CN113661139A

CN113661139A - Attachment facilitating the feeding of pieces of material to be cut in a numerically controlled machine tool (NCM) and NCM comprising said attachment

Info

Publication number: CN113661139A
Application number: CN202080015574.XA
Authority: CN
Inventors: 皮科利诺亚历山德罗·科尔西科
Original assignee: Comelz Co ltd
Current assignee: Comelz Co ltd; Comelz SpA
Priority date: 2019-02-19
Filing date: 2020-02-17
Publication date: 2021-11-16
Also published as: BR112021016213A2; EP3927638A1; EP3927854A1; WO2020169458A1; WO2020169517A1; EP3927854B1; EP3927638C0; CN113692450B; EP3699303A1; EP3699122A1; BR112021016217A2; CN113692450A; EP3927638B1; EP3927854C0

Abstract

The invention relates to an attachment (9) for simplifying the feeding of pieces of material to be cut in a numerically controlled machine tool, comprising: -a loading plane (14) associated with the front of the machine tool to receive the free end of the sheet; -an insert plate (8) supported parallel to said plane (14) and partially projecting towards said machine tool; -means for adjusting the projection of the plate (8) with respect to the plane (14). In said attachment means (9), said plate (8) is supported slidingly on opposite guides (42, 44) below said plane (14) to be folded back before the sheet is held by suitable clamping means in a first feeding step of the sheet to be cut.

Description

Attachment facilitating the feeding of pieces of material to be cut in a numerically controlled machine tool (NCM) and NCM comprising said attachment

Field of application

The invention relates to an attachment for a numerically controlled machine tool.

More specifically, the invention relates to a device for feeding pieces of material to be treated in a blade cutter, for example for cutting pieces of material such as clothing fabrics and hides, footwear, automotive and furniture articles or non-woven fabrics, leather, natural or synthetic leather, soft or semi-rigid synthetic materials for insoles and the like.

The invention also relates to a numerically controlled machine tool for cutting at least one or more sheets of material to be treated, comprising said accessory device.

The type of said numerically controlled machine tool preferably comprises:

-a process chamber or space;

-a conveying device adapted to feed a sheet into the processing chamber in a forward direction;

-a tool head adapted to run on a wafer in the process chamber.

Prior Art

As is well known in the art, there are numerically controlled machines or apparatuses capable of cutting sheets of material in an automated manner according to a predetermined cutting pattern. The material to be cut may be, for example, a sheet of plastic material, natural leather, fabric, non-woven fabric, cellulose-based material, or the like. The cutting may be performed on a single sheet or on a plurality of sheets stacked on top of each other to form multiple layers known in the art as mats.

In particular, these machine tools are equipped with a conveyor belt able to move the sheet to be cut along a plane XY, also defined hereinafter as cutting table, and inside a cutting chamber provided with a cutting tool head for processing the material, activated by computerized means.

The sheet to be cut in the machine tool can be unwound from a roll or other support placed at a short distance from the mouth of the machine tool, in which case multiple layers are prepared beforehand, off-line or in front of the machine tool, by overlapping the sheet on a table of sufficient length. However, particularly when working with fabrics, the use of relatively short accordion-folded portions of material (e.g. a few metres) to be processed near the mouth of the machine and placed on a support table has become widespread.

These relatively short sheets must be loaded into the machine tool at a higher frequency than the frequency of the layers formed from the roll.

Usually, a short free side of a material sheet of several meters length is placed on the conveyor belt only by an initial portion (for example, about 1 meter) to be attracted and cut during a subsequent forward movement of the belt, which at the same time involves recovery by dragging the remaining material.

When a new sheet of multi-layer sheets is placed on the machine tool at the start of a new process, it is necessary to comply with some of the precautions listed below.

