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(11) | EP 1 136 185 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A work centre for cutting panels with work plane having aspirating movable belts |
| (57) A CNC work centre for cutting wood panels (1), comprises a base (2), means (3) for
supporting and horizontally conveying the panels (1), means (4) for securing the panels
(1) by vacuum, a longitudinal member (7) integral with the base (2) and superior to
the support plane of the panels (1), where a spindle (5) for a tool (6) is able to
translate, and in which the means (3) are conveyor belt (11) assemblies (9) along
a direction X, and said assemblies (9) form pairs (9c) whereof one assembly (9a) is
preceding and one (9b) following, according to the direction X; a continuous slit
(10) being configured between the preceding assembly (9a) and the following assembly
(9b), suitable for through work operations by the tool (6); the belt (11) being holed
and sliding on an aspirating surface (17). |
[0001] The present invention relates to a numerically controlled CNC work centre for milling, or generally for cutting, panels or plate-shaped bodies made of wood or the like, of the kind presenting an architecture substantially provided with a base, whereon is obtained a horizontal work plane which serves at least to support panels, and a longitudinal member positioned superiorly to said plane, along which is able to slide a spindle for the operation of a rotating tool; in particular it provides also for the advance of the panels, and where its movement - controlled by the machine CNC - can constitute a motion for feeding the cutting of the panels, whilst said cross member is fixed and the further movements for feeding the cutting operation are imparted to the spindle able to slide on the cross member, so that a work process can take place with interpolation between the three spatial dimensions. The invention relates in particular to work centres where the pieces are secured on the work plane by means of a vacuum system integrated in the work plane itself, whereby the panels are made integral with the work plane, actuated thereby, and machined by the tool.
[0002] In the state of the art in the work centre sector, machines are known, also produced by the same Applicant, whose set up provides both traditional mechanical systems for securing the panels on the work plane, and systems for securing the panels by means of vacuum acting on the same plane which provides for their advance, during the machining operation. The aforesaid machines, in their general architecture, are now part of the common technological background in work centres, but by way of documentary reference to the aforementioned solutions, one could in this regard also cite some patent applications, amongst them the patent application for industrial invention filed in Italy by the same Applicant under No. BO97A000653 pertaining to a work centre for milling-edging panels with two planes movable below a cross member supporting the operating heads. One could also, with reference to the securing by vacuum on work planes, cite the patent application for industrial invention filed in Italy by the same Applicant under No. BO95A000241, pertaining to a plane with automatic configuration of the areas to be subjected to vacuum through the use of small rectangular rubber dominoes; and again, filed in Italy by the same Applicant, the patent application for industrial invention No. BO92A000093, disclosing a work plane for CNC pantographs. In practice, planes similar to those describe in this latter patent configure, in their thickness, a chamber held under vacuum and holed on the plane supporting the pieces, the same plane being appropriately milled, in order to identify chequered crossed grooves, within which may be positioned a rubber peripheral gasket to delimit a determined area of the plane. The piece is thus secured, in such planes, by laying the piece itself on the area peripherally sealed by the gasket, where retention takes place by means of the vacuum acting through the holes of the plane immediately below the piece, and maintained by said peripheral gasket in the predetermined area.
[0003] The piece can also be positioned raised from the work plane with appropriate templates similar thereto, but with smaller perimeter; or with hollow columns having an upper suction cup, which communicate the vacuum coming from the work plane. In these cases the piece is raised relative to the plane, and a through working process can be performed thereon, without any damage to the plane by the tool.
[0004] Lastly, to provide further information, collaterally cited is the state of the art for the securing of pieces in a general type of work centres of a class that is very similar and close to the one of the subject of the present invention, i.e. the class of work centres wherein the plane for supporting and securing the pieces is fixed relative to the base, where in this case the cut feeding movements are attributed only to the spindle, movable on the upper cross member, in turn movable relative to the base. Also relative to the said work centre configurations, the Applicant has filed the patent applications for industrial invention No. BO94A000231 and BO99A000293, disclosing securing systems by vacuum, and specifically by means of blocks with suction cups positioned on transverse joists constituting said fixed work plane.
