Patent Grant
11248317
This application is related to and claims the benefit of Italian Patent Application Number 102019000007320 filed on May 27, 2019, the contents of which are incorporated herein by reference in their entirety.
The present disclosure relates to a spiraling machine, i.e. a machine for making elastic yarns covered by means of spiraling.
As is known, covered elastic yarns consist of a core made of elastic material on which one or more non-elastic yarns, normally neutral yarns of varying weight, are wound. These elastic yarns are used in various clothing fields, for example for the production of women's socks, leggings, trousers made of elastic fabric and the like.
The machines normally used for the production of covered elastic yarns provide systems placed in series and equipped with tens or hundreds of spiraling sections, where each of these spiraling sections comprises a vertical elastomeric yarn feeding and collection system, in which the elastomeric yarn is passed through the central section of rotating spindles where the covering yarn is unwound and, due to the rotation, it is wound on the central elastic yarn to form the covered elastic yarn. The latter is then rewound on a winding upstream. This technique produces elastic yarns with single covering or, in the case of the passage of the elastic yarn through a second non-elastic yarn spindle, elastic yarns with double covering.
The rotation of the spindles bearing the non-elastic yarn is usually carried out by means of a single drive which simultaneously transmits the motion by friction to all the spindles by means of a distribution belt which, given the extension in length of such machines, can be tens of meters long. Bearing in mind that the spindles are equipped with windings with a diameter even of 100 mm and that they must be rotated at a high speed, for example 20,000-25,000 rpm, it is easy to see how this operation requires a very high amount of energy, often forming the predominant part of the cost of the final covered elastic yarn. In some cases, this has led to a transfer of production to countries where energy costs are lower.
Other disadvantages of the known machines are related to the high levels of noise emission (usually greater than 100 db), since the aforementioned transmission of motion, occurring by tangential friction, can generate slippages due to instability, heat and various stresses. This also results in energy expenditure which significantly reduces the energy efficiency of these machines.
The dimensions of the spindles and their equipment, in addition to the inertia absorptions due to their masses, determine considerable energy absorption related to the aerodynamic frictions of both the structures and the covering yarn which, when unwinding to move about the elastic support yarn, determines the so-called “balloon” which affects a large section of air and receives a strong extension and envelope brake. Another penalizing factor of the “balloon” is the mass thereof which, when rotating about the elastomeric yarn, causes a radial load towards the latter which diverges it from the axis, until it comes into contact with the inner surface of the spindle that it crosses, which, due to the rotation, tends to twist it axially. This gives rise to a yarn with non-ideal features.
For the reasons listed above and for other reasons, the current technology allows to obtain only single or double-covered yarns, with finished yarn collection speeds of a few tens of meters per minute and with maximum angular covering speeds of no more than 20,000-25,000 rpm.
The present disclosure provides a machine for the production of covered elastic yarns which overcomes at least part of the drawbacks outlined above.
The machine for making covered elastic yarns of the disclosure is outlined in the appended claims, the definitions of which form an integral part of the present description.
Therefore, the present disclosure relates to a machine for making covered elastic yarns which has a greater energy efficiency than the machines of the prior art, so as to obtain a significant reduction in the production costs of the covered elastic yarn.
The disclosure further relates to a machine for making covered elastic yarns which allows increased productivity in terms of final covered elastic yarn.
The present disclosure further relates to a machine for making covered elastic yarns which has reduced noise emission.
The present disclosure further relates to a machine for making covered elastic yarns which allows the creation of elastic yarns with multiple coverings, i.e. with three or more covering yarns.
More in particular, the disclosure relates to a machine for making covered elastic yarns, comprising a plurality of covering units, in which each of the covering units comprises an elastic yarn feeding spool, a non-elastic yarn feeding system, a member for tensioning the covered elastic yarn and a bobbin for collecting the covered elastic yarn, where the non-elastic yarn feeding system comprises a microspindle which rotates about a vertical axis and at least one non-elastic yarn feeding bobbin separated by and arranged upstream of the microspindle along the sliding path of the non-elastic yarn and arranged outside the rotation axis of the microspindle, said microspindle comprising a channel which is coaxial to the rotation axis for the passage of the elastic yarn.
Further features and advantages of the present disclosure will become more apparent from the description of some embodiments, provided below as an indication any by way of a non-limiting example.
As better shown in
The spindle 4 is rotated, with an angular speed, for example of 20,000-25,000 rpm, by a transmission belt 8, which connects all the spindles 4 placed in line by means of a remote drive. Thereby, the non-elastic yarn unwound by the feeding spindle 4 winds about the elastic yarn to form the covered elastic yarn.
A guide 9 for the covered yarn thus obtained is placed above the feeding spindle 4.
