WO2008012676A1

WO2008012676A1 - Staple making machine

Info

Publication number: WO2008012676A1
Application number: PCT/IB2007/002207
Authority: WO
Inventors: Roberto Risi
Original assignee: Ratec Srl
Current assignee: Ratec Srl
Priority date: 2006-07-28
Filing date: 2007-07-25
Publication date: 2008-01-31
Anticipated expiration: 2009-01-28
Also published as: ATE515339T1; EP2064011A1; EP2064011B1; ITBO20060573A1

Abstract

A machine for making metal staples (2) from a band (3) consisting of a plurality of metal wires (5) joined together comprises means for feeding the band (3) along a processing line (6), in a first direction parallel with the metal wires (5), means (29) for cutting the band (3) into a succession of pieces (12) of predetermined length, finishing means (45) designed to form a set (44) of staples (2) joined together and having a predetermined shape.

Description

Staple making machine

Technical Field

The present invention relates to a machine for making metal staples.

In particular, the present invention relates to an automatic machine for making staples of various types and dimensions. For example, depending on their use, metal staples may have a substantially

U-shaped profile or a straight profile or an L- or a T-shaped profile.

Background Art

As is known, metal staples are used in various sectors and for a variety of purposes.

For example, such staples are used in offices to join sheets of paper and are applied using suitable machines called staplers.

Another common use of metal staples is in the furniture sector, where staples are used for upholstering sofas and armchairs or in similar applications. Metal staples are also used in the building industry and carpentry (in which they are considerably larger than those used in the textile sector or in offices) for fixing wooden boards.

Another example of the use of metal staples relates to the sector for material transport and logistics. Wooden "pallets" are mainly assembled using metal staples applied with suitable tools which are usually pneumatic. Similarly, even common wooden boxes containing fruit and vegetables are assembled using metal staples, like cardboard boxes.

Such staples are normally made in automatic machines fed with a continuous band of metal material arriving directly from a rolling mill or fed using reels. Said band or strap is made by drawing near and gluing a predetermined number of metal wires.

The band is fed to the machine at a feed station. In said station the band is prepared for subsequent processing. The machine then alternately cuts the band into a succession of pieces having predetermined dimensions.

The cutting operations are usually carried out in a station in which there is a press whose movable element supports a respective blade, or knife, able to move from the top downwards and designed to cut the band by opposing a second fixed contact blade.

In the case of substantially U-shaped staples, each piece is fed parallel with itself into a station adjacent to the first, where it is then bent to achieve its final shape by a punch and a die able to move relative to one another alternately.

The punch is usually supported by and integral with the movable element of the press which performs the previous cutting operation.

In that way, the substantially U-shaped bend is made along a direction perpendicular to the longitudinal extension of the wires of which the band consists.

Once bent, the pieces therefore form a set of metal staples to be inserted in a stapler designed to apply the staples on the surfaces to be fixed. In the case of staples having a different shape, that is to say not U-shaped, the punch and die are shaped in such a way as to obtain the required shape of the set of staples.

Automatic staple making machines have several disadvantages.

The alternate movements typical of the presses connected to the relative knives and the punches and dies for bending operations significantly limit machine production capacity in terms of the sets of staples which can be produced per hour.

Moreover, in some cases, the precision of the finished product is unacceptable, since there are no check and adjusting devices. If the dimensions of the staples change from one production batch to another, the machine has to be stopped and important mechanical parts substituted, including the knives, punches and relative dies and their supports, since both the cutting operation and the bending operation take place close to one another. There is no type of equipment for transferring the piece after cutting.

Disclosure of the Invention

The aim of the present invention is therefore to overcome the above- mentioned disadvantages by producing an automatic staple making machine which is fast, reliable and able to make high quality metal staples.

The technical features of the present invention, in accordance with the above aim, are clear from the content of the claims herein, in particular claim 1 and, preferably, from any of the claims directly or indirectly dependent on claim 1.

