Patent Description:
The invention also relates to a system implementing the above-mentioned movement method and also to an animal hide dryer using the above-mentioned system.

Said method and said system can be used to move magnetised elements of any kind to constrain animal hides that are spread onto support surfaces to be dried in drying systems.

It is well known that in the tanning industry, after undergoing wet processing, the hides are dried to remove the excess water they contain, so that they reach the required moisture content.

One of the most widely used drying methods involves the use of special dryers that include a tunnel through which the hides transit, spread out on special frames and immersed in an atmosphere of hot air that is kept in circulation by special fans.

During drying, in order to prevent shrinkage of the hides, which would lead to a significant reduction in their marketable surface area and consequently significant economic loss for the tanner, the hides are kept stretched by firmly tying their edges to the drying frame on which they are spread out.

In the technical jargon of the sector, the operation by which the edges of the hides are bound to the drying frame is commonly known as "nailing" and involves the use of special pliers, each of which includes jaws for gripping the edge of the hide to be stretched and a protruding peg which is inserted into a hole in the drying frame.

In this way, using a plurality of pliers in variable numbers depending on the surface area of the hide to be dried, the latter is fixed to the frame well stretched and tensioned.

During the drying process, the water evaporates and the hide gradually shrinks, creating a state of tension that tends to weaken it and which mainly affects its perimeter edge in the areas where the jaws of the pliers grip.

The weakening of the hide, which basically consists of localised detachment of the upper part of the hide, known as the grain, from the part underneath, significantly compromises the quality of the hide, and areas where this defect appears must be appropriately removed by trimming the hide.

It is understood that this trimming operation leads to a reduction in the surface area of hide that can be sold and therefore to waste, which results in an inevitable economic loss for the tanner.

An alternative technique to nailing the hides with pliers is described in patent document <CIT> and also in patent document <CIT> registered in the name of the holder of the present patent application, which documents teach how to constrain the hides to be dried to the drying frame using magnetised bodies and exploiting the compressive force that the magnetised bodies exert on the hide by the magnetic attraction between each magnetised body and the frame made of ferromagnetic material on which the hide is spread out.

In particular, patent document <CIT> states that the magnetic bodies have a general discoidal or U-shape with a flat surface supporting the hide to be spread out, while patent document <CIT> states that the magnetic bodies have a spherical shape or are provided with one or more curved surfaces in contact with the hide.

It has been found that nailing of hides using magnetic bodies effectively reduces the time for nailing and picking up the hide before and after drying, respectively, and the method and system of the invention are intended to further reduce the above-mentioned times.

In addition, the method and the system of the invention also intend to prevent manipulation of the magnetic bodies by operators.

The purposes are achieved by the method of the invention according to claim <NUM> to which reference will be made, and by the system, which is also the subject matter of the invention, implementing said method.

As will be seen in the following description, the method and the system of the invention effectively enable the time for nailing and picking up the hides to be reduced and thus, advantageously, drying costs to be reduced.

Furthermore, considering that the magnetic bodies are small in size and that they are used in large quantities during the nailing and removal of hides from the frames, it can be understood that, if the operators no longer need to handle them, the same operators will advantageously not be subjected to the stress of having to handle small elements for a long time and quickly.

In addition, advantageously, the accidental dispersal of such small objects in the working environment will be prevented, thus ensuring a tidier and safer working environment.

The aims and advantages listed shall be better highlighted below during the description of preferred but not exclusive embodiments of the method and of the system of the invention, which are provided herein below by way of nonlimiting example, with reference to the appended drawings in which:.

The method of moving the magnetised elements <NUM> for the fixing of animal hides L spread onto support surfaces <NUM> made of magnetic material, which is the subject matter of the invention, is illustrated in the sequences of <FIG>.

According to the invention, the method comprises a step of depositing a plurality of magnetised elements <NUM> on each hide L spread onto a support surface <NUM> to constrain it prior to treatment or processing, and a step of picking up the magnetised elements <NUM> from each of the hides L at the end of the treatment or processing.

