APPARATUS FOR THE MANUFACTURE OF A TUBULAR CONTAINER SLEEVE

Abstract: An apparatus for the manufacture of tubular container sleeves having rounded shapes and made of cardboard or a similar material from a plane container blank (7), comprising a fixed mandrel (2) around which the container sleeve (7) is adapted to be swept and sealed to an integral sleeve, two sweeper arms (8) over which a spring loaded sweeper band (20) extends, guide blocks (16) having guide curves (17) for positively rotating the sweeper arms (8) together with the sweeper bands (20) and a sleeve blank (7) along the periphery of the mandrel (2), and means (13, 14) for displacing the sweeper arms (8) in relation to the mandrel (2) at the same time as the sweeper arms (8) are rotated. The stroke of the displacement of the sweeper arms to and from the mandrel and the positioning of the guide blocks (16) with the guide curves (17) are adjustable for adapting the apparatus to the manufacture of container sleeves of different size and/or form.

Description: Apparatus for the manufacure of a tubular container sleeve. The present invention generally relates to the manufacture of containers, and the invention is more particularly directed to an apparatus for the manufacture of tubular container sleeves from a plane blank of cardboard, plastic, sheet metal, a thin laminated material or a similar material . In the manufacture of certain types of containers, especially containers of rounded shapes, for instance containers having rounded corners or having a circular, elliptical or similar cross section form it has been customery to make a containers!eeve which is closed at one end and which is filled with the material to be packed and thereafter closed at the opposite end. The manufacture of the containers!eeve can be made in several different ways. The sleeve can be made by sprayforming or dieforming a plastic material or by winding a material in a spiralform on a mandrel whereafter the tube may be cut at the ends to a suitable length. This is a ti econsuming method which is not suitable for use in direct connection to the filling and the closing of the container, and the pre- manufactured containers!eeves are bulky, and in many cases the containers!eeves must be sterilized before being filled with the material to be packed. The latter method also gives a container which for many types of goods is not sufficiently liquid- and gasproof. Therefore there is a wish that the containers!eeve is made in direct connection to the filling and the closing of the container, whereby the container sleeve should be made from a plane blank of cardboard, plastic, any laminated material, sheet metal or a similar material. The formation of a containers!eeve having rounded forms, for instance rounded corners or having a circular, elliptical or otherwise rounded cross-section form causes some problems which are directly depending on the fact that the containers!eeve must have a carefully calculated inner size so that the bottom and topclosures can be connected to the containersleeve giving a wellsealed container. This is especially important in containers having inner bottom and topclosures. Several different methods are known in the art for making a containersleeve from a plane blank of cardboard or a similar material. The German patent DE 2928773 discloses a method in which the sleeve is made inside an outer fixed mandrel by means of press semi- cylinders acting from inside the sleeve and thereafter possibly by means of concave press rollers acting from outside. This method is ti econsuming, expensive and complicated, the method is limited to a specific type and size of container and there are great demands on the fitting dimensions between the outer mandrel and the inner press semi- c 1inders. Therefore it is to preferred that the sleeve is formed from outside on an inner fixed mandrel, and such an outer formation method is disclosed in the US-patent US 4,349,345. The patent discusses the problems of having the container blank carefully fit and follow the mandrel at the rounded' corners, and in this patent the formation problems have been solved by means of outer fixed formation jaws which at the upper rounded corners of the container provides a special compression of the corners by means of rotatably mounted wings. Also this apparatus is disadvantagous in that the method is limited to a specific type and size of the containersleeve and that it is important that the inner mandrel and the outer jaws are carefully fitting each other and the method is relatively slow, and the costs for the mandrel and the jaws are relatively high. The German laid open publication DOS 2305702 discloses a method in which a containersleeve is made on a fixed inner mandrel by means of an elastic ribbon acting between two rotatable arms. Since the tension of the elastic ribbon is increasing as the arms are folded up and round the fixed mandrel the tension of the folding or sweeping ribbon is strongly changed during the formation and this may leed to stretchings and tensions