Method and machine for automatically cutting hides

The present invention relates to a method for automatically cutting hides - both natural and synthetic.

In the tanning industry, hides are generally cut by means of a method which comprises a mapping phase of the contours of each hide, a positioning phase of a number of shapes to be cut within the edges of said contours, and a phase of cutting the shapes themselves.

In the past, the mapping phase was carried out by drawing the contours of the hide on a drafting machine or even on a wooden table; the positioning phase was carried out by arranging a number of cardboard outlines within the edges of the contours of the hide until the surface of the hide itself was substantially covered; the cutting phase was carried out by means of simple tools such as pairs of scissors and/or knives, which have been replaced recently with automatic cutters, dinkers with steel blades, laser cutting heads or water jet cutting heads, due to a considerable increase in volume of production.

The introduction of the above-mentioned cutting devices might well cut down on working time, but it does not yet succeed in fulfilling the current demands of the market and also involves further disadvantages due, in the first place, to the necessity of moving a hide which is not securely held down, with the consequent result that fixed points of reference are lost, and, in the second place, said introduction of the above-mentioned cutting devices does not yet permit the entire hide to be used, with the result that too much of the hide is wasted.

Furthermore, the method described above involves other disadvantages which mean that it is not possible to create the shape to be cut from the hide in the most flexible way.

The aim of the present invention is to provide a method for cutting hides which is free of the disadvantages described above.

According to the present invention, a method will be provided for cutting hides comprising a mapping phase regarding the contours of each hide, a positioning

   phase of a number of shapes to be cut within the borders of said contours and a cutting phase of the shapes themselves; the method being characterised by the fact that it comprises an automatic feed phase for each of the said hides along a feed path which extends through a mapping station and a cutting station which are arranged in sequence along the path itself.

The present invention also relates to a machine for cutting hides.

According to the present invention, a machine will be produced for cutting hides, characterised by the fact that it comprises: automatic conveying means to automatically feed each of the said hides along a feed path extending in sequence through a mapping station and a cutting station; mapping means for the mapping of the contours of each hide arranged to correspond to the mapping station; positioning means for the positioning of a number of shapes to be cut inside the said contours, and cutting means for cutting the shapes themselves arranged to correspond to the said cutting station.

The invention will now be described with reference to the attached drawings, which show a non-limiting embodiment of the invention in question, in which:

FIGURE 1

is a diagram of a side elevation of a preferred form of embodiment of a machine for cutting hides using the method as described in the present invention;

FIGURE 2

is a plan view of the machine illustrated in FIGURE 1; and

FIGURE 3

is an enlarged scale view of a detail in FIGURE 1.

With reference to FIGURES 1 and 2, the number 1 refers to a machine 1, in its entirety, for cutting natural and/or synthetic hides 2 and/or other kinds of material, said machine 1 comprising a feed path P for the hides 2 themselves, and a rack conveying means 3 suitable for automatically feeding the hides 2 along the path P itself from a loading station S1 to an unloading station S2.

In the example of the embodiment illustrated, the path P is rectilinear horizontal path, but according to a variation of the machine 1 which is not illustrated, the feed path could also be circular, or even rectilinear and vertical.

The device 3 comprises a frame 4 which is provided with an upper level K1 on which the path P extends, and a lower level K2 which is arranged below the level K1 parallel to the level K1 itself. The device 3 also comprises a determined number of platforms 5 each of which is defined, as is better illustrated in FIGURE 3, by a rectangular frame 6 and a grid 7 for transporting at least one hide 2 according to the dimensions of the hide 2 itself.

The device 3 also comprises a forward transport arm R1 which extends along the level K1 and is suitable for gradually advancing the platform 5 from the station S1 towards the station S4 for transporting the hides 2 along the feed path P; the device 3 also comprises a return transport arm R2 which extends along the level K2 and is suitable for gradually advancing the platform 5 from the station S4 towards the station S1, and two movement devices 8 and 9, the first of which is arranged in the station S1 in order to raise the platform 5 from the level K2 to the level K1 and the second of which is arranged in the station S4 to lower the platform 5 from the level K1 to the level K2.

