Title of Invention

SYNTHETIC RESIN CAP, CLOSING DEVICE, AND CONTAINER-PACKED BEVERAGE

Abstract A synthetip resin cap, a closing device, and a container-packed beverage. The synthetic resin cap comprises a cap body (4) having a top plate part (2) and a tube part (3) extending downward from the peripheral edge part (2b) thereof and an inside seal projection (12) fitted to the inside of a container mouth part (21). A connection part (15) is formed between the top plate part (2) and the inner seal projection (12), and an outside thin-walled part (16) is formed at the top plate part (2). When a container inside pressure rises, the top plate part (2) is deformably swelled upward, and an inward tension is applied to the inside seal projection (12) by the connection part (15). Since the outside thin-walled part (16) is deformably bent, the portion of the cap positioned on the inner side of the outer thin-walled part is deformably swelled largely upward, and the inclination of the top plate part (2) is increased at the formed part of the inside seal projection (12). Thus, the inside seal projection (12) is displaced inward, and gas in the container can be easily discharged to the outside.
Full Text DESCRIPTION
SYNTHETIC RESIN CAP, CLOSING DEVICE, AND CONTAINER-PACKED
BEVERAGE
TECHNICAL FIELD
The present invention relates to a synthetic resin cap that closes a container
] louth portion, a closing device using the cap, and a container-packed beverage.
Priority is claimed on Japanese Patent Application No. 2003-328992, the content
( f which is incorporated herein by reference.
BACKGROUND ART
Conventionally, many conventional synthetic resin caps have been used provided
a top plate portion and a cylinder portion hanging from the circumferential edge thereof,
V ith an annulai- inside seal projection to be fitted into the container mouth portion
p otrudingly formed on the inner surface of the top plate portion (refer for example to
Ji panese Uneximiined Patent Application No. 2002-211605).
FIG. 6A and FIG. 6B show an example of a synthetic resin cap having an inside
s c; Under portion 3 hanging from a circumferential edge portion 2b thereof
The horizontal score 6 demarcates the cylinder portion 3 into a main portion 8
ar d a tamper evidence ring portion (TE ring portion) 9 connected to the main portion 8
b; bridges 7.
On the inner surface of the main portion 8, a thread portion 10 is formed for
th eaded engagement with a male screw 22 formed on an outer surface 21c of a container
m )uth portion 21.

On the inner surface of the TE ring portion 9 are provided tabs 11 that block
movement of the TE ring portion 9 by locking to the container mouth portion when
opening the cap 1.
On the inner surface 2a of the top plate portion 2 is formed an annular inside seal
projection 12 to be fitted into the container mouth portion 21. On the outer surface of
he tip portion of the inside seal projection 12 is formed an annular abutting convex
)ortion 12a to abut the container inner surface 21a.
On the top plate portion 2 are formed an opening end seal projection 13 to abut an
( pening end face 21b of a container mouth portion 21 and an outside seal projection 14
t) abut the outer surface 21c of the container mouth portion 21.
DISCLOSURE OF THE INVENTION
When the cap is opened and then closed again (hereafter, recapped), the internal
p essure of the container increases due to fermentation of the content liquid and the like,
ii which case there has been the problem of the cap readily coming off the container.
For this reason, technology has been desired that can discharge gas in the
ci ntainer to the outside to lower the internal pressure of the container when the internal
p; sssure of the container has risen after recapping.
The present invention was achieved in view of these circumstances, and has as its
ol ject providing a synthetic resin cap that can prevent an excessive increase in the
in emal pressure of a container when the cap is opened and then closed again, a closing
d'; vice and a container-packed beverage.
The synthetic resin cap of the present invention is characterized by including a
ca) body having a top plate portion and a cylinder portion hanging from a
cii cumferential edge portion thereof, an annular inside seal projection to be fitted into a

( ontainer mouth portion being formed on an inner surface of the top plate portion, a
(onnector portion that connects the top plate portion and the inside seal projection being
] 3rmed between the inner surface of the top plate portion and an inner surface of the
i iside seal projection, and an outside thin wall portion formed thinner than the
(ircumferential edge portion being formed on the top plate portion at any position
1 etween a portion where the inside seal projection is formed and the circumferential edge
I ortion.
In the synthetic resin cap of the present invention, a cross-sectional radius of
( urvature at an innier surface side of a junction portion of the top plate portion and the
( ylinder portion is preferably not less than 0.6 mm.
In the synthetic cap of the present invention, the top plate portion at the portion
] ortion where the connector portion is formed and an inside thin wall portion that is
1 ormed to the inside of the outer circumferential side portion, with the inside thin wall
I ortion preferably being formed thinner than the outer circimiferential side portion.
A thickness of the outer circumferential side portion is preferably 0.5 mm to 3
) im.
A width of the outer circumferential side portion is preferably 0.5 mm to 10 mm.
In the synthetic resin cap of the present invention, when attached to the container
1 louth portion, it is preferable that a distance between an inner surface of the cylinder
] ortion and a tip of a male screw formed on an outer surface of the container mouth
] ortion be not more than 1 mm.
In the synthetic resin cap of the present invention, when attached to the container
] louth portion it is preferable that a distance between a tip of a thread portion formed in
' he cylinder portion and the outer surface of the container mouth portion be not more
than 1 mm.
In the synthetic resin cap of the present invention, it is preferable that an opening
end seal projection to abut an opening end face of the container mouth portion be formed
on the top plate portion.
In the synthetic resin cap of the present invention, it is preferable that the inside
seal projection be made to abut the inner surface of the container mouth portion at a
maximum outer diameter portion and that the height position of the maximum outer
diameter portion be set so that the difference in height of the maximum outer diameter
portion and the bottom end of the opening end seal projection is 1 mm to 4 mm.
In the synthetic resin cap of the present invention, it is preferable that an outside
seal projection to abut the outer surface of the container mouth portion be formed on the
top plate portion and that the outside seal projection be formed so that the difference in
height of the bottom end of this projection and the bottom end of the opening end seal
projection is not more than 3 mm.
It is preferable that the flexural modulus of the top plate portion be 500 to 2,000
MPa.
It is preferable that the density of the material constituting the synthetic resin cap
be 0.85 to 0.97 g/cml
The closing device of the present invention is characterized by including a
container and a synthetic resin cap attached to a mouth portion thereof, the synthetic
resin cap including a cap body having a top plate portion and a cylinder portion hanging
from a circumferential edge portion thereof, an annular inside seal projection to be fitted
into the container mouth portion being formed on an inner surface of the top plate portion,
a connector portion that connects the top plate portion and the inside seal projection
being formed between the inner surface of the top plate portion and the inner surface of

