The invention relates to a processing apparatus for processing a sliver, in particular used in a finisher, to make a false twist on a long-fibre sliver in order to give the sliver a consistency that is such as to enable the sliver to withstand the stress that arises (hiring the successive treatments to which it is subjected, such as, for example, a stretching operation, before being fed into a spinning frame, for example a ring spinning frame, to obtain a yam. In the textile industry, upstream of the spinning frame a finisher is arranged that receives an incoming sliver in the form of textile fibres mat are substantially parallel to and alongside one another, a so-called web, coming from a can. This web has virtually no consistency because the fibres are arranged substantially alongside one another without engaging one another reciprocally. Inside the finisher, the web of substantially parallel fibres is subjected to a plurality of processes, such that exiting the finisher a processed sliver is obtained that has a certain consistency conferred by a processing apparatus intended to perform processes, for example a false twist, on the web. The false twist enables the fibres of the web to approach one another and to prevent the surface fibres of the web from curling. This processed sliver provided with a certain consistency is then wound on a reel.

In use, in order to give the false twist, the finisher is interposed between a pair of counter- rotating rollers upstream and a pair of counter-rotating rollers downstream that favour sliding of the sliver.

The pair of counter-rotating rollers upstream interacts with the web that is fed to die finisher, whereas the pair of counter-rotating rollers downstream interacts with the processed sliver exiting the finisher.

Finishers are known comprising a processing apparatus for processing a sliver in the form of a rubbing device that comprises two pairs of cylinders, each cylinder being mounted on a respective shaft. Around each pair of cylinders a sleeve is mounted which is for example made of rubber with scoring obtained on an outer surface thereof. The pair of sleeves made of rubber is provided with a pair of walls mat arc opposite and moved in use with reciprocating motion concordantly between the two walls, to give false twists to the sliver interposed therebetween, hi particular, the two walls are pushed laterally against one another in a direction that is substantially perpendicular to the advancement direction of the sliver. One defect of the processing apparatuses for processing a sliver of known type in the form of a rubbing device is that they are very complicated and have significant dimensions because of the shafts that run along the entire length of the processing apparatus for processing a sliver parallel to a side of the latter. Further, owing to the reciprocating motion with which each sleeve is driven, the forces of inertia are significant and make optimum calibration of the entire sliver processing apparatus indispensable.

Also, owing to the crank drive of the shafts comprising cams or levers, it is not possible to make precise adjustments.

Alternatively to the rubbing devices, processing apparatuses for processing a sliver are known mat apply a false twist to the sliver pneumatically, in particular by a flow of air. Such types of processing apparatuses for processing a sliver each comprise a nozzle intended for emitting a jet of air that, in use, hits the sliver and moves the sliver so as to create said false twist

.One defect of the processing apparatuses for processing a sliver using air of known type is that the jet of air that hits the sliver causes a separation of hairs from the fibres that make up the sliver, the hairs flying through the air until they settle on components of the apparatus, creating dirt that reduces the life of the components. As a result, the processing apparatuses for processing a sliver using air have to be serviced frequently, with resulting high maintenance costs.

Further, generating compressed air has a high energy impact, with resulting significant operating and maintenance costs.

Alternatively to the rubbing devices and to the processing apparatuses for processing a sliver using air, processing apparatuses for processing a sliver are known that comprise a rotor element provided with a shaped hollow shaft mat houses the sliver. The rotor element is rotated to give the sliver a false twist

One defect of the processing apparatuses for processing a sliver that comprise a rotor element with a hollow shaft of known type is that the sliver, when the rotor element is rotated, cooperates through rubbing with portions of inner wall of the hollow shaft This entails a friction force and the occurrence of an electrostatic charge that can cause hairs to be released from the fibres that make up the sliver, in particular from the outermost fibres, with consequent creation of dirt on the components of the processing apparatus for processing a sliver, and can simultaneously break down the outermost fibres of the sliver, which may curl, becoming in subsequent processing steps, defects, so-called neps on the yam, or became positioned partially perpendicularly to the innermost fibres, creating a "hairy" defect that remains on the yam produced subsequently.

