CARTON ASSEMBLING METHOD AND EQUIPMENT

Abstract: Disclosed are carton assembling method and equipment for sucking and taking out flatwise folded cartons one by one from a magazine (1) by means of suction cups (2), unfolding each carton squarely on a conveyance path while transferring it downward along a rotative path, and supplying the thus-unfolded cartons to an encasing machine (8) by means of a conveyance mechanism. Each carton is held squarely by a pair of stoppers (8b₁), utilizing its reaction force acting in the returning direction. Thereafter, the carton is reverse-folded against such reaction force and then unfolded again to remove the folding tendency of the carton acting in the folded direction, thereby permitting the carton to hold itself in a square shape. And at the time of reverse folding, the flaps of each carton are expanded so that a contents charging conveyor can be disposed in close proximity to the cartons.

Description: Background of the Invention (Field of the Invention) The present invention relates to carton assembling method and equipment for sucking and thereby taking out flatwise-folded cartons one by one from a magazine by means of suction cups of a rotative transfer mechanism, then unfolding each carton in a square shape while transferring it downward along a rotative path, and supplying the thus-unfolded carton to an encasing machine by means of a conveyance mechanism. (Description of the Prior Art) According to conventional carton assembling method and equipment of this type, for example as disclosed in Japanese Patent Laid Open No. 60420/86, there is provided a rotative transfer mechanism of a construction wherein three planetary gear trains are engaged with a fixed gear communicating with a drive source and a suction cup is attached to an outer-end gear of each such planetary gear train, and also provided is a conveyance mechanism of a construction wherein a large number of partition plates are erected on a belt conveyor at equal intervals each corresponding to the width of each carton which belt conveyor is driven in synchronism with the above rotative transfer mechanism. Each planetary gear train rotates along the outer periphery of the fixed gear, causing each suction cup to move rotatively downward along a hypotrochoid path, whereby cartons are sucked and taken out successively from the magazine. Folded edges of each carton are brought into sliding pressure contact with the partition plates which are moving horizontally at constant speed, thereby unfolding the carton gradually, then the suction is released and the front and rear faces of the carton are held between adjacent partition plates. In this state the carton is transferred to an encasing machine while being kept upright. However, in such conventional carton assembling method and equipment, each carton unfolded on the conveyance path and held squarely by the partition plates cannot be unfolded exactly in a square shape because the carton is under the action of a continuous folding tendency which tries to return to the folded direction. So in the event of even a slight dimensional error between the width of the carton and the spacing of adjacent partition plates for conveyance to the encasing machine, the carton will be deformed into parallelogram due to the above-mentioned action, thus causing the problem that a squarely unfolded carton is not always obtainable as a product. In the above conventional method and equipment, moreover, not only it is difficult to adjust the timing between the moving path of folded edges of each carton and the horizontal movement of partition plates, but also since the carton is introduced into the space between partition plates at a vertex part of a generally triangular hypotrochoid path, it is impossible to obtain a sufficient time to unfold the carton completely squarely and so the best unfolding condition cannot be expected. This is apparent from the disclosure of Japanese Patent Laid Open No. 26833/84 wherein the carton introducing vertex part of the hypotrochoid path is changed into a generally U shape by means of a cam mechanism to approximately double the carton introducing time and there is made a high speed operation. But the equipment disclosed therein involves the problem that the internal structure of a rotative transfer mechanism is very complicated. The construction disclosed in the foregoing Japanese Patent Laid Open No. 60420/86 also involves problems. More particularly, since each carton is conveyed to the encasing machine by means of the belt conveyor while its flaps are projected in directions perpendicular to the conveyance direction, not only it is impossible to reduce the width of the belt conveyor but also a contents charging conveyor of the encasing machine cannot be disposed in close proximity to the cylindrical portions of the cartons on the conveyor, resulting in increased size of the entire equipment. Besides, a contents charging pusher disposed so that it can protrude and retract with respect to the cylindrical portion of each carton, is required to be longer in stroke by the length corresponding to the projecting length of the flaps, thus resulting in increased time required for the charging of contents. In the above prior art, moreover, since contents are charged into each carton while the flaps are kept projected in