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Title:
MULTIFUNCTIONAL TOOL MACHINE FOR CORRECTION OF PLANARITY ERRORS AND REDUCING TENSIONING IN DISK-SHAPED BLADES, AS WELL AS METHOD AND PROGRAM FOR CONTROLLING SUCH MACHINE
Document Type and Number:
WIPO Patent Application WO/2007/063527
Kind Code:
A3
Abstract:
This invention relates to a multifunctional machine for correction of flatness and tensioning errors in a disk-shaped blade (L), having a bearing frame (2) with locking means (3) mounted thereto for locking a blade to be corrected, sensor means (4) for detecting flatness and tensioning defects in the blade (L), at least one pair of pressure tools (5', 5") having an anvil (6) and a hammer (7) in facing relationship to each other for correcting defects on opposite sides of the blade (L). The machine is characterized in that it comprises at least two pairs of pressure tools (5', 5") having respective anvils (6) on opposite sides of the blade (L), the pressure tools (5', 5") being mounted to a single support element (8) to sequentially act on corresponding opposite faces (S1, S2) of the blade (L). The invention further relates to a method for automatic correction of flatness and tensioning defects in the blade, as well as to a computer program for controlling the machine and carrying out the method.

Inventors:
BRAZZALE DANIELE (IT)
Application Number:
PCT/IB2006/054557
Publication Date:
November 01, 2007
Filing Date:
December 01, 2006
Export Citation:
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Assignee:
AUTOMATISMI BRAZZALE S R L (IT)
BRAZZALE DANIELE (IT)
International Classes:
B23D63/18; B21D1/10
Foreign References:
EP0796693A11997-09-24
DE9313281U11993-11-04
Attorney, Agent or Firm:
MAROSCIA, Antonio (Contra's. Caterina 29, Vicenza, IT)
Download PDF:
Claims:

CLAIMS

1. A multifunctional tool machine for correction of planarity errors and reducing tensioning in a disk-shaped blade (L) of the type having a central disk that defines an axis of rotation and a peripheral ring, which machine comprises: a floor standing bearing frame (2); locking means (3) mounted to said bearing frame (2) for removably locking a blade to be corrected (L) with respect to a first axis (X), substantially coinciding with the axis of rotation of the blade (L); - sensor means (4) for detecting flatness and tensioning defects in the blade (L); at least one pair of pressure tools (5', 5") for correction of flatness defects in the blade (L), by operating on opposite sides of the blade (L) in a first direction (d-i) substantially parallel to said first axis (X), wherein each pair (5', 5") comprises an anvil (6) and a hammer (7) in facing relationship to each other; characterized in that it comprises at least two pairs of said pressure tools

(5', 5") having respective anvils (6) on opposite sides of the blade (L), the pressure tools (5', 5") of said pairs being mounted to a single support element (8) to sequentially act on corresponding opposite faces (S 1 , S 2 ) of the blade (L), while avoiding removal, overturning and further mounting of the blade (L).

2. Machine as claimed in claim 1 , characterized in that it comprises at least one pair of tensioning rollers (9', 9") facing opposite faces (S 1 , S 2 ) of the blade (L) for tensioning state correction by rolling.

3. Machine as claimed in claim 2, characterized in that said tensioning rollers (9', 9") are mounted to said support element (8) with said pressure tools (5', 5").

4. Machine as claimed in claim 1 , characterized in that said locking means (3) are mounted to a carriage (13) that is movable along first guide means (14) integral with said bearing frame (2).

5. Machine as claimed in claim 4, characterized in that it has first actuator means (15) operating on said carriage (13) for promoting translation (y) of the blade (L) parallel to itself along a second axis (Y) substantially perpendicular to the first axis (X).

6. Machine as claimed in claim 5, characterized in that said first actuator means (15) include a feed screw (16) extending along a second direction (d 2 ) substantially parallel to said second axis (Y), said screw (16) being driven by a first motor (17) for promoting translation (y) of said carriage (13).

7. Machine as claimed in claim 1 , characterized in that said locking means (3) comprise a pair of retaining flanges (19) which are rotatable about said first axis (X) and can be removably fixed to the blade (L) at respective opposite faces (S-i, S 2 ) thereof.

8. Machine as claimed in claim 7, characterized in that said first actuator means (15) include a mandrel (20) driven by a second motor (21 ), one of said retaining flanges (19) being mounted to said mandrel (20) to drive the blade (L) into rotation (ω) about said first axis (X).

