Patent ID: 12226945

DETAILED DESCRIPTION

This invention provides a machine for producing containers, preferably shaped containers, from preforms.

As used herein, the term “container” relates to a container for storing a consumable. Containers have an internal cavity defined by an interior surface of the container walls. The internal cavity defines the storage volume of the container. For beverages, single serve containers having a storage volume from about 100 to about 500 milliliters, multi-serve containers having a volume from about 500 to about 3000 milliliters, as well as large containers having volumes from about 3000 milliliters to about 30 liters and more are generally known. For other applications such as storage of liquid drugs, smaller container sizes are also known. For yet other applications such as fuels, larger container sizes are known. The interior cavity of the container is accessible from the outside through an opening. The opening may be closable by a closure such as a cap or a lid. The closure may be an integral part of the container and movably connected to the outer wall of the container for example by means of a hinge. The closure may also be a separate part that is not permanently attached to the container such as screw top or a crown. The closure may be reversibly attachable to the container for repeated opening and closing of the container. The closure may comprise a movable part that can be moved by the user from an open position to a closed position such as a sports cap.

The shape of the container is defined by the outer surface of the container walls. In principal, the container can have any size and shape. The container may have a top portion including the opening, a bottom portion opposite the top portion, and a center portion connecting top and bottom portion. The dimension from the top portion to the bottom portion of the container is generally referred to as the longitudinal dimension. The container may comprise a neck portion surrounding the opening and a shoulder portion connecting the neck portion with the side walls. The container may comprise a base for placing the container on a surface. The base may form part of the bottom portion. When placed on a surface, the base of the container is in contact with the surface at at least three points. The base may also be in contact with the surface along a standing surface such as a standing ring. The side walls connect the base of the container with the container walls in the top portion.

As used herein, the term “shaped containers” refers to containers offering at least partially resistance against a change in geometric shape. For example, a simple plastic pouch is not a shaped container while a plastic bottle is a shaped container. Shaped containers can virtually take any shape including the shape of a bottle, a canister, a box, a keg, or a barrel. The resistance against deformation by external forces can be different for various parts of the container and in different direction of a container. Many containers, such as bottles, have a longitudinal dimension that is substantially larger than any transverse dimension. Often, the resistance to deformation in the longitudinal direction is much larger than the resistance to change in the transverse direction so that the containers are stackable for bulk transport.

As used herein, the term “consumable” refers to any product that is normally protected or supported by a container when being delivered to or transported by an end user. The product can be in gaseous, liquid, or solid form. Typical solid consumables include food and other items that are perishable or require some level of protection against contamination. Typical liquid consumables include beverages, body care products, home and garden care products, medical fluids, fuels, operating fluids, and the like.

As used herein, the term “preform” refers to any piece of material than may be converted into a container by forcing a fluid medium at elevated pressure into it. The preform may have a hollow body and a neck portion with an opening for accessing the internal volume of the preform. A preform may have a shape similar to that of a test tube being closed at lower end and having the neck with the opening at the upper end. The preform may be made from any suitable plastic materials, such as polyesters, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene imine (PEI), polytrimethylene terephthalate (PTT), polylactic acid (PLA), polyethylene furanoate (PEF), or polyolefins, such as polyethylene low density (LDPE) or high density (HDPE), polypropylene (PP), or styrene based materials such as polystyrene (PS), acrylonitrile butadiene styrene (ABS) or other polymers, such as polyvinyl chloride (PVC).

The preforms may generally be produced according to an injection molding process and be molded at a site different from the site where the machine for forming containers according to the present invention is located. In a variant, the preform production platform, such as injection molding, compression molding or injection compression, is integrated in the machine. In this case, the perform production process is conducted such that the body of the perform remains as close as possible to its optimal processing temperature, whereas the neck part is kept at a temperature as close as possible to ambient temperature to prevent later distortion. In this case, the heating station can be replaced by the pre-form production platform and the treatment station(s) is placed downstream of the preform production platform. A heating station can however be arranged downstream of the pre-form production platform in order to submit the preforms to an additional thermal conditioning to optimize the heating profile of the preforms and/or to ensure the activation of the decontamination media optionally introduced in the preforms in the treatment step(s).

