APPARATUS AND METHOD FOR CARRYING OUT WORKING ON A SHEET

Abstract

An apparatus and a related method for carrying out working on the perimeter of a sheet having a first lateral surface an opposing second lateral surface and a perimeter edge, comprising multi-tool working heads and sliding constraint members that can be selectively activated to stabilize the working.

Claims

1. An apparatus for working the perimeter of at least one sheet element comprising two parallel and opposing surfaces, said apparatus comprising means for exercising a relative movement between said sheet elements and at least one working head, said working head comprising at least two spindle units on which one or more tools are mounted in a direction for working the perimeter of said at least one sheet element, said working head comprises a plurality of stabilization units each having first sliding constraint members and opposing second sliding constraint members, and said stabilization units are selectively and independently drivable to bring at least some sliding constraint members from a deactivation condition to an activation condition in interaction with said sheet elements, and vice versa.

2. The apparatus as in claim 1, wherein at least one stabilization unit is associated and cooperates with a respective spindle unit.

3. The apparatus as in claim 1, wherein the interaction of at least some sliding constraint members with said sheet elements is exerted through a physical contact.

4. The apparatus as in claim 1, wherein the interaction of at least some sliding constraint members with said sheet elements is exerted through a pressure exerted by a fluid.

5. The apparatus as in claim 1, wherein an axis of rotation of at least one working head is chosen so as to be in a barycentric position with respect to the distribution of the rotating masses.

6. The apparatus as in claim 1, wherein at least one of said working heads comprises means for selectively moving, in a manner independent of each other, at least one stabilization unit with respect to a reference which is integral with said working head.

7. The apparatus as in claim 6, wherein said movement of at least one stabilization unit consists in a rotation around the axis of said spindle unit.

8. The apparatus as in claim 1, wherein said at least one working head comprises means for moving at least some spindle units in the direction independently of each other.

9. The apparatus as in claim 1, wherein said at least one working head comprises means for moving at least one spindle unit in the direction in a manner that depends on the movement of another spindle unit.

10. The apparatus as in claim 1, wherein said at least one working head comprises at least one spindle unit in which the position in the direction remains fixed.

11. The apparatus as in claim 1, wherein said at least one working head comprises selectively activated jets of fluid for the lubrication and cooling of the working.

12. The apparatus as in claim 1, wherein the number of working heads is chosen preferably equal to two.

13. The apparatus as in claim 1, comprising retractable holding units, lower support means and lateral support means, at least some of which can be excluded when the working tools pass.

14. A method for carrying out perimeter working of sheet elements, which comprise first lateral surfaces, opposing second lateral surfaces and perimeters subject to working, comprising: a step of transporting said sheet elements to be worked in the work zone of an apparatus configured for the peripheral working of said sheet elements; a step of hooking said sheet elements to holding means; a step of acquiring the position of said sheet elements; a constraint step, in which first and second sliding constraint members of a plurality of stabilization units associated with at least one working head are selectively brought to a condition of interaction with said sheet element, a working step, in which at least one working head, each comprising at least two spindle units on which tools for working the perimeter are mounted, carries a succession of workings along said perimeters; a step of transporting said sheet elements toward a subsequent station, wherein during working said plurality of stabilization units are selectively brought to a condition of sliding interaction with said sheet element when they are inside the perimeter, and to an inactive condition when they are outside of said perimeter.

15. The method as in claim 14, wherein said interaction consists in the physical contact between said constraint members and said sheet element.

16. The method as in claim 14, wherein during the working of said perimeter said stabilization units are moved in a reference which is integral with said working head in order to guarantee that said stabilization units are always within the perimeter of said sheet element.

17. The method as in claim 14, wherein during said working step said spindle units are moved relative to the sheet element keeping each tool always engaged on said sheet element.

18. The method as in claim 14, wherein during said working step each rolling element of the stabilization units is moved so that the corresponding rolling plane of each rolling element is always parallel to the direction of feed of the tool with which it is associated.

