Method and apparatus for forming the end closure of a rectangular tubular carton

Abstract: A carton score line breaker for breaking four end closure panels of a carton (12) includes, at a breaking station at which the carton (12) dwells, two oppositely disposed pairs of breaking elements (18,20,30,32) for breaking, in turn, the two oppositely disposed pairs of panels inwardly. Both pairs of elements (18,20,30,32) are continuously rotating.

Description: This invention relates generally to a method of and apparatus for forming an end closure of a rectangular tubular carton, especially, but not exclusively, for breaking plastics-coated, four-sided, paperboard carton end closure panels along score lines formed between the four end panels and the four side panels of the carton, and, more particularly, to such apparatus having breaking elements operative on at least two of the four sides during a dwell occurring during indexing of the carton. Known carton end closure formers (within which term we include various apparatus for pre-breaking, folding and/or tucking of carton bottom closure panels) can be divided into two groups, namely a first group in which the cartons dwell at forming stations at which the formers act upon the panels and a second group in which the cartons advance while the formers act upon the panels. GB-A-1,001,596; US-A-2,410,587; US-A-4,215,522; US-A -4,337,059; US-A-4,738,077 and US-A-5,167,607 disclose formers of the first group and all operating with an oscillatory motion. Packaging machines including those formers are suitable only for a relatively low production rate of cartons. GB-A-1,036,320; US-A-3,166,994; US-A-3,398,659; US-A -3,943,834; US-A-3,999,469; US-A-4,519,181; US-A-4,589,862 and WO-A-82/03834 disclose formers of the second group. At least one forming element of each former rotates continually unidirectionally in GB-A-1,036,320; US-A-3,166,994; US-A -3,398,659; US-A-4,589,862 and WO-A-82/03834, in each of which the cartons are received over mandrels arranged in a ring and serving to carry the cartons past the former while the forming element(s) act(s) upon the end panels. Although packaging machines having such continually rotating forming elements and such a ring of indexing mandrels are suitable for a relatively high rate of carton production, the positioning of the former between dwell stations limits the number of mandrels which can be provided in the ring and thus limits the carton production rate of the ring. In GB-A-1,036,320; US-A-3,166,994 and WO-A-82/03834, the mandrels radiate from an axis in the form of a spider which indexes round the axis, dwelling at various work stations which are distributed around the axis and at which the carton end closure panels are acted upon in various ways. US-A-2272255 discloses a packet-forming machine having an intermittently rotated spider provided with a plurality of horizontally disposed mandrels about which blanks of carton-forming material are wrapped to produce the packet. The machine produces a so-called "double packet" which comprises a body first formed upon the mandrel and an outer wrapper formed over the body on the mandrel. A blank of the body-forming material is wrapped about a mandrel at one station of operation and sealed along a longitudinal side seam to produce a tubular container having one end extending beyond the end of the mandrel. Thereupon, the mandrel is moved to another station of operation where the extended portions are folded over and adhesively secured to form the bottom of the container. Thereafter, the wrapper is formed about the container and the end is closed in a similar manner before removal of the packet from the mandrel. The end-forming mechanism includes a pair of pivotally and yieldingly mounted, oscillatory, folding plates which are arranged to be moved into and from engagement with opposed extended portions of the wrapper. The remaining opposed extended portions of the wrapper are arranged to be folded over into overlapping relation upon the first-mentioned portions by four rotary brushes, a second and a fourth of which are mounted to revolve upon the same shaft. A first and the second of the rotary brushes are arranged to revolve in paths which cause them to form a crease in the unscored wrapper along two opposed edges of the mandrel and to urge the above-mentioned remaining opposed extended portions of the wrapper slightly inwardly in preparation for succeeding folding operations. A third of the rotary brushes is then arranged to engage a lagging extended portion of those two extended portions and to lay this portion down against the previously folded wrapper end portions. The remaining extended portion is folded into engagement with underlying portions by the fourth rotary brush after the intermittently operated mandrel has started to move. The inner surfaces of the extended portions of the wrapper are provided with a coating of adhesive so that, when the above-described folding operations have been completed, the extended portions thereof are adhesively secured to the end of the inner container and to the overlapping portions of the end of the outer wrapper. After the above-described operations have been