Brief Description of the Drawings

The advantages of the present invention are more apparent in the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred, non-limiting embodiment of the invention, in which:

Figure 1 is a schematic side view of a machine made in accordance with the present invention;

Figure 2 is a schematic perspective side elevation view of a detail of the machine of Figure 1;

Figure 3 is a schematic perspective side elevation view of a detail of the machine of Figure 1 in the operating step

Figure 4 is a schematic cross-section of a detail of the machine of Figure 1 ;

Figure 5 is a schematic cross-section of another detail of the machine of Figure 1;

Figure 6 is a schematic perspective side elevation view of a set of staples;

Figure 7 is a schematic perspective side elevation view of a detail of the machine of Figure 1. Detailed Description of the Preferred Embodiments of the Invention

With reference to the accompanying drawings, the numeral 1 denotes a machine for making metal staples 2 from a continuous band 3 or strap wound in a reel 4, illustrated in Figure 1, the band 3 having a respective starting end and final end.

The band 3, schematically illustrated in Figure 1 with a dashed line, comprises a plurality of metal wires 5 kept side by side by gluing.

In another embodiment, not illustrated, the band 3 may be fed directly from a known type of system for drawing, rolling, gluing and/or assembly. The machine 1 comprises a processing line 6 along which there is a plurality of stations designed to perform respective operations on the band 3. The processing line 6 comprises longitudinal sliding guides for the band 3.

The machine 1 comprises a station 7 for preparing the band 3, the station 7 in turn comprising a first 8 guillotine for cutting the starting end of the band 3 and eliminating any defects on the end, for example due to manual band 3 cutting.

In the station 7 for preparing the band 3 there is also a second guillotine 9, a calender 11 and means for detecting the presence of the band 3.

The second guillotine 9 is designed to cut the final end of the band 3 and is inserted, along the processing line 6, between the first guillotine 8 and the calender 11.

The calender 11 comprises a plurality of opposite rollers 13 through which the band 3 slides, and a calender 11 adjusting mechanism 14, said mechanism 14 varying the distance between the calender 11 rollers 13.

The preparation station 7 comprises a pair of motor-driven rollers 10 designed to feed the band along the processing line, unwinding it from the reel 4.

Again with reference to the direction of the arrow F in Figure 1, downstream of the preparation station 7 there is a station 18 for cutting the band 3 into a succession of pieces 12 of predetermined length.

According to the embodiment illustrated in the accompanying drawings, the cutting station 18 comprises a first and a second knife 19, 20 and a first and a second movable element 21, 22 for supporting and moving the knives 19, 20.

With reference to Figures 1 and 4, each movable element 21, 22 comprises a projecting support 23 connected to two eccentric rotary elements 24, the eccentric elements 24 transmitting motion to the projecting support 23. There are also actuator means 25 for the movable elements 21, 22.

The first knife 19 is associated with the first movable element 21 and the second knife 20 is associated with the second movable element 22.

Each knife 19, 20 is also connected to the respective movable element 21, 22 at the projecting support 23 at three points Ml, M2, M3, which are aligned with one another.

Elastic elements 26 are inserted between the blade 19, 20 and the projecting support 23 at the points Ml, M2 and M3.

In the preferred embodiment illustrated in the accompanying drawings the elastic elements are 26 Belleville washers. The point M3 is a pivot point for the knife 19, 20.

The type of connection between the knife 19, 20 and the projecting support 23 therefore allows the knife 19, 20 to make small movements in space, partly depending on the play deriving from the connection to the projecting support 23.

The two knives 19, 20 are opposite one another and the band 3 is inserted between the two knives 19, 20 as it slides along the processing line 6.

As illustrated in Figure 2, each knife 19, 20 has a profile with a central blade 27 designed to cut the band 3 and two lateral projections 28, positioned symmetrically relative to the central blade 27, for retaining the band 3 and the piece 12 produced by the cut. As illustrated in Figure 2, the central blades 27 of the knives 19, 20 lie in two respective planes Pl, P2.

The blades 19, 20 can move cyclically between a first, active cutting configuration, visible in Figure 4, in which they are drawn near one another and a second, non-operating configuration, visible in Figure 2, in which they are distanced from one another. The motion of the knives 19, 20, in cyclically passing between the two above- mentioned configurations, follows a circular trajectory and when the knives 19, 20 are at the position in which they are drawn near one another, has a component parallel with and in the same direction as the direction of band 3 feed along the processing line 6.

