DEVICE AND METHOD FOR SUPPLYING ORIENTED ELEMENTS

Abstract

The sorting device (1) for elements (2) of the type of capsules or stoppers for closing a jar or bottle, or also of the type of plastic preform, comprising a continuous conveying means (3) provided to move in a conveying direction (4) and provided with successive transverse buttresses (5) between which the elements (2) can rest in the form of a transverse alignment; the sorting device (1) is characterized in that it comprises an ejection means (6), for clearing the elements (2) from the conveying means (3) that move essentially along the transverse buttresses (5) and comprising a drive means (7) that can move at least transversely to the conveying direction (4) to push the elements (2) towards the exit (8); the invention also relates to a corresponding method.

Description

The present invention relates to the field of orientation and supply of elements transported in line, and aims, on the one hand, at a method for classifying such elements before being supplied to the downstream machine and, on the other hand, at a device that implements this method. In the field of the invention, the elements can be hot-formed and then blown to create a large-volume container. It can also include capping elements. The supply of capping elements is required upstream of a machine that fills and seals the container. Preferably, the supply of capping elements is carried out using a device comprising a hopper into which a large quantity of capping elements can be deposited in bulk, and an upward-moving conveyor belt that draws the elements from the hopper and carries them to an upper discharge area. Generally, the conveyor belt has transverse struts on which the capping elements rest as they are conveyed upward. Comparable architectures are possible for sorting and supplying preforms, such as those described in WO2009153489 or EP1652801. During circulation on the conveyor belt between the hopper, feed zone and the exit zone, misoriented plugging elements are expelled, preferably and simply by letting them fall from the conveyor belt into the hopper thanks to gravity, as described for example in document US5394972 or US5586637. Generally, when items arrive head-on at the exit area, they are cleared from the conveyor belt by a suitable device. US5394972 also proposes ejecting the plugging elements using an airflow from a chamber mounted on the side of the conveyor belt opposite the exit zone. Such pneumatic ejection is also proposed, for example, in WO2006045928 and US7040489. However, pneumatic ejection presents drawbacks, including energy consumption, noise, and potential contamination of the plugging elements by particles, making the principle unsuitable in fields or areas with strict sanitary and hygiene regulations. US patent 4735343 discloses a fixed oblique strip that creates a wedge effect and exerts a transverse force that evacuates the clogging elements to the outlet. However, this principle generates serious clogging problems, particularly at high flow rates. Furthermore, the outlet opening must be very long, which also leads to likely clogging in this area at high flow rates. Therefore, it is necessary to propose a solution for sorting and supplying capping elements that resolves all or some of the problems mentioned here. In this context, the invention proposes to move the capping elements toward the exit zone by mechanical impulse through contact and, in particular, with the help of a movable impeller on each side of the conveyor belt at the level of the exit zone. The invention also relates to a sorting device for capsule-type elements or stoppers for closing a jar or bottle, or even plastic preform-type elements, comprising a continuous conveying means provided to move in a conveying direction and provided with successive transverse buttresses between which the elements can rest in a transverse alignment and also be conveyed by said conveying means from a feed zone of the sorting device, said sorting device further including an exit zone, at the level of which the elements leave the conveying means after having been supplied by it. This device is characterized in that it comprises an expulsion means, for clearing the elements of the transporting means that moves essentially along the transverse buttresses and that comprises at least one impeller that can be moved at least transversely to the direction of the transporting means to push the elements towards the exit zone. The invention then has as its object a sorting procedure for elements of the type of capsule, stoppers or other parts for closing a container, including of the type of collar such as a plastic bottle preform, said procedure comprising transporting the elements on a means of transport that circulates in a direction of transport, from a feed zone to an output zone located on one side of said means of transport, clearing from the means of transport to the output zone, the elements that are present at the level of the output zone. This procedure is characterized by the fact that clearing the elements of the