PACKAGE FORMING UNIT

Abstract: A package forming unit which comprises two or more handling stations (A-J), which are provided with handling means (4) for forming a package blank into a closed structure, at least one wrapping mandrel (5) which is fixed to a moving structure such as a transfer table (1), which is arranged to move the wrapping mandrel (5) and the casing part (O) of the package blank wrapped around it between the different handling stations (A-J), an arrangement for bringing about the movement of the handling means (4) in the direction of the longitudinal axis of the wrapping mandrel. The movements of the handling means (4) in the direction of the longitudinal axis of the wrapping mandrel (5) are implemented in such a way that at least two handling means (4) are connected kinetically to the same power unit (6), whereby at least two handling means (4) are connected by means of a guide rail arrangement (17) to the same lifting frame (3), which is further connected to a power unit (6), whereby the lifting frame (3) is arranged to move in the direction of the longitudinal axis of the wrapping mandrel (5).

Description: Package forming unit The object of the present invention is a package forming unit which is of the type described in the preamble of the appended claim 1. It is known to form cylindrical packages of liquid packaging board, the said packages being comprised of an upright cylindrical casing part, which is obtained by joining together the opposite vertical edges of a blank provided with a heat-sealable coating, and of end members which close the casing part at the top and at the bottom, the upper end member incorporating an opening. Packages of this type are used for sterile and air-tight packaging of different types of drinks. The package into which the substance to be stored, such as a drink, is fed at a later stage is formed automatically in the package forming unit, which includes a set of so-called wrapping mandrels around which the casing part is formed by wrapping. The wrapping mandrels are arranged in a rotating structure which moves the mandrels between different handling stations, at each of which in turn a certain operation is executed, and thus a can-like package casing is gradually formed and removed from the mandrel at the final handling station and taken to the filling unit for filling and closing. Forming a can-like package casing requires, at some of the handling stations, movement of the handling means, usually essentially in the vertical direction, in the direction of the longitudinal axis of the wrapping mandrel. This applies especially when, while in their operational position, the handling means are at least partly in the transfer path of the wrapping mandrel and/or of the package blank, as, for example, at the handling station for forming the end member of the package and positioning it in place, whereby the handling means may in its operational position be situated partly inside the packaging blank. The wrapping mandrel is in this case stopped at the handling station for the duration of the handling stage, and the handling means must be moved away from its operational position after the handling stage in order that it will not prevent the wrapping mandrel from moving to the next handling station. It is normal that, for example, the handling of the said end member requires several handling stages and thus the vertical movement of several different handling means. Package forming units requiring the functions described above are known in the field and a unit of this type is disclosed, for example, in European patent no. EP-B1 -0 038 448. Arranging the movement of the handling means at specific handling stations may thus easily require as many as six separate power units and power transmission arrangements, each of which further requires, for example, function-specific control automation. This tends to impair the reliability of the package forming unit and to increase the need for and frequency of service measures. The aim of the present invention is to increase the reliability of the package forming unit and to raise the level of the prior art by proposing a package forming unit in which the arrangements required by the movements of the handling means are considerably simpler than in known solutions. To achieve this aim, handling means performing at least two, preferably more than two, vertical movements, are connected kinetically to the same power unit. Preferably, those handling means of all handling stations, that move towards the end of the mandrel, warming, heating or moulding the end of the package, are arranged to move together in the manner described above. In the package forming unit relating to the invention, the said handling means are kinetically connected to the same integrated so-called lifting frame, in which case the vertical movement of the lifting frame brings about the simultaneous movement of each handling means. In such a case, only one power unit moving the lifting frame is required to bring about the vertical movement of the handling means, which simplifies the structure of the package forming unit substantially. This solution increases reliability considerably because the control automatics controlling the movements of the handling means, and at the same time the whole control automatics system controlling the operation of the entire package forming unit, require arrangements that are clearly simpler than known applications. As concerns the other preferred embodiments of the invention, reference is made to the appended dependent claims and the specification presented below. The invention is described in greater detail in the following, with reference to the appended drawings in which Figure 1 shows the can which forms a part of the package as a cross- section in the direction of the longitudinal axis Figure 2 shows a view from above of the package forming unit relating to the invention, and Figure 3 shows a side view of the package forming unit relating to the invention. The following terms are used for the different parts of the liquid packaging container in this connection: - Package: sales package or package casing