(le inside seal projection, and an outside thin wall portion thinner than the
(irciunferential edge portion being formed at any position between the portion where the
i aside seal projection is formed and the circumferential edge portion.
The container-packed beverage of the present invention is a container packed
leverage in which a beverage is filled in a closing device including a container and a
ynthetic resin cap attached to the mouth portion thereof, characterized by the synthetic
esin cap including a cap body having a top plate portion and a cylinder portion hanging
lom the circumferential edge portion thereof, an annular inside seal projection to be
Itted into the container mouth portion being formed on the inner surface of the top plate
Dortion, a connector portion that connects the top plate portion and the inside seal
projection being formed between the irmer surface of the top plate portion and the inner
surface of the inside seal projection, and an outside thin wall portion thinner than the
Dircumferential edge portion being formed on the top plate portion at any position
between the portion where the inside seal projection is formed and the circumferential
edge portion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross sectional view showing one embodiment of a closing
device of the present invention.
FIG. 2 is a main part enlarged view showing a synthetic resin cap of the closing
device shown in FIG. 1.
FIG. 3 is a cross sectional view showing the state of the synthetic resin cap shown
in FIG. 1 attached to a container mouth portion.
FIG. 4 is a transverse cross sectional view showing the synthetic resin cap shown
in FIG. 1.
6
FIG. 5 is an enlarged view showing a main part of the synthetic resin cap shown
in FIG. 1.
FIG. 6A is an overall view showing an example of a conventional synthetic resin
cap.
FIG. 6B is an enlarged view showing a main part of the state of the synthetic resin
cap shown in FIG. 6A attached to a container mouth portion.
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an embodiment of a closing device of the present invention. FIGS.
2 to 4 show a synthetic resin cap used in the closing device.
The closing device shown in FIG. 1 is constituted from a container 20 and a
synthetic resin cap 1 attached to a mouth portion 21 thereof. In the explanation below,
inward and outward mean inward and outwfird in the radial direction of the cap 1.
The container 20 may be used made of a synthetic resin such as polyethylene
terephthalate (PET), glass, metal or the like.
The cap 1 has a cap body 4 having a top plate portion 2 and a cylinder portion 3
langing from a circumferential edge portion 2b thereof
The cylinder portion 3 is demarcated by a horizontal score 6 (weakening line)
nto a main portion 8 from the horizontal score 6 upward and a tamper evidence ring
)ortion (TE ring portion) 9 therebelow that is coupled to a bottom end of the main
lortion 8 by a plurality of fine bridges 7.
A thread portion 10 is formed on an inner surface of the main portion 8 for
t ireaded engagement with a male screw 22 formed on an outer surface 21c of the
c ontainer mouth portion 21.
Tabs 11 that are locking means to prevent movement of the TE ring portion 9 by

locking with a bulging step portion 23 on the container mouth portion 21 when opening
the cap 1 are provided on an inner wall surface of the TE ring portion 9. The tabs 11 are
formed in a plate shape that may rise and fall.
As shown in FIG. 2 and FIG. 3, an annular inside seal projection 12 that is fitted
into the container mouth portion 21 is protrudingly formed facing downward on an inner
surface 2a of the top plate portion 2.
An annular abutting convex portion 12a that abuts a container inner surface 21 a is
formed on an outer surface of a tip of the inside seal projection 12.
The inside seal projection 12 is formed so that when fit in the container mouth
portion 21a maximum outer diameter portion 12d of the abutting convex portion 12a
abuts the container inner surface 21a without clearances to be able to tightly seal the
container mouth portion 21.
The outer diameter of the maximum outer diameter portion 12d is preferably set
o be slightly greater than the inner diameter of the container mouth portion 21.
An opening end seal projection 13 that abuts an opening end face 21b of the
lontainer mouth portion 21 and an outside seal projection 14 that abuts the outer surface
: :lc of the container mouth portion 21 are formed on the top plate portion 2 outward of
1 he inside seal projection 12.
A connector portion 15 that couples the top plate portion 2 and the inside seal
I rojection 12 is foirmed between the inner surface 2a of the top plate portion 2 and the
i mer surface 12b of the inside seal projection 12.
The connector portion 15 firmly fixes the inside seal projection 12 to the top plate
j: ortion 2 and maintains a constant angle of the inside seal projection 12 with respect to
t] e top plate portion 2.
In the exan:iple illustrated, the connector portion 15 is a substantially triangular