completed, the mandrel is moved to the next station, where pressure is applied to the end of the mandrel by a pressure member to set the adhesive firmly. During its travel from the end folding station to the pressure station, the packet is retained upon the mandrel by a fixed guide rail. According to one aspect of the present invention, there is provided a method of forming an end closure of one end of a rectangular tubular carton, comprising mounting said carton around an indexable mandrel with four end panels extending beyond an end of said mandrel, indexing said mandrel and thus said carton to a forming station at which said mandrel and thus said carton dwell, continually rotating unidirectionally each forming element of a first pair of oppositely disposed forming elements at said station to contact and urge inwardly two dwelling, oppositely disposed, end panels at said one end, and operating a second pair of oppositely disposed forming elements at said station to contact and urge inwardly another two dwelling, oppositely disposed, end panels at said one end, characterised in that each forming element of said second pair of oppositely disposed forming elements is continually rotated unidirectionally. According to a second aspect of the present invention, there is provided apparatus for use in forming an end closure of one end of a rectangular tubular carton, comprising an indexable mandrel around which said carton is mountable so that four end panels extend beyond an end of said mandrel, driving means for indexing said mandrel and thus said carton, a forming station at which said mandrel and said carton dwell and which includes a pair of oppositely disposed forming elements operable to contact and urge inwardly two dwelling, oppositely disposed, end panels at said one end, and other driving means which serves to rotate each forming element of said pair continually and unidirectionally, said forming station further comprising a second pair of oppositely disposed forming elements operable to contact and urge inwardly another two dwelling, oppositely disposed, end panels, characterised in that said other driving means serves to rotate each forming element of said second pair continually and unidirectionally. Owing to these aspects of the invention, it is possible to increase the number of mandrels in an indexing ring of mandrels and thereby to increase the rate of production of closed-ended cartons by the ring. It is also possible to provide an improved, high-speed, four-sided breaker for paperboard carton end closure panels. The breaker has two pairs of oppositely disposed breaking elements operative at one indexed position of each mandrel and its associated carton, with both oppositely disposed pairs of breaking elements continuously rotating. The method may include indexing through the forming station a series of cartons with standard fifth panels and, later, effectively turning the forming elements through a right-angle about an axis of the station, and subsequently indexing through the forming station a series of cartons with reverse fifth panels. It is thereby possible to avoid any need to have one packaging machine dedicated to standard fifth panel cartons and another packaging machine separately dedicated to reverse fifth panel cartons. In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:- Figure 1 is a side elevational view of a carton end closure pre-breaker; Figure 2 is an end view of the Figure 1 apparatus; Figure 3 is a top plan view of the Figure 1 apparatus; Figure 4 is an enlarged fragmentary perspective view of a carton, relative to its direction of travel, illustrating its end closure panels after having been pre-broken by the Figure 1 apparatus; Figure 5 is fragmentary top plan view illustrating an alternate embodiment of the Figure 1 apparatus; and Figure 6 is a view corresponding to Figure 4, but of a different configuration of a carton illustrating its end closure panels after having been pre-broken by the alternate embodiment of the Figure 1 apparatus. Referring now to the drawings in greater detail, Figures 1-3 illustrate a continuous-motion, four-way, carton bottom pre-breaker 10 positioned adjacent a tubular carton 12 mounted around a mandrel 14 of an indexing spider 16, the carton 12 having been removed from a magazine (not shown), squared into the tubular shape, and loaded onto the mandrel 14 in a conventional manner. The bottom pre-breaker 10 includes a first pair of oppositely disposed fingers 18 and 20 (Figure 1), having bars 18a and 20a secured to the respective ends thereof, continuously rotated at a constant velocity by respective shafts 22 and 24 in the plane of rotation of the spider 16. The bottom pre-breaker 10 further includes a second pair of oppositely disposed fingers 30 and 32 (Figure 2) continuously rotated at a constant velocity by respective shafts 26 and 28 in a plane perpendicular to the plane of rotation of the spider 16. As shown in Figure 3, the shafts 22, 24, 26 and 28 are rotatably mounted adjacent the respective ends of a + shaped bracket 34. The shaft 22 is the driving shaft, having an extension 36 extending to a suitable drive unit, represented as 38. Pinion gears 