Cutting machine with safety measures

Abstract

A machine (1) for cutting sheet material is described herein, the machine comprising: a table (2) adapted to provide a support plane for a sheet of material to be cut; at least one cutting unit (3) adapted to cut a sheet arranged on the table (2); at least one arm (4) arranged at least partially above the table (2) and adapted to support the cutting unit (3); a support device (9) for the arm (4) supported so as to be movable along a sliding direction (X); and at least one protective screen (18) supported by a support structure, the protective screen (18) being adapted to translate in said sliding direction (X) due to the movement of the arm (4). Suitably, the protective screen (18) is articulated to the support structure at a hinge point (P) so as to be tilted relative to the support structure, the protective screen (18) being adapted to perform at least a partial rotation relative to the hinge point (P) when encountering an obstacle along said sliding direction (X).

Description

[0001] Application Areas

[0002] The invention relates to cutting machines, for example for cutting hides, leathers, synthetic materials etc., and the following description is made with reference to this field of application, with the sole purpose of simplifying the explanation thereof. Prior art

[0003] As is well known in this particular technical field, there are various devices capable of performing the automatic cutting of sheets of material, such as hides, fabrics, nonwovens, synthetic materials, etc., according to a preset cutting pattern. The type of sheet material to be cut is indeed the most varied, even within the same technical field. The clothing, accessories and footwear industries all use, for example, a variety of materials, such as hides, nonwovens, synthetic materials. These materials, although they have significant differences in their manufacture and consistency, still have the common property of being in a sheet and being subjected to a cutting operation.

[0004] There are machines equipped with a conveyor belt able to move the sheet to be cut inside a cutting chamber, which is usually closed at the top and laterally closed on at least two sides, and is equipped with at least one movable cutting unit for cutting the sheet, while the cut parts are sent out of the cutting chamber towards an unloading area by a conveyor belt.

[0005] There are also simpler machines, so-called cutting tables or benches, which do not have a closed cutting chamber (and possibly a conveyor belt feeding the sheets), but only a table (possibly a fixed one) on which the material to be cut is arranged. According to some known solutions, on the opposite main sides of the cutting table, corresponding rails are arranged for the sliding of a carriage which moves at least one transversely extending crosspiece or arm which supports a movable cutting unit for cutting the sheets arranged on the table. Once the cut has been performed, the arm is moved so as to clear the working area and the operator can collect the cut parts, while the cutting head can cut the sheets in another area of ​​the table.

[0006] The above described machine is very flexible and easily allows cutting samples and small products of hides, synthetic materials and all kinds of fabrics.

[0007] However, the primary problem of the above-mentioned machines is associated with the arrangement of the material to be cut on the table, which material generally has a size greater than that of the table, so that there is always an excess of material that cannot be initially arranged on the table. In other words, the overall dimensions of the guides and the racks for the mobile arm do not allow this excess material to be arranged easily. In some known solutions, only a guide system is used, which supports the arm at the second main side of the table opposite to the first side where the operator acts; however, in this solution, it is necessary to create on the second side a bracket forming a suitable seat for receiving the material to be cut wound in a roll, which the operator can unwind from time to time. This solution significantly complicates the structure of the machine and the positioning of the sheets, since the structure of the table must be appropriately shaped in order to form said bracket, in which the roll of material is arranged. In addition, it is difficult to arrange the material in the bracket, since it implies the rolling up of the material and its insertion into the bracket away from the working area.

[0008] Other even more extensive solutions have guides that allow the arm to slide on the two main sides of the table and that, in addition to the above-mentioned brackets, also form a slot on the side opposite to the bracket where the excess material is inserted, thus further complicating the positioning operation. In addition, the presence of the slots and other guides distances the operator from the machine, making it difficult for the operator to work.

[0009] There are solutions in which guides are arranged on the secondary sides of the table, so that the arm slides along these secondary sides; however, the presence of guides along the sides hinders the operator and the machine requires in any case an advanced safety system as shown in the following paragraphs.

[0010] Another more serious problem is the safety of these machines, since there is no cutting chamber surrounding the cutting unit and the movable arm, contact with these cutting units or the movable arm supporting them is more likely to have very dangerous consequences for the operator. For this reason, additional safety measures need to be taken.

[0011] The technical problem of the present invention is to provide a cutting machine having structural and functional characteristics allowing to overcome the above-mentioned limitations and drawbacks still affecting known solutions and in particular able to provide increased safety for the operator. SUMMARY OF THE INVENTION

[0013] The idea behind the solution of the invention is to bring the cutting machine equipped with a protective screen close to the end of the movable arm, said screen being shaped so as to avoid direct contact between the operator and the cutting unit. The protective screen is able to translate integrally with the arm and to tilt relative to it so that when it hits an obstacle, in particular when its lower part, furthest from the arm, hits an obstacle, it can rotate about the articulation axis, thus absorbing the collision and allowing the control unit to stop the operation of the machine punctually and in complete safety. A collision with the upper end of the screen, i.e. closer to the articulation point, is absorbed by an additional protective element, which is for example hinged at the lower end of the screen and is able to perform a pivoting movement towards the edge of the screen, this movement likewise activating the safety stop.

[0014] The machine of the present invention is also equipped with other safety systems, such as photocells, making the cutting machine described herein very safe.

[0015] Based on the concept of this scheme, the above technical problem is solved by a machine for cutting sheets, which includes a workbench suitable for providing a supporting plane for a sheet of material to be cut, at least one cutting unit suitable for cutting a sheet arranged on the workbench, at least one arm at least partially arranged above the workbench and suitable for supporting the cutting unit, a supporting device for the arm supported so as to be able to move along a sliding direction, and at least one protective screen connected to the supporting member, especially connected to the arm at the end of the arm, the protective screen being suitable for translating along the sliding direction due to the movement of the arm, the machine being characterized in that the protective screen is hinged to its supporting structure (i.e., preferably, to the arm) at a hinge point so as to be tilted relative to the arm, and the protective screen being suitable for performing at least partial rotation relative to the hinge point, especially when it encounters an obstacle along the sliding direction.

