The present invention relates to a kit for monitoring conveyor belts and the like and to the related method.

As is known, there are various industrial applications in which the movement of products (finished products, blanks and/or raw materials) is entrusted to automatic transfer apparatuses of the type of conveyor belts.

Despite their various practical variations, which are indeed determined by the specific requirements of application, these apparatuses usually can be traced back to the same basic architecture: they in fact comprise a ribbon-like element that is closed in a loop around a closed path that winds around a pair of shafts extended along mutually parallel directions which are perpendicular to the direction of motion of the products.

Typically, the belt is moved along said closed path indeed by one of the shafts, with which it meshes, indeed so as to transfer the products of interest from an upstream section to a downstream section.

Belts of the type outlined above are subjected to breakages and failures, which inevitably cause machine downtimes and delays in production, with obviously unpleasant consequences (from an economic standpoint but not only).

These problems are often due to progressive wear (or in any case deterioration) of the components that support said belts, which causes their misalignment, i.e., a horizontal slippage (or in any case parallel to the respective belt portion that supports the products) transversely to the transfer direction.

The misalignment (and consequent displacement from the design position) in fact subjects the structure to stresses, vibrations and forces which, over time, also due to the large number of operating cycles that the belts perform each day, indeed cause failures. Similar problems (and most of all similar unpleasant consequences) occur when, due to wear or deterioration, the belts tend to slip with respect to the shafts that support them (i.e., when a relative motion in the longitudinal direction occurs between the surface of the belt and the surface of the shaft on which said belt rests and to which it should be integral).

The need is thus felt to prevent failures (at least most of them) by identifying promptly misalignments and/or slippages, even of a small extent.

Other known constructive solutions have attempted to meet this requirement by providing optical systems comprising sensors or video cameras capable of identifying outlines (or patterns) drawn on the belt. Each video camera in fact has the task of detecting a displacement of the pattern with respect to the ideal position, defined previously: this displacement indeed indicates a corresponding misalignment of the belt on which said pattern is drawn.

However, these constructive solutions are not free from drawbacks.

In fact, in addition to not allowing to detect slippages, these constructive solutions are particularly sensitive to wear and to the progressive deterioration of the pattern drawn on the belt, which causes the corresponding inability of the video camera to perform correct reading. Unfortunately this phenomenon is very frequent, especially if one observes that in the industrial field the products carried by the belt are often themselves made of aggressive materials, which indeed compromise the quality and the optimum definition of the drawn pattern.

More generically, in several contexts, dirt, dust, shavings, oil and impurities in general which affect production departments often cause bad readings of the video cameras, which moreover are subjected to calibration problems.

Moreover, it should be noted that the optical systems described above require direct intervention on the belt (which is often difficult to perform) in order to provide the pattern thereon and it is therefore difficult to use them on existing movement apparatuses.

Other known constructive solutions, based on capacitive sensors, also are affected by similar limitations and problems, and in particular are highly sensitive to humidity and water (thus being fully unsuitable in various practical contexts).

The aim of the present invention is to solve the problems described above, by providing a kit that allows in a practical and easy manner to monitor conveyor belts and the like.

Within this aim, an object of the invention is to propose a method that allows to monitor conveyor belts and the like in a practical and easy manner.

Another object of the invention is to provide a solution that is versatile, capable of detecting promptly the misalignment and/or slippage of conveyor belts (or also of similar apparatuses) in any operating condition and independently of the products being moved.

Another object of the invention is to provide a solution that can be implemented effectively also on existing belts and movement apparatuses.

Another object of the invention is to ensure high reliability in operation, also in view of a large number of rotation cycles of the belt and of a particularly prolonged useful life.

Another object of the invention is to adopt a technical and structural architecture that is alternative to those of kits of the known type.

Another object of the invention is to provide a kit that can be obtained easily starting from commonly commercially available elements and materials.

Another object of the invention is to provide a kit (and propose a method) that has modest costs and is safe in application.

This aim and these and other objects that will become better apparent hereinafter are achieved by a kit according to claim 1 and by a method according to claim 9.

Further characteristics and advantages of the invention will become better apparent from the description of two preferred but not exclusive embodiments of the kit according to the invention, illustrated by way of nonlimiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of the use of the kit according to the invention in the first embodiment and on a first elongated element;

Figure 2 is a perspective view of the use of the kit according to the invention in the second embodiment and on a second elongated element;

Figure 3 is a side elevation view of the kit of Figure 2;

Figures 4 and 5 show, for the kit of Figure 2, charts that illustrate the intensity of the temporary variation of the electromagnetic parameter of the field, respectively in conditions of optimum alignment of the elongated element and of a misalignment thereof.

