It is known in the prior art to form cylindrical containers from liquid packaging board, which cylinders comprise a cylindrical sidewall blank generally situated in a vertical position, formed by fixing together the vertical opposite sidewall margins of the heat-seal-coated blank, and of end members closing the blank at the top and at the bottom, the upper member being provided with an opening which is closed, for example, with a closure cap or a closing flap. Said containers are used for sterile and airtight packaging of various beverages.

The container into which the stored material such as a beverage is fed at a later stage is automatically formed in the container-forming unit, which consists of a series of mandrels, so-called wrapping mandrels, around which the sidewall blank is formed by wrapping. The mandrels are arranged in a rotating structure transferring the mandrels between different processing stations, at which one particular operation is carried out at a time, producing by stages a container- shaped casing, which is removed from the mandrel at the last processing station and conveyed to the filling unit for filling and closing.

The publication EP 456011 is used as a reference for the state of the art. In this publication, such a packaging machine is characterised in that casings are transferred from the casing-forming stage to the next operational stage on a

conveyor on which the casings are placed in succession in a vertical position. Particularly when the objective is to obtain a high-speed container-forming apparatus, the transfer stage in question is process-technically problematic if carried out according to the publication EP 456011. Firstly, the casing is removed from the mandrel in a substantially horizontal position, whereafter the casing has to be turned into a vertical position and placed in a vertical position on the moving conveyor track. The above-mentioned turning motions for bringing the casing onto the conveyor track are very difficult to carry out if high-speed and operationally reliable mass production is the objective. On the other hand, the operating speed of the conveyor track must remain accurate in order to allow the casings to be placed on the track's support without disturbances and to transfer the casings in succession to the next operational stage. Consequently, the state-of-the-art solution for transferring the casings is both technically complex and apt to cause production breakdowns in continuous production.

In US Patent 4318703, a casing transfer turret is presented, wherein a casing is transferred by air impingement from the container-forming unit's mandrel into a pocket of the turret, which turns and lifts the casing up to an upright position, the same position in which it is pushed onto the conveyor leading to the next processing stage. In US Patent 4100842, a tube is presented, into which the casing is ejected from a cup-like groove by means of compressed air introduced into the bottom of the groove. The casings advance in the tube with their open ends first and land in a stack, with the open ends down.

The aim of the present invention is to remedy the above-mentioned defects related to the state of the art and to simultaneously raise the level of technology in such processes carried out in connection with packaging machines in which container forming and container filling and sealing are to be linked to form successive operational stages. To realise these aims, the method according to the invention is mainly characterised in that the casings are transferred in succession onto the conveyor track leading to the next operational stage substantially in the direction of the longitudinal axis of the sidewall blank for the casing, so that at the end of the

transfer, the casings land in succession on the conveyor track leading to the next processing stage. The essential advantage achieved by the method according to the invention is that the whole of the transfer motion of the casings to the next operational stage can be carried out by simple control measures as a direct continuation of the release motion which takes place on the mandrel, and that the transfer motion in the direction of the casings'longitudinal axis takes them directly onto the conveyor track for the next operational stage, where they begin to advance successively in the direction of transfer of the conveyor track towards the next processing stage.

In an advantageous embodiment the casing is placed at the transfer stage so that its end member is before the sidewall blank in the direction of transfer. This solution gives advantages, especially in those applications where the casing is placed in the filling position at the end of the transfer stage, preferably in an upright position with the end member down, because with the end member first in the direction of transfer, the filling position can be achieved simply.

Especially advantageous is an embodiment where the transfer energy directed towards the casing is generated by a gaseous transmission medium, in which case it is extremely advantageous to connect the mandrel and the next stage of the process by means of the flow passage for the gaseous transmission medium.

Other preferred embodiments of the method according to the invention are presented in the accompanying dependent claims.

Another aim of the invention is to produce a packaging machine which allows a simple transfer of the casings to the next unit, in particular to the filling and closing unit. Accordingly, the packaging machine is characterised in that the conveyor track between the container removal station and the subsequent unit is arranged to direct the casings in succession, substantially in the direction of the longitudinal axis of the casing sidewall blank, and to deliver them in the next unit onto the conveyor track leading to the first processing stage.

