized in a specific activity, so that several are set up, on which several operations have to be carried out in succession, which makes the processing process cumbersome and slow and requires handling of the cable between the stations.

b) The already improved device according to DE-A-10033175 is only for certain cable types e.g. Suitable for POF.

The invention is therefore based on the object of providing a device and a method which avoids the disadvantages indicated and is suitable for combining the individual steps of processing cables and thus accelerating them.

This task is solved by

i) the integration of the separation and surface finishing processes.

ii) The cutting tool is characterized in accordance with the invention in that it has a cutting edge with at least one defined or undefined sheath and a defined or undefined cutting edge for the finishing work is arranged on at least one of its two side surfaces.

iii) There is a relative infeed movement in the separating direction (generally radial on the cable) and preferably also in the finishing direction (axial direction of the cable) between the now only separating tool with respect to the cable. In a specific exemplary embodiment, the cutting tool is characterized, for example, by the fact that it has a cutting edge (cutting) on a circular saw blade and at least one defined or undefined cutting edge is arranged on at least one of its two side surfaces.

According to a further development, a grinding wheel is attached to both sides of the circular saw blade, which has at least one single-layer covering, e.g. made of diamond grains. On the back of the saw blade, an elastic pad e.g. Rubber, which increases the elasticity of a sanding film during the finishing process of cable ends.

According to a further development of the invention, an improved effectiveness of the grinding wheels in the finishing of the cable end is achieved in that the grinding wheels are moved in addition to the rotation outside of the axis. As a positive side effect, the surfaces of the grinding wheels are evenly loaded and worn.

In a preferred embodiment, the feed movement of the circular saw blade is motorized in the cutting direction (rotation of the

Circular saw blade and feed across the cable axis). The optical waveguide or the ferrule attached to it is held by a clamping device. The chassis-fixed clamping device can be shifted in the axis of the conductor in order to provide corresponding space for the cutting tool. After disconnecting the light guide, the

Clamping device away from the cutting tool in order to secure enough space for the side-mounted grinding wheel for finishing the cable end. In this exemplary embodiment, the grinding wheel has the task of grinding or polishing the cable end surface with a short time shift or immediately after the optical waveguide has been separated. Alternatively, this removal movement can also be carried out by the cutting tool itself, if it is mounted on a corresponding slide, as is known per se.

If the cutting tool carries a grinding wheel (or defined cutting edges) on both sides and the cable is held by two clamping devices, between which it is to be cut, both cable end surfaces can be finished at their cutting surfaces at the same time.

The feed movements of the cutting tool and the

Clamping devices are preferably synchronized with one another in order to enable rapid and trouble-free operation.

The combination of separation and surface finishing processes described above achieves the following improvements in the following steps:

- With the integration of the processes, the individual activities (cutting and surface processing) are carried out in the same working step in the separating device according to the invention and are thereby simplified and accelerated.

- The integration also ensures that the coordination of the movements can be simplified by a computer and thus the machining precision can be increased. It does not apply

To reclamp between the operations, so that fewer geometric errors result from the clamping process.

Embodiments of the invention and variants thereof are specified in the dependent claims.

The details of the solution to the basic concept of the invention can be implemented in various embodiments. A tube in which a slot for the cutting tool is milled can replace the clamping device, for example. The conductor is held frictionally in the tube and separated from the circular saw blade in the slot.

According to another variant, the grinding wheel can be fully integrated in the circular saw blade. This solution has the advantage that the infeed movement of the clamping devices after cleaving is only limited to the slight movement in the axial direction of the cable required for polishing.

Furthermore, instead of the circular saw, e.g. a cutting edge made of abrasive - as known per se for cutting using an angle grinder.

A CBN, ie. cutting disc made of cubic boron nitride. Such CBN cut-off wheels are used particularly advantageously in the processing of optical fibers.

Another variant is based on the idea that several optical fibers are held by clamping devices lying in parallel, and the feed movement of the saw blade takes place transversely to all clamping devices. In this case, the clamping devices will usually remain in place throughout the process.