depending on context - Sales package: a finished liquid packaging container filled with the contents and closed - Package casing: unfilled and unclosed outer casing of a sales package - Can: a package of which is typical a part wrapped into a closed structure in cross-section perpendicular to the longitudinal axis, that is, a casing part, one or both ends of which are closed by an end member - Package blank: a straight, plane-like piece, usually of liquid packaging board, by combining which pieces a package casing is formed and which may be detached from material with a larger surface area, such as an elongated band - Outer surface of blank or blank material: the surface which forms the outwardly visible surface in a finished package, and which generally has a print and a heat-sealable coating - Inner surface of the blank or blank material: the surface which forms the surface that is in contact with the contents of the package in the finished package, and which generally has a heat-sealable coating - Blank material: the raw material of blanks - usually liquid packaging board coated with heat-sealable coating. The packaging machine comprises a package forming unit, in which is formed the upright part of the can-shaped package casing shown in Figure 1 , which casing is the shape of a closed circle in horizontal cross-section, that is, the casing part O to which is joined an end member P closing its open end. The can-shaped package obtained in this way - one end of which is still open - is moved to the filling unit of the packaging machine in which the final sales package is formed, and which is not shown in greater detail here. In the package forming unit shown in Figure 2 there is a transfer table 1 which is arranged to rotate in the horizontal plane, on the circumference of which are, at constant angular intervals, forming parts supporting the said package at the different stages of its formation. The forming parts are identical and each is comprised of an upright mandrel 5 rising upwards perpendicularly from the level of the table, around which mandrel is formed the casing part of the package casing, and which is subsequently referred to by the term wrapping mandrel. In addition to the transfer table 1 , the package forming unit also comprises a fixed frame 2 on which the table is arranged to rotate, the horizontal part of the said frame, which is situated below the level of the table 1 , is marked generally with the reference numeral 2a. The frame incorporates a number of handling stations corresponding to the number of wrapping mandrels 5, a certain stage of forming the can which is open at one end, being performed at each of the said stations. At the stopping stage, when the handling stations perform certain work stages, the mandrels are at the handling stations, and at the transfer stage they move on by means of a short rotary motion of the table, which corresponds in length to the angular distance between the wrapping mandrels 5, to the next station for the following handling stage. The different handling stations are described in greater detail in the following, mainly on the basis of what their task is in forming the can-like package casing. All handling stations comprise handling means 4, which carry out the work stages desired by means of their movement or other function. The handling means 4 are located mainly outside the circular transfer path of the wrapping mandrels 5 and/or above the wrapping mandrels, or they are located so that they are temporarily on the transfer path of the wrapping mandrels and move out of the way of the wrapping mandrels for the duration of the transfer stage. These various parts are not shown in greater detail in Figure 2, but the figure does on the other hand show the support structures of the different stations to which the above-mentioned operational parts are attached. At the wrapping station A, a blank of a specific height is cut off from the lower end of the blank web L transferred to the station by means of the transfer devices incorporated in the frame, the said blank being pushed into contact with the wrapping mandrel 5 and wrapped around it into a shape determined by the outer shell of the mandrel. In this way the casing part O of the package casing is formed, the horizontal section of which casing part has a closed circumferential shape - in the case of cylindrical mandrels, a round shape. At the side sealing station B, the vertical edges of the casing part O, which have been placed on top of one another at the wrapping station, are joined together finally by sealing. This is carried out by means of a pressing surface which presses the overlapping edges together and at the same time brings about the cooling of the seal coating on the inner surface of the blank, which was previously heated to an adhesive state. At the preheating station C, hot air is blown inside, to the top end of the side- sealed part, in which case the heat seal coating at this point of the inner surface of the blank material heats up suitably. At the end member station D, end members corresponding in outline to the shape of the horizontal section of the casing part O are separated by means of die cutting from the continuous blank web M fed to the station, after which the said member is forced through the opening, which folds its outer edges at the same time. After this the member is pressed down onto the open top end of the casing part O, using the top surface of the wrapping mandrel 5 as a counter surface, so that the outer edges of the end member, which are folded upwards, are pressed against the inner surface of the casing part O. At the first heating station E, hot air is blown onto the outer surface of the end member, directing it towards the edges, whereby the bottom surface of the member heats up at the edge turned upwards towards the inner surface of the top end of the casing part O. The same treatment is carried out at the second heating station F to ensure that the heating will be sufficient over the entire circumference of the top end. At the clenching station G, the top edge of the casing part O, which is above the upward-turned edge of the end member, is folded