US 3800998 A
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.
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United States Patent [1 1 Gask Apr. 2, 1974 THERMOFORMED CONTAINER  Inventor: Bryan R. Gask, Janesville, Wis.
 Assignee: Prent Corporation, Janesville, Wis.
 Filed: Aug. 24, 1972 21 Appl. No.: 283,424
Primary ExaminerWilliam T. Dixson, Jr. Attorney, Agent, or FirmLarson, Taylor & Hinds  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.
5 Claims, 5 Drawing Figures THERMOFORMED CONTAINER 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 ofa 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. Sucha construction is shown, for example, in US. 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 cen' tral 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 crite- 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 accom- 'plished 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, comple- 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 shownin 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 thermoforrning 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 l5 and 16 and base section flanges l7 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 l8 and panels 19 with re spect 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.
lines v 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. and 16 can be attached together by any appropriatemeans, 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 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 l5 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 container is closed by folding it along hinged 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.
I claim: Y
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. I
4. A container according to claim 1 in which the free ends of said flanges are provided with respective opendefining 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.
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