SPOOLING METHOD FROM HANKS AND REELING-OFF DEVICE ACHIEVING SAID METHOD

Abstract: Spooling method from hanks and relative reeling-off device to transfer yarns (11) from a hank (12) to a spool (13), wherein the hank (12) is mounted on a reel (14) suitable to rotate around an axis (24), the method providing to use a magnetic drawing assembly (38) to supply a contribution of power for the rotation of the reel (14) such as will not contrast with or brake the normal unwinding of the yarn (11), the drawing assembly (38) comprising at least a drawing element and a drawn element made to rotate by the magnetic forces generated between the said two elements, the rotation of the drawn element being transferred to the reel (14) by means of a mechanical connection between the drawn element and the rotation shaft (23) of the reel (14).

Description: "SPOOLING METHOD FROM HANKS AND REELING-OFF DEVICE ACHIEVING SAID METHOD" FIELD OF THE INVENTION The invention concerns a spooling method from hanks and the reeling-off device achieving the method as set forth in the respective main claims. To be more exact, the invention is used in spooling operations from hanks wherein the yarn is transferred from the hanks to the spools to be subsequently used. The invention is applied advantageously in all cases where yarns are reeled off from hanks in order to increase the winding speed onto the spool, at the same time decreasing the tensions on the yarn and therefore reducing the risks of damaging and breaking the yarn. BACKGROUND OF THE INVENTION The state of the art includes reeling-off machines, or reeling-off/spooling machines, used to transfer the yarn from the hanks to the spools . After the mercerising and/or dyeing processes, or shrinkage and/or dyeing processes, the hank is mounted on a reel located above or outside the spooling heads and the yarn is unwound from the hank exerting a drawing force which is generally impressed by the rotation of the spooling heads . The operation to off-reel the yarn from the hank can be achieved with two methods: - a first method, the derouler method, provides that the reel is drawn in rotation by the unwinding of the yarn; - a second method, the defiler method, provides that the reel is held stationary and the yarn is unwound axially with respect to the reel itself. Derouler reeling-off allows a more regular unwinding of the yarn from the hank and a lesser risk of tangles and therefore breakages of the yarn and stoppages of the machine, but the fact that the hank is made to rotate does not make this method recommendable for heavy or large size hanks since it greatly limits the speed for fine yarns or yarns with a low breaking point. Defiler reeling-off, vice versa, may be used for large size hanks too, but it has problems in the case of fine yarns due to the frequent snags, tangles and twisting of the yarns which occur, causing breakages and stoppages of the machines. Of the two methods, however, derouler reeling-off has shown itself to be the more efficient method because, in the majority of cases where it is applied, it allows a more regular reeling-off without snags and twisting of the spirals. However, this method has also shown its limits in the low working speeds possible due to the ever more frequent use of large size and heavy hanks. In these cases, users are obliged to considerably reduce the reeling-off speeds, to maximum values of around 250÷300 metres per minute for thinner and less resistant yarns, and around 400÷450 metres per minute for thicker, yarns which are more easily reeled off, such as for example acrylic yarns . Various methods have been proposed to obtain higher reeling-off speeds without causing excessive increases in the tension of the yarn. For example, the patent application UD93A000133, in the name of the present Applicant, proposed to use an auxiliary reeling-off element, attached in idler mode on the shaft of the reel, which is made to rotate by the yarn itself as it unwinds from the reel . The function of the auxiliary reeling-off element is to help the yarn to unwind from the hank, reducing the reeling- off tensions and minimising the risk of blockages and tangles . However, this solution has not given satisfactory results such as to achieve the increases in speed and production expected of the reeling-off machine. In another solution proposed, it was provided to use a reel commanded by an autonomous motor. This solution has not given satisfactory results either, because it is impossible to instantaneously adapt the unwinding speed of the off- reeled yarn, supplied from the hank made to rotate