U.S. patent application number 09/885082 was filed with the patent office on 2001-11-08 for closure system for a pliable container.
This patent application is currently assigned to Arthur D. Little Enterprises, Inc.. Invention is credited to Hausslein, Robert W..
Application Number | 20010037627 09/885082 |
Document ID | / |
Family ID | 27038270 |
Filed Date | 2001-11-08 |
United States Patent
Application |
20010037627 |
Kind Code |
A1 |
Hausslein, Robert W. |
November 8, 2001 |
Closure system for a pliable container
Abstract
A closure system for use in repetitively opening and closing an
openable portion of a pliable container includes at least one shape
memory element which is bowed and adapted to be supported adjacent
the openable portion on a side wall of the pliable container for
rotation about a longitudinal axis defined by the element. The
element includes an elongated, generally concave surface portion
and an opposing, generally convex surface portion. Upon closing of
the container, the closure element is forced to rotate which
functions to place an opposing side wall of the container in
tension. The closure system has application to various types of
pliable containers, including two-sided, multi-ply and gusseted
bags. Provisions are also made for releasably locking the closure
system in a container sealing condition.
Inventors: |
Hausslein, Robert W.;
(Lexington, MA) |
Correspondence
Address: |
DIEDERIKS & WHITELAW, PLC
12471 Dillingham Square, #301
Woodbridge
VA
22192
US
|
Assignee: |
Arthur D. Little Enterprises,
Inc.
|
Family ID: |
27038270 |
Appl. No.: |
09/885082 |
Filed: |
June 21, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09885082 |
Jun 21, 2001 |
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09456526 |
Dec 8, 1999 |
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09456526 |
Dec 8, 1999 |
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08885667 |
Jun 30, 1997 |
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6022144 |
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Current U.S.
Class: |
53/455 |
Current CPC
Class: |
B65D 33/30 20130101;
B31B 70/004 20170801; B31B 70/81 20170801 |
Class at
Publication: |
53/455 |
International
Class: |
B65B 043/04 |
Claims
I claim:
1. A closure system on a pliable container for use in repetitively
opening and sealingly closing an openable portion of the pliable
container comprising: a shape memory element which assumes a bowed
shape in a relaxed state so as to define an elongated, generally
concave surface portion and an opposing, generally convex surface
portion, as well as longitudinal axis, said shape memory element
being supported, for rotation about the longitudinal axis, by one
of opposing side walls of the pliable container, with the generally
concave surface portion of the shape memory element facing another
of the opposing side walls when the pliable container is in an open
condition to maintain the opposing side walls in a spaced
relationship to permit ready access to an interior of the pliable
container and with the generally convex surface portion of the
first shape memory element facing the another of the opposing side
walls when the pliable container is in a closed condition to seal
the openable portion.
2. The closure system according to claim 1, wherein at least the
one of the opposing side walls includes multiple plies, said shape
memory element being positioned between the multiple plies for
rotation relative to the one of the opposing side walls.
3. The closure system according to claim 1, wherein the shape
memory element is rotatably mounted within a sleeve which is
attached to the one of the opposing side walls.
4. The closure system according to claim 1, wherein the shape
memory element extends across a comer portion of the pliable
container.
5. The closure system according to claim 1, wherein the closure
system includes a panel attached to the pliable container, said
shape memory element being rotatably mounted to the panel.
6. The closure system according to claim 5, wherein the one of the
opposing side walls is formed with a slit which defines the
openable portion, said panel being mounted along said slit.
7. The closure system according to claim 6, wherein the panel, in
combination with a portion of the pliable container, defines a
pocket within the pliable container.
8. The closure system according to claim 1, further comprising:
means for locking the closure system when the pliable container is
in the closed condition.
9. The closure system according to claim 8, wherein said locking
means includes a pair of hooking elements provided at respective
end portions of the shape memory element.
10. The closure system according to claim 8, wherein the closure
system further includes a band which supports the shape memory
element for rotation about the longitudinal axis, said locking
means including interengaging locking members provided at spaced
locations along the band.
11. The closure system according to claim 8, wherein the closure
system includes first and second bands attached to respective ones
of the opposing side walls, said locking means interconnecting the
first and second bands to maintain the pliable container in the
closed condition.
12. The closure system according to claim 11, wherein the pliable
container constitutes a gusseted bag.
13. The closure system according to claim 1, wherein the closure
system further comprises: additional closure means always tending
to place the pliable container into the closed condition.
14. In a pliable container including first and second opposing side
walls and an openable portion, a closure system for use in
repetitively opening and sealingly closing the openable portion of
the pliable container comprising: a bowed closure element having a
substantially circular cross-section and defining a longitudinal
axis, said closure element extending across and being supported by
the first side wall for rotation relative to the first side wall
about the longitudinal axis upon shifting of the pliable container
between open and closed conditions wherein, when the pliable
container is in the open condition, the closure element bows away
from the second side wall and, when the pliable container is in the
closed condition, the closure element tensions the openable portion
into a sealed, bowed configuration.
15. The closure system according to claim 14, wherein the first
side wall of the pliable container includes multiple plies, said
closure element being rotatably mounted between the multiple
plies.
16. The closure system according to claim 14, wherein the closure
element is rotatably mounted within a sleeve which is attached to
the first side wall.
17. The closure system according to claim 14, wherein the closure
element extends across a corner portion of the pliable
container.
18. The closure system according to claim 14, wherein the closure
system includes a panel attached to the pliable container, said
closure element being rotatably mounted to the panel.
19. The closure system according to claim 18, wherein the first
side wall is formed with a slit which defines the openable portion,
said panel being mounted along said slit.
20. The closure system according to claim 19, wherein the panel, in
combination with a portion of the pliable container, defines a
pocket within the pliable container.
21. The closure system according to claim 14, further comprising:
means for locking the closure system when the pliable container is
in the closed condition.
22. The closure system according to claim 21, wherein said locking
means includes a pair of hooking elements provided at respective
end portions of the closure element.
23. The closure system according to claim 21, wherein the closure
system further includes a band which supports the closure element
for rotation about the longitudinal axis, said locking means
including interengaging locking members provided at spaced
locations along the band.
24. The closure system according to claim 21, wherein the closure
system includes first and second bands attached to the first and
second side walls respectively, said locking means interconnecting
the first and second bands to maintain the pliable container in the
closed condition.
25. The closure system according to claim 24, wherein the pliable
container constitutes a gusseted bag.
26. The closure system according to claim 14, wherein the closure
system further comprises: additional closure means always tending
to place the pliable container into the closed condition.
27. A method of repetitively opening and sealingly closing an
openable portion of a pliable container comprising: establishing an
open condition for the pliable container by causing a bowed closure
element, which is supported by a first portion of the pliable
container adjacent the openable portion and defines an arcuate
longitudinal axis about which the closure element can rotate, to
maintain the first portion away from a second portion of the
pliable container; and establishing a closed condition for the
pliable container by causing the closure element to rotate about
the longitudinal axis, relative to both the first and second
portions of the pliable container, in order to bow and tension the
second portion of the pliable container.
28. The method according to claim 27, further comprising: locking
the pliable container in the closed condition.
29. The method according to claim 28, wherein the pliable container
is locked in the closed condition by releasably connecting end
portions of the closure element together.
30. The method according to claim 27, further comprising:
pre-assembling a closure panel including the closure element and
subsequently attaching the closure panel to the pliable container
adjacent the openable portion.
31. The method according to claim 27, further establishing the
closed condition for the pliable container by providing at least
one non-rotatable closure element which is attached to the first
portion and naturally bowed towards the second portion.
Description
[0001] The present application represents a continuation-in-part of
U.S. patent application Ser. No. 09/456,526 filed Dec. 8, 1999,
pending, which is a divisional of U.S. patent application Ser. No.
08/885,667 filed Jun. 30, 1997, now U.S. Pat. No. 6,022,144.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention The present invention pertains to
the art of packaging and, more specifically, to a system for
repetitively opening and sealingly closing an openable end of a
pliable container, such as a bag, as well as a method of using such
a closure system.
[0003] 2. Discussion of the Prior Art
[0004] Pliable or flaccid containers are widely used to store both
edible and non-edible products. For example, snack items, such as
various types of chips and cereals, are typically packaged in
pliable containers. These containers are generally sealed at both
ends for initial packaging purposes and then one of the ends is
opened to access the product. It is often desirable to utilize the
container to store the product for extended periods of time and to
repetitively open and close one end of the container to selectively
access the contents thereof.
[0005] When used to store edible food items, it is particularly
advantageous to adequately seal the openable end of the container
between uses in order to prolong the useful life of the food items
stored therein. For this reason, once the initial seal at one end
of the container is broken, it is common practice to roll up the
openable end of the pliable container for storage. Unfortunately,
the rolled-up ends of such pliable containers generally tend to
unroll between uses, which leads to the food items becoming stale
prematurely.