-taking care of the mutual alignment of the multilayer sheets so that the individual layers are aligned with each other to avoid having to reduce the width of the cutting field and/or cut outside some of the layers;

note the horizontal alignment of the sheet relative to the movement of the belt; i.e. to ensure that the sheet does not drift towards the right or left side of the cutting chamber as it moves forward on the belt;

the arrival of the follower pieces is suitably prepared, especially if it is a multilayer, for example on the loading plane outside the conveyor belt, to avoid interrupting or slowing down the cutting flow.

Typically, the material to be cut is held on the conveyor belt by suction means arranged below the belt and kept running as the belt moves forward to ensure the desired holding of the sheet.

However, before the intervention of the suction means, i.e. when the layers are between the loading plane and the mouth of the machine tool, it is generally necessary for one or more operators to intervene to take care of the feeding to the conveyor belt in the absence of misalignments between the sheets.

Basically, the pad of sheets is moved manually from the preparation plane towards the mouth of the cutting machine, and this operation usually requires two people.

More specifically, in the field of clothing, it is common to place a pad of fabric on perforated paper to facilitate the suction retention of the material. The paper is usually slightly larger than the pad and at the right moment the operator slides the pad of sheets over the cutter by pulling the perforated paper.

The technical problem underlying the present invention is that of providing an attachment for simplifying the feeding of a piece of material to be cut in a numerically controlled machine tool, which has structural and functional features to allow the smooth passage of the piece or layers through the loading plane to the mouth of the machine tool, overcoming the drawbacks that still affect the known machine tools.

Another object of the invention is to keep the pads of the sheets loaded into the machine compact and correctly stretched.

A further object of the present invention is to provide a numerically controlled machine tool which, at least in the conditions of use, integrates, according to the above mentioned characteristics, auxiliary means to facilitate the feeding of the multilayer sheets.

Summary of The Invention

The solution idea of the present invention is to provide an attachment device that performs the function of inserting a plate between a folding slide loading plane for a sheet or a multilayer sheet below the plane and the conveyor belt of the machine tool during the first feeding step.

In other words, the insert plate extends the loading plane partially towards the mouth of the machine tool, so as to allow the pressurization means to retain the free end of the multiple tiers after withdrawal of the plate, pulling back the entire loading plane when the conveyor belt is stationary, leaving a sufficient portion of the multiple tiers on the conveyor belt.

The above technical problem is solved by an attachment device for simplifying the entry of pieces of material to be cut into a numerically controlled machine tool, said device comprising:

-a loading plane associated with the front of the machine tool to receive the free end of the sheet;

-an insert plate supported parallel to said plane and partially protruding towards said machine tool;

-means for adjusting the projection of said plate with respect to said plane.

Advantageously, the plate is supported slidingly on opposite guides below said plane.

More specifically, the guide is obtained below in an undercut of the lateral edge of said plane.

Basically, the plate is guided in a sliding folded manner below the plane.

Further, the plate is made of a low surface friction synthetic plastic material. The material may be nylon or polyethylene.

The above-mentioned means for adjusting the projection of the plate with respect to the plane comprise at least one lever associated with one side of the plate and hinged to the plane.

Optionally, the device comprises at least one rack associated with one side of the plate and meshing with a gear actuated by an electric motor.

It is also worth noting that said plane is horizontally translationally mobile in a direction parallel to the forward direction of the sheet, between a withdrawn position in which said plane is spaced from the proximal end of the conveyor belt of the machine tool and a feed position in which said plane overlaps said proximal end portion.

It is clear how the above described structure is particularly effective, since the insert plate only partially extends the loading plane during the first support and feed step on the proximal portion of the band at the mouth of the numerically controlled machine tool.

Thanks to said structure, the attachment according to the invention can be associated with a folding slide parallel to the loading plane, which in turn can be associated in a folding manner with the front part of the machine tool below the proximal portion of the conveyor belt.

Of course, according to the present invention, nothing prevents having a loading plane structurally independent of the numerical control machine and equipping said loading plane with an insertion plate.

