Apparatus for stacking articles in a side-by-side relation

An apparatus for stacking a plurality of articles in a side-to-side relation. The articles are conveyed in an upright end-to-end relation on a conveyor and a bin or article receiving member is positioned adjacent the downstream end of the conveyor and individually receives each article discharged from the conveyor. The bin includes a bottom wall and a rear wall and the bin is movable between a receiving position where the bottom wall extends downwardly and outwardly from the downstream end of the conveyor, to a discharge position where the bottom wall is disposed substantially horizontal. Each article being received within the bin is held in an upright position and is transferred laterally within the bin against a movable support plate, and each succeeding article received in the bin is transferred in a similar manner against the preceding article to form a stack. The bin is then tilted so that the bottom surface is generally horizontal and a pusher plate pushes the stack of articles forwardly out of the bin onto a discharge conveyor.

BACKGROUND OF THE INVENTION 
In a programmed conveyor system for conveying small articles or parts, the 
articles are moved sequentially through a series of workstations or 
operations. For example, in the fabrication of small plastic cases to 
contain compact recording discs, coin collections, or the like it is 
desired to have a programmed system in which the molded casing halves or 
sections are hinged together, folded to a closed condition and then 
stacked in side-by-side relation and fed as a stack into a container or 
box. 
SUMMARY OF THE INVENTION 
The invention s directed to a method and apparatus for stacking a plurality 
of small articles, such as hinged plastic cases, in side-by-side relation. 
In accordance with the invention, the articles are conveyed edgewise in 
end-to-end relation on a conveyor and an article receiving means or bin is 
located adjacent the discharge or downstream end of the conveyor so that 
each article is sequentially transferred from the conveyor to the bin. 
The bin includes a bottom wall and a rear wall and the bin is movable 
between a receiving position where the bottom wall extends downwardly and 
away from the discharge end of the conveyor, to a discharge position where 
the bottom wall is disposed generally horizontally 
As each article is transferred to the bin, it is held in an upright 
condition by a cam operated holding member. The article is then 
transferred laterally by a pusher into engagement with a support plate 
that is mounted for transverse movement relative to the bin. The article 
is held in an upright condition against a support plate by a second cam 
operated latch. 
As each article is sequentially delivered to the bin it is moved laterally 
against the support plate to form a side-by-side stack of the articles. 
When the desired number of articles have been stacked, the bin is tilted to 
bring the bottom wall to a generally horizontal attitude and the stack is 
then pushed from the bin by a pusher mechanism onto a discharge conveyor. 
The apparatus of the invention enables small articles to be automatically 
stacked in a side-by-side relation and delivered as a stack to a discharge 
mechanism for feeding to a box or container. 
As a feature of the invention the rear wall of the bin is provided with an 
ejection slot which is normally closed by a sliding gate. If a malfunction 
occurs in the conveying system, the gate is moved to a non-obstructing 
position so that each article being delivered to the bin will pass 
directly through the ejection slot and not be stacked. 
The apparatus of the invention is useable for stacking a wide variety of 
articles and has particular use for stacking vertically elongated articles 
which would normally tend to tilt and fall when being conveyed. 
Other objects and advantages will appear in the course of the following 
description.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
The drawings illustrate an apparatus for stacking a group of relatively 
thin articles 1 in sideby-side relation. As shown in the drawings, the 
articles are hinged plastic cases adapted to hold compact discs. 
The apparatus comprises a frame or supporting structure 2 and a conveyor 3 
is mounted on frame 2. Conveyor 3 comprises a frame 4 and a belt 5 is 
mounted for endless travel on frame 4. As shown in FIG. 1, articles 1 are 
conveyed edgewise in an end-to-end relation, and as the articles are 
relatively thin, a pair of guide rails 6 are mounted in spaced relation 
above belt 5 and serve to guide the articles 1 in movement. Guides 6 are 
supported by arches 6a which extend over conveyor 3. 
Articles 1 are individually fed to a stacking unit 7 where the articles 1 
are stacked in a side-byside relation to form a stack 8. The stack 8 is 
subsequently discharged onto a second conveyor 9 which is disposed 
parallel to conveyor 3 and located at a lower level than conveyor 3. As in 
the case of conveyor 3, conveyor 9 includes a supporting frame 10 and a 
belt 11 which is mounted for endless travel on frame 10. 
Conveyors 3 and 9 are driven in a conventional manner by a drive mechanism 
not shown. 
Stacking unit 7 includes an article receiving means or bin 12 in which 
articles 1 are individually received. Bin 12 includes a bottom wall 13 
which is covered by a stainless steel surface plate 14 and a rear wall 15 
extends upwardly from the rear edge of bottom wall 13. In addition, a top 
wall 16 extends outwardly from the upper edge of rear wall 15. 