plate nearly perpendicular to the top plate portion 2 formed in the radial direction. A
top edge portion 15a of the connector portion 15 is integrally fixed to the top plate
portion inner surface 2a, and a side edge portion 15b is integrally fixed to the inner
surface 12b of the inside seal projection. An inner edge portion 15c of the connector
portion 15 preferably has a shape descending gradually as outwardly.
It is preferable for the connector portion 15 to be integrally formed with the top
plate portion 2 and the inside seal projection 12.
As shown in FIG. 2, it is preferable for a height A of the connector portion 15 to
be 0.5 mm to 5 mm (preferably 1 mm to 4 mm).
When the height A is less than the aforementioned range, discharge of the gas in
the container 20 is hindered when the internal pressure rises. When the height A
exceeds the aforementioned range, deformation of the inside seal projection 12 is
hindered when fitted into the container mouth portion 21, thereby losing the ease of the
closing operation. In addition, the mold releasability at forming worsens.
It is preferable for a width B in the radial direction of the connector portion 15 to
be 0.1 to 3 mm (i)referably 0.3 mm to 1 mm).
When the width B is less than the aforementioned range, discharge of the gas in
the container 20 is hindered when the internal pressure rises. When the width B
exceeds the aforementioned range, deformation of the inside seal projection 12 is
hindered when fitted into the container mouth portion 21, thereby losing the ease of the
closing operation. In addition, the mold releasability at forming worsens.
The connector portion is not limited to the illustrated shape, and may be made
into an optional shape such as a square plate shape, fan plate shape, rectangular shape,
and pyramid shape.
As shown in FIG. 4, it is preferable for the connector portion 15 to be formed not

ilong the entire circumference of the top plate portion 2 and the inside seal projection 12,
5ut only in partly portions in the circumferential direction.
In the illustrated example, the connector portions 15 are provided in four places
spaced out in the circumferential direction. The connector portions 15 are provided so
that the distances between the two mutually adjacent connector portions 15 are roughly
equivalent.
It is preferable for the number of the connector portions 15 to be formed to be 1
to 6 (preferably 1 to 4).
Having the number of connector portions 15 in this range causes the
aforementioned tensile force to act on the inside seal projection 12 biased in the
circumferential direction, thereby facilitating deformability of the inside seal projection
12 inward. Accordingly, when the internal pressure of the container rises, the gas in the
container 20 may be eaisily discharged to the outside.
When the formed number exceeds the aforementioned range, deformation of the
inside seal projection 12 is hindered when the internal pressure of the container rises,
thereby hindering the discharge of the gas in the container 20.
As shown in FIG. 2, an annular thin concave portion 16a is formed on the bottom
surface of the top plate portion 2 between the portion 12c where the inside seal projection
12 is formed and the portion 13a where the open end seal projection 13 is formed. The
portion of the top plate portion 2 where the thin concave portion 16a is formed is an
outside thin wall portion 16 formed thinner than the circumferential edge portion 2b.
The outside thin wall portion 16 is formed in an adjacent position outward of the
portion 12c where the inside seal projection 12 is formed.
The outside thin wall portion may be formed at any position between the portion
12c where tlie inside seal projection 12 is formed and the circumferential edge portion 2b,

with the forming position thereof not limited by the illustrated example. In addition, the
outside thin wall portion may be formed by a thin concave portion provided on the top
surface of the top plate portion.
The outside thin wall portion 16 is formed so that a thickness C thereof is less
than a thickness D of the circumferential edge portion 2b of the top plate portion 2.
When the thickness C of the outside thin wall portion 16 is equal to or greater
than the thickness D of the circumferential edge portion 2b, discharge of the gas in the
container 20 is hindered when the internal pressure of the container rises.
It is preferable for the thickness C of the outside thin wall portion 16 to be 0.3
mm to 2 mm (preferably 0.5 mm to 1.5 mm).
Having the thickness C in the aforementioned range facilitates bending
deformation of the outside thin wall portion 16, bulging deformation of the top plate
portion 2 at the portion corresponding to the inside of the inside seal projection 12, and
discharge of the gas in the container 20 when the internal pressure of the container rises.
When the thickness C is less than the aforementioned range, the strength of the
outside thin wall portion 16 becomes too low, and when it exceeds this range discharge
of the gas in the container 20 is hindered when the internal pressure of the container
rises.
It is preferable for the thickness C of the outside thin wall portion 16 to be set to a
value corresponding to 0.3 to 0.9 times the thickness D of the circvmiferential edge
portion 2b. Wben the thickness C is less than this range, the strength of the outside thin
wall portion 16 becomes too low, and when it exceeds this range, discharge of the gas in
the container 20 is hindered when the internal pressure of the container rises.
It is desirable for the thickness D of the top plate portion 2 at the circumferential
edge portion 2b be 0.5 mm to 3 mm (preferably 0.8 mm to 2 nmx).