to the centre and downwards by pressing down from above, in which case the said top edge folds around the upward-turned outer edge of the end member. At the first end sealing station H, the edge of the end of the casing part O is pressed against the upwards turned edge of the end member, whereby the seal coatings heated during earlier heating stages cause the parts to adhere to one another and the upward- turned outer edge of the end member remains permanently inside the top edge, which has been folded into a U-shape. At the second end sealing station I, the same work stages that were performed at the previous station are performed at different points in order to make an even seal over the entire circumference of the can-like package casing, which is already finished at this stage. At the final handling station, discharge station J, the can-like package casing is lifted up and off the wrapping mandrel 5 and moved along a conveyor track to the filling unit of the packaging machine. Once the finished can has been removed from the wrapping mandrel 5, the wrapping mandrel moves again by means of a short rotary motion of the table 1 to wrapping station A to receive a new casing part O blank, and the handling stages described above are repeated. Typical handling times at each of the stations A-J may be in the order of 500 ms, including the transfer from one station to the next. Thus the manufacture of a can may be completed in the package forming unit within about 5 seconds, and the production capacity is 1 can/0.5 s, that is, about 120/min. At the handling stations described above, the handling means 4 of usually at least the preheating station C, the first and second heating stations E and F, the clenching station G, and the first and second end sealing stations H and I require vertical movements of substantially the same length in the direction of the longitudinal axis of the wrapping mandrel 5 in order to function, which means that the handling means 4 first move from their non-operational position down to the operational position, into contact with the package blank (the forming tool of the clenching station and the pressing means of the end sealing stations), or close to it and inside it (means for blowing warming and heating air), and after the handling action back up again to their non-operational position. Hereinafter, handling member 4 refers especially to such handling means which perform the movement described above, and as regards other handling means 4, reference is made to the prior art, depending on the context. Figure 3 shows a vertical section of a part of the unit. The package forming unit relating to the invention includes, as an essential component, a lifting frame 3 which, as shown in Figure 3, is preferably located below the horizontal frame plate 2a of the frame, and to which the handling means 4 of the handling station is integrally connected. The lifting frame 3 runs horizontally, parallel with the edge of the table 1 , at the different stations. The lifting frame 3 is connected to a power unit 6 below it to bring about vertical movement of the lifting frame 3. Figure 3 shows especially the clenching station G's handling means 4, which due to its interior design, presses the top edge of the casing part O around the outer edge of the end member (circumferential groove at the bottom of the cup-like interior), but also handling means of the other above- mentioned stations, the said means moving in the axial direction of the mandrel 5 and being connected in the same manner to the lifting frame 3, that is, their movements are determined by the movement of their joint lifting frame 3. Figure 3 shows only the mandrel 5 which is at the clenching station G. According to the preferred embodiment shown in Figure 3, the handling means 4 are connected to the lifting frame 3 by means of a guide rail arrangement 17, which comprises two substantially parallel elongated guide rail units 11 , which are further connected to each other, preferably by substantially horizontal connecting arms 14, 15. The guide rail unit 11 consists of an essentially vertical guide rail sleeve 12 connected to the frame 2, and of a guide rail arm 13 arranged to move inside the said sleeve in the direction of the longitudinal axis of the said arm. At least one of the guide rail arms 13 is connected by means of a detachable joint 18, which preferably allows length adjustment, to the lifting frame 3, which means that the guide rail arms 13 connected to one another by means of the connecting arms 14, 15 move identically as the lifting frame 3 ascends or descends. According to the preferred solution described, the upper connecting arm 14 is in addition formed, for that part of it which is directed towards the transfer table 1 , that is, the wrapping mandrel 5, to continue in such a way that it has been possible to fix a handling means 4 essentially to its end, but it is obvious that separate means can also be formed for connecting the handling means 4 to the guide rail arrangement I. In the frame plate 2a a space 16 has been formed for allowing vertical movement of the lower connecting arm 15, which is advantageous as concerns the guide rail arrangement l, but the connecting arm 15 can also be arranged to move partly, or even completely, outside the frame plate 2a. By means of the guide rail arrangement 17, the reciprocating movement of the lifting frame 3 can be transmitted to bring about a movement of the means 4 that is of the same magnitude. Other connection points which transmit the vertical reciprocating movement of the lifting frame in the same manner by means of the guide rail arrangement 17 to the handling means 4 are also designated by reference numeral 18. The embodiment described above, in which the lifting frame 3 and the power unit 6 are located substantially below the transfer table 1 and the horizontal frame plate 2a below it, is most advantageous, for example, from the point of view of space arrangements, and also the noise level can be reduced by means of the said embodiment because the drive unit which moves the handling means and the lifting frame 3 back and forth can be sound insulated by means