Note: Descriptions are shown in the official language in which they were submitted.
CA 02263051 1999-03-18
PACKAGING MACHINE, MATERIAL AND METHOD
This inventi~~n relates to packaging machinery and more particularly to
a packaging machvie and method of packaging which are especially well suited
S for loading relatively bulky and liquid products sequentially into bags of a
novel, side intercormected, chain of bags.
Bac~round of the Invention
U.S. Patent 4,969,310 issued November 13, 1990 to Hershey Lerner et
al. under the title Packaging Machine and Method and assigned to the assignee
of this patent (the ;iP Patent) discloses and claims a packaging machine which
has enjoyed commercial success. One of the major advantages of the machine
of the SP Patent resides in a novel conveyor belt mechanism for gripping
upstanding lips of bags of a chain as they are transported along a path of
travel
and registered at a load station. The firmness with which the lips are gripped
makes the machine highly suitable for packaging bulky products which are
stuffed into the bags. While the machine of the SP Patent was an advance
over the prior art, especially in terms of its lip gripping capability, even
greater
lip gripping capabilities, if achieved, would be useful in enabling packaging
of
additional products, Expressed another way, the bag gripping forces of the
machine of the SP Patent were dependent on clamping pressure applied
between pairs of belts. Thus, while the machine was a definite advance over
the art, as to any given bag size, it has a finite maximum stuffing pressure
it
can withstand without slippage.
Since the bad; gripping is dependent on the force with which belt pairs
are clamped, the length of the path of travel through the load station is
limited. Thus the length of a bag along the path of travel is limited, loading
of
a bag while it moves along the path of travel is not possible and the
concurrent
loading of two or more bags is not available.
With the machine of the SP Patent there is an intermittent section
which includes the loading station and a continuous section which includes a
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sealing station. Since the section including the loading station is
intermittent,
obviously the through-put of the machine is inherently less than could be
achieved with a continuously operating loading section.
The machine of the SP Patent had further advantages over the prior art,
S including an adjust;~ble bag opening mechanism which was adapted to accept a
wide range of bag sizes and adjustable to provide a range of bag openings.
While an advance over the prior art, the bag openings were six sided so that,
like most of the prior art, a rectangular bag opening was not achievable.
Although one prior machine provides rectangular openings, the
dimensions of the rectangular openings, both longitudinally and transversely,
are limited both by the construction of the chain of bags being filled and by
guide rods used to transport the bags. Thus, if an operator wished to change
from one opening size to another, another and different web of bags was
required. Moreover, to the extent, that the packaging machine could be
adjusted to vary the configuration of the rectangular opening, such available
adjustment was extremely limited because it required substitution of a
different
set up guide rods. :Further, there was excessive packaging material waste in
the form of elongate tubes which slid along the guide rails.
While the machine of the SP Patent has been sold under the
designation SP-100' for vertical orientation in which products can be gravity
loaded into bags and the designation SP-100H for horizontal loading of
stuffable products, neither machine was suitable for adjustment from
horizontal
to vertical and return, nor for orientation at selected angles of product
insertion between the horizontal and the vertical.
A problem has been experienced with prior art sealers having pairs of
opposed belts to transport bags through a seal station. The problem is that
too frequently due to weight of the products there is slippage of bags
relative
to the belts and sometimes of the bag fronts relative to the backs resulting
in
poor seal quality. Alternatively or additionally it is too often necessary to
provide a conveyor or other support for bags as they are transported through
the sealer station.
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Summary of the Invention
With the machine of the present invention, the described problems of
the prior art and others are overcome and an enhanced range of available
packaging sizes is achieved. In its preferred form the machine has two,
independently moveable carriages which are selectively rigidly interconnected.
One of these carriages supports a novel and improved bagging section, while
the other supports a closure mechanism. The disclosed closure mechanism is a
novel and improved sealing section. Because the machine has two separable
carriages other closure carriages supporting other closure mechanisms such as
bag ties and staples can readily be used.
Each of the sections is rotatably mounted on its carriage, such that once
coupled the two sections may be rotated together about a horizontal axis for
product loading, by gravity and/or stuffing when in the vertical and by
stuffing
when in the horizontal. Advantageously the two sections may also be oriented
in any one of a set of angular orientations between the horizontal and the
vertical.
A major feature of the present machine is that the loading section
opens the bags into rectangular configurations. Not only are the bag load
openings rectangular configurations, but the transverse and longitudinal
dimensions of such openings for any given bag size are relatively and readily
adjustable over a wide range.
