TECHNICAL FIELD
[0001] This invention generally relates to a contractible bellows container. More particularly,
this invention relates to a contraction-controlled bellows container.
BACKGROUND ART
[0002] A conventional contractible bellows container chiefly comprises a generally tubular
bottlelike container portion and bellows which protrude at a right angle from the
container portion. A conventional contractible bellows container is generally used
to contain and press out a viscous material. Each conventional bellows ridge is formed
as a ring body, provided around the container body portion, consisting of two plane
rings of the same size. The two plane rings meet at their outer rims with an angle
and provide a circular outer hinge (hereinafter referred to as "outer hinge"). The
inner circular hinges (hereinafter referred to as "inner hinges") of the plane rings
are apart. When the container is pressed generally in the direction of its longitudinal
axis to press out its content, both the plane rings of the bellows are pressed toward
each other hinging on the respective outer hinges, and the bellows are eventually
closed.
[0003] The pressure applied to such a conventional bellows container containing a fluid
receives repulsive forces from the fluid and bellows [from the upper plane rings (hereinafter
referred to as "upper walls") and the lower plane rings [hereinafter referred to an
"lower walls")]. The repulsive forces from the bellows should be eliminated as much
as possible. Technically, bellows walls (upper and lower walls) can be made very thin
to reduce such repulsive forces, however, it is often disadvantageous to make the
bellows walls too flexible. A bellows container needs to be rigid enough to hold its
content stably and must be tough enough to bear the pressure applied to it. Otherwise,
the container cannot be bellowed.
[0004] It has not been practical to provide a hard plastic bottle with a truly workable
bellows feature. A hard plastic bottle like a PET (polyethylene terephthalate) bottle
may be provided with conventional bellows, but it would not be contracted easily because
of the considerable repulsive forces from all its bellows.
[0005] Another drawback with a conventional bellows container is that its bellows once contracted
fully or halfway return to their original configuration when the pressure to the container
is removed, and the bellows open again. Air is sucked into the container, which often
damages its contents.
[0006] Emptied containers whose original configurations are restored are also a serious
volume problem to recycling and disposal as well as to the environment.
[0007] There have been proposed a number of plastic bellows containers in an attempt to
eliminate or ease such drawbacks. The following three proposed bellows containers
are considered by the present inventor "best" among them.
[0008] Japanese Utility Model Laid-Open Publication No. 55-158032 discloses a contractible
plastic bellows container having bellows each ridge formed of a plane upper wall and
a plane lower wall. The upper wall and lower wall of each bellows ridge are differently
angled or mixed in an attempt to reduce the repulsive force from the ridge. However,
the problem of the repulsion is not corrected completely due to the "plane" wall configuration
of the bellows. The problem of shape restoration of the bellows is not addressed,
either. Further, those bellows cannot be fully closed as the upper walls and lower
walls are differently sized, causing unintended distortion in the bellows walls, as
a person skilled in the art will realize.
[0009] Japanese Patent Publication No. 2-19253 discloses a contractible plastic bellows
container having "open rings" provided at the inner hinges of the bellows in an attempt
to ease the contraction of the bellows and prevent degradation of the material at
these hinges in repeated uses. Those open rings are provided astride the upper walls
and lower walls equally. As a person skilled in the art knows, those open rings are
naturally made "thick" by blow molding which is the conventional and most widely utilized
plastic container manufacturing method. These thick rings do not ease contraction
of the bellows very well. The problem of restoration of shape is not dealt with in
this bellows container, either. Those bellows will not fully close as their upper
walls and lower walls are differently sized, causing unintended distortion in the
bellows walls.
[0010] Japanese Patent Publication No. 64-58660 discloses a inflatable plastic bellows container
which utilizes a number of hemispheric (in vertical section) bellows unlike the foregoing
two bellows containers which utilize plane bellows walls. The bellows ridges of this
container are originally contracted and layered to be pulled upward in use to open.
[0011] Even if such a container is to be used conventionally (to be contracted from its
"open" configuration), vertical pressure applied to the container would meet with
considerable repulsion from the bellows whose upper walls and lower walls are formed
substantially identically. The pressure applied would be consumed equally on the upper
walls and lower walls. The dispersed pressure energy would be consumed not only to
close the bellows but to expand the bellows sideways creating no value, and unfavorably
deform the bellows walls. The applied pressure power would not be effectively utilized
in contraction or the bellows.