With reference to the figures, the reference numeral 1 generally designates a kit for monitoring conveyor belts and the like, which in any case comprise an elongated element A, of the type of a belt (as in the accompanying figures), a band, a chain, and the like.

The kit 1 can thus find a valid application whenever one wishes to monitor (the correct alignment of) elongated elements A that are generically wound and can move cyclically around a closed path.

As is well known, first of all this condition is indeed verified for conveyor belts, widely used in various industrial sectors, in order to move between a loading region and an unloading region raw materials, finished products or blanks, which are indeed transferred by such belt, which is extended between such regions.

The use of the kit 1 in this context, moreover shown in the accompanying figures, constitutes a preferred but not exclusive application of the invention and in it the elongated element A is a belt wound around two shafts B, which support it; usually, one of the shafts B is also responsible for its movement along the closed path.

It is useful to note that the protection claimed herein is any case to be understood as extended to the monitoring of other types of elongated element A, such as indeed the bands or chains mentioned earlier (or other transmission elements, or others still), for which the kit 1 is in fact equally indicated, in order to monitor alignment and prevent failures.

According to the invention, the kit 1 comprises a generator 2 of at least one alternating magnetic field, which can be arranged proximate to the elongated element A.

In this regard, it is specified that the generator 2 can be arranged in any point of the area that is adjacent to the elongated element A, and in this point it can be supported rigidly by a respective framework 3, which is appropriately provided or even already exists (for example because it is part of the machine in which such belt is implemented and operates).

As will become better apparent hereinafter (and as shown in Figures 2 and 3), the generator 2 can also be supported by an additional element of the kit 1 , assigned to another function, thus reducing the overall number of components (and the associated costs).

The kit 1 also comprises at least one magnetic body 4, and more precisely a body 4 chosen between a ferromagnetic body 4 and a ferrimagnetic body 4, which can be associated stably with the elongated element A (and for example be integrated within the thickness, as in Figure 1 , or applied externally to the outer surface, as in Figures 2 and 3).

It is noted that the protective scope claimed herein is extended to both types of material indicated above, since both ensure the desired functionality and result. By virtue of its ferromagnetic or ferrimagnetic properties, the body 4 in fact temporarily perturbs the alternated magnetic field produced by the generator 2, in particular when (during its motion integrally with the belt or other elongated element A) it passes proximate to the latter (below it) and thus crosses the field.

Moreover, the protection claimed herein is to be understood as extended to any additional materials (which already exist or will be developed in the future thanks to the progress of technology) which, despite not being within the two categories described above, have properties which are in some way similar to the latter and therefore, most of all, are in any case capable of perturbing a magnetic field upon their passage,

The perturbation of the magnetic field caused by the crossing causes a consequent temporary variation of the at least one electromagnetic parameter of said field: on successive work cycles of the elongated element A, the behavior over time of this temporary variation is therefore monitored by a respective unit (typically an electronic one) for control and management, even indirectly.

The electronic unit can thus identify promptly any modifications in the intensity and/or in the time interval between consecutive variations, modifications which can in any case be correlated with displacements of the body 4, and of the elongated element A, with respect to the ideal rule of motion, achieving from the outset the intended aim.

In fact, as long as the belt (or other elongated element A) maintains optimum alignment, the body 4 that is integral therewith follows at each cycle the same ideal trajectory C, and thus passes iteratively through the magnetic field with the same spatial coordinates and more generally in the same conditions, thereby evidently causing a temporary variation of the parameter of interest of the same intensity.

Moreover, in conditions of optimum alignment (and in the absence of slippages, i.e., of relative longitudinal motions between the elongated element A and the respective support), the time interval between consecutive variations of the parameter (which indeed correspond to consecutive passages of the body 4) remains constant.

If instead a misalignment of the belt occurs, this causes its transverse slippage, which obviously affects the body 4 as well: therefore, as a consequence of the misalignment the control and management unit observes a change in the variation intensity of the electromagnetic parameter, since the body 4 indeed perturbs the field in a different manner due to the changed spatial coordinates (having taken care, of course, to choose accurately the electromagnetic parameter to be observed).

Likewise, when slippage of the belt (or other elongated element A) occurs along the longitudinal direction (the one in which said belt moves), evidently the body 4 crosses the field before or after the instant when it would do so in nominal conditions and therefore the time interval between two consecutive variations of the parameter varies.

The control and management unit can therefore identify promptly, and in a very practical and easy manner, any displacement (for the body 4 and the elongated element A) from the nominal conditions and can activate the necessary countermeasures (for example if said displacement is greater than a preset value).