40 and 42 are mounted on the ends of the shaft 22. The gear 40 meshes with a pinion gear 44 on an end of the shaft 26. The gear 42 meshes with a pinion gear 46 on an end of the shaft 28. A pinion gear 48 on the other end of the shaft 26 meshes with a pinion gear 50 on an end of the shaft 24. In operation, the extension 36, the shaft 22, and the gears 40 and 42 are rotated counterclockwise by the drive unit 38 one complete revolution per turret index cycle, driving the gears 44 and 46, and the respective shafts 26 and 28 respectively clockwise and counterclockwise. The gear 48 drives the gear 50 and the shaft 24 clockwise. As shown in Figure 1, the fingers 18 and 20 on the respective shafts 22 and 24 are thus caused to rotate respectively counterclockwise and clockwise. The finger 18 is mounted on the shaft 22 such that it trails the finger 20 so as to not collide at their closest centre positions during their rotations. The fingers 30 and 32 are mounted on the respective shafts 26 and 28 so as to lead the fingers 18 and 20, without colliding therewith. The timing of the fingers 18, 20, 30 and 32 is such that clearance is provided to permit each carton 12 and mandrel 14 to be indexed into and out of the pre-breaking station containing the pre-breaker 10. Referring now to Figure 4, the container 12 includes the usual outer rectangular bottom end panels 52 and 54, and triangular fold-in panels 56 and 58. Triangular panels 60 and 62 connect between the panel 56 and the respective panels 52 and 54, and triangular panels 64 and 66 connect between the panel 58 and the respective panels 52 and 54. A standard side seam or fifth panel 67 is secured to the edge portions of the rectangular bottom end panel 54 and the adjacent side panel S 1 . All of the panels 52-66 extend beyond the distal end of the mandrel 14 prior to being indexed into position at the pre-breaking station. It is the fingers 30 and 32 which rotate against the respective triangular panels 56 and 58, folding them inwardly about respective score lines 68 and 70. The panels 60 and 62 are thereby caused to fold about score lines 72/74 and 76/78, respectively, and the panels 64 and 66 are caused to fold about score lines 80/82 and 84/86, respectively. The bars 20a and 18a on the fingers 20 and 18 rotate, in turn, against the rectangular panels 54 and 52, folding them inwardly about respective score lines 88 and 90. Thus all the score lines are pre-broken, and subsequent closing and sealing is efficiently performed by conventional means. As shown in Figure 6, so-called "reverse" side seam or fifth panel 92 is secured to the edge portions of the carton side and end panels. The relationship to the Figure 4 carton is such that the top closure arrangement, which is not shown, is in the same orientation for each of the bottom closure arrangements of Figures 4 and 6. The pre-breaker 10 can be made readily adaptable selectively for a standard fifth-panel carton or a reverse fifth-panel carton, by clamping appropriate fingers 18, 20, 30 and 32 to appropriate shafts 22 to 28 with an appropriate timing depending upon whether the pre-breaker 10 is to be fitted to a standard fifth-panel carton packaging machine or a reverse fifth panel carton packaging machine. Alternatively, it is feasible to orientate the whole pre-breaker 10 appropriately to the type of machine, or even to re-orientate through a right-angle about the axis of the pre-breaking station just the fingers 18, 20, 30 and 32 or the whole pre-breaker 10 (as will be described with reference to Figure 5), on one-and-the-same machine. For this to be feasible on a single packaging machine including a spider encircled by work stations for acting on the bottom of the carton, the mandrels, pressure pads and heater heads would also be re-orientated through a right-angle. Figure 5 shows a modification of the shaft 36 of Figure 3 such that it is split at 36a, with the adjacent ends being operatively mounted in a suitable coupling 36b. The latter thus serves to permit the entire pre-breaker 10, along to the split 36a, to be physically turned through 90° so as to accommodate the new position of the bottom panels 52, 54, 56 and 58, as between the cartons of Figures 4 and 6, during the bottom pre-breaking process, with no machine changes being required in top closure forming, filling, and sealing processes beyond the spider 16. It should be apparent that the pre-breaker described above is operative on all four sides of a carton at one indexed position of each mandrel and its tubular carton, and is readily adaptable to either a standard or a reverse fifth panel carton arrangement. It should be further apparent that the pre-breaker is particularly suitable for high-speed machines since the fingers of the pre-breaker continuously rotate and thus the high wear likely to occur with oscillatory fingers at high speed is avoided. Although the two embodiments of the invention shown and described are pre-breakers, it is possible so to arrange the fingers 18, 20, 30 and 32 that they perform, at one-and-the-same forming station, not only pre-breaking but also complete folding-in of the panels 52 to 66 and tucking of the panel 54 behind the panel 52.