The machine may be operated in either a continuous or an intermittent
mode at the operator's selection. Both sections are operated in the same mode.
That is if the loading section is continuous, so too is the sealing section,
while
both operate in the intermittent mode at the same times.
One of the outstanding advantages of the invention resides in the
utilization of a novel and improved mechanism for gripping upstanding lips of
bags as they are transported through the load section.
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Gripping is achieved by coaction of the bags upstanding lips and unique belts
such that belt clamping mechanisms are neither required or relied on. To this
end a
pair of main transport belts are provided and positioned on opposite sides of
a path of
web travel. In the preferred and disclosed embodiment, each main belt has an
upstanding lip contacting surface with a centrally located, transversely
speaking, lip
receiving recess preferably of arcuate cross-sectional configuration. A pair
of lip
transport belts of circular cross-section are respectively caromed into the
main
transport belt recesses to force bag lips into the recesses and fix the lips
with a holding
power far in excess of that achieved with the prior art.
Since the gripping of bag lips for support is accomplished through coaction of
the bag lips and the conveyor belts, there is essentially no limit to the
length of the
loading station. Rather multiple numbers of open bags can be concurrently
conveyed
through the loading station. With a machine operating on a continuous basis
and a
synchronized product supply conveyor adjacent the load station, one is able to
concurrently transfer a set of products into a like numbered set of bags with
the
transfer progressing concurrently as the bags and the conveyed products
advance
through the load station.
Another advantage of an elongated load station is that one may position a
series of vibrator feeders along the station. As an example, a first vibratory
feeder
could deposit a desired number of bolts in a bag at a first location, a second
feeder a
like number of washers at a second location downstream from the first, and a
third
feeder a like number of nuts at a third location still further downstream;
thus,
eliminating the need for a feed conveyor.
With this arrangement extremely high rates of packaging can be achieved. For
example, it is possible to load and seal 130 ten inch bags per minute. Rates
achieved
with the present machine are rates in excess of those that can be achieved
with
virtually all, if not all, prior art machines including so called "form and
fill" machines.
Another feature of the invention resides in a novel and improved mechanism
for breaking frangible interconnections between adjacent sides of
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successive bags. Assuming the machine to be in its gravity fed horizontal
mode, this mechanism comprises a belt which is trained about spaced pulleys
which are rotatable. about respective horizontal axes. The belt has projecting
pins. The belt pulleys are rotated to move the belt in synchronism with
5 positioning of a chain of bags being fed through the load section to cause
one
of the pins to break the frangible bag interconnections each time a set of
such
interconnections is longitudinally aligned with the belt.
Moving in the downstream direction of the machine to consider other
advances, another feature of the invention is in a novel and improved
mechanism for adjusting the width of the load station by varying the spacing
between the pairs of main and lip transport belts. This adjustment, which is
infinite between m~~ximum and minimum limits, coupled with the novel and
improved bag web, provides a wide range of available transverse and
longitudinal dimensions of rectangular bag openings for any given chain of
like
sized interconnected bags.
As loaded bags exit the load station it is desirable to advance the lead
side edge and retard the trailing side edge of each bag of a chain to bring
inside surfaces of the top portions of each bag back into surface to surface
touching orientation for sealing. To this end a novel planetary mechanism is
provided. This mechanism is driven by the moving bags themselves to effect
the stretching action and reestablish inside surface to surface relationship.
For
larger bags opposite:ly directed jets of air are employed which are effective
to
reestablish the surfaice to surface orientation.
At an exit from the bagging section of the machine, the main transport
belts overlie exit belts which in turn overlie the closure section transport
belts,
such that the closure section picks up the now longitudinally stretched top
surfaces of each loaded bag. As the bags are transferred to the closure
section
belts, a rotary knife cuts the bags near their tops such that the lip portions
that
have been carried by the main transport belts are cut off and become
recyclable scrap. The elevation of the cutter relative to the heat sealer is
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adjustable so that the extent to which upper portions of the bags are cut away
provides loaded bags sized to be neat, and if desired tight, finished
packages.
In order to prevent excessive heating of bags passing through the sealing
section and the sealing section belts, the heat source for effecting the seals
is
shifted away from loaded bags and the belts when the machine is stopped and
moved to a location adjacent the bags when the bags are moving. Thus, a
mechanism is provided for shifting the heat sealer from a seal forming
position
to a storage position and return in synchronism with cycling of the machine
when in the intermittent mode.
