Facility for producing containers made of thermoplastic material, comprising a conveying device

Abstract

The invention relates to a facility (10) for producing containers (12B) made of thermoplastic material, comprising a system (32) for conveying the containers (12B), the system (32) comprising at least: - a first upstream wheel (66) provided with grippers (42) for gripping a container (12B), and - a second downstream wheel (68) that is provided with grippers (42) for gripping a container (12B) and is synchronized with the first wheel (66) in order, at a transfer point (73), to transfer a container (12B) from a gripper (42) of the first wheel (66) to a gripper (42) of the second wheel (68), the system (32) comprising ejection means arranged upstream of the transfer point (73), characterized in that the ejection means comprise a multiple ejection device (84) configured to simultaneously eject the containers (12B) from at least two adjacent grippers.

Description

Thermoplastic container manufacturing plant including a conveying device TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to an installation for manufacturing thermoplastic containers, in particular bottles, comprising a container conveying system for containers fitted with a neck, said system comprising at least:

[0002] - a first upstream wheel equipped with grippers for handling a container and driven in rotation, and

[0003] - a second downstream wheel equipped with grippers for gripping a container and driven in rotation in a synchronized manner with the first wheel to operate, at a transfer point, a transfer of a container from a gripper of the first wheel to a gripper of the second wheel,

[0004] the system comprising ejection means arranged upstream of the transfer point, selectively controlled in case of desynchronization between the two wheels to eject the containers conveyed by the first wheel. STATE OF THE ART

[0005] It is known to produce containers from thermoplastic material, such as polyethylene terephthalate (PET), by a stretch-blowing process of preforms implemented in a container manufacturing facility.

[0006] In general, a preform consists of a neck that already has its final shape, while the body of the preform is intended to be deformed during the forming process. To allow this deformation, the body of the preform is heated above a glass transition temperature that makes its walls malleable. Conversely, the neck is kept at a temperature below the glass transition temperature to prevent deformation.

[0007] In order to produce containers with a wall of substantially constant thickness, it is known to perform a so-called biaxial stretching of the material constituting the wall of the preform to deform it plastically by injecting a compressed forming fluid into the body of the preform.

[0008] In the remainder of this description and in the claims, the term "hollow body" will be used interchangeably to refer to a preform, an intermediate container, or a finished container. The invention is particularly suited here to a finished container.

[0009] In a thermoplastic container manufacturing facility, particularly for bottles, a conveyor system is used to ensure successive transfer of preforms and then of containers, respectively between the different stations of the facility.

[0010] As a non-limiting example, document FR-2.972.671 describes a manufacturing facility for thermoplastic containers.

[0011] Such a manufacturing facility mainly comprises a heating station to thermally condition preforms which are then transferred to a forming station (or "blower") to be transformed into containers by stretch-blowing in a mold at one of the stations of said station.

[0012] The resulting containers are then transferred downstream, for example to a filling and capping station and then to a labelling station.

[0013] Alternatively, the arrangement of the filling and capping station and the labeling station can be reversed so that the containers are labeled before being filled and then closed.

[0014] In a container manufacturing facility, the conveying system ensures the transfer of hollow bodies between different stations, in particular between the forming station and the next processing station, for example the filling station.

[0015] To achieve this, the conveying system includes a series of transfer devices, also called "wheels", some of which at least have gripping clamps on their periphery capable of ensuring the individual gripping of a hollow body.

[0016] Document FR-2.972.671 describes a "clamp-to-clamp" type transfer of a hollow body, respectively between a clamp of a first transfer device and another clamp of a second transfer device arranged downstream of the first.

[0017] In document FR-2.972.671, the part of the conveying system described more specifically ensures a transfer of hollow bodies between the exit of the heating station and the forming station.

[0018] Figures 5 to 8 illustrate the clamp-to-clamp transfer of a hollow body and in particular the respective position of the jaws of the first clamp and those of the second clamp which each cooperate with parts of the neck of the hollow body offset vertically so as to avoid any interference between them.

[0019] The clamp-to-clamp transfer of the hollow body takes place at a transfer "point" at which the wheel forming the first transfer device and the wheel forming the second transfer device are tangential.

[0020] To ensure such a transfer from one gripper to another, it is essential to be able to guarantee perfect synchronization between the transfer wheels so that a gripper from the first wheel arrives at the transfer point at the same time as a gripper from the second wheel so that the hollow body can be engaged simultaneously with both grippers at the transfer point.

