EP3303665A1

EP3303665A1 - Twisting and winding device for twisting and winding a thread on a spindle

Info

Publication number: EP3303665A1
Application number: EP16736616.0A
Authority: EP
Inventors: Marco Camelli; Etles ROTONDI; Manlio NOBILI; Roberto APONI
Original assignee: Cogne Macchine Tessili SpA
Current assignee: Cogne Macchine Tessili SpA
Priority date: 2015-05-26
Filing date: 2016-05-25
Publication date: 2018-04-11
Anticipated expiration: 2036-05-25
Also published as: WO2016189480A1; EP3303665B1; ITUB20151069A1

Abstract

Twisting and winding device (1) for twisting and winding a thread on a spindle comprising a twisting and winding unit (5), arranged for permitting twisting and winding of said thread around the spindle and comprising a sleeve (40) provided with a guiding element (43) for guiding the thread, said sleeve (40) being arranged for being rotated by the spindle through the thread, the twisting and winding device (1) further comprising an inner ring (30) fixed outside the sleeve (40), a positioning element (32) arranged for supporting a plurality of revolving bodies (33), and an outer ring (31), mounted concentrically outside the inner ring (30), said positioning element (32) being interposed between the inner ring (30) and the outer ring (31), said inner ring (30) and said outer ring (31) forming a rolling track for said plurality of revolving bodies (33); the twisting and winding device (1) further comprising an electronic control unit (4) arranged for varying a rotation speed of the sleeve (40), the electronic control unit (4) comprising a speed sensor ( 18), arranged for detecting an actual rotation speed of the sleeve (40), an electromagnet (9), arranged for interacting with the sleeve (40), and an electronic card (10) arranged for varying a supply current of the electromagnet (9) to exert a braking action on the sleeve (40), in order to vary the actual rotation speed of the sleeve (40), the electronic card (10) being set up to compare the value of the actual rotation speed detected by the speed sensor (18), with a reference value and varying the supply current on the basis of the result of said comparing.

Description

Twisting and winding device for twisting and winding a thread on a spindle

The invention relates to a twisting and winding device for twisting and winding a thread on a spindle, in particular used in operations of spinning a thread in ring spinning machines to permit the twisting and winding, or spooling, of the thread around a spindle so as to make a spool of a set type of yarn.

Twisting and winding devices are known for twisting and winding a thread on a spindle for a ring spinning machine, each of which comprises an inner ring and an outer ring between which a cage is interposed supporting in preset positions a plurality of revolving bodies, arranged at 120° from one another.

The outer ring, which is fixed, is mounted in use in a circular seat obtained in a bench of the ring spinning machine, whereas the inner ring is fixed to an outer wall of a sleeve that is coaxial with a spindle.

In the body of the sleeve a hole is obtained that is arranged for housing and engaging a substantially C-shaped guiding element for guiding a thread inside which in use the thread is engaged that is to be subjected to twisting and winding that was previously stretched by a plurality of pairs of rollers rotating at different speeds.

The spindle is rotated together with all the other spindles of the same front of the spinning machine by a head motor. The rotation of the spindle tautens the thread, an end of which is fixed to the spindle, which rotates the cage, the inner ring, the sleeve, owing to the interaction between a portion of the thread and an area of the guiding element for guiding a thread. Simultaneously, during the spinning operations, the bench is suitably driven in a vertical direction, i.e. along a direction that is substantially parallel to the axis of each spindle.

The rotary motion of the spindle produces twisting of the thread whilst the latter is wound around the spindle to create a spool.

The productivity of known spinning machines is limited by the rotation speeds that are sustainable by the rotating parts.

In order to increase the number of spools produced, it is thus indispensable to reduce the friction between the revolving bodies and the rolling tracks in which they roll, maintaining at the same time control of the tension of the thread.

For this purpose, the twisting and winding devices for twisting and winding a thread on a spindle of known type, which are shown for example in European patent application EP 0 1 14 580 A2, are each provided with a lubricating system comprising at least two through openings obtained in the outer ring and arranged for permitting the passage therein of a taut sliver, which is impregnated with oil absorbed through capillary action when it is passed through an oil tank outside the device and arranged upstream of the outer ring. The sliver impregnated with oil cooperates through rubbing with a portion of the cage or with a portion of the rolling track in such a manner that part of the oil is removed and lubricating is ensured of the contact zones between the revolving bodies and the rolling tracks.