The above technical problem is also solved by a numerically controlled machine for cutting at least one or more sheets to be processed, comprising:

-a treatment area (preferably defined as a chamber or space);

-a conveying device adapted to feed sheets in a forward direction into the processing zone;

-a tool head adapted to run on a sheet in the processing zone;

it is characterized by also comprising:

-gripping means for gripping the sheet or layers, arranged at least at the mouth of the cutting chamber and movable between a non-operating position, in which the sheet or layers are at a determined distance from the surface of the sheet or the surface of the conveyor belt, and an operating position, in which at least a lower edge is held against the surface of the sheet by pressing the sheet or layers against the conveyor belt; and

-said accessory device associated with said machine tool and constituted according to the above.

The attachment may be part of the machine tool, possibly integrated in the machine tool as well; or alternatively it may be a different device associable with the machine tool under conditions of use.

The machine tool described above may comprise a front device equipped with a support plane for the sheets, which can be folded between a vertical rest position and a horizontal operating position in which it is substantially continuous with the conveyor.

Advantageously, the attachment can be mounted in a lower position and can be moved horizontally between an extended position, in which the cantilever of the attachment projects from below and is close to the loading plane, and a retracted position; in the retracted position, the attachment is folded to be hidden below the loading plane.

The characteristics and advantages of the device and of the machine according to the invention will become apparent from the following description of some exemplary embodiments, given by way of non-limiting example, with reference to the accompanying drawings.

Brief description of the drawings

In the drawings:

figure 1 shows a perspective view of a machine tool equipped with an attachment according to a first embodiment of the invention, provided and configured to facilitate the feeding of a sheet of material to be cut;

figure 1A shows a perspective view of a numerically controlled machine tool without an attachment according to the invention, with the front element and the rear element in the open position;

figure 2 shows a perspective view on an enlarged scale of figure 1 in a loading start and overlapping configuration of the sheets to be cut;

figure 3 shows a perspective view and a rear view of the machine of figure 1, with the accessory folded up under the front part of the machine;

figure 4 shows a perspective view of a machine tool equipped with an accessory according to a first embodiment of the invention, wherein the accessory also conveys four rolls of material in a two-by-two superposed configuration;

figure 5 shows a perspective view on an enlarged scale of figure 1 in a forward configuration of a loading plane equipped with an accessory device of the invention;

figure 6 shows a further perspective view of the machine tool according to the invention in a further operating step thereof;

figure 7 shows another perspective view of the machine tool according to the invention in a further operating step thereof;

figures 8 to 10 show respective perspective views, partially in section, of details of the accessory device of the invention in different operating forms and configurations;

figure 11 shows a perspective view of a machine tool equipped with an attachment according to a second embodiment of the invention, said machine tool being equipped with an attachment according to the invention.

Detailed description of the invention

With reference to these figures, a numerically controlled machine for cutting sheets of material according to the invention has an attachment 9 removably associated with the apparatus 1, indicated in its entirety schematically with the reference number 1.

The drawings are diagrammatic and not drawn to scale, but rather are drawn to emphasize important features of the invention. Furthermore, in the figures, the different elements are depicted in a schematic way, the shape of which varies depending on the desired application.

Further, the same reference numerals refer to elements having the same shape or function. Finally, particular features described with respect to the embodiments shown in the figures may also be applied to other embodiments shown in other figures.

In its more general form, the machine tool 1 is suitable for processing, in particular for automatically cutting, folding or flexible sheets 2, such as fabrics for clothing goods or accessories, leather, natural or synthetic skins, non-woven fabrics, cellulose-based materials, other synthetic materials, etc.

In the context of the present invention, the term "sheet" means any element of any shape and material having a substantially two-dimensional size and a certain thickness (generally reduced), which must be cut by a machine tool. As will be noted in greater detail hereinafter, the cutting of a plurality of sheets, generally stacked on top of each other to form a multilayer and having substantially uniform shape and size, is often, if not necessarily, performed.