9. Machine as claimed in claim 1 , characterized in that said support element (8) is movable with respect to said bearing frame (2) in a plane (π 1 ) substantially parallel to said first axis (X).

10. Machine as claimed in claim 1 , characterized in that said support element (8) comprises a plate (22) which is mounted to second guide means (23) integral with said bearing frame (2) and substantially perpendicular to said first (X) and second (Y) axes.

11. Machine as claimed in claim 1 , characterized in that it comprises second actuator means (24), having at least one pair of hydraulic jacks, having the same line of action (ι), substantially parallel to said first axis (X) and acting from opposite

sides and in opposite directions on both pressure tools (5', 5") and tensioning tools (9', 9") of each pair.

12. Machine as claimed in claim 1 , characterized in that said anvils (6) and said hammers (7) have each a substantially flat head (25', 25") secured to a respective elongate body (26', 26") which is movable relative to said plate (22) along said first direction (d-i).

13. Machine as claimed in claim 12, characterized in that each of said hammers (7) has at least one abutment member (27) which projects out of its corresponding head (25', 25") to contact a respective opposite face (S 1 , S 2 ) of the blade (L).

14. Machine as claimed in claim 1 , characterized in that said pair of tensioning rollers (9', 9") comprises at least one motor driven roller (9') and at least one idle roller (9"), both journalled to corresponding sliders (26', 26") which are movable in said first direction (d-ι) with respect to said plate (22).

15. Machine as claimed in any one of the preceding claims, characterized in that it comprises third actuator means (29), having one or more hydraulic jacks operating on said plate (22) for selectively aligning both pressure tools (5', 5") and tensioning tools (9', 9") of each pair to the pair of hydraulic jacks of said second actuator means (24).

16. Machine as claimed in claim 15, characterized in that said hydraulic jacks of said third actuator means (29) have one end (30) integral with said bearing frame

(2) and the opposite frame (31 ) operating on said plate (22).

17. Machine as claimed in claim 1 , characterized in that said sensor means (4) include at least one transducer (32) connected to a corresponding tracer (33) which is designed to interact with either face of the blade (L) for detecting any flatness errors with respect to a median reference plane (π") of the blade (L).

18. Machine as claimed in claim 17, characterized in that said sensor means (4) include a pneumatic actuator (34) which is operatively connected to the tracer (33) of said transducer (32) to allow contact with either face (S 1 , S 2 ) of the blade (L).

19. Machine as claimed in claim 17, characterized in that said sensor means (4) comprise at least one pair of pneumatic actuators (35', 35") for exerting restective compressive forces (F 2 , F 3 ) on the blade (L) along respective third directions (d 3 , d 3 ) substantially parallel to said first axis (X) to cause bending of the blade (L).

20. Machine as claimed in claim 19, characterized in that said transducer (32) is operatively associated to said pneumatic actuators (35', 35") to detect the deformation caused thereby.

21. Machine as claimed in claim 1 , characterized in that it comprises an electric, hydraulic and pneumatic control unit, which is connected to said first, second, and third actuator means (15, 24, 29).

22. Machine as claimed in claim 21 , characterized in that it comprises a logic processor unit, having inputs connected to said sensor means (4) and outputs connected to said electrical-pneumatic-hydraulic control unit.

23. Machine as claimed in claim 22, characterized in that a control program (38) is installed in said logic processor unit, for bringing said pressure tools (5', 5") and said tensioning tools (9', 9") from an idle position in which they skim the surface of the blade (L) to an operating position in which they deform the blade (L) in response to predetermined error signals generated within said logic unit.

24. Method for automatic correction of flatness and tensioning errors in a disk- shaped blade (L) using a multifunctional machine (1 ) as claimed in any one of claims 1 to 23, comprising the steps of: a) locking a disk-shaped blade (L) to be corrected to the bearing frame (2) of said machine in a first position;

b) translating (y) said disk-shaped blade (L) to a second position along said second axis (Y); c) detecting and analyzing flatness defects of said blade (L); d) actuating at least one pair of pressure tools (5', 5") from opposite sides of the blade (L) in a direction (d-i) substantially parallel to a first axis (X) for correcting flatness defects in the blade (L); e) repeating the detection and analysis step (c) and the tool actuation step (d) for extending defect correction to the whole surface of the faces (S 1 , S 2 ) of the blade (L); characterized in that it said tool actuating step (2) for flatness defect correction is performed using at least two pairs of said pressure tools (5', 5") having respective anvils (6) on opposite sides of the blade (L), the tools (5', 5") of said pairs being mounted to a single support element (8) to sequentially act on corresponding opposite faces (S-i, S 2 ) of the blade (L), while avoiding removal, overturning and further mounting thereof.