One object of this invention is to improve processing apparatuses for processing a sliver of known type.

Still another object is to produce a processing apparatus for processing a sliver that is more efficient, in particular with a reduced force of friction between the sliver and walls of a rotating device that houses the sliver.

A former object is to produce a processing apparatus for processing a sliver having a longer working life than the processing apparatuses for processing a sliver of known type. Yet another object is to produce a processing apparatus for processing a sliver that is cheap and simple to use and to assemble.

According to the invention, a processing apparatus is provided for processing a stiver as shown in claim 1.

The invention can be better understood and implemented with reference to the attached drawings mat illustrate an embodiment thereof by way of non-limiting example in which: Figure 1 is a top view of a processing apparatus for processing a sliver according to the invention provided with one pair of rotation units;

Figure 2 is a perspective view of one of the rotation units of the processing apparatus for processing a sliver of Figure 1 ;

Figure 3 is a perspective view of a rotating device housing the sliver,

Figure 4 is a perspective view of a rotating element with which the rotating device of

Figure 3 is provided;

Figure 5 is a perspective view of a plurality of revolving guide elements for guiding the sliver with which the rotating device of Figure 3 is provided;

Figure 6 is a perspective view of driving supporting means of the rotation unit of Figure 2; Figure 7 is a perspective view of driven supporting means of the rotation unit of Figure 2; Figure 8 is a perspective bottom view of the processing apparatus for processing a sliver of Figure 1 showing driving means of the rotation unit of Figure 2;

Figure 9 is a bottom view of the processing apparatus for processing a sliver of Figure 1 ; Figure 10 is a side view of the processing apparatus for processing a sliver of Figure 1; Figure 11 is a front view of the processing apparatus for processing a sliver of Figure 1. With reference to Figure 1, a processing apparatus 1 is shown for processing at least one sliver S according to the invention, arranged for performing processing on the sliver S, in particular a false twist.

The sliver S is formed by so-called long fibres, such as for example wool fibres.

The processing apparatus 1 for processing at least one sliver S is employed, in use, in a finisher, and is intended for giving a false twist to the sliver S, in order to give it a consistency that is such as to enable the sliver S to be able to withstand the stresses that arise during the subsequent treatments to which it is subjected, such as, for example, a stretching operation, before being fed to a spinning frame, for example a ring spinning frame, to obtain a yam.

Further on in the description, an unprocessed sliver means a sliver entering the processing apparatus 1, i.e. a sliver in the shape of textile fibres that are all substantially parallel, known also as a web, whereas a processed sliver means a sliver exiting the processing apparatus 1, i.e. a sliver subjected to torsion, in which at least one part of the textile fibres does not extend any more parallel to the others, for example a part of the outermost fibres. The processing apparatus 1 for processing a sliver S is provided with at least one processing unit 2, for example one pair of rotation units 2, as shown for example in Figure I, each rotation unit 2 being intended for giving a false twist to a respective sliver S that is fed to the rotation unit 2 along an advancement direction A.

The processing apparatus 1 is arranged, in use, upstream of the spinning frame and receives one pair of unprocessed slivers S at the inlet, i.e. one pair of webs, each unprocessed sliver S coming from a respective can that is not illustrated in the Figures. Bach web has virtually no consistency, inasmuch as the fibres are arranged substantially alongside one another without engaging reciprocally. Each rotation unit 2 of the processing apparatus 1 gives a false twist to a respective unprocessed sliver S so as to form exiting the processing apparatus 1 one pair of processed slivers S, each processed sliver S being provided with a certain consistency inasmuch as the false twist enables the fibres to approach one another and prevents the surface fibres from curling. The processed slivers S arc men wound by a winding device on the same reel, which is also not shown in the Figures.

Thus from each web of fibres entering the processing apparatus 1 two processed slivers S arc obtained that wind around the same reel. In one alternative embodiment, the processing apparatus 1 for processing a sliver S is provided with just one rotation unit 2. Thus in this case, from the web entering the processing apparatus 1 only one processed sliver S is obtained to be wound on the reel. It is nevertheless possible for two processed slivers S from a respective processing apparatus 1 to be anyway wound on the reel.

