EP0368769A1 - Process and apparatus for handling skins or leathers - Google Patents

Abstract

- Handling skins or leathers. <??>- The handling process according to the invention comprises the following stages: - positioning clamping clips on the tail (Q) and front (F) parts of a skin or of a leather, - moving the clips relatively away from each other to obtain a tension of the skin or of the leather along the dorsal superthickness line, - lifting the skin or leather to produce, owing to its free suspension, its folding along the dorsal superthickness line, - moving the skin or the leather suspended in the folded position to the work station, - depositing the stretched and folded skin or leather flat on a receiving area of the work station, and - withdrawing the clips from the tail and front parts of the skin or leather. <??>- Application to the salting of skins in piles. <IMAGE>

Description

The present invention relates to the technical field of handling, in the general sense, of skins or hides, treated or not, and coming, mainly, from mammals, such as equines, bovines, sheep or goats.

The skins have, after their removal from the body of the animal, a face called "hair side" and another face called "flesh side" which shows residues of flesh and fat as well as numerous blood vessels. Such fresh skins, which have a considerable weight and size, must undergo, in order to be transformed into leathers, various processing operations during which numerous manipulations are necessary.

One of these operations concerns the treatment methods aimed at preserving the skins, the most widely used technique of which is salting in pile fresh skins.

This salting technique consists, after a brief cleaning of the fresh skins on the flesh side, of stacking the skins flat with the flesh side placed above them, while proceeding to salting the skin side of the skins, prior to flattening the next upper skin. Stacks of skins up to 1 meter to 1.50 meters are thus obtained and kept in this state for a time necessary for the dehydration of the skins, with a view to preventing or stopping microbial development.

Experience shows that the conditions under which the salting and storage of the skins are carried out have a very great influence on the condition of the preserved skins. Thus, during conservation, many well-known alterations can occur, such as bites on the flesh or on the flower, red or purple spots, heat and / or trees. These alterations or defects all have an impact on the qualities and appearance of the leather obtained.

However, it appears that salting and storage are not always carried out under the best conditions, insofar as these operations represent, in particular, various constraints for the handling personnel having to assume the realization of these Battery. Indeed, the personnel must fully deploy the skins to lay them flat, which represents painful and not easy manual handling operations, due to the size, the weight and the greasy nature presented by the skins, as well as the height of the piles to be made.

Another skins treatment operation, during which various handling operations take place, concerns the crouponnage technique. This technique aims, after removing the salt covering the skins, to cut each skin into four parts, namely, a croup, a collar and two flanks. For this purpose, the handling personnel must grab the skins and shake them to rid the skins of the salt. Then, the personnel folds each skin along the line of extra thickness corresponding to the part covering the vertebral column of the animal, so as to allow the simultaneous cutting of the two sides of the skins.

It is obvious that gripping, gripping and folding are difficult and painful operations for handling personnel, given the size, weight and slippery nature of the skins. In addition, folding the skins along the line of extra back thickness constitutes a delicate operation, the poor execution of which results in an imprecise and erroneous cutting of the parts of the skin, which does not make it possible to obtain parts of leather of homogeneous structure.

Analysis of the two processing operations, described above by way of example, makes it possible to highlight the impact of the handling operations on the appearance of the leathers obtained. It therefore appears the need to be able to have means allowing the handling of skins or leathers in the various treatment operations, in the general sense, of skins or leathers.

The prior art has also proposed, by patent application DE-A-24 07 665 , an apparatus for handling the skins before an exchange operation. The proposed device comprises two clamps each connected to a cable, which is intended to be wound on a drum controlled in rotation. The clamps are intended to be placed on the places of the legs of a skin.

If the implementation of such a device provides assistance relating to handling personnel, practice shows that such a device does not allow the skins to be fully deployed to lay them flat, insofar as the skins are handled by the parts of the legs of a skin. The problems inherent in the salting technique therefore remain unresolved. In addition, this device is in no way suitable for the crouponnage technique.

The present invention therefore aims to propose a new process suitable for the handling of skins or leathers during the various treatment operations and making it possible to overcome the various constraints imposed on the handling personnel and to eliminate the causes of deterioration of the skins. or leathers.

The invention aims to offer a method of storing skins in a stack, suitable for limiting alterations or storage defects.

