Equipment for producing vessels comprising a variable pitch transfer wheel

An equipment (10) for producing vessels (12), includes at least one variable pitch wheel (38) arranged between a blower (14) having a first pitch (P1) and a filler (16) having a second pitch (P2), and that includes transfer elements (40) controlled by control elements adapted for selectively varying the pitch between two successive transfer elements (40) between an initial pitch (P) and a final pitch (P′), the initial pitch (P) being for example equal to once or twice the first pitch (P1) and the final pitch (P′) being equal to the second pitch (P2).

The invention relates to an installation for producing vessels comprising a variable-pitch transfer wheel.

The invention relates more particularly to an installation for producing vessels, in particular bottles, comprising at least:a vessel production unit comprising at least one vessel blower which comprises a plurality of blowing stations which are distributed circumferentially around an axis of rotation with a spacing corresponding to a first pitch between two consecutive stations,a filling unit, called filler, comprising a plurality of filling stations which are distributed circumferentially around an axis of rotation with a spacing corresponding to a second pitch between two consecutive stations, anda vessel transfer device comprising at least a transfer wheel which, interposed between the vessel blower and the filler, comprises a plurality of vessel transfer means distributed circumferentially around an axis of rotation, said transfer means being mounted to move in rotation along a travel executed in a loop between, upstream, a first region for loading each vessel obtained from the vessel blower and, downstream, a second region for unloading each vessel to the filler.

Numerous installations of this type are known for the production of hollow vessels in which the vessel blower and the filler are produced in the form of rotary machines generally comprising a carousel with their various stations distributed over the circumference thereof.

The blowing stations of the vessel blower are thus evenly distributed angularly with a first determined pitch over the circumference of the carousel and each of the blowing stations conventionally comprises a mold and associated blowing or stretching-blowing means which are each capable of transforming at least one preform previously heat treated in an oven into a desired final vessel.

Similarly, the filling stations of the filler are evenly distributed angularly with a second determined pitch over the circumference of the carousel and each of the filling stations comprises at least filling means, such as nozzles, which are capable of filling each of the vessels obtained from the vessel blower situated upstream in the production installation with a given product.

The characteristics of a unit, such as a filler or a vessel blower, are in particular determined according to the vessel to be produced and the product to be packaged in the vessel.

Thus, depending on the applications, each unit comprises a determined number of stations, for example blowing or filling stations, which determines the production capacity of the unit, which is generally expressed as a number of vessels per hour.

However, the maximum number of stations of a unit is dependent on its radius or diameter and the space required for the location of a station of a given footprint such that the abovementioned rotary machines are generally characterized by a determined pitch corresponding to the spacing between two consecutive stations.

The pitch between two stations can be expressed in different ways, notably by the value of the circular arc linking two consecutive stations or else by the angle at the center associated with such an arc, or even by the number of stations.

It will be recalled that the perimeter of a circle of radius R is equal to 2πR such that the length of the circular arc separating two stations is obtained by means of the formula: 2πRα/360; in which the angle α corresponds to the abovementioned angle at the center.

For example, a filler whose filling stations are evenly distributed over the perimeter of the circle with an angle α equal to 36° will have ten stations, such a filler then being said to be of the “36PI” type, whereas a vessel blower said to be of the “45PI” type of the same radius will, conversely, have only eight stations distributed with an angle α of 45°.

Obviously, the greater the radius, the greater the perimeter so that, for a given station footprint, a greater number of stations can be located with a smaller angle α between two consecutive stations.

In the state of the art, the vessel production installations generally comprise vessel blowing and filling units having one and the same pitch, that is to say that the first pitch of the vessel blower is equal to the second pitch of the filler.

Thus, each vessel produced at a given vessel blowing station can be transferred to and filled at a corresponding filling station, the spacing between two successive vessels then being constant throughout the production travel from the vessel blower to the filler.

The transfer device interposed between the vessel blower and the filler then comprises at least one transfer wheel intended to ensure the transfer of each vessel from the output of the mold of the blowing station to the filling station.

However, it is desirable in some cases to be able to associate a filler and a vessel blower that have different operating pitches so that the transfer device must then be able to ensure a transfer of the vessels from one to the other.

In the abovementioned example of a filler of 36PI type and a vessel blower of 45PI type, this makes it possible in particular to retain a first existing 45PI standard transmission wheel, to limit the footprint of the installation and more particularly that of the filler or else to choose for the production of a given vessel the production means that are absolutely necessary, in particular because of the costs of such an installation.