The unit can in fact emit an alarm signal (even remotely), in order to call the attention of technicians and operators, inviting them to perform an intervention aimed at restoring nominal operating conditions before the misalignment causes an unwanted failure.

Moreover, in improved versions of the kit 1 according to the invention the unit can have a user interface that is associated with instruments for adjusting the alignment of the belt, so as to allow the operator to realign the latter directly by means of the unit, also checking in real time the quality of the reset.

Furthermore, by providing at least one of the shafts B with an encoder, it is possible to quantify the extent of the slippage and therefore activate the most suitable countermeasures.

It should be noted that any electromagnetic parameter that is chosen (so long as it is temporarily variable upon the passage of the body 4) can easily allow the detection of slippages, since the control and management unit can identify immediately changes in the time interval between consecutive variations. Likewise, in an embodiment of considerable practical interest, mentioned by way of nonlimiting example of the application of the invention, the control and management unit (a controller, a computer, etc.) comprises first instructions for monitoring the behavior over time of the temporary variation of an electromagnetic parameter which is chosen so as to be correlated with a spatial coordinate of the body 4, measured transversely to the ideal longitudinal trajectory. Preferably, such coordinate is measured indeed along a main axis D, which is perpendicular to the plane that contains the ideal trajectory C. It should be noted that the ideal trajectory C is the one defined by the ideal rule of motion of the body 4, already mentioned in the preceding pages and followed iteratively by the body 4 during the operation of the belt (or other elongated element A).

As can be deduced from the accompanying figures, if the elongated element A is constituted by a belt, the main axis D therefore lies on a plane formed by the surface of the belt (and is perpendicular to the ideal trajectory C).

This preferred choice is of primary interest since, in addition to slippages, it allows to prevent the failures and downtimes that most affect the elongated elements and which indeed occur due to deteriorations and wear, which cause slippages (and misalignments) of the elongated elements A in the direction identified by the main axis D (or in any case transversely to the ideal trajectory C).

In an embodiment of considerable practical interest, which illustrates but does not limit the application of the invention, the generator 2 comprises an (oscillating) circuit, provided with at least one capacitor and at least one inductor. In this preferred (but not exclusive) embodiment, it is therefore the inductor that generates the alternating magnetic field that can be perturbed ' by the passage of the body 4. Furthermore, this parameter is preferably constituted by the oscillation frequency of the magnetic field, which is indeed proportional (or at least monotonic) with respect to the distance between the inductor and the body 4. More particularly, the passage of the body 4 causes a variation of the inductance value of the circuit and this generates a response that is constituted indeed by a variation of the oscillation frequency.

It is useful, moreover, to point out that the monitoring of various parameters of the electromagnetic field, in any case correlated (directly or not) to the spatial coordinate of interest, is not excluded; for example, it should be noted that the passage of the body 4 also causes a variation of the intensity of the current that circulates on the inductor, and this value (or others) also can be monitored in order to identify promptly any misalignment and/or slippage of the elongated element A.

The ferromagnetic or ferrimagnetic material, which ensures that the body 4 has the desired properties, can be any according to the specific requirements of application; for example, the body 4 can comprise a material chosen among iron, ferrite, iron oxide (or any other material indeed provided with ferromagnetic or ferrimagnetic properties).

Preferably, in any case, the body 4 is made entirely or partially of ferrite; resorting to ferrite, by ensuring a response that is the opposite of that of other metals, in fact allows to obtain a variation of intensity that is much sharper and therefore allows greater ease in identifying misalignments and/or slippages (especially in configurations of the type shown in Figure 1 ).

Usefully, in a solution of very high practical interest, the kit 1 comprises two inductors, both arranged proximate to the ideal trajectory C of the body 4 and connected to the control and management unit.

In this solution, the control and management unit is therefore provided with second instructions for monitoring and subsequently comparing the intensities of temporary variation of the parameters of interest of each one of the magnetic fields generated by the respective inductors, when the body 4 passes through said fields. This allows to achieve an improved detection of any spatial misalignment of the elongated element A (as well as of slippages).

More particularly, and as can be deduced also from Figures 4 and 5, in the preferred embodiment the two inductors (constituted for example by flat turns) are arranged along the main axis D, symmetrically with respect to the already mentioned ideal trajectory C followed by the body 4 (in Figure 4) in conditions of optimal alignment of the elongated element A.

Thus, in conditions of optimum alignment the intensities of the temporary variation of the parameters of each magnetic field generated by the respective inductors are substantially symmetrical (since the body 4 is equidistant from the inductors).