[0016] More specifically, the present invention includes the following additional and optional features, if desired, alone or in combination.

[0017] According to an aspect of the invention, the machine may include a control unit configured to stop the movement of the arm based on the rotational movement of the protection screen.

[0018] According to an aspect of the present invention, the protection screen may have a main body configured to at least partially cover the cutting unit at least when viewed from a direction substantially orthogonal to the sliding direction.

[0019] According to an aspect of the invention, the protective screen may be connected directly to the arm. Even if it is preferred to connect the screen directly to the arm, other embodiments are possible in which the screen is connected to the arm via a support.

[0020] According to another aspect of the invention, a protective screen may be arranged at the end of the arm.

[0021] According to another aspect of the present invention, the end of the arm may include a connecting protrusion hingedly connected to the protection screen.

[0022] Furthermore, the machine of the invention may preferably comprise two protection screens arranged on opposite sides of the work table, ie opposite in a direction substantially orthogonal to the sliding direction.

[0023] Furthermore, the machine of the present invention may include at least one pair of photocell arrays configured to move integrally with the arm, the photocells being arranged at least along a vertical direction substantially orthogonal to the worktable and configured to detect the presence of an object therebetween.

[0024] According to an aspect of the present invention, at least one of the photovoltaic arrays may be arranged on a protective screen and may be adapted to move integrally with the protective screen.

[0025] According to an aspect of the invention, the control unit may be configured to stop operation of the machine when there is no alignment between opposing arrays of photocells due to rotation of the protection screen about the hinge point, for example as a result of a collision with an operator.

[0026] Alternatively or in combination, the machine may comprise a sensor operatively connected to the control unit and configured to detect a rotation of the protection screen, wherein the control unit is configured to stop operation of the machine when the sensor detects a rotation of the protection screen.

[0027] According to another aspect of the invention, the machine may comprise an additional protective element connected to the protective screen, the additional protective element having a connection with the protective screen and configured to perform a relative movement towards / away from the protective screen. Preferably, at least one free end of the additional protective element is capable of performing a pivoting movement.

[0028] In particular, the body of the additional protective element may be hinged to the protective screen and configured to perform a pivoting movement towards / away from the protective screen.

[0029] Alternatively, the additional protection element may be translated relative to the protection screen.

[0030] According to another aspect of the present invention, the body of the additional protective element can be configured to extend along an edge side portion of the protective screen, in particular, an edge portion extending along a direction substantially orthogonal to the sliding direction (in a stationary position), the protective screen and the additional protective element being connected to each other and configured so that a rotational movement of one of the protective screen and the additional protective element is triggered based on the position where a collision occurs.

[0031] The additional protective element is arranged along the side of the protective screen that is opposite to the sliding direction.

[0032] According to another aspect of the invention, the array of photocells can be arranged on an additional protection element connected to a screen relative to the longitudinal axis of the arm and suitable for moving integrally with the additional protection element, the control unit being configured to stop the operation of the machine when there is no alignment between the relative arrays of photocells due to a relative movement of one of the additional protection elements relative to the screen (e.g. a rotation around a hinge point), for example due to a collision with an operator.

[0033] Furthermore, the machine may include an elastomeric protective element configured to at least partially cover the arm.

[0034] According to a further aspect of the invention, the protective screen may be connected to the arm by means of pin elements received in suitable seats at the arm.

[0035] Finally, the support means for the arm may be in the form of a crossbar support structure which is held suspended above the workbench by at least one supporting upright extending from the workbench, the workbench being a fixed plane and not obstructing at least two parallel sides of a larger extension, and the arm being supported on the workbench by means of said crossbar cantilever.

[0036] The characteristics and advantages of the cutting machine of the invention will become apparent from the following description of an embodiment thereof, given by way of non-limiting example with reference to the accompanying drawings.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In these drawings:

[0039] - Figure 1 A schematic perspective view of a cutting machine of the present invention is shown;

[0040] - Figure 2 shows a schematic side view of a cutting machine of the present invention;

[0041] - Figure 3 Details of the cutting machine of the invention are shown, and in particular its safety elements are described in detail;

[0042] - Figure 4 A schematic perspective view of a cutting machine of the present invention is shown, which highlights the optical light signal of the photocell associated therewith;

[0043] - Figure 5A-5B The front protective screen of the safety system of the present invention is shown in two different rotational configurations;

[0044] - Figure 6A-6B The rear protective screen of the safety system of the present invention is shown in two different rotational configurations;

[0045] - Figure 7shows a schematic perspective view of a cutting machine according to the invention, with its protective screen in a rotated configuration due to a collision with an operator;

[0046] - Figures 8A-8B The protective screen of the invention is shown in connection with an additional protective element that performs a pivoting movement;

[0047] - Fig. 9 A top view showing a portion of the machine of the invention, with the protective screen visible; and

[0048] - Fig.10 A cross-sectional detail of the protective screen of the invention and its connection to the arm of the machine is shown.

[0049] Details

[0050] With reference to these drawings, in particular Figure 1 , a cutting machine according to the invention is globally and schematically indicated by the reference numeral 1 .

[0051] It is worth noting that the drawings represent schematic views and are not drawn to scale, but they are drawn to emphasize the important features of the present invention. In addition, in the drawings, different elements are depicted in a schematic manner, and their shapes vary based on the desired application. It should also be noted that in the drawings, the same reference numerals refer to elements with the same shape or function. Finally, the specific features described in the embodiments shown in the figures are also applicable to other embodiments shown in other drawings.