[0006] Proposed solutions to this problem include providing various
types of closure structures at the openable end to maintain the
side walls of the container in a close bearing relationship for
sealing purposes. For example, it is known to utilize a clip to
prevent the openable container end from unrolling. Since such clips
are completely separate from the container, they can be misplaced
and are therefore often only used when readily available. In
addition, these clips often tend to break and only directly
maintain a small central section of the openable container end in a
rather tight, closed condition. Zip-type closure arrangements have
also become quite prevalent for use with certain types of bags.
Such closure arrangements are considered advantageous in at least
they generally extend entirely across the width of the openable end
and are formed integral with the container. However, such closure
arrangements are considered to be quite difficult to use,
particularly for children and the elderly, due to the required
dexterity. In addition, these closure arrangements do not provide
an immediate indication that a complete seal has been established.
Instead, the entire arrangement must be systematically sealed from
one end of the opening to the other and if any portion is not
sealed, the purpose of the entire closure can be completely
compromised.
[0007] In addition to the need for providing a closure system for
sealingly closing an openable end of a pliable container, it is
also considered advantageous to enhance the accessibility to an
interior of a container when the container is opened. More
specifically, when the container is opened, it is desirable to
maintain the side walls of the container spaced apart, at least at
the open end of the container, to permit easy access to the
contents. Of course, neither clips nor zip-type closure systems
perform this desired function.
[0008] Other types of closure arrangements for pliable containers
have been proposed to perform both of these desired functions, such
as that represented in U.S. Pat. No. 5,037,138. According to this
patented arrangement, a snap-type closure mechanism includes a
closure strip secured to one side wall of a pliable container,
adjacent an openable end thereof. The closure mechanism is
generally biased to a closed condition, but can be flexed outward
along a centerline of the strip to maintain the container in an
open condition. Merely squeezing the closure strip near the
centerline causes the container to assume the closed condition.
[0009] The problem with such an arrangement is that it really only
maintains a central portion of the container open an adequate
amount, particularly since any biasing force tending to hold the
container open essentially acts between side edge portions of the
container and the closure strip. No closure structure is provided
along the other side wall of the container to co-act with the
closure strip, such that the degree to which the container can be
held open is limited and the sealing effectiveness of the closure
is minimized.
[0010] Based on the above, there exists a need in the art for a
simple, inexpensive closure system for use with pliable containers
which will enhance the accessibility to the contents when the
containers are open and which can be effectively used to
repetitively seal the containers.
SUMMARY OF THE INVENTION
[0011] The present invention is directed to a closure system for
use in repetitively opening and closing an openable end of a
pliable container. In accordance with various preferred embodiments
of the invention, the closure system includes first and second
shape memory elements that are adapted to be attached to respective
opposing side walls of the pliable container adjacent the openable
end thereof. Each of the first and second shape memory elements
includes an elongated, generally concave surface portion and an
opposing, generally convex surface portion. In various embodiments
of the invention, the shape memory elements are provided on the
container with the concave surface portions facing each other when
the pliable container is in an open condition to maintain the
opposing side walls in a spaced relationship in order to permit
enhanced access to an interior of the container. In each of the
embodiments, when the openable end is closed, the generally concave
surface portion of one of the shape memory elements assumes a
position substantially overlying the generally convex surface
portion of the other shape memory element in order to maintain the
container side walls in a close bearing relationship at the
openable end.
[0012] The first and second shape memory elements can take various
forms in accordance with the invention, including arcuate, flexible
bands formed of plastic or metal, curved wires or other bowed,
spring-like elements. In many of the preferred embodiments of the
invention, the first and second shape member elements constitute
similarly constructed shape memory elements which are bowed to
define the opposing concave and convexed surface portions. Both of
the shape memory elements are attached chordwise to an upper end
portion of the container with the shape memory elements being
arranged in vertically spaced planes when the container assumes an
open condition. Upon flexing of the shape memory elements toward
one another during closing of the container, each of the shape
memory elements will tend to flatten out to some extent against the
inherent spring-like characteristics thereof until the two side
walls of the pliable container come close together. At this point,
the upper shape memory element will be caused to automatically fold
over such that it drops down into the plane of the lower shape
memory element and substantially overlies the concave surface
portion of the lower shape memory element. Once in this position,
both of the shape memory elements will be permitted to flex in the
same direction thereby assuming an arcuate sealing condition. When
applied to containers formed with rather flimsy side walls, the
openable end of the container can be reinforced, adjacent the first
and second shape memory elements, by auxiliary support members
which, preferably, do not possess the inherent spring
characteristics of the first and second shape memory elements.
[0013] In certain embodiments of the invention, at least one of the
shape memory elements is constituted by a wire which is bowed in a
relaxed state such that the wire defines opposing concave and
convex surface portions. The wire can be sandwiched between two
film layers, formed from plastic, paper, cloth or the like,
positioned between adjacent layers of a multi-ply container side
wall or otherwise attached adjacent the openable end of the
container. When used in combination with another shape memory
element, the wire shape memory element will also flex outwardly to
provide enhanced access to the interior of the pliable container
and can be caused to conform to the shape of the other shape memory
element upon closing the openable end of the container by either
folding over in the manner described above or rotating about its
arcuate longitudinal axis. With the shape memory elements extending
across the width of the bag, the entire side walls of the container
are maintained in a close bearing relationship at the openable end
when in the closed condition. In accordance with at least certain
embodiments of the invention, a bowed, rotatable closure element,
such as a wire, is required on only one side of the pliable
container, adjacent an openable portion. When the container is in
an open condition, the closure element bows outwardly to aid in
maintaining the open condition. As the container is closed, the
closure element is forced to automatically rotate about an axis
defined by the closure element. When the closure element rotates
through approximately 180.degree., an opposing side wall of the
container will be placed in tension by the closure element, thereby
establishing an effective seal at the openable portion.
[0014] In accordance with further preferred embodiments of the
invention, the two shape memory elements can be attached to the
opposing side walls adjacent the openable end of the container in
identical planes. In still further embodiments, vertically spaced
shape memory elements can be placed on the same side of a
container. In such an arrangement, folding over of the openable end
of the container will cause the shape memory elements to overlie
one another or nest in a manner analogous to other mentioned
embodiments of the invention. Of course, this arrangement will not
bias the container into an open condition when access to the
interior thereof is desired.
[0015] Therefore, in general, the invention is directed to a
closure system for use in repeatedly opening and sealingly closing
an openable end of a pliable container by providing at least one
shape memory elements including an elongated generally concave
surface portion and an opposing, generally convex surface portion,
along a respective side wall of the pliable container adjacent the
openable end or portion. With this arrangement, the pliable
container can be selectively closed to seal the contents thereof by
simply mating multiple shape memory elements and/or utilizing one
or more shape memory elements to tension the pliable container in a
sealed condition. Additional features and advantages of the present
invention will become more readily apparent from the following
detailed description of the preferred embodiments thereof when
taken in conjunction with the drawings wherein like reference
numerals refer to corresponding parts in several views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of a pliable container having
an open end incorporating a closure system constructed in
accordance with a first preferred embodiment of the present
invention;
[0017] FIG. 2 is a perspective view of the pliable container of
FIG. 1 in a closed condition;
[0018] FIG. 3 is a perspective view of a pliable container
incorporating a closure system constructed in accordance with a
second embodiment of the invention;
[0019] FIG. 4 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with a
third embodiment of the invention;
[0020] FIG. 5 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with a
fourth embodiment of the invention, with the closure system shown
in an open condition;
[0021] FIG. 6 is a partial perspective view of an upper portion of
the pliable container shown in FIG. 5 in a closed condition;
[0022] FIG. 7 is a cross-sectional view of a multi-ply container
incorporating a closure system constructed in accordance with a
fifth preferred embodiment of the invention;
[0023] FIG. 8 is a cross-sectional view of a pliable container
incorporating a closure system constructed in accordance with a
sixth embodiment of the invention;
[0024] FIG. 9 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with a
seventh embodiment of the invention;
[0025] FIG. 10 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with a
eighth embodiment of the invention, with the closure system shown
in an open condition;
[0026] FIG. 11 is a partial perspective view of an upper portion of
the pliable container shown in FIG. 10 in a closed condition;
[0027] FIG. 12 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with a
ninth embodiment of the invention, with the closure system shown in
an open condition;
[0028] FIG. 13 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with a
tenth embodiment of the invention, with the closure system shown in
an open condition;
[0029] FIG. 14 illustrates a vertical form, fill and seal apparatus
adapted for continuously making pliable containers incorporating
the closure system of the present invention;
[0030] FIG. 15 illustrates a horizontal form, fill and seal
apparatus adapted for continuously making pliable containers
incorporating the closure system of the present invention;
[0031] FIG. 16 is a perspective view of a pliable container
incorporating a closure system constructed in accordance with an
eleventh embodiment of the invention, with the closure system shown
in an open condition;
[0032] FIG. 17 is a perspective view of the pliable container of
FIG. 16, with the closure system shown in a closed condition;
[0033] FIG. 18 is a partial cross-sectional view of a pliable
container incorporating a closure system constructed in accordance
with a twelfth embodiment of the invention, with the closure system
shown in an open condition;
[0034] FIG. 19 is a partial cross-sectional view of the pliable
container of FIG. 18, with the closure system shown in a closed
condition;
[0035] FIG. 20 is a partial cross-sectional view of a pliable
container incorporating a closure system constructed in accordance
with a thirteenth embodiment of the invention, with the closure
system shown in an open condition;
[0036] FIG. 21A is a perspective view of a pliable container
incorporating a closure system constructed in accordance with a
fourteenth embodiment of the invention, with the closure system
shown in an open condition;
[0037] FIG. 21B is a perspective view of the pliable container of
FIG. 21A, with the closure system shown in a closed condition;
[0038] FIG. 22A is a perspective view of a pliable container
incorporating a closure system constructed in accordance with a
fifteen embodiment of the invention, with the closure system shown
in an open condition;
[0039] FIG. 22B is a cross-sectional view of an upper portion of
the container shown in FIG. 22A;
[0040] FIG. 22C is a cross-sectional view, similar to that of FIG.