19. The method as in claim 14, comprising a step in which at least some spindle units are moved to select the work tool or to centre said tool with respect to the thickness of the sheet element.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0080] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0081] FIG. 1 schematically shows two possible workings that can be carried out according to the present invention;

[0082] FIGS. 2 and 3 show a first constructive embodiment in front view of the working units that are included in the present invention;

[0083] FIG. 4 shows the sectional view A-A drawn in FIG. 2;

[0084] FIG. 5 shows the detail B identifiable in FIG. 4;

[0085] FIGS. 6 and 7 show two working sequences of an edge made by the head according to a first constructive variant of the working units that are included in the following invention;

[0086] FIGS. 8 and 9 respectively show the front view and relative section D-D of a second constructive variant relating to a working unit included in the present invention;

[0087] FIGS. 10 and 11 respectively show the front view and relative lateral view of a first constructive embodiment of the present invention;

[0088] FIG. 12 shows a working sequence according to the first constructive embodiment of the present invention;

[0089] FIG. 13 shows the front view of a second constructive variant of the present invention;

[0090] FIG. 14 shows a lateral view of the second constructive variant;

[0091] FIG. 15 shows an operating sequence in accordance with the second constructive embodiment of the present invention;

[0092] FIGS. 16a and 16b depict a constructive example of a known retractable holding means comprised in the present invention;

[0093] FIG. 17 shows the references to the geometric elements relating to a sheet during working, in front view and in lateral view, with particular reference to a quadrilateral figure.

[0094] We must clarify that in the present description the phraseology and terminology used, as well as the figures in the attached drawings also as described, have the sole function of better illustrating and explaining the present invention, their function being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0095] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications.

DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION

[0096] With reference to the attached figures, the single-digit numbers identify the sheet elements being worked, the two-digit numbers identify the main units of the machine, while the details and constructive mechanisms are indicated with four-digit numbers, the first two digits of which are those of the main unit to which they belong.

[0097] The sheet, or a sheet element, is identified with 1, the sides of which are respectively indicated as follows: front surface la (surface of the sheet from the operator side), rear surface 1b (surface of the sheet from the support side on the planep).

[0098] In the case of a quadrangular sheet, the edges to be worked are called (starting from the lower one and continuing in a counterclockwise direction): 1e, 1f, 1g, 1h.

[0099] The set of said edges constitutes the perimeter of the sheet and will be indicated as a whole with 1c.

[0100] Finally, the edges, given by the intersection of the previously defined edges, are respectively referred to as 1i, 1j, 1k, 1l.

[0101] The thickness of the sheet is identified with the letter T.

[0102] These conventions and numbers are all shown together in FIG. 17.

[0103] FIG. 2 shows the front view of a first embodiment of a working unit 20 suitable for being installed in an apparatus according to the present invention, configured to carry out material removal working on the perimeter lc of sheets 1 made of glass, or more generally in a material having a sheet shape.

[0104] Said working unit 20 consists of a plate 2040 provided with relative motion in the X and Y directions with respect to the sheet 1, meaning that, fixed to a reference system for example integral with the sheet 1, the working unit 20 moves with respect to it.

[0105] A working head 200 is mounted on said plate 2040, which can rotate about its own axis Zp.

[0106] Advantageously, the angular position C assumed by said working head 200 with respect to the plate 2040 can be controlled by the rotation of a drive 2031 and by the relative pinion 2037 keyed thereto, in turn engaged on the ring gear 2038 integral with the plate 2040.

[0107] Advantageously, said axis Zp is expediently chosen to be in a central zone with respect to the rotating masses.

[0108] This makes it possible on the one hand to make the working head balanced, and therefore to optimize the dimensioning of the rotation members (pinion 2037, crown 2038, drive 2031), on the other hand to reduce the size of the working unit 20.

[0109] FIG. 4 shows the working unit 20 illustrated in FIG. 2 sectioned according to the dashed line A-A.

[0110] Two spindle units 2035, 2035 are associated with the working head 200.

[0111] The person skilled in the art will understand, however, that the number of spindle units associable with said working head 200 may also be a number other than two, for example greater than two.

[0112] If the number of spindles is greater than two, the working head may comprise means to move the position of the axis of at least one spindle from a condition of flatness with respect to the axes of the adjacent spindles to a condition of non-planarity, so as to allow the tools being worked to be arranged tangentially with the preset trajectory or, alternatively, to be able to selectively distance them if the corresponding working is not desired.

[0113] Since each spindle unit 2035, 2035 is made in the same or conceptually similar way, only unit 2035 will be described in detail, it being understood, therefore, that what has been described can be applied without appreciable conceptual variations to the other spindle units.

[0114] Said spindle unit 2035 can expediently consist of a spindle 2039 on which a sequence of tools can be mounted, or a single tool 2004, rotatably associated with its own axis of rotation Z1.

[0115] Said sequence of tools can advantageously be composed of a succession in the axial direction of one or more tools with cylindrical symmetry such as, by way of example, plane, sector, V-shaped or trapezoidal grinding wheels, which in turn can be chosen to selectively adapt to different sheet thicknesses.

