WO2012052809A1

WO2012052809A1 - Method and apparatus for the production of a metallic reel for spinning machines and reel for spinning machines thus obtained

Info

Publication number: WO2012052809A1
Application number: PCT/IB2011/000315
Authority: WO
Inventors: Enzo Scaglia
Original assignee: Scaglia Spa
Priority date: 2010-10-21
Filing date: 2011-02-18
Publication date: 2012-04-26
Also published as: ITUD20100192A1; CN103328361B; CN103328361A; IT1403170B1

Abstract

Method and apparatus for the production of a metallic reel (10) for spinning machines, obtained starting from a semi -worked piece (21), comprising a tubular cylindrical body (11), at the ends (15, 16) of which respective flanges (12) are welded, and having an axial through hole (13). The method comprises at least a first step of assembling the semi- worked piece (21) on a finishing machine (29), a second finishing step by removing chip from the flanges (12) and a third finishing step by removing chip from the cylindrical body (11), wherein the first assembly step comprises a first sub- step of inserting a centering device (30) by interference into the through hole (13) of the semi -worked piece (21), and a second sub- step in which the centering device (30) is mounted on the finishing machine (29).

Description

METHOD AND APPARATUS FOR THE PRODUCTION OF A METALLIC REEL FOR SPINNING MACHINES AND REEL FOR SPINNING MACHINES THUS OBTAINED

5 FIELD OF THE INVENTION

The present invention concerns a method for the production of a reel for spinning machines, made of metal material, normally if not necessarily aluminum, its alloys and similar or comparable materials, comprising a cylindrical body at the ends of which flanges are friction welded in order to 10 contain the yarn.

In particular, any type of yarn can be wound onto the reel, whether it is natural, synthetic, metal or mixed, to make cops with weights varying from some hundreds of grams up to 15 - 20 kilograms, even working with very high operating speeds, even in the order of some tens of thousands of rpm.

15 BACKGROUND OF THE INVENTION

A method for the production of a reel for spinning machines, of metal material, preferably aluminum has been known and used for more than 30 years. The method provides to make a reel which comprises a cylindrical body at the ends of which two rough flanges, substantially disc shaped, are associated by 20 means of friction welding in order to contain the yarn.

Subsequently the flanges are holed to make a through hole in the cylindrical body, thus obtaining a semi-worked piece, which is then subjected to a plurality of workings in order to render it usable in the spinning machines.

The plurality of workings induce in the reel thus obtained both non-concentric 25 connection surfaces, which especially affect the fine yarns wound thereon, and also balanced conditions which could be accepted up to a few years ago when the rotation speeds reached around 25,000 rpm.

The tendency to wind ever finer yarns and the need to increase the rotation speed to values above 30,000 rpm impose new production approaches, in order to 30 guarantee the integrity of the reels and safety for the operators.

To this purpose it is necessary to finish with particular care the surfaces of the reel so as to obtain a completely balanced reel, all with very limited costs compared to those which have so far been sustained. The reduction in costs translates into a reduction in time needed to carry out the workings, and therefore saves energy.

In the state of the art, the method for the production of reels provides to mount the semi-worked piece on machines of an automatic type or numerical control machines.

In particular the semi-worked piece is mounted on normal centering devices which cooperate ith the axial holes made in the flanges, which in their turn are disposed between the mandrel and the footstock.

The centering device is inserted under pressure inside the axial hole of the semi-worked piece and subsequently mounted between the mandrel and the footstock.

In order to proceed with the finishing workings of the semi-worked piece it is necessary to define a zero setting of the tools with respect to the piece and then to carry out a correct positioning of the tools with respect to it.

Subsequently, using different tools in one or more passes, the external surfaces of the flanges and of the tubular body are finished one by one so as to obtain the final reel.

These operations require the use of tools dedicated for the facing, butting, longitudinal turning and similar which, in automatic machines, are picked up automatically from tool stores present on them, and then mounted on the tool- bearing turret for the execution of the different working steps.

It is also known that the zero setting operations of the tools with respect to the semi-worked piece, the changing of the tools and the execution times of the workings which are a function of the work travel of each tool, determine the overall working time of the reel and therefore affect the unitary cost.