22B, but depicting the closure system in a closed condition;
[0041] FIG. 23A is a perspective view of a pliable container
incorporating a closure system constructed in accordance with a
sixteenth embodiment of the invention, with the closure system
shown in an open condition;
[0042] FIG. 23B is a perspective view of the pliable container of
FIG. 23A, with the closure system shown in a closed condition;
[0043] FIG. 24 is a perspective view of a portion of a pliable
container provided with a closure system constructed in accordance
with a seventeenth embodiment of the invention, with the closure
system being shown in a closed condition and incorporating a
locking mechanism configured in accordance with an aspect of the
invention;
[0044] FIG. 25 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with a
eighteenth embodiment of the invention, with the closure system
shown in a closed condition and including a second configured
locking mechanism;
[0045] FIG. 26 is a partial perspective view of a pliable container
incorporating a closure system constructed in accordance with an
nineteenth embodiment of the invention, with the closure system
shown in an open condition and including a third configured locking
mechanism;
[0046] FIG. 27 is a perspective view of a pliable container
incorporating a closure system constructed in accordance with a
twentieth embodiment of the invention, with the closure system
shown in an open condition and including a fourth configured
locking mechanism; and
[0047] FIG. 28 is a perspective view of the pliable container of
FIG. 27, with the closure system shown in a closed, locked
condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] With initial reference to the embodiment of FIG. 1, a
closure system constructed in accordance with the present invention
is particularly adapted for use with a pliable container which is
indicated at 2. In the embodiment shown, pliable container 2
constitutes a bag generally of the type known for use in packaging
food items such as potato chips and cereals. Therefore, pliable
container 2 includes opposing side walls 5 and 6, which are
generally formed from wrapping a single piece of material,
typically referred to as a web, along a longitudinal seam line (not
shown). Pliable container 2 includes a closed end 9 and an openable
end 12. The material for pliable container 2 is generally
constituted by paper or plastic, but can take other forms including
foils, laminated structures, leather, cloth and the like. On a
typical chip or cereal bag, closed end 9 would be formed from heat
sealing side walls 5 and 6. Of course, openable end 12 would be
originally provided with a commensurate heat sealed portion which
has been cut off to arrive at the arrangement shown in FIG. 1 but
which typically would extend above openable end 12 as depicted.
Therefore, pliable container 2 includes an outer surface 15 and an
inner surface 17 and the interior of pliable container 2 is filled
with food items such as that indicated at 20.
[0049] In accordance with a first preferred embodiment of the
closure system of the invention, first and second shape memory
elements 26 and 27 are attached to the opposite side walls 5 and 6
respectively. In the embodiment shown, each of the shape memory
elements 26 and 27 is constituted by an elongated band, preferably
formed of plastic. Each of the shape memory elements 26 and 27
preferably extends across substantially the entire width of pliable
container 2 such that ends 31 and 32 of each shape memory element
26 and 27 are adjacent side end portions (not labeled) of pliable
container 2 where crease lines are typically formed. Each shape
memory element 26 and 27 is bowed in a relaxed state so as to
define a concave surface portion 38 and an opposing convex surface
portion 39.
[0050] As clearly illustrated in FIG. 1, first shape memory element
26 is arranged vertically above second shape memory element 27.
Although first and second shape memory elements 26 and 27 are
secured to inner surface 17 of pliable container 2, it should be
recognized that the first and second shape memory elements 26 and
27 could equally be attached to outer surface 15 of pliable
container 2. In addition, the first and second shape memory
elements 26 and 27 can be attached to pliable container 2 in
various ways, including a stitching operation or through the use of
other types of mechanical fasteners known in the art. When such
other fastening arrangements are utilized, first and second shape
memory elements 26 and 27 can be provided with slits, flaps and/or
pockets (not shown) to enhance the securing thereof to pliable
container 2. In addition, various types of adhesives, including
pressure sensitive, heat activated and double-sided tape types, can
be utilized. When applied during the formation of a typical pliable
container for food items and the like, heat sealing the shape
memory elements 26 and 27 would be preferred due to its ease of
implementation and associated economical advantages. In any event,
it should be understood that the shape memory elements employed in
accordance with the present invention may be attached to a pliable
container through the use of various fastening arrangements.
[0051] Again, it should be noted that, although first and second
shape memory elements 26 and 27 are both illustrated to be attached
to inner surface 17 of pliable container 2, the first and second
shape memory elements 26 and 27 may be equally applied to the outer
surface 15, or between layers of each side wall 5 and 6 if a
multi-ply container is selected. In any event, first and second
shape memory elements 26 and 27 are adapted to be secured to
pliable container 2 adjacent openable end 12 with the generally
concave surface portions 38 of each of the first and second shape
memory elements 26 and 27 facing each other when pliable container
2 is in an open condition as illustrated in FIG. 1. Since first and
second shape memory elements 26 and 27 are bowed so as to define
the concave and convex surface portions 38 and 39, side walls 5 and
6 will be maintained in a spaced relationship to permit ready
access to food items 20 within pliable container 2.
[0052] When it is desired to sealingly close pliable container 2
for future access, side walls 5 and 6 are merely drawn closer
together which causes first and second shape memory elements 26 and
27 to momentarily flatten. Of course, this flattening of first and
second shape memory elements 26 and 27 is performed against the
natural tendency of the shape memory elements 26 and 27 to assume
the positions shown in FIG. 1. Therefore, first and second shape
memory elements 26 and 27 essentially act as leaf springs. As the
first and second shape memory elements 26 and 27 are brought closer
together, first shape memory element 26 will inherently tend to
fold over second shape memory element 27 such that the concave
surface portion 38 of first shape memory element 26 overlies the
convexed surface portion 39 of second shape memory element 27 as
best presented in FIG. 2. Once first and second shape memory
elements 26 and 27 are nested in this manner, they automatically
assume their bowed shape, which is also imparted to side walls 5
and 6 of pliable container 2. In this condition, side walls 5 and 6
are maintained in a closed bearing relationship to assure adequate
sealing of the contents within pliable container 2. Pliable
container 2 can be selectively opened at end 12 by momentarily
flattening first and second shape memory elements 26 and 27,
unfolding first shape memory element 26 and then allowing both of
the shape memory elements 26 and 27 to again assume the position
shown in FIG. 1 wherein ready access to the interior of pliable
container 2 is again provided.
[0053] Ideally the web used to make pliable container 2 should be
somewhat stiff rather then totally limp in nature, but should
permit free hinging of the horizontal foldover crease created
between first and second shape memory elements 26 and 27. The
materials referenced above for pliable container 2 satisfy this
criteria. Therefore, the closure system of the present invention
can be advantageously and easily applied to existing food item
packages of this type. The purpose of utilizing a rather stiff
material for pliable container 2 is to assure that first and second
shape memory elements 26 and 27 will be maintained in proper
alignment. However, the closure system of the present invention can
also be utilized with a pliable container formed of a rather thin,
flimsy web, such as a typical polyethylene sandwich bag. In this
case, reinforcing bands, such as those indicated at 45 and 46 with
dotted lines in FIG. 1, are provided to stiffen or reinforce
openable end 12. As shown in FIG. 1, such reinforcing bands 45 and
46 are provided below first shape memory element 26 and above
second shape memory element 27 respectively. Actually, it has been
found that band 45 substantially enhances the sealing of pliable
container 2, particularly when provided with a substantial width
and when extending transversely right out to the edges of pliable
container 2, and band 46 provides marginal benefits. Unlike first
and second shape memory elements 26 and 27, reinforcing bands 45
and 46 are passive in nature in that they readily flex to assume
positions dictated by first and second shape memory elements 26 and
27. To assure that reinforcing bands 45 and 46 only provide this
stiffening function, each of the reinforcing bands 45 and 46 can be
provided with various spaced, vertical grooves 48 which act as
hinges. In general, reinforcing bands 45 and 46 merely need to
exhibit a high flexibility in order to permit the bands 45 and 46
to freely bow, while being vertically stiff to assure that foldover
will occur only along the horizontal crease.
