EP1544109B1 - Method and apparatus for conditioning tyres in stacks. - Google Patents

Abstract

The procedure, in which tyres (P) of the same dimensions are aligned, compressed and held under tension while straps are applied, is performed by machine with rotating rollers (200, 201) to align tyres. After alignment the rollers are halted and tyres compressed by compression plates (300, 301), and held under tension while fastening straps are fitted with the aid of guide rails. The procedure, in which tyres (P) of the same dimensions are aligned, compressed and held under tension while straps are applied, is performed by machine with rotating rollers (200, 201) to align tyres, at least one of the rollers being driven. After alignment the rollers are halted and tyres compressed by 10-15% by compression plates (300, 301) with low friction surface coatings or rollers, and held under tension while plastic or metal fastening straps are fitted with the aid of guide rails.

Description

The present invention relates to the technical sector of tire conditioning, and more precisely tire cases not mounted on a rim, for carrying out the transport or storage of said envelopes.

The constant search for productivity gains, coupled with a constant desire to improve the working conditions of operators in this sector, has led the various players in the industrial sector concerned to optimize the supply chain by acting on storage conditions in stores. transport, loading and unloading operations, as well as the production of easily identifiable lots that can be moved according to the needs of delivery or optimization of storage areas. These optimizations must also not be detrimental to the integrity of the tires.

A first solution is to use pallets specially sized to receive envelopes of various sizes and diameters. As an example, a palette commonly used in storage magazines is described in the application US 5,259,325 in which the envelopes are stored in stack or roll. Pallets of this type have the advantage of constituting homogeneous batches of envelopes, of being able to be arranged on top of one another over great heights, of being able to be handled by mechanical means of the forklift type, of offering good protection of the envelopes against external aggressions. On the other hand, they are less suitable for transport, in particular for long journeys, because of the small number of tires they contain in view of their bulk, and the management of returns of empty pallets.

For transport over long distances, we will try to get the largest number of envelopes in a given volume which can be indifferently a truck trailer, a shipping container or a rail car.

Another commonly used solution is to arrange the envelopes on each other with a particular arrangement called "fishbone" and put the volume thus formed in compression to optimize loading. These methods are described, for example, in the U.S. Patent 5,092,106 . Very effective in optimizing the volume to be loaded, they nevertheless have the disadvantage of having to be carried out partly manually, especially during unloading operations, which is a limiting factor from an ergonomic point of view because of the size and weight envelopes that can be manipulated. In addition, this solution is particularly inefficient in a storage warehouse because of the difficulty in handling and moving the batches thus made, because it imposes a break in conditioning in the supply chain upstream and downstream of the transport operation, and that it is likely to cause mixtures, in case several sizes of envelopes are packaged in the same load. Finally, it is not without influences on the integrity of the tires because of the deformations that these can undergo.

For this purpose it is remarkable to note that each of the solutions mentioned above represents an optimal solution for a particular area such as shopping or transport, but rarely the same technical solution proves to be advantageous over the entire chain. logistics. This leads to introduce additional handling, which come to ruin part of the gains made by choosing the most suitable solution for a particular point of said chain.

This is the reason why intermediate solutions have been developed in order to find a global optimum. One of these solutions consists in packaging the envelopes into piles, generally consisting of about ten envelopes arranged one on the other so as to form a vertical axis cylinder whose outer surface is substantially constituted by the treads. of each of the envelopes.

This solution has the advantage of constituting homogeneous handling batches easily manipulated using suitable means. It provides an interesting compromise to optimize the supply chain for all supply chain operations such as warehousing, loading and unloading operations, as well as transport, especially for large envelopes with difficulty. Manipulable manually, and is particularly suitable when the transport is carried out in several stages.

Once the stack is formed, the casings of the stack can be secured by a link or strap as proposed in the patent GB 166,747 or US 1,507,376 , by a shrink film as described in U.S. Patent 4,858,415 or remain under the sole action of their own weight.

Industrial machines, of the type proposed by the US Patent 3,955,491 , have been developed to build batteries automatically in a first step, then to have one or more retaining straps in a second time.

