Technical field

[0001] The present invention generally finds application in the field of tanning equipment and particularly relates to a tool for changing conveyor belts.

[0002] The invention further relates to a staking machine having the aforementioned tool and to a method of installing and replacing the conveyor belts of a staking machine.

Background art

[0003] Machines for processing flexible sheet products, such as industrial hides and the like, having closed-loop conveyor belts supported by at least one pair of end rollers, have long been known to be used in the tanning industry. [0004] One example of these machines are staking machines for softening and stretching flexible sheet products such as industrial hides and similar products having opposite sides, i.e. a grain side and a flesh side.

[0005] These machines are used in the steps after tanning and/or drying to restore the natural softness of leather, as well as increase its size, i.e. the useful leather area.

[0006] Generally, these machines comprise motorized feeding means, for holding the products and feeding them in a longitudinal direction, which consist, for instance, of a pair of mutually facing conveyor belts, with the sheet products to be staked interposed therebetween.

[0007] These machines further comprise one or more pairs of mutually facing beating plates parallel to the longitudinal direction. The plates are reciprocated to move toward and away from each other substantially perpendicular to the product feeding plane.

[0008] Generally, conveyor belts in this type of machines are consumables because the reciprocating motion of the beating plates tends to rapidly consume the belts, by defibering and breaking them, resulting in the need to change them frequently. [0009] Conveyor belt replacement and installation are neither easy nor quick due to the considerable elastic forces involved and require the use of suitable pulling means, typically lift trucks, in combination with additional tools for inserting the belts relative to the end rollers.

[0010] In addition, belt replacement and installation require skilled and qualified personnel, as well as relatively long replacement and downtime times.

[0011] In order to at least partially obviate these drawbacks, attempts have been made to provide devices for simplifying replacement of conveyor belts in a machine for use in the tanning industry.

[0012] One example of such known solutions is the use of a tool having a hook shape for hooking in one end of a conveyor belt to be inserted at one end of the machine after fitting the other end of the belt on the rollers at the other end of the machine.

[0013] This is a quite basic and simple tool, comprising a kind of big carabiner attached to the end of a cable and inserted into a hole on the tool, with the cable being pulled by a winch or a motorized drum until the belt extends toward the opposite side of the machine.

[0014] Once the belt covers the extent of the machine, it is manually slid along the end rollers of the machine.

[0015] A first drawback of this known solution is that the conveyor belt replacement takes a long time, resulting in increased machine and personnel downtime.

[0016] Another drawback of this solution is the risk of sudden release of the belt under tension, resulting in a serious hazard for the personnel.

[0017] A further drawback consists in the large number of removable devices that are used only for replacement and installation of the new conveyor belt.

[0018] Moreover, these operations must be always carried out by skilled and qualified operators, which increases machine management costs and requires a considerable amount of energy and labor force. [0019] In an attempt to at least partially obviate these drawbacks, an automatic device has been developed for changing the belts of a conveyor, such as the one as disclosed in CN209064866, which provides a telescopic device with a roller adapted to engage and extend the belt.

[0020] Nevertheless, this known device is mounted to the machine in which the belt is to be replaced but is not configured to be removably coupled to and uncoupled from the machine. In addition, when in use it does not reduce the time required to replace the conveyor belt and the machine downtime.

Technical Problem

[0021] In light of the prior art, the technical problem addressed by the present invention is to simplify the operations required to change a conveyor belt with utmost safety and in a relatively short time.

Disclosure of the invention

[0022] The object of the present invention is to obviate the above discussed drawback, by providing a tool and a method for changing conveyor belts in a machine for processing flexible sheet products, that is highly efficient and relatively cost-effective.

[0023] A particular object of the present invention is to provide a tool and a method as described hereinbefore that are simpler than those of the prior art.

[0024] A further object of the present invention is to provide a tool and a method as described hereinbefore, that can avoid the use of lift trucks and other external pulling machines.

[0025] An additional object of the present invention is to provide a tool and a method as described hereinbefore that can considerably reduce the time required to change the conveyor belts, thereby reducing machine downtime. [0026] A further object of the present invention is to provide a tool and a method as described hereinbefore, that can increase the safety of the operators in charge of replacing the conveyor belts.

[0027] Yet another object of the present invention is to provide a tool and a method as described hereinbefore, that require neither a particular skill of the operators in charge of the installation of the conveyor belts nor excessive manual efforts.

[0028] These and other objects, as more clearly shown hereinafter, are fulfilled by a semiautomatic belt-changing tool adapted to be coupled to a machine for processing flexible sheet products, such as industrial hides and the like, according to claim 1 , wherein the machine comprises a frame defining an inlet area and an outlet area for the products, and having at least one pair of closed-loop conveyor belts installed thereon, which face each other and are supported by pairs of end rollers.