[0054] It has been found that, in providing reinforcing bands 45
and 46 when utilizing the closure system of the present invention
on rather flimsy pliable containers, the openable end 12 of the
pliable container is adequately stiffened to assure that first and
second shape memory elements 26 and 27 act in the manner described
above to permit the repetitive opening and closing of the pliable
container. At this point, it should also be noted that reinforcing
bands 45 and 46 can be formed of various materials and in other
ways, such as by thickening the container web material at the
openable end of the pliable container. In fact, the pliable
container can be integrally formed with structure which constitutes
the first and second shape memory elements 26 and 27 as well. This
arrangement can be advantageously carried out if pliable container
2 is made of plastic materials wherein integral shape memory
elements can be created by forming bowed, thickened wall portions
at openable end 12. Therefore, the entire closure system of the
present invention can be formed integral with a pliable container
at the time of manufacturing thereof or first and second shape
memory elements 26 and 27 can be separately formed and attached to
pliable container 2 in the manner described above.
[0055] As indicated above, first and second shape memory elements
26 and 27 generally act as springs and therefore can be made of any
stiff, elastically deformable material including plastic, metal,
wood, ceramics, laminated materials and the like without departing
from the present invention. In the preferred embodiment described
above, shape memory elements 26 and 27 are made of plastic, such as
polystyrene, polyethylene terephthalate or polycarbonate. When
utilizing metal for the shape memory elements, spring steel is
preferably utilized. In the embodiment shown in FIG. 3, a pliable
container 102, including side walls 105 and 106, is formed with a
closed end 109 and an openable end 112. Pliable container 102 also
includes an outer surface 115 and an inner surface 117 and has
attached thereto a closure system defined by first and second
shaped memory elements 126 and 127. As with the embodiment of FIGS.
1 and 2, each of the first and second shape memory elements 126 and
127 preferably extends across the entire width of pliable container
102 and has respective ends 131 and 132 that terminate adjacent
side edges or creases (not separately labeled) of pliable container
102. Again, each shape memory element 126 and 127 includes a
concave surface portion 138 and convex surface 139. In this
embodiment, each of the first and second shape memory elements 126
and 127 is preferably formed with two material layers 143 and 144
between which is sandwiched a bowed wire 146. In this preferred
embodiment, layers 143 and 144 are constituted by extruded plastic
members, however, other laminating materials including paper and
films could be readily utilized.
[0056] Therefore, in accordance with this embodiment, each of the
first and second shape memory elements 126 and 127 take a form
generally commensurate with typical bag ties, however, instead of
utilizing a soft metal such as iron, copper or aluminum for wire
146, a springy metal such as spring steel is utilized in the
preferred embodiment to maintain the desired bowed configuration.
Of course, other materials for wire 146, including plastics, can be
utilized so long as the desired concave and convex surface portions
138 and 139 are established and maintained. In the embodiment shown
in FIG. 3, first and second shape memory elements 126 and 127 are
illustrated as being adhesively secured to outer surface 115 of
pliable container 102 with first shape memory element 126 located
above second shape memory element 127 when pliable container 102
assumes the opened condition illustrated in this figure. As with
the embodiments of FIGS. 1 and 2, squeezing pliable container 102
at openable end 112 to cause initial flattening of first and second
shape memory elements 126 and 127 will result in first shape memory
element 126 folding over second shape memory element 127 such that
first and second shape memory elements 126 and 127 become nested
with concave surface portion 138 of first shape memory element 126
overlying the convex surface portion 139 of second shape memory
element 127 in the manner directly analogous to that described
above with respect to the embodiment of FIGS. 1 and 2. The opening
of pliable container 102 is performed in the manner directly
commensurate with that described above as well.
[0057] FIGS. 4-6 represent additional embodiments of the present
invention wherein sealing of a pliable container is performed by
folding over one side wall of the container onto an opposing side
wall such that shape memory elements applied to the container
overlie one another. In this manner, these embodiments are
generally analogous to those described above with respect to FIGS.
1-3. However, a few additional features of the present invention
are exemplified in FIGS. 4-6 as will be detailed below with initial
reference to FIG. 4.
[0058] In this embodiment, a pliable container 152 includes side
walls 155 and 156 that define an openable end 159, as well as outer
and inner surfaces 163 and 165. As shown, pliable container 152 has
first and second shape memory elements 167 and 168 attached to
outer surface 163 of side wall 156, with first shape memory element
167 being positioned above second shape memory element 168.
Although shape memory elements 167 and 168 can take various forms
in accordance with the present invention, including those described
above with reference to FIGS. 1-3, first and second shape memory
elements 167 and 168 are shown as bowed spring wires which are
positioned between outer surface 163 and respective lamination
layers 173 and 174. As illustrated, each spring wire generally
zig-zags transversely across side wall 156. Although not separately
labeled, as with the other embodiments described, each of the first
and second shape memory elements 167 and 168 define opposing
concave and convex surfaces.
[0059] With first and second shape memory elements 167 and 168
being mounted only on side wall 156, the end 159 of pliable
container 152 is not held open to enhance the access to within
pliable container 152 as in the embodiments described above. To
enhance the opening, another shape memory element (not shown) would
have to be positioned on side wall 155 directly opposite a second
shape memory element 168. In any event, the inclusion of only first
and second shape memory elements 167 and 168 still provides for an
adequate seal for pliable container 152. In order to seal pliable
container 152 in accordance with the invention, first and second
shape memory elements 167 and 168 are vertically spaced by means of
a transverse gap 175 which actually defines a fold line enabling
the upper portion of pliable container 152 to be folded into the
page as viewed in FIG. 4 so that first shape memory element 167 can
nest with second shape memory element 168.
[0060] It should be recognized that the presentation of this
embodiment exemplifies some additional aspects of the present
invention. First of all, this embodiment illustrates that the shape
memory elements can be provided on a single side of a pliable
container if desired. The embodiment also illustrates another
configuration that can be used for the shape memory elements.
Furthermore, the embodiment illustrates how shape memory elements
applied to a pliable container in accordance with the invention can
be provided with varying degrees of bowing strength. For instance,
in order for first shape memory element 167 to properly nest with
second shape memory element 168 upon folding over of the upper
portion of pliable container 152 into the page as shown in FIG. 4,
the surface of first shape memory element 167 that is directed
towards the interior of pliable container 152 assumes a convex
shape in order to mate with the concave curvature of the inside of
second shape memory element 168. However, when pliable container
152 is to be opened as shown in FIG. 4, first shape memory element
167 will actually work against second shape memory element 168 in
that it tries to close openable end 159 of pliable container 152.
This is overcome in accordance with the present invention since
shape memory element 168 has a greater associated bending force
than shape memory element 167. In other words, first shape memory
element 167 is more passive than second shape memory element 168,
thereby enabling pliable container 152 to assume the position shown
in FIG. 4, while also enabling the bending forces associated with
both of the spring wires to combine when pliable container 152 is
closed to assure a proper seal.
[0061] Of course, it should be realized that the closure system of
this embodiment can also function with second shape memory element
168 being more passive than first shape memory element 167. In
addition, the shape memory elements 167 and 168 could take various
forms in accordance with this embodiment, including plastic bands,
laminated wires, etc. and the upper shape memory element could
simple be indirectly attached to the pliable container 152 through
the lower shape memory element. In such an arrangement, when
pliable container 152 is open, the first shape memory element 167
would directly overlie the second shape memory element 168 and,
when pliable container 152 is to be sealed closed, first shape
memory element 167 would be flipped over so as to nest with second
shape memory element 168 with various layers of pliable container
152 therebetween.
[0062] FIGS. 5 and 6 illustrate another embodiment wherein shape
memory elements are again utilized to effect a seal through a
fold-over operation. More specifically, FIG. 5 illustrates a
pliable container 177 having opposing side walls 180 and 181 and an
open end 184. This embodiment is considered generally analogous to
that of FIGS. 1 and 2, however, each side wall 180 and 181 is
provided with multiple shape memory elements. In the embodiment
shown, side wall 180 is provided with shape memory elements 186-189
and side wall 181 is provided with shape memory elements 190-193.
As clearly shown in this figure, shape memory elements 186-193
alternate between upper positions and lower positions about side
walls 180 and 181. In addition, shape memory elements 186, 188, 190
and 192 are spaced slightly above shape memory elements 187, 189,
191 and 193 in order to define potential fold lines between these
shape memory elements.
[0063] When side walls 180 and 181 are drawn together, side walls
180 and 181 will be caused to automatically fold over along the
fold lines defined between the upper and lower shape memory
elements and will assume the position shown in FIG. 6. Of course,
in accordance with the other embodiments of this invention, each of
the shape memory elements 186-193 defines respective concave and
convex surfaces which become nested when pliable container 177
assumes the position shown in FIG. 6. Since multiple shape memory
elements 186-193 are provided, a generally wavy sealing
configuration is established when pliable container 177 is sealed
as clearly shown in FIG. 6.
