Note: Descriptions are shown in the official language in which they were submitted.
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SHRINK WRAP PACKAGING MACHINE
CROSS-REFERENCE:
This application is a division of C~n~ n Patent Application No. 2,177,807,
which is a National Phase Application of PCT/US94/02460 filed March 14, 1994.
FIELD OF THE INVENTION:
This invention relates to an improved stacker for stacking a plurality of flat
objects. The improved stacker is suitable for use with a packaging machine such
as a shrink wrap packaging machine. The invention also relates to an improved
easy open shrink wrap package for a plurality of flat objects.
PRIOR ART STATEMENT:
Various types of packaging machines have been developed in the past for
packaging articles of various shapes and sizes. One very popular type of packaging
machine is a shrink wrap packaging machine for producing a shrink ~,vrap packagefrom a heat shrunk shrink wrap p~rk~ging film
Shrink wrap packaging has become an extremely popular method of
encapsulating a single or plurality of objects. Shrink wrap packages may be usedfor either an internal packaging or for an external packaging. Typically, a shrink
wrap packaging film is formed into a longitudinally extending horizontal film tube.
The lateral edges of the shrink wrap packaging film are established in an
overlapping relationship and are secured by a longitudinal extending seal.
Typically, the longitudinal extending seal is formed by either a static generator or
linear heat seat as should be well-known to those skilled in the art.
A heat seal is formed on a leading end of the horizontal film tube and the
object or objects are aligned and inserted into the longitudinally extending horizontal
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film tube. A heat seal is formed on a trailing end of the horizontal film tube forming
a loose package with the object or objects being disposed therein. The loose
package containing the objects is then passed through a heat shrinking oven to
shrink the shrink wrap packaging film to form the completed hear shrink package.Although a variety of objects have been packaged with packaging machines,
many objects have not been packaged by packaging process due to the shape of theobject. The problem of the shape of the object is especially significant in a shrink
wrap packaging machine. In the past, objects that do not remain in a stable position
during the movement into the longitudinally extending horizontal film tube or
during the movement into the heat shrinking oven have not been packaged by the
shrink wrap packaging process.
One extremely difficult type of object to package is a plurality of flat objects.
A plurality of flat objects present a particular problem because flat objects, when
placed on end, have essentially no stability in either a longitudinal or a lateral
direction. The is problem is further complicated when the flat object is embodied
in a disk-shaped object such as a hamburger patty of the like.
Although some in the prior art have attempted to provide a shrink wrap
packaging machine to solve this problem, a suitable solution has heretofore not been
provided by the prior art. Accordingly, the packaging of flat objects, such as
hamburger patties, fish patties, rice cakes, potato patties is present a hand operation.
Considering the enormous number of these flat objects sold and consumed each day,
such a hand operation significantly adds to the cost of the flat object.
Therefore, it is an object of this invention to provide a machine for stacking
a plurality of flat objects comprising a first and a second rotatable starwheel for
Z5 forming a vertical stack of the flat objects from the plurality of flat objects.
Another object of this invention is to provide a machine for stacking a
plurality of flat objects for form a vertical stack of the flat objects from the plurality
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of flat objects with a second transferred flat object support a first kansferred flat
object.
Another object of this invention is to provide a machine for stacking a
plurality of flat objects including counting means for counting a preselected number
of the plurality of flat objects for form a preselected vertical stack of the flat
objects.
Another object of this invention is to provide a machine for stacking a
plurality of flat objects including an input conveyor stop for intermittently
termin~ting the movement of the plurality of flat objects on an input conveyor to
the starwheels.
Another object of this invention is to provide an improved shrink wrap
packaging machine for packaging a plurality of stackable objects which is capable
of aligning flat objects of the like within a shrink wrap packaging film in a stacked
relationship.
Another object of this invention is to provide an improved shrink wrap
packaging machine for packaging a plurality of stackable objects wherein the
machine is capable of counting the number of flat objects to ensure uniformity of
packaging of the plurality of flat objects.
Another object of this invention is to provide an improved shrink wrap
packaging machine for packaging a plurality of stackable objects which is applicable
for shrink wrap packaging of flat objects and the like.
