U.S. patent application number 10/588447 was filed with the patent office on 2008-12-25 for heat insulating container.
This patent application is currently assigned to FIJI SEAL INTERNATIONAL, INC. Invention is credited to Ryusuke Sakai, Kaoru Takeo.
Application Number | 20080314909 10/588447 |
Document ID | / |
Family ID | 34836168 |
Filed Date | 2008-12-25 |
United States Patent
Application |
20080314909 |
Kind Code |
A1 |
Takeo; Kaoru ; et
al. |
December 25, 2008 |
Heat Insulating Container
Abstract
A heat insulating container enabling a reduction in man-hour and
materials in production while sufficiently securing the strength of
an external body on its bottom side. The container comprises a
bottomed cylindrical container body and the external body formed of
a foam resin sheet with thermal shrinkage properties and covering
the peripheral wall of the container body to form a space between
the peripheral wall and the external body. The external body
comprises a tubular part opposed to the peripheral wall of the
container body and an annular part extended from the bottom opening
edge part, as a base end, in the tubular part. The annular part is
characterized in that the tip side thereof is apart from the inner
peripheral surface of the tubular part more than the base end part
side thereof.
Inventors: |
Takeo; Kaoru; (Osaka,
JP) ; Sakai; Ryusuke; (Osaka, JP) |
Correspondence
Address: |
THE WEBB LAW FIRM, P.C.
700 KOPPERS BUILDING, 436 SEVENTH AVENUE
PITTSBURGH
PA
15219
US
|
Assignee: |
FIJI SEAL INTERNATIONAL,
INC
Osaka
JP
|
Family ID: |
34836168 |
Appl. No.: |
10/588447 |
Filed: |
December 22, 2004 |
PCT Filed: |
December 22, 2004 |
PCT NO: |
PCT/JP2004/019266 |
371 Date: |
August 7, 2006 |
Current U.S.
Class: |
220/592.2 |
Current CPC
Class: |
B65D 81/3869
20130101 |
Class at
Publication: |
220/592.2 |
International
Class: |
B65D 81/38 20060101
B65D081/38 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2004 |
JP |
2004-034161 |
Claims
1: A heat insulating container comprising a container body having a
bottomed tubular shape and an outer shell that is formed by a
foamed resin sheet having heat shrinkability and covers a
peripheral wall of the container body with a space created between
the peripheral wall and the outer shell, the outer shell including
a tubular portion disposed opposite to the peripheral wall of the
container body and an annular portion extending from an opening
edge of a lower end of the tubular portion towards the inside of
the tubular portion, and the annular portion having a distal end
and a proximal end, in which the distal end is located farther from
an inner peripheral surface of the tubular portion than the
proximal end is.
2: The heat insulating container according to claim 1, wherein the
outer shell includes a horizontal annular extension that extends
from the distal end of the annular portion towards the center of
the tubular portion.
3: The heat insulating container according to claim 1, wherein the
annular portion is formed so as to have the distal end with a space
to a bottom portion of the container body so that gas within the
space is communicated with the outside via a lower end opening of
the tubular portion.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a heat insulating container
that includes a container body having a bottomed tubular shape for
placing therein a content such as very hot food or drink and an
outer shell covering the container body with a space between the
outer shell and a peripheral wall of the container body, through
which heat insulating effect is produced.
BACKGROUND OF THE INVENTION
[0002] There have been hitherto proposed various types of heat
insulating containers for placing therein instant foods or the like
such as soup or noodle served by pouring boiled water, or for
placing therein a separately heated drink or the like.
[0003] Of them, one type of the heat insulating containers
includes, as illustrated in FIG. 14, a container body 100 molded
into a bottomed tubular shape, an outer shell 150 covering a
peripheral wall 101 of the container body 100, in which a space 200
is created between the peripheral wall 101 of the container body
100 and the outer shell 150, making it difficult to have heat of a
content P placed in the container body 100 transferred to the outer
shell 150 by the interposition of the space.
[0004] The outer shell 150 is made up of a tubular portion 151
disposed opposite to the peripheral wall 101 of the container body
100, and a horizontal annular portion 152 extending from a lower
end of the tubular portion 151 towards the center of the tubular
portion 151.
[0005] The outer shell 150 (the tubular portion 151 and the
horizontal annular portion 152) is molded into a shape as mentioned
above by placing a foamed resin sheet (not shown) that has heat
shrinkability and has been formed into a tubular shape onto a
substantially cylindrical mold (not shown), and heating the same to
allow the foamed resin sheet to be shrunk.
[0006] Meanwhile, the outer shell having the above structure formed
with the horizontal annular portion 152 copes with an external
force such as a grasping force applied in a radial direction to a
lower end side of the tubular portion 151, by the strength in a
cross section (cross section crossing the direction in which the
external force acts), that is, the buckling strength of the
horizontal annular portion 152 in a direction orthogonal to the
thickness direction of the horizontal annular portion 152.
[0007] However, when the external force has been applied, as
mentioned above, the external force acts locally to an inner
peripheral edge of the horizontal annular portion 152, causing
buckling in the inner peripheral edge, which may lead to inward or
outward buckling or breaking, of the horizontal annular portion
152, posing a problem of not producing a satisfactory strength in
the radial direction in the lower end side of the outer shell 150
merely by the buckling strength of the horizontal annular portion
152.
[0008] Therefore, the heat insulating container has a bottom plate
160 bonded by heat sealing to an inner surface of the horizontal
annular portion 152 so as to close a hole 153 defined by the
horizontal annular portion 152 of the outer shell 150, thereby
allowing the horizontal annular portion 152 and the bottom plate
160 to receive the external force applied in the radial direction,
and hence preventing the external force to locally act and
producing the strength in the radial direction in the lower end
side of the outer shell 150 (heat insulating container).
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0009] However, the heat insulating container having the above
structure is required to have the bottom plate 160 bonded so as to
close the hole 153 defined by the horizontal annular portion 152 of
the outer shell. This poses a problem of inviting the increase in
manufacturing cost and material cost when manufacturing.
[0010] In consideration of the above problems, it is an object of
the present invention to provide a heat insulating container that
is capable of reducing the number of steps and materials for
manufacturing, as well as ensuring a satisfactory strength in the
lower end side of the outer shell.
Means to Solve the Problems
[0011] A heat insulating container of the present invention has
been conceived to achieve the above object. According to claim 1,
there is provided a heat insulating container including a container
body having a bottomed tubular shape and an outer shell that is
formed by a foamed resin sheet having heat shrinkability and covers
a peripheral wall of the container body with a space created
between the peripheral wall and the outer shell, characterized in
that the outer shell comprises a tubular portion disposed opposite
to the peripheral wall of the container body and an annular portion
extending from an opening edge of a lower end of the tubular
portion towards the inside of the tubular portion, and the annular
portion has a distal end and a proximal end, in which the distal
end is located farther from an inner peripheral surface of the
tubular portion than the proximal end is.
[0012] According to the thus structured heat insulating container,
the annular portion has the distal end located farther from the
inner peripheral surface of the tubular portion than the proximal
end is, so that when external force acts on the tubular portion
towards the center, the external force acts not in a direction
orthogonal to the cross section of the annular portion (buckling
direction in the annular portion), but in a direction crossing the
plane of the annular portion.
[0013] Accordingly, the external force acts to bend the annular
portion and this bending action causes elastic force to the annular
portion. Thus, it is possible to cope with the external force by
the elasticity (elastic force) of the annular portion, and hence
increase the strength of a lower end portion of the tubular
portion, to which the proximal end of the annular portion is
connected. Also, the external force can be absorbed by the bending
action (elasticity) of the annular portion, so that the external
force is not applied locally to the distal end (inner peripheral
edge) or proximal end (outer peripheral edge), of the annular
portion and hence deformation or breakage due to the buckling of
the annular portion can be prevented.
[0014] Therefore, while omitting the necessity to provide a bottom
plate for closing a hole defined by an annular portion unlike the
prior art, a satisfactory strength in the radial direction of the
heat insulating container can be provided by the annular portion.
Whereby, it is possible to omit the step of mounting a bottom plate
in a manufacturing process, and hence reduce material costs and
manufacturing costs.