[0005] The aforementioned known solution of the work centre with movable planes below a fixed cross member, where said planes are of the type in which the pieces are secured by vacuum, has the drawback of poor flexibility in changing the format of the pieces, because the disposition of the sealing gasket of the lateral perimeter must clearly reflect the geometry of the piece itself, and must be changed every time it is necessary to cut a different piece, or in a different area of the work plane. In addition, of course, to the fact that in normal holed planes the aspiration holes must be enabled within the selected area, and then manually opened and freed from the respective closure plugs, then manually closed to proceed with the format change. In any case the greatest drawback with these solutions consists in the fact that through work processes are wholly excluded, because the panel is set directly onto the plane, and a work process that extended vertically below the support of the piece would irremediably damage the plane itself.
[0006] Equally, if the aforesaid solutions with the template similar to the piece or with the columns that hold the piece raised relative to the vacuum plane were to be used, thereby allowing the execution of through work processes on the panel, the problem of poor flexibility would arise identically, because also the positioning of the columns themselves would require case by case adaptation, depending on the geometry of the piece and on its positioning on the plane. In addition to a further severe problem inherent in these solutions, relating to the securing of the scraps of the pieces after their separation from the main panel, since generally such scraps remain outside the securing area identified by the perimeter of the rubber sealing gasket or of the template, i.e. are not subject to the seal of none of the suction cups of the different securing columns, hence constituting parts which can potentially and dangerously ejected by the rotating tool.
[0007] Lastly, another drawback can also be noted from the following observation, this time pertaining to machine architectures where the work plane is fixed and the cross member is movable superiorly thereto, with the spindle able in turn to slide on said cross member. In this case, it is necessary to impart to the cross member the accelerations of one of the movements for feeding the cutting operation. And with the current trend towards ever shorter working times for each phase, and ever greater speeds for each operation, the result is - the masses moving with the cross member being considerable - that the forces of inertia will also be large, and the structure will be highly stressed, to the point that stops, starts and direction changes could be so sudden as to simulate actual impacts on the structure and to initiate vibrating phenomena of a certain importance which compromise working precision and stress the components, leading to fatigue. Hence, the advantage of actuating the work plane, much lighter than the cross member, is evident, and this solution provides an advantage for movable work plane machines over those with fixed plane of the type obtained, for instance with said solution of the suction cups placed on the joists.
[0008] The aim of the work centre of the present invention is to eliminate the aforementioned drawbacks. The invention, as it is characterised in the claims, therefore solves the problem of obtaining a work centre where it is not necessary to proceed with preliminary configurations of the plane for working the pieces, i.e. preparing dedicated templates or perimeters fitted with gaskets destined to securing the pieces, and where through machining processes are possible on the piece without even relying on the disposition of the suction cup columns to raise the piece itself relative to the support plane. The invention also provides for the effective retention of scraps after their separation, as well as an absolutely free disposition of the pieces on the plane, except for the identification on the panel of a zero reference point of the piece, whence machining processes are to be started.
[0009] The idea developed hereafter achieves the aforesaid aims with a configuration of the aforesaid type for the work centre for cutting the panels, comprising at least a base supporting means for bearing and actuating said panels, means defining a horizontal geometrical plane XY relative to three mutually orthogonal directions X, Y, Z, where the bearing and actuation of said panels takes place, where said means actuate the panels according to a first motion for feeding the cutting operation along the direction X. Further comprised are vacuum securing means able to render the panels integral with said bearing and actuation means during said first motion for feeding the cutting operation, where said means for securing by vacuum comprise at least a chamber subjected to vacuum by known aspirators, and equipped with at least a horizontal planar surface provided with a multiplicity of through holes relative to its interior, in the manner of a holed plane for retention by vacuum. A longitudinal member is also provided, supported by the base above the work plane, whereon is mounted at least a spindle for actuating at least a tool in rotation; said spindle presents its axis positioned substantially according to said direction Z, and it can be adjustably translated on said longitudinal member according to the directions Y and Z, to generate a second and a third motion for feeding the cutting operation respectively in said directions Y and Z, during the cutting of said panels. Means for electronically controlling at least the operation of the movable machine elements and of said vacuum securing means are also comprised in said work centre, where the peculiarity of said work centre resides in the fact that said bearing and actuation means consist of at least a pair of belt conveyor assemblies, with the belt wound and circulating according to an enclosed path on rollers with parallel axes, each said assembly presenting a tensioned segment of belt superiorly useful for bearing and conveying the panels and configuring part of said orizontal geometric plane; at least one said pair of assemblies comprising said vacuum securing means; said two belt assemblies of at least one said pair being oriented with their direction of conveyance according to said direction X, in such a way as to configure, according to a sense (U) fixed on said direction X, a preceding assembly and a related following assembly in at least one said pair; said preceding assemblies of at least one said pair globally configuring a separation space, respectively with said following assemblies of at least one pair, in the manner of a continuous rectilinear slit, substantially rectangular in said geometric plane, developing longitudinally along said direction Y and able to allow a free vertical traversing of said geometric plane by the tools that perform the cutting operation on the entire thickness of the panels; said longitudinal member developing parallel, and superiorly, in correspondence with said slit, so that said tool of said spindle is movable substantially on a vertical plane YZ passing through said slit.
