Patent Description:
Devices for unloading and storing preforms for the production of containers made of plastics are known which are usually constituted by a cooling plate that defines a plurality of receptacles arranged in a matrix and intended to accommodate respective still-hot preforms for the time required to cool them down at least partially.

Typically, these preforms are fed directly by the injection press to the cooling plate and remain in the respective receptacle for a preset time.

Specifically, once the injection process has ended, the mold opens and the cooling plate is moved toward the preforms partially accommodated in one of the two mold parts so that the receptacles can engage respective portions of preforms that emerge from the mold part in order to extract them therefrom so as to allow the mold to close and allow a new molding cycle.

The unloading of the preforms from the cooling plate occurs following an action of expulsion by pushers arranged at the bottom of the receptacles.

Following expulsion from the cooling plate by the pushers, the preforms by then already at least partially cooled fall by gravity onto a conveyor belt, which then makes them fall, again by gravity, into a container.

The solution described above, despite being widely used, is not however free from drawbacks.

First of all, the preforms, despite having undergone a certain cooling, still have some of their portions, typically the bottom one, that are not perfectly rigid, and accordingly the falls can cause localized deformations.

Moreover, the fall by gravity inside the container causes a random arrangement of the preforms that reduces in practice, the quantity of preforms that can be placed in each container.

<CIT>discloses a plastic preforms moulding device and process comprising an injection mould, containing a plurality of injection cavities, an arm for extracting the preforms from the mould, equipped with guillotine-like gripping elements, which moves between the existing space between the half moulds when in the open position in order to grasp the preforms and the external position, a cooling turret, with the faces housing a group of cups for the conditioning of the preforms, which effects a rotational movement around a horizontal axis and a vertical translation movement between the high position under the extraction arm to receive the preforms and the low position corresponding to the extraction table of the preforms, on which are indented longitudinal slots with teeth shaped constrictions in order to grasp the preforms under the ring and to extract them from the cups.

The aim of the present invention is to eliminate, or at least reduce drastically, the drawbacks described above.

Within this aim, an object of the invention is to provide a device for unloading and storing preforms for the production of containers made of plastics that allows to unload, in an extremely practical and effective manner, the preforms from the cooling plate into the containers.

Another object of the invention is to provide a device for unloading and storing preforms for the production of containers made of plastics that allows to accommodate, inside the containers, a greater number of preforms.

This aim and these and other objects that will become better apparent hereinafter are achieved by a device for unloading and storing preforms for the production of containers made of plastics according to the provisions of claim <NUM>.

Further characteristics and advantages of the invention will become better apparent from the description of some preferred but not exclusive embodiments of a device for unloading and storing preforms for the production of containers made of plastics according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:.

The present invention refers to a device, generally designated by the reference numeral <NUM>, for unloading and storing preforms <NUM> for the production of containers made of plastics.

The unloading and storage device <NUM> comprises at least one cooling plate <NUM>, which defines a plurality of receptacles <NUM> for respective preforms <NUM>.

The device <NUM> is provided with means for transferring the still-hot preforms from an injection molding device, not shown in the figures, to the cooling plate <NUM>.

According to the present invention, the device <NUM> comprises pick-up means <NUM>, which are adapted to pick up the preforms <NUM> from the cooling plate <NUM> and place them inside at least one accommodation container <NUM>.

At the practical level, the pick-up means <NUM> can comprise a robot selected, for example, among:.

According to a practical embodiment, the pick-up means <NUM> comprise at least one Cartesian robot <NUM> (as shown in <FIG>).

Advantageously, as shown in <FIG>, the pick-up means <NUM> comprise an anthropomorphic robot <NUM>.

The pick-up means <NUM> comprise a plate <NUM> that supports a plurality of supporting bodies <NUM> for a respective preform <NUM>.

With reference to the embodiment shown in the figures, the supporting bodies <NUM> comprise respective protrusions that are extended substantially at right angles to the plate <NUM>.

In order to allow the unloading of the preforms <NUM>, the protrusions are associated with at least one pusher body <NUM> to unload the preforms from the respective supporting body <NUM>.

This or these pusher bodies <NUM> is/are movable, on command, substantially at right angles with respect to the direction of extension of the protrusions in order to abut against a portion of the preforms <NUM> and disengage them from said protrusions so as to allow their placement inside the accommodation container <NUM>.

Conveniently, during the preform unloading step the plate <NUM> is arranged substantially parallel to the bottom of the accommodation container <NUM>.

According to a particularly important aspect of the invention, the pick-up means <NUM> are adapted to unload the preforms <NUM> in an orderly manner into the accommodation container <NUM>.