Depending on the size of the envelopes, it is possible to have one or more batteries side by side on a flat pallet, generally not recoverable, so as to optimize the size of handling batches or to treat the battery independently.

However, the optimization of these solutions is related in part to the number of envelopes that can be gathered within the same stack and consequently to the maximum height of the stack.

In particular, it may be particularly advantageous to make piles whose height corresponds to the height of the volume used for transport, and the increase in the height of trailers used in road transport leads to want to use large batteries. height. The term "high height", heights can commonly be up to 3m, or more in some special cases.

It is noted that these batteries are particularly delicate to handle in the absence of means for securing the envelopes that constitute them, because of the risk of possible fall of one or more envelopes during handling. On the other hand, we also note that, under the action of their own weight or under the action of the tension of the straps, these piles have an annoying tendency to deform and to present a vertical projection of their center of gravity very eccentric with respect to the center of their base of levitation, constituted in this case by the contact of the first tire of the pile with the ground, and leading then to instability of the pile and to a high and unacceptable risk of overturning.

The object of the invention is to reduce these disadvantages.

Thus, it has been demonstrated that a precise alignment of the axes of the envelopes constituting the stack, prior to any compression operation, makes it possible to obtain cylindrical stacks having a very substantially vertical axis, allowing the realization of high-stacks. whose center of gravity projects substantially in the center of the base of sustenance.

This precise alignment of the axes of rotation of the tires takes place before putting the battery in compression and after having deposited said tires on alignment rollers, by rotating the set of tires intended to form the stack. By doing so, the zones of contact between the flanks of two adjacent tires are adjusted in pairs so that their axes of rotation are precisely aligned, and all the radial stresses localized at these interfaces and capable of later deforming the battery.

• Disposer les pneumatiques de même dimension et destinés à constituer une pile sur un dispositif de conditionnement comprenant un ensemble de rouleaux d'alignement, montés en rotation autour d'axes parallèles entre eux, chacun des rouleaux étant destiné à venir en contact avec les bandes de roulement de chacun desdits pneumatiques de manière à maintenir ces derniers de manière stable, l'axe de rotation des pneumatiques étant sensiblement parallèle à l'axe des rouleaux d'alignement.
• Puis, mettre en rotation au moins un des rouleaux, de manière à entraîner en rotation l'ensemble des pneumatiques destinés à constituer la pile autour de chacun de leurs axes de rotation respectifs, jusqu'à ce que les axes de rotation de chacun des pneumatiques soient précisément alignés avec l'axe de rotation CC' du cylindre formé par la pile ainsi constituée et dont les génératrices sont tangentes à la bande de roulement de chacun des pneumatiques, et parallèles à l'axe des rouleaux d'alignement,
• Arrêter la rotation des rouleaux d'alignement.
• Comprimer la pile dans la direction axiale à l'aide d'un moyen de compression tout en conservant l'alignement réalisé dans l'étape précédente.
• Disposer des moyens de contention selon des génératrices dudit cylindre permettant de maintenir la pile en compression.
• Relâcher l'action du moyen de compression afin de dégager la pile.
• évacuer la pile.

The method of packaging tires in a stack then comprises the following steps:

• Arranging tires of the same size and intended to form a stack on a packaging device comprising a set of alignment rollers rotatably mounted about axes parallel to each other, each of the rollers being intended to come into contact with the strips of rolling each of said tires so as to maintain these stably, the axis of rotation of the tires being substantially parallel to the axis of the alignment rollers.
• Then, rotating at least one of the rollers, so as to drive in rotation all the tires intended to form the stack around each of their respective axes of rotation, until the axes of rotation of each of the tires are precisely aligned with the axis of rotation CC 'of the cylinder formed by the stack thus formed and whose generatrices are tangent to the tread of each of the tires, and parallel to the axis of the alignment rollers,
• Stop the rotation of the alignment rollers.
• Compress the stack in the axial direction using a compression means while retaining the alignment made in the previous step.
• To dispose of the means of contention according to generatrices of said cylinder making it possible to maintain the stack in compression.
• Release the action of the compression means to clear the stack.
• evacuate the battery.