As the loaded bags pass through the seal section, a series of
longitudinally aligned, juxtaposed and individually biased, pressure members
act against one of the seal section conveyor belts. These pressure members
bias the one belt al;ainst the bags and thence against the other belt to in
turn
bias the other belt against a backup element to maintain pressure on the bag
tops as they are transported through the seal section. Advantageously, unlike
a
prior machine of similar construction, individual coil springs are used to
bias
the pressure members.
The belts used in the seal section are novel and improved special belts
which are effective substantially to prevent any product weight induced
slippage of the bag:. relative to the belts. The novel belts are also
effective to
resist longitudinal movement of the face and back of each bag relative to one
another and to the belts. One provision to prevent this relative slippage is
providing belts which have corrugated belt engaging surfaces with the
corrugations of one belt interlocking with the corrugation of the other to
produce a serpentine grip of the face and back of each bag. Further, the
preferred belts are metal reinforced polyurethane to provide enhanced
resistance to belt stretching. A glue and grit mixture may be applied to the
surfaces of the sealf:r belts, further to inhibit bag slippage. A urethane
coating
is applied over the glue and grit to complete the improvements provided for
the prevention of bag slippage.
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The belts of the sealer section are driven by a stepper motor through a
positive drive, so that the sealer stepper motor in synchronism with bagger
stepper motor mavitain belt and bag feed rates of travel that are consistent
throughout the length of path of bag travel from supply through to finished
package.
Lips of the hags which project from the seal section conveyor belts are
heated by a contiguous heat tube sealer having an elongate opening adjacent
the path of bag lip travel. Heated air and radiation emanating from this
sealer
effect heat seals of the upstanding lips to complete a series of packages.
Because the machine sections, unlike the machine of the SP Patent, are
either both continuous or both intermittent during machine operation,
successive bags passing through the closure section are juxtaposed rather than
spaced. This juxtaposition provides improved sealing efficiency and sealer
belt
life.
A web embodying the present invention is an elongate, flattened,
thermoplastic tube having face and back sides which delineate the faces and
backs of a set of side by side frangibly interconnected bags. The tube
includes
an elongate top section which is slit to form lips to be laid over and then
fixed
in the main transport belts. The top section is interconnected to the bags by
face and back, longitudinally endless, lines of weakness which are separated
from each side edgE: toward the center of each bag to the extent necessary to
achieve the desired rectangular openings. Thus, the present web is far simpler
and less costly than the web of the prior system that provided rectangular bag
openitlgs.
The invention also encompasses a process of packaging which includes
gripping the upstanding front and back lip portions between main and lip
transport belts. The belts are then spread as they pass through a load station
pulling bag openings into rectangular configurations as portions of bag tops
are
separated from the upper lip section. After bag loading, top portions of the
bag inner surfaces a.re returned to abutting engagement, a portion of the lip
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section is trimmed from the bags, and the bags are sealed or otherwise closed
to complete packages.
Accordingly, the objects of this invention are to provide novel and
improved packaging; machine, packaging materials and methods of forming
S packages.