In use, in order to give the false twist to the sliver S, the rotation unit 2 is interposed between a first pair of counter-rotating rollers arranged upstream of the rotation unit 2 and a second pair of counter-rotating rollers arranged downstream of the rotation unit 2, which are not shown in the Figures. The sliver S slides between the rollers of the first pair of counter-rotating rollers and between the rollers of the second pair of counter-rotating rollers.

In use, the two rollers of the pairs of counter-rotating rollers placed above the sliver S rotate in the same direction, i.e. as the two rollers of the pairs of counter-rotating rollers placed below the sliver S rotate in the same direction.

In particular, the first pair of counter-rotating rollers and the second pair of counter- rotating rollers guide the sliver S along the advancement direction A and enable the sliver S to be received from the can, be fed to the processing apparatus 1 and guided, exiting the latter, to the winding device.

The first pair of counter-rotating rollers interacts with the unprocessed sliver S, whereas the second pair of counter-rotating rollers interacts with the processed sliver S.

With reference to Figures 2 to 5, each rotation unit 2, one of which is shown in Figure 2 removed from the processing apparatus 1, comprises a rotating device 4, arranged for housing and rotatmgly dragging the sliver S when the rotating device 4 is rotated by driving means 3.

With reference in particular to Figure 4, the rotating device 4 comprises a rotating element 5 provided with a body 15 made of a metal material, for example Ergal.

The rotating element 5, in use, is rotatable around a rotation axis R, for example according to a rotation direction V.

The rotating element 5 is arranged for interacting with the unprocessed sliver S by rotating the unprocessed sliver S when the rotating device 4 is rotated by the driving means 3. In particular, the rotating element 5 receives the motion from the driving means 3.

The body 15 can be obtained by removing material from a full cylinder made of Ergal anodized in depth to increase resistance to wear of the rotating element 5. The body IS can have a mass of about 118 g.

The body IS comprises one pair of end parts, i.e. a first end part 6 and a second end part 7 arranged opposite and in a mirror-like manner with respect to an axis of symmetry X of the body IS.

The end parts 6 and 7 are connected by a bar 8 shaped for example substantially as a paraMpipedon.

For the sake of simplicity, the first end part 6 is described, the second end part 7 being equal thereto, but arranged according to a central symmetry with respect to the centre of the body 15, i.e. with respect to the axis of symmetry X.

The parts of the end parts 6 and 7 with the same shape or function will be indicated below . and in the drawings by the same reference number.

The first end part 6 comprises a disc 9 in which a through hole 10 is obtained with an inner wall 23 arranged for receiving the sliver S.

The through hole 10 can be obtained concentrically on the disc 9.

The first end part 6 ^" further comprises an annular element 11 made concentrically on the disc 9 and projecting from the periphery of the disc 9 away from the centre of the body IS, i.e. from the axis of symmetry X.

The first end part 6 further comprises a through opening 12 that is suitable for inserting the sliver S into the through hole 10. In use, in fact, the sliver S reaches the through hole 10 from the outside of the rotation unit 2, traversing the thickness of the annular element 11. For this purpose, the through opening 12 traverses the entire thickness of the first end part 6.

The through opening 12 can comprise a first through opening 13 obtained in the thickness of the annular element 11. The first through opening 13 can be obtained obliquely to the longitudinal extent of the annular element 11 , so as to prevent the sliver S from being able to exit the rotating element 5 during rotation of the rotating device 4.

The through opening 12 can further comprise a second through opening 14 obtained in the thickness of the disc 9 and arranged for connecting the first through opening 13 to the through hole 10. The second through opening 14 enables the sliver S to be inserted into the through hole 10. The second through opening 14 can be obtained radially in the disc 9 (Figure 11), but it is possible that it has a different shape from that illustrated in the Figures.

The first end part 6 can have a diameter that is equal to about SO mm. The rotating element 5 can be made as a single body. Alternatively, the end parts 6 and 7 can be connected to the bar 8 by connecting elements of known type or by welding.

In the same manner, each end part 6 and 7 can be made as a single body. Alternatively, the disc 9 and the annular element 11 can be connected by further connecting elements of known type or by welding.

