Device and method for repeatedly forming a preselected arrangement of conveyed articles

Device and method are disclosed for repeatedly forming a predetermined arrangement of conveyed articles. Cylindrical articles, such as cans, are accumulated on a conveying unit at an accumulating area, the articles at the accumulating area being normally in a pattern, such as being in nested relationship. A stop unit is provided to repeatedly allow preselected numbers of articles to pass from the accumulating area on the conveying unit into a sweep area having a sweep unit including sweep arms each of which is utilized to alternately lead and push articles by group through the sweep area to a receiving area, such as a palletizer. The conveying, stop and sweep units are controlled to cause coordinated movement therebetween, the conveying and sweep units being operated at various speeds as each group of articles passes the stop unit. When a particular stagger arrangement, such as a Number One Stagger arrangement, is needed at the receiving area, a repositioning unit is provided adjacent to the stop unit, the repositioning unit removing articles from a first group of passed articles and then inserting the removed articles into a later group of passed articles.

FIELD OF THE INVENTION 
This invention relates to arranging conveyed articles, and, more 
particularly, relates to palletizing tiers of articles in a preselected 
arrangement. 
BACKGROUND OF THE INVENTION 
It is oftentimes necessary to convey articles between different locations 
and/or form the articles into a suitable arrangement for a particular 
purpose. Where cylindrical articles, such as cans, are to be conveyed from 
location to location, it is well known that such articles can be conveyed 
along a belt from one location to another. 
It is also now known that conveyed cylindrical articles can be formed into 
a single line (see, for example, U.S. Pat. Nos. 4,500,229, 4,730,955 and 
Re. 32,684) or formed into a plurality of rows, including being formed 
into a nested relationship (see U.S. Pat. Nos. 2,535,880, 3,685,632, 
4721,419, 4,834,605 and 4,934,508). 
It is likewise known that articles can be repeatedly conveyed by groups of 
articles, such as by tiers of articles to be palletized (see, for example, 
U.S. Pat. Nos. 4,759,673, 4,834,605 and 4,934,508). It is also known that 
tiers of articles can be conveyed to a palletizer using a sweep 
arrangement (see, for example, U.S. Pat. No. 3,934,713). 
In addition, it is also known that a Number One Stagger arrangement of 
articles, such as cans, can be effected by use of a can pick-up unit for 
removing cans and then later inserting the cans with the cans being 
transversely shifted to thereby achieve the needed arrangement for 
palletizing the cans (see, for example, U.S. Pat. No. 4,154,347). 
Finally it is known that articles can be placed by tiers on a pallet with 
such tiers normally having a sheet placed between each tier on the pallet 
(see, for example, U.S. Pat. No. 4,759,673). 
SUMMARY OF THE INVENTION 
This invention provides improved device and method for repeatedly forming a 
preselected arrangement of conveyed articles, such as cylindrical articles 
and particularly cans, including repeatedly forming tiers of palletized 
articles, with the articles in each tier being in a pattern, such as a 
Number One Stagger arrangement, if then needed. 
The device includes accumulating means, conveying means for conveying 
articles through an accumulating area and a sweep area, stop means to 
repeatedly allow groups having preselected numbers of articles to pass 
from the accumulating area to the sweep area, repositioning means for 
rotating preselected articles to remove and then later insert the removed 
articles if a Number One Stagger arrangement is to be formed, sweep means 
for leading and pushing articles through the sweep area toward a receiving 
means, such as a palletizer when the articles are to be palletized, and 
control means for controlling operation of the conveying means, stop 
means, repositioning means if then utilized, and sweep means with the 
conveying means and the sweep means being each operated at different 
speeds during passage of each group of articles through the sweep area in 
conjunction with the repositioning means, if then utilized, to repeatedly 
form the desired arrangement at the receiving area, such as, for example, 
cans in a Number One Stagger arrangement on a pallet. 
It is therefore an object of this invention to provide improved device and 
method for repeatedly forming a preselected arrangement of articles. 