directions perpendicular to the conveyance direction, if the flaps are inclined inwards even slightly, they will be rolled inside in charging the contents, resulting in that the contents are not exactly charged into the carton. Other forms of rotative transfer mechanisms with suction cups for the taking out of flat-wise folded cartons are described in European Patent Application No 0132617 and European Patent Application 0339178, but neither of these disclosures address the problem of the reverse folding of the cartons as described above. In US Patent 4331436 a mechanism for reverse folding cartons is described and illustrated, but the inventors of that mechanism address the reverse folding mechanism by arranging for the flat carton to travel in a guide path in that a pusher pushes the rear edge of the folded carton along the guide path until the front edge meets a stop ledge on a rotating member. The pushing continues and the rotating member is controlled in its movement so that the carton gradually unfolds to square configuration, but the pushing force on the unfolding carton continues in the same direction so that it is moved over centre to a reverse folded condition and eventually is ejected from the guide track and is re-erected to the unfolded state. By its very design, such mechanism does not lend itself to the suction cup extraction method with which the present invention is concerned. Summary of the Invention It is an object of the present invention to unfold a carton squarely in a reverse-foldable manner and remove its folding tendency by a simple structure in order to eliminate the aforementioned inconveniences of the conventional carton assembling method and equipment. It is another object of the present invention to effect both removal of the folding tendency and unfolding of flaps by reverse-folding a carton at an angle of 180° in order to eliminate the aforementioned inconveniences of the conventional carton assembling method and equipment. It is a further object of the present invention to provide a carton assembling equipment capable of easily coping with changes in size of carton. According to the present invention there is provided a method of assembling a box comprising erecting flat folded cartons one by one from a magazine by suction, then unfolding each of the cartons thus taken out to required configuration, while transferring it in a downward rotative path, by applying one of a first pair of folded edges to fixed, enclosed guides which gradually approach the path of movement of said folded edge, thereby bringing said first pair of edges closer together and unfolding the carton gradually so that a second pair of edges of the carton move apart until the carton is squared characterised in that when the carton as squared said first pair of edges define corners which are held squarely between a pair of stationary stoppers and thereafter the carton is moved in a direction transverse to said downward rotative path and the stoppers hold said corners whilst the carton folds about said second pair of edges to a reverse folded condition, then the carton is folded back to squared form prior to feeding it to an encasing machine. Also according to the invention there is provided carton assembling equipment comprising a magazine wherein a plurality of flatwise folded box cartons are stacked, a rotative transfer mechanism with suction caps for extracting the cartons one by one from the magazine to transfer them downwards along a rotative path, fixed, inclined guides arranged gradually to approach a folded edge of each carton as it moves on said rotative path so as to cause erection of the carton to squared configuration at the end of its movement on said rotative path, characterised by a conveyance mechanism disposed along a horizontal conveyance path and on which the cartons act when moved to squared configuration, by lower stoppers disposed below and contiguously to said fixed, inclined guides by upper stoppers adapted to engage folded side corner portions of the upper surface of the carton and disposed above the conveyance path, and by reverse folding means disposed downstream of the upper stoppers on said conveyance path, and by re-unfolding means for erecting the reverse folded carton. According to the above carton assembling method and equipment of the invention in the present case, a folded edge of a carton is brought into sliding pressure contact with the fixed, inclined guides and pushed inwards of the carton to thereby unfold the carton gradually; a pair of opposed, folding-side corner portions on each opening side of the carton thus unfolded are held between a pair of stoppers to hold the carton in a square shape by utilising its reaction force acting in the returning direction; further, the lower surface of the carton is conveyed towards the reverse-folding means against the said reaction force to lower the height of the carton gradually, thereby allowing both the above folding-side corner portions to approach each other to reverse-fold the carton which is then unfolded squarely again. By such a simple structure the carton is squarely unfolded in a reverse-foldable manner and the folding tendency thereof can be removed. Consequently, the square opening of the carton can be retained by itself independently of suction and partition plates. Even in the