under command, to the speed of the yarn summoned by the collecting head. In other words, since the yarn no longer exits freely from the hank due to the drawing force caused by the collecting head alone, but is unwound substantially by the motor which makes the reel rotate, two things can happen: - either the driven reel rotates too slowly with respect to the spool, and then the motor of the reel constitutes a brake on the rotation of the collecting head, and thus does not reduce the tensions of the yarn being unwound; - or the driven reel rotates too quickly, and then the yarn rewinds onto the reel . An example of this solution is shown in DE-A-388 400, which provides to associate with the axis of the reel a pulley commanded by a motor. The pulley causes the reel to rotate in the same direction and at the same speed as the unwinding yarn, in order to reduce to a minimum the resistance of the yarn to being removed from the hank. This solution, as we said above, is valid in theory, but in practice it has proved to be substantially impossible to achieve, since it is extremely difficult to synchronise perfectly and in every situation the speed of the spool which removes the yarn with the speed of the motor which makes the reel rotate . The present Applicant has devised, tested and embodied this invention to overcome these shortcomings, and has achieved a solution which allows to increase the unwinding speed of the yarn from the hank without causing increases of tension on the reeled-off yarn. SUMMARY OF THE INVENTION The invention is set forth and characterised in the respective main claims, while the dependent claims describe other characteristics of the invention. The purpose of the invention is to achieve a derouler reeling-off device wherein the reel on which the hank is mounted is drawn in rotation, not only by the yarn summoned by the spooling head, but also by auxiliary means whose action gives help which in no way contrasts with or brakes the normal unwinding of the yarn. In other words, the action of the auxiliary means supplies a contribution of power to the rotation of the reel which reduces the drawing force exerted on the yarn by the spooling head; this contribution is strictly and directly functional to the increase in tension on the yarn deriving from the use of high reeling-off speeds and which allows to considerably increase the reeling-off speed without increasing tension on the yarn. Therefore, this invention drastically reduces the risks of breakages or damage to the yarn, for example, weakening or fraying, caused by high tensions on the yarn due to the high reeling-off speeds and/or the great weight of the hank. The invention permits to achieve high reeling-off speeds, in the order of at least 500÷800 metres per minute and even more, according to the type of yarn being worked, even when the hanks are very heavy. The device according to the invention comprises a magnetic drawing assembly co-operating with the rotation shaft on which the reel is mounted, and suitable to supply an additional contribution of power for the rotation of the reel . The magnetic drawing assembly substantially consists of two elements : - a first element, or drawing element, comprising a pulley or disk on the circumference of which a plurality of pairs of magnets are mounted, the pulley being associated with means suitable to make it rotate; - a second element, or drawn element, comprising a disk or ring made of ferromagnetic metal, arranged coaxial with and substantially facing the pulley, and suitable to be drawn in rotation by the action of the magnetic forces exerted by the rotating pulley. According to the invention, the magnetic drawing action of the drawing element on the drawn element occurs in such a manner that the speed of the drawing element is always greater than that of the drawn element . The second element, or drawn element, is mechanically associated with the rotation shaft of the reel, and therefore the drawing torque generated between the two elements as a result of the magnetic forces is transferred to the reel as an additional contribution of power to the rotation of the latter. In this way, since the power required to make a hank of determined weight rotate at a determined speed is a defined value, the power contribution supplied by the magnetic drawing assembly will reduce the residual power required of the yarn and therefore the tension of the yarn. With this configuration, which achieves the fundamental characteristic of the invention, the rotation shaft of the reel is not "forced" to rotate, as it would be if there were a motor