Likewise, in case of misalignment (Figure 5, in which indeed it can be seen that the body 4 moves only parallel to the ideal trajectory C), both the intensities of temporary variation change (both therefore reporting misalignment), with a more conspicuous response for the field generated by the inductor toward which the body 4 has moved.

It should be noted therefore that this choice allows to obtain information also on the direction of movement of the body 4 along the main axis D, thus achieving an improved detection which is useful to intervene in a more targeted manner in order to solve the problem.

Providing the kit 1 with three or more inductors arranged in various manners, as well as arranging two inductors in a different manner, with respect to the ideal trajectory C and the elongated element A one wishes to monitor, is in any case not excluded.

For example, as mentioned in the preceding pages, also by virtue of a different arrangement of the inductors the kit 1 according to the invention is used to monitor and detect variations or oscillations of the elongated element A along other directions and for example along a straight line that is perpendicular to the main axis D and to the ideal trajectory C.

Furthermore, it is not excluded to increase the precision of the I I

measurement of the unit and in general of the kit 1 according to the invention by providing the latter with a larger number of bodies 4 and/or by averaging over multiple passages of each body 4.

As shown, in any case, in the preferred application it is provided to monitor the spatial coordinate measured along the main axis D: in this context, it should be noted that any oscillations along a straight line that is perpendicular to the main axis D and to the ideal trajectory C (i.e., oscillations that are perpendicular to the surface of the belt) are an unwelcome source of interference (causing unwanted flexings of the belt).

Advantageously, therefore, in the preferred application the kit 1 can also comprise a presser assembly 5, indeed to keep the elongated element A under tension and prevent oscillations that are directed at right angles to the ideal trajectory C and to the main axis D (which indeed would cause the elongated element A to flex and oscillate).

In particular, in the preferred embodiment the assembly 5 comprises a framework 6, which can be arranged stably so that it faces and is proximate to the elongated element A.

The framework 6 can be fixed to existing structures of the machine that incorporates the elongated element A or can rest and be anchored to the ground by virtue of other known means.

The framework 6 therefore supports rotatably a plurality of rollers 7, which are kept pressed against the elongated element A in order to achieve the desired object.

As can be deduced from Figures 2 and 3, the rollers 7 (which can rotate in order to avoid contrasting the sliding of the belt around the closed path) thus keep under tension the belt (or other elongated element A), preventing oscillations thereof which are perpendicular to the main axis D and to the ideal trajectory C.

It should be noted that in order to ensure maximum versatility for the assembly 5, and allow practical adjustment modes, the pivot that supports rotatably each roller 7 can be fixed at a vertical height at will along guiding slots 8 provided along brackets 9 of the framework 6.

Furthermore, and as mentioned in the preceding pages, the framework 6 can support effectively also the generator 2: Figures 2 and 3 in fact show the possibility that the framework 6 might support (at a vertical height that can be adjusted at will) a plate 10 to which the generator 2 (the inductors) indeed can be anchored.

The present invention (and the protective scope claimed herein) also relates to a method for monitoring conveyor belts and the like, which can be performed (preferably but not exclusively) by means of the kit 1 according to the invention (which therefore comprises one or more of the particularities described in the preceding pages).

The method also is therefore aimed at monitoring apparatuses that comprise an elongated element A, of the type of a belt, a band, a chain, and the like, which is wound and cyclically movable around a closed path.

The method therefore consists, in a step a., in placing a generator 2 of at least one alternating magnetic field proximate to the elongated element A.

Furthermore, the method provides, in a step b., for associating stably with the elongated element A at least one magnetic body 4 which is chosen between a ferromagnetic body 4 and a ferrimagnetic body 4.

The body 4 temporarily perturbs the alternating magnetic field upon its passage proximate to the generator 2 and upon crossing the field, with a consequent temporary variation of at least one electromagnetic parameter of the field.

It should be noted that the methods with which step b. is performed may be any (thereby ensuring high versatility to the invention). Step b. can in fact consist of a step b l . of stable application of the body 4 to the surface of the elongated element A (as in Figures 2 and 3) by means of a respective adhesive layer. The adhesive layer can be of the magnetic type or a simple adhesive. In this constructive option, the body 4 might be for example constituted (partially or integrally) by an adhesive lamina which comprises ferrite or iron oxides. Said lamina can be obtained for example by cutting portions of spools, subsequently applied to the belt, optionally also providing a covering made of polymeric material, which can in turn be applied above the lamina by hot molding, achieving a highly efficient embodiment.

As an alternative, step b. can consist of a step b2. of integration of the body 4 in the thickness of the elongated element A (as in Figure 1 ), by means of a hole provided beforehand (for example with a drill) and subsequently closed (for example with a silicone plug). Insertion in the thickness of the belt can in any case be performed during the production of the belt (or other elongated element A) itself.