in the container blank so that the continersleeve after having been removed from the mandrel may shrink or wrinkle or may be otherwise deformed. The German laid open publication DOS 2906 592 discloses an alternative method using a non-elastical sweeping band which is kept stretched by a tension spring operating between the band ends and in which a pair of rotatable arms are adapted to fold the band together with the sleeve blank round a fixed inner mandrel. The rotatable arms are fixed and provides a folding and sweeping of the plane sleeve blank round a fixed mandrel. In the sweeping process the arms are rotated about fixed shafts in relation to the mandrel. Also in this apparatus stretchings or tensions may be transmitted from the band to the container blank in that the band ends are freely connected to each other actuated by a tension spring so that the band can move on the rotatable arms during the entire sweeping movement. When the sleeve blank is swept round the mandrel quantities of air may be enclosed which can not be pressed out by the spring loaded band. All described apparatus are disadvantagous in that they only allow the manufacture of sleeves having a specific shape and size and in that other shapes or sizes of sleeves can be made only after a substantial rebuilding of the machine. The object of the invention therefore is to solve the problem of providing an apparatus of the above mentioned type in which the sleeve blank is carefully adapted to the inner mandrel without the risk of stretchings and tensions of the blank and without the risk that quantities of air is enclosed between the sleeve blank and the mandrel and without the risk that the ready container sleeve wrinkles or is subjected to tensions. A further object of the invention is to provide an apparatus for the manufacture a container sleeve which apparatus may quickly and simply be readjusted for the manufacture of sleeves having different shapes and different sizes, especially only by substituting the inner mandrel and simply readjusting the scheme of movement for the available sweeping arms. Therefore the invention relates to an apparatus for the manufacture of tubular containers!eeves having rounded shapes and made of cardboard, plastic, sheet metal, any laminated material etc. from a plane sleeve blank and comprising a fixed mandrel around which the sleeve blank is intended to be sweeped and sealed to an integral containersleeve, two sweeping arms over which a spring loaded sweeping band extends, and means for rotating the sweeping arms together with the plane sleeve blank round the mandrel, and means for securing the sleeve blank in the sleeve shaped thereby provided. The most characterizing part of the invention s that the sweeping arms together with their swinging axels are displaceable in relation to the mandrel at the same time as they are rotated about the r shafts so that the arms during the sweeping operation with their ends slide along or close to the mandrel while successively pressing the sleeve blank to the mandrel. The successive displacement of the ends of the sweeping arms over the mandrel may be started anywhere from.the line where the sleeve blank gets into contact with the mandrel to a line located on some distance therefore, but usually it is sufficient that the contact between the arm ends and the mandrel is started from a place at or close to the central line of the mandrel. In a preferred embodiment of the invention the sweeping arms are positively guided in their movement by means of guide grooves, whereby any wanted container shape can be obtained. By a simple readjustment of the length of stroke and the sweeping movement for the sweeping arms and a simple exchange of mandrel the apparatus according to the invention can easily be adapted to the manufacture of containers!eeves of different sizes and different shapes. Further characteristics of the invention will be evident from the following detailed description in which reference will be made to the accompanying drawings. It is, however, to be understood that the illustrated and described embodiments of the invention are only illustrating examples and that many different modifications may be presented within the scope of the appended claims. -^T_RE__ OMPI In the drawings figure 1 is a vertical cross section through an apparatus according to the invention in a position for sweeping a sleeve blank round a fixed mandrel. Figure 2 correspondingly shows the apparatus after the sweeping operation is completed and in a position for sealing the containersleeve. Figure 3 is a cross section in a side view of the apparatus of figure 1, seen along line III-III. Figure 4 is a vertical cross section through an alternative embodiment of the apparatus according to the invention, and figure 5 is a topview of the apparatus according to figure 4. The apparatus shown in figures 1 and 2 generally comprises a carrier 1 for a plane sleeve blank, a fixed mandrel 2 on which a sleeve blank is adapted to be formed to an integral containersleeve, a pair of sweeping