mechanically connected to the shaft, but is "helped" to rotate, still remaining free. The invention provides to correlate the torque or power supplied by the magnetic drawing assembly to the tension on the yarn, so that at every moment the contribution supplied by the drawing assembly compensates in part the power needed for a given reeling-off speed. In a preferential embodiment, the contribution supplied by the magnetic drawing assembly is in the order of 75-98% of the total power required for the rotation of the reel, but never more than 100% because in this case the yarn would rewind on the reel . In a first embodiment of the invention, the magnetic drawing assembly is arranged substantially coaxial with the rotation shaft of the reel and comprises a magnetic pulley, associated with means suitable to make it rotate, and a ring element solid with the rotation shaft of the reel . According to another embodiment, the magnetic drawing assembly is mounted off-axis with respect to the rotation shaft of the reel, and transmission means are provided to transfer the motion from the drawn element to the shaft of the reel . This embodiment is preferential because it is not necessary to correlate the speed of rotation of the magnetic pulley to the speed of the reel; in this way, it is possible to adopt speeds such as to guarantee an optimum efficiency of the drawing assembly. In one embodiment of the invention, the means which make the magnetic pulley rotate consist of a belt driven by the spooling head; the drive of the belt is therefore appropriately correlated to the speed of the collecting head . In another embodiment, the magnetic pulley is made to rotate by an autonomous motor piloted by an inverter. In this case, the magnetic pulley can be mounted in axis with the motor, or at any intermediate position between the axis of the motor and the axis of the reel; in this second case there are appropriate first transmission and return means which transmit the motion from the motor to the pulley and second transmission means which transmit the motion from the disk or ring to the reel. In a variant of this second embodiment, the motor which drives the magnetic pulley is governed by sensor means which continuously monitor the tension on the yarn during the reeling-off operation, regulate the speed of the motor and therefore regulate the contribution of power in such a manner as to maintain the tension at a substantially constant value. In an equivalent variant of the embodiments described above, the functions of the magnetic pulley and of the ring or disk can be inverted, using the ferromagnetic ring or disk associated with rotation means (for example the belt driven by the collection head or an autonomous motor) as a drawing element, and the magnetic pulley associated therewith as a drawn element, mechanically connected to the rotation shaft of the reel. BRIEF DESCRIPTION OF THE DRAWINGS The attached Figures are given as a non-restrictive example and show some preferential embodiments of the invention as follows: Fig. 1 is a part side view, in diagram form, of the reeling- off device according to the invention; Fig. 2 is a part front view, on an enlarged scale, of the reeling-off device shown in Fig. 1; Fig. 3 is a front view of a possible embodiment of the magnetic pulley used in the invention; Fig. 4 shows a detail of a variant of Fig. 2; Fig. 5 shows, with a variant of Fig. 3, the magnetic pulley used in the embodiment shown in Fig. 4 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The reeling-off device 10 shown in diagram form in Fig. 1 is suitable to transfer the yarn 11 from a hank 12 to a spool 13. The hank 12, mounted on a reel 14, is unwound with the derouler method due to the drawing force exerted by the spool 13 being formed, which is made to rotate through friction by a first cylinder 17a commanded by the shaft 15. There is also included a second cylinder 17b on which, in a known manner, a cursor 16 is mounted which moves axially back and forth for the length of the spool 13 , arranging the spirals of yarn in progressive layers on the spool 13. The movement of the two cylinders 17a and 17b, and also of the cursor 16, by a motor 20 and a belt 21, or by two separate motors, is widely known in the state of the art and is therefore not described here in any further detail. The inclusion of an oscillating arm 18 is also widely known; it has one or more small pulleys 19 at the end, inside which the yarn 11 emerging from the hank 12 passes; the function of the arm 18 is to create a reserve of yarn, in combination with the return roller 36 