Patent Publication Number: US-4317320-A

Title: In-line carton slitting, flap folding and flap gluing apparatus

Description:
BACKGROUND OF THE INVENTION 
     Some shipping cartons are manufactured with the closure flaps folded downwardly along the sides and ends of the cartons. The flaps are maintained in the open downturned position along the sides of the carton by short integral paperboard strips or webs which connect the side flaps and end flaps at diagonally opposite corners of the carton. The flaps thus do not extend outwardly and the cartons are more easily handled during filling operations. To close the flaps after the carton is filled, the attaching webs between the end and side flaps are slit or severed to enable folding of the flaps to the closed position over the top of the carton and its contents. Conventional folding apparatus employs folding plows arranged along the sides of the moving carton to flip the flaps upwardly and over the top of the carton as the carton is conveyed between the plows. The carton must be shifted 90° to employ such folding plows to flip the end flaps after the side flaps are folded or vice versa. One such arrangement requires two conveyors at right angles. Other apparatus requires bump turning. This arrangement is impractical where there are space limitations in the carton filling facility. U.S. Pat. No. 3,533,214 is illustrative of right angle conveyors to accomplish slitting of flap webs. 
     SUMMARY OF THE INVENTION 
     The apparatus of the invention includes rotating brush assemblies for folding the leading and trailing flaps of filled cartons as they are conveyed to a glue station and before the other flaps are folded. In the disclosed embodiment, the brush assemblies have circular disc shaped heads with bristles extending outwardly from a bristle mounting head. Brushes having other shapes, i.e. cylindrical, tapered, etc. could be employed to obtain some of the advantages of the invention. The bristle heads are adjustably supported for rotation at an appropriate angle with respect to the conveying path so that the bristles converge into the conveying path to engage and sweep the cartons leading and trailing flaps in the direction required to fold the flaps over the top of the carton. The brushes are easily adjusted for different size cartons by mounting heads which enable universal adjustment. The brush elements are desirably yieldable or compressible because the cartons squeeze through the spaced brushes during the folding action. 
     After the leading and trailing or end flaps are folded, the cartons are conveyed to a glue application station where glue is applied on the folded end flaps and the other flaps are plowed shut over the end flaps. The apparatus of the invention is appropriate for closing carton flaps whether they are end or side flaps if the cartons are conveyed past the brushes as herein disclosed. 
     The brush assemblies provide an efficient and easily adjusted mechanism for folding flaps without the complex mechanisms shown in various prior art patents such as U.S. Pat. Nos. 2,268,423; 3,821,875; and 3,533,214. 
     Further objects, advantages and features of the invention will be apparent from the disclosure hereof. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic plan view of the carton flap folding apparatus of the invention. 
     FIG. 2 is a diagrammatic side view of the carton flap folding apparatus shown in FIG. 1. 
     FIG. 3 is a fragmentary diagrammatic perspective view of the fixed knife and associated conveyor shown in FIGS. 1 and 2. 
     FIG. 4 is an enlarged diagrammatic plan view of pairs of flap folding brushes associated with the carton conveying path. 
     FIG. 5 is a view along line 5--5 of FIG. 4. 
     FIG. 6 is an enlarged diagrammatic perspective view showing action of the brushes on one side of the conveying path. 
     FIG. 7 is a diagrammatic side elevational view similar to FIG. 2 of the carton slitting station and brush folding station and including a glue station and a sealing station. 
     FIG. 8 is a plan view of the apparatus shown in FIG. 7. 
     FIG. 9 is a diagrammatic side elevational view of a modified embodiment of the apparatus of the invention. 
     FIG. 10 is a diagrammatic fragmentary side elevation view of folding brushes and the flap hold down mechanism 
     FIG. 11 is a plan view of the apparatus shown in FIG. 10. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto. 