Another object of this invention is to provide an improved shrink wrap
packaging machine for packaging a plurality of stackable objects wherein the
process time through the heat shrink oven is carefully controlled to ensure thatfrozen items such as hamburger patties, fish, patties, rice cakes, potato patties are
not overly heated to prevent degenerating the flavor of the product.
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Another object of this invention is to provide an improved shrink wrap
packaging machine for packaging a plurality of stackable objects which is relatively
small in size in comparison to conventional shrink wrap packaging machines.
Another object of this invention is to provide an improved shrink wrap
packaging machine for packaging a plurality of stackable objects which is reliable
and sanitary for shrink wrap packaging of food products.
Another object of this invention is to provide an improved shrink wrap
packaging machine for packaging a plurality of stackable objects which elimin:~tes
the need for non-biodegradable wax impregnated cardboard containers.
The foregoing has outlined some of the more pertinent objects of the present
invention. These objects should be construed as being merely illustrative of some
of the more prominent features and applications of the invention. Many other
beneficial results can be obtained by applying the disclosed invention in a different
manner or modifying the invention within the scope of the invention. Accordingly1 j other objects in a full understanding of the invention may be had by referring to the
summary of the invention, the detailed description describing the preferred
embodiment in addition to the scope of the invention defied by the claims taken in
conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION:
The present invention is defined by the appended claims with specific
embodiment being shown in the attached drawings. For the purpose of summarizing
the invention,t eh invention is incorporated into a machine for stacking a plurality
of flat objects with each of the flat objects having first and second side surfaces and
an edge surface means. Each of the flat objects has an aspect ratio whereby the flat
object is generally unstable when placed on the edge surface means. The machine
for stacking a plurality of flat objects comprises an input conveyor for serially
conveying each of the plurality of flat objects on side surface of each of the flat
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objects. A stacker comprises a first and a second starwheel having first and second
central hubs supporting a first and second plurality of radially spaced star
projections. A motor means intermittently rotates the first and second starwheels
about a first and a second spaced apart parallel axle. The input conveyor serially
conveys a first object of the plurality of flat objects between the first and second
starwheels for enabling a star projection from each of the first and second
starwheels. The input conveyor serially conveys a second object of the plurality of
flat objects between the first and second starwheels for enabling another star
projection from each of the first and second starwheels to life the second flat object
upon a second intermiKent rotation of the first and second starwheels and to support
the first flat object upon the second flat object for forming a vertical stack of the
flat objects from the plurality of flat objects.
Preferably, the input conveyor is disposed in a generally horizontal
orientation for individually conveying each of the plurality of flat objects
horizontally to the stacker. The machine for stacking includes counting means for
counting a preselected number of the plurality of flat objects for form a preselected
vertical stack of the flat objects. An input conveyor stop intermittently terminates
the movement of the plurality of flat objects on the input conveyor.
SUMMARY OF THE INVENTION:
The present invention is defined by the appended claims with specific
embodiments being shown in the attached drawings. For the purpose of
summarizing the invention, the invention is incorporated into a machine for stacking
a plurality of flat objects with each of the flat objects having first and second side
surfaces and an edge surface means. Each of the flat objects has an aspect ratiowhereby the flat object is generally unstable when placed on the edge surface
means. The machine for stacking a plurality of flat objects comprises an input
conveyor for serially conveying each of the plurality of flat objects on a side surface
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of each the flat objects. A stacker comprises a first and a second plurality of
radially spaced star projections. A motor means intermittently rotates the first and
second starwheels about a first and a second spaced apart parallel axle. The input
conveyor serially conveys a first object of the plurality of flat objects between the
first and second starwheels for enabling a star projection from each of the first and
second starwheels to lift the first flat object upon a first intermittent rotation of the
first and second starwheels. The input conveyor serially conveys a second objectof the plurality of flat objects between the first and second starwheels for enabling
another star projection from each of the first and second starwheels to lift thesecond flat object upon a second intermittent rotation of the first and second
starwheels and to support the first flat object upon the second flat object for forming
a vertical stack of the flat objects from the plurality of flat objects.