[0052] Positional references used in this specification including phrases such as lower or upper, upper or lower, or similar phrases refer to the operational configurations shown in the drawings, and in no case should they be given a limiting meaning. In any case, the references are used in practice by those skilled in the art when referring to components of the machine of the present invention.

[0053] To facilitate the following description of the machine 1, Figure 1 As shown, by way of example, two orthogonal directions corresponding to the orthogonal movement of the cutting unit of the machine 1 are identified: the Y direction and the X direction. In particular, as will be shown in more detail below, the X direction is also indicated as the sliding direction of the arm of the machine 1.

[0054] In its most general form, the machine 1 is suitable for processing and in particular for automatically cutting hides, leathers, synthetic materials etc. More specifically, the machine 1 is suitable for automatically cutting sheets of foldable or flexible material, such as fabrics and hide products for clothing, articles of footwear, automotive and furniture products, or non-woven fabrics, hides, synthetic materials etc.

[0055] In the context of the present invention, the term "sheet" denotes any element of any shape and material, having substantially two-dimensional dimensions and a certain thickness (generally decreasing), which is to be cut by the machine 1 .

[0056] The machine 1 is a numerically controlled machine comprising a control unit C, for example comprising a suitable memory unit suitably programmed and arranged for its management and automatic control. The control unit C may be, for example, a computerized unit integrated in the machine 1 or external to the machine 1 and operatively connected thereto. Furthermore, the control unit may be a single control unit or may comprise a plurality of local units. Thus, the control unit C is able to control the machine 1 to obtain automatic cutting of the sheet.

[0057] The machine 1 of the invention is a so-called cutting table and comprises a table 2 suitable for providing a support plane or working surface a for a sheet of material to be cut. The table 2 preferably has a quadrilateral plan (more preferably substantially rectangular) and at least one cutting unit 3 or cutting head carried by at least one arm or crosspiece 4 acting thereon.

[0058] In one embodiment of the present invention, the workbench 2 is a fixed plane, even in other embodiments, the workbench may be provided with a conveyor belt (not shown) for moving the materials arranged thereon.

[0059] In the case of a rectangular workbench 2 as shown in the figure, the Y direction (lateral direction of the workbench) is parallel to its secondary side, and the X direction is parallel to its primary side. As mentioned above, the X direction is also referred to as the sliding direction of the arm 4, and therefore, in the embodiment of the present invention, slides along the primary side of the workbench 2. However, for the purpose of the present invention, the arm 4 is not prevented from sliding along the secondary side of the workbench 2, and therefore the sliding direction is the Y direction, and the present invention is not limited to a specific sliding direction of the arm 4.

[0060] Generally, the term workbench 2 refers to a structure supporting a piece of material to be cut, the workbench being provided with at least two opposite sides of a larger extension, and at least two opposite sides of a smaller extension (preferably rectangular or at least defining a rectangular working surface), and being a plane having a certain thickness, so the term side refers to a side edge portion of the workbench.

[0061] Like a conventional cutting table, the machine 1 is provided with a base 5 , for example box-shaped, which is a support for the table 2 and which may enclose mechanical and electronic components to assist the operation of the machine 1 .

[0062] More specifically, the machine 1 comprises at least one cutting unit 3, which is specifically arranged for cutting the sheets arranged on the table 2, said cutting unit 3 being not limited to a particular type. As an example, the cutting may take place by a blade, a laser, a water jet, a milling cutter or in any other suitable way, preferably by a blade.

[0063] According to the embodiment shown in the figures, the machine 1 comprises a single cutting unit 3, even though the invention is not limited thereto and the number of cutting units may vary according to needs and / or circumstances.

[0064] As previously mentioned, the machine 1 comprises at least one arm 4, at least partly arranged above (on top of) the table 2 and adapted to support a cutting unit 3, which can move on said arm 4, in particular slide along a longitudinal axis of said arm 4, said longitudinal axis being parallel to Figure 1 and Figure 2 Y-axis.

[0065] In particular, in one embodiment, the movement of the cutting unit 3 is allowed due to the presence of the frame 6, which can be translated along the longitudinal extension of the arm 4, i.e. along the Y axis, by means of a first guide G1 arranged on the face of the arm 4, for example on the lower surface of the arm 4 facing the workbench 2. In other words, the cutting unit 3 is supported by the frame 6, which acts as a support frame for the cutting unit 3.

[0066] In this way, according to the above embodiment, the movement system of the cutting unit 3 includes an arm 4 and a frame 6, which defines a kinematic structure for moving the cutting unit 3. As mentioned above, the frame 6 is preferably installed under the arm 4 (that is why it is also called the lower frame) and can be translated along the Y direction relative to the frame 6.

[0067] The arm 4 has a generally parallelepiped shape, with a general extension in the Y direction. As mentioned above, it comprises a first guide G1 suitable for allowing relative movement of the frame 6 mounted on the slide block 7. In an embodiment, the first guides G1 are two (even if the invention is not limited thereto), and two slide blocks 7 aligned with each other are inserted on the guides. The movement is obtained by a recirculating ball screw / nut screw system.

[0068] There are also provided power and signal cables connecting the various elements of the kinematic structure, said cables being housed in an anchor chain 8 extending parallel to the arm 4 and forming loops at two opposite ends, for example at Figure 2 Visible in.

[0069] Furthermore, a supporting device 9 is provided which is suitable for supporting the arm 4 on the workbench 2 .

[0070] Hereinafter, an embodiment will be shown in which, by means of the above-mentioned supporting device 9, the arm 4 is cantilever-supported and slides along the X direction. However, although preferred, such an embodiment is merely illustrative, and the teaching of the present invention (i.e., the safety measures described in detail below) is not limited to the specific supporting and sliding configuration of the arm 4.

