A METHOD AND APPARATUS FOR FORMING A CARTON FROM A BLANK

Abstract: A carton (26) of the type comprising a pair of opposite broad side walls, one ofwhich is formed by two separate parts (15, 16), and two narrow side walls having tapered ends, is closed by means of a single length of adhesive tape (29). While one end portion of the carton is compressed, the free end of the adhesive tape is passed down below and adheres to the bottom side of the carton and thereafter in a tightened condition passed around the end portion, along the adjacent side edges of the sidewall parts (15, 16), and around the other end portion, while this end portion is compressed. Thereby it is possible to close both end portions of the carton and to interconnect the separate side wall parts (15, 16) in a single operation. The adjacent tape is preferably arranged in cut­ outs formed in the carton end portions (19, 20) serving a cushioning members. Thus, the contents of the carton or package will be protected from impact which may be absorbed by the cushioning members.

Description: A METHOD AND APPARATUS FOR FORMING A CARTON FROM A BLANK The present invention relates to a method of forming a carton of the type disclosed in US patent No. 3,001,686. By the method according to the invention the carton is formed from a substantially rectangular, flat blank comprising a pair of narrow side wall panels each defined between a pair of spaced, substantially parallel folding lines, having converging end portions at opposite ends, a broad side wall panel defined between said narrow side wall panels, and a pair of part panels each extending along and being connected to a respective one of the narrow side wall panels opposite to the broad side wall panel, the total width of the part panels being substantially equal to the width of the broad side wall. A blank of this type is also used for forming cartons disclosed in the above US patent. According to the above US patent No. 3,001,686 the carton forming process comprises placing a book or another flat object to be packed on the broad side wall panel of the flat blank, and subsequently wrapping the blank around the book by folding the blank along the folding lines so that the part panels are brought into engagement with the upper side of the book or object to be packed so as to substantially cover the same. In order to close the carton, an end panel arranged at each end of the broad side wall panel is folded over and fastened to the sloping end portions of the part panels which are arranged side by side by means of an adhesive, adhesive tape, wire staples, clips, or similar items. From the said US patent it is also known to fold the carton blank into a tubular shape in an empty condition and to fasten the part panels to each other by means of adhesive tape, which is placed on and in overlapping relationship with the closely adjacent edges of these part panels. A book or a similar object to be packed, may then be introduced into the tubular carton or package through an end opening, and the ends of the cartons may then be closed by means of end panels as described above. Thus, the method disclosed in the above US patent requires the use of carton blanks which are provided with special end panels, and complete closing of the known carton requires two different, separate fastening operations, namely interconnection of the adjacent edges of the part panels by means of adhesive tape and folding and glueing or stapling of each of the folded end panels. The present invention provides a method by means of which it is possible to form cartons of the above type by using blanks without said end panels, whereby a substantial saving of blank material is obtained, and which makes it possible to obtain a complete and reliable closing of the carton by a single joining or closing operation. The method according to the invention is of the type comprising folding the bank along the folding lines into a tubular shape so that the outer longitudinal edges of the part panels are located closely adjacent, whereby the part panels in combination form a first broad side wall arranged opposite to a second broad side wall formed by the broad side wall panel, said broad side walls being substantially parallel, but having end portions which converge corresponding to the convergence of the end portions of the folding lines, and interconnecting the adjacent edges of the part panels by means of adhesive tape, and the method according to the invention is characterized in that one or more lengths of adhesive tape is/are passed around at least one end of the carton and adhere to the opposite broad side walls while the end portions of these side walls are maintained pressed together. Such adhesive tape extending around a carton end portion in a tightened condition tends to reduce the perpendicular of the triangular cross-sectional shape of the carbon end portion, whereby the tape tends to maintain the end portions of the broad side walls pressed together. The method according to the invention is suited for automation. Adjacent edge portions of the part panels may be interconnected by means of a separate piece of adhesive tape. However, in the preferred embodiment of the method according to the invention the adhesive