[0116] The base of said spindle unit 2035 can be mounted on pads 2032, slidably associated with guides 2033 integral with the rotating plate 2030, which allow its movement in direction Z1 by means of a known drive (not shown).

[0117] Said translational movements along the Z direction of the spindle units are particularly useful in the working of the sheet elements for the following reasons:

[0118] in the case of shaped tools (for example the tool 2002 of FIG. 1) they make it possible to centre the figure with respect to the thickness of the sheet;

[0119] it is common practice to mount a plurality of tools on each axis of the spindle unit 2035, thus realizing a sequence of tools (2004) in succession along Z. The long movement Z of the spindle unit 2035 allows the tool with which the edge working is planned to be carried out to be changed without stopping the machine;

[0120] in the case of tools of cylindrical geometry, it is possible to continuously vary the position along Z of the tool during working in order to guarantee uniform wear of said tool.

[0121] The movements of the rotation spindles 2039 around their axes Z1, Z2, and the movement of the translation spindle units 2035, 2035 along the same axes, are expediently carried out independently from each other.

[0122] However, it is possible to conceive simpler and cheaper constructive variants in order to make these movements dependent on each other.

[0123] For example, the spindle unit 2035 could receive rotational motion from another motorized spindle unit, via, for example, a mechanical transmission.

[0124] According to another example, two spindles can be mounted on the same carriage, thus making their displacement in the Z direction equal.

[0125] According to a further derivation, a solution is potentially feasible in which at least one of the spindle units is integral with the working head 200 (no translation in the Z direction).

[0126] Jointly with said working head 200, in any envisaged variant, jets 2036, 2036 can optionally be mounted for the introduction of lubricant-cooling fluid during the working.

[0127] The person skilled in the art understands that there can be any number of said jets and they can be positioned in a known manner with respect to said tools.

[0128] Together with said working head 200, sensors 2010 suitable for surveying the actual geometry of the piece being worked can optionally be mounted.

[0129] Said sensors 2010 are configured to allow the machine to remove desired amounts of material rather than working the piece into a predetermined shape. A plurality of stabilization units 2020, 2020, 2020 is mounted integrally to said working head 200, exemplarily illustrated in FIG. 2 in number equal to 3.

[0130] The person skilled in the art will understand, however, that the number of stabilization units associable with said working head 200 can be any, for example equal to or greater than two.

[0131] Expediently, each stabilization unit can be made in the same or similar way as the others, consequently only the unit 2020 will be described in detail, it being understood, therefore, that what has been described can be applied without appreciable variations to the other stabilization units.

[0132] Advantageously, at least one stabilization unit 2020 is associated with and cooperates with a respective spindle unit 2035, 2035.

[0133] The stabilization unit 2020 consists of a first sliding constraint member 2023 and a second sliding constraint member 2022, respectively opposing on the two surfaces 1b and of the sheet 1.

[0134] FIG. 5 shows the detail indicated with the letter B of FIG. 4.

[0135] Each constraint member 2022 and 2023 can advantageously be made of a contact element 2025, 2027 characterized by a high yielding material, to make it possible to minimize the contact pressure on the respective surfaces 1a, 1b of the sheet 1, and by rolling elements 2024, 2026 keyed on said contact elements.

[0136] Alternatively, each constraint member can also be made by placing a plurality of rolling elements and contact elements in succession.

[0137] The rotation axis of the constraint member 2023 can be integrally connected to the rotating plate 2030 of the head 200, while the rotation axis of the constraint member 2022 is driven in the Z direction by the drive 2021.

[0138] This operation makes it possible to move said constraint member 2022 in direction Z, in order to be able to distance it (deactivation step) or approach it (activation step) with respect to the corresponding surface 1a facing it.

[0139] The activation step of each stabilization unit 2020, 2020 and 2020 must necessarily take place when the sheet 1 is between the respective sliding constraint members 2022, 2023, so as to guarantee the interaction between the sheet 1 and said stabilization units.

[0140] In the constructive embodiment described in FIGS. 4 and 5 said interaction consists in the physical contact between said constraint members 2022, 2023 and the respective surface 1a, 1b.

[0141] It follows that, if said interaction is active, at said stabilization units (2020, 2020, 2020, . . . ) said sheet 1 is constrained to slide on a plane parallel to the surface la relative to the working head 200, while displacements (also understood as micro displacements or vibrations) in the Z direction will be locally prevented or damped, thus guaranteeing quality working with high working speeds.

[0142] The person skilled in the art can easily deduce further technical variants that achieve the same effect.

[0143] By way of example, the drive 2021 can be realized by means of pneumatic, electric, hydraulic, or hybrid type actuators (oil-electric, hydro-pneumatic, . . . ).

