BOX MAKING APPARATUS

Abstract: Prior to the assembly of boxes made from blanks of corrugated board consisting of at least one layer of corrugated medium sandwiched between two outer liners, the thickness of the overlapping area of each blank at each side is reduced by means for conveying blanks (L1) in succession past cutting means comprising a first cutter (44; 144) for cutting through an outer layer of each blank to delineate a defined area which will overlap a similar area at an opposite edge of the blank when the blank is assembled into a box, and a second cutter (48; 148) arranged to cut away substantially the entire thickness of the corrugated board over the said defined area.

Description: Box Making Apparatus This invention concerns improvements in or relating to apparatus for treating blanks of corrugated board used in the manufacture of boxes, containers or the like, and in particular to the removal of waste material from defined areas of such blanks. At one stage during the manufacture of such boxes the blanks are folded along pre-formed crease lines and opposite ends of the blanks are stuck together in overlapped relationship, so as to form a flat tube. A disadvantage of this is that when the partly formed boxes are stacked one on top of another, the overlapped portion is of double thickness which causes the boxes to stack unevenly. It is usual in box blanks to use double faced corrugated board in which a single layer of corrugated medium is sandwiched between two outer liners, but in larger containers the board may be still thicker, having two or even three layers of corrugated medium. In such a case the extra thickness accentuates the uneven stacking. Further, when articles to be packed are put into the erected box they may jam against the step formed on the inside of the box by the overlapped portions. It has been proposed in U.S. patent 1,186,087 to provide a box made of corrugated board in which overlapped portions of the blank, which form a joint when the blank is folded as mentioned above, are each cut away to reduce their thickness. According to one aspect of the present invention there is provided a method of reducing the thickness of overlapping areas of box blanks of corrugated board consisting of at least one layer of corrugated medium sandwiched between two outer liners, the method comprising feeding blanks in succession, cutting through an outer liner of each blank to delineate a defined area which will overlap a similar area at an opposite edge of the blank when the blank is assembled into a box, and then cutting away substantially the entire thickness of the corrugated board over the said defined area. According to another aspect of the present invention there is pro ided apparatus for reducing the thickness of overlapping areas of box blanks of co ugated board consisting of at least one layer of corrugated medium sandwiched between two outer liners, including means for conveying blanks in succession past cutting means comprising a first cutter for cutting through an outer layer of each bTank to delineate a defined area which will overlap a similar area at an opposite edge of the blank -when, the blank is assembled into a box, and a second cutter arranged to cut away substantially the entire thickness of the corrugated board over the said defined area. The invention will now be described, by way of example only, with reference to the accompanying drawings in which, Figure 1 is a pl n of a box blank having defined areas which have been reduced in thickness, Figure 2 is a section on the line II - II of Figure 1, Figure 3 is a section through the blank, similar to Figure 2, but after the blank has been folded into a flat tube, Figure 4 is a diagrammatic side view showing one form of aparatu for reducing ,the thickness f the defined areas of the blank of Figure 1, Figure 5 is a plan view of part of Figure 4, Figure 6 is a section on the 1 ine V I - V I of Figure 5, drawn to a larger scale, Figure 7 is a section on the line VII - VII of Figure 5, drawn to a larger scale, Figure 8 is a sectional view of a modified form of apparatus to ih__t _of Fgure 4, and Figure 9-ΪS Ϊ di agτaτrπrιatτc v ' few of a f urther-modif ied form of apparatus to that of Figure 4. Referring to Figures 1 to 3 of the drawings, 2 is a box blank made from double faced corrugated board consisting of a single layer C of corrugated medium sandwiched between two flat outer liners LI, L2. The .blank has parallel .scone IJnes 4 &nά 6 extending between the .blank edges S and 10; opposed pairs of transverse slots 12, 14 and 16 extending between the score lines and the blank edges 18, 20; and score lines 22, 24 and 26 aligned with and extending between respective slots 12, 14 and 16. Flaps 28 and 30 extend respectively from the edges 8 and 10, the flaps being reduced in thickness over their -whole areas, from opposite .faces of the blank, as shown in Figure 2, at each end of the blank. The blank 2 is then folded, in known manner, along crease lines 22 and 26 to form the blank into a flat tube so that the remaining parts of flaps 8 and 10 overlap, and are stuck to, the opposite ends of the blank, as shown in Figure 3. Reference will now also be made to Figures 4 to 7 of the drawings. Box blanks are fed in the direction of the arrow A in Figure 4 from printing and slotting apparatus (not shown) of any known form, one at a time and spaced apart in the direction of feed. The blanks are as described above except that, at this stage, the flaps 8, 10 have