One drawback of the twisting and winding devices for twisting and winding a thread on a spindle of known type is that the lubricating system entails a short life for the devices because of the dirt due to hairs impregnated with oil that get separated from the sliver during rubbing thereof to free oil. As a result, spinning machines provided with such devices have to be serviced frequently and the dirty devices have to be replaced, with consequent high costs of maintenance and replacement of the devices.

During a spinning cycle, the speed of each inner ring, cage and sleeve may have to be varied according to the cycle stage or, for example, when it is necessary to stop and then restart a spindle because of the breakage of the thread.

In order to be able to decrease the speed set by the spindle, on the inner ring, on the cage and on the sleeve, the twisting and winding devices for twisting and winding a thread on a spindle of known type comprise a plurality of magnets, mounted next to one another with opposite polarities that interact magnetically with the inner ring to generate a braking action. By varying the position of the magnets with respect to the inner ring, the braking action can be varied on each inner ring or on each cage.

By varying the position of the magnets, spinning machines of known type comprise a rod that controls all the twisting and winding devices for twisting and winding a thread on a spindle and can be driven axially to act on a lever with which each twisting and winding device for twisting and winding a thread on a spindle is provided that permits axial or radial movement of the magnets.

One drawback of the twisting and winding devices for twisting and winding a thread on a spindle of known type is thus that adjusting braking by a rod-lever system is hardly precise. Further, if it is desired to vary braking in a single twisting device, the respective lever must be disconnected from the rod, which requires the manual intervention of an operator with significant expenditure of time.

Also, in ring spinning machines of known type, in order to ascertain whether a thread has broken during the spinning cycle, an operator has to proceed along the entire length of each front of the spinning machine, trying make to make contact with the thread. When the operator does not feel the contact, s/he deduces that the thread of a given spindle has broken.

Consequently, maintenance operations are long and it is not possible to intervene promptly directly on the broken thread because it is not visible, given the great number of spindles on the same front of the spinning machine, but it is necessary for the operator to check in each spindle the presence of threads until possible broken threads are identified.

Further, the twisting and winding devices for twisting and winding a thread on a spindle of known type do not provide a cooling system, for example to limit the heating of the moving parts and thus wear, but the cooling system is outside the spinning machine and is thus not efficient because it does not act directly on the twisting and winding device for twisting and winding a thread on a spindle, but only in the environment in which the spinning machine is located.

One object of the present invention is to improve the twisting and winding devices for twisting and winding a thread on a spindle of known type.

Another object is to produce a twisting and winding device for twisting and winding a thread on a spindle having a longer life than the twisting and winding devices for twisting and winding a thread on a spindle of known type.

A further object is to permit more rapid maintenance of the twisting and winding devices for twisting and winding a thread on a spindle in the event of breakage of the threads to be twisted and wound on the spindles.

Still another object is to produce a twisting and winding device for twisting and winding a thread on a spindle that enables the braking action to be controlled more efficiently.

A still further object is to produce a twisting and winding device for twisting and winding a thread on a spindle that is more efficient, for example in terms of heat dissipation, and enables the twisting and winding device for twisting and winding a thread on a spindle to be replaced more easily than the twisting and winding devices for twisting and winding a thread on a spindle of known type.

A still further object is to produce a twisting and winding device for twisting and winding a thread on a spindle that is cheap and easy to use and to mount.

According to the invention a twisting and winding device for twisting and winding a thread on a spindle is provided as indicated in claim 1. The invention can be better understood and implemented with reference to the attached drawings, which illustrate an embodiment thereof by way of non-limiting example, in which:

Figure 1 is a perspective top view illustrating a plurality of twisting and winding devices for twisting and winding a thread on a spindle according to the invention mounted on a bench of a ring spinning machine;

Figure 2 is a perspective view like that of Figure 1 but a bottom view;

Figure 3 is a section taken along a plane III-III of Figure 1 ;

Figure 4 is a perspective view of an electronic control unit of the twisting and winding device for twisting and winding a thread on a spindle according to the invention;

Figure 5 is a perspective bottom view of the electronic control unit of Figure 4 with a cover removed to show an electronic card;

Figure 6 is an exploded view of the electronic control unit of Figure 4;

Figure 7 is a perspective top view of a twisting and winding unit of a thread on a spindle provided in the twisting and winding device of Figure 1 ;

Figure 8 is a perspective view like that of Figure 7, but a bottom view;

Figure 9 is a section taken along a plane IX-IX di Figure 7;

Figure 10 is an exploded view of the twisting and winding unit of a thread on a spindle of Figure 7.

With reference to Figures 1 and 2, there is shown a plurality of twisting and winding devices 1 of a thread on a spindle according to the invention mounted next to one another on a bench 2 of a ring spinning machine.