[0029] According to a peculiar aspect of the invention, the tool comprises a first extending device with a head slidingly mounted on longitudinal guide means designed to be secured to the frame of the machine; at least one transverse grip member being associable with the head, for engaging a first portion of a belt, whose second portion, opposite to the first portion, is already wound on the other end roller.

[0030] Advantageously, drive means are provided, which act upon the head to longitudinally move it along the guide means to stretch the belt and allow the first portion of the belt to fit over the adjacent end roller by a transverse sliding motion with little manual effort.

[0031] Conveniently, the first extending device is configured to engage and stretch at least one upper belt of the machine. Thus, the stretching head comprises a support secured to the carriage and having seats for removable insertion of a plurality of sleeves defining the transverse grip members.

[0032] The tool further comprises a second extending device similar to the first extending device and configured to engage and stretch at least one lower belt of the machine.

[0033] The second extending device differs from the first extending device in the shape of the support for the gripping sleeves.

[0034] With this combination of features, the tool affords effective and immediate replacement of the belt to reduce the downtime.

[0035] Advantageous embodiments of the tool are obtained according to the dependent claims.

[0036] The invention further relates to a method of using the above discussed tool according to claim 11 .

Brief description of the drawings

[0037] Further features and advantages of the invention will be more apparent from the detailed description of a preferred, non-exclusive embodiment of a tool and a method for changing at least one conveyor belt of a machine for processing flexible sheet products, which is described as a non limiting example with the help of the annexed drawings, in which:

FIG. 1 is a perspective view of a staking machine for softening and stretching industrial hides, having a pair of conveyor belts supported by end rollers;

FIG. 2 is a perspective view of a first extending device that is part of the tool of the invention;

FIG. 3 is a lateral view of the extending device of FIG. 2;

FIG. 4 is a perspective view of a second extending device that is part of the tool of the invention;

FIG. 5A is a lateral view of the first extending device in a first operating step;

FIG. 5B is a lateral view of the first extending device in a second operating step;

FIG. 6A is a lateral view of the second extending device in a first operating step;

FIG. 6B is a lateral view of second extending device in a second operating step;

FIG. 7 is a block diagram of the method of using the tool of the invention. Detailed description of a preferred exemplary embodiment [0038] Particularly referring to the figures, there is shown a belt-changing tool, generally designated by numeral 1 , designed to be coupled to a machine 2 for processing flexible sheet products, such as industrial hides and the like. [0039] As used hereinafter, the term “machine” refers to a machine of the type for use in the tanning industry as long as it is equipped with at least one conveyor belt for transporting and feeding the hides along a longitudinal direction L.

[0040] In one embodiment, the machine 2 as described and illustrated in the figures is a staking machine for softening and stretching industrial hides and similar products as is well known and is not part of the present invention. [0041] The machine 2 is known to comprise a frame 3 with an inlet area 4 for the products to be treated and an outlet area 5 for the treated products. [0042] The frame 3 has an upper conveyor belt 6 and a lower conveyor belt 7 installed thereon, which are made of a flexible closed-loop material and are supported by at least one pair of end rollers 8, 9 and 10, 11 , respectively. [0043] In detail, the upper belt 6 is wound on an inlet end roller 8 proximate to the inlet area 4 and an outlet end roller 9 proximate to the outlet area 5, whereas the lower belt 7 is wound on an inlet end roller 10 proximate to the inlet area 4 and an outlet end roller 11 proximate to the outlet area 5.

[0044] For completeness, the lower belt 7 has additional return rollers, referenced 12, 13 and 14 respectively, which are used to keep the belt in an ideal tension state, i.e. perfectly tensioned.

[0045] The two belts 6, 7 follow such a path as to define respective substantially horizontal portions 15, 16, which face and substantially contact each other, and are adapted to hold the products therebetween and feed them along a longitudinal direction L from the inlet area 4 toward the outlet area 5. [0046] Still for completeness, at the aforementioned mutually facing horizontal portions 15, 16 the machine comprises pairs of mutually facing beating masses, i.e. stationary upper masses 17 and moving lower masses 18 respectively, the latter being reciprocated, which are equipped with complementarily shaped tools, not shown, for stretching and softening the hides as they are fed between the belts 6, 7 along the longitudinal direction L. [0047] According to the invention, the tool 1 comprises at least one first extending device 20 for changing the upper belt 6 and at least one second extending device 20' for changing the lower belt 7. [0048] Since the two extending devices 20, 20' are very similar and comprise the same essential features, only one of them will be described in detail below, namely the first device 20, and only the features of the second device 20’ differing from the first device will be highlighted.

[0049] The first extending device 20 comprises a first head 21 having a carriage 22 slidably mounted on longitudinal guide means 23 adapted to be removably secured to the frame 3 of the machine 2.