This is why it is known in the state of the art to provide a vessel production installation with a vessel transfer device comprising at least, interposed between the vessel blower and the filler, a transfer wheel, called a variable-pitch transfer wheel, comprising vessel transfer means which are mounted to move in rotation and distributed circumferentially around an axis of rotation, said transfer means being controlled independently of one another by associated control means which are capable of selectively varying the pitch corresponding to the spacing between two successive transfer means in a travel executed in a loop between, upstream, a first region for loading each vessel obtained from the vessel blower and, downstream, a second region for unloading each vessel to the filler, said transfer means being introduced in succession, on the one hand, into said first loading region with an initial pitch corresponding at least to the first pitch of the vessel blower to occupy a determined loading position and, on the other hand, into said second unloading region with a final pitch corresponding to the second pitch of the filler to occupy a determined unloading position.

To this end, the present invention proposes a vessel production installation of the type described previously, characterized in that the control means of each transfer means of the variable-pitch wheel comprise variable-length means which, intended to ensure the variation of the pitch between at least the initial pitch and the final pitch, comprise at least a first link rod and a second link rod which are linked together at one of their ends by a pivoting link, the other end of the first link rod being securely attached via a first pivot to rotational driving means and the other end of the second link rod being securely attached via a second pivot to the associated transfer means.

Advantageously, the variable-pitch transfer wheel makes it possible to associate, in one and the same production installation, units, such as a vessel blower and a filler, that do not have the same operating pitch, but without the implementation of such a variable-pitch transfer wheel being limited to this sole application.

Thus, it is also possible to ensure a total operating flexibility when, the units having or not having the same operating pitch, there is a desire more particularly to use only some of the blowing stations but all the filling stations.

Advantageously, the vessels are displaced in rotation between the first and second regions over a constant radius by the transfer means of the variable-pitch transfer wheel.

According to other characteristics of the invention:the control means comprise actuation means which, intended to selectively drive said variable-length means, comprise at least one roller which cooperates with a complementary guiding cam determining, in the loopwise travel of the transfer means, the variation of the pitch between the initial pitch and the final pitch of said transfer means relative to the transfer means directly preceding it in the direction of rotation of the variable-pitch wheel;the roller of the actuation means has an axis of rotation which is common with the pivoting axis of the pivoting link linking the first and second link rods of the variable-length means;the final pitch being less than the initial pitch, the cam comprises at least:a first cam section which, arranged upstream of the loading position and downstream of the unloading position, is capable of slowing down the transfer means traveling over it to increase the spacing between this transfer means and the transfer means directly preceding it in the direction of rotation of the variable-pitch wheel so that each transfer means is introduced in succession into the loading position with an initial pitch which, determined relative to the transfer means preceding it, is at least equal to the first pitch of the vessel blower, in particular equal to twice the first pitch, anda second cam section which, arranged upstream of the unloading position and downstream of the loading position, is capable of speeding up the transfer means traveling over it to reduce the spacing between this transfer means and the transfer means directly preceding it in the direction of rotation of the variable-pitch wheel so that each transfer means is introduced in succession into the unloading position with a final pitch which, determined relative to the transfer means preceding it, is equal to the second pitch of the filler;the vessel transfer device comprises, upstream, interposed between the vessel blower and the variable-pitch wheel, at least one first transmission wheel which, associated with the vessel blower, comprises first transmission means capable of unloading, from the blowing station, each vessel that is produced and of bringing said vessel into the first loading region of the variable-pitch wheel in order to transfer said vessel to the transfer means of the variable-pitch wheel positioned radially opposite;the vessel transfer device comprises, downstream, interposed between the variable-pitch wheel and the filler, at least one second transmission wheel which, associated with the filler, comprises second transmission means capable of unloading, from the second unloading region, each vessel that is transferred by one of the transfer means of the variable-pitch wheel and of bringing each vessel to one of the filling stations of the filler;the first transmission means of the first wheel are arranged with a constant spacing between two consecutive means, the value of which is equal to the first pitch of the vessel blower and the second transmission means of the second wheel are arranged with a constant spacing between two consecutive means, the value of which is equal to the second pitch of the filler;the initial pitch of the variable-pitch wheel is equal to twice the value of the first pitch of the vessel blower, so that a transfer means of the variable-pitch wheel is introduced synchronously into the loading position at a rate of one blowing station out of two of the vessel blowers or at a rate of one transmission means out of two of a first transmission wheel;the final pitch of the variable-pitch wheel is equal to the second pitch, so that a transfer means of the variable-pitch wheel is introduced synchronously into the unloading position to systematically transfer a vessel to each filling station or to each transmission means of a second transmission wheel.

