U.S. patent number 3,800,998 [Application Number 05/283,424] was granted by the patent office on 1974-04-02 for thermoformed container.
This patent grant is currently assigned to Prent Corporation. Invention is credited to Bryan R. Gask.
United States Patent |
3,800,998 |
Gask |
April 2, 1974 |
THERMOFORMED CONTAINER
Abstract
A one-piece container adapted to be thermo-formed and die cut
out of thermoplastic sheet material comprises two compartment
sections hinged to opposite sides of a central base section.
Peripheral flanges of the compartment sections lie in a common flat
plane when the container is formed and allow it to be die cut out
of the surrounding material along the flat cutting plane. When the
container is folded to its closed condition, complimentary recesses
in the compartment sections confront each other to enclose the
container contents and the peripheral flanges converge from the
base section with their end portions in engagement with each other
at the apex of the container to maintain the latter in that
condition.
Inventors: |
Gask; Bryan R. (Janesville,
WI) |
Assignee: |
Prent Corporation (Janesville,
WI)
|
Family
ID: |
23085990 |
Appl.
No.: |
05/283,424 |
Filed: |
August 24, 1972 |
Current U.S.
Class: |
229/406;
206/362.4 |
Current CPC
Class: |
B65D
75/225 (20130101); B65D 75/52 (20130101) |
Current International
Class: |
B65D
75/22 (20060101); B65D 75/52 (20060101); B65D
75/04 (20060101); B65d 001/00 (); B65d
085/00 () |
Field of
Search: |
;312/207 ;220/31S
;206/78R,56AA,45.34,15.1B ;229/2.5,45,29M |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Dixson, Jr.; William T.
Attorney, Agent or Firm: Larson, Taylor & Hinds
Claims
I claim:
1. A thermoformed plastic container comprising:
a. A generally rectangular central base section;
b. a pair of complementary compartment sections flexibly joined
along their base ends to the corresponding opposed edges of said
base section, each of said compartment sections including a
substantially flat peripheral flange extending along its lateral
edges and its free end opposite its base end, said compartment
sections being movable from a closed condition at which said
flanges are in confronting wedge shaped relation to each other with
their base ends separated by said base section and with their free
ends in mutual engagement and an open condition in which said
flanges are in coplanar relation to each other at opposite sides of
said base section;
c. compartment means defining complementary open-faced recesses in
said compartment sections, said compartment means being adapted
when said compartment sections are in said closed condition to
assume positions at which the open faces of said recesses are in
confronting relation to each other with at least part of said
compartment means extending outwardly beyond the planes of their
respective compartment section flanges; and
d. closure means comprising a closure element located at the free
end of one of said flanges and an opening, located at the free end
of the other of said flanges, for receiving said closure element
therein so as to releasably maintain said compartment sections in
said closed condition.
2. A container according to claim 1 in which the open faces of said
recesses are at least partially surrounded by flat panels of the
corresponding compartment sections, said panels being adapted to
closely confront each other when said compartment sections are in
said closed condition.
3. A container according to claim 2 in which each of said recesses
is angularly intercepted by the plane of the corresponding
peripheral compartment section flange.
4. A container according to claim 1 in which the free ends of said
flanges are provided with respective openings that confront each
other when said compartment sections are in said closed condition
to provide means for suspending said container from a suspension
member extending through said confronting openings.
5. A container according to claim 1 including means defining a
central aperture in said base section to allow an element of an
article packaged by said container to project out of said container
through said central aperture.
Description
BACKGROUND OF THE INVENTION
The present invention relates to thermoformed plastic containers
and more particularly to a thermoformed container comprising three
sections having peripheral flanges that lie in a common flat plane
when the container is formed and that assume a triangular or prism
shaped configuration when the container is closed.