[0010] Further peculiarities of the present invention reside in the fact that the vacuum securing means, which as stated are comprised in at least a pair of belt assemblies, are completed including also the conveyor belts of said assemblies of said at least one pair, which belts are in this manner provided with a multiplicity of through holes, perpendicular to their median surface; at least a said chamber subjected to vacuum regulated by said control means being provided in such a way that to at least one said chamber is at least a said belt assembly, said at least one chamber associated to said at least one belt assembly being positioned within the enclosed path according to which circulates at least one of said belts; said tensioned segments of at least one of said belts sliding, in their conveying motion along said direction X, with their inner surfaces directly on said horizontal and holed planar surfaces of said at least one chamber relatively associated to said assemblies, so that an aspirating and securing effect on said panels is possible during their actuation, by effect of the vacuum acting through the communication of said holes of each said belt with said holes of the respective surfaces of the respective associated chamber.
[0011] Furthermore, another peculiarity resides in the fact that, if the pairs of belt assemblies are at least two - with the assemblies of each pair positioned consecutive along said direction of conveyance X, and with the preceding assemblies of at least two pairs globally configuring, respectively with the following assemblies of at least said two pairs, said rectilinear slit - a vacuum chamber of the described kind is provided, developed longitudinally along the direction Y, traversing the enclosed circulation paths of the belts of the preceding assemblies of at least two pairs; and a similar and parallel chamber traversing the enclosed circulation paths of the belts of the following assemblies of said at least two pairs, where the belts slide on the holed surfaces of the respective chambers, thereby obtaining the effect of securing the pieces on the belts by effect of aspiration.
[0012] The rollers can also be provided with an external toothing which meshes in a corresponding toothing obtained on the inner surface of the belt, and at least a roller of each assembly can be motorised by means of its connection with a respective motor subjected to electronic control. Additionally, laterally to the slit and in proximity thereto, mechanical presser elements, of the roller type, can be provided, supported by the base and operated vertically under the supervision of the electronic control, acting above the panel, for the mechanical securing thereof in the restricted area where the belt winds on the roller and where the effect of the vacuum is less noticeable.
[0013] Use of such a configuration yields the result that the panel can be positioned on the bank of belts of the preceding assemblies, which move in a perfectly synchronous manner under the control of the CNC electronic control means, and advance it beyond the slit; the working tool on the vertical plane YZ passing through the slit can thus perform cutting operations on pieces of any shape separating them from the initial panel, also performing through machining operations with the tool that penetrates vertically into the appropriately obtained slit, without interfering with the belts, and exploiting the composition of the movements controlled by the CNC along the directions X (synchronous belts), and Y and Z (spindle on the fixed longitudinal member).
[0014] The advantages obtained by means of the present invention essentially consist of the fact that all preparation operations are practically eliminated, which were required for securing the piece on the planes with vacuum retention of the prior art, where moreover no through work processes were possible unless one used, in practice, complex and costly special equipment such as the suction cup securing columns, whose disposition needed to be adapted according to the piece. The slit configured now between all the preceding assemblies and all the following assembly, allows instead any kind of through cutting on the panel, whilst the vacuum acting on the belt is able perfectly to operate the retention of the panel during the conveyance and the simultaneous cutting in composition of movements between bank of synchronous belts and spindle on the longitudinal member; additionally, said retention of the panels operates indifferently both on the base piece and on the machining scraps obtained.