[0021] Generally, the transfer wheels in a given station are synchronized with the operation of the station's main component. For example, in a forming station, the molding units are typically mounted on a rotating carousel. The preform infeed transfer wheel(s) and the container outfeed transfer wheel(s) are, by default, synchronized with the forming station's carousel. When the carousel changes speed or stops, the transfer wheels follow this change in speed or stop.

[0022] One of the output wheels of the forming station feeds an input wheel of the next station, for example the filling station. However, the input wheel of the filling station is controlled by the operation of the filling station, for example by a filling wheel.

[0023] The invention is particularly concerned with the transfer point between two wheels, each of which is slaved to a different station.

[0024] According to a known solution, synchronization is achieved electronically between the two successive stations, and therefore between the transfer wheels. Each wheel is equipped with a rotational drive system consisting, for example, of asynchronous motors, particularly of the "brushless" type.

[0025] The motors are generally controlled by a control unit receiving information from a set of synchronization sensors, encoders, etc. in order to automatically synchronize the entire container manufacturing installation, the transfer wheels of the conveyor system, but also the container molding (or "blow molding"), filling and capping, labeling, etc. machines.

[0026] However, such electronic synchronization can malfunction, particularly in the event of power supply problems, typically power cuts or drops, which are sometimes frequent in certain countries.

[0027] Furthermore, one of the stations may need to change speed or stop due to a technical problem. Because of the response time of the electronic synchronization, the other station continues to rotate, which can cause a problem, particularly when the downstream station stops while the upstream station continues to rotate.

[0028] However, such a risk of desynchronization is likely to cause damage to the clamps.

[0029] In the absence of synchronization, there is indeed a significant risk of damage to the gripping jaws at the transfer point of a hollow body, and consequently, of deterioration or even destruction (breakage) of at least one of the jaws. Indeed, when a hollow body is engaged with a jaw on each wheel at the transfer point, and the wheels are out of sync, the hollow body is sheared between the two jaws, whose grips may not be able to withstand the stress.

[0030] Due to the high production rates, the drive speeds of the transfer wheels are also high, and in addition, the neck usually has a significant amount of thermoplastic material, resulting in a similarly high resistance.

[0031] To prevent the containers from causing the grippers to break in case of desynchronization, it has already been proposed to eject the containers successively one by one before they reach the transfer point.

[0032] In this case, the transfer point between two stations is located inside the upstream station, in this case, the forming station. Therefore, the last output wheel of the forming station is not linked to the operation of the next station, in this case, the filling station. This allows the ejected containers to fall into a collection bin located within the upstream station to prevent them from interfering with the station's operation when it is restarted.

[0033] However, such an arrangement is not ideal because it is difficult to operate the upstream station without the downstream station being functional. This poses a problem for conducting tests on the upstream station or when producing empty containers without subsequently transferring them to the downstream station.

[0034] BRIEF SUMMARY OF THE INVENTION

[0035] The invention proposes an installation for manufacturing thermoplastic containers, in particular bottles, comprising a container conveying system with a neck, said system comprising at least: - a first upstream wheel equipped with grippers for gripping a container and driven in rotation, and - a second downstream wheel equipped with grippers for gripping a container and driven in rotation in a synchronized manner with the first wheel to operate, at a transfer point, a transfer of a container from a gripper of the first wheel to a gripper of the second wheel, the system comprising ejection means arranged upstream of the transfer point, selectively controlled in case of desynchronization between the two wheels to eject the containers conveyed by the first wheel,characterized in that the ejection means comprise a multiple ejection device configured to simultaneously eject containers from at least two adjacent grippers.

[0036] According to another feature of the installation made according to the teachings of the invention, each clamp of the first wheel is controlled between a closed position, towards which it is elastically returned, and an open position in which it is likely to be constrained by a cam follower.

[0037] According to another feature of the installation made according to the teachings of the invention, the multiple ejection device comprises an ejection cam which is mounted movably between at least: - a passive position in which the ejection cam is retracted out of the path of the cam followers, and - an active ejection position in which the ejection cam simultaneously presses on the cam followers of at least two clamps to cause their simultaneous opening.

[0038] According to another feature of the installation made according to the teachings of the invention, the conveying system includes at least one second ejection device, called an individual ejection device, which is arranged upstream of the multiple ejection device.