[0064] In order to enhance the sealing characteristics of pliable
container 177, it is preferable to have shape memory elements 186
and 193 extend to and be secured directly adjacent side edge 195
and for shape memory elements 189 and 190 to extend and be secured
directly adjacent to side edge 196. In addition, to avoid any
vertical creases being developed, it should be noted that the shape
memory elements 186-189 partially overlap in the vertical direction
on side wall 180 and shape memory elements 190-193 vertically
overlap along side wall 181. For example, shape memory element 192
has an associated transverse length which is greater than the
lateral distance between shape memory elements 191 and 193 such
that end portions 198 and 199 of shape memory element 192 are
arranged directly above terminal ends (not labeled) of shape memory
elements 191 and 193 respectively. It should also be noted that a
similar wave-like closing condition could be achieved with
alternating convex and concave shaped memory elements at the same
level on a given side of the pliable container so long as the
convex shape memory elements exhibit greater bending forces to hold
the bag open since the intermediate, concave shape memory elements
would always tend to close the container.
[0065] FIG. 7 depicts a still further preferred embodiment of the
invention wherein the closure system is applied to a pliable
container 202 having side walls 205 and 206, each of which is
formed with inner and outer layers 207 and 208. Between inner and
outer layers 207 and 208 of side wall 205, adjacent an openable end
212 of pliable container 202 is a first shape memory element 216.
In the embodiment shown, first shape memory element 216 constitutes
a flexible plastic band constructed identical to that illustrated
in FIG. 1 with respect to either of first or second shape memory
elements 26 and 27. Of course, it should be readily understood that
first shape memory element 216 can take various forms in accordance
with this embodiment, and therefore can be constructed in a manner
commensurate to shape memory elements 126, 127, 167 or 168 as well.
This embodiment of the closure system of the present invention also
incorporates a second shape memory element 217 that preferably
takes the form of a bowed wire having a circular cross-section.
This embodiment differs from the embodiments of FIGS. 1-6 in mainly
three respects. First of all, second shape memory element 217 is
located at a generally commensurate level with first shape memory
element 216. Second, in a manner similar to shape memory element
216, second shape memory element 217 is positioned between the
inner and outer layers 207 and 208 of side wall 206. Finally,
second shape memory element 217 is freely rotatably mounted between
inner and outer layers 207 and 208. Of course, first shape memory
element 216 still includes analogous concave and convex surface
portions 220 and 221 and second shape memory element 217 also
includes concave and convex surface portions 222 and 223
respectively.
[0066] In this embodiment, when pliable container 202 is open, the
concave surface portions 220 and 222 of first and second shape
memory elements 216 and 217 face one another. However, when first
and second shape memory elements 216 and 217 are drawn together to
place pliable container 202 in a closed condition, second shape
memory element 217 will be caused to automatically rotate about its
own axis, i.e., an arcuate longitudinal axis, such that the
arrangement of concave and convex surface portions 222 and 223 will
become reversed and convex surface portion 223 can assume a
position nested with concave surface portion 220 of first shape
memory element 216. Upon opening of pliable container 202, which is
performed by simply spreading side walls 205 and 206, second shape
memory element 217 will again rotate about its own axis to
re-assume the position shown in FIG. 7 wherein openable end 212 is
expanded to provide enhanced access to the interior of pliable
container 202.
[0067] FIG. 8 illustrates a further embodiment of the invention
that utilizes a rotatable wire as a shape memory element. More
specifically, FIG. 8 illustrates a pliable container 227 having
attached along one transverse side thereof a first shape memory
element 230, depicted to constitute a band having an outer convex
surface and an inner concave surface analogous to those described
above with respect to various other embodiments of the invention
(particularly the embodiment of FIG. 1), a second shape memory
element 231 in the form of a bowed wire which is rotatably mounted
to an opposing side of pliable container 227, and a third closure
element 232 that is also illustrated to constitute a band.
Actually, in this embodiment, third closure element 232 either
constitutes a passive, reinforcing element or a weak shape memory
element since element 232 is adapted to conform to the shape of
shape memory element 230 upon closing of pliable container 227.
Therefore, the inner surface of element 232 that is attached
directly to the side wall of pliable container 227 must assume a
convex configuration upon closing of pliable container 227 since
shape memory element is outwardly bowed. Regardless of the
existence of any closure biasing by element 232, when pliable
container 227 is open in the manner depicted in this figure, shape
memory element 231 tends to bias pliable container 227 open to a
degree greater than any tendency of closure element 232 to close
the container.
[0068] As with the embodiment described above with respect to FIG.
7, the rotatable wire of shape memory element 231 will rotate upon
the drawing of the side walls of pliable container 227 together.
Therefore, when pliable container 227 is closed, shape memory
elements 230 and 232 will be nested and shape memory element 231
will actually be tucked slightly under shape memory element 230.
This configuration has been found to provide an enhanced seal for
pliable container 227 since all of the shape memory elements
230-232 are tending to maintain the pliable container 227 in the
sealed condition. In addition, with shape memory element 231
becoming slightly tucked under shape memory element 230, even when
pliable container 227 is turned upside-down, items placed in the
pliable container 227 cannot easily wedge between shape memory
elements 230 and 231. This wedging action would be required if the
contents of pliable container 227 were to open the container.
[0069] Although the wire of shape memory element 231 can be mounted
in various fashions to pliable container 227 in accordance with the
present invention, including above element 232, inside container
227 and sandwiched between element 232 and container 227, shape
memory element 231 is shown to be encapsulated within a wrapping
238 that includes a mounting section 240. Preferably, mounting
section 240 is heat sealed or otherwise fixedly mounted between a
respective side wall of pliable container 227 and shape memory
element 232. This mounting arrangement enables shape memory element
231 to be applied to a container 227 having only a single ply while
still enabling the wire to be completely encapsulated.
[0070] FIG. 9 illustrates a still further rotatable shape memory
element embodiment constructed in accordance with the present
invention. This embodiment is shown illustrated on a pliable
container 252 having side walls 255 and 256 and an openable end
258. Attached to side wall 255 is a first shape memory element 261
and rotatably mounted to side wall 256 is a second shape memory
element 262. As with the other embodiments disclosed, each of these
shape memory elements includes respective concave and convex
surface portions. Since first shape memory element 261 is fixed to
side wall 255, the element is always bowed outward. However, in
accordance with this embodiment, first shape memory element 261
constitutes a wire that includes upstanding portions 264 and 265
arranged directly adjacent side edges 267 and 268 of side wall 255,
a pair of tranversely extending portions 270 and 271 and a central
upstanding portion 273. Although first shape memory element 261 can
be made from various wire sections, it is preferably constituted by
a single wire that is bent to form upstanding portions 264 and 265,
as well as central upstanding portion 273. With this arrangement,
upstanding portions 264, 265 and 273 prevent rotation of first
shape memory element 261 about an axis defined by transversely
extending portions 270 and 271, while also exhibiting torsion and
stiffness enhancing characteristics.
[0071] On the other hand, second shape memory element 262 includes
a pair of transverse portions 278 and 279 that are interconnected
by a central handle portion 281. Mounting transverse portions 278
and 279 to side wall 256 are a pair of transversely spaced,
laminating strips 284 and 285. The strips 284 and 285 secure
transverse portions 278 and 279 to side wall 256 while permitting
rotation of transverse portions 278 and 279 about their associated
arcuate, longitudinal axis.
[0072] With this arrangement, when central handle member 281 is
rotated in one direction, say downward as viewed in this figure, to
a position substantially overlying side wall 256, the concave
surfaces of transverse portions 278, 279 will be arranged away from
side wall 256, thereby causing pliable container 252 to remain open
in order to enhance the accessibility of items placed therein.
Conversely, when central handle portion 281 is rotated upwardly,
side wall 256 will be drawn towards side wall 255 and second shape
memory element 262 will become nested with first shape memory
element 261.
[0073] With respect to this embodiment, it should be noted that
first shape memory element 261 not only tends to open pliable
container 252 through the use of bending forces, but the presence
of upstanding portion 273 functions to develop torsional forces
that further enhance the opening of the pliable container.
Therefore, such an arrangement provides a fair amount of spring
action when it is desired to open pliable container 252. Due to
this fact, the transverse portions 270, 271, 278 and 279 of shape
memory elements 261 and 262 could actually be straight, but angled
with respect to one another to cause side walls 255 and 256 to
assume a generally diamond-shaped configuration when opened and a
generally V-shape in top view when closed. However, the bowing of
shape memory elements 261 and 262 is preferred. Of course, the
bending and torsional forces created by first shape memory element
261 do not counteract the forces used to maintain the pliable
container 252 in a closed condition upon rotation of central handle
member 281. In addition, as with the embodiment of FIG. 7, second
shape memory element 262 will actually tend to rotate on its own
when side walls 255 and 256 are drawn together and therefore
central handle member 281 is not a required element. In the
alternative, central handle member 281 could actually have a
separate gripping element (not shown) attached thereto for
conveniently grasping and shifting handle member 281.