The machine 1 also comprises a mapping device 10 for mapping the contours 11 of each hide 2 said mapping device 10 being arranged to correspond to a mapping station 2; a positioning device 12 for positioning a number of shapes 13 to be cut within the contours 11 of each hide 2; and a cutting device 14 for cutting out the shapes 13 themselves, which is arranged to correspond to a cutting station S3. In particular, while the stations S1 and S4 are arranged at opposite ends of the feed path P, the stations S1 and S3 are arranged in sequence along the feed path P itself and are in an intermediate position between the stations S1 and S4 themselves.

The mapping device 10 is a film device for acquiring images and comprises, the example of the embodiment illustrated, a TV camera 15 arranged above the level K1 and directed towards the level K1 itself, and a number of light sources 16 for illuminating a hide 2 which is stationary in the station S2 below the TV camera 15.

The TV camera 15 can be replaced with a photographic camera, or a scanner, or even with other similar film means, and it can be set with different levels of resolution according to the level of precision and detail that needs to be obtained in defining the contours 11, and said device 15 is also suitable, apart from mapping the shape of the contours 11 themselves, for scanning the hide 2 in order to reveal any further intrinsic characteristics of the hide 2 itself, such as, for example, the direction of the grain in the hide 2 and/or any eventual defective areas in the hide 2 itself.

The light sources 16 are arranged both above the level K1 and below the level K1 itself, in such a way as to illuminate the hide 2 itself and in such a way as to highlight the above-mentioned intrinsic characteristics of the hide 2 itself.

The cutting device 14 comprises a water jet cutting head 17, and a movement device 18 which is suitable for moving the head 17 itself in a direction D1 which is parallel to the feed path P, as well as in a direction D2 which is transversal to the direction D1 and contained within the level K1, and also in a direction D3 which is transversal to the level K1 itself.

The device 18 comprises a portal 19 straddle arranged to the feed path P which is slidingly connected to the opposite ends of the frame 4 in order to slide according to the action of a first linear actuator in the direction D; said device 18 also comprises a support track 20 which is slidingly connected to the portal 19 in order to slide along the portal 19 itself according to the action of a second linear actuator, and a third linear actuator 21 which is supported by the track 20 and is mobile in the direction D3 in order to move the head 17 in the direction D3 itself so as to either move it towards or away from the level K1.

The device 14 also comprises a feed device 22 for the head 17, which comprises a pump 23 for supplying water under pressure to the head 17, and a duct 24 which is interposed between the pump 23 and the head 17. The duct 24 comprises two spiral joints 25 and 26 which are suitable for tolerating the stress caused by the water under pressure inside the duct 24. The joint 25 is connected on one side to a rigid pipe 24a, and on the other side, via the interposition of a set of springs (which are not illustrated) to a crossbar 27, which extends above the level k1 in order to support the duct 24, and is part of the frame 4.

The device 14 also comprises a laser marking head 28, which is linked to the head 17, and which is supported by the track 20, and which is also suitable for marking the shapes 13 in such a way as to associate each of these either to reference lines which can then be used for subsequent working, or to codes for the identification of the shapes 13.

Finally, the device 14 also comprises a fume extraction device 29, which is arranged below the level K1 to correspond to the station S3, and which is linked to a filter 30, and which presents a protective cover for the station S3 itself which is suitable for preventing the dispersion of the fumes themselves, as well as for protecting the station S3.

According to some variations which are not illustrated, the cutting device 14 can also comprise two portals 19 and two heads 17, as well as two laser marking heads 28: this means that it is possible to increase the production capacity of the machine 1 in a considerable manner.

The functions of the machine 1 are automatically controlled by a control unit U, which comprises the positioning device 12, and which is input connected to the TV camera 15, and which is output connected to the conveying device 3 as well as to the cutting device 14.