arms 3, a means 4 for racing and lowering the sweeping arms and a means 5 for rotating the sweeping arms. The carrier 1 for the sleeve blank is in the form of a pair of rails 6 which are fixed mounted in the machine and along which a plane sleeve blank 7 is fed from aside of the sleeve forming apparatus and in the actual direction of the mandrel 2. The rails 6 are provided on opposite,sides of the mandrel and so as to allow a free movement upwards and downwards respectiv __ely of the sweeping arms 3. The mandrel 2 likewise is fixed mounted in a machine support (not shown) and in a position between the rails 6 and above the sweeping arms. The mandrel 2 may have very varied shape, for instance oval, elliptical, circular, polygonal with rounded corners etc. and it may even be conical in the actual direction. The n* t * . usual form and the form which is most simple to handle, hovewer, is the circular- cylindrical form. The mandrel preferably is mounted so that it can easily be removed, whereby a mandrel of a specific shape and size can be substituted by a mandrel having another shape or another size. The sweeping arms 3 are mounted symmetrically with reference to the longitudinal axis of the mandrel 2 and so that the arms can be moved up and down at the same time as the arms are rotated from an open down position which is shown in figure 1 and a closed upright position which is shown in figure 2. Each sweeping arm 8 is mounted for rotation with a rotatable shaft 9 in a guide 10 which is vertically displaceable on to guide bars 11 of the machine support. The swinging shafts 9 are rotatably mounted in the guide 10. An actuation bar 12 is fixed mounted on each swinging shaft 9 for provided a swinging movement of the sweeper arms 8 upon actuation. The guide 10 i s connected to an actuation arm 14 over a l ink 13, and by means not shown in the drawings said actuation arm 14 is adapted to πiove vertical ly up and ' down respectively in relation to the fixed mandrel 2. Each actuation bar 12 which i s fixed mounted on a swinging shaft 9 for a sweeper arm 8 is at the outer end formed wi th a guide rol ler 15 which is sl ideable in a guide block 16 having guide grooves 17. The guide block 16 is fixed mounted in the machine support. The form of the guide groove depends on the form and size of the mandrel 2 and the groove is formed so that the outer ends of the sweeper arms 8 moves closely along or presses the sleeve blank 7 l ightly to the mandrel 2 at least during a part of the sweeping movement. The guide groove which thereby provides a positive guide movement of the sweeper arms 8 always shoul d be formed so that the ends 18 of the sweeper arms 8 at the final point of the sweeping movement are l ocated cl ose to each other at the upper side of the mandrel 2. In case that the sleeve is joined by an over l ap joint or by means of a joining strip provided along the inner surface of the sl eeve the guide grooves 17 further shoul d be formed so that the inner part of the over l ap joint or the sleeve bl ank edge wearing the joining strip respectively is al ays pressed to the mandrel before the other sleeve blank edge. In the right hand part of figure 1 the form . of a guide groove 17a i s diagrammatically il l ustrated which groove provides a pressing of the sleeve bl ank 7 from a l ine substantial ly corresponding to the center of the cyl indrical mandrel 12. It is evident that a first part (the lower part) of the groove extends vertical ly whereas the groove at the end of the movement upwards of the sweeper arms 8 is bowformed so that the outer ends 18 of the sweeper arms exactly fol low the outer surface of _he mandrel . In the lefthand part of figure 1 a guide groove 17b is l ikewise diagrammatical ly il l ustrated which groove is bowformed so that the outer ends 18 of the sweeper arms 8 move close to or are pressed to the - ϊΕEX mandrel 2 from a point adjacent the lower end of the mandrel as far as to a point adjacent the upper most surface of the mandrel . It is obvious that the sweeper arms may be brought to move al ong any actuation path by changing the form of the guide grooves 17. By further changing the stroke for the vertical di spl acement of the actuation arm 14 of the guide 10 i t i s al so possible to change the length of the vertical displ acement. By two simple operations it i s thereby possible to careful ly adapt the movement of the outer ends 18 of the sweeper arms 8 to a mandrel 2 having different form and size. In figure 1 the reference numeral 19 indicates the smal lest size of a mandrel for which the specific apparatus shown in the drawings has been adapted. The sweeper arms 8 cooperate with a sweeper band 20 for sweeping a container blank 7 round the mandrel . Each outer end of the sweeper band 20 is mounted in a spring arm 21 intended to keep the band streched in al l positions of the sweeper arms 8. Each spring arm 21 i s rotatably mounted on the swinging shaft 9 for the sweeper arm 8, and the spring arms 21 are actuated in the direction outwards-downwards by tension springs 