Bag transporter, folder and loader and method for operation

A reciprocative apparatus individually folds a plurality of thin, limp, sheet-type articles, such as sandwich bags, and loads them into a carton. The apparatus includes a delivery assembly for sequentially transferring the bags from a conveyor belt to a folding station. A pivotally operated swatter is employed in the delivery assembly which includes a swatter driving mechanism which gradually decelerates the swatter near the end of its forward movement to minimize article wrinkling.

BACKGROUND OF THE INVENTION 
This invention relates to folding and loading of thin, limp, sheet-type 
articles into a receptacle therefor and particularly relates to folding 
and loading of small plastic bags, such as sandwich bags, into a 
dispensing box or carton. It also, more particularly, relates to an 
improved transporting mechanism for transporting a sheet-type article from 
a conveyor to a folding station and to the combination of the transporting 
mechanism with the conveyor and folding station. 
Plastic sheet materials present many handling and dispensing problems which 
are magnified when the sheet is thin, limp, and subject to loading by 
static electricity. Exemplary plastic sheet materials which are used in 
large quantities at the present time are plastic bags, such as trash bags, 
product bags and sandwich bags. Many of these bag products are assembled, 
shipped and dispensed in roll form. Others, however, are preferably 
handled in folded form because of consumer preferences, economy in 
storage, and/or ease of handling and dispensing. Folding of such bags can 
be performed by in-line machinery without great difficulty when the bags 
are large, as, for example, bulk bags and trash bags. 
However, when the bags are quite small, such as sandwich bags, for example, 
so many difficulties occur with presently available machinery that the 
present practice is to use manual labor for folding and loading plastic 
sandwich bags into dispensing boxes therefor. There is consequently a need 
for new concepts and arrangements that will overcome the specific problems 
peculiar to folding and loading of such thin plastic articles of 
relatively small size. These difficulties arise because the bags must be 
sequentially picked up from a conveyor, folded, folded again, transported 
to a receptacle, loaded into the receptacle and pressed against its bottom 
in order to remove entrapped air. In each of these operations, the 
lightness, limpness, thinness and smallness of the bags present special 
handling problems, particularly when static electricity is present. Simply 
scaling down conventional folding machines does not solve these problems 
because the prior art devices inherently rely upon significantly greater 
stiffness, bulk, basis weight and like properties. 
A method for sequentially packaging flexible plastic refuse bags is taught 
in U.S. Pat. No. 3,842,568, which comprises reeling a bag into a mandrel, 
pulling it sidewise in reeled condition from the mandrel and tamping the 
reeled bag into a carton. 
An apparatus is described in U.S. Pat. No. 3,918,699 for multiple folding 
of soft articles, such as textile and paper articles. It includes a 
plurality of cooperating longitudinal and transverse folding arms which 
are operable according to a predetermined sequence and which cooperate 
with folding plates. More specifically, the middle portion of an article 
to be folded is brought under a folding plate, while its side portions lie 
on the longitudinal side folding arms of the machine. The side folding 
arms then operate toward each other in sequence so they form two folds and 
longitudinally overlap the two side portions. This prefolded article is 
next delivered to a second folding station where transversely disposed 
folding arms sequentially perform similar single foldings. The 
longitudinally and transversely folded article is finally delivered to a 
stacking station. 
An apparatus and method for folding textile materials is taught in U.S. 
Pat. No. 4,008,887. It comprises a plurality of pivotal folding flap 
plates for sequentially folding the material, while gripping devices at 
the movable plates prevent unfolding and/or shifting of the material. The 
gripping members are C-shaped fingerlike elastic elements mounted on 
rotatable gripper shafts which are connected to rotatable flexible shafts 
and to a control mechanism for sequentially controlling the rotation of 
the shafts. 
SUMMARY OF THE INVENTION 
It is accordingly an object of this invention to provide a method and an 
apparatus for picking up a plurality of thin, limp, sheet-type articles 
from a conveyor, folding the articles and sequentially loading the folded 
articles into a receptacle therefor. 
It is also an object to provide a transporting means for partially folding 
each sheet article while delivering it from the conveyor to a folding 
station. 