tape interconnecting the adjacent edges of the part panels is also passed around at least one, and preferably both ends of the carton. This means that it is possible to reliably close both ends of the carton, and to interconnect the adjacent edge portions of the part panels by means of one and the same length of adhesive tape. The method according to the invention may be used in connection with carton blanks, wherein the converging end portions of the folding lines meet or intersect at the outer portions of the adjacent end edges of the broad side wall panel and by the part panels, or the end portions of the folding lines may define a smaller angle therebetween so that their extensions meet or intersect beyond these outer parts of the end edges. However, in connection with the method according to invention it is preferred to use a blank in which the converging end portions of the folding lines meet inside the adjacent end edges of the broad side wall panel and of the part panels. These end edges are not necessarily rectilinear, but may have any other suitable shape, and may for example, be convexly curved. The fact that the end portions of the folding lines intersect inside the outer parts of the end edges results in an improved closure of the carton ends, and when the piece or pieces of adhesive tape are applied, the end portions of the broad side walls of the carton are preferably pressed against each other closely adjacent to and preferably along or inside the straight line interconnecting the meeting points for the converging end portions of the folding lines at the respective end portion of the carton. The carton may be closed by means of a single length of adhesive tape, but it is possible to use two or more lengths of adhesive tape, each being passed around the opposite ends of the carton at spaced locations thereof and arranged so as to extend mutually parallel along at least one of the broad side walls of the carton. In a carton of the type described, the converging end portions of the broad side walls are adapted to provide a cushioning effect by absorbing impacts and blows, and, therefore, the length or lengths of adhesive tape extending around these end portions are rather exposed to damage. However, this may be avoided by passing the length or lengths of adhesive tape around the end portions of the carton so as to be received in cut-outs formed in the end portions of the broad side walls. At the ends of the carton the length or lengths of adhesive tape will then be well protected so that the risk of damage is substantially reduced. When converging end portions of the folding lines intersect inside the outer portions of the adjacent end edges of the broad side walls, the cut-outs are preferably shaped so that they extend to or inside the adjacent meeting points of the folding lines. if the end portions of the broad side walls are maintained pressed together along the inner limits of the cut-outs during closing and are kept in this position by the length or lengths of adhesive tape applied, the end portions of the broad side walls will be forcible pressed against each other so as to obtain a very efficient closure not only at the cut-outs, but along the whole width of the carton. The invention also relates to an apparatus for use in carrying out the method described above, and the apparatus according to the invention is characterized in comprising at least one reservoir for adhesive tape, moving means for successively moving cartons in the form of folded tubular blanks past the reservoir with the first broad side wall formed by the part panels facing the reservoir, means for moving the free end of a length of adhesive tape arranged within the reservoir into contact with the front end portion of the second, oppositely arranged broad side wall of a carton passing the reservoir, means for pressing the front end portions of the broad side walls against each other while the adhesive tape is being brought into contact therewith, means for cutting a tape length exceeding the length of the carton, means for passing the free end of the cut tape length around the trailing edge of the carton and into contact with the second broad side wall of the carton, and means for pressing the trailing end portions of the broad side walls against each other while the adhesive tape is being brought into contact with these end portions. In principle, the cartons may be kept stationary, and the adhesive tape reservoir or reservoirs may then be moved in relation to the cartons or packings. In the preferred embodiment, however, the moving means comprises a conveyer for moving the folded blanks past the tape reservoir or reservoirs, which is/are momounted stationarily or so as to be moveable to a limited extent. The means for moving the adhesive tape into contact with the folded carton blanks may, for example be in the form of guide rolls actuated by means of a pressure medium or other guiding means which may be controlled by cam means, or in any other suitable manner. Furthermore, the means for pressing the front end portions of the broad side walls against each other when the adhesive tape is supplied may, for example, comprise pressing members actuated by means of a pressure medium, for example in