Preferably, the input conveyor is disposed in a generally horizontal
orientation for individually conveying each of the plurality of flat objects
horizontally to the stacker. The machine for stacking includes counting means for
counting a preselected number of the plurality of flat objects to form a preselected
vertical stack of the flat objects. An input conveyor stop intermittently terminates
the movement of the plurality of flat objects on the input conveyor.
The invention is also incorporated into an improved shrink wrap packaging
machine for packaging a plurality of flat objects with a heat shrinkable film. The
plurality of flat objects individually emanate from an input source with each of the
flat objects being disposed on a side face of the flat object. The improved shrink
wrap packaging machine comprises an input conveyor for individually conveying
each of the plurality of flat objects to a stacker. The stacker forms a vertical stack
of the flat objects from the plurality of flat objects. A wrapper transport transfers
the vertical stack of flat objects to a wrapper. The wrapper comprises a wrappertool and a wrapper driver for forming the heat shrinkable film into a film tube with
the vertical stack of flat objects disposed therein. The wrapper includes a sealer for
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sealing a trailing edge of the film tube for encasing the vertical stack of flat objects.
An input oven transport transfers the vertical stack of flat objects to a heat shrink
oven to form a heat shrink package thereby.
In a more specific embodiment of the invention,t he input conveyor is
disposed in a generally horizontal orientation for individually conveying each of the
plurality of flat objects horizontally to the tacker. Preferably, a counting means
counts a preselected number of the plurality of flat objects to form a preselected
vertical stack of the flat objects. An input conveyor stop intermittently termin~tes
the movement of the plurality of flat objects on the input conveyor.
In one embodiment of the invention, the stacker comprises a plurality of
starwheels with each of the starwheels comprising a central hub supporting a
plurality of star projections. The star projections individually lifts the flat objects
upon an incremental movement of the plurality of starwheels.
Preferably, the wrapper transport is oriented for vertically transferring the
vertical stack of flat objects to the wrapper. The wrapper tool is disposed in avertical orientation for forming the heat shrinkable film into a vertically orientated
film tube. The wrapper driver vertically lifts the vertical stack of flat objects
through the wrapper tool within the film tube.
In one embodiment of the invention, the oven conveyor includes an oven
conveyor for vertically moving the vertical stack of flat objects through the heat
shrink oven with the input oven transport horizontally transferring the vertical stack
of flat objects to the oven conveyor. An output conveyor discharges the heat shrink
package with an output oven transport horizontally transferring the heat shrink
package from the oven conveyor to the output conveyor.
The invention is further incorporated into a shrink wrap package for a stack
of flat objects. The shrink wrap package comprises a longitudinally extending sheet
of heat shrinkable film having a first and a second sheet end and a first and a
second sheet edge. The longitudinally extending sheet of heat shrinkable material
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is formed into a film tube with the first sheet edge overlapping the second sheet
edge. The first and second sheet ends are heat sealed for forrning a heat shrinkpackage having a first and a second package end. An electrostatic seal seals thefirst sheet edge tot eh second sheet edge with the stack of flat objects being encased
S therein. The electrostatic seal enables an operator to twist the first package end
relative to the second package end to fracture the electrostatic seal for removing the
stack of flat objects from the heat shrunk package. Preferably, the electrostatic seal
extends longitudinally between the first package end relative to the second package
end.