A suitable process for converting a preform into a container is to provide a heated preform, preferably heated above the glass transition temperature of the preform material, and to force a fluid medium through into the preform at an elevated pressure. The fluid medium then causes the body of the preform to expand. During the expansion, the preform may be placed into a mold such that the body expands until it reaches and conforms to the interior surfaces of the mold. After cooling down, the body of the preform remains in the expanded configuration, now forming a container. By suitable forming the interior surfaces of the mold, the form of the container may be determined. During the expansion of the preform through the opening, the neck portion may remain relatively unchanged. Suitable fluid media for expanding preforms include gaseous media, such as pressurized air (blowing), as well as liquid media, such as water (hydraulic forming or hydroforming).

As used herein, the term “mold” refers to any body having an internal cavity defined by interior surfaces. A mold may comprise an opening for accepting and holding the neck portion of the preform. When the preform is placed into the mold, the opening of the preform can be accessed from outside the mold. A mold generally comprises at least two complementary parts which can be moved from a first closed configuration to a second open configuration. The preform is expanded when the mold parts are in the closed con-figuration such that the closed mold limits the expansion of the preform to the desired container geometry. In the opened configuration, the preform can be placed into the mold cavity and the finished container can be removed after the expansion. A mold may comprise further parts such as a base mold which is longitudinally movable with respect to the above mentioned complementary parts and contains the imprint of the container base.

The mold may comprise suitable locking means for locking the mold in the closed configuration in order to avoid opening of the mold during the expansion of the preform. The locking means can take the form of a ring which can be arranged around the mold when the mold is closed. Preferably the locking means comprises a first locking means for locking the upper portion of the mold and a second locking means for locking the lower portion of the mold. The locking means may comprise two rings which are arranged around the upper part and the lower of the mold respectively. Preferably, the locking means and the mold are configured such that the locking means is carried by the mold when the mold is locked with it.

In the following description, the machine and method according to the invention will be described in relation with a hydraulic forming method of containers. However, it is to be understood that the invention is not limited to hydraulic forming and can also be applied to air forming of containers.

In the description, the terms “upstream” and “downstream” are defined relative to the direction of circulation of the preforms and of the formed containers in the machine according to the invention.

The machine of the present invention comprises a plurality of molds for converting preforms to containers. By providing a plurality of molds, the machine of the present invention is able to convert preforms into containers at a higher throughput because the conversion of a plurality of preforms can be handled in parallel as follows. A first heated preform is placed into the first mold. While the expansion of the first preform is started, a second heated preform is loaded into the second mold and so forth. The first mold is used again after the previous container has been removed from it. To allow parallel expanding of preforms in a plurality of molds in a continuous process, the individual molds may be transported along a closed-loop manufacturing path. The time required for expanding the heated preform and removing the container cannot be shortened below a certain value, taking into account some mechanical limits of the equipment or some technical constraints due to the plastic material itself. Accordingly, each mold can only be used a limited number of times per hour. Further increasing the throughput of the machine thus requires using more molds and using them in parallel. To accommodate the increased number of molds, the manufacturing path has to be extended and the molds have to be transported along the manufacturing path at a higher speed.

The machine of the present invention comprises a mold loading station for placing successive preforms into successive molds, each mold forming a mold cavity having the shape of the container to be produced.

The mold loading station may comprise a mold transportation means for transporting the successive molds along a manufacturing path. The transportation means may be in the form of a wheel rotating around its central rotational axis and transporting the molds along its circumference. The transportation means may comprises suitable holding means for holding molds along its circumference. The transportation means may also be a chain for transporting a plurality of molding means. The mold loading means may comprise means for moving the molds from the open configuration to the closed configuration. The mold loading means may comprise means for moving the molds from the closed configuration to the open configuration. The means for moving the molds may be integrated with the holding means or may be distinct from the holding means. The transportation means may comprise means for locking and unlocking the molds in the closed configuration.

The preforms are preferably transported with their longitudinal axis parallel to the rotational axis of the transportation means, yet more preferably with their longitudinal axis in the vertical position.

