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The invention relates generally to the field of packaging,
and in particular to packaging for long rolls of photosensitive web
material. More specifically, the invention relates to a container with a
nesting feature allowing the stacking of multiple containers.
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Typically, long rolls of photosensitive web material, e.g.,
photographic film used for surveillance, social/portrait, and commercial
imaging, are commonly packaged in containers ensuring light tightness
during shipment from the manufacturer to the film processor. The width
of the photosensitive web used for such applications is typically 35mm,
46mm, 70mm or 105mm. Rolls of photographic film are generally wound
onto cores with or without light protecting flanges. Light-tight containers
suitable for storing and shipping photosensitive film have a film
compartment and a closure adapted to fit rather snugly about the film
compartment. Most often, the containers are fabricated of metal or plastic
materials.
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After using the film, the photographer generally stores it in
the light-tight container and then sends the film to a photoprocessing lab
where it is developed. As a general practice, technicians at the
photoprocessing lab will carry several stacked containers containing
exposed film into a dark room to open the containers and prepare the film
for processing. While existing containers for storing and transporting rolls
of photographic film are stackable, the containers do not have nesting
features. Hence, it is not uncommon for technicians to accidentally drop
containers onto the floor, as the stack is unstable. Such accidents are
known to result in damaged film reels, possible damage to the exposed
film, and unnecessary exposure to liability to the photoprocessing lab.
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It should be appreciated that due to the different widths of
film, film containers must be available to accommodate the several
different sizes. It would, therefore, be advantageous for the manufacturer
to be able to utilize a single common container closure with different sizes
of container bottoms. Such an advantage is identified in U.S. Patent No.
5,740,914, titled "Closure For Stacking Containers Of Different Sizes," by
Herzog, Apr. 21, 1998. However, unlike the containers described in U.S.
Patent No. 5,740,914, the plastic or metal containers used for photographic
film require an angle on the external wall of the container bottom typically
identified as draft angle for ejection from the forming device. Thus, as the
depth of the container bottom changes to accommodate the different
widths of film, the bottom diameter of the container bottom would become
smaller if each size of container bottom had the same draft angle.
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It should be appreciated, therefore, that existing packaging
containers for photosensitive film product have numerous shortcomings.
For instance, as multiple containers are stacked, they become unstable, and
different size container closures are required for different widths of film.
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Therefore, a need persists for stackable packaging
containers for photosensitive film product that incorporates nesting
features to stabilize the stacked array of multiple containers and is cost
effective to produce.
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It is, therefore, an object of the invention to provide a
stackable container that permits stacking of two or more similar stackable
containers.
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It is another object of the invention to provide a stackable
container that secures the containers in a stacked array.
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Yet another object of the invention is to provide a method
of facilitating the stacking of one container about another in a stacked
container array.
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It is, therefore, a feature of the stackable container that a
closure arangeable about the container body has a recess for receiving the
closed base of another similar stackable container.
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The present invention is directed to overcoming one or
more of the problems set forth above. Briefly summarized, according to
one aspect of the present invention, a stackable container comprises a
container body having a closed base, upright standing side walls
surrounding the closed base, an opening formed by the side walls opposite
the closed base. A closure arrangeable on said container body is provided
for closing the opening. The closure includes a recess having an upwardly
extending outer wall at least partially surrounding the recess. The recess
has an interior dimension for receiving the closed base and a portion of the
upstanding side walls surrounding the closed base
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In another aspect of the invention, a method of forming a
stackable container comprises the steps of providing a container having a
closed base and upstanding side walls surrounding the closed base. A
closure is provided for arranging about a portion of the upstanding side
walls for closing the container. The closure is provided with a preferably
generally planar recess having an upwardly extending outer wall or
stacking rim surrounding the recess. This stacking rim limits translation
movement of a closed base nested thereon. Thus, the recess is configured
to have a dimension for receiving the closed base and a portion of the
upstanding side walls. The closure is then arranged on the container by
preferably threadably screwing it about a portion of the upstanding side
walls to form the stackable container.