[0144] In turn, the sliding constraint members can alternatively be made up of rolling elements, swivelling elements, sliding pads or fluidic cushions.

[0145] In the latter case, the condition of interaction with the sheet is obtained by maintaining said fluidic cushions at a controlled distance from the surface to be stabilised (for example a few tenths of a millimetre), a distance necessary to maintain the correct pressure of the fluid with respect to the respective surfaces 1a, 1b of the sheet 1.

[0146] A further variant consists in providing both sliding constraint members 2022, 2023 with movement in the Z direction.

[0147] In this way it is possible to guarantee the complete decoupling of the sheet from both elements.

[0148] FIG. 2 illustrates a reciprocal position of the working sheet with respect to the head 200 in which the respective contact elements 2025, 2027 of the respective constraint members 2022, 2023 of each stabilization unit 2020, 2020 and 2020 are located within the perimeter delimited by the edge 1c of the sheet 1.

[0149] In this case, as already explained above, it is advantageous to activate all said stabilization units, so as to guarantee their interaction with said sheet, thus minimizing vibrations and optimizing the quality of the working.

[0150] In the case of polygonal-shaped sheets, working can take place according to two operating modes.

[0151] In a first mode, which we will define for convenience as sequential working, the head 200 advances, with respect to the sheet 1, in a straight motion parallel to the side being worked, extending as long as the last grinding wheel (in the specific case 2035) is beyond the edge 1i (position 20 of FIG. 2).

[0152] To work the second side 1f, it is necessary to rotate the working head 200 with respect to the working unit 20, and move said unit to a position 20 such that the tools are aligned with the new segment If to be worked but in a position where they are not in interaction with it (FIG. 3).

[0153] Finally, the head 200 will move parallel to the new side If to carry out the working on the second side, and so on for the subsequent sides.

[0154] In the description of this first operating mode it is evident that the tools pass alternately from an active step of interaction with the sheet to an inactive step, in which no working takes place.

[0155] Likewise, the stabilization units can alternatively be located inside the perimeter 1c of the sheet (in which case their activation is appropriate to guarantee interaction with the sheet) or outside it.

[0156] In this second case, it is necessary to selectively deactivate said stabilization units in order to avoid the possibility that they may impact the sheet at a later time when the relative constraint members again affect the sheet.

[0157] In the specific case of FIG. 2, therefore, passing from position 20 (all the units activated) to position 20 (no units activated), the working head 200, upon reaching edge 1f, will first sequentially deactivate the stabilization unit 2020, then the unit 2020 and finally the unit 2020.

[0158] Conversely, starting from position 20 of FIG. 3, the units 2020, 2020 and finally 2020 will be sequentially activated.

[0159] In a second operating mode alternative to the previous one, which we will define for convenience as interpolated working, it is possible to work the edge keeping each tool always gripping said sheet, suitably coordinating the movements of translation in x and y and rotation around Zp.

[0160] FIGS. 6 and 7 illustrate, by way of example, two successive steps of said transitional step.

[0161] In analogy with what was seen in the previous operating mode, FIG. 6 also illustrates a condition in which some stabilization units (2020, 2020) are inside the perimeter delimited by the sheet while the unit (2020) is outside it.

[0162] As already explained, it is useful in these circumstances to keep the units 2020 and 2020 activated so that they can interact with the sheet and, at the same time, deactivate the unit 2020.

[0163] FIG. 7 shows a subsequent step to that shown in FIG. 6.

[0164] In an immediate instant following this step it is useful to reactivate the stabilizer 2020 so that it interacts with the sheet again, while the stabilizer 2020 must be deactivated, as it is located outside said sheet.

[0165] The stabilizer 2020 can expediently remain activated, thus maintaining interaction with the sheet.

[0166] As evident from the above descriptions, the interpolated working mode tends to be faster than sequential working, and is therefore to be preferred.

[0167] Expediently, the sensors 2010 can cooperate with the movements x, y, C associated with said working head 200 to identify the positions of the edges 1i, 1j, 1k, . . . of the sheet 1, in order to correctly guide the path of said head and to correctly pilot the activation and deactivation of said elements of said stabilization units.

[0168] Expediently, if said working unit 20 is piloted to carry out an interpolated working, it is advantageous that said constraint elements allow sliding in all directions of the plane of competence, so as to cancel any sliding, which could lead to a degradation of the surfaces la and 1b.

[0169] For example, the aforementioned rolling swivelling elements (not shown as known) can be used in place of the rolling elements 2024, 2025.

