An apparatus for squaring folded corrugated paperboard boxes and the like includes a frame, an upper drive assembly and a lower roll assembly. The upper drive assembly and lower roll assembly define a split-nip. The upper drive assembly includes a pair of independent wheels which may be controlled to adjust or change the orientation of a folded corrugated box passing through the nip. The upper drive assembly is pivoted to the frame for adjustment of the nip. The apparatus is positioned to deliver folded corrugated boxes to a counter/ejector from a folder/gluer.

BACKGROUND OF THE INVENTION 
The present invention relates to a box making apparatus and more 
particularly to a unique device for squaring folded boxes of corrugated 
material. 
Various types of equipment are used to manufacture corrugated paperboard 
boxes or cartons. The equipment includes printers, rotary die cutters used 
for slotting and scoring and folder/gluers. Typically, blanks of 
corrugated paperboard are slotted and score lines are formed. The 
paperboard blanks are then passed into a folder/gluer. The folder/gluer 
generally employs bars, belts or rollers to progressively fold the blank 
and apply glue to form a folded box or container having the shape of a 
flattened parallelogram. The folded blanks are then transported to a 
counter/ejector or accumulator device. The blanks are stacked, counted and 
ejected in bundles. Examples of such equipment may be found in U.S. Pat. 
No. 3,850,085 entitled METHOD AND APATUS FOR FABRICATING AN ELONGATED 
CARTON, which issued on Nov. 26, 1974 to Clemm; U.S. Pat. No. 3,992,982 
entitled FOLDING APATUS FOR CORRUGATED PAPERBOARD BLANKS, which issued 
on Nov. 23, 1976 to Huiskes; U.S. Pat. No. 4,041,849 entitled APATUS 
FOR FOLDING CARTON SHEET, which issued on Aug. 16, 1977 to Tsukasaki; and 
U.S. Pat. No. 4,254,692 entitled HELICAL FOLDER FOR PAPERBOARD BLANKS, 
which issued on Mar. 10, 1989. 
The flat folded boxes are often out-of-square when they leave the 
folder/gluer. Inherent design and operational problems, such as belt 
slippage and drag on the folding bars, will produce a folded box wherein 
the flaps fold in a skewed or out-of-square manner. The stacks of folded 
boxes can be subjected to an edge beating or "spanking" action in the 
counter/ejector or other accumulator to correct the out-of-square 
condition. Spanking the folded boxes while the glue is still wet will 
square the folded container blanks in the stack. A spanker mechanism, 
however, generally works only if the boxes are slightly skewed. 
Heretofore, it has been proposed to use twisted belts driven by variable 
speed motors in an attempt to correct skewness and slot gap error. The 
twisted belts are typically mounted close to the folding crease of the 
boxes. Consequently, the belts have a limited mechanical advantage for 
correcting skewness in gap area. Such an arrangement has only limited 
utility. The box flaps, upon leaving the folding section and entering the 
counter/ejector, are immediately caught in the nip of the feed rollers of 
the counter/ejector. The rollers prevent the box flaps from shifting since 
they have greater gripping strength than the twisted belts. The rollers, 
therefore, negate the effort of the twisted belts to make any correction 
in the out-of-square condition. A conflict, therefore, exists between the 
powered, variable speed twisted belts at the end of the folding section of 
the apparatus and the fixed speed rollers at the entrance of the 
counter/ejector. 
Examples of prior devices which address the out-of-square condition may be 
found in U.S. Pat. No. 3,744,649 entitled SQUARING AND BUNDLE COUNTING 
MACHINE, which issued on Jul. 10, 1973 to Ward, Jr. and U.S. Pat. No. 
4,976,672 entitled SQUARING FOLDED CONTAINER BLANKS, which issued on Dec. 
11, 1990 to Harrison et al. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, the aforementioned problems with 
squaring of folded corrugated paperboard blanks or boxes are substantially 
eliminated. Essentially, an apparatus is provided which includes an upper 
drive assembly and a lower roll assembly which define a nip therebetween. 
