Field of the invention

[0001] The present invention generally finds application in the field of leather processing and particularly relates to an industrial hide splitting machine.

State of the art

[0002] Splitting machines are known to be used for splitting hides, i.e. cutting them in the direction of thickness into a more valuable layer, known as grain, and a less valuable layer or split.

[0003] Typically, prior art splitting machines comprise a lower table for receiving the hide and an upper head having a driving belt, in the form of a sleeve made of synthetic material, which feeds the hide toward a downstream cutting device.

[0004] Generally, the cutting device comprises a blade, which is wound in a loop around a pair of guiding flywheels in a position transverse to the feed direction of the hide, to be rotated around the rollers.

[0005] The cutting edge of the blade is situated in front of the hide infeed side such that the cut may be made across its entire transverse extent.

[0006] A first drawback of prior art arrangements is that the hides to be cut must be manually accompanied by the operator toward the cutting blade, which implies self-evident risks for the operator's safety.

[0007] In an attempt to obviate this drawback, the Applicant hereof has developed a splitting machine, as disclosed in IT1423320, in which the receiving table defines a feed plane which cooperates with the driving belt to cause the hide to be fed toward the cutting blade without requiring the operator to place his/her hands proximate thereto.

[0008] A further machine, still developed by the Applicant hereof and disclosed in IT1429923 provides a pair of opposed rollers immediately upstream of the cutting blade, which define a gap for the passage of the hide to be cut, and whose mutual position is locally adjustable to calibrate the thickness of the hide. [0009] In this arrangement the feed plane is defined by an annular belt wound around rotatable support rollers to be rotated and facilitate hide infeed.

[0010] The infeed belt of the support table is also wound around one of the two calibration rollers, in particular around the lower calibration roller, whereas the upper feeding belt wraps around the upper calibration roller.

[0011] While this arrangement can effectively eliminate hazards due to the hides being manually introduced by operators, it still has a limit associated with the short distance of the cutting blade from the lower infeed belt, which is as little as a few millimeters.

[0012] Due to this short distance, the infeed belt may accidentally contact the blade, for example as a result of local deformations generated by the motion of the hide being fed, and be accordingly exposed to local cuts, that would significantly reduce its efficiency and durability.

[0013] Similar arrangements are also disclosed in US3165912 and FR2008203, in which the cutting blade acts upon the belts without the interposition of any other members that might prevent accidental contact therebetween.

[0014] Yet another limit of the prior art solutions is the risk that the upper feeding belt might slip sideways under a stress transferred thereto by the hide because, as the blade rotates in a plane orthogonal to the feed direction, it urges the hide to translate parallel to such rotation plane.

[0015] This requires frequent shutdowns to place the belt back to its centered position, which will obviously affect the productivity.

[0016] Further types of splitting machines are disclosed in WO201 1 148077, EP3121293 and US6434978. Nevertheless, these machines have belt arrangements that considerably increase the dimensions and space requirements of the machine.

Technical Problem

[0017] In view of the prior art, the technical problem addressed by the present invention is to preserve the integrity of the lower infeed belt of a splitting machine over time, in order to ensure a high productivity, while limiting the overall dimensions of the machine.

Disclosure of the invention

[0018] The object of the present invention is to solve the aforementioned problem and obviate the drawbacks of the prior art, by providing an industrial hide splitting machine that is highly efficient and relatively cost-effective.

[0019] A particular object is to provide an industrial hide splitting machine that preserves the integrity of the lower infeed belt over time, in order to ensure a high productivity.

[0020] Another object is to provide an industrial hide splitting machine that ensures high safety for the personnel and increased productivity.

[0021] Yet another object is to provide an industrial hide splitting machine that can quickly bring the upper feeding belt to the centered position without requiring long and complex manual operations.

[0022] Another object is to provide an industrial hide splitting machine that affords quick and easy replacement of the feeding belt.

[0023] A particular object is to provide an industrial hide splitting machine that affords optimized thickness calibration of the hide for high quality processing.

[0024] Another important object is to provide an industrial hide splitting machine that can spread the hides in an optimized manner to avoid the presence of depressions that might lead to improper cutting.

[0025] These and other objects as better explained hereafter, are fulfilled by an industrial hide splitting machine as defined in claim 1.