transportation medium is carried out by pushing them through contact with a mobile impeller. The invention will be better understood thanks to the following description, which is based on the possible embodiments, explained in an illustrative and non-limiting manner, with reference to the accompanying figures, in which: - Figure 1 shows a schematic diagram for a modality with an essentially vertical conveyor belt; - Figures 2A and 2B show a section between two transverse buttresses, in the two different configurations, 2A and 2B; - Figures 3A, 3B and 3C illustrate the possible interaction with a frontal buttress medium and - Figures 4A, 4B, 4C and 4D show the evolution of the position of an element column under the action of the expulsion medium. First, the invention relates to a sorting device 1 for elements 2 of the capsule or cap type for closing a jar or bottle, or even of the plastic preform type, comprising a continuous conveying means 3 provided to move in a conveying direction 4 and provided with successive transverse buttresses 5 between which the elements 2 can rest in a transverse alignment and also be conveyed by said conveying means 3 from a feed zone of the sorting device 1, said sorting device 1 further includes an exit zone 8, at the level of which the elements 2 leave the conveying means 3 after having been supplied by it. In this way, the sorting device 1 can also manipulate the elements 2 for sealing a container, such as a bottle, jar, etc., as well as a preform. A typical sealing element 2 is a cap or stopper, in which at least a portion is shaped to complement the neck of a container and is thus cylindrical. A preform is itself a hollow plastic piece with a neck that is intended to be heated and then stretched under the effect of a gas injected under pressure while the preform is in a larger cavity. The sorting device 1 also includes a conveying means 3 that continuously moves the elements 2 in a conveying direction 4. This conveying means 3 can move the elements 2 along a plane, in which case the conveying direction 4 is parallel to that plane. The conveying means 3 can move the elements 2 along a curved profile. The conveying means 3 can transport the elements 2 upwards, for example. This can take the form of a conveyor belt 3 or successive transverse buttresses. In preferred embodiments, the conveying direction 4 is in the direction of a vertical lift, as shown in Figure 1. To transport the elements 2, the conveying medium has transverse buttresses 5 perpendicular to the direction of transport 4, extending transversely on each side of the conveying medium 3. Thus, the elements 2 rest against these buttresses, taking into account their orientation relative to gravity. For example, Figure 2A shows a conveying medium in the form of a conveyor belt on which the buttresses 5 are placed. An element 2 is shown resting against a buttress 5 and positioned against the bottom surface of the conveyor belt. In general, gravity then acts to position the element 2 against the buttress. Figure 2B illustrates another possibility in which the elements 2 can cross the conveying medium 3.The illustrated elements 2 are preforms, provided with collars, which rest on the buttresses 5, under the action of gravity which also acts here against the lower part of the figure. Then, the transverse buttresses 5 take, in particular, the form of struts 5 that have a certain thickness and are placed at the bottom of a conveyor belt, or also strips that allow, two by two, to support a preform-shaped element 2, at the level of its collar. The means of transport 3 itself has the form of an endless conveyor, of the endless belt type, belt, etc. It can be driven by successive transverse belts, gripped at the ends. The conveying means 3 moves the elements 2 from a feeding zone to an output zone 8, where the elements 2 must be ejected by a transverse movement relative to the conveying means 3 in order to transport them all on the same side of said conveying means 3. In operation, the transverse buttresses then pass one after the other at the level of the output zone 8, and the elements 2 resting on them are pushed into the output zone 8, row by row. The feeding zone is primarily located at the level of a feed hopper that can receive a batch of elements 2 to be processed, in the case of elements 2 in the form of plugs or capsules. Generally, the conveying means 3 circulates from a site where the elements 2 are placed in bulk and are carried by the transverse buttresses 5. According to the invention, the sorting device 1 comprises an ejection means 6, for clearing the elements 2 from the transporting means 3 that moves essentially along the transverse buttresses 5 and comprising at least one impeller 7 that can be moved at least transversely to the direction of the transporting means 4 to push the elements 2 towards the exit zone 8. For example, the ejection means 6 comprises at least one jack or other actuator, such as a trailing belt. Its function is to push all the elements 2 located between two successive buttresses in the direction of the