and the yarn supply rollers 22. The oscillating arm 18, as is known in the state of the art, can move from a high position (indicated by a continuous line) to a low position (indicated with a line of dots and dashes) so as to create the reserve of yarn to allow the spool 13 and the reel 14 to be stopped, with known braking devices, without breaking the yarn in the event of blockages . In the case shown in Fig. 1, between the reel 14 and the spool 13 there are rollers 22 around which the yarn 11 winds and which serve to reduce and stabilise the tension before spooling starts, and so as to be able to achieve, in combination with the tensioning 28 and parafinning 37 devices, spools 13 of any desired conformation for the different uses. The path followed by the yarn 11 comprising the passage through the pulleys 19 and the yarn supply rollers 22 is shown by a line of dots and dashes; the line of dashes shows an alternative path for the yarn 11, for high speeds and for yarns which are easily reeled off, which provides a substantially direct winding without any devices between hank 12 and spool 13 to make a reserve of yarn. The reel 14 is mounted on a shaft 23, with a longitudinal axis 24, which is mounted cantilevered at one end to a support 25, shown in Fig. 2. The shaft 23 and the reel 14 are supported, by means of the bearings 27, on a bushing 26 solid with the support 25. According to the invention, in co-operation with the shaft 23 there is a magnetic drawing assembly 38 comprising a magnetic pulley 30 and an associated disk or ring element 35. The magnetic drawing assembly 38 is suitable to supply .an additional contribution of power for the rotation of the reel 14 which helps to reduce the drawing action on the yarn 11 exerted by the rotation of the spool 13. In the embodiment shown in Fig. 2, the pulley 30 is mounted in direct co-operation with the shaft 23 and is suitable to rotate on bearings 29 with respect to the bushing 26. In this case, the pulley 30 is made to rotate by a belt 31 connected on one side to the pulley 30 and on the other side to a small pulley 32 mounted on the rotation shaft 15 which moves the spool 13. In the embodiment shown here, the small pulley 32 is of the type with three throats on which the belt 31 can be alternatively positioned in order to vary the ratio of speed between the spool 13 and the pulley 30. Pairs of magnets 34, arranged in a close position to a ring 35 solid with the rotation shaft 23 of the reel 14, are mounted on the pulley 30, in this case peripherally (Figs. 2 and 3 ) . The ring 35 is made of ferromagnetic steel; the composition and relative level of magnetism of the steel can vary according to the type of application and the results to be obtained. According to the variant shown in Fig. 4, the magnetic assembly 38 is driven by means of an autonomous motor 33. In this embodiment, the motor 33 is suitable to make rotate a disk element 35 arranged facing the magnetic pulley 30, which supports the pairs of magnets 34 at the front. The magnetic pulley 30, which is mounted on bearings 39, is made to rotate by the disk element 35 due to the magnetic forces generated between the disk 35 and the magnets 34. In this case, the magnetic pulley 30, which functions here as the drawn element, is connected to the rotation shaft 23 of the reel 14 by means of a return consisting of a pair of little pulleys 40 and 41 connected by means of respective belts 42 and 43, one to the magnetic pulley 30 and the other to the shaft 23. According to a variant of this embodiment which is not shown here, the magnetic pulley 30 is directly connected by means of pulleys or belts to the shaft 23 of the reel 14 without any intermediate return elements . According to another variant which is not shown here, the magnetic drawing assembly 38 consisting of the pulley 30 and the disk 35 is arranged at any intermediate position between the axis 44 of the motor 33, or the axis of the small pulley 32 connected to the shaft 15, and the axis 24 of the reel 14, there also being included transmission means, such as pulleys, belts and return rollers, to transfer the motion from the motor 33 to the assembly 38 and from the assembly 38 to the shaft 23 of the reel 14. The embodiment which provides the drawing assembly 38 off- axis with respect to the reel 14, for example that shown in Fig. 4 or other equivalents, is preferential since it is not necessary to correlate the speed of the drawn part to that of the reel 14, and therefore it is possible to make the magnetic assembly 38 function with maximum efficiency. The reeling-off device as