WO2004099448A2

WO2004099448A2 - Machine for machining sheet materials such as leather, synthetic materials or similar

Info

Publication number: WO2004099448A2
Application number: PCT/IB2004/001355
Authority: WO
Inventors: Alessandro Pasqualetti
Original assignee: Af S.R.L.
Priority date: 2003-05-05
Filing date: 2004-05-04
Publication date: 2004-11-18
Also published as: WO2004099448A3

Abstract

A machine (10) for punching, incising, embossing, plating or executing other workings on sheet materials (11), such as leather, synthetic materials or similar, comprises a modular support structure apt to allow the dimensions of said machine be easily adapted to greater or smaller dimensions of the sheet material to be machined, means (61,63) for setting, without stopping the production, the work stroke of the machine, means for automatically dragging, at variable speed, a conveyer belt (27) convoying the sheet material, at least one tool saddle (17) linked to said modular structure through high efficiency supporting and sliding means. The machine (10) is apt to be employed in different manufacturing fields involving sheet materials workings.

Description

MACHINE FOR MACHINING SHEET MATERIALS SUCH AS LEATHER. SYNTHETIC MATERIALS OR SIMILAR

Field of the Invention

This invention relates to a machine for automatically machining sheet materials, such as leather, synthetic materials or similar. In particular, the machine performs, among the others, operations of perforating, embossing and/or plating the above said sheet materials, also of relevant dimensions.

Background of the Invention In the shoes manufacturing industry or, in general, in the leather industry, are used leathers or similar materials which are usually finished to confer a specific aesthetic look to the final product. In particular, we refer to operations apt to produce incisions or perforations creating a well defined geometric draw repeated on the surface of the product, as well as stamping operations or operations Which plate on said external surface leafs of materials having various shapes and dimensions, uniformly distributed on the surface.

Automatic machines are presently used to obtain the precise repetition of the basic ornamental pattern upon the whole surface of the sheet materials. Said machines mainly comprise a conveyor belt which unwinds between two rollers placed at opposite sides of the. machine and upon which the sheet material to be machined lays. Said sheets of material are dragged in correspondence of a tool saddle placed in the upper part of the machine and vertically moving of reciprocating motion according to a stroke set to perform the desired working in the sheet material. This working may consist of perforating or incising, or embossing, or applying leafs of material, or of combining embossing and plating. In any case, a proper tool mounted on the tool saddle of the machine is used to perform the specific operation to be made. It is clear that the above said operations evolved in the last years, and they will keep evolving, to follow the stylistic trend of the sector, and it is also clear that, together with the evolution of the patterns' variety, a bigger and bigger quality and precision of said operations is required, especially as we consider the growth of the fields of application and their variability. In fact, they can involve from the small handicrafts production to the big industrial production, such as the car industry or the furniture industry.

Therefore, it is obvious that said operations have to take place through machines and equipments which grant a production cycle of high liability and flexibility and that the construction of the machines could fit to the requirements of the different sectors, as regards their power and dimensions. Summary of the Invention

