The invention relates to an arrangement in a fibre process, which arrangement is equipped with control and pulling means for directing fibre or the like along a desired run and, if necessary, with cutting means for cutting the fibre or the like at a time instant depending on the fibre process. The cutting means can comprise a rotating element that is formed of two parts equipped with gripping surfaces. The fibre or the like is arranged to travel between the gripping surfaces without touching the gripping surfaces before the gripping and/or cutting step, during which the gripping surfaces are arranged to press against each other. The rotating element is arranged to rotate around an axis that is substantially transverse with respect to the direction of travel of the fibre or the like, and a blade means is arranged to the edge of one part of the rotating element or close thereto to cut the fibre or the like as a result of the rotation of the rotating element, whereby the free end of the fibre or the like is arranged to wind around the rotating element.
Arrangements of this kind are today known especially in the cabling processes of optical fibres, wherein the aim is to shorten the mounting time as much as possible during product replacement. The earlier solutions were based on arrangements, in which the fibres were arranged to pass through a pulling device and after the pulling device in the direction of travel of the fibre, a cutting device was mounted to cut the fibre at the desired moment.
One drawback with the prior-art solutions described above is that after cutting, the free end of the fibre in a way flows out of the pulling device to a waste container, for example, whereby fibre goes to waste until the fibre line can be stopped. The amount of wasted fibre can be significantly high, since line speeds can rise up to thousands of meters per minute. In addition, the solutions were in some cases complex, because controlling the free end of the fibre and directing it to the waste container can be difficult at high speeds in particular.
To eliminate the above-mentioned drawbacks, a solution was developed and disclosed in U.S. Pat. No. 6,220,135, in which, before the cutting step, the fibres run between parts forming a rotating element. The presently used line speeds are quite high and at high velocities, fibres often tend to vibrate. As a result of the vibration, the fibres easily touch the parts of the rotating element, since it should be noted that the distance between the fibres and the parts of the rotating elements is in the range of millimetres. Even a momentary contact of the fibres with the parts of the rotating elements causes a jerk that shows in the product as a variation of diameter and excess fibre length.
To eliminate the above-mentioned vibration problem, different separate controllers have been used to direct the fibres to run through the mid-section of the gap between the parts of the rotating element. These controllers always need to be tuned during start-up, so their use is difficult and slows down the start-up of the line.
It is an object of the invention to provide an arrangement, by means of which the drawbacks of the prior art can be eliminated. This is achieved by the arrangement of the invention. The arrangement according to the basic idea of the invention is characterized in that on both sides of the fibre-gripping surfaces, control means are arranged to move according to the movement of the gripping surfaces and to prevent a random contact between the fibre or the like and the gripping surfaces. An arrangement according to a parallel embodiment of the basic idea of the invention is, in turn, characterized in that to both parts of the rotating element or close thereto, on both sides of the gripping surface, control means are arranged to prevent the fibre or the like from vibrating between the gripping surfaces and to thus prevent the fibre or the like from randomly touching the gripping surfaces.
The advantage of the invention is above all that with the invention, the harmful vibration of the fibres can be eliminated without any difficult tuning action that slows down production. A further advantage is that the invention enables a very efficient control of the fibres, whereby the dampening of vibration is also efficient. A yet further advantage of the invention is that threading the fibres through the cutting means becomes easier, because the fibres need not be threaded through separate controllers, etc.
In the following, the invention will be described in greater detail by means of a preferred embodiment shown in the attached drawing, in which
The above-mentioned cutting means 4 comprise a rotating element that is made up of two parts 4a, 4b, between which the fibre or the like 1 runs before the cutting step without touching the parts 4a, 4b.
The parts 4a, 4b are equipped with gripping surfaces 7, 8, which are made of a rubber material, for instance, and which are, in the cutting step, arranged to grip the fibre or the like. The gripping surfaces 7, 8 are especially clearly shown in
After the fibre or the like 1 is cut, its free end is between the gripping surfaces 7, 8 that are pressed together, whereby the fibre or the like winds around the rotating element and, at the same time, fastens to the rotating element, whereby the free end is caught in a controlled manner for the slowing down of the line.
A person skilled in the art is familiar with the matters described above, so they need not be described in more detail herein. With respect to the structure and operation of the cutting means, reference is made herein to the U.S. Pat. No. 6,220,135 mentioned earlier, in which they are described in greater detail.
As earlier mentioned, a drawback with the prior-art solutions is that the fibre or the like tends to vibrate between the parts 4a, 4b during operation, whereby the fibre or the like 1 easily touches the part 4a or 4b. This contact results in problems as mentioned above.
To eliminate the above-mentioned problem, the arrangement of
The invention is based on the idea that by installing the control means 10, 11, 12, 13 immediately on both sides of the gripping surfaces 7, 8, they prevent the fibre or the like from harmfully vibrating at the gripping surfaces 7, 8 and ensure that the fibre or the like does not touch the gripping surfaces. The operation of the control means 10, 11, 12, 13 is clearly shown in
In the embodiment of
Instead of the stepped position, it is possible to place a suitable mechanism to the control means to keep the control means separate from each other when the gripping surfaces are pressed against each other.
In the example of the figures, the control means 10, 11, 12, 13 are rod-like elements. The control means can be made of any suitable material. Examples of suitable materials are ceramic materials that are especially advantageous when the control means are formed in such a manner that they touch the fibre or the like. The control means can also be formed in such a manner that they do not touch the fibre or the like.
The embodiment described above is not in any way intended to limit the invention, but the invention can be freely modified within the scope of the claims. Therefore, it is apparent that the arrangement of the invention or its details need not be exactly as described in the figures, and solutions of other type are also possible. The invention can be applied in such a manner, for instance, that the fibre or the like runs all the time between the parts of the cutting means before the cutting step, or alternatively in such a manner that the fibre or the like is transferred to run between the cutting means just before the cutting step.
The hook means 14 of the device according to
The movement rates of the device of
The device of
The gripping surfaces can be formed as described in the figures, or they can be formed in such a manner that the entire surfaces of the rotating element parts pressing against each other constitute the gripping surfaces. The invention can be used not only with optical fibres or fibre bundles, but also with other fibres and fibre bundles and threads and thread bundles. The invention can also be used elsewhere than in the fibre cutting means, as shown in the above example; it can be applied even more extensively, in other words, even without a cutting means fixed to the structure. The cutting means can be a separate mechanism, if necessary. Examples of such an application are lines for further treatment of fibre or the like, in which the line needs to be stopped for an action, such as chopping or measurement, and the aim is to keep the fibres in the forward end of the line in line so as to avoid re-pulling the fibres into the line before re-starting it. In this case, the gripping surfaces merely grip the fibre or the like so as to keep it from escaping or causing unnecessary extra work when the line is re-started. A device designed for just gripping can be similar to that described in the figures of this application, but without the cutting blade, the structure also does not need to rotate as described in the figures.
Number | Date | Country | Kind |
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20021231 | Jun 2002 | FI | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FI03/00498 | 6/18/2003 | WO | 10/26/2004 |