It is further an object to provide a transporting means for delivering, by 
means of a swatter, a sheet article from a conveyor to a folding station 
without abrupt stopping and overtravel of the swatter to thereby minimize 
wrinkling of the sheet article, while still retaining a high average 
article transporting velocity. 
It is further an object to provide a transporting means of the type 
described in the preceding paragraph in combination with a sheet-type 
article conveyor and folding station. 
According to these objectives and the principles of this invention, an 
apparatus is herein provided for sequentially delivering, folding and 
loading a plurality of thin, limp, sheet-type articles into a receptacle 
or carton, after these articles have been sequentially conveyed to a 
pick-up station, and for packing the loaded articles within the carton.

DESCRIPTION OF THE EMBODIMENTS 
The apparatus of this invention comprises sheet-delivering, sheet-folding 
and folded-sheet loading assemblies, as shown in FIGS. 1-17, which 
sequentially remove a thin, limp article in sheet form from a conveyor, 
fold it into thirds and pack the folded article within a receptacle, such 
as a box or carton. The sheet-folding and folded-sheet loading assemblies 
are described herein as a folder-loader assembly. FIGS. 12-17 
illustratively show a sandwich bag as a suitable thin, limp, sheet-type 
article, but the apparatus is effective with sheet-type articles of any 
size if they are limp enough to be readily folded. 
The sheet delivering assembly comprises a pivotable swatter having prongs 
16 which nest at a pick-up station between conveyor belts 17 before a bag 
10 reaches the pick-up station, as seen in FIGS. 9 and 10. Conveyor belts 
17 stop as soon as a bag 10 arrives at the pick-up station, and shaft 15 
thereupon rotates through an arc of 180.degree., if conveyor belts 17 are 
horizontally disposed, or through an arc of 90.degree., if conveyor belts 
17 are vertically disposed, although other arcs are feasible, such as 
135.degree.. In the latter situation, it is generally desirable and 
sometimes necessary (depending on the size, weight and limpness of the 
article) that vacuum orifices (not shown in the drawings) be disposed at 
the pick-up station, as is known in the art, in order to exert a slight 
holding force upon each bag 10 and maintain it in parallel to belts 17 
before prongs 16 exert a separating force thereupon. 
Alternatively, a cylinder and cylinder rod having a pick-up device may be 
used as the delivery assembly, or an upside-down conveyor may be employed 
to deposit the picked-up article in the folding station seen most clearly 
in FIGS. 5 and 12. 
The swatter lays between conveyor belts 17 of an article-delivering 
conveyor so that prongs 16 and support tines 16a are pivotally beyond each 
sheet-type article that arrives on conveyor belts 17 and are athwart the 
article. Moreover, when conveyor belts 17 stop, each article is initially 
divided into thirds by outer prongs 16, so that center portion 12 of the 
article is between the outermost prongs 16 and the first and second end 
portions 11,13 thereof are endwise beyond these prongs. The swatter is 
actuated by a swatter driving cylinder so that shaft 15 rotates through an 
angle of 90.degree.-180.degree. to deliver the article to a folding 
station to be described hereinafter. After such delivery, the swatter 
pivots in the other direction to its waiting position beyond the surfaces 
of belts 17. 
As visible in FIG. 12, prongs 16 cause bag 10 to be partially folded while 
it is revolving, because end portions 11, 13 of bag 10 trail behind middle 
portion 12 at an angle of approximately 90.degree. and at least 
momentarily remain at this angle after arriving at the folding station, as 
a U-shaped channel which is formed by trays 91,92 and flipper tines 31,61. 
These end portions 11,13 remain, at least momentarily, upright against 
slightly diverging tines 31,61, while prongs 16 are pivoting in reverse 
toward the pick-up station, as seen in FIG. 13 after the reverse movement 
has been completed. 
If it is necessary, however, depending upon the limpness of the material of 
bag 10, tines 31,61 and shafts 32,62 can be provided with passages therein 
which can be connected to a suction/pressure device for selectively 
producing a vacuum for holding portions 11,13 against tines 31,61 and then 
for producing positive pressure to separate end portions 11,13 from tines 
31,61 after folding has been completed. Alternatively, vacuum devices can 
be disposed between tines 31,61. 
