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Title:
CUTTING MACHINE HAVING AN IMPROVED STRUCTURE
Document Type and Number:
WIPO Patent Application WO/2021/165720
Kind Code:
A1
Abstract:
A machine (1) is herein described for cutting sheet material comprising a worktable (2), for instance a fixed plane, that is adapted to provide a support plane for a sheet of material to be cut, said worktable (2) having at least two opposite sides of greater extension and at least two opposite sides of minor extension, at least one cutting unit (3) adapted to cut the sheet arranged on the worktable (2), at least one arm (4) that is arranged at least partially above the worktable (2) and is adapted to support the cutting unit (3) and support means (9) of the arm (4), which is supported cantilevered on the worktable (2) and is movable along a sliding direction (X). Suitably, the support means (9) of the arm (4) are in the form of a crosspiece support structure kept hanging over the worktable (2) by at least one support upright (9a), said worktable (2) being free of encumbrances along at least two opposite sides of greater extension thereof.

Inventors:
CORSICO PICCOLINO ALESSANDRO (IT)
Application Number:
PCT/IB2020/051338
Publication Date:
August 26, 2021
Filing Date:
February 18, 2020
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
COMELZ SPA (IT)
International Classes:
B26D5/02; B26F1/38; B26F3/00
Domestic Patent References:
WO2012120394A12012-09-13
WO2010145724A12010-12-23
Foreign References:
US6293677B12001-09-25
US20120085212A12012-04-12
Attorney, Agent or Firm:
BOTTI, Mario et al. (IT)
Download PDF:
Claims:
CLAIMS

1. Machine (1) for cutting sheet material, comprising:

- a worktable (2) adapted to provide a support plane for a sheet of material to be cut;

- at least one cutting unit (3) adapted to cut the sheet arranged on the worktable (2);

- at least one arm (4) that is arranged at least partially above the worktable (2) and is adapted to support the cutting unit (3); and

- support means (9) of the arm (4), which is cantilever supported over the worktable (2) and is movable along a sliding direction (X), wherein the support means (9) of the arm (4) are in the form of a crosspiece-support structure kept hanging over the worktable (2) by at least one support upright (9a), said worktable (2) being free of encumbrances along at least two opposite sides thereof.

2. Machine (1) according to claim 1, wherein the worktable (2) comprises at least two opposite sides of greater extension and at least two opposite sides of minor extension, said worktable (2) being free of encumbrances along at least the two opposite sides of greater extension thereof.

3. Machine (1) according to claim 2, wherein said at least one support upright (9a) extends vertically from the worktable (2) at one of the sides of minor extension of said worktable (2).

4. Machine (1) according to any one of the previous claims, wherein said support upright (9a) extends from a peripheral portion of the worktable (2) .

5. Machine (1) according to any one of the previous claims, comprising two support uprights (9a), arranged at respective opposite sides of the worktable (2), defining in this way a support gantry comprising said uprights (9) and said crosspiece (9) integral thereto, from which the arm (4) projects cantilevered over said worktable (2).

6. Machine (1) according to claims 2 and 5, wherein said respective opposite sides are the sides of minor extension of the worktable (2).

7. Machine (1) according to any one of the previous claims, wherein the arm (4) is constrained to a carriage (10) that is sliding along at least one guide formed on the crosspiece support structure (9), said guide being configured to allow the sliding in the sliding direction (X) of said carriage (10) and of said arm (4) constrained thereto.

8. Machine (1) according to any one of the previous claims, further comprising a carriage (6) that is translatable along the longitudinal extension (Y) of the arm (4) by means of at least one guide (Gl), preferably two guides (Gl), arranged on a face of said arm (4), the cutting unit (3) being supported by said carriage (6).

9. Machine (1) according to any one of the previous claims, comprising at least one of a control monitor (21), a projector (22), cameras and light elements, said components being supported by the hanging crosspiece support structure (9).

10. Machine (1) according to any one of the previous claims, comprising at least one pair of arrays of photocells (13) arranged at opposite ends (4a, 4b) of the arm (4) and arranged so as to move integrally therewith, the photocells (13) in each of said arrays being arranged at least along a vertical direction that is substantially orthogonal to the worktable (2) and being configured to detect the presence of an object therebetween.

11. Machine (1) according to any one of the previous claims, further comprising at least one protective screen (18) associated therewith close to at least one end (4a, 4b) of the arm (4), said protective screen (18) extending cantilevered from a support thereof and having a body (18’) configured to cover at least partially the cutting unit (3) at least when observed from a direction (Y) that is substantially orthogonal to the sliding direction (X).

12. Machine (1) according to claim 11, wherein the protective screen (18) is hinged to the arm (4) at a hinging point (P) so as to be tilting with respect to said arm (4), said protective screen (18) being configured to be translated in the sliding direction (X) due to the movement of the arm (4), and being also configured to perform at least a partial rotation with respect to the hinging point (P), the movement of said arm (4) being stopped based on the rotational movement of said protective screen (18).

13. Machine (1) according to any one of the previous claims, wherein said worktable (2) is a fixed plane.

14. Machine (1) according to any one of the previous claims, wherein said worktable (2) is substantially rectangular- shaped.

15. Machine (1) according to claim 14, wherein the sliding direction (X) of the arm (4) is substantially parallel to the sides of greater extension of the worktable (2).