With reference in particular to Figure 5, the rotating device 4 further comprises at least three revolving guide elements 16 for guiding the sliver S inside the rotating element 5. The Figures show three revolving guide elements 16 for guiding the sliver S, but a different number of revolving elements 16 can be provided, in particular odd numbers, for example 5 or 7.

The revolving elements 16 are suitable for supporting the sliver S and for guiding the latter along a non-linear path defined on the basis of how the sliver S is mounted on the revolving elements 16, as will be explained better in the remainder of the description.

Each revolving element 16 guiding the sliver S comprises a frame 17 shaped approximately as a pulley.

The frame 17 can be made of a polymeric material, for example comprising nylon 4.6 reinforced with Kevlar or carbon and polytetrafluoroethylene.

The frame 17 can be made by injection moulding.

The frame 17 can comprise a first plate 18 and a second plate 19 arranged substantially parallel and mounted on the rotating element 5 so as to be substantially parallel to the disc 9.

The first plate 18 and the second plate 19 can be mounted substantially concentrically. The first plate 18 and the second plate 19 comprise a respective outer area 20 mat can have a substantially planar conformation.

On a portion of the outer area 20 a plurality of radial fins 21 can be obtained that radiate to the periphery of the outer area 20. Between one radial fin 21 and a further radial fin 21 adjacent said radial fin 21, a hollowed zone 22 is defined that in use, when the rotating device 4 is rotated, is arranged for directing a flow of air away from the centre of the revolving element 16. In this manner, free fibres that can separate from the sliver S during rotation of the rotating device 4 are removed from the centre of the first plate 18 and of the second plate 19.

The frame 17 of each revolving element 16 further comprises a fitting element 24 that joins the first plate 18 to the second plate 19. The fitting element 24 is provided with an annular race 28 arranged for receiving the unprocessed sliver S. The annular race 28 of the fitting element 24 acts as a seat for portions of sliver S whilst the latter is advanced along the advancement direction A. In other words, the sliver S slides on portions of the annular race 28 interacting with the latter by sliding.

In use, each revolving element 16 is mounted on the rotating element 5. In particular, each revolving element 16 is mounted on the rotating element 5 by at least one connecting element 25 that is insertable into a passage 26 obtained in me frame 17. The connecting element 25 engages in a respective connecting hole 27 made in the bar 8 and enables the revolving element 16 to be fixed in a preset position on the bar 8.

Rotation of the rotating element S by the driving means 3 entails rotating the unprocessed sliver S, which is rotated by the interaction between a portion of each annular race 28 and a part of the unprocessed sliver S inserted, owing to the through openings 12, between the through holes 10 of the first end part 16 and of the second end part 7 of the rotating element 5.

The connecting dement 25 can be a pin, for example a mushroom pin.

The connecting element 25 can be made of a metal material, for example hardened steel with roughness of about 0.2 mm.

The connecting element 25 acts as a shaft around which, in use, each revolving element 16 is free to rotate rotatingly dragged by the friction generated between the sliver S, fed in the advancement direction A, and a portion of the annular race 28 of the fitting element 24 with which the sliver S comes into contact during sliding.

The revolving elements 16 can be mounted alongside and aligned on one another. The unprocessed sliver S is mounted thereupon so as to create a path with at least one meander for the sliver S inside the rotation unit 2.

In particular, the sliver S, which is slidable along the advancement direction A, is mounted above the first revolving element 16 which it meets in the rotating device 4 along the advancement direction A, men below the second revolving element 16 that it meets in the rotating device 4 along the advancement direction A, and so on for the number of revolving elements 16 mounted on the bar 8.

The path of the sliver S inside the rotating device 4 is then diverted from the path that the sliver S takes outside the rotating device 4. If, in fact, upstream and downstream of the rotating device 4 the sliver takes a substantially linear path inside the rotating device 4, the . path of the sliver S takes on a substantially sinusoid conformation.

Thus the rotation direction of each revolving element 16 is not concordant with that of the other revolving elements 16, but depends on how the sliver S is mounted thereupon.

