IT202000017926A1 - MACHINE FOR THE ROLLER FINISHING OF LEATHER - Google Patents

Description

DESCRIPTION

of the invention with the TITLE ?Machine for leather roller finishing"

The present invention relates to a machine for roller finishing leather, according to the general part of claim 1.

A known type of leather finishing machine? illustrated in fig.1.

As ? known, for the execution of the finishing operation in the tannery field roller machines are used in particular, commonly called buffering machines, in which the hides P are transported by a rubber belt 1 and pressed against an opposite engraved roller 2, which deposits a uniform film of liquid L on the surface of the leather, previously distributed on said roller engraved by one or more? doctor blades 3.

The engraved roll can rotate in ?synchro?, that is? in a sense that agrees with the direction of advancement of the skin or in ?reverse?, that is? in the opposite direction to the aforementioned direction of the skin.

The perfect success of the leather finishing operation depends on many factors, among which the predominant ones are a regular entry of the leather into the restricted area, that is? that between the engraved roller and the underlying conveyor belt and a well-defined compressive force of the portion of leather which comes into contact, in a substantially tangent manner, with the surface of said engraved roller. The uniformity of this compression force when the roller plugging machine ? equipped with a rubber conveyor belt 1, it depends on the tension of the belt itself to guarantee its winding on a driving roller and on an underlying contrast roller 4, which in some embodiments coincide.

However, it should be noted from now on that the configuration of machines for finishing known types of leather can also be different from that shown in Figure 1.

In some of the machines of the known type, such as the one illustrated explicitly in figure 1, ? expected that the task of the driving roller is performed by one of the rollers 4 or 5, cos? how the other of said two non-driving rollers is in fact an idle roller. In some other finishing machines, the task of the drive roller? vice versa played by an additional roller placed near? means 20 for allowing carpet 1 to be washed and dried which operate continuously on its outer surface. It is therefore reiterated that what is represented in figure 1 ? only one of the possible embodiments of machines of the known type for finishing leather and that the invention relates to all such machines manufactured in accordance with of the general part of claim 1.

How is it? visible in this figure 1 in the devices of the state of the art ? there is also a positioning roller 7, placed inside the volume delimited by the rubberized carpet 1, in contact with the internal surface of the aforesaid carpet and with adjustable positioning, arranged downstream of the contact area between the engraved roller 2 and the rubberized carpet 1 By suitably adjusting the positioning of said roller 7 and keeping the center distance of the axes 2 unchanged? and 4? of reels 2 and 4 ? Is it possible to determine exactly the entity? of the contact area between the hides P and the engraved roller 2 by acting on the geometry of the belt 1. In this way ? is it possible to act directly on the quantity? of liquid that enters the pores of the skin and on the quality? of the spreading of the liquid itself on said leather, adapting the operation of the machine to the characteristics required by the user, both as regards the type of leather on which it is desired to operate, and as regards the liquid actually deposited on the leather P. What? is especially useful when the engraved roll operates in mode? reverse.

In fact, for each type of leather and even, sometimes, for each batch of leather, "field" tests are carried out, modifying the precise positioning of the roller with more adjustable positioning. mentioned times in order to obtain optimal results.

In the machine shown in figure 1 ? also visible is the introducer device 40, as well as? the means 20 for washing and drying carpet 1, already? previously mentioned, which comprise, in particular, a tank 23 containing the liquid cleaning solution, the toothed roller 21, as well as the blades 22 for the continuous abrasion of the residues present on the carpet 1.

In the same figure it can also be seen that the hides P, downstream of the transmission roller 5, are deposited on a conveyor means 6, generally consisting of a carpet.

In addition, the most mentioned times rubber carpet 1 has an external surface covered with a layer of rubber, generally of the synthetic type, which can vary from 2mm to 20mm thick, to which the skins adhere strongly by friction. It is reiterated once again that all of this? constitutes known art.

Must for? consider that modifying the positioning of the roller 7 causes a variation in the geometry of the belt 1 and therefore a variation in the length of its development, with a consequent increase or decrease in the tension of the belt.