The folder-loader assembly of this invention, as seen primarily in FIGS. 
1-7, comprises a base 26, a pair of left vertical supports 21 which are 
rigidly attached to base 26, a left horizontal support 23 which is rigidly 
attached to top ends of supports 21, a pair of right vertical supports 22 
which are rigidly attached to base 26 and a right horizontal support 24 
which is rigidly attached to the top ends of supports 22. In combination, 
base 26, vertical supports 21,22 and horizontal supports 23,24 form a 
rigid frame which supports the folding, loading and packing means of the 
folder-loader assembly of the invention. 
Guide rods 25 are also attached to base 26 and to right horizontal support 
24, as partially indicated in FIG. 7. Coil springs 27, as seen in FIGS. 2, 
4 and 7, encircle guide rods 25 and perform important biasing functions 
which separate secondary folding, loading and packing operations, as is 
described hereinafter. A loading cylinder 29, having a cylinder rod 28, is 
also attached to base 26 between supports 22. 
A left flipper assembly 30, for performing the first folding operation on 
the left end portion 11 of bag 10, comprises a left flipper having tines 
31 and shaft 32, a mounting bracket 34, to which shaft 32 is rotatably 
attached and a left flipper cylinder 38 which is attached to left 
horizontal support 23 with a mounting block 37 and mounting block bracket 
36. The rod for cylinder 38 has at its lower end a clevis 39 which is 
attached to left flipper arm 41. 
An assembly 40 comprises left flipper arm 41, an upper stop 43 for arm 41 
and a lower stop 45 for arm 41. Stops 43 and 45 are rigidly attached to 
rear left support 21, as seen in FIG. 4, although they are omitted in FIG. 
1. Tines 31 revolve in direction 33 to perform their folding movement, 
while arm 41 revolves in direction 49 from stop 45 to stop 43. 
Left flipper assembly 30 is promptly actuated by cylinder 38 after the 
swatter has pivotally departed. Its tines 31 pivot in direction 33 and 
fold end portion 11 onto middle portion 12, as seen in FIG. 14, and then 
immediately return to an upright position. 
The second folding operation, the loading operation and the packing 
operation are performed by a double-function means utilizing a singly and 
linearly applied force in order to perform a pivoting movement and then a 
linear movement, wherein the pivoting movement accomplishes the second 
folding operation and the linear movement accomplishes both the loading 
operation and the packing operation. This double-function means is a 
combined apparatus which is attached to right vertical supports 22 and/or 
right horizontal support 24. Specifically, a rocker arm assembly 50, 
comprising a rocker arm 51, a rocker arm pivot 53, and a right flipper 
link 55, is pivotally attached to the upper end of cylinder rod 28 so that 
the right portion of rocker arm 41 is pulled in movement 57 as rod 28 is 
retracted. Correspondingly, the left portion of rocker arm 51 pivots in 
direction 59 as rod 28 retracts. This pivoting movement of arm 51 causes 
right flipper link 55 to move leftwardly and upwardly, as seen in FIG. 5, 
to position 55'. 
Right flipper assembly 60 comprises a right flipper having flipper shaft 62 
and tines 61 which are perpendicularly attached to flipper shaft 62, and a 
right flipper arm 66, having a link stop channel 68 therewithin, which is 
pivotally attached to the lower end of link 55. 
A pair of carriers 70 each comprise a bushing within cylinders 71 for a 
guide rod 25, a carrier support plate 73 which is rigidly attached to 
cylinder 71, a carrier support arm 77 which is extended downwardly from 
the inner end of plate 73 and is rigidly attached thereto, and a carrier 
tie bar 75 which is rigidly attached to the top edges of plates 73 and 
maintains them in parallel and rigidly aligned relationship. Carrier 
assembly 70 further comprises a rocker arm attachment bracket 79 which is 
rigidly attached to the lower side of carrier tie bar 75 and midway 
between cylinders 71, as seen best in FIG. 2. Rocker arm pivot 63, 
supporting rocker arm 51, passes through bracket 79. 