In particular, two adjacent revolving elements 16 will have a discordant rotation direction. For example, considering the case of the three revolving elements 16 of Figure 3, the unprocessed sliver S ΪΒ passed above the revolving elements 16, i.e. further from the axis of symmetry X, and below the central revolving element 16, i.e. interposed between the revolving elements 16. In particular, the central revolving element 16 can be arranged at the axis of symmetry X. In this case, considering the advancement direction A of the sliver S of Figure 3, the revolving elements 16 rotate in a first rotation direction D, whereas the central revolving element 16 rotates in a second rotation direction D\ opposite said first rotation direction D.

A spacer element 30 can be mounted interposed between the bar 8 and a revolving element 16 to prevent the latter contacting surface areas of the bar 8.

The spacer element 30 can be ring-shaped and can be made of a metal material, for example steel. In particular, the spacer element 30 can be a shim.

In this manner a deterioration of the rotating element 5 and of the revolving elements 6 is avoided that is due to the rotation of the latter against surface areas of the bar 8.

The spacer element 30 is mounted concentrically on the connecting element 25. In particular, the connecting element 25 is inserted inside the spacer element 30.

The first plate 18 and the second plate 19 are suitable for retaining the sliver S during rotation of the rotating device 4, preventing extended side movements of the sliver S that could cause the sliver to slide out of the annular race 28 of the fitting element 24. For this purpose, the width of the annular race 28 must be chosen in such a way as to encompass the sliver S without leaving it excessive clearance.

A plate, for example the first plate 18, can have a smaller dimension man the other plate, for example the second plate 19, to facilitate the fitting of the sliver S on the fitting element 24. The increased dimensions of a plate, i.e. of the second plate 19 in the Figures with respect to the first plate 18, enable the sliver S to be retained with greater security during the torsion step, i.e. during rotation of the rotating device 4. As a result, the first plate 18 and the second plate 19 have to be mounted according to the rotation direction V of the rotating element 5. In particular, considering the rotation direction V of the Figures, the plate of larger dimensions must be mounted to the rear with respect to the path of the sliver S in the revolving elements 16 positioned in an odd position along the advancement direction A (for example in the first or third position like the revolving elements 16), whereas it has to be mounted forward with respect to the path of the sliver S in the revolving elements 16 positioned in an even position along the advancement direction A (for example in a second position like the central revolving element 16). To the rear means the direction in which the centrifugal force acts on the sliver S during rotation whereas forward means the direction opposite me previous direction.

Owing to the plate of lesser dimensions (first plate 18 in the Figures) and owing to the through opening 12, fitting the sliver S in the rotating device 4 is extremely facilitated. In addition, owing to the oblique first through opening 13, the sliver S is prevented from exiting the rotating device 4 during rotation of the latter.

Each revolving element 16 can be made as a single body. Alternatively, the first plate 18 and the second plate 19 can be connected to the fitting element 24 by connecting members of known type or by welding.

When the revolving elements 16 are mounted on the rotating element 5, the rotating device 4 must be perfectly balanced when rotating.

In order to permit balancing of the rotating device 4, the first end part 6 can further comprise a protruding portion 31 that protrudes from an inner circular surface 32 of the disc 9 to me centre of the body 15.

In addition, the disc 9 can further comprise a further through hole 33.

The protruding portion 31 and further through hole 33 are dimensioned in such a manner as to obtain a balanced rotating device 4.

"With reference in particular to Figures 6 and 7, the rotation unit 2 comprises driving supporting means 34 (Figure 6) arranged for supporting the rotating device 4 on one side and further, for transmitting the rotary motion generated by the transmitting means 3 to the rotating device 4. The rotation unit 2 further comprises driven supporting means 35 (Figure 7) arranged for supporting the rotating device 4 from the other side.

The driving supporting means 34 comprises at least one pair of driving wheels 36 on which is restingly arranged, in use, the annular element 11 of an end part, for example the second end part 7. Each driving wheel 36 can be clad in rubber to enable, in use, great adhesion between one portion of an external annular surface 37 (Figure 2) of the annular element 11 of the second end part 7 and a portion of an outer surface 38 of the driving wheels 36.