[0071] Specifically, in the non-limiting exemplary embodiment of the figures, the arm 4 is cantilever-supported on the table 2 by means of the support device 9 and can move along the sliding direction X.

[0072] Suitably, the support means 9 of the arm 4 is in the form of a crosspiece (or lintel) support structure, still indicated by reference numeral 9, which is held suspended on the workbench 2 by at least one support element or column 9a. More specifically, in one embodiment, the support column 9a extends vertically from the workbench 2, in particular at an edge peripheral portion of said workbench 2. More specifically, the support column 9a is arranged at one of the secondary sides of the workbench 2, as will be described in detail below. In one embodiment, the crosspiece 9 is extruded aluminum, although other configurations are obviously possible and within the scope of the present invention.

[0073] In one embodiment, there are two supporting columns 9a arranged on two opposite sides of the workbench 2, that is, at opposite edges, in such a way that a supporting frame including the two columns and an upper crosspiece integral therewith is defined, in other words, the supporting columns 9a allow the supporting crosspiece 9 to remain hung on the workbench 2 and connect it to the workbench 2.

[0074] Obviously, the shape of the uprights 9a indicated by the vertical axis and protruding from the workbench 2 and the specific shape of the crosspiece 9 are merely exemplary and other suitable shapes may be used.

[0075] In the preferred embodiment shown in the accompanying drawings, the workbench 2 is essentially rectangular (or at least defines a working area having two main sides and two secondary sides), and the supporting columns 9a are arranged on the secondary sides of the workbench so that the two main sides are completely unrestricted, that is, no parts for supporting the arms 4 are provided at the sides, and the sides are the sides from which excess material protrudes, and the material is then dragged onto the workbench 2.

[0076] Thus, the support uprights 9a allow the holding crosspiece 9 to be suspended on the table 2, making it possible to form thereon guides which allow the connection and support of the cantilevered arm 4. In this way, it is no longer necessary to support the arm 4 with the aid of guides integrated on the table 2 (in particular arranged at the main sides of the table, instead of being present in known solutions). Thanks to this suspended crosspiece configuration, the table 2 thus protrudes freely along at least two of its parallel sides, in particular along its main sides, from which the excess material to be cut can protrude freely, without the need to use the means described in the prior art, such as forming housing supports.

[0077] In other words, the structure of the machine 1 has many advantages, especially for a rectangular table, since the main side has no curvature at all, so the excess material hangs freely on said side and can be easily dragged onto the plane when it is cut. It should also be noted that the side without curvature is the side that the operator works on, greatly simplifying the latter's work. Moreover, thanks to the presence of the hanging crosspiece 9, the operator can easily work on the two free sides of the table.

[0078] In an embodiment, in order to facilitate the work of the operator, the support column 9a is arranged closer to one end of the secondary side (i.e. the rear end according to the local reference system of the drawing) relative to the opposite end, so as to allow the primary side connected to said opposite end to be connected even more freely. In other words, relative to the longitudinal symmetry axis, parallel to the X axis, the support column 9a is moved more towards one of the two ends of the secondary side (not necessarily to this end), which is advantageous in the case where the crosspiece 9 also supports other components, such as a display screen and a projector, as will be described below, thereby leaving more space for the operator in this way.

[0079] Furthermore, as mentioned above and as Figure 3 As better shown in the figures, the arm 4 is constrained to a frame 10 which slides along at least one guide, preferably two guides (not shown in the figures), formed on the crosspiece 9, which allow sliding in the sliding direction X of the frame 10 and therefore of the arm 4 constrained thereto. In other words, the arm 4 is thus connected to the support means 9 via the frame 10, which allows movement of the arm 4 in the X direction.

[0080] As indicated for the rack 6, the rack 10 also comprises a slide block 11 and is associated with a guide by means of said slide block. In the preferred case of two guides, two slide blocks 11 aligned with each other are plugged onto the guide.

[0081] In an embodiment, the rack 10 is arranged below the crosspiece 9 , ie it is constrained to its face facing the table 2 and is therefore arranged between said crosspiece 9 and the arm 4 , the racks 6 and 10 being moved by suitable means controlled by the control unit C.

[0082] Management of the machine 1 by the user may take place, for example, through a control panel 12 equipped with a screen and buttons arranged, for example, at the periphery of the workbench and operatively connected to the control unit C.

[0083] In one embodiment, the machine 1, in particular the work table 2, is ideally divided into two working areas. In this way, while in a first area the sheet parts are cut by the cutting unit 3, in a second, continuous area the operator can collect the already cut material parts, said areas being alternated during the operation of the machine 1. Thus, it is possible to perform the cutting and unloading in time masking, i.e. in the masking time, with greater efficiency and productivity; this type of machine is also called a "commuter". This operation can be performed by a single cutting unit, which is appropriately controlled by the control unit C and moves from an area to a continuous area, as well as by two cutting units appropriately controlled by the control unit C.

[0084] Since the cutting unit 3 and the arm 4 supporting it are not enclosed in a closed cutting chamber, a machine 1 with suitable safety measures is required, also taking into account the fact that, as mentioned above, the collection of cut parts can take place simultaneously with the cutting operation in a continuous area of ​​the workbench 2.

[0085] refer to Figure 3 and Figure 4 , a first safety measure is to employ a photocell 13 suitable for detecting the presence of a user and therefore stopping the machine 1 if a dangerous situation is detected.

[0086] More specifically, the machine 1 comprises a plurality of photocells 13 at the two opposite ends 4a and 4b of the arm 4 and arranged to move integrally therewith, said photocells 13 being configured to detect the presence of an object between them.