As best seen in FIG. 5, when cylinder rod 28 is retracted, bringing the 
right end of rocker arm 51 downward in movement 57 and the left end in 
reverse corresponding movement 59, so that link 55 moves to position 55', 
right flipper arm 66 pivots to position 66' and prongs 61 pivot in 
direction 63 to position 61', as seen in FIG. 1 and in phantom in FIG. 5, 
thereby laying end portion 13 onto end portion 11, as seen in FIGS. 5, 12 
and 15. 
The sheet-folding assembly has completed its operations at this point in 
time, except for returning tines 61 to upright position. However, tines 61 
and right flipper shaft 62 must first take part in loading and packing 
each folded bag 14 before returning to upright position, as parts of a 
folded-sheet loading and packing assembly which additionally comprises a 
tray actuator bracket assembly 80 and a pair of stacking tray assemblies. 
Tray actuator bracket assembly 80 comprises a bracket connection 81, a 
T-member 83, a pair of pivots 85 and a pair of tray links 87, as shown in 
FIGS. 1 and 3. A pair of stacking tray assemblies comprises left stacking 
tray 91, right stacking tray 92, a pair of left stacking tray arms 93, a 
pair of right stacking tray arms 94, left stacking tray arm upper pins 95, 
right stacking tray arm upper pins 96 and lower stacking tray pins 97. 
Bracket connection 81 attaches tray actuator bracket assembly 80 to front 
carrier support plate 73. The pair of pins 85 attach the pair of tray 
links 87 to T-member 83, and the pair of pins 97 attach links 87 to trays 
91,92 to which tray arms 93,94 are rigidly attached. Pins 95,96 
respectively attach arms 93,94 to vertical supports 21,22 at both front 
and back of the frame. 
The folded-sheet loading assembly thereupon begins to operate by sidewardly 
revolving trays 91,92 in directions 99 and pushing each folded bag 14 
toward bottom 101 of box 100 by propelling shaft 62 and tines 61 of the 
right flipper in direction 98, as shown in FIGS. 5 and 16, until the 
folded bags 14 are squeezed against bottom 101 with a force controlled by 
a packing force which equals the force of cylinder 29 less the force of 
springs 27 plus the weight of rocker arm assembly 50, right flipper 
assembly 60, carrier assembly 70, tray actuator bracket assembly 80, right 
stacking tray 92, right stacking tray arms 94 and right stacking tray pins 
95,96,97. The sheet-folding assembly then upwardly raises shaft 62 and 
tines 61 and finally pivots tines 61 to upright position, to be ready for 
delivery of the next bag 10, as seen in FIG. 11. 
This combination of folding, loading and stacking operations is achieved by 
providing in springs 27 the correct amount of force to support at least 
the combined weights of the right flipper assembly, the carrier arm 
assembly and the rocker arm assembly and additionally to resist the force 
required for cylinder 29 to pull rocker arm 51 in a clockwise pivotal 
movement, as seen in FIG. 5, until tines 61 have completed the second 
folding operation. As further downward movement of rod 28 occurs, cylinder 
29 overcomes the force of springs 27 and moves carrier assembly 70 and 
tray actuator bracket assembly 80 downwardly as a unit until the right 
flipper propels folded bag 14 onto bottom 101 or onto previously stacked 
bags 14 with a selected packing force. 
Coil springs 27, as the biasing means, are suitably five springs 
surrounding each guide rod 25. Each spring is suitably 21/4 inches high 
when uncompressed and 0.46 inch high when fully compressed. The loading is 
3.68 pounds per inch of compression. The springs are pre-loaded by fitting 
five springs into a total height of 7 inches for rods 25. The total travel 
distance when packing sandwich bags is four inches, which is divided among 
the five springs on each rod 25. Suitable springs are LC-038G11, sold by 
the Lee Spring Co. 
After the completion of these loading and stacking operations, cylinder 29 
extends rod 28, thereby relieving the pressure on springs 27 and allowing 
the entire unitary combination of right flipper assembly 60, carrier 
assembly 70 and tray actuator bracket assembly 80 to rise to the level of 
the folding station, as seen in FIG. 5, as trays 91,92 simultaneously 
return to restore the platform of the U-shaped channel. Thereafter, as rod 
28 continues to move upwardly, the right end of rocker arm 51 pivots 
counterclockwise and right flipper arm 66 pivots clockwise, as seen from 
the front of the folder-loader, so that tines 61 also pivot clockwise to 
come back to approximately upright position, thereby restoring the 
U-shaped channel of the folder-loader. 