22. The sweeper band 20 extends from the ends of the spri ng arms 21 over a rol l er 23 at^the end of each sweeper arm 8 and provides a continuous sl ing between the spring arms. The central point of the sweeper band 20 is mounted in a fixed press device so that the band 20 can not be displaced in relation to the mandrel and the sleeve blank whi l e sweeping said sl eeve bl ank round the mandrel . The press device comprises a press arm 24 which is mounted on a rotatable pin 25 and w hich at the top has a press-body 26 providing a press locking of a container sleeve 7 to the mandrel 2 w hen rotating the pin 25 with the arm 24. Thereby a displacement of the blank in relation to the mandrel is prevented during the sweeping operation. As previously mentioned the sweeper band 20 is mounted in the press-body 26 for preventing a displacement of the band in one direction or the other in connection to the sweeping operation. For joining of the sleeve blank 7 after having been swept round the mandrel the apparatus includes a sealing block 27 provided above the mandrel and movable between an upper position in w hich the sleeve blank can be freely swept round the mandrel 2 and a lower position in which the sealing block 27 presses the sleeve blank to the mandrel. The sealing block may be a heated block which by constant heat, high frequence heat or ultrasonar heat provides a weldjoining of the sleeve blank edges, or it may be a cold press block which by means of a pressure sticking glue joirvs the two edges of the sleeve blank. Preferably the sleeve blank is formed with a weldable material like a weldable plastic material at one or both edges, and said weldable material makes it possible to join the two edges of the sleeve by a simple overlap weldjoint. In a preferred embodiment the sleeve blank is at one end formed with a projecting weldable strip attached to the inner surface of the sleeve to be formed. By means of said weldable strip the sleeve can be joined edge to edge (butt joint) . The apparatus shown in figures 4 and 5 differs from the above described apparatus mainly in that the two sweeper arms are mounted on a com mon shaft 9'. Otherwise the apparatus works in the same way as the previously described apparatus. The function of the appatratus i s as fol l ows; The starting position of the apparatus is shown in figure 1, in which the sweeper arms 8 are located in their lower positions and the press device 24, 26 is retracted from the mandrel 2. D epending on the form of the guide grooves 17a or 17b the sweeper arms 8 take the position show n in the right hand part or the left hand part respectively of figure 1. A sleeve blank 7 is fed to a position underneath the mandrel 8 and is kept in a predetermind position by the carrier rails 6. The press device 24, 26 is rotated to its upper position together with the band which is fixed mounted thereon, whereby the pressblock 26 together with the band presses the sleeve blank 7 locked against the mandrel 2. Thereafter the actuation arm 14 is moved up so that the link 13 and the guide 10 together with the sweeper arms 8 are moved upwards. Depending on the form of the guide grooves 17 the sweeper arms 8 are moved according to a predetermind path while being moved upwards, and the sweeper band 20 sweeps the container blank 7 round the mandrel 2. In the case illustrated in the right hand part of figure 1 the ends 18 of the sweeper arms do not get in contact with the mandrel 2 until at a OMPI ~ ipo- ΛJ line substantially at the center of the mandrel, in the left hand case of figure 1 the ends 18 of the sweeper arms get into contact with the mandrel already adjacent the bottom surface thereof. Of course the two sweeper arms 8 should be actuated by mirror sym metrical guide grooves 17 so that said arms obtain substantially the same scheme of movement. As previously mentioned, however, one edge of the sleeve blank should be moved slightly in advance bf the other edge, so that the edges to be joined are located over each other. This is important whether the joint is made as an overlap joint or edge to edge by a butt joint by means of an inner joining strip. The guide blocks 16 with the guide grooves 17 should be adjusted so that the sweeper arms 8 with a slight pressure keep the container blank pressed to the mandrel 2. W hen the container blank is completely swept round the mandrel and the joining edges have been put over each other the ceiling block is moved down and the blank is joined to a sealed unit. After the different parts of the apparatus have returned to their starting positions the container sleeve is released from the mandrel and is formed with bottom, is filled and is sealed with a topclosure. W hen changing the form and size of sleeve the mandrel is exchanged to another mandrel and the stroke of the link 13 and the adjustments of the guide blocks 16 are adjusted in accordance with the new mandrel. If the form of the sleeve is changed it may be necessary to substitute the guide blocks to guide blocks having another form of the guide grooves 17.