The machine tool 1 is therefore a numerically controlled machine tool equipped with data and program memory. In particular, the device 1 comprises a control unit 21, the control unit 21 comprising said memory and being suitably programmed and configured for its management and automatic control. The control unit 21 may be, for example, an integrated computerized unit, or may be external to the machine tool 1 and operatively connected to the machine tool 1. Furthermore, it is noted that the control unit may be a unique central unit or may comprise a plurality of local units, which are considered to be controllers associated with various actuators arranged on and in the machine tool.

A

conventional user interface

30, 35 is available for an operator to activate or program the operating algorithms of the machine tool. Both said

interfaces

30, 35 are supported at the front and rear of the machine, possibly active on the relative front and rear elements.

In general, the machine tool 1 of the invention comprises a frame F made of, for example, metallic material, which supports and encloses the main elements of the machine tool.

More specifically, the machine tool 1 comprises a cutting chamber or cell 3 in which the piece 2 is processed on a work plane α. The cutting chamber 3 has a loading inlet 4 through which the sheet 2 is fed and an unloading outlet 5 from which the cut portion of the sheet 2 is recovered 5.

Furthermore, the apparatus 1 comprises a motorized conveyor belt 6, which conveyor belt 6 passes through the cutting chamber 3 from the inlet 4 to the outlet 5 and is adapted to feed and convey the sheets 2 into said cutting chamber 3. In a preferred embodiment, the conveyor belt 6 extends horizontally.

The conveyor belt 6 may be covered by a protective and air-permeable support layer (not shown in the figures) which undergoes a plurality of cutting steps during the various processes and is replaced periodically. Below the supporting layer, conventional suction means (also not shown in the figures) are provided, which allow to retain the sheet 2 on the conveyor belt 6 during the forward movement due to suction. Possibly, perforated paper is provided as the first layer to facilitate cutting, creating better differentiation for the blade.

Inside the cutting chamber, one or more tool heads (not shown) adapted to run on the sheet 2 to perform the cutting are active.

In fig. 1A, the sliding direction or advancing direction of the conveyor belt 6 is indicated by direction Y, and the direction transverse thereto is indicated by direction X. That is, the direction Y indicates the direction in which the conveyor 6 moves the sheet, and the arrow a in fig. 1A indicates the feeding direction of the sheet.

The machine tool 1 according to the invention is equipped with

closure elements

10a, 10b located on the inlet 4 of the cutting chamber 3 and on the outlet 5 of the cutting chamber 3.

The closing element may be, for example, a glass or plexiglas plate or screen connected to the frame F of the device 1, or be provided with its own frame, which in turn is connected to the frame F.

The purpose of the closing element is to isolate the cutting chamber 3 during the treatment step and at the same time to protect the operator close to the machine tool from noise. However, for the purposes of the present invention, the movement of the front screen 10a in cooperation with the accessory device 9 will also be used.

The front closure element 10a is movable between a first or open position (shown in fig. 1A), in which access to the cutting chamber 3 is possible from the inlet 4, and a second or closed position (shown in fig. 7, end-of-stroke position), in which the lower edge 16 is close to the working plane α.

In fact, the closing element 10a can be moved towards and away from the working plane α.

When the closing element 10a is in the closed position, with the edge 16 close to the work plane α, it is not only prevented from entering the cutting chamber 3, but when the conveyor belt 6 is stationary, it is held at the end free edge of the mat of sheets 2 before the cutting operation is continued.

In this way, the front screen 10a cooperates with the attachment 9 to facilitate loading of the single sheets 2 or sheet mats, as will be seen in the remainder of the present description.

With reference now in particular to the examples of figures 2 to 7, the variants advantageously adopted in the apparatus 1 to more easily feed and properly place the sheets 2 on the conveyor belt 6 will now be described in detail.

As mentioned above, according to the invention, the machine tool 1 comprises attachment means 9 to facilitate the feeding of the piece 2 of material to be cut.