During the entire contact arc, the relative speed between the knives 19, 20 and the band 3 is equal to zero.

The two knives 19, 20 are fixed to the respective movable parts 21, 22 in such a way that the two planes Pl and P2 identified by the blades 27 of the respective knives 19, 20 are parallel.

The cutting station 18 forms cutting means 29 for the machine 1.

Again with reference to the direction of the arrow F in Figure 1, downstream of the cutting station 18, the machine 1 comprises a pair of accelerator rollers 30 designed to space the pieces 12 cut by the cutting station 18. At the rollers 30 and downstream of them, the machine 1 comprises a first and a second conveyor chain 31, 32, positioned parallel along the processing line 6 and set apart. The chains 31, 32 are moved in a synchronised fashion by motor elements of the known type and not illustrated.

The band 3 preparation station 7 also comprises an optical detection element 15 which, according to the embodiment illustrated in the accompanying drawings, is a laser source and a control unit 17 interacting with the laser source and with the adjusting mechanism 14.

The calender 11, the calender 11 adjusting mechanism 14, the control unit and the optical detection element 15 form means 16 for correcting the curvature of the band 3.

In response to a change in the curvature of the band 3 detected by the detection element 15, the control unit 17 operates the calender 11 adjusting mechanism 14.

As illustrated in Figure 1, the two chains 31, 32 have a plurality of teeth 33, said teeth 33 positioned at the same distance from one another on both chains 31, 32. The teeth 33 are designed to make contact with the rear part of the pieces 12, again with reference to the direction indicated by the arrow F in Figure 1, and to transport the pieces 12 along the processing line 6 towards a rotation station 34.

As they slide along the processing line 6, the pieces 12 and the band 3 identify a plane P in which the band 3 and the pieces 12 lie.

The rotation station 34 also comprises magnetic supports 35 connected to a cam profile and designed to receive and retain the pieces 12 transported by the chains 31, 32.

The magnetic supports 35 comprise a rod 35a rotatably mounted on a plate 35b which moves cyclically along a path closed in a loop, consisting of a cam profile.

The path closed in a loop comprises an upper branch 36 along which the plates 35b are fed parallel with the processing line 6 according to the direction of the arrow F. The rod 35a can rotate about a respective axis of rotation A substantially perpendicular to the plane P in which the pieces lie, illustrated in Figure 1. The rod 35a is rigidly connected to a yielding arm, not illustrated, which engages with the cam profile, also not illustrated, in that way causing the support 35 to rotate about its own axis A, when the plate 35b travels along the upper branch 36, and a translational motion along a predetermined path defined by the cam profile itself.

The rotation station 34 forms means 104 for transferring the pieces 12.

The magnetic supports 35 form means 37 for rotating the pieces 12.

Downstream of the magnetic supports 35 there is a bending unit 38.

Similarly to the cutting station 18, the bending unit 38 comprises a first and a second movable element 39, 40 comprising two eccentric elements 41, each rotary.

The first movable element 39 is positioned above the pieces 12 and the second movable element 40 is positioned below the pieces 12.

The first movable element 39 supports a punch 42, whilst the second movable element 40 supports a die 43. The punch 42 and the die 43 are shaped to match one another and can move between a position in which they are distanced from one another, in which they are not in contact, and a position in which they are close to one another, in which the punch 42 penetrates the die 43. The punch 42 has a longitudinal extension parallel with the processing line 6 and has a length greater than the width of the band 3. The die 43 consists of two lateral walls 43a and a base wall 43b, able to move relative to the two lateral walls 43a, as illustrated in Figure 7.

The motion of the punch 42 and the die 43, as they pass cyclically between the two above-mentioned configurations, follows a circular trajectory whose motion, when the punch 42 and the die 43 are in the position close to one another, has a component parallel with and in the same direction as the direction of band 3 feed along the processing line 6.

During the entire contact arc, the relative speed between the punch 42, the die 43 and the piece 12 is equal to zero.