It is the object of the present invention to provide a machine for automatically machining sheet materials, such as leather, synthetic materials or similar through which a high productivity and liability is obtained. Another object of the invention is to provide a machine for automatically machining sheet materials, which could be made with characteristics of power and dimensions well fitting to the requirements of the various application sectors. According to its broadest aspect, the present invention provides a machine for automatically machining sheet materials, such as leather, synthetic materials or similar comprising a modular structure which provides dragging means with speed control of a conveyer belt convoying the sheet material, at least one tool saddle moving of vertical reciprocating motion and placed above said conveyer belt, at least one sliding table, whose vertical position is adjustable, placed in correspondence of said tool saddle under the conveyer belt, high efficiency sliding and supporting means of said tool saddle. The structure of the machine is composed of vertical side panels to which are bound, trough removable means, a shelf supporting a main electric motor and a central crosspiece apt to support said adjustable sliding table, to said side panels being also bound the mechanical parts which move and drive side columns belonging to the tool saddle and, further, the rollers which drag the conveyor belt. Two main rollers supporting the belt, respectively dedicated to unwind and rewind the belt, are mounted at the ends of two parallel arms fixed to said side panels. The roller dedicated to rewind the conveyer belt is acted by a specific electric motor whose torque is electronically controlled by an external control unit. Said control unit is also dedicated to control the speed rate of the main electric motor according to the productivity required. An adjustable lever mechanism, driven by said main electric motor, is used to change the working pitch as a function of the width of the tool to be applied to the tool saddle to obtain the desired pattern. A position sensor associated to the side columns of the tool saddle is used to give to the control unit information useful to execute the production cycle and to correctly position the tool saddle during specific machine set-up or maintenance phases. The stroke of the tool, varying with the type of operation required, is finely set, without stopping the production, by changing, through specific set means, the vertical position of the sliding table comprised in the central crosspiece. In the case that the sheets on which the aesthetic pattern has to be made are very large, it has to be exerted a relevant force upon the tool mounted in the tool saddle. To avoid, under the action of said force, an inflection of the central crosspiece placed under the sheet material that could result in a not uniform machining of the central part of said sheet material with respect to the side parts, or, even, in a lack of machining in the central hollow, it is adopted a particular embodiment of the invention in which the crosspiece comprises adjacent portions whose total length correspond to the length of said tool saddle, each of said portions being separately vertically adjustable, so that the work stroke can be finely adjusted through out the tool saddle work length.

The central crosspiece preferably comprises three adjacent portions. Each of said portions comprises at least one down sliding table and at least one upper sliding table coupled along inclined planes, the horizontal position of said down sliding table being finely adjustable in order to attain the vertical adjustment of the upper sliding table.

An aluminum, or similar material, plate lays on said adjacent portions. Said plate forms a single, continuous, layer to support the conveyer belt, independently from the vertical position of each crosspiece portion; in the central zone of said plate is housed a strip of material apt to constitute a counter mould. The upper sliding table of one, or more, of said crosspiece's portions is advantageously disjointed in longitudinal direction; in one part of said upper sliding table are housed two more sliding tables coupled and placed one on the other according to a further inclined plane, the upper of these two more sliding tables being vertically adjustable by means of the horizontal movement of the lower sliding table. In this case, also the strip of material apt to work as a counter mould is advantageously disjointed in two longitudinally adjacent portions. It is clear, from what above disclosed, that is realized, by the machine of the invention, a very liable and rational machining of sheet materials. The settings of the machine and its connection to a programmable control unit allow commanding in a simple and effective way the production cycle. The structural layout of the machine allows the machine to fit by simple modifications, to different industrial sectors, as regards dimensions and power. Brief Description of the Drawings

For a better understanding of the characteristics and the advantages of the machine of present invention, this will now be described by way of examples with reference to the accompanying drawings, in which: -Figure 1 shows a schematic side view, in partial section, of a machine according to the invention;

-Figure 2 shows a view, in detail of a part of the machine of fig.l;

-Figure 3 shows a further view, in detail, of a tool suitable for the machine of the invention;

-Figure 5 shows a front view of the machine of the invention;

-Figure 6 shows a section of the machine through the section plane I-I of fig.5;

-Figure 7 shows an exploded view of the structural components of the machine of the present invention; -Figure 8 shows a view, in detail, of a component of the machine of the invention;

-Figure 9 shows a section view relating to a component of the previous figure, according to the section plane HI-DI of said figure;

-Figure 10 shows a schematic lateral view, in partial section, of a different embodiment of the machine of the invention;

-Figure 11 shows a view, in detail, of a part of the machine of the invention;

-Figure 12 shows a detailed view relating, in particular, to the central crosspiece of the machine of fig.10 ;

-Figure 13 shows a further view, in detail, relating to a different configuration of the central crosspiece of the machine of fig.10 ;

-Figure 14 and 15 show section views according to planes V-V and VI- VI of fig.13.

Description of Preferred Embodiments

Referring to fig.l, it is indicated as a whole with 10 a machine for automatically machining sheet materials, 11, such as leather, synthetic or similar. The structure of the machine essentially comprises two parallel side panels, 12, 13, well shown in fig.5, bound each other, in this embodiment, through a lower shelf, 14, also supporting a main electric motor of the machine, and through a central crosspiece, 15, apt to support, among the others, a plane where the sheet material to be machined slides.