The foregoing has outlined rather broadly the more pertinent and important
features of the present invention in order that the detailed description that follows
may be better understood so that the present contribution to the art can be morefully appreciated. Additional features of the invention will be described hereinafter
which form the subject of the claims of the invention. It should be appreciated by
those skilled in the art that the conception and the specific embodiments disclosed
may be readily utilized as a basis for modifying or designing other structures for
carrying out the same purposes of the present invention. It should also be realized
by those skilled in the art that such equivalent conskuctions do not depart from the
spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS:
For a fuller understanding of the nature and objects of the invention,
reference should be made to the following detailed description taken in connection
with the accompanying drawings in which:
Figure 1 is an isometric view of a first example of a flat object for wrapping
in the shrink wrap packaging machine of the present invention;
Figure 2 is an isomekic view of a second example of a flat object for
wrapping in the shrink wrap packaging machine of the present invention;
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Figure 3 is an isometric view of an improved easy open shrink wrap package
of a plurality of the first example of the flat objects;
Figure 4 is a top view of the improved easy open shrink wrap package of
Figure 3;
Figure 5 is a left side view of Figure 4;
Figure 6 is a right side view of Figure 4;
Figure 7 is an isometric view of the improved easy open shrink wrap
package of Figure 3 with an operator grasping and twisting the package;
Figure 8 is an isometric view similar to Figure 7 illustrating the opening of
the improved easy open shrink wrap package;
Figure 9 if a front elevational view of a shrink wrap packaging machine of
the present invention;
Figure 10 is a top view of Figure 9;
Figure 11 is a section view along lien 11 - 11 in Figure 9;
Figure 12 is a sectional view along line 12 - 12 in Figure 9;
Figure 13 is an enlarged isometric view of an input conveyor and stacker of
the shrink wrap packaging machine of the present invention;
Figure 14 is an enlarged view of a portion of Figure 9 illustrating a first flatobject being transferred from the input conveyor to the stacker;
Figure 14A is a left side view of Figure 14;
Figure 15 is a view similar to Figure 14 illustrating the first flat object
disposed in the stacker;
Figure 15A is a left side view of Figure 15;
Figure 16 is a view similar to Figure 15 illustrating the stacking of the first
flat object by the stacker;
Figure 16A is a left side view of Figure 16;
Figure 17 is a view similar to Figure 16 illustrating a second flat object
disposed in the stacker;
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Figure 17A a left side view of Figure 17;
Figure 18 is a view similar to Figure 17 illustrating the stacking of the
second flat object by the stacker;
Figure 18A is a left side view of Figure 18;
Figure 19 is a view similar to Figure 18 illustrating a completed stack of flat
objects in the stacker;
Figure 19 A is a left side view of Figure 19;
Figure 20 is a view similar to Figure 19 illustrating a first stage of
transferring the stack of flat objects to a wrapper;
Figure 20A is a left side view of Figure 20;
Figure 21 is a view similar to Figure 20 illustrating a second stage of
transferring the stack of flat objects to the wrapper;
Figure 21A is a left side view of Figure 21;
Figure 22 is a view similar to Figure 21 illustrating the returning of the firststage to an original position;
Figure 22A is a left side view of Figure 22;
Figure 23 is a front elevational view similar to Figure 9 illustrating the firststage of transferring the stack of flat objects to the wrapper;
Figure 24 is a front elevational view illustrating the second stage of
transferring the stack of flat objects to a wrapper;
Figure 25 is a front elevational view illustrating the movement of a wrapper
driver for forming a film tube with the stack of flat objects disposed therein;
Figure 26 is a front elevational view illustrating the movement of an input
oven transport transferring the stack of flat objects to a heat shrink oven;
Figure 27 is a front elevational view illustrating the movement of an oven
conveyor moving the stack of flat objects through a heat shrink oven; and
Figure 28 is a front elevational view illustrating the movement of an output
oven transport transferring the stack of flat objects to an output conveyor.
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Similar reference characters refer to similar parts throughout the several
Figures of the drawings.
DETAILED DISCUSSION:
Figure 1 is an isometric view of a first example of a flat object 10 which is
to be encased in a heat shrink package of the present invention. For the purposes
of this disclosure, a flat object is considered to be an object having first and second
side surfaces 11 and 12 and an edge surface means 13 defining an aspect ratio
whereby the flat object 10 is generally unstable when placed on the edge surfacemeans 13. In the first example, the flat object 10 is shown as a disc-shaped object
such as a frozen hamburger patty or the like. Although a frozen hamburger patty
may be placed on the edge surface means 13, vibration and movement of the flat
object 10 normally encountered in a shrink wrap packaging machine will generallyresult in the flat object 10 falling on either of the first and second side surfaces 11
and 12. The present invention solves the problem encountered with the heat shrink
wrapping of the flat object 10 having the above characteristics.