of the frame. It is obvious that other embodiments are also possible and the joint drive of the handling means 4 could also be located on the other side of the frame plate 2a. The lifting frame 3 may also be located, for example, above the transfer path of the transfer table 1 and the wrapping mandrels 5, and the power unit 6 can be positioned in many different ways by means of suitable power transmission arrangements. Similarly, it is possible to realise the guide rail arrangement 17, especially as regards the location of the lifting frame 3, in a manner other than according to the preferred embodiment described, and there may be only one guide rail, and correspondingly one guide rail arm. Figure 3 also shows a power transmission arrangement 19 for transmitting the movement of the power unit 6 to the lifting frame 3. The power unit is of a reciprocating type and the power transmission arrangement, in this case a ball screw, converts the rotary movement of the shaft of the power unit into a reciprocating linear movement of the lifting frame 3. The power unit may also be one which produces a reciprocating linear movement, in which case the lifting frame 3 can be connected directly to the power unit. It is also obvious that the movement effected by the power unit 6, essentially in the direction of the longitudinal axis of the mandrel 5, can also be changed mechanically at the handling stations into movement in another direction with the help, for example, of a means that is connected in such a way that it transmits movement to the guide rail arm 13. Figure 3 also shows an elevating ring under reference numeral 7 at the bottom end of the wrapping mandrel 5, by means of which the position of the casing part O around the wrapping mandrel 5 can be adjusted. The elevating ring 7, the movement of which is controlled by a suitable guideway located in the frame structure 20 below the table, raises the casing part O from the starting position to a higher position at the stations C-J, to enable handling to be carried out at its top end. The motor rotating the transfer table 1 , which motor is fixed to the frame plate 2a and is located below it, is marked with the reference M. The invention is also not limited only to the handling of approximately cylindrical packages as shown in Figure 1 , but may also be applied to all such forming units in which a closed structure is formed around a mandrel, the shape of the structure being determined by the shape of the shell of the mandrel, and the cross-section of this structure may also be other than a circle. The package may also be cone-shaped in the longitudinal direction. In order to bring about the movement of the lifting frame 3 and the package forming unit, and to synchronise them with respect to each other, normal solutions of mechanics and automation, such as pneumatic cylinders, sensors and servo drive can be used.

Claims: Claims: 1. A package forming unit which comprises - two or more handling stations (A-J), which are provided with handling means (4) for forming a package blank into a closed structure, - at least one wrapping mandrel (5) which is fixed to a moving structure such as a transfer table (1 ), which is arranged to move the wrapping mandrel (5) and the casing part (O) of the package blank wrapped around it from one handling station to another(A-J), - an arrangement for bringing about the movement of the handling means (4) in the direction of the longitudinal axis of the wrapping mandrel (5), characterised in that the movements of the handling means (4) in the direction of the longitudinal axis of the wrapping mandrel (5) are implemented in such a way that at least two handling means (4) are connected kinetically to the same power unit (6) in order to effect the movement simultaneously by means of the same power unit (6). 2. A package forming unit as claimed in claim 1 , characterised in that at least two handling means (4) are connected by means of a guide rail arrangement (17) to the same lifting frame (3), which is further connected to a power unit (6), whereby the said lifting frame (3) is arranged to move in the direction of the longitudinal axis of the wrapping mandrel (5). 3. A package forming unit as claimed in claim 2, characterised in that the guide rail arrangement (17) comprises at least one guide rail unit (11 ), which consists of an elongated guide rail sleeve (12) fixed to the frame of the package forming unit, the said sleeve being parallel with the longitudinal axis of the wrapping mandrel (5), and of an elongated guide rail arm (13) arranged to move inside the said sleeve in its longitudinal direction, the said arm being parallel with the guide rail sleeve (12) and further connected at one end to the handling means (4) and at the other end to the lifting frame (3). 4. A package forming unit as claimed in claim 3, characterised in that the guide rail arrangement (17) comprises two substantially identical and parallel guide rail units (11 ), the guide rail arms (13) of which are connected integrally to each other by means of an upper connecting arm (14) and a lower connecting arm (15). 5. A package forming unit as claimed in claim 4, characterised in that the handling means (4) is connected integrally to the connecting arm (14, 15). 6. A package forming unit as claimed in any of the above claims , characterised in that the power unit (6) is located with respect to the wrapping mandrels (5) on the other side of the mobile structure, such as a rotary table (1 ), which moves the wrapping mandrels (5). 7. A package forming unit as claimed in claim 6 , characterised in that the mobile structure, such as a rotary table (1 ), which moves the wrapping mandrels (5), is arranged to move in the horizontal plane and the power unit (6) is located below the said mobile structure. 8. A package forming unit as claimed in claim 7, characterised in that the power unit (6) is located below the frame plate (2a) of the of the package forming unit.

Inventors: HAEGGMAN JAAKKO, HAEGGMAN, JAAKKO
Applicants: HAEGGMAN JAAKKO, UPM KYMMENE CORP, HAEGGMAN, JAAKKO, UPM-KYMMENE CORPORATION
Application year: 1999
Main classification: B31B17
IPC codes: B31B17