Variants are also conceivable in which the grinding wheel does not have a coherent surface, but the diamonds or cutting edges are distributed over several cutting blocks. The individual cutting blocks are spaced apart from one another at certain intervals and are preferably located further outside on the disk, so that the higher peripheral speed of the saw blade leads to a faster cutting speed. In further development of this thought the cable end can also be refined by a single cutting block, which contains a defined cutting edge, for example.

According to a further variant, the cutting of the saw blade and / or the sheaths of the side surface can also be done with a liquid abrasive - e.g. is sprayed on during the grinding or polishing process.

Furthermore, it is thus conceivable that the rotating tool is sprinkled or built up with hard grains such as corundum split or diamond split both on one or on both side surfaces and possibly also on its edge, which thus also fulfills the separating function in addition to the surface finishing function.

The possibility in the separating device according to the invention that only one cable end is treated by the rotating tool is not excluded. This is done with a clamping device (without

Infeed movement), in which only one end of the cable is fastened, the infeed movement usually being carried out by the separating device.

Another application of the invention relates to the separation and refinement of a glass fiber which is held in a ferrule with adhesive. The fiber is separated (cleave) with the edge of a sanding film and then - using the axial elasticity of the film and possibly the underlay - the end surface is refined. This end surface consists of the glass fiber and possibly also of adhesive, which protrudes over the end of the ferrule. Under favorable conditions, finishing is possible even without an additional axial feed movement. The ferrule, which is normally made of a hard plastic, is able to reject the resilient tool without being significantly machined on its end face. Preferably, however, the ferrule can also be machined with a rigid grinding wheel, even if it is to be shortened to a certain length. The list of reference symbols and the drawings, together with the objects described or protected in the claims, form an integral part of the disclosure of this application.

figure description

The figures are described coherently and comprehensively. The same reference symbols mean the same components, reference symbols with different indices indicate components with the same function.

It shows:

1 shows a representation of the separating device according to the invention, which consists of a separating tool and two clamping devices and in which the separating tool and, if appropriate, also the clamping devices can be moved or delivered;

2 shows the side surface of a cutting tool which, in addition to its cutting edge, also contains an abrasive coating (grinding wheel);

3 shows the side face of a cutting tool, in which the defined (n) or undefined (n) cutting edge (s) is (are) arranged or formed on a plurality of cutting blocks;

4 shows the side face of a cutting tool according to FIG. 3, in which the defined or undefined cutting edge is arranged or formed on a cutting block; 5 shows a separating tool, the side face and preferably also the separating edge of which are covered with hard material grains (such as corundum or diamond split);

6 shows an illustration of a separating device in which the cable is held by a (single) clamping device, the separating tool not being movable in the axial direction of the cable;

7 shows a separating device according to FIG. 6, which has two clamping devices, the separating tool of which can be moved up and down or transversely to the cable and normally additionally back and forth in the longitudinal direction of the cable;

FIG. 8 shows an illustration of a separating device according to FIG. 6, in which instead of the clamping device the separating tool carries out the respective feed movement (s);

9 shows the side face of an elongated saw blade which - comparable to a file or jigsaw - can be moved up and down and optionally back and forth in the longitudinal direction of the cable;

FIG. 10 the side surface of an elongated saw blade according to FIG. 9, in which a grinding or polishing surface is integrated instead of defined cutting edges;

Fig. 11 is a side view of a separating tool that has an elastic base between the actual tool and the holder, e.g. made of rubber;

12 shows a view from slightly obliquely above of a separating device according to the invention, with the possibility of finishing the cable end; FIG. 13 shows a detail of the clamping device which is arranged in the separating device according to FIG. 12;

1 shows a separating device 1 according to the invention, which has a separating tool 2 and two clamping devices 4. The cable

(Optical fiber) 3 is held by the clamping devices 4, which are fixed to the chassis and can be moved back and forth in the longitudinal direction of the cable.

The cutting tool 2 is characterized in that on both side surfaces (at a certain distance) a grinding tool 8 e.g. is provided with diamond.