[0015] According to claim 2, the outer shell may include a
horizontal annular extension that extends from the distal end of
the annular portion towards the center of the tubular portion. As
described above, when the bending action occurs on the annular
portion, the resulting elastic force acts thereto so as to expand
the diameter of the opening (inner peripheral edge) of the distal
end of the annular portion. The horizontal annular extension formed
on the distal end of the annular portion increases the strength of
the distal end of the annular portion so as to be able to limit the
deformation of the distal end of the annular portion and
efficiently disperse the external force in the peripheral direction
of the annular portion and hence absorb the same. Whereby, it is
possible to further increase the strength of the lower end side of
the tubular portion (outer shell).
[0016] According to claim 3, the annular portion is preferably
formed so as to have the distal end with a space to a bottom
portion of the container body so that gas within the space is
communicated with the outside via a lower end opening of the
tubular portion.
[0017] With the above structure, even when air within the space
between the peripheral wall of the container body and the tubular
portion is heated via the peripheral wall of the container body by
very hot content placed in the container body, it is possible to
cool within the space by air convection caused in the space via a
lower end opening of the tubular portion (outside air having a
temperature lower than air within the space flows into the space,
while air within the space is released to the outside) by lifting
up (separating) the heat insulating container from a mounting
surface thereof. Therefore, even if very hot content is placed in
the heat insulating container for a long time, it is possible to
prevent the tubular portion of the outer shell from being heated by
air within the space and hence bring the heat insulating container
in better conditions.
EFFECTS OF THE INVENTION
[0018] As described above, according to the heat insulating
container of the present invention, there is provided a container
body having a bottomed tubular shape and an outer shell that is
formed by a foamed resin sheet having heat shrinkability and covers
a peripheral wall of the container body with a space created
between the peripheral wall and the outer shell, in which the outer
shell includes a tubular portion disposed opposite to the
peripheral wall of the container body and an annular portion
extending from an opening edge of a lower end of the tubular
portion towards the inside of the tubular portion, and the annular
portion has a distal end and a proximal end, in which the distal
end is located farther from an inner peripheral surface of the
tubular portion than the proximal end is. Whereby, it is possible
to produce an excellent advantage to reduce the number of steps and
materials in manufacturing as well as ensuring a satisfactory
strength of the lower end side of the outer shell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a side view with a partially cross section of a
heat insulating container according to a first embodiment of the
present invention.
[0020] FIG. 2 is a partially cross sectional view of an upper end
portion of the heat insulating container of the first
embodiment.
[0021] FIG. 3 is a partially cross sectional view of a lower end
portion of the heat insulating container of the first
embodiment.
[0022] FIG. 4 is an entire perspective view of a mold and a press
die for molding an outer shell of the first embodiment.
[0023] FIG. 5 are explanatory views for molding steps of the outer
shell of the first embodiment. FIG. 5(a) illustrates a state in
which a tubular portion has been formed by placing a foamed resin
sheet on the mold and heating the same. FIG. 5(b) illustrates a
state in which a second end of the foamed resin sheet has been
formed into a horizontal annular shape by heating. FIG. 5(c)
illustrates a state in which the second end of the foamed resin
sheet formed into the horizontal annular shape is being pressed by
the press die. FIG. 5(d) illustrates a state in which an annular
portion and a horizontal annular extension have been molded by the
mold and the press die.
[0024] FIG. 6 is a front view of a heat insulating container
according to a second embodiment of the present invention.
[0025] FIG. 7 is a vertical cross sectional view of the heat
insulating container of the second embodiment.
[0026] FIG. 8 is an enlarged view with a partially cross section of
a flange portion and its proximity, of the heat insulating
container of the second embodiment.
[0027] FIG. 9 is an enlarged view with a partially cross section of
a bottom portion and its proximity, of the heat insulating
container of the second embodiment.
[0028] FIG. 10 is a front view of a heat insulating container
according to a third embodiment of the present invention.
[0029] FIG. 11 is a vertical cross sectional view of the heat
insulating container of the third embodiment.
[0030] FIG. 12 is an enlarged view with a partially cross section
of a flange portion and its proximity, of the heat insulating
container of the third embodiment.
[0031] FIG. 13 is an enlarged view with a partially cross section
of a bottom portion and its proximity, of the heat insulating
container of the third embodiment.
[0032] FIG. 14 is a side view of a conventional heat insulating
container with a partially cross section.
DESCRIPTION OF THE REFERENCE CODES
[0033] 1: container body, 2: outer shell, 5: connection portion,
10: peripheral wall, 10a: upper peripheral wall portion, 10b: lower
peripheral wall portion, 11: connection portion, 12: flange
portion, 12a, 12b: pieces, 13: engaging protrusions, 14: bottom
portion, 14a: bottom plate section, 14b: bottom connection section,
20: tubular portion, 21: annular portion, 22: curled portion, 23:
horizontal annular extension, 40: space, 50: mold, 51: press die,
52: recess, 53: annular protrusion, 54: protrusion, 100a: gutter,
100b: ridge, 110: peripheral wall body part, 111: annular
connection part, 112: large diameter part, 113: flange part, 113a:
top plate section, 113b: downward extension, 114: lower tubular
portion, 114a: thick tubular section, 114b: thin tubular section,
115: vertical rib, 117: reinforcing piece
BEST MODE FOR CARRYING OUT THE INVENTION
[0034] Now, the description will be made for the first embodiment
of the present invention with reference to the attached
drawings.
[0035] A heat insulating container of this embodiment is made up of
a container body 1 having a bottomed tubular shape, and an outer
shell 2 that covers a peripheral wall 10 of the container body 1,
as illustrated in FIG. 1.
[0036] The container body 1 is a resin molded product molded by a
molding technique such as injection molding, blow molding, vacuum
molding or pressure molding. The container body 1 is formed into a
tubular shape with the peripheral wall 10 being decreased in
diameter towards the lower end. An upper end of the peripheral wall
10 of the container body 1 is provided with an annular connection
portion 11 that extends outward and has an outer peripheral edge
connected with a lower end of an inner peripheral piece 12a of an
annular flange portion 12 having a downwardly opening U-shaped
cross section.
[0037] An outer peripheral piece 12b of the flange portion 12 has
plural engaging protrusions 13 that bulge towards the inner
peripheral piece 12a and are aligned in the peripheral direction
with a predetermined distance from each other.
[0038] The outer shell 2 is formed from a foamed resin sheet having
heat shrinkability, and includes a tubular portion 20 covering the
peripheral wall 10 of the container body 1 so as to be disposed
opposite to the peripheral wall 10, and an annular portion 21
extending (folded back) from a lower end of the tubular portion 20
towards the inside of the tubular portion 20. The description will
be made later for the steps of molding the outer shell 2 by the use
of the foamed resin sheet.
[0039] The tubular portion 20 has an upper end provided with a
curled portion 22 that is curled towards the outside. The curled
portion 22 is fitted in the flange portion 12 of the container body
1 while having a shape being at this position engageable with the
engaging protrusions 13.
[0040] The annular portion 21 is formed with a distal end (inner
peripheral edge) disposed away from an inner peripheral surface of
the tubular portion 20. Specifically, the annular portion 21 has a
distal end (inner peripheral edge) positioned inwardly to the
inside of the tubular portion 20 than a proximal end (outer
peripheral edge) is, and is tapered towards the distal end. The
incline angle of the annular portion 21 relative to the inner
peripheral surface of the tubular portion 20 is set preferably in a
range of 30.degree. to 60.degree..
[0041] A horizontal annular extension 23 extends from the inner
peripheral edge of the annular portion 21 towards the center of the
tubular portion 20.
[0042] In the thus structured heat insulating container, the
container body 1 is placed in the outer shell 2 so as to have the
inner peripheral surface of the tubular portion 20 disposed
opposite to the outer peripheral surface of the peripheral wall 10
of the container body 1, and as illustrated in FIG. 2, the curled
portion 22 is fitted in the flange portion 12 of the container body
1 so as to create a space 40 between the peripheral wall 10 of the
container body 1 and the tubular portion 20 of the outer shell
2.
[0043] With the above positioning, as illustrated in FIG. 3, the
distal end of the annular portion 21 and the inner surface of the
horizontal annular extension 23 are disposed with a distance from
the bottom portion 14 of the container body 1, and the space 40 is
communicated with the outside via the distal end of the annular
portion 21, the space between the horizontal annular extension 23
and the bottom portion 14 of the container body 1, a hole defined
by the annular portion 21 and a lower end opening of the tubular
portion 20.
