Loading apparatus for bag packaging system and method of operating the same

A bag loading apparatus (26) of a packaging system (10) includes a platen (68) having a convex upper surface upon which layers of bags (16) are sequentially placed, with the platen (68) being lowered upon receipt of each layer, until a full stack is supported on the platen (68). The loading apparatus (26) also includes a pivotally mounted pusher plate (98) against which the layered bags (16) are arranged when supported on the platen (68). Furthermore, a shelf (58) is arranged above both the platen (68) and the pusher plate (98) and is preferably pivotally mounted about a common axis with the pusher plate (98). With a stack of bags (16) on the platen (68), the pusher plate (98) accelerates across the platen (68) to shift the bags (16) into an open container (28), with the bags (16) preferably assuming a generally wedge-shape to aid in the loading of the bags (16) into the container (28). The shelf (58) preferably moves in unison with the pusher plate (98) during the loading sequence and retreats following the loading process to, receive a first layer of bags (16) for a subsequent stack which is transferred to the platen (68) following a full return of the pusher plate (98) and shifting of the platen (68) to a raised position.

BACKGROUND OF THE INVENTION 
The present invention pertains to the art of packaging and, more 
particularly, to a method and apparatus for loading a stack of pliable 
bags into a container of an overall packaging system. 
Various automated packaging arrangements wherein bags or the like are 
stacked in a desired array and then simultaneously loaded into a carton or 
other type of container have been proposed over the years. For instance, 
it is known in the art to provide a carrier for receiving and transporting 
bags which are individually dropped or otherwise directed into an open 
carton. This type of packaging system results in a packed carton having a 
considerable amount of wasted space between adjacent bags housed therein. 
Another known type of packaging system first stacks a predetermined number 
of bags upon a pallet or other supporting surface and then places a carton 
over the entire stack of bags. Thereafter, both the carton and pallet are 
inverted. Finally, the pallet is removed to arrive at the fully loaded 
carton. Such a packaging system can be fairly time consuming and often 
requires a considerable amount of operating space. In still another known 
type of packaging system, bags are collated upon a planar supporting 
surface and then shifted along the surface by a pusher plate into a 
carton. This kind of packaging system is considered to exhibit 
considerable advantages in efficiency and overall associated costs, yet 
can exhibit significant drawbacks depending on the particular system 
design and layout. 
In developing a pliable bag packaging system, various parameters must be 
considered. For instance, the contents of bags can significantly impact 
the manner in which the bags can be loaded. For example, if the bags 
contain rather fragile food items, such as potato chips or the like which 
can be easily crushed, the packaging system must safeguard against 
damaging the stored product. In addition, it is desirable to minimize any 
wasted space in the packaged cartons in order to reduce potential shifting 
and damaging of the bags during subsequent transporting, while also 
reducing the amount of material needed to form the cartons. Of course, the 
smaller the size tolerance between the carton and the stacked bags, the 
more difficult it is to assure a rapid and reliable overall packaging 
system. 
SUMMARY OF THE INVENTION 
The present invention addresses these and other concerns in the structure 
and operation of a packaging system by providing an apparatus for loading 
pliable bags into a carton or other form of container, with the loading 
apparatus being designed to actually utilize the contents of the bags to 
aid in both efficiently supporting and loading of the bags. In particular, 
the present apparatus includes a shelf upon which an initial layer of bags 
is placed prior to being transferred to a support platen. The platen has a 
generally convexly curved upper surface upon which additional layers of 
the pliable bags are stacked, with the platen being lowered following 
receipt of each layer. When the platen is completely stacked, a pusher 
plate is shifted to move the stack of bags along the platen and into an 
open container. 
In a preferred form of the invention, the bags are stacked upon one end 
portion of the platen and against the pusher plate. This arrangement tends 
to force the contents of the bags in an arched condition as the majority 
of the contents settles toward the pusher plate such that a generally 
wedge-shaped stack is formed. The pusher plate is preferably accelerated 
through an arcuate path to move the stack along the upper surface of the 
platen in order to maintain the wedge-shape of the stack which enhances 
the loading process. 
It is thus an object of the present invention to provide an apparatus for 
enhancing the loading of bags into an open container. 