[0039] According to another feature of the installation made according to the teachings of the invention, the individual ejection device is capable of causing the opening of only one clamp at a time.

[0040] According to another feature of the installation made according to the teachings of the invention, the individual ejection device comprises an ejection cam which is mounted movably between at least: - a passive position in which the ejection cam is retracted out of the path of the cam followers, and - an active ejection position in which the ejection cam presses on a single cam follower 46 at a time to cause the successive opening of each clamp of the first wheel.

[0041] According to another feature of the installation made according to the teachings of the invention, the ejection devices are arranged on the first wheel so that at any given time, between the gripper that can be controlled by the individual ejection device and the transfer point, there are at most only the number of grippers that can reach the transfer point during the fastest stop that can be made by the first wheel.

[0042] According to another feature of the installation made according to the teachings of the invention, the first wheel is arranged in the same enclosure as a forming station.

[0043] According to another feature of the installation made according to the teachings of the invention, the second wheel is arranged outside the enclosure of the forming station, a window for the passage of containers being provided at the transfer point.

[0044] According to another feature of the installation made according to the teachings of the invention, the containers ejected by the individual ejection device fall into a receiving area, while the containers ejected by the multiple ejection device fall beside said receiving area. BRIEF DESCRIPTION OF THE FIGURES

[0045] Other features and advantages of the invention will become apparent during the reading of the detailed description that follows, for the understanding of which reference should be made to the attached drawings.

[0046] is a top view which schematically represents a container manufacturing installation made according to the teachings of the invention.

[0047] is a side view that represents a preform intended to be processed by the installation of the.

[0048] is a top view which represents an individual gripping clamp of a hollow body having a neck similar to that of the preform shown at the and which equips at least one wheel of a conveying system of the installation of the.

[0049] is a larger scale top view which represents two wheels of the conveying system which are equipped with container ejection devices made according to the teachings of the invention.

[0050] is a view from below which represents on a larger scale the first wheel of the equipped container ejection devices.

[0051] DETAILED DESCRIPTION OF THE FIGURES

[0052] In the following description, we will adopt, without limitation, the longitudinal, vertical and transverse orientations with reference to the trihedron (L, V, T) represented in the figures.

[0053] By convention, the longitudinal and transverse orientations are fixed relative to the transfer wheel of the conveying system so that the position of the transfer arms containing the grippers has no effect on said orientations.

[0054] The terms "front" and "rear" will also be used, without limitation, in reference to longitudinal orientation, as well as "upper" and "lower" or "top" and "bottom" in reference to vertical orientation, and finally "left" and "right" in reference to transverse orientation.

[0055] The terms "upstream" or "downstream" are used respectively in relation to the direction of flow of hollow bodies, preforms or containers, conveyed by the wheels of the conveying system through the installation.

[0056] We have represented on the example of the realization of an installation 10 for the manufacture of containers 12B in thermoplastic material.

[0057] The manufacture of containers 12B, such as bottles, is carried out from preforms 12A, notably obtained by injection molding. Hereafter, preforms 12A and containers 12B will be referred to collectively as "hollow bodies 12".

[0058] An example of a preform 12A intended for use with the manufacturing installation 10 is illustrated in Figure 1. Such a preform 12A is made of thermoplastic material, here polyethylene terephthalate (PET). It is conventionally produced by injection molding. It has a substantially axisymmetric shape around a principal axis "A" shown vertically in Figure 1.

[0059] It comprises a body 14 in the form of an elongated tube along the main axis "A", having a closed axial end and, at its opposite end, shown at the top of the figure, an axially open neck 16. In the example shown in the figure, the base of the neck 16, at the junction with the body 14, has a collar 18 that extends radially in projection relative to the rest of the preform 12A.

[0060] Neck 16 has its final shape, while body 14 is intended to be stretched in a subsequent forming operation to form the body of the finished container 12B.

[0061] Installation 10 mainly comprises a heating station 20, a forming station 22, and a processing station 24 arranged directly downstream of the forming station 22. This processing station 24 is here a filling station, but it could also be a labeling station or any other station suitable for processing the containers 12B immediately after they have been formed.

[0062] The manufacture of the containers is achieved in a manner similar to that described previously.

[0063] The heating station 20 is designed to thermally condition the body 14 of the preforms 12A using heating elements 26 such as infrared lamps or laser diodes. The preforms 12A, thus heated, are then introduced into molds 28 of the forming station 22, where they are transformed into containers 12B by blow molding or stretch-blow molding.