[0044] The heat insulating container is structured so that when
external force has been applied to the outer shell 2 (lower end
portion) in the radial direction by grasping the outer shell 2, the
external force acts in a direction towards the center of the
tubular portion 20 (in a direction orthogonal to the center line of
the tubular portion 20), and thus acts so as to cause radial
shrinkage or flattening deformation, of the opening edge of the
lower end of the tubular portion 20. At the same time, the external
force acts on the proximal end (outer peripheral edge portion) of
the annular portion 21 in a direction towards the center of the
tubular portion 20.
[0045] Accordingly, since the annular portion 21 is formed into an
annular shape, which is tapered towards the inside of the tubular
portion 20, the external force acts on the annular portion 21 in a
direction crossing the plane thereof, so that reaction force in a
direction different from the acting direction of the external force
(in a direction as to expand the inner peripheral edge) is cased in
the leading end side of the annular portion 21. Whereby, bending
action is caused between the proximal end and the distal end, of
the annular portion 21, and thus radial deformation of the tubular
portion 20 due to the external force is prevented by elastic force
caused in the annular portion 21 by the bending action.
[0046] That is, the heat insulating container is structured to have
the annular portion 21 extending towards the inside of the tubular
portion 20 and tapered to have the distal end located away from the
inner peripheral surface of the tubular portion 20 so that when
external force has been applied, elastic force is caused in the
annular portion 21 and thus it is possible to produce a
satisfactory radial strength to the lower end side of the outer
shell 2 by utilizing the elastic force.
[0047] The heat insulating container is also structured to have the
horizontal annular extension 23 extending from the distal end of
the annular portion 21, thereby increasing the strength of the
inner peripheral edge and its proximity of the annular portion 21
to limit deformation of the inner peripheral edge and its proximity
of the annular portion 21 due to reaction force to the external
force and hence achieve a further increased radial strength. That
is, the strength of the lower end side of the tubular portion 20 is
further increased by effectively utilizing, against the external
force, the elasticity of the annular portion 21 caused between its
proximal end and its distal end.
[0048] Furthermore, with the structure in which a clearance is
created between the inner surfaces of the distal end of the annular
portion 21 and the horizontal annular extension 23, of the outer
shell 2 and the bottom portion 14 of the container body 1 (the
annular portion 21 is formed to have the distal end thereof with a
distance from the bottom portion 14 of the container body 1), even
when air in the space 40 of the container body 1 is heated by a hot
food product or the like placed therein, air convection is caused
in the space 40 (outside air having a temperature lower than air
heated in the space 40 flows in through the lower end opening of
the outer shell 2) by lifting up the heat insulating container from
a mounting surface, on which the heat insulating container has been
mounted.
[0049] Thus, it is possible to suppress the temperature increase
within the space 40, suppress the transfer of heat of air within
the space 40 to the outer shell 2, and hence further enhance the
function of the heat insulating container.
[0050] The heat insulating container has the annular portion 21
extending inwardly at an angle to the inner peripheral surface of
the tubular portion 20 from the lower end of the tubular portion 20
so as to have a shape with a recessed portion on the bottom and
therefore can be held with a finger engaged with the annular
portion 21. Thus, it is possible to grasp and hold the heat
insulating container in a stabilized manner without slipping-off
the same. Furthermore, even when the heat insulating container is
held with a finger engaged with the annular portion 21, the
horizontal annular extension 23 extending from the inner peripheral
edge (distal end) of the annular portion 21 can prevent the finger
engaged with the annular portion 21 from touching the bottom
portion 14 of the container body 1, and hence prevent burns or any
other troubles with the container body 1 even when a food heated at
a high temperature is placed therein, thus achieving safety.
[0051] Now, the description will be made for the steps of
manufacturing the thus structured outer shell 2. When manufacturing
the outer shell 2, as illustrated in FIG. 4, a mold 50 for forming
the tubular portion 20 of the outer shell 2, a press die 51 for
forming the annular portion 21 and the horizontal annular extension
23, and a strip-like foamed resin sheet S (having been formed into
a tubular shape in the Figure) for forming the outer shell 2 are
first prepared. The description for the steps of forming the curled
portion 22 is omitted, while the description for the mold 50, the
press die 51 and the foamed resin sheet S will be first made prior
to the description for the manufacturing steps of the outer shell
2.
[0052] The mold 50 has a shape corresponding to the shape of the
tubular portion 20 with an outer diameter decreasing from a first
end to a second end, and is formed into a truncated right circular
cone. By the truncated right circular cone is meant a shape of a
right circular cone with a vertex truncated in a direction
orthogonal to the axis. The mold 50 has the diametrically smaller
second end having a recess 52 formed therein for fittingly
receiving the press die 51 and having an outer peripheral edge
portion formed with an annular protrusion 53 having a substantially
horizontal upper end. The annular protrusion 53 has an inner
peripheral surface formed into a tapered shape so that the angle of
an outer peripheral surface of the mold 50 relative to the inner
peripheral surface of the annular protrusion 53 is set to
correspond to the tapered angle of the annular portion 21 relative
to the tubular portion 20 of the outer shell 2.
[0053] The press die 51 has a protrusion 54 for being fitted into
the recess 52. The protrusion 54 is formed into a truncated right
circular cone corresponding to the shape of the inner peripheral
surface of the annular protrusion 53.
[0054] The short side of the foamed resin sheet S has a length
longer than the length between the first end and the second end, of
the mold 50. For the foamed resin sheet S, a sheet of foamed
polystyrene having a first side with characters, patterns or the
like printed thereon, which side turns to be an outer surface when
the outer shell 2 has been molded, and having a foaming rate of 2
to 10 times (preferably 2.5 to 7 times) having heat shrinkability.
The foamed resin sheet S is heat shrinkable in one direction
(lengthwise direction).
[0055] As foamed polystyrene for forming the foamed resin sheet S,
there may be employed those produced by foaming general use
polystyrene with various foaming agents, or those produced by
foaming with various forming agents an intermediate with a content
of 50% by weight or more (preferably 70% by weight or more) of a
styrene component, which intermediate has copolymer as a main
component produced by copolymerizing polystyrene with butadiene,
acrylonitrile, methacrylic acid, acrylic acid or acrylic ester. The
foamed resin sheet S has a thickness of 0.1 to 1.0 mm and
preferably 0.2 to 0.5 mm.
[0056] When manufacturing the outer shell 2 by the use of the thus
structured mold 50 and press die 51, the foamed resin sheet S
having the above structure is first formed into a tubular shape
with both lengthwise ends bonded together. Under this state, the
foamed resin sheet S can be heat shrunk in a circumferential
direction (towards the center). The heat shrinkage of the foamed
resin sheet S may be a heat shrinkage measured, for example, by
immersing it in oil of a predetermined temperature for 10 seconds,
and the heat shrinkage of the foamed resin sheet S of this
embodiment formed into a tubular shape is, in the circumferential
direction, 5% or lower at 80.degree. C. and 30 to 60% at
110.degree. C.
[0057] The foamed resin sheet S formed into a tubular shape is
fitted on the mold 50 so as to cover the outer peripheral surface
thereof, with an opening edge of a first end of the foamed resin
sheet S matched in position to a first end of the mold 50. Under
this state, an opening edge of a second end of the tubular foamed
resin sheet S lies outside the second end of the mold 50, as
illustrated in FIG. 5(a). By the application of heat to the foamed
resin sheet S with blasts of hot air A, the foamed resin sheet S
having heat shrinkability is shrunk in the radial direction towards
the center and thus brought into tight contact with the outer
peripheral surface of the mold 50. Thus, the tubular portion 20 is
formed. By the further application of heat to the foamed resin
sheet S (particularly the second end), the second end is shrunk
towards the center and directed towards the axis of the mold 50,
and thus formed into an annular shape in a horizontal orientation,
as illustrated in FIG. 5(b).