the form of hydraulic or pneumatic cylinders, which may, for example, be controlled by photoelectric cells or other types of detectors which may detect the position of a carton or carton blank in relation to the adhesive tape reservoir. Alternatively, the pressing means may be in the form of clips, or clamps, which are mounted on the conveyer for maintaining the end portions of the broad side walls pressed against each other, and which may possibly be automatically opened or closed by cam means or other control means arranged along the conveyer. According to a further aspect, the invention also relates to a substantially rectangular, flat blank for forming a carton and comprising a pair of narrow side wall panels each defined between a pair of spaced, substantially parallel folding lines having converging end portions at opposite ends, a broad side wall panel defined between said narrow side wall panels, and a pair of part panels extending along and being connected to the respective narrow side wall panel opposite to the broad side watl panel, the total width of the part panel being substantially equal to the width of the broad side wall, which blank may be folded along the folding lines into a tubular shape, so that the outer, longitudinal edges of the part panels are located closely adjacent to each other, whereby the part panels in combination form a first broad side wall arranged opposite to a second broad side wall formed by the broad panel, said broad side wall being substantially parallel, but having end portions which converge corresponding to the convergence of the end portions of the folding lines, and the blank according to the invention is characterized in that the converging end portions of the folding lines meet inside the adjacent end edges of the broad side wall panel and the part panels. It has been found that a blank of this type is especially suited for use in connection with the method and apparatus described above. The invention will now be further described with reference to the drawings, wherein Fig. 1 shows an embodiment of a carton or package blank, which may be used in connection with the method according to the invention, Fig. 2 is an embodiment of a carton or package made by folding and taping the blank shown in Fig.1, Fig. 3a is a fragmentary view of a second embodiment of a carton blank which may be used iii connection with the method according to the invention, Fig. 3b is a fragmentary view of a carton made by folding the blank shown in Fig. 3a, Fig. 4a is a fragmentary view of a third embodiment of a blank which may be used in connection with the method according to the invention, Fig. 4b is a fragmentary view showing a corner of a carton or package made by folding the blank shown in Fig. 4a, and Figs. 5-8 diagrammatically show an embodiment of the apparatus according to the invention in various operational positions. The carton or package blank shown in Fig. 1 may be cut or stamped from paperboard, cardboard, thick plastic film, or a similar sheet material. The blank has a substantially rectangular outline and comprises a broad side wall panel 10', two narrow side wall panels 11' and 12', each of which is defined between a pair of parallel extending folding lines 13' and 14', respectively. The blank further comprises a pair of part panels 15' and 16' arranged at opposite ends of the blank. Each end portion 17' of the narrow side wall panels 11' and 12' has a substantially triangular shape or W-shape, because the end portions of the otherwise parallel extending folding lines 13' and 14' converge so that they meet or intersect at or closely adjacent to the edge of the blank. These end portions 17' are separated from the other part of the side wall panel by means of transversely extending folding lines 18', which also define end portions 19' and 20' of the broad side wall panel 10' and of the part panels 15' and 16', respectively. As shown in the drawings, the broad side wall panel 10' may be provided with a cut-out 21' for receiving a dispatch note or the like, and cut-outs 22' for receiving a length of adhesive tape may be formed in the end portions 19' and 20' as explained in closer detail below. A carton or package as that shown in Fig. 2 for packing records, books, or other flat articles, may be made by folding the blank shown in Fig. 1 along the longitudinally extending folding lines 13' and 14'. In Fig. 2 the same reference numerals are used as in Fig. 1, but has been left out. It is understood that by folding the blank shown in Fig. 1 the triangular end portions 17 of the narrow side walls 11 and 12 are bent outwards, while the end portions 19 and 20 of the broad side wall are bent against each other so that the ends of the carton or package are closed. As shown in Fig. 2 the final closing may be performed by means of a length of adhesive tape 23, which is arranged in the cut-outs 22, and which may interconnect the part panels or the side wall panels 15 and 16 forming the upper broad side wall of the carton. As indicated in Figs. 1 and 2, the end portions 19 and 20 of the broad side wall panels may also be provided with holes 24 for receiving a string or thread, which may assist in maintaining the said end portions pressed against each other, if