U.S. patent number 3,851,789 [Application Number 05/334,367] was granted by the patent office on 1974-12-03 for container fastening means.
This patent grant is currently assigned to Standard Oil Company. Invention is credited to Charles B. Case, David M. Hebert, Maylin J. Olson, John C. Schubert.
United States Patent |
3,851,789 |
Case , et al. |
December 3, 1974 |
CONTAINER FASTENING MEANS
Abstract
Deformable plastic containers, generally foamed, are widely used
in the food service field where containers are filled at one
location and transmitted to another location. These normally are
either two-piece containers where a lid and base member snap
together or one-piece having a hinged common border and a snap-in
feature at the other end.
Inventors: |
Case; Charles B. (Eau Claire,
WI), Hebert; David M. (Chippewa Falls, WI), Olson; Maylin
J. (Augusta, WI), Schubert; John C. (Chippewa Falls,
WI) |
Assignee: |
Standard Oil Company (Chicago,
IL)
|
Family
ID: |
23306893 |
Appl.
No.: |
05/334,367 |
Filed: |
February 21, 1973 |
Current U.S.
Class: |
220/4.23;
220/835; 220/789; 220/787; 383/41; 229/406 |
Current CPC
Class: |
B65D
43/162 (20130101); B65D 2251/1041 (20130101) |
Current International
Class: |
B65D
43/16 (20060101); B65d 043/10 () |
Field of
Search: |
;220/6R,20,315 ;229/2.5
;150/.5 ;206/4 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hall; George T.
Attorney, Agent or Firm: Cochran; Robert R. Gilkes; Arthur
G. McClain; William T.
Claims
We claim:
1. A container made of deformable plastic having first and second
members, one of said members constituting the top of the container
and the other the bottom thereof, each member being provided with a
generally flat surface, one of said members having a sidewall
attached to said flat surface which slopes away from said planer
surface and a lip extending outwardly from the end of said
sidewall, said lip being generally parallel to the flat surface of
said member; the other of said members having a sidewall attached
to the flat surface thereof adapted to engage frictionally the lip
on the other of said members and having four sloping sections, the
first sloping outwardly from the flat surface, the second sloping
outwardly from the end of the first at an angle of 10.degree. to
45.degree. from the flat surface, the third sloping inwardly from
the end of the second, and the fourth sloping outwardly from the
end of the third, the apex of the angle between said second and
third sections engaging the lip on said other member, said fourth
cooperating with said lip to force said lip into position when said
members are pushed together; said sidewalls extending substantially
completely around said first and second members when these are
separate pieces, and when said first and second members are hinged
together along a contiguous section, at least the sidewalls
opposite said contiguous section having the structure set
forth.
2. The container of claim 1 wherein the angle between said second
sloping section and the flat surface is 20.degree. to
30.degree..
3. A container made from a continuous sheet of deformable foamed
plastic comprising first and second portions hinged together along
a contiguous section, said first and second portions each including
circumferential lips which abut when the container is closed, the
first member also having, integral with the lip thereof, receiving
means which includes a locking portion opposite the contiguous
section, said locking portion including a reverse-tapered sidewall
which provides means into which the lip of the second member is
force fitted upon closure of the container wherein the improvement
consists of: the portion of said circumferential lip of the first
member which is integral with the second member receiving means
which includes the locking portion opposite the contiguous section
being sloped at a 10.degree. to 45.degree. slope away from the lip
such that said portion of the lip of the second member which comes
into contact with the reverse-tapered sidewall locking portion is
free to pass below the abutting circumferential lips during
closure.
4. The container of claim 3 wherein the slope is from 20.degree. to
30.degree..
Description
Disclosed is an improvement in the locking means by which the top
and bottom of the container are locked together.
FIELD OF THE INVENTION
This invention relates to containers having top and bottom portions
adapted to be locked together.
PRIOR ART
The present invention represents an improvement over the structure
shown in Cyr et al. U.S. Pat. No. 3,633,785 (1972), the general
description thereof being incorporated herein by reference.
SUMMARY OF THE INVENTION
This invention relates to containers made of deformable plastic
having first and second members. For heat insulating properties,
such containers are frequently made of foamed plastic such as
described by Cyr et al. but the invention is equally applicable
solid plastic containers. One of the members constitutes the top of
the container and the other the bottom thereof. Each member has a
generally flat surface although one or both can be divided into
compartments where a variety of foods are served in one container.
One member has a generally outwardly extending sidewall attached to
the flat surface and, at the end of said sidewall, a lip extending
outwardly in a direction generally parallel to the flat surface of
the member. The other member is adapted to lock in place on the lip
of the first member. To this end, structure is provided so that
there is a frictional engagement between the lip of the member
described and the sidewall attached to the second member. The
sidewall on the second member has four sloping members or sections,
the first sloping outwardly from the flat surface, the second
sloping outwardly from the end of the first at an angle of
10.degree. to 45.degree., preferably 20.degree. to 30.degree., from
the flat surface. The third slopes inwardly from the end of the
second and the fourth again slopes outwardly. The apex of angle
between the second and third sections engages the lip 15 on the
other member and the fourth surface, which slopes outwardly, serves
to force the lip into position when the members are pushed
together. Where two separate members are used, the structure
described generally extends all of the way around the container
although, on rectangular containers satisfactory results can
frequently be obtained where the structure described is present
only on two opposite sides. For circular containers, the particular
structure is present completely around the circumference.