By way of example, the means for transferring the still-hot preforms from the injection molding device to the cooling plate <NUM> comprise a device for moving the cooling plate <NUM> with respect to the molding device in order to pick up directly the still-hot preforms from the molding device in the open condition.

In particular, the injection molding device is constituted by a first mold part and a second mold part which can move with respect to each other between a closure position, in which they cooperate in order to define cavities that correspond to the shape of the preform <NUM>, and an opening position, in which the still-hot preforms <NUM> obtained by the injection process protrude at least partially from the first mold part so that they can be picked up from the receptacles <NUM> defined on the cooling plate <NUM>.

In order to allow the preforms <NUM> to cool down enough, the cooling plate <NUM> is provided with a plurality of series or arrays of receptacles <NUM> that are mutually spaced in a manner that corresponds to the position of the preforms <NUM> obtained by the injection molding device.

Obviously, the supporting bodies <NUM> also are arranged on the plate <NUM> in a manner similar to the series of receptacles <NUM>.

Advantageously, the device <NUM> according to the invention provides for the possibility that at least the container or containers <NUM> are arranged within a confinement region <NUM> in which a pressure that is higher than atmospheric pressure is provided.

This pressure higher than atmospheric pressure is, for example, obtained by means of a device <NUM> for injecting and withdrawing air, advantageously filtered, in and from the confinement region <NUM>.

By keeping the containers <NUM> (and therefore the preforms <NUM> accommodated therein) in a confinement region <NUM> with pressure higher than atmospheric pressure the risk that dirt and/or impurities might in some way contaminate the preforms is reduced substantially.

Advantageously, the confinement region <NUM> comprises at least one opening that can be crossed by the pick-up means <NUM> during the operations for storing the preforms <NUM> in the container <NUM>.

Conveniently, the opening is closed by an air curtain generated by a device <NUM> for producing an air flow.

With reference to the embodiment shown in <FIG>, the confinement region <NUM> accommodates the container or containers <NUM>.

As an alternative, as shown in <FIG>, the confinement region <NUM> accommodates the container or containers <NUM> and the pick-up means <NUM>.

According to a further embodiment shown in <FIG>, the confinement region <NUM> accommodates the container or containers <NUM>, the pick-up means <NUM> and the cooling plate <NUM>.

In some cases, the confinement region can have an opening that can be closed by means of a device other than an air curtain, such as for example a shutter device.

With reference to the constructive variation shown in <FIG>, the device <NUM> can have means <NUM> for separating at least one container <NUM> from the confinement region <NUM>.

Specifically, the separation means <NUM> are intended to separate the accommodation region of the container <NUM>, when it is full, from the confinement region <NUM>, so that its pick-up and replacement with a container <NUM> to be filled does not contaminate the confinement region <NUM>.

By way of example, the separation means <NUM> can comprise at least one upper partition <NUM>, which can be moved, on command, in order to arrange it above the access opening of the full container <NUM>.

Advantageously, the separation means <NUM> have only one upper partition <NUM>, which can move on a substantially horizontal plane in order to be arranged, in each instance, above the access opening of the container <NUM> to be unloaded.

Preferably, the separation means <NUM> have lateral partitions <NUM>, <NUM>.

Advantageously, there is at least one vertical dividing partition <NUM> arranged between the containers <NUM>: conveniently, the vertical dividing partition <NUM> is fixed.

Preferably, there is at least one fixed or movable vertical partition <NUM> for lateral closure, and an access door <NUM>, which is preferably associated with a respective container <NUM> and can be opened in order to be able to access the container to be unloaded when the fixed or movable partitions are arranged so as to isolate such container from the remaining part of the confinement region <NUM>.

The separation means <NUM> can be associated, obviously, also with devices <NUM> that have different types of confinement regions <NUM> such as, for example, the ones shown in <FIG> and <FIG>.

Moreover, it is noted that in some embodiments the separation means <NUM> can define the shutter device intended to close the opening of the confinement region <NUM>.

According to a further aspect, the present invention relates to a device <NUM> for unloading and storing preforms <NUM> for the production of containers made of plastics.

The device <NUM> comprises at least one cooling plate <NUM> that defines a plurality of receptacles <NUM> for respective preforms <NUM> and means for transferring the still-hot preforms from an injection molding device to the cooling plate <NUM>.

The device <NUM>, moreover, is provided with a device for transferring the preforms <NUM> from the cooling plate <NUM> to the container <NUM>.

Such transfer device can comprise the pick-up means <NUM> described previously or a traditional device comprising, for example, belt conveyors.