[0012] Those bellows are provided with a small protruding or depressed circumferential wedge
at each outer hinge to smooth the opening of the bellows. Such wedges would eliminate
the aforementioned unfavorable deformation of the bellows walls to an extent. However,
these protrusions or concavities are equally provided astride the upper walls and
lower walls of the bellows, and no distinction of function between these walls is
intended. Bellows having such a hemispheric configuration would intrinsically warp
to one side when contracted. (This is one of the features intended in the present
invention.) The direction of warping is not controlled, and therefore the randomly
(upwardly or downwardly) warping bellows would likely hinder the layering of the bellows
ridges.
[0013] As will be understood by a person skilled in the art, the aforementioned problem
of restoration of shape is intrinsically coped with to a degree by that hemispheric
bellows shape. However, because the inner hinges (upper and lower) of each bellows
ridge are vertically wide apart when the ridge is open, it would take a considerable
"time" for each bellows ridge to show the termination of the restoration of shape
when used conventionally. The bellows would retain a restorative function during most
of use.
[0014] That container additionally utilises open rings provided at the inner hinges (not
on the upper walls or inner walls of the bellows) to ease the opening of the bellows.
However, the open rings are intrinsically made thick and would not function as desired.
Rather, these open rings would prevent full contraction of the bellows ridges.
[0015] Accordingly, it is an object of the present invention to provide a contractible bellows
container whose bellows repulsion is substantially reduced. It is another object of
the present invention to control the order of contraction of bellows ridges to further
reduce the repulsion. It is still another object of the present invention to provide
early termination of restoration of shape of bellows and substantially retain the
fully or half contracted configuration of the bellows in use. It is an additional
object of the present invention to provide truly workable bellows to a hard plastic
container such as a PET bottle. Other objects of the present invention intrinsically
belong to the bellows containers made according to the present invention.
SUMMARY OF THE INVENTION
[0016] Generally, plastic containers including contractible plastic bellows containers are
manufactured by blow molding, which is suitable for mass production of plastic containers.
The farther the container wall portion of a plastic bellows container is from the
longitudinal axis of the container, the thinner the container wall portion becomes.
The outer hinge portions are made the thinnest and the inner hinge portions are made
the thickest (excluding the top and bottom portions of the container). It is impractical
not to take such so intrinsic feature of blow molding into consideration in designing
a plastic bellows container. As a person skilled in the art knows, there also exist
a number of restrictions intrinsic to blow molding. It is also impractical not to
take these intrinsic restrictions into consideration. Bellows containers according
to the present invention are designed so that they can be advantageously manufactured
by blow molding, however, contractible bellows containers according to the present
invention may be manufactured by other molding methods presently known in the art.
Plastic materials for manufacturing the containers of the present invention may be
freely selected from those known in the art as well.
[0017] Hereinafter, the present invention is described supposing containers are placed at
a standing position i.e., their longitudinal axes are vertical. The bellows of the
present invention are generally and basically convex, their upper walls and lower
walls being roundly protruded in their overall configurations. When such a convex
bellows ridge is pressed vertically at its inner hinges, eventually only one of its
walls is pressed into the ridge. The bellows ridge gradually loses restoration of
shape when a wall is gradually turned from its convex configuration to concave configuration,
eventually to a substantially symmetrical configuration. Once that wall assumes the
shape of concavity, the wall is next provided with a motion or energy working toward
the other wall and it finally contacts the other wall. The contracted bellows ridge
warps toward that concave wall.
[0018] It is an intention of the present invention to control at will the depression properties
of the bellows of containers and the direction of the warping of the bellows ridges.
[0019] Besides that "basic" convex configuration, the bellows ridges or the present invention
can assume other configurations and still enjoy the features intended by the present
invention, which will be explained later in detail. For example, the wall of a bellows
ridge may be substantially "plane."
[0020] Bellows containers of the present invention can have various configurations in horizontal
section, not only a circular configuration but also oval or square configurations
to name a few. Accordingly, the term "circular configuration" as used hereinafter
should be construed as including an oval configuration and other configurations which
are continuous circumferential "ring" configurations.