The top plate portion 2 at the portion corresponding to the inside of the inside
seal projection 12 has an outer circumferential portion 17 where the connector portion 15
is formed and an inner circumferential portion 18.
It is desirable for a thickness E of the outer circumferential portion 17 be 0.5 mm
to 3 mm (preferably 0.8 mm to 2 mm).
Having the thickness E in the aforementioned range may impart sufficient
strength to this portion. Consequently, the action that displaces the inside seal
projection 12 by the coimector portion 15 when the pressure in the container increases is
enhanced, which may facilitate discharge of the gas in the container 20.
When the thickness E is less than the aforementioned range, the strength of the
op plate portion 2 becomes too low, the action that displaces the inside seal projection 12
ly the connector portion 15 diminishes, and so the discharge of the gas in the container
; 0 is hindered when the internal pressure of the container rises. When the thickness E
( xceeds this range, bulging deformation of the top plate portion 2 is hindered, and so the
(ischarge of the gas in the container 20 is hindered when the internal pressure of the
c DUtainer rises.
It is preferable for a width F of the outer circumferential portion 17 to be 0.5 mm
1110 mm (preferably 2 mm to 7 mm).
Having the width F in the aforementioned range enhances the action that
d splaces the inside seal projection 12 by the connector portion 15, and may thereby
facilitate the disch^irge of the gas in the container 20 to the outside when the internal
p essure of the container rises.
When the wdth F is less than the aforementioned range, the action that displaces
fi e inside seal projection 12 due to the connector portion 15 diminishes, hindering
d scharge of the gas in the container 20 when the internal pressure of the container rises.

When the width F exceeds the aforementioned range, bulging deformation of the top
plate portion 2 is hindered, and so the discharge of the gas in the container 20 is hindered
when the internal presswe of the container rises.
A thinned concave portion 18a is formed on the iimer surface of the inner
circumferential portion 18. Thereby, the inner circumferential portion 18 becomes the
inside thin wall portion 18b formed thinner than the outer circumferential portion 17.
The thinned concave portion 18a is preferably circular.
It is desirable for a thickness G of the inside thin wall portion 18b to be 0.3 mm
:o 2 mm (preferably 0.5 mm to 1.5 mm).
Having the thickness G in the aforementioned range facilitates bulging
ieformation of the top plate portion 2, whereby displacement of the inside seal projection
12 occurs easily. Consequently, discharge of the gas in the container 20 is facilitated
Nhen the internal pressure of the container rises.
When the thickness G is less than the aforementioned range, the strength of the
nside thin wall portion 18b becomes too low, thereby degrading the durability of the cap
. When the thickness G exceeds this range, bulging deformation of the top plate
)ortion 2 is hindered, and so discharge of the gas is hindered when the internal pressure
' »f the container rises.
In the illustrated example, the entire inner circumferential portion 18 assumes the
j nside thin wall portion 18b formed thinner than the outer circumferential portion 17, but
J a the present invention, only a portion of the inner circumferential portion 18 may be
1 linned. To wit, the annular thiimed concave portion may be formed at only the portion
1 ear the circumferential edge of the inner circumferential portion 18, and this annular
I ortion may serve as the inside thin wall portion.
It is prefenred for the height of the maximum outer diameter portion 12d of the

inside seal projection 12 to be set so that a difference in height H between the maximum
outer diameter portion 12d and the bottom end of the open end seal projection 13 is 1
mm to 4 mm (preferably 1.5 mm to 3 mm).
Having the difference in height H in the aforementioned range may facilitate
discharge of the gas in the container when the internal pressure of the container rises and
enhance tamper evidence.
When the difference in height H is less than the aforementioned range,
iisplacement of the inside seal projection 12 is hindered during bulging deformation of
he top plate portion 2 when the internal pressure of the container rises, thereby hindering
iischaxge of the gas in the container. It is also not preferred from the aspect of tamper
jvidence because seal breakage during the opening process occurs earlier.
When the difference in height H exceeds the aforementioned range, the seal
] ireakage during the opening process is delayed, giving rise to the risk of the cap 1
I sadily coming off by the internal pressure of the container.
It is preferable that the protruding height of the outside seal projection 14 be set
5 3 that a difference in height I between the bottom end of the projection 14 and the
t ottom end of the opening end seal projection 13 is 3 mm or less (preferably 1.5 mm or
! ;ss).
Having the difference in height I in the aforementioned range facilitates discharge
0 ~the gas in the container when the internal pressure of the container rises.
When the difference in height I exceeds this range, detachment of the outside seal
p ejection 14 from the container mouth portion 21 is hindered during bulging
d formation of the top plate portion 2 when the internal pressure of the container rises,
ai d thereby hinders discharge of the gas from inside the container.
In consideration of the sealing property, it is preferred that the difference in