not been reduced in thickness, and thus are as shown in dotted lines at B in Figure 2. Each blank, lying flat, is fed with the liner LI uppermost and edge 18 leading, towards two pairs of belts which are spaced apart across the width of the blank so that the edges 8, 10 extend beyond the belts * Each pair of belts consists of respective upper and lower belts 32 and 34 between adjacent runs of which a blank is gripped and fed along a feed path defined by the adjacent runs of the belts, the belts extending between respective pulleys 36, 38 (Figure 4). Whilst a blank is being fed by the belts 32, 34 the flaps 28, 30 are reduced in tnickness over their whole areas by cutting away one of the liners LI, L2 and substantially the whole of the layer C, by means of respective cutting units indicated generally at 40 and 42. As the units 40, 42 are very similar, in the following description the same reference number will be used for like parts in both units but with 100 added to the parts of unit 42. Each unit 40, 42 consists of a first circular cutter 44, 144 fixed on a shaft 46, 146 and, downstream therefrom, a second circular cutter 48, 148 fixed on a shaft 50, 150. The shafts 46, 50 and 146, 150 are driven by means of respective belts 52, 54 and 152, 154 from motors 56, 156, so that the peripheral speed of the cutters 44, 144, 48, 148 is 10 to 12 times faster than the speed at which the blanks are fed by the belts 32, 34, with all the cutters rotating in a vertical plane. As viewed in Figure 4 the cutters 44, 48 rotate in an anti-clockwise direction, and the cutters 144, 148 rotate in a clockwise direction. The shafts 46, 50 are mounted so that the cutters 44, 48 are positioned below the feed path of the blanks and the shafts 146, 150 are mounted so that the cutters 144, 148 are positioned above the feed path. Each cutter is provided with a number of cutting edges 58 in a similar manner to that of a milling cutter. Positioned above each of the cutters 44, 48 is a respective suction box 60, 61 having slots 62, 63 in their bottom sides (see Figures 6 and 7) and to which suction is applied through pipes 54, 65. Siππlarl , -positioned below each of the cutters 144, 148 is a respective section box 90, 92 having slots 94, 96 in their top sides and to which suction is applied through pipes 98,100. A fixed plate 66 is positioned as shown in Figures 4, 5 to help support the blank near the edge 8 thereof, and a further fixed plate 68 supports the edge 10 of the blank. The operation of the apparatus will now be described by following the passage of a single blank through the apparatus. After having printing and slotting operations performed on it, the blank is fed towards the cutters 44, 144. The latter are positioned so that when they engage the respective flaps 28, 30, they do so in line with the edges 8, 10 of. the; blank, Just prior to. he. flap 8 engaging the cutter 44, suction is applied through the slot 62 so as to hold the flap flat as it passes the cutter. On engaging with the leading end of the flap 28 the cutter starts to cut through the bottom liner L2 and also the corrugated liner C, leaving the top liner LI uncut, as shown in Figure 6. As the bl ank continues to be fed by the belts 32, 34, the cutter 44 makes a narrow cut 70 (the cutter may be, for example, 3mm wide) along the blank, at the base of the flap 28, in l ne with tke edge -8, -When the rail ng end of fla ,.28.pa e out of engagement with the cutter " 44, the area of flap 78 which is to be reduced in thickness is delineated from the rest of the blank by the narrow cut 70. Also the flap 28 passes away from the suction box 60. Simultaneously with the cut 70 being made, the cutter 144 makes a simil ar cut 72 at the base of the fl ap 30, in 1 ine with the edge 10 of the blank. -However, -in this .case . , AS il-is positioned xibove the blank, the cutter T44 cuts through the top liner LI and also the corrugated layer C, leaving the bottom liner L2 uncut. The area of flap 30 to be reduced in thickness is thus delineated from the rest of the blank by the cut 72. Whilst the latter is being made, the flap 30 is held f abby suction applied to the suction box 90. As the- lank continues to be -fed b -the belts 32, 34 the flap 28 engages the cutter 48 which progressively removes the remaining portions of the liner L2 and the corrugated layer C from that flap. During this operation the flap 28 is held against the bottom of the box 61 by suction applied through the slot 63. Simultaneously, the cutter 148 removes the remaining portions of the liner LI and the .corrugated layer C from the flap 30, with the flap being held flat by suction applied to the suction box 92. Thus when the flaps 28, 30 pass out of engagement with the respective cutters 48, 148, the flaps 28, 30 comprise only the liners LI and L2 respectively. The waste material removed by the cutters 44, 48 is guided by baffle plates 74 (Figure 4) so that it falls into a trough 76 and is carried away for disposal. For this purpose the trough 76 may be vibrated, or may form part of any suitable type of air conveyor. A similar trough (not shown) is provided to collect waste material removed by the cutters 144, 148. Alternatively the waste material may be removed by means of suction pipes (not shown) positioned adjacent the cutters, as is well known in the box making industry. After passing away from the cutters 48, 148 the blank is fed to further apparatus (not shown) which forms the blank into a flat tube, as described above. In a