[0026] The selected cutting device may be kept sufficiently close to the hide to ensure precision cutting, with no risk of contact with the infeed belt, even when the latter has depressions or deformations caused by the movement of the hide being fed.

[0027] As a result, the infeed belt will be preserved from any accidental cut throughout its operation, while ensuring increased overall productivity and lower maintenance costs. [0028] Advantageously, the upper guide roller of the pair of rollers is a calibration roller for calibrating the size of the outlet and is associated with adjustment means adapted to locally vary the distance between the calibration roller and the compensation roller.

[0029] This additional feature will afford high-precision hide thickness control, allowing continuous adjustment for high-quality processing.

[0030] Conveniently, the driving head may comprise a load-bearing frame having a pair of lateral supports each with a shoulder for supporting the transverse ends of the first return and/or driving rollers.

[0031] Furthermore, the lateral shoulders may be associated with first drive means adapted to translate each of the shoulders to vary the inclination of the first rollers.

[0032] Thus, should the feeding belt slip sideways due to transverse stresses transferred by the cutting device through the hide being processed, the feeding belt may be automatically returned to its centered position by simply tilting the rollers on which it is wound, without requiring complex and time-consuming manual operations.

[0033] Furthermore, the frame may be hinged at least at one of its transverse ends to pivot about a corresponding vertical axis and allow the tubular sleeve to fit around the first rollers.

[0034] With this additional feature, if the feeding belt needs replacement, the frame will be simply pivoted to release one of the transverse ends of the first rollers, such that the old belt may be removed therefrom and a new one may be quickly fitted thereon.

[0035] Advantageously, the driving head may comprise a hide spreading member having a lower profile made of flexible material placed above the infeed belt and associated with second drive means which are adapted to promote its translation in a vertical direction to adjust its distance from the receiving surface of the driving belt.

[0036] This additional feature will afford constantly optimized spreading of the hide, and avoid any depression or fold that might affect processing quality.

Brief description of the drawings

[0037] Further features and advantages of the invention will be more apparent from the detailed description of preferred, non-exclusive embodiments of the inventive machine, which are described as a non-limiting example with the help of the annexed drawings, in which:

FIG. 1 is a front view of the inventive machine in a first preferred configuration;

FIG. 2 is a sectional lateral view of the machine of Fig. 1 ;

FIG. 3A is an enlarged view of a detail of Fig. 2;

FIG. 3B is an enlarged front view of the detail of Fig. 3A;

FIG. 4 is a top view of the machine of Fig. 1 ;

FIG. 5 is a front view of the machine according to a second configuration, with certain members thereof being omitted;

Detailed description of a preferred exemplary embodiment

[0038] Referring to the accompanying figures, there is shown an industrial hide processing machine for use with any kind of leather to perform a splitting process, i.e. cutting the hide in the direction of thickness into two superimposed layers, typically known as grain and split. As used herein “hide” is intended to designate an industrial hide of variable thickness with a variously shaped contour depending on the animal from which the hide originates.

[0039] FIG. 1 shows a splitting machine, generally designated by reference numeral 1 , comprising a lower infeed table 2 for infeeding the hide P and a driving head 3 arranged above the infeed table 2.

[0040] The infeed table 2 comprises a lower infeed belt 4 for infeeding the hide P, having a receiving surface 5 for the hide to be processed P to be positioned thereupon.

[0041] The driving head 3 has in turn an upper feeding belt 6 wound in a closed-loop configuration around first support roller means 7 and adapted to cooperate with the lower infeed belt 4 to cause the hide P to be fed in a predetermined feed direction D.

[0042] Preferably, but without limitation, the feeding belt 6 may be a tubular rubber sleeve having lower rigidity than the infeed belt 4, the latter being possibly formed, on the other hand, from a sheet of polymeric material wound in a loop and sealed at its transverse end edges.

[0043] Furthermore, the feeding belt 6 may comprise a ribbed surface with helical projections of varying depths for improved grip on the hide P and facilitated feed thereof in the machine 1.

[0044] As the feeding belt 6 rotates, it will always present a lower driving surface 8 facing the receiving surface 5 of the infeed belt 4 which faces upwards from time to time, on which the hide P will be positioned.

[0045] The two mutually opposed surfaces 5, 8 will thus define a gap 9 therebetween for receiving the hide P.