conveying means 3, where the exit zone 8 is located, and from the opposite side. Therefore, its operation is repeated for each passage of a transverse buttress, whether empty or full of elements 2 on each side, or when there is only one element 2 near the exit zone 8. The drive 7 thus has an active movement, during which it pushes the elements 2 from each side, after a return movement to the initial position. Preferably, if there is a drive 7, the forward and return movements are sufficiently rapid to be performed between two successive passages of transverse buttresses. Of course, this is adapted to the number of 7 impellers used. Therefore, the ejection means 6 comes into contact, at the level of the impeller 7, with the element 2 furthest from the exit zone 8 and pushes it towards it, thus dragging the elements 2, one after the other, that are located between them. The orientation of the transport means 3 at that point, in relation to gravity and / or the separation between two successive transverse buttresses, can be particularly useful in preventing jamming. As will be explained later, the impeller 7 can move relative to buttresses that are only parallel to each other. Therefore, it is also necessary to provide the impeller 7 with a movement in the transport direction 4 relative to a common reference point. Thus, according to an additional possible feature, there is at least one impeller 7 that can also move in the direction of transport 4 and in the same sense. The relative movement between the transport medium 3 and the impeller 7 can then only be transverse. Both the transport medium 3 and the impeller 7 thus have, relative to a fixed point of the sorting device 1, a movement in the direction of transport 4 and in the same sense. This movement of the impeller 7 can be achieved by design, depending on the retained actuator. To avoid any interaction with the transverse buttresses 5, it is advantageous to ensure that the impeller 7 has a small movement relative to that of the transporting means 3 in a longitudinal direction, i.e., in the transporting direction 4. Generally, at least one impeller 7 is arranged to follow the movement of a transverse buttress 5 in the transporting direction 4 when the impeller 7 moves transversely to that direction. For example, it is also possible for the impeller 7 to occupy the entire space between two buttresses 5 or, in any case, to not interfere with the elements 2 of the next row. In the particular embodiments, the expulsion means 6 comprises an endless belt 9, on which a cantilevered finger 10 forming the impeller 7 is mounted, the end of which acts on the elements 2. This belt 9 circulates mainly around mobile drag wheels 13 rotating around an axis essentially perpendicular or parallel to the transport means 3. This belt 9 mainly has a direction of displacement with a component transverse to the transport direction 4 of the transport means 3, or further comprises another component parallel to this direction. For example, Figure 1 illustrates the particular case where the ejection means 6 comprises two impellers 7 that have the shape of a finger projecting externally from the surface of the belt band 9. According to a possible additional feature, the classification device 1 further comprises a front buttress means 11, of the retaining plate type, extending a distance from the transport means 3 to hold the elements 2 against the latter. At least one impeller 7 extends from each side of the front buttress means 11, to be drawn into the area located to one side of the front buttress 11 and to act on the elements 2 in the opposite area. This is particularly represented in Figures 3A and 3B. The end of the front buttress middle 11 extends mainly with an oblique end portion to follow the movement of the elements 2 in the transportation direction 4 when these are sent to the exit zone 8, the at least one impeller 7 takes the form of hooks that extend above said end, see figure 3B. Alternatively, the front buttress half 11 has an essentially linear oblique opening 12 to follow the movement of the elements 2 in the transportation direction 4 when they are sent to the exit zone 8, the at least one impeller 7 crosses the buttress half level 11 at the level of said opening 12, figure 3A. In both cases, the active part of the impeller 7 is then located on one side of the middle of the front buttress 11, while its base, connected to the actuator that sets it in motion, of the jack type, band 9, etc., is located on the other side of the middle of the front buttress 11. Figure 3C shows a particular alternative where the impeller 7 is integrally on the same side of the front buttress midpoint 11. The invention also relates to a sorting procedure for elements 2 of the type of capsule, stoppers or other parts for closing a container, including of the collar type such as a plastic bottle preform, said procedure comprising transporting the elements 2 on a transporting means 3 that circulates in a transporting direction 4, from a feeding zone to an exit zone 8 located on one side of said transporting means 