The conveyor track is preferably the flow passage for the gaseous medium, in which both the transfer and the feeding of the casings into the passage can be performed by using the force caused by the pressure and the flows of the gaseous medium.

Other preferred embodiments of the packaging machine according to the invention are presented in the accompanying dependent claims.

The invention is further illustrated in the following explanation referring to the embodiment presented in the accompanying drawings, wherein FIG. 1 is a vertical cross-section of the casing formed in the container-forming unit, FIG. 2 is a view of the container-forming unit seen from above, FIG. 3 is a view seen from direction III of FIG. 2 of the embodiment of the method according to the invention for the container-forming unit, FIG. 4 presents a vertical section of part IV in FIG. 3 to clarify the ejector embodiment according to FIG. 3 and to illustrate the removal of the casing, FIG. 5 is a side view of a preferred embodiment according to the invention, FIG. 6 is a view from above of the embodiment of FIG. 5, and FIG. 7 presents a vertical section of part Vil in FIG. 5 to clarify the embodiment according to FIG. 5.

Here the following terms are used to refer to the different parts of the liquid container :

-Container : a sales package or a casing depending on the context -Sales package: a finished and a closed liquid container filled with the contents -Casing : an unfilled and unclosed outer shell of a sales package -Can : a container characterised in having a portion, namely a sidewall blank, wrapped to form a closed structure in the cross-section perpendicular to the longitudinal axis, having one or both ends closed with an end member -Container blank: a straight, plane piece, generally made of liquid packaging board, which is joined to form a casing, and which can be separated from a material with a larger surface area, such as a long strip -Outer surface of a blank or blank material: a surface forming the surface of a finished container visible outwards and generally being printed and having a heat seal coating -Inner surface of a blank or blank material: a surface forming the surface of the finished container in contact with the container contents and generally having a heat seal coating -Blank material: raw material of blanks, generally liquid packaging board coated with a heat seal coating The packaging machine contains a container-forming unit in which is formed the can-shaped vertical portion presented in FIG. 1, the horizontal section of which forms a closed shape, that is a sidewall blank O, to which is fixed the end member P closing its open end. The thus formed can-shaped container with one end still open is transferred to the filling unit of the packaging machine, where the finished sales package is formed, and which is not described here in more detail.

The container-forming unit presented in FIG. 2 contains a horizontally revolving transfer table 1, on the perimeter of which there are forming parts at fixed angular intervals from one another, supporting the above-mentioned container at its different forming stages. The forming parts are identical, each consisting of a vertical mandrel 2 around which the sidewall blank for the casing is formed, and which hereafter will be referred to as a wrapping mandrel.

In addition to the transfer table 1, the container-forming unit also contains a fixed frame to which the table is arranged to rotate and which is referred to overall by the reference number 10. There are as many processing stations on the frame as there are wrapping mandrels 2, on each of which a single stage of forming the can open at one end is performed. At the stopping points, when the processing stations carry out certain operational stages, the mandrels are at the processing stations, and at the transfer stage the mandrels advance by a short rotational movement equal in length to the angular distance between the wrapping mandrels 2 to the next station for the next processing stage.

In the following, the different processing stations are described in more detail on the basis of their function in the forming of the can-shaped casing. At every station there are parts attached to the frame 10, which as a result of their motion or other activity, bring about the desired operational stages. The moving parts are situated on the frame mainly outside the circular track of the wrapping mandrels and/or above the mandrels or they are situated temporarily on the mandrels'track and transferred out of the mandrels'way during the transfer stage. In FIG. 2, these different parts are not presented in more detail, but the different stations' supporting structures, to which the functional parts are attached, are presented.

At wrapping station A, a blank of fixed height is cut from the lower end of the blank web L transferred to the station by means of transfer devices attached to the frame, whereafter the blank is pushed to the wrapping mandrel 2 and wrapped around it into the shape of the outer surface of the mandrel. In this way the sidewall blank for the can-shaped casing is formed, the blank having a closed

shape in horizontal section, a round shape when the mandrels are cylindrical.