It is another object of the present invention to reposition the contents of 
bags being stacked in order to create a generally wedge-shaped stack which 
can effectively aid in loading the bags into an open container. 
It is a further object of the present invention to utilize a pivoting 
pusher plate to shift the stack of bags across the platen and into the 
container. 
It is a still further object of the present invention to incorporate a 
shelf, adapted to be arranged above a bag supporting platen, for initially 
receiving a first layer of bags to be transferred to the platen. 
Additional objects, features and advantages of the method and apparatus for 
loading bags in accordance with the present invention will become more 
readily apparent from the following detailed description of the preferred 
embodiment thereof when taken in conjunction with the drawings wherein 
like reference numerals refer to corresponding parts in the several views.

It should be noted that all figures are drawn for ease of explanation of 
the basic teachings of the present invention only; extension of the 
figures with respect to number, position, relationship and dimension of 
the parts to form the preferred embodiment will be within the skill of the 
art after the following teachings of the present invention have been read 
and understood. Further, the exact dimensions and dimensional proportions 
to conform to specific force, weight, strength and similar requirements 
will likewise be within the skill of the art after the following teachings 
of the present invention have been read and understood. 
Furthermore, when the terms "top", "bottom", "first", "second", "upper", 
"lower", "upwardly", "downwardly", "vertical", "horizontal", and similar 
terms are used herein, it should be understood that these terms have 
reference only to the structure shown in the drawings as it would appear 
to a person viewing the drawings and are utilized only to facilitate 
describing the invention. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
A system for mechanically processing pliable bags according to the 
preferred teachings of the present invention is shown in the drawings and 
generally indicated at 10. In general, packaging system 10 includes a 
conveyor 12 for transporting pre-filled bags 16 to a position below a 
transfer mechanism 22. Although the contents of bags 16 can vary in 
accordance with the invention, in the most preferred form, bags 16 are 
pliable and contain fragile food items, such as various types of chips. 
Transfer mechanism 22 systematically picks up and deposits bags 16 unto a 
loading apparatus 26 until a predetermined array of bags are placed in a 
stack which is then loaded into a container 28, such as a foldable, 
cardboard carton. Thereafter, carton 28 is lifted by a hoisting device 32 
for delivery to a subsequent processing stage of packaging system 10. The 
present invention is particularly directed to the structure and operation 
of loading apparatus 26. However, for the sake of completeness, the 
general manner in which the overall packaging system 10 operates in 
conjunction with loading apparatus 26 will be discussed more fully below. 
In the preferred embodiment shown, transfer mechanism 22 includes a pick 
and place unit 40 incorporating a pneumatic suction head 42 which can be 
raised and lowered by means of a linear actuator 44. Suction head 42 is 
mounted for linear movement in a first direction upon a rail 48 that is 
carried by a header support 50. In addition, although not clearly shown, 
suction head 42 is also movable in a direction substantially perpendicular 
to the first direction, i.e., into and out of the page as viewed in FIG. 
1, through the use of a similar rail arrangement. In general, the 
structure and operation of transfer mechanism 22 is known in the art, does 
not form part of the present invention and will not be further discussed 
here. 
For purposes of the present invention, mechanism 22 functions to transfer 
bags 16 from atop conveyor 12 to loading apparatus 26. More specifically, 
a first layer of bags 16 are placed upon a shelf 58 of loading apparatus 
26. In the most preferred form of the invention, each layer of bags 16 
defines a row including from 2-4 adjacent bags 16, although a single bag 
16 could define each layer. As shown, shelf 58 preferably has a 
curvilinear upper surface and projects from an upper portion of a frame 62 
which is mounted for pivotal movement about a pivot shaft 64. A linear 
actuator 66 is connected to an intermediate section of frame 62. With this 
arrangement, extension and retraction of linear actuator 66 causes 
pivoting of frame 62 and arcuate movement of shelf 58. 
Arranged below shelf 58 is a platen 68 which has a convexly curved upper 
surface defined by a first end portion 70, a central apex portion 72 and a 
second end portion 74. Platen 68 is adapted to be raised and lowered 
through the use of a lifting device 76. Although lifting device 76 can 
take various forms without departing from the invention, in the preferred 
form of the invention, lifting device 76 includes a sleeve 78 that is 
slidably mounted about a fixed guide rod 80. Guide rod 80 is attached to 
an endless drive element 82 which is adapted to be selectively driven to 
raise or lower platen 68. As shown, lifting device 76 also includes a pair 
of stabilizing rods 84 and 86 which extend between and are fixedly secured 
to both sleeve 78 and platen 68. 