[0087] The photocells 13 are arranged on a suitable support (e.g. a suitable rod) on which they define an array of photocells, in particular arranged on opposite sides of the table 2, i.e. a pair of arrays on opposite sides along the longitudinal direction Y of the arm 4, and connected (directly or indirectly) to said arm 4 so as to move therewith. In this way, each photocell arranged on one side of the table 2 has a corresponding photocell arranged on the opposite side and aligned therewith so as to appropriately receive / send optical signals 13' for detecting an object, such as Figure 3 and Figure 4 as shown in .

[0088] Suitably, the array of photocells extends vertically (i.e. the photocells are arranged at least along a vertical direction substantially orthogonal to the table 2, and therefore substantially orthogonal to the Y and X directions) so as to cover at least the entire vertical overall extent of the system formed by the cutting unit 3 and the arm 4, unlike what happens in known solutions using a single photocell per side. In other words, the photocells extend in a vertical plane perpendicular to the table 2, thereby defining a predetermined vertical area in which objects can be detected by light signals.

[0089] In a preferred embodiment of the present invention, there are two arrays of photocells 13 on one side of the workbench 2 and two arrays of photocells 13 on the opposite side, and the arrays on each side are arranged in relative positions relative to the arm 4 so as to provide protection for the movement of the arm 4 in both directions along the X direction.

[0090] Suitably, the photocell 13 is operatively connected to a control unit C, which is programmed to automatically control the movement of the arm 4 and the actuation of the cutting unit 3 according to the signal from the photocell. In particular, upon detecting the presence of an operator (e.g. the presence of the operator's hand), the photocell sends a signal to the control unit C, which is suitably configured to stop the operation of the machine 1.

[0091] Therefore, in its more general form, a cutting machine is provided, which comprises a workbench 2, a cutting unit 3 suitable for cutting a sheet arranged on the workbench 2, an arm 4 arranged at least partially above the workbench 2 and a support device 9 for the arm, the machine being equipped with the above-mentioned photocell 13 in order to provide safety to the operator.

[0092] In any case, the mere presence of a photovoltaic cell (although a very important safety element) does not always ensure total safety for the operator, and there is also a need to reduce the risks resulting from collisions with the support of the photovoltaic cell itself.

[0093] Advantageously, according to the invention, in order to equip the machine 1 with other effective safety measures, it also comprises a protective screen 18 associated with the machine 1 close to at least one end 4 a and / or 4 b of the arm 4 .

[0094] This safety system may have its own dedicated support or, preferably, it is directly connected to the arm 4 , in particular at the end of said arm 4 , thus acting as a support.

[0095] Preferably, there are two protection screens 18, each arranged at a respective end of the arm 4, i.e. opposite in the Y direction at opposite sides of the workbench 2, and therefore the following description will hereinafter refer to the preferred but non-limiting case of two opposite protection screens 18.

[0096] In an embodiment of the invention, the protective screen 18 is substantially rectangular, even though other shapes may obviously be used. In its more general form, the protective screen 18 comprises a lower side, an upper side and at least two sides opposite each other with respect to the sliding direction.

[0097] Furthermore, the protective screen 18 may be made of any suitable material, including metal materials and plastic materials.

[0098] The protective screen 18 has a body 18' which is cantilevered, in particular projects downwardly relative to its support, and is configured to at least partially cover the cutting unit 3 when viewed in the Y direction, ie when viewed from the front, so as to avoid direct contact between the cutting unit and the operator.

[0099] In particular, the protective screen 18, more particularly the body 18', extends in a vertical plane at the front part of the machine 1 for protecting an operator operating at the main side of the workbench 2, i.e. connected to the front part of the arm 4, more particularly, the protective screen 18 extends substantially orthogonally to the workbench 2 at its main side.

[0100] In order to allow the correct arrangement of the material on the workbench 2, a protective screen 18 is associated with the machine 1 so as to leave an empty space G' between itself and the edge of the workbench 2, as shown in FIG. Figure 2 As shown, in addition, the protective screen 18 extends below the working surface a of the workbench 2 in order to prevent dangerous situations for the user. In other words, the protective screen 18 extends from the arm 4 beyond the working surface a of the workbench 2. As will be noted below, the protective screen 18 also serves as a housing for the photocell 13, and its extension relative to the working surface a allows the photocell 13 to be properly covered.

[0101] As mentioned above, in a preferred embodiment of the invention, the protective screen 18 is directly associated with (particularly connected to) the end of the arm 4 .

[0102] More specifically, in an embodiment, the arm 4 comprises at its end a connection protrusion 4p connected to the protective screen 18. Obviously, the arm 4 may also not comprise the connection protrusion 4p, and for the purposes of the present invention, the longitudinal extension of the arm 4 (i.e. along the Y axis) is overall, for example, greater than the corresponding extension of the workbench 2, so as to protrude and leave a space between the protective screen 18 and the workbench 2 (as previously shown), and prevent the protective screen 18 from hitting the workbench 2. In any case, the actual longitudinal extension of the arm 4 is not a limiting feature of the present invention.

[0103] Suitably, the protective screen 18 is hinged to the arm 4 at a hinge point P so as to be tilted relative to the arm 4 about the hinge point P. In an embodiment, the hinge point P is located at the end of the protective screen 18 (specifically the upper end of the screen), and the opposite end extends beyond (below) the working surface a, as described above, even though the specific position of the hinge point is not a limiting feature of the present invention.

[0104] In this way, the protective screen 18 is adapted to move in translation along the sliding direction X, due to the movement of the arm 4, when no obstacle is encountered. Advantageously, when sliding along the X direction, the protective screen 18 is also able to perform a rotational movement relative to the hinge point P, when it moves against an obstacle, for example when a user is bumped. The protective screen 18 is thus able to perform a relative movement relative to the arm 4, said movement being in this case a partial rotational movement, such as Figure 5A-5B , 6A-6B and Figure 7 in which the axis of rotation is substantially parallel to the Y axis and therefore to the longitudinal axis of the arm 4; in other words, the hinge point P is located on an axis coinciding with the Y axis or at least parallel to the Y axis and about which the protective screen 18 performs the above-mentioned pivoting movement.