[0074] It should be realized that the closure system of the present
invention can actually be applied to various types of containers,
including paper and plastic bags. Therefore, although the closure
system of the present invention has been depicted for use in each
of the above-described embodiments on pliable containers having
only a pair of spaced, generally vertically extending side edges or
seams, it should be readily understood that the invention can also
be applied to various types of containers including gusseted bags,
such as typical grocery shopping bags or coffee bags which have two
main side panels and two pairs of folding side panels or infolds.
Reference will now be made to FIGS. 10-13 in describing a few
preferred embodiments wherein the closure system of the present
invention is incorporated in gusseted bags.
[0075] FIGS. 10 and 11 depict a gusseted bag 302 having a pair of
main side panels 304 and 305 and multiple folding side panels
307-310. Attached to each of the side panels 304, 305 and 307-310
is a respective, shape memory element 312-317. At least shape
memory elements 312 and 315, but preferably each shape memory
element 312-317, are bowed so as to include respective concave and
convex surface portions. What is important to note in this
embodiment is the fact that the shape memory elements 312-317
alternate between upper and lower vertical positions as they extend
around gusseted bag 302. With this arrangement, the drawing of main
side panels 304 and 305 together will cause the closure system of
the present invention to assume the position as shown in FIG.
11.
[0076] Since the embodiments of FIGS. 12 and 13 illustrate the
closure system of the present invention applied to an identical
type of gusseted bag 302 as that shown and described with respect
to FIG. 10, the same reference numerals have been brought forward
to these figures to identify corresponding parts. The embodiment of
FIG. 12 differs in that wire shape memory elements 327 and 328 are
utilized. More specifically, shape memory element 327 includes an
upstanding portion 330 that is affixed to gusseted bag 302 directly
adjacent a fold line 332 arranged between folding side panels 307
and 308, a generally horizontal portion 334 that extends along
folding side panel 308, an upstanding section 336 that extends on
either side of a fold line 338 between folding side panel 308 and
main side panel 304, a main transverse portion 340 extending across
main panel 304, an upstanding section 342 making the transition
between main side panel 304 and folding side panel 309, a
horizontal portion 344 extending along folding side panel 309 and
an upstanding portion 346 positioned between folding side panels
309 and 310. Shape memory element 328 is essentially inversely
arranged to shape memory element 327 and includes a down-turned
portion 349, a first generally horizontal portion 352, a downwardly
extending section 354 that extends about a fold line 356 between
folding side panel 307 and main side panel 305, a main transverse
section 358, a downwardly extending section 360, a generally
horizontal portion 362 and a down-turned portion 364.
[0077] As with the embodiment of FIG. 9, the use of upstanding and
down-turned portions 336, 342, 354 and 360 in shape memory elements
327 and 328 additionally provide torsional forces which enhance the
automatic opening of gusseted bag 302. In fact, in the embodiment
depicted, horizontal portions 334, 344, 352 and 362 are preferably
constituted by straight sections of wires to better conform to the
shape of folding side panels 307-310 respectively. However, given
their construction, the torsional forces developed adequately aid
in maintaining bag 302 open. Due to this arrangement, the developed
forces tending to maintain bag 302 closed is made greater than
these torsional forces. In other words, the bending forces
associated with main transverse sections 340 and 358 are made to
greatly counteract the combined torsional forces tending to open
bag 302 such that bag 302 can be adequately sealed when
desired.
[0078] The embodiment of FIG. 13 is substantially identical to that
of FIG. 12 except that four wire shaped memory elements are
utilized. The first shape memory element 378 is provided with a
transverse portion 380 and a pair of up-turned end portions 382 and
383; the second, opposing shape memory element 384 is provided with
a transverse portion 386 and down-turned end portions 388 and 389;
and side shape memory elements 390 and 391 are each provided with
upstanding end members 392 and 394, horizontal end portions 396 and
397, and an upstanding central member 398 formed from a bent
portion of a respective shape memory element 390 and 391. Again,
the presence of the upstanding central members 398 in this
embodiment function to develop torsional forces with further aid in
opening the gusseted bag, along with the bending forces developed
by the bowed shape memory elements 378 and 384. Also, as with the
embodiments of FIGS. 10-12, the embodiment of FIG. 13 provides for
sealing of the gusseted bag by a folding over of the top portion of
the bag such that shape memory element 384 nests with shape memory
element 378. With respect to the embodiments of FIGS. 12 and 13, it
should again be understood that the horizontal portions 396 and 397
extending along folding side panels 307-310 need not be bent but
could simply be constituted by straight wire portions. The
torsional forces developed due to the presence of the upstanding
central member 398 provide for an adequate propping open of the
gusseted bag 302 as desired.
[0079] As mentioned above, the shape memory elements incorporated
in the closure system of the present invention can be either
integrally formed with the pliable containers or simply attached
thereto. When integrated into the manufacture of a pliable
container, the shape memory elements can be again applied to either
the inside or outside of the pliable containers. When utilizing a
known type of vertical form, fill and seal machine, application of
the shape memory elements to an outside surface of the pliable bag
is preferably performed prior to filling of the bag such that any
contents placed in the bag will not hamper the attachment of the
shape memory elements. With reference to FIG. 14, a section of a
vertical form, fill and seal machine is generally indicated at 403.
As is known in the art, machine 403 will receive a web 405 that
extends about a roller 407 and is inverted about a mandrel 409. The
mandrel 409 shapes the web 405 into an elongated tubular member 411
following application of a longitudinal seam sealer 413. A lower
heat sealer/bag cutter unit 416 simultaneously creates a lower end
seal for a first pliable container 419 and an upper seal for the
next pliable container, while cutting the pliable container 419
from the remainder of the tubular member 411. Actually, the tubular
member 411 is shown inverted such that the lower end of pliable
container 419 actually constitutes the top thereof which defines
the openable end 421 in accordance with the present invention.
[0080] Again, this structure of vertical form, fill and seal
machine 403 is known in the art and not considered part of the
present invention. However, in accordance with the present
invention, the heat sealer/bag cutter 416 has mounted thereon upper
shape memory element applicators 423 and 424, each of which
receives a band 427 or other type of shape memory element as
described above that is delivered over a guide roller 429 and a
shaping wheel 431. Upper shape memory applicators 423 and 424 would
also include cutters (not shown) for the bands 427. In any event, a
respective shaping wheel 431 can be effectively utilized to give
each band 427 its relaxed, bowed shape such that band 427 is
delivered to the applicator 423 or 424 with the desired concave and
convex surfaces. Although not shown in this figure for simplicity
of the drawings, a similar arrangement would be provided to supply
a shape memory element to applicator 424. With this arrangement,
when heat sealer/bag cutter 416 is drawn against tubular member
411, applicators 423 and 424 will heat sealingly apply respective
shape memory elements, such as that indicated at 434, adjacent the
openable end 421 of each pliable container 419, to each pliable
container in succession.
[0081] In embodiments where various shape memory elements are
arranged in spaced planes, the applicator bars would typically
extend a distance twice as high as the shape memory elements to
accommodate for the offset vertical positioning thereof. If applied
internally on the bag, inner and outer applicator bars would be
utilized to apply each shape memory element. In addition, for
gusseted bags, further applicators would be utilized for applying
the shape memory elements on the infolds. To apply shape memory
elements to an inside surface of a pliable container on a typical
form, fill and seal machine, methods that have been utilized in the
past to apply zip-type fasteners could also be readily employed.
For example, the shape memory elements could be inserted as a pair
through an edge fin seal or a separate, temporary slit with the aid
of a retractable probe or could simply be applied vertically just
inside the fin seal.
[0082] Similar results can be achieved utilizing horizontal form,
fill and seal machines such as that indicated in FIG. 15. In this
arrangement, a web supply 441 runs through a folding stage 443 and
then to a vertical sealer 445. Since the web is folded over onto
itself and vertical sealer 445 creates side seals, a pliable
container 447 with a single open end 449 is formed. Next, the
pliable container is delivered to a shape memory element applicator
stage generally indicated at 452 wherein bands or other types of
shape memory elements 455 are delivered to opposing sides of the
pliable container 447 from spools, one of which is indicated at
457. Following applicator stage 452, pliable container will have
attached thereto desired shape memory elements, one of which is
indicated at 460. Next, the pliable container will be delivered to
a filling stage 462, an upper end sealing stage 465 and a cutting
stage 467. By providing applicator stage 452 prior to filling stage
462, the shape memory elements can be properly positioned on the
sides of pliable container 447 to assure proper nesting thereof
during later use when the closure formed by upper end sealer 465 is
torn open to access the contents placed within pliable container
447 and the closure system of the present invention is used to
repetitively open and sealingly close the pliable container.