height I be set so as to be not less than 0.2 mm (preferably not less than 0.3 mm).
The cross-sectional radius of curvature of a junction portion 19 that is the portion
where the top plate portion 2 and the cylinder portion 3 are joined is preferably not less
than 0.6 mm (preferably not less than 0.8 mm).
Having the radius of curvature in the aforementioned range increases the strength
of the junction portion 19, which may hinder displacement of the top plate portion 2 at
the portion corresponding to the outside of the outside thin wall portion 16 when the
internal pressure of the container rises.
Consequently, the top plate portion 2 at the portion corresponding to the inside of
;he outside thin wall portion 16 is greatly bulged and the slope of the top plate portion 2
it the portion 12c where the inside seal projection 12 is formed is increased, facilitating
nward displacement of the inside seal projection 12. Accordingly, discharge of the gas
n the container is facilitated.
When the radius of curvature less than the aforementioned range, inward
lisplacement of ttie inside seal projection 12 is hindered, thereby hindering the discharge
if the gas in the container.
The aforeraentioned radius of curvature is preferably not more than 2 mm.
Vhen the radius of curvature exceeds the aforementioned range, separation of the
I pening end seal projection 13 and the outside seal projection 14 from the container
I louth portion 21 is hindered, thereby hindering the discharge of the gas in the container.
A distance J between an inner surface 3 a of the cylinder portion 3 (base end of the
t iread portion 10) and the male screw 22 when the cap 1 is attached to the container
r louth portion 21 is preferably not more than 1 mm (preferably 0.1 mm to 0.5 mm).
Having the distance J in the aforementioned range enhances the holding power of
t le cap 1 with respect to the container mouth portion 21, which may prevent the cap 1

from coming off the container mouth portion 21 when opening.
When the distance J is less than the aforementioned range, attachment of the cap
1 to the container mouth portion 21 may be hindered. When the distance J exceeds the
aforementioned range, the cap 1 readily comes off the container mouth portion 21 during
opening.
A distance K between the tip of the thread portion 10 and the outer surface 21c of
the container mouth portion 21 is preferably not more than 1 mm (preferably 0.1 mm to
0.5 mm).
Having the distance K in the aforementioned range enhances the holding power
of the cap 1 with respect to the container mouth portion 21, which may prevent the cap 1
from coming off the container mouth portion 21 when opening.
When the distance K is less than the aforementioned range, attachment of the cap
1 to the container mouth portion 21 may be hindered. When the distance K exceeds the
aforementioned rtmge the cap 1 readily comes off the container mouth portion 21 during
opening.
The synthetic resin material constituting the cap 1 may include a material
containing polypropylene or polyethylene.
It is preferable that the flexural modulus of the top plate portion 2 be 500 to 2,000
MPa (preferably 1,000 to 1,800 MPa).
Having the flexural modulus in the aforementioned range may facilitate discharge
of the gas in the container when the internal pressure of the container is increased and
prevent breakage of the cap 1. Doing so also enhances the holding power with respect
to the container mouth portion 21, which may prevent the cap 1 from readily coming off
during opening.
When the flexural modulus is less than the aforementioned range, cracking

readily occurs in the top plate portion 2.
When the flexural modulus exceeds the aforementioned range, displacement of
the inside seal projection 12 is hindered when the internal pressure of the container is
increased, thereby hindering discharge of the gas in the container. Also, the cap 1
readily comes off during opening.
It is preferable for the density of the material constituting the cap 1 to be 0.85 to
0.97 g/cm^ (preferably 0.87 to 0.95 g/cm^).
Having the density in the aforementioned range may facilitate discharge of the
gas in the container when the internal pressure of the container is increased and may
prevent breakage of the cap 1. Doing so also enhances the holding power with respect
:o the container mouth portion 21, which may prevent the cap 1 from readily coming off
luring opening.
When the density is less than the aforementioned range, displacement of the
nside seal projection 12 is hindered when the internal pressure of the container is
1 ncreased, thereby hindering discharge of the gas in the container. Also, the cap 1
13adily comes off during opening. When the density exceeds the aforementioned range,
c racking readily occurs in the cap 1.
Below, the method of using the cap 1 is explained referring to FIG. 3 and FIG. 5.
The cap 1 is attached to the mouth portion 21 of the container 20 filled with a
c )ntent liquid as shown in FIG. 3. At this time, the inside seal projection 12 is inserted
i] the container mouth portion 21.
The inside seal projection 12 abuts the container inner surface 21a at the abutting
c. mvex portion 12a, sealing this portion. By doing so the container 20 is hermetically
S( aled.
In this hermetically sealed state (when unopened), the opening end seal projection

13 abuts the opening end face 21b and the outside seal projection 14 abuts the container
outer surface 21c.
Also, the tabs 11 provided on the TE ring portion 9 surmount the annular bulging
step portion 23 provided directly under the male screw 22, reaching below the bulging
step portion 23.
When the cap 1 attached to the container mouth portion 21 is rotated in the
opening direction, the cap 1 rises, the inside seal projection 12 is pulled out of the
container mouth portion 21, and the hermetic seal of the container 20 is broken.
Because at this time the tabs 11 provided on the inner surface of the TE ring
Dortion 9 lock wilJi the lower portion of the bulging step portion 23, while the main
Dortion 8 rises in accordance with the rotation, upward movement of the TE ring portion
? is blocked. Consequently, tensile force acts on the bridge 7 connecting the main
)ortion 8 and TE ring portion 9 of the cap 1, by which the bridges 7 break, and the TE
ing portion 9 is detached from the main portion 8. By detaching the TE ring portion 9,
t is evident that the cap 1 is opened.
When the cap 1 is opened and then recapped, the internal pressure of the
( ontainer 20 may rise considerably (for example, 0.4 MPa or more) due to fermentation
( f the content liquid and the like.
When the pressure in the container 20 rises, upward force acts on the top plate
j: artion 2 due to the internal pressure of the container.
As shown in FIG. 5, applying force upwardly to the top plate portion 2 from the
i] temal pressure of the container causes upward bulging deformation (so-called doming)
0 'the top plate portion 2.
Along with the bulging deformation of the top plate portion 2, top edge portions
1 la of the connector portions 15 are displaced upward, and as a result, tensile force is