modification, illustrated in Figure 8, the cutter 144 is replaced by a disc knife 77 fixed on the shaft 146, and the cutter 148 is replaced by a disc knife 78 fixed on a shaft 80 mounted at right angles to the shaft 146 so that the knife 78 rotates in a horizontal plane. In this case the knife 77 makes a cut in the same position as the narrow cut 72 described above, and the knife 78 cuts through the corrugated la er C forming the flap 30 parallel to the liner L2 and as close to that liner as possible without damaging it. The knife 78 extends into the cut made by the knife 77, so that when the flap 30 passes away from the knife 78 the waste material is removed in one piece in any suitable way. Alternatively the knife 78 may be replaced by a milling cutter similar to the cutter 148, but mounted in the same way as the knife 78. It will, of course, be appreciated that the same modification may be made to the cutter 48. In a further modification, illustrated in Figure 9, the waste material is removed from the flap 30 by a cutting unit 82 comprising a disc knife 84 similar to knife 77, and a circular cutter 86 similar to the milling cutter 148. The knife 84 and the cutter 86 are mounted on a common shaft (not shown) so that, as the blank is fed by the belts 32, 34, the knife 84 makes a cut along the base of flap 30 to delineate the material to be removed therefrom, and the cutter 86 simultaneously removes that waste material. A similar cutting unit wil also, of course, be^provided to remove the waste material f ro flap 28. It will be appreciated that a disc knife, such as knife 84, could be used in place of each of the cutters 44, 144 in Figures 4 to 7. In the following cl ims, the reference numerals are quoted purely by way of example and are ^ not intended to limit the scope of the claims.

Claims: Claims 1. A method of forming box blanks of corrugated board, in which blanks are fed in succession along a feed path in a direction parallel to opposite edges of the blank which are to be overlapped and joined to form a flat tube prior to formation into a box, opposite edges of the blank being reduced in thickness, in the areas which are to overlap, by cutting means arranged adjacent to the feed path. 2. A method of reducing the thickness of overlapping areas of box blanks of corrugated board consisting of at least one layer of corrugated medium sandwiched between two outer liners, the method comprising feeding blanks on succession, cutting through an outer liner of each blank to delineate a defined area which will overlap a similar area at an opposite edge of the blank when the blank is assembled into a box, and then cutting away substantially the entire thickness of the corrugated board over the said defined area. 3. A method according to claim 2 in which the second cutting operation is performed by a milling tool. 4. A method according to claim 3 in which the first cutting operation to delineate the defined area is performed by a milling tool which is narrower than the milling tool performing the second cutting operation so as to cut a narrow groove in the board. 5. A method according to claim 2 in which at least the first cutting operation is performed by a disc knife. 6. A method according to any one of claims 1 to 5 in which both overlapping portions of the blank are reduced in thickness so as to leave substantially only a liner to overlap with the other portion of the blank when the box is assembled. 7. Apparatus for forming box blanks of corrugated board, including means (32,34) for feeding blanks in succession along a feed path in a direction parallel to .opposite edges (8,10) of the. blank (2) which are to be overlapped and joined together to form a flat tube prior to formation into a box, and cutting means (44,48; 144,148; 77,78; 84,86) arranged to act upon the opposite edges of the blank, while the blank is moving past the cutting means, to cut away portions of the respective outer liners and corrugated medium from the areas of the blank which are to overlap. 8. Apparatus for reducing the thickness of overlapping areas of box blanks (2) of corrugated board consisting of at least one layer (C) of corrugated medium sandwiched between two outer liners (L1,L2), including means C3234) for;: conveying blanks .in succession past cutting means comprising a first cutter (44; 144; 77; 84) for cutting through an outer layer of each blank to delineate a defined area which wil 1 overl ap a simil ar area at an opposite edge of the bl ank when the blank is assembled into a box, and a second cutter (48; 148; 78; 86) arranged to cut away substantially the entire thickness of the corrugated board over the said defined area. 9. Apparatus according to claim 8 in which the second cutter comprises a mill ng tool (4S-; 148.. 10. Apparatus according to claim 9 in which the first cutter comprises a milling tool (44; 144) which is narrower than the second cutter to cut a narrow groove in the board. 11. Apparatus according to claim 8 in which at least the first cutter (77; 84) comprises a disc knife. 12. Apparatus according to any one of claims 7 to 11 including at least one box member (60; 61; 90; 92) for supporting the blank while it is being cut and having at least one aperture (62; 63; 9.4; 9 ' 6) through which suction within the box is transmitted to hold the blank in contact with the box.

Inventors: STUTT COLIN, STUTT, COLIN
Applicants: LANGSTON MACHINE, THE LANGSTON MACHINE COMPANY
Application year: 1987
Main classification: B31B1
IPC codes: B31B1, B31F7