Description:
Title: Cutting machine having an improved structure

DESCRIPTION

Field of application

The present invention relates to a cutting machine, for instance for cutting hides, leather, synthetic materials and the like, and the following description is made with reference to this application field with the only purpose of simplifying the exposition thereof.

Prior art

As it is well known in this specific technical field, there are various apparatuses capable of performing the automated cutting of sheets of material according to a pre-set cutting pattern, the material to be cut being for instance hide, a fabric, a non-woven fabric, a synthetic material and the like. The types of sheet material to be cut are indeed the most varied, even in the same technical field. The clothing, accessory and footwear industries all use for instance multiple materials such as hide, non-woven fabrics, synthetic materials. These materials, while having evident differences in their manufacture and consistency, nevertheless have the common denominator of being in sheets and of being subjected to cutting operations.

There are machines equipped with a conveyor belt capable of moving the sheet to be cut inside a cutting chamber, which is generally closed at the top and laterally on at least two sides, said cutting chamber being equipped with at least one movable cutting unit for cutting the sheet, whereas the cut portions are conveyed by the conveyor belt out of the cutting chamber towards an unloading area.

There are also simpler machines, the so-called cutting tables or benches, which do not have a closed cutting chamber (and possibly do not have a conveyor belt that feeds the sheet) but only a worktable (possibly a fixed one) whereon the material to be cut is arranged. According to some known solutions, on the opposite major sides of the cutting table, respective rails are arranged for the sliding of carriages that move at least one crosspiece or arm extended transversely, which supports a movable cutting unit to cut the sheet arranged on the worktable. Once the cutting has been performed, the arm is moved in order to clear the work area and the operator can collect the cut portions, possibly while the cutting head cuts the sheet at another area of the worktable.

The aforementioned machines are very flexible and easily allow cutting samples and small productions of hides, synthetic materials and fabrics of all kinds.

However, a first problem of the above machines is linked to the arrangement of the material to be cut on the worktable, said material generally having dimensions that are greater than the worktable, so that there is always exceeding material that initially cannot be arranged on said worktable. In other words, the overall dimensions of the guides and of the carriages for moving the arm do not allow an easy arrangement of the exceeding material. In some known solutions, only one guide system is used, which supports the arm at the second major side of the worktable that is opposite the first side at which the operator acts; however, in this solution there is the need to create, at said second side, a cradle that forms the suitable seat for receiving the material to be cut that is wound in a roll, which the operator may unwind from time to time. Such a solution considerably complicates the structure of the machine and the positioning of the sheet, since the structure of the worktable must be suitably shaped so as to form said cradle, where the material roll is arranged. Moreover, the arrangement of the material into the cradle is difficult since it implies the rolling up of said material and the insertion thereof into the cradle, which is distant from the work area.

Other even more widespread solutions have guides that allow the arm to slide on both major sides of the worktable and provide forming, in addition to the above cradle, a slot at the side opposite that of the cradle into which the exceeding material is inserted, thus making the positioning operation even more complicated. Furthermore, the presence of the slot and of the further guide move the operator away from the machine, so that the operator does not work easily.

There are solutions where the guides are arranged on the minor sides of the table, so that the arm slides along these minor sides; however, the presence of the guides along the sides is an encumbrance for the operator, said machines requiring in any case advanced safety systems, as illustrated in the following paragraph.

Another problem is due to the safety of these machines because, since there is no cutting chamber enclosing the cutting units and the movable arm, a contact with these cutting units or with the moving arm supporting them is much more likely, with very dangerous consequences for operators. For this reason, there is the need to adopt additional safety measures. The technical problem of the present invention is to provide a cutting machine having structural and functional features so as to allow overcoming the above-mentioned limitations and drawbacks, which still affect the known solutions, in particular capable of reducing the encumbrances on the worktable, thus facilitating the arrangement of the sheet to be cut and the operator’s work.

Another object is to increase safety for the operators.

Summary of the invention

The solution idea at the basis of the present invention is to make a cutting machine, for instance a cutting bench including a worktable, in which an arm that supports the cutting unit is kept cantilevered on the worktable by a hanging-crosspiece support structure, said hanging crosspiece comprising the guides that allow the arm to slide, for instance arranged on a lower face thereof. The hanging crosspiece is only supported by support uprights arranged on the minor sides of the worktable, for instance having a vertical extension starting from the surface of the worktable, so as not to have encumbrances on said worktable, in particular on the major sides thereof. The cutting machine is further equipped with safety systems which make it extremely safe.

Based on this solution idea, the above technical problem is solved by a machine for cutting sheet material comprising a worktable adapted to provide a support plane for a sheet of material to be cut, at least one cutting unit adapted to cut the sheet arranged on the worktable, at least one arm that is arranged at least partially above the worktable and is adapted to support the cutting unit, and supporting means of the arm, which is cantilever supported on the worktable and is movable along a sliding direction, wherein the support means of the arm are in the form of a crosspiece support structure kept hanging over the worktable by at least one support upright, said worktable being free of encumbrances along at least two opposite sides thereof. In particular, the sides not comprising the uprights are completely free of encumbrances. In the preferred embodiment in which the table is rectangular, it is preferable for the sides free of encumbrances to be the major sides.

More particularly, the invention comprises the following additional and optional features, taken individually or in combination if needed.

According to an aspect of the present invention, the worktable may comprise at least two opposite sides of greater extension and at least two opposite sides of minor extension (preferably it is rectangular), said worktable being free of encumbrances along at least the two opposite sides of greater extension thereof.