[0058] Under this state, the heating is stopped and the second end
of the foamed resin sheet S having an annular shape in a horizontal
orientation is pressed with the press die 51, as illustrated in
FIG. 5(c). When this pressing operation is made, the heating to the
foamed resin sheet S is stopped, but the foamed resin sheet S
remains softened by the heat applied up to then. Therefore, as
illustrated in FIG. 5(d), the second end of the foamed resin sheet
S is smoothly pressed to the inside of the recess 52 of the mold 50
by the protrusion 54 of the press die 51 while being bent around an
upper end of the annular protrusion 53.
[0059] Thus, the annular portion 21 is formed to have a tapered
shape corresponding to the shape of the outer periphery of the
press die 51, with a first end (lower end) of the tubular portion
20 acting as a proximal end. At the same time, shrinking force acts
towards the center on a part of the tubular portion 20 closer to
the second end than the annular portion 21, thereby enabling the
second end to keep the annular shape in a horizontal orientation
while being pressed to the inside of the tubular portion 20 (the
recess 52 of the mold 50). Thus, the horizontal annular extension
23 is formed. Under this state, the press die 51 is moved away from
the mold 50 and the mold 50 is removed, so that the outer shell 2
having the above structure is formed from the tubular foamed resin
sheet S.
[0060] Therefore, as described above, it is not necessary to carry
out the step of providing a bottom plate for closing a hole defined
by an annular portion unlike the conventional technique, when
manufacturing the outer shell 2 that is capable of providing a
satisfactory strength to the lower end side of the heat insulating
container (outer shell 2). Hence, it is possible to reduce the
manufacturing costs and the material costs for manufacturing the
heat insulating container.
[0061] Now, the description will be made for a heat insulating
container of the second embodiment of the present invention. In
this embodiment, the identical or corresponding parts or members to
those of the first embodiment are given the same names and the same
reference characters as those of the first embodiment.
[0062] The heat insulating container of this embodiment is made up
of a container body 1 having a bottomed tubular shape and an outer
shell 2 that covers a peripheral wall 10 of the container body 1,
as illustrated in FIGS. 6 and 7.
[0063] The container body 1 is a resin molded product molded by
injection molding by using polypropylene, high-density polyethylene
or the like as a material. The container body 1 is made up of a
tubular peripheral wall 10, and a bottom portion 14 that closes a
lower end opening of the peripheral wall 10.
[0064] The peripheral wall 10 is formed into a tubular, inverted
conical shape with a diameter decreasing towards the lower end.
Specifically, the peripheral wall 10 is made up of a tubular upper
peripheral wall portion 10a defining an opening of the heat
insulating container, a lower peripheral wall portion 10b having a
diameter smaller than the upper peripheral wall portion 10a and
disposed below the upper peripheral wall portion 10a, and an
annular connection portion 5 for connection between an opening edge
of a lower end of the upper peripheral wall portion 10a and an
opening edge of an upper end of the lower peripheral wall portion
10b.
[0065] The upper peripheral wall portion 10a is made up of a
tubular peripheral wall body part 110 with an opening edge of the
lower end connected to an outer peripheral edge of the connection
portion 5, an annular connection part 111 having an annular shape
in a horizontal orientation with an inner peripheral edge connected
to an opening edge of an upper end of the peripheral wall body part
110, a tubular, large diameter part 112 with an opening edge of a
lower end connected to an outer peripheral edge of the annular
connection part 111, and a flange part 113 extending outwards from
an opening edge of an upper end of the large diameter part 112.
[0066] The peripheral wall body part 110 is formed into a tubular,
inverted conical shape with an outer diameter and an inner diameter
decreasing towards the lower end. The peripheral wall body part 110
is formed with plural gutters 110a and plural ridges 110b, which
extend the axial direction and are formed alternately in the
circumferential direction.
[0067] The gutters 110a each define an inwardly curved surface in
the circumferential direction, while the ridges 110b each define an
outwardly curved surface in the circumferential direction. With
this, the outer peripheral surface of the peripheral wall body part
110 defines a corrugated curved surface with the inwardly curved
surfaces and the outwardly curved surfaces alternately formed.
[0068] In other words, the ridges 110b each have a gentle mountain
shape in cross section, and the gutters 110a are defined by the
connected portions between the adjacent ridges 110b. In this
embodiment, the gutters 110a are spaced each other in the
circumferential direction with a predetermined angle (about
7.5.degree. in this embodiment) with the axis of the peripheral
wall body part 110 as the center. Therefore, the plural ridges 110b
are also formed to have the apexes of the adjacent ridges 110b with
the gutters 110a therebetween spaced each other in the
circumferential direction with a predetermined angle (7.5.degree.
in this embodiment) with the axis of the tubular peripheral wall
body part 110 as the center
[0069] Reinforcing pieces 117 extend downwards from the lower end
of the peripheral wall body part 110 of this embodiment so as to
increase the radial strength of the container body 1. The
reinforcing pieces 117 are formed with a predetermined distance
from the outer peripheral surface of the lower peripheral wall
portion 10b (a lower tubular part 11 hereinafter described), each
having lateral sides connected to later-described vertical ribs
115.
[0070] The annular connection part 111 has, as described above, the
outer peripheral edge connected to the opening edge of the upper
end of the peripheral wall body part 110, and is formed into a
flange around the peripheral wall body part 110.
[0071] The large diameter part 112 has a substantially circular
tubular shape and has an opening edge of the lower end connected to
the outer peripheral edge of the annular connection part 111. With
this, the large diameter part 112, the annular connection part 111
and the peripheral wall body part 110 together form a stepped
portion around an opening of the upper end of the upper peripheral
wall portion 10a (container body 1), so that a top surface of the
annular connection part 111 can be used as a formed line providing
an indication for the amount of boiled water or the like to be
poured in.
[0072] The flange part 113 is made up of a top plate section 113a
having an annular shape in a horizontal orientation and a downward
extension 113b extending downwards from an outer peripheral edge of
the top plate section 113a, and has a substantially L-shape in
cross section. The flange part 113 has the top plate section 113a
whose inner peripheral edge is connected to the opening edge of the
upper end of the large diameter part 112, so that an upper surface
of the top plate section 113a forms an upper end surface of the
heat insulating container. The flange part 113 is designed to allow
a sealing lid (not shown) made of a laminate of aluminium foil and
synthetic resin film or paper to be detachably attached to the top
plate section 113a, so as to seal the container body 1 with a
content (such as instant noodles or soup eatable by pouring boiling
water thereinto).
[0073] The lower peripheral wall portion 10b is made up of a lower
tubular part 114 with an opening edge of an upper end connected to
the upper peripheral wall portion 10a via the connection portion 5,
and plural vertical ribs 115 vertically extending and projecting
from an outer peripheral surface of the lower tubular part 114.
[0074] The lower tubular part 114 is formed into a tubular,
inverted truncated conical shape (tubular body having an inverted
conical shape) with an outer diameter and an inner diameter
decreasing towards the lower end. The lower tubular part 114 of
this embodiment is made up of a thick tubular section 114a close to
an upper end opening connected to the connection portion 5, and a
thin tubular section 114b connected to an opening edge of a lower
end of the thick tubular section 114a with taking into account the
flow of a resin during molding.
[0075] Since the lower tubular part 114 is, as described above,
connected to the upper peripheral wall portion 10a via the
connection portion 5, the thick tubular section 114a has an outer
diameter of the opening edge of the upper end, which is smaller
than the inner diameter of the lower end opening of the upper
peripheral wall portion 10a (peripheral wall body part 110) due to
the interposition of the connection portion 5 therebetween, and is
formed into a tubular, inverted conical shape with a diameter
decreasing towards the lower end.
[0076] The thin tubular section 114b has an opening edge of an
upper end connected to an opening edge of the lower end of the
thick tubular section 114a so as to form a continuous surface
substantially uniform to the inner peripheral surface of the thick
tubular section 114a. The thickness of the thin tubular section
114b is smaller than the thick tubular section 114a, and is set at
about 0.2 mm to 0.4 mm in this embodiment. The thin tubular section
114b is also formed into a tubular body having a substantially
inverted conical shape with a diameter decreasing towards the lower
end, in the same manner as the thick tubular section 114a.
[0077] The plural vertical ribs 115 are arranged on the outer
peripheral surface of the lower tubular part 114 in a radial
pattern with the axis of the lower peripheral portion 10b as the
center. Specifically, the plural vertical ribs 115 are arranged
with the axis of the lower tubular part 114 as the center as
extending through the thick tubular section 114a and the thin
tubular section 114b. The vertical ribs 115 of this embodiment each
have an upper end connected to a bottom surface of the connection
portion 5, and the projection amount of each rib gradually
decreases as it advances from the upper end towards the lower end,
of the lower tubular part 114.