In the Drawings
Figure 1 is a top plan view of the machine of the present invention;
Figure 2 is a fragmentary top plan view of the bagger section of the
machine of Figure :l and on an enlarged scale with respect to Figure 1;
Figure 3 is a foreshortened elevational view of the bagger section as
seen from the plane; indicated by the line 3-3 of Figure 1;
Figure 4 is a perspective view of the novel and improved bag web of the
present invention showing sections of the transport belts transporting the web
through the load station and a novel mechanism for providing spacing of the
sides of loaded bags particularly of a small size;
Figure 5 is a perspective view of a portion of the bag flattening
mechanism shown nn Figure 4 and on an enlarged scale;
Figure 6 is a fragmentary perspective view on the scale of Figure 5
showing an alternate arrangement to the mechanism of Figure 5 for flattening
bags;
Figures 7 and 8 are enlarged sectional views from the planes
respectively indicated by the lines 7-7 and 8-8 of Figure 4 show the main and
lip transport belts together with a fragmentary top portion of the bag as bag
lips are folded over the main transport belts and then trapped in the grooves
of the main belts;
Figure 9 is a sectional view of the bag flattening or stretching
mechanism of Figures 4 and S as seen from the plane indicated by the line 9-9
of Figure 2;
Figure 10 is an enlarged sectional view of the mechanism of Figure 9 as
seen from the plane indicated by the line 10-10 of Figure 2;
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Figure 11 is an enlarged, fragmentary, sectional view of the transport
belt spacing adjustment mechanism as seen from the plane indicated by the
lines 11-11 of Figure 2;
Figure 12 is an elevational view of a portion of the machine as seen
from the plane indiicated by the line 12-12 of Figure 1 showing a bag support
conveyor underneath the loading and seal sections;
Figure 13 is an elevational view of the seal section on an enlarged scale
with respect to Figure 12;
Figure 14 is an elevational view of the angular orientation maintenance
mechanism on an enlarged scale with respect to other of the drawings and as
seen from the plane indicated by the line 14-14 of Figure 12;
Figure 15 is an enlarged sectional view of the sealer positioning
mechanism and a bag support conveyor as seen from the plane indicated by
the lines 15-15 of Figure 13;
Figure 16 is a sectional view of a web guide as seen from the plane
indicated by the line 16-16 of Figure 3;
Figure 17 is a sectional view of the lip plow as seen from the plane
indicated by the line 17-17 of Figure 3;
Figure 18 is an enlarged plan view of a force application element and a
fragmentary plan view of the sealer belts;
Figure 19 is an enlarged fragmentary plan view of a transfer location
between the bagger and the closure sections, including a knife for trimming
the
tops of loaded bags prior to closure;
Figure 20 is a further enlarged sectional view of the structure of Figure
19 as seen from the plane indicated by the line 20-20 of Figure 19;
Figure 21 is a still further enlarged view of the knife and its height
adjustment mechanism as seen from the plane indicated by the line 21-21 of
Figure 20;
Figure 22 is a plan view of an alternate and preferred sealer for the
closure section; and,
Figure 23 is an elevational view of the sealer of Figure 22.
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Detailed Description of the Preferred Embodiment
I. The Overall Machine
Referring to Figures 1 and 4 a web 15 of side connected bags is
5 provided. The web 15 is fed from a supply shown schematically at 16 to a
bagger section 17. The bagger section 17 is reparably connected to a sealer
section 19. The bagger and sealer sections respectively include wheeled
support carriages 2n, 21. The support carriages 20, 21 respectively include
support frames for supporting bagging and sealing mechanisms.
10 In the drawings the bagging and sealing mechanisms are shown in their
vertical orientations for gravity loading. The machine will be described in
such
orientation it being recognized that, as described more fully in section IV,
the
mechanisms may be positioned in a horizontal orientation and at other angular
orientations.
II. The Web 15
The web 15 is an elongated flattened plastic tube, typically formed of
polyethylene. The tube includes a top section 23 for feeding along a mandrel
24, Figures 4 and 16. The top section 23 is connected to the tops of a chain
of
side connected bags, 25 by front and back lines of weakness in the form of
perforations 27, 28. Frangible connections 30 connect, adjacent bag side
edges,
Figures 3 and 4. E;~ch bag 25 includes a face 31 and a back 32 interconnected
at a bottom 33 by a selected one of a fold or a seal. Side seals adjacent the
intercDnnections 30 delineate the sides of the bags 25. The bag faces and
backs 31, 32 are respectively connected to the top section 23 by the lines of
weakness 27, 28, such that the top section 23 when the web is flattened itself
is
essentially a tube.
III. The Bagger ;section 17
A. A BaQ Feed and Preparation Portion 35
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The web 15 is fed from the supply 16 into a bag feed and
preparation portion, 35 of the bagger section 17. The feed is over the mandrel
24 and past a slitter 36, Figure 4. The slitter 36 separates the top section
23
into opposed face and back lips 38, 39. The feed through the bag feed and
preparation portion. 35 is caused by a pair of endless, oppositely rotating,
main
transport belts 40, ~El supported by oppositely rotating pulley sets 42, 43.
The
main belts 40, 41 are driven by a stepper motor 44, Figure 3 through toothed
pulleys 42T, 43T of the sets 42, 43. Other of the pulleys 42S, 43S are spring
biased by springs S, Figure 2, to tension the belts.
A plow 45 is provided and shown in Figures 3, 4 and 17. For
clarity of illustration the slitter and the plow have been omitted from Figure
1.
The plow is positioned a short distance upstream from a roller cam 46. As the
lips are drawn alon;; by the main transport belts 41, 42, the lips 38, 39 are
respectively folded over the top bag engaging surfaces 41S, 42S, of the main
transport belts under the action of the plow 45 as depicted in Figure 7.
