Note: Descriptions are shown in the official language in which they were submitted.
Improved Access Reclosable Package
Field of the Invention
The present invention relates to reclosable packag-
ing, and more particularly to reclosable packaging for food
products wherein the package is sealed and also includes an
adhesive openable/reclosable strip along at least two sides
of the package or improved access to the contained food
product.
Background of the Invention
Many products, especially food products, are pack-
aged in flexible or semi-rigid packaging materials made from
polymeric films or laminates. In the case of food products
such as luncheon meats t frankfurters, and the like, it is
often desirable to use a portion of the contents and store
the remainder in the refrigerator for later use.
Hermetic sealing of packaging materials for ood
applications is well known in the art. Because these packag-
es are typically opened by a knife or other implement, they
are not easily opened and are not reclosable.
Much effort has been directed towards the produc-
tion of easy open packages where incompatible sealants or
other systems are used to produce a package which can be
opened without the use of a knife or other implement. Howev-
er, such packages often are too easily opened, and the
4/890726.lA/PROSLB
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structural integrity and safety of the contained food product
is therefore jeopardized.
Even in the case of many easy open packages, these
packages are often not reclosable and therefore do not pro-
vide the possîbility of use of a portion of the contained
product, and reclosure and storage of the remainder of the
product in the same package without the need for separate
reclosure means.
It is therefore desirable to provide the combina-
tion of package integrity and product safety associated with
a hermetic seal, and a reclosable feature which allows the
end user to store unused portions of the package, once
opened, in the same package for later use.
Efforts have been made even in this area to provide
such a combination. U. S. Patent No. 4,782,951 ~Griesbach et
al) discloses a reclosable package having interlocking clo-
sure strips positioned outside of a hermetic seal or seal
area. The hermetic seal is of the easy open type so as not
to destroy the integrity of the package or closure strips on
opening.
Such a combination requires the use of interlocking
closure strips which require either an extrusion of the clo-
sure strips during production of the package material, or the
separate step of applying the strips as discrete components
to the packaging material prior to or during the final packag-
ing operation. Additionally, such closure strips add an
additional expense to the cost of producing such a package.
It is therefore also desirable to provide a
reclosable package which preferably is hermetically sealed,
and a means of opening and reclosing the package to preserve
unused portions of the contained product, but without the
necessity of utiliziny interlocking closure strips, or compli-
4/890726.lA/PROSLB
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cating the extrusion process by incorporating closure stripsinto the extrusion steps.
It is a further object of the present invention to
provide a reclosable package in which access along more than
one side of the package by means of the openable/reclosable
feature is availa~le.
It is yet another object of the present invention
to provide a reclosable package which is tamper evident so
that the package changes in appearance after it has bcen
opened and reclosed.
Summary of the Invention
In one aspect of the present invention, a
reclosable package having four sides comprises a first film
web; a second film web; a means for connecting the film webs
at a first side of the package; a product placed between the
two film webs; an openable and reclosable adhesive strip
bonded to and disposed between the first and second film
webs, along a second and third side of the package; and a
seal located along a fourth side of the package~
In another aspect of the present invention, a
reclosable package havin~ four sides comprises a first film
web; a second film web; a means for connecting the film webs
at a first side of the package; a product placed between the
two film webs; and an openable and reclosable adhesive strip
bonded to and disposed between the first and second film
webs, along the second, third and fourth sides of the pack-
age.
In yet another aspect of the invention, a
reclosable package having four sides comprises a first film
web; a second film web; a product placed between the two film
webs; and an openable and reclosable adhesive strip bonded to
4/890726.lA/PROSLB
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;32~
~nd disposed between the first and second film webs along
each side of the package.
In still another aspect of the presen-t invention, a
reclosable package having four sides comprises a first film
web; a second film web; an integral fold at a first side of
the package, the webs having been formed from a single film;
a product placed between the two film webs; an openable and
reclosable adhesive strip bonded to and disposed between the
first and second ~ilm we~s, along the side of the package
opposite the first side; and a seal located along the third
and fourth sides of the package.