described above functions as follows : During the reeling-off operation, the reel 14 is made to rotate by the drawing force exerted by the yarn 11 when summoned by the rotation of the spool 13. Together with the spool 13, the magnetic pulley 30 is also made to rotate, either directly by means of the belt 31 in the case of Fig. 2, or by the drive of the autonomous motor 33 in the case of Fig. 4. Due to the magnetic forces which are generated between the pairs of magnets 34 and the ring or disk 35 mechanically connected with the rotation shaft 23 of the reel 14, the rotation of the pulley 30 causes a contribution of power for the rotation of the reel 14 which is added to the residual power required of the yarn 11 summoned by the spool 13 and which is the power which causes the actual tension on the yarn 11. By operating in a suitable manner on the additional torque supplied thanks to the magnetic drawing force, it is possible, for any reeling-off speed, to maintain the residual power required from the yarn 11 to a low level, for example 10-20%, and this allows to use high reeling-off speeds with relatively low tensions on the yarn 11. The value of the additional torque depends not only on the number of pairs of magnets 34, the value of the air gap and the materials used, but also on the relative speed of the drawing element and the drawn element, since the value of the torque increases as that relative speed increases. According to the applications, the speed of the drawing element can vary from 1.3 to 4 times the speed of the drawn element . In the case of Fig. 4, the motor 33 is advantageously governed by a tension sensor 45 which commands, through a suitable electronic control logic, the motor inverter in such a manner that the variations - either increases or reductions - in the tension of the yarn 11 are compensated by variations - either increases or reductions - in the speed of the motor 33. According to a variant of the embodiment shown in Fig. 4, the disk or ring 35 and the magnets 34 are arranged in such a manner as to be able to be displaced axially so as to be distanced or brought nearer. This allows to vary in a desired manner the torque supplied by the magnetic assembly 38 to the reel 14, and therefore the relative auxiliary power supplied. Although we have described this embodiment, all the equivalent embodiments also come within the field and scope of this invention, for example, the embodiment which, in Fig. 2, provides for the magnets 34 to be solid with the rotation shaft 23 of the reel 14 and for the ring 35 to be made to rotate by the belt 31; or the embodiment which provides, as shown in Fig. 4, for the magnetic pulley 30 to be mounted on the axis of the motor 33 and the disk 35 to be drawn into rotation due to the magnetic forces generated.

Claims: CLAIMS 1 - Spooling method from hanks to transfer yarns (11) from a hank (12) to a spool (13), wherein the hank (12) is mounted on a reel (14) including a shaft (23) suitable to rotate around an axis (24) due to the drawing action exerted by the yarn (11) when summoned by the spool (13), the method being characterised in that it provides to use a magnetic drawing assembly (38) co-operating with the rotation shaft (23) of the reel (14) , to supply a contribution of power for the rotation of the reel (14) such as will not contrast with or brake the normal unwinding of the yarn (11), the drawing assembly (38) comprising at least a drawing element (30 or 35) and a drawn element (35 or 30) , the drawing action providing to make the drawing element rotate, to induce in the drawn element a non-forced rotation due to the magnetic forces generated between the said two elements and to transfer the rotation of the drawn element to the rotation shaft (23) of the reel (14) by means of a mechanical connection between the drawn element and the shaft (23). 2 - Spooling method as in Claim 1, characterised in that it provides that the contribution of power for the rotation of the reel (14) is functional to the value of tension of the yarn (11) during the reeling-off operation. 3 - Spooling method as in Claim 1 or 2 , characterised in that it provides to make the drawing element of the drawing assembly (38) rotate by taking motion directly from the rotation organs (15) of the spool (13). 4 - Spooling method as in Claim 1 or 2 , characterised in that it provides to make the drawing element of the drawing assembly (38) rotate by taking motion from autonomous drive means (33). 5 - Spooling method as in any claim hereinbefore, characterised in that it provides that the drawing assembly (38) supplies a contribution to the rotation of the reel (14) of around 75-98% of the total power necessary. 