The feed movements of the separating tool 2 and the clamping devices 4 are synchronized with one another. The cable 3 is separated from the cutting tool 2 first. After separation, the clamping devices 4 diverge to provide enough space for the grinding tools 8 to polish the cable ends.

In Fig. 1, another possibility is conceivable than after which the separating tool 2, which is located between the clamping devices 4 after the cable 3 has been severed, stops during the entire machining process between the cable ends, and the feed movement of the cables 3 and / or Clamping devices 4 for cutting and / or polishing is carried out by the clamping devices 4 by the cutting tool being displaceable on an X or XY slide.

2 shows a side face of a cutting tool 2 which, in addition to the cutting blade 7, also contains a grinding wheel 9 (or grinding pad). The radius of the grinding wheel 9 should preferably be smaller by at least the diameter of the cable 3 than the radius of the cutting tool 2. In this construction, the width of the cutting tool 2 and that of the grinding wheel 9 are preferably the same. 3 shows a side face of a cutting tool 2, in which tools for finishing on the surface of the cutting tool 2 are distributed over several cutting blocks 8. Either at least one undefined cutting edge (eg corundum or diamond) or a defined cutting edge (eg a milling tool), the shape of which can be formed on the surface, is provided on a cutting block 8.

The cutting blocks 8, which are spaced apart from one another at certain intervals (preferably irregularly in order to prevent sound being generated by rotation as far as possible), are located at least on one of the two side surfaces of the separating tool 2.

It is worthwhile to position the cutting blocks 8 as far as possible radially outside on the surface of the cutting tool 2 so that the greater peripheral speed can be used.

FIG. 4 shows the side face of a separating tool 2 according to FIG. 3, in which the tool for finishing is attached to a single cutting block 8 on the surface of the separating tool 2. Either at least one undefined cutting edge (e.g. corundum or diamond) or a defined cutting edge (e.g. a milling tool), the shape of which can be formed on the surface, is provided on the cutting block 8.

5 shows a cutting tool 2 in which both the surface of the cutting blade 7 and that of the grinding wheel (or grinding pad) 9 - which is located on at least one of the two side surfaces of the cutting tool 2 - have undefined cutting edges, for example diamond or corundum are busy. In addition to cutting, the undefined cutting edges are also responsible for polishing. 2004/053551

12

FIG. 6 shows a separating device 1 which has a separating tool 2 and a clamping device 4. The separating tool 2 is characterized in that it cannot be moved together with the cable in this exemplary embodiment. The feed movement is carried out by the clamping device 4, which can either be moved up and down or in the longitudinal direction of the cable 3 back and forth.

7 shows a separating device 1 according to FIG. 6 with the difference that the separating device 1 has two clamping devices 4 which are arranged parallel to one another. With this construction, two cable ends are processed simultaneously.

The processing of cable ends can, if necessary, also be carried out without the feed devices of the clamping devices 4 having their own feed movement if the separating edge and the sliding side surfaces are correspondingly coordinated with one another and e.g. elastic intermediate layers allow a spring-loaded pressing of the grinding surfaces on the cable ends.

8 shows a separating device 1 according to FIG. 6, in which the feed movement is carried out by the separating tool 2, which takes place up and down, or transversely to the cable 3 or in the longitudinal direction of the cable 3 and back can.

Fig. 9 shows an elongated saw blade with a defined cutting edge, the feed movement for processing cable ends can be carried out in at least two different directions.

FIG. 10 shows a saw blade according to FIG. 9, in which an abrasive coating with preferably undefined cutting edges - for example diamond or corundum bound or glued - is provided. 11 shows a section through a side view of a separating tool 2, between whose grinding film and the holder 5 an elastic base 10, for example made of rubber, is also provided. The back of the cutting edge 7 is only partially covered by the elastic base 10. The elastic base 10 increases the elasticity of the grinding film 6 during the finishing process of cable ends, so that their cable end surfaces can be ground or polished more optimally.

12 shows the view, from slightly obliquely above, of a separating device 1 according to the invention. The ferrule 17, which is located in a plug 16, is supplied to the receptacle 12 and held by the clamping device 4, the feed movement of which is by the control slide 19 is coordinated.