It should be noted that the depositing step preferably, but not exclusively, simultaneously involves a plurality of magnetised elements <NUM> sufficient to fix each hide L to the support surface <NUM> and, similarly, the pick-up step simultaneously involves all the magnetised elements <NUM> positioned during the depositing step.

The steps of depositing and picking up the magnetised elements are performed by means of a plurality of movement units, and, according to an embodiment for moving each magnetised element <NUM>, the method provides for the use of a single movement unit <NUM> for moving magnetic masses and carrying out a plurality of operations, wherein the first operation consists of:.

A second operation is then carried out, as illustrated in <FIG>, which consists of.

This is followed by the operation seen in <FIG>, which involves.

With the depositing of the magnetised element <NUM>, the hide L is constrained to the support surface <NUM> and the depositing step ends with the return of the first magnetic mass <NUM> above the housing <NUM>, as can be seen in <FIG>.

After the treatment or processing of the hide L, the step of picking up the magnetised elements <NUM> previously deposited is performed, which comprises a plurality of operations in which the first of said operations is represented in <FIG> and involves.

After the sample is taken, the operation is carried out of.

At the end of the separation the spontaneous operation takes place of.

When the magnetised element <NUM> is received in the housing <NUM>, it adheres to the first magnetic mass <NUM>, as observed in <FIG>, and a new depositing step on another hide L can be repeated.

As illustrated in <FIG>, the displacements of the first magnetic mass <NUM> during the depositing step and the displacements of the second magnetic mass <NUM> during the pick-up step are carried out by means of one single movement unit <NUM>.

The construction details of the movement unit <NUM> can be seen in particular in the axonometric representations of <FIG>, where it can be seen that it comprises a support structure <NUM> which extends along a longitudinal axis X.

There are also contrast means <NUM> that are preferably, but not exclusively, associated with the movement unit <NUM>.

In particular, the contrast means <NUM> comprise, as can be observed particularly in <FIG>, a stopping fork <NUM> which is configured to act against the magnetised element <NUM> and in it a housing <NUM> is obtained, which is configured with a profile 3a adapted to receive the magnetised element <NUM>.

Also associated with the support structure <NUM> are motorisation means <NUM> for moving a sliding block <NUM>, positioned above the stopping fork <NUM>, which in turn supports the second magnetic mass <NUM> and the first magnetic mass <NUM> which is received in a seat obtained in a non-magnetic block <NUM> side by side to the second magnetic mass <NUM>.

The motorisation means <NUM> comprise a motor unit <NUM> which rotates a ball screw <NUM> connected to the sliding block <NUM> which, during its movement, is guided by a sliding shaft <NUM>, also connected to the support structure <NUM>.

Finally, there are also movement means, not shown, for moving the movement unit <NUM> towards and away from the direction Z orthogonal to the direction defined by the longitudinal axis X, for depositing and picking up each magnetised element <NUM> on/from the hide L spread onto the support surface <NUM>. Operationally, the movement unit <NUM> moves the magnetised element <NUM> and performs all the operations of the method of the invention that have been previously described with reference to <FIG>.

With regard, in particular, to the separation of the magnetised element <NUM> from the second magnetic mass <NUM>, which has been illustrated and described with reference to <FIG> and <FIG>, it occurs due to the particular constructive characteristics of the sliding block <NUM> and of the stopping fork <NUM> in which the housing <NUM> is located.

In particular, when the sliding block <NUM> is moved in the direction indicated by the arrow in <FIG>, when the magnetised element <NUM> is received in the stopping fork <NUM>, as can be seen in <FIG> and <FIG>, it stops above the housing <NUM> while the sliding block <NUM> continues its movement in the direction indicated by the arrow in <FIG>.

In this way, the contrast created by the stopping fork <NUM> and the displacement of the sliding block <NUM> create reciprocal sliding between the second magnetic mass <NUM> and the magnetised element <NUM> until the magnetised element <NUM> is removed from the attraction of the second magnetic mass <NUM> which occurs when the magnetised element <NUM> comes into contact with the non-magnetic block <NUM>.