The driven supporting means 35 comprises at least one pair of freely rotatable wheels 39 on which is restingly arranged, in use, the annular element 11 of the other end part, for example me first end part 6.

Each freely rotatable wheel 39 can comprise side edges 40 that prevent longitudinal movements of the annular element 11 of the first end part 6.

In particular, in use, a portion of the external annular surface 37 of the annular element 11 of the first end part 6 interacts with a portion of surface area 42 of the freely rotatable wheels 39, as shown in Figure 2.

Each freely rotatable wheel 39 can be splincd on a respective shaft 48 mounted for example on a plate 49 of the driven supporting means 35.

The first through opening 13 is made obliquely also in order to avoid a loss of contact with the driving supporting means 34 and with driven supporting means 35 during rotation of the rotating element 5, when the first through opening 13 reaches the outer surface 38 of the driving wheels 36 and of the surface area 42 of the freely rotatable wheels 39.

With reference to Figures 8 to 11 , the driving means 3 can comprise a motor 43 arranged for rotating one pair of rotating devices 4.

In one alternative embodiment that is not shown in the Figures, a motor 43 is provided that is arranged for driving each rotating device 4.

The driving means 3 further comprises a transmitting member 44 for example in the shape of a flexible web, such as a belt, which enables the motion to be transmitted from the motor 43 to the driving supporting means 34 and, thus, to the rotating device 4.

In particular, the transmitting member 44 engages at least one pair of pulleys 45 (Figure 6) of the driving means 3, each pulley 45 being connected to a respective driving wheel 36 for transmitting the motion of the motor 43 to the driving wheels 36 and, through the interaction between the latter and the second end part 7, to the rotating element 5. In particular, each pulley 45 is splined on the same axis 46 of each driving wheel 36. The axes 46 can be mounted on a plate 47. The driving wheels 36 and the pulleys 45 can be arranged on opposite sides of the plate 47. In use, the transmitting member 44 rotates the pulleys 45 and thus the axes 46, which, in turn, transmit the rotary motion to me driving wheels 36 and from the latter the motion is men transmitted to the rotating element 5.

Using a belt as a transmitting member 44 and using distinct supporting means 34, 35 for each rotating element 5 enables the distance to be varied easily between the slivers S to be subjected to torsion, i.e. between two rotation units 2, when in the processing apparatus 1 more man one rotation unit 2 is provided, and thus more man a sliver S.

Hie driving means 3 can further comprise a tensioning roller, not shown in the Figures, arranged for tensioning and maintaining in tension the transmitting member 44.

Also, the driving means 3 can comprise a freely rotatable roller, not shown in the Figures, arranged for varying the path of the transmitting member 44.

Again with particular reference to Figure 7, the rotation unit 2 further comprises vertical retaining means 50 arranged for locking a movement of the rotating device 4, in particular away from the driving supporting means 34 and from the driven supporting means 35, i.e. an upward movement

In other words, me vertical retaining means 50 of the rotating device 4 enables a portion of the external annular surface 37 of the annular element 11 of the first end part 6 on one side and a portion of the external annular surface 37 of the annular element 11 of the second end part 7 on the other side to remain in contact with the outer surface 38 of the driving wheels 36.

The vertical retaining means 50 provided to retain the first end part 6 will be disclosed below, but similar vertical retaining means 50 is provided to retain the rotating device 4 also at the second end part 7.

The' vertical retaining means 50 comprises a plurality of retaining rollers 51, each retaining roller 51 being splined on a respective pin 52 mounted on a retaining block 53.

In the Figures, four retaining rollers 51 are shown, but naturally a different number of retaining rollers 51 can be provided.

In use, the retaining rollers 51 are inserted inside the annular element 11. In particular, they are mounted such that, in use, a portion of an inner annular surface 54 (Figure 4) of the annular element 11 of the first end part 6 interacts with a portion of surface zone 55 of the retaining rollers 51.

The retaining block S3 is slidable vertically along a vertical trajectory B towards or away from the driven supporting means 35. Hie vertical retaining means SO further comprises at least one guiding rod 56 arranged for guiding the retaining block S3 along the vertical trajectory B.