FIG. 13 shows a novel clamping device 4 which fits into the separating device 1 according to FIG. 12. Spring slots 15 are milled in the clamping device 4, by means of which the installation of the clamping device 4 in the separating tool 2 is facilitated and the ferrule can be optimally held in the receptacle 12 and processed there. The control shoulders 14 receive control pins 20 (FIG. 12). Moving the control pin 20 parallel to the slots 15 causes the receptacle 12 to be opened or closed easily. The clamping device 4 is preferably made of plastic.

LIST OF REFERENCE NUMBERS

I- separating device - separating tool

3- cable clamp

5- bracket

6- grinding foil 7- cutting edge

8- cutting block

9- Grinding wheel, covering or film

10- elastic pad

I I- jig 12- holder

13- mother

14- Control shoulder for control pin

15- spring slot

16- connector 17- ferrule

18- base.

19- spool

20- control pin

Claims

claims

1. Separating device (1) for cutting cables (3), in particular optical fibers, with a clamping device (4) for the cable (3), for the ferrule enclosing the cable or for the

Connecting element and a cutting tool (2) with at least one cutting edge, wherein defined or undefined cutting edges are present on the cutting edge, characterized in that at least one defined or undefined cutting edge is provided on at least one side surface of the cutting tool (2) and that, between the cutting tool (2) and the clamping device (4) a feed movement of the cable (3) or the separating tool (2) can be carried out.

2. Separating device according to claim 1, characterized in that at least one side surface of the separating tool (2) is designed as a grinding, scraping (9) or milling tool.

3. Cutting device according to claim 2, characterized in that the cutting edge (7) and the grinding (9), scraping or milling tool

Separating tool (2) are integrally formed.

4. Separating device according to one of the preceding claims, characterized in that the separating tool (2) is axially movable.

5. Separating device according to one of the preceding claims, characterized in that the clamping device (4) is mounted fixed to the chassis and is movable along the cable axis.

6. Separating device according to one of the preceding claims, characterized in that the feed movements of the separating tool (2) and the clamping device (4) are synchronized with one another.

7. Separating device according to one of the preceding claims, characterized in that flanges are provided on the side of the separating tool (2) which carry grinding wheels (9).

8. Separating device according to one of the preceding claims, characterized in that the separating tool (2) consists of a film with scattered grains and the edge on the circumference of the film can be used as a separating edge.

9. Separating device according to claim 8, characterized in that the film can be pressed against the cable end by means of an elastic body (10).

10. Separating device according to claim 6, characterized in that the

Disconnecting device is connected to a winder, so that the cables, which are separated in length and processed at least at one end, can be further processed as a bobbin, preferably as a first step in an automatic machine for cable assembly.

11. Separating device according to one of the preceding claims, characterized in that the separating tool is a CBN (cubic

Boron nitride) cutting disc.

12. A method for severing and finishing cable ends, characterized in that a separating tool (2) is provided which, in addition to a separating cutting edge (7), also has at least one side surface provided with a defined or undefined cutting edge (8; 9) The separating tool (2) is set into a separating movement and is relatively advanced on the cable until it is severed, after which the cable is first pulled back relatively axially by a clamping device (4) holding it and then relatively advanced on the side face.

13. A method for severing and finishing cable ends by means of a device according to one of the preceding claims, characterized in that an optical waveguide fastened in the ferrule or in another connecting element, which at most of

Adhesive is surrounded, cut and refined, so that the separating surface is normal or oblique to the cable axis and / or is convex.

14. The method according to claim 12, characterized in that the end face of the ferrule or the other connecting element is also refined and / or the length of this connecting element is defined by ablation with the same separating device.

15. The method according to claim 12 or 13, characterized in that the tool is supported elastically during the processing at the front end of the ferrule or another connecting element, so that the machined end face on the cable is oriented locally and geometrically to the contour of this connecting element.

16. Using a CBN (cubic bomitride) cutting wheel as a cutting tool for an optical fiber.