It is another object of this invention to provide improved device and 
method for repeatedly forming a preselected arrangement of tiers of 
articles on a pallet. 
It is still another object of this invention to provide improved device and 
method for repeatedly forming articles into a Number One Stagger 
arrangement by tiers on a pallet. 
It is yet another object of this invention to provide improved device and 
method for repeatedly forming articles into a preselected orientation 
wherein articles are caused to be conveyed by groups with such conveyance 
including movement of such articles at different speeds by both a belt 
conveyor and sweep arms operating in conjunction with a stop unit passing 
the articles by groups and a repositioning unit for effecting a Number One 
Stagger arrangement when utilized. 
With these and other objects in view, which will become apparent to one 
skilled in the art as the description proceeds, this invention resides in 
the novel construction, combination, arrangement of parts and method 
substantially as hereinafter described, and more particularly defined by 
the appended claims, it being understood that changes in the precise 
embodiments of the herein disclosed invention are meant to be included as 
come within the scope of the claims.

DESCRIPTION OF THE INVENTION 
As best shown in FIGS. 1 through 3, this invention allows received articles 
12 (such as cylindrical articles and particularly cans as illustrated) to 
be conveyed through accumulating area 14 and sweep area 16 in a manner 
such that a predetermined arrangement of articles is repeatedly conveyed 
to receiving area 18. 
While not essential for some uses, it is preferred that articles received 
at accumulator area 14 either be in a pattern when received or be arranged 
in a pattern at accumulator area 14, which pattern is preferably a nested 
arrangement when used in connection with a pallet 20 for palletizing 
articles at receiving area 18. A nested arrangement of articles is known 
as brought out in the background set forth above. 
As shown in FIG. 1, an endless belt conveyor 22 extends through both 
accumulating area 14 and sweep area 16 to receive articles to be conveyed. 
As also shown, side rails 24 are provided at the opposite sides of belt 22 
to maintain articles on the belt conveyor. 
As also shown, endless belt conveyor 22 extends around rollers 26 and 28 
(journaled for rotation on main frame 30), with roller 26 being rotatively 
driven by electric motor 32 through gear box 33. Motor 32 is preferably a 
constant torque, variable speed motor the speed of which is controlled by 
control unit 34 (control unit 34 is preferably a programmable 
microprocessor controller capable of energizing motor 32 to cause the 
motor to operate at varying speeds during predetermined portions of each 
cycle of operation of the device). 
Stop unit 36 is provided at discharge end 37 of accumulating area 14. Stop 
unit 36 may be operated as an independent unit as shown in FIGS. 4A and 
4B, or may be operated in conjunction with repositioner unit 38 as shown 
in FIGS. 5A and 5B. 
As shown in FIGS. 4A and 4B, stop unit 36 includes a plurality of spaced 
fingers, or plungers, 40 each of which is inserted into a different one of 
the leading row of articles 12 extending transversely across the top of 
endless belt conveyor 22. Sufficient fingers must be provided to assure 
against passage of articles past the stop unit when the stop unit is in 
the stop position as shown in FIGS. 4A and 4B (with a nested arrangement, 
plungers are inserted into the lead article of every other longitudinally 
extending row of articles). 
As best shown in FIGS. 4A and 4B, plungers 40 are mounted along arm 42, 
which arm is mounted on brackets 44 positioned at the outer edges of 
movable frame 46. Brackets 44 have a bore 47 therein to receive a rod 49 
mounted at opposite ends on rod mount 50 so that brackets 44 can slide in 
either direction along rod 49. 
Pneumatic cylinder 52 is mounted on main frame 30 (as is rod mount 50), and 
piston 53 of pneumatic cylinder 52 is connected with movable frame 46 
through piston linkage 54 so that plungers 40 are moved (in a generally 
vertical direction) toward and away from articles due to movement of 
piston 53 moving brackets 45 along rod 49. As best indicated in FIG. 4A, a 
second pneumatic cylinder 56 is connected to main frame 30 and piston 58 
of pneumatic cylinder 56 is connected to rod mount 50 so that rod 49 is 
rotated about pivot pin 60 received through an aperture in main frame 30 
and an aperture in flange 61 of rod mount 50 to cause plungers 40 to be 
rotated in an arc parallel to the intended direction of article travel in 
passing from accumulating area 14 to sweep area 16. 