Moreover, it is not excluded to perform step b. of the method according to the invention in other manners, as a function of the particular requirements of application (material that constitutes the belt, type of products to be moved on the latter, etc.).

In any case, after completing the steps a. and b., the method provides, in a step c, for monitoring even indirectly, on successive work cycles of the elongated element A, the behavior over time of the temporary variation of the parameter cited earlier.

As shown, step c. can be performed by the control and management unit (a controller, a computer, etc.) proposed in the preceding pages.

This allows therefore, in a step d., to identify promptly any changes in the intensity and/or time interval between consecutive variations of the electromagnetic parameter, modifications which in any case can be correlated with displacements of the body 4, and of the elongated element A, with respect to the ideal rule of motion.

It has thus already been shown that the kit 1 and the method according to the invention achieve the intended aim in a fully practical and easy manner.

By arranging appropriately, in the described manners, a generator 2 and a body 4 it is possible to monitor the behavior over time of the temporary variations in the electromagnetic parameters of the field produced by the generator 2, induced by the cyclic passage of the body 4, which is integral with the belt.

If a progressive misalignment of the belt (or other elongated element A), i.e., a movement with respect to the design position, occurs, the control and management unit detects promptly a change in the intensity of the temporary variation, over successive cycles, that is indeed caused by the different spatial coordinates at which the body 4 crosses the field.

Likewise, any slippage of the belt (or a relative movement of the latter with respect to the surface of the shaft B on which it rests, in the longitudinal direction, identified by the ideal trajectory C), causes a change in the time interval between successive variations of the monitored electromagnetic parameter, which in any case can be detected promptly by the control and management unit.

This allows to implement the adequate countermeasures, which can be activated by an alarm signal emitted by the unit.

It should be noted, therefore, that the desired result can be achieved simply by arranging a generator 2 proximate to the belt, without therefore interfering with it and with the products that it conveys, and a body 4 (which has a disk-like, cylindrical, parallelepipedal, laminar shape, etc.) even of extremely small size.

As a function of the type of material of which the belt is made, of the products to be conveyed and of the other requirements of application, it is always possible to choose at least one method for anchoring stably the body 4 to the belt, such as to in any case ensure optimum operation.

In case of aggressive products and/or of a high degree of impurities present in the surrounding environment, one can for example integrate the body 4 in the thickness of the belt, so that it is not damaged or disturbed in any way by the external conditions, at the same time ensuring optimum readings on the part of the unit.

Evidently, even mechanical or electronic interference, besides oils, water, water vapor and other substances, which might be present within the environment in which the belt is assembled, cannot harm in any way the optimum operation of the invention.

Especially if one wishes to integrate the body 4 within the thickness of the belt, therefore, achieving optimum protection against external agents, it is possible to ensure optimum operation even for a large number of operating cycles and/or in view of a particularly prolonged useful life of the belt.

Moreover, the possibility to use bodies 4 of small size (and evidently of any shape, since there is no functional or constructive constraint in this regard), which can be applied in different and simple manners to the elongated element A, ensures extreme versatility to the invention, allowing the adoption of the kit 1 and/or the execution of the method according to the invention also on belts or other elongated elements A that already exist (by providing a hole therein or by resorting to an adhesive layer).

The correct application of the invention, in other words, does not require any particular execution of the belt or chemical-physical property thereof, being adaptable easily and with great flexibility to existing belts or to belts that are already installed and/or in use.

Both on said existing belts and on first installation elongated elements A, the kit 1 and the method according to the invention further ensure high resistance to wear and stresses (for example to repeated torsions).

As a further confirmation of the extreme simplicity and practicality of the invention, it should be noted also that its embodiment does not require permanent magnets (or the like) coupled to the belt and preset to generate stationary magnetic fields (or external stationary fields for their magnetization), since a simple body 4 adapted to perturb the alternating magnetic field generated by the generator 2 is sufficient.

As anticipated briefly in some preceding paragraphs, it is useful to point out, finally, that belts or elongated elements A can be designed and manufactured beforehand together with the kit 1 according to the invention, thus being already sold provided with the generator 2, the body 4 and the other described components. Moreover, indeed in view of supplies of belts already including the kit 1 , said kit can be sold directly to the manufacturers of elongated elements A, further increasing the potential market and the appeal of the product.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements.

In the exemplary embodiments shown, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

In practice, the materials used, as well as the dimensions, may be any according to the requirements and the state of the art.

The disclosures in Italian Patent Application no. 102015000082099

(UB2015A006789), from which this application claims priority, are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.