Purpose of the present invention is to considerably reduce the finishing times of the reel in order to obtain a reel which, given the same quality and mechanical resistance, is more economical and at the same time is already balanced at the end of the mechanical finishing operations.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purpose, the present invention concerns a method for the production of metallic reels for spinning machines which is obtained starting from a semi-worked piece comprising a tubular cylindrical body, having commercial finishing, at the ends of which respective rough flanges are welded, in which respective through axial holes are made having a diameter close if not equal to the axial hole of the cylindrical body, the holes in the flanges being centered axially with the axial hole of the cylindrical body.

The method comprises a step of mounting the semi-worked piece on a finishing machine, a finishing step, by chip removal, of the two flanges, and a finishing step, again by chip removal, of the cylindrical body, obtaining an even external surface, well rounded, and a balanced reel with values such as to support a rotation speed higher than 30,000 rpm.

According to a characteristic feature of the present invention, the assembly step of the semi-worked piece comprises a sub-step of insertion by interference of a centering device into the through hole of the semi-worked piece, and a sub- step in which the centering device is mounted on the finishing machine, allowing in this way to carry out all the finishing workings of the semi-worked piece always on the same centering device, obtaining completely concentric worked surfaces.

The centering device comprises a centering portion having an interference tolerance with the through hole of the semi-worked piece and, advantageously, its external surface has been subjected to a surface hardening treatment, which increases its resistance to wear.

According to another feature, the centering device is mounted on an attachment part of an insertion apparatus which achieves the insertion of the centering device. The semi-worked piece is inserted in a clamping mean of the insertion apparatus, and an actuator, associated with the attachment part, allows the insertion of the centering device in the through hole of the semi-worked piece. The centering device is thrust inside the through hole until a part of the centering device abuts against an abutment element of the insertion apparatus: this solution allows to make a precise and repetitive positioning of the centering device with respect to the semi-worked piece.

According to a further feature of the invention, the centering device is provided with an attachment portion which is inserted in a corresponding seating made in the attachment part of the insertion apparatus.

According to another feature of the present invention, the step of finishing the flanges is carried out with a single working travel of an apparatus on which at least two tools are mounted. During the working travel of the apparatus all the surfaces of each flange are finished simultaneously, and, in particular, a first surface and a second surface, respectively facing toward the inside and the outside of the semi-worked piece, and a peripheral circumferential connector. Moreover, the base is prepared so that the workings of the cylindrical body do not create undesired or unexpected plugs, ridges or connectors.

It is advantageous to provide that a first facing tool, a second facing tool and a heading tool are stably mounted on the clamping apparatus in predetermined positions: these are suitable to finish respectively the first surface, the second surface and the connector for each flange.

It is also an advantageous variant to provide that the clamping apparatus comprises a first tool-bearing turret and a second tool-bearing turret, each suitable to finish, advantageously but not necessarily simultaneously, one of the flanges.

In this case too, on each of the tool-bearing turrets the first and second facing tool and the heading tool are mounted.

The finishing step of the cylindrical body instead comprises the finishing of the external surface of the cylindrical body by means of a single working travel of a finishing tool.

The finishing tool, used during the finishing step of the cylindrical body, is provided with a cutting edge which substantially covers the entire length of the cylindrical body, so that in a single travel which develops tangentially to the desired diameter, it is possible to completely finish the cylindrical body.

According to a variant, the cutting edge, seen in plane, extends angled with respect to the axis of the cylindrical body, so that during its working travel only one of its portions is removing material. In this configuration the cutting edge is mounted substantially tangent with the desired circumference of the cylindrical body of the reel.

According to an advantageous variant of the method, before the finishing steps of the flanges and of the cylindrical body, the method provides to finish at least one portion of the axial through hole of the semi-worked piece. This stratagem in the meantime, allows to clamp in a vice, with suitable centering means, the semi- worked piece in proximity to the portions of the hole just finished, guaranteeing, at the same time, its correct axial alignment and the subsequent workings which will be carried out.

In a further variant of the present invention, during the finishing step of the through axial hole, it is also provided to make, in proximity to each of its ends, a centering bevel which facilitates the insertion of the reel on a spindle of the spinning machine when it is loaded.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a section of a reel for spinning machines, finished with the method according to the present invention;

- fig.2 is a schematic representation of a semi-worked piece, before the final reel is obtained;

- fig. 3 is a schematic representation of a step of the method according to the present invention;

- fig. 4 is a schematic representation of a detail of a machine to finish the reel;

- fig. 5 is a lateral view of a centering device;

- fig. 6 is a front view of fig. 5;

- fig. 7 is a schematic representation of a step of the method according to the present invention;

- fig. 8 is a schematic representation of a subsequent step of fig. 7;

- fig. 9 is a schematic representation of a subsequent step of fig. 8;

- fig. 10 is a transverse schematic representation of fig. 9.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify common elements in the drawings that are substantially identical. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.

