EP2315657A2

EP2315657A2 - Machine and method for compacting an annular part made of a flexible material

Info

Publication number: EP2315657A2
Application number: EP09740361A
Authority: EP
Inventors: Didier André Louis Marrel; Crm
Original assignee: Centre de Recherches Metallurgiques CRM ASBL
Current assignee: Centre de Recherches Metallurgiques CRM ASBL
Priority date: 2008-07-22
Filing date: 2009-07-22
Publication date: 2011-05-04
Also published as: US20110192292A1; WO2010010300A2; JP2011528994A; CN102245375A; WO2010010300A3; FR2934197A1; FR2934197B1

Abstract

The invention relates to a machine (1) for compacting an annular part (2) made of flexible material, said machine (1) including a swage channel (4) through which the annular part (2) is intended to pass forcibly so as to be folded, said machine (1) being characterized in that said swage channel (4) is defined by at least one swage plate (5) rotatably mounted such that, under the pressure of said annular part (2), said swage plate (5) pivots so as to close on said annular part (2) to compress the latter. The invention further relates to swage machines.

Description

MACHINE AND METHOD FOR COMPACTING AN ANNULAR WORKPIECE

SOFT MATERIAL

TECHNICAL AREA

The present invention relates to the general technical field of waste treatment processes, and in particular to methods for reducing the bulk of waste for storage and subsequent processing.

The present invention relates more particularly to a machine for compacting an annular piece of flexible material, said machine comprising a necking passage in which the annular piece is intended to pass in force to be folded.

The present invention also relates to a method of compacting an annular piece of flexible material, in which the annular piece passes in force in a necking passage to be folded.

The invention finally relates to a system comprising a tire folded so as to form two lobes connected by a section restriction, the latter resulting from a local centripetal compression of the tire, said lobes being folded against each other.

PRIOR ART

The annular parts, by their shape, occupy a very large volume compared to the volume of material that it really represents. Indeed, if they are stacked to store or transport, their annular shape leaves empty the entire central part. In addition to the size they generate, it is difficult, depending on their size, to manipulate them in a simple way.

This large size of the annular parts is proving to be considerable problems especially with regard to the treatment of used tires. It is therefore extremely wise (especially from an economic point of view) to compact the used tires prior to their storage and subsequent transport.

For this purpose, it is known from FR-2 631 563 A1 to fold the used tires in two perpendicular diameters in a plane orthogonal to the tire axis, the tire thus folded being ligated to be maintained in its folded form.

The method described in document FR-2 631 563 thus makes it possible to significantly reduce the size of the tire.

Nevertheless, it presents a number of disadvantages.

In the first place, this known method requires the implementation of cutting operations of the tire prior to the actual bending of the latter. These cutting operations require the implementation of specific tools (involving investment and maintenance) and are time consuming and resources, which does not contribute to optimize the cost of the process.

In addition, these cutting operations generate at least four tire falls per tire, these falls constituting as much additional waste to be treated, which is of course again not in the sense of reducing the complexity and cost of treatment.

The document FR-2 631 563 A1 also provides, once the tire cut into at least four parts, a bending operation according to two perpendicular diameters in a plane orthogonal to the axis of the tire, by force passing the tire between two plates. . More specifically, this passage force is achieved through a cylinder that acts radially on the tire, the right of any of the four notches (or cuts) previously made on the tire. The four notches in question thus play the role of folding hinge for folding the tire according to the desired profile. In order to facilitate the folding operation, the plates form a flared entry equipped with two guide rollers with adjustable spacing. The presence of these mechanical components contributes, of course, to increasing the complexity of design of the machine and increases the risk of failure (for example by seizing one or other of the rollers). Finally, the only force passage of the tire between the plates is not necessarily sufficient to obtain a sufficiently tight bend. Therefore, one of the plates between which the tire passes force to be bent is mounted in translation by means of a jack which allows a final tightening of the tire. This final tightening operation with a jack of course also increases the complexity of design of the machine, and consumes cycle time and energy.