At the sidewall sealing station B, the blank's vertical sidewall margins placed on top of one another at the wrapping station are sealed together permanently. This is done with a pusher surface which presses together the overlapping margins and simultaneously cools the heat seal coating on the blank's inner surface, which has previously been heated to bonding temperature.

At preheating station C, hot air is blown into the side-sealed part at the top end, causing the heat seal coating at the same point on the blank material's inner surface to heat up to a suitable temperature.

At the end member station D, end members corresponding in outline to the sidewall blank's horizontal section are die-cut from the continuous blank web M fed to the station, whereafter one member at a time is forced through a hole, simultaneously bending the outer edges. Then the member is pushed down into the sidewall blank's open top end using the wrapping mandrel's top surface as a counter-surface, pressing the member's folded-up outer edges against the inner surface of the sidewall blank.

At the first heating station E, hot air is blown onto the end member's outer surface directing it towards the edges, causing the member's lower surface to heat up at the edge folded up towards the inside of the top end of the sidewall blank.

At the second heating station F, the same procedure is performed to assure sufficient heating on the whole perimeter of the top end.

At the clenching station G, the upper edge of the sidewall blank, which is over the end member's folded-up edge, is turned down towards the centre by pressing it from above, so that it covers the end member's folded-up outer edge.

At the first end sealing station H, the marginal portion of the sidewall blank is

pressed against the folded-up edge of the end member so that the heal seal coatings, which were heated up at previous heating stages, seal the parts together, and the end member's folded-up outer edge remains permanently inside the U-folded upper edge.

At the second end sealing station 1, the same operational stages are carried out at different points than at the previous station, so that the seal is even around the whole the perimeter of the casing, which at this point is already in its finished can- shaped form.

At the last processing station, container removal station J, the can-shaped casing is lifted up from the wrapping mandrel 2 and transferred to the next stage of the process PV, more particularly to the filling unit of the packaging machine, where the said can-shaped casing is also closed.

After the finished can has been removed from the wrapping mandrel 2, the mandrel is transferred by the short rotational movement of the table 1 to wrapping station A to receive a new sidewall blank, whereafter the above-described processing stages are repeated.

The typical processing time at each of the stations A-J may be approximately 500 ms, including the transfer from one station to the next. Therefore, a can may be produced and finished in the container-forming unit in approximately 5 seconds, with the production capacity being 1 can/0.5 s equalling approximately 120/min.

From the container removal station J, the casings OP advance along the conveyor track towards the next operational stage PV in the direction of the longitudinal axis of the sidewall blank. The direction of transfer substantially converges with the direction of their longitudinal axes. The length of the conveyor track is dependent on the placing of the different stations and other machine parts and on the distance between the different units, but its horizontal length, that is the track's horizontal transfer distance, is several times the length of a casing, ordinarily more than 0.5 metres, generally more than one metre.

FIG. 3 illustrates in more detail an embodiment of the method according to the invention. In this, the first aperture 12 of the flow passage 11 is placed at the container removal station J. The passage 11 forms a conveyor track into the packaging machine unit forming the next operational stage, and the passage is preferably a transparent tube (advantageous for monitoring the process) shaped like an upside-down U, with the casings OP being transferred directly upwards from the mandrel 2 into the tube's first aperture 12, at which point the longitudinal central axis of the vertical mandrel 12 (connects to the central axis of the first vertical portion 11 a of the passage. The passage 11 in the presented embodiment is thus comprised of the first vertical portion 11 a used to elevate the casings OP to a suitable level for the apparatus and its proper functioning, and in the top part of which the casings are turned towards the flow passage's 11 horizontal portion 11 b, which is used to carry out the horizontal transfer necessary for the process and the structure of the apparatus. The last portion of the flow passage is the second vertical portion 11 c used to bring the casings OP to the desired lower level for the next operational stage PV. It is obvious that the shape of the passage 11 may differ from the above within the functional demands of the apparatus and the process. The cross-sectional shape of the flow passage 11 corresponds to the form of the horizontal cross-section of the casing OP, and grounds relating to flow technology it has been decided that the cross-section of the passage 11 be somewhat larger in size than that of the casing OP.