DETAILED DESCRIPTION OF SOME PREFERENTIAL FORMS OF

EMBODIMENT

With reference to fig. 1 , a reel for spinning machines is shown in its finished form, with the method according to the present invention, which is indicated in its entirety with the reference number 10.

In particular the reel 10 comprises a cylindrical body 1 1 and two flanges 12 which are associated by friction welding to the respective ends 15 and 16 of the cylindrical body 1 1.

Both the cylindrical body 1 1 and the flanges 12 are made of metal material, in this case an aluminum alloy, in order to guarantee an optimum compromise between mechanical resistance and lightness.

The cylindrical body 1 1 has a substantially tubular shape and has an external surface 14 on which the yarn is wound when in use.

The flanges 12 are substantially disc shaped and after the friction welding are axially holed with the same internal diameter as the cylindrical body 1 1, to define a through hole 13 into which, when in use, the spindle of a spinning wheel is accommodated.

The flanges 12 are circumferentially connected with a peripheral connector 19 so as to prevent the latter, during the winding step of the yarn, from being worn or broken due to rubbing; they each have a first surface 17 facing toward the outside and a second surface 18 facing toward the inside of the reel 10.

Moreover, in proximity to the ends of the hole 13, the flanges 12 have a bevel 20 which, during the loading step of the reel 10 on a spindle, allows its correct centering, avoiding problems of jamming.

The method for the production of a reel 10 as described above provides the execution of chip-removal workings on a semi-worked piece 21 (fig. 2) in which both the flanges 12 and the cylindrical body 1 1 have machining allowances which are removed in order to obtain the desired surface finishing and balance of the reel 10. The semi-worked piece 21 also includes welding burrs 22 in proximity to the joining zones between the cylindrical body 1 1 and the flanges 12 which will have to be removed during the working.

The method provides a step of finishing the through hole 13, a step of inserting a centering pin 30, a step of finishing the surfaces of the flanges 12 and a step of finishing the cylindrical body 1 1.

The step of finishing the through hole (fig. 3) provides to clamp the semi- worked piece 21, in proximity to a flange 12, on a mandrel 23, in order to execute the bevels 20 and to turn the through hole 13 internally, so as to achieve an even circular surface which the centering pin 30 will subsequently grip.

The step of inserting the centering pin 30 provides to insert it in the through hole 13 of the semi-worked piece 21.

More specifically the centering pin 30 (fig. 5) comprises a first end 50 and a second end 51 in which the mandrel 23 and the footstock 28 of the finishing machine 29 are respectively gripped.

On both the first and second ends 50, 51 of the centering pin 30 two centering holes 52 are made.

In succession starting from the first end 50, the centering pin 30 also has a conical portion 53, an attachment portion 55, a connection portion 56, a first centering portion 57, an intermediate portion 58 and a second centering portion 59.

The conical portion 53 allows a correct axial alignment with the mandrel 23, and also generates a condition of interference therewith, in proximity to a mating conical surface 54.

The attachment portion 55 has a first and a second abutment surface 61 and 62, respectively on opposite sides with respect to each other, and is provided with four drawing eyelets 63 (fig. 6) made equidistant and angularly at 90° with respect to each other on the external surface.

When the centering pin 30 is mounted on the mandrel 23, at least one of the drawing eyelets 63 cooperates with a drawing pin 65 (fig. 4) provided on the mandrel 23, and obstructs the sliding of the centering pin 30 during the workings, as will be described hereafter.

The first and the second centering portion 57 and 59 (fig. 5) have an interference tolerance with the diameter of the through hole 13, so that the centering pin 30 is inserted under pressure into the through hole 13.

Both the first and the second centering portion 57 and 59 have been subjected to a surface hardening treatment in order to increase their resistance to wear due to the repeated insertions of semi- worked pieces 21. The hardening treatments are, simply to give an example, nitriding treatments, cementation or similar.

The intermediate portion 58 has a smaller diameter with respect to the centering portions 57 and 59 in order to reduce the contact surface during the insertion of the centering pin 30 into the through hole 13 of the semi-worked piece 21.