Said attachment 9 is associated with the machine tool 1 and comprises at least one loading mobile plane 14 supported in an operating position close to the proximal end 13 of the conveyor belt 6 by means of a suitable support structure 25 associated and connected to the lower portion of the front portion 20 of the frame F of the machine tool 1.

The movable plane 14 is a substantially rectangular plate support on which the free edges of the short sides of the sheets 2 to be loaded on the conveyor belt 6 are arranged. Optionally, lateral surfaces 39, 41 are provided on both sides of the movable plane 14 to facilitate the side alignment of the sheets 2 or more particularly of the multilayer formed by the superposed stack of sheets 2. The positioning of the

sides

39, 41 can be adjusted by means of a scale.

As shown in fig. 3, the movable plane 14 is movably guided from a rest position, in which said movable plane 14 extends vertically close to the aforementioned lower front portion 20, to an operating position; in the operating position, the movable plane 14 extends horizontally.

In the figures, the movable plane 14 is always shown in a horizontal operating position, in addition to fig. 3.

The translation motor means for actuating the movable plane 14 of said plane are arranged between two horizontally extending extreme positions. Said motorised means are electric motors, for example brushless motors or the like, which can be adjusted with a certain precision and interlocked with the control unit 21 of the device 1.

The plane 14 is thus guided movably in a substantially horizontal plane between an initial position of retraction of the loading (fig. 4) and a final and extended position of release (fig. 5, 6 and 7), in which extended position the plane 14 extends up to the cutting chamber 3.

It is worth noting that the plane 14 is also foldable, so as to be compact close to the lower front portion 20 of the frame F of the machine tool 1, as shown for example in fig. 1A and 3. In this compact position, the plane 14 is manually folded under the proximal end 13 of the conveyor belt 6, which is useful for example in the transport of the machine 1 or in some treatment of the flaps when the plane 14 is merely an obstacle.

However, it is possible to provide motorized means and relative supporting guides to initiate the roto-translation of the movable plane 14 from the rest laying position and to bring it to a coplanar operating position, or to position it partially above the proximal end 13 of the conveyor belt 6. In the rest position of fig. 1A or 3, the plane 14 is folded parallel to the lower front portion 20 of the shelf F.

The movable plane 14 is also configured to facilitate feeding of the sheet 2 to be processed on the conveyor belt 6.

In this respect, the plane 14 is equipped with an attachment 9 according to the invention in the form of an insertion plate 8 extending parallel to the plane 14 below the plane 14.

The plate 14 is made of a synthetic plastics material.

In one embodiment, the plate 14 is constructed of a nylon sheet. Important for the purposes of the present invention is the very low surface coefficient of friction of the plate 14, allowing the plate 14 to slide even in the presence of pressure on the overlying pads of the sheet.

In alternative embodiments, the sheet 14 is Polyethylene (PE) or polyene.

Among plastic materials, polyenes are known for their various properties, such as: resistance to impact and to wear, low coefficient of friction, resistance to corrosion and to chemical products. Furthermore, the material has good dimensional stability and is easy to process and weld.

For the purpose of the present invention, PE polyene sheets having a molecular weight of 300 to 1000, preferably PE 1000 having a low coefficient of friction and high impact resistance, can be used.

Advantageously, the plate 8 slides under the plane 14.

More specifically, the plate 8 is supported by two

opposite guides

42, 44, the

guides

42, 44 being obtained below them in undercuts of the lateral edges of said plane 14. The plates 8 slide on opposite guides away from and towards each other towards the proximal edge 40 of the plane 14.

Alternatively, it is also possible to provide at least one rail central support of the plate 8, possibly tapered towards the protruding direction, or at least one pair of rail supports extending parallel but not necessarily at two opposite lateral ends.

It is important for the purpose of the invention that at least a portion of the plate 8 or the strip 10 can extend in a distal projection towards the loading direction emerging from the lower side of the plane 14.