[0015] The invention is described in greater detail below, with the aid of the drawings that illustrate an embodiment provided purely by way of example, non binding and non limiting for the purposes of the present invention:
- Figure 1 shows the four fundamental views in orthogonal projection of the work centre, where some parts are removed the better to understand the structure of other parts;
- Figure 2 is a section of the machine according to a vertical plane parallel to the direction X of actuation of the panels, clearly showing the two conveyor belt assemblies forming a pair, and positioned one preceding the other relative to a sense (U) selected on the direction X; also shown is a detail of the belt and driving roller, provided with related meshing toothings; also shown are the two sections of the longitudinal chambers that transversely traverse the enclosed circulation paths of all the belts of the preceding assemblies and, respectively, of all the following assemblies, as well as the auxiliary roller pressers positioned in proximity to the slit;
- Figure 3 shows a front view, from the panel introduction side, of the work centre, clearly illustrating the spindle, the preceding belt assemblies all side by side, and the pressing rollers acting in proximity to the slit;
- Figure 4 shows a partial section plan view of the work centre, where the upright columns supporting the upper longitudinal member have been omitted for the sake of clarity, and where are shown the six pairs of belt assemblies with the six preceding assemblies and the six following assemblies, and the slit configured thereby where the tool performs also the through cutting operation; the two longitudinal chambers kept in a vacuum, on the holed surface whereof each belt slides, are shown with dashed lines, as are the contours of possible pieces cut by the tool and separated from the initial panel;
- Figure 5 shows a plan view of the spindle engaged at the end of the slit, beyond the longitudinal member supporting the spindle itself;
- Figure 6 shows a partial section of a conveyor belt assembly, illustrating the section of the chamber subjected to vacuum with its upper surface holed, the belt, holed in turn, which slides on said surface, and the panel shown in dashed and dotted lines, bearing on the belt itself and retain thereon by the vacuum.
[0016] This CNC numerical control work centre, with many constructive details essentially known although innovative in the architecture of its part tasked with actuating and securing the pieces and in the configuration of the area where the cutting operation takes place, essentially comprises a machine base 2 developed longitudinally along a horizontal direction Y of a set of three mutually orthogonal directions X, Y, Z which base rises at its ends with two fixed uprights, which integrally sustain a longitudinal member 7 positioned according to the same direction Y, above the base. The longitudinal member 7 presents, also positioned according to Y, guides 7g of the translating motion whereon is able to slide a spindle 5 for actuating in rotation a milling tool 6, positioned vertically according to the direction Z. The spindle is composed according to a usual layout comprising a base slide of the head, able to slide on the guides 7g of the longitudinal member, and whereon is movable - now along the vertical direction Z - the body of the head itself, directly bearing the electrical spindle with the related rotating tool 6. The actuation of the base slide and of the body of the spindle take place by means of the usual motor-screw-lead nut systems, not described in detail because they are known.
[0017] Relative to the base 2 are securely fastened conveyor assemblies 9, each of which is substantially constituted by a belt 11 wound and circulating on cylindrical rollers 12 with parallel axes, fastened to the body of each assembly 9.
[0018] In regard to each individual assembly 9, it superiorly presents a segment of tensioned belt 14 which configures part of a geometric plane 3p with horizontal lay XY, representing the segment of belt useful for bearing and conveying the panels 1 during the cutting operation; said belt segment 14 is held tensioned by two motorised rollers 12m, whereof the first is connected directly to a motor 13 with associated reduction gear 24, and the second connected to another reduction gear 26 which takes its motion from a shaft 25, coming in turn from the same motor 13. The other rollers 12 of each assembly 9 are to be considered tensioning rollers or rollers for deviating the path of the belt. A CNC control system 8 is present aboard the work centre and renders rigorously synchronous, by acting on the motors 13 of each assembly 9, the motion of all the belts of each assembly present in the machine, and it establishes the clockwise motion law for them.
[0019] It should be added, again in regard to the assemblies 9 considered individually, that the belt has a toothing 19n obtained in its inner surface 11i of contact with the rollers; and equally the driving rollers 12m present a similar toothing 19r obtained on their lateral surface, where the two toothings 19n of the belt and 19r of the driving rollers are mutually enmeshed during the circulating motion of the belt on the rollers.