The rubber carpet 1, although it intrinsically has some properties? of elasticity? in the longitudinal direction (its longitudinal development can therefore be modified) it is destined to undergo considerable stress from a mechanical point of view as a result of these continuous variations. Tests carried out have made it possible to ascertain that following the variation in the positioning of the roller 7, variations in longitudinal development are determined which can exceed 5 - 10 mm, with high stresses on the belt; There? necessarily determines a reduction in the life of the carpet, making it necessary to replace it when cracks or the like appear on the external rubber layer. Also more the aforementioned is tense, pi? you determine a difficulty? to keep the aforementioned centered in relation to the rollers around which it moves.

Main purpose of the present invention ? that of realizing a machine for finishing leather which is capable of obviating the considerable drawback mentioned concerning the variations in the longitudinal development of the rubberized carpet.

Further purpose of the invention ? that of making this machine simple from the construction point of view and at the same time being particularly easy to use and effective for the user.

There? it is obtained, according to the invention, by conforming the machine according to the characteristics described in the characterizing part of claim 1.

Further characteristics of the invention are present in the dependent claims. Furthermore, a particular operation of the machine according to the invention ? described in claim 9.

These and other characteristics of the invention will now be described in detail below. Some of its particular embodiments will be taken into consideration, as illustrated in the attached drawings and given as a non-limiting example, where:

- fig. 1 (Tab. I) represents an overall schematic view of a machine for roller finishing of hides according to the state of the art;

- figs. 2, 3 (Tab. II) show two schematic side views of a first embodiment of the device according to the invention, in two different operating conditions;

- figs. 4, 5 and 6 (Drawings III - IV) represent respectively an axonometric view and two side views of a portion of the machine according to the invention in this first embodiment;

- figs. 7, 8 (Tab. V) show two schematic side views of the first embodiment of the device according to the invention in two different operating conditions, applied for? to a machine of a different type to that shown in figures 2 and 3;

- figs. 9, 10 (Tab. VI) show two schematic side views of a second embodiment of the device according to the invention in two different operating conditions;

- figs. 11, 12 (Tav. VII) show two schematic side views of a third embodiment of the device according to the invention in two different operating conditions;

- figs. 13, 14 (Tab. VIII) show two schematic side views of a fourth embodiment of the device according to the invention in two different operating conditions;

- figs. 15, 16 (Tab. IX) show two schematic side views of a fourth embodiment of the device according to the invention in two different operating conditions, applied for? to a machine of a different type from the one shown in figures 13, 14;

- in figs. 17, 18 (Pl. X - XI) ? a portion of the machine according to the invention is shown, in a particular embodiment thereof described in one of the dependent claims, respectively under "usual" conditions and under the conditions in which the operating characteristics of this particular embodiment are achieved.

The first embodiment of the devices which allow the leather finishing machine to act according to the purposes of the invention ? represented in figures 2 and 3. It should be noted that many of the numeral references present in these figures are already? been extensively cited in the description and in figure 1, which represents the state of the art. In this embodiment ? in particular, it is foreseen that the roller 7 with adjustable positioning acts jointly and in an opposite way with a second positioning roller 8, both being in contact with the internal surface of the rubberized carpet 1. For this reason, when is it? If the second positioning roller 8 is present, the roller 7 is called the first positioning roller. ? in particular, it is envisaged that said rollers 7, 8 extend longitudinally along the transversal development of the rubberised carpet 1. In practice, as can be seen by carefully comparing the two figures 2 and 3 and how will it be? better specified below, said rollers act in such a way as to keep the longitudinal development of the carpet 1 substantially constant in correspondence with each position of the rollers 7, 8. In correspondence with the roller 5 the hide is delivered to the subsequent conveyor means 6, which in fact consists of a carpet.

From an operational point of view, as can be seen in figures 2 and 3, said rollers 7, 8 are pivoted, at both of their ends, to a single bar 9, such as to guarantee maintenance of contact between said rollers 7, 8 and the inner surface of the carpet 1. Constructively, as clearly visible in figures 4 to 6, the pins 11 are integral with the rollers 7, 8 and are pivoted in suitable seats 11? (fig.4) formed on said bar 9. As clearly visible in these figures, identical structures are provided with all the aforementioned elements in correspondence with both the two lateral sides of the machine. ? it is also provided that a hydraulic, pneumatic or electric operated element 50 acts on each of the bars 9. Therefore ? it is quite evident that, by acting on the bars 9 through the element 50, the precise positioning of the pins 11 is determined, thus determining the corresponding positioning of the rollers 7, 8. however it is clear that, given the geometry of the system, a corresponding "lengthening" of the carpet in correspondence with the upper part causes a corresponding ?shortening? of the carpet 1 in the lower part, there? determining the substantial constancy of the longitudinal development of the carpet even when its geometry varies.