[0064] The forming station 22 here includes a rotating carousel 27 around the periphery of which the molds 28 are arranged so that the forming operation takes place during the movement of the hollow bodies 12.

[0065] In the embodiment example, the 12B containers obtained are transferred to the treatment station 24 directly arranged downstream.

[0066] In this manufacturing installation 10, the hollow bodies 12 are moved in a line along a common path, called the production path 30. Along this production path 30, each hollow body 12 is held individually by its neck 16, and in particular by means of its flange 18, by gripping means of a conveying system 32. Indeed, the preforms 12A and the containers 12B are identical objects to be conveyed because they are equipped with the same neck 16.

[0067] During their conveying by such a conveying system 32 through the manufacturing installation 10, the hollow body 12 is either supported by means of its collar 18, or grasped by its neck 16 by a clamp, for example at the level of an annular groove located vertically above the collar 18.

[0068] To ensure the conveyance of the hollow bodies 12, the conveying system 32 comprises a plurality of conveying devices which are arranged to successively transport said objects through the manufacturing installation 10.

[0069] The conveying system 32 includes rotary conveying devices, shown schematically on the.

[0070] In the example, the conveying devices of system 32 are capable of conveying the hollow bodies 12 from one station to the next.

[0071] Two main types of conveying devices are distinguished depending on whether the hollow body 12 is supported via its collar 18 or whether a grip is made at the neck 16.

[0072] In the embodiment example, each device of the conveying system 32 is driven in rotation by a motor (not shown) which is electronically controlled synchronously.

[0073] Regardless of their type, conveying devices are driven in rotation around a vertical axis by motorized drive means, which is why these conveying devices are also called "wheels".

[0074] The first type of conveying device includes at least one circumferentially movable platform 34 provided at its periphery with a plurality of notches 36 having for example a radially open "U" shape.

[0075] The hollow bodies 12 are inserted radially into the notches 36 and supported by means of their collar 18 resting on the periphery of the notch 36. Such a device is sometimes called for this reason a "notched wheel 38".

[0076] The second type of conveying device includes at least one movable wheel 40 provided at its periphery with a plurality of clamps 42 each having two jaws 43.

[0077] Generally, each clamp 42 is mounted on the wheel 40 via a transfer arm 44. The transfer arm 44 can be articulated on the wheel 40.

[0078] There are different types of pliers 42 depending in particular on the part of the hollow body 12 with which the jaws 43 of the pliers 42 cooperate. Thus, pliers 42 are distinguished according to whether the jaws 43 are positioned below the collar 18 or whether the jaws 43 ensure a grip with a clamping force of the neck 16 above the collar 18.

[0079] The jaws 43 are mounted to move between at least one open position and one closed position

[0080] The open position corresponds to a position in which the object can be inserted into or removed from the clamp 42. The opening is controlled by means of a mechanism, for example a cam and follower type actuation mechanism 46, in particular a roller type.

[0081] The jaws 43 of the clamp 42 are generally automatically returned by return means, such as a spring, to the closed position.

[0082] We have represented on the one part only of the conveying system 32 according to the one located straddling the forming station 22 and the following processing station 24, here the filling station.

[0083] For hygiene reasons, the forming station 22 is generally enclosed in a chamber 58 which is kept under positive pressure relative to the surrounding pressure to prevent the entry of dust and polluting particles.

[0084] When the next processing station 24 is a filling station, it can also be enclosed in a separate enclosure 60, distinct from the enclosure 58 of the forming station 22. The enclosure 60 of the next processing station 24 is kept sterile by positive pressure relative to that of the forming station 22, because the filling operation must be carried out under very strict hygiene and sterilization conditions.

[0085] The containers 12B pass from the forming station 22 to the next processing station 24 through a window 62 whose dimensions are adjusted to allow the containers 12B to pass through while minimizing the risk of entry of polluting particles.

[0086] Inside the enclosure 58 of the forming station 22 is arranged a container 12B output wheel 64 which is equipped with grippers 42 arranged at the end of transfer arms 44 and which grasp the containers 12B as they exit the mold 28.

[0087] The conveying system 32 includes at least one first upstream conveying wheel 66 and a second downstream conveying wheel 68, respectively referred to below as first wheel 66 and second wheel 68.

