U.S. patent number 3,871,521 [Application Number 05/253,371] was granted by the patent office on 1975-03-18 for shock-proof container and method for making same.
This patent grant is currently assigned to Continental Can Company, Inc.. Invention is credited to Richard R. Szatkowski.
United States Patent |
3,871,521 |
Szatkowski |
March 18, 1975 |
SHOCK-PROOF CONTAINER AND METHOD FOR MAKING SAME
Abstract
An improved shock-proof container comprising two hollow shells
having mating surfaces adapted to encapsulate an article for
storage or shipping. A foamed cellular polymer fills the space
within each of the shells to provide rigidity and a shock absorbing
capacity. Additionally, an integral locking structure for locking
the two shells together about the article is disclosed as well as
preferred means for making the container.
Inventors: |
Szatkowski; Richard R. (Western
Springs, IL) |
Assignee: |
Continental Can Company, Inc.
(New York, NY)
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Family
ID: |
26930441 |
Appl.
No.: |
05/253,371 |
Filed: |
May 15, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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237194 |
Mar 22, 1972 |
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Current U.S.
Class: |
206/524; 53/449;
53/474; 264/46.6; 53/472; 220/902; 220/920 |
Current CPC
Class: |
B65D
81/113 (20130101); Y10S 220/92 (20130101); Y10S
220/902 (20130101) |
Current International
Class: |
B65D
81/113 (20060101); B65D 81/107 (20060101); B65d
081/02 (); B65b 023/00 () |
Field of
Search: |
;206/46FC,524 ;229/14C
;220/9F ;264/45 ;53/14,16,17,18,36 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Price; William I.
Assistant Examiner: Marcus; Stephen
Attorney, Agent or Firm: Diller, Brown, Ramik &
Wight
Parent Case Text
CROSS-REFERENCE
This is a continuation-in-part of application Ser. No. 237,194,
filed Mar. 22, 1972, now abandoned.
Claims
I claim:
1. An improved container comprising two hollow shells each
constructed of one-piece polymeric material, a surface of one shell
mating with a surface of the remaining shell, said mating surfaces
defining therebetween a container interlocking as well as parting
area, said surfaces having apertures therein for permitting
communication between the shells, an article containing space
between said surfaces, and cellular plastic material filling each
of said shells and interlocking said shells together across said
area through said apertures to protectively encapsulate an article
within said article containing space while permitting said shells
to be parted across said parting area for the removal of an article
from said article containing space.
2. The container as defined in claim 1 wherein said surfaces are
more flexible than the remainder of each shell.
3. The container as defined in claim 1 wherein said surfaces are
each of a smaller cross-sectional dimension than the material
forming the remainder of each shell.
4. The container as defined in claim 1 wherein the number of
apertures in said shells are different.
5. The container as defined in claim 1 wherein at least one of said
surfaces includes continuous uninterrupted channel means
circumscribing said article containing space, and said aperture are
in communication with said channel mean.
6. The container as defined in claim 1 wherein both said surfaces
include channel means circumscribing said article containing space,
and said apertures are in communication with said channel
means.
7. The container as defined in claim 1 wherein at least one of said
surfaces includes channel means circumscribing said article
containing space, and said apertures are in communication with said
channel mean.
8. The container as defined in claim 7 wherein said surfaces are
more flexible than the remainder of each shell.
9. The container as defined in claim 7 wherein said surfaces are
each of a smaller cross-sectional dimension than the material
forming the remainder of each shell.
10. A process of containerizing an article comprising the steps of
providing two hollow one-piece shells having apertured mating
surfaces having therebetween a container interlocking as well as
parting area, placing an article between said surfaces, and
introducing expandable liquefied plastic foams in said shells and
positioning said mating surfaces contiguous each other whereby said
foams upon expansion will interlock the shells to each other
through the aperture thereof.
11. The process as defined in claim 2 including the step of
circumscribing the article with the introduced expanded liquefied
plastic foams.
Description
BACKGROUND OF THE INVENTION
This invention relates to a shock absorbing storage and shipping
container. More specifically, it relates to containers for shipping
fragile or other products which must be delicately handled.
THE PRIOR ART
Containers for such purposes have previously taken the form of an
exterior shell such as a cardboard or wooden box with a shock
absorbing material surrounding the article within the shell. As
indicated by the article entitled "More Economies in Foam-In Place"
appearing in the magazine, Modern Packaging, at pages 48 and 49,
dated Feb. 1972, the application of the shock absorbing material is
facilitated by in-situ plastic foam molding. Additionally, U.S.
Pat. No. 3,389,195, issuing to S. Gianakos on June 18, 1968,
suggest the utilization of two outer sheets of stretchable material
which enclose a foam product expanded therein to form a
container.