In another aspect of the inventi~n, a method for
making a reclosable package comprises applying an openable
and reclosable adhesive strip along at least two sides of a
first film web, on an interior surface thereof; placing a
product on the first film web; covering the product and first
film web with a second film web; and sealing the first and
second film webs together to form the finished package.
In yet another aspect of the invention, a method of
making a reclosa~le package comprises folding a single film
to form an integral fold at a first side of the package, and
a first film web and second film web; applying an openable
and reclosable adhesive strip along the side of the first
film web opposite the integxal fold, on an interior surface
of the first film web; placing a product on the first film
web; covering the product and first f ilm web With the second
film web and sealin~ the first and second film webs together
to form the finished package.
In still another aspect of the invention, a method
of making a reclosable package comprised folding a single
film to form an integral fold at a first side of the package,
and a first film web and a second film web; applying an
openable and reclosable adhesive strip along -the side of the
first film web opposite the integral fold, on an exterior
4/890726.1A/PRoSLs
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~3~
surface of -the first film web; placing a product on the first
film web; covering the product and Eirst film web with the
second film web which overlaps the side of the first web at
which the openable and reclosable adhesive strip has been
applied; folding the second film web so that an interior
surface thereof comes in contact with the adhesive strip; and
sealing the first and second film webs together to form the
finished package. This last method avoids any food contact
with the adhesive strip.
Brief Description of the Drawlngs
Figure 1 is a plan view of a reclosable package in
accordance with the present invention.
Figure 2 is a partially schematic cross-sectional
view of the package of Figure 1.
Figures 3-4 are plan views of alternative embodi-
ments of the inventive package.
Figure 5 is a partially schematic cross-sectlonal
view of the package of Figure 4.
Figures 6, 7 and 8 are plan views of other alterna-
tive embodiments of the inventive package.
Figure 9 is a partially schematic cross-sectional
view of the alternative embodiment of Figure 8.
Figures 10, 11 and 12 are plan views of still other
embodiments of the invention.
Figures 13A, B through Figures l9A, B are
elevational end views of various combination seals that may
be used as part of the present invention.
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Figures 20 and 21 are cross-sectional views of
packages with an overlapping web in accordance with -th~
present invention.
Figures 22 and 23 are perspective views of a
thermoforming system in connection with the present inven-
tion.
Figure ~4 is a perspective view of a vertical
form/fill/seal system in connection with the present inven-
tion.
Figure 25 is a partially schematic cross sectional
view of an easy open mechanism in connection with the present
invention.
Definitions
The term "heat seal" is used herein to mean a sPal
bonding together two film webs which may or may not be dis-
crete films, by the application oE a heated seal bar or other
device at sufficient temperature, pressure and dwell time to
xesult in a bond between the respective film webs in the heat
seal area. Such a bond would not be easily peelable under
normal usage, and would normally result in a hermetic seal.
The term "film" is used both in a stricter sense to
denote a relatîve thin monolayer ox multilayer thermoplastic
or cross-linked thermoplastic structure useful as packaging
material, and also in a broader sense to include
thermoformable materials such as laminates wherein convention-
al adhesives, corona treating, flame treating, and like pro-
cesses are used to bond together discrete films or layers
into a final multilayer packaging material.
The term "folded film" is used herein to describe a
single iilm or film web that has been folded upon itself to
4/890726.lA/PROSLB
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l2~
provide in effect two xesulting film webs ~hich can be sealed
together in various ways described in more detail below.
The term "adhesive strip" is used herein to de-
scribe adhesives which can be applied by nozzles or other
dispensing means to a film web to promote adhesion between
contacting surfaces of the film web and the adhesive. This
term implies that the adhesive strip is not a true reclosable
strip, although it may be one which can be easily peeled.
The term "peelable heat seal" is used herein to
describe a heat seal as discussed above which is made under
such conditions of temperature, pressure and dwell time that
the resulting heat seal has an opening force of between one
pound and about six pounds. Peelable heat seals are there-
fore heat seals which can be made by for e~ample seal bars or
other such devices, but which can be peeled open by manually
pulling apart a package. The use of a knife or other imple-
ment to open the package by puncturing or tearing is not
needed if a peelable heat seal is part of the package in
accordance with the present invention.