Each twisting and winding device 1 is mounted concentrically on a respective circular opening 3 obtained in the bench 2.

In use, inside each circular opening 3 a spindle is positioned which is rotated by a head motor of the spinning machine together with all the other spindles of the same front of the spinning machine. As will be explained better further on in the description, the rotation of the spindle tautens the thread, one end of which is fixed to the spindle, which rotates some components of the twisting and winding device 1. Simultaneously, during the spinning operations, the bench 2 is driven to move opportunely in a vertical direction, i.e. along a direction that is substantially parallel to an axis X (Figure 3) of each circular opening 3. Owing to the twisting and winding device 1 , the thread, which has been previously stretched by a plurality of pairs of rollers rotating at different speeds, is twisted and wound around the spindle so as to make a spool of a set type of yarn.

The bench 2 is made of extruded aluminium that enables the weight thereof to be limited with respect to the benches of traditional spinning machines made by folding a steel sheet to compensate for the greater weight of the twisting and winding devices 1 according to the invention with respect to the twisting and winding devices of known type, due to the presence of an electromagnet with relative control electronics, for each device, as will be explained below.

Each circular opening 3 can have a diameter of about 75 mm and the distance between the axes X of two adjacent circular openings 3 can be about 82,5 mm. Such dimensions enable the assembly and maintenance operations to be facilitated that are to be performed on the twisting and winding devices 1.

Each twisting and winding device 1 comprises an electronic control unit 4, which is visible in Figure 2 and shown in particular in Figure 4, and a twisting and winding unit 5 visible in Figure 1.

As will be explained better below, the twisting and winding unit 5 comprises rotating components that engage the thread and are rotated by the tension of the thread that is tautened between the components and the rotated spindle. In this manner, these rotating components enable the thread to be twisted and wound around the spindle. The electronic control unit 4 is arranged, in particular, for exerting a controlled braking action on the rotating components of the twisting and winding unit 5 according to the advancement of a spinning cycle of the thread.

During a spinning cycle, in fact, the speed of the rotating components may have to be varied according to the cycle stage or, for example, when it is necessary to stop and then restart a spindle because of the breakage of the thread.

With reference to Figure 3, the bench 2 has a substantially C-shaped section and comprises a plurality of cooling fins 6 protruding from an outer side wall 7 of the bench 2 to the outer environment so as to thus increase the radiant surface to promote dissipation of heat through convection.

In particular, the cooling fins 6 are arranged parallel to one another and substantially travel the entire length of the bench 2.

The cooling fins 6 act as heat sinks, in particular of the heat generated by the twisting and winding unit 5, thus enabling the ambient temperature to be lowered and preventing the twisting and winding unit 5 and/or the electronic control unit 4 from overheating, causing wear thereto and/or a malfunction thereof.

With reference to Figures 4 to 6, each electronic unit 4 comprises a braking device, in particular an electromagnet 9, and an electronic card 10 arranged for controlling a braking action that the electromagnet 9 exerts on a rotating component of the twisting and winding unit 5.

Each electronic unit 4 comprises a body 8 that is preferably made of plastics, in which a housing 19 is made for the electromagnet 9 and a further housing 20 for the electronic card 10, which are shown schematically in Figures 5 and 6.

The body 8 is approximately parallelpipedon-shaped and can have profiles with grooved zones 1 1 arranged for decreasing the volume of the electronic control unit 4 and, consequently, the corresponding mass, to be less of a burden on the support elements of the spinning machine that have to support the bench 2.

In the body 8 a through hole 12 is further obtained that, in use, like the circular opening 3, surrounds the spindle.

In order to enable the electronic control unit 4 to be fixed to the bench 2, in the body 8 through openings 13 are provided that are arranged for housing connecting means 14, of known type, comprising for example screws and shown from above in Figure 1 , which interacts with respective connecting holes made in the bench 2 and enables the electronic control unit 4 to be fixed in a preset position on the bench 2.

Owing to suitable positioning of the through openings 13 and of the connecting holes, the through hole 12 and the circular opening 3 are concentric when the electronic unit 4 is mounted on the bench 2.

In the Figures there are shown three through openings 13 with three respective connecting means 14 and three connecting holes, but the number of such elements can also be different.

The electronic control unit 4 further comprises a light source 15 arranged for sending an optical signal to an operator, or to an optical supervision system, to indicate an operating condition of the twisting and winding unit 5.