The pieces 12 bent by the bending unit 38 form a set 44 of staples side by side along a predetermined direction.

The bending unit 38 forms means 45 for finishing the pieces 12 designed to bend the pieces 12 into a U shape.

The machine 1 comprises an extractor unit 46 positioned close to the bending unit 38 and designed to extract the sets 44 of staples from the bending unit 38. With reference to Figure 7, the extractor unit 46 comprises a lower extractor

100, an upper extractor 101 and a lateral extractor 102.

The upper extractor 101 comprises a fixed bar 101a, parallel with the processing line 6 and positioned above it, close to the punch 42, as shown in Figure 7. The lower extractor 100 comprises the base wall 43b of the die 43 and is operated by two preloaded springs 100a, schematically illustrated in Figure 1, designed to apply an elastic reaction force on the wall 43b which in turn pushes the set 44 of staples upwards to extract it from the die 43.

The springs 100a are an elastic element of the lower extractor 100. The lateral extractor 102 comprises a plurality of teeth 102a able to move along a looped path 103 adjacent to the bending unit 38. The teeth 102a are moved in such a way that they are synchronised with the punch 42 and are designed to make contact with the set 44 of staples, at its rear part, relative to the direction of feed along the line 6, when the set 44 has been formed and extracted, to move the set towards the conveyor unit 47.

Extending from the extractor unit 46 there is a conveyor unit 47 for the sets 44 of staples comprising a lateral wall 48 on which the sets 44 of staples rest, equipped with magnets to keep the sets 44 of staples adhering to the wall 48 and a conveyor chain for the sets 44 of staples having a plurality of teeth which are set apart from one another.

The teeth are designed to engage with the rear part of each set 44 of staples.

Downstream of the conveyor unit 47 there is a coupling station 49, designed to temporarily couple the sets 44 of staples in pairs, to reduce the space occupied in the boxes. As illustrated in Figure 5, the coupling station 49 comprises a rotary body 50, having a first and a second inner cavity 51, 52, an inlet 50a and an outlet 50b, as illustrated in Figure 1.

The rotary body 50 preferably has a substantially cylindrical longitudinal extension along a direction parallel with the processing line and the two cavities 51, 52 extend inside it according to the same direction.

Each of the two cavities 51, 52 is made in such a way that it can house two sets 44 of staples bent into a U shape, positioned in such a way that they are interpenetrating with the respective concave parts opposite each other.

The two cavities 51, 52 are preferably parallelepipeds and their length is practically equal to the length of each set 44 of staples.

In the embodiment illustrated in Figure 5 the two cavities 51, 52 are perpendicular to one another and have a respective central portion 53 coinciding in such a way as to form a single cavity having the shape of a Greek cross.

The coupling station 49 forms machine 1 coupling means 54. Inserted between the coupling station 49 and the conveyor unit 47, along the processing line 6, there is a quality control laser 55 for the sets 44 of staples, the laser connected, by means of a control unit, to a pneumatic ejector.

The pair of rollers, the toothed chains, and the chain form machine feed means. In practice, the band 3 reel 4 is drawn near the machine 1 and the starting end of the band 3 is inserted in the pair of rollers which begin rotating and pull the band 3 along the processing line 6 according to the direction of the arrow F in Figure 1.

When the starting end of the band 3 reaches the band 3 preparation station 7, the rollers stop and so stop band 3 feed, in such a way that its starting end is beyond the cutting point of the first guillotine 8.

The first guillotine 8 is operated and cuts the starting end of the band 3, eliminating any finishing defect on the end and making it flat.

This operation is necessary because the bands wound in the reels on sale usually have the ends cut manually and therefore not very precisely. Once the starting end of the band 3 has been cut and made flat, the rollers start rotating again and restart the motion of the band 3 along the processing line 6.