The upper drive assembly includes a pair of independently controlled or 
driven upper wheels or rolls. The independently controlled upper wheels 
eliminate the aforementioned conflict between powered belts at the end of 
a folding section and fixed speed rollers at the entrance to the 
counter/ejector by allowing either wheel to advance or retard the flap 
which it is controlling. The operator of the equipment may, by observing 
the gap between the flaps of the folded corrugated blank, make the 
necessary adjustments to the relative speed of the upper split-nip wheels 
to square the folded box. 
In narrower aspects of the invention, the split-nip wheels are horizontally 
adjustable. The wheels can be mounted near the glue joint of the folded 
corrugated box to provide the maximum possible mechanical advantage for 
squaring the box. In addition, a pair of free wheeling pull-down wheels 
may be included. Further, the lower nip roll may be an elongated roller 
mounted independently of the upper drive assembly. The lower nip roll is 
powered in relationship to the speed of the folding belts of the 
folder/gluer, which feeds the folded boxes to the apparatus. In addition, 
provision is made for adjusting the nip or gap between the upper drive 
assembly and the lower roll assembly to accommodate the thickness of the 
folded box and to provide sufficient pressure to advance or retard the 
individual box flaps as required.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
A preferred embodiment of a squaring apparatus in accordance with the 
present invention is illustrated in the drawings and generally designated 
by the numeral 10. Device 10 includes a frame 12 having vertical uprights 
or side members 14, 16. Device 10 further includes an upper drive 
subassembly 18, a lower roll subassembly 20 and an adjustment mechanism 
22. Upper roll assembly 18 and lower roll assembly 20 define a nip 26. 
Frame 12 is positioned at the exit or output end of a folder/gluer and at 
the entrance to a counter/ejector. Folded corrugated board boxes 28 are 
delivered to the nip 26 along a longitudinal axis 29 of the box making 
equipment. Apparatus 18 transports corrugated board to the 
counter/ejector. 
Lower roll assembly 20 includes an elongated roller 30. Roller 30 includes 
end shafts 32, 34 supported in bearings 36, 38, respectively. Bearings 36, 
38 are supported on mounting plates 42. Plates 42 are secured to frame 
members 14, 16. Roller 20 is, therefore, rotatably supported on the frame. 
The roller is powered in relationship to the speed of the folding belts of 
the folder/gluer. The lower roll drive may be a mechanical interconnection 
with the folder/gluer, such as a pulley and belt arrangement, or an 
electrical interconnection may be used. It is preferred that the lower 
roll be driven by a variable speed drive motor and that the relationship 
be achieved electrically. The drive is schematically shown in FIG. 1 and 
designated by the numeral 45. It is presently preferred that the surface 
speed of roller 30 have substantially a one-to-one relationship to the 
speed of the folding belts. 
Upper drive assembly 18 includes mounting brackets 46 secured to frame 
uprights 14, 16. Side mounting plates 48, 50 are pivoted to a respective 
mounting bracket 46 by a pivot pin 54. An elongated cross member 56 
extends between plates 48, 50. A bearing support block or mounting plate 
60 is secured to cross member 56 intermediate the ends thereof and 
generally intermediate or centrally of plates 48, 50. A first shaft 62 
extends between plate 48 and block 60. A second shaft 64 extends between 
block 60 and plate 50. Shafts 62, 64 are rotatably mounted by suitable 
bearings at their ends at the plates 48, 50 and the block 60, 
respectively. 
A first drive motor 66 is mounted on plate 48. A second drive motor 68 is 
mounted on plate 50. Motor 66 includes an output shaft 70 to which a fly 
wheel 72 and a drive gear or pulley 74 are mounted. Output shaft 70 is 
connected to shaft 62 by a flexible drive transmission member, gear belt 
or chain 78. Flexible drive transmission member 78 extends between shaft 
70 and a gear, pulley or sprocket 80 nonrotatably fixed to an end of shaft 
62. In the same fashion, motor 68 includes an output shaft 84. A fly wheel 
86 is also mounted on the end of shaft 84. Pulleys, gears or sprockets 88, 
90 and a flexible drive transmission member 92 interconnect output shaft 
84 with shaft 64. It is currently preferred that gear belt drives connect 
the motor to the shafts. 