3, clearing from the transporting means 3 to the exit zone 8, the elements 2 that are present on the transporting means (3) at that time, i.e., the elements 2 that reach the level of the exit zone 8, thanks to a transverse movement.In fact, the transportation from the feed zone to the output zone 8 is generally accompanied at the same time by the removal of elements 2 that do not conform to a positioning criterion or that do not allow the transportation of correctly positioned elements 2. This procedure puts into operation the classification device 1 as described below. During the aforementioned transportation stage, this procedure can also remove from transportation medium 3 any elements 2 that are not positioned in a predefined orientation, or it can force their positioning. Generally, at the level of exit zone 8, elements 2 must be in a predefined position. The clearance of elements 2 to the level of the exit zone 8 can be carried out by a transverse movement of elements 2 to the transportation direction 4, and this movement is caused by an expulsion means 6 comprising at least one impeller 7 displaced by an actuator. Thus, according to the invention, clearing the elements 2 of the transporting means 3 is done by pushing by contact with the movable impeller 7, which then moves from one side to the other of the transporting means 3, towards the exit zone 8. The at least one impeller 7 then acts on the element 2 located opposite the exit zone 8, so that it pushes it towards it, this element 2 acts on the next one in the direction of said exit zone 8 and so on. This impeller 7 can then be moved towards the exit zone side 8 from the opposite side, transversely to the transportation direction 4. According to an additional possible feature, the impeller 7 is movable both transversely to the direction of transportation 4, i.e., from one side to the other of the transportation medium 3, and along said transportation direction 4, so that, during its action against the elements 2 to push them transversely towards the exit zone 8, it can accompany the movement of said elements 2 in the transportation direction 4 and in the same sense, the relative movement is eventually zero in the transportation direction 4. Therefore, according to a possible additional feature, the circulation speed of the impeller 7 in the transportation direction 4 is such that said impeller 7 follows the movement of the transportation medium 3 in that direction. Advantageously, the displacement speed of the impeller 7, transverse to the conveying direction 4, is fast enough to allow both an element 2 located at one end of the conveying medium 3 to approach the exit zone 8 and an element 2 located at the other end to pass through an outlet in the cozcnn / zznz / E / YiAi exit zone 8, taking into account the displacement of the conveying medium 3 in the conveying direction 4. A high transverse speed is also preferable because the outlet can be small. In fact, a very large outlet can cause jamming problems when attempting to reduce displacement in a single column. Furthermore, this speed is sufficiently fast so that at least one impeller 7 does not impede the progression of the conveyor belt 3 in the conveying direction 4. Finally, according to an additional possible feature concerning the operation of the sorting device 1, the circulation speed of the impeller 7 is proportional to the circulation speed of the transport medium 3. As will also be described later, the speed of the impeller 7 is homogeneous during its path, but, preferably, it is proportional to the forward speed of the transport medium 3. Now, the invention will be explained with reference to the illustrated embodiments. Thus, Figure 1 illustrates a sorting device 1 that includes a hopper, not illustrated, in which elements 2 of the capsule or stopper type for closing a bottle can be arranged in bulk. A conveyor belt 3, which forms a means of transport, extends from an opening at the bottom of the hopper, forming the feeding zone. The conveyor belt 3 takes the form of an endless belt that rises from the feeding zone to a height that sometimes depends on the height at which the elements 2 need to be supplied to the downstream machine. Then, conveyor belt 3 advances in a transportation direction 4 that corresponds to the great length of said conveyor belt 3 and pulls the elements 2 upwards, to an exit zone 8. The transportation direction 4 then has a vertical component and can also have a horizontal component that allows gravity to plant the elements 2 against the conveyor belt 3. The conveyor belt 3 comprises successive struts 5, forming transverse buttresses that extend transversely to the conveying direction 4, according to the width of the conveyor belt 3. During lifting in the conveying direction 4, the elements 2 rest on the struts 5, which pull them along in that direction. These struts are regularly spaced along the conveyor belt 3 with a specific pitch and height that allows them to support the elements 2. Furthermore, they preferably extend from one side of the conveyor belt 3 to the