[0105] Therefore, since the protective screen 18 is not fixedly constrained to the arm 4, but is inclined, when it hits an obstacle (such as an operator), it tends to rotate relative to the hinge point P, which rotation reduces the impact effect and further causes the cessation of the operation of the machine 1, as will be shown below.

[0106] In particular, the protective screen 18 provides protection for the lower part of the screen, ie the part closest to the workbench 2 and therefore furthest from the arm 4, from impacts which would result in a pivoting movement of the screen as described above.

[0107] In order to protect the operator from collisions also on the relatively upper part of the protective screen 18, ie the part closest to the arm 4, in an embodiment of the present invention, the protective screen 18 is provided with an additional protective element 23 connected thereto. Fig. 8A and 8B Shown in.

[0108] The additional protection element 23 includes an elongated body 23' (not limited to a specific shape) connected to the protection screen 18. Preferably, two additional protection elements 23 are connected to the protection screen 18 so as to be arranged along two opposite sides of the protection screen 18 (i.e., on the left and right sides as viewed from the front position of the protection screen 18). In other words, for the protection screen 18, there are two additional protection elements 23, which are arranged along the side opposite to the sliding direction X.

[0109] In one embodiment, the additional protective element 23 extends at least over the entire length of the vertical side of the protective screen 18 and is constrained at its end to the screen, in particular to the lower part of the screen, while the opposite end of the additional protective element remains free. Obviously, this embodiment is not intended to limit the invention and other configurations are possible.

[0110] As mentioned above, the connection point between the protective screen 18 and the additional protective element 23 can be located, for example, at the lower end of the protective screen 18, i.e., the part farthest from the arm 4, so as to allow the relative rotation described in detail below. In any case, the specific shape and the specific connection mode and position of the additional protective element 23 are not intended to limit the scope of the present invention, and other suitable configurations are also possible.

[0111] Suitably, the additional protective element 23 is not fixedly constrained to the protective screen 18 but is hinged and can perform a partial rotation towards / away from the protective screen 18 until it contacts the protective screen 18. In particular, the additional protective element 23 is able to perform a pivoting movement in which its free end (i.e. the non-hinged end) moves over the protective screen 18.

[0112] In other words, advantageously, according to the above embodiment, a collision with the upper part of the protective screen 18 is absorbed by the additional protective element 23 which is suitable for performing a pivoting movement towards the protective screen 18 , in particular in the upper part opposite the hinge point of said protective screen 18 .

[0113] In an embodiment, the protective screen 18 acts as a support for the array of photocells 13, which therefore moves integrally with said protective screen 18. Thus, the operation of the machine 1 is stopped based on a rotational movement of the protective screen 18, since said rotational movement causes a loss of alignment between the photocells 13 relative to the longitudinal axis of the arm and arranged on opposite screens, with the subsequent generation of a stop signal from the control unit C. Obviously, even other methods of generating a stop signal are possible, such as for example the presence of a sensor S operatively connected to the control unit C, which is configured to detect the relative rotation of the protective screen 18 with respect to the arm 4 and to generate a signal to the control unit upon detection of said relative movement, said signal stopping the operation of the machine.

[0114] More specifically, four additional protection elements 23 are provided (two for each opposing screen) and the photocells 13 are accommodated on said additional protection elements 23, which perform collision and pivoting movements resulting in misalignment between the photocells arranged on opposite sides of the workbench 2 (or they cause triggering of the sensors S as described above).

[0115] In other embodiments, the stopping of the operation of the machine 1 is caused by the pressure of a safety switch caused by the additional protection element 23 during the rotation, said switch being pressed between the body of the additional protection element 23 and the body of the protective screen 18. Obviously, the specific stopping mode of the operation of the machine 1 does not limit the scope of the invention and other modes are possible, the important thing being that said stopping occurs due to a collision and therefore due to the rotation of the protective screen 18 and / or the movement of the additional protection element 23. In yet another embodiment, the presence of an element protruding from the screen or the additional protection element can be provided and configured to block (cover) at least one ray of the photocell 13 during the movement of the screen and / or the additional protection element, thus causing the stopping of the machine; in the latter case, the photocell is not integral with the screen (but for example with the arm 4).

[0116] Operator safety is therefore provided by the combination of the protective screen 18 and the additional protective element 23 .

[0117] In fact, if said additional protective element 23 were not present, a possible collision with the upper part of the screen 18 would cause harm to the operator, since the pivoting movement of said protective screen 18 about the articulation point with the arm 4 would not be properly triggered. Therefore, according to the invention, if a collision with an operator occurs at the upper part of the protective screen 18, the additional protective element 23, which is preferably articulated at the opposite lower part, rotates and causes an emergency stop of the machine 1.

[0118] If a possible collision with an operator occurs in the lower part of the protective screen 18, the entire inclined protective screen 18 rotates and causes an emergency stop of the machine 1, and in this case the additional protective element 23 rotates integrally with the protective screen 18. Thus, depending on the height at which the collision occurs, one or the other protection intervenes, or even both.

[0119] In other words, in the event of a collision occurring near the hinge point P, the influence of the relative movement of the additional protection element 23 is dominant, whereas the effect of the rotation of the protection screen 18 becomes dominant by moving away from the hinge point P toward the opposite end.

[0120] Therefore, it is obvious that the above measures ensure extreme safety for the operator.

[0121] In this way, there are safety measures aimed at covering any possible dangerous situation. In fact, in summary, it is worth protecting the user from three main sources of danger:

[0122] a) colliding with the lower part of the protection screen 18;

[0123] b) colliding with the upper part of the protection screen 18;

[0124] c) Collision with the sliding arm 4.