Claims: A method of forming an end closure of one end of a rectangular tubular carton (12), comprising mounting said carton (12) around an indexable mandrel (14) with four end panels (52-66) extending beyond an end of said mandrel (14), indexing said mandrel (14) and thus said carton (12) to a forming station at which said mandrel (14) and thus said carton (12) dwell, continually rotating unidirectionally each forming element (18,20) of a first pair of oppositely disposed forming elements (18,20) at said station to contact and urge inwardly two dwelling, oppositely disposed, end panels (52,54) at said one end, and operating a second pair of oppositely disposed forming elements (30,32) at said station to contact and urge inwardly another two dwelling, oppositely disposed, end panels (56,58) at said one end, characterised in that each forming element (30,32) of said second pair of oppositely disposed forming elements (30,32) is continually rotated unidirectionally. A method according to claim 1, wherein the forming elements (18,20) of said first pair, while acting upon said carton (12), continually turn about respective axes (22,24) substantially perpendicular to a longitudinal axis of said carton (12), characterized in that the forming elements (30,32) of said second pair, while acting upon said carton (12), continually turn about respective axes (26,28) substantially perpendicular to the first-mentioned respective axes (22,24) and said longitudinal axis. A method according to claim 2 and followed by turning through a right-angle a unit comprised of the pairs of oppositely disposed forming elements (18,20,30,32). Apparatus for use in forming an end closure of one end of a rectangular tubular carton (12), comprising an indexable mandrel (14) around which said carton is mountable so that four end panels (52-66) extend beyond an end of said mandrel (14), driving means for indexing said mandrel (14) and thus said carton (12), a forming station at which said mandrel (14) and said carton (12) dwell and which includes a pair of oppositely disposed forming elements (18,20) operable to contact and urge inwardly two dwelling, oppositely disposed, end panels (52,54) at said one end, and other driving means (38-50) which serves to rotate each forming element (18,20) of said pair continually and unidirectionally, said forming station further comprising a second pair of oppositely disposed forming elements (30,32) operable to contact and urge inwardly another two dwelling, oppositely disposed, end panels (56,58), characterised in that said other driving means serves to rotate each forming element (30,32) of said second pair continually and unidirectionally. Apparatus according to claim 4, wherein said forming elements (18,20) of said first pair are arranged to rotate about respective axes (22,24) substantially perpendicular to a longitudinal axis of said mandrel (14) in its condition at said forming station, characterised in that the forming elements (30,32) of said second pair are arranged to rotate about respective axes (26,28) substantially perpendicular to the first-mentioned respective axes (22,24) and to said longitudinal axis. Apparatus according to claim 5, wherein a unit comprised of the pairs of oppositely disposed forming elements (18,20,30,32) is mounted so as to be turnable through a right-angle about said longitudinal axis. Apparatus according to any one of claims 4 to 6, wherein said driving means (38-50) comprises an external drive unit (38), a plurality of pinion gears (40-50) operatively connected to the pairs of forming elements (18,20,30,32) and a shaft (36) operatively connected between said drive unit (38) and one (40) of said plurality of pinion gears (40-50). Apparatus according to claim 7 as appended to claim 6, wherein said shaft (36) is split, and a coupling (36b) is operatively connected to the adjacent ends of the split shaft so as to permit the turning of the first-mentioned unit through said right-angle.

Inventors: JACKSON RANDY D, OWEN BARRY CHARLES, JACKSON, RANDY D., OWEN, BARRY CHARLES
Applicants: ELOPAK SYSTEMS, ELOPAK SYSTEMS AG
Application year: 1995
Main classification: B65B43
IPC codes: B65B43, B31B5, B65B7, B65B51