Figure 2is an isometric view of a second example of a flat object 15 which
is to be encased in a heat shrink package of the present invention. In this
embodiment, the flat object 15 includes side surfaces 16 and 17 with four edge
surfaces 18A through 18D. The flat object 15 may be characteristic of a tape
cassette or any other suitable object of similar configuration. Although Figures 1
and 2 illustrate two examples of a flat object 10 and 15, it should be appreciated by
those skilled int he art that numerous types and shapes of flat objects, including
food products and non-food products may be embraced as having the characteristics
set forth above.
Figure 3 is an isometric view of a heat shrink package 20 encasing a
plurality of the flat objects 10 shown in Figure 1. The heat shrink package 20
includes a first end 21 and a second end 22. As more fully shown in Figures 5-6,
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the shrink wrap package 20 comprises a longitudinally extending heat shrinkable
material 25 having a firs and a second end 26 and 27 and a first and a second edge
28 and 29. The heat shrink package 20 is formed into a film tube 30 with the first
and second edges 28 and 29 overlapping one another forming a longitudinally
S extending seam 32. The first and second ends 26 and 27 of the sheet of heatshrinkable material 25 are closed by heat seals 34 and 36 in a conventional manner.
The heat shrink package 20 is formed by passing the film tube 30 cont:~ining the flat
objects through a heat shrink oven to form the heat shrink package shown in Figures
3-6. Preferably, the longitudinally extending seam 32 is electrostatically sealed
thereby creating a frangible longitudinal seam. The electrostatic seam is created by
intermittently electrostatically affixing the first sheet edge 28 to the second sheet
edge 29 by an electrostatic generator. An optional heat seal 33 may be interposed
within the longitudinally extending seam 32 for additional strength if desired by the
user.
Figure 7 illustrates an operator grasping the heat shrink package 20 with a
left and a right hand. The heat shrink package 20 of the present invention enables
the operator to twist the first end 21 of the heat shrink package 20 relative to the
second end 22 of the heat shrink package thereby breaking the frangible seam 32
creating apertures 38. The apertures 38 permit a portion or all of the flat objects
10 to be easily removed from the heat shrink package 20. As it can be apparent
from Figure 8, the flat objects 10 can be readily removed from the apertures 38 of
the heat shrink package 20 while the first and second ends 21 and 22 of the heatshrink package 20 retain the flat objects 10 therein. Accordingly, a portion of the
flat objects 10 can be removed from the central portion of the heat shrink package
20 with the remainder of the objects 10 rem~ining in the first and second ends 21
and 22.
The heat shrink package shown in Figures 3-8 provides a novel heat shrink
package having a frangible seam for removing a portion of a plurality of flat objects
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10 therefrom. Although the frangible package operates with various types of flatobjects 10, the improved heat shrink package 20 operates in a superior fashion with
disc-shaped objects such as perishable, frozen hamburger patties and the like.
Figures 9 - 13 illustrate various views of an improved heat shrink packaging
machine O for packaging the plurality of the flat objects 10 into the heat shrink
package 20 as shown in Figures 3-8. The shrink wrap packaging machine 40
comprises a frame 42 for supporting an input conveyor 44 for individually receiving
the plurality of flat objects 10 from an external source shown as a chute 46. The
plurality of flat objects 10 emanate from the chute 46 with each of the flat objects
10 disposed on one of the first and second side surfaces 11 and 12 in a single file.
The input conveyor 44 includes guides 48 and 49 for ~ligning each of the flat
objects 10 into a single file to pass the flat objects 10 to a stacker 50.
As shown in more detail in figure 13, the stacker 50 comprises a plurality
of star wheels shown as a first and a second star wheel 51 and 52. The star wheels
51 and 52 comprise central hub 51A and 52A for supporting a plurality of star
projections 51B and 52B extending from the central hubs 51A and 51B. The star
wheel 51 and 52 are rotatably mounted through axles 51C and 52C extending
through the central hubs 51A and 52A. The first and second axles 51C and 52C aremounted in a parallel spaced apart relationship for rotationally supporting the first
and second central hubs 5 lA and 52A of the first and second starwheels 51 and 52.