It is well-known in the packaging art to provide a unitary
thermoformed container with flexibly connected complementary
compartment sections adapted to confront each other to define a
compartment for an article received in the closed container. In the
thermoforming process, such a container is made by causing a heated
area of a sheet of thermoplastic material to conform to a forming
die provided with various cavities and projections that define the
three dimensional configuration of the container. Following the
forming operation, the container is cut out of the surrounding
material by means of a so-called ruling die, which leaves
peripheral flanges around the outer edges of the container
sections. Various considerations dictate that the ruling die cut
along a single flat plane, which means that the container must be
designed so that the peripheral flanges initially lie in such a
plane.
If the container comprises only two compartment sections hinged
together along a central folding line, the flanges of those two
sections confront each other and can be joined together to maintain
the container in its closed condition and to provide convenient
means for hanging it to a display rack or the like. A typical
embodiment of such a container is shown, for example, in U. S. Pat.
No. 3,645,384 entitled SINGLE-PIECE BLISTER PACKAGE, issued on Feb.
29, 1972. Because of the central folding line along its base,
however, such a container is incapable of standing upright, which
is often desirable for display purposes. Alternatively, a similar
container can comprise two compartment sections hinged to opposite
edges of a central base section, whereby the flanges of the
compartment sections lie in spaced parallel planes when the
container is closed. Such a construction is shown, for example, in
U.S. Pat. No. 3,400,873 entitled MOLDED RECEPTACLE, issued on Sept.
10, 1968. Although this type of container can stand upright on its
base section, the spaced location of the compartment section
flanges prevents them from being joined directly together; thereby
requiring the provision of additional elements to hold the
container in its closed condition. Furthermore, this generally
parallel spaced location of the compartment section flanges
inherently prevails against pleasing aesthetic design.
SUMMARY OF THE INVENTION
A principal object of the present invention is to improve one-piece
thermoformed plastic containers of the type having three flexibly
connected sections provided with initially co-planar peripheral
flanges, by enabling those flanges to engage each other at the
openable end or apex of the container to retain the latter in its
closed condition.
Another object of the invention is to provide such a container that
it is adapted to stand upright on its central base section and also
to be conveniently suspended by the mutually engaged portions of
its peripheral flanges.
Still another object of the invention is to provide such containers
with improved structural innovations that are particularly
compatible with aesthetic design criteria.
Yet another object of the invention is to achieve the foregoing
objectives by means consistent with simple and economical
production and packaging equipment and operations.
Briefly, these and other related objects are accomplished in
accordance with the present invention by means of a one-piece
thermoformed container comprising two compartment sections hinged
to opposite sides of a central base section. Peripheral flanges of
the three sections lie in a common flat plane when the container is
formed and allow it to be die cut out of the surrounding material
along the flat cutting plane. When the container is folded to its
closed condition, complementary recesses in the compartment
sections confront each other to enclose the container contents and
the peripheral flanges assume a prism shaped configuration with the
end portions of the compartment section flanges mutually engaged
with each other at the apex of the closed container to maintain the
latter in that condition.
Various means for practicing the invention and other advantages and
novel features thereof will be apparent from the following detailed
description of illustrative preferred embodiments of the invention,
reference being made to the accompanying drawings in which like
reference characters denote like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a perspective view of a one-piece thermoformed plastic
container according to a preferred embodiment of the invention,
showing the container in the open or flat condition in which it is
initially produced;
FIG. 2 is a fragmentary longitudinal cross section view of the
container shown in FIG. 1, taken along line 2--2 of that
figure;
FIG. 3 is a perspective view of the container shown in FIGS. 1 and
2, depicting it in its closed condition standing upright on its
central base section;
FIG. 4 is a perspective view of a container according to an
alternate embodiment of the present invention, which is especially
adapted to hang from a merchandising rack or panel to display paint
brushes or similar articles; and
FIG. 5 is a perspective view showing the initial condition of the
container depicted in FIG. 4.
DESCRIPTION OF THE ILLUSTRATIVE PREFERRED EMBODIMENTS
The illustrative embodiment of the invention shown in FIGS. 1 - 3
of the drawings comprises a thermoformed container 10 adapted to
enclose an irregularly shaped article such as a cosmetic bottle or
the like. As best depicted in FIGS. 1 and 2, the container is
initially formed in a flat or open condition by means of a
conventional vacuum or pressure thermoforming process. When it is
initially produced, the container comprises a central or base
section 11 of triangular cross sectional profile and a pair of
complementary compartment sections 12 and 13 hingedly attached at
their base ends to the base section along flexible hinge lines 14.