Both the centering portions 57 and 59 are provided with a bevel 66, in this case at 30° which promotes their insertion into the through hole 13.

The insertion of the centering pin 30 into the through hole 13 of the semi- worked piece 21 is carried out by means of an insertion apparatus 70 (fig.7).

The apparatus 70 comprises a base 71, to which a hydraulic actuator 73 and a clamping mean 72 of the semi-worked piece 21 are connected in a known manner.

At the end of the hydraulic actuator 73 an attachment part 75 is coupled, which comprises a hollow 76, with a cylindrical bottom, on the circumferential surface of which a circumferential seating 77 is made, defining a first surface 79 and a second surface 80, respectively upper and lower.

The blocking mean 72 comprises, in succession, a base portion 81 firmly attached to the base 71, an intermediate portion 82 and an upper portion 83, mounted with respect to each other by means of connection means of a known type or, in other forms of embodiment, in a single body.

On the base portion 81 a first eyelet 85 is made, with transverse sizes a little bigger than the diameter of the second end 51 of the centering pin 30.

On the intermediate portion 82 a second eyelet 86 is made, with transverse sizes a little bigger than the external diameter of the flange 12 of the semi- worked piece 21.

On the third portion 83 a third eyelet 87 is made, with transverse sizes substantially equal to the external diameter of the cylindrical body 1 1 of the semi-worked piece 21. The step of inserting the centering pin 30 into the through hole 13 of the semi- worked piece 21 comprises a first sub-step of inserting the semi-worked piece 21 into the clamping mean 72, a second sub-step of inserting the centering pin 30 into the attachment part 75, and a third sub-step of inserting the centering pin 30 into the through hole 13 of the semi-worked piece 21.

During the first sub-step one of the two flanges 12 of the semi-worked piece 21 is inserted into the second eyelet 86 of the intermediate portion 82 of the clamping mean 72, so that its external surface goes into contact with the lower abutment 90 of the clamping mean 72.

The second sub-step provides that the hydraulic actuator 73 is completely raised and that the centering pin 30 is inserted into the hollow 76 of the attachment part 75, inserting the attachment portion 55 of the centering pin 30 into the seating 77, so that the first end 50 is inside the hollow 76.

The second surface 62 of the centering pin 30 goes into contact with the second abutment surface 80 of the attachment part 75, and prevents its axial removal.

In this condition, the centering pin 30 is disposed above the semi-worked piece 21 and its axis is substantially aligned with the axis of the through hole 13.

During the third sub-step, the actuator 73 thrusts the centering pin 30 inside the through hole 13, causing the second centering portion 59 and the first centering portion 57 to enter in succession.

The centering pin 30 is thrust inside the through hole 13, until the second end 51 goes into contact with the base 71 of the apparatus 70, which acts as an abutment element.

During the insertion of the centering pin 30, the first surface 61 of the centering pin 30 abuts against the first abutment surface 79.

This allows to define a positioning of the centering pin 30 with respect to the semi-worked piece 21 which is precise and repetitive over time. By repetitive we mean that the centering pin 30 is always disposed in the same position with respect to the semi-worked piece 21.

In this way, when the centering pin 30 is mounted on the machine 29 it disposes the semi-worked piece 21 to be worked always in the same position, obviating the need of having to reset the tools to zero at the beginning of each working cycle.

Similarly, the same apparatus 70 is used to extract the centering pin 30 from the semi-worked piece 21 , for example after the finishing operations.

The attachment portion 55 of the centering pin 30 is inserted in the seating 77 of the attachment part 75 whilst the flange 12, which is in the opposite position, is inserted into the second eyelet 86.

Driving the actuator 73 provides to extract the pin from the through hole 13.

During this operation the flange 12 attached in the clamping mean 72 goes into contact with the upper abutment 89 of the latter, and the second surface 62 of the centering pin 30 goes into contact with the second abutment surface 80 of the attachment part 75.

When the centering pin 30 is inserted into the through hole 13 of the semi- worked piece 21, as described above, this is mounted on the finishing machine 29, clamping the first end 51 to the mandrel 27 and inserting the footstock 28 into the centering hole 52 of the second end 51.

The finishing machine 29 (fig. 8), in this case, comprises two tool-bearing turrets 31 and 32, mounted on guides which allow translation in an axial and radial direction with respect to an axis of rotation Z.

The tool-bearing turrets 31 and 32 are equipped with three tools, that is, a first and a second facing tool 35 and 36 and a heading tool 37.