The term "openable/reclosable adhesive stripl' is
used herein to describe a strip of a green i.e. uncured hot
melt adhesive or similar material preferably applied by a
nozzle or like dispensing means to a film during a packaging
process. These adhesives have the property of providing a
peelable seal which can be reclosed after the package has
been opened by pressing the film webs together in the vicini-
ty of the adhesive strip.
The term 'lintermittent heat seal" means a heat seal
as described above, but one which is discontinuous along its
length so that periodic alternating portions of the seal are
actually defined by thermally unsealed areas.
The term "combination seal" is used to describe
various alternative embodiments in which an
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3~2~
openable/reclosable adhesive strip is used in combination
with intermittent heat seals either in a superimposed fashion
or in a juxtaposed fashion to provide a seal which is peel
able and reclosable.
The legend beneath Figure 1 of the drawings graphi-
cally depicts the various types of seals defined above.
Terms such as "second side of the package" and
"third side of the package" mean generally the peripheral
area around a typical four sided package at which one or more
seals of the various types discussed herein is present. The
relative location of these "sides" can best be determined by
reference to the plan views of for example Figures 1, Figures
3 and 4, and so on. Thus, the terms "side" or "sicles" are to
be distinguished from the terms "surface" or "surfaces" which
refer to the two major surfaces or external faces of a film
web.
Of course~ those skilled in the art will understand
that although the invention is descri~ed in some detail below
with reference to a ~our sided package, packages with less or
more than four sides, may be made using the seals and combina-
tions of seals described herein for the present invention.
Description of the Preferred Embodiments
Referring to Figure 1 a packag~ 10 includes a Eirst
film web 12 (see Figure 2) and a second film web 14. Packag-
ing films especially for food applications are well known in
the art, and vary according to the desired end use properties
including heat sealability, abuse resistance, shrinkability,
optics, and other considerations.
When a suitable film is selected, it may be used in
various processes such as thermoforming or vertical
form/fill/seal operations, in connection with the present
invention, to provide a package having a reclosable feature
4/890726.lA/PROSLB
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~3~
~nd preferably a hermetic seal. As indicated above, the term
"film" here includes laminates such as thermoformable
multilayer thermoplastic constructions made by coextrusion,
extrusion coating, conventional lamination, corona treating
and like processes. Figure 1 shows a food product 16 pack-
aged within film webs 12 and 14.
Although the packages of the present invention are
preferably hermetic, as required in many end-use applica-
tions, this is not required in all applications and the
present invention is broad enough to include non-hermetic
packaging made using the various combinations of seals de-
scribed in more detail below.
Referring to Figures 1 and 2, film webs 12 and 14
are actually a part of a single film which is folded at fold
18 upon itself to form the two film webs. Between them is
trapped the product such as a food product 16. Depending on
the equipment used, film types, and processing conditions,
portions of the first and second film webs 12 and 14 may
self-weld or otherwise be in close contact along some portion
20 of the package.
Product 16 is typically a food product, and the
present invention is especially useful for packaging luncheon
meats and franks.
An adhesive strip 22 is located on one side of
films 12 and 14 i.e. towards one side or end of the final
package, and in the case of Figure 1 is located between a
relevant peripheral portion 24 of the film web 14, and the
food product 16.
It will be noticed throughout the drawings that in
typical conventional apparatus for thermoforming
thermoplastic materials, placing the product in the cavity,
covering the product and ~irst material with a second web and
applying the appropriate seals some peripheral material will
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~3~3;~
~e outside the bounds of the final Einished and cut package.
This material is depicted throughout as reference numeral
24. The extent of this peripheral film will vary depending
on the process and equipment used.
An openable and closable adhesive strip 26 is de-
fined along two adjoining sides of the package of Figure 1.
Upon opening the package, the openable and
reclosable adhesive strip 26 can ~e peeled back to gain ac-
cess to food product 16.
