U.S. patent application number 13/811487 was filed with the patent office on 2013-05-16 for check valve, manufacturing method thereof and container having check valve.
This patent application is currently assigned to KIKKOMAN CORPORATION. The applicant listed for this patent is Hitoshi Hagimoto, Takehisa Hashimoto, Denmi Kuwagaki, Taizo Minami, Michio Sugawa. Invention is credited to Hitoshi Hagimoto, Takehisa Hashimoto, Denmi Kuwagaki, Taizo Minami, Michio Sugawa.
Application Number | 20130119092 13/811487 |
Document ID | / |
Family ID | 45496976 |
Filed Date | 2013-05-16 |
United States Patent
Application |
20130119092 |
Kind Code |
A1 |
Kuwagaki; Denmi ; et
al. |
May 16, 2013 |
CHECK VALVE, MANUFACTURING METHOD THEREOF AND CONTAINER HAVING
CHECK VALVE
Abstract
In order to provide a check valve capable of sufficiently
suppressing the mixing of air into the container even if a certain
impact is applied to the container and also capable of stably
maintaining good pouring of the content, a check valve 10 of the
invention is formed of rubber material and manufactured by integral
molding. The check valve 10 has a tubular main body 1 having
openings 1a and 1b at opposite ends, a lid 3 arranged to close one
opening 1a of the main body 1, and a hinge 5 that connects the main
body 1 and the lid 3. The lid 3 has a projection 3a on the side
surface 3b, the projection 3a coming in contact with a peripheral
edge of the opening 1a of the main body 1.
Inventors: |
Kuwagaki; Denmi; (Noda-shi,
JP) ; Sugawa; Michio; (Ageo-shi, JP) ;
Hagimoto; Hitoshi; (Ageo-shi, JP) ; Minami;
Taizo; (Kitakatsuragi-gun, JP) ; Hashimoto;
Takehisa; (Kitakatsuragi-gun, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kuwagaki; Denmi
Sugawa; Michio
Hagimoto; Hitoshi
Minami; Taizo
Hashimoto; Takehisa |
Noda-shi
Ageo-shi
Ageo-shi
Kitakatsuragi-gun
Kitakatsuragi-gun |
|
JP
JP
JP
JP
JP |
|
|
Assignee: |
KIKKOMAN CORPORATION
Chiba
JP
MIKASA INDUSTRY CO., LTD.
Nara
JP
ASAHI KASEI PAX CORPORATION
Tokyo
JP
|
Family ID: |
45496976 |
Appl. No.: |
13/811487 |
Filed: |
July 22, 2011 |
PCT Filed: |
July 22, 2011 |
PCT NO: |
PCT/JP2011/066678 |
371 Date: |
January 22, 2013 |
Current U.S.
Class: |
222/494 ;
222/556; 264/154 |
Current CPC
Class: |
B65D 25/46 20130101;
B65D 47/2018 20130101; B65D 75/5883 20130101; B65D 47/08
20130101 |
Class at
Publication: |
222/494 ;
222/556; 264/154 |
International
Class: |
B65D 35/38 20060101
B65D035/38; B65D 47/08 20060101 B65D047/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 23, 2010 |
JP |
2010-165562 |
Claims
1. A check valve formed of rubber material and manufactured by
integral molding, comprising: a tubular main body having openings
at opposite ends; a lid arranged to close one opening of the main
body; and a hinge that connects the main body and the lid and is
adapted to open the one opening when force is applied to the lid
outwardly from the main body side, wherein the lid has a projection
on a side surface thereof, the projection coming in contact with a
peripheral edge of the one opening of the main body.
2. The check valve according to claim 1, wherein the one opening is
constituted by a linear portion which serves as the hinge and an
arc-shaped portion.
3. The check valve according to claim 2, wherein an outer diameter
R.sub.1 of an arc-shaped portion of the lid is greater than a
diameter R.sub.2 of the arc-shaped portion of the opening and
wherein the difference between R.sub.1 and R.sub.2 is from 0.06 mm
to 0.50 mm.
4. The check valve according to claim 3, wherein the side surface
of the lid and an inner surface of the main body form an angle of
15-25 degrees.
5. The check valve according to claim 4, wherein the rubber
material has a hardness of 30-80 degrees and an elongation of
200-900%.
6. A container comprising: a container main body formed of a film;
and a check valve according to claim 1, which is attached to the
container main body.
7. The container according to claim 6, further comprising a spout
in which the check valve is mounted.
8. The container according to claim 7, wherein a liquid outlet at a
tip of the spout is shaped to be narrowed in the middle and again
broadened.
9. The container according to claim 8, wherein at least part of the
main body of the check valve is formed to be thin enough to be able
to deform according to a difference from atmospheric pressure when
the check valve has a negative pressure inside and thereby allow
the check valve to have a reduced volume.
10. The container according to claim 9, wherein the main body of
the check valve has a stepped form composed of a small diameter
part and a large diameter part and the one opening is formed at the
small diameter part.
11. The container according to claim 10, wherein the small diameter
part is formed to be thinner than the large diameter part.