[0021] The bellows or a bellows container according to the present invention at least selectively
have a circular or circumferential indentation or indentations in their upper walls
and/or lower walls. A circular indentation is provided generally adjacent the outer
hinge or one of the inner hinges of a bellows ridge. Hereinafter the term "circular
indentation" or "circumferential indentation" is generally referred to as "indentation"
for the convenience of description. One bellows ridge may have two or more of such
indentations in its lower wall or upper well, or each wall may have one indentation
or more.
[0022] The intended features of indentations and their functions will be described hereinafter
in detail. When the term "pressure" is used hereinafter to describe the features and
functions of the indentations of a bellows container, it should be construed as also
meaning "suction" from an opening of the container since the bellows containers of
the present invention will function substantially similarly in both cases.
[0023] Vertical pressure applied to a bellows ridge having an indentation or indentations
is effectively and preferentially absorbed and utilized by the indentation or indentations,
and contraction of the ridge takes place effectively and less strenuously as the wall
or walls including the indentation or indentations are depressed inwardly together
with the inwardly "moving" indentation or indentations. It is possible to select which
wall to be depressed by selectively providing an indentation or indentations to bellows
walls. Because the wall having such on indentation or indentations is generally convex
in its overall configuration, the wall entering the bellows ridge eventually and substantially
gets turned or reversed in shape, losing its shape restoration momentum, and gains
a momentum to approach the other wall. The contracting bellows ridge will warp toward
the depressed wall.
[0024] If such indentations are provided in an arrangement, e.g. only on the upper walls
of bellows, then the warping of the bellows ridges can be arranged in one direction,
and these bellows ridges will be neatly layered. There will be no conflict between
warping bellows ridges.
[0025] The function of an indentation is subject to the overall design of the indentation,
including its "size" which may be conveniently represented by the vertical sectional
depression area. However, that function is also subject to the shape of the indentation
including the depth and length as well as local angles of the indentation Generally,
a large size indentation will provide a better utilization of pressure energy than
a small size indentation. Here, "better utilization" means that a bellows ridge having
a large indentation can be further depressed preferentially to and more easily thin
another bellows ridge having a small indentation. The order of contraction of bellows
ridge, can thus be controlled by providing the bellows ridges with different size
indentations, respectively, which substantially reduces the pressing energy required
since the pressing energy can be substantially concentrated on one bellows ridge,
or utilized ridge by ridge.
[0026] It is now possible to provide even a hard plastic container such as a PET bottle
with a truly workable bellows function utilizing aforedescribed indentations, more
advantageously utilizing size controlled indentations.
[0027] The present invention will be described in more detail hereunder using the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a vertical sectional view of a bellows container having bellows according
to an embodiment of the present invention, taken along its longitudinal axis, and
a partially enlarged view showing a bellows ridge portion in vertical section. Fig.
1(a) to Fig. 1(c) show the contraction process of the ridge portion.
[0029] FIG. 2 is a vertical sectional view of a bellows ridge portion according to another
embodiment of the present invention. Fig. 2(a) to Fig. 2(c) show the contraction process
of the ridge portion.
[0030] FIG. 3 is a vertical sectional view of a bellows ridge portion according to another
embodiment of the present invention.
[0031] FIG. 4 is a vertical sectional view, showing an arrangement of bellows portions according
to an embodiment of the present invention.
[0032] FIG. 5 is a vertical sectional view, showing a fully contracted state of the bellows
portions of Figure 4.
[0033] FIG. 6 is a vertical sectional view, showing another arrangement of bellows portions
according to another embodiment of the present invention.
[0034] FIG. 7 is a vertical sectional view, showing still another arrangement of bellows
portions according to still another embodiment of the present invention.
[0035] FIG. 8 is a vertical sectional view of a bellows ridge portion according to an applied
embodiment of the present invention. Fig. 8(a) to Fig. 8(c) show the contraction process
of the ridge portion.
[0036] FIG. 9 is a vertical sectional view of a bellows ridge portion according to a special
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Fig. 1 shows a bellows container 1 according to an embodiment of the present invention,
each bellows ridge portion 2 (hereinafter generally referred to on "bellows ridge"
or just "ridge" for the convenience of description) having a convex upper wall 21
and a substantially convex lower wall 22. The degrees of the convexities will be determined
depending upon factors much as use, material, size, etc., of the container 1. Here
and with all the other embodiments to be described hereunder, pressure (suction) is
vertically applied substantially on the longitudinal axis 11.