The guiding rod 56 can be received in a passage hole, that is not illustrated in the Figures, obtained in the retaining block 53, that extends over the entire height of the latter. The guiding rod 56 is further received in a locking hole 57 (Figure 8) obtained in the supporting means 34, 35, in particular in the plate 49, and is locked there by connecting means of known type. For example, locking can be of the screw-nut screw type, in which the locking hole 57 acts and is shaped like a nut screw and the guiding rod 56 acts and is shaped as a screw.

The vertical retaining means SO can further provide elastic means 58 mat enables, together with the guiding rod 56, the retaining block 53 to be pressed against the rotating element 5. The elastic means 58 further enables a determined pressure to be applied to the supporting means 34, 35.

The elastic means 58 can comprise at least one spring 59 fitted on the guiding rod 56. The number of the springs 59 is thus the same as the number of the guiding rods 56 provided in me processing apparatus 1 for processing a sliver S. In such a configuration of the elastic means 58, the guiding rod 56 thus acts as a guiding pin of also for the springs 59.

The shape of the retaining means 50, which provides at least one guiding rod 56 locked on the plate 49 permits extremely facilitated dismantling of the rotating element 5.

The guiding rod 56 can be provided with a cap 60 for locking the stroke of the elastic means 58, preventing the elastic means 58 from being able to move from its seat and such that it can store elastic energy.

In use, die processing apparatus 1 for processing a sliver S is fixed at a preset distance from the first pair of counter-rotating rollers and from the second pair of counter-rotating rollers on the basis of the features of the processed sliver S that it is desired to obtain.

The unprocessed sliver S is fitted on the annular races 28 of the revolving dements 16 provided in the processing apparatus 1. In particular, the unprocessed sliver S is placed on the annular races 28 such that it can follow a substantially sinusoid path, i.e. a path that has at least one meander.

The unprocessed sliver S is then fed to the processing apparatus 1 along the advancement direction A sliding between the first pair of counter-rotating rollers of the processing apparatus 1 and the second pair of counter-rotating rollers of the processing apparatus 1. The rotating device 4, and thus the rotating element 5, is subsequently driven around the rotation axis R by the transmitting means 3 at a rotation speed that is preset on the basis of the features of the processed sliver S that it is desired to obtain.

The rotating element 5 rotating] y drags the unprocessed sliver S owing to the interaction between portions of annular races 28 of the revolving elements 16 mounted on the rotating element 5 and the part of the unprocessed sliver S inserted between the through holes 10 of the first end part 16 and of the second end part 7.

The arrangement of the unprocessed sliver S on the revolving elements 16 that determines a path with at least one meander of the sliver S, together with the rotation of the rotating device 4 around the rotation axis R, enables a false twist to occur on the sliver S.

In particular, a positive torsion of the sliver S will be obtained between the first pair of counter-rotating rollers and the rotation unit 2 and a negative torsion (i.e. of a value opposed to positive torsion) between the rotation unit 2 and the second pair of counter- rotating rollers.

The residual torsion on the sliver S is influenced by different factors, including the position of tiie rotating device 4 with respect to the pairs of counter-rotating rollers, the rotation speed of the rotating device 4 and the arrangement of the unprocessed sliver S on the revolving elements 16. By varying these factors, it is possible to obtain a processed sliver S that has the desired torsion and thus consistency characteristics when it exits the processing apparatus 1.

Owing to the conformation of the rotating device 4 and, in particular, owing to the use of the revolving elements 16, the processing apparatus 1 is very efficient. In fact, the friction forces between the sliver S and internal walls of the rotating device 4 are minimized, inasmuch as die sliver S interacts with, and is guided by only the revolving elements 16 that enable limited friction to be obtained between the annular races 28 and the sliver S. The decrease in friction forces further enables a long working life to be ensured for the components of the processing apparatus 1 with respect to prior-art processing apparatuses. In fact, owing to the reduction of the rubbing of the sliver S against the inner walls of the rotating element 5, the separation of fibres from the sliver S is reduced or avoided with consequent reduction or absence of dirt that could be deposited on the components of the processing apparatus 1 for processing a sliver S.