12. A method for manufacturing a check valve which comprises: a
tubular main body having openings at opposite ends; a lid arranged
to close one opening of the main body; and a hinge that connects
the main body and the lid and is adapted to open the one opening
when force is applied to the lid outwardly from the main body side,
the lid having a projection on a side surface thereof, the
projection coming in contact with a peripheral edge of the one
opening of the main body, the method comprising: a molding step of
obtaining a molded body of rubber material in a cavity having a
concave portion to form the projection, the rubber material having
a hardness of 30-80 degrees and an elongation of 200-900%; a
mold-releasing step of removing the molded body from the cavity;
and a cutting step of separating the main body and the lid from
each other except a portion serving as the hinge.
Description
TECHNICAL FIELD
[0001] The present invention relates to a check valve, a
manufacturing method thereof and a container having a check
valve.
BACKGROUND ART
[0002] Some foods and beverages gradually deteriorate with time and
one reason is oxidation due to contact with air. So-called vacuum
containers are known as containers for inhibiting such oxidation of
the content (see, for example, Patent Document 1).
[0003] In the container described in Patent Document 1, a check
valve for preventing air from entering the container is attached to
a pouring spout. The check valve has a structure having a slit
formed in its domed head and the slit is configured to be opened
when pressure is applied in the pouring direction of the content
whereas it is closed when pressure is applied in the filling
direction.
PRIOR ART REFERENCES
Patent Documents
[0004] Patent Document 1: JP10-338239 A
SUMMARY OF THE INVENTION
Problem to be Solved by the Invention
[0005] When manufacturing a container having a pouring spout with a
check valve incorporated in the spout, the size of the pouring
spout of the container is designed depending on the kind,
viscosity, etc., of the content and the size of the check valve to
be incorporated in the pouring spout is determined accordingly. For
example, when adopting a vacuum container for a tabletop soy sauce
container and providing a check valve in the pouring spout of the
container, the outer diameter of the check valve is limited to
around 10-15 mm. In order to mass-produce such small-size check
valves at low cost, integral molding using a mold is suitable.
[0006] The present inventors made various types of check valves and
containers having such valves as trial products by way of integral
molding and evaluated the trial products with regard to the
occurrence of air mixing into the container and the pouring of the
content. As a result, it was found that a lid 53 of a check valve
50 illustrated in FIGS. 8A and 8B got stuck in a tubular main body
51 when a certain impact was applied to the container and the lid
53 did not sufficiently serve as a valve (see Comparative Example
1). Note that a hinge 55 shown in FIGS. 8A and 8B is a portion
connecting the main body 51 and the lid 53.
[0007] The invention has been made in order to solve the
above-described problem and an object of the invention is to
provide a check valve and a container having the same, whereby the
mixing of air into the container can be sufficiently suppressed
even if a certain impact is applied to the container and good
pouring of the content can be stably maintained. Another object of
the invention is to provide a method for manufacturing a check
valve having the above advantageous effects in a manner
sufficiently efficient at low cost.
Means for Solving the Problem
[0008] The check valve according to the invention is formed of
rubber material and manufactured by integral molding. The check
valve comprises: a tubular main body having openings at opposite
ends; a lid arranged to close one opening of the main body; and a
hinge that connects the main body and the lid and is adapted to
open the one opening when force is applied to the lid outwardly
from the main body side, and the lid has a projection on a side
surface thereof, the projection coming in contact with a peripheral
edge of the one opening of the main body.
[0009] The above check valve has the projection formed on the side
surface of the lid and when the one opening of the main body is
closed, the projection comes in contact with the peripheral edge of
the one opening of the main body. Since such projection is formed,
the lid does not easily get stuck in the opening of the main body
even if a certain impact is applied to the check valve and the lid
can stably serve as a valve.
[0010] Here, the projection formed on the side surface of the lid
will be a so-called undercut portion in the molding process. When a
molded body is manufactured through integral molding and if it
includes an undercut portion, it cannot properly be taken out from
the mold in the mold-releasing step because the undercut portion
gets caught in the mold and the molded body could be broken in some
cases. On the other hand, increasing the number of molds so as to
avoid undercut portions would cause another problem of raising
cost.
[0011] The check valve according to the invention can sufficiently
avoid such problem arising from undercut without the use of any
special mold. That is, since the check valve according to the
invention is formed of rubber material having a predetermined
hardness and elongation, the projection of the lid can properly be
taken out from the mold even if the projection is an undercut
portion. Accordingly, the manufacturing cost of the check valve can
sufficiently be reduced. Note that the hardness of silicone rubber
indicated herein is a value measured in accordance with JIS K6249
and the elongation indicated herein is a value measured in
accordance with JIS K7127.
[0012] In the check valve according to the invention, from the
viewpoint of simplifying the manufacturing process, it is
preferable that the one opening of the main body be constituted by
a linear portion which serves as the hinge and an arc-shaped
portion. The term "arc" used herein means part of a circle or part
of an ellipse.