The device enabling the implementation of this method comprises alignment means, means for compressing the tire stack, and means for placing restraint means, and is characterized in that the alignment means are constituted by at least two alignment rollers mounted in rotation about axes parallel to each other, each of the rollers being intended to come into contact with the treads of each of said tires so as to maintain the latter in a stable manner, at the at least one of the rollers being capable of rotating all the tires around their respective axes of rotation.

The alignment rollers may be arranged horizontally or alternatively, vertically.

• la figure 1 représente une vue schématique d'une implantation industrielle comprenant un dispositif de conditionnement conforme à l'invention,
• la figure 2 représente une vue schématique d'un dispositif de conditionnement conforme à l'invention,
• la figure 3a représente une vue schématique d'une pile de pneumatique réalisée avec un procédé traditionnel,
• la figure 3b représente une vue schématique d'une pile de pneumatique réalisée avec un procédé de conditionnement en pile des pneumatiques conforme à l'invention

The following description proposes to give a non-limiting example of embodiment of an apparatus the implementation of which is in accordance with the invention based on the figures in which

• FIG. 1 represents a schematic view of an industrial plant including a packaging device according to the invention,
• FIG. 2 represents a schematic view of a packaging device according to the invention,
• FIG. 3a is a schematic view of a tire stack made with a conventional method,
• FIG. 3b represents a schematic view of a tire stack made with a tire stacking method according to the invention;

In what follows, the same references will denote the elements of the apparatus having identical functions, as represented in FIGS. 1 to 3.

Figure 1 shows a general schematic view of the production process in which the packaging machine is integrated. A forklift 1 brings the tires packaged in vertical piles P on a supply belt 2.

A loading and turning device 3 grasps the stack P and deposits it in the conditioning device 4.

It will be noted, as will be described in detail later, that this conditioning device is disposed horizontally and that it is therefore necessary to rotate the axis of rotation of the envelopes so as to bring them in a horizontal position.

Furthermore, when the stack to be packaged represents a number of envelopes too large for their stability to be controllable during the upstream transfer operations, it is quite possible to introduce the envelopes in several loading operations in the packaging device 4.

Once the conditioning operation has been performed on the conditioning device 4, the same device 3 serves to extract the battery P and, after rotation, to arrange it on the conveyor belt 5.

FIG. 2 represents a schematic view of a conditioning device 4 according to the invention, and configured in the following manner.

A frame 100, 101, supports a horizontal axis XX 'on which are disposed the two compression plates 300 and 301. These plates are movable in translation along the axis XX' under the action of the cylinders 302 and 303, and in rotation around the axis XX 'via a drive motor (not shown).

The compression plates support two alignment rollers 200 and 201 whose axes are parallel to each other, and form a substantially horizontal plane. They are arranged symmetrically with respect to a vertical plane passing through the axis XX '.

The rollers 200 and 201 are rotatably mounted, and one of these rollers is provided with a drive motor (not shown). The other roller may also be provided with a motor enabling it to be rotated or simply free to rotate about its axis.

The rollers 200 and 201 are also movable in the horizontal plane and their ends move in slots 304 and 305 (not visible) so that it is possible to vary their spacing "e" according to the dimension of pneumatic to condition.

The means for laying the restraining means is based on a widely distributed technology, and consists of a stationary station 400 in which are arranged a heat-sealable strap dispenser, a circulating strapping head and a tensioner and a thermal cutting and welding tool (not shown). Guiding rails 401, 402 404 and 405 are arranged on a substantially horizontal plane passing substantially through the axis XX 'and the equator of the stack and form a rectangular parallelepiped surrounding the battery P. The rails 404 and 405 are arranged in the compression plates 300 and 301. It is thus possible, using the strapping head, to circulate the strap along the rails 401, 404, 402, and 405 and, using the tensioner tension the strap by applying a calibrated force which will release the strap from the rails and press against two generators diametrically opposite of the stack and on the flanks of the two tires located at both ends of the stack. The strap is then cut and both ends are welded.