By convention, in the following description and the claims, the terms “upstream” and “downstream” will be used in a nonlimiting manner to designate the general direction of circulation of the flow of vessels through the production installation.

FIG. 1shows an exemplary embodiment of an installation10for producing vessels12, such as bottles.

The installation10for producing vessels12comprises, in succession, a manufacturing unit comprising at least one unit (not represented) for heat treating preforms1made of plastic material associated with a vessel blower14and a filling unit16, called filler.

As is known, the heat treatment unit comprises at least one oven which, provided with heating means such as infrared radiation lamps, is intended to heat treat preforms1made of plastic material, for example of PET, in order to allow for their subsequent transformation by blowing or by stretching-blowing in the manufacturing unit or vessel blower14.

After having been heat treated, the preforms1are directly routed to the vessel blower14by a transfer device18which is interposed between the output of the oven and an input region E of the vessel blower14.

The transfer device18comprises, for example, an output wheel20provided with notches and an associated transmission wheel22.

The transmission wheel22comprises transmission means24intended, on the one hand, to remove in succession each preform1from a notch of the output wheel20in which the preform1is conventionally kept supported via its collar and, on the other hand, to transfer said preform1to the input region E of the vessel blower14in order to introduce said preform1into a mold26comprising at least one cavity in the form of the desired final vessel12.

Each transmission means24comprises handling means25which are arranged at a free end of the transmission means24and cooperate with the preform.

Each transmission means24is controlled selectively to grip or place the preform1, each transmission means24also being controlled to selectively perform a translational movement when gripping or placing a preform.

A transmission means24therefore operates, in succession, a first translational displacement to grip the preform on the output wheel20, a rotation to the input region E of the vessel blower14and a second translational displacement to place the preform in the mold so that the preforms are not displaced over a constant radius during the transmission.

The vessel blower14comprises a carousel having a plurality of blowing stations PS which are evenly distributed circumferentially around an axis of rotation O14.

Only a bottom portion of the vessel blower14and a portion of the blowing stations PS are represented.

More specifically,FIG. 1represents only three successive stations PS1, PS2and PS3in the output region S of the vessel blower14, output region S in which the manufactured vessels12are unloaded.

The blowing stations PS have a spacing between two consecutive blowing stations which is equal to a first pitch P1.

By convention, the term “pitch” hereinafter in the description designates the spacing between two stations or two transfer means but it could, in a totally equivalent manner, be considered as the spacing between two consecutive vessels12, for example the spacing between the vertical axes of the two consecutive vessels12taken as reference.

In the case of the vessel blower14, the first pitch P1corresponds to the circular arc linking two determined points each belonging to a blowing station PS, said circular arc being geometrically characterized by an angle “α1” represented at the center of the vessel blower14of radius R1.

Preferably, said determined points linked by the circular arc corresponding to a given pitch are points respectively merged with the main vertical orientation axis of the vessel12when a vessel occupies the blowing or filling station or the transfer/transmission means of a wheel of the transfer device28.

Thus, the cycle of transformation into a vessel12of the preform1is implemented in succession along the circular travel around the axis of rotation O14performed by each blowing station PS from the input region E, in which the loading is performed by the transmission means24of the transmission wheel22of the preform1previously heat treated in the oven, to the output region S.

Each blowing station PS is equipped with a mold26and associated blowing or stretching-blowing means (not represented) which are capable of transforming each preform1into a vessel12.

Preferably, each mold26is a portfolio-type mold produced in two or three parts and comprising a single cavity to form the vessel12.

The installation10comprises, downstream of the vessel blower14, the filling unit or filler16comprising a plurality of filling stations PR which are evenly distributed circumferentially around an axis of rotation O16.

The filling stations PR have a spacing between two consecutive filling stations PR which is equal to a second pitch P2corresponding to an angle “α2” between two consecutive filling stations PR or, in an equivalent manner, as explained previously, between two consecutive vessels12.

Each filling station PR is equipped with means for filling the vessels12which, obtained from the vessel blower14, are intended to be transmitted to it by a transfer device28.

The installation10therefore comprises a vessel transfer device28which is interposed between the vessel blower14and the filler16.