The band 3, calendered and therefore flat, reaches the cutting station 18 which cuts the continuous band 3 into a succession of pieces 12 having predetermined dimensions and which, once bent, will form the various sets 44 of staples. The eccentric elements 24, driven by electric motors to which they are connected by means of belts, move the movable elements 21, 22 which cause the knives 19, 20 they support to move cyclically, with an elliptical motion, between the position in which they are distanced from one another and the position in which they are drawn near one another. The band 3 is inserted between the two knives 19, 20 which, when they are in the position drawn near one another, apply respective cutting forces on the band 3, separating it into the above-mentioned pieces 12.

The profile of the knife 19, 20, which has the central blade 27 and two projections 28 symmetrical relative to the central blade 27, on one hand allows the band 3 to be cut by the central blade 27, and on the other hand allows the band 3 and the piece cut 12 to be retained by the projections 28.

If the projections 28 were not present, the forces generated during cutting would tend to shoot the piece 12 cut along the processing line 6.

Advantageously, the fact that the knives 19, 20 are connected to the respective movable elements 21, 22 by the elastic elements 26 allows the knives 19, 20 to perform small oscillations in space, that is to say, to float.

In this way, during the cutting step, each knife 19, 20 applies a uniform pressure on the entire band 3 making a precise cut along the entire width of the band 3. The pieces 12 produced in the cutting station 18 then pass through the accelerator rollers 30 which space the pieces 12 and position them on the conveyor chains 31, 32.

By means of projecting teeth 33 resting on the rear part of the pieces 12, the chains 31, 32 push the pieces 12 towards the rotation station 34. The band 3 reaches the calender 11 which is automatically adjusted by detection of the curvature by the optical element 15. The value detected is sent to the control unit, which operates the calender 11 adjusting mechanism 14 which, if the curvature of the band 3 increases, reduces the distance between the calender 11 rollers 13, thus increasing their effect. Vice versa, if the curvature of the band 3 is reduced, the distance between the rollers 13 is increased.

The curvature of the band 3 is due to it being wound in the reel 4 and is greater the closer to the centre of the reel 4 the band 4 is.

Consequently, as the band 3 is gradually unwound from the reel 4, the element 15 will measure a greater curvature, and the distance between the calender 11 rollers 13 is gradually reduced.

Advantageously, said operation is performed completely automatically.

The rotation station 34 magnetic supports 35 rotate each piece 12 through 90° about the axis A and simultaneously move them towards the bending unit 38 thanks to their translation along the path defined by the cam profile. Once it has deposited its piece 12, each magnetic support continues its movement along the path, so that it returns to the position for picking up a new piece 12.

The pieces 12 are deposited at the bending unit 38 and, once rotated through 90°, have the metal wires 5 positioned perpendicular to the direction of feed indicated by the arrow F, as illustrated in Figures 1 and 3.

As they pass through the bending unit 38 the various pieces 12 pass between the punch 42 and the die 43 and are bent into a U shape, perpendicularly to the extension of the metal wires 5 of which each piece 12 consists, to form the above- mentioned sets 44 of metal staples 2.

Once one piece 12 has been bent into a set 44 of staples, the extractor unit 46 extracts the set 44 from the die 43 and punch 42, and carries it towards the coupling station 49.

To prevent the set 44 of staples from remaining inserted in the die 43 after bending, the lower extractor 100 pushes it out of the die 43.

Once the punch 42 no longer applies a force on the die and therefore on the springs, said springs 100a apply a thrusting action on the base wall 43b of the die 43, which can move relative to the lateral walls 43a of the die 43.

If, after bending, the set 44 of staples still has the punch 42 inserted in it and is transported by the punch 42 in its circular motion, when the punch 42 moves upwards to go to its distanced position, the fixed bar 101a makes contact with an upper portion of the set 44 of staples, removing it from the punch 42.

In both cases, the lateral extractor 102 then, by means of the teeth 102a, moves the set 44 of staples towards the conveyor unit 47. The sets 44 which come out of the bending unit 38 with the concave part facing upwards, slide towards the coupling station 49 which couples the sets 12 in pairs to reduce the space they occupy in the boxes.

Close to the rotary body 50 for coupling the sets 12, the quality control laser 55 detects the dimensions of each set 44 of staples. If the value detected is greater than the preset value, a pneumatic ejector pushes the set out of the processing line. Otherwise, the set 44 is inserted in the rotary body 50 in one of the two cavities 51, 52, depending on which at that moment is aligned with the set 44 of staples sliding on the processing line 6.