[0170] However, said swivelling elements are constructively very bulky and therefore hardly compatible with the construction of a machine for the perimeter working of sheets.

[0171] It is therefore preferable to use fixed axis rolling elements, which are also much cheaper and easier to find commercially.

[0172] A variant of the working unit 20 that allows interpolated working using fixed-axis rolling elements is shown by the working unit 21 depicted in its frontal view in FIG. 8.

[0173] As in unit 20, said unit 21 also consists of a plate 2040 provided with relative movement in the x and y direction with respect to the sheet being worked 1.

[0174] The working head 210 is constrained to said plate 2040 and can rotate with respect to its own axis Zp.

[0175] As in unit 20, two spindle units 2035 and 2035 are also constrained to said head 210.

[0176] Unlike the head 200, however, in said head 210 the stabilization units 2020 and 2020 are equipped with planar movement with respect to said head 210.

[0177] In particular, in the example shown said stabilization units 2020, 2020 are expediently each associated with their own spindle unit 2035, 2035, are positioned at a fixed distance with respect to their respective axes Z1, Z2 and can rotate with respect to them by an angle respectively equal to C1 and C2.

[0178] Said rotations allow the rolling plane of each revolving element 2024 and 2026 of each stabilization unit (2020, 2020) to be independently aligned with each other in the direction of feed of the respective spindle unit 2035, 2035 to which each is associated.

[0179] This reduces relative creep between rolling elements and sheet, guaranteeing the integrity of surfaces 1a and 1b and, at the same time, maximizing productivity thanks to interpolated working.

[0180] Said working can take place both on the basis of a preset program and, more expediently, on the basis of a self-learning process, in which during working a sensor 2010 operates a scan of the actual geometry of the perimeter 1c of the piece, generating a signal that can be used by the control unit of the machine to determine the path of the tools.

[0181] In this way, for example, it is advantageously possible to remove a defined thickness of material along the perimeter.

[0182] Said sensor can also make it possible to accurately read the position of the edges 1i, 1j, 1k, . . . of the sheet 1, in order to correctly control the movements of the axes associated with the working unit 21, in particular the axes C, C1 and C2.

[0183] As an alternative to the constructive solution shown in FIG. 8, said head 210 may comprise known means suitable for translating and/or rotating said stabilization units 2020, 2020 along axes other than those shown.

[0184] FIG. 9 shows the section according to the plane D-D of FIG. 8, which makes it possible to describe its operation in more detail.

[0185] The stabilization unit 2020, according to the constructive embodiment shown exemplarily in this variant, is completely similar to the analogous unit already described with reference to the head 200, except that it is made integral with a frame 2060 that can rotate around the ZI axis by means of rolling coupling 2061.

[0186] Said frame 2060 associated with said stabilization units 2020 is angularly positionable in this case by means of a toothed belt 2062 or similar mechanical means, connected in turn to suitable drives (not shown as known).

[0187] Also in said head 21 there are phases of activation of the constraint members 2022 and 2023 and their deactivation in a selective and progressive manner, in particular in the beginning and end phases of the working.

[0188] Said movements C1 and C2 make it possible to work adjacent sides of the perimeter 1c facing non-rectilinear sections or discontinuities tangentially while maintaining the perfect interaction between the sheet being worked and said stabilization units.

[0189] Said working units 20 or 21 are suitable for being integrated into suitable sheet working machines, thus creating high productivity apparatuses.

[0190] Generally, said machines are characterized by a single sheet laying plane p during all movements, or by a single inclination of the Y axis with respect to the horizontal plane.

[0191] It is therefore possible to have machines that are horizontal (if the Y axis is horizontal) or vertical (when the Y axis is between 80 and 88.

[0192] As the discussion of the following is easily adaptable for the person skilled in the art to all the most common configurations (horizontal or vertical machine), from now on the discussion will be deepened with reference to vertical machines, it being understood that similar considerations can easily be adapted to any laying angle.

[0193] A first constructive example of vertical machine 30 that integrates working heads 20 or 21 as described above is shown in FIG. 10.

[0194] The machine 30 comprises a main body 3001 to which support means 3020 and 3010 of the sheet 1 are fixed, which define a sliding plane p on which said sheet is supported during translation in the X direction.

[0195] Typically, the support plane of said means makes use of idle wheels placed tangentially to it, but other constructive solutions are also widely used, such as, for example, compressed air cushions.

[0196] The support from the lower side of said sheet takes place with lower support means 3040, which can optionally also provide the movement in the X direction of said sheet, dragging by friction the lower edge le of the sheet 1.