Said crosspiece, 15, also act as a striking and reaction plane for a tool saddle, 17, exactly placed vertically over the crosspiece 15 and moving with vertical reciprocating motion, in the central plane of the machine 10. The tool saddle 17 is connected, at its ends, to side columns, 18, 19, externally bound to the side panels 12, 13, and hinged, at their lower ends, to connecting rods 20, 21, joined to shafts, 22, 23, rotating by means of a main electric motor, 24, and a drive belt 25. It has to be noticed that the above shafts are jointed each other through a joint, 26, useful to easily disjoint the shafts in case of maintenance.

The feeding of the sheet materials, 11, along the sliding plane, 16, in aluminum, is obtained through a conveyer belt, 27, in cardboard, which provides a friction coefficient suitable to drag the sheets of material which are simply supported on it and, at the same time, has characteristics of distortion and malleability suitable to properly machining sheet materials. Said conveyer belt winds off between two main supporting rollers, 28, 29, respectively dedicated to unwind and rewind the belt, said rollers being placed at the opposite sides of the machine 10, mounted at the ends of two parallel arms 30, 31, fixed to the lower parts of said side panels 12, 13. The right pitch of the belt, between two consecutive strokes of the tool saddle 17, is determined by rotating, of a specific angle, a dragging roller, 32, placed at the exit of the work surface, the right rotation angle being attained by the proper positioning of the two ends of a rod, 33, comprised in a dedicated crank mechanism. As we can see in fig.l, a first end of said rod is hinged to a slot, 34, comprised in a disk, 35, connected to the shaft 22, while the other end of said rod 33 is hinged to a second slot, 36, comprised in an appendix of a sleeve, 37, mounted on the axle of the roller 32. Between the external sleeve, 37, and the axle of the roller 32, we find an idler wheel, 38, apt to allow movement of the sleeve 37 only in counter-clockwise direction, referring to fig.l. The roller 32 is externally coated with a rubber porous cylinder to grant the maximum adherence to the conveyer belt 27 to be dragged; the thickness of said coating is shown with hatched line in fig.5. It has to be noticed that a second idler wheel interposes between the rubber cylinder and the axle of the roller 32, so that the movement transmits from the axle to the cylinder but not vice versa. Therefore the pitch of the conveyer belt, and, as a consequence, of the supported sheets of material, is determined just by the counter-clockwise rotation of the sleeve 37, angle which can be finery set thanks to the above described hinged mechanism, to obtain the desired pattern with high precision. The adherence of the conveyer belt 27 to the rubber cylinder 32, useful to assure the above said dragging operation, is optimised by pulling over, toward the lower roller 32, a further roller, 58, shown in the section view of fig.6, the conveyer belt 27 moving between the two rollers. When the machine is powered, the roller 58 is pulled over, through pneumatic cylinders 39, 40, bound to the side panels 12, 13. The conveyer belt 27 is rewound on the roller, 29, by the rotation of the roller itself, by means of a specific electric motor, 41, whose torque is electronically controlled by the control unit of the machine as a function of the various work parameters, which can be set through the same control unit, such as the frequency of the tool saddle movement, the total number of strokes in a single production cycle, and other more.

The belt 27 unwinds properly from the roller 28 thanks to the braking action performed on the roller 28 by a special pneumatic disk brake, 42, and also thanks to the damping action of a roller, 43, elastically supported at the ends of two transversal arms 44, 45 integral to said side panels 12, 13, of the machine, as shown in fig.2.

Two further rollers, 46, 47, complete conveyer belt 27 dragging mechanism. The tool, 50, associated to the tool saddle, 17, consists, in this embodiment, of a series of hollow punches apt to make multiple perforations in sheets of material, according to the drawing of fig.4. Said tool 50, as we can see in fig.3, provides, at its lower end, a plate 51, joined through elastic means to the main body of the tool and apt to keep the sheet 11 in firm position, during the perforation executed by the hollow punches 53 when the tool saddle comes down in its work stroke. The stick, 54, comprising the punches 53, can be easily changed, sliping it off through the side aperture 55 of the side panel 12, after disengaging the blocking jib 56; for this purpose special threaded pins are provided on the side surface of the tool 50.