desired. It is understood that the end portions 17, 19, and 20 form cushioning members for protecting the contents of the carton against impact in all directions of the plane of the drawings. Fig. 3a shows an embodiment where the folding lines forming the triangular end portion 17' meet or intersect at a small distance inside the free edge of the end portions 19' and 20', whereby a triangular or W-shaped cut-out 25' is formed. By folding such a modified blank a carton is provided in which the end portions 19 and 20 are pressed together with particular force, whereby an improved closure of the carton ends is obtained. In this embodiment the end edges of the broad side walls may have a convexly curved shape, if desired. In the modified embodiment of the blank shown in Fig. 4a the free end portion 17' of the narrow side wall panel 11' is substantially trapezodial, and when this blank is folded the end portions 19 and 20 will tend to define a narrow space as shown in Fig.4b, so that the closure of the carton ends will be less complete. Figs. 5-8 diagrammatically illustrate an embodiment of an apparatus for carrying out the method according to the invention. This apparatus comprises a conveyer belt 26 or another conveyer to which the plane or flat blanks may be fed manually or mechanically so that they are arranged mutually spaced with the folding lines 13' and 14' of the blanks extending in the longitudinal direction of the conveyer belt. The article or articles, such as books, records, dishes, plates, or other flat articles to be packed may be arranged on the broad side wall panel 10' of each blank. When the conveyer belt 26 moves the carton blanks and the articles placed thereon towards a carton closing station shown in Figs. 5-8, the carton blanks are folded along the folding lines 13' and 14' so as to be wrapped around the article or articles to be packed, whereby the part panels 15' and 16' are positioned in engagement with the upper surface of the article(s). Thus, when arriving to the closing station each of the blanks have been formed into a carton or package as that shown in Fig. 2, but without the adhesive tape 23. When the conveyer belt 26 has moved such a carton 27 into such position at the closing station (shown in Fig. 5) that the leading edge of the carton or package has passed a position detector 28, for example in the form of a photoelectric cell, the conveyer belt 26 is stopped. A free end portion 29 of a roll 30 of adhesive tape rotatably mounted in a holder 31 will then hang substantially vertically down into the cut-out 22 in the leading edge of the carton 27 so that the adhesive tape extends a small distance down below the bottom side of the carton 27. The end portions 19 and 20 of the broad side wall at the leading edge of the carton are now pressed into tight mutual engagement by means of a pair of cooperating compressing members 32 which are each moved by a pneumatic cylinder 33. At the same time a pair of horizontally movable pressing members 35 operated by pneumatic cylinders 34 may compress the carton in a transverse direction so that the adjacent side edges of the part panels 15 and 16 are maintained in mutual engagement. While the end portions 19 and 20 and the part panels 15 and 16 are thus pressed into mutual engagement, the lower free end of the adhesive tape is moved into contact with and adheres to the bottom side of the carton 27 by means of a tape application member 36, which is movable in an upwardly inclining direction by means of a pneumatic cylinder 37. The rotational axis of the roller 30 of adhesive tape may be displaced along a guide slot or channel 38 defined in the holder 31 between first and second end positions shown in Figs. 5 and 6, respectively, by driving means, not shown. When by means of the application member 36, the free end of the adhesive tape has been brought into contact with and adheres to the bottom side of the carton 27, i.e. the broad side wall 10, the adhesive tape roller 30 is moved to said second position shown in Fig. 6, and simultaneously, the end portion 29 of the adhesive tape is caused to engage with the upper side of the carton 27 in a tightened condition along the closely adjacent side edges of the side wall panels 15 and 16 by means of a second application member 39. This application member 39 is preferably in the form of a roller, and by means of a pneumatic cylinder 40 it may be moved obliquely downward towards and away from the upper side of the carton 27, vide Fig.6. Each of the pneumatic cylinders 34 for moving the compressing members 35 is arranged on an endless transfer belt 41 making it possible to transfer the partly closed parton 27 from the conveyer belt 26 to a second conveyer belt 42 arranged in continuation of the conveyer belt 26. The transfer belts 41 which are driven by a reversible motor 43, are adapted to move the pneumatic cylinders 34 and the associated compressing members 35 reciprocatingly between a first position shown in Figs. 5 and 6, and a second position shown in Figs. 7 and 8. These positions may, for example be defined by micro switches 44 and 45, which are actuated when the cylinders 34 reach their respective positions. When, by means of the application roller 39, the adhesive tape 29 