The first and second starwheels 51 and 52 are spaced for enabling the flat object 10
to be received between adjacent star projections 51B and 52B.
Figures 14-22 illustrates the sequence of operation of the input conveyor 44,
the stacker 50 and a wrapper transport 60 comprising a first and a second wrapper
transport 61 and 62. Figure 14 and 14A illustrate a first, second and a third flat
object lOA-lOC being kansferred by the conveyor 44 toward the stacker 50.
Preferably, the conveyor 44 operates continuously for providing maximum
throughput of the heat shrink wrapping machine 40.
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Figure 15 and 15A illustrate the first flat object lOA being transferred by the
conveyor 44 into the stacker 50. When the first flat object lOA is transferred and
is properly positioned within a stacker 50, the first flat object lOA triggers a sensor
64 shown in Figure 9. The sensor 64 is preferably a photoelectric sensor 64 for
sensing the presence of a flat object 10 in the proper position within the stacker 50.
When the sensor 64 senses the presence of the first flat object lOA in the proper
position within the stacker 50, the sensor 64 activates an input conveyor stopper 66.
The input conveyor stopper 66 is raised into the path of the input conveyor 44 to
terminate the movement of the second and third flat objects lOB and lOC from theinput conveyor 44 into the stacker 50.
Figure 16 and 16A illustrate the first flat object lOA being raised by the
stacker 50 into an elevated position. Upon the sensor 64 sensing the presence ofthe first flat object lOA in the proper position within the stacker 50, the sensor 64
activates a motor 68 shown in Figure 9 to partially rotate the star wheels 51 and 52
for elevating the first flat object lOA by the star projections 51A and 51B. The star
projections 51A and 52A support the first flat object lOA in the elevated position
enabling the second flat object lOB to be received by the stacker 50. Upon
completion of the partial rotation of the star wheels 51 and 52, the input conveyor
stopper 66 is lowered from the path of the input conveyor 44 to allow the
movement of the second flat object lOB from the input conveyor 44 into the stacker
50.
Figure 17 and 17A illustrate the second flat object lOB being transferred by
the conveyor 44 into the stacker 50. When the second flat object lOB is transferred
and is properly positioned within the stacker 50, the second flat object lOB triggers
the sensor 64 for activating the input conveyor stopper 66 to terminate the
movement of the third flat object lOC from the input conveyor 44 into the stacker
50.
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Figure 18 and 18A illustrate the second flat object lOB being raised by the
stacker 50 into an elevated position. Upon the sensor 64 sensing the presence ofthe second flat object lOB in the proper position within the stacker 50, the motor
68 partially rotates the star wheels 51 and 52 for elevating the second flat object
lOB by the star projections 51A and 51B. The second flat object lOB contacts andsupports the first flat object lOA with the star projections 51A and 52A supporting
both the second flat object lOB and the first flat object lOA in the elevated position.
The third flat object lOC may be received by the stacker 50 upon the input
conveyor stopper 66 being lowered from the path of the input conveyor 44.
Figure 19 and l9A illustrate a stack of flat objects lOS being stacked by the
stacker 50 into an elevated position. The stack of flat objects lOS are aligned in a
uniform stack by alignment rods 69. A counter 70 shown in Figure 9 is provided
for counting a predetermined number of flat objects 10 to form the stack of flatobjects lOS for packaging within the heat shrink package 20. When a sufficient
number of flat objects 10 has been received and stacked by the stacker 50 to form
the stack of flat objects lOS, the counter 70 activates the first wrapper transport 61.
As best shown in Figures 9-13, the first wrapper transport 61 comprises a
generally L-shaped elevator 72 having a base 74 connected to an arm 76. The arm
76 is secured to a pivot actuator 78 for pivoting the base 74 and arm 76 about apivot 76A. Figure 11 illustrates the pivot actuator 78 being slidably mounted on a
rod 80 into an upper position from the lower position shown in Figure 9.