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The present invention has the following advantages: the
containers comprising the stacked array are easier to stack; the containers
have limited translation movement in the stacked array; the container base
and closure can be easily adapted to various sizes and configurations.
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The above and other objects, features, and advantages of
the present invention will become more apparent when taken in
conjunction with the following description and drawings wherein identical
reference numerals have been used, where possible, to designate identical
features that are common to the figures, and wherein:
- Fig. 1 is a cross section view of a stacked container array;
- Fig. 2 is a perspective view of either of the containers in the
stacked array; and,
- Fig. 3 is a perspective view of a closure for the container in
Figure 2.
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Turning now to the drawings, and in particular to Figs.
1 - 3, the stacked container array 10 of the invention is illustrated. Such a
stacked container array 10 may contain, for instance, rolls of
photosensitive web material (e.g., film) which require storage and
shipment in light-tight containers. The inventors have developed a design
for multiple-sized light-tight containers that can be nested and, therefore,
solve the problem with existing containers for film product. The invention
includes a variable taper (as described below) on the stacked containers 12,
14 to facilitate nesting.
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Referring to Figs. 1 and 2, broadly defined, stacked
container array 10 includes a first container 12 and at least a second
container 14 for stacking with the first container 12. It should be apparent
that any number of containers 12, 14 of the invention can be safely stacked
in the container array 10. According to Fig. 2, more particularly, first
container 12 and at least second container 14 each includes a closed base
16 and upright standing side walls 18 surrounding closed base 16 forming
a container body. Preferably, closed base 16 is generally planar for more
stable stacking although it need not be. An opening 20 opposite the closed
base 16 provides access to an interior compartment for storing articles
therein such as a roll of photographic film. Preferably first and second
containers 12, 14 are generally circular although other geometric shapes
may be used, such as any generally polygonal shape.
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Referring to Fig. 3, a generally circular closure 22 is
provided for closing the opening 20. A plurality of cooperating threads 27
arranged both in the interior of the closure 22 and about the circumference
of the first and second containers 12, 14 provide means for fastening the
closure 22 to a respective container 12, 14. Skill artisans will appreciate
that other fastening means may be used such as a snug friction fit. In the
preferred embodiment, closure 22 has a generally circular shape and is
configured to conform to the shape of either of the first and second
containers 12, 14. Further, closure 22 includes a recess 24 and an
upwardly extending outer wall (or stacking rib) 26 at least partially
surrounding the recess 24. In the preferred embodiment, recess 24 has a
generally planar surface and an interior diameter for receiving both the
closed base 16 and a portion 18p of the upstanding side walls 18
surrounding the closed base 16 of the other of the first container and
second container.
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Moreover, in the preferred embodiment, the upright
standing side walls 18 of closure 22 form a slight acute angle to the closed
base 16 although the sidewalls 18 may very well be oriented at a right
angle to the closed base 16. The advantages of the acute angle orientation
or variable taper is that it enables the containers 12, 14 to be easily stacked
and removed from the stacked array. Further, the variable taper with each
size container tends to facilitate nesting, so that the diameter of the closed
base 16 is similar but independent of depth. The stacked container array
10 of the invention is thereby formed.
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In the preferred embodiment, recess 24 is formed by a bead
of molten resin during the injection molding process protruding from the
closure 22 at least partially forming the upwardly extending outer wall 26
or stacking rib. This stacking rib limits translation movement of the closed
base 16 seated in the recess 24. Preferably, the outer wall 26 or stacking
rib extends continuously around the circumference of recess 24 (shown in
Fig. 3). Alternatively, outer wall 26 may include minimally three wall
stacking rib portions (not shown) that are arranged along the
circumference of the recess 24 to limit translation movement of the closed
base 16 seated thereon.
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Preferably first and second containers 12, 14 are made of a
rigid thermoplastic material, such as high-density polyethylene. Those
skilled in the art will appreciate that other materials may be used with
equal results including polystyrene and polypropylene.