[0038] Each bellows ridge 2 in this embodiment is provided with a circular indentation 3
on its lower wall 22 adjacent the outer hinge 23. The highest portion of the indentation
3 will not generally go above the imaginative horizontal plane including the outer
hinge 23. The overall configuration of the indentation 3 including vertical depth
(d) and horizontal width (w) will be designed subject to the shape, size, material,
etc., of the bellows ridge 2 as well as the contractional feature desired of the bellows
ridge 2.
[0039] Generally, the wider (w) and the deeper (d) in indentation, the more easily a bellows
will having the indentation will be depressed into the bellows ridge.
[0040] The local angles of an indentation will affect the work of the indentation as well.
In abort, the feature of in indentstion will greatly depend upon the overall design
of the indentation.
[0041] Such an indentation way be configured with a combination of (a) curves, (b) curves
and lines, or (c) a combination of lines. Throughout the embodiments, only representative
configurations are provided for the purpose of describing the present invention.
[0042] As a person skilled in the art will know, such an indentation in a bellows will of
a bellows ridge will be made thinner by blow molding than the corresponding portion
of the other wall of the bellows ridge, since the length of a stretched indentation
is larger than the corresponding portion of the other wall. Therefore, such on indentation
is always considerably more flexible than that corresponding portion, which will advantageously
assist the work of an indentation.
[0043] When the bellows container 1 is pressed vertically, the pressure first acts upon
the inner hinges 24 of the bellows ridges 2 in opposite directions, respectively.
Then the pressures working on the inner hinges 24 are partially converted into the
"rotary moments" to work on the upper walls 21 and lower walls 22 of the bellows ridges
2, the outer hinges 23 working as circular rotary fulcrums, respectively.
[0044] The indentations 3 provided in the lower walls 22 absorb and utilize the rotary moments
prior to the corresponding portions of the upper walls 21 and are depressed further
into the bellows ridges 2, bringing together the other portions of the lower walls
22. The upper walls 21 will substantially retain their original convex configuration
(which provides considerable resistance against deformation, as will be understood
by a person skilled in the art) and will assist further depression of the indentations
3 without utilizing the rotary moments acting upon the upper walls 21 for themselves.
Thus, the pressure applied on the container 1 is effectively absorbed and utilized
at the indentations 3 and the bellows ridges 2 are easily deformed from the lower
walls 22, as shown in Fig. 1(a). Simply said, bellows ridges 2 having such indentations
3 will start closing with less pressure on the container 1 than bellows ridges having
no such indentations.
[0045] When the pressure is continuously applied on the container 1, the lower walls 22
start to eventually and substantially be reversed in shape as shown in Fig. 1(b).
The lower walls 22 are given upward momentums and will no longer go back to their
original convex shape. When the contents (not shown) in the bellows ridges 2 are all
pressed out, the lower walls 22 contact the corresponding upper walls 21. The bellows
ridges 2 are warped toward the lower walls 22 as shown in Fig. 1(c), and layered neatly.
[0046] It is advantageous that the length of the upper walls 21 and that of the lower walls
22 having the indentations 3 (when stretched) are substantially the same to avoid
generation of strain in the walls 21 and 22. Such is attainable by appropriately designing
the bellows ridges 2. This would advantageously apply to all the other embodiments
of the present invention.
[0047] Fig. 2 shows a bellows ridge 2 according to another embodiment of the present invention.
Generally, a plurality of such bellows ridges 2 are to be incorporated in a bellows
container. This applies to the other embodiments showing only a single bellows ridge.
This bellows ridge 2 has an indentation 3 in the lower wall 22 adjacent its inner
hinge 24. When a pressure is applied on the container (not shown) vertically, the
inner hinges 24 of the bellows ridge 2 receive the pressure (the upper wall 21 receiving
a downward pressure and the lower wall 22 receiving an upward pressure). The downward
pressure on the upper inner hinge 24 is converted into a rotary moment working on
the upper wall 21, and the upward pressure on the lower inner hinge 24 is converted
into a rotary moment working on the lower wall 22, both hinging on the outer hinge
23. These rotary moments are first partially consumed to deform the outermost portions
of the bellow ridge 2 substantially equally, as shown in Fig. 2(a). Then the rotary
moment of the lower wall 22 is partially utilized at the indentation 3 prior to the
corresponding portion of the upper wall 21, and the lower wall 22 starts entering
the bellows ridge 2 as shown in Fig. 2(b). Fig. 2(c) shows the state of the bellows
ridge 2 which is fully contracted.