A restraint of this type is marketed as an example by the Delonca Company under the trade name Jumbo.

The implementation of the device comprises a series of steps that will illuminate the functions of each of the organs described above.

The tires are deposited in a first step on the alignment rollers 200, 201 by arranging the axes of rotation of the tires in a direction substantially parallel to the alignment rollers.

The number of tires intended to form the stack is carefully determined so that the height of the stack once constituted is substantially equal to the height of the most commonly used means of transport. This height varies from 2.5m to 3.m depending on the type of standard used by the logistics and can in some cases go up to 3.5m. Care shall be taken to subtract a reserve of custody necessary for carrying out loading and unloading operations by mechanical means. The length of the alignment rolls 200, 201, and the spacing between the compression plates 300, 301 will be determined accordingly.

The compression ratio required to ensure the cohesion of the battery once strapped must then be taken into account.

• la compression nécessaire pour assurer la cohésion de la pile P pendant toutes les opérations de manutention ultérieures ; en faisant en sorte qu'à aucun instant, des glissements entre les flancs des pneumatiques ne puissent se produire, et détruisent alors la coaxialité de la pile avec pour conséquence l'introduction d'un facteur de déséquilibre lorsque cette dernière est stockée verticalement,
• les déformations sous contrainte (provisoire) des enveloppes et principalement la déformation des pneumatiques situés aux deux extrémités de la pile,

Experimentally determined, this compression ratio varies from 10 to 15% depending on the dimensions. The criteria for determining the optimum rate take into account:

• the compression necessary to ensure the cohesion of the stack P during all subsequent handling operations; by ensuring that at no time slippage between the sidewalls of the tires can occur, and then destroy the coaxiality of the stack with the consequence of introducing an imbalance factor when the latter is stored vertically,
• stress deformation (temporary) envelopes and mainly the deformation of the tires located at both ends of the stack,

It is particularly useful as will be seen later to match the axis of the stack with the axis of rotation XX 'of the compression plates 300, 301, so as to ensure a laying means as regular contention as possible. By judiciously presetting the spacing "e" between the rollers 200 and 201 as a function of the dimension to be conditioned, it is ensured that the axes of the tires and the axis of the stack will be substantially aligned with the axis XX '.

Resting by two generatrices of their tread on each of the alignment rollers 200, 201, it will be noted that in this arrangement the tires are held stably because their centers of gravity are located substantially on a vertical plane passing through the XX 'axis and between the alignment rollers 200 and 201.

Before the actual alignment operation, it may be useful to reform the battery and position the tires as evenly as possible. For this purpose, the compression plates 300, 301 will be brought together a first time so as to cause a slight compression of the stack, then the pressure will be released by positioning the plates as close as possible to the point of last contact between their respective inner faces and tire sidewalls at both ends of the stack.

The rotation of one of the alignment rollers will cause the rotation of each of the tires around its axis of rotation. This overall movement has the effect of precisely aligning each of the tires relative to each other and to ensure that the axis of rotation of each of the tires coincides with the axis CC 'of a cylinder formed by the a stack thus formed and whose generatrices are tangent to the tread of each of the tires, and parallel to the axis of the alignment rollers 200, 201, in order to obtain the required maximum concentricity. It is the precision of this alignment, combined with compression to preserve the effects, which gives the stack the desired stability.

This operation is completed after having made a small number of turns to the tire stack; ten rounds seems to experimentally give satisfaction.

Once the alignment obtained it is necessary to compress the battery and bring the two compression plates 300, 301.

It should be noted, however, that it may be particularly advantageous to avoid that, once this alignment operation has been performed, the tires lose their alignments due to lack of axial cohesion. This is why it has been suggested above to position the compression plates 300, 301, as close as possible to the outer faces of the tires located at both ends of the stack.

However, in order to avoid any friction that may occur during the alignment phase between the inner face of the compression plates and the outer flanks of the two tires located at both ends of the stack and likely to impair their proper alignment, it is particularly interesting to provide the inner face of said plates of devices promoting sliding. This device may consist of a film of low friction material such as Poly Tetra Fluoro Ethylene film or a set of bearings.