SUMMARY OF THE INVENTION

The objects assigned to the invention therefore aim to remedy the various disadvantages of the prior art mentioned above, and to propose a new machine and method for compacting an annular piece of flexible material, of the tire type, which are particularly simple, reliable and cheap, which can treat annular parts of all sizes, without requiring the implementation of a prior shear said annular parts.

Another object of the invention is to provide a new machine and method for compacting an annular piece of flexible material which allow a particularly fast and effective folding of said annular pieces.

Another object of the invention is to provide a novel machine and method for compacting an annular piece of flexible material which implement particularly simple and inexpensive means.

Another object of the invention is to provide a novel machine and method for compacting an annular piece of flexible material which operate quickly while limiting unwanted mechanical forces may damage the machine.

Another object of the invention is to provide a novel machine and method for compacting an annular piece made of flexible material that are easily automated and allow fast rates. Another object of the invention is to provide a novel machine and method for compacting an annular piece of flexible material which can significantly reduce, for example up to about 70%, the size of said annular piece.

Another object of the invention is to propose a new system comprising a tire, preferably used, to significantly reduce the size of the tire and to facilitate handling and subsequent processing.

The objects assigned to the invention are achieved by means of a machine for compacting an annular piece of flexible material, said machine comprising a necking passage in which the annular piece is intended to pass in force to be folded, said machine characterized in that said necking passage is defined by at least one necking plate rotatably mounted so that under the thrust of said annular member, said necking plate pivots so as to be closed on said annular member to compress it.

The objects assigned to the invention are also achieved by means of a method of compacting an annular piece of flexible material, in which the annular piece passes in force in a necking passage to be folded, characterized in that said narrowing passage is delimited by at least one necking plate rotatably mounted and in that under the thrust of said annular piece, said necking plate pivots so as to be closed on said annular piece to compress it.

The objects assigned to the invention are finally also achieved by means of a system comprising a tire folded so as to form two lobes connected by a section restriction, the latter resulting from a local centripetal compression of the tire, said lobes being folded against each other, characterized in that said tire is substantially whole. SUMMARY DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will appear and will appear in more detail on reading the description given below, with reference to the accompanying drawings, given for purely illustrative and non-limiting purposes, in which:

Figure 1 illustrates, in a schematic front view, a compacting machine according to the invention.

FIG. 2 illustrates, in a schematic side view, the machine of FIG. 1.

FIG. 3 illustrates a step of receiving and centering the tire implemented in the context of the method according to the invention, using the machine of FIGS. 1 and 2.

FIG. 4 illustrates a pre-compression step of the method according to the invention, carried out using the machine of FIGS. 1 and 2.

FIG. 5 illustrates a folding step of the method according to the invention, carried out using the machine of FIGS. 1 and 2.

FIG. 6 illustrates a binding step implemented as part of the process according to the invention, carried out using the machine of FIGS. 1 and 2.

FIG. 7 illustrates a step of releasing the method according to the invention, carried out with the help of the machine of FIGS. 1 and 2, and making it possible to obtain a system according to the invention.

BEST MODE OF REALIZING THE INVENTION

According to a first aspect, the invention relates to a machine 1 for compacting an annular piece 2 of flexible material. The annular piece 2 in question thus has a circular shape, and preferably a symmetry of revolution about an axis of symmetry perpendicular to the plane of the sheet bearing the figures 3 to 7. Preferably, the machine is designed to compact an annular piece made of flexible material having a shape of revolution generated by the rotation of a U-shaped profile around an axis of revolution, the U arms extending substantially perpendicular to said axis of rotation, towards the latter. By "flexible material" is meant here an elastic material, easily deformable, such as rubber. In the example illustrated in the figures, the machine 1 thus makes it possible to shrink the annular piece 2, that is to say to make a reduction of the empty central section 2A circumscribed by the annular piece 2, in order to reduce the 'congestion of the latter. The machine 1 according to the invention can be described as shrinking machine. The reduction in size operated by the machine 1 facilitates handling, storage and transport of the annular piece 2, the size of which can be reduced for example by about 60 to 70% by the machine 1.