applied inwardly on the inside seal projection 12 by the connector portions 15.
The bulging deformation of the top plate portion 2 causes the center portion
thereof to rise. Whereby, the top plate portion 2 assumes a sloped state descending
gradually from the center portion thereof heading outward.
Because the strength of the top plate portion 2 is lower at the outside thin wall
portion 16, when an upward force is applied on the top plate portion 2 from the internal
pressure of the container, the top plate portion 2 undergoes bending deformation at the
outside thin wall portion 16, and the portion inward of the outside thin wall portion 16
undergoes significant bulging deformation upward.
Due to the slope of the top plate portion 2 during bulging deformation (the slope
with respect to the top plate portion 2 when undeformed) being greater nearer the
circumferential edge of the deformed portion, the slope of the top plate portion 2 inward
of the outside thin wall portion 16 is greater nearer the outside thin wall portion 16.
Consequently, the slope of the top plate portion 2 at the portion 12c where the
nside seal projection 12 is formed increases compared to the case of the entire top plate
)ortion 2 deformably swelling.
Moreover, due to the strength of the junction portion 19 being sufficiently raised
»y its cross-sectional radius of curvature being within the aforementioned range, the top
] ilate portion 2 at the portion corresponding to the outside of the outside thin wall portion
6 is hindered from deforming upward.
Consequently, the portion positioned inward of the outside thin wall portion 16
c eformably swells upward to a greater extent, and the slope of the top plate portion 2 at
t le portion 12c where the inside seal projection 12 is formed further increases.
In this way, due to inward tensile force being applied to the inside seal projection
i I by the connector portions 15 and the top plate portion 2 (the portion 12c where the

inside seal projection 12 is formed) greatly sloping, at least a portion of the inside seal
projection 12 is displaced in the direction of inward movement of the tip, and the
abutting convex portion 12a separates from the container inner surface 21a.
This causes the gas in the container 20 to be discharged to the outside through the
gap between the container inner surface 21a and the inside seal projection 12.
The aforementioned cap 1 exhibits the following effects:
(1) By having connector portions 15 formed between the top plate portion 2 and
the inside seal projection 12, sloping of the top plate portion 2 by bulging deformation
due to rising of the internal pressure of the container causes inward tensile force to be
applied to the inside seal projection 12.
Also, because the outside thin wall portion 16 is formed on the top plate portion 2,
:he top plate portion 2 undergoes bending deformation at the outside thin wall portion 16,
causing the portion positioned inside the outside thin wall portion 16 to undergo
;ignificant bulging deformation upward.
Because of this, the slope of the top plate portion 2 at the portion 12c where the
nside seal projection 12 is formed increases compared to the case of the entire top plate
j lortion 2 deformably swelling.
Consequently, the inside seal projection 12 is displaced in the direction of inward
t lovement of the tip, facilitating discharge of the gas in the container 20 through the gap
I: etween the container iimer surface 21a and the inside seal projection 12.
Accordingly, the cap 1 may prevent an excessive increase in the internal pressure
c f the container 20 after recapping.
In the case of the outside thin wall portion 16 not being formed, when the internal
p -essure of the container rises, because the entire top plate portion 12 deformably swells,
tl e slope of the portion 12b where the inside seal projection 12 is formed is lessened.

thereby hindering inward displacement of the inside seal projection 12. Accordingly,
discharge of the gas in the container 20 is hindered.
(2) Having the cross-sectional radius of curvature of the junction portion 19 in the
aforementioned range sufficiently raises the strength of the junction portion 19, which
may thereby hinder displacement of the top plate portion 2 at the portion corresponding
to outside of the outside thin wall portion 16.
For this reason, the portion positioned inward of the outside thin wall portion 16
deformably swells upward to a greater extent, and so the slope of the top plate portion 2
at the portion 12c where the inside seal projection 12 is formed may be further increased.
Accordingly, an excessive increase in the internal pressure of the container may
be surely prevented after recapping.
(3) Since the connector portion 15 is formed only in a portion of the
circumferential direction, the inward tensile force acts locally only on a portion of the
inside seal projection 12.
Since the tensile force acts on the inside seal projection 12 biased in the
circumferential direction, the strain produced in the inside seal projection 12 by inward
lisplacement of the inside seal projection 12 at the portions where the connector portion
15 are formed is absorbed by the portions where the connector portions 15 are not
brmed.
Consequently, the inside seal projection 12 at the portion where the tensile force
cts is easily displaced inward, compared to the case of the connector portion being
: ormed over the entire circumference.
(4) A common method of sterilizing the inside of a cap is to run hot water over
t le outer surface of the cap attached to a container mouth portion.
As shown in FIG. 3, since in the cap 1 the outside thin wall portion 16 is formed