According to an aspect of the present invention, the at least one support upright may extend vertically from the worktable at one of the sides of minor extension of said worktable. In particular, the at least one support upright may extend from a peripheral portion of the worktable.

According to an aspect of the present invention, the machine may comprise two support uprights, arranged at respective opposite sides of the worktable (in particular at the minor sides), defining in this way a support gantry comprising said uprights and the crosspiece integral thereto, from which the arm projects cantilevered over the worktable.

According to an aspect of the present invention, the arm may be constrained to a sliding carriage along at least one guide formed on the crosspiece, for instance on a lower face thereof facing the worktable, said guide being configured to allow the sliding in the sliding direction of said carriage and of said arm constrained thereto.

According to an aspect of the present invention, the machine may further comprise a carriage that is translatable along the longitudinal extension of the arm by means of at least one guide, preferably two guides, arranged on one face of said arm, the cutting unit being supported by said carriage.

According to another aspect of the present invention, the machine may comprise at least one of a control monitor, a projector, cameras and light elements, said components being supported by the hanging-crosspiece support structure.

According to another aspect of the present invention, the machine may comprise at least one pair of arrays of photocells arranged at opposite ends of the arm and arranged so as to move integrally therewith, the photocells in each of said arrays being preferably arranged at least along a vertical direction that is substantially orthogonal to the worktable and being configured to detect the presence of an object therebetween. Even other orientations of the photocells are anyway provided by the present invention.

According to another aspect of the present invention, the machine may further comprise at least one protective screen associated therewith close to at least one end of the arm, said protective screen extending cantilevered from a support thereof on the machine and having a body that is configured to cover at least partially the cutting unit, at least when observed from a direction that is substantially orthogonal to the sliding direction.

Still according to another aspect of the present invention, the protective screen may be hinged to the arm at a hinging point so as to be tilting with respect to said arm, said protective screen being configured to be translated in the sliding direction due to the movement of the arm, and being also configured to perform an at least partial rotation with respect to the hinging point, for instance when it hits an obstacle, the movement of arm being stopped based on the rotational movement of the protective screen.

Still according to another aspect of the present invention, the worktable may be a fixed plane.

Furthermore, the worktable may be substantially rectangular- shaped. Finally, there is to say that the sliding movement of the arm may preferably occur along the sides of greater extension of the worktable, i.e. the sliding direction is substantially parallel to said sides, but other configurations are any way possible.

The features and advantages of the cutting machine according to 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.

Brief description of the drawings

In those drawings:

- figure 1 shows a schematic perspective view of a cutting machine according to the present invention;

- figure 2 shows a schematic side view of the cutting machine according to the present invention;

- figure 3 shows a detail of the cutting machine of the present invention, in particular a detail the safety elements thereof;

- figure 4 shows a schematic perspective view of the cutting machine according to the present invention, with highlighted the optical light signals of the photocells associated therewith;

- figures 5A-5B show a front protective screen of the safety system of the present invention in two different rotation configurations;

- figures 6A-6B show a rear protective screen of the safety system of the present invention in two different rotation configurations;

- figure 7 shows a schematic perspective view of the cutting machine according to the present invention, with the protective screen in a rotated configuration due to a collision with an operator;

- figures 8A-8B show the protective screen of the present invention connected to an additional protection element that performs a pivoting movement;

- figure 9 shows a top view of a portion of the machine according to the present invention, with the protective screen visible; and

- figure 10 shows sectional details of the protective screen and of the connections thereof to an arm of the machine according to the present invention.

Detailed description

With reference to those figures, and in particular to figure 1, a cutting machine according to the present invention is globally and schematically indicated with the reference number 1.

It is worth noting that the figures represent schematic views and are not drawn to scale, but instead they are drawn so as to emphasize the important features of the invention. Moreover, in the figures, the different elements are depicted in a schematic manner, their shape varying depending on the application desired. It is also noted that in the figures the same reference numbers refer to elements that are identical in shape or function. Finally, particular features described in relation to an embodiment illustrated in a figure are also applicable to the other embodiments illustrated in the other figures.

The positional references used in the present description, comprising indications such as lower or upper, above or below, or similar phrases, are referred to the operating configuration shown in the figures, and in no case should they be assigned a limiting meaning. In any case, said references, when referred to the components of the machine of the present invention, are used in practice by a skilled person.

To facilitate the following description of the machine 1, as illustrated in figure 1, two orthogonal directions corresponding to orthogonal movements of a cutting unit of the machine 1 are identified by way of example: a Y direction and a X direction. In particular, as it will be illustrated in greater detail hereinafter, the X direction is also indicated as sliding direction of an arm of the machine 1.

In its most general form, the machine 1 is adapted to process, and in particular is adapted to automatically cut, hides, leather, synthetic materials and the like. Still more particularly, the machine 1 is adapted to automatically cut sheets of foldable or flexible material, for instance fabrics for clothing and hide goods, footwear items, automotive and furnishing articles, or non-woven fabrics, hides, synthetic materials and the like.

In the context of the present invention, the term “sheet” indicates any element of any shape and material, having a substantially two- dimensional size and a certain thickness (generally reduced), which is to be cut through the machine 1.

The machine 1 is a numerical control machine comprising a control unit C, for instance including suitable memory units, suitably programmed and arranged for the management and automatic control thereof. The control unit C may be for instance a computerized unit that is integrated in 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. The control unit C is thus capable of controlling the machine 1 to obtain the automated cutting of sheet material.