It should be noted that the term substantial constancy of the longitudinal development of the carpet means the fact that, advantageously, the variation of the longitudinal development of said carpet ? with a value lower than 1mm in correspondence with its geometry variation.

In figures 7 and 8 we see that, as already? previously mentioned, the previously illustrated and described system is also suitable for use with machines which have different configurations from the one illustrated in figures 2 and 3, which mirrors the configuration illustrated in figure 1. In particular in the machine illustrated in figures 7 and 8 the function of motor roller ? carried out by roll 100, arranged near? of the means 20 for washing and drying carpet 1. For the rest, both structurally and functionally, the means which keep the longitudinal development of carpet 1 substantially constant as its geometry varies (rollers 7 and 8, bar 9, element 50, etc. ) act exactly like those illustrated above, as well as being identically shaped.

As can be seen in figures 9 and 10, according to another embodiment of the device according to the invention ? provided that each of the two positioning rollers 7, 8 is pivoted to its own arm 14, which is capable of rotating around its end? 15 opposite to the one to which said rollers 7, 8 are pivoted. in particular, provision is made for each of said arms 14 to be supported by a fixed support element integral with the machine, not shown in the figure for the sake of simplicity. ? also provided that on the axes 7?, 8? of the shaft around which said positioning rollers 7, 8 rotate, elements 19 with hydraulic, pneumatic or electric actuation managed by an electronic control unit act. In practice, actuating said elements 19 causes an upward and downward movement of the rollers 7, 8 while maintaining the axes 7?, 8? parallel to the axes 2?, 4? of rolls 2, 4, there? determining the variation of the geometry of belt 1.

In figures 11, 12 ? shown a further embodiment of the device according to the invention in which ? provided that, also in this case, the first positioning roller 7 is pivoted, as in the previous case, to an arm 17, which is capable of rotating around its end? opposite 15 to that correspondence of which ? pivoted said roller 7. The arm 17 ? supported by a fixed support element integral with the machine, not shown in the figure for simplicity?. On the pin at axis 7? an element 19 with hydraulic, pneumatic or electric actuation managed by an electronic control unit acts on the shaft around which said first positioning roller 7 rotates. All of that? exactly corresponding to the previous embodiment of the invention.

In this case ? For? Is there an element 21, also with hydraulic, pneumatic or electric drive, managed by an electronic control unit, which acts on the end? of axis 5? around which said second roller 5 rotates, in correspondence with which the hides P are positioned on a further conveyor means 6, constituted in the figures by a carpet.

Comparing figures 11, 12 in particular, it can be seen that in figure 11 the roller 7 is in position for what? "raised", which corresponds to the "retracted" position of the roller 5; conversely in figure 12 it can be seen that the roller 7 is in a so-called "lowered" position, which corresponds to the "extended" position of the roller 5. In in any case it is clear that, thanks to the corresponding and coordinated positioning of the two rollers 5, 7, the longitudinal development of the belt 1 is maintained substantially constant, while varying its geometry.

In figures 13, 14, 15 and 16 ? illustrated a fourth embodiment of the device according to the invention, applied by way of non-limiting example to two different machines of two different types; in particular figures 13, 14 are applied to the machine of figs. 2, 3, while figures 15, 16 relate to the machine illustrated in figs. 7, 8. This alternative embodiment provides that the bar 9 has a region of elasticity? adjustable guaranteed by the presence of an elastic element 60, of which ? Is it possible to adjust the load and that element 50 acts only on axis 7? of the roller 7. In particular figs. 13, 15 refer to situations in which the positioning of the carpet 1 in correspondence with the engraved roller 2 minimizes the contact area between said engraved roller and the hide P; conversely Figs. 14, 16 refer to a positioning of the carpet 1 with maximum contact area between said engraved roller 2 and leather P.

