The invention relates to a method for adjusting the distribution of a spooler in order to distribute during the spooling a cable or the like on the surface of a spool in a closely packed even layer by means of a distributor of the spooler, in which method the pitch of the distribution of the cable or the like is given a set value and the information necessary for adjusting the distribution is measured from the spooler. The invention further relates to an arrangement for adjusting a spooler.

The above-described methods and arrangements are rather well known in the cable industry at present . In known arrangements, the adjustment of the distribution is based on the measurement information obtained from the rotational velocity of the spool. An example of typical known arrangements is the arrangement disclosed in Finnish patent 47976. The drawback of the known arrangements is that in order to adjust the distribution, the exact rotational velocity of the spool must be known. This means in practice that the system must comprise the sensing and measurement of the rotational velocity. If the spooler does not comprise this sensing as a standard operation, it must be installed on the spool axis. This naturally increases the costs.

The purpose of the invention is to provide a method and an arrangement by means of which the drawbacks associated with the prior art can be eliminated. This is achieved with the method and arrangement according to the invention. The method according to the invention is characterized in that the advance of the distributor during one rotation of the spool is measured from the spooler, and that the result

of the measurement is compared with the set distribution pitch, whereupon if there is a difference between the measured advance of the distributor and the set distribution pitch, the distribution speed is adjusted so that the advance approaches the set pitch. The arrangement according to the invention is in turn characterized in that the measuring means are arranged to measure the advance of the distributor during one rotation of the spool, and that the arrangement comprises means arranged to compare the measurement result with the set distribution pitch, whereupon if there is a difference between the measured advance of the distributor and the set distribution pitch, the distribution speed is arranged to be adjusted so that the advance approaches the set pitch.

The primary advantage of the invention is that the adjustment of the distribution can be performed without information of the rotational velocity of the spool. This makes it simpler to perform the adjustment in connection with such drives that do not comprise the sensing of the rotational velocity as a standard element . Another advantage is that the advance the distributor makes during one rotation of the spool can be measured by means of the position sensing provided permanently in the distributor. The distributor must always comprise the position sensing for the purpose of identifying the width of the distribution. This sensing can be employed in the present invention also for the other use mentioned above, whereupon no separate rotational sensing is needed, as stated above.

The invention will be described below in greater detail by means of the prior art and a preferred embodiment of the invention, shown in the accompanying drawing, in which

Figure 1 illustrates the characteristic features of a typical prior art arrangement, and

Figure 2 illustrates the characteristic features of the arrangement according to the invention. Figure 1 shows the characteristic features of a typical prior art arrangement . Reference numeral 1 denotes a spool and reference numeral 2 denotes generally the rotating apparatus of the spool 1, comprising a motor 2a. Reference numeral 3 in Figure 1 denotes a distributor and reference numeral 4 denotes a setting device with which the pitch N of the cable or the like 5 is given a set value. Figure 1 also shows the main functions of the arrangement by means of arrows.

The known arrangement according to Figure 1 operates in such a way that the pitch of the distribution is entirely dependent on the speed of the distribution. The distribution speed in turn is directly dependent on the rotational velocity of the spool 1 and on the value set for the pitch of the distribution by means of the setting device 4 in the following way:

distribution speed reference = set value of distribution pitch x spool rpm measurement

The principle of the rpm measurement of the spool 1 is shown in Figure 1 by means of the arrow M _r . The distribution speed reference in the arrangement of Figure 1 always requires an accurate result of the measurement of the rotational velocity of the spool 1. The system must thus always comprise the sensing and measurement of the rotational velocity. If the spooler does not comprise this sensing function as a constant element, it must be installed separately.

Figure 2 shows the characteristic features of a preferred embodiment of the arrangement according to

the invention. Reference numeral 11 denotes a spool and reference numeral 12 denotes generally the rotating apparatus of the spool 11, comprising a motor 12a. Reference numeral 13 denotes in Figure 2 a distributor and reference numeral 14 denotes a setting device with which the pitch N of the cable or the like 15 is given a set value. Figure 2 also illustrates with arrows the main functions of the arrangement with the same principle as in Figure 1. The distributor 13 moves rectilinearly in the direction of the axis of the spool 11. The movement of the distributor can be implemented for example by means of a servo drive 17.

According to the essential idea of the invention, the advance of the distributor 13 during one rotation of the spool is measured from the spooler. The principle of measuring the advance of the distributor 13 is shown in Figure 2 by means of .the arrow M _β . The result of the measurement is compared with the distribution pitch set by means of the setting device 14, whereupon the distribution pitch and the advance during one rotation should be equal. If they are not, the distribution speed is changed so that the advance approaches the set distribution pitch. The afore¬ mentioned comparison is performed with means 16. The advance of the distributor 13 during one rotation of the spool 11 can be measured for example in such a way that the rotation of the spool 11 is sensed with a separate limiting sensor which can be preferably the same limiting sensor that identifies the initial position of the spool 11.

The arrangement of Figure 2 solves the problem related to the known technology, since by means of the invention the distribution pitch is adjusted exactly to the desired value, i.e. the distribution speed is always correct without information concerning the rotational

velocity of the spool. This helps avoid the installation of the rotational velocity sensing on the spool axis in drives wherein the sensing is not a standard element, as stated above. The distribution speed of the arrangement of

Figure 2 can be obtained for example in the following manner:

distribution speed reference = constant coefficient x (set value of distribution pitch - advance of distributor)

The operation of the distributor 13 can be provided with better dynamics, however, by adding at least inaccurate information of the possible speed of the distributor 13 to the distribution speed reference. Such inaccurate information can be derived for example from the rotational velocity reference of the spool 11 or, in connection with frequency converters, from the actual value of the frequency of the spool's rotating motor. In such a case, the inaccurate signal provides more dynamics when the speed of the distributor changes, and the method according to the invention ensures that the distribution pitch is set exactly to the correct value after the change. The distribution speed can be obtained in the following manner:

distribution speed reference = (constant coefficient x (set value of distribution pitch - advance of distributor) ) + inaccurate signal

The above-described embodiment is not intended to limit the invention in any way, but the invention can be modified quite freely within the scope of the claims. It is therefore clear that the arrangement according to

the invention or the details thereof do not necessarily have to correspond exactly to those shown in the figure, but other kinds of arrangements are also possible. Drives, controls, the input of set values, etc, can be implemented with any technique known per se. Even though the embodiment described above is related to a cable, it is clear that the invention is not restricted merely to cables, but it can also be applied in connection with ropes, cable wires, wires and other similar products.