[0013] In the check valve according to the invention, from the
viewpoint of further ensuring that the lid is prevented from
getting stuck in the through hole of the main body, it is
preferable that the outer diameter R.sub.1 of an arc-shaped portion
of the lid be greater than the diameter R.sub.2 of the arc-shaped
portion of the opening and that the difference between R.sub.1 and
R.sub.2 be from 0.06 mm to 0.50 mm. In the check valve according to
the invention, it is further preferable that the side surface of
the lid and the inner surface of the main body form an angle of
15-25 degrees. It is still further preferable that the rubber
material have a hardness of 30-80 degrees and an elongation of
200-900%, since such rubber material allows check valves with
sufficient mechanical strength to be obtained easily without
causing problems due to undercut during the manufacturing
process.
[0014] The container according to the invention comprises a
container main body formed of a film and the above-described check
valve attached to the container main body. Since the container has
the above-described check valve, the mixing of air into the
container can sufficiently be suppressed even if a certain impact
is applied to the container. Consequently, deterioration of the
content due to oxidation can sufficiently be suppressed. In
addition, since good pouring of the content can be stably
maintained by the effect of the above-described check valve, the
container can be used for a substantially long period of time
without any special handling by a user.
[0015] It is preferable that the container according to the
invention further comprise a spout in which the check valve is
mounted. In that case, it is also preferable that a liquid outlet
at the tip of the spout be shaped to be narrowed in the middle and
again broadened.
[0016] In the container according to the invention, it is further
preferable that at least part of the main body of the check valve
be formed to be thin enough to be able to deform according to a
difference from atmospheric pressure when the check valve has a
negative pressure inside and thereby allow the check valve to have
a reduced volume. When the above-described container is returned to
the upright position from the discharging position, the liquid
which is going back to the lower part of the container causes
negative pressure in the upper part of the container. When negative
pressure is created as such, the main body of the check valve
partly deforms to be dented according to the difference from
atmospheric pressure. Due to the deformation of the check valve,
negative pressure is created in the space between the check valve
and the tip of the liquid outlet in the spout and, as a result, the
liquid left at the tip of the liquid outlet is sucked back (returns
to the container) by a volume corresponding to the deformed volume
of the check valve. If the container is capped after such
suck-back, no liquid adheres to the surrounding portion of the
liquid outlet, resulting in the prevention of any dripping.
[0017] In the above-described container, it is preferable that the
main body of the check valve have a stepped form composed of a
small diameter part and a large diameter part and that the one
opening be formed at the small diameter part.
[0018] In the above-described container, it is further preferable
that the small diameter part be formed to be thinner than the large
diameter part.
[0019] The invention provides a method for manufacturing the
above-described check valve. That is, the invention provides a
method for manufacturing a check valve which comprises: a tubular
main body having openings at opposite ends; a lid arranged to close
one opening of the main body; and a hinge that connects the main
body and the lid and is adapted to open the one opening when force
is applied to the lid outwardly from the main body side, the lid
having a projection on a side surface thereof, the projection
coming in contact with a peripheral edge of the one opening of the
main body. The method comprises: a molding step of obtaining a
molded body of rubber material having a hardness of 30-80 degrees
and an elongation of 200-900% in a cavity having a concave portion
to form the projection; a mold-releasing step of removing the
molded body from the cavity; and a cutting step of separating the
main body and the lid from each other except a portion serving as
the hinge.
[0020] According to the above-described manufacturing method, since
the hardness and elongation of the rubber material are 30-80
degrees and 200-900%, respectively, the portion to be formed into
the projection of the lid can sufficiently be prevented from
getting caught in the concave portion of the cavity and the molded
body can smoothly be taken out of the mold. As a result, no special
mold is needed and this attains sufficiently reduced manufacturing
costs.
Effect of the Invention
[0021] By using the check valve according to the invention, the
mixing of air into the container can be sufficiently suppressed
even if a certain impact is applied to the container and good
pouring of the content can be stably maintained. Further, by
adopting the manufacturing method of a check valve according to the
invention, a check valve having the above advantageous effects can
be manufactured sufficiently efficiently at low cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a perspective view of a preferred embodiment of
the check valve according to the invention.
[0023] FIG. 2A is a top view and FIG. 2B is a cross-sectional view
of the check valve shown in FIG. 1.
[0024] FIG. 3 is a cross-sectional view of the check valve shown in
FIG. 1 when the lid thereof is opened.
[0025] FIG. 4 is a partial cross-sectional view of the check valve
shown in FIG. 1 in which the vicinity of the lid is enlarged.
[0026] FIG. 5 is a perspective view of a flexible vacuum container
comprising the check valve shown in FIG. 1.
[0027] FIG. 6A is a perspective view and FIG. 6B is a
cross-sectional view of an outer body having the check valve shown
in FIG. 1 incorporated therein.
[0028] FIG. 7 is a partial cross-sectional view illustrating
another embodiment of the check valve according to the
invention.
[0029] FIGS. 8A and 8B are cross-sectional views of a check valve
according to comparative example 1.
[0030] FIG. 9 is a cross-sectional view of another embodiment of
the invention including a check valve and an outer body (spout)
having the check valve mounted therein.
[0031] FIG. 10 is a cross-sectional view of a check valve.
[0032] FIG. 11 is a cross sectional view of a check valve when the
main body thereof is partly deformed.
[0033] FIG. 12 is a cross-sectional view of an outer body (spout)
in which the liquid outlet thereof is enlarged.