[0083] Again, although various types of sealing arrangements can be
utilized as indicated above, heat sealing is considered to be the
most economical and feasible application method and enables the
shape memory elements to be applied to the pliable container before
the pliable container is fully formed. In addition, the shape
memory elements themselves can be formed as separate elements and
attached to the pliable containers as indicated above, or the shape
memory elements, whether formed as plastic bands, wires or
otherwise, could be integrated with the web that is fed to the
form, fill and seal machines. Therefore, the shape memory elements
could be incorporated in the supply rolls and then unwound
commensurate with the web. In addition, the shape memory elements
could be formed as separate supply rolls, either taking the form of
a narrow strip which is then cut into individual spring members
end-to-end or a wide strip which is cut into individual spring
members side-to-side. Furthermore, the shape memory elements could
be formed from the bag material itself, such as by accordion
pleating, folding or rolling up sections of the bag material and
then flattening the same through a heat sealing operation. Of
course, it should be readily recognized that the shape memory
elements in accordance with the present invention could also be
separately packaged and sold to be directly applied to pliable
containers by the consumer, such as by utilizing a double-sided
tape or an adhesive layer with a release strip provided on each
shape memory element.
[0084] As clearly exemplified by the embodiments described above,
the shape memory elements of the closure system of the present
invention may take various forms, including bands and wires. It
should also be noted that the shape memory elements can have
constant or varying widths and cross-sectional configurations,
regardless of whether they are formed integral with the pliable
containers or separately therefrom. What is important in accordance
with the embodiments described to this point is the provision for
opposing shape memory elements to be complementary in shape when
the pliable container is placed in a closed condition to assure
adequately sealing thereof. Furthermore, provisions can be
incorporated to enhance the sealing of the pliable container, such
as incorporating a compliant strip of material inside the container
at the fold line to act as a running gasket to ensure air
tightness. If desired, additional fasteners, e.g. snaps, hook and
loop or zip-type connectors, can be added if it is desired to more
securely maintain the pliable container in a closed condition. Such
additional fasteners can be particularly advantageously applied to
the embodiments shown in FIGS. 4 and 7 since the closure systems
therein tends to more easily opened when pressurized from within,
such as occurs when inverting a bag having a heavy content.
[0085] Bag closures which essentially rely upon tensioning a side
wall of a bag or other pliable container are also encompassed by
the present invention. That is, it is possible to provide a shape
memory element on only one side wall of a pliable container in
accordance with the present invention wherein, when the container
assumes a closed condition, the shape memory element functions to
place the opposing side wall of the container in tension in order
to maintain a desired seal at an openable portion of the container.
More specifically, in a manner directly analogous to that described
above with respect to the embodiments of at least FIGS. 3, 7 and 8,
a bowed closure element in the form of a shaped memory wire or the
like is rotatably supported on one side wall of a pliable
container. With the closure element in one position, the concave
surface thereof faces toward the opposing side wall in order to
enhance access to within or dispensing from the pliable container.
When the side walls of the pliable container are drawn together,
the closure element is forced to rotate, about a longitudinal axis
defined by the closure element, such that the opposing side wall is
forced to conform in shape to the concave configuration of the
closure element. In this manner, the opposing side wall is placed
in tension which has been found in accordance with the present
invention to provide an effective overall sealing arrangement.
Therefore, variations of the above-identified embodiments, with
simplified closure assemblies, are possible in accordance with the
invention. To further accentuate the potential variations,
discussed below are numerous embodiments further emphasizing these
aspects of the invention.
[0086] FIGS. 16 and 17 represent an embodiment, similar to that
described above with reference to FIG. 3, but wherein only shape
memory element 127 is provided. FIG. 16 depicts bag 102 is an open
state, while FIG. 17 illustrates a closed state. Since
corresponding reference numerals are utilized in these figures to
those described in detail with respect to the FIG. 3 embodiment, a
corresponding description will not be duplicated here. What is
important to note in accordance with this embodiment is that, when
shifted from the position of FIG. 16 to that of FIG. 17, wire 146
rotates such that convex portion 139 extends along surface 117 to
tension side wall 105. That is, the bowed nature of wire (closure
element) 146 aids in maintaining pliable container 102 in the open
condition shown in FIG. 16, but when first and second side walls
105 and 106 are drawn together, wire 146 is forced to automatically
rotate relative to side wall 106 through substantially 180.degree.
until the bowed state of FIG. 17 is reached. In this closed
condition, side wall 105 of pliable container 112 is in tension
which provides for an effective seal. In the most preferred form of
this embodiment, wire 146 extends to directly adjacent the edges
(not separately labeled) of side wall 106 in order to enhance the
sealing in these regions when the closed condition is
established.
[0087] FIGS. 18 and 19 represent an embodiment, similar to that of
FIG. 7, but wherein only shape memory element 217 is provided. In
general, this embodiment functions in a manner directly
corresponding to that of FIGS. 16 and 17 in that tensioning of side
wall 205 effects the desired seal. More specifically, when pliable
container 202 is closed, i.e., shifted from the position of FIG. 18
to the position of FIG. 19, side wall 205 is placed in tension due
to the bowed nature of rotatable wire 217 in order to establish a
seal adjacent openable end 212. In this embodiment, rotatable wire
223 is sandwiched between side wall layers of pliable container
202. The embodiment of FIG. 20 only differs from that of FIGS. 18
and 19 in that a single ply container 202 is provided and wire 217
is rotatably mounted within a tubular sheath or sleeve 400 which is
attached to side wall 208, preferably along an inner surface of
side wall 208 through a heat seal. It is considered that this
embodiment of the invention is rather simple to construct and
therefore a quite cost effective way to employ the invention.
Although not shown, the embodiment of FIG. 20 would assume a closed
configuration corresponding to the embodiment of FIGS. 18 and 19.
Therefore, these two embodiments only differ in the construction of
the pliable container 202 and the manner in which the rotatable
wire 217 is mounted. However, with respect to the overall manner in
which the sealing function is performed, these embodiments are
considered to be quite analogous. Of course, it should be realized
that sleeve 400 could be equally used to support wire 217 on an
outer surface 208 of side wall 206.
[0088] Additional "tensioning" embodiments are represented in the
remaining Figures. In FIGS. 21A and 21B, a rotatable closure
element 401, such as a wire or other similar, preferably circular
cross-sectional member, is arranged across a comer section (not
separately labeled) of a pliable container 402. With this
arrangement, the pliable container 402 can be torn open to define
an openable portion of pliable container 402 at the comer, as
depicted at 410 in FIG. 21A, in order to dispense snack products or
the like from container 402. However, a slight force tending to
draw the opposing sides 414 and 416 of pliable container 402
together will cause closure element 401, which is shown supported
by side wall 416 inside container 402, to rotate in order to
tension the opposing side wall 414, thereby sealing the openable
portion 410 at the torn comer of the pliable container 402 as
clearly shown in FIG. 21B.
[0089] In accordance with this embodiment, closure element 401 can
be supported for rotation relative to side walls 414 and 416 in
various ways. For instance, closure element 401 could be mounted in
a manner directly corresponding to any of the embodiments of FIGS.
16-20. In the alternative, closure element 401 could be attached to
a panel (not shown) which is itself attached to side wall 416.
Therefore, closure element 401 need not be directly attached to
side wall 416, but can be carried by a panel which itself is
attached to side wall 416 both laterally across pliable container
402 and at the side edges thereof. In any case, the rotatable,
bowed closure element 401 will press against side wall 414 when the
closed condition is assumed, with either side wall 416 also
directly abutting side wall 414 in the case of closure element 401
being directly attached to side wall 416 or side walls 414 and 416
being interconnected through the internal panel. This internal
panel arrangement will actually become more fully apparent
following the discussion of the embodiments depicted in FIGS.
22A-22C and 23A-23B.
[0090] With reference to the embodiment of FIGS. 22A-22C, a pliable
container 450 is shown to include side walls 452 and 453, as well
as an upper, openable end 455. In accordance with this embodiment
of the invention, a closure system is incorporated that includes a
panel 460 having an upper transverse edge 462, lateral side edges
463 and 464, and a lower transverse edge 465. Lower transverse edge
465 rotatably supports a bowed closure element in the form of a
wire 468.
[0091] In this embodiment, bowed wire 468 is indirectly attached to
side wall 452 through panel 460. More specifically, panel 460 is
preferably attached to side wall 452 along upper transverse edge
462, as well as lateral side edges 463 and 464. Most preferably,
lateral side edges 463 and 464 extend directly to and are joined
with side edges 471 and 472 of pliable container 450. If the
pliable container is of the type that includes side seams, lateral
side edges 463 and 464 would preferably be incorporated into the
seam. In any event, panel 460 is therefore attached to side wall
452 along three of its four edges 462-465.
[0092] When pliable container 450 assumes the open condition shown
in FIGS. 22A and 22B, closure element 468 is bowed away from side
wall 453 such that pliable container 450 maintains an open
condition. On the other hand, when side walls 452 and 453 are
brought together in order to cause closure element 468 to rotate
relative to panel 460, closure element 468 will bow in an opposing
direction such that the closure system will assume the position
shown in FIG. 22C. Here you will note that side walls 452 and 453
can be somewhat spaced, at least in the center portion of the bag,
while any contents in pliable container 450 will be prevented from
falling out due to the creation of a pocket 473 between panel 460
and side wall 452. In fact, with this construction, turning pliable
container 450 upside down provides an extremely effective seal
since the contents would merely function to force panel 460 toward
side wall 453 and further engagement between lower transverse edge
465 and side wall 453.
