Stacking machine and method

The disclosure relates to a stacking machine which cuts a multiply rope into bundles, clamps the lead ends of the bundles against a conveyor which moves the bundles to stacking stations where the bundles are collected in stacks. Completed stacks are transferred to a takeaway conveyor.

FIELD OF THE INVENTION 
The invention relates to machines for cutting, conveying and stacking web 
material and related methods. 
DESCRIPTION OF THE PRIOR ART 
Conventional stacking machines receive a continuous rope of web material, 
cut the rope into multiply bundles and stack the bundles. The stacks are 
discharged for subsequent processing. In a prior machine, disclosed in 
U.S. Pat. No. 5,328,323, handling of the severed bundles is facilitated 
because the plies are wetted and cohere to each other. The cohesion holds 
folded plies on the top of the bundles down flat on the bundles as the 
severed bundles are moved from the cutting rolls downstream to a stacking 
station. However, this stacking machine is unsuitable for stacking bundles 
severed from multiply ropes formed of folded dry web material where the 
plies are not wetted and the top ply is not cohesively bonded to the lower 
plies and is susceptible to being blown up and then bent out of proper 
position on the bundle. 
SUMMARY OF THE INVENTION 
The invention is an improved article stacking machine and method for 
continuously stacking articles, typically folded sheets or stacks of 
folded sheets, supplied to the machine. A cutter cuts a continuous rope to 
form the articles. 
The machine and method are particularly useful in high production rate 
continuous stacking of bundles severed from the lead end of an indefinite 
length multiply dry rope fed to the machine. The rope typically includes 
four or five stacked plies of folded dry web material, such as fabric 
softener sheets or paper towel sheets. The plies may be folded as desired. 
A Z-fold is typical. Bundles are stacked without fold back of the sheet 
edges. While the machine is particularly adapted to rapid production 
stacking of dry bundles, it may also be used to stack bundles which have 
been wetted. 
Other objects and features of the invention will become apparent as the 
description proceeds, especially when taken in conjunction with the 
accompanying drawings illustrating the invention, of which there are five 
sheets and one embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Stacking machine 10 includes a rectangular frame 12 supporting a cutter, a 
pair of bundle cutoff rolls 14, a bundle conveyor 16 extending downstream 
from the rolls 14, a pair of like drop-type stations 18 and 20 spaced 
along conveyor 16 and a stack takeaway conveyor 22 located to one side of 
bundle conveyor 16. 
Cutoff rolls 14 are of the type disclosed in U.S. Pat. No. 5,363,728, 
assigned to Elsner Engineering Works, Inc., the disclosure of which is 
incorporated herein by reference. The cutter includes a knife roll 24 
having three radially extending and circumferentially spaced cutoff knives 
26 and an anvil roll 28 located below the knife roll and cooperative with 
the knife roll. Both rolls 24 and 28 are rotated by appropriate drives in 
the directions of arrows 30 shown in FIG. 2 to sever the lead end of a 
flat multiply rope of folded web material. The rope is fed downstream in 
the direction of arrow 32 between the rolls, as shown in FIGS. 1 and 2. 
The end of the rope is cut into multiply segments or bundles which are 
discharged from the cutoff rolls and are fed downstream to the bundle 
conveyor 16 which moves the bundles to stacking stations 18 and 20. 
Conveyor 16 includes a pair of elongate horizontally extending vertical 
plates 34 and 36 extending in a downstream direction from rolls 14. 
Continuous flat conveyor belt 38 is wound around a pair of rollers 40 and 
42. Roller 40 is located immediately downstream and slightly above the nip 
between cutoff rolls 14. A suitable drive rotates roll 40 in the direction 
of arrow 44 to move the lower run 46 of belt 38 in a downstream direction 
away from the cutoff rolls. Lower run 46 faces downwardly and slides along 
a fixed elongate support plate 48 extending over and past stations 18 and 
20. 
Endless toothed clamp conveyor belt 50 is wound around a pair of toothed 
rollers 52 and 54 as shown in FIGS. 1 and 2 and includes an upper run 56 
extending between the rollers. Belt 50 and rollers 52 and 54 are offset to 
one side of belt 38, as illustrated best in FIG. 1. A plurality of clamp 
arms 58 are mounted on belt 50 and extend from belt 50 toward and under 
belt 38. 
Each clamp arm 58 includes an elongate base 60 extended transversely across 
the outer surface of belt 38 and an arm extension 62 which projects from 
the base toward and under belt 38, as illustrated in FIG. 3. The extension 
62 is connected to base 60 by horizontal hinge connection 64 to permit 
upward pivoting of the extension toward the lower run 46 of belt 38. 