[0088] As illustrated in figures 1 and 4, the first wheel 66 is arranged downstream of the carousel 27, here directly after the exit wheel 64, and the second wheel 68 is located immediately downstream of the first wheel 66.

[0089] The objects conveyed by the first wheel 66 and the second wheel 68 are therefore made up of containers 12B, for example bottles.

[0090] The first wheel 66 is arranged inside enclosure 58 of forming station 22.

[0091] The second wheel 68 is arranged outside enclosure 58 of forming station 22.

[0092] The first wheel 66 is equipped with a plurality of grippers 42 for gripping a container 12B which are distributed circumferentially in a regular manner on a rotating plate 70.

[0093] We have shown a non-limiting example of the realization of such a clamp 42. The clamp 42 can be made according to different kinematics from the moment that its opening is controlled by the cam follower 46.

[0094] The clamp 42 here comprises a plate 48 on which the two jaws 43 are mounted to pivot about an axis "B" at one end. The other free end of the jaws 43 comprises a gripping member 49 for the neck 16 of the hollow bodies 12. The two jaws 43 are pivotally linked by means of two gears 50 meshed with each other.

[0095] The jaws 43 are controlled between a closed position, represented in solid lines, in which the gripping organs 49 are brought together so as to be able to grasp a collar 16, and an open position, represented in dashed lines, in which the gripping organs 49 are spread apart to release a collar 16 or to introduce a collar 16.

[0096] The jaws 43 are elastically returned to their closed position by means of an elastic element 52, such as a spring.

[0097] The jaws 43 are actuated in their open position, against the elastic return force, by a lever 54 which is pivotally mounted on the plate 48 about an axis "C" parallel to the axes "B" of the jaws 43. One end of the lever 54 is connected to one of the jaws 43 by means of a connecting rod 56. A second end of the lever is fitted with a cam follower 46, formed here by a roller. When the cam follower 46 is pushed towards the free end of the jaws 43, the lever 54 pivots, pulling the jaw 43 towards its open position via the connecting rod 56.

[0098] The first wheel 66 is driven around a first axis D1 of rotation by first drive means comprising at least one motor (not shown).

[0099] A cam 72, of which only a part has been shown in the figure, is for example fixedly mounted under a rotating plate 70 of the first wheel 66.

[0100] The second wheel 68 is of similar design to the first wheel 66.

[0101] The second wheel 68 has a movable plate 74 equipped at its periphery with a plurality of clamps 42 for gripping a container 12B.

[0102] The second wheel 68 is driven by second means (not shown) of drive around a second axis D2 of rotation, the second wheel 68 being driven in a direction of rotation opposite to that of the first wheel 66.

[0103] The first drive means and the second drive means respectively motorized are electronically synchronized to operate, at a transfer point 73, a clamp-to-clamp transfer of the containers 12B from the first wheel 66 to the second wheel 68 located downstream.

[0104] Synchronization is achieved so that each clamp 42 of the first wheel 66 arrives at the same time as a clamp 42 of the second wheel 68 so that the container 12B can be engaged simultaneously with both clamps 42 at the transfer point 73.

[0105] The first wheel 66 is primarily controlled by the operation of the carousel 27 of the forming station 22. When the carousel changes speed or stops, the first wheel 66 follows the change of speed or the stop.

[0106] Similarly, the second wheel 68 is primarily controlled by the operation of the next processing station 24. When the next processing station 24 changes speed or stops, the second wheel 68 follows the change in speed or the stop.

[0107] Thus, the transfer point 73 is located not only at the interface between the first wheel 66 and the second wheel 68, but it is located, more generally, at the interface between the forming station 22 and the next processing station 24.

[0108] However, in the event of an emergency shutdown of one of the two stations 22, 24, the other of the two stations 22, 24 is also shut down after a delay. This delay may depend on the operating speed, the inertia of the various devices in the station, and the response time of the electronic synchronization.

[0109] The conveying system 32 includes an individual ejection device 76 which is arranged upstream of the transfer point 73.

[0110] Preferably, the individual ejection device 76 is arranged fixed under the rotating plate 70 of the first wheel 66 so as to eject the preforms into an individual ejection zone 78.

[0111] The individual ejection device 76 is selectively controlled in case of desynchronization between the first drive means and the second drive means.

[0112] The individual ejection device 76 has the function of ejecting, in the event of desynchronization, the containers 12B conveyed by the first wheel 66 in order to avoid any damage to the clamps 42 of either of the first and second wheels 66, 68 in the vicinity of the transfer point 73.