The light source 15 can comprise a first light source 16 and a second light source 17 each of which is arranged for emitting a light of a different colour from one another, for example green and red, respectively. A different meaning known to the operator can be assigned to this colour, depending on the condition that it is desired to indicate. For example, the light emission of the first light source 16 can be assigned a condition of good operation of the twisting and winding unit 5, i.e. a condition in which the thread is kept taut and is not therefore interrupted, and in which the rotating components of the twisting and winding unit 5 rotate correctly. On the other hand, the light emission of the second light source 17 can be assigned a condition of malfunction of the twisting and winding unit 5, which is either due to the fact that the rotating components of the twisting and winding unit 5 do not rotate correctly, which indicates a problem with the twisting and winding unit 5, or is due to the fact that the twisting and winding unit 5 is stationary, which indicates an interruption to the thread, which, no longer being taut, does not rotate the rotating components of the twisting and winding unit 5 around the spindle.

The conditions of good operation or malfunction of the twisting and winding unit 5 are established on the basis of the actual rotation speed of the rotating components of the twisting and winding unit 5 detected by a speed sensor 18 provided in the electronic control unit 4.

The speed sensor 18 is arranged in a still further housing 21 obtained in the body 8 shaped in such a manner that the speed sensor 18 faces the through hole 12, once it has been mounted in the still further housing 21. In this manner, the speed sensor 18, in use, is able to detect a rotation speed of the rotating components of the twisting and winding unit 5. The speed sensor 18 can be, for example, of the optical Hall-effect type.

If the speed sensor 18 is optical, it comprises a reflective strip arranged on about 50% of the circumference of the through hole 12, so as to detect with precision also the higher speeds (30-40.000 rpm) of the rotating components of the twisting and winding unit 5. The value of the rotation speed of the twisting and winding unit 5 is then transmitted by the speed sensor 18 to the electronic card 10, which compares the value of the detected speed with that of the set reference value. The set reference value is variable during the spinning cycle, for example depending on the stage of creation of the spool.

The first and the second light source 16, 17 can be supplied alternately by the electronic card 10, in particular by a switch driven by a relay supplied by the electronic card 10.

For example, if the rotation speed of the rotating components of the twisting and winding unit 5 falls below a reference value set for the speed of the twisting and winding unit 5, the electronic card 10 commands the relay to supply the second light source 17, whereas when the rotation speed of the rotating components of the twisting and winding unit 5 remains within a range of values around the set reference value, the electronic card 10 commands the relay to keep the first light source 16 supplied.

A rotation speed below the set reference value of the rotation speed is a sign of a malfunction of the twisting and winding unit 5, inasmuch as the rotating components of the latter rotate, but at reduced speed, whereas a rotation speed in particular equal to 0 is a sign of a breakage of the thread inasmuch as the twisting and winding unit 5 no longer rotates. The first light source 16 and the second light source 17 can each comprise a LED to generate the respective light emission.

Alternatively, the light source 15 can also comprise a single LED, which, for example, is assigned a good operation condition of the twisting and winding unit 5 when it does not generate a light emission, or which is assigned a malfunction condition when it is supplied, i.e. when it generates a light emission.

Owing to the light source 15, the operator is able to establish whether a thread which a given twisting and winding device 1 was twisting and winding is broken or not by merely checking visually the light signal. In this manner it is avoided that the operator has to proceed along the entire length of each front of the spinning machine, trying to make contact with the thread to check whether the thread broke during the spinning cycle.

Consequently, the maintenance operations of the twisting and winding devices 1 of a thread on a spindle are more rapid than the twisting and winding devices of known type and it is possible for the operator to intervene promptly and directly on the broken thread or on the malfunctioning twisting and winding unit 5.

Naturally, in order to be able to be visible externally and at a distance, the light source 15 has to protrude from an upper face 22 of the electronic unit 4 and a suitable passage 23 has to be obtained in the bench 2 to be able to permit that, when the electronic control unit 4 is mounted on the bench 2, the light source 15 protrudes to the outer environment.

The electronic card 10 is supplied through a power supply line 24 carrying live voltage into which the electronic card 10 is plugged by electric connecting plugs 25 when the electronic control unit 4 is mounted on the bench 2. In fact, the electric connecting plugs 25 have a length that is such as to enable contact with the supply line 24 during assembly. In this manner, the electronic card 10 is easily connected to the electric supply without any additional wiring having to be provided. This permits very rapid maintenance and assembly. The supply line 24 is arranged in a longitudinal seat 26 obtained along the entire length of the bench 2.

The electronic card 10, in addition to controlling the supply of the light source 15, communicates through a data communication channel, not shown, for example a data transmission bus, with a central control unit of the spinning machine.