The plate 8 is substantially rectangular, with dimensions substantially corresponding to those of the plane 14, or slightly smaller in longitudinal extension.

The plate 8 is intended to project partially in the direction of the cutting chamber 3 below the plane 14.

The distal portion of plate 8, which emerges below plane 14, is indicated with reference number 10 and represents a support strip for the free end of sheet 2 or multilayer sheet 2.

In the operating position, the strip 10 projects from the distal edge 15 of the plane 14 by a few centimeters, for example by less than 10cm, which obviously does not represent any limitation of the applicant's rights. The tabs may be selected based on the type of material to facilitate withdrawal so as to avoid disturbing the alignment of the sheets making up the pad to be treated.

The opposite side of plate 8, the proximal portion, is constrained to a rod 45, rod 45 having an end 46 hinged to a lower edge 48 of plane 14.

More specifically, a bar 45 is provided at each proximal angle of plate 8 near proximal edge 40 of plane 14.

The two opposite levers 45 have respective control levers 49 emerging from planar slotted portions obtained from opposite lateral portions close to the proximal edge 40. The operator can grasp the control lever 49.

The lever 45 is angularly movable at a predetermined angular offset from a rest position shown in fig. 10, in which the plate 8 is completely withdrawn below the plane 14, to an operating position (fig. 8 and 9); in the operative position, the plate 8 protrudes beyond the distal edge 15 of the plane 14, leaving the support band 10 exposed.

In the embodiment provided by the invention, the movement of the plate 8 is entirely automatic and is performed by motorized means interlocked with the control unit 21 of the machine tool 1.

For example, motorized means for moving the lever 45 interlocked with the control unit 21 of the machine tool 1 can be provided.

Alternatively, the lateral portions of the plate 8 can be equipped with respective racks (not shown) coupled with corresponding gears actuated by an electric motor (for example a stepper motor).

Each rack is mounted longitudinally on a

corresponding guide

42, 44 below the plane 14 and is actuated to adjust the projection of the plate 8 with the opposite rack.

In an alternative embodiment, using a single rack on one side of the plate, clearly with a single drive motor, the opposite side, associated with the other side of the plate 8 and sliding in the

corresponding guide

42 or 44, may be adapted as a further alternative.

It should also be noted that the movable plane 14 is movably guided towards and away from the proximal end 13 of the conveyor belt 6.

More specifically, the movable plane 14 is moved in translation horizontally in a direction parallel to the direction of movement of the conveyor belt 6 (i.e. direction Y), and is in particular movably guided between a loading withdrawn position, in which the movable plane 14 faces the proximal end of the conveyor belt 6, and a feeding and release position, as shown in fig. 4; in the feeding and release positions, the movable plane 14 partially overlaps the conveyor belt 6, as shown in fig. 5.

More specifically, when the movable plane 14 is in the loading withdrawn position (fig. 4), the pad of sheet 2 can be dragged and extended on plane 14 until the end of the free edge (in the case of a single sheet) or the end of the overlapping edges of the layers coincides with the projecting outer edge of belt 10 of plate 8.

The programmed forward movement of the movable plane 14 causes the pad of sheets to be dragged towards the cutting chamber until it reaches the predetermined position shown in fig. 5, in which the exposed strip 10 of the plate 8 is located on the projection of the front screen 10 a.

At this point, it is possible to withdraw plate 8 and obviously belt 10, which slides under the free end of the pad of sheet 2 due to the low friction coefficient.

By actuating lever 45 (manually or automatically), plate 8 is withdrawn, so that belt 10 returns to folding completely below the plane, sliding off under the free end of the pad of the sheet due to very little surface friction.

Only after this pass is the front screen 10a lowered, blocking the pad of the sheet in position.

At this point, the plane 14 may be withdrawn while the material to be cut remains gripped and captured by the lower edge 16 of the front screen 10 a.

At this point, after lowering the front screen 10a, the plane can also be withdrawn without moving the material, thereby laying it down on the conveyor belt in a considerable portion (for example about 40 cm).