Once the lips are folded over the tops of the main transport belts
41, 42, the roller cam 46 presses endless, lip transport and clamp belts 48,
49
into complemental grooves S 1, 52 in the main transport belts 41, 42
respectively. Thus, the grooves 51, 52 function as bag clamping surfaces that
are complemental v~~ith the clamping belts 48, 49. More specifically, the
clamp
belts are circular in cross section, while the grooves 51, 52 are segments of
circles, slightly morf; than 180° in extent. The camming of the clamp
belts into
the grooves traps the lips 38, 39 between the clamp belts and the grooves. The
lip clamping firmly :>ecures the lips between the coasting belt pairs such
that
the lips, due to their coaction with the belts, are capable of resisting
substantial
stuffing forces as pr~~ducts are forced into the bags at a load station 60.
Sections of the clamp belts which are not in the grooves 51, 52 are trained
around a set of lip transport belt pulleys S0.
A bag side separator mechanism 53 is provided at a bag
connection breaking station. The separator mechanism 53 includes an endless
belt 54 which is trained around a pair of spaced pulleys 55 to provide spans
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which, as shown in Figures 3 and 4, are vertical. The pulleys 55 are driven by
a motor 57, Figure 2. As the belt is driven breaking pins 58 projecting from
the belt 54 pass belween adjacent sides of bags to break the frangible
interconnections 30. Thus, as the bags depart the bag feed and preparation
portion 35, they are; separated from one another but remain connected to the
lips 38, 39.
B. The Load Station 60
The lead station 60 includes a pair of parallel belt spreaders 61,
62. The belt spreaders are mirror images of one another. As is best seen in
Figure 11, the belt spreaders respectively include channels 63, 64. The
channels 63, 64 respectively guide the main transport belts 40,41, on either
side
of the load station ~i0. When the transport belts 40,41, are in the channels
63,
64, as is clearly seen in Figures 4 and 11, the bags 25 are stretched between
the belts in a rectangular top opening configuration.
A schematic showing of a supply funnel 66 is included in Figure
4. As suggested by that figure, the products to be packaged are deposited
through the rectangular bag openings each time a bag is registered with the
supply funnel at the load station.
A space adjusting mechanism is provided. This mechanism
includes a spaced p;~ir of adjustment screws 68, 69, Figure 2. The adjustment
screw 68, 69 are respectively centrally journaled by bearings 70, 71. The
screws
have oppositely threaded sections on either side of their bearings 70, 71
which
threadably engage t,'~he belt spreaders 61, 62. Rotation of a crank 72 causes
rotation of the adju:>tment screw 69. The screw 69 is connected to the screw
70 via belts or chains 73, which function to transmit rotation forces so that
when the crank 72 is operated the screws 68, 69 are moved equally to drive the
spreaders equally into an adjusted spacial, but still parallel, relationship.
As the: spreaders are movably adjusted toward and away from
one another, the spring biased pulleys 42S, 43S maintain tension on the main
transport belts 40, 41 while permitting relative movement of spans of the
belts
passing through the spreader channels 63, 64. Similarly, spring biased lip
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transport belt pulleys SOS maintain tension on the clamp belts 48, 49. The
spring biased pulleys of both sets are the pulleys to the right as seen in
Figure
2, i.e. the entrance end pulleys in the bag feed and preparation portion 35.
The main transport pulley sets 42, 43 include two idler pulleys
75, 76 downstream from the load station 60. The idler pulleys 75, 76 are
relatively closely spaced to return the main transport belts 40, 41 into
substantially juxtaposed relationship following exit from the load station 60.
C. Bag Stretching
As lo;~ded bags exit the load station, it is desirable to return
upper portions of the bag faces and backs into juxtaposition. To facilitate
this
return with smaller bags a novel and improved planetary stretcher 90 is
provided. This planetary bag stretcher is best understood by reference to
Figures 5, 9 and 10. The stretcher 90 includes a support shaft 92 mounted on
frame members 94 ~~f the bagger section, Figure 10.
The planetary stretcher includes a bag trailing edge engaging
element 95. The element 95 includes six bag engaging fingers 96. As is best
seen in Figures 4 and 5, one of those fingers 96 is shown in a lead one of the
bags 25 while the nE:xt finger is being moved into the next bag in line as the
next bag departs the; load station 60. As the bags move from right to left as
viewed in Figure S, an internal ring gear portion 100 drives a planet gear
102.