25. Method as claimed in claim 24, characterized in that said actuation step (d) includes a step (d') of sequential displacement of said blade (L) about the first axis (X) and along said second axis (Y), and a correcting step (d") using one of said pairs of pressure tools (5', 5") for removing flatness defects.

26. Method as claimed in claim 24, characterized in that, after said step (c) of detection and analysis of flatness defects in said blade (L), it includes a first step (c') for checking the maximum number of flatness defect correction attempts.

27. Method as claimed in claim 24, characterized in that it comprises at least one second step (f) of detection and analysis of the tensioning state of said blade

(L).

28. Method as claimed in claim 27, characterized in that said second step (f) of detection and analysis of the tensioning state is performed after said step (c) of detection and analysis of flatness defects.

29. Method as claimed in claim 24, characterized in that it comprises a second step (g) of actuation of the pair of rollers (9', 9") for correction of the tensioning state of said blade (L).

30. Method as claimed in claim 29, characterized in that said second actuation step (g) includes a step (g 1 ) of displacement of said blade (L) about said first axis (X) and a step (g") of tensioning of an annular section of said blade (L), obtained by rolling.

31. Method as claimed in claim 29, characterized in that it includes a second step (f) for checking the maximum number of tensioning state correction attempts, after said second step (f) of detection and analysis of the tensioning state of said blade (L).

32. Method as claimed in claim 24, characterized in that it includes a step (h) for unlocking and removing the corrected blade (L) from said bearing frame (2).

33. A microprocessor program for operatively controlling a multifunctional tool machine as claimed in any claims 1 to 23 and for carrying out the method as claimed in any claims 24 to 32, comprising:

- a first operating routine (i) for input and storage of physical parameters (D) of a disk-shaped blade (L) to be corrected;

- a second operating routine (ii) for placing said blade (L) in a first operating position; - a third operating routine (iii) for collection and analysis of the shape and size characteristics (P) detected by sensor means (4) to generate at least one output signal (39');

- a fourth operating routine (iv) for comparison of said at least one output signal (39') generated by said third subprogram (iii) with a reference signal, to generate at least one control signal (40) for controlling said first, second and third actuator means (15, 24, 29), which is susceptible of correcting flatness and tensioning defects of the blade (L).

34. Program as claimed in claim 33, characterized in that said third operating subroutine (iii) includes a first logical sequence of instructions (v) for analysis of flatness defects of the blade (L) and a second logical sequence of instructions (vi) for analysis of the tensioning state of the blade (L), said first and second logical sequence (v, vi) performing a comparison between the parameters (P) detected by said sensor means (4) and the data (D) acquired by said first subprogram (i) for generating, when appropriate, output error signals (39', 39") and transmitting it to said fourth operating subprogram (iv).

35. Program as claimed in claim 34, characterized in that said fourth operating subroutine (iv) includes a third logical sequence of instructions (vii), which interacts with said first logical sequence (v), for generating said flatness defect correction control (40) to be transmitted to said first, second and third actuator means (15, 24, 29).

36. Program as claimed in claim 34, characterized in that said fourth operating subroutine (iv) includes a fourth logical sequence of instructions (viii), which interacts with said second logical sequence (vi), for generating a tensioning state correction control (41 ) to be transmitted to said first, second and third actuator means (15, 24, 29).

37. Program as claimed in claim 33, characterized in that said third operating subroutine (iii) includes a fifth logical sequence of instructions (ix) for final surface analysis of the blade (L).

38. Program as claimed in claim 33, characterized in that it includes a fifth operating subroutine (x) for controlling removal of said blade (L) from said machine

(1 )-

Description:

MULTIFUNCTIONAL TOOL MACHINE FOR CORRECTION OF PLANARITY ERRORS AND REDUCING TENSIONING IN DISK-SHAPED BLADES, AS WELL AS METHOD AND PROGRAM FOR CONTROLLING SUCH MACHINE

Field of the invention

This invention is generally directed to the field of machine tools and particularly relates to a multifunctional tool machine for correction of planarity errors and reducing tensioning in disk-shaped blades.

The invention further relates to a method for controlling operation of the machine by a special computer program.