As a function of the pattern to obtain the tool and its stroke may vary. The adjustment of the stroke is performed, as we can see in fig.l 1, changing the vertical position of the striking plate, 61, integral with the upper surface of the crosspiece, 15, said plate being supported by sliding tables, 62, 63 coupled each other along an inclined plane in order to set the position of one in respect of the other one. To a specific horizontal position of the lower sliding table, 63, corresponds a well defined vertical position of the upper sliding table, 62, and, then, of the plate 61 bound to the upper sliding table through screw means, 64. With 65 is schematically shown a command device which, interfacing with the lateral restraining plates, 66, 67, of the sliding tables, causes the movement of the lower sliding table; with 68 is shown a sensor detecting the position of the lower sliding table, while, with 69 is shown a pin for setting the vertical stroke of the upper sliding table.

To assure the adherence of the single sheet of material to the conveyer belt in correspondence of the work surface two more rollers, 71, 72, are provided, placed alongside the tool, the right position of each roller being changed, according to the width of the tool, thanks to supports, 73, 74, placed at their ends and provided with multiple adjacent slots. It has to be noticed that, advantageously, the roller 72, placed at the enter side of the work zone is heavier than the roller 71 placed at the exit of the work zone, in order to promote the exit of the machined sheet from the work zone. A sensor position, 75, is bound to the side panel 12 to detect the presence, or the absence, of the column, 18, of the tool saddle in the upper end-stroke position. The relating information is sent to the machine control unit, both to allow the control of the production cycle, and to allow the stop of the machine, at end cycle, in the upper position, so that substitution or maintenance of the tool may take place. The stop in said position is obtained by setting in action a pneumatic actuator 76 apt to bring braking jaws 77 in contact with a disk 78 joined to the shaft 23. Fig.8 shows, in detail, the way a column, 18, of the tool saddle is bound to the relating side panel, 12. As we can notice, the carriages, 81, integral to the columns, 18, 19, slide in the rails, 82, integral to the side panels, 12, 13, by ball coupling, so that a high efficiency is obtained and a high liability. It is shown, with 83 in fig.9, a fitting for a lubricating circuit internal to each carriage 81. In the view of fig.7, made from the opposite side from the one of fig.5 and indicating the side carters 91, 92, are shown, in exploded view, the components of the machine comprised between the side panels 12, 13, the dimensions of said components being changed if the machine has to be adapted to greater or smaller dimensions of the sheet material to be machined. In particular, in the case the sheets have very relevant dimensions it is advantageously adopted the embodiment shown in fig.10 in which two crosspieces 14' and 15' are placed respectively in upper and central position in the machine.

The central crosspiece, 15', in this case also supports the main motor, 24', in addiction at being the work crosspiece apt to support the sheets of material while machined by the tools acting on the sheets at the end of the stroke of the tool saddle, 17', vertically placed over it.

It has to be noticed that, in this embodiment, the winding and rewinding rollers of the conveyor belt, are supported by two separated arms, 30', laterally extending from the side panel 12' and, by two arms, 31', not shown in figure, extending from the opposite side panel, 13'.

The elements 18', 20', 23' and 41', in this embodiment, correspond to the analogue elements 18, 20, 23 and 41 of the first embodiment. The stroke adjustment is obtained thanks to a mechanism which is similar to the mechanism disclosed in the embodiment of fig.l. But, in this case, as we can see in the partial section view shown in fig.12, made according to the plane Hi-Ill of fig.l 1, the lower sliding table and the upper sliding table are disjointed in three parts, composing three couples which can be set in a separate way with respect of each other.

In particular in this embodiment the settings provide that the vertical position of the upper external sliding tables, 62 'a, 62 'b, is higher then the position of the upper central sliding table 62 'c. In fact we can see that between the external sliding tables 62'a, 62'b and the striking plate form spacings, 93', 94' which diminish at their ends because said plate 61', which in this case is as long as the crosspiece 15', takes a concave shape with downward concavity. This is useful to abridge the inflection of the crosspiece 15' under the force exerted by the tool saddle 17' during the machining, at the end of its stroke. The different height of the three upper sliding tables 62'a, 62'b, 62 'c, is obtained separately setting the horizontal position of the corresponding lower sliding tables 63'a, 63'b, 63'c, by the relating commands, 65', acting upon the riveted bars, 95', which engage with the bushings, 96", integral to said lower sliding tables, hi particular, the central lower sliding table, 63'c, takes a delayed position with respect to the external sliding tables 63'a, 63'b, as we can see in the section view of fϊg.15 with respect to the one of fϊg.14.