The central control unit comprises software arranged for managing the spinning cycle and rotating the motors of the spindles.

The central control unit, further, sends data to the electronic card 10, on the basis of which the latter controls the twisting and winding unit 5. In particular, the central control unit informs the electronic card 10 of the specific operating parameters for each stage of a spinning cycle.

In turn, the electronic card 10 sends the central control unit status signals and alarms, for example indicating a malfunction of the twisting and winding unit 5.

Thus, between the electronic card 10 and the central control unit a two-way communication is established.

In the Figures a supply line 24 is shown in the form of an electrified track. In other words, the supply line 24 comprises a pair of supply cables, in particular that supply a direct current. In this case, the data transmission bus uses the same cables as the supply line 24. Nevertheless, the supply line 24 can provide several cables, and, correspondingly, the electronic card 10 will comprise a number of electric connecting plugs 25 equal to the number of cables of the supply line 24, the signal transmission cable being, in this case, independent of the supply line 24.

The electronic card 10 comprises electronic components 27 of known type, schematically illustrated in Figures 5 and 6, suitable for establishing the communication with the central control unit of the spinning machine and with the light source 15.

The further housing 20 obtained in the body 8 for housing the electronic card 10 has an upwardly open substantially box shape. The electronic card 10 is located during the assembly step inside the further housing 20.

The further housing 20 can be made integrally on the body 8 and can be provided at a first end of the body 8.

A cover 28 is provided for engaging with a perimeter 29 of the further housing 20 such as to close the latter and protect the electronic components 27 from foreign bodies, for example from dust. Similarly to the electronic card 10, also the electromagnet 9 is connected electrically to the supply line 24 with a fixed connector, which is not shown, that engages automatically during the assembly step. In this manner, maintenance and assembly are facilitated and rapid. For connection to the supply line 24, suitable electric tracks are provided that are not illustrated that are arranged for taking the electric supply to the electromagnet 9.

The electromagnet 9 is further arranged on an opposite side of the through hole 12 with respect to the electronic card 10 and is separated from the latter.

The electromagnet 9 can comprise a plurality of packed insulated laminations and a winding with a great number of coils in order to have minimum absorption.

The housing 19 of the electromagnet 9 is arranged in the body 8 in such a manner that the electromagnet 9, once it is mounted, embraces at least partially the through hole 12 and thus, in use, the twisting and winding unit 5, in order to interact with a rotating component of the twisting and winding unit 5 to vary the rotation speed thereof, in particular to exert a braking action on the aforesaid rotating component.

In fact, the electromagnet 9 generates a magnetic field due to the passage of the current through the winding thereof. When the winding is supplied with a variable current, the magnetic field is in turn variable and thus also the intensity of the braking force produced. By thus piloting the current that traverses the winding, it is possible to modulate the intensity of the magnetic field and, thus, the intensity of the braking action, which is naturally proportional to that of the magnetic field.

In particular, during the entire spinning cycle, the electronic card 10 constantly receives the value of the actual rotation speed of the rotating components of the twisting and winding unit 5 detected by the speed sensor 18, the reference value for the rotation speed of the rotating components of the twisting and winding unit 5 so as to obtain correct twisting and tensioning of the thread around the spool, this reference value being sent by the central control unit to the electronic card 10, and, lastly, an operating parameter indicating the cyclical vertical movement of the bench 2 in such a manner that the electronic card 10 can make the necessary corrections according to the actual winding diameter of the thread on the spindle, also this parameter being sent by the central control unit to the electronic card 10.

The electronic card 10 compares the detected speed with the set speed. When the detected speed is greater than the set speed, it commands an increase in the intensity of the electric current of the electromagnet 9 so as to increase the intensity of the magnetic field generated and, consequently, the braking action thereof, vice versa, if the detected speed is less than the set speed, it commands a reduction in the intensity of the current of the electromagnet 9, so as to decrease the intensity of the magnetic field generated and, consequently, the braking action thereof.

In other words, the speed value that is detected constantly by the speed sensor 18 is used to decide if it is necessary to exert and to what extent braking of the sleeve 40 by comparing the detected speed value with a reference value that is stored in the electronic card 10 and is variable during the spinning cycle.

Also, the electronic card 10, owing to the modulation of the current that passes through the winding of the electromagnet 9, is able to perform a start-up procedure until the working speed of a twisting and winding unit 5 is reached, for example, after breaking of the thread and the subsequent repair performed by an operator on the basis of the operating parameters sent by the central control unit.