Plungers 40 (which may be tapered at the lower end as shown if FIG. 4A) are 
rotated and lowered into articles 12 to establish a stop position of stop 
unit 36 (as shown in FIGS. 4A and 4B) and are rotated and raised from 
articles 12 to establish a pass position of stop unit 36 by pneumatic 
cylinders 52 and 56 operated by solenoids under the control of control 
unit 34. 
For effecting some preselected patterns, and particularly for effecting a 
Number One Stagger arrangement, repositioner unit 38 is used. As best 
shown in FIGS. 5A and 5B, repositioner unit 38 operates using a vacuum 
applied through a vacuum inlet 62 to a plurality of spaced suction 
elements 63 (although magnetic or gripping fingers, for example, might 
also be utilized) with each suction element being inserted into a 
different one of articles 12 extending transversely across the top of 
endless belt conveyor 22. As best shown in FIG. 6A, suction elements 63 
are inserted in alternate rows of articles adjacent to, but offset from, 
articles having plungers 40 of stop unit 36 inserted therein (assuming a 
nested arrangement of articles as illustrated in FIGS. 6A and 6B) with 
suction elements 63 being inserted in the transverse row immediately 
downstream from the row having plungers 40 inserted therein. When removed 
articles are later inserted, the articles are transversely shifted by 
cylinder 64, connected with frame 46, and piston 65, connected with arm 66 
through slider 67, as indicated in FIG. 5A, with operation being 
controlled by a solenoid that is controlled by control unit 34. 
As shown in FIG. 5B and 6A, an additional plunger 68 of stop unit 36 is 
inserted into one article (near one edge of the conveyor belt) in 
transverse alignment with suction elements 63. As brought out hereinafter, 
this allows the longitudinally extending outer row (i.e., extending in the 
intended downstream direction of travel of articles) to be displaced 
rearwardly by one article diameter (while shown in FIGS. 6A and 6B to be 
the left outer row that is displaced, the right outer row could be 
displaced instead of the left outer row if desired). 
As best shown in FIGS. 5A and 5B, suction elements 63 are mounted along arm 
66, and arm 66 is connected with pivot element 69 to pivot about pin 70 
connected with movable frame 46 of stop unit 36. Pivot element 69 is 
connected to piston 71 of pneumatic cylinder 72 (allowing movement of 
piston 71 along pivot element 69, such as sliding movement, as necessary 
to accommodate transverse shifting of the repositioner unit), and 
pneumatic cylinder 72 is connected with movable frame 46 so that actuation 
of piston 71 by a solenoid under the control of control unit 34 causes 
suction elements 63 to be rotated in an arc parallel to the direction of 
intended downstream travel of articles 12 toward sweep area 16 from 
accumulator area 14. Since repositioner unit 38 is connected with movable 
frame 46 of stop unit 36, repositioner unit 38 is also moved upwardly and 
downwardly along with stop unit 36. 
When the repositioner unit is utilized, articles to be repositioned are 
contacted by suction elements 63 and rotated out of the path of the 
articles following behind the articles being removed (i.e., the articles 
travelling along conveyor belt 22 toward sweep area 16, as is shown in 
FIG. 7). For a Number One Stagger arrangement, the articles removed from a 
first group of articles passed by stop unit 36 are removed and then later 
inserted into a third group of articles by rotation of the articles in the 
opposite direction, as brought out more fully hereinafter. 
The articles passing the stop unit (and not removed by the repositioner 
unit, if utilized) are conveyed into sweep area 16 by conveyor belt 22. 