MODE FOR CARRYING OUT THE INVENTION
[0034] Hereinafter, preferred embodiments of the invention will be
described in detail with reference to the attached drawings. In the
descriptions below, the same or corresponding components are given
the same reference numerals and any repetitive description will be
omitted.
[0035] Check Valve
[0036] Referring to FIGS. 1-4, descriptions will be made regarding
a check valve to be incorporated into a soy sauce container for
household use, as an example. A check valve 10 according to the
present embodiment is made of elastomer, such as rubber material,
and manufactured, for example, by integral molding. As illustrated
in FIGS. 1, 2A and 2B, the check valve 10 has: a tubular main body
1 having openings 1a and 1b at opposite ends thereof; a lid 3
arranged to close the opening 1a at the tip of the main body 1; and
a hinge 5 that connects the main body 1 and the lid 3. As is seen
from FIG. 3, the hinge 5 functions as a hinge for the lid 3 and has
flexibility to allow the opening 1a of the main body 1 to be open
when force F is applied to the lid 3 outwardly from the main body 1
side.
[0037] The main body 1 has a through hole 1c longitudinally
extending therethrough and the openings 1a and 1b are the opposite
ends of the through hole 1c. From the viewpoints of the pouring of
soy sauce and usability, the through hole 1c preferably has an
inner diameter of about 5.0-7.0 mm. As shown in FIG. 1, the lower
part of the main body 1 has a thick wall and the upper part has a
thin wall. The outer diameters of the lower part (thick-wall
portion) and the upper part (thin-wall portion) of the main body 1
are preferably about 12.8 mm and about 7.7-10.0 mm,
respectively.
[0038] As shown in FIG. 1, the outer surface of the lower part of
the main body 1 is partly formed as a planar surface 1d and a
projection 1e is provided on the planar surface 1d. The projection
1e serves as a positioning mark used when fixing the check valve 10
to an outer body 32 (see FIGS. 6A and 6B).
[0039] The opening 1a at the tip of the main body 1 is constituted
by a linear portion L and an arc-shaped portion R, as shown in FIG.
1. The linear portion L of the opening 1a is formed by a raised
part if which is provided inside the through hole 1c of the main
body 1 in the vicinity of the opening 1a. The hinge 5 is formed by
making the linear portion L and a linear portion of the lid 3 as a
continuous portion. Configuring the portion other than the portion
constituting the hinge 5 in an arc shape can simplify the
manufacturing process and is thus advantageous. That is, after
integral molding, the lid 3 can be cut out of the main body 1
except the hinge 5 by a simple step of increasing the pressure
inside the main body 1.
[0040] The lid 3 is connected to the main body 1 via the hinge 5
and arranged to close the opening 1a of the main body 1. The lid 3
has a projection 3a on the side surface 3b thereof, the projection
3a coming in contact with the peripheral edge of the opening 1a of
the main body 1. With this projection 3a on the side surface 3b of
the lid 3, the lid 3 does not easily get stuck in the through hole
1c of the main body 1 even if a certain impact is applied to the
check valve 10 and the lid 3 can stably function as a valve. Here,
in the lid 3, if the side close to the hinge 5 is called a base end
and the opposite side is called a tip end, the projection 3a is
preferably provided at the tip end.
[0041] The projection 3a preferably has a height (length from the
side surface 3b of the lid 3 to the tip of the projection 3a) of
0.4-0.6 mm and more preferably 0.45-0.55 mm. When the height of the
projection 3a is less than 0.35 mm, the effect of preventing the
lid 3 from getting stuck in the through hole 1c cannot be
sufficiently obtained. On the other hand, when the height exceeds
1.0 mm, problems due to undercut easily occur in the manufacturing
process.
[0042] In order to further ensure that the lid 3 is prevented from
getting stuck in the through hole 1c of the main body 1, it is
preferable that the outer diameter R.sub.1 of an arc-shaped portion
of the lid 3 be greater than the diameter R.sub.2 of the arc-shaped
portion R of the opening 1a. The difference between R.sub.1 and
R.sub.2 is preferably 0.06-0.50 mm and more preferably 0.08-0.25
mm. By making the difference greater than 0.06 mm, the lid does not
easily get stuck in the through hole of the main body even if a
certain impact is applied to the container due to a fall, etc.,
and, consequently, pouring is not obstructed. By making the
difference less than 0.50 mm, the lid and the main body are not
likely to be in a quasi-adhesion state, and, consequently, pouring
is not obstructed. If the outer diameter of the lid is not uniform,
for example, if the side surface of the lid 3 is tapered as shown
in FIG. 2B, R.sub.1 is regarded as representing the maximum outer
diameter.
[0043] In order to form the hinge 5 and to efficiently cut out the
main body 1 and the lid 3 from each other in the manufacturing
process, the side surface 3b of the lid 3 is preferably tapered
such that the outer diameter decreases toward the main body 1 side
from the top. The angle formed by the side surface 3b of the lid 3
and the inner surface of the main body 1 (angle .alpha. in FIG. 4)
is preferably 15-25 degrees. When the angle is greater than 15
degrees, the lid does not easily get stuck in the through hole of
the main body and pouring is, consequently, not obstructed. When
the angle is smaller than 25 degrees, functioning as a check valve
can be further facilitated and the mixing of air does not easily
occur.