Preferably, the machine 1 according to the invention is a tire compacting machine, and more preferably used tires, to reduce the storage volume and transport of the latter.

In this preferred embodiment, which corresponds to the illustrated example, the machine 1 is thus specifically designed to compact an annular part 2 constituted by a tire. Such a tire conventionally has a tread 3 from the lateral ends of which two blanks 3A extend. In the following, reference will be made exclusively, for the sake of simplicity and brevity of description, to a machine 1 for compacting used tires, it being understood however that the invention is absolutely not limited to this preferred application.

According to the invention, the machine 1 comprises a necking passage 4 in which the annular piece 2 is intended to pass in force to be folded. In other words, the machine 1 comprises means for forcing the annular piece 2 through the necking passage 4, the path of the annular piece 2 in the necking passage 4 operating a folding deformation of the annular piece 2 Preferably, as illustrated in the figures, the necking passage 4 is designed to operate on the workpiece annular 2, during its path along the necking passage 4, a compression action which is exerted diametrically, that is to say in the mean plane of the empty section 2A. According to the invention, the narrowing passage 4 is delimited by at least one necking plate 5 rotatably mounted so that under the thrust of the annular piece 2 (caused by the passage of force in the necking passage 4) , said necking plate 5 pivots so as to be closed on the annular piece 2 to compress it. In other words, the narrowing passage 4 is of variable conformation, and more precisely of variable passage section, the variation of the conformation of the narrowing passage 4 being controlled by the thrust exerted by the annular piece 2 on the plate. 5 when the annular piece 2 passes in force in the necking passage 4. The necking plate 5 is preferably mounted to free rotation, so as to be naturally set in motion under the effect of the passage of the annular part. 2 in the necking passage 4. With this technical feature, the narrowing passage 4 closes gradually and automatically on the annular piece 2 as the latter advances in the necking passage 4. This facilitates the inlet of the annular piece 2 in the necking passage 4, and without the recourse to specific members of the type flared entry or guide rollers is n necessary.

The progressivity of the compression force exerted by the narrowing passage 4, thanks to the natural pivoting of the necking plate 5, also makes it possible to significantly compress the annular piece 2, reducing the risk of implementing mechanical stresses likely to damage the machine 1. In addition, the use of a necking plate 5 mounted free rotation automatically optimizes the positioning of the annular part 2 relative to the passage of necking 4, which allows to limit the risks to bend the annular part 2 incorrectly because of a bad positioning of the latter.

Ultimately, the implementation of a narrowing passage 4 formed at least in part of a rotating, mobile necking plate 5 makes it possible to compact the annular piece 2 in an extremely fast, simple and efficient manner, making it particularly useless the use of a prior cutting of the annular part 2. Preferably, the machine 1 is thus devoid of cutting means of the annular part 2, and in particular is devoid of means for cutting the annular piece 2 prior to its passage in force in the necking passage 4.

Preferably, as illustrated in the figures, the narrowing passage 4 is delimited by two necking plates 5, 6 each rotatably mounted so that under the thrust of the annular piece 2, caused by the relative displacement of the narrowing passage 4 and the annular piece 2, said necking plates 5, 6 pivot so as to come close on the annular piece 2 to compress it. Advantageously, as illustrated in the figures, the plates 5, 6 are substantially identical and mounted vis-à-vis, symmetrically with respect to a median plane, represented by the axis XX 'in FIG. 1. In the example illustrated in the figures, the necking plates 5, 6 are advantageously constituted by steel plates whose width is substantially greater than or equal to the width of the tread 3 of the tire forming the annular piece 2 to be compacted.