Background of the invention

Cutting or shearing of materials such as metals, glass, wood, stone materials in general, are known to be performed using toothed circular blades or similar disk- shaped tools, essentially formed of a disk-shaped metal plate having one or more sets of cutting edges along its periphery.

These blades should always have an adequate planarity, to provide the processing accuracy required to meet specific applicable tolerances, while avoiding undesired deviations from the cutting line by the peripheral cutting edges.

Nevertheless, the various steps for manufacturing these tools often generate such tensions and surface deformations within the structure of the disks, as to cause flatness deviations out of tolerance ranges.

These deviations are mainly observed at the outermost circumference of the disks, where deviations are generally of the maximum value.

Therefore, use of the tools requires prior correction of these flatness errors, i.e. either concavities or convexities with respect to the median plane of the disk, and removal of residual tensions within the structure.

A number of solutions are currently known in which flatness error correction and tension reduction are automatically performed by machine tools of variable complexity.

In these machines, the tool to be corrected has to be mounted to a support frame, which has suitable means for tool displacement and automatic control and error correction.

This avoids hammering of the blade by a specially skilled operator, which requires the use of tools such as anvils and hammers, and enhances processing speed and safety.

In these machines, the control means are generally proximity sensors, which detect errors and use a transducer to transmit information thereof to one or more actuators for operating the corresponding tools.

Generally, these tools are of the anvil and hammer type for straightening and of the roller or roller pair type for reduction of inner tensions by stretching or tensioning operations.

Solutions of this type are known, for example, from EP1294517, by the applicant hereof, and from US3,964,348.

However, these prior art solutions do not allow selective operation on both faces, and require difficult and time-consuming operations for overturning the disk- shaped tool to subject either side thereof to the action of the correcting tools.

USRE37,833 and US6,823,759 disclose machines for leveling and tensioning toothed circular saws, using a pair of substantially semi-spherical pressers or bearings, which exert the correction load simultaneously on both sides of the disk.

While these solutions eliminate the disk overturning step, thereby reducing the overall processing time, they still use a single pair of stretching or tensioning tools, whereby a limited number of operations may be performed on the blade.

Summary of the invention

The object of this invention is to overcome the above drawbacks, by providing a multifunctional machine tool for correction of planarity errors and reducing tensioning in a disk-shaped blade that is highly efficient and relatively cost- effective.

A particular object is to provide a machine that allows to correct flatness defects of both faces of a blade while avoiding undue handling thereof for removal, overturning and further mounting to the machine, for enhanced reliability and safety.

A further object is to provide a machine that performs both flatness defect correction and straightening operations on both faces of the blade in a fast repetitive manner.

Another object of the invention is to provide a machine that allows to reduce dead times associated to tool replacement, while allowing simplified processing of the whole surface of the blade.

Yet another important object of the present invention is to provide a machine in which control and defect correction operations are automatically managed by a computer and a program loaded therein, thereby enhancing versatility and allowing the machine to fit the various geometries of the tool to be corrected.

These and other objects, as better explained hereafter, are fulfilled by a multifunctional tool machine for correction of planarity errors and reducing tensioning in a disk-shaped blade as defined in claim 1 , which has a floor-standing bearing frame, locking means mounted to the bearing frame for removably locking a blade to be corrected with respect to a first axis, substantially coinciding with the axis of rotation of the blade, sensor means for detecting flatness and tensioning defects in the blade, at least one pair of pressure tools for correcting flatness defects of the blade from opposite sides of the blade in a direction substantially parallel to the first axis, wherein each pair comprises an anvil and a hammer in facing relationship to each other.

The invention is characterized in that it comprises at least two pairs of pressure tools having respective anvils on opposite sides of the blade, wherein the pairs of pressure tools are mounted to a single support element to sequentially act on corresponding opposite faces of the blade.

Thanks to this configuration of the invention, flatness defects may be corrected by sequentially operating on both sides of a blade, even when the latter has a large size.

Also, any manual removal, overturning and further mounting of the blade to the machine will be avoided, for increased reliability and safety.

Conveniently, the machine may comprise at least one pair of tensioning rollers facing opposite faces of the blade and mounted to the support element with the pressure tools for tensioning state correction by rolling.

Thanks to this additional feature, the machine tool may perform both flatness defect correction and straightening operations on both faces of the blade in a fast and repetitive manner.