[0197] Said known means may consist of rollers coated with polymeric material or by belts or chains. They can be motorized or idle.

[0198] At least some of said lower support means 3040 can be moved between an active position 3041, suitable for supporting and transporting the sheet in the X direction, and an inactive position 3041, spaced from said sheet to allow the passage of the working head (see FIG. 11).

[0199] Among the lateral support means 3010 and 3020 are further movable lateral support means 3030, which have the function of supporting the sheet both during the possible translation and during the working.

[0200] Said movable lateral support means 3030 are located in the working area 3032, where sheet working will take place.

[0201] Each movable lateral support means 3030 includes supports 3031, of known type, which make it possible to temporarily support the sheet at the plane p or to move away from it to avoid interference due to the passage of the tools.

[0202] Said movement can preferably take place by translation along the Y and/or Z axes and said supports can be exemplified by a linear arrangement of idle wheels.

[0203] Advantageously, said long movement Y allows said movable lateral support means to be able to adapt to the different heights of the sheet to be worked during the support step.

[0204] Said machine 30 comprises a holding unit 3050 consisting of a plurality of retractable holding means 50, each selectively movable and activatable.

[0205] A constructive example of one of said means 50 is illustrated in FIG. 16a and in FIG. 16b, respectively in lateral and top view.

[0206] Said means can consist of a fixed support 52 to which gripping means 53 movable between an active position 51 and an inactive position 51 are constrained by means of a suitable actuator 54.

[0207] Said active position 51 allows said gripping means 53 to be positioned with their active surfaces 55 in correspondence with the support plane of the sheet p, in such a way that said surfaces can exert their gripping action on said sheet.

[0208] Advantageously, said gripping means 53 can be made by means of suction cups, the gripping action of which is exerted by activating the relative vacuum circuit (not shown as widely known).

[0209] Advantageously, said movement between the active position 51 and the inactive position 51 can be achieved by translation in the Z direction, constrained by linear guides 56.

[0210] Optionally, in position 51 locking means (not shown) for play recovery can also be activated, to guarantee a rigid support of the sheet during working.

[0211] Said machine 30 also comprises one or more portals 3060, 3070 movable in the X direction, along the guides 3062, 3063.

[0212] Each portal may in turn comprise at least one working unit of the type 20 or 21, as previously described, movable in direction Y with respect to said portals along guides 3061, 3071.

[0213] Advantageously, said machine 30 also comprises a sensor 3080 that allows the position of the sheet to be read in the X direction. Advantageously, said sensor 3080 can be mounted in a fixed position along X or on a suitable carriage that can be slidably positioned in the X direction.

[0214] Alternatively, said sensor 3080 may also be installed on board one of the two portals 3060, 3070.

[0215] Optionally, said machine 30 also comprises sensors suitable for detecting the thickness and dimensions of the sheet (not shown).

[0216] Said machine 30 also comprises a control unit (not shown) operatively connected to said movable means and to said sensors and in which the data relating to the geometry intended to be given to the sheet 1 are stored or inserted.

[0217] Operationally, the process begins with a positioning along the direction Y of the supports 3031 in a position 3031 along the direction Y compatible with the dimensions of the sheet and at a height in Z such as to position said supports tangentially to the p support plane of said sheet.

[0218] The sheet can expediently be introduced by an upstream machine sequentially placed on one side of the machine 30 (for example to the left thereof looking at FIG. 10).

[0219] The sheet will then be moved in direction X by the lower support means 3040, controlling its position by means of the sensor 3080, in order to position it precisely inside the working area 3032.

[0220] Optionally, the sheet may be loaded directly into working area 3032 by known manual or automatic means.

[0221] Also in this case, the sensor 3080 will acquire the position in the X direction, in order to start the working from a certain reference.

[0222] As is well known in this field to the person skilled in the art, optionally, other physical quantities of the sheet can also be acquired, such as for example thickness, dimensions, and, in the case of glass with a low emission coating, also the orientation of said coating.

[0223] Once the sheet is positioned, the gripping means 53 of the relative unit 3050 that are inside the perimeter of the sheet are selectively moved towards the p support plane of the sheet and activated in order to guarantee the gripping thereof.

[0224] The lower support means 3040 are then brought into an inactive position 3041, so that the sheet is suspended by virtue of the means 50.

[0225] The portals 3060, 3070 can then begin to move the relative working units 20 or 21, which, in turn, progressively remove the material on the perimeter of the sheet.

[0226] The working at the discontinuity of the tangency of the perimeter can alternatively be carried out in sequential or interpolated mode, as defined above (FIG. 2, 3, 6, 7, 8), while, if the tangency is continuous (for example radiated curves), it is more convenient to work in interpolated mode.