Preferably, the preforms are supplied to the mold loading station in a form ready for being expanded such as by having a temperature above the glass transition temperature of the preform material. The preforms may be supplied from a heating station comprising a transportation means for transporting the preforms through the heating station along a predetermined path in a continuous process. Suitable heating stations such as ovens for preparing and supplying heated preforms are well known.

Optionally, before undergoing the heating step described before, the preforms can be decontaminated or cleaned, for example to remove dust, or exposed to ultraviolet radiations or submitted to combined or successive treatments. In this case, the machine may comprises one or several appropriate station(s) for performing this or these treatments located upstream of the heating station. The heating station can then be arranged to apply a temperature profile ensuring the activation of the decontamination media optionally introduced in the preforms in the treatment step(s).

The machine of the present invention further comprises a forming station for forming the containers by injecting a gaseous or liquid fluid into the preform contained in each mold in order to deform said preform such that each preform acquires the shape of the container defined by the mold cavity.

The forming station may comprise a mold transportation means for transporting the successive molds along a manufacturing path. The transportation means may be in the form of a wheel rotating around its central rotational axis and transporting the molds along its circumference. Preferably, the rotational axis of the transportation means of the forming station is substantially parallel to the rotational axis of the transportation means of the mold forming station. The transportation means may comprises suitable holding means for holding molds along its circumference. The transportation means may also be a chain for transporting a plurality of molding means.

The forming station may comprise a nozzle for engaging with the opening of the preform contained in the mold and for injecting the pressurized fluid into the preform causing it to expand. The forming station may comprise a plurality of such nozzles successively engaging with preforms contained in successive molds.

For the forming station and its reliable operation, a rotational or track speed of the mold holders along the manufacturing path which is as low as possible is desired. The minimum possible speed for a continuously operating machine is determined by the combined width of the molds divided by the process time for one conversion in a mold. The width of each mold is the width of the widest configuration of the mold which is in the open configuration for inserting the preform and removing the container.

The open configuration is only needed for some time when the mold is loaded and un-loaded in the mold loading station. During the forming step when the mold is in the forming station, the mold has to remain in the closed configuration. Accordingly, it is possible to arrange successive molds with a smaller separation (pitch) in the forming station as compared to the loading station. The forming station can thus operate at a lower rotational or track speed of the molds while still having the same throughput as the mold loading station.

The machine of the present invention comprises a forming station that is distinct from the mold loading station. Preferably, the forming station has a smaller pitch than the mold loading station. Preferably, the forming station operates at a lower rotational or track speed than the forming machine.

The machine comprises a transferring station for transferring successive molds from the mold loading station to the forming station. The transferring station may comprise mold holders for holding and transporting molds. The transferring station can be in the form of a star wheel having a plurality of radial arms having mold holders at their distal ends. The transferring station is arranged such that the mold holders may receive molds from the mold loading station and such that the mold holders may release the molds to the forming station. Preferably, the pitch of the transferring station when receiving the molds is substantially similar to the pitch of the mold loading station when releasing the molds. Preferably, the pitch of the transferring station when releasing the molds is identical to the pitch of the forming station receiving the mold. The transferring station may comprise means for reducing the pitch between successive molds. A suitable means for reducing the pitch is an actuator moving the arms of the star wheel such that the pitch to the preceding mold is reduced. For example the arms may be rotated around the same central rotational axis as the wheel of the transferring station, thereby reducing the angular distance between two successive molds. After releasing the mold to the forming station, the pitch between the two successive molds holder may be increased again, preferably by the same means, so that the pitch adjusted gain for receiving the molds from the mold loading station.

The machine of the present invention may further comprise a mold unloading station in which the molds are opened and the formed containers are retrieved from the mold cavity of the opened successive molds. Preferably, the mold unloading station is unitary with the mold loading station in substantial aspects and shares components. Preferably, the mold loading stations is configured such that it can also perform the function of the mold unloading station. Preferably, the mold loading station performs the steps of unloading and loading the mold while the mold is being held in the same mold holder. Preferably, the same mold holder is transported by the same transportation means during the unloading and loading of the mold.