has been brought into contact with and been caused to adhere to the upper side of the carton 27, the pressure members 32 and the application member 36 are returned to their retracted positions by means of the associated hydraulic cylinders 33 and 37. Thereafter the motor 43 is energized, and this causes the transfer belt 41 to move the carton 27 from the position shown in Fig. 6 on the conveyer belt 26 to the position shown in Fig. 7 on the conveyer belt 42, while the carton is still clamped between the compression members 35. When the micro switch 45 has been actuated by one of the cylinders 34 or by an actuating member connected thereto, the transfer belt 41 will stop. During movement of the carton 27 from the conveyer belt 26 to the conveyer belt 42, the adhesive tape 29 is contacted with and brought to adhere to the upper side of the carton 27 in the total length thereof by means of the application roller 39 as shown in Fig. 7, whereby the side wall parts 15 and 16 are interconnected. In the position of the carton 27 shown in Fig. 7, the two pairs of pressure members are placed on opposite sides of the cut-out 22 in the trailing end of the carton, and when the cylinders 33 are actuated, the pressure members 32 are caused to press the trailing side wall end portions 19 and 20 into tight mutual engagement. Furthermore, a cutting member 46 which may be fork-shaped as shown in Figs. 7 and 8, is moved towards the adhesive tape in a horizontal direction by means of an associated pneumatic cylinder 47 so as to cut the tape in such a position that a free end portion of the tape will hang freely down and extend a certain distance below the bottom side of the carton. An application member corresponding to the application member 36 shown in Figs. 5 and 6 is moved in an upwardly sloping direction towards the bottom side of the carton by means of a pneumatic cylinder 48 (Figs. 7 and 8) so that the trailing free end portion of the adhesive tape 29 is pressed against and adheres to the bottom side of the carton. The pressure and compression members 32 and 35 are now returned to their retracted positions by means of their respective cylinders, the adhesive tape roll 30 is returned to its starting position shown in Figs. 5 and 6, and the compression members 35 are moved to their starting position by the motor 43 being energized so that the transfer belt 41 is moved in a backward direction till the microswitch 44 is actuated. The application member associated with the cylinder 48 and the application member 39 as well as the cutting member 46 are also returned to their retracted positions. The free end portion 29 of the adhesive tape will now again hang vertically downwards, and another folded carton blank may be moved to the position shown in Fig. 5, whereafter the closing procedure may be repeated for the new carton. The completed closed carton may be removed by starting the conveyer belt 42 till the carton has been moved to a desired position. Thereafter the belt 42 is stopped so as to be ready to have another carton which is about to be closed, transferred thereto. It should be understood that the closure of the carton by applying the adhesive tape thereto may, within the scope of the present invention, be made in many other manners than the one illustrated in Figs. 5-8. However, it is substantial that each end portion of the carton is compressed while the adhesive tape is passed around the respective end portion. It should also be noted that the adhesive tape may be applied to the carton also along the full length of the bottom side thereof, if desired. It is also possible to use two or more lengths of adhesive tape extending in spaced parallel relationship in the longitudinal direction of the carton. Thus, two or more mutually spaced cut-outs 22 may be formed in the end portions of the carton, and the parallel lengths of tape may be applied to the carton at the same time, for example in the manner described above. EXAMPLE In order to obtain a reliable closure of the ends of a carton of the type described above, the end portions 19 and 20 of the side wall should be dimensioned in regard to the carton height h, which is the distance between the folding lines 13' or 14'. It has been found that in a carton of the type illustrated in Figs. 3a and 3b, such suitable dimensioning for practical values of the carton height is obtained, when the perpendicular of the triangular end portions in the direction of the folding lines 13' and 14' is approximately h+5, and when the perpendicular of the triangular notch or cut-out 25' in the same direction is approximately 5, which means that the dimension of the end portions 19 and 20 of the side walls in the direction of the folding lines 13' and 14' may suitably be h+10. As an example, the broad side wall may mave the dimensions 207x134 mm, while the height of the carton, which means the width of the narrow side walls 11 and 12 may be 24 mm. The perpendicular of the triangular end portions 17 should then be approximately 24+5=29mm, and the perpendicular of the triangular notch 25' should be approximately 5 mm. Thus, the total dimension of the end portions 19 and 20 of the side walls in the direction of the folding lines 13' and 14' should be approximately 34 mm.