If the elastic yarn is to receive a second covering with a different non-elastic yarn (as in
The covered elastic yarn then passes through a movable yarn guide 12 with reciprocating motion along the axis of the collecting bobbin 6 on which the final yarn is wound after passing through a pressing roller 13, thus creating the so-called “traversing stroke”, i.e. zig-zag winding so as to evenly distribute the yarn on the bobbin.
As previously mentioned, although both the spool 3 and the collecting bobbin 6 and the yarn guide 12 for the zig-zag windings are driven, much of the energy absorbed by the system is that required for rotating the non-elastic yarn feeding spindle 4 at a high angular speed by means of the transmission belt 8.
With reference to
The feeding system 104 comprises at least one feeding bobbin 14, commonly provided with pressure rollers 14a, from which the non-elastic yarn F for feeding a microspindle 15 is unwound. The feeding bobbin 14 is separated from and placed upstream of the microspindle 15 along the sliding path of the non-elastic yarn F and is arranged outside the rotation axis X of the microspindle 15.
The feeding bobbin 14 is arranged with a horizontal rotation axis, but nothing prevents it from being arranged at 90°, i.e. with a vertical rotation axis.
A tensioning roller 16, vertically movable by gravity or by means of connection to a vacuum chamber, allows to obtain a constant tensioning of the non-elastic yarn F which is wound on the microspindle 15.
The elastic yarn FE, unwound by the feeding spool 3 and tensioned by the tensioning member 5 according to the methods described above for the known machines, passes through a channel 18 inside the microspindle 15 and coaxial to the rotation axis thereof.
The microspindle 15 comprises a lower portion 15a and an upper portion 15b. A yarn guide feeding ring 19 is arranged close to the lower portion 15a, so that the non-elastic yarn F, unwound by the feeding bobbin 14, is kept close to the rotating surface of the microspindle 15, at the base thereof, and therefore may wind about the microspindle 15.
As better shown in
The upwards sliding speed of the elastic yarn FE, determined by the drive of the collecting bobbin 6, the feeding bobbin 3 and its degree of tensioning, determined by the tensioning member 5, allow to obtain covered elastic yarns FR with different structural features, as is well known to those skilled in the art.
The presence of several holes 21 for running the yarn allows the elastic yarn FE to be covered with different non-elastic yarns F, as will be better clarified below.
As in the known machines, a guide 9 for the covered elastic yarn FR is placed above the microspindle 15 which is formed therein. The yarn FR is then wound, according to the conventional methods, on the collecting bobbin 6.
The microspindle 15 comprises an independent drive 17, consisting for example of a synchronous or digital micromotor or a fluid-operated microturbine, adapted to rotate the microspindle 15 about the rotation axis X thereof.
The microspindle 15 preferably has a diameter which is less than 20 mm, preferably between 5 mm and 20 mm, and is intended to receive a minimum winding of non-elastic yarn F so that the total diameter of the microspindle 15 together with the winding of the yarn F is equivalent to the diameter of the microspindle plus twice the section of the spiraling yarn. Thereby, the masses to be rotated are minimal, which allows to obtain high energy savings while simultaneously increasing the rotation speed—which can also be greater than 100,000 rpm—and therefore the productivity of the system. It can be calculated that the machine of the disclosure allows to obtain even five times the amount of covered elastic yarn at an energy cost of about a quarter of that of the currently produced yarn.
It is apparent that, with the same expedients, it is possible to obtain a double covering, a triple covering or, in principle, even a covering with five or more yarns. If only a double covering is desired, the feeding bobbins 14, 14′ may be placed at the top of a segment perpendicular and incident to the rotation axis X. In the case of three or more feeding bobbins 14, 14′, 14″, they may generally be arranged at the top of convenient polygons, in the middle of which the microspindle 15 is arranged.
In any case, the feeding bobbins may have either a vertical (as in
In such an embodiment, the microspindle 15 comprises a coupling portion 22, arranged below the lower portion 15a and integral therewith. A tubular magnet 23 is arranged on the coupling portion 22. A metal belt 208 (shown in the figure in cross-section), moved by a remote drive as the belt 8 of the known spiraling machines, passes substantially tangent to and almost in contact with the tubular magnet 23. Thereby, due to the magnetic attraction, the microspindle 15 is rotated at the desired angular speed.
This embodiment, while having a common drive in place of the independent drive 17 of the first embodiment described above, solves the problems related to friction, i.e. the noise and energy dispersion present in the traditional system with in-contact belt transmission.
From the above, it is apparent that the spiraling machine of the disclosure allows to overcome the disadvantages of the known machines, and in particular achieves one or more of the following:
It is apparent that only certain particular embodiments of the present disclosure have been described, to which those skilled in the art will be able to make all those modifications required for its adaptation to particular applications, without departing from the scope of protection of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102019000007320 | May 2019 | IT | national |
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| Number | Date | Country |
|---|---|---|
| 1489421 | Aug 1966 | FR |
| 9205302 | Apr 1992 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20200378037 A1 | Dec 2020 | US |