When hinged containers are used in which the top and bottom are
formed in one piece with an integral hinge therebetween, the
particular frictional engaging surfaces need only be present on the
edges opposite the contiguous hinged portion.
Thus, one aspect of the invention comprises a container made from a
continuous sheet of deformable foamed plastic comprising first and
second portions hinged together along a contiguous section, said
first and second portions each including circumferential lips which
abut when the container is closed, the first member also having,
integral with the lip thereof, receiving means which includes a
locking portion opposite the contiguous section, said locking
portion including a reverse-tapered sidewall which provides means
into which the lip of the second member is force fitted upon
closure of the container wherein the improvement consists of: the
portion of said circumferential lip of the first member which is
integral with the second member receiving means which includes the
locking portion opposite the contiguous section being sloped at a
10.degree. to 45.degree. slope away from the lip such that said
portion of the lip of the second member which comes into contact
with the reverse-tapered sidewall locking portion is free to pass
below the abutting circumferential lips during closure.
BRIEF DESCRIPTION OF THE DRAWING
Accompanying and forming a part of this application is a drawing in
which:
FIG. 1 shows a plan view of one form of the container of the
present invention.
FIG. 2 is a perspective view of the container of FIG. 1, in closed
position, party in section.
FIGS. 3, 4, and 5 show the closure of the prior art, FIG. 3 showing
a desired closed structure, while FIGS. 4 and 5 show difficulties
which arise due to deformation of the plastic material.
FIGS. 6 and 7 illustrate the structure of the invention, FIG. 6
just before closing and FIG. 7 showing the top and bottom in closed
position.
The terms "top" and "bottom" are used herein interchangeably and
the top in one structure can serve as the bottom in another
structure. Stated in another way, the figures can be viewed upside
down and what functions as the top in one use may be the bottom in
another.
An object of the present invention is to produce a container of
deformable plastic material having an improved closure system.
SPECIFIC EMBODIMENTS OF THE INVENTION
Directing attention to the drawing, our invention will be described
in more detail. For an understanding of the problem, attention is
first directed to FIGS. 3, 4, and 5. The prior art lip
configuration is shown in FIG. 3. This closure works quite
adequately when both members were properly formed but if one or
both are distorted, which is a common occurrence either through
process deviations or from handling or shipping damage, the closure
fails as shown in FIGS. 4 and 5. The closure of the present
invention is designed to overcome this problem.
The one-piece structure is shown in FIGS. 1 and 2. The first member
9 having a generally flat area 11 is hingedly fixed to the second
member 10 having generally flat area 12 by means of a hinge section
13. The first member 9 has sloping sidewalls 14 which extend
outwardly and upwardly from the flat surface 11. Extending
outwardly from the sloped wall sections 14 is a lip 16 which
extends outwardly substantially parallel to flat surface 11. If
desired, an indentation 17 can be provided to facilitate opening
and closing of the container.
Second member 10 has the sloping sidewalls 18 which extend
outwardly and upwardly from the flat surface 12. In the hinged
version of our invention we provide a lip 16 at the outer end of
sidewall 18 along the contiguous or hinged portion B and on the
sides adjacent thereto. Lips 15 and 16 abut when the container is
closed. Up to this point, the structure is conventional and that
shown in the Cyr et al. patent, supra. The novel feature resides in
the addition of a sloping section 19, sloping sidewall 18, at the
end of member 12 opposite the hinged portion 13. This slopes
outwardly at an angle of 10.degree. to 45.degree., preferably
20.degree. to 30.degree. from the plane of the flat surface 12. At
the end of surface 19 is an inwardly sloping or reverse-tapered
sidewall surface 21. The apex 20 of the angle between surface 19
and surface 21, the second and third sloping portions of the wall
portion engage the outer end of lip 15 on the other member in the
closed position. Finally, another outwardly extending portion 22 is
provided which acts as a lever to force the frictionally engaging
members outwardly as they are pressed into position. Optionally, a
horizontal portion can be added to outwardly extending portion 22
if desired.
FIGS. 6 and 7 show the structure of our invention as the two
members are brought together, FIG. 7 just before closing and FIG. 8
in the closed position. In FIG. 6 as the first member 9 descends
downwardly, lip 15 contacts inclined plane 22. Since the material
is deformable, the wall of member 9 is pushed inwardly while a wall
of member 10 is pushed outwardly. This allows 15 to pass into the
space between sections 19 and 21. Even if the wall members of
either top or bottom are distorted, the edge 15 will still be
securely locked within the angle made by sections 19 and 21. While
not wishing to be bound by any theory of operation, we believe that
the advantage of the invention is a result of the fact that, in
closing, lip 15 can be pushed below apex 20. If there is
deformation, as shown in FIGS. 4 or 5, upon relaxation lip 16
assumes the position shown in FIG. 7.
In addition to the hinged container just described, the invention
is equally applicable to two-piece containers. Referring to FIG. 2,
one of the pieces would have the sloping wall 14 and lip 15. The
other piece would have the combinations of sloping sections 18, 19,
21, and 22. For a generally circular container the described
structure generally extends completely around the circumference. In
a generally rectangular container the described structure can
extend around all four sides or simple abutting lips, as 15 and 16,
can be formed on two opposite sides while the interlocking
structure can be used on the other sides.
Modifications of the present invention will be apparent to those
skilled in the art upon reading the present disclosure.
* * * * *