These prior art containers, although acceptable for many purposes,
remain deficient in certain respects. In those cases in which the
exterior shell is formed of cardboard or wood, the outer shell is
either weak and hence not resistant to punctures, or if so, the
container is relatively expensive. Additionally, where in-situ
foaming within such shells takes place, problems remain in
protecting the article to be packed from the foamed polymer such
that it will not adhere thereto. With respect to the Gianakos
patent, such appears to relate primarily to a relatively flexible
package, and the method of making same does not appear amendable to
quality control in terms of external or internal dimensions of the
container. Too, additional means of locking this container in a
closed position must be provided. Finally, U.S. Pat. No. 3,618,287
which issued to Gobhai et al on Nov. 9, 1971 discloses the use to
two matching shells, filled with a foamed cellular composition.
Each shell has a body which is vacuum formed and covered with a
flexible web attached thereto by a mastic. The article is merely
placed upon the web with the shells closed about it. The shells are
then sealed together by an adhesive or heat with foam being
expanded with the shell to encapsulate the articles. Thus, this
disclosure requires several distinct manufacturing steps to obtain
the desired package configuration.
SUMMARY OF THE INVENTION
In order to overcome disadvantages of the prior art and to provide
a more economical container, the instant invention utilizes two
hollow integral shells which may be joined by a hinge design which
mate with one another and close about an article. Each of the
shells are made of a polymeric material which preferably has a high
tensile and impact strength. The shells may have a box shape
appearance with external walls preferably of a thickness of less
than 25 mils. At least one surface of each of the shells is
modified so as to permit sealing engagement with the other shell,
and define an article containing space for enclosing an article.
Additionally, each shell contains a foamed polymer therein to
provide a sufficient shock-proof characteristic and to inherently
form a lock and/or between the two shells so as to provide a closed
container.
Accordingly, it is an object of the instant invention to provide a
most economical shock-proof container for fragile articles which is
light, and upon forming, inherently produces a locking and sealing
structure so as to preclude the admission of moisture and other
contaminants into the container. Another object is to provide a
shock-proof container which is fire suppressing, puncture-proof,
and extremely resistant to stress cracks, but yet economical and
efficient to manufacture in mass volume. Additionally, the
container is designed to conform its article containing cavity to
the configuration of the article so as to firmly encapsulate the
article and preclude its movement within the container. Too, it is
an object to provide a container in which the position of the
article therein is specifically defined and spaced from the seal
and external surface of the container so as to enhance the
container's sealing and protection characteristics. Finally, it is
an object of the instant invention to provide a process for making
such containers.
DESCRIPTION OF THE DRAWINGS
The manner in which the objects of this invention are attained will
be made clear by a consideration of the following specification and
claims when taken in conjunction with the drawings in which:
FIG. 1 is a perspective view of the exterior of a preferred
embodiment;
FIG. 2 is an exploded view in perspective of the two halves of this
embodiment;
FIG. 3 is a side elevational view of this embodiment taken in
section along the lines 3--3 of FIG. 1.
FIG. 4 is a perspective view of the locking and sealing mechanism
for the instant embodiment;
FIG. 5 is an exploded perspective view of a mold utilized in making
this embodiment;
FIG. 6 is an elevational view taken in section along the lines 6--6
of FIG. 5 of the upper portion of the mold;
FIG. 7 is a symbolic view of one apparatus and method of forming
the shell of this embodiment within the mold of FIG. 5;
FIG. 8 is an exploded perspective view of the two shells of this
embodiment prior to closing;
FIG. 9 is a side elevational view in section of the lower shell of
the embodiment taken along the lines 9--9 of FIG. 8;
FIG. 10 is a side elevational view in section of a complete
container taken along the lines 10--10 of FIG. 3;
FIG. 11 is an elevational view in section of another embodiment of
the instant invention;
FIG. 12 is an elevational view in section of a third embodiment of
the instant invention; and
FIG. 13 is a perspective view of the embodiment of FIG. 12 prior to
the closing of the container.
DETAILED DESCRIPTION
As depicted in the preferred embodiments of FIGS. 1 through 4, the
instant invention utilizes two shells of a polymeric material which
will produce the desired characteristics of high tensile strength
and toughness. The two shells so formed are adapted to mate with
one another about the fragile article which is to be shipped. As
explained, the container is completed by placing an expandable
liquified foam in the interior of each of the shells which
provides, upon expanding, a shock-absorbing, rigid cellular
character to the package. Additionally, this liquified foam upon
expanding will provide a self-locking characteristic.