Tension spring 66 extends between supports extending above the base 60 and 
extension 62 to bias the extension upwardly about the hinge connection. 
Upward pivotal movement of the arm extension is limited by adjustable stop 
68 on the base which engages an abutment 70 on extension 62 adjacent the 
hinge. See FIG. 5. 
Mounting plate 72 is secured to the side of base 60 away from spring 66 
with belt 50 sandwiched between the plate and the base. The plate includes 
a rib which fits within a groove on the side of the belt away from the 
base to accurately hold the clamp arm on the belt in a desired 
longitudinal position on the belt and with the base extending 
perpendicularly to the belt. 
Clamp element 74, which may be formed of relatively low friction nylon, is 
mounted on the free end of extension 62 on a pivot pin 76 which permits 
pivoting of the element about an axis extending parallel to the axis of 
hinge 64 and along the length of lower belt run 46. Free pivoting of the 
upwardly facing clamp element about pin 76 insures that the clamp surface 
on the top of the element is held up flush against a bundle clamped 
between the member and belt 38, independent of the thickness of the 
bundle. 
A suitable drive continuously moves the upper run 56 of belt 50 downstream 
between rollers 52 and 54 at the same speed that the lower run 46 of belt 
38 moves downstream from roller 40 to roller 42. The mounting plates 60 
extend beyond the edges of clamp belt 50, as indicated in FIG. 3, and are 
seated in opposed recesses 78 formed in the flanges of rollers 52 and 54 
as the clamp arms are moved around the rollers. Positive engagement 
between the clamp arms and rollers supports the arms as they are brought 
up and into engagement with the under sides of lead ends of severed 
bundles to clamp the bundles against lower run 46 of belt 38, as 
illustrated more clearly in FIGS. 8-10 and described more fully below. The 
drive for belt 50 rotates roller 52 in the direction of arrow 80. 
As the clamp arms 58 are moved downstream from roller 52, the end of the 
base away from belt 38 is fed into a slot in longitudinal guide bar 82. At 
the same time the end of the base adjacent hinge 64 is brought into 
engagement on longitudinal support bar 84. Bars 82 and 84 extend along the 
length of the upper belt run 56. The bars 82 and 84 support arms 58 to 
insure bundles are properly clamped against the lower run of belt 38 
during movement to the stacking stations 18 and 20. Each plate 72 has a 
close sliding fit between bars 82 and 84 to prevent longitudinal shifting 
of the clamp arms. Longitudinal shifting of the clamp elements could shift 
the plies in the multiply bundles and cause uneven stacks. 
As illustrated in FIG. 2, roller 40 is located immediately downstream from 
the nip between knife roll 24 and anvil roll 28, and is located above 
driven roller 86. Plate 88 extends from the nip downstream past roller 86 
and under the upstream end of run 46. 
Stacking stations 18 and 20 are spaced along bundle conveyor 16 under belt 
38. Station 20 is located further downstream from rolls 14 than station 18 
and includes a slotted stack support plate 90 moveably mounted on a pair 
of vertical support rods 92 permitting vertical movement of the plate 
between full lowered and elevated positions indicated in FIG. 3. Plate 90 
is raised and lowered by a suitable drive, as will be described below. The 
upstream and downstream ends of the stacking stations are defined by 
adjustable upstream vertical guide plate 94 and downstream vertical guide 
plate 96. Plate 96 is mounted on frame 10 by eccentric vibrators 98 which 
vibrate or jog plate 96 for even stacking of bundles on the support plate. 
Stack shift comb 100 is mounted on a pair of parallel horizontal rods 102 
and includes a number of spaced fingers 104 which extend upwardly through 
slots formed in the stack support plate 90. The comb is moveable along 
rods 102 and is connected to piston rod 108 of hydraulic cylinder 110 
which, in turn, is mounted on frame 12. Cylinder 110 moves the fingers 104 
from a retracted position where the fingers are located at the bottoms of 
the slots in plate 90, as shown in solid line in FIG. 3, to an extended 
position where the fingers have been moved out of the slots in plate 90 
and into slots formed in support plate 112 of takeaway conveyor 22. Ninety 
degree slotted guide plate 114 extends along the outer side of station 20 
between plates 94 and 96 to assist in maintaining the orientation of the 
bundles during stacking. Plate 114 is slotted to permit movement of the 
fingers between the extended and retracted positions. Bundle support plate 
95 extends upstream from the top of plate 94 under conveyor run 46 and 
includes a right angle upstream-extending portion of plate 94. The plate 
95 supports trailing portions of bundles moved downstream by conveyor 16. 