According to the invention, whichever mandrel 2 is at the container removal station J is connected to the next stage PV of the process by the flow passage 11 for the gaseous transmission medium. In this case, the first aperture 12 of the flow passage 11, that is the inlet for a casing OP, is in the direction of the end face 2a of the mandrel 2, that is in a horizontal position, at a distance from and above the end face. The second aperture 13 of the flow passage, which aperture is the outlet for a casing OP, is placed in contact with the next stage PV of the process, more particularly the filling unit.

As illustrated in FIG. 3, the transfer is carried out substantially in the direction of

the longitudinal axis of the sidewall blank for the casing OP (excluding the changes of direction 11a (11b and 11b (11c in the arched portions, where the longitudinal axis follows the tangent of the direction-changing arcs but also follows the direction and the arching of the conveyor track). Furthermore, as best seen in FIG. 3, in this case the casing OP is situated so that the end member P is placed before the sidewall blank O in the direction of transfer. Most often, as for instance in an embodiment according to FIG. 3, the casing OP is placed in the filling position at the end of the transfer stage, preferably in an upright position, on the conveyor track leading to the first processing stage of the operational stage (unit), since its end member P is in the direction of transfer before the sidewall blank.

Therefore, the casing OP can directly receive the container contents at this operational stage PV due to the fact that the casing can be advanced for filling in the same position as it exits the flow passage 11 via the outlet 13 at the end of the flow passage's second vertical portion 11 c. After being filled the casing can be closed with another end member. Alternatively, before filling, the casing can at this point be closed with another end member having an open filling opening, whereafter the casing is filled and the filling opening is closed with a closure means.

The casings OP exit the flow passage 11 at intervals set by the capacity of the container-forming unit. After the outlet 13, the conveyor track leading to the next processing stage can be a continuously advancing conveyor, in which the casings remain in succession in line, in the same position as they exit the flow passage.

Preferably, the energy for transferring the casing OP is created by a gaseous transmission medium. This is especially advantageous for the reason that a suction effect can be generated at the first aperture 12 in order to bring the casing into the flow passage 11 by employing the ejector structure K according to FIG. 4.

The casing OP is subjected to the suction effect of the gaseous transmission medium acting at the first aperture 12 in the flow passage 11 by removing the casing OP at least partly from the mandrel 2 by means of a backward force which is separate from the suction effect exerted on the casing OP. This backward force

separate from the suction effect may be a backward force from the mandrel and preferably onto the inner surface of the casing OP, particularly the end member P, and created by a gaseous pressure medium. In another possible alternative, the backward force generated when the casing OP is removed from the mandrel 2 is so powerful that the kinetic energy of the casing is enough to transfer the casing OP into the flow passage 11, within range of the gaseous transmission medium. It must be noted that persons skilled in the art have the knowledge to select the flow rates and pressure levels that will create sufficient kinetic energy of the casing combined with a sufficient suction effect to ensure the functioning of this operational stage.

As shown in FIG. 4, an annular feed channel 14 surrounding the transmission medium flow passage 11 is placed in connection with the first aperture 12 of the flow passage 11, at a set distance from the entrance of aperture 12, a connector 15 being located in the said feed channel 14 to feed the gaseous transmission medium to the said feed channel 14. Nozzle apertures 16, facing diagonally upwards in the direction of transfer, are formed in the walls of the flow passage 11 being placed at substantially equal intervals in the direction of the circumference of the flow passage 11. Consequently, the gaseous transmission medium, preferably air, flows diagonally upwards (arrows V) towards the inner surface of the flow passage 11, and generates at the first aperture a suction effect in accordance with the ejector principle (arrow IV), causing the casing OP being removed from the mandrel 2 by the separate backward force, to come within the range of the suction effect IV and to advance into the flow passage, where it continues to advance towards the second aperture 13 in consequence of the transfer energy directed at the casing OP by the gaseous transmission medium.