The machine of the present invention may further comprise a closing station for closing the containers formed at the forming station, preferably while the containers are still being held inside the mold. Preferably, the closing station is arranged between the forming station and the mold unloading station. The closing station may comprise means applying a lid to the neck portion of the container. The closing station may comprise transportation means for transporting the molds along the manufacturing path. The transportation means may be in the form of a wheel rotating around its central rotational axis and transporting the molds along its circumference. The transportation means may comprises suitable holding means for holding molds along its circumference. The rotational axis of the transportation means may preferably be substantially parallel to some or all other rotational axes of the machine. The transportation means may also be a chain for transporting a plurality of molding means.

The closing station also operates best when the rotational or track speed of the molds is as low as possible. Accordingly, the closing station preferably has a smaller pitch than the mold loading station, and yet more preferably the same pitch as the forming station.

The machine of the present invention may comprise a second transferring station for transferring the successive molds from the closing station to the mold unloading station. The second transferring station may comprise mold holders for holding and transporting molds. The second transferring station can also be in the form of a star wheel having a plurality of radial arms having mold holders at their distal ends. The second transferring station is arranged such that the mold holders may receive molds from the closing station and such that the mold holders may release the molds to the mold unloading loading station. Alternatively, for example when no closing station is present, the mold holders of the second transfer means may receive the molds from the forming station. Preferably, the pitch of the second transferring station when receiving the molds is substantially similar to the pitch of the closing station or the forming station when releasing the molds. Preferably, the pitch of the second transferring station when releasing the molds is identical to the pitch of the mold unloading station receiving the mold. The transferring station may comprise means for increasing the pitch between successive molds. A suitable means for increasing the pitch is an actuator moving the arms of the star wheel such that the pitch to the preceding mold is increased. For example the arms may be rotated around the same central rotational axis as the wheel of the transferring station, thereby increasing the angular distance between two successive molds. After releasing the mold to the mold unloading station, the pitch between the two successive molds holder may be reduced again, preferably by the same means, so that the pitch is adjusted again for receiving the molds from the closing station or the forming station.

In the following, the machine and process of the present invention are described with reference to more specific embodiments and the figures. It is to be understood that, while some features may be described only in connection with one embodiment, these features may be readily transferred to some or all embodiments of the invention.

FIGS.1and2show a machine for producing containers1, such as bottles, for example sterile or aseptic bottles containing water or carbonated water based drinks, starting from preforms2.

Each preform2may comprise a body4in the general shape of a tube of U-shaped longitudinal section, which is closed at one end and the other end of which already has the final shape of the neck6of the container1. InFIG.4, a preform2is shown, by way of non-limiting example, having a cylindrical body4extending along a substantially vertical axis A which coincides with the axis of the neck6. The lower end8of the body4is closed and has the general shape of a hemisphere, while the upper end of the preform2forms the neck6, which defines an inner opening10and which is, in this case, provided with an outer radial part, like a threading12, adapted to receive a lid or a cap14, for example by screwing. Below the neck, there is a circular flange13, that extends radially outwardly from the periphery of the preform2and is used to carry the preform or maintain it in the mold.

Successive preforms2are introduced in the machine and first undergo a step of heating in a thermal conditioning oven16, or heating station. In a conventional manner, the preforms2are successively loaded on a carrier18, forming a closed loop, circulating within the oven16. During the passage of the preforms2within the oven, the preforms are continuously heated up to a temperature compatible with its later transformation into a container1. Such an oven16and heating step are conventional in methods and machines for producing containers and will not be described in greater detail here.

At the outlet of the oven16, or in a variant of the preform production platform or of a treatment station, the preforms are transferred to a mold loading station20, via a transfer wheel22, only shown diagrammatically inFIG.1, adapted to pick up the preforms at said outlet and to carry the preforms2to the loading station20.

The loading station20comprises a wheel24, or carousel, shown in greater detail inFIG.6, movable in rotation around an axis B, substantially parallel to the axis A of the preform2, i.e. a substantially vertical axis B. The wheel24, carries a plurality of mold holders26distributed on the circumference of the wheel24and oriented radially towards the exterior of the wheel24. Each mold holder26is intended to receive a mold28for forming a container, as will be described hereunder.