[0125] With respect to a), the rotational movement of the protection screen 18 provides the desired protection.

[0126] As for b), protection is provided by an additional protective element 23 (which easily performs a pivoting movement because it is hinged at the lower part of the screen) which sets the machine in an emergency by rotating it. This system is very easy and light and is independent of the movement of the protective screen 18.

[0127] As for c), suitably, according to the invention, the protection is given by a photocell 13. In practice, said photocell is supported by a protective screen 18, the arm 4 being arranged in a substantially central position relative to the body of said protective screen 18, so that when the photocell is covered, the machine 1 stops before the arm 4 can touch the operator.

[0128] In the implementation scheme, Fig. 9 and Fig.10 As shown, the protective screen 18 is connected to the arm 4 via a pin element 19 (e.g. protruding from the face of the body 18' of the screen), the pin element 19 being received in a suitable seat 19' (e.g. formed on a portion 4p protruding from the end of the arm 4 or formed directly in the body of the arm 4 and having a shape complementary to the pin), the connection being sufficient to ensure the desired effect.

[0129] From the above, it is clear that in a preferred embodiment of the invention, a safety system is provided, which comprises a protective screen 18 articulated with the arm, an additional protective element 23 supporting the photocell 13, thereby essentially forming a unique safety element with multiple functions. However, other configurations are also possible, in which the various elements can be separated from each other; for example, as described above, the photocell can be provided with its own support fastened directly to the arm 4 (it is important that the photocell 13 is arranged vertically to cover at least an area corresponding to the total size of the arm 4, the cutting unit 3 and the frame 10), and the protective screen 18 can be associated with the machine 1 in other ways.

[0130] It should also be noted that in an embodiment, the additional protective element 23 may be connected to the protective screen 18 so as to be able to translate relative to said screen (for example, it may have an elongated body mounted on guides connecting it to the screen), in which case a collision with the user causes a translation of the additional protective element 23. Obviously, all considerations for pivoting movement also apply exactly to translational movement.

[0131] In any case, a return element is provided, connected to the protective screen 18 and the additional protective element 23 (such as a spring or a piston), which is configured to return said additional protective element 23 to the rest position after a collision and thus after a translational or rotational movement.

[0132] Furthermore, in an embodiment of the invention, an elastomeric protection element 20 is provided, which is also referred to in the art by the term "buffer stop" (which is essentially a compressible rubber protection piece), and which covers the arm 4 at the top. In this way, the elastomeric protection element 20 arranged above the arm 4 acts as a covering element, thereby preventing the operator from coming into contact with the cutting device also at the upper part of the arm 4, for example by sliding his hand from above, and also absorbing any impacts.

[0133] In an embodiment, the elastomeric protective element 20 is in the form of a covering extending in the sliding direction by an extension substantially equal to the extension of the protective screen 18 (e.g. so as to be in line with the photovoltaic cell), and extending in a transverse direction thereof to cover the space between two opposing protective screens. The elastomeric protective element 20 is arranged on the arm 4 (e.g. in direct contact therewith) so as to wrap the shelf 10. In any case, any suitable mode of association is included within the scope of the invention.

[0134] If the operator's body is arranged so as not to hit the protective screen 18, then when the arm of the machine approaches, as a first thing, the rays of the photocell 13 intervene, and then in the upper part, the operator comes into contact with the buffer stop, thereby absorbing the collision. In any case, before the maximum compression of the buffer stop, the machine will be completely stopped.

[0135] In another embodiment, the covering of the arm 4 is not formed completely by the elastomeric protective element 20, but is formed, for example, by a simple covering (e.g. metal) fixed to the arm 4, on the edge of which the elastomeric protective element 20 is arranged. In this way, the elastomeric protective element 20 is kept at a distance from the arm 4 by the covering (which is connected to the upper side of the arm 4) and represents a partial covering element, which is still able to absorb collisions with an operator.

[0136] In an embodiment, an elastic protective element 20 is also provided on the edge of the additional protective element 23, thereby ensuring further protection of the operator.

[0137] Finally, the machine 1 is equipped with a control monitor 21, a projector 22, a camera and lights, said components being advantageously supported by the suspension crosspiece 9, without requiring the use of other supports.

[0138] In summary, the invention provides a cutting machine equipped with a protective screen close to the end of a movable arm, said screen being shaped so as to avoid direct contact between the operator and the cutting unit. The protective screen is capable of translation as one with the arm and of inclination relative to the arm, so that when it collides with an obstacle, in particular when its lower part, which is furthest from the arm, collides with an obstacle, it can rotate about the axis of articulation, thus absorbing the collision and allowing the control unit to stop the operation of the machine punctually and in complete safety. A collision with the upper end of the screen, i.e. closer to the articulation point, is absorbed by an additional protective element, which is for example articulated with the lower end of the screen and is capable of performing a pivoting movement towards the edge of the screen, said movement actuating a safety stop. The machine of the invention is also equipped with other safety systems, such as a photocell, making the cutting machine described here very safe.

[0139] Advantageously, there is a significantly increased safety for the operator, since every possible risk factor related to the structure and operation of the cutting table (i.e. a cutting machine not equipped with a closed cutting chamber) is eliminated, or at least significantly reduced. In fact, according to the known solutions, there is only one photocell to stop the operation of the machine once the presence of a user is detected, for example the presence of the operator's hand near the cutting unit. On the contrary, suitably, according to the invention, in addition to the safety provided by the photocell (which provides greater protection by covering a vertical space greater than the known solutions), there is provided the above-mentioned safety system, which includes a tilting screen (thus providing additional safety with respect to the only photocell), preventing accidents to the operator by contact with the support of the photocell itself, which is mounted on the tilting screen, in particular on the additional protection element, and which is subjected to said relative movement in the event of a collision. In fact, it should be noted that if the photocell can prevent contact with the cutting head at least to a certain extent, in addition to the increased safety provided by the only photocell, the safety system described herein alone can reduce the effects of a collision with the photocell itself.