To achieve these goals, the handling method according to the invention, comprising a median line of back thickness delimited by extreme parts, called tail and forehead, of the type consisting in moving the skin to a work station or leather by means of two clamps of a handling device is characterized in that it comprises the following steps:
- put clamps on the tail and forehead parts of a hide or leather,
- proceed with the relative spacing of the clips between them to obtain a tension of the skin or the leather according to the line of extra thickness on the back,
- lift the skin or leather to ensure, by its free suspension, its folding along the line of extra back thickness,
- move the hanging skin or leather to the workstation in the folded position,
- lay the skin or leather stretched and folded flat, on a workstation reception plan,
- and remove the pliers from the tail and forehead parts of the skin or leather.

The invention also aims to provide a handling device suitable in particular for implementing the techniques of crouponnage and salting of stacked skins.

The invention also aims to offer a handling device of simple design and at a reduced cost.

The apparatus, for implementing the method comprises two slings each equipped with a clamp for clamping a skin or a leather depending on its thickness, two means for spacing the slings one relative to the another according to at least one substantially horizontal plane and at least one motor member acting on at least one of the slings to ensure a relative distance from the clamps, is characterized in that the means are adapted to be separated from one another of a value at least greater than the length of a skin or leather, to ensure the folding and suspension of the skin or leather tightened by the clamps, according to its line of back thickness and in that the motor element is controlled to at least ensure a spacing of the clamps of a value corresponding to the length of a skin or of a leather making it possible to tighten the skin or the leather along the line of back thickness.

• La fig. 1 est une vue en élévation d'un appareil de manipulation conforme à l'invention.
• La fig. 2 est une vue d'un détail caractéristique de l'invention.
• La fig. 3 est une vue en coupe prise, sensiblement, selon les lignes III-III de la fig. 1.
• La fig. 4 est une vue de dessus d'une peau ou d'un cuir pouvant être manutentionné par l'appareil selon l'invention.
• Les fig. 5A à 5C sont des vues en élévation de l'appareil de manipulation dans diverses phases de manutention caractéristiques.
• La fig. 6 est une vue schématique en plan de dessus montrant un exemple d'application de l'appareil selon l'invention.
• La fig. 7 est une vue transversale prise selon la ligne VII-VII de la fig. 6.

Various other characteristics will emerge from the description given below with reference to the appended drawings which show, by way of nonlimiting examples, embodiments of the subject of the invention.

• Fig. 1 is an elevational view of a handling device according to the invention.
• Fig. 2 is a view of a characteristic detail of the invention.
• Fig. 3 is a sectional view, taken substantially along the lines III-III of FIG. 1 .
• Fig. 4 is a top view of a skin or a leather which can be handled by the apparatus according to the invention.
• Figs. 5A to 5C are elevation views of the handling apparatus in various characteristic handling phases.
• Fig. 6 is a schematic top plan view showing an example of application of the apparatus according to the invention.
• Fig. 7 is a transverse view taken along line VII-VII of FIG. 6 .

Fig. 1 illustrates an embodiment of an apparatus for implementing the method according to the invention ensuring the handling of skins or leathers, in the various treatment operations intended to transform fresh skins into leather. By skins or leathers, it should be understood those or those coming, mainly, from mammals, such as equines, bovines, sheep or goats.

The apparatus according to the invention comprises two slings or cables 1 , made of any suitable material and each equipped, at one of its ends, with a clamp 2 adapted for tightening, depending on its thickness, a skin or of a leather P resting, for example, on a ground S. As shown more precisely in fig. 2 , each clamp 2 comprises two jaws 3, 4 articulated together and each having a clamping surface arranged to preferably include protruding imprints 5 . The jaws 3, 4 are urged closer together by an elastic member, not shown, to exert a determined effort to tighten the skin while not damaging the leather. The jaw, for example 5 , is provided with a lever 6 ensuring the attachment of the sling and the opening of the clamp which can be locked in this position, for example, by means of an elastic ball cooperating with a complementary cavity, not shown.