The machine 1 of the present invention is a so-called cutting bench arid comprises a worktable 2 adapted to provide a support plane or work surface a for a sheet of material to be cut. The worktable 2 preferably has a quadrangular plan (still more preferably substantially rectangular) and at least one cutting unit or cutting head 3 carried by at least one arm or crosspiece 4 acts thereon.

In an embodiment of the present invention, the worktable 2 is a fixed plane, even if, in other embodiments, said worktable may be equipped with a conveyor belt (not illustrated in the figures) for moving the material arranged thereon.

In case of a rectangular-shaped worktable 2, as illustrated in the figures, the Y direction (transversal direction of the worktable) is parallel to its minor sides and the X direction is parallel to its major sides. As previously indicated, the X direction is also called sliding direction of the arm 4, which therefore, in an embodiment of the present invention, slides along the major sides of the worktable 2. For the purposes of the present invention, however, nothing prevents the arm 4 from sliding along the minor sides of the worktable 2, and therefore the sliding direction from being the Y direction, the present invention not being limited by a particular sliding direction of the arm 4.

In general, the term worktable 2 indicates the structure supporting the sheet of material to be cut, said worktable being provided with at least two opposite sides of greater extension and with at least two opposite sides of minor extension (preferably rectangular or at least defining a rectangular work surface), and being a plane having a certain thickness, the term side thus indicating a side edge portion of the worktable.

Like in the conventional cutting benches, the machine 1 is equipped with a base 5, for instance box-shaped, which is the support for the worktable 2 and possibly encloses mechanical and electronic elements to assist the operation of the machine 1.

More particularly, the machine 1 comprises at least one cutting unit 3 specifically arranged for cutting the sheet arranged on the worktable 2, said cutting unit 3 not being limited to a particular type. By way of example, the cutting may occur through blade, laser, water jet, milling cutter or in any other suitable way, preferably through a blade.

According to an embodiment, illustrated in the figures, the machine 1 comprises a single cutting unit 3, even if the present invention is not limited thereto, and the number of the cutting units may vaiy according to the needs and/or circumstances.

As previously noted, the machine 1 comprises at least one arm 4 that is at least partially arranged above (on the top of) the worktable 2 and is adapted to support the cutting unit 3, which is movable on said arm 4, in particular sliding along the longitudinal axis of said arm 4, said longitudinal axis being parallel to the Y axis of figures 1 and 2.

Specifically, in an embodiment, the movement of the cutting unit 3 is allowed thanks to the presence of a carriage 6, which is translatable along the longitudinal extension of the arm 4, i.e. along the Y axis, by means of first guides G1 arranged on a face of said arm 4, for instance arranged on a lower face thereof facing the worktable 2. In other words, the cutting unit 3 is supported by the carriage 6, which acts as a support shelf for said cutting unit 3.

In this way, according to the above embodiment, the movement system of the cutting unit 3 comprises the arm 4 and the carriage 6, which define a kinematic structure for moving said cutting unit 3. As mentioned above, the carriage 6 is preferably mounted below the arm 4 (which is why it is also referred to as “lower carriage”, although other configurations are possible) and is translatable with respect thereto along the Y direction.

The arm 4 has a substantially parallelepiped shape with prevalent extension along the Y direction. As above indicated, it comprises the first guides G1 that are adapted to allow the relative movement of the carriage 6 that is mounted on sliding blocks 7. In an embodiment, the first guides G1 are two (even if the present invention is not limited thereto) and two sliding blocks 7 aligned to each other are inserted on the guides. The movements are obtained through a recirculating ball screw/ nut screw system.

Power and signal cables connecting the various elements of the kinematic structure are also provided, said cables being housed in a drag chain 8 that runs parallel to the arm 4 and forms, at the two opposite ends, a loop, as visible for instance in figure 2.

Suitably, support means 9 adapted to support the arm 4 over the worktable 2 are provided.

Hereinafter, an embodiment will be illustrated wherein, through the above support means 9, the arm 4 is cantilevered supported and slides along the X direction. However, such an embodiment, though preferred, is merely indicative and the teachings of the present invention (i.e. the safety measures as below detailed) are not limited by the particular support and sliding configuration of said arm 4.

In particular, in the non-limiting exemplifying embodiment of the figures, the arm 4 is cantilevered supported on the worktable 2 by means of the support means 9 and is movable along the sliding direction X.

Advantageously according to the present invention, the support means 9 of the arm 4 are in the form of a crosspiece (or lintel) support structure, still indicated with the reference number 9, which is kept hanging over the worktable 2 by at least one support element or upright 9a. More particularly, in an embodiment, the support upright 9a extends vertically from the worktable 2, in particular at an edge peripheral portion of said worktable 2. Still more particularly, the support upright 9a is arranged at one of the minor sides of the worktable 2, as it will be described in detail below. In an embodiment, the crosspiece 9 is an extruded aluminum, even if other configurations are obviously possible and are within the scope of the present invention.

In an embodiment, there are two support uprights 9a arranged at two opposite sides of the worktable 2, i.e. at opposite edges, defining in this way a support gantiy comprising said two uprights and the upper crosspiece integral thereto, from which the arm 4 cantilevered projects on the worktable 2. In other words, the support uprights 9a allow the support crosspiece 9 to remain hanging over the worktable 2 and connect it to said worktable 2.

Obviously, the shape of the uprights 9a, represented with a vertical axis and projecting from the worktable 2, as well as the specific shape of the crosspiece 9, is only indicative and other suitable shapes may be used.