[0113] Furthermore, the individual ejection device 76 can also be used in other situations. For example, to selectively remove a container 12B for the purpose of assessing production quality. As another example, it can be used to selectively eject a container in the event of a failure of an upstream device, such as a mold, or to eject a bottle that does not meet the expected quality standards.

[0114] Damage to the clamps 42 is likely to occur in particular in the event of a collision between the neck 16 of a container 12B conveyed by a clamp 42 of the first wheel 66 and a clamp 42 of the second wheel 68, out of sync with the first wheel 66.

[0115] The individual ejection device 76 is designed to eject a container 12B one by one and one after the other as they pass through the individual ejection zone 78. The ejected containers 12B fall into a receiving area 80 formed by a basket and / or a chute leading to said basket, designed to collect the ejected containers 12B. The receiving area 80 is positioned adjacent to the individual ejection zone 78. The receiving area 80 must extend over a sufficient space to receive the containers 12B, which are likely to move at high speed and follow a parabolic curve, rather than a straight line, when ejected.

[0116] However, the receiving area 80 is located inside the enclosure 58. It is not possible to arrange the ejection device 76 as close as possible to the transfer point 73 located at the level of the passage window 62 because the containers 12B would then fall randomly into one or the other of the enclosures 58, 60 and / or hit a separating wall between the two enclosures 58, 60. In addition, there is no space available to extend the receiving area 80 leading to the basket to the separating wall.

[0117] There is therefore a dead zone 82 located between the individual ejection zone 78 and the transfer point 73 in which the grippers 42 may carry containers 12B that have not been ejected by the individual ejection device 72. This can be problematic because the containers 12B carried by these grippers 42 may arrive at the transfer point 73 while the wheels 66 and 68 are out of sync. Even if the first wheel 66 manages to stop before these containers 12B reach the transfer point 73, if they are not ejected from their grippers 42 before the restart of the manufacturing installation 10, they may cause malfunctions by arriving at the transfer point 73 too early, before the next processing station 24 has reached its operating speed.

[0118] To avoid these problems, the first wheel 66 includes a multiple ejection device 84 arranged upstream of the transfer point 73, is selectively controlled in case of desynchronization between said first and second drive means to simultaneously eject the containers 12B from at least two adjacent clamps 42 located in the dead zone 82.

[0119] In the embodiment shown in the figures, the ejection device 84 is capable of simultaneously ejecting the containers 12B from two adjacent clamps 42 located in the dead zone 82, the clamp 42 closest to the transfer point 73 and the clamp 42 directly next.

[0120] At least the container 12B carried by the gripper 42 closest to the transfer point 73 in the dead zone 82, when ejected by the multiple ejection device 84, falls beside the receiving area 80. This container 12B is even likely to fall outside the enclosure 58 of the forming station 22.

[0121] The other containers 12B ejected by the multiple ejection device 84 fall inside the enclosure 58 of the forming station 22, making them easier to collect. They may fall either beside the receiving area 80 or into the ejection area 80, depending in particular on their speed of movement and / or their inertia, for example.

[0122] The ability to drop the container 12B held by the clamp 42 located closest to the transfer point 73 into the dead zone 82 ensures that the first wheel 66 no longer has any container 12B during an emergency stop.

[0123] Furthermore, when the emergency stop is activated, the response time of an individual ejection device may be insufficient to prevent the most advanced container 12B from reaching the transfer point 73. Moreover, if such an individual ejection device is placed too close to the transfer point 73, the containers 12B may block the passage window or fall out of the enclosure 58 of the forming station 22, for example, into the enclosure 60 of the next processing station 24.

[0124] To be able to eject this container 12B in time, having a multiple ejection device allows at least one more container 12B to be ejected than a single ejection device, while reducing the number of containers 12B falling out of enclosure 58 of forming station 22.

[0125] The ability to drop the containers 12B carried by the clamp 42 adjacent to the clamp 42 closest to the transfer point 73 into the dead zone 82 makes it easier to collect the ejected containers 12B, even when they do not fall into the receiving area 80.

[0126] Thus, thanks to this device, it is guaranteed that the first wheel 66 no longer carries any container 12B after the individual ejection zone 78 during an emergency stop.

[0127] In addition, the multiple ejection device 84 simplifies the collection of ejected 12B containers by reducing the number of 12B containers that fall outside the enclosure 58 of the forming station 22.