The apparatus of this invention is simplified because left flipper assembly 
40 is actuated by air cylinder 38, swatter shaft 15 is actuated by a 
separate cylinder (not shown in FIGS. 1-17), and all the rest of the 
motion is accomplished by cylinder 29 acting through a linkage. The right 
flipper pivots on shaft 62 at the bottom ends of vertical arms 77 of the 
carrier assembly 70 because carrier cylinders 71 are supported by springs 
27 on guide rods 25. When cylinder rod 28 pulls on rocker arm 51, it is 
trying to pull down the main supports of carrier assembly 70 and tray 
actuator bracket assembly 80, because rocker arm 51 is pivoted on carrier 
tie bar 75, but the spring force of springs 27 is sufficiently great that 
it is easier for rocker arm 51 to pivot. This downward force then pulls 
flipper link 55 upwardly, which in turn pivots flipper 66, causing the 
right flipper to rotate counterclockwise in direction 63. It is stopped in 
a horizontal position when right flipper link 55 strikes link stop channel 
68. 
Then, as cylinder 29 continues to pull downwardly, it overcomes the force 
of springs 27 and moves carrier assembly 70 and bracket assembly 80 
downwardly, causing arms 93,94 to pivot and trays 91,92 to revolve 
downwardly and outwardly to the sides, so that relative to folded bag 14, 
trays 91,92 simply move sidewardly out of the way as the right flipper and 
bag 14 are propelled in direction 98 toward bottom 101 of carton 100. 
There is sufficient travel distance available in direction 98 for each 
folded bag 14 to be pressed against bottom 101 or against previously 
stacked bags 14, with the full packing force to effectuate stacking of the 
bags into carton 100. 
Because link stop channel 68 remains in contact with right flipper link 55 
after the downward movement begins and until the right flipper returns to 
the folding station, the right flipper is held in its horizontal position 
during its up-and-down vertical travel. Stops 78 on support 24 are 
adjusted for accurately positioning tines 61 in standby or 
article-receiving position, slightly outwardly of vertical, after 
completion of the return movement of cylinder rod 28. 
As seen in FIGS. 1-17, the folding station comprises trays 91,92 and left 
and right flipper tines 31,61. The folding means comprises left and right 
flipper assemblies 30,60, left flipper arm assembly 40 and rocker arm 
assembly 50. 
The propulsion means comprises loading cylinder 29 and loading cylinder rod 
28. The fixed part of the support and guide means comprises vertical 
supports 21,22 horizontal supports 23, 24, guide rods 5 and base 26. The 
movable part of the support and guide means comprises carrier assembly 70 
and tray actuator bracket assembly 80. Carrier assembly 70, bracket 
assembly 80, rocker arm assembly 50 and right flipper assembly 60 (while 
the right flipper is horizontal) can be collectively described, on a 
functional basis, as a "stomper" apparatus. The guides utilized by the 
movable part are guide rods 25 which are acted upon by the bushings within 
carrier cylinders 71. 
As noted earlier, a separate cylinder is provided for reciprocally 
actuating swatter shaft 15. This cylinder can be connected to an arm fixed 
to the swatter shaft and a stop may be provided at each end of the swatter 
arcuate movement to ensure its proper beginning and terminating 
positioning. However, when the swatter is abruptly stopped at the end of 
its travel by cessation of a constant velocity cylinder operation and/or 
by the hitting of a stop, it undergoes a large, sudden deceleration, which 
may contribute to wrinkling of bag 10. Slowing down the rate of operation 
of the swatter driving cylinder to overcome this problem slows down the 
entire bag folding and loading process. To minimize bag wrinkling 
problems, while achieving a high average velocity, the swatter linkage 
mechanism shown in FIG. 18 has been devised. This linkage mechanism, which 
couples the swatter driving cylinder with the swatter shaft 15, achieves a 
high average velocity of swatter movement coupled with a gradual 
deceleration of the swatter to a stop when it reaches a folder-loaded, 
thereby minimizing bag wrinkling. 