As shown inFIGS.4and5, a mold28comprises two parts30movable relative to each other, between an opened configuration (FIG.4) and a closed configuration (FIG.5). The two parts30are for example hinged together and are movable in rotation relative to each other around an axis C substantially parallel to the axis A of the preform2. Each part30comprises a body31comprising a hollow recess32having the shape of a half bottle to be formed. According to the non-limiting example shown inFIG.4, the hollow recess32of one part30comprises a semi-cylindrical portion34, closed at its lower end by a bottom surface36having a the shape of a semi-circle, and terminated at its upper end by a tapered, then semi-circular opening38of a diameter substantially complementary to the half diameter of the body4of the preform2under the flange13, in order to maintain the perform below the flange13. The hollow recess of the other part30of the mold28is symmetrical to the hollow recess32described above.

Preferably, and in a well-known manner, not shown in the drawings, the part of the mold intended to form the bottom of the container1is not formed by the bottom surfaces36of the recesses32, but by a separate part, named base mold, which is longitudinally movable with respect to the above mentioned complementary parts when the mold is in the opened configuration, and contains the imprint of the container base. In that case, the hollow recess32does not have the shape of a half bottle to be formed but only that of the half wall part of the bottle, its bottom part being excluded.

In the opened configuration, the parts30of the mold28and the base mold when it is present are separated from each other such that a preform2can be introduced between the two parts30, as shown inFIG.4, and such that a previously finished container can be removed from the mold.

In the closed configuration, the two parts30are applied against each other, such that the hollow recesses32face each other and define together a mold cavity40having the shape of the container1to be formed. If a base mold is present, it is placed in a position such that, when the parts30are applied against each other, it contributes to achieve the shape of the container to be formed. The mold cavity40therefore comprises a cylindrical portion, defined by the semi-cylindrical portions34of the recesses32and intended to form the body of the container1, closed at its lower end by a circular bottom surface, formed either by the bottom surfaces36of the recesses32or by the base mold and intended to form the bottom of the container1, and terminated at its upper end by a collar, substantially complementary to part of the body4of the preform2. When the mold is closed, the preform2is held in the mold cavity40by the opening38of the mold cavity. The opening38holds the preform2just below the flange13provided under the neck6of the preform, which extends above the opening of the mold cavity40outside of said cavity, as shown inFIG.5. The mold cavity40is closed with the preform2extending inside the mold cavity. The inner opening10defined by the neck6of the preform2remains accessible as shown inFIG.4. The outer face42of the mold28is substantially cylindrical in the closed configuration.

According to the embodiment shown inFIGS.4and5, the outer face42of the mold28comprises a groove43extending all around the outer face42and forming a recess in the mold28. The groove43allows the mold28to be maintained at various places of the machine, as will be described below.

The mold28further comprises locking means44arranged to maintain the mold28in its closed configuration when the locking means are activated.

The locking means44comprise for example at least one ring46defining an inner opening48having a diameter substantially equal to the diameter of the outer face42of the mold28in its closed configuration. When the ring46is engaged around the mold28, the periphery of the inner opening48is applied against the outer face42of the mold and the ring46prevents the mold28from moving towards its opened configuration, as shown inFIG.5. By activating the locking means44, it is meant in this case engaging the ring46around the mold28.

According to the particular embodiment shown inFIGS.3to5, the locking means comprise an upper and a lower rings46and the outer face42comprises an upper and a lower areas50for respectively receiving the upper and lower rings46, the inner openings48of the lower and upper rings46having a diameter substantially equal to that of the upper and lower areas50. The upper area50extends from the upper end of the mold28, comprising the opening38, to a central area52having a diameter larger than the diameter of the upper area50, a shoulder54joining the central area52and the upper area50, as shown inFIG.4. Likewise, the lower area50, having the same diameter as the upper area50, extends from the lower end of the mold28to the central area52, with a shoulder54joining the lower area50and the central area52. When the upper ring46, respectively the lower ring46, is engaged on the upper area50, respectively the lower area50, for locking the mold28in its closed configuration, the upper ring46, respectively the lower ring46, comes into abutment against the shoulder54to retain the ring46around the mold28, as shown inFIG.5. The upper and lower areas50each further comprise a tapered area56, joining the upper area50, respectively the lower area50, to the upper end, respectively the lower end, of the mold28. The tapered areas56are arranged such that the diameter of the outer face42of the mold increases toward the upper and lower areas50in order to ease and to guide the engagement of the upper and lower rings46on the upper and lower areas50.