The electronic card 10 is thus able to optimise braking during the entire spinning cycle, according to the speed variations of the thread provided according to the steps of the spinning cycle.

With reference to Figures 7 to 10, the twisting and winding unit 5 comprises an inner ring 30 and an outer ring 31 between which an annular positioning element 32 supporting in preset positions a plurality of revolving bodies 33 is interposed.

The revolving bodies 33 can be three in number, as in the Figures, arranged substantially at 120° from one another, but the number can be varied.

The revolving bodies 33 are made of ceramic material so as to be able to reach and maintain high rotation speeds. In particular, the revolving bodies 33 are made of silicon nitride.

The annular positioning element 32 is provided with a plurality of substantially C-shaped downward-facing projections 34, each of which forms a positioning seat 35 for a respective revolving body 33, this positioning seat 35 being arranged for embracing partially a respective revolving body 33 and maintaining the revolving body 33 in the aforesaid preset position. The plurality of projections 34 is shaped in such a manner that, in use, each revolving body 33 is inserted inside a respective positioning seat 35 with clearance in such a manner as to be free to rotate in the interior thereof. Accordingly, for this purpose, the positioning seat 35 has to be suitably dimensioned according to the dimensions of the revolving bodies 33. Each revolving body 33 can have a substantially spherical shape.

In use, the outer ring 31 is mounted on an edge of the circular opening 3 of the bench 2 and is the only component of the twisting and winding unit 5 that does not rotate around the spindle. The outer ring 31 is moreover arranged resting on a resting seat 51 provided in the body 8 of the electronic control unit 4, shown for example in Figure 6. The resting seat 51 is positioned and shaped in such a manner that when the outer ring 31 rests thereupon the connecting means 14 can interact with a portion of an upper surface 53 of the outer ring 31 to immobilise the outer ring 31 on the bench 2 together with the electronic control unit 4. The outer ring 31 and the inner ring 30 can be made of a ceramic material, or of steel. The outer ring 31 and the inner ring 30 have a substantially C-shaped section, such sections facing one another in an assembly step. In fact, an inner surface 36 of the outer ring 31 has a first groove 37, whereas an outer surface 38 of the inner ring 30 has a second groove 39 that in use, facing one another, make up a rolling track for the revolving bodies 33.

The rolling track of the revolving bodies 33 can have an oblique contact that enables also axial loads to be supported in addition to radial loads. In this manner, the twisting and winding unit 5 is able to contrast traction upwards due to the fact that the traction of the thread is greater than the mass of the rotating revolving bodies 33.

The twisting and winding unit 5 further comprises a sleeve 40 made of a highly conductive metal material that is suitable for interacting with the electromagnet 9, and is obtained, for example, by turning an extruded bar. The inner hole of the sleeve 40 can have a diameter of 55 mm. Aluminium is preferably used as a highly conductive metal material because of the low specific weight thereof.

It is on the sleeve 40 that the magnetic field of the electromagnet 9 interacts to exert braking action thereupon according to the commands of the electronic card 10.

The inner ring 30 is mounted, in use, against a portion of an outer wall 41 of the sleeve 40. In particular, the inner ring 30 can be fixed to the outer wall 41 by a structural adhesive so as to avoid mechanical stress to the inner ring 30.

The annular positioning element 32 can be made of a technopolymer that is suitable for high temperatures, is hard-wearing and has a very low friction coefficient. Such a technopolymer gives the annular positioning element 32 a high degree of elasticity that enables the revolving bodies 33 to be mounted correctly without requiring the ceramic or steel internal and external rings 30, 31 to be deformed. In use, an upper edge 52 of the inner ring 30 is received with interference fit in a connecting seat of the annular positioning element 32, which is not illustrated in the Figures. In this manner, the inner ring 30 and consequently also the sleeve 40, are connected to the annular positioning element 32, which is then coupled during the assembly step with the outer ring 31 so as to be interposed between the inner ring 30 and the outer ring 31.

Once mounted, the inner ring 30, with the sleeve 40 fixed thereto, and the outer ring 31 are mounted concentrically to the circular opening 3 and thus substantially coaxially with the spindle provided inside the circular opening 3.

Thus the diameters of the inner ring 30 and of the sleeve 40 have to be less than the diameter of the outer ring 31.

Lastly, once both the electronic control unit 4 and the twisting and winding unit 5 have been mounted on the bench 2, the connecting means 14 is inserted in such a manner as to engage the electronic control unit 4, the twisting and winding unit 5 and the bench 2 reciprocally through the interaction with the through openings 13 of the electronic control unit 4, with the portion of the upper surface 53 of the twisting and winding unit 5 and with the connecting holes of the bench 2.