[0046] A pair of mutually opposed, counter-rotating guide rollers 10, 1 1 are arranged downstream of the gap 9 and rotate about respective rotation axes transverse to the feed direction D, defining in turn an outlet 12 for the hide P to be cut, as more clearly shown in FIG. 2 and in the detailed view of FIG. 3A, in which the machine 1 is shown in profile and in cross-section.

[0047] Furthermore, a cutting device 13 is placed downstream of the outlet 12, as viewed in the feed direction D, and may be a blade wound in a loop around a pair of motorized rollers or flywheels, not shown.

[0048] The blade 13 will be arranged transverse to the feed direction D of the hide P and will have its cutting edge 14 immediately downstream of the outlet 12 such that the cut will be made along the entire transverse extent of the hide P and divide it into two layers.

[0049] Still in a known manner, the blade 13 may be associated with feeding means, not shown, which will controllably feed its cutting edge 14 in a transverse direction toward the outlet 12, so that the cutting edge 14 will be constantly kept at the proper distance from the outlet 12 even when the blade 13 is worn upon repeated contact with the hides P.

[0050] In addition, the cutting edge 14 may be associated with sharpening tools, not shown and within the skill of the art, which are designed to ensure that the cutting blade 13 will always have a sharp edge.

[0051] FIG. 2 also shows that the feed belt 6 is wound around the first support roller means 7 which comprise a plurality of first return and/or tensioning rollers 15, 16, 17, 18, at least one whereof is motorized, to also enclose the upper guide roller 10 therein.

[0052] Thus, the upper guide roller 10 and the plurality of first return and/or tensioning rollers 15-18 are arranged inside and in contact with the feeding belt 6, to reduce the space requirements of the splitting machine 1.

[0053] Conversely, the infeed belt 4 is wound in a closed-loop configuration around second support roller means 19 which do not include the lower guide roller 11 , the latter being thus external to the infeed belt 4.

[0054] The infeed belt 4 has an outfeed section 20 for outfeeding the hide P, which is located upstream of the outlet 12 and faces it at such a distance as to be spaced apart from the cutting device 13 and not in contact therewith.

[0055] The first 7 and the second 19 support roller means will be configured to rotate their respective belts 6, 4 in opposite directions of rotation and in concurrent directions of feed.

[0056] The second support roller means 19 comprise at least one or more driving rollers 21 , 22, one whereof is motorized, located upstream of the gap 9, an intermediate tensioning roller 23, preferably located outside the infeed belt 4, and a return roller 24 located at the outfeed section 20 of the infeed belt 4.

[0057] The lower roller 1 1 of the pair of opposed guide rollers will preferably be a compensation roller designed to recover any irregularity in the thickness of the hide P, possibly due to differences in its constitution or to the formation of folds or depressions.

[0058] In particular, the lower compensation roller 1 1 will be configured to automatically deform upon passage of the hide P and to vary the size of the outlet 12.

[0059] According to a preferred, not exclusive configuration, the compensating roller 11 will comprise a transverse supporting rod 25 and a plurality of rolls 26 that are fitted onto the rod 25 and can radially translate relative thereto, with a predetermined maximum radial clearance, in response to the action of the hide P.

[0060] In particular, according to a configuration that is not shown in the figures, the support rod 25 may comprise a plurality of radial projections adapted to engage corresponding inner radial grooves of the rolls 26 with a predetermined maximum radial clearance, to rotate therewith about the respective axis of rotation.

[0061] In a first variant embodiment, the support rod 25 is motorized to also drive the rolls 26 into rotation.

[0062] In a further variant that corresponds to the configuration of the figures, the lower guide roller 1 1 is associated with a driving roller 27 having a rubber-coated surface resting upon the rolls 26 to allow radial translation thereof.

[0063] Possibly, the rubber-coated driving roller 27 may be motorized to drive the rolls 26 into rotation. Here, the support rod 25 may or may not be motorized.

[0064] Conversely, the upper guide roller 10 may be a calibration roller for calibrating the size of the outlet 12.

[0065] In particular, the upper guide roller 10 will be associated with adjustment means adapted to locally vary the distance between the upper calibration roller 10 and the lower compensation roller 1 1 , to adapt the size of the outlet 12 to the thickness of the hides being processed.