The transfer device28is intended, upstream, to successively unload each vessel12that is produced from the blowing station PS, or from one of the molds26, and to transfer this vessel12downstream for it to be loaded at a filling station PR of the filler16.

Preferably, the device28for transferring vessels12comprises at least one first transmission wheel30which is associated with the vessel blower14.

The first transmission wheel30comprises first transmission means32, such as arms, intended to successively unload each vessel12that is produced from the mold26to transfer it downstream.

As can be seen inFIG. 1, the spacing between the blowing stations PS1to PS3is equal to the first pitch P1.

Similarly, the first transmission means32of the first wheel30are arranged around an axis of rotation O1with a constant spacing equal to the first pitch P1between two consecutive means32.

The vessels12therefore have between them a first pitch P1at the output of the vessel blower14, which pitch P1is retained by the first transmission wheel30.

Preferably, the transfer device28comprises a second transmission wheel34which is associated with the filler16and which comprises second transmission means36.

The spacing between two consecutive filling stations PR of the filler16is equal to a second given angle α2, the value of the second angle α2corresponds to the second pitch P2which is different from the first pitch P1.

Preferably, the second transmission means36of the second wheel34are arranged with a constant spacing between two consecutive means36with a value equal to the second pitch P2.

Advantageously, the value of the second angle α2is less than the value of the first angle α1and the second pitch P2is less than the first pitch P1.

In order to provide each of the filling stations PR of the filler16with a vessel12, it is necessary to modify the value of the pitch between two successive vessels12, that is to say, in this case, to change from the first pitch P1to the second pitch P2.

Advantageously, the transfer device28comprises at least one transfer wheel38, called a variable-pitch transfer wheel, which is capable of modifying the value of the pitch between two consecutive vessels12in order for the vessels taken upstream with a first pitch P1to be transferred downstream with a second pitch P2.

For this, the variable-pitch wheel38comprises a plurality of transfer means40which are distributed circumferentially around an axis of rotation O and which are each provided at a free radial end with means42for holding a vessel12.

The transfer means40of the wheel38are independent of one another and are mounted to move in rotation around the axis O along a travel executed in a loop between a first region Z1for loading each vessel12obtained from the vessel blower14and a second region Z2for unloading each vessel12to the filler16.

Advantageously, the vessel transfer device28comprises at least said variable-pitch transfer wheel38which is interposed between the vessel blower14and the filler16.

Advantageously, the transfer means40of the variable-pitch wheel38are controlled independently of one another by associated control means44, said control means44being capable of selectively varying, in said travel, the value of the pitch corresponding to the spacing between two successive transfer means40, that is to say, between two consecutive vessels12, respectively between an initial pitch P and a final pitch P′.

Advantageously, the control means44are capable of selectively varying the value of the pitch so that the transfer means40are introduced in succession, on the one hand, to occupy a determined loading position in the first loading region Z1with an initial pitch P corresponding at least to the first pitch P1of the vessel blower14and, on the other hand, to occupy a determined unloading position in the second unloading region Z2with a final pitch P′ corresponding to the second pitch P2of the filler16.

The initial pitch P is therefore determined according to the vessel blower14and to the first pitch P1and the final pitch P′ according to the filler16and to the second pitch P2, the second pitch P2being less than the pitch P1when the filling stations PR are closer to one another than the blowing stations PS whose molds26require a greater space, in particular to enable them to be opened.

Preferably, the device28for transferring the vessels12comprises, from upstream to downstream, the first transmission wheel30, the variable-pitch wheel38and the second transmission wheel34.

The variable-pitch wheel38is interposed between the first transmission wheel30and the second transmission wheel34so that the first transmission wheel30is interposed between the vessel blower14and the variable-pitch wheel38and the second transmission wheel34is interposed between the variable-pitch wheel38and the filler16.

Each of the wheels30,34and38is positioned so as to present a portion which is tangential to the adjacent wheel or unit14,16in order to define common transmission or transfer regions in which the vessel12is loaded or loaded from one to the other.

As a variant, the transfer device28does not comprise first and second transfer wheels30,34but only a variable-pitch wheel38which is directly interposed between the vessel blower14and the filler16.

The first transmission wheel30is capable of bringing into the first loading region Z1each vessel12borne by one of its transmission means32, radially opposite the holding means42of a transfer means40of the variable-pitch wheel38located in the loading position in order to transfer said vessel12to it.