[0093] FIGS. 23A and 23B illustrate the use of a closure system
according to the invention at an intermediate section 500 of a
pliable container 502. Actually, this closure arrangement can be
easily retrofitted to an existing pliable container 502 by mounting
the closure system about a slit 505 formed in one side wall 510 of
container 502. More specifically, the closure system of this
embodiment takes the form of a panel 515 interconnected to side
wall 510. Panel 515 includes a closure strip or band 520 which is
attached to side wall 510 along an upper edge portion of slit 505.
As shown, closure strip 520 actually extends beyond the lateral
dimension of slit 505 and rotatably supports a closure element 525
in the form of a bowed wire. Panel 515 therefore includes both band
520 and closure element 525. The closure system also includes a
pliable attachment strip 545 that includes lateral edges 550 and
551 which are seamed to closure strip 520, as well as an extension
560 which is affixed to a lower edge portion of slit 505.
[0094] With this arrangement, the closure system functions in a
manner corresponding to that discussed above in that rotatable
closure element 525 is employed to selectively maintain open or
sealing close an openable portion of pliable container 502.
However, rotatable closure element 525 is not directly attached to
side wall 510. Instead, closure element 525 is attached to closure
strip 520 of panel 515 which, in turn, is attached to side wall
510. With this arrangement, a pocket is actually defined, in a
manner similar to that described above with reference to the
embodiment of FIGS. 23A and 23B, between closure strip 520 and
attachment strip 545 which is spread apart when pliable container
502 is open at slit 505 (FIG. 23A) and sealed when the closure
system assumes a closed condition (FIG. 23B).
[0095] At this point, it should be noted that the panels of these
embodiments can be easily mounted internally of the pliable
container. The actual panel design can be readily suited to the
requirements of a given bag. That is, the vertical width,
stiffness, upper and lower strip shapes, and specific configuration
of the panel can greatly vary within the scope of the invention. In
addition, the panel can be attached at substantially any desired
position on the pliable container, e.g., across an open end portion
or along a slit created in a face portion of the container. When
the panel is used in a retrofit manner, it essentially constitutes
a patch which is attached to an existing pliable container, as
opposed to being integrated during the actual manufacturing of the
container. Furthermore, it should be noted that the panel could
readily incorporate tabs or the like which enable portions of the
closure system to be easily grasped, such as for enhanced opening
of the closure. In accordance with preferred embodiments of the
invention, such an arrangement can range from a single hand hold or
tab extending from the closure strip or multiple tabs, such as one
extending from the closure strip and another extending from the
opposing side wall of the pliable container. In any event, these
optional elements do not alter the invention concerning the manner
in which the closure system operates to seal the pliable container
through the use of the rotatable closure element.
[0096] The remaining figures illustrate further embodiments
configured to create a seal through a tensioning effect. In
addition, these embodiments also illustrate potential locking
arrangements for the closure systems which prevent any undesired
rotation of the shape memory elements when a respective pliable
container is in a closed condition. The embodiment of FIG. 24 is
similar to that of FIGS. 16 and 17 except that the ends 146a and
146b of wire 146 project laterally outwardly of side wall 106 of
pliable container 102. In general, ends 146a and 146b generally
constitute hooks. With this arrangement, ends 146a and 146b can be
interlocked by drawing ends 146a and 146b together once the pliable
container 102 is sealed. Obviously, when ends 146a and 146b are
interengaged, the curvature of wire 146 is increased which further
tensions side wall 105 in order to enhance the seal, i.e., increase
the resistance to leakage and sliding apart of the mating
members.
[0097] Of further interest with such an arrangement wherein ends
146a and 146b extend beyond the lateral side edges of the pliable
container 102 is the ability to provide handles at these locations
to manually force rotation of wire 146. For example, plastic grips
could be attached at ends 146a and 146b. In the alternative, a grip
could be provided at a mid-region of wire 146 in a manner
corresponding to that shown in FIG. 9 at 281. In essence, such
grips merely provide for another way to open and close the pliable
container, as opposed to simply flexing the pliable container back
and forth in the vicinity of the closure element.
[0098] In FIG. 25, a band 600 is employed to support two rotatable
elements 602 and 603 within respective, elongated tubular cavities
610 and 611. As also shown in this figure, ends 620 and 621 of the
band project from side edges 625 and 626 of the container 630. As
represented in this figure, the ends 620 and 621 of the band can be
selectively interconnected, with deflectable hook or catch elements
640 and 641 provided on end 620 being slidably received between and
snap-locked to in-turned flanges 650 and 651 of end 621. Again,
this locking arrangement enhances the overall seal by increasing
the tensioning effect.
[0099] The same is true with respect to the embodiment of FIG. 26
wherein multiple, rotatable wire closure members 702, 703 and 704
are carried by a band 710 having ends 720 and 721 which project
beyond lateral edges 725 and 726 of a pliable container 730. In
this embodiment, an additional element 740, shown arranged in a
zig-zagging configuration but which could take various shapes, is
provided on side wall 749 with band 710, wherein element 740 is
naturally bowed in a direction which tends to further tension the
opposing container side wall 750 upon sealing the openable
container end. Preferably, element 740 is adhesively bonded or
otherwise attached to sidewall 749. With this arrangement, the
entire band 710 can be made to assume an extremely bowed condition,
similar to that of FIG. 25, upon sealing of the pliable container
730. Of course, the bowing of wire members 702-704 is stronger than
the natural bowing of element 740 in order to maintain the open
shape shown in FIG. 26. However, when pliable container 730 is
closed, element 740 provides an enhanced tensioning force beyond
that available from wire members 702-704 themselves.
[0100] Again, locking of the ends 720 and 721 of band 710 is
provided in this embodiment. As shown, end 720 is preferably formed
with a tab 760 which is receivable in a cut-out section 765 formed
in end 721. As should be clearly evident from the illustration
provided, tab 760 would be initially received in the enlarged
portion (not separately labeled) of cutis out section 765 and then
shifted to catch at the reduced portion (again, not separately
labeled) of cut-out section 765. As such types of interlocking
arrangements are used in other fields, a further explanation of the
operation of this locking arrangement will not be provided
here.
[0101] Finally, FIGS. 27 and 28 illustrate an embodiment wherein
rotatable wire closure elements 802 and 803 are applied for use
with a gusseted pliable container or bag 830. In the preferred
embodiment shown, wire elements 802 and 803 are rotatably supported
within sleeves 840 and 841 carried by a first band 845. First band
845 is attached to one side wall 850 of the bag 830, and a second
band 850, having in-turned, hooking end portions 860 and 861, is
attached to an opposing side 865 of the bag 830. Upon sealing of
the bag 830, the ends of the first band 845 will be received behind
end portions 860 and 861 of second band 850 to selectively lock the
closure system in place. Due to the bowed nature of wire elements
802 and 803 which causes first band 845 to be bowed when bag 830 is
open (see FIG. 27), first band 845 can pass by hooking end portions
860 and 861 upon initially sealing bag 830. However, when first
band 845 abuts second band 850 and then is further depressed in a
central region thereof, wire elements 802 and 803 will be forced to
rotate which, in turn, will cause the tensioning of side wall 865
and the ends of first band 845 to be caught by hooking end portions
860 and 861 (see FIG. 28).
[0102] From the above description of preferred embodiments of the
invention, it should be readily apparent that various changes
and/or modifications can be made without departing from the spirit
of the invention. For instance, the closure system is not limited
for use with a container or bag which is entirely pliable, but
rather one in which only the opening/sealing portion of the
container is pliable. Also, the container need not have one end
which is always closed. Instead, the invention could be applied to
a sleeve-like container which itself is slipped into or otherwise
secured to another bag as an insert. In addition, it should be
realized that the various shape memory elements could range in size
and shape in accordance with the invention. Furthermore, when
referring to various directions in the description provided, such
as the vertical or lateral direction, it should be readily
understood that reference is only being made to the arrangement of
the containers as depicted in the drawings. Therefore, such
directions are relative and not intended to be specifically
limiting.
[0103] Although not shown in the drawings, the mating container
faces can also be modified in accordance with the invention to
further enhance the overall seal created. For example, a compliant
coating, such as rubber, could be provided at these faces to
essentially define a gasket. An anti-slip coating, such as silica
particles, would be applied to reduce any tendency of the faces to
slide relative to each other. Also, interleaving ridges, similar to
those of zip-lock bags, could be used for locking/sealing purposes.
In fact, a rotatable closure element could be incorporated directly
into one of the zip-lock elements. Preferably, in such an
arrangement, the zip-lock elements would be modified to reduce the
pull force needed to open the bag. Additional measures, such as
strategically located heat seals, could be provided at edge
portions of the pliable container to prevent terminal ends of the
rotatable wire from becoming exposed to the consumer, i.e., to
prevent sideways creep of the wire. This function can also be
performed by providing the wire with one or more wider diameter
sections or beads which would still enable the desired rotation but
which would prevent sideways creep. In any event, the invention is
only intended to be limited by the scope of the following
claims.
* * * * *