other. In this way, each strut 5 pulls a plurality of elements 2, depending on the quantity present in the feeding zone. At most, a strut 5 can pull a row of elements 2 that spans its entire width.Since elements 2 that are not correctly positioned on the conveyor belt 3 are cleared between the feed zone and the output zone 8, there may be far fewer elements 2 to clear, or none at all, when the sway bar 5 reaches the level of the output zone 8. Therefore, it is necessary to be able to eject both an element 2 located at the end of the sway bar 5 closest to the output zone 8 and an element 2 located at the opposite end. The speed of the ejection mechanism 6 is then adjusted to ensure these ejections, taking into account the displacement of the conveyor belt 3 and the dimensions of the passage in the output zone 8. To clear the elements 2 from the conveyor belt 3 to the level of the exit zone 8, the sorting device 1 comprises an ejection means 6 that pushes, by contact, the elements 2 that are against a strut 5, and to said exit zone 8. For example, figure 1 shows a column of elements 2 against a strut 5 that are to be pushed by the ejection means 6 towards the exit zone 8. The ejection means 6 acts against the element 2 furthest from the exit zone 8 and moves towards it; each of the elements 2 in the column acts against another in front of it in the direction of the exit zone 8. As illustrated in Figure 1, the ejection means 6 comprises an endless belt or conveyor belt 9, which rotates thanks to two wheels 13 rotating around an essentially vertical axis. At least one of the two wheels 13 is movable and drives the belt 9, possibly by means of a notched coupling. The sorting device 1 then comprises a motor 14 that drives at least one of the wheels 13. Each of the two wheels 13 is positioned beyond the conveyor belt 3, so that the belt 9 has a linear plane movement close to the conveyor belt 3 across the width of the latter. Therefore, with this type of configuration, the belt 9 follows a path such that it runs along the conveyor belt 3 in one direction, acting on the elements 2, and then returns around a wheel 13, which reverses the path, moving away from the conveyor belt 3, along its return path to the initial position. The useful path, in which the ejection means 6 acts on the elements 2, pushing them towards the side of the conveyor belt 3 where the exit zone 8 is located from the opposite side of the conveyor belt 3, is then performed against the conveyor belt 3, while the return to the starting point is performed on a plane further away from the conveyor belt 3, which particularly prevents any mechanical interaction between the ejection means 6 and the conveyor belt 3 on the return path.Of course, other arrangements are possible to adapt the return: for example, the axles of the wheels 13 can be essentially horizontal, the forward and return lines form approximately a plane parallel to the conveyor belt 3, etc. It is worth mentioning that in general, the expulsion means 6 can implement different types of actuator to create the movement of at least one impeller 7 in the direction of cozcnn / zznz / E / YiAi the output of elements 2. The ejection means 6 comprises at least one impeller 7 for acting by contact on the column of elements 2 to be cleared towards the exit zone 8. In the embodiment illustrated in Figure 1, the ejection means 6 comprises a belt 9 over which at least one finger 10 extends cantilevered, which comes into contact with the element 2 that is furthest from the exit zone 8. Figure 1 shows the coincidence of two fingers 10 that each form an impeller 7. The impeller 7 then extends cantilevered from the portion of the belt 9 near the conveyor belt 3, until it is against the elements 2. To ensure good traction, it is useful for the impeller 7 to act against the largest possible portion of element 2. Therefore, it is preferable that the impeller 7 act not only against the portion of element 2 that protrudes from the sway bar 5, but also against the portion of element 2 that corresponds to the height of the sway bar 5 from the bottom of the conveyor belt 3. This means that the impeller 7, in its active path from one end of the sway bar 5 to the end at the level of the exit zone 8, must also circulate in the hollow volume between two successive sway bars 5.Since the struts 5 are mounted on a moving conveyor belt 3 during the action of the impeller 7, it is necessary to arrange the transverse displacement of the impeller 7 on each side of the conveyor belt 3 with the forward movement of said conveyor belt 3, to prevent a very slow transverse movement of the impeller 7 from causing a collision between it and the longitudinally approaching strut 5. In specific cases where the codals 5 are widely spaced, it may be quite acceptable to have a push button 7 that does not move in a direction strictly transverse to the transportation direction 4 and is fast enough to avoid the collisions described above. The speed of push button 7 depends on whether the rhythm is weak. In general, it is preferable to arrange the impeller 7 in a