Bin 12 is mounted for pivoting movement so that the bin is movable between 
a receiving position where bottom wall 13 extends downwardly and away from 
the downstream end of conveyor 3, to a discharge position where bottom 
wall 13 is generally horizontal. To provide the tilting action, a pair of 
arms 17 extend upwardly from frame 2 and pivotally connects the bin at the 
side edges of plate 13, approximately midway between the front and rear 
ends of the plate. 
To tilt the bin 12, an arm 20 is secured to rear wall 15 and the lower end 
of arm 20 is pivotally connected to the outer end of a piston rod 21 which 
is mounted for sliding movement within fluid cylinder 22 that is carried 
by frame 2. The rear end of cylinder 22 is pivotally connected to lugs 
which extend downwardly from plate 23 of frame 2. 
By introducing a fluid, such as air, into one end of cylinder 22, piston 
rod 21 will be retracted to tilt bin 12 to the inclined receiving position 
and by extending piston rod 21 the bin will be moved to the generally 
horizontal discharge position. 
The location of the connection of arms 17 with bin 12 insures that if 
cylinder 22 should lose pressure, the bin will remain in a tilted position 
due to the weight distribution and will not fall by gravity to the 
horizontal position. 
As each article 1 is received in bin 12 it is held in an upright condition 
between a transfer unit 24 and a holding member 25 which is engaged with 
the upper edge of article 1. 
Transfer unit 24 includes a transfer plate 26 having upper and lower 
protective strips 27 and 28 made of nylon or the like. A piston rod 29 of 
fluid cylinder 30 is connected to transfer plate 26. Cylinder 30 is 
mounted to side plate 31 of bin 12. By extending piston rod 29 the article 
1 can be transferred laterally across the bottom wall 13 of bin 12, as 
will hereinafter be described. 
Rear wall 15 is provided with an ejection slot 32 which is located in 
alignment with the path of travel of articles 1 as they are delivered to 
bin 12. Slot 32 is normally closed or obstructed by a gate or abutment 33 
so that the articles cannot pass through the slot. Gate 33 is connected to 
the piston or rod of a fluid cylinder unit 33a and by operation of 
cylinder unit 33a, the gate can be moved between the closed and open 
positions. However, if a malfunction occurs in the conveying system, a 
signal will be transmitted to operate cylinder unit 33a and move the gate 
33 to an open or non-obstructing position so that the articles being 
delivered to bin 12 will pass directly through slot 32 and will not be 
stacked. 
Holding member 25 is pivotally connected by pin 34 to a bracket 35 that 
extends upwardly from transfer plate 26. Holding member 25 is provided 
with a downwardly extending leg 36 which engages the upper edge of article 
1 as the article is delivered to the bin, as shown in FIG. 4. Member 25 is 
held down in the holding position by engagement of the upper surface of 
the holding member with a fixed stop 37 which projects downwardly from top 
wall 16. 
After article 1 has been received in the space between transfer plate 26 
and holding member 25 cylinder 30 is actuated to extend piston rod 29 and 
transfer the article laterally. Holding member 25 being attached to 
transfer plate 26, moves with the transfer plate and the outer end of 
member 25 is provided with an inclined cam surface 38 which engages a 
fixed roller 39 as the member 25 moves laterally. Engagement of cam 
surface 38 with roller 39 will cam holding member 25 upwardly to a release 
position to enable the article 1 to move laterally into bearing engagement 
with vertical plate 40 or with a previously stacked article 1, as shown in 
FIG. 5. The upper and lower edges of plate 40 are provided with nylon 
strips 41 which are engaged by the article 1. Strips 41, as well as strips 
27 and 28, are provided with angular supporting surfaces so that contact 
with articles 1 will be an edge contact rather than a surface contact. 
This aids in preventing scratching or marring of plastic articles 1. 
Roller 39 is mounted on the end of an arm 42 which is attached to the lower 
end of a bracket 43 that extends downwardly from top wall 16. With this 
connection, roller 39 is fixed in position relative to bin 12. 
A pivotable latch 44 is employed to hold article 1 against plate 40. One 
end of latch 44 is pivoted by pin 45 to bracket 43 and the lower surface 
of latch 44 is provided with a shoulder 46 which engages the upper edge of 
article 1, as shown in FIG. 4. 
Located between shoulder 46 and pivot 45 is an inclined cam surface 47 
which is adapted to be engaged by the upper edge of the article as the 
article is being transferred laterally by transfer plate 26. Latch 44 is 
biased downwardly by a leaf spring 48 which connects the outer end of the 
latch with bracket 43. As article 1 is moved laterally the upper edge of 
the article will engage cam surface 47, pivoting latch 44 upwardly against 
the force of spring 48 to enable the article to pass beyond the shoulder 
46. The spring will then urge the latch downwardly to move shoulder 46 
into engagement with article 1 and hold the article in an upright position 
against the plate 40, or against a previously stacked article, as shown in 
FIG. 5. 