Claims: C l a i m 1. Apparatus for the manufacture of tubular containersleeves having rounded shape and made of cardboard, plastic, sheet metal, any laminated material etc. from a plane container blank (7) and comprising a fixed mandrel (2) around which the sleeve blank (7) is intended to be swept and sealed to an integral sleeve, to sweeper arms (8) over which a spring loaded sweeper band (20) extends and means (16, 17, 22) for rotating the sweeper arms (8) together with the plane container blank (7) round the mandrel (2) and means (27) for joining the edges of the sleeve blank (7) in the sleeve shape thereby provided, c h a ra c te r- ι z e d in that the sweeper arms (8) are mounted on rotatable shafts (9) which are movable to and from the mandrel (2) at the same time as the sweeper arms (8) rotate about their shafts (9). 2. Apparatus according to claim 1, c h a ra c te ri z e d in that the movement of the sweeper arms (8) on their shafts (9) is provided by an actuation arm (14) the stroke of which can be varied for adapting the movement to the size of the mandrel (2). 3. Apparatus according to claim 1 or 2, c h a ra c t e r i z e d in that the sweeper arm __s (8) are positively guided with reference to the rotatable movement by means of guide blocks (16) having guide grooves (17) the form of which defines the scheme of movement for the rotatable movement during the displacement of the arms (8) in relation to the mandrel (2). 4. Apparatus according to claim 3, c h a r a c te ri z e d in that th» guide grooves (17) of the guide blocks (16) are formed so that the outer ends (18) of the sweeper arms (8) over the sweeper band (20) with a slight pressure presses the sleeve blank (7) to the mandrel (2) while the arms (8) are moved and rotated. 5. Apparatus according to claims 3 and 4, c h a ra c te r¬ i z e d in that the guide grooves (17) of the guide blocks (16) are formed as a curve bringing the outer ends (18) of the sweeper arms (8) to slightly press the sleeve blank (7. to the mandrel (2) at least from a position corresponding to the center of the mandrel (2) and as far as to a position located close to the place of the mandrel (2) at which the -1iJREΛ OMPI edges of the sleeve blank (7) meet or overlap each other. 6. Apparatus according to claim 1, c h a r a c t e r i z e d in " that the means for sealing the sleeve blank comprises a sealing block (27) which can press the sleeve blank edges to the mandrel (2) and which by constant heat, high frequence heat or ultra sonar heat welds the sleeve blank edges together. 7. Apparatus according to claim 1, c h a r a c t e r i z e d in that the sweeper band is a non-elastic band (20) which at each end is mounted in a arm (21) which is spring loaded in the direction out from the mandrel (2) and which keeps the band streched, and which with a central part is fixed mounted to a machine part for preventing a displacement of the band (20) in relation to the mandrel (2) during the sweeping operation. 8. Apparatus according to claim 7, c h a r a c t e r i z e d in that the fixed part of the machine is a press arm (24) which in the active pressposition presses the sleeve blank (7) to the mandrel (2) and prevents a displacement of the blank during the sweeping operation. 9. Apparatus according to claim 3, c h a r a c t e r i z e d in that the mandrel (2) is adapted to easily be exchanged, and that th£ guide blocks (16) with the guide curves (17) can be easily readjusted for adapting the apparatus to the manufacture of container sleeves having a different size and/or form. List of reference numerals 1 carrier 2 mandrel 3 sweeping arms 4 raising/lowering means 5 rotation means 6 rails 7 sleeve blank 8 arm (sweeper arm) 9 shaft (swinging shaft) /97 10 guide 11 guide bar 12 actuation bar 13 link 14 actuation arm 15 guide roller 16 guide block 17 guide groove (17a, 17b) 18 end (of sweeper arm 8) 19 (smallest size) 20 sweeper band 21 spring arm 22 tension spring 23 roller 24 press arm 25 pin 26 press body 27 sealing block

Inventors: JANSSON TAGE, JANSSON, TAGE
Applicants: ESSELTEPACK AB, ESSELTE PAC AB
Application year: 1984
Main classification: B31B3
IPC codes: B31B1, B31B3, B31B17