The locking means44described above are given by way of non-limiting example. The locking means44could be different, for example a retractable pin provided on one part30of the mold28and engaged in a corresponding housing on the other part in the closed configuration of the mold28or disengageable clipping means or any other appropriate disengageable locking means.

In each embodiment, the locking means44are carried by the mold28, at least when the mold is closed and locked.

The groove43is for example provided in the central area52, as shown inFIGS.4and5.

Each mold holder26of the loading station20is adapted to hold the mold28described above. To that end, each mold holder26comprises two jaws58movable relative to each other between an opened configuration, as shown by the mold holder26aofFIG.6, wherein a closed and locked mold28can be introduced between the jaws58, and a closed configuration, as shown by the mold holder26bofFIG.6, wherein the jaws58are brought closer to each other and wherein the mold28is retained between the jaws58. When the mold holder26moves from its opened configuration to its closed configuration, the mold holder26also moves the mold28it holds to its closed configuration if the mold28was in its opened configuration. When the mold holder26moves to its opened configuration, it can either also move the mold28to its opened configuration via appropriate connection between the mold holder26and the mold28or leave the mold28in its closed configuration, as will be subsequently described. The loading station20is arranged to actuate the mold holders26between their opened configuration and their closed configuration either via appropriate means provided on the mold holders or via one or several external actuators. The loading station20is also arranged to activate the locking means44of the molds28either via the mold holders26or via one or several external actuators. When the locking means44comprise rings46as described previously, the mold holders26or the external actuator(s) are arranged to engage the rings46on the molds28when said molds28are in their closed configuration to lock said molds in their closed configuration. The mold holders26or actuator(s) are also arranged to disengage the rings46in order to allow the molds28to be moved to their opened configuration. The mold holders26do not need to lock the molds in the closed configuration, since said locking is performed by the molds themselves. The structure of the mold holders can therefore be simplified and the mold holders can be made more compact, thereby making it possible to increase the number of mold holders on the wheel22.

Each mold holder26receives a mold28. The mold holder26and its mold28are in their opened configurations when they are opposite the transfer wheel22at the outlet of the oven16, as shown diagrammatically by mold holder26cinFIGS.1and3. The successive preforms2are loaded in successive molds28when said molds are located opposite the transfer wheel22and are in their opened configuration22. The loading of the preforms2is for example performed by a robot arm arranged to pick up a preform2from the transfer wheel22and to place said preform2in the opened mold28such that the body of the preform2extends in the mold cavity40.

According to a particular embodiment, at least one additional element can be loaded in the mold28prior or in parallel of the loading of the preform2. The additional element can, for example, be a label which is applied against part of the wall of the mold cavity40and which is intended to cover a part of the formed container1, in order to obtain a labeled container1at the outlet of the machine. The additional element could also be another functional or ornamental element to be glued or welded to the container, such as a handle or a grip portion. The shape of the mold cavity is then adapted to receive the additional element.

Prior to loading the preforms2, the mold cavities40can optionally be heated if needed for the forming process of the container. This is the case for example for containers intended to be filled with a hot or warm liquid or in order to maintain the preforms2at a temperature adapted for their forming into containers1. The heating can be performed by contact heat transfer or by powering an electrical power cartridge heater installed in the mold cavities40.

Once the preform2is loaded in the mold28, the mold28is moved to its closed configuration with the mold holder26holding it as shown by the mold holder26dinFIG.3. The locking means44are then activated to lock the mold28in its closed configuration as shown by reference26einFIG.3. Meanwhile, the wheel24of the loading station20rotates to place a subsequent mold holder26and its mold28opposite the transfer wheel and to allow a subsequent preform2to be loaded.

The closed mold holder26, containing a closed and locked mold28containing a preform2, and optionally an additional element, is moved by the wheel24to a transferring station60, where the mold holder26is opened as shown by reference26finFIGS.1and3. The mold holder26is moved to its opened configuration without opening the mold28, which remains closed and locked.