Those section views, to tell the truth, concern the crosspiece, 15", as arranged in fig.13, where is provided that the upper sliding table, 62 "a, of one of the three couples of sliding tables comprised in said crosspiece is shaped so that it houses two more sliding tables 97', 98',which cover longitudinally half the length of said sliding table, 62 "a. In this case also the striking plate is longitudinally disjointed in two different parts 101', 102', as well as the central strip 110',of material of said plate is also longitudinally disjointed in two symmetrical parts 111', 112'. It has to be noticed that said strip 110' act as a counter-mould, being made of a material, such as aluminum, in which rabbets of each hollow bunch of the tool saddle 17' can be provided.

The disjointed arrangement of fig.13 allows regulating separately, if needed, the height of the rabbet for the different rows of bunches relating to a specific work zone, said regulation occurring by a special actuator, 121', acting on the screw, 122', engaging the lower sliding table 98', of the couple of sliding tables relating to said work zone.

It has also to be noticed that in this arrangement of the crosspiece, 15", the striking plate is longitudinally disjointed only in correspondence with one of the parts in which are disjointed the setting sliding tables, while, as regards the two other parts, the upper plate is a single part, 61", and it is as large as the sum of the two other plates. Alternatively, in different embodiments of practical use, said plate could be longitudinally disjointed in two identical parts all along its length equal to the length of the crosspiece. The choice of the proper arrangement of the crosspiece depends, according to the various possible applications, on the need to regulate the rabbet in different zones of the work surface covered by the tool saddle.

The way of working of the machine of the invention provides, in fact, that before automatically proceeding with the operations, the vertical position of the various upper portions of the crosspiece is set, the setting being performed acting separately upon the various actuators, 65', 121 ', or calling back, from a specific control panel, the vertical position settings optimised for the specific application and stored in memory means of the machine, said settings being automatically obtained by the control means of the machine. The advantages coming from the way of coupling the columns to the side panels and other advantages coming from what above disclosed, such as the high productivity and quality of the operations that the machine is able to perform, as well as the advantages relating to the structural flexibility of the crosspiece of the second embodiment disclosed remain safe also in presence of changes and modifications.

For example, the shape and dimensions of the structure may change, in particular the side panels and the other removable components may change, as a function of the dimensions of the material to be machined.

The conveyer belt could be made of a different material, or of a different type, or, even, it could completely lack, for example when the material to be machined is in coils. The pitched dragging system of the machine could also vary; in fact, an electric actuator with electronic control could be used.

The tool mounted in the tool saddle could be a blade if we need to perform an incision rather than a perforation, or it could be a pantograph stick or a different special tool in case of moulding or plating. The number of the tool saddles comprised in a single structure may also change, the tool saddles being effected by a single motor or by separate motors.

As well, referring particularly to the embodiment in which the crosspiece is composed of several adjacent parts, the number of the components comprised in the upper zone of the crosspiece of the invention could vary with respect to the ones disclosed. The longitudinal disjunction of said parts could affect just one of them, as well as all of them, in the same or different manners.

The upper striking plate could be a single one for every part or it could be disjointed, both longitudinally and transversalfy. The means setting the vertical position of the various components comprised in the upper part of the crosspiece could obviously differ from the sliding tables with inclined plane used in the disclosed embodiments.

The application sector of the apparatus of the invention could be not only the leather sector, but also sectors where similar materials are used, such as polyvinyl materials or other materials having surfaces which are to be machined through perforation, incision, moulding, plating leaf materials, such as the automotive sector, naval sector or furniture sector.