In the preferred embodiment illustrated in the figures, the worktable 2 is substantially rectangular- shaped (or at least defines a work area having two major sides and two minor sides) and the support uprights 9a are arranged at the minor sides of said worktable, so that the two major sides are totally free of encumbrances, i.e. no component for the support of the arm 4 is arranged at said sides, which are the sides which the exceeding material is projected from, said material being subsequently dragged onto the worktable 2.

The support uprights 9a thus allow keeping the crosspiece 9 hanging over the worktable 2, so that it is possible to form thereon the guides that allow the connection and the support of the arm 4, which is cantilever supported. In this way, it is no longer necessary to support the arm 4 by means of guides integrated on the worktable 2 (in particular arranged at the major sides of the table, as instead occurs in the known solutions). Thanks to this hanging-crosspiece configuration, the worktable 2 is thus free of encumbrances along at least two parallel sides, in particular along the major sides thereof, which the exceeding material to be cut may freely project from, without the need to use the expedients described in connection to the prior art, such as for instance the formation of housing cradles.

In other words, the structure of the machine 1 of the present invention has many advantages, in particular for rectangular worktables, due to the fact that the major sides are totally free of encumbrances, so that the exceeding material may freely hang from said sides and can be easily dragged onto the plane when it is to be cut. It is further noted that said sides free of encumbrances are the sides at which the operator acts, greatly simplifying the latter’s work. Furthermore, thanks to the presence of the hanging crosspiece 9, the operator may easily work on both free sides of the table.

In an embodiment of the present invention, in order to facilitate the operator’s work, the support uprights 9a are arranged closer to one end of the minor sides (i.e. the rear end according to the local reference system of the figures) with respect to the opposite end, so as to leave the major side connected to said opposite end even more free of encumbrances. In other words, with respect to a longitudinal axis of symmetry, parallel to the X axis, the support uprights 9a are moved more towards one of the two ends of the minor sides (without necessarily reaching this end), which is advantageous in case the crosspiece 9 also supports other components, such as for instance display screens and projectors, as it will be described below, leaving in this way more space for the operator.

Furthermore, as above mentioned and as better illustrated in figure 3, the arm 4 is constrained to a carriage 10 that is sliding along at least one guide, preferably two guides (not illustrated in the figures), formed on the crosspiece 9, said guides allowing the sliding in the sliding direction X of the carriage 10 and thus of the arm 4 constrained thereto. In other words, the arm 4 is thus connected to the support means 9 through the carriage 10, which allows the movement of the arm 4 in the X direction.

As noted for the carriage 6, the carriage 10 as well comprises sliding blocks 11 and is associated with the guide through said sliding blocks. In the preferred case of two guides, two sliding blocks 11 aligned to each other are inserted on the guides.

In an embodiment, the carriage 10 is arranged below the crosspiece 9, i.e. it is constrained to a face thereof facing the worktable 2 and thus is arranged between said crosspiece 9 and the arm 4. The carriages 6 and 10 are moved through suitable means controlled by the control unit C.

The management of the apparatus 1 by the user may occur, for instance, through a control panel 12, equipped with screen and buttons, arranged for instance at the periphery of the worktable and operatively connected to the control unit C.

In an embodiment, the machine 1, in particular the worktable 2, is ideally divided into two work areas. In this way, while in a first area sheet portions are cut through the cutting unit 3, in a second contiguous area the operator may collect material portions already cut, said areas being alternated during the operation of the machine 1. It is thus possible to work in time masking, i.e. cutting and unloading take place in masked time, with greater efficiency and productivity; machines of this type are also called “commuters”. This operation may be performed by a single cutting unit that is suitably controlled by the control unit C and moved from an area to the contiguous area, as well as by two cutting units that are suitably controlled by the control unit C.

Since the cutting unit 3, as well as the arm 4 supporting it, are not enclosed in a closed cutting chamber, there is the need to equip the machine 1 with suitable safety measures, also considering the fact that, as above illustrated, the collection of cut portions may occur simultaneously to the cutting operation in a contiguous area of the worktable 2.

With reference to figure 3 and to figure 4, a first safety measure is the adoption of photocells 13 adapted to detect the presence of a user and thus to stop the machine 1 in case a dangerous situation is detected.

More particularly, the machine 1 of the present invention comprises a plurality of photocells 13 at both opposite ends 4a and 4b of the arm 4 and arranged so as to move integrally therewith, said photocells 13 being configured to detect the presence of an object therebetween.

The photocells 13 are arranged on proper supports (for instance proper sticks) whereon they define an array of photocells, in particular a pair of arrays arranged on opposite sides of the worktable 2, i.e. opposite along the longitudinal direction Y of the arm 4, and are connected (directly or indirectly) to said arm 4 so as to move along therewith. In this way, each photocell arranged at a side of the worktable 2 has a corresponding photocell arranged at the opposite side and is aligned therewith, so as to suitably receive/ send the light signal 13’ for detecting objects, as illustrated in figure 3 and in figure 4.

Suitably, the array of photocells extends vertically (i.e. the photocells are arranged at least along the vertical direction that is substantially orthogonal to the worktable 2 and thus substantially orthogonal to the Y and X directions), so as to cover at least the entire vertical overall dimensions of the system made of the cutting unit 3 and the arm 4, unlike what happens in the known solutions in which a single photocell per side is used. In other words, the photocells extend on a vertical plane that is orthogonal to the worktable 2, thus defining, through the light signals, a predetermined vertical area within which objects can be detected.