The second transmission wheel34comprises second transmission means36which are intended to successively load into the second unloading region Z2each vessel12transferred by the wheel38, from the first loading region Z1to said second unloading region Z2, with an automatic variation of pitch from the initial pitch P, which is, for example, equal to the first pitch P1, to the final pitch P which is equal to the second pitch P2.

After having completed such a loading of the vessel12, the second transmission wheel34continues its rotation until it arrives opposite the filler16, the vessel12then being loaded onto one of the stations PR of the filler16.

By virtue of the variable-pitch wheel38, it is possible in one and the same installation10to produce vessels12for the blowing14and filling16units to have mutually different pitches, and different numbers of stations.

Advantageously, the vessels carry out, from the vessel blower to the filler, a travel enabling them to be cooled before they are filled.

Preferably, cooling means (not represented) are positioned on the travel of the vessels which are successively conveyed by the first transmission wheel, the variable-pitch wheel and the second transmission wheel, in particular cooling means based on the projection of air or water targeting more particularly the bottom of the vessel so as to avoid the risk of it toppling over.

There now follows a description, according to the invention, of a preferred exemplary embodiment of the control means44of the transfer means40of the variable-pitch wheel38which are schematically represented inFIG. 2.

The control means44of each transfer means40of the variable-pitch wheel38comprise variable-length means which are intended to ensure the variation of the pitch between at least the initial pitch P and the final pitch P′.

Preferably, the variable-length means comprise at least one first link rod46and one second link rod48which are linked together at one of their ends by a pivoting link50.

The other end of the first link rod46is securely attached to rotational driving means52via a first pivot54while the other end of the second link rod48is securely attached to the associated transfer means40via a second pivot56.

The transfer means40is mounted to move in rotation at one of its radially internal ends about the axis of rotation O of the wheel38and comprises, at its other free end, holding means42for a vessel12.

Thus, the transfer means40and the means52intended to drive it rotationally are linked in displacement by the assembly of the articulated link rods46and48and the distance between the fixed points respectively formed by the first pivot54and the second pivot56can vary depending on the relative position of each of the link rods46,48.

The control means44comprise actuation means58which, intended to selectively drive said variable-length means46,48, comprise at least one roller60which cooperates with a complementary guiding cam62determining, in the loopwise travel of the transfer means40, the variation of pitch of said transfer means40relative to the transfer means40directly preceding it in the direction of rotation of the variable-pitch wheel38.

Advantageously, the roller60of the actuation means58has an axis of rotation which is common with the pivoting axis of the pivoting link50linking the first and second link rods46,48of the variable-length means.

The actuation means58are therefore designed to act on the means that form the link rods46and48in order to provoke the spacing or the convergence of the pivots54and56and thus vary the relative position of the transfer means40relative to the other transfer means40, that is to say, vary the pitch, in particular the spacing relative to the transfer means40preceding it and also supporting a vessel12.

Preferably, the cam62is configured to selectively ensure the variation of the pitch of the transfer means40when each transfer means40is driven around the axis of rotation O in said loopwise travel.

Advantageously, the cam62selectively ensures the variation of the pitch of the transfer means40so that the pitch of the transfer means40varies from the value of the initial pitch P to the final pitch P′ when the transfer means40travel over a section, called go section, of the cam62which extends from the loading position in the first region Z1to the unloading position in the second region Z2and, conversely, from the final pitch P′ to the initial pitch P when the transfer means40travel over a section, called return section, of the cam62which extends from the unloading position in the second region Z2to the loading position in the first region Z1.

Thus, since the value of the final pitch P′ is less than the value of the initial pitch P, the cam62advantageously includes at least a first cam section T1and a second cam section T2.

The first section T1of the cam62is arranged upstream of the loading position and downstream of the unloading position and the first cam section T1is capable of slowing down the transfer means40traveling over it to increase the spacing between this transfer means40and the transfer means40which, in the direction of rotation of the variable-pitch wheel38, directly precedes it.

This means that each transfer means40is successively introduced into the loading position with an initial pitch P which, determined relative to the transfer means40preceding it there, is at least equal to the first pitch P1of the vessel blower14.

The second section T2of the cam62is arranged upstream of the unloading position and downstream of the loading position and the second cam section T2is capable of speeding up the transfer means40traveling over it to reduce the spacing between this transfer means40and the transfer means40which, depending on the direction of rotation of the variable-pitch wheel38, directly precedes it.

This means that each transfer means40is successively introduced into the unloading position with a final pitch P′ which, determined relative to the transfer means40preceding it, is equal to the second pitch P2of the filler16.