The ultimate container is depicted in FIG. 1 which represents a
container formed of upper and lower shells 12 and 14 which have
been joined or locked together by in-situ plastic foam molding as
hereinafter explained. Each of the mold shells may take the form of
a hollow rectangular box having four sides 16, an exposed surface
18 which may be either the top or bottom of the container, and a
mating surface 20. This mating surface may be formed so as to
define a first flat surface 21 extending around the periphery of an
article containing space, a sealing channel 24 of semi-circular
configuration and a second flat surface 25. Appropriately located
on the surface 25 are article containing spaces 22 which have a
general configuration of the article to be contained. As depicted,
these spaces 22 are semi-cylindrical in shape, and define article
containing cavities 26 when the upper and lower shells 12 and 14
are joined together at the mating surfaces 20. The semi-circular
sealing channel 24 which circumscribes the cavaties 26 will define
a circular channel around this space upon mating of the two shells.
Additionally, it will be observed that apertures 30 are formed,
preferably, within the channel 24, so as to permit the interior of
each of the shells 12 and 14 to communicate with one another. Thus,
just prior to joining the shells together about an enclosed
article, a liquified foam plastic is to be injected through these
apertures and into the hollow shells. The subsequent rapid
expansion of such foam will fill the space within the two shells
with a rigid cellular composition 40. As the foam 40 expands
through the apertures 30 and solidifies, it will integrally lock
the two shells together about the article within cavity 26 so as to
form a self-locking, tamper-proof, self-sealing closure means 44
which is appropriately depicted in FIG. 4. Thus, expanding foam 40
will completely fill the sealing channel 24 so as to form a
cylindrical sealing means 46 extending about the enclosed articles,
with extensions 47 extending inwardly into each of the other shells
and forming a solid lock. To facilitate opening of the container
and to insure that the seal remains intact with one of the shells,
the apertures 30 in one shell may be reduced in number or offset
with respect to the apertures in the shell to which the seal is to
remain attached. Additionally, if the material forming the shell
has a reduced thickness or flexibility in the cavity defining areas
the expansion of the foam will cause the cavity to conform to the
article therein.
Preferably, the exterior shell is formed of a polymeric material
which has a high tensile and impact strength, which is relatively
rigid and resistant to punctures. Suitable materials for forming
such a shell would include such polymers as polybutylene
terrepthalate which is marketed under the trademark VALOX by
General Electric Company, Inc. and having a sales office at One
Plastics Avenue, Pittsfield, Mass. or any fluorohalocarbon material
such as TEFLON. These materials are most appropriate when a
fire-resistant container is desired. Other polymers which provide
desirable exterior packaging characteristics may be found
acceptable. For example, polyethylene, polyurethane or
polycarbonate polymers may be utilized if desired. With respect to
the foam composition, polyethylene or polyurethane foams are
generally employed, but any plastic which is capable of forming a
cellular structure and provides the desired rigidity for the
container is acceptable.
A preferred method of manufacturing such a container is depicted in
FIGS. 5 through 10. The hollow shells 12 and 14 are preferably
formed through a rotational molding process. Thus, a plastic charge
of the polymer material which forms the shell is placed inside a
hollow mold 50 which is then rotated about two axes at
predetermined speed ratios within an oven so as to subject the mold
and the polymeric material to heat. During the rotational and
heating process, the powder contacting the heated metal surfaces
will melt to form a film thereon which solidifies through a
subsequent cooling process.
With reference to FIG. 5, a suitable mold for each of the shells is
identified by the numeral 50 and includes an upper mold half 52 and
a lower mold half 60. The lower mold half 60 is merely a
rectangular metal box taking the general configuration of the
external portion of the shell, and has four sides 62 and a bottom
61. Prior to the rotational molding process, the polymer material
is placed within the lower half 60 with the upper half 52 being
placed thereon. The upper mold half is designed as a flat plate 53
with core forming elements 54 extending downwardly to define the
article containing spaces 22 within the finished container. As
indicated, the elements 54 are of a substantially thicker
cross-section than the remainder of the upper mold half for
purposes hereinafter described. Additionally, a core forming
element 56, having a general semi-circular configuration extends
around the periphery of plate 53 so as to form the sealing channel
24. Finally, plugs 57 of a thermally non-conducting material (such
as a phenolic resin) extend through the plate and the core forming
elements 56 at selected points for purposes hereinafter described.
Thus, the upper mold half has an interior surface contoured so as
to define a shell having the configuration identified in FIGS. 1
through 4. If desired, one mold might be utilized to make both
shells with a hinge interconnecting them.
To manufacture the shells, the polymeric material is placed within
the lower mold half 60 with the upper mold being closed thereon.