Each necking plate 5, 6 is mounted for free rotation along a corresponding axis 5A, 6A which preferably extends substantially parallel to the axis of symmetry of the tire, when the latter is to force into the narrowing passage 4, as illustrated in FIG.

Each axis of rotation 5A, 6A is preferably positioned equidistant from an axis XX 'coinciding with a diameter of the tire, so that the necking plates 5, 6 act simultaneously and symmetrically as the pressure increases. tire advancement in the narrowing passage 4.

Advantageously, the machine 1 according to the invention comprises means for receiving and centering the annular piece 2. The receiving and centering means 7 is intended to receive and support the annular piece 2 which will be the object of the invention. compaction. This reception and centering means 7 advantageously comprises a longitudinal centering means 8, on which the annular piece 2 is intended to rest in a predetermined longitudinal position which it preferably adopts naturally under the effect of its own weight. For this purpose, the longitudinal centering means 8 is designed to interact with the annular piece 2 so that this is in a predetermined position (shown in FIG. 3) centered on the median axis XX 'of the necking passage 4. For this purpose, the longitudinal centering means 8 is advantageously designed so that the annular piece 2 rests on on said longitudinal centering means 8 by its edge, that is to say by its tread 3 when the annular piece 2 is constituted by a tire as illustrated. For this, the longitudinal centering means 8 advantageously comprises two longitudinal centering tubes 8A which extend substantially parallel to the axis of symmetry of the annular piece 2 and to the axes of rotation 5A, 6A of the necking plates 5, 6.

Advantageously, the receiving and centering means 7 comprises a lateral centering means 9 (shown only in FIG. 2) making it possible to correctly position the annular piece 2 in the lateral direction (represented by the axis YY 'in FIG. 2). perpendicular to the longitudinal direction. Preferably, the lateral centering means 9 is provided with at least one movable clamping plate 9A, and preferably with two movable clamping plates 9A, 9B providing lateral centering of the annular piece 2. The two clamping plates 9A and 9B are advantageously mounted on a slide, and are displaced, preferably symmetrically, by a crank-handle system 10A advantageously actuated by a jack 10B, as illustrated in FIG.

Advantageously, the receiving and centering means 7 comprises a sliding receiving and centering carriage 11. Preferably, the receiving and centering carriage 11 slides in the vertical direction represented by the axis X-X ', which direction corresponds to the direction of the relative displacement of the annular piece 2 and the necking passage 4.

Advantageously, the receiving and centering carriage 11 is slidably mounted on a frame 12 between a low abutment position, illustrated in FIGS. 5 to 7, and an upper abutment position, illustrated in FIGS. 1 to 3. Preferably, the centering receiving carriage 11 is subjected to the action of one (or two, as illustrated) return spring (s) 110, so as to be permanently recalled in its upper abutment position. Advantageously, the machine 1 further comprises a sliding pre-compression trolley 13 on which is mounted the narrowing passage 4, that is to say that the (or, according to the embodiment) plate (s) of 5, 6 are pivotally mounted on the pre-compression carriage 13. Preferably, the pre-compression carriage 13 is slidably mounted on the frame 12. It preferably slides vertically, that is to say according to the direction represented by the axis XX 'in FIG. 1. Thus, the centering receiving carriage 11 and the pre-compression carriage 13 slide in the same direction, and preferably according to exactly the same sliding axis (materialized by the axis X-X '), as illustrated in the figures. Preferably, the machine 1 comprises an actuating means 14 (visible in FIG. 2) of the pre-compression carriage 13 designed to control the displacement of the pre-compression carriage 13, that is to say preferably to make slide said pre-compression carriage 13 in the direction shown by the axis X-X '. Preferably, the actuating means 14 comprises a jack 15 which actuates the pre-compression carriage 13 to effect the displacement of the latter between an upper abutment position (illustrated in FIGS. 1 to 3) and a lower abutment position ( illustrated in Figures 5-7).