[0066] The step of adjusting the outlet 12 may be carried out for each individual hide P, during its passage, or after a predetermined number of cuts based on the calculated thicknesses.

[0067] In this embodiment, the upper guide roller 10 is composed of a plurality of axial sections 28 each associated with a respective actuator 29, selected from the group of pneumatic, hydraulic, oil-operated and electromechanical actuators, and adapted to exert a radial stress on its respective axial section 28.

[0068] Thus, the various axial sections 28 may move radially independent of one another to locally vary the distance of the upper guide roller 10 from the lower guide roller 11 and locally change the size of the outlet 12 based on the thicknesses of the hides P as detected by special sensor means, which are not described or shown because they are known per se.

[0069] The driving head 3 comprises a load-bearing frame 30 having a pair of lateral supporting shoulders 31 , 32 for supporting the transverse ends of the first return and/or driving rollers 15-18.

[0070] In a further highly advantageous aspect, the lateral shoulders 31 , 32 are associated with first drive means adapted to translate each of the shoulders 31 , 32 and vary the inclination of the first rollers 15-18.

[0071] In particular, the first drive means will be configured to drive the two shoulders 31 , 32 independent of each other and to incline the axes of the first rollers in two opposite directions.

[0072] For example, the first drive means will comprise, at each of their respective shoulders 31 , 32, a double-acting hydraulic piston 33 which is adapted to cause an upward or downward translation of the corresponding lateral shoulder 31 , 32 and to center the belt 6 along the first rollers 15-18.

[0073] FIG. 4 also shows that the frame 30 is hinged at least at one of its transverse ends to pivot about a corresponding vertical axis.

[0074] This will provide lateral access to one of the transverse ends of the first return and/or tensioning rollers 15-18 to fit the tubular sleeve 6 around the first rollers 15-18.

[0075] FIG. 5 shows a variant of the inventive machine 1 , in which the driving head 3 has a central spreading member 35 for spreading the hide P which has a lower profile 36 made of a flexible material placed above the infeed belt 4.

[0076] The spreading member 35 is associated with second drive means 37 which are adapted to cause its translation along a vertical direction to adjust its distance from the receiving surface 5 of the infeed belt 4. [0077] Thus, the lower profile 36 made of flexible material may be brought to contact with the hide P being processed to exert a stress thereupon in the vertical direction, that will help to stretch the hide parallel to the plane defined by the receiving surface 5 and cause the hide P to be spread to eliminate any depressions, and enhance evenness.

[0078] Preferably, the splitting machine 1 comprises a device, inside the belt 6, for restrain the hides P upstream of the cutting blade 13 as best shown in FIGS. 3A and 3B.

[0079] The hide-restraining device basically comprises a pressure plate 38 which extends substantially over the entire width of the driving head 3 and is arranged between the upper guide roller 10 and one of the first return and/or driving rollers 15. The pressure plate 38 faces the lower surface 8 of the belt 6 and is urged downwards perpendicular to the inner surface of the belt 6 by a series of pistons 39 attached to a load-bearing beam 40 of the head 3 and arranged over the entire extent of the pressure plate 38.

[0080] As better shown in FIG. 3A, due to the pressure applied by the pistons 39 on the plate 38, the belt 6 will be urged toward the hide and will exert a holding and restraining action thereupon, in combination with a stretching action, before interacting with the cutting blade 13.

[0081] It will be appreciated from the above that the splitting machine fulfills the intended objects, and can namely preserve the integrity of the lower infeed belt of a splitting machine over time, to ensure high productivity.

[0082] The machine of the invention is susceptible of a number of changes and variants, within the inventive concept disclosed in the appended claims.

[0083] All the details thereof may be replaced by other technically equivalent parts, and the materials may vary depending on different needs, without departure from the scope of the present invention.

[0084] While the machine has been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

[0085] Reference herein to "one embodiment" or "the embodiment" or "some embodiments" indicates that a particular features, structure or member that is being described is included in at least one embodiment of the inventive subject matter.

[0086] Furthermore, the particular features, structures or members may be combined together in any suitable manner to provide one or more embodiments.

Industrial Applicability

[0087] The present invention may find application in industry, because it can be produced on an industrial scale by mechanical and splitting machine producing factories.