[0078] The vertical ribs 115 of this embodiment have a projection
amount of about 1.5 mm to 2.7 mm around the connection portion
between the thick tubular section 114a and the thin tubular section
114b, with reference to the outer peripheral surface of the thin
tubular section 114b, and a portion connected to the thin tubular
section 114b has a thickness of about 0.6 mm to 0.7 mm. With this,
the container body 1 of this embodiment has the outer peripheral
surface of the peripheral wall body part 110, an end of each
vertical rib 115 and the outer surface of the bottom portion 14,
all of which lie on a continuous surface. When the vertical ribs
115 are set at the above size, it is preferable to set the
thickness of the thick tubular section 114a in a range of about 0.3
mm to 0.8 mm on the condition that it is thicker than the thickness
of the thin tubular section 114b, and the length in the axial
direction in a range of about 1 mm to 10 mm, respectively.
[0079] The bottom portion 14 is made up of a bottom plate section
14a having a rounded shape as viewed in plan, and a bottom
connection section 14b for connecting the bottom plate section 14a
to an opening edge of the lower end of the thin tubular section
114b (peripheral wall 10). The bottom plate section 14a has a
rounded area on a substantially center portion bulging slightly and
inwardly of the container body 1.
[0080] The bottom connection section 14b is formed into an annular
shape, and has a first side constituting an inner surface of the
container body 1, and a second side constituting an outer surface
of the container body 1, in which the first side defines a concave
surface and the second side defines a convex surface. The bottom
connection section 14b has an inner peripheral edge connected to an
outer peripheral edge of the bottom plate section 14a, and together
with the bottom plate section 14a constitutes the bottom portion 14
of a substantially dish-like shape. An outer peripheral edge of the
bottom connection section 14b is connected to an opening edge of a
lower end of the lower tubular part 114 (peripheral wall 10).
[0081] The outer shell 2 is formed from a foamed resin sheet having
heat shrinkability in the same manner as the first embodiment, and
includes a tubular portion 20 covering the peripheral wall 10 of
the container body 1 so as to be disposed opposite to the
peripheral wall 10, and an annular portion 21 extending (folded
back) towards the inside of the tubular portion 20, starting from
the lower end of the tubular portion 20.
[0082] The tubular portion 20 has an inner diameter set so as to
allow itself to be fitted around the peripheral wall 10 of the
container body 1 with a predetermined space to the peripheral wall
of the container body 1 (specifically, the outer peripheral surface
of the peripheral wall body part 110, and the outer edge of each
vertical rib 115 on the outer peripheral surface of the lower
peripheral wall portion 10b), and is formed into a tubular,
inverted conical shape in this embodiment, corresponding to the
peripheral wall 10 of the container body 1.
[0083] The tubular portion 20 of this embodiment is not provided at
an upper end opening with the curled portion 22 unlike the first
embodiment, and is formed into a substantially circular tubular
shape. The upper end opening of the tubular portion 20 has an inner
diameter set so as to allow itself to be fitted around the large
diameter part 112 of the container body 1.
[0084] The annular portion 21 is formed so as to have an end side
(inner peripheral edge side) disposed away from the inner
peripheral surface of the tubular portion 20. Specifically, the
annular portion 21 has a distal end (inner peripheral edge)
positioned more inwardly of the tubular portion 20 than a proximal
end (outer peripheral edge), and is formed into a tapered shape so
as to be tapered towards the distal end. The annular portion 21 is
inclined at an angle of preferably 30.degree. to 60.degree. to the
inner peripheral surface of the tubular portion 20. The annular
portion 21 has an inner peripheral edge, from which the horizontal
annular extension 23 extends towards the center of the tubular
portion 20. The outer shell 2 is fabricated by the same steps as
those of the first embodiment and therefore the description on the
steps of fabrication of the outer shell 2 will be omitted.
[0085] According to the thus structured heat insulating container,
the container body 1 is fitted into the outer shell 2 with the
inner peripheral surface of the tubular portion 20 disposed
opposite to the outer peripheral surface of the peripheral wall 10
of the container body 1, and as illustrated in FIG. 8, when the
upper end of the tubular portion 20 is brought into contact with
the lower surface of the top plate section 113a while having the
upper end opening of the outer shell 2 (tubular portion 20) fitted
around the large diameter part 112 of the container body 1, the
bottom portion 14 (bottom plate section 14a) is brought into a
state where it is supported with contact to the horizontal annular
extension 23, as illustrated in FIG. 9. Whereby, it is possible to
prevent the bottom portion 14 (bottom plate section 14a) formed
with a thin wall, which is softened by boiled water poured into the
container body 1, from being deformed as being bent downwards due
to the weight of boiled water or the content. In this state, the
space 40 exists between the peripheral wall 10 of the container
body 1 (the tubular peripheral wall body part 110, and the lower
tubular part 114) and the tubular portion 20 of the outer shell 2,
so that a heat insulating effect can be produced by heat conduction
through air (cf. FIG. 7).
[0086] According to the thus structured heat insulating container,
when external force has been applied onto the outer shell 2 (lower
end) in the radial direction by the grasping of the outer shell 2,
the external force acts towards the center of the tubular portion
20 (in a direction orthogonal to the center line of the tubular
portion 20), and therefore acts to reduce the diameter of the
opening edge of the lower end of the tubular portion 20 or deform
the opening edge into a flat shape. At the same time, the external
force also acts on the proximal end (outer peripheral edge) of the
annular portion 21 in a direction towards the center of the tubular
portion 20.
[0087] Accordingly, the annular portion 21, which is formed into an
annular shape, tapered towards the inside of the tubular portion
20, allows the external force to act on the annular portion 21 in a
direction crossing the plane of the annular portion 21, and
therefore reaction force against the external force is caused on
the distal end side of the annular portion 21 in an acting
direction different from the external force (in such a direction as
to expand the inner peripheral edge). Whereby, bending action
occurs on the portion of the annular portion 21 between the
proximal end and the distal end, so that elastic force caused in
the annular portion 21 due to the bending prevents the radial
deformation of the tubular portion 20 due to the external
force.
[0088] That is, according to the heat insulating container, the
annular portion 21 is disposed inwardly of the tubular portion 20
and is tapered with the distal end side positioned away from the
inner peripheral surface of the tubular portion 20, so that elastic
force is caused on the annular portion 21 when external force has
been applied thereon, and this elastic force is utilized so that a
satisfactory strength in the radial direction can be produced to
the lower end of the outer shell 2.
[0089] According to the heat insulating container, the horizontal
annular extension 23 extends from the distal end of the annular
portion 21, thereby capable of enhancing the strength of the inner
peripheral edge and its proximity of the annular portion 21 to
suppress deformation of the inner peripheral edge and its proximity
of the annular portion 21 through the reaction force against
external force and hence further increase the strength in the
radial direction. That is, the strength of the lower end side of
the tubular portion 20 is further increased by efficiently
utilizing the elasticity between the proximal end and the distal
end, of the annular portion 21 against elastic force. Therefore,
when the outer shell 2, which can provide a satisfactory strength
for the lower end side of the heat insulating container (outer
shell 2), is to be manufactured, it is not necessary to carry out
the step of providing a bottom plate for covering a hole defined by
the annular portion unlike the prior art, and therefore it is
possible to reduce manufacturing costs and material costs for
manufacturing the heat insulating container.
[0090] Further, according to the heat insulating container, the
annular portion 21 extends in an inclined orientation from the
lower end to the inside, of the tubular portion 20, with respect to
the inner peripheral surface of the tubular portion 20, thereby
forming a recessed portion on the bottom, so that it is possible to
hold the heat insulating container with a finger engaged with the
annular portion 21. Thus, it is possible to grasp and hold the heat
insulating container in a stabilized manner without slipping-off
the same. Furthermore, even when the heat insulating container is
held with a finger engaged with the annular portion 21, the
horizontal annular extension 23 extending from the inner peripheral
edge (distal end) of the annular portion 21 can prevent the finger
engaged with the annular portion 21 from touching the bottom
portion 14 of the container body 1, and hence prevent burns or any
other troubles with the container body 1 even when a food heated at
a high temperature is placed therein, thus achieving safety.