     The apparatus disclosed herein (FIGS. 7 and 8) includes a carton slitting station 10, a flap folding station 12, a glue station 14 and a sealing station 16. The cartons 18 processed by the apparatus are best shown in FIGS. 3 and 6. The cartons 18 have front or leading end flaps 20 and rear or trailing end flaps 22 and side flaps 24 and 26. The cartons as manufactured have connecting webs 28 and 30 at diagonally opposite corners (FIG. 5) which connect the end and side flaps and maintain these flaps in close relation to the container side and end walls to facilitate handling of the cartons prior to loading and sealing. Although the apparatus disclosed is provided with a slitting station 10 to slit the webs 28, 30 prior to folding the flaps over the container, the brush folding apparatus of the invention hereinafter described can be employed with cartons which are manufactured without the connecting webs 28 and 30. 
     The cartons 18 are transported during the sequence to and through the slitting station 10 and brush folding station 12 to a gluing station 14 and sealing station 16 with a series of in-line conveyors. Index conveyor 32 (FIGS. 1 and 2) delivers the cartons 18 to the conveyor 34 which moves the cartons 18 through the slitting station to a conveyor 36 which conveys the cartons through the folding station 12. The conveyor 32 delivers the cartons 18 to the conveyor 34 in timed and spaced sequence to prevent interference with the flight bars or lugs 44 (FIG. 2) carried by spaced chains 35. 
     The index conveyor 32 includes a retractable stop 46 which is adjustable longitudinally of the conveyor 32 and swung into and from the path of cartons carried by conveyor 32 by a linkage and power cylinder assembly 48. Actuation of the power cylinder linkage assembly 48 to lower the stop 46 beneath the conveyor path releases the cartons 18 so that they are picked up and pushed by the lugs 44 on the chains 45. 
     Associated with conveyor 34 is a fixed slitting blade 50 for severing the web 30 which connects the trailing flap 22 to the side flap 26. The moving flight bar of lugs 44 urges the carton web 30 against the knife 50 to make the cut. The knife blade 50 is positioned so that it will enter the gap 52 (FIG. 5) between the side flap 26 and the carton side wall and pass along inside the flap 26 until the web 30 is severed. 
     The web 28 connecting the leading flap 20 and the side flap 24 is severed by a traveling knife 60 (FIGS. 1, 2) carried by a chain 62 which makes a circuit spanning both conveyors 32 and 34. A stop 66 which is movable from beneath the conveyor bed into the conveying path holds the carton against movement while the knife 60 enters the gap 78 (FIG. 5) and moves forwardly along the side of the carton toward the front web 28. The side flaps 24 and 26 can be flared slightly outwardly by vacuum heads arranged along the sides of the conveyor to facilitate entry of the slitting knives under the flaps. 
     FIG. 9 illustrates a modified embodiment of the conveying and slitting system which includes an index conveyor 31 which is cycled to deliver cartons in sequence to a conveyor 33. Slitting of the connecting web is accomplished by a fixed knife 50 on one side of the conveyor 33 and a rotary fly knife 39 on the other side of the conveyor. Lugs or bars 41 carried on spaced chains 43 drive the carton past the fixed knife 50. The conveyor 33 deposits the carton on a conveyor 45 which supports the cartons for movement through the flap folding station and gluing station. As the carton (FIG. 9) moves down the incline to conveyor 45, the flight bar 41, which is moving faster than the carton, walks up under the rear carton flap 22 to slightly raise the flap to facilitate engagement with the folding brushes presently described. This arrangement is appropriate for long flaps. 
     In accordance with the invention, flap engaging brushes or elements are provided to raise the leading flap 20 and raise and fold the trailing flap 22. In the disclosed construction, the flap engaging elements comprise brush assemblies 70 and 72 (FIGS. 4, 5, 6). FIG. 6 shows a single brush assembly 72 for raising the leading flap 20 and a single brush assembly 70 for raising and folding the trailing flap 22. FIG. 4 shows two rear flap brush assemblies 70, 72 and two leading flap brush assemblies 72. The four brush assemblies arranged as shown in FIG. 4 maintain the cartons in a centered position on the conveyor 36 during the flap folding sequence. It may be preferable to employ one of the opposite pairs of rear brushes 70 to engage and lift the trailing flap 22 upward to the position shown in FIG. 6, and the other brush 70 of the rear pair can be used to complete the arc of folding movement from the FIG. 6 position to a position folded over the top of the carton. 