Advantageously, the guiding cam62is borne by a circular deck mounted on the axis of rotation O of the variable-pitch wheel38so that the variation of pitch between the initial pitch P and the final pitch P′ is able to be easily modified by changing said deck including the cam62.

The actuation means58based on shape cooperation between a roller60and the cam62complementing one another that have just been described with reference toFIG. 2constitute only one possible exemplary embodiment for implementing the function for selectively varying the pitch by acting on the control means44.

As a variant, other actuation means58, such as electrical or electromechanical means in particular, can also be used to obtain the selective variation of the pitch between two successive transfer means40.

As a nonlimiting example, the actuation means58of the link with two articulated link rods46and48forming the control means44could be implemented by an actuator of electrical, hydraulic or pneumatic type controlling, for example, a rod designed to act on said control means44.

Preferably, the actuation means58act on the pivoting link50with two link rods46,48in order to selectively modify the position of the link rods between at least one first position corresponding to the initial pitch P and one second position corresponding to the final pitch P′.

Advantageously, the implementation of an intermediate transfer wheel38with variable pitch is in no way limited to the application described previously, namely allowing for the operation of units, such as a vessel blower and a filler, having a different station-to-station pitch.

In practice, an installation10should advantageously be multipurpose and allow for the production of different vessels, in particular the production of bottles with different volumes or shapes, for example equally with a value of 0.5 l and values of 1.5 or 2 l.

Consequently, to start the production of 1.5 l vessels for example after having produced 0.5 l vessels, modifications must first be made to the production installation10and its units14,16.

Advantageously, the filler16more often than not requires little in the way of modifications in order to fill vessels of different volumes or shapes.

Thus, when the filling station PS is in particular equipped with support means capable of holding the vessel12suspended by its neck in the filling position, it is then unimportant whether the body of the vessel extending vertically in the void under the support means is that of a small or large volume vessel.

However, the same does not apply to the vessel blower14for which major modifications must often be made before starting production of another vessel12.

It will be understood that the molds26for producing a vessel12of 0.5 l or of 1.5 l are not the same and that the blowing stations PS of the vessel blower14must then be adapted, in particular with new molds26mounted on the carousel.

Obviously, such is also the case when starting production of a new vessel12which, whether or not of the same volume, has a different shape obtained by means of a new mold26including the corresponding cavity and which is intended to be filled with another product.

It is with this logic concerning the improved flexibility of the installation10in mind that the variable-pitch wheel38described previously is advantageously applicable by offering wide flexibility of use.

In practice, sometimes there is a wish not to use all the blowing stations PS of the vessel blower14, but, for example, only half of them.

There may be various reasons for such a use of a reduced number of blowing stations PS.

Among these reasons, there are, for example, the search for an overall reduction in costs, such as the significant mold acquisition costs or the costs attributable to production downtime, with efforts then focused on reducing the time needed to make the requisite changes to the installation10in order to start production of a new vessel12.

Such will also be the case if the vessel blower deliberately operates in a degraded mode, that is to say, not at its maximum rate, in particular to allow for vessels of complex shapes to be blown.

Furthermore, the use of a reduced number of blowing stations PS can sometimes be partly compensated by an increase in the rate of operation of the vessel blower14, but within the limits of the maximum rate that the vessel blower can achieve.

However, in an installation10comprising a vessel blower14and a filler16having one and the same operating pitch and a transfer device according to the state of the art, the partial use of half the total number of blowing stations PS also results in only half the filling stations PR being used on the filler16.

Now, it is preferable for all the filling stations to be used to limit the risks of pollution of the stations that are not occupied by a vessel12.

By virtue of the variable-pitch wheel38, it is also possible to ensure total operating flexibility of the installation10when, whether or not the units14,16have the same operating pitch, there is a desire more particularly to use only some of the blowing stations PS but nevertheless all of the filling stations PR.

There now follows a description, by way of nonlimiting example, of such a particular application in which the transfer device38of an installation10for producing vessels12, similar to that ofFIG. 1, comprises at least one variable-pitch wheel38according to the invention.

Such an application in which the vessel blower14operates at a rate of one blowing station PS out of two is more particularly represented inFIGS. 1 and 3to10which successively illustrate the various steps thereof.

As can be seen inFIG. 1, the spacing between two consecutive blowing stations PS of the vessel blower14is equal to a first pitch P1corresponding here to an angle α1.