Advantageously, the device provides for the possibility that at least the container or containers <NUM> is/are arranged within a confinement region <NUM> in which a pressure higher than atmospheric pressure is provided.

Such pressure higher than atmospheric pressure is, for example, obtained by means of a device <NUM> for injecting and extracting air, advantageously filtered, in and from the confinement region <NUM>.

By keeping the containers <NUM> (and therefore the preforms <NUM> accommodated therein) in a confinement region <NUM> with a pressure higher than atmospheric pressure, the risk that dirt and/or impurities might in some way contaminate the preforms is reduced substantially.

Advantageously, the confinement region <NUM> comprises at least one opening that can be crossed by the transfer device during the operations for storing the preforms <NUM> in the container <NUM>.

Conveniently, the opening is closed by an air curtain generated by an air flow generation device <NUM>.

Specifically, the separation means <NUM> are intended to separate the accommodation region of the container <NUM>, when it is full, from the confinement region <NUM>, so that its pick-up and replacement with a container <NUM> to be filled do not contaminate the confinement region <NUM>.

By way of example, the separation means <NUM> can comprise at least one upper partition <NUM>, which can move, on command, in order to be arranged above the access opening of the full container <NUM>.

Advantageously, the separation means <NUM> have a single upper partition <NUM>, which can move on a substantially horizontal plane in order to be arranged, in each instance, above the access opening of the container <NUM> to be unloaded.

Preferably, there is at least one fixed or movable vertical lateral closure partition <NUM> and there is an access door <NUM>, which is preferably associated with a respective container <NUM> and can be opened in order to be able to access the container <NUM> to be unloaded when the fixed or movable partitions are arranged so as to isolate said container from the remaining part of the confinement region <NUM>.

The separation means <NUM> can be associated, obviously, also with devices <NUM> that have different types of confinement regions <NUM>, such as, for example, the ones shown in <FIG> and <FIG>.

Operation of the device <NUM> according to the invention is evidently clear from what has been described above.

In particular, at each molding cycle of the preforms by the injection molding device, the cooling plate <NUM> is arranged at the mold part that accommodates part of the still-hot preforms in order to transfer them into the series of receptacles <NUM>.

While the molding device performs a new preform molding cycle, the cooling plate <NUM> moves away from said molding device and the pick-up means <NUM> proceed to pick up, from a series of receptacles <NUM>, the respective preforms <NUM> in order to deposit them inside the accommodation container <NUM>.

The cooling plate <NUM> is thus moved again near the molding device so that the series of receptacles, now emptied of the preforms, can receive the freshly formed preforms.

The devised solution allows a more orderly unloading of the preforms <NUM>.

Moreover, the device according to the invention allows to reduce substantially the number of falls, rebounds and scrapings, or in any case of potential opportunities for damage to the preform independently of the temperature, with respect to the solutions commonly used with belt conveyance.

Traditional systems in fact entail a first fall onto a conveyor belt, the transfer of the preforms stacked thereon with the various preform-preform and/or preform-conveyor belt frictions, and also the last conveyor belt- and/or preform-conveyor belt frictions, and also the last conveyor belt-storage container fall, which in traditional solutions can be improved only with the use of a further machine (soft drop) that "guides" the last fall of the preforms by entering the storage container with a sort of bucket.

The device according to the invention eliminates, moreover, one "handling" since with a single pass the preforms are transferred directly from the cooling plate to the container, with a clear reduction of the risk of damaging the preform.

Moreover, the release of the preforms within the container is far "gentler" than known solutions, since it is possible to enter the container directly with the plate that supports the preforms.

The individual characteristic presented with reference to general teachings or to particular embodiments can be all present in other embodiments or can replace characteristics in these embodiments.

In practice, the materials used, so long as they are compatible with the specific use, as well as the shapes and dimensions, may be any according to requirements.

All the details may further be replaced with other technically equivalent elements.

Claim 1:
A device (<NUM>) for unloading and storing preforms (<NUM>) for the production of containers made of plastics, comprising at least one cooling plate (<NUM>) that defines a plurality of receptacles (<NUM>) for respective preforms (<NUM>) and means for transferring the still-hot preforms from an injection molding device to said cooling plate (<NUM>), and pick-up means (<NUM>) adapted to pick up said preforms (<NUM>) from said cooling plate (<NUM>) and to place them inside at least one accommodation container (<NUM>), characterized in that said pick-up means (<NUM>) comprise a plate (<NUM>) that supports a plurality of supporting bodies (<NUM>) for a respective preform (<NUM>) wherein said supporting bodies (<NUM>) comprise respective protrusions that are extended substantially at right angles with respect to said plate (<NUM>).