In a second aspect, the invention relates to a method for automatic correction of flatness and tensioning defects as defined in claim 24, comprising a step in which a disk-shaped blade to be corrected is locked to the bearing frame of the machine in a first position, a step in which the disk-shaped blade is displaced along the second axis to a second position, a first step of detection and analysis of blade flatness defects, a first step of actuation of at least one pair of pressure tools from opposite sides of the blade in a direction substantially parallel to a first axis for correcting flatness defects in the blade, the steps of detection and control and tool actuation being repeated to extend defect correction to the whole surface of the blade faces.

According to the invention the tool actuation step for correcting flatness defects is performed by at least two pairs of said pressure tools having respective anvils on opposite sides of the blade, the pairs being mounted to a single support element to sequentially operate on corresponding opposite faces of the blade, thereby avoiding removal, overturning and further mounting thereof.

Thanks to this operation sequence, both faces of the blade may be corrected for flatness defects, while providing simpler and faster tool removal and reducing the associated dead times.

In a third aspect, the invention provides a computer program as defined in claim 33, which comprises a first operating subprogram for input and storage of physical parameters of a disk-shaped blade to be corrected, a second operating subprogram for positioning the blade in a first processing position, a third operating subprogram for collection and analysis of the shape and size characteristics detected by sensor means to generate an output signal, a fourth operating subprogram for comparison of the output signal generated by the third subprogram with a reference signal, to generate a signal for controlling the second and third actuator means, which is susceptible of correcting flatness and tensioning defects of the blade.

Thanks to the above program, all correction and tensioning operations may be automatically handled, thereby enhancing versatility and allowing the machine to fit the various geometries of the tool to be corrected.

Brief description of the drawings

Further features and advantages of the invention will appear more clearly upon reading the detailed description of a preferred, non-exclusive embodiment of a multifunctional machine according to the invention, as well as a method for correcting flatness and tensioning defects and a computer program for controlling such a machine and carrying out such method, which are described as a non- limiting example with the help of the annexed drawings, in which:

FIG. 1 is a perspective view of a machine according to the invention; FIG. 2 is a perspective view of a first detail of the machine of FIG. 1 ; FIG. 3 is a perspective view of a second detail of FIG. 1 ;

FIG. 4 is a perspective view of a third detail of FIG. 1 ; FIG. 5 is an enlarged view of a detail of FIG. 4; FIG. 6 is a first side view of the detail of FIG. 5;

FIG. 7 is a second side view of the detail of FIG. 5, as taken along the median plane /-/;

FIG. 8 shows a flowchart of a method for correcting flatness and tensioning defects according to the invention;

Fig. 9 shows a flowchart of a computer program for computerized control of the machine for carrying out the method of the invention.

Detailed description of a preferred embodiment

Referring to the above figures, the machine tool of the invention, which is generally designated by numeral 1 , may be particularly used to correct flatness and tensioning defects in tools having a disk-shaped blade L of the type having a central disk that defines an axis of rotation and a peripheral ring with a plurality of cutting edges thereon.

As shown in FIG. 1 , the machine tool has a floor standing bearing frame 2, locking means 3 mounted to the frame 2 for removably locking the blade L to be corrected with respect to a first axis X, substantially coinciding with its axis of rotation, sensor means 4 for detecting flatness and tensioning defects in the blade L, and at least one pair of pressure tools 5', 5" for correction of such defects.

Each pair of tools 5', 5" comprises an anvil 6 and a hammer 7 in facing relationship to each other to operate on opposite faces S 1 , S 2 of the blade L along a first direction di substantially parallel to the first axis X.

According to the invention, the machine 1 comprises at least two pairs of pressure tools 5', 5" having respective anvils 6 on opposite sides of the blade L, the pairs 5', 5" being mounted to a single support element 8 to sequentially operate on corresponding opposite faces S-i, S 2 of the blade L.

Thus, the disk-shaped blade L may be corrected for flatness defects without having to be removed from the machine 1 , overturned and mounted again to the bearing frame 2 in a reversed position.

Furthermore, the machine 1 comprises at least one pair of tensioning rollers 9', 9" facing opposite faces S-i, S 2 of the blade L for tensioning state correction by rolling.

The tensioning rollers 9', 8" are mounted to the support element 8 with the pairs of pressure tools 5', 5".

In the embodiment that is shown in the annexed figures, there are provided two pairs of pressure tools 5', 5" and one pair of tensioning rollers 9', 9" thereunder.

However, the number of each type of pairs of tools 5', 5", 9', 9" mounted to the support element 8, as well as their relative positions, may be susceptible to changes for adapting the functional and construction features of the machine 1 to

operational requirements, without departure from the inventive concept as defined in the claims.