Preferably, to avoid the abovementioned risks of contamination of the unused filling stations, all the filling stations PR of the filler16are used and the spacing between two consecutive filling stations PR of the filler is equal to a second pitch P2corresponding to an angle α2.

In order to systematically transfer a vessel12to each filling station PR, the variable-pitch wheel38must be controlled synchronously for each transfer means40to follow the others in the unloading region with a final pitch P′ which is equal to the second pitch P2.

Preferably, the vessel12is here transferred, from the unloading region of the variable-pitch wheel38to the filler16, via one of the transmission means36of the second transmission wheel34.

As a variant, the vessel12is transferred directly to the filling station PR in the absence of such a second transmission wheel34.

In the present application example, the variable-pitch wheel38is capable of transferring each vessel12from the blowing station PS to the filling station PR by introducing, relative to the transfer means40preceding it in the direction of rotation of the wheel38, on the one hand a transfer means40in the loading position with an initial pitch P which is equal to twice the first pitch P1and, on the other hand, a transfer means40in the unloaded position with a final pitch P′ which is equal to the second pitch P2.

Advantageously in the particular application, the value of the initial pitch P therefore corresponds to twice the value of the first pitch P1in order for a transfer means40of the variable-pitch wheel38to be introduced synchronously into the loading position at a rate of one transmission means32out of two of the first transmission wheel30which corresponds to the use of one blowing station PS out of two of the vessel blower14.

FIG. 1illustrates the taking-over of a first vessel12which has just been produced at the blowing station PS3whose mold26, in this case of portfolio type, is opened to allow a first transmission means32of the first transmission wheel30to load said first vessel12.

In the present case, the mold26of the second blowing station PS2has no vessel12since no preform1has been introduced therein in the input region E, the second transmission means32following the first in the direction of rotation indicated by the arrows is therefore empty while the third transmission means32following the second will take charge of the second vessel12produced by the first blowing station PS1.

Preferably, the blowing station PS2has no mold26.

The transmission means32of the first transmission wheel30are driven in rotation around the axis of rotation O1about which they are evenly distributed with a determined pitch equal to the first pitch P1.

After loading of the manufactured vessels12, the transmission means32each continue their travel until they reach the first loading region Z1that the variable-pitch wheel38has in common with it and does so with a spacing between the transmission means32which remains constantly equal to the first pitch P1.

FIG. 3more particularly illustrates the arrival of the first transmission means32of the first transmission wheel30in the first region Z1in which a transfer means40of the variable-pitch wheel38is also positioned parallel and synchronously, in particular the holding means42of the means40are positioned around the vessel12.

The transfer means40then reaches the so-called loading position illustrated inFIG. 4, that is to say, the position in which the transfer means40and the transmission means32are situated radially opposite one another, the transfer of the first vessel12from one to the other taking place from the moment when this loading position is reached.

The transmission means32and the transfer means40continue their respective rotation just the same after having passed through the first region Z1of tangency between the wheels30and38, and the means32and40then separate respectively from one another as is illustrated byFIG. 5.

Advantageously, each transmission means32includes a portion which, supporting the vessel12, can pivot to accompany the operations of loading from the mold26and of unloading to the transfer means40of the variable-pitch wheel38.

Advantageously, guiding means64are arranged in the vicinity of the first region Z1of tangency between the wheels30and38to facilitate the release of the vessels to the transfer means40of the variable-pitch wheel38.

While the first transmission means32has released the first vessel12, now held by the holding means42of the transfer means40of the variable-pitch wheel38which continues its rotation to the unloading position downstream, the second transmission means32which, distant by a first pitch P1from the means32preceding it, is introduced in turn, although empty, into the first loading region Z1.

In the present application and asFIGS. 4 to 6illustrate in succession by comparison, the second transmission means32without any vessel12passes through the first loading region Z1without any transfer means40of the variable-pitch wheel38appearing opposite, by default such a transfer means40would have no vessel12and all the filling stations PS would not each be loaded with a vessel12.

This is why the actuation means58of the control means44will act in succession on the variable-length means consisting of the two link rods46and48in order to provoke, in succession, a slowing down of the transfer means40so that it is introduced into the loading position with an initial pitch P which, since it is equal to twice the first pitch P1, ensures its synchronization with the third transmission means32of the second transmission wheel30including the second manufactured vessel12obtained from the mold26of the first blowing station PS1.

For this, the cam62includes at least a first cam section T1which is arranged upstream of the loading position and downstream of the unloading position.