[0020] In regard instead to the assemblies 9 as a whole, for the purposes of the invention the disposition of said belt assemblies, both relative to the base and relative to each other, is extremely important. Relative to the base, said assemblies are positioned with their direction of conveyance along the horizontal direction X (normal to the direction Y of development of the longitudinal member 7), and are joined in pairs 9c of assemblies 9, one said pair 9c being constituted by two assemblies 9 positioned consecutively along said direction of conveyance X and with the tensioned segments 14 of belt positioned on the same horizontal plane 3p, where therefore are identified a preceding assembly 9a of the pair and a respective following assembly 9b thereof, relative to a sense U selected on the direction X, and the two assemblies 9a and 9b constituting the pair 9c are identical and positioned in front of each other in mirror-like fashion, as Figure 2 clearly shows.
[0021] In the embodiment described herein, six pairs 9c of assemblies 9 are provided, and these six pairs are set mutually side by side according to the direction Y of the longitudinal member, in such a way that all the preceding assemblies 9a of all the pairs 9c are perfectly side by side and that all the following assemblies 9b of all the pairs 9c are perfectly side by side. With such a disposition of the assemblies 9, see also Figure 4, a slit 10 is identified between all the preceding assemblies 9a and all the following assemblies 9b, practically having rectangular shape elongated in the plane 3p and developing along the direction Y, where the disposition of the pairs 9c is such that said slit 10 is exactly underneath the longitudinal member 7 and parallel thereto, and belonging - in addition to the plane 3p - also to a vertical plane YZ containing the tool 6 of the spindle. In practice, therefore, said slit 10 is configured by the mutual mirror-like facing disposition of the bank of preceding assemblies 9a and of the bank of following assemblies 9b, and represents the area where the tool 6, coming from above, can perform through work processes below the bearing plane 3p of the panels themselves, without thereby damaging in any way the belt of any assembly 9.
[0022] In regard to the system for securing the pieces on the tensioned segments 14, the task is assigned to vacuum securing means 4 integrated in the same belt assemblies 9, where said means 4 comprise: two identical vacuum chambers 16 and 16' presenting related planar surfaces 17 provided with holes 18; the plurality of the conveyor belts 11, each provided with holes 15 normal to its median surface and passing through the belt 11; a known centrifugal fan 20 able - under the control of the CNC means 8 - to create the required vacuum in said chambers 16 and 16'.
[0023] Said chambers 16 and 16' have tubular shape, elongated according to the direction Y, and are positioned parallel to each other, the chamber 16 traversing the closed paths of the belts of the bank of preceding assemblies 9a, and the chamber 16' traversing the closed paths of the belts of the bank of following assemblies 9b, and are arranged in such a way that all the belts 11 of all the assemblies 9 slide on said respective holed planar surfaces 17 of the chamber 16 or 16' whereby the belt is traversed. The retention by vacuum of the panels deposited on the belts 11 is also assured by the substantially continuous communication of the multitude of the holes 15 of each belt, with the multitude of the holes 18 on the surface 17, whereon the belt slides, as Figure 6 clearly shows.
[0024] The belt area adjacent to the slit 10, where the belt winds on its own rollers 12m to be curved downward, represents an area in which the effect of the vacuum is weak, since the holes of the belt in that area no longer communicate with either of the two vacuum chambers 16 or 16', and if the panel were not properly secured by the vacuum present in the belts before and after the slit 10, for instance because of its reduced size, securing could be defective when the panel segments before and/or after the slits were too short. For this purpose additional roller pressers 21 are provided, which impart a downward thrust on the panel in correspondence with the upper generatrix of each roller 12m adjacent to the slit 10. The vertical actuation of said roller pressers 21 is performed by known actuators 22, slaved to the CNC control 8.
[0025] Functionally, when the panel is deposited on the plane of the belts - and this can be done as seen without any preparation of the belts themselves, but only establishing a zero reference piece on the panel - the CNC control 8 establishes the correlation between the synchronous movement of all the belts 11 of each assembly 9 along the direction X, and the movements of the spindle 5 on the longitudinal member 7, along the directions Y and Z. In this way, by interpolation, all desired shapes of the piece can be cut starting from the panel 1, even using through cutting operations, since the tool 6 can work immersed in the slit 10 identified as described above, not interfering on the belt in any way. The work operation obviously comprises forward and backward motions of the bearing plane constituted by the tensioned segments 14, also to obtain closed perimeter curves on the pieces.