In a preferred embodiment of the present invention, there are two arrays of photocells 13 at a side of the worktable 2 and two arrays of photocells 13 at the opposite side, the arrays of each side being arranged in opposite positions with respect to the arm 4, so as to offer protection against the movement of said arm 4 in both directions along the X direction.

Suitably the photocells 13 are operatively connected to the 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 coming from said photocells. In particular, once the operator’s presence (for instance the presence of the operator’s hand) is detected, the photocells send a signal to the control unit C, which is suitably configured to stop the operation of the machine 1.

Consequently, in its more general form, a cutting machine is provided which comprises a worktable 2, a cutting unit 3 adapted to cut the sheet arranged on the worktable 2, an arm 4 that is arranged at least partially above the worktable 2 and support means 9 of the arm, said machine being equipped with the above described photocells 13, so as to provide safety to the operator.

In any case, the presence of the sole photocells, though being a very important safety element, is not always capable of ensuring total safety for the operator, as well as there is also the need to reduce the risks due to a collision with the supports of the photocells themselves.

For this reason, in order to equip the machine 1 with further effective safety measures, it also comprises a protective screen 18 that is associated with the machine 1 close to at least one end 4a and/or 4b of the arm 4.

This safety system may have an own dedicated support or, preferably, it is directly connected to the arm 4, in particular at an end of said arm 4, which thus acts as a support.

Preferably, there are two protective screens 18, each arranged at a respective end of the arm 4, i.e. opposite along the Y direction at opposite sides of the worktable 2. Thus, the following description will refer hereinafter to the preferred, but not limiting, case of two opposite protective screens 18.

The protective screen 18 may be substantially rectangular-shaped, even if 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 that are opposite each other with respect to the sliding direction.

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

The protective screen 18 has a body 18’ that is cantilevered extended, in particular it projects downwards, with respect to its support, and is configured to cover at least partially the cutting unit 3 when observed along the Y direction, i.e. when observed frontally, so as to avoid a direct contact between the cutting unit and the operator.

In particular, the protective screen 18, more specifically the body 18’, extends in a vertical plane at a frontal portion of the machine 1 for the protection of an operator who operates at the major sides of the worktable 2, i.e. it is connected to the frontal portion of the arm 4. Still more particularly, the protective screen 18 extends substantially orthogonally to the worktable 2 at the major sides thereof.

In order to allow the correct arrangement of the material on the worktable 2, the protective screen 18 is associated with the machine 1 so as to leave an empty space G’ between itself and an edge of the worktable 2, as illustrated in figure 2. Furthermore, the protective screen 18 extends below the work surface a of the worktable 2, so as to prevent dangerous situations for the user. In other words, the protective screen 18 extends from the arm 4 beyond the work surface a of the worktable 2. As it will be noted hereinafter, the protective screen 18 also acts as a housing for the photocells 13, its extension with respect to the work surface a allowing a suitable covering by said photocells 13.

As previously mentioned, in an embodiment, the protective screen 18 is directly associated (in particular connected) to an end of the arm 4.

More particularly, in an embodiment, the arm 4 comprises, at the ends thereof, a connection projecting portion 4p, which the protective screen 18 is connected to. Obviously, the arm 4 may also not comprise the connection projecting portion 4p, what matters for the purposes of the present invention is that the longitudinal extension (i.e. along the Y axis) of said arm 4 is as a whole such as to be greater than the corresponding extension of the worktable 2, so as to project and to leave an empty space between the protective screen 18 and the worktable 2 (as previously illustrated) and prevent said protective screen 18 from hitting said worktable 2. In any case, the actual longitudinal extension of the arm 4 is not a limiting feature of the present invention.

The protective screen 18 is hinged to the arm 4 at a hinging point P, so as to be tilting with respect to said arm 4 about said hinging point P. In an embodiment, the hinging point P is at an end of the protective screen 18 (in particular the upper end of the screen), the opposite end extending beyond (below) the work surface a as previously described, even if the particular position of the hinging point is not a limiting feature of the present invention. In this way, the protective screen 18 is adapted to be translated along the sliding direction X due to the movement of the arm 4 when obstacles are not hit. The protective screen 18 is also capable of performing a rotational motion with respect to the hinging point P when, during the sliding along the X direction, it hits an obstacle to the movement, for instance when a user is hit. The protective screen 18 is thus capable of performing a relative movement with respect to the arm 4, said movement being in this case a partial rotational movement, as illustrated in figures 5A-5B, 6A-6B and in figure 7, wherein the rotation axis is substantially parallel to the Y axis and thus parallel to the longitudinal axis of the arm 4; in other words, the hinging point P lies on an axis that is coincident, or at least parallel, to the Y axis and about which the protective screen 18 performs the above-mentioned pivoting movement.

Consequently, since the protective screen 18 is not fixedly constrained to the arm 4 but is tilting, when it hits an obstacle (for instance an operator), it is apt to rotate with respect to the hinging point P, said rotation reducing the collision effect and further causing the stop of the operation of the machine 1 , as it will be illustrated herein below.

In particular, the protective screen 18 provides protection from collisions against the lower portion of said screen, i.e. the portion that is closest to the worktable 2 and thus the furthest from the arm 4, said collisions causing the pivoting movement of the screen as above illustrated.