The first cam section T1is capable of slowing down the transfer means40whose roller60travels over the first section T1of the cam62to increase the spacing between this transfer means40and the transfer means40, in the direction of rotation of the variable-pitch wheel38, directly precedes it.

Because of this, the transmission means32which is empty passes through the first region Z1and the transfer means40which succeeds the transfer means40having taken charge of the vessel12from the blowing station PS3will advantageously be slowed down to be synchronized with the next transmission means32which includes the next vessel12from the first blowing station PS1, which is more particularly illustrated inFIGS. 7 and 8.

The actuation means58of the variable-length means of the wheel38are therefore configured so that each transfer means40is introduced in succession into the loading position with an initial pitch P which, determined relative to the transfer means40preceding it, is equal to twice the first pitch P1for the present particular application.

As illustrated inFIG. 8, since the initial pitch P is equal to twice the first pitch P1, the transfer means40is introduced into the loading position synchronously with the transmission means32including the second vessel12.

The transfer of the vessel12from one to the other is performed as described previously for the vessel12from the blowing station PS3.

After the transfer, the variable-pitch wheel38therefore has two vessels12supported respectively by the holding means of a transfer means40, the two transfer means40following one another with a spacing between them which is substantially equal to the initial pitch P, therefore to twice the first pitch P1.

Now, in order to transfer each of these vessels12to one of the filling stations PR of the filler16, the transfer means40supporting the vessels12must be brought into the second unloading region Z2of the wheel38with a final pitch P′ between them which is equal to the second pitch P2corresponding to the spacing between two successive filling stations PS.

Since the value of the final pitch P′ is in this case less than the value of the initial pitch P, the transfer means40in second position must be speeded up to catch up with the one preceding it and obtain a spacing between them which is equal to the second pitch P2.

For this, and as illustrated inFIG. 9, the actuation means58will again act on the variable-length means formed by the link rods46and48so as to obtain the change of pitch, from the initial pitch P equal to twice the pitch P1to the final pitch P′ equal to the second pitch P2.

For this, the cam62includes a second cam section T2which is arranged upstream of the unloading position and downstream of the loading position.

The second cam section T2is configured so that, when the roller60of the transfer means40in second position travels over it, an acceleration occurs which is designed to reduce the spacing with the transfer means40preceding it and therefore a reduction of the pitch to the value of the final pitch P′ equal to the second pitch P2.

The second cam section T2is therefore capable of speeding up the roller60of the associated transfer means40traveling over it to reduce the spacing between this transfer means40and the transfer means40which, in the direction of rotation of the variable-pitch wheel, precedes it.

Because of this, each transfer means40is introduced in succession into the unloading position with a final pitch P′ which, determined relative to the transfer means preceding it, is equal to the second pitch P2of the filler16.

Preferably, since the transfer device28comprises a second transmission wheel34, the vessels12are—as illustrated in FIG.10—transferred to the holding means36of the second transmission wheel34, which wheel34will then transfer each of the vessels12, received with a pitch equal to the second pitch P2, to each of the filling stations PR which will then be occupied by a vessel12.

Advantageously, the cam62is configured to selectively ensure the variation of the pitch between the transfer means40when each transfer means40is driven around the axis of rotation O according to said loopwise travel and more specifically so that the pitch of the transfer means varies from the value of the initial pitch P to the final pitch P′ when the transfer means40travel over a portion, called go portion, of the cam62which, extending from the loading position in the first region Z1to the unloading position in the second region Z2corresponding to the second section T2and, conversely, the pitch of the transfer means40varies from the value of the final pitch P′ to the initial pitch P when the transfer means40travel over a portion, called return portion, of the cam62which, extending from the unloading position in the second region Z2to the loading position in the first region Z1, corresponds to the first cam section T1.

The driving means52are displaced around the axis of rotation O of the variable-pitch wheel38at a constant speed so that the speeding up or slowing down undergone by each transfer means40to obtain the desired pitch is only due to the control means44, in this case to the displacement of the roller60in the corresponding sections T1, T2of the guiding cam62which form the actuation means58acting on the variable-length means46,48.

The invention relates to a variable-pitch wheel38for an installation10for producing vessels12, said variable-pitch wheel38, which is interposed between a vessel blower14having a first pitch P1and the filler16having a second pitch P2, comprising transfer means40controlled by control means44capable of selectively varying the pitch between two consecutive transfer means40between an initial pitch P and a final pitch P′, the initial pitch P being, for example, equal to or twice the first pitch P1and the final pitch P′ equal to the second pitch P2.