     Each brush assembly includes a brush mounting head 74 (FIG. 6) which contains a clump of bristles 76 which extend outwardly from the head 74. Each brush assembly includes a motor 80 for rotating the brush head. Means are also provided for supporting the brushes for universal movement to enable adjustment of the brush heads to the appropriate position for the carton size being processed and for the desired folding action. In the construction disclosed in FIG. 1, the means comprises a swivel mount 82 which provides movement about two transverse axes. The motors 80 can also be mounted on slides 84 to afford movement of the brush heads longitudinally along one of the axes. The mounts 82 enable the brushes to be locked in the selected position. Alternatively, they can be oscillated into the conveyor path in appropriate timed sequence. Other brush drive and mounting arrangements can be employed. In FIGS. 10 and 11, the brush heads 83 are driven by flexible cables 85. The brush heads in FIGS. 10 and 11 can be supported on vertically, laterally and angularly adjustable brackets 87 to enable proper positioning of the brushes relative to the cartons. Good folding action results if the centers of the brush heads are about the same height as the corners 77 (FIG. 6) of the cartons. 
     As shown in FIG. 1, the brushes may be inclined at an angle A with respect to a line normal or perpendicular to the carton sides and conveying path. Inasmuch as the bristles 76 which sweep the rear flaps 22 upwardly, forwardly and downwardly are traveling in arcs 85 and 86 illustrated in FIG. 6 to accomplish this movement, the bristles need not engage the carton during arc portion 85 and thus the brush head can be inclined at angle A to provide clearance during arc portion 85. One brush 70 can be employed to cause flap movement during arc 85 and another positioned to provide engagement and flap movement through arc 86. Similarly, with the brush assembly 72 the bristles 76 only have to be engaged with the leading flaps 20 and the carton during the arc portion 88 illustrated in FIG. 6 to swing the forward flaps 20 upwardly so that it can be engaged by a swing arm as subsequently described. 
     In addition to inclination of the brushes with respect to a line normal to the carton sides, the brushes also may be inclined at an angle B (FIG. 5) with respect to a horizontal plane. The angle B insures good gripping of the brush elements with the flaps during the sweeping action. Although bristle brushes are illustrated, compressible or deformable pads with a friction surface can be employed. 
     Means are provided for completing the closing of the leading and trailing end flaps after the folding action of the brushes. In the disclosed construction, as best illustrated in FIGS. 10 and 11, the means includes swing arms 102 and 104. Means are provided for moving the swing arms from advanced positions to engage the leading and trailing end flaps and retracted clearance positions above the cartons. As disclosed, the means comprises an air cylinder 106 which is connected to a gear rack 108. The rack 108 is in mesh with a gear on the shaft 110 which is fixed to arm 108. Actuation of the cylinder 106 causes counter-clockwise movement (FIG. 10) of arm 102 downwardly and forwardly from the position shown in broken lines to the position shown in full lines to engage a partially folded rear flap and complete the fold. Similarly, the swing arm 104 is moved by an air cylinder 112 and rack and gear assembly. The arm 104 is moved in a clockwise direction (FIG. 10) downwardly and rearwardly. The swing arms 102, 104 and the mechanism for swinging the arms are mounted on a frame 114 which is vertically adjustable with a hand crank 131 and elevating mechanism 118 to accommodate different size cartons. Alternatively, a fixed plow 120 (FIG. 9) located above the carton conveying path can be employed to complete the closure of the leading flap 20 and hold down both the leading and trailing flaps 20 and 22 while glue is being applied to the tops of flaps 20 and 22 by a glue applicator 100 at the glue station 14. The plow 120 desirably holds the flaps 20 and 22 down over the top of the carton until the spaced folding plows 130 located on opposite sides of the carton conveying path fold the side flaps 24 and 26 up and over the end flaps and the pressure belt 101 causes bonding of the glue on the flaps.