event of a slight dimensional error between the partition plate spacing and the width of the carton, there can be obtained a squarely unfolded carton as a product without deformation thereof. Further, unlike the conventional equipment, laterally moving partition plates are not used, but fixed, inclined guides are used to unfold each carton squarely, so not only it is no longer necessary to make a timing adjustment between the moving path of each carton and the horizontal movement of partition plates, but also the carton can be fully unfolded squarely even when it is introduced along a hypotrochoid path. Besides, the portions to be squarely opened of the carton can each be so opened by a single fixed, inclined guide independently of dimensional changes of the carton. According to the above carton assembling method and equipment of the second invention in the present case, each carton is reverse-folded at an angle of 180° and its flaps are expanded approximately orthogonally, thereafter the carton is compressed in the front and rear direction and again unfolded squarely, so that the removal of the folding tendency and enfolding of the flaps can be done simultaneously by reverse folding of the carton. Consequently, a contents charging conveyor of the encasing machine can be disposed in proximity to the cylindrical portion of the unfolded carton, so that not only it is possible to reduce the size of the entire equipment but also the contents charging time can be shortened because of a shorter stroke of a contents charging pusher. Besides, the charging of contents can be done in a satisfactory manner without rolling inside of the flaps. Brief Description of the Drawings Fig. 1 is a side view of a carton assembling equipment according to an embodiment of the present invention; Fig. 2 is a plan view thereof; Fig. 3 is a side view showing a principal portion on a larger scale; Fig. 4 is a plan view thereof; Figs. 5 to 8 are enlarged side views of a principal portion, stepwise showing operating conditions of a rotative transfer mechanism; Fig. 9 is a schematic view showing a gradually opening state of a carton in sliding pressure contact with a fixed, inclined guide; Fig. 10 is an enlarged perspective view of a principal portion, showing a carton held in an unfolded state; Fig. 11 is an enlarged perspective view of a principal portion, showing a state in which reverse-folding was started; Figs. 12 and 13 are enlarged perspective views of a principal portion, showing a completely reverse-folded state of a carton; Fig. 14 is an enlarged perspective view of a principal portion, with a guide member inserted between upper and lower flaps of a reverse-folded carton; Fig. 15 is an enlarged sectional view taken along line (15) - (15) of Fig. 14; Fig. 16 is an enlarged perspective view of a principal portion, with upper and lower flaps expanded by the guide member; Fig. 17 is an enlarged perspective view of a principal portion, with upper and lower flaps enfolded approximately orthogonally by means of an upper and lower flap enfolding plate; Fig. 18 is an enlarged perspective view of a principal portion, with a front flap expanded by means of a front and rear flap enfolding plate; Fig. 19 is an enlarged sectional view taken on line (19) - (19) of Fig. 18; Fig. 20 is an enlarged perspective view of a principal portion, with a rear flap expanded by the front and rear flap enfolding plate; Fig. 21 is an enlarged perspective view of a principal portion, with a reverse-folded carton being squarely unfolded again; Fig. 22 is a side view of a principal portion, showing a state in which a rear half portion of conveyance means was vertically moved in response to a change in height of a carton; Fig. 23 is an enlarged perspective view thereof; Fig. 24 is a side view of a carton assembling equipment according to another embodiment of the present invention, showing only a principal portion; and Fig. 25 is an enlarged perspective view thereof. Detailed Description of the Preferred Embodiments According to an embodiment of the present invention, as shown in Fig. 1, flatwise folded cartons A are taken out by suction one by one from a slantwise disposed magazine 1 by means of a rotative transfer mechanism 2 comprising plural, say three, planetary gear trains engaged with a fixed gear and three suction cups 2a attached to outer-end gears of those planetary gear trains. The carton A thus taken out is rotatively transferred along a hypotrochoid path to right and left, fixed, inclined guides 3 disposed below the rotative transfer mechanism 2, and the suction of the corresponding suction cup 2a is released at an appropriate timing. Each fixed, inclined guide 3 is erected at the rear end with respect to a conveyance direction of a conveyance path 4 along a lower vertex part of a moving path of the suction cup 2a, i.e., a hypotrochoid path. On the front side thereof is formed an inclined surface 3a so as to approach the moving path of one folded edge A₁ of the carton A in a folded state gradually in a downward direction. With downward movement of the suction cup 2a, the one folded edge A₁ is brought into sliding pressure contact with the inclined surface 3a of each inclined guide 3 to push the carton A inwards gradually. A vertical surface 3b is formed below and contiguously to the inclined surface 3a. The vertical