The planet gear orbits a fixed sun pinion 104. The planet gear is journaled on
and carried by a lead edge engaging element 105 journaled on the shaft 92.
The lead edge engaging element 105 has four fingers 106 which orbit at one
and a_half times the rate of the fingers 96. Rotation of the lead edge
engaging
element causes one of the fingers 106 to enter the next bag as it exits the
load
station and to engage a leading edge 108 of the bag, thereby stretching the
bag
until top portions of the bag face and back are brought into juxtaposition.
For larger bags this stretching of the now loaded bags as they
exit the load station is accomplished with jets of air from nozzles 110, 112
which respectively bllow against the lead and trailing edges of the bag, thus
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stretching the bags from their rectangular orientation into a face to back
juxtaposed relationship as the transport belts are returned to juxtaposition.
D. A Tr~~nsfer Location
After loaded bags have exited the load station 60 and the face
S and back of each bag have been brought into juxtaposition, the loaded bags
are
transferred to the closure section 19 at a transfer location 114. Exit
conveyors
115, 116 underlie the main transport belts 40, 41 at an exit end of the bagger
section 17. Loadedl bags are transferred from the main transport belts to the
exit conveyors. The exit conveyors in turn transfer the loaded bags to closure
section conveyor belts 118, 119.
Referring to Figures 19-21, a rotary knife 120 is positioned a
short distance downstream from the exit conveyors. The knife is rotatively
mounted in an externally threaded support tube 121. The tube in turn is
threadedly connected to a knife support frame section K. An adjustment lock
123 is slidably carried by the frame section K. When the lock 123 is in the
position shown in solid lines in Figure 21, it engages a selected one of a
plurality of recesses R in the perimeter of the support tube 121 to fix the
knife
in an adjusted height position. When the lock 123 is slid to the phantom line
position of Figure 21, the tube 121 may be rotated to adjust the vertical
location of the knife; 120.
The knife 120 is driven by a motor 122 to sever the bag lip
portions 38, 39, leaving only closure parts of the lip portions for closure,
in the
disclosed arrangement, by heat sealing. The trimmed plastic scrap 124, Figure
12, from the severed lip portions is drawn from the machine with a
conventional mechanism, not shown, and thereafter recycled.
IV. The Closure Section 19
As is best seem in Figure 1, the novel and improved sealer includes a
plurality of independently movable force application elements 125. One of the
force elements is shown on an enlarged scale in Figure 18. The force elements
125 slidably engage the outer surface of a bag engaging run 126 of the belt of
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the conveyor 119. Springs 128 bias the elements 125 to clamp the bag faces
and backs together against a coacting run 130 of the conveyor belt 118. A
backup 132 slidably engages the coasting run 130 to resist the spring biased
force of the application elements 125.
5 A stepper motor 134, Figure 1, is drivingly connected to the closure
section conveyor belts 118, 119 to operate in synchronism with the stepper
motor 44 of the balger section, either intermittently or continuously.
As is best seen in Figures 13 aad 15, a heater tube 135 is provided. A
heat element 136, Figure 15, is positioned within the tube to provide heat to
10 fuse upstanding bag; lips when the heater tube 135 is in the position shown
in
solid lines in Figure: 13. The heat transfer to the lips is effected by both
radiation and convection through an elongate slot 135S in the bottom of the
tube.
The heater tube 135 is connected to a pair of supports 137, 138. When
15 the bags 25 are vertical the heater tube 135 is suspended by the supports
137,
138. The supports iin turn are pivotally connected to and supported by a pair
of cranks 140, 142. The cranks 140, 142 are pivotally supported by a section
of
the frame of the sealer carriage 21. The cranks 140, 142 are interconnected by
a rod 144 which in :urn is driven by an air cylinder 145. The air cylinder 145
is
interposed between the carriage frame and the rod 144. Reciprocation of the
air cylinder is effective to move the heat tube between its seal position
shown
in solid lines and a storage position shown in phantom, Figure 13. When the
conveyor belts 118, 119 are operating to transport bags through the closure
sectiop the sealer is down, while whenever the machine is stopped the sealer
is
shifted to its storage: or phantom position of Figure 13.
As is best seen in Figure 18, the adjacent runs 126, 130 of the sealer
conveyor belts 118, 119 have surfaces that are corrugated and interfitting.