In the configuration of the figures, the blade L to be corrected is placed on the machine 1 in a vertical plane π, wherefore its first axis of rotation X is horizontal.

In an alternative embodiment of the machine 1 , the blade L may be placed in a substantially horizontal or inclined plane, with the locking means 3 being configured in such a manner that the first axis X is always orthogonal to such plane π.

As particularly shown in FIG. 2, the bearing frame 2 may be formed of a first bearing unit 10 for the locking means 3, and a second bearing and guiding unit 11 for the support element 8 for the pairs of tools 5', 5", 9', 9" and a gantry-type structure 12 for strengthening and connecting together the various parts of the machine 1.

FIG. 3 shows the locking means 3 mounted to a carriage 13 that is movable along first guide means 14 integral with the bearing frame 2.

The blade L may be driven parallel to itself along a second axis Y, substantially perpendicular to the first axis and horizontal in the illustrated configuration, by first actuator means 15 that operate on the carriage 13 by means of a feed screw 16 extending in a second direction d 2 substantially parallel to the second axis Y.

Such screw 16, which is a worm actuated by a first motor 17, transmits its motion to the carriage 13 through a slider which is placed on the worm 16 under the carriage 13 and is not shown, thereby causing translation y of the carriage 13 and thence of the blade L.

The first guide means 14 may be, for example, a pair of parallel and substantially horizontal guides with the carriage 13 being slideably mounted thereto.

Furthermore, the locking means 3 may comprise a pair of retaining flanges 19 on respective faces S 1 , S 2 , which are rotatable about the first axis X and are mounted to the same actuator means 15.

Also, the first actuator means 15 comprise a motor-driven mandrel 20 for rotatably driving the flanges 19 about the first axis X, thereby allowing the blade L to perform full turns ω about it.

The shaft of the mandrel 20 may be connected to a second motor 21 either directly or, preferably, through a gearmotor 18 by means of a toothed belt transmission.

Thanks to this particular configuration of the invention, the machine 1 can process the whole surface of the blade L by a simple sequence of translational y and rotational ω movements.

Suitably, the support element 8 is movable with respect to the bearing frame 2 in a plane π' substantially parallel to the first axis X.

In the illustrated embodiment, the plane π' is substantially vertical.

Furthermore, the support element 8 comprises a plate 22 mounted to second guide means 23, which is integral with the bearing frame 2 and substantially perpendicular to the first X and the second axis Y.

As particularly shown in Figures 4 to 7, second actuator means 24 are provided, i.e. a pair of hydraulic or oil jacks, having the same line of action ι, substantially parallel to the first axis X and acting from opposite sides in opposite directions on both pressure tools 5', 5" and tensioning tools 9', 9" of each pair.

The anvils 6 and hammers 7 of each pair of pressure tools 5', 5" have each a substantially flat head 25', 25" secured to a respective elongate body 26', 26"

which is movable relative to the plate 22 along the first direction di substantially parallel to the first axis X.

The hammers 7 have at least one substantially cylindrical abutment member 27 at their respective heads 25", which is designed to hit the corresponding face S-i, S 2 of the blade L at the correction point, and to impart thereto the required corrective deformation F 1 transmitted by the jacks 24.

The pair of tensioning rollers 9', 9" comprises, in turn, a motor driven roller 9' and an idle roller 9", both journalled to corresponding sliders 26', 26" which are movable in the first direction d-i with respect to the plate 22.

The torque required for rotation of the rollers 9', 9" is provided by further motor means 18 connected to the drive roller 9', whereas the other roller 9" will be set into rotation by the friction generated upon contact with the surface of the corresponding face S 2 of the blade L.

Third actuator means 29 will be further provided, having a pair of hydraulic or oil jacks operating on the plate 22 for selectively aligning one of the pairs of tools 5', 5", 9', 9" to the pair of hydraulic jacks 24, depending on the particular processing operation to be performed.

The jacks 29 have the bottom end 30 integral with the bearing frame 2 and the opposite top end 31 operating on the plate 22.

In the illustrated embodiment, each pair of jacks 29 is composed of two coaxial and substantially vertical opposite pistons 29', 29".

The relative position of the pistons 29', 29" of each jack 29 allows the plate 22 to be set at three different heights corresponding to the alignment of a specific pair of tools with the jacks 24.

In the illustrated exemplary configuration, the pair of pressure tools 5" has the anvil 6 against the left face S 1 of the blade L and the hammer on the other face S 2 aligned with the jacks 24.