The apparatus also comprises two means 8 for separating the slings 1 from one another, along at least one substantially horizontal plane and the function of which will be better understood in the following description of the process according to the invention. The spacing means 8 are constituted, in the example illustrated, by two pulleys cooperating with the slings and each adapted to one of the ends of a heavy beam 11 extending substantially in a horizontal plane. Each pulley 8 is preferably associated with a downstream counter pulley 12 and an upstream counter pulley 13 , making it possible to obtain suitable cooperation of the slings with the pulleys 8 .

The beam 11 is carried by a superimposed frame 14 , by means of at least two spaced rods 15 , integral with the beam and intended to be guided in vertical sliding by bearings 16 fixed on the frame 14 . The rods 15 are provided, at their free end portion, with a stop stop 17 able to cooperate with the transverse face of the bearing to limit the vertical downward sliding of the beam 11 .

The frame 14 , constituted in the form of a bar, carries, substantially in its median part, a plate 18 for adapting at least one controlled drive member 19 acting on at least one and, preferably, on the two slings 1 . As shown more precisely in fig. 3 , the driven motor member 19 is preferably constituted by a motor 19 a controlling in rotation a double drum 19 b on which are fixed the ends of the slings opposite to those carrying the clamps. Advantageously, the slings 1 are mounted on the drum 19b , so that the two slings are wound or take place simultaneously, in relation to the direction of rotation of the motor 19a .

The frame 14 is preferably equipped with two return pulleys 21 mounted at each end of the frame to cooperate each with a sling. The frame 14 carries two levers 22 each articulated to the frame in close relation with a return pulley 21 . Each lever 22 is provided, at its free end, with a roller 23 cooperating with a sling allowing the tensioning of the sling.

The frame 14 is, for example, suspended from a rail 24 , by means of rollers 25 carried by extensions 26 of the plate 18 . For example, at least one of the rollers 25 is controlled in rotation by a motor 27 making it possible to move the device along the running rail 24 . To ensure the stability of the device, during its movement, the frame 14 is provided with wheels 28 cooperating with a support structure 29 carrying the rail 24 and adapted on a ceiling 30 .

The apparatus described above makes it possible to implement the handling method according to the invention for a skin or a leather P having, as illustrated in FIG. 4 , a line L of extra thickness corresponding to the part of skin initially covering the vertebral column of the animal. The extra thickness line L is delimited at its ends by so-called tail Q and front F parts , in relation to the corresponding regions of the animal's body initially covered by the skin.

The method according to the invention consists in placing the clamps 2 on the front F and tail Q parts of the skin or of the leather P to be handled. Although the skin or leather P , illustrated in fig. 4 , be shown fully unfolded, it should be considered that the method of the invention can be implemented with skins or leathers which can be in various forms and, in particular, in bulk, folded and / or superimposed regularly or not .

The clamps 2 are engaged, by their jaws 3, 4 , on the forehead F and tail Q parts of the skin or leather to keep the skins or the leathers firmly tightened. The motor 19 a is then controlled to obtain the winding of the slings 1 on the drum 19 b . This results, on the one hand, in a relative spacing of the clamps 2 exerting a tension in the skin or in the leather along its length along the line of excess thickness L and, on the other hand, a lifting in the vertical plane of the skin or leather which is folded naturally under the effect of its own weight, along line L ( fig. 5A, 5B ). The skin or leather P is thus stretched, folded in two parts and suspended freely under the beam 11 and between the pulleys 8 .

Of course, it must be considered that the pulleys 8 are distant from each other by a value at least greater than the length of the skins to be handled, so as to authorize the suspension, between the pulleys 8 , of skins or leathers having various sizes. In this regard, it could be envisaged to use spacing means 8 of a different type and / or to move at least one of the means 8 in a substantially horizontal plane, directly or not, by a drive member. allowing to assume the same function, that is to say, a spacing of the clamps to stretch the skin or the leather.

When the tension of the skin or leather reaches a maximum considered value, corresponding to a limit stretching of the skin or leather, it appears that the continued winding of the slings 1 causes the beam 11 to be lifted in the vertical plane ( fig. 5C ). The engine 19 a is stopped to obtain a positioning of the skin or the leather at a chosen height relative to the ground S , in relation to the obstacles to be overflown during the subsequent movement which will be described more precisely below.