The upstream end of plate 94 is located above plate 96 of stacking station 
18. 
Station 18 is like station 20 and need not be described further. Plate 95 
of station 18 extends upstream to roller 52, as illustrated in FIG. 2. 
A pair of fixed stop or release fingers 116 associated with station 20 are 
mounted on a cross bar 118 extending between plates 34 and 36 and extend 
down from the bar to either side of the support plate 48 and clamp arm 
clamp members 74. The fingers 116 are located above vibrated end plate 96 
at the downstream side of the stacking station. 
A pair of retractable stop fingers 120 are associated with station 18 are 
mounted on rotatable shaft 122 journaled in bearings in plates 34 and 36. 
An air cylinder 124 is mounted on a cross bar 126 extending between plates 
34 and 36 and is connected to an end of radial arm 128 on shaft 122. 
Extension of cylinder 124 positions the stop fingers 120 to either side of 
the support plate 48, lower conveyor belt run 46 and clamp elements 74, as 
illustrated in FIG. 6, where the ends of the stop fingers are in the path 
of downstream movement of the edges of product bundles clamped between 
elements 74 and lower conveyor run 46. See FIG. 6. Retraction of cylinder 
124 rotates and retracts the adjustable stop fingers 120 above the bottom 
of support plate 48, out of the path of downstream movement of the clamped 
bundles. 
Stack takeaway conveyor 22 includes a pair of spaced apart sprocket gears 
130, 132 and a drive chain 134 wound around the gears and having an upper 
run 136 located a short distance below plate 112. A plurality of spaced 
pusher fingers 138 are mounted at spaced intervals on chain 134. The 
fingers 138 on the upper run 136 extend upwardly through slot 140 in the 
plate and project above the plate to engage product stacks discharged from 
stacking stations 18 and 20 and onto plate 112 and move the stacks 
downstream to discharged belts 142 on takeaway conveyor extension 144. 
The operation of stacking machine 10 will now be described. 
The stacking machine operates continuously to sever successive bundles of 
folded web material from the lead end of a multiply rope fed in the 
direction of arrow 32 to cutoff rolls 14. The rope is fed downstream 
through the cutoff rolls 14 and onto plate 88. The downstream end 150 of 
the rope is fed between downstream rotating rolls 40 and 86 before the 
rope is severed to form a bundle. Belt 38 and roll 86 move downstream at a 
speed faster than the feed speed of the rope and the belt and roll slip on 
the top and bottom of the lead end of the rope until the bundle is 
severed, then engage the new bundle and accelerate the bundle away from 
the nip of cutter rolls 14. The severed bundle is then fed downstream 
between roll 86 and the conveyor belt 38 wrapped around the roll 40 at a 
speed greater than the speed at which the rope is fed downstream, creating 
gap 148 between the end of the rope and the bundle. The downstream fed 
bundle, confined between the conveyor belt 38 and plate 88 is fed past the 
end of plate 88, as shown in FIG. 8. At this time a clamp arm 58 on belt 
50 is rotated up around roller 52 and is raised up under belt run 46 and 
into contact with the downstream end of bundle 146 to positively clamp the 
lead end of the bundle against the downstream conveyor run 46, which, in 
turn, is supported by plate 48. Clamping occurs while the bundle is held 
between the belt and roller 86 and while the base of the clamp arm is 
positively supported in a notch 78 on roller 52 to increase the initial 
contact pressure between the clamp element 74 and the conveyor belt run 
46. Positive clamping ensures that the bundle is held on the belt and 
moves downstream with the belt. Clamping occurs without longitudinal or 
lateral relative movement between belt run 46, bundle 146 and the clamp 
element 74. Gap 148 widens until the next bundle is severed from the rope. 
The lead ends of the rope and of bundles cut from the rope are positively 
held on the conveyor at all times prior to release at a stacking station, 
to insure proper feeding and to prevent fold back of the edges of the dry 
webs in the bundle. Rolls 40 and 86 are spaced a distance downstream from 
the nip of cutoff rolls 14 less the length of the bundle to insure that 
the bundle is captured prior to severing from the rope. Likewise, the 
position on conveyor 16 at which the lead end of the bundle is securely 
clamped against run 46 and plate 48 is located a distance downstream from 
rolls 40 and 86 less than the length of the bundle 146. The speed of 
conveyor 16 is greater than the speed at which rope 150 is fed to the 
cutoff rolls and insures a wide gap 148 between adjacent bundles so that 
bundles are dropped at stations 18 and 20 free of adjacent upstream 
bundles. 