[0227] If the path of one of the working units 20, 21 interferes with one of the supports 3031, said apparatus is configured to first move said supports in a non-interference position (for example in the y or z direction) and to restore their positioning at a later stage.

[0228] The working can be carried out by a single working unit or, more expediently and if available, by a plurality of working units that simultaneously process different parts of the same sheet or each different sheet.

[0229] In the specific case where there are 2 working units (as shown in FIG. 10) and they are made of quadrangular sheet, it is possible to choose a working strategy that consists of starting the working from one of the edges of the sheet and ending the working in the opposite edge, making each of the two tool units follow two distinct paths.

[0230] In this way, each tool will have traversed a similar perimeter portion (the same in the case of parallelogram or rectangular shaped sheets), thus further reducing working times.

[0231] By way of example, FIG. 12 schematically shows successive instants of working of a rectangular sheet, starting from the edge 11 (tool position 390,391) and ending at the edge 1j (position 390-3, 391-3).

[0232] The unit 390, starting from the edge 11, runs along the lower side le and subsequently the right side If (see subsequent positions 390-1, 390-2, 390-3) while the head 391 runs along the left side 1h and subsequently the upper side 1g, until it reaches the edge 1j (see subsequent positions 391-1, 391-2, 391-3).

[0233] As already described, it is easy to understand how the leading and trailing edges of the working can be chosen in any way, advantageously in opposing pairs in order to optimize process times.

[0234] For example, it is alternatively possible to start from the edge 1k and conclude the working in the edge 1i obtaining the same result.

[0235] When the working is finished, said working heads return to the position originally assumed before the process (in this example, at the bottom left).

[0236] At the same time, the lower support means (3041) will be restored to the active position and the retractable holding means 50 will be deactivated and brought into the inactive position outside of the plane p.

[0237] The sheet can then optionally be picked up by the operator or moved in the X direction to a subsequent station.

[0238] A second constructive example is shown by the machine 40 of FIG. 13.

[0239] This too, as in version 30 described above, is easily achievable in both horizontal and vertical versions.

[0240] In the latter version, it is constructively similar to what is already described in EP3525984B1, except that the working units are of type 20 or 21.

[0241] It comprises a main body 4030 sequentially connected to two conveyors 4010 and 4020, arranged respectively upstream and downstream thereof.

[0242] The input conveyor 4010 may expediently be connected to an upstream working station, or, alternatively, the sheet 1 may be loaded directly by known manual or automatic means.

[0243] The output conveyor 4020 can instead be connected to a downstream working section, for example, in the case of glass working, to a line for the manufacture of insulating glass or, alternatively, the sheet 1 can be unloaded directly by known manual or automatic means.

[0244] The input 4010 and output 4020 conveyors comprise means for supporting the lower edge of the sheet 4011, 4021, which may optionally be configured to move the sheet in the X direction.

[0245] Said support means 4011, 4021 can be exemplarily made by means of a series of rollers or by means of belts or chains of the known type, which in turn can be motorized or idle.

[0246] The conveyors 4010, 4020 also comprise support means 4012, 4022, for supporting the p rear surface 1b of the sheet 1 along the plane.

[0247] Said support means may, for example, be made by means of a plurality of idle wheels or an air cushion.

[0248] The input conveyor 4010 may optionally comprise a thickness detector of known type, for measuring the thickness of the sheet to be worked before its entry into the working sections, useful for carrying out the correct initial approach of the tools to the glass sheet.

[0249] Said conveyor 4010 can comprise a sheet height detector, in order to correctly set the strokes in direction Y of the working heads.

[0250] Said height detector can be expediently placed in the working units.

[0251] Advantageously, said machine 40 is also equipped with an appropriate known sensor 4080 that allows the position of the sheet to be read in the X-direction.

[0252] Advantageously, said sensor can be mounted in a fixed position along X or on a suitable carriage that can be slidably positioned in the X direction.

[0253] Two independent movable holding units 4040, 4050 are located along the conveyors 4010, 4020 and the machine body 4030 on the sheet support side.

[0254] Each of these can hold a working sheet 1, 2 and move it precisely in the X direction.

[0255] Constructively, each unit 4040, 4050, can comprise trolleys 4043, 4053 integral with a plurality of retractable holding means 50 (as described above, FIGS. 16a and 16b), slidably associated with guides 4041 4051 and with drives (not shown) that guarantee their precise positioning (FIG. 14).