Once the first set 44 is positioned inside the cavity 51, 52, the rotary body 50 rotates through 180° moving the set 44 in the cavity 51, 52 so that the concave part is facing downwards and the cavity 51, 52 in which it is inserted is still aligned with the line 6 on which the sets of staples slide, so that the next set 44 arriving is inserted in it.

When the next set 44 of staples arrives, with the concave part facing upwards, it interpenetrates the set 44 of staples previously inserted in the same cavity 51, 52 and in this way the two sets 44 are coupled with the respective concave parts opposite one another.

After this step, the rotary body 50 rotates through 90° to move the empty cavity 51, 52 so that it is aligned with the line 6 on which the sets 44 of staples slide. In this way the two sets 44 of staples coupled in the other cavity 51, 52 are perpendicular to the empty cavity 51, 52.

When a new set 44 of staples moves close to the rotary body 50 and begins to be inserted in the empty cavity 51, 52, the same set 44 simultaneously applies a thrust on the two sets 44 previously coupled, moving them out of the rotary body 50 cavity 51, 52 through the outlet end 50b, as shown in Figure 5.

When the set 44 of staples is fully inserted in the empty cavity 51, 52, the two sets 44 coupled have completely exited their cavity 51, 52, since the length of the cavities 51, 52 is equal to the length of the sets 44 of staples.

Then, a new set 44 of staples is inserted in one of the two cavities 51, 52 with the concave part facing upwards and the coupling cycle is repeated as described above, until the desired production of sets 44 of staples is achieved. The invention brings important advantages.

Thanks to the configuration of the cutting station and the bending station, the machine allows continuous production of the staples with a large number of sets of staples produced per hour. Moreover, thanks to the freedom of movement of the knives, a high degree of finished product quality can be achieved.

The invention described above is susceptible of industrial application and may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted by technically equivalent elements.

Claims

1. A machine for making metal staples (2) from a band (3), the band (3) consisting of a plurality of metal wires (5) joined together, comprising: means for feeding the band (3) along a processing line (6), in a first direction parallel with the metal wires (5), means (29) for cutting the band (3) into a succession of pieces (12) of predetermined length, finishing means (45) designed to form a set (44) of staples (2) joined together and having a predetermined shape, means (104) for transferring the pieces (12) from the cutting means (29) to the finishing means (45), for feeding the pieces to the finishing means (45).

2. The machine according to claim 1, characterised in that the transfer means (104) are designed to feed the pieces (12) from the cutting means (29) to the finishing means (45) along a second direction at a right angle to the metal wires (5).

3. The machine according to claim 1 or 2, characterised in that the cutting means (29) comprise at least one knife (19, 20) and at least one respective movable element (21, 22) for supporting and moving the knife (19, 20).

4. The machine according to claim 3, characterised in that the knife (19, 20) has a profile comprising a central blade (27) designed to cut the band (3) and two lateral projections (28), positioned symmetrically relative to the central blade (27), for retaining the band (3) and the piece (12) during cutting.

5. The machine according to claim 3 or 4, characterised in that the knife (19, 20) is supported by the movable element (21, 22) by the insertion of elastic elements (26) between the knife (19, 20) and the element (21, 22).

6. The machine according to claim 5, characterised in that the elastic elements (26) are Belleville washers.

7. The machine according to any of the claims from 1 to 6, characterised in that the cutting means (29) comprise a first and a second knife (19, 20) opposite one another and respectively supported by a first and a second movable element (21, 22), the knives (19, 20) lying in respective planes (Pl, P2) which are parallel with each other.

8. The machine according to claim 7, characterised in that the knives (19, 20) can move with a continuous motion relative to one another between a first, active cutting configuration, in which they are drawn near one another and a second, non-operating configuration, in which they are distanced from one another.

9. The machine according to claim 8, characterised in that each knife (19, 20) can move cyclically with a predetermined motion which, at the position in which they are drawn near one another, has a component parallel with and in the same direction as the direction of band (3) feed.