At the bottom of FIG. 4, the removal of the casing OP in its axial direction from the mandrel 2 towards the inlet 12 is illustrated, the said being carried out advantageously as follows: When the casing OP has moved on the mandrel 2 to the container removal station J of the container-forming unit, the inner surface of the sidewall blank 0 for the casing OP and the outer surface of the wrapping mandrel 2 are released from contact with each other in the radial direction (arrow

X). This is performed by feeding a gaseous pressure medium, air in particular, into the chamber inside the mandrel, which has contact with the apertures opening to the mandrel's outer surface, causing the inner surface of the sidewall blank O and the outer surface of the wrapping mandrel 2 to lose contact, and the possible frictional contacts between the said surfaces are eliminated. This medium is blown, for example, by using the sliding member in contact with the transfer table 1 at the container removal station J, the pressure being directed from the sliding member into the mandrel chamber through the channel passing via table 1. After the said stage the actual exhaust (arrow Y) is carried out by using the gaseous medium directed to the channel running inside the mandrel and opening out towards its end surface, that is the end face of the mandrel. The channel can run, for instance, in a tube passed through the chamber, to the end face opening. Due to the pressure of the pressure medium used conveyed through the opening, the casing OP is removed from the wrapping mandrel 2 as a result of the energy effect directed in the axial direction of the wrapping mandrel 2 towards the bottom P of the casing. This transmission medium can also be blown by using the sliding member connected with the transfer table 1 at the container removal station J, the pressure being directed from the sliding member through the channel passing via the table 1, into the channel leading to the mandrel's end face. The blowing of both the mediums can be timed in relation to one another by means of solenoid valves, for example. The removal of and initial impulse taking the casing OP towards the flow passage 11 is in fact carried out by the effect of the pressure medium directed towards the end of the casing. However, in the case of cylindrical casings, in particular, (the diameter of the sidewall blank does not substantially change in the axial direction of the casing) it is preferable to use an energy effect directed via the side surface of the mandrel to facilitate the removal of the casings.

The sidewall blank 0 is wrapped at station A onto the outer surface of the mandrel 2 by an arrangement that exerts a suction effect on the apertures opening onto the mandrel's outer surface, the suction pulling the blank transferred to the station around the mandrel. However, the invention is not dependent on how the casing

is formed around the mandrel and how it has been handled before the mandrel 2 and the casing are transferred to the container removal station J.

It is, of course, obvious to one skilled in the art that the preferred arrangement of the passage 11 is a closed structure, at least as regards the parts where the transfer energy cannot be created by other forces, such as gravitational forces.

For example, the second aperture 13 of the passage 11 and the vertical portion 11c upwards from the aperture can be left partly open, whereby the gaseous transmission medium discharges itself from the flow passage 11 at the end of the horizontal portion 11 b of the passage 11, and the casings OP move downwards to the second aperture 13 of the passage 11 by force of gravity.

As best seen in FIG. 3, the passage is supported on the frame 10 by means of a vertical supporting device 17. Furthermore, a rotator 18 for the transfer table 11, which is a servo motor, can be seen in FIG. 3.

Although FIG. 3 illustrates the first aperture 12 situated just above the mandrel 2, it may also be situated at a distance from the end face of the mandrel 2 that is greater than the length of the casing OP, i. e. the length of the can, in the direction of the longitudinal axis of the sidewall blank. Consequently, it is possible, by air impingement, to create a sufficiently powerful backward force away from the end face of the mandrel, i. e. the initial impulse, which moves the can in a longitudinal direction away from the mandrel 2 before its front portion enters the aperture 12. This makes it possible to remove cans sideways mechanically or by air impingement, for the purpose of quality control or the removing of cans at the initial stages of production, for example. When moving the cans released from the mandrel to the side, the suction can also be turned off at aperture 12.

FIG. 5 illustrates another alternative, where the distance between the mandrel 2 and the aperture 12 is sufficiently long for moving the casings OP ejected from the mandrel to the side as described above. What is unique about this alternative is that the flow passage 11 is rotatable around the longitudinal axis of its starting

portion, so that the pivoting axle forms the centre point of the aperture 12 and the aperture 12 remains in the same place at the container removal station J. By rotating the passage flow 11, the outlet for the casings OP can be changed, enabling them to be placed in the next unit in adjacent lines on the conveyor track leading to the first processing stage.