To this end, the motor 27 is controlled in rotation to move the frame 14 along the rail 24 to a determined work station T ( fig. 6 ). The motor 19 a is then controlled in rotation to unwind the slings 1 , so that the beam 11 descends until the stops 17 cooperate with the transverse faces of the bearings 16 . Slings continue their descent until the motor stops 19a which occurs when skin or leather is laid flat, in the folded position on a receiving station plan, consisting, for example, by the ground. After removing the clamps 2 from the skin or the leather, the motor 27 can be controlled to return the device to its initial position and start another handling cycle.

The apparatus described above makes it possible to implement a new method of salting in pile fresh skins consisting of obtaining, during the lifting operation, the folding of the skins according to the line of back thickness L , with the flesh side placed externally and the hair side of the two strips of skins placed one against the other. Such folding can be easily obtained by placing, before adapting the pliers, the flesh side directed towards the beam 11 and the bristle side towards the ground.

The movement of the skin in the hanging position can be used to carry out natural or forced cooling and / or cleaning of the flesh side of the fresh skin which shows residues of flesh and fat, as well as numerous blood vessels. . The cleaning and / or cooling of the skin can consist, for example, of subjecting the latter to jets of water. Preferably, the duration of movement of the skin, after cleaning, is chosen to allow a natural flow of water, so as to obtain a drained skin at the work station. Of course, it can be envisaged to incorporate a forced drying station between the cleaning station and the work station.

Advantageously, the reception area for the skins of the work station is subjected, prior to the deposition of the first skin, to salting which is also carried out after the deposition of the skin on the flesh side of the skin placed above. Thus, the device can be controlled to bring, successively, other skins which are each deposited on the previously salted skin and laid flat. As shown more precisely in fig. 7 , the skins are preferably deposited to partially overlap and constitute a row R₁ formed by a series of skins P between each of which is interposed a layer of salt s . It should be noted that the salting of the skins can be carried out automatically by the machine provided, for this purpose, with a salt storage tank ( fig. 6 ) mounted, for example, on the beam 11 and controlled to deliver a quantity salt determined on the skin previously laid flat.

Preferably, the skins are offset two by two by a value d between 10 and 50 cm. Furthermore, it can be carried out to form an upper row superimposed on the row R₁ and so on, to constitute a pile P pile for storing skins allowing the dehydration of the skins.

The process for storing cleaned, folded and placed flesh against flesh, limits the contact of the salt with the leather side, which avoids major storage defects.

In a preferred embodiment, the rail 24 can be provided, at its ends, with rolling members intended to cooperate with a suspended track 32 being established, for example, in a direction perpendicular to that of the rail, so as to authorize the formation of stacks of skins P₂, P₃ ... P _n , formed side by side.

Advantageously, such an apparatus can be used in a slaughterhouse for handling fresh hides arriving from the slaughter line, by a feed chute 33 .

Of course, it should be considered that this device is controlled by a circuit making it possible to control, in particular, the motor member for winding the slings and the motors moving the device on the rail and the track. The control circuit is associated, in particular, with sensors not shown, at the end and at the start of the stroke and with proximity detection to detect the distance between the reception plane and the beam. The circuit can be of the programmable type, so as to control the device automatically according to a training and battery management cycle.

It appears that the implementation of this device in the application of salting and storage of skins is particularly advantageous, insofar as this device eliminates, in particular, the main constraints of the handling personnel. Indeed, the personnel must, essentially, put in place and, if necessary, remove the pliers from the forehead and tail parts of the skins. In addition, this device makes it possible to constitute stacks formed of perfectly overlapping rows, insofar as the skins or leathers are always positioned in the same place between the pulleys 8 . To synchronize the movement of these pulleys, provision may be made to connect the two pulleys 13 by a crossed belt 33 ( FIG. 5C ).

The apparatus described above also finds a particularly advantageous application in the technique of crouponnage which aims to cut skins previously salted and, in general, stored in stacks.

In fact, the device is particularly suitable for ensuring the movement of the skins from a storage stack to a reception plane constituted by a cutting table. The suspension of the skins, during their movement, makes it possible to rid the skins of the salt which falls by gravity. Advantageously, the skins are folded, for this technique, along the line of extra back thickness, by placing the hair side outwardly to allow it to be cut properly. Thus, the skins are laid flat and folded perfectly according to the extra thickness line, allowing a precise cutting of the skin parts, allowing the obtaining of leather parts of homogeneous structure.