Then, upon the arrival of the non-magnetic block <NUM>, the magnetic attraction exerted by the second magnetic mass <NUM> on the magnetised element <NUM> ceases, which element is received in the housing <NUM> and then adheres to the first magnetic mass <NUM> when, as observed in <FIG> and <FIG>, the sliding block <NUM> stops at the end of its stroke.

An embodiment of the method of the invention is illustrated in the sequences of <FIG> and differs from the embodiment described above mainly in that the depositing step and the pick-up step are each carried out by a different movement unit.

In particular, with reference to <FIG> it is observed that the displacement of the first magnetic mass <NUM> during the depositing step of each magnetised element <NUM> takes place by means of a first movement unit 105a which extends mainly along a first longitudinal axis Xa while, with reference to <FIG>, the displacement of the second magnetic mass <NUM> during the pick-up step takes place by means of a second movement unit 105b which extends prevalently according to a second longitudinal axis Xb.

Similarly to the embodiment of the method described above, the depositing step envisages, for the movement of each magnetised element <NUM>, a plurality of operations which involve:.

After the depositing of the magnetic element <NUM>, the depositing step ends with the displacement of the first magnetic mass <NUM> above the housing <NUM>, as can be seen in <FIG>.

The step of picking up the magnetised elements <NUM> previously deposited is carried out by means of a plurality of operations, which include:.

At the end of the separation, the magnetised element <NUM> is spontaneously deposited, preferably but not necessarily by gravity, in the housing <NUM> and the second magnetic mass <NUM> is spaced above the magnetised element <NUM>, as observed in <FIG>.

As regards the first movement unit 105a, it is represented in an axonometric view in <FIG> where it can be observed that it comprises a first support structure 130a with which a first sliding block 108a is associated, supporting the first magnetic mass <NUM>, which is provided with a shaped seat 4a housing the magnetised element <NUM>.

As regards, instead, the second movement unit 105b, it is represented in an axonometric view in <FIG>, where it can be observed that it comprises a second support structure 130b and a second sliding block 108b which in turn supports the second magnetic mass <NUM> and a non-magnetic plate <NUM> placed alongside and coplanar to the second magnetic mass <NUM>.

There are also contrast means 107a which preferably, but not exclusively, pertain to the second movement unit 105b.

Similarly to the embodiment described above, each of the movement units 105a, 105b extends along a longitudinal axis Xa, Xb, respectively, and also comprises motorisation means 110a, 110b for moving each respective sliding block 108a, 108b and a sliding shaft 111a, 111b guiding the respective sliding block 108a, 108b during movement.

With respect to the motorisation means 110a, 110b, they comprise a motor unit 118a, 118b rotating a ball screw 119a, 119b connected to a respective sliding block 108a, 108b.

Finally, similarly to the embodiment described above, the contrast means <NUM> comprise a stopping fork <NUM>, whereas, differently, the housing <NUM> is made in a container <NUM> which is observed in <FIG> and in the detail <FIG>.

Operationally, the separation of the magnetised element <NUM> from the second magnetic mass <NUM> to be received in the housing <NUM>, like to the variant of the method described above, takes place due to the constructional features of the second sliding block 108b.

In fact, during the movement of the second sliding block 108b in the direction indicated by the arrow of <FIG>, when the magnetised element <NUM> is received in the stopping fork <NUM>, it stops above the housing <NUM> created in the container <NUM>, while the second sliding block 108b continues its displacement.

In this way, the contrast created by the stopping fork <NUM> and the displacement of the second sliding block 108b create mutual sliding between the second magnetic mass <NUM> and the magnetised element <NUM> until the magnetised element <NUM> is subtracted from the attraction of the second magnetic mass <NUM> which occurs when the magnetised element <NUM> comes into contact with the non-magnetic plate <NUM>.