[0026] It should lastly be noted that, in order to obtain an appropriate tensioning of each segment 14, two drive rollers 12m are provided, and both are positioned at the ends of said tensioned segment, where moreover the propeller shaft between the reduction gear 24 of the first roller 12m positioned on the motor 13, and the reduction gear 26 of the second roller 12m, is keyed at its ends in the respective reduction gears in order to induce a pre-tensioning of the segment 14 through the counter-rotation of said two rollers 12m, in such a way that there is no slackening of the belt when its motion is inverted, relative to a predetermined sense U on the direction X.
1. Numerically controlled work centre for cutting panels (1) made of wood or similar
materials, comprising at least:
- a base (2) supporting means (3) for bearing and actuating said panels (1) to be
machined, defining a geometric plane (3p) where the bearing and actuation of said
panels (1) takes place, said plane (3p) having horizontal lay XY relative to a set
of three mutually orthogonal directions X, Y, Z, said means (3) actuating said panels
(1) relative to said base (2) with a first motion for feeding the cutting operation
along said direction X;
means (4) for securing by vacuum, able to make said panels (1) integral with said
bearing means (3) during said first motion for feeding the cutting operation, comprising
at least a chamber (16), subjected to vacuum by known aspirating means (20) and presenting
at least a respective horizontal planar surface (17) provided with a multiplicity
of holes (18), passing through relative to the interior of said at least one chamber
(16), in the manner of a holed plane for vacuum retention;
- a longitudinal member (7) supported by said base (2) superiorly to said plane (3p), whereon is mounted, with the axis positioned substantially according to said direction Z, at least a spindle (5) for actuating in rotation at least a tool (6), said spindle being able adjustably to translate on said longitudinal member (7) according to the directions Y and Z to generate a second and a third motion for feeding the cutting operation respectively in said directions Y and Z, during the cutting of said panels (1);
- means (8) for electronically controlling at least the operation of the movable machine elements and said vacuum securing means (4),
characterised in that said means (3) consist of at least a pair (9c) of conveyor belt (11) assemblies (9), with said belt (11) wound according to an enclosed path on rollers (12) in contact and in relative sliding motion on the inner surface (11i) of said belt (11) with parallel axes, each said assembly (9) of at least one said pair (9c) presenting a tensioned segment (14) of said belt (11) superiorly useful for bearing and conveying said panels (1) and configuring part of said plane (3p); at least one pair (9c) of assemblies (9) comprising said vacuum securing means (4); said two assemblies (9) of at least one said pair (9c) being oriented with their direction of conveyance according to said direction X, in such a way as to configure, according to a sense (U) fixed on said direction X, a preceding assembly (9a) and a following assembly (9b) in at least one said pair (9c); said preceding assemblies (9a) of at least one said pair (9c) globally configuring a separation space, respectively with said following assemblies (9b) of at least one pair (9c), in the manner of a continuous rectilinear slit (10), substantially rectangular in said plane (3p), developing longitudinally along said direction Y and able to allow a free vertical traversing of said plane (3p) by said tools (6) that perform the cutting operation on the entire thickness of said panels (1); said longitudinal member (7) developing parallel, and superiorly, in correspondence with said slit (10), so that said at least one tool (6) of said at least one spindle (5) is movable substantially on a vertical plane YZ passing through said slit (10).2. Numerically controlled work centre as claimed in claim 1 characterised in that said vacuum securing means (4) comprised in said at least one pair (9c) of assemblies
(9) also include the belts (11) of said assemblies (9) of said at least one pair (9c),
said belts (11) being in this manner provided with a multiplicity of through holes
(15), perpendicular to their median surface; at least a said chamber (16) subjected
to vacuum regulated by said control means (8) being provided in such a way that to
at least one said chamber (16) is associated at least a said belt assembly (9), said
at least one chamber (16) associated to said at least one belt assembly (9) being
positioned each within the enclosed path according to which circulates at least one
of said belts (11); said tensioned segments (14) of at least one of said belts (11)
sliding, in their conveying motion along said direction X, with their inner surfaces
(11i) directly on said horizontal and holed planar surfaces (17) of said at least
one chamber (16) relatively associated to said assemblies, so that an aspirating and
securing effect on said panels (1) is possible during their actuation, by effect of
the vacuum acting through the communication of said holes (15) of each said belt (11)
with said holes (18) of the respective surfaces (17) of the respective associated
chamber (16).