More specifically, the first facing tool 35 is suitable to remove a layer of machining allowance 38 from a first more external surface 17 of each flange 12. The second facing tool 36 is suitable to remove a layer of machining allowance 39 from a second surface 18 of each flange 12, facing toward the inside of the semi-worked piece 21. The heading tool 37 allows to remove a layer of machining allowance 40 in order to make the connector 19, and is shaped in the same way.

The tools are mounted on the respective tool-bearing turrets 31 and 32 in a predetermined position to allow, with a single radial travel, the complete finishing of both the flanges 12.

In particular the tools mounted on the tool-bearing turret 31 have a symmetrical position and configuration with respect to those mounted on the tool-bearing turret 32. During the travel of the tool-bearing turret 31 and 32, the first tool 35, the second tool 36 and finally the heading tool 37 begin to work in succession.

During the finishing step of the external surface of the cylindrical body 1 1 (figs. 9 and 10) a layer of machining allowance 40 is removed from the semi- worked piece 21, from the external surface 14 of the cylindrical body 1 1, in order to obtain an even cylindrical surface.

During this step a third tool 42 is used, having a cutting edge 43 which substantially covers the entire length of the cylindrical body 1 1 and which, seen in plane, is inclined by an angle a with respect to the axis Z.

The third tool 42, seen laterally (fig. 10), is mounted in an inclined position, by a determinate angle β, with respect to a vertical axis Y of the semi-worked piece 21 , so that its cutting edge 43 is disposed in a substantially tangent position with the diameter of the finished external surface 14 of the cylindrical body 1 1.

More specifically, during the working, the third tool 42, given its particular disposition begins to remove the layer of machining allowance in proximity to the end 15 of the cylindrical body 1 1 to then remove in succession the machining allowance 40 along the axial direction until it reaches the end 16 of the cylindrical body 1 1.

This particular configuration of the third tool 42 allows to further reduce the travel of the tool solely to the maximum distance of the cutting edge 43 from the point of tangency, avoiding having to make the third tool 42 perform a travel equal to the axial extension of the cylindrical body 1 1.

In one form of embodiment, the step of finishing the flanges 12 and the step of finishing the cylindrical body 1 1 can be carried out simultaneously, mounting the third tool 42 opposite with respect to the two tool-bearing turrets 31 and 32, in this way achieving a reduction in working times.

It is clear that modifications and/or additions of parts may be made to the reel for spinning machines and to the reel for spinning machines thus obtained, as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of method for the production of a reel for spinning machines and the reel for spinning machines thus obtained, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Method for the production of a metallic reel (10) for spinning machines, obtained starting from a semi-worked piece (21), said semi-worked piece (21) comprising a tubular cylindrical body (1 1), at the ends (15, 16) of which respective flanges (12) are welded, and having an axial through hole (13), said method comprising at least a first step of assembling said semi-worked piece (21) on a finishing machine (29), a second finishing step by removing chip from said flanges (12) and a third finishing step by removing chip from said cylindrical body (1 1), characterized in that said first assembly step comprises a first sub-step of inserting a centering device (30) by interference into the through hole (13) of said semi-worked piece (21), and a second sub-step in which said centering device (30) is mounted on said finishing machine (29).

2. Method as in claim 1, characterized in that in said first insertion sub-step said centering device (30) is first mounted on an attachment part (75) of an insertion apparatus (70), then said semi-worked piece (21) is inserted into a clamping mean (72) of said insertion apparatus (70), and then an actuator (73), associated with said attachment part (75), inserts said centering device (30) into said through hole (13) so that one end (51) of said centering device (30) abuts against an abutment element (71) of said insertion apparatus (70).

3. Method as in claim 2, characterized in that it provides that an attachment portion (55) of said centering device (30) is inserted into a corresponding seating (77) made in said attachment part (75) of said insertion apparatus (70).

4. Method as in claim 1, characterized in that said second finishing step of the flanges (12) is carried out with a single working travel of a clamping apparatus (31, 32) on which at least two tools (35, 36, 37) are mounted, wherein said two tools (35, 36, 37), during said travel of the apparatus (31, 32), simultaneously finish a first surface (17), a second surface (18), respectively facing toward the outside and toward the inside of said semi-worked piece (1 1), and a peripheral circumferential connector (19), of each of the flanges (12).