surface 3b and the upper surface of the horizontal conveyance path 4 constitute a lower stopper 3′ for retaining one folding-side corner portion A₃ of the carton A which is in an unfolded state to prevent it from moving backward and downward with respect to the conveyance direction. In this embodiment, the fixed, inclined guides 3 are erected on a pair of later-described right and left rear support portions 4a₃ movably in the conveyance direction. Their inclined surfaces 3a are at an angle of approximately 25 degrees. The conveyance path 4 is a horizontal path extending from each fixed inclined guide 3 to an encasing machine (not shown). The lower surface of the carton A in an unfolded state is positioned along the upper surface of the path 4. The conveyance path 4 has a conveyance mechanism 4a for conveying only the lower surface side of the carton A forwardly in the conveyance direction. The conveyance mechanism 4a is constituted by a belt conveyor having projections 4a₁ formed outwards at equal intervals. A pair of such conveyance mechanisms 4a are disposed inside the right and left, fixed, inclined guides 3. In each conveyor 4a, a support portion which journals driving and driven pulleys is divided into two portions in front and in the rear with respect to the conveyance direction. These front and rear support portions, indicated at 4a₂ and 4a₃, are interconnected through parallel moving members 4a₄, e.g. parallel links, extending in the conveyance direction, whereby the rear support portion 4a₃ is supported vertically movably in a horizontal state together with the fixed, inclined guide 3 with respect to the front support portion 4a₂, and its positioning is effected using a fixing handle 4a₅. Above the conveyance path 4 are disposed upper stoppers 5 at a height corresponding to the vertical height of the carton A in an unfolded state and in a front position in the width of the carton A with respect to the vertical surface 36. The upper stoppers 5 are each composed of a holding pawl 5a disposed so that it can pop in and out of the moving path of the other folded edge A₂ of the carton A in a folded state, and a vertical surface 56 opposed to the front upper end of the carton A in an unfolded state. The holding pawl 5a is normally projected above the said moving path by means of a resilient member such as a spring 5c. But when the holding pawl 5a comes into contact with the other folded edge A₂ with downward movement of the suction cup 2a, it swings to let the folded edge pass downward and thereafter projects again to prevent an upward movement of the other folded edge A₂. The upper and lower stoppers 5 and 3′ constitute holding means for holding the folding-side corner portions A₃ and A₄ of the carton A on a diagonal line therebetween. By the holding means the carton A is held in a square shape, utilizing its reaction force acting in the returning direction, i.e., the folding direction. Although in this embodiment the holding pawl 5a for preventing an upward movement of the other folded edge A₂ of the carton A in an unfolded state is disposed so that it can pop in and out of the moving path of the other folded edge A₂, this arrangement does not constitute any limitation. By utilizing elastic deformations of the carton A, the other folded edge A₂ can be held in a fixed state of the holding pawl 5a even without swing motion of the pawl. Further, where the holding pawl 5a is fixed, it can be made contiguous to the vertical surface 5b integrally. In this embodiment the vertical surfaces 5b of the upper stoppers are formed at the rear end faces of parallel mounting plates 5d extending in the conveyance direction, and the holding pawls 5a are supported by the mounting plates 5d through shafts and thus disposed right and left in a pair. Further, the mounting plates 5d are each provided with elongated apertures 5d₁ extending in the conveyance direction through the wall thereof. Each mounting plate 5d is attached to and supported by a support portion 6a₂ of a later-described reverse-folding conveyor 6a through the elongated apertures 5d₁ so as to be movable forward and backward with respect to the conveyance direction. Further, in the lower end position of each upper stopper 5 is disposed a reverse-folding means 6 extending forward in the conveyance direction from that position along the conveyance path 4, in an inclined manner so that its height from the upper surface of the conveyance path 4 is lower toward the front. Consequently, the carton A in an unfolded state is inclined by the reverse-folding means 6 so that its opposed, folding-side corner portions A₃ and A₄ approach each other whereby the carton is folded in a direction reverse to the pre-folded direction in the magazine 1. The reverse-folding means 6, which are disposed in a pair outside the right and left upper stoppers 5, are each constituted by a belt conveyor 6a with a projection 6a₁ inclined downward toward the front in the conveyance direction. The spacing between the lower end faces of the right and left, reverse-folding conveyors 6a and the upper surfaces of the right and left transfer conveyors 4a is set at approximately the same as the thickness of the carton A in a folded state, whereby a reverse folding of 180 degrees is effected. In this embodiment, moreover, in addition to the reverse-folding conveyors 