Of course, the apparatus according to the invention can be used to carry out various manipulations appearing during the various operations for transforming fresh skin into leather.

The invention is not limited to the examples described and shown, since various modifications can be made thereto without going beyond its scope.

Claims (15)

1 - Process for handling skins or leathers ( P ) comprising a median line ( L ) of dorsal extra thickness delimited by extreme parts called tail ( Q ) and forehead ( F ), of the type consisting in moving, up to a work station ( T ), skin or leather ( P ) via two clamps of a handling device,
characterized in that it comprises the following stages:
- put clamps on the tail ( Q ) and forehead ( F ) parts of a hide or leather,
- proceed with the relative spacing of the clips between them to obtain a tension of the skin or the leather according to the line of extra thickness on the back,
- lift the skin or leather to ensure, by its free suspension, its folding along the line of extra back thickness,
- move the hanging skin or leather to the workstation in the folded position,
- lay the skin or leather, stretched and folded, flat on a workstation receiving plan,
- and remove the pliers from the tail and forehead parts of the skin or leather. 2 - Method according to claim 1, characterized in that it consists in folding the leather or the skin along the line of back thickness, placing the flesh side externally. 3 - Process according to claim 2, characterized in that it consists in subjecting the flesh side of the skin or of the leather suspended to cooling and / or cleaning during its movement. 4 - Method according to claim 1 or 3, characterized in that it consists in moving the skin or the suspended leather for a determined period necessary for its drying and / or its draining. 5 - Method according to claim 1, characterized in that that it consists in salting the reception plan, prior to the deposition of the leather or the skin on the plan. 6 - Method according to claim 1, characterized in that it consists in placing each skin or leather flat by partially overlapping the skin or leather previously deposited and subjected to salting, so as to constitute a row. 7 - Process according to claims 1 and 6, characterized in that it consists in depositing the skins or leathers on a row of skins or leathers already formed, so as to form a pile. 8 - Process according to claim 1, characterized in that it consists in folding the leather or the skin along the line of extra back thickness, placing the hair side externally. 9 - Apparatus for implementing the process for handling skins or leathers, according to one of claims 1 to 8, of the type comprising two slings ( 1 ) each equipped with a clamp ( 2 ) for clamping a skin or leather ( P ) depending on its thickness, two means ( 8 ) for spacing the slings one with respect to the other along at least one substantially horizontal plane and at least one motor member ( 19 ) acting on at least one of the slings, to ensure a relative distance from the clamps,
characterized in that the means ( 8 ) are adapted to be separated from each other by a value at least greater than the length of a skin or leather, to ensure the folding and the suspension of the skin or leather tightened by the clips, according to its line of back thickness and in that the motor member ( 19 ) is controlled to at least ensure a spacing of the clips of a value corresponding to the length of a skin or d '' a leather allowing to tighten the skin or the leather according to the line of back thickness. 10 - Apparatus according to claim 9, characterized in that the two spacing means ( 8 ) each consist of a pulley cooperating with a sling and adapted to the end of a heavy beam ( 11 ) extending in a horizontal plane. 11 - Apparatus according to claims 8 and 9, characterized in that the drive member ( 19 ) is constituted by a drive drum on which the slings are fixed to wind or unwind simultaneously, so as to raise or lower the beam ( 11 ) which keeps the skin or leather in the suspended position. 12 - Apparatus according to claim 11, characterized in that the motor drum is fixed to a suspended frame ( 14 ) having bearings ( 16 ) for guiding in vertical sliding for rods ( 15 ) carried by the beam. 13 - Apparatus according to claim 12, characterized in that the frame comprises, at each end, a return pulley ( 21 ) cooperating with a sling and, a lever ( 22 ) for tensioning a sling. 14 - Apparatus according to claim 12, characterized in that the frame ( 14 ) is suspended from at least one rail ( 24 ) of rolling and comprises a motor ( 27 ) for moving the frame on the rail. 15 - Apparatus according to claim 14, characterized in that the running rail ( 24 ) is movable on a guide track ( 32 ) of transverse direction relative to that of the rail.

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