Claims: CLAIMS 1. A method of forming a carton (27) from a substantially rectangular flat blank, which comprises a pair of narrow side wall panels (11',12') each defined between a pair of spaced, substantially parallel folding lines (13',14') having converging end portions at opposite ends, a broad side wall panel (10') defined between said narrow side wall panels, and a pair of part panels (15',16') extending along and being connected to the respective narrow side wall panel opposite to the broad side wall panel (10'), the total width of the part panels being substantially equal to the width of the broad side walls, said method comprising folding the blank along the folding lines (13',14') into a tubular shape so that the outer longitudinal edges of the part panels (15',16') are located closely adjacent to each other, whereby the part panels in combination form a first broad side wall (15,16) arranged opposite to a second broad side wall (10) formed by the broad side wall panel (10'), said broad side walls (10,15,16) being substantially parallel, but having end portions (19,20), which converge corresponding to the convergence of the end portions of the folding lines (13,14), and interconnecting the adjacent edges of the part panels (15',16') by means of adhesive tape (23,29), characterized in that one or more lengths of adhesive tape (23,29) is/are passed around at least one end of the carton and is brought to adhere to the opposite broad side walls (10;15,16) while the end portions (19,20) of these side walls are maintained pressed together. 2. A method according to claim 1, characterized in that the adhesive tape (23,29) interconnecting the adjacent edges of the part panels (15,16) is passed around at least one end, and preferably around both ends of the carton. 3. A method according to claim 1 or 2, characterized in using a blank in which the converging end portions of the folding lines (13',14') meet inside the adjacent end edges of the broad side wall panel (10') and of the part panels (15',16') (Fig. 3a). 4. A method according to any of the claims 1-3, characterized in that the carton is closed by means of two or more lengths of adhesive tape, each being passed around the opposite ends of the carton (27) at spaced locations thereof and arranged so as to extend mutually parallel along at least one of the broad side walls (10;15,16) of the carton. 5. A method according to any of the claims 1-4, characterized in that the length or lengths of adhesive tape (23,29) is/are passed around the end portions of the carton so as to be received in cut-outs (22) formed in the end portions (19,20) of the broad side walls. 6. A method according to claims 3 and 5, characterized in using a blank in which the cut-outs (22) extend to or inside the adjacent meeting points of the folding lines. 7. An apparatus for use for carrying out the method according to claim 2, characterized in comprising at least one reservoir (30) for adhesive tape, moving means (26,41,43) for successively moving cartons (27) in the form of folded tubular blanks past the reservoir with the first broad side wall formed by the part panels (15',16') facing the reservoir, means (36,37) for moving the free end of a length of adhesive tape arranged within the reservoir into contact with the leading end portion of the second oppositely arranged broad side wall (10) of a carton passing the reservoir, means (32,33) for pressing the leading end portions (19,20) of the broad side walls against each other while the adhesive tape is being brought to adhere thereto, means (46,47) for cutting a tape length exceeding the length of the carton, means (48) for passing the free end of the cut tape length around the trailing edge of the carton and into contact with the second broad side wall (10) of the carton, and means (32,33) for pressing the trailing end portions (19,20) of the broad side walls against each other while the adhesive tape is being brought into contact with these end portions. 8. An apparatus according to claim 7, characterized in that the moving means comprise a conveyer (41) for moving the folded blanks past the tape reservoir or reservoirs which is/are mounted stationarily or so as to be movable to a limited extent. 9. An apparatus according to claims 7 or 8, characterized in that the pressing means comprise hydraulic or pneumatic cylinders (33). 10. A substantially rectangular, flat blank for forming a carton and comprising a pair of narrow side wall panels (11',12') each defined between a pair of spaced, substantially parallel folding lines (13',14') having converging end portions at opposite ends, a broad side wall panel (10') defined between said narrow side wall panels, and a pair of part panels (15',16') extending along and being connected to the respective narrow side wall panel opposite to the broad side wall panel (10'), the total width of the part panels being substantially equal to the width of the broad side walls, which blank may be folded along the folding lines (13',14') into a tubular shape so that the outer longitudinal edges of the part panels (15',16') are located closely adjacent to each other, whereby the part panels in combination form a first broad side wall (15,16) arranged opposite to a second broad side wall (10) formed by the broad side wall panel (10'), said broad side walls (10;15,16) being substantially parallel, but having end portions (19,20), which converge corresponding to the convergence of the end portions of the folding lines (13,14), characterized in that the converging end portions of the folding lines (13',14') meet inside the adjacent end edges of the broad side wall panel (10') and the part panels (15',16') (Fig. 3a).

Inventors: ASTRUP, NIELS
Applicants: COLON EMBALLAGE A/S
Application year: 1984
Main classification: B65D5
IPC codes: B65D5