Conveyor belt 22 preferably extends to dead plate 73 positioned adjacent 
to receiving area 18. At sweep area 16, the transverse leading row of 
articles come into contact with sweep arm 74 of sweep unit 75 (shown in 
FIGS. 8A and 8B), and sweep arm 74 leads the articles through the sweep 
area toward receiving area 18. Sweep unit 75 is shown to include dual 
sweep arms 74 and 76 (which arms are preferably contoured as shown in FIG. 
8B) and arms 74 and 76 are mounted on endless chain 78 so that the sweep 
arms are alternately moved through the sweep area (as best shown in FIGS. 
9A through 9D, sweep unit 75 extends over dead plate 73 and a portion of 
receiving area 18), with sweep unit 75 including transverse support bars 
79. 
While dual sweep arms are shown herein, three sweep arms could be utilized 
for some uses (such as, for example, for less stable articles) to allow 
two arms to lead and push articles for a greater length of time than when 
dual sweep arms are utilized. When three sweep arms are utilized, 
operation is essentially the same as outlined herein for dual arms except 
that one arm is not utilized for each group of articles conveyed. 
Chain 78 is wrapped about sprocket wheels 80 and 81 at each side of the 
device with wheels 81 at opposite sides of the device being mounted on rod 
82 so that wheels 81 are rotatively driven by electric motor 83 through 
gear box 84, the speed of motor 83 being controlled by control unit 34, 
preferably through a closed loop servo system, so that the sweep arms are 
moved at different speeds, by increments, and reversed in direction as 
needed, as brought out more fully hereinafter. 
After sweep arm 74, acting as a stabilizer, has led the first group of 
articles into the receiving area, arm 74 is rotated up out of the path of 
the articles (about sprocket wheel 81) and arm 74 is thereafter moved 
rearwardly (i.e., upstream with respect to article travel) above the 
articles while sweep arm 76 (which initially was moving rearwardly above 
the articles) is now rotated down (about sprocket 80) to be behind the 
first group of articles and sweep arm 76 then pushes the articles into the 
receiving area, after which arm 76 is moved rearwardly to act as a leader 
for the second group of articles. Thus, each time the articles are moved 
by groups (or tiers), one sweep arm leads the articles while the other 
sweep arm later pushes the articles, with the sweep arms alternately 
serving as a leader and then a pusher. 
At receiving area 18, receiving means, such as palletizer unit 85, is 
utilized for receiving articles for effecting a particular end (such as 
placing the articles on a pallet when palletizer unit 85 is utilized). 
Palletizer unit 85 can be a known palletizer and preferably is a 
palletizer of the type shown in U.S. Pat. No. 4,759,673. When a palletizer 
is used, each tier of articles is conveyed onto pallet 20 at the 
palletizer (which normally includes side rails and an end rail to maintain 
the articles of each tier in the palletizer) and a separator sheet is 
normally placed between each tier with the tiers being stacked vertically 
on the conveyor as is common. 
When a palletizer is used as shown in U.S. Pat. No. 4,759,673, the 
separator sheets are transferred by a sheet transfer unit that lifts the 
sheets vertically, and, when so lifted, the sweep arms of the sweep unit 
cannot extend outwardly over the palletizer when sheet transfer is to be 
accomplished. By utilizing sweep arms as set forth herein and controlling 
movement of the sweep arms (sweep unit 75 has no portion extending into 
the area above the palletizer except for the sweep arms), it has been 
found that a satisfactory sweep can be accomplished and the arms do not 
extend over the palletizer during sheet transfer. 
Control unit 34 is accessible to an operator, and when programmed, controls 
application of electrical power to electric motors 32 and 83 (driving 
conveyor belt 22 and sweep unit 75) and controlling application of fluid 
(normally air) to pneumatic cylinders 52, 56, 64 and 72. Sensor 86 
(specifically illustrated in FIG. 1 to sense the presence of the sweep arm 
at home position) is preferably a proximity detector (where the sensed 
element is metallic), and this sensor may, if desired, be used with 
additional sensors, proximity and/or optical sensors, for example, to 
sense movement and/or position of the movable portions of each unit and/or 
article movement thereat for monitoring and/or timing purposes, it being 
appreciated that the movable portions must operate in the manner and in 
the sequence as set forth hereinafter. It is also to be appreciated that 
timing and sequencing could be carried out by a timing unit and associated 
sensors carrying out the steps of operation as set forth hereinafter. 