After the lead end of a bundle has been firmly clamped between a clamp 
element 74 and the downstream moving run 46 the arm 58 is moved from notch 
78 and downstream with run 46 to convey the clamped bundle downstream 
toward the stacking stations 18 and 20. A continuous stream of severed 
bundles are each clamped against run 46 and moved toward the stacking 
stations. Springs 66 hold the clamp elements up against the bundles. 
Clamped bundles 146 are moved downstream along conveyor 16 and are stripped 
from between the clamp arms and belt 38 at either stacking station 18 and 
20, depending upon the position of adjustable stop fingers 120. Stripping 
of a bundle from between a clamped element 74 and lower conveyor run 46 
occurs when the sides of the lead end of the bundle are brought into 
contact with a pair of stop fingers 116, 120 which are extended into the 
path of movement of the bundle. See, for instance, FIG. 6. The clamped, 
moving bundle contacts and is stopped by the fingers. The lower conveyor 
run 46, and clamp element 74 on the arm 58 continue to move downstream 
past the stripped bundle. Stop fingers 116 and 120 are located above the 
downstream end plates 96 of stacking stations 20 and 18, respectively, so 
that stripped bundles fall down into the stations. When the fingers 120 
are in the extended solid line position shown in FIGS. 6 and 7 the bundles 
are stripped from the arms and conveyor at stacking station 18 and are 
collected in a stack at station 18. When fingers 120 are retracted as 
shown in dashed lines in FIG. 7 the bundles are conveyed downstream past 
station 18 to station 20 and are stripped from the arms and conveyor belt 
at station 20 by fixed stop figures 116 to be collected into a stack at 
station 20. 
Stacking machine 10 operates continuously feeding bundles 146 alternately 
to stations 18 and 20 to form bundle stacks 152 at each station and then 
discharge the stacks from the stations onto the takeaway conveyor 22 for 
discharge from the machine. During stacking a set number of successive 
bundles 146 are stripped from between the clamp arms and belt 38 at one of 
the stacking stations and fall down onto the station stack support plate 
90. Before stacking begins, plate 90 is raised to an extended position 
illustrated in dashed lines in FIG. 3, a short distance below lower belt 
run 46. The plate is automatically lowered as the stack height grows to 
maintain a constant drop distance for the bundles to insure uniform 
stacking. During stacking vibrators 98 are actuated to jog plates 96 and 
improve the quality of the stacks. The length of bundles 146 is slightly 
less than the spacing between end plates 94 and 96. Further, the width of 
the bundles is slightly less than the spacing between fingers 104 of comb 
100, when retracted and guide plate 114. The geometries of the two 
stations 18 and 20 insure that the rectangular bundles fall down from 
conveyor 16 and are collected in a uniform stack 152 on descending support 
plate 90. 
After the proper number of bundles for making up full stack 152 have been 
collected at a first station 18, 20 cylinder 124 is actuated to either 
retract or extend arms 120 so that the bundle conveyor moves successive 
bundles to the other stacking station where the bundles are stripped from 
between the clamp arms and belt, fall down on raised plate 90 and form a 
second stack. 
At this time, the support plate at the first stacking station is fully 
lowered or has previously been lowered to the level of plate 112 of 
takeaway conveyor 22 as shown in FIG. 3. Cylinder 110 for the station is 
then retracted to move the shift comb 100 from the extended solid line 
position to the retracted dashed line position shown in FIG. 3 and shift 
the completed stack 152 from support plate 90 onto plate 112 between a 
pair of pusher fingers 138. The drive for takeaway conveyor chain 134 is 
then actuated to push the completed stack downstream along conveyor 22 and 
onto the takeaway belts 142 for subsequent operations, which 
conventionally include packaging of the stack. Cylinder 110 is then 
extended to retract the comb 100 and the plate drive is actuated to fully 
raise plate 90 and return the stacking station to position for receiving 
the first bundle of the next stack to be formed at the station. The drive 
for takeaway conveyor 22 is deactivated until another stack is placed on 
plate 112. 
Rope 150 may be formed from a number of plies of folded dry web material. 
These plies do not adhere to each other in the rope. The lead ends of the 
rope and of the bundles are confined during transfer from the cutting 
rolls to clamping on conveyor belt 38 in order to prevent displacement or 
fold back of the leaves or edges of the web material. 
Machine 10 operates at a high production rate and is capable of cutting and 
stacking as many as 480 to 600 eight and one-half inch long bundles per 
minute to form 16 to 20 full height stacks per minute. The bundles may 
have as many as six or more plies. 
While I have illustrated and described a preferred embodiment of my 
invention, it is understood that this is capable of modification, and I 
therefore do not wish to be limited to the precise details set forth, but 
desire to avail myself of such changes and alterations as fall within the 
purview of the following claims.