in the top plate portion 2, by supplying hot water to the outer surface of the top plate
portion 2, sufficient heat can be transmitted through the outside thin wall portion 16 to an
inner space L (the space surrounded by the inner seal projection 12, the top plate portion
2, the opening end seal projection 13 and the container mouth portion 21).
Accordingly, the inner space L may be surely sterilized.
By filling a beverage such as juice, tea or coffee in the container 20 and attaching
the cap 1 to the mouth portion 21, a container-packed beverage filled with the beverage
may be provided with the aforementioned closing device.
INDUSTRIAL APPLICABILITY
The synthetic resin cap of the present invention exhibits the following effects:
(1) By having connector portions formed between the top plate portion and the
inside seal projection, sloping of the top plate portion by bulging deformation due to
rising of the internal pressure of the container causes inward tensile force to be applied to
the inside seal projection.
Also, because the outside thin wall portion is formed on the top plate portion, the
top plate portion undergoes bending deformation at the outside thin wall portion, causing
the portion positioned inside the outside thin wall portion to undergo significant bulging
deformation upward.
Because of this, the slope of the top plate portion at the portion where the inside
seal projection is formed increases.
Consequently, the inside seal projection is displaced in the direction of inward
movement of the tip and separates from the container inner surface, thereby facilitating
the discharge of the gas in the container to the outside.
Accordingly, an excessive increase in the internal pressure of the container may

be prevented after recapping.
(2) Having the cross-sectional radius of curvature of the junction portion in the
aforementioned range sufficiently raises the strength of the junction portion, which may
thereby hinder displacement of the top plate portion at the portion corresponding to the
outside of the outside thin wall portion.
For this reason, the portion positioned inward of the outside thin wall portion
deformably swells upward to a greater extent, and so the slope of the top plate portion at
the portion where the inside seal projection is formed may be iurther increased.
Accordingly, an excessive increase in the internal pressure of the container may
be surely prevented after recapping.

CLAIMS
1. A synthetic resin cap (1) comprising:
a cap body (4) having a top plate portion (2) and a cylinder portion (3) hanging
from a circumferential edge portion (2b) thereof;
an aimular inside seal projection (12) to be fitted into a container mouth portion
(21) being formed on an inner surface (2a) of the top plate portion (2);
a connector portion (15) that connects the top plate portion and the inside seal
projection being formed between the inner surface of the top plate portion and an inner
surface (12b) of the inside seal projection; and
an outside thin wall portion (16) formed thinner than the circumferential edge
portion being fbnned on the top plate portion at any position between a portion (12c)
Adhere the inside seal projection is formed and the circumferential edge portion.
;. The synthetic resin cap according to claim 1, wherein a cross-sectional radius of
( urvature at the inner surface side of a junction portion (19) of the top plate portion and
I le cylinder portion is not less than 0.6 mm.
3 The synthetic resin cap according to claim 1 or claim 2, wherein the top plate
portion at the portion corresponding to the inside of the inside seal projection has an
o iter circumferential side portion (17) where the connector portion is formed and an
ir side thin wall portion (18b) that is formed to the inside of the outer circumferential side
p( rtion, with the inside thin wall portion being formed thinner than the outer
ci cumferential side portion.

4. The synthetic resin cap according to claim 3, wherein a thickness (E) of the outer
circumferential side portion is 0.5 mm to 3 mm.
5. The synthetic resin cap according to claim 3 or claim 4, wherein a width (F) of
the outer circumferential side portion is 0.5 mm to 10 mm.
6. The synthetic resin cap according to any one of claims 1 to 5, wherein when
attached to the container mouth portion, a distance (J) between an inner surface (3 a) of
the cylinder portion and a tip of a male screw (22) formed on an outer surface (2 Ic) of
the container mouth portion is not more than 1 mm.
7. The synthetic resin cap according to any one of claims 1 to 6, wherein when
ittached to the container mouth portion, a distance (K) between a tip of a thread portion
10) formed in the cylinder portion and the outer surface of the container mouth portion
s not more than 1 nmi.
;. The synthetic resin cap according to any one of claims 1 to 7, wherein an opening
I nd seal projection (13) to abut an opening end face (21b) of the container mouth portion
i 3 formed on the top plate portion.
i. The synthetic resin cap according to claim 8, wherein:
the inside seal projection is made to abut an inner surface (21a) of the container
n louth portion at a maximum outer diameter portion (12d); and
the height position of the maximum outer diameter portion is set so that a
d fference in height (H) of the maximum outer diameter portion and a bottom end of the

opening end seal projection is 1 mm to 4 mm.
10. The synthetic resin cap according to claim 8 or claim 9, wherein:
an outside seal projection to abut the outer surface of the container mouth portion
is formed on the top plate portion; and
the outside seal projection is formed so that the difference in height (I) of a
bottom end of this projection and the bottom end of the opening end seal projection is not
more than 3 mm.
11. The synthetic resin cap according to any one of claims 1 to 10, wherein the
flexural modulus of the top plate portion is 500 to 2,000 MPa.
12. The synthetic resin cap according to any one of claims 1 to 11, wherein the
density of the material constituting the synthetic resin cap is 0.85 to 0.97 g/cm'.
13. A closing device comprising a container and a synthetic resin cap attached to a
nouth portion thereof, wherein:
the synthetic resin cap comprises a cap body having a top plate portion and a
. ylinder portion hanging from a circumferential edge portion thereof;
an annular inside seal projection to be fitted into the container mouth portion is
i Drmed on an iimer surface of the top plate portion;
a connector portion that connects the top plate portion and the inside seal
projection is formed between the iimer surface of the top plate portion and an inner
s irface of the inside seal projection; and
an outside thin wall portion formed thinner than the circumferential edge portion