In accordance with the invention, platen 68 can assume a lowermost position 
as shown in solid lines in FIG. 1, a fully raised position shown in 
phantom just below shelf 58 and a number of discrete, intermediate 
positions depending on the number of layers of bags 16 to be placed 
thereon. Guide rod 80 extends at an acute angle to the vertical, 
preferably in the order of 35.degree.-40.degree., such that platen 68 is 
shifted closer to container 28 when lowered. When in its lowermost 
position, platen 68 is positioned directly adjacent a flap 88 of container 
28. During a loading process, flap 88 is adapted to be trapped to assure a 
fully open condition for container 28 by the pivoting of a trap plate 92 
about an axis defined by a pivot pin 94. 
Loading apparatus 26 also includes a pusher plate 98 which, during the 
loading of bags 16 upon platen 68, assumes the position shown in FIG. 1. 
More specifically, pusher plate 98 is positioned just outward of first end 
portion 70 of platen 68. Furthermore, pusher plate 98 extends 
substantially parallel to guide rod 80, i.e., at approximately 
35.degree.-40.degree. to the vertical such that platen 68 remains directly 
adjacent pusher plate 98 throughout its range of motion. Pusher plate 98 
is carried by a frame 100. In the most preferred form of the invention, 
frame 100 includes support arm section 104, an upper leg 108 which is 
curved in conformance with shelf 58, and a generally L-shaped frame 
section 112. Frame section 112 is preferably pivotally mounted about a 
common axis, defined by pivot shaft 64, with frame 62. Frame 100 is 
pivoted in unison with a lever 116 to which is attached a control rod 120. 
Control rod 120 is, in turn, rotatably attached to a link 122 associated 
with a cam driver 124. 
The operating of cam driver 124 is known in the art and does not constitute 
an aspect of the present invention. However, in general, rotation of cam 
driver 124 causes movement of a follower (not shown) which causes link 122 
to oscillate. Movement of link 122 results in the pivoting of pusher plate 
98 relative to platen 68 through control rod 120, link 122 and frame 100. 
An adjustment unit 126 can be provided to finely adjust the stroke of 
frame 100 during a loading operation. 
The manner in which bags are stacked upon platen 68 and then loaded into 
container 28 by loading apparatus 26 in accordance with the present 
invention will now be described. Following the loading of a prior array of 
bags 16 from atop platen 68, frame 62 is pivoted away from container 28 
and assumes the position shown in FIG. 2. Transfer mechanism 22 then 
arranges one layer of bags 16 atop shelf 58, while frame 100 is pivoted 
from the position shown in FIG. 2 to the position shown in FIG. 1. 
Thereafter, platen 68 is shifted to its fully raised position. In this 
position, pusher plate 98 is arranged at the first end portion 70 of 
platen 68. Next, shelf 58 is moved from above platen 68 by the further 
retraction of actuator 66. This movement forces the layer of bags 16 on 
shelf 58 to engage an abutment plate 128, beneath which shelf 58 shifts, 
such that the first layer of bags 16 are caused to drop onto platen 68. 
With platen 68 fully raised, the first layer of bags 16 are dropped only a 
short distance so as to prevent any damage thereto. 
Next, platen 68 is lowered a predetermined increment by lifting device 76. 
In the most preferred form of the invention, platen 68 is adapted to 
receive four layers of bags 16 such that platen 68 is to be lowered from 
its fully raised to its lowermost position in three incremental stages. In 
any event, platen 68 is lowered following the placement of each layer 
thereon. FIG. 3 best illustrates the shifting of platen 68 following 
receipt of the first layer of bags 16, with the second layer being 
completed by transfer mechanism 22. This operation continues until a 
requisite number of layers is supported upon platen 68. Again, in the most 
preferred form of the invention, four layers of bags 16 are stacked upon 
platen 68. 