In the body of the sleeve 40 a hole 42 is obtained arranged for housing and engaging a guiding element 43 for guiding the thread. The guiding element 43 is substantially C- shaped, in such a manner that one end of the C can be inserted inside the hole 42.

The guiding element 43 for guiding the thread is arranged in order that the stretched thread to be subjected to twisting and winding is inserted therein and engages a portion of an inner area 44 of the guiding element 43.

When the head motor of the spinning machine rotates a spindle, together with all the other spindles of the same front of a spinning machine, the rotation of the spindle tautens the stretched thread, one end of which is fixed to the spindle itself, which rotates the sleeve 40 and, consequently, the annular positioning element 32 and the inner ring 30 that are connected to the sleeve 40 as disclosed above, owing to the interaction between the thread and the portion of inner area 44 of the guiding element 43.

Simultaneously, during the spinning operations, the bench is driven appropriately in a vertical direction, i.e. along a direction that is substantially parallel to the axis of each spindle. In this manner, the rotary motion of the spindle produces twisting of the thread whereas the latter is wound around the spindle to create a spool.

From what has been set out above, the rotating components of the twisting and winding unit 5 are the inner ring 30, the annular positioning element 32, the revolving bodies 33 and the sleeve 40. The outer ring 31 is on the other hand fixed.

The guiding element 43 for guiding the thread can comprise a protruding element, not shown in the Figures, made of a ceramic material and arranged for reducing wear and increasing the range of curvature of the thread in transit. This protruding element is fixed in an upper portion of the C of the guiding element 43 for guiding the thread.

Owing to the protruding element it is possible to prevent impurities, for example possible hairs freed by the thread, penetrating inside the twisting and winding unit 5 and, in particular, inside the rolling track, compromising correct rolling of the revolving bodies 33. Also, in order to prevent impurities entering between the rotating components of the twisting and winding unit 5, the twisting and winding device 1 comprises a pressurised air delivery system 45 obtained in the body 8, shown in particular in Figure 3.

The pressurised air delivery system 45 communicates on one side with a conduit 46 obtained in the thickness of the bench 2 through an air supply hole 47 (Figure 6), and on the other side leads into an upper zone of the body 8 located near the circular opening 3 through an air outlet hole 48.

The air outlet hole 48 is in flowing communication with the rolling track when the twisting and winding unit 5 and the electronic control unit 4 are mounted on the bench 2.

The compressed air, generated for example by an external pump, is supplied to the pressurised air delivery system 45 through the conduit 46.

The pressurised air delivery system 45 can comprise one or more air delivery channels obtained in the body 8.

Around the air supply hole 47 a seal 49 is arranged, for example an O-ring, for maintaining the pressurised air delivery system 45.

The seal 49 is housed in a respective seat 50 obtained in the body 8 of the electronic control unit 4.

The flow of compressed air supplied to the rolling track is further used to cool the rotating components and lubricate the components occasionally, for example by means of a fluidifier in the form of powder. Owing to the pressurised air delivery system 45, it is possible to avoid or minimise lubrication, which enables the life of the rotating components of the twisting and winding unit 5 to be considerably lengthened. In particular, using a sliver impregnated with oil as a lubricating element in prior art twisting and winding devices is avoided, which sliver creates dirt, i.e. hairs impregnated with oil that are released by the sliver, that affect the length of life of prior art twisting and winding devices. As a result, the maintenance costs of twisting and winding devices 1 according to the invention are significantly reduced with respect to prior art twisting and winding devices.

Further, the twisting and winding devices 1 according to the invention have a much longer life than those of the prior art owing to the use of compressed air delivered into the rolling track of the revolving bodies 33 by the pressurised air delivery system 45. This means that maintenance costs are considerably lower than those of prior art twisting and winding devices 1.

Also, by eliminating lubrication by an oil lubricant, there is no need to provide an oil tank and the total mass of the bench 2 with the twisting and winding devices 1 mounted thereon is less than that of prior art twisting and winding devices, being less of a burden on the support elements of the spinning machine.

The twisting and winding devices according to the invention are very versatile, because both the electronic control unit 4 and the twisting and winding unit 5 can also be mounted on a bench of a traditional spinning machine, i.e. be made of folded sheet metal. The only modification to be made to a traditional bench is to provide an electrified supply line for the electric/electronic components of the electronic control unit 4.