[0044] Further, providing asperities on one or both of the contact
portions of the main body 1 and the lid 3 of the check valve 10 is
preferable. Such asperities can reduce the surface tension,
resulting in preventing the main body 1 and the lid 3 from adhering
to each other due to the surface tension of the content liquid and
thereby allowing the valve to be easily opened. Examples of the way
to provide asperities include adding a filler to the rubber
material, more specifically, using a rubber material mixed with a
filler for one or both of the main body 1 and the lid 3 of the
check valve 10. Examples of such filler include pyrogenic silica
fine powder, titanium oxide powder, alumina powder, ground quartz,
ground cristobalite, diatomite powder, aluminosilicate powder,
magnesium oxide powder, aluminium hydroxide powder, iron oxide
powder, zinc oxide powder and heavy calcium carbonate powder. The
content of the filler in the rubber material is preferably 1-50% by
weight and more preferably 5-40% by weight. The average particle
diameter of the filler is preferably 0.1-50 .mu.m and more
preferably 5-40 .mu.m.
[0045] The check valve 10 is made of rubber material and
manufactured through integral molding. Specific examples of the
rubber material include silicone rubber and NBR. If the check valve
is used for a food container, it is preferable to use silicone
rubber for the rubber material.
[0046] The rubber material that constitutes the check valve 10 has
a hardness of 30-80 degrees, preferably 40-70 degrees, and more
preferably 50-60 degrees. The rubber material has an elongation of
200-900%, preferably 300-800%, and more preferably 400-700%. If the
rubber material has a hardness of less than 30 degrees or an
elongation of greater than 900%, the check valve 10 would not have
sufficient mechanical strength. On the other hand, if the rubber
material has a hardness of greater than 80 degrees or an elongation
of less than 200%, problems due to undercut would occur in the
manufacturing process.
[0047] Method for Manufacturing Check Valve
[0048] The method for manufacturing the check valve 10 includes (a)
molding step, (b) cutting step and (c) cutting step.
[0049] (a) Molding Step
[0050] The molding step is to obtain a molded body of a rubber
material having a hardness of 30-80 degrees and an elongation of
200-900% in a cavity having a concave portion to form the
projection 3a. When the raw material is cured within the cavity by
applying heat or pressure, the process conditions are set so that
the resulting molded body has a hardness and elongation within the
above range.
[0051] (b) Mold-Releasing Step
[0052] The mold-releasing step is to remove the molded body from
the cavity. The molded body is removed from the cavity, for
example, by pulling the male and female molds in opposite
directions along the longitudinal direction of the molded body. In
the present embodiment, the portion to be formed into the
projection 3a of the check valve 10 is an undercut portion;
however, since the rubber material that constitutes the molded body
has a hardness and elongation within the above-described range,
problems arising from the undercut portion can be sufficiently
suppressed.
[0053] (c) Cutting Step
[0054] The cutting step is to cut the main body 1 and the lid 3
from each other, except the portion serving as the hinge 5. Since
the opening 1a of the main body 1 is constituted by the linear
portion L and the arc-shaped portion R, when air is supplied into
the molded body to increase the pressure inside the molded body,
stress is concentrated to the arc-shaped portion R, which allows
only the arc-shaped portion R to be cut out.
[0055] Flexible Vacuum Container with Check Valve
[0056] Referring next to FIGS. 5, 6A and 6B, descriptions will be
made regarding a self-standing readily-transportable flexible
vacuum container 30 having an outer body 32 in which a check valve
10 is incorporated. The container 30 comprises a container main
body 31 formed of a transparent film having flexibility, an outer
body 32 disposed diagonally at a shoulder of the container main
body 31 and a check valve 10 incorporated in the outer body 32. The
check valve 10 is incorporated in an orientation such that the lid
3 is located at the tip of the outer body 32 and that the hinge 5
extends horizontally and the projection 3a is located below the
hinge 5 when the container 30 stands with its bottom down (the
state shown in FIG. 5).
[0057] Although the film constituting the container main body 31
may be a single layer film, a multilayer film is preferable. When
the film is formed of multiple layers, the film is constituted by,
for example, a base layer that serves as an outer layer when formed
into a bag-like shape, a sealant layer that serves as an inner
layer and an adhesive layer that bonds the base layer and the
sealant layer to each other.
[0058] The outer body 32 is composed of a cap attachment part 32a,
a check valve fixing part 32b provided below the cap attachment
part 32a and a joint 32c provided further below the check valve
fixing part 32b. Note that no cap is shown in FIG. 5. The outer
body 32 is attached to the container main body 31 by bonding the
outer surface of the joint 32c and the peripheral edge of the
container main body 31 so that the cap attachment part 32a and the
check valve fixing part 32b protrude out from the container main
body 31. The outer body 32 may be one prepared by injection
molding, etc. Examples of the material of the outer body 32 include
synthetic resin such as polyethylene and polypropylene. Welding
between the container main body 31 and the joint 32c may be carried
out by heat sealing, high-frequency sealing, hot air sealing,
microwave heating, ultrasonic sealing and the like.