Food product 16 is depicted in Figure 1 in general
fashion, but can be for example luncheon meats, frankfurters,
and other food products, often in discrete portions, which
may be used in part with the remainder resealed by closing
the package back along openable/reclosable adhesive strip
26.
Figure 3 shows an alternative em~odiment of the
invention in which heat seal 28 is located along one side of
the package.
The openable/reclosable adhesive strip 26 may be
applied by various means and in various ways to either the
first film 12 or second film 14, or both. It is preferably
applied in a substantially straight line along a relatively
narrow portion of one side of the film 12 or 14, or both.
Also preferably, the openable/reclosable adhesive strip 26
will be suhstantially parallel to a relevant side of the
finished package.
The adhesive used in the openable/reclosable adhe-
sive strip 26 is preferably a green, l.e. uncured hot melt
adhesive. Such adhesives are well known in the art. The
adhesive is preferably applied by a nozzle or like dispensing
means to the film during the packaging process. In this way,
roll stock ~Ised in the packaging process will not be compli-
4/890726.lA/PROSLB
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~2~3~
~ated by the presence of the adhesive before the packagingsteps are initiated. However, the adhesive may also be ap-
plied as a discrete strip of material, for example a
thermoplastic polymeric material to which a hot melt or simi-
lar material has been appliedO The adhesi~e may be applied
as a hot melt spray, cold glue spray, hot melt coating, or
cold glue coating to a film web as it is fed from a rollstock
to create longitudinal adhesive strips. Transverse adhesive
strips may be applied by intermittently spraying a hot melt
or cold glue. These processes may be combined to produce any
combination of one, two, three or four side
openable/reclosable adhesive strip seals in the finished
package.
Apparatus conventional in the art can be used to
install a heat seals or other seals described herein parallel
to or superimposed on any or all of the openable/reclosable
adhesive strips to produce various seal arrangements on one
or more sides of the finished package. Figures 22 and 23
graphically illustrate methods of applying the adhesive mate-
rial to a film web.
Figure 2 shows a cross sectional view of the pack-
age of Figure 1, and the relationships among the various
components of the package.
The films 12 and 14 of the drawings are depicted as
monolayer films, and preferably comprise a heat sealable
material when needed to produce a finished package having a
heat seal, peelable heat seal, or combination or intermittent
seal. Other types of films having for example radiation
frequency sealability may also be used when needed. Also,
multilayer thermoplastic constructions are included within
the scope of this invention.
Referring to Figure 3, an alternative embodiment
includes the use of a heat seal 28 along one side of the
4/890726.lA/PROSLB
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3~
package with the package otherwlse resembling that of Figure
1.
Referring to Figures 4 and 5, an alternative embodi-
ment of the invention includes the use of an openable and
reclosable adhesive strip 26 on two sides of the package, and
a peelable heat seal 30 bonding together the first and second
film webs along a portion of the package substantially paral-
lel to the openable and reclosable adhesive strips, and he-
tween such strips and the food product 16.
Figures 6 and 7 show two additional alternative
embodiments. In Figure 6, an intermittent heat seal is dis-
posed between and substantially parallel to the respective
openable and reclosable adhesive strips 26 and the food prod-
uct 16 in a manner similar to the seal arrangement of Figure
4. One side of the package has a continuous heat seal 28.
In Figure 7 a package is depicted similar to that of Figure
6, but having a combination heat seal 34 , and an adhesive
strip 22 along the fourth side of the package.
Figures 8 and 9 show another alternative embodiment
in which the openable and reclosable adhesive strip is locat-
ed along two adjacent sides of the package, but this time
inboard of i.e. closer to the food product than the intermit-
tent heat seal 32. Unlike the previous figures, Figure 8
shows that the remaining two sides of the package are heat
seals, so that instead of a folded ~ilm folded at 18, heat
seals 28 are used for the third and fourth sides of the pack-
age.
Figure 10 depicts a package in accordance with the
invention in which openable and reclosable adhesive strips
are used along two sides of the package and then another set
of openable and reclosable adhesive strips are positioned
substantially parallel to respective outer strips. An adhe-
sive strip bonds a third side of the package, and a heat seal
bonds a fourth side of the package.