The compression of the battery is carried out by axially actuating the jacks 302, 303 and moving the plates 300, 301. It may be advisable to compress the battery to a value slightly greater than the desired final value so as to take into account the elasticity of the straps.

Care will be taken during this operation not to compromise the alignment achieved during the previous step.

Once the stack is placed in compression and held between the two plates 300, 301, it is then possible to arrange the restraining means so as to clamp the movements of the stack in the axial direction. In order to ensure the best regularity of the clamping of the stack, it is recommended to have at least two straps so that the traces of the straps on the sides of the tires located at the two ends of the stack define substantially equal sectors. Thus we will have two straps with a 90 ° angle, three straps with an angle of 60 ° and possibly four straps with an angle of 45 °.

Care should be taken to ensure that the tension of the straps is constant.

It is also particularly interesting to be able to rotate the battery around its axis CC 'so as to have the means of contention as regularly as possible. For this purpose, the simultaneous rotation of the plates rotating about the axis XX ', substantially coincident with the axis CC' of the stack, makes it possible to arrange the stack in as many angular positions as contention means to deposit, while maintaining the stack in compression to prevent radial movement of the tires relative to each other. For this purpose the plates 300, 301 each comprise as many sets of rails as necessary to ensure the continuity of guiding the strapping head is, in the configuration used to support this description, two rails arranged at 90 °, 403, 404 , 405, 406 (not visible). In case one wishes to have three straps, it would be necessary to make three rails arranged at 60 ° on each of the trays 300, 301.

The choice of straps 407 (Figure 3B) is adapted according to the dimension to be packaged. Namely that the width and thickness will be determined according to the stresses on the strap, but also as a function of the pressure that can be exerted on the sidewalls of the tires located at both ends of the stack without inducing permanent deformations. Thus one will choose a 25 mm strap for a tourism-type dimension and a strap of 35 mm for a dimension of the heavyweight type.

The strap may be made of a flexible material such as polyester, polyamide or polyethylene. Metal links may optionally be used in heavy weight dimension preferably.

Once the means of contention are linked, the compression plates 300, 301 are returned to their initial angular position, and by moving said compression plates away, the battery P is released, which can then be evacuated with unloading means 3 and return to a vertical position.

The stack thus formed has sufficient internal cohesion to be able to undergo any subsequent handling without harmful evolutions.

Figures 3A and 3B show a stack as obtained with traditional means (3A) and a stack obtained with the method as described above (3B).

The configuration of the device used to support the description of the invention corresponds to a preferred embodiment. It will be noted, however, that it is possible to propose equivalent embodiments remaining within the scope of the teachings proposed by the present invention.

Those skilled in the art can thus adapt the device without difficulty so as to arrange the two alignment rollers 200, 201 horizontally and parallel to each other but forming a plane forming an angle with the horizontal.

Similarly, while keeping the alignment rollers horizontal and parallel to each other, it is possible to arrange a device comprising three or more rollers.

Another configuration is to arrange the rollers vertically, which can be an advantage in terms of handling and organization of the packaging workshop.

In this context it is necessary to implement at least three alignment rollers so as to stably clamp the stack to be packaged. These rollers will be arranged so that the trace of the intersection of the axes of the alignment rollers with a horizontal plane forms a substantially regular polygon. It will be necessary to provide a mechanism for approaching and removing the rollers in the radial direction so as to release a space for introducing and extracting tires from the alignment device. Finally, the contention device will be positioned accordingly.

In this configuration it will also be necessary to adapt the radial pressure of the rollers on the treads of the tires so as to constrain these the latter to align correctly in a radial direction by combating the frictional forces existing between the flanks of each of the tires in the stack.

The choice of a strap through the diametrically opposed generators remains the most suitable form of implementation. However it is possible to perform a strap by passing the strap along a path passing through an outer generator of the stack, by the radial paths adjacent to this generator and located on the sides of the two tires located at both axial ends of the battery, and by the inner part of the battery. This requires having a rail passing through the inside of the stack and remove at each end of cycle, which is not without consequences on the overall size and the cycle time of the conditioning device.