Advantageously, the pre-compression carriage 13 is designed to move the centering receiving carriage 11 as it moves, by means of the annular piece 2 resting on the latter.

Preferably, the pre-compression carriage 13 is positioned above the receiving and centering carriage 11, so that the annular part 2 is interposed between the receiving and centering carriage 11 (and more precisely the tubes 8A). and the pre-compression trolley 13 (and more specifically the necking plates 5, 6). Thus, when the pre-compression carriage 13 descends vertically under the effect of the action of the jack 15, the necking plates 5, 6 abut on the annular piece 2 and exert a downward thrust on the latter, thrust descending vertical which is transmitted through the tubes 8A to the receiving carriage and centering 11. The latter, under the effect of this downward thrust, leaves its upper abutment and return position to descend, against the action of the springs 110, to its lower abutment position. This descent sequence of the reception and centering carriage 11 is illustrated in FIGS. 3 and 4. During the down the receiving carriage and centering 11, the annular part 2 simultaneously undergoes a gradual deformation, which will be described in more detail below.

The use of such a system with two sliding carriages makes it possible in particular to generate a pre-folding of the annular piece 2 (as illustrated in FIG. 4) which will facilitate the subsequent operation of folding itself.

Advantageously, the machine 1 according to the invention further comprises a thrust member 16, said narrowing passage 4 and push member 16 being movable relative to each other to force the annular piece 2 into the narrowing passage 4.

Thus, in the embodiment illustrated in the figures, the thrust member 16 and the pre-compression trolley 13 are mounted movable relative to each other, so as to exert on the annular piece 2 an effort tending to passing the latter into the air gap of the necking plates 5, 6 forming the narrowing passage 4.

Advantageously, the machine 1 is designed to perform the following sequence of operations:

- The actuating means 14 of the pre-compression carriage 13 slides the pre-compression carriage 13 in the direction X-X '(downwards). The pre-compression carriage 13 in turn pushes the receiving and centering carriage 11 through the annular piece 2 resting on said receiving and centering carriage 11, to bring and hold it in a abutment position, corresponding in this case to the lower abutment position. The movement of the receiving and centering carriage 11 towards said abutment (lower) position presses the annular piece 2 against the thrust member 16, which generates a pre-folding (or pre-compression) of the annular piece 2 as shown in Figure 4.

- The push member 16 then exerts on the annular part 2 pre-folded, while the receiving carriage and centering 11 is held in its abutment position (low) by the pre-compression trolley 13 and its means 14, a thrust (preferably upward vertical) on the annular piece 2 to force the latter in the necking passage 4.

Thus, as illustrated in the figures, the machine 1 allows a treatment of the annular part 2 according to two main stages:

- A pre-compression step in which the thrust member 16 behaves as a passive support against which the annular piece 2 is squeezed by the descent of the necking plates 5, 6. Under the effect of this descent, the plates necking 5, 6 are pressed against the edge of the annular piece 2 (that is to say the tread 3 when the annular piece 2 is constituted by a tire) and pivot to adopt a V-shaped profile reversed, as illustrated in Figures 3 and 4. The pre-compression carriage 13, actuated by the cylinder 15, thus crushes the annular part 2 on the thrust member 16.

- Once the downward stroke of the pre-compression trolley 13 completed, then begins a folding step itself (illustrated in Figures 5 to 7) in which the thrust member 16 plays an active role and exerts an upward thrust that forces the annular piece 2 pre-folded into the air gap of the necking plates 5, 6, which has the effect of rotating the latter so that they are closed on the annular piece 2 to compress and fold it. The shrink plates 5, 6 thus change from an inverted V configuration to a configuration where they are parallel to each other as shown in FIGS. 5 to 7.