5. Method as in claim 4, characterized in that said flanges (12) are each finished by means of a first facing tool (35), a second facing tool (36), and a heading tool (37), each mounted on a first tool-bearing turret (31) and a second tool-bearing turret (32) of said clamping apparatus (31, 32), and suitable to finish respectively the first surface (17), the second surface (18), and the circumferential connector (19) of each flange (12).

6. Method as in claim 1, characterized in that said third finishing step of the cylindrical body (1 1) comprises the finishing of an external surface (14) thereof by means of a single travel of a finishing tool (42), operating in tangency with the diameter of said external surface (14) and is provided with a cutting edge (43) which substantially covers the entire length of the cylindrical body (1 1).

7. Method as in claim 6, characterized in that said cutting edge (43) is made angled by a determinate angle (a) with respect to the axis of the cylindrical body (1 1), and is driven so that, during its working travel, only one portion thereof removes material.

8. Method as in any claim hereinbefore, characterized in that before said step of assembling said semi-worked piece (21) on a finishing machine (29), a finishing step is provided of at least a portion of said through hole (13) of the semi- worked piece (21).

9. Method as in any claim hereinbefore, characterized in that said second finishing step of the flanges (12) and said third finishing step of the cylindrical body (1 1) are performed simultaneously.

10. Apparatus to make a metallic reel (10) for spinning machines, obtained starting from a semi-worked piece (21), said semi-worked piece (21) comprising a tubular cylindrical body (1 1), at the ends of which respective flanges (12) are welded, and having an axial through hole (13), said apparatus comprising at least an assembly unit (30, 70) to assemble said semi-worked piece (21) on a finishing machine (29), a first finishing unit (31, 32) for said flanges (12) and a second finishing unit (42) for said cylindrical body (1 1), characterized in that said assembly unit comprises a centering device (30) having a centering portion (57, 59) suitable to be inserted with an interference tolerance into said through hole (13).

1 1. Apparatus as in claim 10, characterized in that said centering portion (57, 59) has a high resistance to wear.

12. Apparatus as in claim 10 or 1 1, characterized in that said centering portion comprises a first centering portion (57), a second centering portion (59) and an intermediate portion (58) interposed between said first centering portion (57) and said second centering portion (59), and with a reduced diameter with respect to said first centering portion (57) and said second centering portion (59).

13. Apparatus as in any claim from 10 to 12, characterized in that said centering device (30) comprises an attachment portion (55) interposed between a first end (50) and a connection portion (56) of said centering portion (57, 59), having a larger external diameter than said first end (50) and than said connection portion (56), so as to allow it to be gripped by an insertion apparatus (70) and a mandrel (23) of a finishing machine (29).

14. Apparatus as in claim 13, characterized in that said attachment portion (55) is provided with at least a drawing eyelet (63) suitable to cooperate with a drawing pin (65) of said mandrel (23).

15. Apparatus as in claim 13 or 14, characterized in that it comprises an attachment part (75) suitable to grip the attachment portion (55) of the centering device (30), and associated with an actuator (73) suitable to insert said centering device (30) into said through hole (13) of the semi-worked piece (21), and a clamping mean (72) suitable to keep said semi-worked piece (21) clamped and in a predefined position.

16. Apparatus as in claim 15, characterized in that said attachment part (75) comprises a hollow (76) suitable to accommodate a first end of said centering device (30) and provided with a circumferential seating (77), mating in shape and suitable to accommodate an attachment portion (55).

17. Apparatus as in claim 15 or 16, characterized in that said clamping mean (72) of said semi-worked piece (21) is associated with an abutment element (71) of said centering device (30), to define a reciprocal positioning of said semi-worked piece (21) and said centering device (30).

18. Apparatus as in claim 15, characterized in that said first finishing unit for said flanges (12) comprises at least two tools (35, 36) mounted on a clamping apparatus (31, 32) and suitable to simultaneously finish, with a single working travel of said clamping apparatus (31 , 32), a first surface (17), a second surface (18), respectively facing toward the outside and toward the inside of said semi-worked piece (21), and a peripheral circumferential connector (19), of each of the flanges (12).

19. Apparatus as in claim 15, characterized in that said second finishing unit comprises a finishing tool (42), suitable to finish the external surface (14) of said cylindrical body (1 1), and having a cutting edge (43) which extends substantially for the entire length of the cylindrical body (1 1).

20. Reel for spinning machines obtained with the method or apparatus as in any claim from 1 to 9 or from 10 to 19.