Although this can in practice be carried out by means of one continuous flow passage 11, the final portion of which moves and divides the casings OP into adjacent lines on the conveyor track at the same time as the casings advance through the passage at a frequency set by the rate of production, FIG. 6, in particular, illustrates a preferred structure where the initial portion 11a+b of the passage 11 is rotatable and the end of the initial portion is connected to a series of fixed-station final portions 11 b+c, each of which feeds its own line of casings onto the conveyor track through its own outlet 13. The final portions 11 b+c are placed so that their inlets are approximately adjacent on the circumference of the circle drawn with the pivoting axle as its centre point, and arrive at the outlet of the initial portion in the appropriate order. The initial portion 11 a+b, in which one casing OP is travelling at a time, is rotated to the appropriate final portion 11b+c and the casing is directed into it. The distribution can be made according to a suitable plan to distribute the casings adjacent to each other on the conveyor track. After feeding the previous casing OP, the initial portion can be rotated rapidly past one or more inlets to the next selected inlet, so that the division is not necessarily carried out one aperture at a time moving from one edge to the other. The rotatable structure is smaller and the width of the rotating motion is shorter compared to an entire rotation of the flow passage. In FIG. 5 and 6, the break point of the flow passage 11, where the outlet of the initial portion and the inlet of the final portion meet, is in the horizontal portion 11 b. It can be seen, especially in FIG. 5, that the shape of the flow passage 11 does not differ in its other parts from that of FIG. 3 and that the gap between the portions may be very short, so that the parts of the passage form a functionally continuous tube. Furthermore, it can be seen in FIG. 5, that the outlets 13 are in the side walls of the final portions 11 b+c and that the casings OP exit the flow passage via these apertures in the direction

of transfer of the conveyor track side by side onto the conveyor track, which can be a suitably wide forward-moving base, for example, a wide belt.

FIG. 7 illustrates the rotating structure of the initial portion of the passage 11a+b as a vertical section. The lower end of the cylindrical passage's initial portion has been attached on bearings to the frame part 20 attached by a pillar 19 to the frame of the container-forming unit so as to pivot around the vertical axis. The turning motion is created by a servo motor 21 using a belt transmission 22, which is connected to the passage below the bearing 23, the belt transmission being connected for example to the gear 24 around the passage, the belt in this case being a timing belt. Furthermore, the annular feed channel 14 of the ejector structure K and the nozzle apertures 16 are situated away from the gear towards the aperture 12. The lower end of the passage described above can be formed as a separate rotating nave box 25, to the other end of which the rest of the passage's initial portion 11a+b is attached so as to resist torsion (illustrated by a broken line).

A container-forming unit has been described above, in which the wrapping mandrels 2 are in an upright position with respect to the horizontal plane, and due to the effect of the table 1 they move along a horizontal track between different stations. In this, at least the initial portion of the passage is in a vertical position and at the same time forms an extension to the longitudinal axis of the mandrel 2 and that of the casing OP. Nevertheless, it is possible for the mandrel 2 and similarly the initial portion of the passage to be directed in other directions at the container removal station J, such as in the horizontal direction, for example, when applying the so-called starwheel structure in the container-forming unit. If it is desired that the casing advancing with the end member ahead of it arrives on the conveyor track, open end up, at the end of the conveyor track, there is a corresponding arch in the passage where the casing's longitudinal axis changes to correspond to this position.

Although the figures have shown essentially cylindrical casings and cylindrical

mandrels 2, the invention is not limited to transferring such casings, but it can be used with any casings that can be formed by using a sidewall blank to be wrapped around a suitably designed mandrel and an end member to be placed at the end of the sidewall blank. The invention is, therefore, also suitable for casings that do not have an exactly circular cross-section but can diverge from the said shape, being, for example, polygon-shaped with rounded corners, for example, square- shaped. Similarly, the cross-sectional diameter in the axial direction of the sidewall blank does not have to be the same at every point, but the sidewall blank can be more or less tapered towards the end member. Furthermore, the order of forming the casing does not necessarily have to be as described. For example, it is possible to first place the end member on the end surface of the mandrel and thereafter wrap the sidewall blank around the mandrel.