Advantageously, the thrust member 16 exerts a substantially local, punctual, radially directed thrust force, preferably in the vertical direction indicated by the X-X 'axis. Advantageously, the thrust member 16 comprises a push rod 16A actuated by a jack 16B. Preferably, the push rod 16A is formed directly by the rod of the jack 16B, said rod 16A being guided by a centering flange 17, fixed on the nose of the jack 16B and having a guide ring. Such a construction is extremely compact, simple, reliable and cheap. Preferably, as will be explained in more detail in the following, the push rod 16A also acts as the release rod of the workpiece 2.

Under the effect of the radial thrust exerted by the push rod 16A, the annular piece 2 is propelled into and along the necking passage 4, which pivots the necking plates 5, 6 along their respective axes 5A, 6A , said necking plates 5, 6 then forming a clamp ensuring the necking of the annular piece 2, as shown in Figure 5.

Advantageously, the machine 1 is designed to also ensure binding of the compressed annular piece 2 at the outlet of the necking passage 4. Preferably, as shown in FIG. 6, the binding of the compressed annular piece 2 (ie say, the annular piece 2 folded) begins before the annular piece 2 is completely out of the necking passage 4, this to prevent inadvertent unfolding of the annular piece 2 by springback. The binding advantageously consists in encircling (around the axis X-X ') the annular piece 2 folded, by one or more links (for example at least two links) according to any known method. Once the binding is done, the machine is designed so that the thrust member 16 releases the workpiece 2 out of the grip of the necking passage 4, the folded and bound piece 2 can thus be recovered and continue its treatment cycle. having a significantly reduced bulk.

The invention also relates as such to a method of compacting an annular piece 2 made of flexible material, which advantageously constitutes a method of compacting tires to reduce the storage and transport volume of the latter. The method according to the invention is advantageously intended to be implemented using the machine 1 according to the invention. The method according to the invention is a method in which the annular piece 2 passes in force in a narrowing passage 4 to be folded. The narrowing passage 4 is delimited by at least one necking plate 5 rotatably mounted, said necking plate 5 pivoting, under the thrust of the annular piece 2, so as to come close on the annular piece 2 to compress it. As illustrated in the figures, and as explained in more detail in the foregoing, the narrowing passage 4 is advantageously delimited by two plates of 5 shrimp, 6 each rotatably mounted so that under the thrust of the annular piece 2, the necking plates 5, 6 pivot so as to come close on the annular piece 2 to compress it.

Advantageously, the method according to the invention comprises a step of receiving and centering the annular piece 2, illustrated in FIG. 3. This receiving and centering step corresponds to a loading operation of the compacting machine 1 with a annular piece 2 in flexible material to compact.

Advantageously, during said step of receiving and centering the annular piece 2, the latter is deposited on a sliding receiving and centering carriage 11, as explained in the foregoing and as illustrated in FIG. the said necking plate (s) 5, 6 are pivotally mounted on a sliding pre-compression carriage 13, as explained in the foregoing.

The method furthermore advantageously comprises a pre-compression step (illustrated in FIG. 4) in which the pre-compression carriage 13 slides so as to push the reception and centering carriage 11 through the annular part 2 resting on the latter, to bring and maintain the receiving carriage and centering 11 in a stop position (corresponding to the low position mentioned in the foregoing). The movement of the receiving and centering carriage 11 towards said stop position pressing the annular piece 2 against a thrust member 16, which generates a pre-folding of the annular piece 2.

During the pre-compression step, the reaction thrust exerted by the annular piece 2 on the necking plates 5, 6 leads the latter to pivot symmetrically along their respective axes 5A, 6A, so that at the end of this pre-compression step, said necking plates 5, 6 form an inverted V-shaped profile, as illustrated in FIG. 4. The thrust member 16 preferably has a vertical reaction force. ascending significantly localized.

In this way, the annular piece 2 pre-folded has a bilobed shape, that is to say, it forms two lobes (shaped loops) connected by a section restriction corresponding to the place where is exerted the action of the thrust member 16 on the annular piece 2.