[0091] With the plural vertical ribs 115 formed on the lower
peripheral wall portion 10b of the peripheral wall 10 of the
container body 1, even when the outer shell 2 is deformed in the
radial direction by the action of grasping force caused by grasping
the outer shell 2, the outer shell 2 contacts the vertical ribs 115
so that the space 40 constantly exists between the lower peripheral
wall portion 10b and the outer shell 2 and therefore can constantly
keep the heat insulating effect by heat conduction in the space
40.
[0092] According to the heat insulating container of this
embodiment, the connection section (bottom connection section 14b)
between the peripheral wall 10 and the bottom portion 14, of the
container body 1 is rounded to be prevented from being interfered
with the outer shell 2, so that the bottom plate section 14a can be
held in such a position as to be supported by the horizontal
annular extension 23, and hence the strength of the heat insulating
container can be further increased.
[0093] The concave surface defined by the inner surface of the
bottom portion 14 of the container body 1 (inner surface of the
bottom connection section 14b) allows the content of the container
body 1 to be easily lifted by a spoon with its leading end moving
along the inner peripheral surface of the bottom portion 14 with no
content remained in the container body 1.
[0094] Now, the description will be made for a heat insulating
container of a third embodiment of the present invention. In this
embodiment, the identical or corresponding parts or members to
those of the first and second embodiments are given the same names
and the same reference characters as those of the first and second
embodiments.
[0095] The heat insulating container of this embodiment is made up
of a container body 1 having a bottomed tubular shape and an outer
shell 2 that covers a peripheral wall 10 of the container body 1,
as illustrated in FIGS. 10 and 11, in the same manner as the first
and second embodiments.
[0096] The container body 1 is a resin molded product molded by
injection molding by using polypropylene, high-density polyethylene
or the like as a material. The container body 1 is made up of a
tubular peripheral wall 10, and a bottom portion 14 that closes a
lower end opening of the peripheral wall 10.
[0097] The peripheral wall 10 is formed into a tubular, inverted
conical shape with a diameter decreasing towards the lower end.
Specifically, the peripheral wall 10 is made up of a tubular upper
peripheral wall portion 10a defining an opening of the heat
insulating container, a lower peripheral wall portion 10b having a
diameter smaller than the upper peripheral wall portion 10a and
disposed below the upper peripheral wall portion 10a, and an
annular connection portion 5 for connection between an opening edge
of a lower end of the upper peripheral wall portion 10a and an
opening edge of an upper end of the lower peripheral wall portion
10b.
[0098] The upper peripheral wall portion 10a is made up of a
tubular peripheral wall body part 110 with an opening edge of the
lower end connected to an outer peripheral edge of the connection
portion 5, an annular connection part 111 having an annular shape
in a horizontal orientation with an inner peripheral edge connected
to an opening edge of an upper end of the peripheral wall body part
110, a tubular, large diameter part 112 with an opening edge of a
lower end connected to an outer peripheral edge of the annular
connection part 111, and a flange part 113 extending outwards from
an opening edge of an upper end of the large diameter part 112.
[0099] The peripheral wall body part 110 of this embodiment has a
substantially uniform wall thickness in the peripheral direction
and the axial direction, and is formed into a tubular, inverted
conical shape with a diameter decreasing towards the lower end. The
opening edge of the lower end is connected to the outer peripheral
edge of the connection portion 5. Reinforcing pieces 117 extend
downwards from the lower end of the peripheral wall body part 110
so as to increase the strength of the container body 1 in the
radial direction. The reinforcing pieces 117 are formed with a
predetermined distance from the outer peripheral surface of the
lower peripheral wall portion 10b, each having lateral sides
connected to later-described vertical ribs 115.
[0100] The annular connection part 111 has, as described above, the
outer peripheral edge connected to the opening edge of the upper
end of the peripheral wall body part 110, and is formed into a
flange around the peripheral wall body part 110.
[0101] The large diameter part 112 has a substantially circular
tubular shape and has an opening edge of the lower end connected to
the outer peripheral edge of the annular connection part 111. With
this, the large diameter part 112, the annular connection part 111
and the peripheral wall body part 110 together form a stepped
portion around an opening of the upper end of the upper peripheral
wall portion 10a (container body 1), so that a top surface of the
annular connection part 111 can be used as a formed line providing
an indication for the amount of boiled water or the like to be
poured in.
[0102] The flange part 113 is made up of a top plate section 113a
having an annular shape in a horizontal orientation and a downward
extension 113b extending downwards from an outer peripheral edge of
the top plate section 113a, and has a substantially L-shape in
cross section. The flange part 113 with the top plate section 113a
whose inner peripheral edge is connected to the opening edge of the
upper end of the large diameter part 112, so that an upper surface
of the top plate section 113a forms an upper end surface of the
heat insulating container. The flange part 113 is designed to allow
a sealing lid (not shown) made of a laminate of aluminium foil and
synthetic resin film or paper to be detachably attached to the top
plate section 113a, so as to seal the container body 1 with a
content (such as instant noodles or soup eatable by pouring boiling
water thereinto) placed therein.
[0103] The lower peripheral wall portion 10b has an opening edge of
the upper end connected to the upper peripheral wall portion 10a
via the connection portion 5, and a lower end opening closed by the
bottom portion 14. The lower peripheral wall portion 10b is formed
into a tubular, inverted conical shape (tubular body having an
inverted truncated conical shape) with an outer diameter and an
inner diameter decreasing towards the lower end. Likewise the lower
tubular part 114 of the second embodiment, the lower peripheral
wall portion 10b of this embodiment is made up of a thick tubular
section 114a close to an upper end opening connected to the
connection portion 5, and a thin tubular section 114b connected to
an opening edge of a lower end of the thick tubular section 114a
with taking into account the flow of a resin during molding.
[0104] Since the lower peripheral wall portion 10b is, as described
above, connected to the upper peripheral wall portion 10a via the
connection portion 5, the thick tubular section 114a has an outer
diameter of the opening edge of the upper end, which is smaller
than the inner diameter of the lower end opening of the upper
peripheral wall portion 10a (peripheral wall body part 110) due to
the interposition of the connection portion 5 therebetween, and is
formed into a tubular, inverted conical shape with a diameter
decreasing towards the lower end.
[0105] The thin tubular section 114b has an opening edge of an
upper end connected to an opening edge of the lower end of the
thick tubular section 114a so as to form a continuous surface
substantially uniform to the inner peripheral surface of the thick
tubular section 114a. The thickness of the thin tubular section
114b is smaller than the thick tubular section 114a, and is set at
about 0.2 mm to 0.4 mm in this embodiment. The thin tubular section
114b is also formed into a tubular body having a substantially
inverted conical shape with a diameter decreasing towards the lower
end, in the same manner as the thick tubular section 114a.
[0106] The peripheral wall 10 of the thus structured container body
1 is provided on its outer peripheral surface with plural vertical
ribs 115 arranged in a radial pattern with the axis of the
container body 1 as the center as extending through the peripheral
wall body part 110 and the lower peripheral wall portion 10b. The
plural vertical ribs 115 are formed so as to each have an upper end
connected to a bottom surface of the annular connection part 111,
and an upper end defining a continuous surface with the outer
peripheral surface of the large diameter part 112 (the upper end
positioned not protruding outwardly from the outer peripheral
surface of the large diameter part 112), and to extend downwards
while protruding outwards from the reinforcing pieces 117. The
projection amount of each vertical rib 115 in its second side lower
than the reinforcing pieces 117 gradually decreases towards the
lower end, so that the lower end defines a continuous surface with
the outer surface of a later described bottom portion 14 (bottom
connection section 14b). The vertical ribs 115 of this embodiment
have a projection amount of about 1.5 mm to 2.7 mm around the
connection portion between the thick tubular section 114a and the
thin tubular section 114b, with reference to the outer peripheral
surface of the thin tubular section 114b, and a portion connected
to the thin tubular section 114b has a thickness of about 0.6 mm to
0.7 mm. With this, the container body 1 of this embodiment has the
outer peripheral surface of the peripheral wall body part 110, an
end of each vertical rib 115 and the outer surface of the bottom
portion 14, all of which lie on a continuous surface. When the
vertical ribs 115 are set at the above size, it is preferable to
set the thickness of the thick tubular section 114a in a range of
about 0.3 mm to 0.8 mm on the condition that it is thicker than the
thickness of the thin tubular section 114b, and the length in the
axial direction in a range of about 1 mm to 10 mm, in the same
manner as the second embodiment.