Claims

C L A I M S - Machine for automatically machining sheet materials, such as leather, synthetic materials or similar, characterized in that it comprises

-a modular support structure composed by elements coupled each other in a removable way,

-dragging means, with speed control, of a conveyer belt convoying the sheet material,

-at least one tool saddle moving of vertical reciprocating motion and placed above said conveyer belt, said tool saddle being linked to said modular structure by low friction supporting and sliding means,

- means for setting, without stopping the production, the work stroke of the machine. - Machine according to the previous claim characterized in that said support structure comprises parallel side panels (12, 13) linked each other through at least one lower shelf (14) also supporting a main electric motor of the machine, and through at least one central crosspiece (15) apt to act as striking and reaction plane at the end of the stroke of the tool (50). - Machine according to claim 1 characterized in that said means apt to set the work stroke include at least one sliding table (62) placed in correspondence of the upper surface of said central crosspiece (15), under said conveyer belt (27), the vertical position of said table being adjustable. - Machine according to the previous claim characterized in that the vertical position of said sliding table (62) is adjustable by setting the horizontal position of a lower counter-sliding table (63), said horizontal setting taking place by acting on command means (65). - Machine according to claim 1 characterized in that said conveyer belt (27) is made of paper, or pressed cardboard, and winds off between two rollers (28, 29) respectively dedicated to the unwinding and rewinding of said belt, said rollers being placed at the opposite sides of the machine (10), mounted at the ends of two parallel arms (30, 31) fixed to the lower parts of said side panels (12, 13). - Machine according to claim 5 characterized in that said conveyer belt (27) rewinds rotating around said roller (29) by means of an electric motor (41) whose torque is electronically controlled. - Machine according to claim 5 or 6 characterized in that said conveyer belt (27) properly unwinds from the roller (28) thanks to the braking action of a pneumatic disk brake (42) and thanks to the damping action of a roller (43) elastically supported at the ends of two transversal arms (44, 45) integral to said side panels (12, 13). - Machine according to one of the previous claims characterized in that said tool saddle (17) is connected, at its ends, to side columns (18, 19) externally fixed to said side panels (12, 13) and hinged, at their lower ends, to connecting rods (20, 21) joined to shafts (22, 23) rotating by means of a main electric motor (24), said shafts being jointed each other through a joint (26). - Machine according to the previous claim characterized in that it comprises a position sensor (75) fixed to said side panel (12) in order to detect the upper end-stroke position of said tool saddle (17). 0- Machine according to claim 8 or 9 characterized in that it comprises a pneumatic actuator (76) apt to bring braking jaws (77) in contact with a disk (78) joined to at least one of said shafts (22, 23). 1- Machine (10') according to claim 1 characterized in that said supporting structure comprises parallel side panels (12', 13') linked each other through at least one upper shelf (14'), and at least one central crosspiece

(15') apt to act as striking and reaction plane of the work stroke of the tool saddle (17') and also as support of the main motor of the machine. 2- Machine according to the previous claim characterized in that said central crosspiece comprises adjacent portions whose total length correspond to the length of said tool saddle (17'), each of said portions being separately vertically adjustable, so that the work stroke can be set all along the work surface upon which said tool saddle acts. - Machine (10') according to the previous claim characterized in that said central crosspiece (15') comprises three adjacent portions, each of said portions comprises at least one down sliding table (63'a, 63'b, 63'c) and at least one upper sliding table (62'a, 62'b, 62'c) coupled together along inclined planes, the horizontal position of said down sliding table being finely adjustable, by specific actuators (65'), in order to attain the vertical adjustment of the corresponding upper sliding table. - Machine according to claim 12 or 13 characterized in that it comprises at least one striking plate (61') fixed on said adjacent portions. - Machine according to the previous claim characterized in that said plate (61 ') comprises at least one central strip (110') apt to act as a counter mould. - Machine according to one of the claims from 12 to 15 characterized in that the upper sliding table (62"a) of at least one of said adjacent portions of the crosspiece is longitudinally disjointed. - Machine according to the previous claim, characterized in that in one part of said upper sliding table (62 "a) are housed two more sliding tables (97',

98') coupled and placed one on the other according to a further inclined plane, the upper (97') of these two more sliding tables being vertically adjustable by means of the horizontal movement of the lower sliding table (98'). - Machine according to the previous claim characterized in that it comprises, fixed on said upper sliding table (62"a), a striking plate longitudinally disjointed in two, or more, different parts (101', 102'), a central strip of material of said plate being also longitudinally disjointed in two, or more, parts (111 ', 112').