6a,6a, squeezing rollers 6b are connected to the support portions 6a₂ which journal driving and driven pulleys of the reverse-folding conveyors 6a, so as to be movable vertically as well as forward and backward with respect to the conveyance direction. Lower corner portions A₅ on the front side of the carton A in an unfolded state are pressed flatwise by the right and left squeezing rollers 6b, and thereafter the carton is conveyed by the right and left reverse-folding conveyors 6a, whereby it is intended to effect reverse folding smoothly. But, if reverse folding can be done with the reverse-folding conveyors 6a,6a alone, it is not necessary to provide the squeezing rollers 6b. In front of the reverse-folding means 6 in the conveyance direction are disposed flap folding means 7 for expanding upper flaps A₆, lower flaps A₇, front flaps A₈ and rear flaps A₉ of the carton A in a reverse-folded state along the right and left side edges of the conveyance path 4. The flap folding means 7 are composed of a pair of right and left guide members 7a adapted to be inserted between the upper and lower flaps A₆ and A₇, respectively, to expand those flaps in the vertical direction, a pair of right and left, upper and lower flap enfolding plates 7b for enfolding at an expanded angle of 90° the upper and lower flaps A₆ and A₇ which have been expanded by the guide members 7a,7a and a pair of right and left, front and rear flap enfolding plates 7c for enfolding the front and rear flaps A₈ and A₉ at an expanded angle of 90°, the guide members 7a and the flap enfolding plates 7b and 7c being successively disposed forward in the conveyance direction and each supported movably in the transverse direction. Each guide member 7a is formed in the shape of a horizontal batten whose rear half portion extends up to the rear end position of the reverse-folding means 6 in parallel with the right and left side edges of the conveyance path 4, and the said horizontal batten portion, indicated at 7a₁, is inserted between the upper and lower flaps A₆ and A₇ by utilizing a front-rear dislocation of those flaps occurring when the carton A is reverse-folded. Further, there are formed upper and lower inclined surfaces 7a₂ which are inclined at an angle of about 30° gradually upward and downward, respectively, from a position intermediate between the front and the rear toward the front. The upper and lower flaps A₆ and A₇ are moved forward along the inclined surfaces 7a₂ whereby they are gradually expanded in the vertical direction. The upper and lower flap enfolding plates 7b are each provided in a pair of upper and lower plates through a gap 7b₁ which is for the insertion of the front and rear flaps A₈ and A₉; they are disposed inside the upper and lower inclined surfaces 7a₂, namely in the positions corresponding to the base ends of the upper and lower flaps A₆ and A₇. On the respective rear face sides are formed inclined surfaces 7b₂,7b₂ which are inclined gradually upward and downward toward the front and inclined toward the inside of the conveyance path 4. The upper and lower flaps A₆ and A₇ are advanced along the upper and lower inclined surfaces 7b₂ whereby they are enfolded at an angle of 90° while being further expanded in the vertical direction. The front and rear flap enfolding plates 7c are each disposed inside the guide member 7a like the upper and lower flap enfolding plates 7b. On the rear face side thereof is provided a vertex 7c₁ in a vertically intermediate position so as to be located between the front and rear flaps A₈ and A₉, and there are formed upper and lower inclined surfaces 7c₂ inclined gradually upward and downward respectively from the vertex 7c₁ toward the front. The front and rear flaps A₈ and A₉ are advanced along the upper and lower inclined surfaces 7c₂, whereby they are enfolded at an angle of 90° while being expanded in the vertical direction. Further, in front of the flap folding means 7 in the conveyance direction there is disposed a reunfolding means 8 for compressing the carton A which is in a reverse-folded state, in the conveyance direction and again unfolding it squarely. The reunfolding means 8 comprises belt conveyors 8a disposed in front of the transfer conveyors 4a and interlocked therewith in synchronism, the belt conveyors 8a having a pair of right and left projections 8a₁, discharge conveyors 8b disposed at a falling distance from downwardly curved surfaces 8a₂ at the front ends of the right and left reunfolding conveyors 8a, the discharge conveyors 8b having a large number of conveyance pawls 8b₁ erected thereon at equal intervals each corresponding to the width of the carton A, the conveyance pawls 8b₁ being movable forward and backward with respect to the conveyance direction, and inclined plates 8c for guiding a front edge A₁₁ of the carton A, the inclined plates 8c being disposed in a downwardly inclined state opposed to the downwardly curved surfaces 8a₂. A rear edge A₁₀ of the carton in a reverse-folded state is pushed forward by the projections 8a₁ and the front edge A₁₁ thereof is moved along the inclined plates 8c and is brought into abutment with conveyance pawls 8b₁ moving horizontally to compress the carton in the front and rear direction while the carton is allowed to fall along the downwardly curved surfaces 8a₂, whereby the carton is unfolded