[0107] The bottom portion 14 is made up of a bottom plate section
14a having a rounded shape as viewed in plan, and a bottom
connection section 14b for connecting the bottom plate section 14a
to an opening edge of the lower end of the thin tubular section
114b (peripheral wall 10). The bottom plate section 14a has a
rounded area on a substantially center portion bulging slightly and
inwardly of the container body 1.
[0108] The bottom connection section 14b is formed into an annular
shape, and has a first side constituting an inner surface of the
container body 1, and a second side constituting an outer surface
of the container body 1, in which the first side defines a concave
surface and the second side defines a convex surface. The bottom
connection section 14b has an inner peripheral edge connected to an
outer peripheral edge of the bottom plate section 14a, and together
with the bottom plate section 14a, constitutes the bottom portion
14 of a substantially dish-like shape. An outer peripheral edge of
the bottom connection section 14b is connected to an opening edge
of a lower end of the lower peripheral wall portion 10b (peripheral
wall 10).
[0109] The outer shell 2 is made of a foamed resin sheet having
heat shrinkability in the same manner as the first and second
embodiments, and includes the tubular portion 20 covering the
peripheral wall 10 of the container body 1 so as to be disposed
opposite to the peripheral wall 10, and an annular portion 21
extending (folded back) towards the inside of the tubular portion
20, starting from the lower end of the tubular portion 20.
[0110] The tubular portion 20 has an inner diameter set so as to
allow itself to be fitted around the peripheral wall 10 of the
container body 1 with a predetermined space to the peripheral wall
10 of the container body 1 (specifically, the outer peripheral
surface of the peripheral wall body part 110, and the outer edge of
each vertical rib 115 on the outer peripheral surface of the lower
peripheral wall portion 10b), and is formed into a tubular,
inverted conical shape in this embodiment, corresponding to the
peripheral wall 10 of the container body 1.
[0111] The tubular portion 20 of this embodiment is not provided at
upper end opening of with the curled portion 22 unlike the first
embodiment, and is formed into a substantially circular tubular
shape. The upper end opening of the tubular portion 20 has an inner
diameter set so as to allow itself to be fitted around the large
diameter part 112 of the container body 1.
[0112] The annular portion 21 has a distal end (inner peripheral
edge) positioned more inwardly of the tubular portion 20 than a
proximal end (outer peripheral edge), and is formed into a tapered
shape so as to be tapered as it advances towards the distal end, in
the same manner as the first and second embodiments. The outer
shell 2 is fabricated by the same steps as those of the first and
second embodiments and therefore the description on the steps of
fabrication of the outer shell 2 will be omitted.
[0113] According to the thus structured heat insulating container,
the container body 1 is fitted in the outer shell 2 with the inner
peripheral surface of the tubular portion 20 disposed opposite to
the outer peripheral surface of the peripheral wall 10 of the
container body 1, and as illustrated in FIG. 12, when the upper end
of the tubular portion 20 is brought into contact with the lower
surface of the top plate section 113a while having the upper end
opening of the outer shell 2 (tubular portion 20) fitted around the
large diameter part 112 of the container body 1, the bottom portion
14 (bottom plate section 14a) is brought into a state where it is
supported with contact to the horizontal annular extension 23, as
illustrated in FIG. 13. Whereby, it is possible to prevent the
bottom portion 14 (bottom plate section 14a) formed with a thin
wall, which is softened by boiled water poured into the container
body 1, from being deformed as being bent downwards due to the
weight of boiled water or a content. In this state, the space 40
exists between the peripheral wall 10 of the container body 1 (the
tubular peripheral wall body part 110, and the lower peripheral
wall portion 10b) and the tubular portion 20 of the outer shell 2,
so that a heat insulating effect can be produced by heat conduction
through air (cf. FIG. 11).
[0114] According to the thus structured heat insulating container,
when external force has been applied onto the outer shell 2 (lower
end) in the radial direction by the grasping of the outer shell 2,
the external force acts towards the center of the tubular portion
20 (in a direction orthogonal to the center line of the tubular
portion 20), and therefore acts to reduce the diameter of the
opening edge of the lower end of the tubular portion 20 or deform
the opening edge into a flat shape. At the same time, the external
force also acts on the proximal end (outer peripheral edge) of the
annular portion 21 in a direction towards the center of the tubular
portion 20.
[0115] Accordingly, the annular portion 21, which is formed into an
annular shape, tapered towards the inside of the tubular portion
20, allows the external force to act on the annular portion 21 in a
direction crossing the plane of the annular portion 21, and
therefore reaction force against the external force is caused on
the distal end side of the annular portion 21 in an acting
direction different from the external force (in such a direction as
to expand the inner peripheral edge). Whereby, bending action
occurs on the portion of the annular portion 21 between the
proximal end and the distal end, so that elastic force caused in
the annular portion 21 due to the bending prevents the radial
deformation of the tubular portion 20 due to the external
force.
[0116] That is, according to the heat insulating container, the
annular portion 21 is disposed inwardly of the tubular portion 20
and is tapered with the distal end side positioned away from the
inner peripheral surface of the tubular portion 20, so that elastic
force is caused on the annular portion 21 when external force has
been applied thereon, and this elastic force is utilized so that a
satisfactory strength in the radial direction can be produced to
the lower end of the outer shell 2.
[0117] According to the heat insulating container, the horizontal
annular extension 23 extends from the distal end of the annular
portion 21, thereby capable of enhancing the strength of the inner
peripheral edge and its proximity of the annular portion 21 to
suppress deformation of the inner peripheral edge and its proximity
of the annular portion 21 and hence further increase the strength
in the radial direction. That is, the strength on the lower end
side of the tubular portion 20 is increased by efficiently
utilizing the elasticity between the proximal end and the distal
end, of the annular portion 21 against elastic force. Therefore,
even in the heat insulating container of this embodiment, when the
outer shell 2 is to be manufactured, it is not necessary to carry
out the step of providing a bottom plate for covering a hole
defined by the annular portion unlike the prior art, and therefore
it is possible to reduce manufacturing costs and material costs for
manufacturing the heat insulating container.
[0118] Further, according to the heat insulating container, the
annular portion 21 extends in an inclined orientation from the
lower end to the inside, of the tubular portion 20, with respect to
the inner peripheral surface of the tubular portion 20, thereby
forming a recessed portion on the bottom, so that it is possible to
hold the heat insulating container with a finger engaged with the
annular portion 21. Thus, it is possible to grasp and hold the heat
insulating container in a stabilized manner without slipping-off
the same. Furthermore, even when the heat insulating container is
held with a finger engaged with the annular portion 21, the
horizontal annular extension 23 extending from the inner peripheral
edge (distal end) of the annular portion 21 can prevent the finger
engaged with the annular portion 21 from touching the bottom
portion 14 of the container body 1, and hence prevent burns or any
other troubles with the container body 1 even when a food heated at
a high temperature is placed therein, thus achieving safety.
[0119] According to the heat insulating container of this
embodiment, the connection section (bottom connection section 14b)
between the peripheral wall 10 and the bottom portion 14, of the
container body 1 is rounded to be prevented from being interfered
with the tubular portion 20 of the outer shell 2, so that only the
bottom connection section 14b can be held in such a position as to
be supported by the horizontal annular extension 23, and hence the
strength of the heat insulating container can be further
increased.
[0120] Further, according to the heat insulating container, with
the plural vertical ribs 115 formed on the peripheral wall 10 of
the container body 1 throughout its entire area, even when the
outer shell 2 is deformed in the radial direction by the action of
grasping force caused by grasping the outer shell 2, the outer
shell 2 contacts the outer edges of the vertical ribs 115 so that
the space 40 exists throughout substantially the entire area
between the peripheral wall 10 and the outer shell 2 and therefore
can constantly keep the heat insulating effect by heat conduction
in the space 40.