Once that one of the platforms 5 has been arranged on the level K1 in order to correspond to the station S1, an operator, who must work at the same rate as the cycle of the machine 1, sprays onto the grid 7 a water based glue or similar product of such a kind as not to damage the hide 2 in any way, after which said operator positions on the grid 7 itself one or more hides 2, according to the dimensions of the hides 2 in comparison with the dimension of the grid 7. The act of spraying the glue guarantees that the hide 2 is held firmly on the grid 7 for several working cycles rather than just one and it also prevents any accidental movement of the hide 2 itself, above all during the cutting phase.

At this point, the operator must analyse the hide 2 on the platform 5 and examine the hide 2 itself in such a way as to highlight any defective areas in the hide 2 itself and the operator must also determine the direction of the fibres in the hide 2: for this operation, the operator should use a colour which contrasts with the colour of the hide 2 itself and which may thus be easily identified by the TV camera 15. The aforementioned operation is not only useful for identifying the defective areas in the hide 2, but is also useful for identifying the highest quality areas in the hide 2. Such high quality areas can thus be reserved for specific kinds of shapes 13, which can then be used for the production of special articles or high quality articles according the quality of the hide 2 which has been identified.

Once the identifying operation has been carried out, the device 3 advances the platform 5, with the relative hide 2, along the feed path P according to a distance which is substantially equal to the length of the platform 5 itself, and it then arranges the platform 5 in the station S2, where the TV camera 15 identifies the contours 11, as well as all the above-mentioned intrinsic characteristics, which are then sent to the control unit U. The control unit U then operates in tandem with the positioning device 12 to determine how may shapes 13 can be obtained within the contours 11 which have been identified in the manner described above.

In particular, the device 12 arranges the shapes 13 on the hide 2 in a virtual fashion, taking into account various defective areas, holes, high quality areas and the direction of the grain in the hide 2. The device 12 also takes into account the non-intrinsic characteristics of the hide 12, such as the kinds of shape 13 which are necessary, as well as the number of the shapes 13 which have to be obtained. In other words, the use of the devices 10 and 12 means hat each hide 2 is exploited to the maximum, with a minimum of waste, and it also means that extremely high volumes of production, including various different shapes 13, can be fulfilled in a short time and also in a highly flexible manner.

Furthermore, the device 12 is capable of precisely identifying the areas in the hide 2 which can be used in the best way possible.

As soon as the mapping and positioning phases have been carried out, the device 3 moves the platform 5, with the relative hide 2, along the feed path P by one step; it then arranges the platform 5 in the station S3, where the laser head 28 marks the shapes 13 so that it is easier to store the shapes 13 themselves according to orders which have been placed. On the other hand, this operation is also valid for collecting the shapes 13 into groups of similar shapes. The device 18 then moves the head 17 above the hide 2 along a cutting path which is determined and calculated by the control unit U in such a way as to optimise the movements of the head 17 itself, as well as the cutting phase so that the stress on the feed device 22 is reduced to a minimum.

At this point, the device 3 advances the platform 5 to the station S4, in which an operator must remove the shapes 13 which have been cut, and then said operator must store said shapes 13 as quickly as possible, using the marks carried out by the head 28 before the platform 5 has been moved by the unloading device 9 from the level K1 to the level K2, where the arm R2 of the device 3 itself moves the platform 5 to the station S1.

The number of the platforms 5 which are simultaneously present along the two arms R1 and R2 is mainly in function of the size of the machine 1, in each case, for each working cycle, there are always at least four platforms 5 present along the feed path P, which means one for each station S1, S2, S3 and S4, and which are simultaneously advanced by the rack conveyor means or a conveyor means of another type.

Finally, the fact that the machine 1 is extremely versatile means that it is possible to vary the settings of the control unit U in such a way as to effect minute corrections during each production cycle, as and when the operator deems that such corrections might be necessary.

It is not intended that the present invention be limited to the embodiments herein described and illustrated. The embodiments herein described and illustrated are to be considered as examples of the embodiment of a machine for cutting hides, which might be subject to further modifications in terms of the shape and arrangement of the parts herein described, as well as further modifications in terms of details regarding construction and assembly.