The transferring station60comprises a wheel61, movable in rotation around an axis substantially parallel to the axis A of the preform2, i.e. a substantially vertical axis, and comprising a plurality of imprints opened radially towards the exterior of the wheel61and arranged to each receive a closed mold28to move it in rotation. The molds28are for example guided towards the imprints of the wheel61by appropriate guiding means, such as rails and/or a conveyor (not shown), once they are released from the loading station20by the opening of the mold holders26. The molds are maintained in the imprints for example by an arcuate rail (not shown) extending around a part of the wheel61such that the molds28move in rotation with the wheel.

The imprints of the wheel61are for example each formed by a fork63and an abutment65, as shown inFIG.5. The fork63comprises two arms67and69extending substantially radially from the wheel61and spaced from each other by a distance substantially equal to the diameter of the groove43of the mold28. Therefore, the two arms67and69are able to hold the mold28vertically and radially when they are engaged in the groove43. At the transferring station60, each mold28is pushed toward the wheel61and the arms are naturally engaged in the groove43. The abutment65also extends radially from the wheel61and comprises a surface71having a shape substantially complementary of part of the outer face42of the mold28. When the fork63is engaged in the groove43, the outer face42of the mold28rests and the surface71, which holds the mold28axially, i.e. which prevents the mold28from being tilted in the wheel61.

The imprints described above are given by way of example and other means for holding the molds28vertically and radially on the wheel could be foreseen. It should be noted that the imprints are fixed relative to the wheel61and do not need to be actuated, which limits the space required for each imprint on the wheel.

At the transferring station60, the pitch, i.e. the distance, between two successive molds28is reduced by providing imprints that are closer from each other on the wheel61than the mold holders26of the loading station20. The pitch can be reduced because the molds28are no longer held by mold holders26which require space to allow the movement of the jaws58. By reducing the pitch between successive molds, it is possible to increase the throughput of the machine, without increasing the speed of rotation of the various wheels of the machine.

From the transferring station60, the molds28are moved to a forming station64comprising a wheel66, movable in rotation around an axis substantially parallel to the axis A of the preform2, i.e. a substantially vertical axis, and comprising a plurality of imprints68opened radially towards the exterior of the wheel66and arranged to each receive a closed and locked mold28to move it in rotation. The imprints68are for example each formed by a fork63and an abutment65, as described previously in relation with the transferring station60. The molds28are for example guided towards the imprints of the wheel61by appropriate guiding means, such as rails and/or a conveyor (not shown), when the molds28, in the transferring station60, are located opposite the wheel of the forming station64. The molds are maintained in the imprints for example by an arcuate rail (not shown) extending around a part of the wheel66such that the molds28move in rotation with the wheel.

The forming station64comprises means for injecting a gaseous or liquid fluid in the preforms2held by the molds28. Such means are known per se and will not be described in detail herein. In the case of hydraulic forming as shown in the drawings, the injecting means are for example arranged to inject water in the preforms2, which are deformed and acquire the shape of the mold cavity40, i.e. the shape of the containers1to be produced, as shown by references70and72inFIGS.1and3.

At the forming station64, the pitch between successive molds28is the same as in the transferring station60.

In the case of hydraulic forming, after the forming step, the molds28, now each containing a formed and filled container1, are moved to a closing station74.

According to the embodiment shown inFIG.1, the transfer to the closing station74is performed for example by an endless belt76forming successive imprints78and arranged to move the molds28in translation, as shown by arrow F ofFIG.1. The imprints78are for example each formed by a fork63and an abutment65, as described previously in relation with the transferring station60. In this case, the filled containers2exit the forming station64according to a direction tangential to the wheel66, which limits the acceleration imparted on the containers and prevents a brutal change in the centrifugal force imparted on the containers, thereby limiting the constraints applied on the containers and limiting the risks of spilling or of breakage of the containers.