Plate 40 is mounted for movement along the length of bin 12 and as each 
article 1 is transferred by transfer plate 26, plate 40 will move against 
the pressure of transfer plate 26. To provide this action, the lower end 
of plate 40 is provided with a bracket 49 which is attached to a carrier 
50 of band cylinder 51. Carrier 50 is attached to a piston (not shown) 
which is slidable within cylinder 51 and a connector extends through a 
sealed slot in the cylinder to connect the piston to the carrier. End 
plates 52 support cylinder 51 from bottom plate 13 and bottom plate 13 is 
formed with a slot 53 which receives bracket 49, thereby permitting 
support plate 40 to move along the length of bin 12. 
As articles 1 are being stacked against plate 40 there is no fluid pressure 
in cylinder 51 so that support plate 40 can move as the articles are 
stacked. However, the friction in the cylinder unit prevents free movement 
of the plate 40. After the stack 8 has been discharged from the stacking 
unit 7 cylinder 51 is actuated to return support plate 40 to its original 
condition, as shown in FIG. 4. 
Mounted forwardly of rear wall 15 of bin 12 is a pusher plate 54 and the 
upper and lower edges of pusher plate 54 are provided with protective 
strips 55 formed of nylon or the like. Pusher plate 54 is adapted to move 
forwardly across the surface 13 of bin 12 to discharge the stack 8 onto 
conveyor 9. To provide this movement, a cylinder 56 is mounted through 
angle brackets to the upper surface of top wall 16 of bin 12. Cylinder 56 
is a band cylinder, similar in construction to cylinder 51, and includes a 
carrier 57 which is attached to the piston and is movable along the length 
of the cylinder. Carrier 57 is connected through bracket 58 to pusher 
plate 54 and bracket 58 extends through an opening in plate 16. Thus, by 
operating cylinder 56, pusher plate 54 can be moved across bottom wall 13 
to discharge the stack 8 of articles onto conveyor 9. 
As shown in FIG. 1 a pair of spaced guides 59 are located along the side 
edges of conveyor 9 and serve to guide stack 8 in movement along the 
conveyor. Guides 59 are supported by an arch 60 that is connected to frame 
10 and extends upwardly over the conveyor. 
The apparatus provides a mechanism for automatically guiding and stacking 
articles in side-by-side relation and transferring the stack to a 
discharge site. 
The apparatus can be used to stack a wide variety of different products and 
has particular use in stacking articles which are thin or vertically 
elongated and tend to tilt or fall when being conveyed. 
In operation, articles 1 are normally conveyed in spaced relation on 
conveyor 3 and are supported between the parallel guide rails 6. As each 
article is discharged from the downstream end of conveyor 3, it slides 
along sloping bottom wall 13 of bin 12 and into engagement with the gate 
33, which is mounted on rear wall 15. The article will be supported in an 
upright condition in bin 12 between transfer plate 26 and holding member 
25. 
Transfer cylinder 30 is then actuated to move the article laterally across 
bottom wall 13 of bin 12 and into engagement with support plate 40. As 
previously described, holding member 25 will be pivoted upwardly by 
engagement with the roller 39 as the holding member 25 is moved with the 
transfer plate 26 to release the article and enable the article to be held 
against plate 40 by latch 44. 
With article 1 disposed in engagement with plate 40, transfer cylinder rod 
29 is then retracted to move the transfer plate 26 back to its original 
position. 
Each succeeding article is stacked in the same manner and support plate 40 
moves along bottom plate 13 to accommodate the stacking. 
When the desired number of articles have been stacked in bin 12, piston rod 
21 of cylinder 22 is extended to tilt the bin, so that the bottom wall 13 
is in a generally horizontal position. Cylinder 56 is then operated to 
cause pusher plate 54 to move forwardly to discharge the stack onto 
conveyor 9 where it can be transferred to other processing equipment. 
After discharge of the stack from bin 12, cylinder 56 is activated to 
return pusher plate 54 to its retracted position and the support plate 40 
is returned to its original position by action of cylinder unit 51. 
If for some reason, articles 1 are not spaced on the conveyor, but instead 
are in end-to-end relation, a stop 61 , which is located at the downstream 
end of conveyor 3, is employed to sequentially feed the articles to bin 
12. Stop 61 is supported from arch 6a by bracket 62. Stop 61 can be 
constructed in the manner as shown in U.S. Pat. No. 4,487,309 and is 
movable between an obstructing position, where it will be engaged by the 
leading edge of an article 1 to prevent movement of the article on the 
moving conveyor belt 5, to an non-obstructing position where the stop will 
not interfere with movement of the article on the belt 5. Stop 61 is 
actuated by a sensing system and acts to stop the end-to-end train of 
articles and sequentially release each article to bin 12. 
Various modes of carrying out the invention are contemplated as being 
within the scope of the following claims particularly pointing out and 
distinctly claiming the subject matter which is regarded as the invention.