A pair of driven rollers or upper nip wheels 102, 104 are nonrotatably 
positioned on shafts 62, 64, respectively. Wheels 102, 104 may be adjusted 
horizontally or towards and away from mounting plates 48, 50. Also 
supported on shafts 62, 64 are a pair of free wheeling hold-down wheels 
106, 108. Wheels 102, 104 divide or split nip 26 into two independent 
sections. 
The size of nip 26 is adjusted through mechanism 22. As shown in the 
drawings, the mechanism 22 includes mounting plates or brackets 120 and a 
bellcrank arrangement 122. Arrangement 122 includes first and second arms 
124, 126. The angular relationship between arms 124, 126 is fixed, and the 
arms are pivoted to support brackets or plates 120 by a pivot pin 128. A 
shaft 130 is threaded through an aperture in arm 126. A hand wheel or 
ratchet 132 is fixed to the shaft. Rotation of hand wheel or ratchet 132 
with the shaft 130 in engagement with a side frame member 14, 16 shifts 
the position of arm 126. Arm 126, which supports adjustment wheel 132, is 
connected to arm 126 at upright 14 by an elongated linkage shaft 143. As a 
result, a change in the position of arm 126 is translated to a change in 
the position of both plates 48, 50. Arms 124 are connected to mounting 
plates 48, 50 by adjustable links 138. 
Rotation of hand wheel or ratchet 132 moves plates 48, 50 and, hence, 
wheels 102, 104 through an angle "a" (FIG. 2). It is currently preferred 
that angle "a" be a maximum of at least 10 degrees. Wheels 102, 104 may be 
moved towards and away from roll 30 to adjust the nip or spacing 
therebetween to accommodate the folded corrugated boxes. 
A piston/cylinder actuator 146 is mounted on frame member 16. Actuator 146 
includes a rod 148 connected to arm 126. Actuator 146 permits rapid 
opening of nip 26 if a folded box jams between the upper and lower 
assemblies 18, 20. 
In use, a folded, corrugated box 28 is delivered to the split nip 26 
between driven wheels 102, 104, freely rotating wheels 106, 108 and the 
lower roll 30. Wheels 102, 104 are independently controlled or driven by 
their own DC or other variable speed motors 66, 68. The operator, by 
observing the gap or skewness condition of the folded corrugated box, can 
adjust the speed of the motors 66, 68 to advance or retard the flap which 
is controlled by and engaged by the respective wheels 102, 104. In the 
alternative, an automatic gap sensing device could be used to sense 
skewness and control the drive motors to correct gap error automatically. 
A skewed box 28 with an out-of-square flap 31 before entering apparatus 10 
in accordance with the present invention is illustrated in FIG. 3A. FIG. 
3B illustrates a squared box after passing through apparatus 10. 
Wheels 102, 104 may be moved horizontally so that they are near the ends of 
the flaps and, hence, towards the gap of the folded corrugated box. The 
maximum possible mechanical advantage for squaring the box may, therefore, 
be obtained. The adjustment of the nip, the positioning of the driven 
wheel and use of the hold-down wheels ensure that sufficient pressure is 
provided to advance or retard the individual flaps as required. The 
subject split-nip squaring device eliminates the conflict heretofore 
experienced between powered, variable speed twisted belts at the end of 
the folding section and fixed speed nip rollers at the entrance of the 
counter/ejector. 
In view of the foregoing description, those of ordinary skill in the art 
may envision various modifications to the present invention which would 
not depart from the inventive concepts disclosed herein. For example, the 
individual DC motors could be replaced with a single drive motor and 
variable speed pulleys. In the alternative, variable speed pulleys could 
be driven off a powered roll of the box making equipment. The lower roll 
assembly could be a belt as opposed to the elongated roller illustrated. 
The above description should, therefore, be considered as only that of the 
preferred embodiment. The true spirit and scope of the present invention 
may be determined by reference to the appended claims.