movement that includes not only a main component transverse to the direction of conveying 4 to push the elements 2 towards one side of the conveyor belt 3, but also a longitudinal component in the same direction of conveying 4. Preferably, the ejection means 6 is arranged so that the longitudinal movement of the impeller 7 during its path from one side of the conveyor belt 3 to the other during ejection corresponds to the sudden longitudinal movement simultaneously experienced by the swivel 5. The longitudinal movement of the impeller 7 is obtained by construction in the case of an expulsion means 6 which is based on a belt principle 9 as illustrated in figure 1. It is then sufficient to displace one with respect to the other in the transportation direction 4 of the wheels 13 around which the belt 9 rotates so that the wheel 13 on the side of the cozcnn / zznz / E / YiAi outlet zone 8 is further forward than the other in the transportation direction 4. It is important to emphasize that the amplitude of the movement of conveyor belt 3 during the ejection of elements 2 towards outlet zone 8 defines the longitudinal dimension of the outlet of zone 8. In fact, this outlet must be large enough to allow all elements 2 to pass through, even in the extreme case where they are so numerous that they occupy the entire width of conveyor belt 3. The element 2 initially closest to outlet zone 8 is then ejected as soon as the ejection mechanism 6 begins its action, while those initially farther away are ejected at the end of the ejection mechanism 6's maneuver and after having traveled a certain longitudinal distance. However, a large outlet can lead to jams, because it is necessary to ultimately obtain a flow of elements 2 arranged in a single column. In this way, to avoid having to provide a very large outlet, it is preferable to provide an expulsion means 6 capable of clearing all elements 2 in the shortest possible time and, therefore, preferably with a weak displacement in the longitudinal direction. The circulation speed of the impeller 7 is proportional, with a fixed factor, to the circulation speed of the transport medium 3. The dimension of the longitudinal window through which the elements 2 are peeled off on one side is also fixed, as is the angle between the direction of movement of the impeller 7 and the direction of transport 4. The sorting device 1 further comprises a front buttress 11, which serves to hold the elements 2 against the conveyor belt 3. Vibrations could displace the elements 2, causing them to move away from the bottom of the conveyor belt 3, i.e., perpendicular to it. If the conveyor belt 3 is oriented so that gravity does not press the elements 2 against it, this front buttress 11 ensures that the elements 2 do not move away from the conveyor belt 3 and are thus held securely by the struts 5.The front buttress 11 can then essentially take the form of a plate, parallel to the conveyor belt 3, at a distance from the bottom of the conveyor belt 3 that is of course greater than the height of the struts 5 and at least slightly greater than the height of the elements 2. The front buttress 11 is no longer necessary beyond the exit zone 8 since the elements 2 have normally already been cleared from the conveying means 3. The front buttress 11 then delimits a first zone or working zone 15, where the elements 2 move, and a second zone, or outer zone 16, on the other side, where the belt 9 or other drive moves. At least one drive 7 of the ejection means 6 is actuated from the outer cozcnn / zznz / E / YiAi zone 16, where the actuator of the ejection means 6, the belt 9, the jack, etc. are located. Since at least one impeller 7 must act against the elements 2, and they circulate in the working zone 15, the at least one impeller 7 must extend from both parts of the front buttress means 11 or at least from its projection, i.e., it has a portion in the working zone 15 to act against the elements 2, as well as a portion in the outer zone 16, to be dragged by the actuator of the ejection means 6. To allow the passage of at least one impeller 7 from one side to the other of the delimitation defined by the front buttress means 11, which has a passage or opening 12 in which the at least one impeller 7 can circulate during its action against the elements 2 in view of its clearance through the exit zone 8. For example, the front buttress 11, in the form of a plate parallel to the conveying means in the form of a conveyor belt 3, may comprise an opening 12 that follows the path of at least one impeller 7, in particular a linear opening 12 extending from one side of the conveyor belt 3 to the other and, potentially, also in the conveying direction 4 and in the same sense. The buttress 11 may then assume the form of two successive elements, separated by said opening 12, which ensures that the same elements 2 are maintained during their transverse displacement. The impeller 7 may then be straight, extending essentially perpendicular to the plane of the conveyor belt 3 at that location.Thus, element 2 is guided by the front buttress 11 