Optionally, a cross piece (not shown in the drawings) may be provided having the following functions: the free end of the pad of the clamping tab, or in any case its end, releases the function of the screen retention pad when the plate 8 has been withdrawn.

In general, it is also possible to provide gripping means arranged laterally on the plane 14, but integral with the machine tool, to retain the pads of the sheet laterally during the withdrawal step of the plane. The device may be supported by lateral longitudinal elements of a sliding guide supporting the plane.

Basically, the machine tool of the invention comprises clamping means for clamping the piece or layers arranged at least at the mouth 4 of the cutting chamber 3 and movable between a non-operating position, in which the piece or layers are at a determined distance from the surface of the piece or the surface of the conveyor belt 6, and an operating position, in which at least a lower edge abuts against the surface of the piece, almost abutting against the conveyor belt.

In any case, thanks to the presence of the attachment means 9, it is possible to place the sheet 2 or sheets 2 in a simple and effective manner and in a semi-automatic manner on the conveyor belt 6. In fact, the movable plane 14 is substantially supported by a cantilever outside the machine tool 1 and makes the activities of preparing a new sheet to be loaded easy for the operator, for example grasping the free end and dragging the sheet from the support roll or from the folded material.

In addition, attachment means 9 also facilitate the alignment and overlapping of the layers of sheet 2 with each other and their movement relative to the conveyor belt.

Suitably, the movement of the movable plane 14 is controlled in an automatic manner by the control unit 21 and, in an embodiment, is synchronized with the movement of the conveyor belt 6 and with the movement of the front screen 10 a.

Now, for the sake of completeness of the description, and with particular reference to the example of fig. 10, it should be noted that the movable plane 14 laterally has two arms 60 hinged with respect to a number of uprights 61 integral with the support structure 25.

Another accessory 50 or 50' for supporting the roll of sheet 2 is associated with the plane 14; said appendages comprise two longitudinal elements 51, a plurality of planar appendages 54 associable with said longitudinal elements 51 and with the supports 53, and a transverse bar of guides 56 supported by the aforementioned appendages 54 in opposite positions on the two longitudinal elements 51.

All these elements are variably configured, as illustrated in the figures, to support one or more rolls 57 of material 2 to be cut; the roll is placed on a support bar 53 and in different positions. The use of more rolls 57 allows to unroll more layers of material 2 at the same time to make the layers or mats to be cut in the machine tool 1.

The guide bars 56 allow the rolls to return to a substantially continuous planar orientation with respect to the orientation of the conveyor 6, avoiding interference between the unwound sheets from the continuous roll 57.

The longitudinal element 51 is preferably made as a metal part with rectangular or square sections and the cantilever is fixed to the machine tool 1 or to the movable plane 14.

The appendages 54 are pairs including right and left appendages that are mirror images of each other. The appendages 54 of each pair must be associated oppositely facing with the two longitudinal elements 51 and provide distinct primary 52 and secondary 55 slots suitable for supporting the support 53 and guide 56 transverse bars, respectively.

The appendages 54 are removably mounted on the longitudinal elements 51 so that they can be used in different numbers in various configurations of the device 50.

Each appendage 54 is preferably made of sheet metal and thus has a substantially planar configuration.

It has two wings, an upper wing 54a and a lower wing 54b, which are opposite and substantially mirror-symmetrical to each other. Both wings have a main slot 52. The groove is made as a C-shaped groove, preferably by shearing, which results in a lowered seat in which the transverse bar 53 is housed.

In two different embodiments, the appendages 50 or 50' are shown in the figures, which are different from each other, in different arrangements of the rolls just above and below the plane, or all aligned with each other, as shown in fig. 11. The foregoing description applies to both embodiments.

In both embodiments, the appendage 50 is associated with an end of the movable plane 14 when the appendage 50 is in the raised configuration.