squarely. At the same time, the front and rear faces of the carton A are held between the said conveyance pawls 8b₁ and other conveyance pawls 8b₁ which rise gradually from behind the reunfolded carton A with advance of the former conveyance pawls 8b₁, and in this state the carton A is conveyed to an encasing machine (not shown). Further, horizontal surfaces 8c₁ for preventing the floating of the carton A are contiguous to the lower ends of the inclined plates 8c with a spacing a little longer than the vertical height of the carton A with respect to the upper surfaces of the discharge conveyors 8b. The right and left transfer conveyors 4a,4a, reverse-folding conveyors 6a,6a and reopening conveyors 8a,8a are threadedly engaged with either the right or the left of right and left support portions 4a₂,4a₂; 6a₂,6a₂; and 8a₃,8a₃ which journal driving and driven pulleys, through three screw shafts 9a extending between those support portions in the direction perpendicular to the conveyance direction. The screw shafts 9a are connected to an adjusting motor 9b so that the spacings of the right and left support portions 4a₂,4a₂; 6a₂,6a₂; and 8a₃,8a₃ are adjusted simultaneously in the transverse or the right and left direction by forward and reverse rotations of the motor 9b. Further, to the moving-side support portions 4a₂, 6a₂ and 8a₃ are connected either in each set of the right and left guide members 7a,7a of the flap folding means, the upper and lower flap enfolding plates 7b,7b and the front and rear flap enfolding plates 7c,7c through connecting members (not shown) so that the right and left guide members 7a, the upper and lower flap enfolding plates 7b and the front and rear flap enfolding plates 7c are adjusted interlockedly with adjustment in spacing of the right and left support portions 4a₂,4a₂; 6a₂,6a₂; 8a₃,8a₃. The operation of such carton assembling equipment will be described below. First, the rotative transfer mechanism 2 is driven to take out by suction the flatwise folded cartons A one by one from the magazine 1. Each carton A thus taken out is rotatively transferred downward along such a hypotrochoid path as shown in Figs. 5 to 8. When the carton A approaches the lower vertex portion of the said hypotrochoid path, one folded edge A₁ of the carton A comes into sliding pressure contact with the inclined surfaces 3a,3a of the fixed, inclined guides 3,3. And, as shown in Fig. 9, with downward movement of the carton A, one folded edge A₁ is gradually pushed inwards of the carton A to unfold the carton. As one folded edge A₁ of the carton A being unfolded gradually goes down along the vertical surfaces 3b,3b and the lower surface of the carton A approaches the upper surface of the conveyance path 4, the other folded edge A₂ causes the holding pawls 5a,5a of the upper stoppers 5,5 to swing and pass outside the moving path of the edge A₂, to give a square shape. The opposed folding-side corner portions A₃ and A₄ of the thus squarely unfolded carton A are held immovably between the lower stoppers 3′,3′ comprising the vertical surfaces 3b,3b and the upper surface of the conveyance path 4 and the upper stoppers 5,5 comprising the lower surfaces of the holding pawls 5a,5a and the vertical surfaces 5b,5b. Consequently, the carton A is held in a square shape by utilizing its reaction force acting in the returning direction or the folding direction. At this time, the suction of the suction cup 2a is released. Thereafter, as shown in Fig. 10, only the lower surface side of the carton A is moved forward by operation of the transfer conveyors 4a,4a while the front upper end of the carton A is kept forwardly immovable by the vertical surfaces 5b,5b of the upper stoppers 5,5, whereby the carton A is gradually reverse-folded so that the folding-side corner portions A₃ and A₄ approach each other. As shown in Fig. 11, the lower corner portion A₅ on the front side of the carton A is pressed flatwise by the squeezing rollers 6b,6b which constitute the reverse-folding means 6, and thereafter the carton is conveyed by the reverse-folding belt conveyors 6a,6a. Alternatively, as shown in Figs. 12 and 13, the carton A is conveyed to between the lower end faces of the conveyors 6a,6a and the upper surface of the conveyance path 4 directly by means of only the reverse-folding conveyors 6a,6a and is thereby reverse-folded at an angle of 180°. The upper and lower flaps A₆,A₆, A₇,A₇ of the 180° reverse-folded carton A are vertically expanded and enfolded at an angle of 90° by the guide members 7a,7a and the upper and lower flap enfolding plates 7b,7b, which constitute the flap folding means 7, as shown in Figs. 14 to 17. Likewise, the front and rear flaps A₈,A₈, A₉,A₉ are so expanded and enfolded by the front and rear flap enfolding plates 7c,7c as shown in Figs. 18 to 20. Thereafter, as shown in Fig. 21, the carton A is compressed in the conveyance direction and again unfolded squarely by the projections 8a₁,8a₁ of the reunfolding conveyors 8a,8a and the conveyance pawls 8b₁,8b₁ of the discharge conveyors 8b,8b, then conveyed to the encasing machine (not shown) while being held between the conveyance pawls 8b₁,8b₁ of the discharge conveyors 8b,8b. On the other hand, in the case of change in size of the carton A, that is, in the case of change in vertical height, front-to-rear width or right-to-left