10. The machine according to claim 9, characterised in that said motion follows a circular trajectory with a relative speed equal to zero between the knives and the band.

11. The machine according to any of the claims from 3 to 10, characterised in that it comprises actuator means (25) for the movable elements (21, 22).

12. The machine according to claim 11, characterised in that the actuator means (25) comprise at least one eccentric element (24).

13. The machine according to any of the claims from 1 to 12, characterised in that it comprises coupling means (54) for the sets (44) of staples, the coupling means (54) being designed to interpenetrate two sets (44) of staples bent into a U shape so that the sets (44) have their concave parts opposite one another.

14. The machine according to claim 13, characterised in that the coupling means (54) comprise a rotary body (50) having at least one inner cavity (51, 52) designed to receive two of the sets (44) of staples, the rotary body (50) having a longitudinal extension along a direction (L) parallel with the processing line.

15. The machine according to claim 14, characterised in that the inner cavity (51, 52) has a longitudinal extension along the direction (L).

16. The machine according to claim 14 or 15, characterised in that the rotary body (50) comprises two inner cavities (51, 52), each designed to receive two sets

(44) of staples.

17. The machine according to any of the claims from 14 to 16, characterised in that the inner cavities (51, 52) are parallelepipeds, perpendicular to one another.

18. The machine according to any of the claims from 1 to 17, in which the processing line (6) extends according to a substantially straight path, characterised in that the transfer means (104) comprise rotation means (37) for rotating the pieces (12).

19. The machine according to claim 18, characterised in that the rotation means (37) are inserted between the cutting means (29) and the finishing means (45).

20. The machine according to claim 19, characterised in that the rotation means (37) comprise magnetic elements (35) for retaining the pieces (12), each of the magnetic elements (35) being able to rotate about a respective axis (A) transversal to the straight path.

21. The machine according to any of the claims from 1 to 20, in which there is a station (7) for preparing the band (3), characterised in that the preparation station (7) comprises means (16) for correcting the curvature of the band (3).

22. The machine according to claim 21, characterised in that the correction means (16) comprise a calender (11), a calender (11) adjusting mechanism (14), an element (15) for detecting the curvature of the band (3) and a control unit (17), the control unit (17) operating the adjusting mechanism (14) in response to a change in the curvature of the band (3) detected by the detection element (15).

23. The machine according to claim 22, characterised in that the detection element (15) comprises a laser source.

24. The machine according to any of the claims from 1 to 23, characterised in that the finishing means comprise a punch (42) and a die (43) opposite one another and respectively supported by a first and a second movable element (21, 22).

25. The machine according to claim 24, characterised in that the punch (42) and the die (43) can move, with continuous motion, relative to one another at least between a first, active bending configuration, in which they are drawn near one another and a second, non-operating configuration, in which they are distanced from one another.

26. The machine according to claim 25, characterised in that the punch (42) and the die (43) can move cyclically with a predetermined motion which, at the position in which they are drawn near one another, has a component parallel with and in the same direction as the direction of band (3) feed.

27. The machine according to any of the claims from 1 to 26, characterised in that it comprises a unit (46) for extracting the staples (2) from the finishing means

(45), the extractor unit (46) comprising a lower extractor (100), an upper extractor (101) an a lateral extractor (102).

28. The machine according to claim 27, characterised in that the upper extractor (101) comprises a metal bar (101a) parallel with the processing line (6) and positioned above it, the bar (101a) being fixed relative to the punch (42) and the pieces (12) and being drawn near the punch (42).

29. The machine according to claim 27, characterised in that the lower extractor (100) comprises an elastic element (100a) designed to apply an elastic reaction force on the sets (44).

30. The machine according to claim 27, characterised in that the lateral extractor (102) comprises a plurality of teeth (102a) able to move along a looped path (103) adjacent to the bending unit (38), the teeth (102a) being moved in such a way that they are synchronised with the punch (42) and the die (43) and designed to make contact with the rear part of the sets (44) of staples.