is formed on the top plate portion at any position between a portion where the inside seal
projection is formed and the circumferential edge portion.
14. A container-packed beverage in which a beverage is filled in a closing device
comprising a container and a synthetic resin cap attached to the mouth portion thereof,
wherein:
the synthetic resin cap comprises a cap body having a top plate portion and a
cylinder portion hanging from a circumferential edge portion thereof;
an annular inside seal projection to be fitted into the container mouth portion is
formed on an inner surface of the top plate portion;
a connector portion that connects the top plate portion and the inside seal
projection is formed between the inner surface of the top plate portion and an inner
surface of the inside seal projection; and
an outside thin wall portion formed thinner than the circumferential edge portion formed on the top plate portion at any position between a portion where the inside seal
p rojection is formed and the circumferential edge portion.

A synthetip resin cap, a closing device, and
a container-packed beverage. The synthetic resin cap comprises
a cap body (4) having a top plate part (2) and a tube
part (3) extending downward from the peripheral edge part
(2b) thereof and an inside seal projection (12) fitted to the inside
of a container mouth part (21). A connection part (15) is
formed between the top plate part (2) and the inner seal projection
(12), and an outside thin-walled part (16) is formed at
the top plate part (2). When a container inside pressure rises,
the top plate part (2) is deformably swelled upward, and an inward
tension is applied to the inside seal projection (12) by the
connection part (15). Since the outside thin-walled part (16)
is deformably bent, the portion of the cap positioned on the
inner side of the outer thin-walled part is deformably swelled
largely upward, and the inclination of the top plate part (2) is
increased at the formed part of the inside seal projection (12).
Thus, the inside seal projection (12) is displaced inward, and
gas in the container can be easily discharged to the outside.

Documents:

01983-kolnp-2005-abstract.pdf

01983-kolnp-2005-claims.pdf

01983-kolnp-2005-description complete.pdf

01983-kolnp-2005-drawings.pdf

01983-kolnp-2005-form 1.pdf

01983-kolnp-2005-form 3.pdf

01983-kolnp-2005-form 5.pdf

01983-kolnp-2005-international publication.pdf

1983-KOLNP-2005-ABSTRACT-1.1.pdf

1983-kolnp-2005-abstract.pdf

1983-KOLNP-2005-AMENDED CLAIMS.pdf

1983-KOLNP-2005-ASSIGNMENT-1.1.pdf

1983-kolnp-2005-assignment.pdf

1983-KOLNP-2005-CANCELLED PAGES.pdf

1983-kolnp-2005-claims.pdf

1983-KOLNP-2005-CORRESPONDENCE 1.1.pdf

1983-kolnp-2005-correspondence.pdf

1983-KOLNP-2005-DESCRIPTION (COMPLETE)-1.1.pdf

1983-kolnp-2005-description (complete).pdf

1983-KOLNP-2005-DRAWINGS-1.1.pdf

1983-kolnp-2005-drawings.pdf

1983-KOLNP-2005-FORM 1-1.1.pdf

1983-kolnp-2005-form 1.pdf

1983-KOLNP-2005-FORM 13.pdf

1983-kolnp-2005-form 18.pdf

1983-KOLNP-2005-FORM 2.pdf

1983-kolnp-2005-form 27.pdf

1983-KOLNP-2005-FORM 3-1.1.pdf

1983-kolnp-2005-form 3.pdf

1983-KOLNP-2005-FORM 5-1.1.pdf

1983-kolnp-2005-form 5.pdf

1983-KOLNP-2005-FORM-27.pdf

1983-kolnp-2005-gpa.pdf

1983-KOLNP-2005-OTHERS.pdf

1983-KOLNP-2005-PA.pdf

1983-KOLNP-2005-PETITION UNDER RULE 137.pdf

1983-KOLNP-2005-REPLY TO EXAMINATION REPORT.pdf

1983-kolnp-2005-specification.pdf

abstract-01983-kolnp-2005.jpg


Patent Number 244223
Indian Patent Application Number 1983/KOLNP/2005
PG Journal Number 48/2010
Publication Date 26-Nov-2010
Grant Date 24-Nov-2010
Date of Filing 06-Oct-2005
Name of Patentee ALCOA CLOSURE SYSTEMS JAPAN, LIMITED
Applicant Address 148, OAZA NOGI, NOGI-MACHI, SHIMOTSUGA-GUN, TOCHIGI-KEN
Inventors:
# Inventor's Name Inventor's Address
1 NISHIJIMA, MASAHITO C/O ALCOA CLOSURE SYSTEMS JAPAN, LIMITED, 148, OAZA NOGI, NOGI-MACHI, SHIMOTSUGA-GUN, TOCHIGI-KEN
2 TAKAMATSU, KOICHI C/O ALCOA CLOSURE SYSTEMS JAPAN, LIMITED, 148, OAZA NOGI, NOGI-MACHI, SHIMOTSUGA-GUN, TOCHIGI-KEN
PCT International Classification Number B65D 51/16
PCT International Application Number PCT/JP2004/011120
PCT International Filing date 2004-07-28
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2003-328992 2003-09-19 Japan