[0140] Suitably, the relative rotation of the protection screen during a collision is combined with pivoting of the additional protection element, thereby preventing contact with said screen leading to accidents for the operator.

[0141] All these measures make the machine much safer with respect to known solutions, thus making it particularly suitable for obtaining all the main safety certifications, such as TUV certification.

[0142] It is therefore clear that the machine of the invention solves the technical problem appropriately without overcomplicating its mechanical structure. In fact, the user obtains complete safety thanks to a simple, light, easy to install and economical structure.

[0143] Obviously, those skilled in the art may make several changes and modifications to the above-mentioned cutting machine in order to meet specific needs and specifications, all of which are included in the protection scope of the present invention as defined in the attached claims.

Claims

1. A machine (1) for cutting sheet material, comprising: - a work table (2) suitable for providing a support surface for the sheet of material to be cut; - at least one cutting unit (3) suitable for cutting the sheets arranged on the workbench (2); - at least one arm (4) arranged at least partially above the table (2) and suitable for supporting the cutting unit (3); - a supporting device (9) of the arm (4), supported so as to be movable along a sliding direction X; as well as - at least one protective screen (18) connected to said arm (4), said protective screen (18) being adapted to translate along said sliding direction X as a result of the movement of said arm (4), The machine (1) is characterized in that the protective screen (18) is articulated at an articulation point (P) so as to be tilted relative to the arm (4), the protective screen (18) being adapted to perform at least a partial rotation relative to the articulation point (P), The machine further comprises a control unit (C) configured to stop the movement of the arm (4) based on the rotational movement of the protection screen (18).

2. The machine (1) as claimed in claim 1, wherein: The protective screen (18) has a main body (18') configured to at least partially cover the cutting unit (3) at least when viewed from a direction Y substantially orthogonal to the sliding direction X.

3. The machine (1) according to claim 1, wherein: The protective screen (18) is directly connected to the arm (4).

4. The machine (1) according to claim 1, wherein: The protective screen (18) is arranged at the end of the arm (4).

5. Machine (1) according to claim 4, wherein said end of said arm (4) comprises a connecting protrusion (4p) articulated to said protective screen (18).

6. The machine (1) according to claim 1, comprising two protection screens (18) arranged on opposite sides of said table (2) along a direction Y substantially orthogonal to said sliding direction X.

7. The machine (1) as claimed in claim 1 comprises at least one pair of arrays of photocells (13) configured to move integrally with the arm (4), the arrays of photocells (13) being arranged at least along a vertical direction substantially orthogonal to the workbench (2) and configured to detect the presence of an object between them.

8. Machine (1) according to claim 7, wherein at least one of said arrays of photocells (13) is arranged on said protective screen (18) and is adapted to move integrally with said protective screen (18).

9. The machine (1) according to claim 8, wherein: The control unit (C) is configured to stop the operation of the machine (1) when there is no alignment between the opposing arrays of photocells (13) due to the rotation of the protection screen (18) about the hinge point (P).

10. The machine (1) according to claim 9, wherein: The control unit (C) is configured to stop the operation of the machine (1) when there is no alignment between the opposing arrays of photocells (13) due to rotation of the protection screen (18) about the hinge point (P), as a result of a collision with an operator.

11. The machine (1) as claimed in claim 8, comprising a control unit (C) configured to stop the movement of the arm (4) based on the rotational movement of the protective screen (18), and further comprising a sensor (S) operably connected to the control unit and configured to detect the rotation of the protective screen (18), wherein the control unit (C) is configured to stop the operation of the machine (1) when the sensor (S) detects the rotation of the protective screen (18).

12. The machine (1) according to claim 1, comprising an additional protective element (23) connected to the protective screen (18), the additional protective element (23) being configured to perform a relative movement towards / away from the protective screen (18).

13. The machine (1) according to claim 12, wherein: The additional protection element (23) is hinged to the protection screen (18) and is configured to perform a pivoting movement towards / away from the protection screen (18).

14. A machine (1) as claimed in claim 13, wherein the additional protective element (23) extends along an edge side portion of the protective screen (18) and includes at least one free end configured to perform the pivoting movement, and wherein the protective screen (18) and the additional protective element (23) are connected to each other and configured so that the rotational movement of one of the protective screen (18) and the additional protective element (23) is triggered based on the position where the collision occurs.

15. The machine (1) as claimed in claim 11, comprising a control unit (C) configured to stop the movement of the arm (4) based on the rotational movement of the protection screen (18), and further comprising two protection screens (18) arranged on opposite sides of the workbench (2) along a direction Y substantially orthogonal to the sliding direction X, wherein the array of photocells (13) is arranged on an additional protection element (23) connected to the screen opposite to the longitudinal axis of the arm (4), the array of photocells (13) being suitable for moving integrally with the additional protection element (23), the control unit (C) being configured to stop the operation of the machine (1) when there is no alignment between the relative arrays of the photocells (13) due to the movement of one of the additional protection elements (23).

16. The machine (1) as claimed in claim 1, comprising an elastomeric protective element (20) configured to at least partially cover the arm (4).

17. Machine (1) according to claim 1, wherein said protective screen (18) is connected to said arm (4) by means of a pin element (19) received in a suitable seat (19') at said arm (4).

18. A machine (1) as claimed in claim 1, wherein the supporting device (9) of the arm (4) is in the form of a cross-bar supporting structure, which is kept suspended above the workbench (2) by at least one supporting column (9a) extending from the workbench (2), wherein the workbench (2) is a fixed plane and does not hinder at least two parallel sides of a larger extension, and wherein the arm (4) is supported on the workbench (2) by the cross-bar cantilever.

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