According to the embodiment shown inFIG.2, the transfer is performed by a wheel77, movable in rotation around an axis substantially parallel to the axis A of the preform2, i.e. a substantially vertical axis, and comprising a plurality of imprints79opened radially to-wards the exterior of the wheel77and arranged to each receive a closed and locked mold28to move it in rotation. The imprints79are for example each formed by a fork63and an abutment65, as described previously in relation with the transferring station60. In this case, the machine is more compact and requires less space than the machine according to the embodiment ofFIG.1.

The closing station74comprises a wheel80, movable in rotation around an axis substantially parallel to the axis A of the preform2, i.e. a substantially vertical axis, and comprising a plurality of imprints opened radially towards the exterior of the wheel80and arranged to each receive a closed and locked mold28to move it in rotation. The imprints of the wheel80are for example each formed by a fork63and an abutment65, as described previously in relation with the transferring station60. The closing station74comprises means for screwing a lid or a cap14on the neck6of each container2protruding outside of the mold28. Such means are known per se and will not be described in detail herein.

Once the containers1are closed, the molds28containing the closed containers are moved to another transferring station82, which comprises a wheel84, movable in rotation around an axis substantially parallel to the axis A of the preform2, i.e. a substantially vertical axis, and comprising a plurality of imprints opened radially towards the exterior of the wheel84and arranged to each receive a closed mold28to move it in rotation.

The transferring station82is arranged to move the molds28to the loading station20, which also forms an unloading station for the containers1, as will be described subsequently.

At the transferring station82, the pitch between successive containers1is increased to correspond to the pitch between two successive mold holders26of the loading station20.

At the loading station20, once a mold holder26has moved to its opened configuration opposite the first transferring station60to release a mold28, it remains open and continues its rotation as shown by reference26ginFIG.1. The mold holder26in its opened configuration rotates until it is located opposite the second transferring station82where a mold28, containing a container1, is transferred between its jaws58, as shown by reference26hinFIGS.1and3. The mold holder26is moved to its closed configuration to retain the mold28, as shown by reference26iinFIGS.1and3.

The locking means44are then deactivated by the loading station20, i.e. the rings46are removed from the mold28in the embodiment shown in the figures, as shown by reference26jinFIG.3.

The mold holder26is then reopened, i.e. moved from its closed configuration to its opened configuration, along with the mold28retained by said mold holder26, i.e. the mold28also moves from its closed to its opened configuration as shown by reference26kinFIGS.1and2. The formed container1can then be retrieved from the mold28, for example by a robot arm at a transfer wheel86.

The mold holder26holding the mold28in its opened configuration continues its rotation until it is located opposite the transfer wheel22, where it receives a new preform2.

Optionally, at the loading and unloading station20, means for picking up a mold28can be provided in order to move a mold towards a cleaning station in case of accidental container leakage.

As described above, the preforms2and then the formed containers1are moved in the machine within a closed and locked mold28, the mold28being moved between the various stations of the machine. The preforms2and containers1are therefore no longer carried by their neck only and are thus not subjected to distortions or breakage. The preforms and containers within the molds28can sustain greater rotation speeds and centrifugal forces.

The mold loading and unloading station20is distinct from the forming station64. In other words, the forming station64is dissociated from the mold loading and unloading station20, which allows to reduce the pitch between successive molds28at the forming station and therefore to increase the throughput of this station at constant rotation speed. Furthermore, in the case of hydraulic forming, the containers are filled with the forming liquid outside mold holders26, which eliminates the risk of soiling the mold holder26, which are difficult to clean up, in case of spilling of the forming liquid.

The machine and method described above were given by way of example and various modifications can be foreseen in the machine.

The machine has been described for a hydraulic forming method of the containers. In case of compressible gas forming, the machine remains substantially identical, except that the forming station64is equipped with means for injecting gas, possibly with an axial stretching rod, in the containers1instead of liquid injecting means. Furthermore, a supplementary station is provided for filling the formed containers.

In the machine, the closing station is optional and closing of the containers can be performed outside the machine. In this case, the second transferring station82may be suppressed and the transfer of the molds28from the forming station to the unloading station20can be carried out by the first transferring station60. The machine enables the production of filled, capped and optionally labeled containers at a higher throughput than conventional machines, while limiting the risks of containers distortions, spilling and leakage.