At this point, it should be noted that at least a majority of each bag 16 
is supported by the first end portion 70 of platen 68. Due to the 
curvature of the upper surface of platen 68, the contents of the bags 16 
are generally forced to assume an arched configuration, with a majority of 
the contents settling toward pusher plate 98. Therefore the bags tend to 
somewhat lean against pusher plate 98 and this relationship is maintained 
for each layer since platen 68 is lowered in a plane which is 
substantially parallel to pusher plate 98. In any event, this arrangement 
advantageously promotes a wedge or funnel shape formation of the bags 16 
as perhaps best shown in FIGS. 3 and 4. Once platen 68 is fully lowered, 
frames 62 and 100 are caused to simultaneously pivot about shaft 64 for 
loading of bags 16 in container 28. At this time, trap plate 92 is also 
caused to pivot in order to maintain flap 88 in a fully open condition 
which creates a loading chamber defined by platen 68, pusher plate 98 and 
the sides relative to which platen 68 and pusher plate 98 move and which 
contains bags 16 in their pack pattern. 
The movement of pusher plate 98 above platen 68 results in the shifting of 
bags 16 from first end portion 70, across apex portion 72, along second 
end portion 74 and into container 28. While shifting the bags 16 toward 
container 28, it is desirable to maintain the wedge configuration of the 
bags 16 to enhance the loading of the bags 16 into container 28. This 
preferred feature of the present invention is aided by pusher plate 98 
being continually accelerated while forcing bags 16 across the upper 
surface of platen 68. However, pusher plate 98 stops short of container 28 
to prevent a high pressure rise at container 28 which could result in bags 
16 blowing out of the established pack pattern. In addition, pusher plate 
98 is caused to travel on a radius substantially equal to an associated 
radius of platen 68. 
At this point, it should be recognized that container 28 preferably extends 
at an angle substantially tangent to second end portion 74 during loading. 
With this arrangement, the stacked bags 16 can be efficiently shifted into 
container 28, from a generally horizontal condition upon loading apparatus 
26 to a more vertical condition within container 28, without being 
displaced from the desired pack pattern. Of course, this efficient 
operation is enhanced by the arrangement of trap plate 92 which 
essentially acts as an extension of platen 68 during loading of bag 16 
into container 28. 
Once the stack of bags 16 is loaded into container 28, pusher plate 98 
starts to pivot back to the position shown in FIG. 3. Once pusher plate 98 
has returned approximately 10.degree., trap plate 92 opens to allow the 
loaded container 28 to be removed by hoisting device 32 and replaced by a 
new, empty container 28. However, shelf 58 does not fully retract but 
rather, as indicated above, assumes the position of FIG. 2 in order to 
initiate the next loading cycle so that the production line can continue 
at a desired rate without stopping during the loading process. Once pusher 
plate 98 is fully returned, platen 68 is fully raised. Again, shelf 58 
retracts after a new layer of bags 16 is placed thereon to allow the new 
layer of bags 16 to drop onto platen 68, followed by a lowering of platen 
68 and a repeat of the above-described operation cycle. 
Based on the above, it should be readily apparent that loading apparatus 26 
incorporates various structural features which combine in a synergistic 
manner to enhance the efficient loading of bags 16 onto platen 68, as well 
as into container 28. More particularly, due to the curative of the upper 
surface of platen 68 and the arrangement of pusher plate 98, a stack of 
bags 16 can be caused to assume a desirable pack pattern and shape for 
loading. In addition, the manner in which the angled pusher plate 98 is 
pivoted across the upper surface of the platen 68 enables the pack pattern 
to be maintained throughout the loading sequence for the bags 16. This 
loading operation is further enhanced by the arrangement of trap plate 92 
and the angling of container 28. 
Now that the basic teachings of loading apparatus 26 according to the 
present invention have been set forth, it should also be apparent that 
other variations will be obvious to persons skilled in the art. Thus the 
invention disclosed herein may be embodied in other specific forms without 
departing from the spirit or general characteristics thereof, some of 
which forms have been indicated, and the embodiment described herein 
should be considered in all respects illustrative and not restrictive. The 
scope of the invention is to be indicated by the appended claims, rather 
than by the foregoing description, and all changes which come within the 
meaning and range of equivalents of the claims are intended to be embraced 
therein.