In order to protect the operator also from collisions against the opposite upper portion of the protective screen 18, i.e. the portion that is closest to the arm 4, in an embodiment the protective screen 18 is equipped with an additional protection element 23 connected thereto. The operation of this additional protection element 23 is illustrated in figures 8A and 8B.

The additional protection element 23 comprises an elongated body 23’ (not limited to a particular shape) connected to the protective screen 18. Preferably, two additional protection elements 23 are connected to the protective screen 18, so as to be arranged along two opposite sides of said protective screen 18 (i.e., looking in a frontal position at the protective screen 18, on both left and right sides). In other words, given a protective screen 18, there are two additional protection elements 23 arranged along the sides thereof that are opposite with respect to the sliding direction X.

In an embodiment, the additional protection element 23 extends at least by the whole length of the vertical side of the protective screen 18 and is constrained to said screen, in particular to the lower portion the screen, at an end of the additional protection element, whereas an opposite end of said additional protection element is kept free. Obviously, this embodiment must not be intended as limiting of the present invention and other configurations are also possible.

As above mentioned, the connection point between the protective screen 18 and the additional protection element 23 may be for instance at the lower end of the protective screen 18, i.e. the portion that is furthest from the arm 4, allowing a relative rotation as below detailed. In any case, the particular shape, as well as the particular connection mode and position of the additional protection element 23 must not be intended as limiting of the scope of the present invention and other suitable configurations are also possible.

The additional protection element 23 is not fixedly constrained but hinged to the protective screen 18 and may perform a partial rotation towards/ away from the protective screen 18, until it touches it. In particular, the additional protection element 23 is capable of performing a pivoting movement in which the free end thereof (i.e. the non-hinged end) moves at the upper portion of the protective screen 18.

In other words, a collision against the upper portion of the protective screen 18 is absorbed by the additional protection element 23, which is apt to perform a pivoting movement towards the protective screen 18, in particular a pivoting movement in the upper portion thereof that is opposite the hinging point with said protective screen 18.

In an embodiment, the protective screen 18 acts as a support for the arrays of photocells 13, which thus move integrally with said protective screen 18. The operation of the machine 1 is thus stopped based on the rotational movement of the protective screen 18, since said rotational movement causes a loss of alignment between the photocells 13 that are opposite with respect to the longitudinal axis of the arm and arranged on opposite screens, with the consequent generation of the stop signal from the control unit C. Obviously, even other methods of generation of the stop signal are possible, such as for instance the presence of a sensor S, that is 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 towards the control unit as soon as said relative movement has been detected, said signal stopping the operation of the machine.

Still more particularly, four additional protection elements 23 are provided (two for each opposite screen) and the photocells 13 are housed on said additional protection elements 23, which, performing the pivoting movement further to the collision, cause a misalignment between the photocells arranged on the opposite sides of the worktable 2 (or they cause the triggering of the sensor S as above described).

In an alternative embodiment, the stop of the operation of the machine 1 is caused by the pressure, by the additional protection element 23 during the rotation, of a safety switch, said switch being pressed between the body of the additional protection element 23 and the body of the protective screen 18. Obviously, the particular stop mode of the operation of the machine 1 is not limiting of the scope of the present invention and other modes are also possible, what matters is that said stop occurs as a consequence of the collision, and thus as a consequence of the rotation of the protective screen 18 and/or the movement of the additional protection element 23. In still another embodiment, it is possible to provide for the presence of an element that is projecting from the screen or from the additional protection element and configured to stop (cover) at least one ray of the photocells 13 during the movement of the screen and/or of the additional protection element, causing the stop of the machine; in this latter case the photocells are not integral with the screen (but for instance are integral with the arm 4) .

Safety for the operator is therefore provided by the combination of the protective screen 18 and of the additional protection element 23.

In fact, if said additional protection element 23 were not present, a possible collision with the upper portion of the screen 18 would cause a harm to the operator, since the pivoting movement of said protective screen 18 about the hinging point with the arm 4 would not be suitably triggered. Therefore, if a collision with the operator occurs with the upper portion of the protective screen 18, then the additional protection element 23, which is preferably hinged at the opposite lower portion, rotates and causes the emergency stop of the machine 1.

If a possible collision with the operator occurs with the lower portion of the protective screen 18, then the entire tilting protective screen 18 rotates and causes the emergency stop of the machine 1, and in this case the additional protection element 23 rotates integrally with the protective screen 18. Consequently, according to the height at which the collision occurs, one or the other protection intervenes, or even both.

In other words, in case the collision occurs near the hinging point P, the effect of the relative movement of the additional protection element 23 is predominant, whereas the effect of the rotation of the protective screen 18 becomes predominant by moving away from the hinging point P towards the opposite end.

It is therefore apparent that the aforementioned measures guarantee extreme safety for the operator.

In this way, there are safety measures aiming at covering any possible dangerous situation. In fact, summing up, it is worth protecting the user from three main sources of danger: a) collisions with the lower portion of the protective screen 18; b) collisions with the upper portion of the protective screen 18; c) collisions with the sliding arm 4.

As for point a), the rotating movement of the protective screen 18 offers the desired protection.

As for point b), the protection is offered by the additional protection element 23 (that is apt to perform a pivoting movement since it is hinged at the lower portion of the screen), which, by rotating, sets the machine in emergency. Such a system is veiy easy and light and is independent of the movement of the protective screen 18. As for point c), the protection is given by the photocells 13. In fact, said photocells are supported by the protective screen 18, the arm 4 being arranged in a position that is substantially central with respect to the body of said protective screen 18, so that, when the photocells are covered, the machine 1 stops before the arm 4 can touch the operator.