Suitably, the sensor means 4 include a transducer 32 connected to a tracer 33 which is designed to interact with either face of the blade L for detecting any flatness errors with respect to a median reference plane π" for the blade L, which substantially coincides with its lying plane π.

Also, the sensor means 4 include a pneumatic actuator 34 which is operatively connected to the tracer 33 to move it toward the blade L into contact with the face

The tensioning state of the blade L is read by combining the action of the pair of actuators 35', 35", which are designed to exert respective equal compressive forces F 2 , F 3 on the blade L along respective third directions d 3 , d 3 > substantially parallel to each other and to the first axis L to cause bending of the blade L, which bending will be suitably detected by the transducer 32.

The machine 1 may further include an electric, hydraulic and pneumatic control unit, not shown, which is connected to the first, second and third actuator means 15, 24, 29 for control and actuation thereof.

Furthermore, a logic processor unit may be provided, also not shown, having inputs connected to the sensor means 4 and outputs connected to the control unit.

A control program, generally designated as 38 in FIG. 9, is installed in the logic unit, for bringing the pressure tools 5', 5" and the tensioning tools 9', 9" from an idle position in which they skim the surface of the blade L to an operating position in which they deform the blade in response to predetermined error signals generated within the logic unit.

FIG. 8 shows a flowchart of a method for correcting flatness and tensioning defects in a disk-shaped blade L, using a multitool machine 1 as described hereinbefore.

The method includes a step a) in which a disk-shaped blade L is locked on a bearing frame 2 in a first position, a step b) in which the blade L is translated y into a second position along the second axis Y, a first step c) of detection and analysis of flatness defects of opposite faces S 1 , S 2 of the blade L, a first step d) of actuation of the pair of pressure tools 5', 5" from opposite sides of the blade in a direction di substantially parallel to the first axis X, for correcting flatness defects.

The steps c) and d) are then repeated (step e)) for analyzing and correcting all flatness defects of the blade L.

The method is characterized in that the first actuation step d) for correcting flatness defects is performed by at least two pairs of pressure tools 5', 5" having respective anvils 6 on opposite sides of the blade L, and mounted to a single support element 8 to sequentially operate on corresponding opposite faces S-i, S 2 of the blade L, thereby avoiding removal, overturning and further mounting thereof on the machine 1.

The first actuation step d) may in turn include a step d') of sequential displacement of the blade L about the first axis X and along the second axis Y, alternated to a defect correcting step d") using one of the pairs of pressure tools 5', 5".

During the first actuation step d), the third actuator means 29 operate on the plate 22, depending on the face S 1 , S 2 of the blade L to be corrected, for aligning one of the pairs of pressure tools 5', 5" with the hydraulic jacks 24 which will provide the force F 1 required for correction processing.

Next, the blade L is rotated about the first axis X and translated along the second axis Y for correcting all flatness defects detected by the sensor means 4.

At the end of the correction step d'), the first detection and analysis step c) may be repeated to confirm that the blade L has been restored to proper flatness within the predetermined tolerance range.

If such analysis gives a negative result, the flatness defect correction step d") may be repeated until the blade L is restored to flatness within the predetermined tolerance range.

Conveniently, after the first detection and analysis step c), a first checking step c') may be executed for checking if the number of flatness defect correction attempts is greater than a predetermined maximum number of attempts, above which the blade L will be discarded.

Advantageously, a second step f) of detection and analysis of the tensioning state of the blade L may be executed after the step c), using the pair of pneumatic actuators 35', 35" and the sensor means 4.

Such tensioning state may be detected by having the actuators 35', 35" exert a compressive force F 2 , F 3 on the blade L along third directions d 3 , O 3 - substantially parallel to each other and to the first axis X and by detecting the deformation resulting therefrom, using the transducer 32.

Thus, the tensioning state will be determined at the points of contact with the actuators 35', 35", depending on the type of bending deformation of the blade L.

The blade L may be rotated by fixed angular steps, to allow full analysis thereof.

The second tension detection and analysis step f) may be followed by a second step g) of actuation of the pair of rollers 9', 9" for correcting the tensioning state of the blade L.

Preferably, the second tensioning step g) may in turn include a step g') of displacement of the blade L along the second axis Y, to determine the radial position in which the pair of rollers 9', 9" has to be disposed, and a step g") of tensioning of an annular section of the blade L, obtained by rolling the pair of rollers 9', 9" on the plate 22.