4/890726.1A/PROSLB
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;32~!~
It should be n~ted that various combinations of the
different seal types utilized in this invention are inter-
changeable, so that for example in Figure 8 the openable and
reclosable adhesive strips are located between the intermit-
tent heat seal and the food product. The reverse is also
possible. Either a fold 18 or one of the seal types dis-
cussed herein is suitable for a third side of the package,
and a fourth side of the package may include any of the seal
types discussed. These seal types may be produced by conven-
tional apparatus and processes well known in the art.
Several functions are served by these different
seal arrangements.
First, by providing peelable access along more than
one side of the package, easier access to the contained prod-
uct is provided.
Secondly, by including an openable and reclosable
adhesive strip along at least two sides of the package, not
only is access to the package improved, but the package can
be more easily reclosed in a way to provide the same improved
access on reopening the package a second and third time.
Using a folded film with a fold 18 along one side
of the package, only one film ls necessary to produce the
finished package rather than two discrete rollstocks. This
is especially useful in vertical form-fill-seal applications
as depicted for example in Figure 24.
A third important function of these seal arrange-
ments is that in the case of the intermittent heat seals and
combination seals, once the package is opened, reclosing the
package will produce a package with a different appearance.
This makes the package a tamper evident package and allows
the consumer to determine whether the package has been opened
before sale.
4/890726.lA/PROSLB
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13
~3~
A four~h fea~ure of the present invention is -that
the package can be made hermetic by the use of peelable heat
seals, adhesive strips and heat seals as depicted in the
drawings, so that a packa~e with extended shelf life and
freshness can be obtained. The openable and reclosable adhe-
sive strip can itself be made hermetic or not hermetic depend-
in~ on the process and desired end-use, and the manner in
which the adhesive is applied to the film.
Figures 1-10 describe a package in which two sides
include an openable and reclosable adhesive strip. Figure 11
discloses a similar package but one in which three sides of
the package include the openable and reclosable adhesive
strip 26. In Figure 11, a peelable heat seal 30 runs paral-
lel to the openable and reclosable strip along each of the
three respective sides. A fold 18 along the fourth side of
the package completes the sealing arrangement.
In Figure 12, the openable and reclosable adhesive
strips 28 surround the food product along all four sides, as
does the peelable heat seal 30.
As in the case of the package configurations with
openable and reclosable adhesive strips along two sides, the
packages of Figures 11 and 12 can be modified in the various
ways described above. For example, the positions of the
o~enable and reclosable adhesive strips 26 and peelable heat
seals 30 can be reversed , so that the peelable heat seals
are peripheral to the openable and reclosable adhesive
strips. In the case of the package disclosed in Figure 11,
an adhesive strip or heat seal may be substituted for the
fold 18 on the fourth side of the package.
In addition, a third seal of the various types
described above may be included along any side of the package
so that for example in the package of Figure 11 an additional
openable and reclosable adhesive strip 28 may ~e disposed
substantially parallel to the peelable heat seal and between
4/890726.lA/PROSLB
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14
2~i3~
tne peelable heat seal 30 and the food product 16 so that in
effect thre~ discrete seals are located substantially paral-
lel to one another along at least one side of the package.
The choice of the number, type and positioning of
the various seal types described will depend on the end-use
application, types of films, process, apparatus, need for
tamper evidence, and need for improved access to the prod-
uct.
With respect to the combination seal depicted in
the legend beneath Figure 1, and in Figure 7, several seals
of this type can be produced in accordance with the inven-
tion. Figures 13A through l9A disclose elevational end views
of an openable and reclosable adhesive strip at one side of
the package of the invention. The thicknesses of the strip
in relation to the wid~h of the package are somewhat exagger-
ated for clarity. As can be seen in Figure 13A through l9A,
the openable and reclosable adhesive is applied in the vari-
ous ways described above along certain portions of a side of
the package depending on the desired combination seal to be
produced. The portions of the space between film webs 12 and
14 within which the openable and reclosable adhesive material
will be located is indicated at reference numeral 36 in Fig-
ure 13A through 19A. The portions of the space between the
respective film webs where the adhesive is not applied is
indicated at reference numeral 38 in the same figures.