In an embodiment, as illustrated in figures 9 and 10, the protective screen 18 is connected to the arm 4 through a pin element 19 (for instance projecting from a face of the body 18’ of the screen) housed in a suitable seat 19’ (for instance formed on the portion 4p that is projecting from the end of the arm 4 or directly in the body of the arm 4 and having a shape that is complementary to the pin), said connections being enough to ensure the desired effect.

From the above it is clear that, in a preferred embodiment of the present invention, a safety system is provided, which comprises the protective screen 18 hinged to the arm, the additional protection element 23, which in turn supports the photocells 13, thus forming substantially a unique safety element having multiple functions. However, other configurations are possible, in which the single elements could be separated from each other; for instance, as above mentioned, the photocells could be equipped with an own support that is directly fastened to the arm 4 (what matters is that said photocells 13 are arranged vertically to cover an area corresponding at least to the overall dimensions of the arm 4, of the cutting unit 3 and of the carriage 10), as well as the protective screen 18 could be associated with the machine 1 in other ways.

It is further noted that, in an embodiment, the additional protection element 23 may be connected to the protective screen 18 so as to be capable of translating with respect to said screen (for instance it may have an elongated body mounted on guides connecting it to the screen), the collision with the user causing in this case the translation of the additional protection element 23. Obviously, all the considerations for the pivoting movement also exactly apply to the translating movement.

In any case, return elements are provided, which are connected to the protective screen 18 and to the additional protection element 23 (such as springs or pistons) , configured to return said additional protection element 23 to the rest position after the collision, and thus after the translating or rotational movement.

Furthermore, in an embodiment, an elastomeric protection element 20 is provided, which is also known in the field with the term “bumper” (it is substantially a compressible rubber protection), and which covers the arm 4 at the top. In this way, the elastomeric protection element 20 that is arranged above the arm 4 acts as covering element, thus preventing the operator from coming into contact with the cutting means also at the upper portion of the arm 4, for instance slipping the hands from above, and also absorbs any collision.

In an embodiment, the elastomeric protection element 20 is in the form of a covering extending along the sliding direction by an extension that is substantially equal to that of the protective screen 18 (for instance so as to be in line with the photocells), as well as it extends in the transversal direction so as to cover the space between the two opposite protective screens. The elastomeric protection element 20 is arranged on the arm 4 (for instance in direct contact with its upper face), so as to wrap the carriage 10. In any case, any suitable association mode is comprised in the scope of the present invention.

If the operator’s body is arranged so as not to hit the protective screen 18, when the arm of the machine approaches, then as a first thing a ray of the photocell 13 intervenes, and then in the upper part the operator comes into contact with the bumper, absorbing the collision. In any case, prior to the maximum compression of the bumper, the machine will be completely stopped.

In another embodiment, the covering of the arm 4 is not entirely formed by the elastomeric protection element 20, but for instance by a simple covering (for instance a metal one) fixed to the arm 4, the elastomeric protection element 20 being arranged on the edges of said covering. In this way, the elastomeric protection element 20 is kept distanced apart from the arm 4 by said covering (which is connected to the upper face of the arm 4) and represents a partial covering element, still capable of absorbing a collision with the operator.

In an embodiment, the elastomeric protection element 20 is also arranged on the edges of the additional protection element 23, thus ensuring further protection for the operator.

Finally, the machine 1 is equipped with control monitors 21, projectors 22, cameras and lights, said components being advantageously supported by the hanging crosspiece 9, without the need of using other supports.

In conclusion, the present invention provides a cutting machine, for instance a cutting bench including a worktable, in which an arm that supports the cutting unit is kept cantilevered on the worktable by a hanging-crosspiece support structure, said hanging crosspiece comprising the guides that allow the arm to slide, for instance arranged on a lower face thereof. The hanging crosspiece is only supported by support uprights arranged on the minor sides of the worktable, for instance having a vertical extension from the surface of the worktable, so as not to have encumbrances on the sides of said worktable, in particular on the major sides thereof. The cutting machine is further equipped with safety systems which make it extremely safe.

Advantageously, all of the main components of the machine, such as the arm and the cutting unit, are arranged on the crosspiece support structure kept hanging over the worktable, so that at least two sides, in particular the major sides, of said worktable are free of encumbrances. The major sides, which are the ones the operator faces, thus have total accessibility, as well as the other sides have at least great accessibility.

In this way it is possible to easily arrange the material to be cut on the worktable, thus allowing the exceeding material to hang from the major sides of the table that are free of encumbrances, without the need of complicated structural measures as seen in connection with the prior art.

Furthermore, the measures made allow a significantly increased safety for the operator. For instance, the photocells cover a vertical space that is greater than the known solutions, thus offering greater protection, so as to cover at least the entire vertical overall dimensions of the system made of the cutting unit and the arm. Added to this are the tilting screen and the additional pivoting or translating protection element. All these measures contribute making the present machine much safer with respect to the known solutions, thus making it particularly suitable for obtaining all of the major safety certifications, such as the TUV certification for instance. Even the hanging crosspiece reduces the risk of collision with the operator since it is more vertically spaced apart from the worktable, where generally operator’s hands are present during the arrangement/ collection of material.

Obviously, a person skilled in the art, in order to meet particular needs and specifications, can carry out several changes and modifications to the cutting machine described above, all included in the protection scope of the invention as defined by the following claims.