Operation of the device with the repositioner unit not being utilized is as 
follows for each cycle: as indicated in FIG. 9A, sweep unit 75 is at (or 
brought to) a home position, stop unit 36 is in (or brought to) the pass 
(up) position, conveyor belt 22 is operating (or brought to operation) at 
its designated fast speed (preferably about 130 to 140 feet per minute for 
aluminum cans and 100 feet per minute for steel cans), and a preselected 
number of articles to form a group of articles have been conveyed by 
conveyor belt 22 toward sweep arm 74 to thereby be positioned between 
sweep arm 74 and stop unit 36 (at commencement of operation, no articles 
are positioned between sweep arm 74 and stop unit 36); stop unit 36 is 
moved to the stop (down) position with plungers 40 being inserted in the 
transverse lead row of articles (i.e., the transverse row of articles 
immediately behind sweep arm 74); sweep arm 74 is moved forward (i.e., in 
the downstream direction of intended article movement) at a designated 
slow speed (which speed is slightly slower than that of the fast speed of 
belt 22) so that articles are led by sweep arm 74 through the sweep area 
and into the receiving area; after sweep arm 74 is indexed at the up 
position and sweep arm 76 is indexed to the down position, as shown in 
FIG. 9B, the speed of conveyor belt 22 is decreased to a slow speed (about 
half that of the fast speed of conveyor belt 22) and the speed of sweep 
unit 75 is increased to a speed about double that of the slow speed of 
sweep unit 75 (which speed is then greater than that of belt 22), and 
sweep arm 76 pushes the articles onto the receiving means (such as a 
pallet when the receiving means is a palletizer); after all articles in 
the group (or tier) have been positioned at the receiving means by sweep 
arm 76, the direction of movement of sweep arm 76 is reversed and sweep 
arm 76 is moved upstream (with respect to the intended direction af 
article movement) to the home position, as shown in FIG. 9C: plungers 40 
of stop unit 36 are moved forward a short distance (about one inch for 
articles having a diameter of about 2.5 inches and proportionately less 
for articles having a smaller diameter) and is brought to the pass (up) 
position while the sweep arm is returning to home position and conveyor 
belt 22 is increased in speed (to a speed about three-fourths of the fast 
speed of conveyor belt 22) to move a second group (or tier) of articles 
toward sweep arm 76 (which is now a lead, or stabilizer, bar), as shown in 
FIG. 9D. 
The operation is then repeated for each group, or tier, of articles to be 
positioned on the receiving means (or palletizer). 