Claims (15)

1. Method of packaging tyres in a stack, characterised in that it comprises the following steps:

   - disposing the tyres of the same size and intended to constitute a stack (P) on a packaging device (4) comprising a set of alignment rollers (200, 201), mounted for rotation about axes parallel to each other, each of the rollers being intended to come into contact with the treads of each of the said tyres so as to hold the latter in a stable fashion, the rotation axes of the tyres being substantially parallel to the axis of the alignment rollers,

   - then rotating at least one of the rollers, so as to rotationally drive all the tyres intended to constitute the stack about each of their respective rotation axes until the rotation axes of each of the tyres are precisely aligned with the rotation axis CC' of the cylinder formed by the stack thus formed,

   - stopping the rotation of the alignment rollers,

   - compressing the stack in the axial direction using a compression means (300, 301) whilst keeping the alignment produced in the previous step,

   - disposing restraint means (407) along the generatrices of the said cylinder,

   - releasing the action of the compression means in order to release the stack,

   - discharging the stack.
2. Method according to Claim 1, in which the alignment means comprise at least two alignment rollers (200, 201) disposed substantially horizontally so as to hold the said tyres in a stable fashion.
3. Method according to Claim 1, in which the alignment means comprise at least three alignment rollers (200, 201) disposed substantially vertically so as to hold the said tyres in a stable fashion.
4. Method according to Claim 1, in which the degree of compression of the tyres is between 10 and 15%.
5. Method according to Claim 1, in which the restraint means (407) consist of continuous tensioned straps.
6. Device for packaging tyres in a stack, comprising alignment means, means of compressing the stack of tyres, and means of positioning restraint means, characterised in that the alignment means consist of at least two alignment rollers (200, 201), mounted for rotation about axes parallel to each other, each of the rollers been intended to come into contact with the treads of each of the said tyres so as to hold the latter in a stable fashion, at least one of the rollers being able to rotationally drive all the tyres around their respective rotation axes.
7. Device according to Claim 6, characterised in that the alignment rollers (200, 201) are disposed substantially horizontally.
8. Device according to Claim 6, comprising at least three alignment rollers (200, 201) disposed substantially vertically.
9. Device according to one of Claims 7 or 8, in which the compression means are formed by two plates (300, 301), the internal faces of which are parallel to each other and perpendicular to the axis of the alignment rollers, and where at least one of the plates is able to move in translation along an axis parallel to the axis of the alignment rollers.
10. Device according to Claim 9, in which the internal face of the plates (300, 301) is covered with a film consisting of a material offering a low resistance to friction and intended to assist the sliding of the sidewalls of the tyres on the internal faces of the plates.
11. Device according to Claim 9, in which the internal face of the plates (300, 301) comprise bearings intended to assist the sliding of the sidewalls of the tyres on the internal faces of the plates.
12. Device according to one of Claims 7 or 8, in which the means of placing the restraint means (400, 401, 402, 403, 404, 405, 406) are arranged so as to dispose the said restraint means under tension, along a line passing through two external and diametrically opposed generatrices of the cylinder formed by the stack, and by the sidewalls of the tyres situated at the two axial ends of the stack.
13. Device according to one of Claims 7 or 8, in which the means of placing the restraint means are arranged so as to dispose the said restraint means under tension, along a line passing through an external generatrix of the stack, through the radial pathways adjoining this generatrix and situated on the sidewalls of the two tyres situated at the two axial ends of the stack, and through the internal part of the stack.
14. Device according to one of Claims 12 or 13, in which the plates (300, 301) are able to move in rotation about an axis XX', parallel to the axis of the alignment rollers, so as to orient the stack circumferentially according to as many angular positions as there are restraint means to be deposited.
15. Device according to Claim 14, in which the distance (e) between the alignment rollers (200, 201), is adjustable according to the size to be packaged, so that the axis CC' of the stack, once formed, is substantially merged with the axis XX' of the compression plates.

Images