[0059] When the container 30 containing soy sauce therein is
inclined, force is applied to the lid 3 of the check valve 10 in a
direction from the inside to the outside thereof and the lid 3 is
consequently opened outwardly, making the soy sauce pour out. When
the container 30 is returned to the original orientation, negative
pressure is created within the container 30 and force is applied to
the lid 3 in a direction from the outside to the inside thereof. As
a result, the opening 1a of the check valve 10 is closed,
preventing air from entering the container 30.
[0060] Since the container 30 has the check valve 10, the mixing of
air into the container 30 can sufficiently be suppressed even if a
certain impact is applied to the container 30. As a result,
deterioration of soy sauce due to oxidation can be sufficiently
suppressed. Further, good pouring of the content can stably be
maintained due to the effect of the check valve 10 and the
container 30 can thus be used for a considerably long period of
time without any special handling of a user.
[0061] A preferred embodiment of the invention has been described
in detail; however, the invention is not limited to the
above-described embodiment. For example, while the projection 3a is
formed on part of the side surface 3b of the lid 3 in the
above-described embodiment, a configuration shown in FIG. 7 is
possible in which the entire side surface 13b of a lid 13 is
tapered and the upper part thereof serves as a projection 13a. In
this configuration, the projection 13a is an undercut portion;
however, similarly to the above-described embodiment, problems due
to the undercut portion can be sufficiently prevented by using a
rubber material having a hardness and an elongation within the
above-described range.
[0062] Further, the shape of the main body of the check valve is
not limited to a cylindrical shape and the main body may have a
tubular shape with an ellipse, rectangular or polygonal
cross-section. Still further, the cross-section of the flow path of
the through hole 1c and the shape of the lid are not limited to an
approximately circular shape and may be ellipse, rectangular or
polygonal.
[0063] Furthermore, descriptions have been made in the
above-described embodiment concerning a check value to be used for
a soy sauce container, but the application of the check value and
container according to the invention is not limited to such soy
sauce containers. Containers provided with the check valve of the
invention may be filled with other liquids, such as soft drinks,
alcohol beverages, salad oil or liquid detergent.
[0064] Suck-Back Mechanism
[0065] As another embodiment of the invention, a container 30
having a suck-back mechanism will be described below (see FIGS.
9-12).
[0066] In the container 30 according to this embodiment, a liquid
outlet 32d formed at the tip of an outer body (hereinafter also
referred to as a spout) 32 has a shape good for preventing liquid,
such as soy sauce, from dripping when it is stopped pouring. For
example, the liquid outlet 32d is shaped to be narrowed in the
middle and again broadened (see FIG. 9). However, when the
container 30 is inclined to pour out a required amount of soy sauce
and then returned to the upright position, some soy sauce remains
at the liquid outlet 32 and such soy sauce could consequently cause
dripping or contamination. In view of the above point, the
container 30 according to the present embodiment is equipped with a
suck-back mechanism.
[0067] Specifically, in the container 30, at least part of the main
body 1 of the check valve 10 is formed to be thin enough to be able
to deform according to the difference from atmospheric pressure
when a negative pressure is created inside the check valve 10 and
thereby allow the check valve 10 to have a reduced volume (see FIG.
10, etc.). Here, which portion is formed to be thin is not
particularly limited; however, the check valve 10 used in the
present embodiment is configured such that the main body 1 has a
stepped form composed of a small diameter part 11 and a large
diameter part 12 and the small diameter part 11 is formed of a
thinner wall than that of the large diameter part 12 so as to have
flexibility (see FIG. 11, etc.).
[0068] The operation of the suck-back mechanism in the
above-described container 30 is as follows. First, when the
container 30 is returned from the inclined discharging position to
the upright (upstanding) position, the discharging of the soy sauce
stops. Further, when the container is returned to the upright
position, the lid 3 of the check valve 10 is by itself closed due
to the elasticity of elastomer and the space from the lid 3 of the
check valve 10 to the liquid outlet 32d (represented by A in FIG.
9) and the space from the lid 3 of the check valve 10 toward the
interior of the container 30 (represented by B in FIG. 9) are
separated from each other within the spout 32. Here, if a cap (not
shown in the drawings) is attached to the cap attachment part 32a
of the spout 32 with some soy sauce left at the tip of the liquid
outlet 32d (see FIG. 12), the left soy sauce will adhere to the
surrounding portion of the liquid outlet 32d, which would cause
dripping.
[0069] In this respect, when the container 30 of the present
embodiment is returned from the discharging position to the upright
position, the soy sauce which is going back to the lower part of
the container creates negative pressure in the upper part of the
container 30 (represented by P in FIG. 1). When negative pressure
is created as such, the main body 1 of the check valve 10 partly
(in the present embodiment, the wall of the small diameter part 11)
deforms to be dented according to the difference from atmospheric
pressure (see FIG. 11). Due to the partial deformation of the check
valve 10, negative pressure is created in space A of the spout 32
(the space between the lid 3 of the check valve 10 and the liquid
outlet 32d) and, as a result, the soy sauce left at the tip of the
liquid outlet 32d can be sucked back by a volume corresponding to
the deformed volume of the check valve 10 (see FIG. 12). If a cap
is attached after such suck-back, no soy sauce adheres to the
surrounding portion of the liquid outlet 32d, resulting in the
prevention of any dripping. Note that the time taken for a user to
attach a cap after the user has returned the container 30 from the
discharging position to the upright position is expected to be 1-2
seconds if all goes smoothly, but this is enough time to suck back
the soy sauce left at the liquid outlet 32d in the container 30
according to the present embodiment.