These interfittings c~~rrugations provide both enhanced bag gripping and
holding power and resistance to relative longitudinal movement of the runs as
well as the faces and backs of the bag. The gripping and holding power of the
belts is further enhanced by coating the belts with a glue and sand slurry and
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16
applying a polyurethane coating over the slurry to further enhance the
frictional grip of th~~ belts on bags being transported. The combined effects
of
the belt corrugations and coating substantially prevent slippage of the bags
due
to weight in the bags.
S
V. Section Interconnection and Adjustments
A. Section Interconnection
The bagger and closure sections 17,19 are physically
interconnected when in use. In the disclosed arrangement this interconnection
includes a pair of lock bars 150. The lock bars which are removably positioned
in apertures 151,15; formed in bosses 154,155 respectively projecting from
frames of the bagger and closure stations 17,19.
B. Angular Positioning
As ha:~ been indicated, the bagger and closure sections are
adjustable to horizontal or vertical orientations as well as angular
orientations
between the horizontal and the vertical.
The bagger section 17 is rotatably supported on a pair of trunions one
of which is shown a1: 157 in Figure 3. As can best be seen in Figures 12 and
13, the sealer section 19 is rotatably supported on the carriage 21 by spaced
trunions 170, 172. 7:'he trunions 157,170 & 172 are axially aligned. The end
trunion 170, to the left as viewed in Figures 12 and 13, is associated with an
angular position hol~3er. The holder includes an apertured plate 174 secured
to and forming part of the frame of the carriage 21, Figure 14. The plate 174
includes a set of apertures 175 spaced at 15° intervals to provide
incremental
angular adjustments of 15° each between the horizontal and vertical
orientations of the machine. Each of the apertures 175 may be selectively
aligned with an aperture in a sealing section plate 176. A pin in the form of
a
bolt 178 projects through aligned apertures to fix the sealer section and the
interconnected bagger section in a selected angular orientation.
VI. A Su~~ort Conveyor
CA 02263051 1999-03-18
17
While there normally is no need for bottom support of the bags 25 as
they pass through the bagger section 17, nonetheless a conventional support
conveyor 160 may be provided, see Figure 3. More frequently a conveyor 162
will be provided under the closure section 19. In either event, suitable
height
adjustment and loclidug mechanisms 164 are provided to locate the conveyors
160,162 in appropriate position to support the weight of loaded bags being
processed into pacls:ages.
VII. The Preferred Sealer
Referring to Figures 22 and 23, the preferred sealer for the closure
mechanism is disclosed. The sealer includes an air manifold 180 for receiving
air from a blower 182. In an experimental prototype a 300 cubic foot per
minute variable pressure blower was used to determine optimized air flows and
pressures.
T'he manifold 180 has three pairs of oppositely disposed outlets
184,185,186. Each outlet is connected to an associated one of six flexible
tubes
188. The tubes in turn are connected to pairs of oppositely disposed, T-shaped
sealer units 190,191,192 to respectively connect them to the outlets
184,185,186. The T'-shaped sealer units respectively include tubular legs
190L,191L,192L e~rtending vertically downward from their respective
connections to the flexible tubes 188 to horizontal air outlet sections
190H,191H,192H. 'I'lle outlet sections are closely spaced, axially aligned,
cylindrical tubes which collectively define a pair of elongate heater
mechanisms
disposed on opposite sides of an imaginary vertical plane through the loaded
bag path of travel.
Each horizontal outlet section includes an elongate slot for directing air
flow originating with the blower 182 onto upstanding bag lips being sealed.
Each of the sealer unit legs 191,192 houses an associated heater element of a
type normally used in a toaster. Thus air flowing through the T-shaped units
191,192 is heated and the escaping hot air effects seals of the upstanding bag
CA 02263051 1999-03-18
18
lips. Air flowing through the units 190 is not heated, but rather provides
cooling air to accelerate solidification of the seals being formed.
The t-shaped sealer units 190,191,192 are respectively connected to the
rod 144 for raising .and lowering upon actuation of the air cylinder 145 in
the
same manner and f~~r the same purpose as described in connection with the
embodiment of Fig~ires 12 and 13.
A further unique feature of the embodiment of Figures 22 and 23 is a
vertical adjustment mechanism indicated generally at 194. The vertical
adjustment 194 permits adjustment of the slope of the horizontal sections of
the t-shaped units 190-192 such that the outlet from 191H is lower than that
of
192H. This downw;~rd sloping of the heater mechanism in the direction of bag
travel assures optimized location of the hot air being blown on the plastic.