In this case, the plane defined by the longitudinal elements 51 is substantially at the level of the plane of the machine bed 1 or slightly higher, i.e. it is a substantially continuous feeding plane with respect to the plane of the conveyor 6, except for a slight difference in level represented by the partial overlap of the plane 14 and the relative plate 8.

In this case, the longitudinal element 51 is telescopically introduced into an arm 60 of the movable plane, said arm 60 being advantageously configured as a hollow part. The longitudinal element 51 can be blocked in a position more or less extracted with respect to the arm, according to the use requirements of the machine tool 1.

It is obvious that a person skilled in the art, in order to satisfy specific needs and specifications, is able to make numerous variations and modifications of the invention, all of which are included within the scope of protection of the invention as defined by the following claims.

Claims

1. Attachment (9) for simplifying the feeding of pieces of material to be cut in numerically controlled machine tools, comprising:

-a loading plane (14) associated with the front of the machine tool to receive the free end of the sheet;

-an insert plate (8) supported parallel to said plane (14) and partially projecting towards said machine tool;

-means for adjusting the protrusion of the plate (8) with respect to said plane.

2. The attachment (9) of claim 1, wherein the plate (8) is slidingly supported on opposite guides (42, 44) below the plane (14).

3. The attachment (9) according to claim 2, wherein the opposite guides (42, 44) are obtained below in undercuts of the lateral edges of the plane (14).

4. The attachment (9) according to claim 1, wherein the plate (8) is guided in a sliding folded manner below the plane (14).

5. The attachment (9) according to claim 1, wherein the plate (8) is made of a low surface friction synthetic plastic material.

6. The attachment (9) of claim 1, wherein the plate (8) is made of nylon.

7. The attachment (9) according to claim 1, wherein the plate (8) is made of polyethylene.

8. An attachment (9) according to claim 1, wherein said means comprise at least one lever (45) associated with one side of said plate (8) and hinged to said plane (14).

9. The attachment (9) according to claim 1, wherein said means comprise at least one rack associated with one side of said plate (8) and engaged by a gear actuated by an electric motor.

10. The attachment (9) according to claim 1, wherein the plane (14) is horizontally translationally movable in a direction parallel to the forward direction (Y) between a withdrawn position, in which the plane (14) is spaced from the proximal end (13) of the conveyor belt (6), and a feed position, in which the plane (14) partially overlaps the belt (6).

11. Numerical control machine (1) for cutting at least one sheet (2) or a multilayer sheet of material to be treated, comprising:

-a treatment zone or cutting chamber (3);

-conveying means (6) adapted to feed said sheets (2) in a forward direction (Y) into said treatment area (3);

-a tool head (8) adapted to run on a sheet (2) in the treatment zone;

it is characterized by also comprising:

-gripping means for gripping the sheet or layers arranged at least at the mouth (4) of the cutting chamber (3) and movable between a non-operating position, in which the sheet or layers are at a determined distance from the surface of the sheet or the surface of the conveyor belt (6), and an operating position, in which at least a lower edge is held against the surface of the sheet, pressing the sheet or layers against the conveyor belt (6);

-said accessory device (9) associated with said machine tool (1) and constituted according to any one of claims 1 to 10.

12. Machine (1) according to claim 11, characterized in that said accessory device (9) comprises a loading and support plane (14) for said sheet (2) or said multilayer sheet (2), said sheet (2) or said multilayer sheet (2) being foldable under said conveyor belt (6) on the front of said machine (1).

13. Machine (1) according to claim 11, characterized in that said at least a lower edge (16) of said clamping means holds the free edge of said multilayer at said mouth (4) of said cutting chamber (3).

14. Machine tool (1) according to claim 11, characterized in that said accessory device (9) is configured to support one or more rolls (57) of said material to be cut.

15. Machine tool (1) according to claim 11, characterized in that said gripping means are screen closing elements (10a) which are movably guided between an open and a closed position of said cutting chamber (3).