3. A numerically controlled work centre as claimed in claim 2 characterised in that it comprises at least two pairs (9c) of assemblies (9), which include said vacuum
securing means (4), a first said chamber (16) subjected to vacuum regulated by said
control means (8), and longitudinally developing along said direction means Y, being
provided in common for said preceding assemblies (9a) of at least two said pairs (9c),
and traversing said enclosed paths according to which circulate the related belts
(11) of said preceding assemblies (9a); a second chamber (16') similar to the previous
one and subjected to vacuum regulated by said control means (8), and longitudinally
developing along said direction Y, being provided in common for said following assemblies
(9b) of said at least two pairs (9c), and traversing said enclosed paths according
to which circulate the related belts (11) of said following assemblies (9b); said
tensioned segments (14) of at least one of said belts (11) sliding, in their conveyance
motion along said direction X, with said inner surfaces (11i) directly on said horizontal
and holed planar surfaces (17) of said chambers (16) and (16'), so that and aspirating
and securing effect on said panels (1) is possible during their conveyance, by effect
of the vacuum acting through the communication of said holes (15) of each said belt
(11) with said holes (18) of said surfaces (17) of the chambers (16), and (16'), respectively
associated.
4. A numerically controlled work centre as claimed in one of the previous claims characterised in that in at least one said belt assembly (9) exists at least a roller (12m) of said rollers
(12), motorised by a motor (13) subject to said control means (8).
5. A numerically controlled work centre as claimed in one of the previous claims, characterised in that in each said belt assembly (9) exists at least a roller (12m) of said rollers (12),
motorised by a motor (13) subject to said control means (8).
6. A numerically controlled work centre as claimed in claim 4 or 5, characterised in that at least one driving roller (12m) of at least one said assembly (9) presents an external
toothing (19r) obtained on its winding surface, and in that said inner surface (11i)
of the related belt (11) of said at least one assembly (9) presents a corresponding
toothing (19n), so that the circulating motion of said belt (11) on the related said
at least one driving roller (12m) takes place with the mutual meshing of said external
(19r) and corresponding (19n) toothings.
7. A numerically controlled work centre as claimed in the previous claims, characterised in that it comprises presser means (21) acting on said panels (1), superiorly to said tensioned
segments (14) of said belts (11), said presser rollers (21) being positioned with
their axis substantially parallel to said slit (10) and laterally thereto; actuators
(22) being provided, subject to said electronic control means (8), for the vertical
actuation of said presser rollers (21) relative to said machine base (2), from an
excluded position to a position of pressing on the surface of said panels (1), opposite
to their surface bearing on said tensioned segments (14) of said belts (11).
8. A numerically controlled work centre as claimed in one of the previous claims, characterised in that it comprises at least two said spindles (5) for actuating in rotation respective
at least one said tool (6), said at least two spindles (5) being mounted on said longitudinal
member (7) with the axis positioned substantially along said direction Z and being
adjustable and able to be translated independently on said longitudinal member (7)
according to said directions Y and Z to generate respective motions for feeding the
cutting operation on said panels (1); said control means (8) further providing for
collision-proof travel of said spindles (5) along said longitudinal member (7).
9. A numerically controlled work centre as claimed in one of the previous claims, characterised in that it comprises a carriage (23) movable along said direction X on said machine base
(2), said carriage (23) presenting a cross member (7') superiorly to said plane (3p)
and longitudinally positioned according to said direction Y; said cross member supporting
at least a spindle (5') - with the axis oriented according to said direction Z - for
actuating in rotation at least a tool (6'); said spindle (5') being able to translate
adjustably on said cross member (7') according to the directions Y and Z to generate
further motions for feeding the cutting of said panels (1) according to said directions;
said control means (8) providing also for the collision-proof travel of said movable
carriage (23) with integral cross member (7'), relative to said fixed longitudinal
member (7).
10. A numerically controlled work centre as claimed in claim 9, characterised in that said carriage (23) subject to said control means (8), and said cross member (7')
integral therewith, achieves a pursuing motion of said panels (1) along said direction
X, so that said at least one tool (6') of said at least one spindle (5') movable on
said cross member (7') performs substantially non-through work operations in any point
of said panel (1) supported by said tensioned segments (14) of said belts (11), by
composition of the motion of said carriage (23) and integral cross member (7') relative
to said base (2) along said direction X, and of the conveyance motion of said panel
(1) along said direction X, and of the movements of said spindle (5') relative to
said cross member (7') along said directions Y and Z.