This last solution? able to compensate even more the tension of the carpet to vary the geometry and to maintain almost? the development of belt 1 is constant, with variations of less than 1 mm as the geometry of the same varies.

In figure 17 ? illustrated a particular embodiment of the device according to the invention; in this figure, which basically takes up what there? That ? shown in the previous figure 4, the positioning rollers 7, 8 in particular are clearly visible. In the situation represented in figure 17 these positioning rollers 7, 8 are presented in the usual situation in which they are in contact with the internal surface of the belt and in a perpendicular position to the feed direction of the hides, not shown in this case. Indeed, the person skilled in the art when considering the normal "positioning" of any of the rollers present in the machine (for example the contrast roller 4, the engraved roller 2, the return roller 5, etc.) clearly understands that their axis, in this "normal" condition, ? precisely arranged perpendicular to the advancement direction of the hides and parallel to the axes of the other rollers.

Conversely, as visible in figure 18, the second positioning roller 8 has a pin 11 arranged in a seat 12, schematically represented in the figure with a larger diameter than that of the pin 11, so as to allow slight displacements from the "normal" position of said pin 11. In fact, a cylinder 90 with hydraulic, pneumatic or electric actuation acts on the end of said pin 11, so as to cause the displacement of the end of said pin 11. Figure 18 shows the displacement from the position "normal" end of one of the pins 11 of the roller 8, but the presence of a similar structure could also be envisaged at the opposite side of the machine, which acts in a coordinated and opposite way to the one just described.

In fact, one of the problems encountered during use of the machine according to the invention consists in the fact that sometimes the belt 1 changes its "centered" position which is? precisely the one represented in figure 17, giving rise to bad results of the finishing operation. Tests carried out have made it possible to ascertain that, by deviating the second positioning roller 8 from its position for so? say "normal", in which, among other things, said second positioning roller 8 is arranged parallel to the first positioning roller 7, transversal forces are generated on the rubberized carpet 1, causing it to return to its correct "centered" position ".

It should also be noted that the same configuration need not necessarily be applied to the second positioning roller 8, among other things sometimes not present in the various embodiments of the machine of the invention previously described. As an example, this configuration could be applied also to the return roller 5. It is specified that this configuration could? however be applied to any roller inside the development of the rubberized belt 1 other than the contrast roller 4 and the first positioning roller 7.

In all embodiments of the device of the invention which provide for the use of a second positioning roller 8, it is possible to apply an electronic, pneumatic or mechanical device capable of inclining the axis 8? (figs.

15, 16) of said roller with respect to axis 4? of the contrast roller 4 in such a way as to maintain the centering of the rubberized belt 1. The same device can? advantageously be applied to the roller 5 to incline the relative axis 5? (figs. 13, 14) in embodiments of the invention in which the use of a second positioning roller 8 is not envisaged.

From the foregoing it can therefore be seen how by means of the various devices illustrated above it is possible to obtain the predetermined purpose of keeping the longitudinal development of the carpet substantially constant, while also varying its geometry considerably, in particular in correspondence with the area near the belt. of which ? present the roller engraved, there? which undoubtedly allows us to state that the objects of the invention have been largely achieved.

However, it is reiterated once again that in all embodiments of the present invention, both those described and illustrated, and others which in any case fall within the scope of the claims that follow, the substantially constant term, referred to the longitudinal development of the carpet, is advantageously understood as a variation of said development of a value lower than 1 mm in correspondence with the variation of geometry of the belt.

Finally, it should be noted that the present invention could assume forms and aspects different from those described, without prejudice to its essential characteristics, defined in the following claims, without thereby departing from the scope of the patent.