EXAMPLES
[0070] The invention will be more specifically described below
based on examples and comparative examples; however, the invention
is not limited to the examples below.
[0071] Preparation of Molded Bodies of Examples 1-3
[0072] In order to prepare check valves having the configuration
illustrated in FIG. 1 and having the dimensions shown in the
respective columns of Examples 1-3 in Table 1, molded bodies were
prepared in the following manner. That is, silicone rubber material
was charged into a cavity constituted by two molds and subsequently
cured within the cavity at 175.degree. C. for six minutes, thereby
obtaining a molded body. When the obtained molded body was removed
out and its projection was observed under a microscope, no breakage
was found. In each of Examples 1-3, the silicone rubber
constituting the molded body had a hardness of 55 degrees and an
elongation of 380%.
[0073] Preparation of Molded Bodies of Examples 4 and 5
[0074] In order to prepare check valves having the configuration
illustrated in FIG. 1 and having the dimensions shown in the
respective columns of Examples 4 and 5 in Table 2, molded bodies
were prepared in the following manner. That is, silicone rubber
material was charged into a cavity constituted by nine molds and
subsequently cured within the cavity at 170.degree. C. for 135
seconds, thereby obtaining a molded body. When the obtained molded
body was removed out and its projection was observed under a
microscope, no breakage was found. In each of Examples 4 and 5, the
silicone rubber constituting the molded body had a hardness of 60
degrees and an elongation of 350%.
[0075] Preparation of Molded Body of Comparative Example 1
[0076] In order to prepare a check valve having the configuration
illustrated in FIGS. 8A and 8B and having the dimensions shown in
the column of Comparative Example 1 in Table 2, silicone rubber
material was charged into a cavity constituted by one mold and the
charged material was cured in the same manner as in Examples 1-3.
As a result, a molded body having no projection in the lid was
prepared. The silicone rubber constituting the molded body of
Comparative Example 1 had a hardness of 55 degrees and an
elongation of 380%.
[0077] Preparation of Check Valves of Examples 1-5 and Comparative
Example 1
[0078] Check valves of Examples 1-5 and Comparative Example 1 were
prepared by increasing the pressure inside the obtained molded
bodies to cut out the portion other than the linear portion serving
as a hinge in an arc-like form. In each of the check valves of
Examples 1-5 and Comparative Example 1, the angle .alpha. between
the side surface of the lid and the inner surface of the main body
was set to 20 degrees.
[0079] Preparation of Flexible Vacuum Containers
[0080] Containers having the configuration illustrated in FIG. 7
were prepared by mounting the check valves of Examples 1-5 and
Comparative Example 1 each into an outer body and welding the outer
body and the container main body to each other. A multilayer film
of PET/ON/L-LDPE was used for a flexible film that constitutes the
container main body.
[0081] Evaluation Test
[0082] The containers according to Examples 1-5 and Comparative
Example 1 were each filled with 500 ml of soy sauce to prepare test
samples and each sample was subjected to the following drop test.
After dropping each sample freely from the respective heights shown
in Tables 1 and 2, the occurrence of the mixing of air into the
container (air mixing) and the pouring of the soy sauce were
evaluated. The occurrence of the mixing of air was determined
visually and whether the pouring of the soy sauce was good or not
was determined according to whether the soy sauce came out smoothly
when the container was 45 degrees inclined. The results are shown
in Tables 1 and 2.
TABLE-US-00001 TABLE 1 Item Unit Example 1 Example 2 Example 3
Check Outer Diameter of mm 6.41 4.42 4.49 Valve Lid (R.sub.1)
Dimensions Inner Diameter of 6.30 4.31 4.30 Main Body (R.sub.2)
Difference (R.sub.1 - R.sub.2) 0.11 0.11 0.19 Height of Drop Unit
Air Mixing Pouring Air Mixing Pouring Air Mixing Pouring Drop Test
10 cm No Good No Good No Good 20 No Good No Good No Good 40 No Good
No Good No Good 60 No Good No Good No Good 80 No Good No Good No
Good 100 No Good No Good No Good 120 No Good No Good No Good 140 No
Good Yes Not Good No Good 160 Yes Not Good No Good 180 No Good 200
Yes Not Good Note Tow-Mold Type
TABLE-US-00002 TABLE 2 Item Unit Example 4 Example 5 Comparative
Example 1 Check Outer Diameter of mm 6.35 6.37 6.30 Valve Lid (R1)
Dimensions Inner Diameter of 6.29 6.29 6.30 Main Body (R2)
Difference (R1 - R2) 0.06 0.08 0.00 Height of Drop Unit Air Mixing
Pouring Air Mixing Pouring Air Mixing Pouring Drop Test 10 cm No
Good No Good Yes Not Good 20 Yes Not Good No Good 40 Yes Not Good
60 80 100 120 140 160 180 200 Note Nine-Mold Type One-Mold Type
[0083] Next, several containers according to Example 1 were
prepared and each filled with 500 ml of soy sauce to prepare test
samples. The following test was performed for each sample to
evaluate the performance of the check valve in more detail.