[0050] In particular, the guide means 23 comprise a profile that can be fixed to the side of the frame 3 and has a cross-section adapted to define a pair of substantially parallel longitudinal rails 24, 25 on which the carriage 22 slides. [0051] The head 21 may be associated with at least one grip member 26, essentially in the form of a tube or a sleeve, which is adapted to engage and be wrapped by a first portion 27 of the belt 6 adjacent to an inlet end roller 8, whereas the second portion of the belt 6, opposite to the first portion 27, is wound on the outlet end roller 9 of the machine 2.

[0052] In particular, the head 21 comprises a support 28 secured to the carriage 22 with at least two tubular seats for slidingly receiving one or more grip members 26 from the outside.

[0053] In the illustrated embodiment, the head 21 substantially has an open V shape with a vertical portion and an inclined portion.

[0054] Conveniently, the device 20 comprises semi-automatic drive means 29 for moving the head 21 along the longitudinal guide means 23 to thereby stretch the belt 6 and allow the first portion 27 of the belt 6 to transversely slide on the adjacent end roller 8, or be removed therefrom with little physical effort. [0055] The drive means 29 may be of any type, i.e. mechanical, pneumatic, hydraulic, magnetic or electrical means.

[0056] In one illustrated embodiment, the semi-automatic drive means 29 comprise at least one threaded bar 30 adapted to be engaged in at least one nut 31 rigidly joined to the carriage 22 and locked in its rotation relative thereto. [0057] The threaded bar 30 may have an end joint adapted to be coupled to actuation means, not shown, which are designed to be actuated by an operator when needed, to cause the head 21 to travel along the pair of longitudinal rails 24, 25.

[0058] Conveniently, the electric motor may be stationary and fixed to the profile of the guide means 23 or may consist of a simple industrial screwdriver held by an operator.

[0059] The drive mechanism with the threaded bar 30 and the nut 31 is configured so that the travel of the carriage 22, and therefore the head 21 , extends between a retracted position in which the grip member 26 can be inserted into the first portion 27 of the belt 6 and act as an end roller, and an forward position in which the head 21 stretches the belt 6 to a sufficient extent as to allow the first portion 27 of the belt 6 to transversely slide on the adjacent end roller 8.

[0060] With this arrangement, the first extending device 20 can afford simple and safe replacement and installation, i.e. changing the upper conveyor belt 6, while avoiding the use of complex and expensive machinery and improving the safety conditions for the operators.

[0061] The second extending device 20', which is configured to change the lower belt 7, is substantially identical to the first one 20, all the matching parts being designated by the same references provided with a prime mark. [0062] The only difference is given by the shape of the support 28', which in this case is a straight bar, that is or can be inclined with respect to the vertical to conform with the arrangement of the return rollers 12, 13, 14.

[0063] The support 28’ also has respective seats for the grip members 26’ at its ends.

[0064] In a further aspect, the invention relates to a method of installing and replacing conveyor belts 6, 7 of a staking machine 2.

[0065] The method of the invention includes the following steps: a) providing a first extending device 20 and coupling it to one side of the frame 3 of the machine 2 for replacing an upper belt 6; b) placing the head 21 of the first device 20 in a retracted position by rotating the threaded bar 30 in a predetermined direction; c) inserting at least one grip member 26 into a first portion 27 of the upper belt 6; d) rotating the threaded bar 30 in the opposite direction and longitudinally moving said head 21 from a retracted position to a forward position substantially in line with the inlet end roller 8 thereby stretching the upper conveyor belt 6; e) sliding the upper belt 6 along the transverse sleeve 26 and transferring it onto the inlet end roller 8; f) removing the support 28 of the first extending device 20, mounting a second extending device 20' to the frame 3 of the machine 2 to replace a lower belt 7; g) repeating the steps from b) to e); h) removing the first 20 and second 20' devices from the machine 2. [0066] In one embodiment, the longitudinal guide means 23 of the first extending device 20 and the guide means 23' of the second extending device 20' coincide with each other.

[0067] Thus, in order to change the lower belt 7, the step f) of removing may comprise the vertical displacement of the guide means 23 of the first extending device 20 and the installation of the support 28' of the second extending device 20’ thereon.

[0068] The steps of the above discussed method can considerably reduce the time required to install the conveyor belts of a staking machine in case of replacement, thereby increasing the safety of the operators during replacement.

[0069] The above disclosure clearly shows that the tool and the method of the invention fulfill the intended objects and namely afford effective and immediate replacement of the belt thereby reducing machine downtime with utmost safety for the operators.

[0070] The tool and method of the invention are susceptible to a number of changes or variants, within the inventive concept disclosed in the appended claims. [0071] While the tool and method have 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. [0072] Reference herein to "one embodiment" or "the embodiment" or

"some embodiments" indicates that a particular characteristic, structure or element that is being described is included in at least one embodiment of the inventive subject matter.

[0073] Furthermore, the particular characteristics, structures or elements may be combined together in any suitable manner to provide one or more embodiments.

Industrial Applicability

[0074] The present invention may find application in industry, because it can be produced on an industrial scale in tanning machine factories.