31. A device for cutting a continuous band in machines for making sets (44) of metal staples, characterised in that it comprises at least one knife (19, 20) and at least one respective movable element (21, 22) for supporting the knife (19, 20).

32. The device according to claim 31, characterised in that the knife (19, 20) has a profile comprising a central blade (27) for cutting the band and two lateral projections (28), positioned symmetrically relative to the central blade (27), for retaining the band (3) and the piece (12) during cutting.

33. The device according to claim 31 or 32, characterised in that the knife (19, 20) is supported by the movable element (21, 22) with elastic elements (26) inserted between them.

34. The device according to claim 33, characterised in that the elastic elements (26) are Belleville washers.

35. The device according to any of the claims from 31 to 34, characterised in that it comprises a first and a second knife (19, 20) opposite one another and respectively supported by a first and a second movable element (21, 22).

36. The device according to claim 35, characterised in that the blades (19, 20) can move relative to one another between a first, active cutting configuration, in which they are drawn near one another and a second, non-operating configuration, in which they are distanced from one another.

37. The device according to claim 36, characterised in that each knife (19, 20) can move cyclically with a predetermined motion which, at the position in which they are drawn near one another, has a component parallel with and in the same direction as the direction of band feed.

38. The device according to claim 37, characterised in that said motion follows a circular trajectory with a relative speed equal to zero between the knives and the band.

39. The device according to any of the claims from 31 to 37, characterised in that it comprises actuator means (25) for the movable elements (21, 20).

40. The device according to claim 39, characterised in that the actuator means (25) comprise at least one eccentric element (26).

41. A device for coupling sets of staples in machines for making metal staples (44), characterised in that it comprises a rotary body (50) having at least one inner cavity (51, 52) designed to receive at least two of the sets (44) of staples, the rotary body (50) having a longitudinal extension along a direction (L) parallel with the processing line.

42. The device according to claim 41, characterised in that the inner cavity (51, 52) has a longitudinal extension along the direction (L).

43. The device according to claim 41, characterised in that it comprises two inner cavities (51, 52), each designed to receive at least two sets (44) of staples.

44. The device according to any of the claims from 41 to 43, characterised in that the inner cavities (51, 52) are parallelepipeds and are perpendicular to one another.

45. A device for rotating metal staples in machines for making metal staples (44), characterised in that it comprises a plurality of magnetic elements (35) for retaining the sets (44) of staples.

46. The device according to claim 45, characterised in that the magnetic elements (35) comprise a rod rotating about an axis (A) and able to move along a predetermined path.

47. A finishing device for sets (44) of staples in machines for making metal staples (2), characterised in that it comprises a punch (42) and a die (43) opposite one another and respectively supported by a first and a second movable element (39, 40).

48. The device according to claim 47, characterised in that the punch (42) and the die (43) can move, with continuous motion, relative to one another between a first, active bending configuration, in which they are drawn near one another and a second, non-operating configuration, in which they are distanced from one another.

49. The device according to claim 48, characterised in that the punch (42) and the die (43) can move cyclically with a predetermined motion which, at the position in which they are drawn near one another, has a component parallel with and in the same direction as the direction of band (3) feed.

50. The device according to any of the claims from 47 to 49, characterised in that it comprises a unit (46) for extracting the staples (2) from the punch (42) and die (43), the extractor unit (46) comprising a lower extractor (100), an upper extractor (101) and a lateral extractor (102).

51. The device according to claim 50, characterised in that the upper extractor (101) comprises a metal bar (101a) parallel with the processing line (6) and positioned above it, the bar (101a) being fixed relative to the punch (42) and the pieces (12) and being drawn near the punch (42).

52. The device according to claim 50 or 51, characterised in that the lower extractor (100) comprises an elastic element (100a) designed to apply an elastic reaction force on the sets (44).

53. The device according to any of the claims from 50 to 52, characterised in that the lateral extractor (102) comprises a plurality of teeth (102a) able to move along a looped path (103) adjacent to the bending unit (38), the teeth (102a) being moved in such a way that they are synchronised with the punch (42) and the die (43) and designed to make contact with the rear part of the sets (44) of staples.