Thus, upon the arrival of the non-magnetic plate <NUM>, the magnetic attraction exerted by the second magnetic mass <NUM> on the magnetised element <NUM> ceases, which element is thus received, preferably but not necessarily, by gravity into the housing <NUM> of the container <NUM> when, as observed in <FIG>, the second sliding block 108b stops at the end of its stroke.

The invention also relates to a movement system of the magnetised elements <NUM>, shown in <FIG> wherein it is collectively referred to as <NUM>, using the movement method of the invention described with reference to <FIG>. The movement system <NUM> comprises a single frame <NUM> which supports, side by side and spaced apart, a plurality of movement units <NUM> of the magnetised elements <NUM>.

The frame <NUM> may be made in any shape but preferably, though not necessarily, it will be a flat polygonal shape.

In particular, in the case that is described and with reference to <FIG>, it is observed that the frame <NUM> has a rectangular or square shape and its sides <NUM> define a perimeter that contains the perimeter of the support surface <NUM> and of the hide L spread onto the support surface <NUM>, when the frame <NUM> is arranged above said support surface <NUM>, as observed in <FIG>.

In addition, the movement units <NUM> are projecting towards the inside of the frame <NUM> so as to be arranged above at least the perimeter edge of the underlying hide L when the frame <NUM> is arranged above the support surface <NUM>.

There are also displacement means, not represented but in any case of a known type, to bring the frame <NUM> closer and further away above the support surface <NUM> for carrying out the depositing or pick up step on the magnetised elements <NUM>.

Thus, the aforementioned movement system <NUM> employs a single frame <NUM> for both picking up and depositing the magnetised elements <NUM> from/on the hides L spread onto the support surface <NUM>.

The invention also relates to an embodiment variant of the movement system just described, which can be seen in <FIG> wherein it is collectively referred to as <NUM> and which differs from the preceding system in that it comprises a first frame 310a with which a plurality of first movement units 105a of the magnetised elements <NUM> are associated and a second frame 310b with which a plurality of second movement units 105b of the magnetised elements <NUM> are associated.

The two frames 310a and 310b are the same as each other and, for simplicity of description, only one of them is shown in <FIG>, with respect to which the numbering of the elements that compose both is referred.

Also in this embodiment variant, each frame 310a and 310b may be made with any shape but preferably, though not necessarily, it will be of a flat polygonal shape.

In particular, in the case being described and with reference to <FIG>, it is observed that each frame 310a and 310b has a rectangular or square shape and its sides 311a and 311b define a perimeter containing the perimeter of the support surface <NUM> corresponding to each of them.

In addition, the movement units 105a, 105b are fixed to the respective frame 310a, 310b, are spaced apart from each other and are projecting towards the inside of the same frame 310a, 310b so as to be arranged above at least the perimeter edge of the underlying hide L when the frame 310a, 310b is arranged above the respective support surface <NUM>.

Also in this embodiment variant there are displacement means, not represented but in any case of a known type, to bring each frame closer and further away above the respective support surface <NUM> to perform:.

In addition, on the perimeter edge 2a of each support surface <NUM>, a plurality of the containers <NUM> is arranged, each of which is adapted to house a respective magnetised element <NUM>.

The method and the system of the invention, in both embodiments described, preferably but not exclusively, provides that the magnetised elements <NUM> are spheres.

The method and the system of the invention are particularly adapted to constrain animal hides spread onto the support surface during the drying process, but can also be used to constrain animal hides or any other kind of flexible laminar elements during processes other than drying.

The invention also comprises a dryer indicated overall by <NUM> and shown in <FIG> in a side and plan view, respectively, comprising a drying tunnel <NUM> along which the hides L to be dried are passed spread onto the respective support surfaces <NUM>.

For the movement of the magnetised elements <NUM>, the movement system <NUM> described above and already shown in <FIG> is used, which uses the single frame <NUM>.

In particular, the steps of picking up and depositing the magnetised elements <NUM> take place in a work station <NUM> by means of the single frame <NUM> of the movement system <NUM>, which is raised and lowered according to the vertical displacement direction <NUM> by a known type of displacement means to allow the operators to access the support surface <NUM> to pick up the dried hide and deposit a subsequent hide to be dried.