Figures 20 and 20A illustrate the stack of flat objects lOS raised by the first
wrapper transport 61 into an elevated position. Upon the counter 70 counting theselected number of flat objects 10 to form the stack of flat objects lOS, the counter
70 activates the pivot actuator 78 to move the pivot actuator 76 from the lower
position shown in Figure 19 to the upper position shown in Figure 20 to raise the
stack of flat objects lOS. preferably, the movement of the pivot actuator 76 is
synchronized with the partial rotation of the starwheels 51 and 52 in order to
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commence movement of the first wrapper transport 61 when the input conveyor
stopper 66 is in a raised position for inhibiting the movement of the flat objects 10
from the input conveyor 44 into the stacker 50. This synchronization allows the
stacker 50 to operate continuously without interference from the first wrapper
transport 61. After the first stack of flat objects lOS is raised by the first wrapper
transport 61, the input conveyor stopper 66 is lowered from the path of the input
conveyor 44 to allow the movement of the additional flat objects from the input
conveyor 44 into the stacker 50. In addition, the counter 70 is again engaged
allowing the stacker 50 to count a subsequent stack of flat objects 10 by the star
wheels 51 and 52 as described heretofore.
Figure 21 and 21A illustrate the stack of flat objects lOS being horizontally
moved by the second wrapper transport 62. The second wrapper transport
comprises a pneumatically operated pusher 82 for pushing the stack of flat objects
lOS along a slide 84 to a wrapper 90.
Figure 22 and 22A illustrate the movement of the pivot actuator 78 to the
lower position. Upon the completion of the horizontal movement of the stack of
flat objects lOS to the wrapper 90, the pivot actuator 78 pivots the pivoting the base
74 and arm 76 about the pivot 76A to the position as shown in Figure 22.
Thereafter, the pivot actuator 78 vertically moves along the rod 80 from the upper
position as shown in Figure 22 to the lower position as shown in Figures 14 - 19.
Upon the pivot actuator 78 vertically moving to the lower position, the pivot
actuator 78 pivots the base 74 and the arm into the position shown in Figure 14 -
19 for lifting a subsequent stack of flat objects 10. The pivoting of the base 74 and
arm 76 about the pivot 76A to the position as shown in Figure 22 allows the stacker
50 to operate continuously without interference from the first wrapper transport 61.
Figure 23 is a front elevational view similar to Figure 9 illustrating the firststage of transferring the stack of flat objects lOS to the wrapper 90 as shown in
Figure 20. The stack of flat objects lOS is shown raised by the first wrapper
16
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transport 61 into an elevated position. A second stack of flat objects lOT is shown
being assembled in the stacker 50.
Figure 24 is a front elevational view illuskating the second stage of
transferring the stack of flat objects lOS by the pneumatically operated pusher 82
for pushing the stack of flat objects lOS along the slide 84 to the wrapper 90 as
shown in Figure 21.
Figure 25 is a front elevational view illustrating the movement of a wrapper
driver 92 for forming a film tube 30 from the heat shrinkable material 25 with the
stack of flat objects lOS disposed therein. The wrapper 90 comprises a spool 94 of
the heat shrinkable material 25 supported by a holder 96 for threading the heat
shrinkable material 25 through a plurality of guides to a forming tool 98 for forming
the film tube 30. The forming tool 98 overlaps the first and second edges 28 and29 of the heat shrinkable material 25 as shown in Figures 3 - 8 to form the
longitudinally extending film tube 30. An electrostatic seam along the first andsecond edges 28 and 29 of the film tube 30. In the alternative, a heat sealing seam
(not shown) may be formed between the first and second edges 28 and 29 of the
film tube 30. A reciprocally acting seal bar 100 seals the film tube 30 for forming
the first end 21 of the heat shrink package 20.
The wrapper driver 92 vertically raises the stack of flat objects lOS through
the forming tool 98 to insert the stack of flat objects lOS within the film tube 30.
Continued movement of the wrapper driver 92 elevates the stack of flat objects lOS
within the film tube 30 through scissor doors 101 and 102 shown best in Figure 10
to an oven slide 104. The scissor doors 101 and 102 respectively pivot upon pivots
105 and 106 and define a central aperture 107.