Advantageously, and as illustrated in FIG. 5, the method according to the invention comprises a folding step (also referred to as a "shrinking step") during which the thrust member 16 exerts on the annular piece 2 pre-folded (obtained at the end of the pre-compression step), while the centering receiving carriage 11 is held in its abutment position, a thrust (preferably vertical upward) on the annular piece 2 to pass through. force the latter in the necking passage 4. Thus, in the folding step illustrated in Figure 5, the pre-compression carriage 13 is held stationary and the pre-bent part 2 is pushed between the necking plates 5, 6 by the pushing member 16. This has the effect of pivoting the necking plates 5, 6 towards each other, until said necking plates 5, 6 are naturally positioned parallel to one another. to the other and then form a clip ssurant the narrowing of the part 2 which is propelled between them. In the course of the folding step, the thrust member 16 advantageously has a radial thrust, preferably localized, on the annular piece 2.

Finally, the method advantageously comprises a step of binding the compressed annular piece 2 at the outlet of the necking passage 4, as explained in the foregoing.

The invention also relates as such to a system 20 obtainable by the method according to the invention.

This system 20 comprises a tire (preferably used) folded so as to form two lobes 20A, 20B, connected by a section restriction, the latter resulting from a local centripetal compression of the tire, said lobes 20A, 20B being folded down. against the other, as shown in Figures 6 and 7. According to the invention, the tire thus folded is substantially whole, that is to say, it has not been the subject of material removal like cutting or shearing. In other words, the system 20 according to the invention comprises a crude tire, substantially devoid of cutting or punching. Advantageously, the system 20 according to the invention comprises a means 21 for holding the tire thus folded. The means 21 for holding the folded tire preferably comprises at least one link 21A surrounding the folded tire, and for example three links as in the example illustrated in the figures.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the compacting of flexible parts.

Claims

- Machine (1) for compacting an annular piece (2) of flexible material, said machine (1) comprising a necking passage (4) in which the annular piece (2) is intended to pass in force to be folded, said machine (1) being characterized in that said narrowing passage (4) is delimited by at least one necking plate (5) rotatably mounted so that under the pressure of said annular piece (2), said necking plate (5) pivots so as to close on said annular piece (2) to compress it. - Machine (1) according to claim 1 characterized in that the necking passage (4) is delimited by two necking plates (5, 6) each rotatably mounted so that under the thrust of said annular piece (2), said necking plates pivot to close on said annular piece (2) to compress it.

- Machine according to claim 1 or 2 characterized in that it comprises means for receiving and centering the annular piece. - Machine (1) according to claim 3 characterized in that said receiving and centering means (7) comprises a longitudinal centering means (8) on which said annular piece (2) is intended to rest in a predetermined longitudinal position that it adopts naturally under the effect of its own weight. - Machine (1) according to claim 4 characterized in that said longitudinal centering means (8) is designed so that said annular piece (2) rests on said longitudinal centering means by its edge. - Machine (1) according to claim 5 characterized in that said longitudinal centering means (8) comprises two longitudinal centering tubes (8A). 7 - Machine (1) according to one of claims 3 to 6 characterized in that the receiving and centering means (7) comprises a lateral centering means (9) provided with at least one movable clamping plate (9A , 9B).

8 - Machine (1) according to one of claims 3 to 7 characterized in that said receiving and centering means (8) comprises a sliding receiving and centering carriage (11).

9 - Machine (1) according to one of claims 1 to 8 characterized in that it comprises a sliding pre-compression trolley (13) on which are mounted pivotally said necking plate (s) (5, 6).

10 - Machine according to claims 8 and 9 characterized in that said pre-compression carriage is designed to slide in the same direction as the carriage receiving and centering.

11 - Machine (1) according to claim 10 characterized in that it comprises an actuating means (14) of the pre-compression carriage (13) designed to slide said pre-compression carriage (13), the latter being designed to move the receiving and centering carriage (11) as it moves, via the annular piece (2) resting on the latter.