on each side of the opening 12, the impeller 7 acting approximately at the center of element 2, as shown in Figure 3A, which shows the section along the path of each side of the conveyor belt 3. This figure illustrates that anywhere between the two sides of the conveyor belt 3, element 2 is held by the front buttress 11 on each side of the impeller 7. As shown in Figure 3B, it is also possible to simply provide a front buttress means 11 whose free-end contour follows the path of the impeller 7 during its active path on the elements 2. This path 7 is preferably coordinated with that of the elements 2 when they are, on the one hand, transported in the transport direction 4 by the transport means and, on the other hand, transported transversely to that direction towards the exit zone 8 by at least one impeller 7. Preferably, this path takes the form of a finger, which has a component transverse to the transport direction 4, as well as a component in the transport direction 4 and in the same sense, such that the finger advances in the transport direction 4 as it advances towards the exit zone 8.Then, element 2 follows this trajectory, as well as the impeller 7 and the end of the front buttress medium 11. The transverse movement of impeller 7 is then coordinated with the movement of the transport medium 3 so that a sufficient part of element 2 is permanently covered by the front buttress medium 11, at any point along the path to the exit zone side 8. Figure 3B also shows that in this case, the impeller 7 is preferably elbow-shaped, with a portion extending from the outer zone 16 to the working zone 15, beyond the end of the front buttress 11. The elbow's return allows the impeller 7 to reach element 2, while the latter is sufficiently positioned between the conveyor belt 3 and the front buttress 11 to ensure the desired guidance. The return extends between the front buttress 11 and the conveyor belt 3, between two successive elbows 5. With these modes, it is possible to push the last element 2 of the cross column, with an actuator of the ejection means 6 located in the outer zone 16, and a drive 7 that advances from the other side, in the working zone 15, while the element 2 remains, throughout its journey from one side to the other of the conveyor belt 3 contained between, on one side, the surface of the conveyor belt 3 and, on the other side, the front buttress means 11. Of course, the impeller 7 can be provided at its end with a plate for contact with element 2, allowing the impeller 7 to have a movement in the transportation direction 4 that is not necessarily the same as that of element 2 itself, while maintaining a well-balanced transverse stress and limiting jamming between the transverse buttresses. In this way, the ejection means 6 mirrors a row of products 2 from the conveying means 3 once the previous row has been cleared. Each row, or the entire batch or set, corresponds to the assembly of products 2 that are against the same buttress means 5. At a certain point, a single impeller 7 is then active to eject the products 2, and the contents of a single transverse buttress 5 are processed by the ejection means 6. The exit zone 8, located at the top of the conveying means 3, is then sized to receive a column of a single product 2 facing forward. Downstream of the exit zone 8, the flow is organized into successive series of products 2, one after the other.The products 2 of the outflow then cross the outflow zone 8 one before the other, essentially transverse to the direction of transportation 4 and continue moving away from the means of transportation 3. The exit zone 8, located on one side of the transport means 3, then allows each product 2 to go successively to the next stage of the process, correctly oriented, so that only the products 2 conforming to the next stage of the process circulate through the exit zone 8, in a lateral position with each other, by successive series cozcnn / zznz / E / YiAi obtained by pushing transversely all the products 2 aligned in a row side by side against a transverse buttress 5. The size of the outlet 8 allows it to receive both a product 2 that is very close to the side where it is located and a product 2 further away, and then at the level of the opposite side, the two products 2 are against the same transverse buttress 5. The outlet 8 corresponds to the size of one or even two products 2. The outlet 8 then narrows slightly to a channel sized for the circulation of a large column of a single product 2. This slight narrowing of the outlet allows the length of the same axis of all the products 2 initially to be aligned against the same transverse buttress 5, it being understood that, in absolute terms, the last product 2 in the line passes through the outlet which is slightly displaced in relation to the first product 2 in the direction of transport 4, this displacement corresponding to the path traveled by the transport medium 3.This slightly narrowed area is not meant to reduce a large flow of several products 2 facing each other into a single column, but to reduce displacement and