length of the carton, the following adjustment is made. First, in the case of change in height of the carton A, as shown in Figs. 22 and 23, the fixing handle 4a₅ is released to let the rear support portions 4a₃,4a₃ move vertically in a horizontal state with respect to the front support portions 4a₂,4a₂, to thereby adjust the height from the rear upper surfaces of the transfer conveyors 4a,4a up to the holding pawls 5a,5a of the upper stoppers 5,5. At the same time, the right and left, fixed, inclined guides 3,3 are moved forward or backward for adjustment. Also, the inclined plates 8c,8c are moved forward or backward and up or down to make adjustment and the projecting positions of the projections 8a₁,8a₁ of the reunfolding conveyors 8a,8a are shifted forward or backward to adjust the timing between the front ends of the reunfolding conveyors 8a,8a and the conveyance pawls 8b₁,8b₁ of the discharge conveyors 8b,8b. If necessary, moreover, the squeezing rollers 6b,6b are adjusted in their vertical position. In the case of change in width of the carton A, the mounting plates 5d,5d of the upper stoppers 5,5 are moved forward or backward with respect to the support portions 6a₂,6a₂ of the reverse-folding conveyors 6a,6a along the elongated apertures 5d,5d to thereby adjust the width from the vertical surfaces 3b,3b of the lower stoppers 3′,3′ to the vertical surfaces 5b,5b of the upper stoppers 5,5, and the inclined plates 8c,8c are moved forward or backward to make adjustment. Further, the projecting positions of the projections 8a₁,8a₁ of the reunfolding conveyors 8a,8a are shifted forward and backward to adjust the timing with the conveyance pawls 8b₁,8b₁, and the spacing between the conveyance pawls 8b,8b of the discharge conveyors 8b,8b is adjusted. If necessary, the squeezing rollers 6b,6b are adjusted positionally in the front and rear direction. In the case of change in length of the carton B, the adjusting motor 9b is rotated forward or reverse to adjust the right-left spacings of the right and left transfer conveyors 4a,4a, the reverse-folding conveyors 6a,6a and the reunfolding conveyors 8a,8a and also adjust the right-left spacings of the right and left guide members 7a,7a, the upper and lower flap enfolding plates 7b,7b and the front and rear flap enfolding plates 7c,7c. Also adjusted are the right-left spacings of the right and left, fixed, inclined guides 3,3 as well as the upper and lower stoppers 3′,3′, 5,5. Although in the above embodiment the fixed, inclined guides 3 as well as the upper and lower stoppers 3′,5 are respectively provided right and left in a pair, this arrangement does not constitute any limitation. They may be each provided one centrally in the right and left direction. Further, although each upper stopper 5 is attached to the support portion 6a₂ of the reverse-folding belt 6a so as to be movable forward and backward to cope with changes in width of the carton A, the arrangement for adjustment is not limited thereto. For example, as shown in Figs. 24 and 25, the driven pulley 6a₃ of the belt 6a, the upper stopper 5 and the squeezing roller 6b may be attached to the support portion 6a₂ of the reverse-folding belt 6a so as to be movable forward and backward, to thereby adjust them simultaneously. Further, although in the above embodiment the right and left flaps are expanded simultaneously by the flap folding means 7, this is not a limitation. Only the flaps on the contents charging side may be expanded.

Claims: A method of assembling a box (A) comprising erecting flat folded cartons (A) one by one from a magazine (1) by suction, then unfolding each of the cartons (A) thus taken out to required configuration, while transferring it in a downward rotative path, by applying one (A1) of a first pair of folded edges (A1, A2) to fixed, enclosed guides (3) which gradually approach the path of movement of said folded edge (A1), thereby bringing said first pair of edges (A1, A2) closer together and unfolding the carton (A) gradually so that a second pair of edges of the carton move apart until the carton (A) is squared characterised in that when the carton (A) is squared said first pair of edges (A1, A2) defines corners (A3, A4) which are held squarely between a pair of stationary stoppers (3', 5), and thereafter the carton (A) is moved in a direction transverse to said downward rotative path and the stoppers (3', 5) hold said corners (A3, A4) whilst the carton folds about said second pair of edges to a reverse folded condition, then the carton (A) is folded back to squared form prior to feeding it to an encasing machine. A method according to Claim 1, characterised in that the cartons (A) are reverse folded at an angle of 180°. A method according to Claims 1 and 2, characterised in that the carton (A) has flaps (A⁶, A⁷, A⁸, A⁹) which are expanded and enfolded approximately orthogonally when the carton (A) is reverse folded. Carton assembling equipment comprising a magazine (7) wherein a plurality of flatwise folded box cartons (A) are stacked, a rotative transfer mechanism (2) with suction caps (2a) for extracting the cartons (A) one by one from the magazine (1) to transfer them downwards along a rotative path, fixed, inclined guides (3) arranged gradually to approach a folded edge (A₁) of each carton (A) as it moves on said rotative path so as to