The linkage mechanism interconnects the swatter driving cylinder 111, which 
is pivotably fixed at one end thereof to an upper portion of a fixed 
support 113, to the shaft 15 of the swatter. The moving rod 115 of 
cylinder 111 is connected to one arm member 117 of an L-shaped crank arm 
119, another arm member 120 of which is pivotably fixed to a lower portion 
of support 113. An additional straight linkage member 121 is pivotably 
connected at its one end to a portion 123 of L-shaped crank arm 119 
located near the intersection of the two arm members 117,120. Linkage 
member 121 is pivotably connected at its other end to one end of a swatter 
arm 125, which in turn is fixedly connected at its other end to shaft 15 
of the swatter. When the swatter is at the termination of its movement 
towards the folder-loader, the position of the swatter cylinder and 
linkage mechanism is as shown by the solid lines in FIG. 18, while the 
position of the swatter cylinder and linkage mechanism, when the swatter 
is at the termination of its movement at the conveyor side, is shown by 
the dotted lines in FIG. 18. 
When the swatter is to be rotated to convey a bag to the folder-loader, 
piston rod 115 is retracted at a substantially constant velocity, but the 
linkage mechanism formed by crank arm 119 and linkage member 121 is 
arranged so that a relatively large displacement of swatter arm 125 
initially occurs upon rod 115 displacement, but the amount of swatter arm 
displacement (and thus its velocity) is gradually reduced, as the swatter 
approaches the terminus of its movement toward the folder-loader. At the 
end of this movement arm 121 is linearly aligned with arm member 120 of 
the crank arm 119, which defines the end of the swatter movement, i.e., 
the position where it stops. The gradual deceleration of the swatter arm 
125 as the swatter approaches the termination of its forward movement 
occurs because of the changing angular relationship between the arm member 
120 of crank arm 119 and linkage member 121, which causes a gradual 
deceleration of the displacement of the swatter arm in the direction of 
its forward movement until straight arm 121 and arm member 120 are 
linearly aligned, as shown in solid lines in FIG. 18. The linkage 
mechanism positively stops the swatter arm 125 at the end of the movement 
of the swatter toward the folder-loader without requiring mechanical stops 
and minimizes over-travel due to inertia and consequent possible wrinkling 
of bag 10. 
The cylinder 111 displacement is large enough so that the inertia of the 
linkage mechanism and swatter parts represent a small portion of the 
cylinder's force capability. 
As a modification to the linkage mechanism, a spring 129 can be attached at 
one end to the pivotal connection of arms 120 and 121 and at its other end 
to a fixed support 131 located approximately along the bisector of the 
path of movement of the pivotal connection of arms 120 and 121. Spring 129 
applies an increasing tensioning force on arm member 120 as it approaches 
the terminating ends of its reciprocal movement, which opposes the force 
being applied by cylinder 111 thereto, thereby assisting in the 
deceleration of the swatter. The tension applied by spring 129 operates as 
an additive force to that of cylinder 111 when cylinder 111 begins to move 
arm member 120 from either of the two positions illustrated in FIG. 18, 
which helps overcome the inertia of the linkage mechanism and produces a 
quick acceleration of the swatter. In effect, spring 129 tends to bias arm 
member 120, and thus the swatter arm 125 and swatter to intermediate 
positions in their respective paths of reciprocal travel. 
Other crank arm 119 arrangements can be employed. For example, piston rod 
115 could be connected to one distal end of an arm member of an L-shaped 
crank arm, while the distal end of the other arm member is connected to 
linkage member 121, the crank arm being pivoted to a fixed point at a 
portion near the intersection of the arm members. It is also possible to 
use a linear crank arm, essentially consisting of arm member 120 with 
piston rod 115 being pivotably coupled thereto at a point between the 
fixed pivotal connection of the crank arm 119 shown in FIG. 18 and the 
pivotal connection of crank arm 119 and linkage member 121. 
Although preferred embodiments of the invention have been shown and 
described, it should be appreciated that many modifications may be made 
thereto without departing from the spirit and scope of the invention. 
Accordingly, the invention is not limited by the foregoing description, 
but is only limited by the scope of the claims appended hereto.