Compartment section flanges 15 and 16 and base section flanges 17
surround the container and initially lie in a flat plane defined by
a corresponding flat face of the forming die. As previously
mentioned, this flat plane permits the container to be cut out of
the surrounding sheet material by means of a simple conventional
ruling die conforming to the outline of the container.
Each of the two compartment sections includes an open-faced
box-like recess or compartment 18 partially surrounded by a
generally flat panel 19 that merges with the plane of the
corresponding compartment section flange near the free end thereof
and that slopes upwardly from the flange towards the base section
of the container. As best illustrated in FIG. 2, this sloped
disposition of compartments 18 and panels 19 with respect to the
planes of the corresponding compartment section flanges causes the
compartments to be intersected diagonally by the respective flange
planes so that each compartment projects above its flange plane
adjacent the base section and below its flange plane adjacent the
free end of its compartment section. As will also be evident from
FIG. 2, the downwardly facing surfaces of the container that engage
the forming die are provided with appropriate slope or draft to
permit the thermoformed container to be removed easily from the
die.
The container is closed by folding it along hinged lines 14 to
bring the two panels 19 and the open faces of the complementary
compartments 18 into closely confronting relation to each other;
whereby the two compartments or recesses cooperate to completely
enclose the packaged article. In this condition, shown in FIG. 3,
the compartment section flanges 15 and 16 converge in wedge or
prism shaped relation to each other with their free ends 20 flexed
slightly into confronting mutual engagement at the openable end or
apex of the container. To maintain the container in its closed
condition, the free ends 20 of flanges 15 and 16 can be attached
together by any appropriate means, for example by a staple. In the
illustrative container 10, however, this is accomplished by means
of an integral closure structure comprising die cut openings 21 and
22 in the free ends 20 of the respective compartment flanges 15 and
16. After the container has been closed, tongue 23 of opening 21 is
pushed through the adjacent opening 22 between the opposed flexible
ears 24 thereof to releaseably maintain the free ends of flanges 15
and 16 in engagement with each other. This arrangement provides a
releasable closure structure that is particularly suited to
automatic packaging operations, but which also allows the container
to be opened and re-closed easily by the purchaser.
Because the hinge lines 14 are located along the edges of the
container base section 11 in coplaner relation to each other, the
container can stand upright in a stable condition for display
purposes, as shown in FIG. 3. Alternatively, it can be hung from
either a single or double display panel hook projecting through the
aligned openings 21 and 22 in the confronting compartment section
flanges. Furthermore, it will be apparent from FIG. 3 that the
subject container construction presents an attractive aesthetic
appearance and is adaptable to many different pleasing forms.
Preferably, the container is made of transparent material to
display its contents, but it obviously can be made of opaque
material, if desired.
The container 25 shown in FIGS. 4 and 5 as an alternate embodiment
of the invention is basically similar to the previously described
container 10, but is provided with a base section 26 comprising two
spaced prism shaped elements 27 at opposite sides of a central
opening 28 adapted to receive the handle 29 of a paint brush 30 or
a similar article. The closure means for this container is also
somewhat different, comprising an ear 31 at the free end of
compartment section flange 32 which extends through a slot 33 in
the free end of the other compartment section flange 34. Opening 35
in ear 31 and a corresponding opening 36 in flange 34 are aligned
with each other when the container is closed and are adapted to
receive either a single or double display panel hook to suspend the
container from a merchandising rack or the like. In the case of a
relatively large container such as a shoe box, similar openings in
the same type of closure structure could also be made large enough
to serve as a carrying handle.
The invention has been described in detail with particular
reference to illustrative preferred embodiments thereof, but it
will be understood that variations and modifications can be
effected within the spirit and scope of the invention as described
hereinabove and as defined in the appended claims.
* * * * *