[0256] This defines a positioning axis X1 associated with the unit 4040 and a similar axis X2 associated with the unit 4050, optionally synchronizable with the translation movement produced by the support means 4011, 4021.

[0257] Working units 4060, 4070 are located in the machine body 4030 and can move independently and in a coordinated manner according to the vertical axes (Y1, Y2), each in the constructive embodiment 20 or 21.

[0258] Therefore, by coordinating the translation movements along X of the sheet (X1 or X2) with the movement of the working heads along Y (Y1, Y2) and the relative rotation C of each working head, each working head can be moved in any position of the plane relative to the sheet, in the same way as seen for the machine 30, with the only exception that, in this case, the movement in direction X is given by a movement of the sheet instead of the tool.

[0259] The working cycle begins by placing all the gripping members 50 in the inactive position.

[0260] The sheet 1, coming from the previous working station, or loaded directly on the infeed conveyor 4010, is advanced in direction X by means of support means 4011 or one of the two retractable holding units 4040 or 4050.

[0261] The machine management software identifies the optimal number n of holding means 50 that should be activated to support said sheet and positions along X1 one of the two holding units (for example 4040) so that said n optimal holding means to be activated are in a position inside the perimeter of the sheet and centred with respect to it.

[0262] Said n holding means are then activated, in order to guarantee the grip of the sheet.

[0263] Once the sheet is hooked by the holding means 50, it is moved towards the sensor 4080 in order to acquire the position If of the front edge.

[0264] In the following steps, the removal of material on the perimeter of the piece begins. FIG. 15 schematically depicts some representative instants of this succession of phases, indicated with a progressive numbering initials (T1, . . . . T4).

[0265] At an initial instant (T1) the tool units 4060, 4070 are positioned along the respective axes Y1, Y2 below the edge le of the first sheet 1.

[0266] The unit working head 4060 is rotated with vertical alignment of the spindle axes, while the unit head 4070 is rotated with horizontal alignment.

[0267] With reference to a rectangular shape, the sheet is moved in the direction X1 so as to position the front side If at the unit 4060, which then carries out the working of said side (T2).

[0268] Upon reaching the upper edge (1j) of the working, the working head of the unit 4060 can optionally carry out the working of the edge by interpolation or in a sequential manner.

[0269] The sheet 1 is then advanced according to X1, thus promoting the working of the upper edge 1g by means of the head 4060.

[0270] After having traversed a stretch corresponding to the long distance X that separates the working units 4060 from 4070, the latter unit will start working the edge 1e (instant T3).

[0271] For much of the working, both horizontal sides will then be worked at the same time, respectively by the unit 4060 and 4070.

[0272] When the head 4060 reaches edge 1k, it will move to its starting position, ready to carry out the front side 2f of a subsequent sheet 2, which in the meantime has been taken over by the other holding unit 4050.

[0273] Expediently, it is possible to synchronise the positioning of the front side 2f of the sheet 2 in favour of the working unit 4060 with the working of the rear side 1h of the sheet 1 that can be carried out by the working unit 4070 after the working of the side 1e (instant T4).

[0274] At the end of the working of the 1h side, the head 4070 will return to the starting position (as in T1), ready to work the edge 2e of the second sheet.

[0275] The holding unit engaged with the sheet 1 will then move said sheet out of the work area to facilitate its unloading and, subsequently, to hook and prepare in place a third sheet that will be worked after the sheet 2.

[0276] This process can then be repeated several times, in order to achieve the desired production efficiently and with good quality.

[0277] The succession of the described workings is such that a first holding unit will take charge of a first sheet, a third, a fifth and so on (odd sheets), while a second holding unit will take charge of the respective even sheets (second, fourth, sixth, . . . ).

[0278] Similarly, in the case of quadrangular sheets, each working unit will process two sides per sheet each (in the case of rectangular sheets, one vertical side and one horizontal side).

[0279] Both the machine type 30 and the machine type 40 can also be used for the working of non-rectangular and non-quadrangular sheets.

[0280] The expert in the field, in fact, drawing on the technical literature and other patent titles, can easily deduce optimal procedures to optimize the routes, taking advantage of the presence of several working heads that can expediently be made to work in parallel.

[0281] It is evident how this invention in the various constructive configurations allows the limitations of the known art to be overcome, realising peripheral working of a sheet of excellent quality in at least 70% less time than a similar traditional machine.

[0282] It is clear that modifications and/or additions of parts may be made to the apparatuses and related methods for working sheet as described heretofore, without departing from the field and scope of the present invention, as defined by the claims.

[0283] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve other equivalent forms of an apparatus and a method for carrying out working on a sheet, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

[0284] In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.