[0121] In the same manner as the second embodiment, the concave
surface defined by the inner surface of the inner peripheral
surface (bottom connection section 14b) of the bottom portion 14 of
the container body 1 allows the content of the container body 1 to
be easily lifted by a spoon with its leading end moving along the
inner peripheral surface of the bottom portion 14 with no content
remained in the container body 1.
[0122] The heat insulating container of the present invention is
not necessarily limited to the first to third embodiments, and it
is a matter of course that various modifications may be applied
thereto within the scope not departing from the gist of the present
invention.
[0123] In the first to third embodiments, as the foamed resin sheet
S for forming the outer shell 2, a sheet of foamed polystyrene is
solely used, but the foamed resin sheet S for forming the outer
shell 2 is not necessarily limited thereto. For example, it is
possible to employ a sheet having a non-foamed resin layer arranged
on one or each of both sides of a foamed polystyrene layer, or the
like.
[0124] In this case, the foaming rate and the components, of the
foamed polystyrene layer are set to be the same as those of foamed
polystyrene sheet of the above embodiment. For the non-foamed resin
layer, a styrene type resin such as polystyrene, styrene, butadiene
copolymer and styrene acrylic copolymer or the mixture thereof, or
a styrene type resin with a resin such as polyethylene and
ethylene-vinyl acetate copolymer mixed therein is preferable, but
also polyethylene or a polypropylene type resin may be employed.
This non-foamed resin layer has a thickness of preferably about 3
to 30 .mu.m. A non-foamed resin layer may be formed by coextrusion
with a foamed resin sheet. Alternatively, it may be formed by
laminating with a separately prepared film. In this case, it is
possible to print on a non-foamed resin film.
[0125] For the foamed resin sheet (foamed layer), those of the
aforesaid polystyrene type resin are preferable since they are
excellent in heat insulating performance and stiffness, but it is
also possible to employ a laminate of a foamed layer of a
polypropylene type resin or a polyethylene type resin and a
non-foamed, heat shrinkable polyester film.
[0126] In the above embodiments, the annular portion 21 is provide
at its distal end (inner peripheral edge) with the horizontal
annular extension 23, but it is not necessary to limit to this. The
strength in the radial direction of the tubular portion 20 may be
obtained only by the annular portion 21.
[0127] Although the tubular portion 20 of the outer shell 2 as
employed in the first to third embodiments has a diameter
decreasing towards the lower end, it is not necessary to limit to
this. For example, it is a matter of course that the tubular
portion 20 may be formed into a substantially circular tubular
shape or rectangular tubular shape.
[0128] In the first to third embodiments, the outer shell 2 is
molded by the use of the mold 50 having the second end with the
annular protrusion 53 formed thereon and the press die 51, but it
is possible to employ the mold 50 having a tubular shape. That is,
it is essential that the mold 50 has an outer peripheral surface
for forming the tubular portion 20 and allows the press die 51 to
press an opposite end of the tubular foamed resin sheet S fitted on
the mold 50.
[0129] The annular protrusion 53 is not also necessarily limited to
the shape of the first to third embodiments, which is formed to
correspond to the incline angle of the inner peripheral surface to
the annular portion 21, of the tubular portion 20. That is, since
the outer shell 2 is formed by the foamed resin sheet S having
shrinkability, shrinking force acts on the tubular foamed resin
sheet towards the center when the sheet is pressed by the press die
51. This shrinking force thus enables the formation of the annular
portion 21 conforming to the outer peripheral shape of the
protrusion 54. Therefore, since the annular portion 21 is not
formed by the inner peripheral surface of the annular protrusion
53, it is possible to form the annular portion 21 corresponding to
the outer peripheral surface of the protrusion 54 when the
protrusion 54 of the press die is formed with high precision.
[0130] In the second and third embodiments, the reinforcing pieces
117 are arranged along the lower end edge of the peripheral wall
body part 110 so as to increase the strength of the peripheral wall
10 of the container body 1 in the radial direction. This is not
essential and therefore it is possible to increase the strength in
the radial direction by, for example, forming the peripheral wall
10 into a step shape. Even with this arrangement, since the heat
insulating container includes the outer shell 2, the grasping force
when grasping the heat insulating container does not directly act
on the container body 1, and therefore a satisfactory strength is
ensured. However, in view of the safety or the like reason, it is
preferable to provide the reinforcing pieces 117 in the same manner
as the second and third embodiments.
[0131] Although the container body 1 is supported with the
horizontal annular extension 23 of the outer shell 2 held in
contact with the bottom portion 14 (bottom plate section 14a) of
the container body 1 in the second and third embodiments, it is not
necessary to limit to this. It is a matter of course to employ the
arrangement in which a clearance is created between the horizontal
annular extension 23 and the bottom plate section 14a, thereby
allowing air between the peripheral wall 10 of the container body 1
and the tubular portion 20 of the peripheral wall 10 to be
communicated with the outside.
[0132] Although the top surface of the annular connection part 111
is used as a formed line providing an indication for boiled water
to be poured in second and third embodiments, it is not necessary
to limit to this. For example, a ridge may be formed on the inner
peripheral surface of the container body 1 in the peripheral
direction, and this ridge may be served as a formed line. However,
it is not essential to provide a formed line, and therefore it may
be appropriately provided according to the content placed.
[0133] Although the peripheral wall 10 is formed into a step shape
in the second and third embodiments, it is not necessary to limit
to this. The peripheral wall 10 may be formed into a substantially
circular tubular shape or a tubular, inverted conical shape without
providing a step shape oriented in a direction from the lower end
towards the upper end. Even with the thus structured peripheral
wall 10, the vertical ribs 115 extending from the upper end to the
lower end, of the peripheral wall 10 can provide a heat insulating
effect in the same manner as the second and third embodiments,
since the vertical ribs 115 prevent the peripheral wall 10 to be
tightly contacted with the outer shell 2 (tubular portion 20) even
when the outer shell 2 is deformed by grasping the same, and can
constantly create a space for enhancing the heat insulating
performance in the area where the vertical ribs 115 are
disposed.
[0134] Although, in the first embodiment, the annular portion 21 is
disposed so as to have the distal end with a space to the bottom
portion 14 of the container body 1, thereby allowing air within the
space 40 to be released to the outside, it is not necessary to
limit to this. The bottom portion 14 of the container body 1 may be
supported by the distal end of the annular portion 21. That is,
since the tubular portion 20 (outer shell 2) is formed by a foamed
resin, it is possible to produce a satisfactory heat insulating
effect even without releasing air within the space 40 to the
outside. Therefore, it is not necessary to employ the structure
enabling air within the space 40 to be released to the outside, so
that a required heat insulating effect may be produced in
consideration of the content placed in the container body 1, or the
like.
[0135] Although, in the second embodiment, the tubular peripheral
wall body part 110 of the upper peripheral wall portion 10a are
formed with plural gutters 110a and plural ridges 110b formed
alternately, it is not necessary to limit to this. It is a matter
of course to have the peripheral wall body part 110 set to a
uniform wall thickness. However, in order to efficiently form the
peripheral wall body part 110 with stable quality when molding the
container body 1 of the heat insulating container, it is preferable
to form the peripheral wall body part 110 with the gutters 110a and
the ridges 110b in the same manner as the second embodiment.
Therefore, while the peripheral wall 10 of the container body 1 is
formed with a substantial uniform thickness in the first
embodiment, it is not necessary to limit to this. It is a matter of
course to form the peripheral wall 10 with plural gutters and
plural ridges alternately formed, in the same manner as the
peripheral wall body part 110 of the second embodiment.
[0136] Although the lower peripheral wall portion 10b of the
container body 1 is provided with the vertical ribs 115 in the
second embodiment, it is not necessary to limit to this. The
vertical ribs 115 may be provided in the substantially entire area
of the peripheral wall 10 of the container body 1 in the same
manner as the third embodiment. That is, when the vertical ribs 115
are to be provided, they may be provided to at least one of the
peripheral wall body part 110 and the lower peripheral wall portion
10b, and preferably at least to the lower peripheral wall portion
10b. However, it is not necessary to provide the vertical ribs 115
on the peripheral wall 10 of the container body 1, and it is a
matter of course to form the peripheral wall 10 of the container
body 1 with a substantially uniform wall thickness in the same
manner as the first embodiment.
* * * * *