[0048] Fig. 3 shows a bellows ridge 2 according to another embodiment of the present invention,
having two indentations 3 and 3' in the lower wall 22, one 3 adjacent the outer hinge
23, and the other 3' adjacent its inner hinge 24. Both the indentations 3 and 3' will
respectively function as explained earlier. The lower wall 22 will be depressed prior
to the upper wall 21 more easily than a case of only a single indentation due to the
dual function of two indentations.
[0049] The indentations 3 (and 3') described in the foregoing three embodiments may be provided
on their respective upper walls 21 instead (not shown here), in which cases the functions
of the indentations 3 take place on the upper walls 21, and the bellows ridges 2 will
warp upwards when closed.
[0050] Fig. 4 shows an arrangement of bellows ridges 2 according to an embodiment of the
present invention. Indentations 3 here are provided on the upper walls 21 adjacent
their outer hinges 23. The upper walls 21 will be depressed toward the lower walls
22 respectively. The contracted bellows 2 will warp upwards and will be layered neatly
as shown in Fig. 5.
[0051] Fig. 6 shows another arrangement of bellows ridges 2 according to another embodiment
of the present invention, which will be utilized to greater advantage in a hard plastic
container such as a PET bottle (not shown). The "sizes" of indentations 3 respectively
provided in the lower walls 22 of the bellows 2 adjacent their outer hinges 23 are
different. The uppermost indentation 3 is the largest in size and the lowermost indentation
3 is the smallest in size.
[0052] The term "size" here is defined as described earlier as meaning that a larger size
will provide the aforementioned function of an indentation better than a smaller size.
[0053] The indentation 3 and lower wall 22 of the uppermost bellow, ridge 2 will be first
depressed by utilizing the applied pressure prior to the others, and the indentation
3 and lower wall 22 of the lowermost bellows ridge 2 will be depressed last. All bellows
ridges 2 will warp downwards and will be layered neatly (not shown). Thus, it is possible
to selectively control the order of depression timing of bellows ridges by adjusting
the "size" of each indentation. When provided with this type of indentation arrangement,
a hard plastic bottle having such bellows will only require substantially less pressure
to contract as the pressure energy is utilized substantially ridge by ridge.
[0054] Fig. 7 shows another arrangement of bellows ridges 2 according to another embodiment
of the present invention, having indentations 3 on their lower walls 22 adjacent the
respective inner hinges 24. Here the lowermost indentation 3 has the largest size
and the uppermost indentation has the smallest size. The lower wall 22 of the lowermost
bellows ridge 2 will be depressed first and the lower wall 22 of the uppermost bellows
ridge 2 will be depressed last. All bellows ridges 2 will warp downwards and will
be layered neatly (not shown).
[0055] The indentations 3 of different sizes of the two embodiments above may be respectively
provided on the upper walls 21 instead (not shown), in which cases, the functions
of the indentations 3 will take place on the upper walls 21, and the bellows ridges
2 will warp upward to be layered neatly.
[0056] A hard plastic bellows bottle having such size controlled indentations on its bellows
will be very easily depressed. When a carbonated drink is contained in such a bottle,
the freshness of the drink can be kept a long time since the bottle can be depressed
ridge by ridge as the content decreases, and each contracted bellows ridge will be
held contracted. As will be understood by a person skilled in the art, the loss of
shape restoration of a single hollows ridge will take place quickly. Therefore, only
little air will be sucked into the bottle.
[0057] Fig. 8 shows a bellows ridge 2 according to an applied embodiment of the present
invention. In this embodiment, the upper wall 21 has an indentation 3' adjacent its
inner hinge 24, and the lower wall 22 has an indentation 3 adjacent the outer hinge
23. As shown from Fig. 8(a) to Fig. 8(c), the bellows ridge 2 will generally be depressed
from the lower wall 22 since the indentation 3 provided nearer the outer hinge 23
will utilize the aforedescribed rotary moment prior to the corresponding portion of
the upper wall 21 as well as prior to the indentation 3' provided adjacent the inner
hinge 24.