The location is optimized because as the plastic melts it sags lowering the
optimum location far the direction of the hot air. Further the cooling air
from
the unit 190 is directed onto a now formed bead.
VIII. Operation
The caniage:~ 20, 21 are independently wheeled to a desired location.
The two are then physically interconnected by inserting the lock bars 150 into
the apertures 151,152.
Assuming the bagger and sealer are in a vertical orientation, the relative
heights of the bagger and closure section conveyors are adjusted as is the
height of the knife 120. If the angular orientation of the machines is to be
adjusted, the bolts) 178 is(are) removed and the bagger and sealer section are
rotated about the axis of the trunions 157,170, 172 to a desired orientation.
Following this rotati~~n the bolts) is(are) reinserted to fix the mechanism in
its
desired angular orientation.
Next a web 1:5 of bags 25 is fed through the bagger and sealer by
jogging the two. The transverse spacing of the main conveyor belts 40, 41 is
adjusted by rotating the crank 72 until the load station 60 has the desired
transverse dimension. A control, not shown, is set to provide a desired feed
CA 02263051 1999-06-16
19
rate and a selected one of continuous or intermittent operation. Assuming
continuous operation, the feed rate may be as high as 130 ten inch bags per
minute.
Once the machine is in operation, the top section 23 of the web 15 is
fed along the mandrel 24 and slit by the slitter 36. This forms the lips 38,
39
which are folded over the main transport belts 41, 42 by the action of the
plow
45. The lip clamp belts 48, 49 descend from the elevated and spring biased
pulleys SOS, as shown in Figure 3. The roller cam 46 cams the clamp belts 48,
49 respectively into the transport belt recesses 51, 52 to provide very
positive
and firm support for the bags as they are further processed. As successive
side
connections 30 of the bags are registered with the bag side separator 53, the
motor 55 is operated to drive the belt 54 and cause the breaker pins 58 to
rupture the side connections 30.
As adjacent runs of the transport belts 41, 42 progress downstream
from the bag feed and preparation portion 35, the belts are spread under the
action of the belt spreaders 61, 62. As the belts are spread, the lips 38, 39
cause the front and back faces 31, 32 adjacent the lead edge of each bag to
separate from the lips 38, 39 by tearing a sufficient length of the
perforations
between them to allow the lead edge to become the mid point in a bag span
between the belts as the bag passes longitudinally through the load station
60.
Similarly, the perforations adjacent the trailing edge are torn as the
trailing
part of the bag is spread until the bag achieves a full rectangular opening as
shown in Figure 4 in particular.
Next a product is inserted into the rectangular bag as indicated
schematically in Figures 3 and 4. While the schematic showing is of discrete
fasteners, it should be recognized that this machine and system are well
suited
to packaging liquids and bulky products which must be stuffed into a bag,
such as pantyhose and rectangular items, such as household sponges.
After the product has been inserted, the adjacent runs of the main
transport belts are brought back together and the loaded bag tops are spread
CA 02263051 1999-03-18
longitudinally of the path of travel either by the planetary stretcher 90 or
opposed air streams from nozzles 110, 112.
As is best seen in Figure 3, exit ones SOE of the lip belt pulley set are
spaced from the m~~in transport belt and rotatable about angular axes.
5 Expressed more accurately, when the machine is in a vertical loading
orientation, the pulleys SOE are above the main transport belt such that the
lip
transport belts are pulled from the grooves 51, 52.
The now loaded bags pass through the transfer location onto the exit
conveyors 115, 116 and thence to the seal station conveyors 118, 119. At this
10 juncture the scrap 124 is severed from the loaded bags by the action of the
laiife 120. As the bags are advanced through the sealer section, the heater
tube 135 is ma.intair~ed in its lowered and solid line position of Figures 12,
13
and 15. If the machine is operated in its intermittent mode, the cylinder 145
is
cycled in coordination with the starts and stops of the intermittently
operated
15 machine to shift the heater tube 135 between its solid line seal position
and its
storage position shown in phantom in the Figure 13.
Although the invention has been described in its preferred form with a
certain degree of particularity, it is understood that the present disclosure
of
the preferred form has been made only by way of example and that numerous
20 changes in the details of construction, operation and the combination and
arrangement of parts may be resorted to without departing from the spirit and
the scope of the invention as hereinafter claimed.