Subsequently, this mold and the material therein is clamped to a
rotational molding unit identified symbolically in FIG. 7. This
rotational molding element is designed to rotate the mold within a
heating unit about two different axes so as to insure a relatively
uniform distribution of polymer material about the interior of the
mold. Accordingly, a primary drive shaft 72 suitably journalled
within an appropriate supporting means (not shown) is rotatably
driven by an electric motor or other means 74 so as to rotate a
yoke 76 about the axis of this primary shaft. A means of carrying
the mold may include two shafts 78 suitably journalled within the
yoke so as to permit rotational motion of the mold in a second
direction which is generally perpendicular to the axis of the
primary drive shaft 72. To effect rotation in the second direction,
the primary drive shaft 72 is provided with an extension 79
carrying a gear 81 for driving a chain 82. This chain is then
coupled with a second gear 84 on a secondary drive shaft 85 which
is rotationally supported by an appropriate means (not shown). At
the distant end of the secondary drive shaft 85 is a bevel gear 89
which meshes with the drives a pinion gear 90 constrained for
rotation with the shaft 78. Thus, this apparatus is capable of
rotating the mold in at least two directions of varying speeds so
as to cause the polymer material in contact with the metal to melt
about the mold forming a completed shell 12 or 14. However, since
the phenolic plugs do not conduct heat, powder falling on them will
not melt and apertures 30 in the sealing channel 24 will result.
Alternatively, these apertures may be formed after molding by
boring operations.
After the shell has been rotationally molded within the oven (not
shown), the mold 50 is then permitted to cool thus solidifying the
shell such that it may be removed.
As indicated in FIG. 8, two of the two shells are appropriately
placed side by side, and fragile articles 100 which are to be
shipped are placed upon the article defining surfaces 22 of the
shell 14. Subsequently, a liquified polymer foam is injected into
the apertures 30 of each of the shells 12 and 14 by any
conventional in-situ foaming process. As herein depicted, the
liquid foam is to be injected by nozzles 105 of a conventional foam
console-ejector gun through the apertures 30 into the shells.
Alternatively, other apertures might be provided for the injection
process. After the liquid foam has been injected, the top shell 12
is placed over the lower shell 14 to encase the fragile article 100
at which time the two shells may be placed in a compression chamber
(not shown) during the expansion and solidification of the foam
such that they will maintain their shape. Alternatively, the shells
may adequately support themselves without distortion during such
expansion. As the liquified foam expands and solidifies within each
of the shells, such will fill the upper and lower shells 12 and 14
and pass through the apertures 30 so as to provide an integral
connection between the foam within two shells to lock them together
about the article 100, such locking effect resulting from the
mechanical interlocking of the foam and from the adhesive character
of the foam adhering to the surfaces of the sealing channel.
Finally, one other favorable characteristic is designed to take
place during the foam in-place operation. As previously mentioned,
the core members 54 of the upper mold section 52 has a much thicker
metallic cross section than the remainder of the upper mold
section. This increased cross section results in less heat transfer
to the interior surface of the mold adjacent the spaces 22. Thus,
less material will melt on these surfaces and accordingly, the
shell thickness adjacent the article to be enclosed will be much
thinner in cross-section and less rigid. The purpose of this
flexibility is explained with reference to FIGS. 9 and 10. When the
article 100 are placed onto the article containing surface 22, it
may not completely fill the space as originally molded and voids 99
between the article 100 and the cavity may result, permitting the
article some freedom of movement. However, during the in-situ
foaming process, the expanding foam will act with sufficient force
against these thinned areas of the article defining cavity 22 so as
to cause same to move upwardly and rigidly encapsulate the article
100 so as to preclude any movement thereof.
FIG. 11 depicts another modification of my invention which includes
a bottom shell 14 similar to that previously described. However, a
different closure 104 is illustrated. This closure may take the
form of a flat sheet of plastic material, wood, or container board
which is provided with a peripheral sealing groove 105. After the
material is placed into the space 26, the foam 40 is injected into
the bottom shell 14 and expands into the annular sealing channel
24. In this instance, the seal and lock between the top 104 and the
shell 14 is one of adhesion. if desired, the surfaces of the
channels 105 and 24 may be provided with different textures so as
to vary the strength of the adhesive lock.
Finally, FIGS. 12 and 13 illustrate another embodiment of my
invention, and comprises two shells similar to that of the
embodiment of FIGS. 1-4. However, the apertures 30 are omitted with
the foam being inserted through other openings (not shown). Upon
the closing of the two shells about an article within space 26,
another shot of foam may be injected through an aperture 111 formed
through on or both sealing surfaces 21. Here, the foam in-place
feature of my invention relates to the sealing and adhesive locking
characteristics of the foam. Thus through a single application of
expandable foam solution, a moisture proof, sealed and locked
container can be obtained.
Accordingly, it should be clear that applicant has proferred a
tamper-proof container containing locking characteristics for
rigidly encapsulating an article in a shock-proof manner. Too, a
process for making same is included, and both the process and the
container may take many forms. Too, the in-situ foaming may be
accomplished by any one of several known procedures, some of which
are referred to in U.S. Pat. No. 3,618,287 referred to above. Such
foaming can be used for simultaneously filling the shell and
sealing or for sealing alone.
* * * * *