Operation of the device with repositioner unit 38 utilized and tiers of 
articles conveyed to a palletizer in a Number One Stagger arrangement is 
as follows for each cycle: as indicated in FIG. 9A, sweep unit 75 is at 
(or brought to) a home position, stop unit 36 is in (or brought to) the 
pass (up) position, suction elements 63 of the repositioner unit are 
rotated down with respect to stop unit 36, vacuum to the suction elements 
is off, stop unit 36 is shifted to an A position (i.e., shifted away from 
displacement block 87 on sweep arm 74), conveyor belt 22 is operated at 
fast speed (as above set forth), and a preselected number of articles to 
form a third tier of articles is positioned between sweep arm 74 and stop 
unit 36 (at commencement of operation, no articles are positioned between 
sweep arm 74 and stop unit 36); sweep unit 75 is indexed forward one-half 
diameter of the articles, stop unit 36 is moved to the stop (down) 
position with plungers 40 being inserted in the second transverse row of 
articles immediately behind sweep arm 74, and suction elements 63 of 
repositioner unit 38 are inserted in the first transverse row immediately 
following sweep arm 74 (except that plunger 68 is inserted in the lead row 
of articles adjacent to displacement block 87), as shown in FIG. 6A; 
vacuum is applied to suction elements 63 and sweep arm 74 is moved in the 
downstream direction at a designated slow speed (as set forth above); 
repositioning unit 38 is rotated in the downstream direction parallel to 
the direction of intended article movement to rotate the articles in 
contact with suction elements 63 to thereby position the removed articles 
out of the path of travel of the following articles, as shown in FIG. 7; 
sweep arm 74 continues to move forward (i.e., in the downstream direction 
of article travel) at the slow speed (which speed is slower than that of 
belt 22) so that the articles of a first tier are led by sweep arm 74 
through the sweep area and onto the palletizer; after sweep arm 74 is 
indexed to the up position and sweep arm 76 is indexed to the down 
position as shown in FIG. 9B, the speed of conveyor belt 22 is decreased 
to a slow speed (about half that of the fast speed of conveyor belt 22) 
and the speed of sweep unit 75 is increased to a speed about double that 
of the slow speed of sweep unit 75 (which speed is then greater than that 
of conveyor belt 22) and sweep arm 76 pushes the articles onto the 
palletizer; after all articles of the first tier are on the palletizer, 
the direction of movement of sweep arm 76 is reversed and sweep arm 76 is 
moved upstream (with respect to the intended direction of article 
movement) to the home position, as shown in FIG. 9C; stop unit 36 is moved 
forward a short distance (about one inch for articles having a 2.5 inch 
diameter and proportionately less for articles having a smaller diameter), 
brought to the pass (up) position and shifted to a B position (i.e., 
toward displacement block 87 as shown in FIG. 6A) while the sweep arm is 
returning to home position, and conveyor belt 22 is increased in speed (to 
a speed that is about three-fourths of the fast speed of conveyor belt 22) 
to move a second tier of articles toward sweep arm 76 (which is now a 
lead, or stabilizer, bar), as shown in FIG. 9D; and conveyor belt 22 is 
then returned to fast speed and ready to convey the second and third tiers 
of articles to the palletizer. 
The second and third tiers of articles are conveyed as follows: stop unit 
36 is moved downward to the stop position with plungers 40 in contact with 
the then front row of articles of the third tier; sweep arm 76 starts to 
move at its slow speed with conveyor belt 22 operating at its fast speed 
so that sweep arm 76 starts to lead the second tier of articles into the 
palletizer; repositioner unit 38 rotates the previously removed articles 
to conveyor belt 22 to form a new front transverse row of articles of the 
third tier, after which the vacuum on suction elements 63 is removed; the 
speed of conveyor belt 22 is decreased by about one-half and the speed of 
sweep arm 74 is increased to about double when sweep arm 76 is indexed to 
the up position and sweep arm 74 is indexed to the down position so that 
sweep arm 74 pushed the second tier of articles onto the palletizer, after 
which the direction of movement of sweep arm 74 is reversed to move sweep 
arm 74 upstream to the home position; stop unit 36 is moved forward a 
short distance (about one inch for articles having a 2.5 inch diameter and 
proportionately less for articles having a smaller diameter), brought to 
the pass (up) position and shifted to the A position (i.e., away from 
displacement block 87) while the sweep arm is returning to the home 
position, and conveyor belt 22 is increased in speed (to a speed that is 
about three-fourths of the fast speed of conveyor belt 22) to move the 
third tier of articles toward sweep arm 74 (which is now again a lead, or 
stabilizer bar). 
The cycle of operation is then repeated for each group of three tiers of 
articles positioned on the palletizer to form a Number One Stagger 
arrangement of articles on the palletizer. 
As can be appreciated from the foregoing, this invention provides improved 
method and apparatus for repeatedly forming a preselected arrangement of 
articles and provides improved forming of tiers of cylindrical articles at 
a palletizer, including forming of such tiers into a Number One Stagger 
arrangement.