A fragmentary view of seal bars 4G of various con-
figurations is shown in the upper portion of each o~ figures
13B through l9B. Each of these figures corresponds to a like
numbered figure depictin~ the position of the adhesive within
the openable and reclosable adhesive strips at a side of the
package. By applying the seal bar to a side of the package
in which the adhesive is so positioned, various combination
seals can be produced as shown in Figures 13B through l9B.
4/890726.lA/PROSLB
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~3~3;~
For example, in Figure 13B a heat seal is applied
in a discontinuous manner across the one side oE the film
along which the adhesive has been applied as shown in Figure
13A. The result is a combination seal in which some portions
42 are heat sealed and some portions 44 are held together by
the openable and reclosable adhesive. One advantage of such
a seal is the tamper evidence produced by opening and then
reclosing the seal. In addition, the seal is itself
reclosable so that tamper evidence, peelability and
reclosability are all combined in one combination seal. The
remaining Figures 14B through l9B show various ways in which
a heat seal can be applied to a portion of but not the entire
length of the openable and reclosable adhesive strip 26 repre-
sented by Figures 14A through 19A. These seals are all re-
ferred to as combination seals in -the ~ense that an uncured
hot melt adhesive or similar material which provides
openability and reclosability is combined at discontinuous
portions with a heat seal created by the application of a
seal bar or similar device to the respective film webs.
Referring to Figure 22, a thermoforming system is
shown in a fragmentary perspective view. The system 60 in~
cludes a thermoforming machine 62 and cavities 64 formed
within a film 12 fed from a roll 68. As film 12 proceeds
from right to left, cavities 64 are formed in the film. A
source 70 of a hot melt uncured adhesive delivers the adhe~
sive to noz~les 72 which apply the adhesive in a strip pat-
tern 74 along the film 12 as it is advanced. A food product
may then be placed in the formed cavities in film 12 and
covered with a second film to produce a package like that
depicted in e.g. Figures 1 and 2, but with a formed cavity in
the lower film.
O course, the ilm 14 depicted in for example
Figures 1 and 2 may itself be thermoformed according to the
process and using the apparatus described in Figure 22.
Thus, one or both of the first and second film webs may be
thermoformed.
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~13~3~
Figure 23 shows a variation of the process shown in
Figure 22, in which transverse adhesive strips are applied by
a similar process using a spray nozzle system 76 to apply the
adhesive in transverse strip patterns 78~
A combination of both longitudinal and transverse
openable/reclosable adhesive strips may b~ applied using the
combination of the process shown in Figure 22 and 23.
Figure 24 shows the use of the present invention in
a vertical form/fill/seal system 80 in which film 82 is in-
dexed around a mandrel 84 and a food product is introduced
through a tube 86 in a sequence well known in the art. A
source of hot melt adhesive 88 introduces the adhesive to the
interior of the tubular film as it is being formed. The
tubular film is longitudinally sealed at 90 and transversely
sealed at 92 to produce a package having a longitudinal seal,
two transverse seals (top and bottom of the finished packa~e~
and an adhesive strip located substantially parallel to and
spaced apart from the longitudinal seal 90.
To improve the consistency of openability, one web
can be corona treated to obtain greater adhesion of the adhe-
sive strip to that web than to the second web. Other methods
can also be used to achieve this difference in adhesion.
These include the use of different surface (sealant3 materi-
als for the two webs; manipulating the conditions under which
the hot melt is applied; and applying a coating to one or
both of the webs to either improve release or improve adhe~
sionO
Figure 25 shows a partially opened package in
which, because of dissimilar adhesion as described above, the
openable and reclosable adhesive strip 26 remains bonded to
web 12 rather than web 14 as the package is opened.
While the present invention has been described in
terms of preferred embodiments, those skilled in the art will
4/89o726.lAJpRosLB
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2IC~3~i3~
understand that mod.ifications may be made after review of the
speci~ication and drawings. Such modifications are deemed to
be within the scope of the claims that follow.
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