Owing to the invention, in the event of a fault or malfunction of a twisting and winding unit 5 it is sufficient for the operator or the optical supervision system to check the light sources 15, owing to which prompt intervention on the twisting and winding unit 5 affected by the fault or malfunction is possible.

Further, both the electronic control unit 4 and the twisting and winding unit 5 are mountable in plug-and-play mode and specific electric installation procedures are not necessary owing to the absence of cabling, this significantly simplifying assembly and maintenance operations.

Again, owing to the electronic card 10, the braking action exerted by the electromagnet 9 on the sleeve 40 is controlled very efficiently. In fact, an electronic card 10 is provided for each twisting and winding device 1 assigned to a respective spindle, so as to control a single braking device on the basis of the detected rotation speed of the rotating components and on the characteristic parameters of the various stages of a spinning cycle, permitting both productivity and the quality of the obtained yarn to be increased.

Claims

Twisting and winding device (1) for twisting and winding a thread on a spindle comprising a twisting and winding unit (5), arranged for permitting twisting and winding of said thread around said spindle and comprising a sleeve (40) provided with a guiding element (43) for guiding said thread, said sleeve (40) being arranged for being rotated by said spindle through said thread, said twisting and winding device (1 ) further comprising an inner ring (30) fixed outside said sleeve (40), an annular positioning element (32), arranged for supporting a plurality of revolving bodies (33), and an outer ring (31), mounted concentrically outside said inner ring (30), said annular positioning element (32) being interposed between said inner ring (30) and said outer ring (31 ), said inner ring (30) and said outer ring (31 ) forming a rolling track for said plurality of revolving bodies (33), said twisting and winding device (1) being characterised in that it further comprises an electronic control unit (4) arranged for varying a rotation speed of said sleeve (40), said electronic control unit (4) comprising a speed sensor (18), arranged for detecting an actual rotation speed of said sleeve (40), an electromagnet (9), arranged for interacting with said sleeve (40), and an electronic card (10) arranged for varying a supply current of said electromagnet (9) to exert a braking action on said sleeve (40), in order to vary said actual rotation speed of said sleeve (40), said electronic card (10) being set up to compare the value of said actual rotation speed detected by said speed sensor (18) with a reference value and to vary said supply current on the basis of the result of said comparing.

Twisting and winding device (1) for twisting and winding a thread on a spindle according to claim 1 , wherein said electronic card ( 10) is set up for varying said supply current on the basis of operating parameters of a stage of a spinning cycle of said thread, said operating parameters being sent to said electronic card (10) from a central control unit with which said electronic card communicates via a data communication bus.

Twisting and winding device (1 ) for twisting and winding a thread on a spindle according to claim 1 or 2, wherein said electronic control unit (4) further comprises a light source (15) arranged for sending an optical signal to an operator, or to an optical supervision system, to indicate an operating condition of said twisting and winding unit (5).

Twisting and winding device (1) for twisting and winding a thread on a spindle according to claim 3, wherein said light source (15) comprises a first light source (16) and a second light source (17) each of which arranged for emitting a respective light that is of a different colour from one another, said first light source ( 16) and said second light source (17) being supplied alternately by said electronic card (10).

5. Twisting and winding device (1) for twisting and winding a thread on a spindle according to any preceding claim, wherein said electronic control unit (4) and said twisting and winding unit (5) are configured for being mounted in plug-and-play mode on a bench (2) of a spinning machine.

6. Twisting and winding device (1) for twisting and winding a thread on a spindle according to any preceding claim, wherein said electronic control unit (4) further comprises a pressurised air delivery system (45) obtained in a body (8) of said electronic control unit (4) arranged for supplying compressed air to said rolling track for said plurality of revolving bodies (33).

7. Bench (2) for a spinning machine provided with at least one twisting and winding device (1) according to any one of claims 1 to 6, said bench (2) being made of extruded aluminium and comprising at least one circular opening (3) for housing a spindle of said spinning machine, an outer side wall (7) and a plurality of cooling fins (6) protruding from said outer side wall (7) to an outer environment so as to increase a radiant surface of said bench (2).

8. Bench (2) according to claim 7, wherein said outer ring (31) is mounted on said circular opening (3).

9. Bench (2) according to claim 8, and further comprising a longitudinal seat (26) running the entire length of said bench (2) and housing a supply line (24) arranged for supplying said electronic card (10) of said twisting and winding device (1 ).

10. Bench (2) according to claim 8 or 9, and further comprising a conduit (46) obtained in a thickness of said bench (2) to permit the passage of compressed air to be introduced into a pressurised air delivery system (45) of said twisting and winding device (1).