cause erection of the carton (A) to squared configuration at the end of its movement on said rotative path, characterised by a conveyance mechanism (4) disposed along a horizontal conveyance path and on which the cartons (A) act when moved to squared configuration, by lower stoppers (3') disposed below and contiguously to said fixed, inclined guides (3), by upper stoppers (5) adapted to engage folded side corner portions (A₄) of the upper surface of the carton (A) and disposed above the conveyance path, and by reverse folding means (6) disposed downstream of the upper stoppers (5) on said conveyance path, and by re-unfolding means (8) for erecting the reverse folded carton (A). Carton assembling equipment according to Claim 4, characterised by flap folding means (7) for expanding the flaps (A₁, A₂, A₈, A₉) on the carton (A) approximately orthogonally. Carton assembling equipment according to Claim 5, characterised in that said flap folding means (7) comprises guide members (7a2) for insertion between upper and lower flaps (A₆, A₇) of each said carton (A) to expand the flaps (A₆, A₇) in the vertical direction, upper and lower flap enfolding plates (7 b ) for enfolding the thus-expanded upper and lower flaps (A₆, A₇) approximately orthogonally, and front and rear flap enfolding plates (7 c ) for expanding and enfolding futher front and rear flaps (A₈, A₉) approximately orthogonally, said guide member (7 a2 ), said upper and lower flap enfolding plates (7b) and said front and rear flap enfolding plates (7c) being Successively disposed in the conveyance direction. Carton assembling equipment according to Claim 4, 5 or 6 characterised in that said rotative transfer mechanism (2) comprises plural planetary gear trains meshing with a fixed gear connected to a drive source, and suction cups (2a) attached to outer-end gears of said planetary gear trains, each said suction cup (2a) being moved along a hypotrochoid path by rotation of each said planetary gear train along the outer periphery of said fixed gear. Carton assembling equipment according to any of claims 4, 5, 6 or 7 characterised in that said conveyance mechanism (4) is constituted by a belt conveyor (4a) having a plurality of outward projections (4a1) disposed at equal intervals, and the cartons (A) are each conveyed by being driven by said projections (4a1). Carton assembling equipment according to any of claims 4 to 8 characterised in that said lower stoppers (3') are each constituted by a vertical surface (3b) formed below and contiguously to the inclined surface (3a) of each said fixed, inclined guides (3) and the upper surface of the conveyance path which is horizontal; and said upper stoppers (5) are each constituted by a holding paw (5a) disposed on the path of movement of the folded edge (A2) of each carton (A) and opposed to the upper surface of the carton (A) in the squared condition and a vertical surface (5b) erected in opposition to the front face of the unfolded carton. Carton assembling equipment according to any of claims 4 to 9 characterised in that said reverse-folding means (6) is constituted by a belt conveyor (6a) having a plurality of outward projections (6a1) disposed at equal intervals and whose rear end with respect to the conveyance direction is inclined forwardly downwards in the conveyance direction, and the cartons (A) are each reverse-folded while being conveyed forward by driving said projections (6a1). Carton assembling equipment according to any of claims 4 to 10 claimed characterised in that wherein said unfolding means (8) is composed of a belt conveyor (8a) having a plurality of outward projections (8a1) formed at equal intervals and a discharge conveyor (8b) disposed at a falling distance from a downwardly curved surface (7c2) formed at the front end in the conveyance direction of said belt conveyor (8a), said discharge conveyor (8b) having a plurality of conveyance pawls (8b) erected at equal intervals corresponding to the width of the carton (A), and wherein the reverse-folded carton is conveyed forward and allowed to fall along the downwardly curved surface (7c2) by operation of said projections (8a1) and conveyance pawls (8b1) while the front edge thereof is brought into abutment with a horizontally moving one of said conveyance pawls (8b1) to compress the carton (A) in the front and rear direction, thereby unfolding it again. Carton assembling equipment according to any of claims 4 to 11, characterised in that a rear half portion of said conveyance mechanism (A) positioned just under said rotative transfer mechanism is connected to a front half portion thereof vertically movably through parallel moving members (4a4) said fixed, inclined guides (3) are each erected on said rear half portion so as to be adjustable forward and backwards; said upper stoppers (5) and said reunfolding means (8) are each mounted so that the compressing distance thereof in the front and rear direction can be adjusted; and said conveyance mechanism (4), said reverse-folding means (6) and said reunfolding means (8) are each constructed so that the right-to-left dimension thereof can be adjusted, to match the size of the carton.

Inventors: MAGAHASHI, TOSHIO, SATO, MINORU, YAMASHITA, KIYOSHI
Applicants: TOKYO AUTOMATIC MACHINERY WORKS LIMITED
Application year: 1988
Main classification: B31B5
IPC codes: B31B5