[0128] The individual ejection device 76 and the multiple ejection device 84 are arranged on the first wheel 66 so that at any given time, between the gripper 42 passing through the individual ejection zone 78 and the transfer point 73, there are at most only the number of grippers 42 that can reach the transfer point 73 during the fastest possible stop that can be achieved by the first wheel 66. For example, in the present case, the dead zone 82 has four grippers 42, two of which can be directly actuated by the multiple ejection device 84.

[0129] Each ejection device 76, 84 is selectively controlled between a passive state occupied when the first drive means and the second drive means are synchronized and an active ejection state occupied only when the first drive means and the second drive means are desynchronized, for example during an emergency stop of the next processing station 24.

[0130] According to the embodiment illustrated by the, each ejection device 76, 84 comprises ejection means which are mounted movable between at least one passive position and one active ejection position corresponding to said states.

[0131] The passive position corresponds to a position in which the said ejection means do not actuate the clamps 42 of the first wheel 66 which remain in the closed position in the respective ejection zones 78, 82.

[0132] The active ejection position corresponds to a position in which said ejection means intervene to control the opening of the clamps 42 when they pass through the associated ejection zone 78, 82 to cause the ejection of the containers 12B conveyed by the first wheel 66.

[0133] The ejection means of the individual ejection device 76 are here formed by an ejection cam 86 which is movably mounted between at least:

[0134] - a passive position in which the ejection cam 86 is retracted out of the path of the cam followers 46, and

[0135] - an active ejection position in which the ejection cam 86 presses on a single cam follower 46 at a time to cause the successive ejection of the containers 12B conveyed by the first wheel 66 as they pass through the individual ejection zone 78.

[0136] For example, the ejection cam 86 is mounted under the rotating plate 70.

[0137] Cam 86 is mounted here pivoting around an axis parallel to that of the first wheel 66.

[0138] The individual ejection device 76 includes an actuator 88 for the individual ejection cam 86 to move it into at least one of said passive and active ejection positions.

[0139] Preferably, the actuator 88 is controlled to hold the cam 86 in the passive position, while the cam 86 is automatically returned to the active ejection position.

[0140] Advantageously, the actuator 88 of the individual ejection device 76 consists of at least one pneumatic cylinder.

[0141] Alternatively, actuator 88 consists of an electric motor.

[0142] The ejection means of the multiple ejection device 84 are here formed by an ejection cam 90 which is movably mounted between at least:

[0143] - a passive position in which the ejection cam 90 is retracted out of the path of the cam followers 46, and

[0144] - an active ejection position in which the ejection cam 90 simultaneously presses on the cam followers 46 of at least two clamps to cause the simultaneous ejection of the containers 12B conveyed by the first wheel 66 as they pass through the dead zone 82.

[0145] For example, the ejection cam 90 is mounted under the rotating plate 70.

[0146] The cam 90 is here mounted pivotally around an axis parallel to that of the first wheel 66. It has dimensions greater than those of the cam 72 of the individual ejection device 76 so that the cam followers 46 of two successive clamps 42 can roll simultaneously on the cam 90 in the open position.

[0147] The multiple ejection device 84 includes an actuator 92 for the multiple ejection cam 90 to move it into at least one of said passive and active ejection positions.

[0148] Preferably, the actuator 92 is controlled to hold the cam 90 in the passive position, while the cam 90 is automatically returned to the active ejection position.

[0149] Advantageously, the actuator 92 of the multiple ejection device 84 consists of at least one pneumatic cylinder.

[0150] Alternatively, actuator 92 consists of an electric motor.

[0151] During normal operation of the manufacturing installation 10, the containers 12B are transported by the first wheel 66 to the second wheel 68. The two ejection cams 86, 90 occupy their passive position.

[0152] When a non-compliant container 12b is detected, the individual ejection device 76 is activated for the time necessary to eject said non-compliant container 12B towards the receiving area 80 before resuming its passive position.

[0153] When the next processing station 24 experiences a problem that forces it to stop, the ejection cams 86 and 90 of the individual ejection device 76 and the multiple ejection device 84 are activated. They remain in the active position until the forming station 22 has completely stopped.

[0154] The container 12B present in the individual ejection zone 78 when the cam 86 is actuation towards its active position is ejected because the cam 86 presses on the cam follower 46 to command the clamp 42 towards its open position.