thus reduce the width of a row of products 2 one behind the other. The ejection means 6, on the one hand, and the transport means 3, on the other, are then set in motion by separate motors, whose speeds are controlled in a coordinated manner. This eliminates the need for a drive 7 in the transport means 3, and synchronization is performed electronically, preventing premature wear and damage due to friction and force transmission. The outlet zone 8 then has an outlet or passage, in the form of an opening in a wall-type guide boundary, extending from one side of the conveying means 3 along the conveying direction 4. The outlet zone 8 then extends into a channel in which the products 2 move in the form of an outlet flow consisting of a large column of a single product 2. That single column flow is formed by the succession of batches of products 2, each batch corresponding to the assembly of products 2 that are previously against the buttress means 5. The products 2 are on a circular base, which, at the operating speeds of this type of sorting device 1, can lead to blockages if it becomes necessary to narrow the flow until a single column of a larger product 2 stream passes through the outlet 8, or a stream with two products 2 passes through the outlet 8, or a stream with two or more products 2 passes head-on. The outlet 8 is then sized for the flow of a large column of a single product 2, and also to accommodate the movement of the conveying medium 3 between the first and last product 2 discharged, as explained above. cozcnn / zznz / E / YiAi Expelling the products 2 through the outlet of discharge zone 8 in successive batches or series of a single product 2 width avoids the need for a convergence guide in discharge zone 8 to carry a flow significantly larger than a single product 2 into a single column flow, and the associated clogging problems. Preferably, the outlet of discharge zone 8 does not exceed the size of the products 2, thus preventing any overlap of the products 2 or transverse displacement to their advance, which would result from a large flow. Furthermore, to expel the contents of a single buttress 5 at a time, the spacing between successive buttress 5s is the same dimension as the outlet of discharge zone 8, for example, around two products 2.The passage between successive buttress means 5 is preferably slightly larger than the outlet zone 8, therefore slightly larger than one or two products 2. The transverse movement of an impeller 7 from one side of the conveying medium 3 to the other is therefore carried out with a longitudinal movement in the conveying direction 4 of the same size as that of the outlet. Taking into account the size of the outlet, particularly between one and two products 2, to avoid the aforementioned jamming problems, the movement of the ejection medium 6 is therefore almost perpendicular to the conveying direction 4. Thanks to the invention, it is also possible to eject items from a sorting device equipped with a continuous conveyor, and it is done safely and quickly, while limiting energy consumption and maintaining high hygiene standards. Although the above description is based on particular modalities, it does not limit the scope of the invention, and modifications can be made, mainly by substituting technical equivalents or by a different combination of all or parts of the features developed above.

Claims

1. - A method of sorting items including capsules, caps and other parts configured to close a container, and items with a collar, including a plastic bottle preform, said method comprising: transporting the items on a conveying system that circulates in a one direction of transport, from a feeding zone to a discharge zone located on one side of said conveying system, clearing from the conveying system, towards the discharge zone, the items that are present in the conveying system;and clearing the elements of the transportation system by pressing the elements by contact with a movable impeller, wherein the speed of a movement of the impeller transverse to the direction of transportation is sufficiently fast to ensure that the movement of the impeller causes an element located at one end of the transportation system near the discharge zone and an element located at the other end to pass through an opening of the discharge zone, taking into account the movement of the transportation system in the direction of transportation, and the impeller can be moved both transversely to the direction of transportation, from one side of the transportation system to the other, and in said direction of transportation.

2. The classification method according to claim 1, further characterized in that the circulation speed of the impeller in the transportation direction is such that said impeller follows the movement of the transportation device in said direction.

3. The classification method according to claim 1, further characterized in that the circulation speed of the impeller is proportional to the circulation speed of the transportation system.

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