In operation, the rollers 9', 9" are aligned with the jacks 24, by means of the hydraulic jacks 29, hence the drive roller 9' is actuated, whereas the idle roller 9" is driven into rotation by friction.

At the end of the tensioning step g"), the steps f) and g) may be repeated (step e 1 )).

Next, the step f) may be executed again to confirm that the new tensioning state of the blade L is within the predetermined tolerance range.

If such analysis gives a negative result, the step g") may be repeated until the tensioning state is within the predetermined tolerance range.

Conveniently, after the step f), a second checking step f) may be executed for checking if the number of tensioning state correction attempts is greater than a predetermined maximum number of attempts, above which the blade L will be discarded.

Preferably, a last step h) may be provided for unlocking and removing the corrected blade L from the bearing frame 2.

The step h) may be executed by translating the blade L along the second axis Y to an unloading position, possibly coincident with the loading position, so that it can be removed manually or by suitable unloading means, not shown.

Fig. 9 shows a flowchart of a computer program 38 for controlling the machine 1 and for carrying out the method as disclosed above.

The program comprises a first operating routine i which interacts with a data input unit M for input and storage of physical parameters D of a disk-shaped blade L to be corrected, a second operating routine ii for positioning the blade L in a first processing position, a third operating routine iii for collection and analysis of the shape and size characteristics P detected by sensor means 4 to generate at least one output signal 39', 39", a fourth operating subroutine iv for comparison of the output signal 39', 39" generated by the third subprogram iii with a reference signal, to generate at least one control signal 40, 41 to the first, second and third actuator means 15, 24, 29, which is susceptible of correcting flatness and tensioning defects of the blade L.

In operation, the input parameters may be data concerning the size, construction and/or functional features of the blade L to be processed and flatness and tensioning tolerance parameters.

The parameters D may be input using any magnetic storage means M or manually entered by an operator from a terminal.

Suitably, the third operating routine iii may include a first logical sequence of instructions v for analysis of flatness defects of the blade L and a second logical sequence of instructions vi for analysis of the tensioning state.

The logical sequences v, vi may perform a comparison between the parameters P detected by the sensor means 4 and the parameters D acquired by the first subprogram i for generating, when appropriate, an output error signal 39', 39" and transmitting it to the fourth operating routine iv.

This subprogram may include a third logical sequence of instructions vii, which interacts with the first logical sequence v, for generating a flatness defect

correction control 40 to be transmitted to the first, second and third actuator means 15, 24, 29.

In operation, the first and third actuator means 15, 29 receive angular and radial input parameters of the points to be corrected, related to predetermined reference planes.

The second actuator means 24 receive an instruction regarding the strength of the force F 1 to be exerted on the pair of pressure tools 5', 5" prepared by the third actuator means 29.

Also, the fourth operating routine iv may include a fourth logical sequence of instructions viii, which interacts with the second logical sequence vi, for generating a tensioning state correction control 41 to be transmitted to the same first, second and third actuator means 15, 24, 29.

In operation, the first and third actuator means 15, 29 receive radial input parameters of the annular sections of the blade where rolling is required, with respect to a predetermined reference plane, whereas the second actuator means 24 receive an instruction regarding the torque to be applied to the rollers 9', 9".

Furthermore, the third operating subprogram iii may include a fifth logical sequence of instructions ix for final surface analysis of the blade L

Finally, a fifth operating routine x may be provided for controlling removal of the blade L from the machine 1 , in response to a specific output control 42 of the third subprogram iii, e.g. generated by the fifth logical sequence ix, regardless of whether correction has had a positive result or the piece has to be discarded.

The above description clearly shows that the machine 1 of the invention fulfils the intended objects and particularly the object of correcting flatness defects by

operating on both faces S-i, S 2 of a blade L, while avoiding removal, overturning and further mounting thereof.

Thanks to the particular arrangement of the tools 5', 5", 9', 9" and to the use of a suitable microprocessor control program 38, correction and tensioning operations may be performed in a sequential and automatic manner, while reducing the dead times associated to tool replacement.

The machine, method and control program of the invention are susceptible to a number of changes and variants, within the inventive concept disclosed in the annexed claims. All the details thereof may be replaced by other technically equivalent parts, and the materials may vary depending on different needs, without departure from the scope of the invention.

While the machine, method and program have been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

The instant application is based upon and claims priority of patent application no. VI2005A000320, filed on 02.12.2005 in Italy, the disclosure of which is hereby expressly incorporated here in reference thereto.