12 - Machine (1) according to one of claims 1 to 1 1 characterized in that it comprises a thrust member (16), said narrowing passage (4) and push member (15) being movable one relative to the other for forcing the annular piece (2) into the narrowing passage (4).

13 - Machine (1) according to claims 11 and 12 characterized in that it is designed to provide the following sequence of operations:

- The actuating means (14) of the pre-compression trolley (13) slides the pre-compression trolley which in turn pushes the receiving and centering trolley (11) through the annular part (2) resting on the latter, to bring and maintain the carriage receiving and centering (11) in a stop position, the movement of the receiving and centering carriage (11) towards said stop position pressing the annular piece (2) against the thrust member (16) which generates a pre-folding of the annular piece (2); - The thrust member (16) exerts on the annular piece (2) pre-folded, while the receiving carriage and centering (11) is held in its abutment position, a thrust on the annular piece (2) for forcing the annular piece (2) into the narrowing passage (4).

14 - Machine (1) according to claim 12 or 13 characterized in that the thrust member (16) comprises a push rod (16A) actuated by a jack (16B).

15 - Machine (1) according to one of claims 12 to 14 characterized in that said thrust member (16) is designed to exert a radial thrust on the annular piece (2).

16 - Machine (1) according to one of claims 1 to 15 characterized in that it is designed to ensure a binding of the annular piece (2) compressed at the outlet of the necking passage (4).

17 - Machine (1) according to one of claims 1 to 16 characterized in that it constitutes a tire compacting machine to reduce the storage volume and transport of the latter.

18 - A method of compacting an annular piece (2) of flexible material, wherein the annular piece (2) passes in force in a narrowing passage (4) to be folded, characterized in that said narrowing passage is delimited by at least one necking plate (5) mounted for rotation and in that under the thrust of said annular piece (2), said necking plate (5) pivots so as to close on said annular piece (2) to compress it.

19 - Process according to claim 18 characterized in that the necking passage is defined by two necking plates (5, 6) each rotatably mounted so that under the pressure of said annular piece, said necking plates (5, 6) pivot so as to be closed on said annular piece (2) to compress it.

- Method according to claim 18 or 19 characterized in that it comprises a step of receiving and centering the annular piece.

- Method according to claim 20 characterized in that during said step of receiving and centering the annular piece (2), the latter is deposited on a carriage receiving and centering (11) sliding.

- Method according to claim 21 characterized in that said one or more necking plate (s) (5, 6) are pivotally mounted on a slide precompression carriage (13), said method further comprising a precompression step (13) in which the pre-compression carriage (13) slides so as to push the receiving and centering carriage (11) through the annular piece (2) resting on the latter, to bring and maintain the carriage receiving and centering (11) in a stop position, the movement of the receiving and centering carriage (11) towards said stop position pressing the annular piece (2) against a pushing member (16) which generates a pre-folding the annular piece (2).

-Procédé according to claim 22 characterized in that it comprises a folding step during which the thrust member (16) exerts on the annular piece (2) pre-folded, while the carriage receiving and centering (11) is held in its abutment position, a thrust on the annular piece (2) to force it into the necking passage (4).

- Method according to claim 23 characterized in that said thrust member (16) exerts, during the folding step, a radial thrust on the annular piece (2). - Method according to claim 23 or 24 characterized in that it comprises a step of bonding the annular piece (2) compressed at the outlet of the necking passage (4).

- Method according to one of claims 18 to 25 characterized in that it constitutes a tire compacting method for reducing the storage volume and transport of the latter.

- System (20) comprising a tire folded to form two lobes (20A, 20B) connected by a section restriction, the latter resulting from a local centripetal compression of the tire, said lobes (20A, 20B) being folded the against each other, characterized in that said tire is substantially whole.

-System (20) according to claim 27 characterized in that it comprises means (21) for holding the tire thus folded.

- System (20) according to claim 28 characterized in that said means (21) for holding the folded tire comprises at least one link surrounding the folded tire.