[0155] The containers 12B positioned upstream of the individual ejection zone 78 are ejected successively into the receiving area 80 until the forming station 22 comes to a complete stop because the cam followers 46 of the following grippers 42 roll successively on the cam 86 in the active position.

[0156] Some containers 12B are already in the dead zone 82 at the instant the cam 86 of the individual ejection device 76 moves into its active position. These containers 12B, which could not be ejected by the individual ejection device 76, are ejected by the cam 90 of the multiple ejection device 84. During its movement to its active position, said cam 90 presses on the cam follower 46 of the gripper 42 closest to the transfer point 73 to cause it to open and the container 12B to fall out of the enclosure 58 of the forming station 22. At the same time, said cam 90 presses on the cam follower 46 of the immediately following gripper 42 to cause the ejection of the container 12B, which falls inside the enclosure 58 of the forming station 22.

[0157] The other grippers 42 present in the dead zone 82 when the ejection devices 76, 84 are commanded in their active state pass successively over the cam 90 of the multiple ejection device 84 to successively cause the containers 12B to fall inside the enclosure 58 of the forming station 22.

[0158] The invention thus makes it possible to eject all the containers 12B carried by the first wheel 66 before arriving at the transfer point 73 and minimizing the number of containers 12B falling out of the enclosure 58 of the forming station 22.

Claims

Installation (10) for manufacturing thermoplastic containers (12B), in particular bottles, comprising a container (32) conveying system (32) for containers (12B) equipped with a neck (16), said system (32) comprising at least: - a first upstream wheel (66) equipped with grippers (42) for gripping a container (12B) and driven in rotation, and - a second downstream wheel (68) equipped with grippers (42) for gripping a container (12B) and driven in rotation in a synchronized manner with the first wheel (66) to operate, at a transfer point (73), a transfer of a container (12B) from a gripper (42) of the first wheel (66) to a gripper (42) of the second wheel (68), the system (32) comprising ejection means arranged upstream of the transfer point (73), selectively controlled in case of desynchronization between the two wheels (66, 68) to eject the containers (12B) conveyed by the first wheel (66),characterized in that the ejection means comprise a multiple ejection device (84) configured to simultaneously eject the containers (12B) from at least two adjacent grippers. Installation (10) according to the preceding claim, characterized in that each clamp (42) of the first wheel (66) is controlled between a closed position, towards which it is elastically returned, and an open position in which it is likely to be constrained by a cam follower (46). Installation (10) according to claim 2, characterized in that the multiple ejection device (84) comprises an ejection cam (90) which is movably mounted between at least: - a passive position in which the ejection cam (90) is retracted out of the path of the cam followers (46), and - an active ejection position in which the ejection cam (90) simultaneously presses on the cam followers (46) of at least two clamps (42) to cause their simultaneous opening. Installation (10) according to any one of the preceding claims, characterized in that the conveying system (32) comprises at least one second ejection device, referred to as the individual ejection device (76), which is arranged upstream of the multiple ejection device (84). Installation (10) according to the preceding claim, characterized in that the individual ejection device (76) is capable of causing the opening of only one clamp (42) at a time. Installation (10) according to claim 5, characterized in that the individual ejection device (76) comprises an ejection cam (86) which is movably mounted between at least: - a passive position in which the ejection cam (86) is retracted out of the path of the cam followers (46), and - an active ejection position in which the ejection cam (86) presses on a single cam follower (46) at a time to cause the successive opening of each clamp (42) of the first wheel (66). Installation (10) according to any one of claims 5 or 6, characterized in that the ejection devices (76, 84) are arranged on the first wheel (66) so that at any given time, between the gripper (42) capable of being controlled by the individual ejection device (76) and the transfer point (73), there are at most only the number of grippers (42) capable of reaching the transfer point (73) during the fastest stop that can be achieved by the first wheel (66). Installation (10) according to any one of the preceding claims, characterized in that the first wheel (66) is arranged in the same enclosure (58) as a forming station (22). Installation (10) according to the preceding claim, characterized in that the second wheel (68) is arranged outside the enclosure (58) of the forming station (22), a window (62) for the passage of containers (12B) being provided at the transfer point (73). Installation (10) according to any one of claims 4 to 9, characterized in that the containers (12B) ejected by the individual ejection device (76) fall into a receiving area (80), while the containers (12B) ejected by the multiple ejection device (84) fall beside said receiving area (80).

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