The stack of flat objects lOS within the film tube 30 are driven through the
open scissor doors 101 and 102 and the scissor doors 101 and 102 pivot upon pivots
105 and 106 to a closed position. The central aperture 107 allows the wrapper
driver 92 to withdraw through the central aperture 107 to be retracted to the initial
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position shown in Figure 24 while the scissor doors 101 and 102 support the stack
of flat objects 10S. Thereafter, the sealer bar 100 seals the second end 27 of the
film tube 30 to form the second end of the heat shrink package 20.
Figure 26 is a front elevational view illustrating the movement of an input
oven transport 110 moved by an air cylinder 111 for transferring the stack of flat
objects 10S within the film tube 30 on the oven slide 104 into a heat shrink oven
112. The input oven transport 110 moves the stack of flat objects 10S within thefilm tube 30 onto an oven conveyor 120 disposed within the heat shrink oven 112.The oven conveyor 120 comprises a vertical elevator controlled by an air cylinder
122 or the like.
Figure 27 is a front elevational view illustrating the movement of the oven
conveyor 120 moving the stack of flat objects 10S within the film tube 30 through
the heat shrink oven 112. The oven conveyor 120 linearly lowers the stack of flat
objects 10S within the film tube 30 through the heat shrink oven 112 to a lower
position as shown in Figure 27. The linear motion of the oven conveyor 120 heatsthe film tube 30 to form the heat shrink package 20 shown in Figures 3 - 8. The
linear motion of the oven conveyor 120 may be accurately controlled, thereby
subjecting the film tube 30 and the stack of flat objects 10S to only a sufficient
amount of heat to form the heat shrink package 20 while being insufficient to
deteriorate the stack of flat objects 10S. When the stack of flat objects 10S are
perishable food products such as hamburger patties and the like, the accuracy of the
oven conveyor 120 insures that the food products are not unduly subjected to
excessive heat to m~int~in the quality and wholesomeness of the food product.
Optional guide tubes 130 are located adjacent the oven conveyor 120 for
supporting and m~int~ining alignment of the stack of flat objects 10S within the film
tube 30 while the oven conveyor 120 linearly lowers the stack of flat objects 10S
through the heat shrink oven 112. Preferably, the guide tubes 130 transport a flow
of fluid such as a cooling liquid or a cooling gas for cooling the guide tubes 130.
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CA 02239939 1998-07-31
The cooling of the guide tubes 130 prevent the heat shrinkable material 25 from
adhering to the guide tubes 130 when the stack of flat objects lOS is passed through
the heat shrink oven 112.
Figure 28 is a front elevational view illustrating the movement of an output
oven transport 140 transferring the heat shrink package 20 to an output conveyor150. The output oven transport 140 shown as an air cylinder transfers the heat
shrink package 20 to an output conveyor 150. The output conveyor 150 is disposedhorizontally for interfacing with a carton machine or the like wherein the shrink
wrap packages 20 may be automatically inserted within a cardboard shipping
container or the like.
The improved shrink wrap packaging machine provides a package for a
plurality of stackable items such as food products such as hamburger patties, fish
paKies, rice cakes, potato patties and the like as well as non-food products such as
compact and floppy disks, cassettes, books, as well as other flat objects. The
improved shrink wrap packaging machine controls the process time through the heat
shrink oven to insure that frozen items are not overly heated to prevent degenerating
the flavor of the frozen hamburger patty. The improved shrink wrap packaging
machine provides a reliable and sanitary means for shrink wrap packaging of foodproducts. Since the flat objects are packaged in a shrink wrap package, the need for
wax impregnated cardboard containers is elimin~ted by this invention. Wax
impregnated cardboard containers is not biodegradable and is not recyclable in
contrast to the heat shrink film which is recyclable.
The present disclosure includes that contained in the appended claims as well
as that of the foregoing description. Although this invention has been described in
this 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 changes in the details of construction and the combination and
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CA 02239939 1998-07-31
arrangement of parts may be resorted to without departing from the spirit and scope
of the invention.