[0084] Static Standing Test
[0085] The containers containing soy sauce therein were kept at
room temperature and the occurrence of the mixing of air into the
container and the pouring of the soy sauce were observed after the
elapse of 12, 24, 36, 48 and 120 hours, respectively. Five samples
were tested under the respective conditions. The results are shown
in Table 3.
TABLE-US-00003 TABLE 3 Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
Conditions Air Air Air Air Air Item Time h Mixing Pouring Mixing
Pouring Mixing Pouring Mixing Pouring Mixing Pouring Sealing Test
12 No Good No Good No Good No Good No Good 24 No Good No Good No
Good No Good No Good 36 No Good No Good No Good No Good No Good 48
No Good No Good No Good No Good No Good 120 No Not No Not No Not No
Not No Not Good Good Good Good Good
[0086] After the elapse of 12, 24, 36 and 48 hours, respectively,
air mixing did not occur in any samples and the pouring was good.
After the elapse of 120 hours (5 days), although air mixing was not
observed, some soy sauce hardened at a contact portion (seal
portion) between the lid and the peripheral edge of the opening of
the main body and the soy sauce did not come out by itself even if
the container was inclined.
[0087] Drop Test I
[0088] The containers containing soy sauce therein were dropped
under the respective conditions of (i) and (ii) below. By changing
the height from which the container was dropped, the occurrence of
the mixing of air into the container and the pouring of the soy
sauce were observed after each drop. The evaluation criteria for
the occurrence of air mixing and the pouring of the soy sauce were
as described above. Five samples were tested under the respective
conditions.
[0089] (i) No cap was attached to the cap attachment part of the
outer body and the container was freely dropped once with the
bottom of the container main body down. The results are shown in
Table 4.
[0090] (ii) A cap was attached to the cap attachment part of the
outer body and the container was dropped freely once with the
bottom of the container main body down. After that, the container
was freely dropped once with the side surface of the container main
body down. The results are shown in Table 5.
TABLE-US-00004 TABLE 4 Conditions Sample 1 Sample 2 Sample 3 Sample
4 Sample 5 Height of Drop Air Air Air Air Air Item cm Mixing
Pouring Mixing Pouring Mixing Pouring Mixing Pouring Mixing Pouring
Drop Test 80 No Good No Good No Good No Good No Good 120 No Good No
Good No Good No Good No Good 140 No Good No Good No Good No Good No
Good 160 Yes Not Good Yes Not Good Yes Not Good Yes Not Good Yes
Not Good
TABLE-US-00005 TABLE 5 Conditions Sample 1 Sample 2 Sample 3 Sample
4 Sample 5 Height of Drop Air Air Air Air Air Item cm Mixing
Pouring Mixing Pouring Mixing Pouring Mixing Pouring Mixing Pouring
Drop Test 80 No Good No Good No Good No Good No Good 120 No Good No
Good No Good No Good No Good 140 No Good No Good No Good No Good No
Good 160 Yes Not Good Yes Not Good Yes Not Good Yes Not Good Yes
Not Good
[0091] Regardless of whether a cap was attached or not, air mixing
did not occur in any samples until the height of drop reached 140
cm. In addition, the pouring was good. Meanwhile, when the height
of drop was 160 cm, the lid of the check valve got stuck and air
mixing occurred. In addition, due to the stuck lid of the check
valve, the soy sauce did not come out by itself even if the
container was inclined. Note that no leakage of the content was
observed in any test with a height of drop up to 160 cm.
[0092] Drop Test II
[0093] Using the container with no cap attached to the cap
attachment part of the outer body, the container was freely dropped
five times or ten times from a fixed height of drop of 120 cm, with
the bottom of the container main body down. The results are shown
in Table 6. Two samples were tested under the respective
conditions.
TABLE-US-00006 TABLE 6 Sample 1 Sample 2 Air Air Item Conditions
Mixing Pouring Mixing Pouring Drop Test Consecutive 5 No Good No
Good drops of 120 cm Consecutive 10 Yes Not Good Yes Not Good drops
of 120 cm
[0094] After the consecutive five drops, air mixing did not occur
in any samples. In addition, the pouring was good. On the other
hand, after the consecutive ten drops, the lid of the check valve
got stuck and air mixing occurred. In addition, due to the stuck
lid of the check valve, the soy sauce did not come out by itself
even if the container was inclined.
DESCRIPTION OF REFERENCE NUMERALS
[0095] 1 . . . Main body; 1a, 1b . . . Opening; 3, 13 . . . Lid;
3a, 13a . . . Projection; 3b, 13b . . . Side surface; 5 . . .
Hinge; 10 . . . Check valve; 11 . . . Small diameter part; 12 . . .
Large diameter part; 30 . . . Flexible vacuum container
(container); 31 . . . Container main body; 32 . . . Outer body
(spout); 32b . . . Liquid outlet; F . . . Force; L . . . Linear
portion; P . . . Negative pressure; and R Arc-shaped portion.
* * * * *