[0058] The indentation 3' in this case will work to assist and promote the whole depression
of the bellows ridge 2. However, if the "size" of the indentation 3' is substantially
larger than the indentation 3, then the upper wall 21 may be depressed instead of
the lower wall 22 (not shown).
[0059] Fig. 9 shows a bellows ridge 2 according to a special embodiment of the present invention.
In this embodiment, a sufficient indentation 3 is provided in the lower wall 22 adjacent
the outer hinge 23. The upper wall 21 is substantially plane. As will be understood
by a person skilled in the art, the upper wall 21 is made thicker conventionally than
when it is convex or concave, thus the upper wall 21 is considerably more rigid than
the lower wall 22.
[0060] The lower wall 22 will be depressed into the bellows ridge 2 additionally assisted
by the indentation 3. The upper wall 21 will eventually and slightly warp downwards.
The ridge configuration may be provided upside down, in which case the upper wall
21 will enter the bellows ridge 2 (not shown).
[0061] The lower wall 22 can be substantially plane so well except the portion of the indentation
3 (not shown), in which case, the lower wall 22 will still be depressed into the ridge
2 due to the function of the indentation 3. The lower wall 22 will assume a shape
of concavity, and lose it, shape restoration just like the embodiment shown in Fig.
9. Eventually, the upper wall 21 will warp downwards slightly.
[0062] The bellows ridges of a contractible plastic bellows container according to the present
invention may be selectively and optionally provided with indentations described above.
All bellows ridges need not have such indentations.
[0063] The bellows warping of a bellows container need not be only in a single direction.
For example, the bellows ridges of the upper half of a bellows container can be warped
upwards, and the bellows ridges of the lower half can be warped downwards. It is also
possible to randomly provide indentations adjacent the outer hinges and lower hinges
of the bellows ridges.
[0064] Utility of indentations according to the present invention can be largely the decision
of the manufactures of bellows containers in accordance with the teaching of the present
invention.
[0065] A bellows container according to the present invention may take various configurations
is seen vertically, e.g., a cylinder, truncated cone, etc.
[0066] Accordingly, the claims appended hereto are meant to cover all modifications and
changes within the spirit and scope of the present invention.
1. A contractible bellows container including a plurality of bellows ridges each comprising
in upper wall and lower wall, wherein one of each upper wall and lower wall of at
least some of said plurality of bellows ridges is provided with at least one circumferential
indentation.
2. The contractible bellows container according to claim 1, wherein said at least one
indentation is an indentation provided adjacent the outer hinge of each bellows ridge
or said at least some of said plurality of bellows ridges.
3. The contractible bellows container according to claim 1, wherein said at least one
indentation is an indentation provided adjacent the inner hinge of each bellows ridge
of said at least some of said plurality of bellows ridges.
4. The contractible bellows container according to claim 1, wherein said at least one
indentation is two indentations respectively provided adjacent the outer hinge and
inner hinge of each bellows ridge of said at least some of said plurality of bellows
ridges.
5. The contractible bellows container according to claim 1, wherein a bellows wall or
each bellows ridge of said at least some of said plurality of bellows ridges without
said at least one indentation is substantially plane.
6. The contractible bellows container according to claim 1, wherein a bellows wall of
each bellows ridge at said at least some of said plurality of bellows ridges without
said at least one indentation is substantially convex, and the other bellows wall
with said at least one indentation is substantially convex except the portion or said
at least one indentation.
7. The contractible bellows container according to claim 1, wherein said at least one
indentation is provided on the same side wall of each bellows ridge of said it least
some of said plurality of bellows ridges.
8. A contractible bellows container including a plurality of bellows ridges each comprising
an upper wall and lower wall, wherein a circumferential indentation is provided in
one of the upper wall and lower wall of each bellows ridge of at least some of said
plurality of bellows ridges adjacent the outer hinge, and another indentation is provided
in the other wall adjacent its inner hinge.
9. The contractible bellows container according to claim 8, wherein the upper wall and
lower wall of each bellows ridge of said at least some of said plurality of bellows
ridges with said indentations are substantially convex except the portions of said
indentations.
10. The contractible bellows container according to claim 8, wherein the provision of
said indentations in said at least some of said plurality of bellows ridges is in
the same arrangement.
11. The contractible bellows container according to claim 1 or 8, wherein the sizes of
said indentations are respectively and selectively adjusted.