The invention also includes a variant embodiment of the dryer just described, indicated overall with <NUM> and represented in <FIG> respectively in side and plan view, which includes a drying tunnel <NUM> along which the hides L to be dried are passed, spread onto the respective support surfaces <NUM> and which differs from the embodiment just described only in that the movement system <NUM> previously described and already represented in <FIG> is used for moving the magnetised elements <NUM>.

It should be noted that in this variant embodiment the step of picking up the magnetised elements <NUM> from a dried hide is carried out by the second frame 310b in a pick-up station 510b, while the step of depositing the magnetised elements <NUM> on a subsequent hide to be dried is carried out by the first frame 310a in a depositing station 510a.

The depositing station 510a and pick-up station 510b are superimposed on each other, and the picking up of a dried hide and the deposit of a subsequent hide to be dried from/onto the support surface <NUM> take place in the work station <NUM> which is located upstream of the depositing station 510a and the pick-up station 510b and on which the support surface <NUM> is alternately moved in the horizontal direction indicated by the arrows <NUM>.

On the basis of what has been described and illustrated, it is understood that the movement method, the movement system and the dryer using the movement system which are all the subject matter of the invention achieve the intended purposes.

First of all, the use of any one of the methods and any one of the systems described makes it possible to automate the movement operations of the magnetised elements <NUM> and thus, compared to the prior art, to reduce the time required for handling the hides in order to arrange them and pick them up on/from the support surfaces on which they are dried inside a dryer.

In addition, the method and the system of the invention are also intended to prevent operators from being subjected to the stress caused by the fast and prolonged handling of such small magnetic bodies.

Claim 1:
Method for moving magnetised elements (<NUM>) for fixing animal hides (L) spread onto support surfaces (<NUM>) made of magnetic material, comprising:
- a step of depositing a plurality of said magnetised elements (<NUM>) on each of said hides (L) spread onto said support surface (<NUM>),
characterised in that said depositing step comprises, for each of said magnetised elements (<NUM>), the following operations:
- picking up a magnetised element (<NUM>) from a housing (<NUM>; <NUM>) by means of a first magnetic mass (<NUM>) by magnetic attraction between said first magnetic mass (<NUM>) and said magnetised element (<NUM>);
- moving said first magnetic mass (<NUM>) and said magnetised element (<NUM>) adherent to each other and placing said magnetised element (<NUM>) above said hide (L);
- separating said magnetised element (<NUM>) from said first magnetic mass (<NUM>) to deposit said magnetised element (<NUM>) on the underlying hide (L), said separation and said depositing being obtained by magnetic attraction between said support surface (<NUM>) underneath said hide (L) and said magnetised element (<NUM>) which is greater than the magnetic attraction between said first magnetic mass (<NUM>) and said magnetised element (<NUM>);
the method also including
- a step of picking up by means of a movement unit (<NUM>; 105b) said plurality of magnetised elements (<NUM>) from each of said hides (L) spread on said support surface (<NUM>), said pick-up step comprising, for each of said magnetised elements (<NUM>), the following operations:
- picking up each of said magnetised elements (<NUM>) from the underlying hide (L) by means of a second magnetic mass (<NUM>) by magnetic attraction between said second magnetic mass (<NUM>) and said magnetised element (<NUM>) which is greater than the magnetic attraction between said magnetised element (<NUM>) and said support surface (<NUM>);
- moving said second magnetic mass (<NUM>) and said magnetised element (<NUM>) adhering to each other towards said housing (<NUM>) to place said magnetised element (<NUM>) above said housing (<NUM>) and in contact with said contrast means (<NUM>; <NUM>);
- separating said magnetised element (<NUM>) from said second magnetic mass (<NUM>) by reciprocal sliding produced by said contrast means (<NUM>; <NUM>) acting on said magnetised element (<NUM>);
- depositing said magnetised element (<NUM>) in said housing (<NUM>; <NUM>).