Claims (9)

1. MACHINE FOR THE ROLLER FINISHING OF LEATHER, which comprises a rubberized belt (1), which transports said leathers (P) previously deposited manually or through one or more? carpets and in which ? also present is an engraved roller (2) arranged above said skins (P), which rotates synchronously or in reverse with respect to the direction of advancement of the skins and which deposits on the surface of the aforementioned a uniform film of liquid (L), previously distributed on said roller from one or more? doctor blades (3), said carpet (1) being supported by a plurality? of rollers arranged inside the volume delimited by the rubberised carpet (1), at least one of said rollers being a drive, there being a contrast roller (4), arranged below the engraved roller (2), each of said two rollers (2 , 4) respectively rotating around mutually parallel axes (2?, 4?), a return roller (5) being also provided, arranged inside the volume delimited by the rubberized carpet (1), in correspondence with which the deposit of the hides (P) on a subsequent conveyor means (6), said machine also providing means (20) for washing and drying the carpet (1), which operate continuously on its external surface, being also provided, inside the volume delimited by the rubberized carpet (1), a first positioning roller (7), with adjustable positioning, placed in contact with the internal surface of said rubberized carpet (1) and downstream of the contact area between the engraved roller (2) and the aforementioned, the variation of the positioning of said first positioning roller (7) determining the variation of the geometry of the rubberized belt (1) and consequently the variation of the contact area between the skins (P) and the engraved roller (2), equal ? of distance between the axes (2?, 4?), respectively of the engraved roller (2) and of the first contrast roller (4), said machine being characterized in that at least one of the rollers arranged inside the volume delimited by the rubberized belt (1) and in contact with the internal surface of the same, distinct from the first contrast roller (4) and from the first positioning roller (7), ? also equipped with means suitable for allowing its adjustable positioning and ? adapted to determine the variation of the geometry of the aforementioned belt (1). 2. MACHINE, according to claim 1, characterized in that the roller equipped with adjustable positioning, distinct from the first positioning roller (7) and which allows the geometry of the belt (1) to be modified, consists of a further roller (8 ) of positioning, connected to the first positioning roller (7) through a bar (9), it being provided that said positioning rollers (7, 8) extend at least for the entire width of the rubberized carpet (1), it being also provided that on the supports of said rollers (7, 8) act means which determine their movement. 3. MACHINE, according to claim 1, characterized in that it provides that the roller equipped with adjustable positioning, distinct from the first positioning roller (7) and which allows the geometry of the rubberized belt (1) to be modified, consists of a second further roller (8) not mechanically connected to the first positioning roller (7), each of said positioning rollers (7, 8) being pivoted to its own arm (14), able to rotate around its end? (15) opposite to that to which said positioning rollers (7, 8) are pivoted, said pivot being provided in correspondence with a fixed support element integral with the machine, which also provides for the support of said positioning rollers (7, 8 ). 4. MACHINE, according to claim 3, characterized in that elements (19) with hydraulic, pneumatic or electric actuation act on the axes (7?, 8?) of the shafts around which said further positioning rollers (7, 8) rotate managed by an electronic control unit. 5. MACHINE, according to claim 1, characterized in that it provides that the roller equipped with adjustable positioning, distinct from the first positioning roller (7) and which allows the geometry of the rubberized belt (1) to be modified, consists of the return roller (5), which ? supported by a fixed support element integral with the machine, a further element (21) being provided with hydraulic, pneumatic or electric actuation, managed by an electronic control unit, which acts on one end? of the axis (5?) around which the transmission roller (5) rotates. 6. MACHINE, according to claim 2, characterized in that it provides that the connection bar (9) between the further positioning rollers (7, 8) ? internally equipped with an elastic element (60). 7. MACHINE, according to claim 6, characterized in that the elastic element (60) is? equipped with means to allow the variation of its development at rest. 8. MACHINE, according to any one of the preceding claims, characterized in that at least one of the ends? of the roller equipped with adjustable positioning, distinct from the first positioning roller (7) and which allows to modify the geometry of the rubberized belt (1), ? supported by means adapted to modify the usual positioning of said roller from a first position, in which its axis is? arranged parallel to the axis of the first positioning roller (7) and perpendicular to the advancement direction of the rubberized carpet, to a second position, different from the above. 9. OPERATION OF THE MACHINE, according to one or more? of the preceding claims, characterized in that the geometry variation of the rubberized belt (1) induced by the movement of at least one of the adjustable positioning rollers distinct from the first positioning roller (7) causes a variation of the longitudinal development of said belt (1) opposite to the variation of the longitudinal development of the aforementioned belt (1) induced by the movement of the first positioning roller (7), said variation maintaining the overall modification of the longitudinal development of the belt (1) at a value lower than 1 mm as the geometry of the said carpet.