6 - Spooling method as in any claim hereinbefore, characterised in that it provides that the speed of the drawing element is between 1.3 and 4 times more than the speed of the drawn element. 7 - Reeling-off device to transfer yarns (11) from a hank (12) to a spool (13), comprising a reel (14) supporting the hank (12) mounted on a shaft (23) rotary around an axis (24), a shaft (15) suitable to make the spool (13) rotate, guide means for the yarn (11) arranged between the hank (12) and the spool (13), the reeling-off device being characterised in that it comprises a magnetic drawing assembly (38) co-operating with the rotation shaft (23) of the reel (14), the magnetic drawing assembly (38) comprising at least a first element, or drawing element (30 or 35), associated with means (31, 33) suitable to make it rotate, and a second element, or drawn element (35 or 30), arranged coaxial to the drawing element and suitable to be made to rotate due to the magnetic forces by the said drawing element, the drawn element (30 or 35) being mechanically connected to the rotation shaft (23) of the reel (14) and being suitable to supply the shaft (23) with a non-forced and additional contribution of power which is added to the drawing action on the yarn (11) exerted by the spool (13) to reduce, in a corresponding manner, the tension on the yarn (11) generated by the drawing action exerted by the spool (13) . 8 - Device as in Claim 7, characterised in that the first element comprises a rotary pulley (30) supporting on its circumference pairs of magnets (34) and that the second element comprises a disk or ring element (35) arranged substantially facing and coaxial with the rotary pulley. 9 - Device as in Claim 8, characterised in that the pairs of magnets (34) are arranged peripherally on the circumference of the magnetic pulley (30) . 10 - Device as in Claim 8, characterised in that the pairs of magnets (34) are arranged frontally on the circumference of the magnetic pulley (30) . 11 - Device as in Claim 8, characterised in that the rotary pulley (30) and the disk or ring element (35) are assembled coaxial with the axis of rotation (24) of the reel (14) . 12 -Device as in Claim 11, characterised in that the disk or ring element (35) is solid with the rotation shaft (23) of the reel (14) . 13 - Device as in Claim 8, characterised in that the rotary pulley (30) and the disk or ring element (35) are assembled off-axis with respect to the axis of rotation (24) of the reel (14) , there also being included means to transmit the motion to transfer the motion from the disk or ring element (35) to the rotation shaft (23) of the reel (14). 14 - Device as in any claim from 7 to 13 inclusive, characterised in that the means to make the drawing element (30 or 35) rotate comprise belt means (31) which receive the motion from the means (15) suitable to make the spool (13) rotate. 15 - Device as in any claim from 7 to 13 inclusive, characterised in that the means to make the drawing element (30 or 35) rotate comprise an autonomous motor (33). 16 - Device as in Claim 15, characterised in that the drawing element (30 or 35) and the drawn element (35 or 30) are arranged coaxial with the motor (33), the drawing element (30 or 35) being mechanically connected to the motor (33) and the drawn element (35 or 30) being mechanically connected to the shaft (23) of the reel (14) by motion transmission means. 17 - Device as in Claim 16, characterised in that the motion transmission means comprise at least return means (40, 41) suitable to differentiate the number of revolutions of the drawing element (30 or 35) from the number of revolutions of the reel (14) . 18 - Device as in Claim 15, characterised in that the drawing element (30 or 35) and the drawn element (35 or 30) are arranged in an intermediate position between the motor (33) and the rotation shaft (23) of the reel (14), there being included transmission means to transfer the motion from the motor (33) to the drawing element and transmission means to transfer the motion from the drawn element to the shaft (23) . 19 - Device as in Claim 15, characterised in that it comprises means (45) to monitor the instantaneous tension of the yarn (11) being unwound suitable to condition the drive of the motor (33) .

Inventors: D AGNOLO ARMANDO, D'AGNOLO, ARMANDO
Applicants: AGNOLO ARMANDO D, RICAMBI TESSILI RI TE S P A, D'AGNOLO, ARMANDO, RICAMBI TESSILI RI.TE - S.P.A.
Application year: 1999
Main classification: B65H59
IPC codes: B65H49, B65H54, B65H59